1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 3 -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2015, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Aspects; use Aspects; 27with Atree; use Atree; 28with Checks; use Checks; 29with Debug; use Debug; 30with Elists; use Elists; 31with Einfo; use Einfo; 32with Errout; use Errout; 33with Eval_Fat; use Eval_Fat; 34with Exp_Ch3; use Exp_Ch3; 35with Exp_Ch9; use Exp_Ch9; 36with Exp_Disp; use Exp_Disp; 37with Exp_Dist; use Exp_Dist; 38with Exp_Tss; use Exp_Tss; 39with Exp_Util; use Exp_Util; 40with Fname; use Fname; 41with Freeze; use Freeze; 42with Ghost; use Ghost; 43with Itypes; use Itypes; 44with Layout; use Layout; 45with Lib; use Lib; 46with Lib.Xref; use Lib.Xref; 47with Namet; use Namet; 48with Nmake; use Nmake; 49with Opt; use Opt; 50with Restrict; use Restrict; 51with Rident; use Rident; 52with Rtsfind; use Rtsfind; 53with Sem; use Sem; 54with Sem_Aux; use Sem_Aux; 55with Sem_Case; use Sem_Case; 56with Sem_Cat; use Sem_Cat; 57with Sem_Ch6; use Sem_Ch6; 58with Sem_Ch7; use Sem_Ch7; 59with Sem_Ch8; use Sem_Ch8; 60with Sem_Ch10; use Sem_Ch10; 61with Sem_Ch13; use Sem_Ch13; 62with Sem_Dim; use Sem_Dim; 63with Sem_Disp; use Sem_Disp; 64with Sem_Dist; use Sem_Dist; 65with Sem_Elim; use Sem_Elim; 66with Sem_Eval; use Sem_Eval; 67with Sem_Mech; use Sem_Mech; 68with Sem_Prag; use Sem_Prag; 69with Sem_Res; use Sem_Res; 70with Sem_Smem; use Sem_Smem; 71with Sem_Type; use Sem_Type; 72with Sem_Util; use Sem_Util; 73with Sem_Warn; use Sem_Warn; 74with Stand; use Stand; 75with Sinfo; use Sinfo; 76with Sinput; use Sinput; 77with Snames; use Snames; 78with Targparm; use Targparm; 79with Tbuild; use Tbuild; 80with Ttypes; use Ttypes; 81with Uintp; use Uintp; 82with Urealp; use Urealp; 83 84package body Sem_Ch3 is 85 86 ----------------------- 87 -- Local Subprograms -- 88 ----------------------- 89 90 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id); 91 -- Ada 2005 (AI-251): Add the tag components corresponding to all the 92 -- abstract interface types implemented by a record type or a derived 93 -- record type. 94 95 procedure Analyze_Object_Contract (Obj_Id : Entity_Id); 96 -- Analyze all delayed pragmas chained on the contract of object Obj_Id as 97 -- if they appeared at the end of the declarative region. The pragmas to be 98 -- considered are: 99 -- Async_Readers 100 -- Async_Writers 101 -- Effective_Reads 102 -- Effective_Writes 103 -- Part_Of 104 105 procedure Build_Derived_Type 106 (N : Node_Id; 107 Parent_Type : Entity_Id; 108 Derived_Type : Entity_Id; 109 Is_Completion : Boolean; 110 Derive_Subps : Boolean := True); 111 -- Create and decorate a Derived_Type given the Parent_Type entity. N is 112 -- the N_Full_Type_Declaration node containing the derived type definition. 113 -- Parent_Type is the entity for the parent type in the derived type 114 -- definition and Derived_Type the actual derived type. Is_Completion must 115 -- be set to False if Derived_Type is the N_Defining_Identifier node in N 116 -- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the 117 -- completion of a private type declaration. If Is_Completion is set to 118 -- True, N is the completion of a private type declaration and Derived_Type 119 -- is different from the defining identifier inside N (i.e. Derived_Type /= 120 -- Defining_Identifier (N)). Derive_Subps indicates whether the parent 121 -- subprograms should be derived. The only case where this parameter is 122 -- False is when Build_Derived_Type is recursively called to process an 123 -- implicit derived full type for a type derived from a private type (in 124 -- that case the subprograms must only be derived for the private view of 125 -- the type). 126 -- 127 -- ??? These flags need a bit of re-examination and re-documentation: 128 -- ??? are they both necessary (both seem related to the recursion)? 129 130 procedure Build_Derived_Access_Type 131 (N : Node_Id; 132 Parent_Type : Entity_Id; 133 Derived_Type : Entity_Id); 134 -- Subsidiary procedure to Build_Derived_Type. For a derived access type, 135 -- create an implicit base if the parent type is constrained or if the 136 -- subtype indication has a constraint. 137 138 procedure Build_Derived_Array_Type 139 (N : Node_Id; 140 Parent_Type : Entity_Id; 141 Derived_Type : Entity_Id); 142 -- Subsidiary procedure to Build_Derived_Type. For a derived array type, 143 -- create an implicit base if the parent type is constrained or if the 144 -- subtype indication has a constraint. 145 146 procedure Build_Derived_Concurrent_Type 147 (N : Node_Id; 148 Parent_Type : Entity_Id; 149 Derived_Type : Entity_Id); 150 -- Subsidiary procedure to Build_Derived_Type. For a derived task or 151 -- protected type, inherit entries and protected subprograms, check 152 -- legality of discriminant constraints if any. 153 154 procedure Build_Derived_Enumeration_Type 155 (N : Node_Id; 156 Parent_Type : Entity_Id; 157 Derived_Type : Entity_Id); 158 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration 159 -- type, we must create a new list of literals. Types derived from 160 -- Character and [Wide_]Wide_Character are special-cased. 161 162 procedure Build_Derived_Numeric_Type 163 (N : Node_Id; 164 Parent_Type : Entity_Id; 165 Derived_Type : Entity_Id); 166 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create 167 -- an anonymous base type, and propagate constraint to subtype if needed. 168 169 procedure Build_Derived_Private_Type 170 (N : Node_Id; 171 Parent_Type : Entity_Id; 172 Derived_Type : Entity_Id; 173 Is_Completion : Boolean; 174 Derive_Subps : Boolean := True); 175 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex 176 -- because the parent may or may not have a completion, and the derivation 177 -- may itself be a completion. 178 179 procedure Build_Derived_Record_Type 180 (N : Node_Id; 181 Parent_Type : Entity_Id; 182 Derived_Type : Entity_Id; 183 Derive_Subps : Boolean := True); 184 -- Subsidiary procedure used for tagged and untagged record types 185 -- by Build_Derived_Type and Analyze_Private_Extension_Declaration. 186 -- All parameters are as in Build_Derived_Type except that N, in 187 -- addition to being an N_Full_Type_Declaration node, can also be an 188 -- N_Private_Extension_Declaration node. See the definition of this routine 189 -- for much more info. Derive_Subps indicates whether subprograms should be 190 -- derived from the parent type. The only case where Derive_Subps is False 191 -- is for an implicit derived full type for a type derived from a private 192 -- type (see Build_Derived_Type). 193 194 procedure Build_Discriminal (Discrim : Entity_Id); 195 -- Create the discriminal corresponding to discriminant Discrim, that is 196 -- the parameter corresponding to Discrim to be used in initialization 197 -- procedures for the type where Discrim is a discriminant. Discriminals 198 -- are not used during semantic analysis, and are not fully defined 199 -- entities until expansion. Thus they are not given a scope until 200 -- initialization procedures are built. 201 202 function Build_Discriminant_Constraints 203 (T : Entity_Id; 204 Def : Node_Id; 205 Derived_Def : Boolean := False) return Elist_Id; 206 -- Validate discriminant constraints and return the list of the constraints 207 -- in order of discriminant declarations, where T is the discriminated 208 -- unconstrained type. Def is the N_Subtype_Indication node where the 209 -- discriminants constraints for T are specified. Derived_Def is True 210 -- when building the discriminant constraints in a derived type definition 211 -- of the form "type D (...) is new T (xxx)". In this case T is the parent 212 -- type and Def is the constraint "(xxx)" on T and this routine sets the 213 -- Corresponding_Discriminant field of the discriminants in the derived 214 -- type D to point to the corresponding discriminants in the parent type T. 215 216 procedure Build_Discriminated_Subtype 217 (T : Entity_Id; 218 Def_Id : Entity_Id; 219 Elist : Elist_Id; 220 Related_Nod : Node_Id; 221 For_Access : Boolean := False); 222 -- Subsidiary procedure to Constrain_Discriminated_Type and to 223 -- Process_Incomplete_Dependents. Given 224 -- 225 -- T (a possibly discriminated base type) 226 -- Def_Id (a very partially built subtype for T), 227 -- 228 -- the call completes Def_Id to be the appropriate E_*_Subtype. 229 -- 230 -- The Elist is the list of discriminant constraints if any (it is set 231 -- to No_Elist if T is not a discriminated type, and to an empty list if 232 -- T has discriminants but there are no discriminant constraints). The 233 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components. 234 -- The For_Access says whether or not this subtype is really constraining 235 -- an access type. That is its sole purpose is the designated type of an 236 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype 237 -- is built to avoid freezing T when the access subtype is frozen. 238 239 function Build_Scalar_Bound 240 (Bound : Node_Id; 241 Par_T : Entity_Id; 242 Der_T : Entity_Id) return Node_Id; 243 -- The bounds of a derived scalar type are conversions of the bounds of 244 -- the parent type. Optimize the representation if the bounds are literals. 245 -- Needs a more complete spec--what are the parameters exactly, and what 246 -- exactly is the returned value, and how is Bound affected??? 247 248 procedure Build_Underlying_Full_View 249 (N : Node_Id; 250 Typ : Entity_Id; 251 Par : Entity_Id); 252 -- If the completion of a private type is itself derived from a private 253 -- type, or if the full view of a private subtype is itself private, the 254 -- back-end has no way to compute the actual size of this type. We build 255 -- an internal subtype declaration of the proper parent type to convey 256 -- this information. This extra mechanism is needed because a full 257 -- view cannot itself have a full view (it would get clobbered during 258 -- view exchanges). 259 260 procedure Check_Access_Discriminant_Requires_Limited 261 (D : Node_Id; 262 Loc : Node_Id); 263 -- Check the restriction that the type to which an access discriminant 264 -- belongs must be a concurrent type or a descendant of a type with 265 -- the reserved word 'limited' in its declaration. 266 267 procedure Check_Anonymous_Access_Components 268 (Typ_Decl : Node_Id; 269 Typ : Entity_Id; 270 Prev : Entity_Id; 271 Comp_List : Node_Id); 272 -- Ada 2005 AI-382: an access component in a record definition can refer to 273 -- the enclosing record, in which case it denotes the type itself, and not 274 -- the current instance of the type. We create an anonymous access type for 275 -- the component, and flag it as an access to a component, so accessibility 276 -- checks are properly performed on it. The declaration of the access type 277 -- is placed ahead of that of the record to prevent order-of-elaboration 278 -- circularity issues in Gigi. We create an incomplete type for the record 279 -- declaration, which is the designated type of the anonymous access. 280 281 procedure Check_Delta_Expression (E : Node_Id); 282 -- Check that the expression represented by E is suitable for use as a 283 -- delta expression, i.e. it is of real type and is static. 284 285 procedure Check_Digits_Expression (E : Node_Id); 286 -- Check that the expression represented by E is suitable for use as a 287 -- digits expression, i.e. it is of integer type, positive and static. 288 289 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id); 290 -- Validate the initialization of an object declaration. T is the required 291 -- type, and Exp is the initialization expression. 292 293 procedure Check_Interfaces (N : Node_Id; Def : Node_Id); 294 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2) 295 296 procedure Check_Or_Process_Discriminants 297 (N : Node_Id; 298 T : Entity_Id; 299 Prev : Entity_Id := Empty); 300 -- If N is the full declaration of the completion T of an incomplete or 301 -- private type, check its discriminants (which are already known to be 302 -- conformant with those of the partial view, see Find_Type_Name), 303 -- otherwise process them. Prev is the entity of the partial declaration, 304 -- if any. 305 306 procedure Check_Real_Bound (Bound : Node_Id); 307 -- Check given bound for being of real type and static. If not, post an 308 -- appropriate message, and rewrite the bound with the real literal zero. 309 310 procedure Constant_Redeclaration 311 (Id : Entity_Id; 312 N : Node_Id; 313 T : out Entity_Id); 314 -- Various checks on legality of full declaration of deferred constant. 315 -- Id is the entity for the redeclaration, N is the N_Object_Declaration, 316 -- node. The caller has not yet set any attributes of this entity. 317 318 function Contain_Interface 319 (Iface : Entity_Id; 320 Ifaces : Elist_Id) return Boolean; 321 -- Ada 2005: Determine whether Iface is present in the list Ifaces 322 323 procedure Convert_Scalar_Bounds 324 (N : Node_Id; 325 Parent_Type : Entity_Id; 326 Derived_Type : Entity_Id; 327 Loc : Source_Ptr); 328 -- For derived scalar types, convert the bounds in the type definition to 329 -- the derived type, and complete their analysis. Given a constraint of the 330 -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with 331 -- T'Base, the parent_type. The bounds of the derived type (the anonymous 332 -- base) are copies of Lo and Hi. Finally, the bounds of the derived 333 -- subtype are conversions of those bounds to the derived_type, so that 334 -- their typing is consistent. 335 336 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id); 337 -- Copies attributes from array base type T2 to array base type T1. Copies 338 -- only attributes that apply to base types, but not subtypes. 339 340 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id); 341 -- Copies attributes from array subtype T2 to array subtype T1. Copies 342 -- attributes that apply to both subtypes and base types. 343 344 procedure Create_Constrained_Components 345 (Subt : Entity_Id; 346 Decl_Node : Node_Id; 347 Typ : Entity_Id; 348 Constraints : Elist_Id); 349 -- Build the list of entities for a constrained discriminated record 350 -- subtype. If a component depends on a discriminant, replace its subtype 351 -- using the discriminant values in the discriminant constraint. Subt 352 -- is the defining identifier for the subtype whose list of constrained 353 -- entities we will create. Decl_Node is the type declaration node where 354 -- we will attach all the itypes created. Typ is the base discriminated 355 -- type for the subtype Subt. Constraints is the list of discriminant 356 -- constraints for Typ. 357 358 function Constrain_Component_Type 359 (Comp : Entity_Id; 360 Constrained_Typ : Entity_Id; 361 Related_Node : Node_Id; 362 Typ : Entity_Id; 363 Constraints : Elist_Id) return Entity_Id; 364 -- Given a discriminated base type Typ, a list of discriminant constraints, 365 -- Constraints, for Typ and a component Comp of Typ, create and return the 366 -- type corresponding to Etype (Comp) where all discriminant references 367 -- are replaced with the corresponding constraint. If Etype (Comp) contains 368 -- no discriminant references then it is returned as-is. Constrained_Typ 369 -- is the final constrained subtype to which the constrained component 370 -- belongs. Related_Node is the node where we attach all created itypes. 371 372 procedure Constrain_Access 373 (Def_Id : in out Entity_Id; 374 S : Node_Id; 375 Related_Nod : Node_Id); 376 -- Apply a list of constraints to an access type. If Def_Id is empty, it is 377 -- an anonymous type created for a subtype indication. In that case it is 378 -- created in the procedure and attached to Related_Nod. 379 380 procedure Constrain_Array 381 (Def_Id : in out Entity_Id; 382 SI : Node_Id; 383 Related_Nod : Node_Id; 384 Related_Id : Entity_Id; 385 Suffix : Character); 386 -- Apply a list of index constraints to an unconstrained array type. The 387 -- first parameter is the entity for the resulting subtype. A value of 388 -- Empty for Def_Id indicates that an implicit type must be created, but 389 -- creation is delayed (and must be done by this procedure) because other 390 -- subsidiary implicit types must be created first (which is why Def_Id 391 -- is an in/out parameter). The second parameter is a subtype indication 392 -- node for the constrained array to be created (e.g. something of the 393 -- form string (1 .. 10)). Related_Nod gives the place where this type 394 -- has to be inserted in the tree. The Related_Id and Suffix parameters 395 -- are used to build the associated Implicit type name. 396 397 procedure Constrain_Concurrent 398 (Def_Id : in out Entity_Id; 399 SI : Node_Id; 400 Related_Nod : Node_Id; 401 Related_Id : Entity_Id; 402 Suffix : Character); 403 -- Apply list of discriminant constraints to an unconstrained concurrent 404 -- type. 405 -- 406 -- SI is the N_Subtype_Indication node containing the constraint and 407 -- the unconstrained type to constrain. 408 -- 409 -- Def_Id is the entity for the resulting constrained subtype. A value 410 -- of Empty for Def_Id indicates that an implicit type must be created, 411 -- but creation is delayed (and must be done by this procedure) because 412 -- other subsidiary implicit types must be created first (which is why 413 -- Def_Id is an in/out parameter). 414 -- 415 -- Related_Nod gives the place where this type has to be inserted 416 -- in the tree. 417 -- 418 -- The last two arguments are used to create its external name if needed. 419 420 function Constrain_Corresponding_Record 421 (Prot_Subt : Entity_Id; 422 Corr_Rec : Entity_Id; 423 Related_Nod : Node_Id) return Entity_Id; 424 -- When constraining a protected type or task type with discriminants, 425 -- constrain the corresponding record with the same discriminant values. 426 427 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id); 428 -- Constrain a decimal fixed point type with a digits constraint and/or a 429 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity. 430 431 procedure Constrain_Discriminated_Type 432 (Def_Id : Entity_Id; 433 S : Node_Id; 434 Related_Nod : Node_Id; 435 For_Access : Boolean := False); 436 -- Process discriminant constraints of composite type. Verify that values 437 -- have been provided for all discriminants, that the original type is 438 -- unconstrained, and that the types of the supplied expressions match 439 -- the discriminant types. The first three parameters are like in routine 440 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation 441 -- of For_Access. 442 443 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id); 444 -- Constrain an enumeration type with a range constraint. This is identical 445 -- to Constrain_Integer, but for the Ekind of the resulting subtype. 446 447 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id); 448 -- Constrain a floating point type with either a digits constraint 449 -- and/or a range constraint, building a E_Floating_Point_Subtype. 450 451 procedure Constrain_Index 452 (Index : Node_Id; 453 S : Node_Id; 454 Related_Nod : Node_Id; 455 Related_Id : Entity_Id; 456 Suffix : Character; 457 Suffix_Index : Nat); 458 -- Process an index constraint S in a constrained array declaration. The 459 -- constraint can be a subtype name, or a range with or without an explicit 460 -- subtype mark. The index is the corresponding index of the unconstrained 461 -- array. The Related_Id and Suffix parameters are used to build the 462 -- associated Implicit type name. 463 464 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id); 465 -- Build subtype of a signed or modular integer type 466 467 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id); 468 -- Constrain an ordinary fixed point type with a range constraint, and 469 -- build an E_Ordinary_Fixed_Point_Subtype entity. 470 471 procedure Copy_And_Swap (Priv, Full : Entity_Id); 472 -- Copy the Priv entity into the entity of its full declaration then swap 473 -- the two entities in such a manner that the former private type is now 474 -- seen as a full type. 475 476 procedure Decimal_Fixed_Point_Type_Declaration 477 (T : Entity_Id; 478 Def : Node_Id); 479 -- Create a new decimal fixed point type, and apply the constraint to 480 -- obtain a subtype of this new type. 481 482 procedure Complete_Private_Subtype 483 (Priv : Entity_Id; 484 Full : Entity_Id; 485 Full_Base : Entity_Id; 486 Related_Nod : Node_Id); 487 -- Complete the implicit full view of a private subtype by setting the 488 -- appropriate semantic fields. If the full view of the parent is a record 489 -- type, build constrained components of subtype. 490 491 procedure Derive_Progenitor_Subprograms 492 (Parent_Type : Entity_Id; 493 Tagged_Type : Entity_Id); 494 -- Ada 2005 (AI-251): To complete type derivation, collect the primitive 495 -- operations of progenitors of Tagged_Type, and replace the subsidiary 496 -- subtypes with Tagged_Type, to build the specs of the inherited interface 497 -- primitives. The derived primitives are aliased to those of the 498 -- interface. This routine takes care also of transferring to the full view 499 -- subprograms associated with the partial view of Tagged_Type that cover 500 -- interface primitives. 501 502 procedure Derived_Standard_Character 503 (N : Node_Id; 504 Parent_Type : Entity_Id; 505 Derived_Type : Entity_Id); 506 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles 507 -- derivations from types Standard.Character and Standard.Wide_Character. 508 509 procedure Derived_Type_Declaration 510 (T : Entity_Id; 511 N : Node_Id; 512 Is_Completion : Boolean); 513 -- Process a derived type declaration. Build_Derived_Type is invoked 514 -- to process the actual derived type definition. Parameters N and 515 -- Is_Completion have the same meaning as in Build_Derived_Type. 516 -- T is the N_Defining_Identifier for the entity defined in the 517 -- N_Full_Type_Declaration node N, that is T is the derived type. 518 519 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id); 520 -- Insert each literal in symbol table, as an overloadable identifier. Each 521 -- enumeration type is mapped into a sequence of integers, and each literal 522 -- is defined as a constant with integer value. If any of the literals are 523 -- character literals, the type is a character type, which means that 524 -- strings are legal aggregates for arrays of components of the type. 525 526 function Expand_To_Stored_Constraint 527 (Typ : Entity_Id; 528 Constraint : Elist_Id) return Elist_Id; 529 -- Given a constraint (i.e. a list of expressions) on the discriminants of 530 -- Typ, expand it into a constraint on the stored discriminants and return 531 -- the new list of expressions constraining the stored discriminants. 532 533 function Find_Type_Of_Object 534 (Obj_Def : Node_Id; 535 Related_Nod : Node_Id) return Entity_Id; 536 -- Get type entity for object referenced by Obj_Def, attaching the implicit 537 -- types generated to Related_Nod. 538 539 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id); 540 -- Create a new float and apply the constraint to obtain subtype of it 541 542 function Has_Range_Constraint (N : Node_Id) return Boolean; 543 -- Given an N_Subtype_Indication node N, return True if a range constraint 544 -- is present, either directly, or as part of a digits or delta constraint. 545 -- In addition, a digits constraint in the decimal case returns True, since 546 -- it establishes a default range if no explicit range is present. 547 548 function Inherit_Components 549 (N : Node_Id; 550 Parent_Base : Entity_Id; 551 Derived_Base : Entity_Id; 552 Is_Tagged : Boolean; 553 Inherit_Discr : Boolean; 554 Discs : Elist_Id) return Elist_Id; 555 -- Called from Build_Derived_Record_Type to inherit the components of 556 -- Parent_Base (a base type) into the Derived_Base (the derived base type). 557 -- For more information on derived types and component inheritance please 558 -- consult the comment above the body of Build_Derived_Record_Type. 559 -- 560 -- N is the original derived type declaration 561 -- 562 -- Is_Tagged is set if we are dealing with tagged types 563 -- 564 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from 565 -- Parent_Base, otherwise no discriminants are inherited. 566 -- 567 -- Discs gives the list of constraints that apply to Parent_Base in the 568 -- derived type declaration. If Discs is set to No_Elist, then we have 569 -- the following situation: 570 -- 571 -- type Parent (D1..Dn : ..) is [tagged] record ...; 572 -- type Derived is new Parent [with ...]; 573 -- 574 -- which gets treated as 575 -- 576 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...]; 577 -- 578 -- For untagged types the returned value is an association list. The list 579 -- starts from the association (Parent_Base => Derived_Base), and then it 580 -- contains a sequence of the associations of the form 581 -- 582 -- (Old_Component => New_Component), 583 -- 584 -- where Old_Component is the Entity_Id of a component in Parent_Base and 585 -- New_Component is the Entity_Id of the corresponding component in 586 -- Derived_Base. For untagged records, this association list is needed when 587 -- copying the record declaration for the derived base. In the tagged case 588 -- the value returned is irrelevant. 589 590 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id); 591 -- Propagate static and dynamic predicate flags from a parent to the 592 -- subtype in a subtype declaration with and without constraints. 593 594 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean; 595 -- Subsidiary to Check_Abstract_Overriding and Derive_Subprogram. 596 -- Determine whether subprogram Subp is a procedure subject to pragma 597 -- Extensions_Visible with value False and has at least one controlling 598 -- parameter of mode OUT. 599 600 function Is_Valid_Constraint_Kind 601 (T_Kind : Type_Kind; 602 Constraint_Kind : Node_Kind) return Boolean; 603 -- Returns True if it is legal to apply the given kind of constraint to the 604 -- given kind of type (index constraint to an array type, for example). 605 606 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id); 607 -- Create new modular type. Verify that modulus is in bounds 608 609 procedure New_Concatenation_Op (Typ : Entity_Id); 610 -- Create an abbreviated declaration for an operator in order to 611 -- materialize concatenation on array types. 612 613 procedure Ordinary_Fixed_Point_Type_Declaration 614 (T : Entity_Id; 615 Def : Node_Id); 616 -- Create a new ordinary fixed point type, and apply the constraint to 617 -- obtain subtype of it. 618 619 procedure Prepare_Private_Subtype_Completion 620 (Id : Entity_Id; 621 Related_Nod : Node_Id); 622 -- Id is a subtype of some private type. Creates the full declaration 623 -- associated with Id whenever possible, i.e. when the full declaration 624 -- of the base type is already known. Records each subtype into 625 -- Private_Dependents of the base type. 626 627 procedure Process_Incomplete_Dependents 628 (N : Node_Id; 629 Full_T : Entity_Id; 630 Inc_T : Entity_Id); 631 -- Process all entities that depend on an incomplete type. There include 632 -- subtypes, subprogram types that mention the incomplete type in their 633 -- profiles, and subprogram with access parameters that designate the 634 -- incomplete type. 635 636 -- Inc_T is the defining identifier of an incomplete type declaration, its 637 -- Ekind is E_Incomplete_Type. 638 -- 639 -- N is the corresponding N_Full_Type_Declaration for Inc_T. 640 -- 641 -- Full_T is N's defining identifier. 642 -- 643 -- Subtypes of incomplete types with discriminants are completed when the 644 -- parent type is. This is simpler than private subtypes, because they can 645 -- only appear in the same scope, and there is no need to exchange views. 646 -- Similarly, access_to_subprogram types may have a parameter or a return 647 -- type that is an incomplete type, and that must be replaced with the 648 -- full type. 649 -- 650 -- If the full type is tagged, subprogram with access parameters that 651 -- designated the incomplete may be primitive operations of the full type, 652 -- and have to be processed accordingly. 653 654 procedure Process_Real_Range_Specification (Def : Node_Id); 655 -- Given the type definition for a real type, this procedure processes and 656 -- checks the real range specification of this type definition if one is 657 -- present. If errors are found, error messages are posted, and the 658 -- Real_Range_Specification of Def is reset to Empty. 659 660 procedure Propagate_Default_Init_Cond_Attributes 661 (From_Typ : Entity_Id; 662 To_Typ : Entity_Id; 663 Parent_To_Derivation : Boolean := False; 664 Private_To_Full_View : Boolean := False); 665 -- Subsidiary to routines Build_Derived_Type and Process_Full_View. Inherit 666 -- all attributes related to pragma Default_Initial_Condition from From_Typ 667 -- to To_Typ. Flag Parent_To_Derivation should be set when the context is 668 -- the creation of a derived type. Flag Private_To_Full_View should be set 669 -- when processing both views of a private type. 670 671 procedure Record_Type_Declaration 672 (T : Entity_Id; 673 N : Node_Id; 674 Prev : Entity_Id); 675 -- Process a record type declaration (for both untagged and tagged 676 -- records). Parameters T and N are exactly like in procedure 677 -- Derived_Type_Declaration, except that no flag Is_Completion is needed 678 -- for this routine. If this is the completion of an incomplete type 679 -- declaration, Prev is the entity of the incomplete declaration, used for 680 -- cross-referencing. Otherwise Prev = T. 681 682 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id); 683 -- This routine is used to process the actual record type definition (both 684 -- for untagged and tagged records). Def is a record type definition node. 685 -- This procedure analyzes the components in this record type definition. 686 -- Prev_T is the entity for the enclosing record type. It is provided so 687 -- that its Has_Task flag can be set if any of the component have Has_Task 688 -- set. If the declaration is the completion of an incomplete type 689 -- declaration, Prev_T is the original incomplete type, whose full view is 690 -- the record type. 691 692 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id); 693 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we 694 -- build a copy of the declaration tree of the parent, and we create 695 -- independently the list of components for the derived type. Semantic 696 -- information uses the component entities, but record representation 697 -- clauses are validated on the declaration tree. This procedure replaces 698 -- discriminants and components in the declaration with those that have 699 -- been created by Inherit_Components. 700 701 procedure Set_Fixed_Range 702 (E : Entity_Id; 703 Loc : Source_Ptr; 704 Lo : Ureal; 705 Hi : Ureal); 706 -- Build a range node with the given bounds and set it as the Scalar_Range 707 -- of the given fixed-point type entity. Loc is the source location used 708 -- for the constructed range. See body for further details. 709 710 procedure Set_Scalar_Range_For_Subtype 711 (Def_Id : Entity_Id; 712 R : Node_Id; 713 Subt : Entity_Id); 714 -- This routine is used to set the scalar range field for a subtype given 715 -- Def_Id, the entity for the subtype, and R, the range expression for the 716 -- scalar range. Subt provides the parent subtype to be used to analyze, 717 -- resolve, and check the given range. 718 719 procedure Set_Default_SSO (T : Entity_Id); 720 -- T is the entity for an array or record being declared. This procedure 721 -- sets the flags SSO_Set_Low_By_Default/SSO_Set_High_By_Default according 722 -- to the setting of Opt.Default_SSO. 723 724 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id); 725 -- Create a new signed integer entity, and apply the constraint to obtain 726 -- the required first named subtype of this type. 727 728 procedure Set_Stored_Constraint_From_Discriminant_Constraint 729 (E : Entity_Id); 730 -- E is some record type. This routine computes E's Stored_Constraint 731 -- from its Discriminant_Constraint. 732 733 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id); 734 -- Check that an entity in a list of progenitors is an interface, 735 -- emit error otherwise. 736 737 ----------------------- 738 -- Access_Definition -- 739 ----------------------- 740 741 function Access_Definition 742 (Related_Nod : Node_Id; 743 N : Node_Id) return Entity_Id 744 is 745 Anon_Type : Entity_Id; 746 Anon_Scope : Entity_Id; 747 Desig_Type : Entity_Id; 748 Enclosing_Prot_Type : Entity_Id := Empty; 749 750 begin 751 Check_SPARK_05_Restriction ("access type is not allowed", N); 752 753 if Is_Entry (Current_Scope) 754 and then Is_Task_Type (Etype (Scope (Current_Scope))) 755 then 756 Error_Msg_N ("task entries cannot have access parameters", N); 757 return Empty; 758 end if; 759 760 -- Ada 2005: For an object declaration the corresponding anonymous 761 -- type is declared in the current scope. 762 763 -- If the access definition is the return type of another access to 764 -- function, scope is the current one, because it is the one of the 765 -- current type declaration, except for the pathological case below. 766 767 if Nkind_In (Related_Nod, N_Object_Declaration, 768 N_Access_Function_Definition) 769 then 770 Anon_Scope := Current_Scope; 771 772 -- A pathological case: function returning access functions that 773 -- return access functions, etc. Each anonymous access type created 774 -- is in the enclosing scope of the outermost function. 775 776 declare 777 Par : Node_Id; 778 779 begin 780 Par := Related_Nod; 781 while Nkind_In (Par, N_Access_Function_Definition, 782 N_Access_Definition) 783 loop 784 Par := Parent (Par); 785 end loop; 786 787 if Nkind (Par) = N_Function_Specification then 788 Anon_Scope := Scope (Defining_Entity (Par)); 789 end if; 790 end; 791 792 -- For the anonymous function result case, retrieve the scope of the 793 -- function specification's associated entity rather than using the 794 -- current scope. The current scope will be the function itself if the 795 -- formal part is currently being analyzed, but will be the parent scope 796 -- in the case of a parameterless function, and we always want to use 797 -- the function's parent scope. Finally, if the function is a child 798 -- unit, we must traverse the tree to retrieve the proper entity. 799 800 elsif Nkind (Related_Nod) = N_Function_Specification 801 and then Nkind (Parent (N)) /= N_Parameter_Specification 802 then 803 -- If the current scope is a protected type, the anonymous access 804 -- is associated with one of the protected operations, and must 805 -- be available in the scope that encloses the protected declaration. 806 -- Otherwise the type is in the scope enclosing the subprogram. 807 808 -- If the function has formals, The return type of a subprogram 809 -- declaration is analyzed in the scope of the subprogram (see 810 -- Process_Formals) and thus the protected type, if present, is 811 -- the scope of the current function scope. 812 813 if Ekind (Current_Scope) = E_Protected_Type then 814 Enclosing_Prot_Type := Current_Scope; 815 816 elsif Ekind (Current_Scope) = E_Function 817 and then Ekind (Scope (Current_Scope)) = E_Protected_Type 818 then 819 Enclosing_Prot_Type := Scope (Current_Scope); 820 end if; 821 822 if Present (Enclosing_Prot_Type) then 823 Anon_Scope := Scope (Enclosing_Prot_Type); 824 825 else 826 Anon_Scope := Scope (Defining_Entity (Related_Nod)); 827 end if; 828 829 -- For an access type definition, if the current scope is a child 830 -- unit it is the scope of the type. 831 832 elsif Is_Compilation_Unit (Current_Scope) then 833 Anon_Scope := Current_Scope; 834 835 -- For access formals, access components, and access discriminants, the 836 -- scope is that of the enclosing declaration, 837 838 else 839 Anon_Scope := Scope (Current_Scope); 840 end if; 841 842 Anon_Type := 843 Create_Itype 844 (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope); 845 846 if All_Present (N) 847 and then Ada_Version >= Ada_2005 848 then 849 Error_Msg_N ("ALL is not permitted for anonymous access types", N); 850 end if; 851 852 -- Ada 2005 (AI-254): In case of anonymous access to subprograms call 853 -- the corresponding semantic routine 854 855 if Present (Access_To_Subprogram_Definition (N)) then 856 857 -- Compiler runtime units are compiled in Ada 2005 mode when building 858 -- the runtime library but must also be compilable in Ada 95 mode 859 -- (when bootstrapping the compiler). 860 861 Check_Compiler_Unit ("anonymous access to subprogram", N); 862 863 Access_Subprogram_Declaration 864 (T_Name => Anon_Type, 865 T_Def => Access_To_Subprogram_Definition (N)); 866 867 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then 868 Set_Ekind 869 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type); 870 else 871 Set_Ekind (Anon_Type, E_Anonymous_Access_Subprogram_Type); 872 end if; 873 874 Set_Can_Use_Internal_Rep 875 (Anon_Type, not Always_Compatible_Rep_On_Target); 876 877 -- If the anonymous access is associated with a protected operation, 878 -- create a reference to it after the enclosing protected definition 879 -- because the itype will be used in the subsequent bodies. 880 881 -- If the anonymous access itself is protected, a full type 882 -- declaratiton will be created for it, so that the equivalent 883 -- record type can be constructed. For further details, see 884 -- Replace_Anonymous_Access_To_Protected-Subprogram. 885 886 if Ekind (Current_Scope) = E_Protected_Type 887 and then not Protected_Present (Access_To_Subprogram_Definition (N)) 888 then 889 Build_Itype_Reference (Anon_Type, Parent (Current_Scope)); 890 end if; 891 892 return Anon_Type; 893 end if; 894 895 Find_Type (Subtype_Mark (N)); 896 Desig_Type := Entity (Subtype_Mark (N)); 897 898 Set_Directly_Designated_Type (Anon_Type, Desig_Type); 899 Set_Etype (Anon_Type, Anon_Type); 900 901 -- Make sure the anonymous access type has size and alignment fields 902 -- set, as required by gigi. This is necessary in the case of the 903 -- Task_Body_Procedure. 904 905 if not Has_Private_Component (Desig_Type) then 906 Layout_Type (Anon_Type); 907 end if; 908 909 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs 910 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify if 911 -- the null value is allowed. In Ada 95 the null value is never allowed. 912 913 if Ada_Version >= Ada_2005 then 914 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N)); 915 else 916 Set_Can_Never_Be_Null (Anon_Type, True); 917 end if; 918 919 -- The anonymous access type is as public as the discriminated type or 920 -- subprogram that defines it. It is imported (for back-end purposes) 921 -- if the designated type is. 922 923 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type))); 924 925 -- Ada 2005 (AI-231): Propagate the access-constant attribute 926 927 Set_Is_Access_Constant (Anon_Type, Constant_Present (N)); 928 929 -- The context is either a subprogram declaration, object declaration, 930 -- or an access discriminant, in a private or a full type declaration. 931 -- In the case of a subprogram, if the designated type is incomplete, 932 -- the operation will be a primitive operation of the full type, to be 933 -- updated subsequently. If the type is imported through a limited_with 934 -- clause, the subprogram is not a primitive operation of the type 935 -- (which is declared elsewhere in some other scope). 936 937 if Ekind (Desig_Type) = E_Incomplete_Type 938 and then not From_Limited_With (Desig_Type) 939 and then Is_Overloadable (Current_Scope) 940 then 941 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type)); 942 Set_Has_Delayed_Freeze (Current_Scope); 943 end if; 944 945 -- Ada 2005: If the designated type is an interface that may contain 946 -- tasks, create a Master entity for the declaration. This must be done 947 -- before expansion of the full declaration, because the declaration may 948 -- include an expression that is an allocator, whose expansion needs the 949 -- proper Master for the created tasks. 950 951 if Nkind (Related_Nod) = N_Object_Declaration and then Expander_Active 952 then 953 if Is_Interface (Desig_Type) and then Is_Limited_Record (Desig_Type) 954 then 955 Build_Class_Wide_Master (Anon_Type); 956 957 -- Similarly, if the type is an anonymous access that designates 958 -- tasks, create a master entity for it in the current context. 959 960 elsif Has_Task (Desig_Type) and then Comes_From_Source (Related_Nod) 961 then 962 Build_Master_Entity (Defining_Identifier (Related_Nod)); 963 Build_Master_Renaming (Anon_Type); 964 end if; 965 end if; 966 967 -- For a private component of a protected type, it is imperative that 968 -- the back-end elaborate the type immediately after the protected 969 -- declaration, because this type will be used in the declarations 970 -- created for the component within each protected body, so we must 971 -- create an itype reference for it now. 972 973 if Nkind (Parent (Related_Nod)) = N_Protected_Definition then 974 Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod))); 975 976 -- Similarly, if the access definition is the return result of a 977 -- function, create an itype reference for it because it will be used 978 -- within the function body. For a regular function that is not a 979 -- compilation unit, insert reference after the declaration. For a 980 -- protected operation, insert it after the enclosing protected type 981 -- declaration. In either case, do not create a reference for a type 982 -- obtained through a limited_with clause, because this would introduce 983 -- semantic dependencies. 984 985 -- Similarly, do not create a reference if the designated type is a 986 -- generic formal, because no use of it will reach the backend. 987 988 elsif Nkind (Related_Nod) = N_Function_Specification 989 and then not From_Limited_With (Desig_Type) 990 and then not Is_Generic_Type (Desig_Type) 991 then 992 if Present (Enclosing_Prot_Type) then 993 Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type)); 994 995 elsif Is_List_Member (Parent (Related_Nod)) 996 and then Nkind (Parent (N)) /= N_Parameter_Specification 997 then 998 Build_Itype_Reference (Anon_Type, Parent (Related_Nod)); 999 end if; 1000 1001 -- Finally, create an itype reference for an object declaration of an 1002 -- anonymous access type. This is strictly necessary only for deferred 1003 -- constants, but in any case will avoid out-of-scope problems in the 1004 -- back-end. 1005 1006 elsif Nkind (Related_Nod) = N_Object_Declaration then 1007 Build_Itype_Reference (Anon_Type, Related_Nod); 1008 end if; 1009 1010 return Anon_Type; 1011 end Access_Definition; 1012 1013 ----------------------------------- 1014 -- Access_Subprogram_Declaration -- 1015 ----------------------------------- 1016 1017 procedure Access_Subprogram_Declaration 1018 (T_Name : Entity_Id; 1019 T_Def : Node_Id) 1020 is 1021 procedure Check_For_Premature_Usage (Def : Node_Id); 1022 -- Check that type T_Name is not used, directly or recursively, as a 1023 -- parameter or a return type in Def. Def is either a subtype, an 1024 -- access_definition, or an access_to_subprogram_definition. 1025 1026 ------------------------------- 1027 -- Check_For_Premature_Usage -- 1028 ------------------------------- 1029 1030 procedure Check_For_Premature_Usage (Def : Node_Id) is 1031 Param : Node_Id; 1032 1033 begin 1034 -- Check for a subtype mark 1035 1036 if Nkind (Def) in N_Has_Etype then 1037 if Etype (Def) = T_Name then 1038 Error_Msg_N 1039 ("type& cannot be used before end of its declaration", Def); 1040 end if; 1041 1042 -- If this is not a subtype, then this is an access_definition 1043 1044 elsif Nkind (Def) = N_Access_Definition then 1045 if Present (Access_To_Subprogram_Definition (Def)) then 1046 Check_For_Premature_Usage 1047 (Access_To_Subprogram_Definition (Def)); 1048 else 1049 Check_For_Premature_Usage (Subtype_Mark (Def)); 1050 end if; 1051 1052 -- The only cases left are N_Access_Function_Definition and 1053 -- N_Access_Procedure_Definition. 1054 1055 else 1056 if Present (Parameter_Specifications (Def)) then 1057 Param := First (Parameter_Specifications (Def)); 1058 while Present (Param) loop 1059 Check_For_Premature_Usage (Parameter_Type (Param)); 1060 Param := Next (Param); 1061 end loop; 1062 end if; 1063 1064 if Nkind (Def) = N_Access_Function_Definition then 1065 Check_For_Premature_Usage (Result_Definition (Def)); 1066 end if; 1067 end if; 1068 end Check_For_Premature_Usage; 1069 1070 -- Local variables 1071 1072 Formals : constant List_Id := Parameter_Specifications (T_Def); 1073 Formal : Entity_Id; 1074 D_Ityp : Node_Id; 1075 Desig_Type : constant Entity_Id := 1076 Create_Itype (E_Subprogram_Type, Parent (T_Def)); 1077 1078 -- Start of processing for Access_Subprogram_Declaration 1079 1080 begin 1081 Check_SPARK_05_Restriction ("access type is not allowed", T_Def); 1082 1083 -- Associate the Itype node with the inner full-type declaration or 1084 -- subprogram spec or entry body. This is required to handle nested 1085 -- anonymous declarations. For example: 1086 1087 -- procedure P 1088 -- (X : access procedure 1089 -- (Y : access procedure 1090 -- (Z : access T))) 1091 1092 D_Ityp := Associated_Node_For_Itype (Desig_Type); 1093 while not (Nkind_In (D_Ityp, N_Full_Type_Declaration, 1094 N_Private_Type_Declaration, 1095 N_Private_Extension_Declaration, 1096 N_Procedure_Specification, 1097 N_Function_Specification, 1098 N_Entry_Body) 1099 1100 or else 1101 Nkind_In (D_Ityp, N_Object_Declaration, 1102 N_Object_Renaming_Declaration, 1103 N_Formal_Object_Declaration, 1104 N_Formal_Type_Declaration, 1105 N_Task_Type_Declaration, 1106 N_Protected_Type_Declaration)) 1107 loop 1108 D_Ityp := Parent (D_Ityp); 1109 pragma Assert (D_Ityp /= Empty); 1110 end loop; 1111 1112 Set_Associated_Node_For_Itype (Desig_Type, D_Ityp); 1113 1114 if Nkind_In (D_Ityp, N_Procedure_Specification, 1115 N_Function_Specification) 1116 then 1117 Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp))); 1118 1119 elsif Nkind_In (D_Ityp, N_Full_Type_Declaration, 1120 N_Object_Declaration, 1121 N_Object_Renaming_Declaration, 1122 N_Formal_Type_Declaration) 1123 then 1124 Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp))); 1125 end if; 1126 1127 if Nkind (T_Def) = N_Access_Function_Definition then 1128 if Nkind (Result_Definition (T_Def)) = N_Access_Definition then 1129 declare 1130 Acc : constant Node_Id := Result_Definition (T_Def); 1131 1132 begin 1133 if Present (Access_To_Subprogram_Definition (Acc)) 1134 and then 1135 Protected_Present (Access_To_Subprogram_Definition (Acc)) 1136 then 1137 Set_Etype 1138 (Desig_Type, 1139 Replace_Anonymous_Access_To_Protected_Subprogram 1140 (T_Def)); 1141 1142 else 1143 Set_Etype 1144 (Desig_Type, 1145 Access_Definition (T_Def, Result_Definition (T_Def))); 1146 end if; 1147 end; 1148 1149 else 1150 Analyze (Result_Definition (T_Def)); 1151 1152 declare 1153 Typ : constant Entity_Id := Entity (Result_Definition (T_Def)); 1154 1155 begin 1156 -- If a null exclusion is imposed on the result type, then 1157 -- create a null-excluding itype (an access subtype) and use 1158 -- it as the function's Etype. 1159 1160 if Is_Access_Type (Typ) 1161 and then Null_Exclusion_In_Return_Present (T_Def) 1162 then 1163 Set_Etype (Desig_Type, 1164 Create_Null_Excluding_Itype 1165 (T => Typ, 1166 Related_Nod => T_Def, 1167 Scope_Id => Current_Scope)); 1168 1169 else 1170 if From_Limited_With (Typ) then 1171 1172 -- AI05-151: Incomplete types are allowed in all basic 1173 -- declarations, including access to subprograms. 1174 1175 if Ada_Version >= Ada_2012 then 1176 null; 1177 1178 else 1179 Error_Msg_NE 1180 ("illegal use of incomplete type&", 1181 Result_Definition (T_Def), Typ); 1182 end if; 1183 1184 elsif Ekind (Current_Scope) = E_Package 1185 and then In_Private_Part (Current_Scope) 1186 then 1187 if Ekind (Typ) = E_Incomplete_Type then 1188 Append_Elmt (Desig_Type, Private_Dependents (Typ)); 1189 1190 elsif Is_Class_Wide_Type (Typ) 1191 and then Ekind (Etype (Typ)) = E_Incomplete_Type 1192 then 1193 Append_Elmt 1194 (Desig_Type, Private_Dependents (Etype (Typ))); 1195 end if; 1196 end if; 1197 1198 Set_Etype (Desig_Type, Typ); 1199 end if; 1200 end; 1201 end if; 1202 1203 if not (Is_Type (Etype (Desig_Type))) then 1204 Error_Msg_N 1205 ("expect type in function specification", 1206 Result_Definition (T_Def)); 1207 end if; 1208 1209 else 1210 Set_Etype (Desig_Type, Standard_Void_Type); 1211 end if; 1212 1213 if Present (Formals) then 1214 Push_Scope (Desig_Type); 1215 1216 -- Some special tests here. These special tests can be removed 1217 -- if and when Itypes always have proper parent pointers to their 1218 -- declarations??? 1219 1220 -- Special test 1) Link defining_identifier of formals. Required by 1221 -- First_Formal to provide its functionality. 1222 1223 declare 1224 F : Node_Id; 1225 1226 begin 1227 F := First (Formals); 1228 1229 -- In ASIS mode, the access_to_subprogram may be analyzed twice, 1230 -- when it is part of an unconstrained type and subtype expansion 1231 -- is disabled. To avoid back-end problems with shared profiles, 1232 -- use previous subprogram type as the designated type, and then 1233 -- remove scope added above. 1234 1235 if ASIS_Mode and then Present (Scope (Defining_Identifier (F))) 1236 then 1237 Set_Etype (T_Name, T_Name); 1238 Init_Size_Align (T_Name); 1239 Set_Directly_Designated_Type (T_Name, 1240 Scope (Defining_Identifier (F))); 1241 End_Scope; 1242 return; 1243 end if; 1244 1245 while Present (F) loop 1246 if No (Parent (Defining_Identifier (F))) then 1247 Set_Parent (Defining_Identifier (F), F); 1248 end if; 1249 1250 Next (F); 1251 end loop; 1252 end; 1253 1254 Process_Formals (Formals, Parent (T_Def)); 1255 1256 -- Special test 2) End_Scope requires that the parent pointer be set 1257 -- to something reasonable, but Itypes don't have parent pointers. So 1258 -- we set it and then unset it ??? 1259 1260 Set_Parent (Desig_Type, T_Name); 1261 End_Scope; 1262 Set_Parent (Desig_Type, Empty); 1263 end if; 1264 1265 -- Check for premature usage of the type being defined 1266 1267 Check_For_Premature_Usage (T_Def); 1268 1269 -- The return type and/or any parameter type may be incomplete. Mark the 1270 -- subprogram_type as depending on the incomplete type, so that it can 1271 -- be updated when the full type declaration is seen. This only applies 1272 -- to incomplete types declared in some enclosing scope, not to limited 1273 -- views from other packages. 1274 1275 -- Prior to Ada 2012, access to functions can only have in_parameters. 1276 1277 if Present (Formals) then 1278 Formal := First_Formal (Desig_Type); 1279 while Present (Formal) loop 1280 if Ekind (Formal) /= E_In_Parameter 1281 and then Nkind (T_Def) = N_Access_Function_Definition 1282 and then Ada_Version < Ada_2012 1283 then 1284 Error_Msg_N ("functions can only have IN parameters", Formal); 1285 end if; 1286 1287 if Ekind (Etype (Formal)) = E_Incomplete_Type 1288 and then In_Open_Scopes (Scope (Etype (Formal))) 1289 then 1290 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal))); 1291 Set_Has_Delayed_Freeze (Desig_Type); 1292 end if; 1293 1294 Next_Formal (Formal); 1295 end loop; 1296 end if; 1297 1298 -- Check whether an indirect call without actuals may be possible. This 1299 -- is used when resolving calls whose result is then indexed. 1300 1301 May_Need_Actuals (Desig_Type); 1302 1303 -- If the return type is incomplete, this is legal as long as the type 1304 -- is declared in the current scope and will be completed in it (rather 1305 -- than being part of limited view). 1306 1307 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type 1308 and then not Has_Delayed_Freeze (Desig_Type) 1309 and then In_Open_Scopes (Scope (Etype (Desig_Type))) 1310 then 1311 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type))); 1312 Set_Has_Delayed_Freeze (Desig_Type); 1313 end if; 1314 1315 Check_Delayed_Subprogram (Desig_Type); 1316 1317 if Protected_Present (T_Def) then 1318 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type); 1319 Set_Convention (Desig_Type, Convention_Protected); 1320 else 1321 Set_Ekind (T_Name, E_Access_Subprogram_Type); 1322 end if; 1323 1324 Set_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target); 1325 1326 Set_Etype (T_Name, T_Name); 1327 Init_Size_Align (T_Name); 1328 Set_Directly_Designated_Type (T_Name, Desig_Type); 1329 1330 Generate_Reference_To_Formals (T_Name); 1331 1332 -- Ada 2005 (AI-231): Propagate the null-excluding attribute 1333 1334 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def)); 1335 1336 Check_Restriction (No_Access_Subprograms, T_Def); 1337 end Access_Subprogram_Declaration; 1338 1339 ---------------------------- 1340 -- Access_Type_Declaration -- 1341 ---------------------------- 1342 1343 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is 1344 P : constant Node_Id := Parent (Def); 1345 S : constant Node_Id := Subtype_Indication (Def); 1346 1347 Full_Desig : Entity_Id; 1348 1349 begin 1350 Check_SPARK_05_Restriction ("access type is not allowed", Def); 1351 1352 -- Check for permissible use of incomplete type 1353 1354 if Nkind (S) /= N_Subtype_Indication then 1355 Analyze (S); 1356 1357 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then 1358 Set_Directly_Designated_Type (T, Entity (S)); 1359 1360 -- If the designated type is a limited view, we cannot tell if 1361 -- the full view contains tasks, and there is no way to handle 1362 -- that full view in a client. We create a master entity for the 1363 -- scope, which will be used when a client determines that one 1364 -- is needed. 1365 1366 if From_Limited_With (Entity (S)) 1367 and then not Is_Class_Wide_Type (Entity (S)) 1368 then 1369 Set_Ekind (T, E_Access_Type); 1370 Build_Master_Entity (T); 1371 Build_Master_Renaming (T); 1372 end if; 1373 1374 else 1375 Set_Directly_Designated_Type (T, Process_Subtype (S, P, T, 'P')); 1376 end if; 1377 1378 -- If the access definition is of the form: ACCESS NOT NULL .. 1379 -- the subtype indication must be of an access type. Create 1380 -- a null-excluding subtype of it. 1381 1382 if Null_Excluding_Subtype (Def) then 1383 if not Is_Access_Type (Entity (S)) then 1384 Error_Msg_N ("null exclusion must apply to access type", Def); 1385 1386 else 1387 declare 1388 Loc : constant Source_Ptr := Sloc (S); 1389 Decl : Node_Id; 1390 Nam : constant Entity_Id := Make_Temporary (Loc, 'S'); 1391 1392 begin 1393 Decl := 1394 Make_Subtype_Declaration (Loc, 1395 Defining_Identifier => Nam, 1396 Subtype_Indication => 1397 New_Occurrence_Of (Entity (S), Loc)); 1398 Set_Null_Exclusion_Present (Decl); 1399 Insert_Before (Parent (Def), Decl); 1400 Analyze (Decl); 1401 Set_Entity (S, Nam); 1402 end; 1403 end if; 1404 end if; 1405 1406 else 1407 Set_Directly_Designated_Type (T, 1408 Process_Subtype (S, P, T, 'P')); 1409 end if; 1410 1411 if All_Present (Def) or Constant_Present (Def) then 1412 Set_Ekind (T, E_General_Access_Type); 1413 else 1414 Set_Ekind (T, E_Access_Type); 1415 end if; 1416 1417 Full_Desig := Designated_Type (T); 1418 1419 if Base_Type (Full_Desig) = T then 1420 Error_Msg_N ("access type cannot designate itself", S); 1421 1422 -- In Ada 2005, the type may have a limited view through some unit in 1423 -- its own context, allowing the following circularity that cannot be 1424 -- detected earlier. 1425 1426 elsif Is_Class_Wide_Type (Full_Desig) and then Etype (Full_Desig) = T 1427 then 1428 Error_Msg_N 1429 ("access type cannot designate its own classwide type", S); 1430 1431 -- Clean up indication of tagged status to prevent cascaded errors 1432 1433 Set_Is_Tagged_Type (T, False); 1434 end if; 1435 1436 Set_Etype (T, T); 1437 1438 -- If the type has appeared already in a with_type clause, it is frozen 1439 -- and the pointer size is already set. Else, initialize. 1440 1441 if not From_Limited_With (T) then 1442 Init_Size_Align (T); 1443 end if; 1444 1445 -- Note that Has_Task is always false, since the access type itself 1446 -- is not a task type. See Einfo for more description on this point. 1447 -- Exactly the same consideration applies to Has_Controlled_Component 1448 -- and to Has_Protected. 1449 1450 Set_Has_Task (T, False); 1451 Set_Has_Controlled_Component (T, False); 1452 Set_Has_Protected (T, False); 1453 1454 -- Initialize field Finalization_Master explicitly to Empty, to avoid 1455 -- problems where an incomplete view of this entity has been previously 1456 -- established by a limited with and an overlaid version of this field 1457 -- (Stored_Constraint) was initialized for the incomplete view. 1458 1459 -- This reset is performed in most cases except where the access type 1460 -- has been created for the purposes of allocating or deallocating a 1461 -- build-in-place object. Such access types have explicitly set pools 1462 -- and finalization masters. 1463 1464 if No (Associated_Storage_Pool (T)) then 1465 Set_Finalization_Master (T, Empty); 1466 end if; 1467 1468 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant 1469 -- attributes 1470 1471 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def)); 1472 Set_Is_Access_Constant (T, Constant_Present (Def)); 1473 end Access_Type_Declaration; 1474 1475 ---------------------------------- 1476 -- Add_Interface_Tag_Components -- 1477 ---------------------------------- 1478 1479 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is 1480 Loc : constant Source_Ptr := Sloc (N); 1481 L : List_Id; 1482 Last_Tag : Node_Id; 1483 1484 procedure Add_Tag (Iface : Entity_Id); 1485 -- Add tag for one of the progenitor interfaces 1486 1487 ------------- 1488 -- Add_Tag -- 1489 ------------- 1490 1491 procedure Add_Tag (Iface : Entity_Id) is 1492 Decl : Node_Id; 1493 Def : Node_Id; 1494 Tag : Entity_Id; 1495 Offset : Entity_Id; 1496 1497 begin 1498 pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface)); 1499 1500 -- This is a reasonable place to propagate predicates 1501 1502 if Has_Predicates (Iface) then 1503 Set_Has_Predicates (Typ); 1504 end if; 1505 1506 Def := 1507 Make_Component_Definition (Loc, 1508 Aliased_Present => True, 1509 Subtype_Indication => 1510 New_Occurrence_Of (RTE (RE_Interface_Tag), Loc)); 1511 1512 Tag := Make_Temporary (Loc, 'V'); 1513 1514 Decl := 1515 Make_Component_Declaration (Loc, 1516 Defining_Identifier => Tag, 1517 Component_Definition => Def); 1518 1519 Analyze_Component_Declaration (Decl); 1520 1521 Set_Analyzed (Decl); 1522 Set_Ekind (Tag, E_Component); 1523 Set_Is_Tag (Tag); 1524 Set_Is_Aliased (Tag); 1525 Set_Related_Type (Tag, Iface); 1526 Init_Component_Location (Tag); 1527 1528 pragma Assert (Is_Frozen (Iface)); 1529 1530 Set_DT_Entry_Count (Tag, 1531 DT_Entry_Count (First_Entity (Iface))); 1532 1533 if No (Last_Tag) then 1534 Prepend (Decl, L); 1535 else 1536 Insert_After (Last_Tag, Decl); 1537 end if; 1538 1539 Last_Tag := Decl; 1540 1541 -- If the ancestor has discriminants we need to give special support 1542 -- to store the offset_to_top value of the secondary dispatch tables. 1543 -- For this purpose we add a supplementary component just after the 1544 -- field that contains the tag associated with each secondary DT. 1545 1546 if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then 1547 Def := 1548 Make_Component_Definition (Loc, 1549 Subtype_Indication => 1550 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc)); 1551 1552 Offset := Make_Temporary (Loc, 'V'); 1553 1554 Decl := 1555 Make_Component_Declaration (Loc, 1556 Defining_Identifier => Offset, 1557 Component_Definition => Def); 1558 1559 Analyze_Component_Declaration (Decl); 1560 1561 Set_Analyzed (Decl); 1562 Set_Ekind (Offset, E_Component); 1563 Set_Is_Aliased (Offset); 1564 Set_Related_Type (Offset, Iface); 1565 Init_Component_Location (Offset); 1566 Insert_After (Last_Tag, Decl); 1567 Last_Tag := Decl; 1568 end if; 1569 end Add_Tag; 1570 1571 -- Local variables 1572 1573 Elmt : Elmt_Id; 1574 Ext : Node_Id; 1575 Comp : Node_Id; 1576 1577 -- Start of processing for Add_Interface_Tag_Components 1578 1579 begin 1580 if not RTE_Available (RE_Interface_Tag) then 1581 Error_Msg 1582 ("(Ada 2005) interface types not supported by this run-time!", 1583 Sloc (N)); 1584 return; 1585 end if; 1586 1587 if Ekind (Typ) /= E_Record_Type 1588 or else (Is_Concurrent_Record_Type (Typ) 1589 and then Is_Empty_List (Abstract_Interface_List (Typ))) 1590 or else (not Is_Concurrent_Record_Type (Typ) 1591 and then No (Interfaces (Typ)) 1592 and then Is_Empty_Elmt_List (Interfaces (Typ))) 1593 then 1594 return; 1595 end if; 1596 1597 -- Find the current last tag 1598 1599 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then 1600 Ext := Record_Extension_Part (Type_Definition (N)); 1601 else 1602 pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition); 1603 Ext := Type_Definition (N); 1604 end if; 1605 1606 Last_Tag := Empty; 1607 1608 if not (Present (Component_List (Ext))) then 1609 Set_Null_Present (Ext, False); 1610 L := New_List; 1611 Set_Component_List (Ext, 1612 Make_Component_List (Loc, 1613 Component_Items => L, 1614 Null_Present => False)); 1615 else 1616 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then 1617 L := Component_Items 1618 (Component_List 1619 (Record_Extension_Part 1620 (Type_Definition (N)))); 1621 else 1622 L := Component_Items 1623 (Component_List 1624 (Type_Definition (N))); 1625 end if; 1626 1627 -- Find the last tag component 1628 1629 Comp := First (L); 1630 while Present (Comp) loop 1631 if Nkind (Comp) = N_Component_Declaration 1632 and then Is_Tag (Defining_Identifier (Comp)) 1633 then 1634 Last_Tag := Comp; 1635 end if; 1636 1637 Next (Comp); 1638 end loop; 1639 end if; 1640 1641 -- At this point L references the list of components and Last_Tag 1642 -- references the current last tag (if any). Now we add the tag 1643 -- corresponding with all the interfaces that are not implemented 1644 -- by the parent. 1645 1646 if Present (Interfaces (Typ)) then 1647 Elmt := First_Elmt (Interfaces (Typ)); 1648 while Present (Elmt) loop 1649 Add_Tag (Node (Elmt)); 1650 Next_Elmt (Elmt); 1651 end loop; 1652 end if; 1653 end Add_Interface_Tag_Components; 1654 1655 ------------------------------------- 1656 -- Add_Internal_Interface_Entities -- 1657 ------------------------------------- 1658 1659 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is 1660 Elmt : Elmt_Id; 1661 Iface : Entity_Id; 1662 Iface_Elmt : Elmt_Id; 1663 Iface_Prim : Entity_Id; 1664 Ifaces_List : Elist_Id; 1665 New_Subp : Entity_Id := Empty; 1666 Prim : Entity_Id; 1667 Restore_Scope : Boolean := False; 1668 1669 begin 1670 pragma Assert (Ada_Version >= Ada_2005 1671 and then Is_Record_Type (Tagged_Type) 1672 and then Is_Tagged_Type (Tagged_Type) 1673 and then Has_Interfaces (Tagged_Type) 1674 and then not Is_Interface (Tagged_Type)); 1675 1676 -- Ensure that the internal entities are added to the scope of the type 1677 1678 if Scope (Tagged_Type) /= Current_Scope then 1679 Push_Scope (Scope (Tagged_Type)); 1680 Restore_Scope := True; 1681 end if; 1682 1683 Collect_Interfaces (Tagged_Type, Ifaces_List); 1684 1685 Iface_Elmt := First_Elmt (Ifaces_List); 1686 while Present (Iface_Elmt) loop 1687 Iface := Node (Iface_Elmt); 1688 1689 -- Originally we excluded here from this processing interfaces that 1690 -- are parents of Tagged_Type because their primitives are located 1691 -- in the primary dispatch table (and hence no auxiliary internal 1692 -- entities are required to handle secondary dispatch tables in such 1693 -- case). However, these auxiliary entities are also required to 1694 -- handle derivations of interfaces in formals of generics (see 1695 -- Derive_Subprograms). 1696 1697 Elmt := First_Elmt (Primitive_Operations (Iface)); 1698 while Present (Elmt) loop 1699 Iface_Prim := Node (Elmt); 1700 1701 if not Is_Predefined_Dispatching_Operation (Iface_Prim) then 1702 Prim := 1703 Find_Primitive_Covering_Interface 1704 (Tagged_Type => Tagged_Type, 1705 Iface_Prim => Iface_Prim); 1706 1707 if No (Prim) and then Serious_Errors_Detected > 0 then 1708 goto Continue; 1709 end if; 1710 1711 pragma Assert (Present (Prim)); 1712 1713 -- Ada 2012 (AI05-0197): If the name of the covering primitive 1714 -- differs from the name of the interface primitive then it is 1715 -- a private primitive inherited from a parent type. In such 1716 -- case, given that Tagged_Type covers the interface, the 1717 -- inherited private primitive becomes visible. For such 1718 -- purpose we add a new entity that renames the inherited 1719 -- private primitive. 1720 1721 if Chars (Prim) /= Chars (Iface_Prim) then 1722 pragma Assert (Has_Suffix (Prim, 'P')); 1723 Derive_Subprogram 1724 (New_Subp => New_Subp, 1725 Parent_Subp => Iface_Prim, 1726 Derived_Type => Tagged_Type, 1727 Parent_Type => Iface); 1728 Set_Alias (New_Subp, Prim); 1729 Set_Is_Abstract_Subprogram 1730 (New_Subp, Is_Abstract_Subprogram (Prim)); 1731 end if; 1732 1733 Derive_Subprogram 1734 (New_Subp => New_Subp, 1735 Parent_Subp => Iface_Prim, 1736 Derived_Type => Tagged_Type, 1737 Parent_Type => Iface); 1738 1739 -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp 1740 -- associated with interface types. These entities are 1741 -- only registered in the list of primitives of its 1742 -- corresponding tagged type because they are only used 1743 -- to fill the contents of the secondary dispatch tables. 1744 -- Therefore they are removed from the homonym chains. 1745 1746 Set_Is_Hidden (New_Subp); 1747 Set_Is_Internal (New_Subp); 1748 Set_Alias (New_Subp, Prim); 1749 Set_Is_Abstract_Subprogram 1750 (New_Subp, Is_Abstract_Subprogram (Prim)); 1751 Set_Interface_Alias (New_Subp, Iface_Prim); 1752 1753 -- If the returned type is an interface then propagate it to 1754 -- the returned type. Needed by the thunk to generate the code 1755 -- which displaces "this" to reference the corresponding 1756 -- secondary dispatch table in the returned object. 1757 1758 if Is_Interface (Etype (Iface_Prim)) then 1759 Set_Etype (New_Subp, Etype (Iface_Prim)); 1760 end if; 1761 1762 -- Internal entities associated with interface types are 1763 -- only registered in the list of primitives of the tagged 1764 -- type. They are only used to fill the contents of the 1765 -- secondary dispatch tables. Therefore they are not needed 1766 -- in the homonym chains. 1767 1768 Remove_Homonym (New_Subp); 1769 1770 -- Hidden entities associated with interfaces must have set 1771 -- the Has_Delay_Freeze attribute to ensure that, in case of 1772 -- locally defined tagged types (or compiling with static 1773 -- dispatch tables generation disabled) the corresponding 1774 -- entry of the secondary dispatch table is filled when 1775 -- such an entity is frozen. 1776 1777 Set_Has_Delayed_Freeze (New_Subp); 1778 end if; 1779 1780 <<Continue>> 1781 Next_Elmt (Elmt); 1782 end loop; 1783 1784 Next_Elmt (Iface_Elmt); 1785 end loop; 1786 1787 if Restore_Scope then 1788 Pop_Scope; 1789 end if; 1790 end Add_Internal_Interface_Entities; 1791 1792 ----------------------------------- 1793 -- Analyze_Component_Declaration -- 1794 ----------------------------------- 1795 1796 procedure Analyze_Component_Declaration (N : Node_Id) is 1797 Id : constant Entity_Id := Defining_Identifier (N); 1798 E : constant Node_Id := Expression (N); 1799 Typ : constant Node_Id := 1800 Subtype_Indication (Component_Definition (N)); 1801 T : Entity_Id; 1802 P : Entity_Id; 1803 1804 function Contains_POC (Constr : Node_Id) return Boolean; 1805 -- Determines whether a constraint uses the discriminant of a record 1806 -- type thus becoming a per-object constraint (POC). 1807 1808 function Is_Known_Limited (Typ : Entity_Id) return Boolean; 1809 -- Typ is the type of the current component, check whether this type is 1810 -- a limited type. Used to validate declaration against that of 1811 -- enclosing record. 1812 1813 ------------------ 1814 -- Contains_POC -- 1815 ------------------ 1816 1817 function Contains_POC (Constr : Node_Id) return Boolean is 1818 begin 1819 -- Prevent cascaded errors 1820 1821 if Error_Posted (Constr) then 1822 return False; 1823 end if; 1824 1825 case Nkind (Constr) is 1826 when N_Attribute_Reference => 1827 return Attribute_Name (Constr) = Name_Access 1828 and then Prefix (Constr) = Scope (Entity (Prefix (Constr))); 1829 1830 when N_Discriminant_Association => 1831 return Denotes_Discriminant (Expression (Constr)); 1832 1833 when N_Identifier => 1834 return Denotes_Discriminant (Constr); 1835 1836 when N_Index_Or_Discriminant_Constraint => 1837 declare 1838 IDC : Node_Id; 1839 1840 begin 1841 IDC := First (Constraints (Constr)); 1842 while Present (IDC) loop 1843 1844 -- One per-object constraint is sufficient 1845 1846 if Contains_POC (IDC) then 1847 return True; 1848 end if; 1849 1850 Next (IDC); 1851 end loop; 1852 1853 return False; 1854 end; 1855 1856 when N_Range => 1857 return Denotes_Discriminant (Low_Bound (Constr)) 1858 or else 1859 Denotes_Discriminant (High_Bound (Constr)); 1860 1861 when N_Range_Constraint => 1862 return Denotes_Discriminant (Range_Expression (Constr)); 1863 1864 when others => 1865 return False; 1866 1867 end case; 1868 end Contains_POC; 1869 1870 ---------------------- 1871 -- Is_Known_Limited -- 1872 ---------------------- 1873 1874 function Is_Known_Limited (Typ : Entity_Id) return Boolean is 1875 P : constant Entity_Id := Etype (Typ); 1876 R : constant Entity_Id := Root_Type (Typ); 1877 1878 begin 1879 if Is_Limited_Record (Typ) then 1880 return True; 1881 1882 -- If the root type is limited (and not a limited interface) 1883 -- so is the current type 1884 1885 elsif Is_Limited_Record (R) 1886 and then (not Is_Interface (R) or else not Is_Limited_Interface (R)) 1887 then 1888 return True; 1889 1890 -- Else the type may have a limited interface progenitor, but a 1891 -- limited record parent. 1892 1893 elsif R /= P and then Is_Limited_Record (P) then 1894 return True; 1895 1896 else 1897 return False; 1898 end if; 1899 end Is_Known_Limited; 1900 1901 -- Start of processing for Analyze_Component_Declaration 1902 1903 begin 1904 Generate_Definition (Id); 1905 Enter_Name (Id); 1906 1907 if Present (Typ) then 1908 T := Find_Type_Of_Object 1909 (Subtype_Indication (Component_Definition (N)), N); 1910 1911 if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then 1912 Check_SPARK_05_Restriction ("subtype mark required", Typ); 1913 end if; 1914 1915 -- Ada 2005 (AI-230): Access Definition case 1916 1917 else 1918 pragma Assert (Present 1919 (Access_Definition (Component_Definition (N)))); 1920 1921 T := Access_Definition 1922 (Related_Nod => N, 1923 N => Access_Definition (Component_Definition (N))); 1924 Set_Is_Local_Anonymous_Access (T); 1925 1926 -- Ada 2005 (AI-254) 1927 1928 if Present (Access_To_Subprogram_Definition 1929 (Access_Definition (Component_Definition (N)))) 1930 and then Protected_Present (Access_To_Subprogram_Definition 1931 (Access_Definition 1932 (Component_Definition (N)))) 1933 then 1934 T := Replace_Anonymous_Access_To_Protected_Subprogram (N); 1935 end if; 1936 end if; 1937 1938 -- If the subtype is a constrained subtype of the enclosing record, 1939 -- (which must have a partial view) the back-end does not properly 1940 -- handle the recursion. Rewrite the component declaration with an 1941 -- explicit subtype indication, which is acceptable to Gigi. We can copy 1942 -- the tree directly because side effects have already been removed from 1943 -- discriminant constraints. 1944 1945 if Ekind (T) = E_Access_Subtype 1946 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N))) 1947 and then Comes_From_Source (T) 1948 and then Nkind (Parent (T)) = N_Subtype_Declaration 1949 and then Etype (Directly_Designated_Type (T)) = Current_Scope 1950 then 1951 Rewrite 1952 (Subtype_Indication (Component_Definition (N)), 1953 New_Copy_Tree (Subtype_Indication (Parent (T)))); 1954 T := Find_Type_Of_Object 1955 (Subtype_Indication (Component_Definition (N)), N); 1956 end if; 1957 1958 -- If the component declaration includes a default expression, then we 1959 -- check that the component is not of a limited type (RM 3.7(5)), 1960 -- and do the special preanalysis of the expression (see section on 1961 -- "Handling of Default and Per-Object Expressions" in the spec of 1962 -- package Sem). 1963 1964 if Present (E) then 1965 Check_SPARK_05_Restriction ("default expression is not allowed", E); 1966 Preanalyze_Default_Expression (E, T); 1967 Check_Initialization (T, E); 1968 1969 if Ada_Version >= Ada_2005 1970 and then Ekind (T) = E_Anonymous_Access_Type 1971 and then Etype (E) /= Any_Type 1972 then 1973 -- Check RM 3.9.2(9): "if the expected type for an expression is 1974 -- an anonymous access-to-specific tagged type, then the object 1975 -- designated by the expression shall not be dynamically tagged 1976 -- unless it is a controlling operand in a call on a dispatching 1977 -- operation" 1978 1979 if Is_Tagged_Type (Directly_Designated_Type (T)) 1980 and then 1981 Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type 1982 and then 1983 Ekind (Directly_Designated_Type (Etype (E))) = 1984 E_Class_Wide_Type 1985 then 1986 Error_Msg_N 1987 ("access to specific tagged type required (RM 3.9.2(9))", E); 1988 end if; 1989 1990 -- (Ada 2005: AI-230): Accessibility check for anonymous 1991 -- components 1992 1993 if Type_Access_Level (Etype (E)) > 1994 Deepest_Type_Access_Level (T) 1995 then 1996 Error_Msg_N 1997 ("expression has deeper access level than component " & 1998 "(RM 3.10.2 (12.2))", E); 1999 end if; 2000 2001 -- The initialization expression is a reference to an access 2002 -- discriminant. The type of the discriminant is always deeper 2003 -- than any access type. 2004 2005 if Ekind (Etype (E)) = E_Anonymous_Access_Type 2006 and then Is_Entity_Name (E) 2007 and then Ekind (Entity (E)) = E_In_Parameter 2008 and then Present (Discriminal_Link (Entity (E))) 2009 then 2010 Error_Msg_N 2011 ("discriminant has deeper accessibility level than target", 2012 E); 2013 end if; 2014 end if; 2015 end if; 2016 2017 -- The parent type may be a private view with unknown discriminants, 2018 -- and thus unconstrained. Regular components must be constrained. 2019 2020 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then 2021 if Is_Class_Wide_Type (T) then 2022 Error_Msg_N 2023 ("class-wide subtype with unknown discriminants" & 2024 " in component declaration", 2025 Subtype_Indication (Component_Definition (N))); 2026 else 2027 Error_Msg_N 2028 ("unconstrained subtype in component declaration", 2029 Subtype_Indication (Component_Definition (N))); 2030 end if; 2031 2032 -- Components cannot be abstract, except for the special case of 2033 -- the _Parent field (case of extending an abstract tagged type) 2034 2035 elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then 2036 Error_Msg_N ("type of a component cannot be abstract", N); 2037 end if; 2038 2039 Set_Etype (Id, T); 2040 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N))); 2041 2042 -- The component declaration may have a per-object constraint, set 2043 -- the appropriate flag in the defining identifier of the subtype. 2044 2045 if Present (Subtype_Indication (Component_Definition (N))) then 2046 declare 2047 Sindic : constant Node_Id := 2048 Subtype_Indication (Component_Definition (N)); 2049 begin 2050 if Nkind (Sindic) = N_Subtype_Indication 2051 and then Present (Constraint (Sindic)) 2052 and then Contains_POC (Constraint (Sindic)) 2053 then 2054 Set_Has_Per_Object_Constraint (Id); 2055 end if; 2056 end; 2057 end if; 2058 2059 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry 2060 -- out some static checks. 2061 2062 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then 2063 Null_Exclusion_Static_Checks (N); 2064 end if; 2065 2066 -- If this component is private (or depends on a private type), flag the 2067 -- record type to indicate that some operations are not available. 2068 2069 P := Private_Component (T); 2070 2071 if Present (P) then 2072 2073 -- Check for circular definitions 2074 2075 if P = Any_Type then 2076 Set_Etype (Id, Any_Type); 2077 2078 -- There is a gap in the visibility of operations only if the 2079 -- component type is not defined in the scope of the record type. 2080 2081 elsif Scope (P) = Scope (Current_Scope) then 2082 null; 2083 2084 elsif Is_Limited_Type (P) then 2085 Set_Is_Limited_Composite (Current_Scope); 2086 2087 else 2088 Set_Is_Private_Composite (Current_Scope); 2089 end if; 2090 end if; 2091 2092 if P /= Any_Type 2093 and then Is_Limited_Type (T) 2094 and then Chars (Id) /= Name_uParent 2095 and then Is_Tagged_Type (Current_Scope) 2096 then 2097 if Is_Derived_Type (Current_Scope) 2098 and then not Is_Known_Limited (Current_Scope) 2099 then 2100 Error_Msg_N 2101 ("extension of nonlimited type cannot have limited components", 2102 N); 2103 2104 if Is_Interface (Root_Type (Current_Scope)) then 2105 Error_Msg_N 2106 ("\limitedness is not inherited from limited interface", N); 2107 Error_Msg_N ("\add LIMITED to type indication", N); 2108 end if; 2109 2110 Explain_Limited_Type (T, N); 2111 Set_Etype (Id, Any_Type); 2112 Set_Is_Limited_Composite (Current_Scope, False); 2113 2114 elsif not Is_Derived_Type (Current_Scope) 2115 and then not Is_Limited_Record (Current_Scope) 2116 and then not Is_Concurrent_Type (Current_Scope) 2117 then 2118 Error_Msg_N 2119 ("nonlimited tagged type cannot have limited components", N); 2120 Explain_Limited_Type (T, N); 2121 Set_Etype (Id, Any_Type); 2122 Set_Is_Limited_Composite (Current_Scope, False); 2123 end if; 2124 end if; 2125 2126 Set_Original_Record_Component (Id, Id); 2127 2128 if Has_Aspects (N) then 2129 Analyze_Aspect_Specifications (N, Id); 2130 end if; 2131 2132 Analyze_Dimension (N); 2133 end Analyze_Component_Declaration; 2134 2135 -------------------------- 2136 -- Analyze_Declarations -- 2137 -------------------------- 2138 2139 procedure Analyze_Declarations (L : List_Id) is 2140 Decl : Node_Id; 2141 2142 procedure Adjust_Decl; 2143 -- Adjust Decl not to include implicit label declarations, since these 2144 -- have strange Sloc values that result in elaboration check problems. 2145 -- (They have the sloc of the label as found in the source, and that 2146 -- is ahead of the current declarative part). 2147 2148 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id); 2149 -- Determine whether Body_Decl denotes the body of a late controlled 2150 -- primitive (either Initialize, Adjust or Finalize). If this is the 2151 -- case, add a proper spec if the body lacks one. The spec is inserted 2152 -- before Body_Decl and immedately analyzed. 2153 2154 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id); 2155 -- Spec_Id is the entity of a package that may define abstract states. 2156 -- If the states have visible refinement, remove the visibility of each 2157 -- constituent at the end of the package body declarations. 2158 2159 ----------------- 2160 -- Adjust_Decl -- 2161 ----------------- 2162 2163 procedure Adjust_Decl is 2164 begin 2165 while Present (Prev (Decl)) 2166 and then Nkind (Decl) = N_Implicit_Label_Declaration 2167 loop 2168 Prev (Decl); 2169 end loop; 2170 end Adjust_Decl; 2171 2172 -------------------------------------- 2173 -- Handle_Late_Controlled_Primitive -- 2174 -------------------------------------- 2175 2176 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id) is 2177 Body_Spec : constant Node_Id := Specification (Body_Decl); 2178 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec); 2179 Loc : constant Source_Ptr := Sloc (Body_Id); 2180 Params : constant List_Id := 2181 Parameter_Specifications (Body_Spec); 2182 Spec : Node_Id; 2183 Spec_Id : Entity_Id; 2184 Typ : Node_Id; 2185 2186 begin 2187 -- Consider only procedure bodies whose name matches one of the three 2188 -- controlled primitives. 2189 2190 if Nkind (Body_Spec) /= N_Procedure_Specification 2191 or else not Nam_In (Chars (Body_Id), Name_Adjust, 2192 Name_Finalize, 2193 Name_Initialize) 2194 then 2195 return; 2196 2197 -- A controlled primitive must have exactly one formal which is not 2198 -- an anonymous access type. 2199 2200 elsif List_Length (Params) /= 1 then 2201 return; 2202 end if; 2203 2204 Typ := Parameter_Type (First (Params)); 2205 2206 if Nkind (Typ) = N_Access_Definition then 2207 return; 2208 end if; 2209 2210 Find_Type (Typ); 2211 2212 -- The type of the formal must be derived from [Limited_]Controlled 2213 2214 if not Is_Controlled (Entity (Typ)) then 2215 return; 2216 end if; 2217 2218 -- Check whether a specification exists for this body. We do not 2219 -- analyze the spec of the body in full, because it will be analyzed 2220 -- again when the body is properly analyzed, and we cannot create 2221 -- duplicate entries in the formals chain. We look for an explicit 2222 -- specification because the body may be an overriding operation and 2223 -- an inherited spec may be present. 2224 2225 Spec_Id := Current_Entity (Body_Id); 2226 2227 while Present (Spec_Id) loop 2228 if Ekind_In (Spec_Id, E_Procedure, E_Generic_Procedure) 2229 and then Scope (Spec_Id) = Current_Scope 2230 and then Present (First_Formal (Spec_Id)) 2231 and then No (Next_Formal (First_Formal (Spec_Id))) 2232 and then Etype (First_Formal (Spec_Id)) = Entity (Typ) 2233 and then Comes_From_Source (Spec_Id) 2234 then 2235 return; 2236 end if; 2237 2238 Spec_Id := Homonym (Spec_Id); 2239 end loop; 2240 2241 -- At this point the body is known to be a late controlled primitive. 2242 -- Generate a matching spec and insert it before the body. Note the 2243 -- use of Copy_Separate_Tree - we want an entirely separate semantic 2244 -- tree in this case. 2245 2246 Spec := Copy_Separate_Tree (Body_Spec); 2247 2248 -- Ensure that the subprogram declaration does not inherit the null 2249 -- indicator from the body as we now have a proper spec/body pair. 2250 2251 Set_Null_Present (Spec, False); 2252 2253 Insert_Before_And_Analyze (Body_Decl, 2254 Make_Subprogram_Declaration (Loc, Specification => Spec)); 2255 end Handle_Late_Controlled_Primitive; 2256 2257 -------------------------------- 2258 -- Remove_Visible_Refinements -- 2259 -------------------------------- 2260 2261 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id) is 2262 State_Elmt : Elmt_Id; 2263 begin 2264 if Present (Abstract_States (Spec_Id)) then 2265 State_Elmt := First_Elmt (Abstract_States (Spec_Id)); 2266 while Present (State_Elmt) loop 2267 Set_Has_Visible_Refinement (Node (State_Elmt), False); 2268 Next_Elmt (State_Elmt); 2269 end loop; 2270 end if; 2271 end Remove_Visible_Refinements; 2272 2273 -- Local variables 2274 2275 Context : Node_Id; 2276 Freeze_From : Entity_Id := Empty; 2277 Next_Decl : Node_Id; 2278 Spec_Id : Entity_Id; 2279 2280 Body_Seen : Boolean := False; 2281 -- Flag set when the first body [stub] is encountered 2282 2283 In_Package_Body : Boolean := False; 2284 -- Flag set when the current declaration list belongs to a package body 2285 2286 -- Start of processing for Analyze_Declarations 2287 2288 begin 2289 if Restriction_Check_Required (SPARK_05) then 2290 Check_Later_Vs_Basic_Declarations (L, During_Parsing => False); 2291 end if; 2292 2293 Decl := First (L); 2294 while Present (Decl) loop 2295 2296 -- Package spec cannot contain a package declaration in SPARK 2297 2298 if Nkind (Decl) = N_Package_Declaration 2299 and then Nkind (Parent (L)) = N_Package_Specification 2300 then 2301 Check_SPARK_05_Restriction 2302 ("package specification cannot contain a package declaration", 2303 Decl); 2304 end if; 2305 2306 -- Complete analysis of declaration 2307 2308 Analyze (Decl); 2309 Next_Decl := Next (Decl); 2310 2311 if No (Freeze_From) then 2312 Freeze_From := First_Entity (Current_Scope); 2313 end if; 2314 2315 -- At the end of a declarative part, freeze remaining entities 2316 -- declared in it. The end of the visible declarations of package 2317 -- specification is not the end of a declarative part if private 2318 -- declarations are present. The end of a package declaration is a 2319 -- freezing point only if it a library package. A task definition or 2320 -- protected type definition is not a freeze point either. Finally, 2321 -- we do not freeze entities in generic scopes, because there is no 2322 -- code generated for them and freeze nodes will be generated for 2323 -- the instance. 2324 2325 -- The end of a package instantiation is not a freeze point, but 2326 -- for now we make it one, because the generic body is inserted 2327 -- (currently) immediately after. Generic instantiations will not 2328 -- be a freeze point once delayed freezing of bodies is implemented. 2329 -- (This is needed in any case for early instantiations ???). 2330 2331 if No (Next_Decl) then 2332 if Nkind_In (Parent (L), N_Component_List, 2333 N_Task_Definition, 2334 N_Protected_Definition) 2335 then 2336 null; 2337 2338 elsif Nkind (Parent (L)) /= N_Package_Specification then 2339 if Nkind (Parent (L)) = N_Package_Body then 2340 Freeze_From := First_Entity (Current_Scope); 2341 end if; 2342 2343 -- There may have been several freezing points previously, 2344 -- for example object declarations or subprogram bodies, but 2345 -- at the end of a declarative part we check freezing from 2346 -- the beginning, even though entities may already be frozen, 2347 -- in order to perform visibility checks on delayed aspects. 2348 2349 Adjust_Decl; 2350 Freeze_All (First_Entity (Current_Scope), Decl); 2351 Freeze_From := Last_Entity (Current_Scope); 2352 2353 elsif Scope (Current_Scope) /= Standard_Standard 2354 and then not Is_Child_Unit (Current_Scope) 2355 and then No (Generic_Parent (Parent (L))) 2356 then 2357 null; 2358 2359 elsif L /= Visible_Declarations (Parent (L)) 2360 or else No (Private_Declarations (Parent (L))) 2361 or else Is_Empty_List (Private_Declarations (Parent (L))) 2362 then 2363 Adjust_Decl; 2364 Freeze_All (First_Entity (Current_Scope), Decl); 2365 Freeze_From := Last_Entity (Current_Scope); 2366 end if; 2367 2368 -- If next node is a body then freeze all types before the body. 2369 -- An exception occurs for some expander-generated bodies. If these 2370 -- are generated at places where in general language rules would not 2371 -- allow a freeze point, then we assume that the expander has 2372 -- explicitly checked that all required types are properly frozen, 2373 -- and we do not cause general freezing here. This special circuit 2374 -- is used when the encountered body is marked as having already 2375 -- been analyzed. 2376 2377 -- In all other cases (bodies that come from source, and expander 2378 -- generated bodies that have not been analyzed yet), freeze all 2379 -- types now. Note that in the latter case, the expander must take 2380 -- care to attach the bodies at a proper place in the tree so as to 2381 -- not cause unwanted freezing at that point. 2382 2383 elsif not Analyzed (Next_Decl) and then Is_Body (Next_Decl) then 2384 2385 -- When a controlled type is frozen, the expander generates stream 2386 -- and controlled type support routines. If the freeze is caused 2387 -- by the stand alone body of Initialize, Adjust and Finalize, the 2388 -- expander will end up using the wrong version of these routines 2389 -- as the body has not been processed yet. To remedy this, detect 2390 -- a late controlled primitive and create a proper spec for it. 2391 -- This ensures that the primitive will override its inherited 2392 -- counterpart before the freeze takes place. 2393 2394 -- If the declaration we just processed is a body, do not attempt 2395 -- to examine Next_Decl as the late primitive idiom can only apply 2396 -- to the first encountered body. 2397 2398 -- The spec of the late primitive is not generated in ASIS mode to 2399 -- ensure a consistent list of primitives that indicates the true 2400 -- semantic structure of the program (which is not relevant when 2401 -- generating executable code. 2402 2403 -- ??? a cleaner approach may be possible and/or this solution 2404 -- could be extended to general-purpose late primitives, TBD. 2405 2406 if not ASIS_Mode and then not Body_Seen and then not Is_Body (Decl) 2407 then 2408 Body_Seen := True; 2409 2410 if Nkind (Next_Decl) = N_Subprogram_Body then 2411 Handle_Late_Controlled_Primitive (Next_Decl); 2412 end if; 2413 end if; 2414 2415 Adjust_Decl; 2416 Freeze_All (Freeze_From, Decl); 2417 Freeze_From := Last_Entity (Current_Scope); 2418 end if; 2419 2420 Decl := Next_Decl; 2421 end loop; 2422 2423 -- Analyze the contracts of packages and their bodies 2424 2425 if Present (L) then 2426 Context := Parent (L); 2427 2428 if Nkind (Context) = N_Package_Specification then 2429 2430 -- When a package has private declarations, its contract must be 2431 -- analyzed at the end of the said declarations. This way both the 2432 -- analysis and freeze actions are properly synchronized in case 2433 -- of private type use within the contract. 2434 2435 if L = Private_Declarations (Context) then 2436 Analyze_Package_Contract (Defining_Entity (Context)); 2437 2438 -- Build the bodies of the default initial condition procedures 2439 -- for all types subject to pragma Default_Initial_Condition. 2440 -- From a purely Ada stand point, this is a freezing activity, 2441 -- however freezing is not available under GNATprove_Mode. To 2442 -- accomodate both scenarios, the bodies are build at the end 2443 -- of private declaration analysis. 2444 2445 Build_Default_Init_Cond_Procedure_Bodies (L); 2446 2447 -- Otherwise the contract is analyzed at the end of the visible 2448 -- declarations. 2449 2450 elsif L = Visible_Declarations (Context) 2451 and then No (Private_Declarations (Context)) 2452 then 2453 Analyze_Package_Contract (Defining_Entity (Context)); 2454 end if; 2455 2456 elsif Nkind (Context) = N_Package_Body then 2457 In_Package_Body := True; 2458 Spec_Id := Corresponding_Spec (Context); 2459 2460 Analyze_Package_Body_Contract (Defining_Entity (Context)); 2461 end if; 2462 end if; 2463 2464 -- Analyze the contracts of subprogram declarations, subprogram bodies 2465 -- and variables now due to the delayed visibility requirements of their 2466 -- aspects. 2467 2468 Decl := First (L); 2469 while Present (Decl) loop 2470 if Nkind (Decl) = N_Object_Declaration then 2471 Analyze_Object_Contract (Defining_Entity (Decl)); 2472 2473 elsif Nkind_In (Decl, N_Abstract_Subprogram_Declaration, 2474 N_Generic_Subprogram_Declaration, 2475 N_Subprogram_Declaration) 2476 then 2477 Analyze_Subprogram_Contract (Defining_Entity (Decl)); 2478 2479 elsif Nkind (Decl) = N_Subprogram_Body then 2480 Analyze_Subprogram_Body_Contract (Defining_Entity (Decl)); 2481 2482 elsif Nkind (Decl) = N_Subprogram_Body_Stub then 2483 Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl)); 2484 end if; 2485 2486 Next (Decl); 2487 end loop; 2488 2489 -- State refinements are visible upto the end the of the package body 2490 -- declarations. Hide the refinements from visibility to restore the 2491 -- original state conditions. 2492 2493 if In_Package_Body then 2494 Remove_Visible_Refinements (Spec_Id); 2495 end if; 2496 end Analyze_Declarations; 2497 2498 ----------------------------------- 2499 -- Analyze_Full_Type_Declaration -- 2500 ----------------------------------- 2501 2502 procedure Analyze_Full_Type_Declaration (N : Node_Id) is 2503 Def : constant Node_Id := Type_Definition (N); 2504 Def_Id : constant Entity_Id := Defining_Identifier (N); 2505 T : Entity_Id; 2506 Prev : Entity_Id; 2507 2508 Is_Remote : constant Boolean := 2509 (Is_Remote_Types (Current_Scope) 2510 or else Is_Remote_Call_Interface (Current_Scope)) 2511 and then not (In_Private_Part (Current_Scope) 2512 or else In_Package_Body (Current_Scope)); 2513 2514 procedure Check_Ops_From_Incomplete_Type; 2515 -- If there is a tagged incomplete partial view of the type, traverse 2516 -- the primitives of the incomplete view and change the type of any 2517 -- controlling formals and result to indicate the full view. The 2518 -- primitives will be added to the full type's primitive operations 2519 -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which 2520 -- is called from Process_Incomplete_Dependents). 2521 2522 ------------------------------------ 2523 -- Check_Ops_From_Incomplete_Type -- 2524 ------------------------------------ 2525 2526 procedure Check_Ops_From_Incomplete_Type is 2527 Elmt : Elmt_Id; 2528 Formal : Entity_Id; 2529 Op : Entity_Id; 2530 2531 begin 2532 if Prev /= T 2533 and then Ekind (Prev) = E_Incomplete_Type 2534 and then Is_Tagged_Type (Prev) 2535 and then Is_Tagged_Type (T) 2536 then 2537 Elmt := First_Elmt (Primitive_Operations (Prev)); 2538 while Present (Elmt) loop 2539 Op := Node (Elmt); 2540 2541 Formal := First_Formal (Op); 2542 while Present (Formal) loop 2543 if Etype (Formal) = Prev then 2544 Set_Etype (Formal, T); 2545 end if; 2546 2547 Next_Formal (Formal); 2548 end loop; 2549 2550 if Etype (Op) = Prev then 2551 Set_Etype (Op, T); 2552 end if; 2553 2554 Next_Elmt (Elmt); 2555 end loop; 2556 end if; 2557 end Check_Ops_From_Incomplete_Type; 2558 2559 -- Start of processing for Analyze_Full_Type_Declaration 2560 2561 begin 2562 Prev := Find_Type_Name (N); 2563 2564 -- The type declaration may be subject to pragma Ghost with policy 2565 -- Ignore. Set the mode now to ensure that any nodes generated during 2566 -- analysis and expansion are properly flagged as ignored Ghost. 2567 2568 Set_Ghost_Mode (N, Prev); 2569 2570 -- The full view, if present, now points to the current type. If there 2571 -- is an incomplete partial view, set a link to it, to simplify the 2572 -- retrieval of primitive operations of the type. 2573 2574 -- Ada 2005 (AI-50217): If the type was previously decorated when 2575 -- imported through a LIMITED WITH clause, it appears as incomplete 2576 -- but has no full view. 2577 2578 if Ekind (Prev) = E_Incomplete_Type 2579 and then Present (Full_View (Prev)) 2580 then 2581 T := Full_View (Prev); 2582 Set_Incomplete_View (N, Parent (Prev)); 2583 else 2584 T := Prev; 2585 end if; 2586 2587 Set_Is_Pure (T, Is_Pure (Current_Scope)); 2588 2589 -- We set the flag Is_First_Subtype here. It is needed to set the 2590 -- corresponding flag for the Implicit class-wide-type created 2591 -- during tagged types processing. 2592 2593 Set_Is_First_Subtype (T, True); 2594 2595 -- Only composite types other than array types are allowed to have 2596 -- discriminants. 2597 2598 case Nkind (Def) is 2599 2600 -- For derived types, the rule will be checked once we've figured 2601 -- out the parent type. 2602 2603 when N_Derived_Type_Definition => 2604 null; 2605 2606 -- For record types, discriminants are allowed, unless we are in 2607 -- SPARK. 2608 2609 when N_Record_Definition => 2610 if Present (Discriminant_Specifications (N)) then 2611 Check_SPARK_05_Restriction 2612 ("discriminant type is not allowed", 2613 Defining_Identifier 2614 (First (Discriminant_Specifications (N)))); 2615 end if; 2616 2617 when others => 2618 if Present (Discriminant_Specifications (N)) then 2619 Error_Msg_N 2620 ("elementary or array type cannot have discriminants", 2621 Defining_Identifier 2622 (First (Discriminant_Specifications (N)))); 2623 end if; 2624 end case; 2625 2626 -- Elaborate the type definition according to kind, and generate 2627 -- subsidiary (implicit) subtypes where needed. We skip this if it was 2628 -- already done (this happens during the reanalysis that follows a call 2629 -- to the high level optimizer). 2630 2631 if not Analyzed (T) then 2632 Set_Analyzed (T); 2633 2634 case Nkind (Def) is 2635 when N_Access_To_Subprogram_Definition => 2636 Access_Subprogram_Declaration (T, Def); 2637 2638 -- If this is a remote access to subprogram, we must create the 2639 -- equivalent fat pointer type, and related subprograms. 2640 2641 if Is_Remote then 2642 Process_Remote_AST_Declaration (N); 2643 end if; 2644 2645 -- Validate categorization rule against access type declaration 2646 -- usually a violation in Pure unit, Shared_Passive unit. 2647 2648 Validate_Access_Type_Declaration (T, N); 2649 2650 when N_Access_To_Object_Definition => 2651 Access_Type_Declaration (T, Def); 2652 2653 -- Validate categorization rule against access type declaration 2654 -- usually a violation in Pure unit, Shared_Passive unit. 2655 2656 Validate_Access_Type_Declaration (T, N); 2657 2658 -- If we are in a Remote_Call_Interface package and define a 2659 -- RACW, then calling stubs and specific stream attributes 2660 -- must be added. 2661 2662 if Is_Remote 2663 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id) 2664 then 2665 Add_RACW_Features (Def_Id); 2666 end if; 2667 2668 when N_Array_Type_Definition => 2669 Array_Type_Declaration (T, Def); 2670 2671 when N_Derived_Type_Definition => 2672 Derived_Type_Declaration (T, N, T /= Def_Id); 2673 2674 when N_Enumeration_Type_Definition => 2675 Enumeration_Type_Declaration (T, Def); 2676 2677 when N_Floating_Point_Definition => 2678 Floating_Point_Type_Declaration (T, Def); 2679 2680 when N_Decimal_Fixed_Point_Definition => 2681 Decimal_Fixed_Point_Type_Declaration (T, Def); 2682 2683 when N_Ordinary_Fixed_Point_Definition => 2684 Ordinary_Fixed_Point_Type_Declaration (T, Def); 2685 2686 when N_Signed_Integer_Type_Definition => 2687 Signed_Integer_Type_Declaration (T, Def); 2688 2689 when N_Modular_Type_Definition => 2690 Modular_Type_Declaration (T, Def); 2691 2692 when N_Record_Definition => 2693 Record_Type_Declaration (T, N, Prev); 2694 2695 -- If declaration has a parse error, nothing to elaborate. 2696 2697 when N_Error => 2698 null; 2699 2700 when others => 2701 raise Program_Error; 2702 2703 end case; 2704 end if; 2705 2706 if Etype (T) = Any_Type then 2707 return; 2708 end if; 2709 2710 -- Controlled type is not allowed in SPARK 2711 2712 if Is_Visibly_Controlled (T) then 2713 Check_SPARK_05_Restriction ("controlled type is not allowed", N); 2714 end if; 2715 2716 -- A type declared within a Ghost region is automatically Ghost 2717 -- (SPARK RM 6.9(2)). 2718 2719 if Comes_From_Source (T) and then Ghost_Mode > None then 2720 Set_Is_Ghost_Entity (T); 2721 end if; 2722 2723 -- Some common processing for all types 2724 2725 Set_Depends_On_Private (T, Has_Private_Component (T)); 2726 Check_Ops_From_Incomplete_Type; 2727 2728 -- Both the declared entity, and its anonymous base type if one was 2729 -- created, need freeze nodes allocated. 2730 2731 declare 2732 B : constant Entity_Id := Base_Type (T); 2733 2734 begin 2735 -- In the case where the base type differs from the first subtype, we 2736 -- pre-allocate a freeze node, and set the proper link to the first 2737 -- subtype. Freeze_Entity will use this preallocated freeze node when 2738 -- it freezes the entity. 2739 2740 -- This does not apply if the base type is a generic type, whose 2741 -- declaration is independent of the current derived definition. 2742 2743 if B /= T and then not Is_Generic_Type (B) then 2744 Ensure_Freeze_Node (B); 2745 Set_First_Subtype_Link (Freeze_Node (B), T); 2746 end if; 2747 2748 -- A type that is imported through a limited_with clause cannot 2749 -- generate any code, and thus need not be frozen. However, an access 2750 -- type with an imported designated type needs a finalization list, 2751 -- which may be referenced in some other package that has non-limited 2752 -- visibility on the designated type. Thus we must create the 2753 -- finalization list at the point the access type is frozen, to 2754 -- prevent unsatisfied references at link time. 2755 2756 if not From_Limited_With (T) or else Is_Access_Type (T) then 2757 Set_Has_Delayed_Freeze (T); 2758 end if; 2759 end; 2760 2761 -- Case where T is the full declaration of some private type which has 2762 -- been swapped in Defining_Identifier (N). 2763 2764 if T /= Def_Id and then Is_Private_Type (Def_Id) then 2765 Process_Full_View (N, T, Def_Id); 2766 2767 -- Record the reference. The form of this is a little strange, since 2768 -- the full declaration has been swapped in. So the first parameter 2769 -- here represents the entity to which a reference is made which is 2770 -- the "real" entity, i.e. the one swapped in, and the second 2771 -- parameter provides the reference location. 2772 2773 -- Also, we want to kill Has_Pragma_Unreferenced temporarily here 2774 -- since we don't want a complaint about the full type being an 2775 -- unwanted reference to the private type 2776 2777 declare 2778 B : constant Boolean := Has_Pragma_Unreferenced (T); 2779 begin 2780 Set_Has_Pragma_Unreferenced (T, False); 2781 Generate_Reference (T, T, 'c'); 2782 Set_Has_Pragma_Unreferenced (T, B); 2783 end; 2784 2785 Set_Completion_Referenced (Def_Id); 2786 2787 -- For completion of incomplete type, process incomplete dependents 2788 -- and always mark the full type as referenced (it is the incomplete 2789 -- type that we get for any real reference). 2790 2791 elsif Ekind (Prev) = E_Incomplete_Type then 2792 Process_Incomplete_Dependents (N, T, Prev); 2793 Generate_Reference (Prev, Def_Id, 'c'); 2794 Set_Completion_Referenced (Def_Id); 2795 2796 -- If not private type or incomplete type completion, this is a real 2797 -- definition of a new entity, so record it. 2798 2799 else 2800 Generate_Definition (Def_Id); 2801 end if; 2802 2803 -- Propagate any pending access types whose finalization masters need to 2804 -- be fully initialized from the partial to the full view. Guard against 2805 -- an illegal full view that remains unanalyzed. 2806 2807 if Is_Type (Def_Id) and then Is_Incomplete_Or_Private_Type (Prev) then 2808 Set_Pending_Access_Types (Def_Id, Pending_Access_Types (Prev)); 2809 end if; 2810 2811 if Chars (Scope (Def_Id)) = Name_System 2812 and then Chars (Def_Id) = Name_Address 2813 and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N))) 2814 then 2815 Set_Is_Descendent_Of_Address (Def_Id); 2816 Set_Is_Descendent_Of_Address (Base_Type (Def_Id)); 2817 Set_Is_Descendent_Of_Address (Prev); 2818 end if; 2819 2820 Set_Optimize_Alignment_Flags (Def_Id); 2821 Check_Eliminated (Def_Id); 2822 2823 -- If the declaration is a completion and aspects are present, apply 2824 -- them to the entity for the type which is currently the partial 2825 -- view, but which is the one that will be frozen. 2826 2827 if Has_Aspects (N) then 2828 2829 -- In most cases the partial view is a private type, and both views 2830 -- appear in different declarative parts. In the unusual case where 2831 -- the partial view is incomplete, perform the analysis on the 2832 -- full view, to prevent freezing anomalies with the corresponding 2833 -- class-wide type, which otherwise might be frozen before the 2834 -- dispatch table is built. 2835 2836 if Prev /= Def_Id 2837 and then Ekind (Prev) /= E_Incomplete_Type 2838 then 2839 Analyze_Aspect_Specifications (N, Prev); 2840 2841 -- Normal case 2842 2843 else 2844 Analyze_Aspect_Specifications (N, Def_Id); 2845 end if; 2846 end if; 2847 end Analyze_Full_Type_Declaration; 2848 2849 ---------------------------------- 2850 -- Analyze_Incomplete_Type_Decl -- 2851 ---------------------------------- 2852 2853 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is 2854 F : constant Boolean := Is_Pure (Current_Scope); 2855 T : Entity_Id; 2856 2857 begin 2858 Check_SPARK_05_Restriction ("incomplete type is not allowed", N); 2859 2860 Generate_Definition (Defining_Identifier (N)); 2861 2862 -- Process an incomplete declaration. The identifier must not have been 2863 -- declared already in the scope. However, an incomplete declaration may 2864 -- appear in the private part of a package, for a private type that has 2865 -- already been declared. 2866 2867 -- In this case, the discriminants (if any) must match 2868 2869 T := Find_Type_Name (N); 2870 2871 Set_Ekind (T, E_Incomplete_Type); 2872 Init_Size_Align (T); 2873 Set_Is_First_Subtype (T, True); 2874 Set_Etype (T, T); 2875 2876 -- An incomplete type declared within a Ghost region is automatically 2877 -- Ghost (SPARK RM 6.9(2)). 2878 2879 if Ghost_Mode > None then 2880 Set_Is_Ghost_Entity (T); 2881 end if; 2882 2883 -- Ada 2005 (AI-326): Minimum decoration to give support to tagged 2884 -- incomplete types. 2885 2886 if Tagged_Present (N) then 2887 Set_Is_Tagged_Type (T, True); 2888 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams); 2889 Make_Class_Wide_Type (T); 2890 Set_Direct_Primitive_Operations (T, New_Elmt_List); 2891 end if; 2892 2893 Push_Scope (T); 2894 2895 Set_Stored_Constraint (T, No_Elist); 2896 2897 if Present (Discriminant_Specifications (N)) then 2898 Process_Discriminants (N); 2899 end if; 2900 2901 End_Scope; 2902 2903 -- If the type has discriminants, non-trivial subtypes may be 2904 -- declared before the full view of the type. The full views of those 2905 -- subtypes will be built after the full view of the type. 2906 2907 Set_Private_Dependents (T, New_Elmt_List); 2908 Set_Is_Pure (T, F); 2909 end Analyze_Incomplete_Type_Decl; 2910 2911 ----------------------------------- 2912 -- Analyze_Interface_Declaration -- 2913 ----------------------------------- 2914 2915 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is 2916 CW : constant Entity_Id := Class_Wide_Type (T); 2917 2918 begin 2919 Set_Is_Tagged_Type (T); 2920 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams); 2921 2922 Set_Is_Limited_Record (T, Limited_Present (Def) 2923 or else Task_Present (Def) 2924 or else Protected_Present (Def) 2925 or else Synchronized_Present (Def)); 2926 2927 -- Type is abstract if full declaration carries keyword, or if previous 2928 -- partial view did. 2929 2930 Set_Is_Abstract_Type (T); 2931 Set_Is_Interface (T); 2932 2933 -- Type is a limited interface if it includes the keyword limited, task, 2934 -- protected, or synchronized. 2935 2936 Set_Is_Limited_Interface 2937 (T, Limited_Present (Def) 2938 or else Protected_Present (Def) 2939 or else Synchronized_Present (Def) 2940 or else Task_Present (Def)); 2941 2942 Set_Interfaces (T, New_Elmt_List); 2943 Set_Direct_Primitive_Operations (T, New_Elmt_List); 2944 2945 -- Complete the decoration of the class-wide entity if it was already 2946 -- built (i.e. during the creation of the limited view) 2947 2948 if Present (CW) then 2949 Set_Is_Interface (CW); 2950 Set_Is_Limited_Interface (CW, Is_Limited_Interface (T)); 2951 end if; 2952 2953 -- Check runtime support for synchronized interfaces 2954 2955 if VM_Target = No_VM 2956 and then (Is_Task_Interface (T) 2957 or else Is_Protected_Interface (T) 2958 or else Is_Synchronized_Interface (T)) 2959 and then not RTE_Available (RE_Select_Specific_Data) 2960 then 2961 Error_Msg_CRT ("synchronized interfaces", T); 2962 end if; 2963 end Analyze_Interface_Declaration; 2964 2965 ----------------------------- 2966 -- Analyze_Itype_Reference -- 2967 ----------------------------- 2968 2969 -- Nothing to do. This node is placed in the tree only for the benefit of 2970 -- back end processing, and has no effect on the semantic processing. 2971 2972 procedure Analyze_Itype_Reference (N : Node_Id) is 2973 begin 2974 pragma Assert (Is_Itype (Itype (N))); 2975 null; 2976 end Analyze_Itype_Reference; 2977 2978 -------------------------------- 2979 -- Analyze_Number_Declaration -- 2980 -------------------------------- 2981 2982 procedure Analyze_Number_Declaration (N : Node_Id) is 2983 Id : constant Entity_Id := Defining_Identifier (N); 2984 E : constant Node_Id := Expression (N); 2985 T : Entity_Id; 2986 Index : Interp_Index; 2987 It : Interp; 2988 2989 begin 2990 -- The number declaration may be subject to pragma Ghost with policy 2991 -- Ignore. Set the mode now to ensure that any nodes generated during 2992 -- analysis and expansion are properly flagged as ignored Ghost. 2993 2994 Set_Ghost_Mode (N); 2995 2996 Generate_Definition (Id); 2997 Enter_Name (Id); 2998 2999 -- A number declared within a Ghost region is automatically Ghost 3000 -- (SPARK RM 6.9(2)). 3001 3002 if Ghost_Mode > None then 3003 Set_Is_Ghost_Entity (Id); 3004 end if; 3005 3006 -- This is an optimization of a common case of an integer literal 3007 3008 if Nkind (E) = N_Integer_Literal then 3009 Set_Is_Static_Expression (E, True); 3010 Set_Etype (E, Universal_Integer); 3011 3012 Set_Etype (Id, Universal_Integer); 3013 Set_Ekind (Id, E_Named_Integer); 3014 Set_Is_Frozen (Id, True); 3015 return; 3016 end if; 3017 3018 Set_Is_Pure (Id, Is_Pure (Current_Scope)); 3019 3020 -- Process expression, replacing error by integer zero, to avoid 3021 -- cascaded errors or aborts further along in the processing 3022 3023 -- Replace Error by integer zero, which seems least likely to cause 3024 -- cascaded errors. 3025 3026 if E = Error then 3027 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0)); 3028 Set_Error_Posted (E); 3029 end if; 3030 3031 Analyze (E); 3032 3033 -- Verify that the expression is static and numeric. If 3034 -- the expression is overloaded, we apply the preference 3035 -- rule that favors root numeric types. 3036 3037 if not Is_Overloaded (E) then 3038 T := Etype (E); 3039 if Has_Dynamic_Predicate_Aspect (T) then 3040 Error_Msg_N 3041 ("subtype has dynamic predicate, " 3042 & "not allowed in number declaration", N); 3043 end if; 3044 3045 else 3046 T := Any_Type; 3047 3048 Get_First_Interp (E, Index, It); 3049 while Present (It.Typ) loop 3050 if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ)) 3051 and then (Scope (Base_Type (It.Typ))) = Standard_Standard 3052 then 3053 if T = Any_Type then 3054 T := It.Typ; 3055 3056 elsif It.Typ = Universal_Real 3057 or else 3058 It.Typ = Universal_Integer 3059 then 3060 -- Choose universal interpretation over any other 3061 3062 T := It.Typ; 3063 exit; 3064 end if; 3065 end if; 3066 3067 Get_Next_Interp (Index, It); 3068 end loop; 3069 end if; 3070 3071 if Is_Integer_Type (T) then 3072 Resolve (E, T); 3073 Set_Etype (Id, Universal_Integer); 3074 Set_Ekind (Id, E_Named_Integer); 3075 3076 elsif Is_Real_Type (T) then 3077 3078 -- Because the real value is converted to universal_real, this is a 3079 -- legal context for a universal fixed expression. 3080 3081 if T = Universal_Fixed then 3082 declare 3083 Loc : constant Source_Ptr := Sloc (N); 3084 Conv : constant Node_Id := Make_Type_Conversion (Loc, 3085 Subtype_Mark => 3086 New_Occurrence_Of (Universal_Real, Loc), 3087 Expression => Relocate_Node (E)); 3088 3089 begin 3090 Rewrite (E, Conv); 3091 Analyze (E); 3092 end; 3093 3094 elsif T = Any_Fixed then 3095 Error_Msg_N ("illegal context for mixed mode operation", E); 3096 3097 -- Expression is of the form : universal_fixed * integer. Try to 3098 -- resolve as universal_real. 3099 3100 T := Universal_Real; 3101 Set_Etype (E, T); 3102 end if; 3103 3104 Resolve (E, T); 3105 Set_Etype (Id, Universal_Real); 3106 Set_Ekind (Id, E_Named_Real); 3107 3108 else 3109 Wrong_Type (E, Any_Numeric); 3110 Resolve (E, T); 3111 3112 Set_Etype (Id, T); 3113 Set_Ekind (Id, E_Constant); 3114 Set_Never_Set_In_Source (Id, True); 3115 Set_Is_True_Constant (Id, True); 3116 return; 3117 end if; 3118 3119 if Nkind_In (E, N_Integer_Literal, N_Real_Literal) then 3120 Set_Etype (E, Etype (Id)); 3121 end if; 3122 3123 if not Is_OK_Static_Expression (E) then 3124 Flag_Non_Static_Expr 3125 ("non-static expression used in number declaration!", E); 3126 Rewrite (E, Make_Integer_Literal (Sloc (N), 1)); 3127 Set_Etype (E, Any_Type); 3128 end if; 3129 end Analyze_Number_Declaration; 3130 3131 ----------------------------- 3132 -- Analyze_Object_Contract -- 3133 ----------------------------- 3134 3135 procedure Analyze_Object_Contract (Obj_Id : Entity_Id) is 3136 Obj_Typ : constant Entity_Id := Etype (Obj_Id); 3137 AR_Val : Boolean := False; 3138 AW_Val : Boolean := False; 3139 ER_Val : Boolean := False; 3140 EW_Val : Boolean := False; 3141 Prag : Node_Id; 3142 Seen : Boolean := False; 3143 3144 begin 3145 -- The loop parameter in an element iterator over a formal container 3146 -- is declared with an object declaration but no contracts apply. 3147 3148 if Ekind (Obj_Id) = E_Loop_Parameter then 3149 return; 3150 end if; 3151 3152 if Ekind (Obj_Id) = E_Constant then 3153 3154 -- A constant cannot be effectively volatile. This check is only 3155 -- relevant with SPARK_Mode on as it is not a standard Ada legality 3156 -- rule. Do not flag internally-generated constants that map generic 3157 -- formals to actuals in instantiations (SPARK RM 7.1.3(6)). 3158 3159 if SPARK_Mode = On 3160 and then Is_Effectively_Volatile (Obj_Id) 3161 and then No (Corresponding_Generic_Association (Parent (Obj_Id))) 3162 3163 -- Don't give this for internally generated entities (such as the 3164 -- FIRST and LAST temporaries generated for bounds). 3165 3166 and then Comes_From_Source (Obj_Id) 3167 then 3168 Error_Msg_N ("constant cannot be volatile", Obj_Id); 3169 end if; 3170 3171 else pragma Assert (Ekind (Obj_Id) = E_Variable); 3172 3173 -- The following checks are only relevant when SPARK_Mode is on as 3174 -- they are not standard Ada legality rules. Internally generated 3175 -- temporaries are ignored. 3176 3177 if SPARK_Mode = On and then Comes_From_Source (Obj_Id) then 3178 if Is_Effectively_Volatile (Obj_Id) then 3179 3180 -- The declaration of an effectively volatile object must 3181 -- appear at the library level (SPARK RM 7.1.3(7), C.6(6)). 3182 3183 if not Is_Library_Level_Entity (Obj_Id) then 3184 Error_Msg_N 3185 ("volatile variable & must be declared at library level", 3186 Obj_Id); 3187 3188 -- An object of a discriminated type cannot be effectively 3189 -- volatile (SPARK RM C.6(4)). 3190 3191 elsif Has_Discriminants (Obj_Typ) then 3192 Error_Msg_N 3193 ("discriminated object & cannot be volatile", Obj_Id); 3194 3195 -- An object of a tagged type cannot be effectively volatile 3196 -- (SPARK RM C.6(5)). 3197 3198 elsif Is_Tagged_Type (Obj_Typ) then 3199 Error_Msg_N ("tagged object & cannot be volatile", Obj_Id); 3200 end if; 3201 3202 -- The object is not effectively volatile 3203 3204 else 3205 -- A non-effectively volatile object cannot have effectively 3206 -- volatile components (SPARK RM 7.1.3(7)). 3207 3208 if not Is_Effectively_Volatile (Obj_Id) 3209 and then Has_Volatile_Component (Obj_Typ) 3210 then 3211 Error_Msg_N 3212 ("non-volatile object & cannot have volatile components", 3213 Obj_Id); 3214 end if; 3215 end if; 3216 end if; 3217 3218 if Is_Ghost_Entity (Obj_Id) then 3219 3220 -- A Ghost object cannot be effectively volatile (SPARK RM 6.9(8)) 3221 3222 if Is_Effectively_Volatile (Obj_Id) then 3223 Error_Msg_N ("ghost variable & cannot be volatile", Obj_Id); 3224 3225 -- A Ghost object cannot be imported or exported (SPARK RM 6.9(8)) 3226 3227 elsif Is_Imported (Obj_Id) then 3228 Error_Msg_N ("ghost object & cannot be imported", Obj_Id); 3229 3230 elsif Is_Exported (Obj_Id) then 3231 Error_Msg_N ("ghost object & cannot be exported", Obj_Id); 3232 end if; 3233 end if; 3234 3235 -- Analyze all external properties 3236 3237 Prag := Get_Pragma (Obj_Id, Pragma_Async_Readers); 3238 3239 if Present (Prag) then 3240 Analyze_External_Property_In_Decl_Part (Prag, AR_Val); 3241 Seen := True; 3242 end if; 3243 3244 Prag := Get_Pragma (Obj_Id, Pragma_Async_Writers); 3245 3246 if Present (Prag) then 3247 Analyze_External_Property_In_Decl_Part (Prag, AW_Val); 3248 Seen := True; 3249 end if; 3250 3251 Prag := Get_Pragma (Obj_Id, Pragma_Effective_Reads); 3252 3253 if Present (Prag) then 3254 Analyze_External_Property_In_Decl_Part (Prag, ER_Val); 3255 Seen := True; 3256 end if; 3257 3258 Prag := Get_Pragma (Obj_Id, Pragma_Effective_Writes); 3259 3260 if Present (Prag) then 3261 Analyze_External_Property_In_Decl_Part (Prag, EW_Val); 3262 Seen := True; 3263 end if; 3264 3265 -- Verify the mutual interaction of the various external properties 3266 3267 if Seen then 3268 Check_External_Properties (Obj_Id, AR_Val, AW_Val, ER_Val, EW_Val); 3269 end if; 3270 3271 -- Check whether the lack of indicator Part_Of agrees with the 3272 -- placement of the variable with respect to the state space. 3273 3274 Prag := Get_Pragma (Obj_Id, Pragma_Part_Of); 3275 3276 if No (Prag) then 3277 Check_Missing_Part_Of (Obj_Id); 3278 end if; 3279 end if; 3280 3281 -- A ghost object cannot be imported or exported (SPARK RM 6.9(8)) 3282 3283 if Is_Ghost_Entity (Obj_Id) then 3284 if Is_Exported (Obj_Id) then 3285 Error_Msg_N ("ghost object & cannot be exported", Obj_Id); 3286 3287 elsif Is_Imported (Obj_Id) then 3288 Error_Msg_N ("ghost object & cannot be imported", Obj_Id); 3289 end if; 3290 end if; 3291 end Analyze_Object_Contract; 3292 3293 -------------------------------- 3294 -- Analyze_Object_Declaration -- 3295 -------------------------------- 3296 3297 procedure Analyze_Object_Declaration (N : Node_Id) is 3298 Loc : constant Source_Ptr := Sloc (N); 3299 Id : constant Entity_Id := Defining_Identifier (N); 3300 T : Entity_Id; 3301 Act_T : Entity_Id; 3302 3303 E : Node_Id := Expression (N); 3304 -- E is set to Expression (N) throughout this routine. When 3305 -- Expression (N) is modified, E is changed accordingly. 3306 3307 Prev_Entity : Entity_Id := Empty; 3308 3309 function Count_Tasks (T : Entity_Id) return Uint; 3310 -- This function is called when a non-generic library level object of a 3311 -- task type is declared. Its function is to count the static number of 3312 -- tasks declared within the type (it is only called if Has_Tasks is set 3313 -- for T). As a side effect, if an array of tasks with non-static bounds 3314 -- or a variant record type is encountered, Check_Restrictions is called 3315 -- indicating the count is unknown. 3316 3317 ----------------- 3318 -- Count_Tasks -- 3319 ----------------- 3320 3321 function Count_Tasks (T : Entity_Id) return Uint is 3322 C : Entity_Id; 3323 X : Node_Id; 3324 V : Uint; 3325 3326 begin 3327 if Is_Task_Type (T) then 3328 return Uint_1; 3329 3330 elsif Is_Record_Type (T) then 3331 if Has_Discriminants (T) then 3332 Check_Restriction (Max_Tasks, N); 3333 return Uint_0; 3334 3335 else 3336 V := Uint_0; 3337 C := First_Component (T); 3338 while Present (C) loop 3339 V := V + Count_Tasks (Etype (C)); 3340 Next_Component (C); 3341 end loop; 3342 3343 return V; 3344 end if; 3345 3346 elsif Is_Array_Type (T) then 3347 X := First_Index (T); 3348 V := Count_Tasks (Component_Type (T)); 3349 while Present (X) loop 3350 C := Etype (X); 3351 3352 if not Is_OK_Static_Subtype (C) then 3353 Check_Restriction (Max_Tasks, N); 3354 return Uint_0; 3355 else 3356 V := V * (UI_Max (Uint_0, 3357 Expr_Value (Type_High_Bound (C)) - 3358 Expr_Value (Type_Low_Bound (C)) + Uint_1)); 3359 end if; 3360 3361 Next_Index (X); 3362 end loop; 3363 3364 return V; 3365 3366 else 3367 return Uint_0; 3368 end if; 3369 end Count_Tasks; 3370 3371 -- Start of processing for Analyze_Object_Declaration 3372 3373 begin 3374 -- There are three kinds of implicit types generated by an 3375 -- object declaration: 3376 3377 -- 1. Those generated by the original Object Definition 3378 3379 -- 2. Those generated by the Expression 3380 3381 -- 3. Those used to constrain the Object Definition with the 3382 -- expression constraints when the definition is unconstrained. 3383 3384 -- They must be generated in this order to avoid order of elaboration 3385 -- issues. Thus the first step (after entering the name) is to analyze 3386 -- the object definition. 3387 3388 if Constant_Present (N) then 3389 Prev_Entity := Current_Entity_In_Scope (Id); 3390 3391 if Present (Prev_Entity) 3392 and then 3393 -- If the homograph is an implicit subprogram, it is overridden 3394 -- by the current declaration. 3395 3396 ((Is_Overloadable (Prev_Entity) 3397 and then Is_Inherited_Operation (Prev_Entity)) 3398 3399 -- The current object is a discriminal generated for an entry 3400 -- family index. Even though the index is a constant, in this 3401 -- particular context there is no true constant redeclaration. 3402 -- Enter_Name will handle the visibility. 3403 3404 or else 3405 (Is_Discriminal (Id) 3406 and then Ekind (Discriminal_Link (Id)) = 3407 E_Entry_Index_Parameter) 3408 3409 -- The current object is the renaming for a generic declared 3410 -- within the instance. 3411 3412 or else 3413 (Ekind (Prev_Entity) = E_Package 3414 and then Nkind (Parent (Prev_Entity)) = 3415 N_Package_Renaming_Declaration 3416 and then not Comes_From_Source (Prev_Entity) 3417 and then 3418 Is_Generic_Instance (Renamed_Entity (Prev_Entity)))) 3419 then 3420 Prev_Entity := Empty; 3421 end if; 3422 end if; 3423 3424 -- The object declaration may be subject to pragma Ghost with policy 3425 -- Ignore. Set the mode now to ensure that any nodes generated during 3426 -- analysis and expansion are properly flagged as ignored Ghost. 3427 3428 Set_Ghost_Mode (N, Prev_Entity); 3429 3430 if Present (Prev_Entity) then 3431 Constant_Redeclaration (Id, N, T); 3432 3433 Generate_Reference (Prev_Entity, Id, 'c'); 3434 Set_Completion_Referenced (Id); 3435 3436 if Error_Posted (N) then 3437 3438 -- Type mismatch or illegal redeclaration, Do not analyze 3439 -- expression to avoid cascaded errors. 3440 3441 T := Find_Type_Of_Object (Object_Definition (N), N); 3442 Set_Etype (Id, T); 3443 Set_Ekind (Id, E_Variable); 3444 goto Leave; 3445 end if; 3446 3447 -- In the normal case, enter identifier at the start to catch premature 3448 -- usage in the initialization expression. 3449 3450 else 3451 Generate_Definition (Id); 3452 Enter_Name (Id); 3453 3454 Mark_Coextensions (N, Object_Definition (N)); 3455 3456 T := Find_Type_Of_Object (Object_Definition (N), N); 3457 3458 if Nkind (Object_Definition (N)) = N_Access_Definition 3459 and then Present 3460 (Access_To_Subprogram_Definition (Object_Definition (N))) 3461 and then Protected_Present 3462 (Access_To_Subprogram_Definition (Object_Definition (N))) 3463 then 3464 T := Replace_Anonymous_Access_To_Protected_Subprogram (N); 3465 end if; 3466 3467 if Error_Posted (Id) then 3468 Set_Etype (Id, T); 3469 Set_Ekind (Id, E_Variable); 3470 goto Leave; 3471 end if; 3472 end if; 3473 3474 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry 3475 -- out some static checks 3476 3477 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then 3478 3479 -- In case of aggregates we must also take care of the correct 3480 -- initialization of nested aggregates bug this is done at the 3481 -- point of the analysis of the aggregate (see sem_aggr.adb). 3482 3483 if Present (Expression (N)) 3484 and then Nkind (Expression (N)) = N_Aggregate 3485 then 3486 null; 3487 3488 else 3489 declare 3490 Save_Typ : constant Entity_Id := Etype (Id); 3491 begin 3492 Set_Etype (Id, T); -- Temp. decoration for static checks 3493 Null_Exclusion_Static_Checks (N); 3494 Set_Etype (Id, Save_Typ); 3495 end; 3496 end if; 3497 end if; 3498 3499 -- Object is marked pure if it is in a pure scope 3500 3501 Set_Is_Pure (Id, Is_Pure (Current_Scope)); 3502 3503 -- If deferred constant, make sure context is appropriate. We detect 3504 -- a deferred constant as a constant declaration with no expression. 3505 -- A deferred constant can appear in a package body if its completion 3506 -- is by means of an interface pragma. 3507 3508 if Constant_Present (N) and then No (E) then 3509 3510 -- A deferred constant may appear in the declarative part of the 3511 -- following constructs: 3512 3513 -- blocks 3514 -- entry bodies 3515 -- extended return statements 3516 -- package specs 3517 -- package bodies 3518 -- subprogram bodies 3519 -- task bodies 3520 3521 -- When declared inside a package spec, a deferred constant must be 3522 -- completed by a full constant declaration or pragma Import. In all 3523 -- other cases, the only proper completion is pragma Import. Extended 3524 -- return statements are flagged as invalid contexts because they do 3525 -- not have a declarative part and so cannot accommodate the pragma. 3526 3527 if Ekind (Current_Scope) = E_Return_Statement then 3528 Error_Msg_N 3529 ("invalid context for deferred constant declaration (RM 7.4)", 3530 N); 3531 Error_Msg_N 3532 ("\declaration requires an initialization expression", 3533 N); 3534 Set_Constant_Present (N, False); 3535 3536 -- In Ada 83, deferred constant must be of private type 3537 3538 elsif not Is_Private_Type (T) then 3539 if Ada_Version = Ada_83 and then Comes_From_Source (N) then 3540 Error_Msg_N 3541 ("(Ada 83) deferred constant must be private type", N); 3542 end if; 3543 end if; 3544 3545 -- If not a deferred constant, then the object declaration freezes 3546 -- its type, unless the object is of an anonymous type and has delayed 3547 -- aspects. In that case the type is frozen when the object itself is. 3548 3549 else 3550 Check_Fully_Declared (T, N); 3551 3552 if Has_Delayed_Aspects (Id) 3553 and then Is_Array_Type (T) 3554 and then Is_Itype (T) 3555 then 3556 Set_Has_Delayed_Freeze (T); 3557 else 3558 Freeze_Before (N, T); 3559 end if; 3560 end if; 3561 3562 -- If the object was created by a constrained array definition, then 3563 -- set the link in both the anonymous base type and anonymous subtype 3564 -- that are built to represent the array type to point to the object. 3565 3566 if Nkind (Object_Definition (Declaration_Node (Id))) = 3567 N_Constrained_Array_Definition 3568 then 3569 Set_Related_Array_Object (T, Id); 3570 Set_Related_Array_Object (Base_Type (T), Id); 3571 end if; 3572 3573 -- Special checks for protected objects not at library level 3574 3575 if Is_Protected_Type (T) 3576 and then not Is_Library_Level_Entity (Id) 3577 then 3578 Check_Restriction (No_Local_Protected_Objects, Id); 3579 3580 -- Protected objects with interrupt handlers must be at library level 3581 3582 -- Ada 2005: This test is not needed (and the corresponding clause 3583 -- in the RM is removed) because accessibility checks are sufficient 3584 -- to make handlers not at the library level illegal. 3585 3586 -- AI05-0303: The AI is in fact a binding interpretation, and thus 3587 -- applies to the '95 version of the language as well. 3588 3589 if Has_Interrupt_Handler (T) and then Ada_Version < Ada_95 then 3590 Error_Msg_N 3591 ("interrupt object can only be declared at library level", Id); 3592 end if; 3593 end if; 3594 3595 -- The actual subtype of the object is the nominal subtype, unless 3596 -- the nominal one is unconstrained and obtained from the expression. 3597 3598 Act_T := T; 3599 3600 -- These checks should be performed before the initialization expression 3601 -- is considered, so that the Object_Definition node is still the same 3602 -- as in source code. 3603 3604 -- In SPARK, the nominal subtype is always given by a subtype mark 3605 -- and must not be unconstrained. (The only exception to this is the 3606 -- acceptance of declarations of constants of type String.) 3607 3608 if not Nkind_In (Object_Definition (N), N_Expanded_Name, N_Identifier) 3609 then 3610 Check_SPARK_05_Restriction 3611 ("subtype mark required", Object_Definition (N)); 3612 3613 elsif Is_Array_Type (T) 3614 and then not Is_Constrained (T) 3615 and then T /= Standard_String 3616 then 3617 Check_SPARK_05_Restriction 3618 ("subtype mark of constrained type expected", 3619 Object_Definition (N)); 3620 end if; 3621 3622 -- There are no aliased objects in SPARK 3623 3624 if Aliased_Present (N) then 3625 Check_SPARK_05_Restriction ("aliased object is not allowed", N); 3626 end if; 3627 3628 -- Process initialization expression if present and not in error 3629 3630 if Present (E) and then E /= Error then 3631 3632 -- Generate an error in case of CPP class-wide object initialization. 3633 -- Required because otherwise the expansion of the class-wide 3634 -- assignment would try to use 'size to initialize the object 3635 -- (primitive that is not available in CPP tagged types). 3636 3637 if Is_Class_Wide_Type (Act_T) 3638 and then 3639 (Is_CPP_Class (Root_Type (Etype (Act_T))) 3640 or else 3641 (Present (Full_View (Root_Type (Etype (Act_T)))) 3642 and then 3643 Is_CPP_Class (Full_View (Root_Type (Etype (Act_T)))))) 3644 then 3645 Error_Msg_N 3646 ("predefined assignment not available for 'C'P'P tagged types", 3647 E); 3648 end if; 3649 3650 Mark_Coextensions (N, E); 3651 Analyze (E); 3652 3653 -- In case of errors detected in the analysis of the expression, 3654 -- decorate it with the expected type to avoid cascaded errors 3655 3656 if No (Etype (E)) then 3657 Set_Etype (E, T); 3658 end if; 3659 3660 -- If an initialization expression is present, then we set the 3661 -- Is_True_Constant flag. It will be reset if this is a variable 3662 -- and it is indeed modified. 3663 3664 Set_Is_True_Constant (Id, True); 3665 3666 -- If we are analyzing a constant declaration, set its completion 3667 -- flag after analyzing and resolving the expression. 3668 3669 if Constant_Present (N) then 3670 Set_Has_Completion (Id); 3671 end if; 3672 3673 -- Set type and resolve (type may be overridden later on). Note: 3674 -- Ekind (Id) must still be E_Void at this point so that incorrect 3675 -- early usage within E is properly diagnosed. 3676 3677 Set_Etype (Id, T); 3678 3679 -- If the expression is an aggregate we must look ahead to detect 3680 -- the possible presence of an address clause, and defer resolution 3681 -- and expansion of the aggregate to the freeze point of the entity. 3682 3683 if Comes_From_Source (N) 3684 and then Expander_Active 3685 and then Nkind (E) = N_Aggregate 3686 and then Present (Following_Address_Clause (N)) 3687 then 3688 Set_Etype (E, T); 3689 3690 else 3691 Resolve (E, T); 3692 end if; 3693 3694 -- No further action needed if E is a call to an inlined function 3695 -- which returns an unconstrained type and it has been expanded into 3696 -- a procedure call. In that case N has been replaced by an object 3697 -- declaration without initializing expression and it has been 3698 -- analyzed (see Expand_Inlined_Call). 3699 3700 if Back_End_Inlining 3701 and then Expander_Active 3702 and then Nkind (E) = N_Function_Call 3703 and then Nkind (Name (E)) in N_Has_Entity 3704 and then Is_Inlined (Entity (Name (E))) 3705 and then not Is_Constrained (Etype (E)) 3706 and then Analyzed (N) 3707 and then No (Expression (N)) 3708 then 3709 return; 3710 end if; 3711 3712 -- If E is null and has been replaced by an N_Raise_Constraint_Error 3713 -- node (which was marked already-analyzed), we need to set the type 3714 -- to something other than Any_Access in order to keep gigi happy. 3715 3716 if Etype (E) = Any_Access then 3717 Set_Etype (E, T); 3718 end if; 3719 3720 -- If the object is an access to variable, the initialization 3721 -- expression cannot be an access to constant. 3722 3723 if Is_Access_Type (T) 3724 and then not Is_Access_Constant (T) 3725 and then Is_Access_Type (Etype (E)) 3726 and then Is_Access_Constant (Etype (E)) 3727 then 3728 Error_Msg_N 3729 ("access to variable cannot be initialized with an " 3730 & "access-to-constant expression", E); 3731 end if; 3732 3733 if not Assignment_OK (N) then 3734 Check_Initialization (T, E); 3735 end if; 3736 3737 Check_Unset_Reference (E); 3738 3739 -- If this is a variable, then set current value. If this is a 3740 -- declared constant of a scalar type with a static expression, 3741 -- indicate that it is always valid. 3742 3743 if not Constant_Present (N) then 3744 if Compile_Time_Known_Value (E) then 3745 Set_Current_Value (Id, E); 3746 end if; 3747 3748 elsif Is_Scalar_Type (T) and then Is_OK_Static_Expression (E) then 3749 Set_Is_Known_Valid (Id); 3750 end if; 3751 3752 -- Deal with setting of null flags 3753 3754 if Is_Access_Type (T) then 3755 if Known_Non_Null (E) then 3756 Set_Is_Known_Non_Null (Id, True); 3757 elsif Known_Null (E) and then not Can_Never_Be_Null (Id) then 3758 Set_Is_Known_Null (Id, True); 3759 end if; 3760 end if; 3761 3762 -- Check incorrect use of dynamically tagged expressions 3763 3764 if Is_Tagged_Type (T) then 3765 Check_Dynamically_Tagged_Expression 3766 (Expr => E, 3767 Typ => T, 3768 Related_Nod => N); 3769 end if; 3770 3771 Apply_Scalar_Range_Check (E, T); 3772 Apply_Static_Length_Check (E, T); 3773 3774 if Nkind (Original_Node (N)) = N_Object_Declaration 3775 and then Comes_From_Source (Original_Node (N)) 3776 3777 -- Only call test if needed 3778 3779 and then Restriction_Check_Required (SPARK_05) 3780 and then not Is_SPARK_05_Initialization_Expr (Original_Node (E)) 3781 then 3782 Check_SPARK_05_Restriction 3783 ("initialization expression is not appropriate", E); 3784 end if; 3785 3786 -- A formal parameter of a specific tagged type whose related 3787 -- subprogram is subject to pragma Extensions_Visible with value 3788 -- "False" cannot be implicitly converted to a class-wide type by 3789 -- means of an initialization expression (SPARK RM 6.1.7(3)). 3790 3791 if Is_Class_Wide_Type (T) and then Is_EVF_Expression (E) then 3792 Error_Msg_N 3793 ("formal parameter with Extensions_Visible False cannot be " 3794 & "implicitly converted to class-wide type", E); 3795 end if; 3796 end if; 3797 3798 -- If the No_Streams restriction is set, check that the type of the 3799 -- object is not, and does not contain, any subtype derived from 3800 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to 3801 -- Has_Stream just for efficiency reasons. There is no point in 3802 -- spending time on a Has_Stream check if the restriction is not set. 3803 3804 if Restriction_Check_Required (No_Streams) then 3805 if Has_Stream (T) then 3806 Check_Restriction (No_Streams, N); 3807 end if; 3808 end if; 3809 3810 -- Deal with predicate check before we start to do major rewriting. It 3811 -- is OK to initialize and then check the initialized value, since the 3812 -- object goes out of scope if we get a predicate failure. Note that we 3813 -- do this in the analyzer and not the expander because the analyzer 3814 -- does some substantial rewriting in some cases. 3815 3816 -- We need a predicate check if the type has predicates, and if either 3817 -- there is an initializing expression, or for default initialization 3818 -- when we have at least one case of an explicit default initial value 3819 -- and then this is not an internal declaration whose initialization 3820 -- comes later (as for an aggregate expansion). 3821 3822 if not Suppress_Assignment_Checks (N) 3823 and then Present (Predicate_Function (T)) 3824 and then not No_Initialization (N) 3825 and then 3826 (Present (E) 3827 or else 3828 Is_Partially_Initialized_Type (T, Include_Implicit => False)) 3829 then 3830 -- If the type has a static predicate and the expression is known at 3831 -- compile time, see if the expression satisfies the predicate. 3832 3833 if Present (E) then 3834 Check_Expression_Against_Static_Predicate (E, T); 3835 end if; 3836 3837 Insert_After (N, 3838 Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc))); 3839 end if; 3840 3841 -- Case of unconstrained type 3842 3843 if Is_Indefinite_Subtype (T) then 3844 3845 -- In SPARK, a declaration of unconstrained type is allowed 3846 -- only for constants of type string. 3847 3848 if Is_String_Type (T) and then not Constant_Present (N) then 3849 Check_SPARK_05_Restriction 3850 ("declaration of object of unconstrained type not allowed", N); 3851 end if; 3852 3853 -- Nothing to do in deferred constant case 3854 3855 if Constant_Present (N) and then No (E) then 3856 null; 3857 3858 -- Case of no initialization present 3859 3860 elsif No (E) then 3861 if No_Initialization (N) then 3862 null; 3863 3864 elsif Is_Class_Wide_Type (T) then 3865 Error_Msg_N 3866 ("initialization required in class-wide declaration ", N); 3867 3868 else 3869 Error_Msg_N 3870 ("unconstrained subtype not allowed (need initialization)", 3871 Object_Definition (N)); 3872 3873 if Is_Record_Type (T) and then Has_Discriminants (T) then 3874 Error_Msg_N 3875 ("\provide initial value or explicit discriminant values", 3876 Object_Definition (N)); 3877 3878 Error_Msg_NE 3879 ("\or give default discriminant values for type&", 3880 Object_Definition (N), T); 3881 3882 elsif Is_Array_Type (T) then 3883 Error_Msg_N 3884 ("\provide initial value or explicit array bounds", 3885 Object_Definition (N)); 3886 end if; 3887 end if; 3888 3889 -- Case of initialization present but in error. Set initial 3890 -- expression as absent (but do not make above complaints) 3891 3892 elsif E = Error then 3893 Set_Expression (N, Empty); 3894 E := Empty; 3895 3896 -- Case of initialization present 3897 3898 else 3899 -- Check restrictions in Ada 83 3900 3901 if not Constant_Present (N) then 3902 3903 -- Unconstrained variables not allowed in Ada 83 mode 3904 3905 if Ada_Version = Ada_83 3906 and then Comes_From_Source (Object_Definition (N)) 3907 then 3908 Error_Msg_N 3909 ("(Ada 83) unconstrained variable not allowed", 3910 Object_Definition (N)); 3911 end if; 3912 end if; 3913 3914 -- Now we constrain the variable from the initializing expression 3915 3916 -- If the expression is an aggregate, it has been expanded into 3917 -- individual assignments. Retrieve the actual type from the 3918 -- expanded construct. 3919 3920 if Is_Array_Type (T) 3921 and then No_Initialization (N) 3922 and then Nkind (Original_Node (E)) = N_Aggregate 3923 then 3924 Act_T := Etype (E); 3925 3926 -- In case of class-wide interface object declarations we delay 3927 -- the generation of the equivalent record type declarations until 3928 -- its expansion because there are cases in they are not required. 3929 3930 elsif Is_Interface (T) then 3931 null; 3932 3933 -- In GNATprove mode, Expand_Subtype_From_Expr does nothing. Thus, 3934 -- we should prevent the generation of another Itype with the 3935 -- same name as the one already generated, or we end up with 3936 -- two identical types in GNATprove. 3937 3938 elsif GNATprove_Mode then 3939 null; 3940 3941 -- If the type is an unchecked union, no subtype can be built from 3942 -- the expression. Rewrite declaration as a renaming, which the 3943 -- back-end can handle properly. This is a rather unusual case, 3944 -- because most unchecked_union declarations have default values 3945 -- for discriminants and are thus not indefinite. 3946 3947 elsif Is_Unchecked_Union (T) then 3948 if Constant_Present (N) or else Nkind (E) = N_Function_Call then 3949 Set_Ekind (Id, E_Constant); 3950 else 3951 Set_Ekind (Id, E_Variable); 3952 end if; 3953 3954 -- An object declared within a Ghost region is automatically 3955 -- Ghost (SPARK RM 6.9(2)). 3956 3957 if Comes_From_Source (Id) and then Ghost_Mode > None then 3958 Set_Is_Ghost_Entity (Id); 3959 3960 -- The Ghost policy in effect at the point of declaration 3961 -- and at the point of completion must match 3962 -- (SPARK RM 6.9(15)). 3963 3964 if Present (Prev_Entity) 3965 and then Is_Ghost_Entity (Prev_Entity) 3966 then 3967 Check_Ghost_Completion (Prev_Entity, Id); 3968 end if; 3969 end if; 3970 3971 Rewrite (N, 3972 Make_Object_Renaming_Declaration (Loc, 3973 Defining_Identifier => Id, 3974 Subtype_Mark => New_Occurrence_Of (T, Loc), 3975 Name => E)); 3976 3977 Set_Renamed_Object (Id, E); 3978 Freeze_Before (N, T); 3979 Set_Is_Frozen (Id); 3980 return; 3981 3982 else 3983 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E); 3984 Act_T := Find_Type_Of_Object (Object_Definition (N), N); 3985 end if; 3986 3987 Set_Is_Constr_Subt_For_U_Nominal (Act_T); 3988 3989 if Aliased_Present (N) then 3990 Set_Is_Constr_Subt_For_UN_Aliased (Act_T); 3991 end if; 3992 3993 Freeze_Before (N, Act_T); 3994 Freeze_Before (N, T); 3995 end if; 3996 3997 elsif Is_Array_Type (T) 3998 and then No_Initialization (N) 3999 and then Nkind (Original_Node (E)) = N_Aggregate 4000 then 4001 if not Is_Entity_Name (Object_Definition (N)) then 4002 Act_T := Etype (E); 4003 Check_Compile_Time_Size (Act_T); 4004 4005 if Aliased_Present (N) then 4006 Set_Is_Constr_Subt_For_UN_Aliased (Act_T); 4007 end if; 4008 end if; 4009 4010 -- When the given object definition and the aggregate are specified 4011 -- independently, and their lengths might differ do a length check. 4012 -- This cannot happen if the aggregate is of the form (others =>...) 4013 4014 if not Is_Constrained (T) then 4015 null; 4016 4017 elsif Nkind (E) = N_Raise_Constraint_Error then 4018 4019 -- Aggregate is statically illegal. Place back in declaration 4020 4021 Set_Expression (N, E); 4022 Set_No_Initialization (N, False); 4023 4024 elsif T = Etype (E) then 4025 null; 4026 4027 elsif Nkind (E) = N_Aggregate 4028 and then Present (Component_Associations (E)) 4029 and then Present (Choices (First (Component_Associations (E)))) 4030 and then Nkind (First 4031 (Choices (First (Component_Associations (E))))) = N_Others_Choice 4032 then 4033 null; 4034 4035 else 4036 Apply_Length_Check (E, T); 4037 end if; 4038 4039 -- If the type is limited unconstrained with defaulted discriminants and 4040 -- there is no expression, then the object is constrained by the 4041 -- defaults, so it is worthwhile building the corresponding subtype. 4042 4043 elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T)) 4044 and then not Is_Constrained (T) 4045 and then Has_Discriminants (T) 4046 then 4047 if No (E) then 4048 Act_T := Build_Default_Subtype (T, N); 4049 else 4050 -- Ada 2005: A limited object may be initialized by means of an 4051 -- aggregate. If the type has default discriminants it has an 4052 -- unconstrained nominal type, Its actual subtype will be obtained 4053 -- from the aggregate, and not from the default discriminants. 4054 4055 Act_T := Etype (E); 4056 end if; 4057 4058 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc)); 4059 4060 elsif Nkind (E) = N_Function_Call 4061 and then Constant_Present (N) 4062 and then Has_Unconstrained_Elements (Etype (E)) 4063 then 4064 -- The back-end has problems with constants of a discriminated type 4065 -- with defaults, if the initial value is a function call. We 4066 -- generate an intermediate temporary that will receive a reference 4067 -- to the result of the call. The initialization expression then 4068 -- becomes a dereference of that temporary. 4069 4070 Remove_Side_Effects (E); 4071 4072 -- If this is a constant declaration of an unconstrained type and 4073 -- the initialization is an aggregate, we can use the subtype of the 4074 -- aggregate for the declared entity because it is immutable. 4075 4076 elsif not Is_Constrained (T) 4077 and then Has_Discriminants (T) 4078 and then Constant_Present (N) 4079 and then not Has_Unchecked_Union (T) 4080 and then Nkind (E) = N_Aggregate 4081 then 4082 Act_T := Etype (E); 4083 end if; 4084 4085 -- Check No_Wide_Characters restriction 4086 4087 Check_Wide_Character_Restriction (T, Object_Definition (N)); 4088 4089 -- Indicate this is not set in source. Certainly true for constants, and 4090 -- true for variables so far (will be reset for a variable if and when 4091 -- we encounter a modification in the source). 4092 4093 Set_Never_Set_In_Source (Id); 4094 4095 -- Now establish the proper kind and type of the object 4096 4097 if Constant_Present (N) then 4098 Set_Ekind (Id, E_Constant); 4099 Set_Is_True_Constant (Id); 4100 4101 else 4102 Set_Ekind (Id, E_Variable); 4103 4104 -- A variable is set as shared passive if it appears in a shared 4105 -- passive package, and is at the outer level. This is not done for 4106 -- entities generated during expansion, because those are always 4107 -- manipulated locally. 4108 4109 if Is_Shared_Passive (Current_Scope) 4110 and then Is_Library_Level_Entity (Id) 4111 and then Comes_From_Source (Id) 4112 then 4113 Set_Is_Shared_Passive (Id); 4114 Check_Shared_Var (Id, T, N); 4115 end if; 4116 4117 -- Set Has_Initial_Value if initializing expression present. Note 4118 -- that if there is no initializing expression, we leave the state 4119 -- of this flag unchanged (usually it will be False, but notably in 4120 -- the case of exception choice variables, it will already be true). 4121 4122 if Present (E) then 4123 Set_Has_Initial_Value (Id); 4124 end if; 4125 end if; 4126 4127 -- Initialize alignment and size and capture alignment setting 4128 4129 Init_Alignment (Id); 4130 Init_Esize (Id); 4131 Set_Optimize_Alignment_Flags (Id); 4132 4133 -- An object declared within a Ghost region is automatically Ghost 4134 -- (SPARK RM 6.9(2)). 4135 4136 if Comes_From_Source (Id) 4137 and then (Ghost_Mode > None 4138 or else (Present (Prev_Entity) 4139 and then Is_Ghost_Entity (Prev_Entity))) 4140 then 4141 Set_Is_Ghost_Entity (Id); 4142 4143 -- The Ghost policy in effect at the point of declaration and at the 4144 -- point of completion must match (SPARK RM 6.9(16)). 4145 4146 if Present (Prev_Entity) and then Is_Ghost_Entity (Prev_Entity) then 4147 Check_Ghost_Completion (Prev_Entity, Id); 4148 end if; 4149 end if; 4150 4151 -- Deal with aliased case 4152 4153 if Aliased_Present (N) then 4154 Set_Is_Aliased (Id); 4155 4156 -- If the object is aliased and the type is unconstrained with 4157 -- defaulted discriminants and there is no expression, then the 4158 -- object is constrained by the defaults, so it is worthwhile 4159 -- building the corresponding subtype. 4160 4161 -- Ada 2005 (AI-363): If the aliased object is discriminated and 4162 -- unconstrained, then only establish an actual subtype if the 4163 -- nominal subtype is indefinite. In definite cases the object is 4164 -- unconstrained in Ada 2005. 4165 4166 if No (E) 4167 and then Is_Record_Type (T) 4168 and then not Is_Constrained (T) 4169 and then Has_Discriminants (T) 4170 and then (Ada_Version < Ada_2005 or else Is_Indefinite_Subtype (T)) 4171 then 4172 Set_Actual_Subtype (Id, Build_Default_Subtype (T, N)); 4173 end if; 4174 end if; 4175 4176 -- Now we can set the type of the object 4177 4178 Set_Etype (Id, Act_T); 4179 4180 -- Non-constant object is marked to be treated as volatile if type is 4181 -- volatile and we clear the Current_Value setting that may have been 4182 -- set above. Doing so for constants isn't required and might interfere 4183 -- with possible uses of the object as a static expression in contexts 4184 -- incompatible with volatility (e.g. as a case-statement alternative). 4185 4186 if Ekind (Id) /= E_Constant and then Treat_As_Volatile (Etype (Id)) then 4187 Set_Treat_As_Volatile (Id); 4188 Set_Current_Value (Id, Empty); 4189 end if; 4190 4191 -- Deal with controlled types 4192 4193 if Has_Controlled_Component (Etype (Id)) 4194 or else Is_Controlled (Etype (Id)) 4195 then 4196 if not Is_Library_Level_Entity (Id) then 4197 Check_Restriction (No_Nested_Finalization, N); 4198 else 4199 Validate_Controlled_Object (Id); 4200 end if; 4201 end if; 4202 4203 if Has_Task (Etype (Id)) then 4204 Check_Restriction (No_Tasking, N); 4205 4206 -- Deal with counting max tasks 4207 4208 -- Nothing to do if inside a generic 4209 4210 if Inside_A_Generic then 4211 null; 4212 4213 -- If library level entity, then count tasks 4214 4215 elsif Is_Library_Level_Entity (Id) then 4216 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id))); 4217 4218 -- If not library level entity, then indicate we don't know max 4219 -- tasks and also check task hierarchy restriction and blocking 4220 -- operation (since starting a task is definitely blocking). 4221 4222 else 4223 Check_Restriction (Max_Tasks, N); 4224 Check_Restriction (No_Task_Hierarchy, N); 4225 Check_Potentially_Blocking_Operation (N); 4226 end if; 4227 4228 -- A rather specialized test. If we see two tasks being declared 4229 -- of the same type in the same object declaration, and the task 4230 -- has an entry with an address clause, we know that program error 4231 -- will be raised at run time since we can't have two tasks with 4232 -- entries at the same address. 4233 4234 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then 4235 declare 4236 E : Entity_Id; 4237 4238 begin 4239 E := First_Entity (Etype (Id)); 4240 while Present (E) loop 4241 if Ekind (E) = E_Entry 4242 and then Present (Get_Attribute_Definition_Clause 4243 (E, Attribute_Address)) 4244 then 4245 Error_Msg_Warn := SPARK_Mode /= On; 4246 Error_Msg_N 4247 ("more than one task with same entry address<<", N); 4248 Error_Msg_N ("\Program_Error [<<", N); 4249 Insert_Action (N, 4250 Make_Raise_Program_Error (Loc, 4251 Reason => PE_Duplicated_Entry_Address)); 4252 exit; 4253 end if; 4254 4255 Next_Entity (E); 4256 end loop; 4257 end; 4258 end if; 4259 end if; 4260 4261 -- Some simple constant-propagation: if the expression is a constant 4262 -- string initialized with a literal, share the literal. This avoids 4263 -- a run-time copy. 4264 4265 if Present (E) 4266 and then Is_Entity_Name (E) 4267 and then Ekind (Entity (E)) = E_Constant 4268 and then Base_Type (Etype (E)) = Standard_String 4269 then 4270 declare 4271 Val : constant Node_Id := Constant_Value (Entity (E)); 4272 begin 4273 if Present (Val) and then Nkind (Val) = N_String_Literal then 4274 Rewrite (E, New_Copy (Val)); 4275 end if; 4276 end; 4277 end if; 4278 4279 -- Another optimization: if the nominal subtype is unconstrained and 4280 -- the expression is a function call that returns an unconstrained 4281 -- type, rewrite the declaration as a renaming of the result of the 4282 -- call. The exceptions below are cases where the copy is expected, 4283 -- either by the back end (Aliased case) or by the semantics, as for 4284 -- initializing controlled types or copying tags for classwide types. 4285 4286 if Present (E) 4287 and then Nkind (E) = N_Explicit_Dereference 4288 and then Nkind (Original_Node (E)) = N_Function_Call 4289 and then not Is_Library_Level_Entity (Id) 4290 and then not Is_Constrained (Underlying_Type (T)) 4291 and then not Is_Aliased (Id) 4292 and then not Is_Class_Wide_Type (T) 4293 and then not Is_Controlled (T) 4294 and then not Has_Controlled_Component (Base_Type (T)) 4295 and then Expander_Active 4296 then 4297 Rewrite (N, 4298 Make_Object_Renaming_Declaration (Loc, 4299 Defining_Identifier => Id, 4300 Access_Definition => Empty, 4301 Subtype_Mark => New_Occurrence_Of 4302 (Base_Type (Etype (Id)), Loc), 4303 Name => E)); 4304 4305 Set_Renamed_Object (Id, E); 4306 4307 -- Force generation of debugging information for the constant and for 4308 -- the renamed function call. 4309 4310 Set_Debug_Info_Needed (Id); 4311 Set_Debug_Info_Needed (Entity (Prefix (E))); 4312 end if; 4313 4314 if Present (Prev_Entity) 4315 and then Is_Frozen (Prev_Entity) 4316 and then not Error_Posted (Id) 4317 then 4318 Error_Msg_N ("full constant declaration appears too late", N); 4319 end if; 4320 4321 Check_Eliminated (Id); 4322 4323 -- Deal with setting In_Private_Part flag if in private part 4324 4325 if Ekind (Scope (Id)) = E_Package and then In_Private_Part (Scope (Id)) 4326 then 4327 Set_In_Private_Part (Id); 4328 end if; 4329 4330 -- Check for violation of No_Local_Timing_Events 4331 4332 if Restriction_Check_Required (No_Local_Timing_Events) 4333 and then not Is_Library_Level_Entity (Id) 4334 and then Is_RTE (Etype (Id), RE_Timing_Event) 4335 then 4336 Check_Restriction (No_Local_Timing_Events, N); 4337 end if; 4338 4339 <<Leave>> 4340 -- Initialize the refined state of a variable here because this is a 4341 -- common destination for legal and illegal object declarations. 4342 4343 if Ekind (Id) = E_Variable then 4344 Set_Encapsulating_State (Id, Empty); 4345 end if; 4346 4347 if Has_Aspects (N) then 4348 Analyze_Aspect_Specifications (N, Id); 4349 end if; 4350 4351 Analyze_Dimension (N); 4352 4353 -- Verify whether the object declaration introduces an illegal hidden 4354 -- state within a package subject to a null abstract state. 4355 4356 if Ekind (Id) = E_Variable then 4357 Check_No_Hidden_State (Id); 4358 end if; 4359 end Analyze_Object_Declaration; 4360 4361 --------------------------- 4362 -- Analyze_Others_Choice -- 4363 --------------------------- 4364 4365 -- Nothing to do for the others choice node itself, the semantic analysis 4366 -- of the others choice will occur as part of the processing of the parent 4367 4368 procedure Analyze_Others_Choice (N : Node_Id) is 4369 pragma Warnings (Off, N); 4370 begin 4371 null; 4372 end Analyze_Others_Choice; 4373 4374 ------------------------------------------- 4375 -- Analyze_Private_Extension_Declaration -- 4376 ------------------------------------------- 4377 4378 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is 4379 T : constant Entity_Id := Defining_Identifier (N); 4380 Indic : constant Node_Id := Subtype_Indication (N); 4381 Parent_Type : Entity_Id; 4382 Parent_Base : Entity_Id; 4383 4384 begin 4385 -- The private extension declaration may be subject to pragma Ghost with 4386 -- policy Ignore. Set the mode now to ensure that any nodes generated 4387 -- during analysis and expansion are properly flagged as ignored Ghost. 4388 4389 Set_Ghost_Mode (N); 4390 4391 -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces 4392 4393 if Is_Non_Empty_List (Interface_List (N)) then 4394 declare 4395 Intf : Node_Id; 4396 T : Entity_Id; 4397 4398 begin 4399 Intf := First (Interface_List (N)); 4400 while Present (Intf) loop 4401 T := Find_Type_Of_Subtype_Indic (Intf); 4402 4403 Diagnose_Interface (Intf, T); 4404 Next (Intf); 4405 end loop; 4406 end; 4407 end if; 4408 4409 Generate_Definition (T); 4410 4411 -- For other than Ada 2012, just enter the name in the current scope 4412 4413 if Ada_Version < Ada_2012 then 4414 Enter_Name (T); 4415 4416 -- Ada 2012 (AI05-0162): Enter the name in the current scope handling 4417 -- case of private type that completes an incomplete type. 4418 4419 else 4420 declare 4421 Prev : Entity_Id; 4422 4423 begin 4424 Prev := Find_Type_Name (N); 4425 4426 pragma Assert (Prev = T 4427 or else (Ekind (Prev) = E_Incomplete_Type 4428 and then Present (Full_View (Prev)) 4429 and then Full_View (Prev) = T)); 4430 end; 4431 end if; 4432 4433 Parent_Type := Find_Type_Of_Subtype_Indic (Indic); 4434 Parent_Base := Base_Type (Parent_Type); 4435 4436 if Parent_Type = Any_Type or else Etype (Parent_Type) = Any_Type then 4437 Set_Ekind (T, Ekind (Parent_Type)); 4438 Set_Etype (T, Any_Type); 4439 goto Leave; 4440 4441 elsif not Is_Tagged_Type (Parent_Type) then 4442 Error_Msg_N 4443 ("parent of type extension must be a tagged type ", Indic); 4444 goto Leave; 4445 4446 elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then 4447 Error_Msg_N ("premature derivation of incomplete type", Indic); 4448 goto Leave; 4449 4450 elsif Is_Concurrent_Type (Parent_Type) then 4451 Error_Msg_N 4452 ("parent type of a private extension cannot be " 4453 & "a synchronized tagged type (RM 3.9.1 (3/1))", N); 4454 4455 Set_Etype (T, Any_Type); 4456 Set_Ekind (T, E_Limited_Private_Type); 4457 Set_Private_Dependents (T, New_Elmt_List); 4458 Set_Error_Posted (T); 4459 goto Leave; 4460 end if; 4461 4462 -- Perhaps the parent type should be changed to the class-wide type's 4463 -- specific type in this case to prevent cascading errors ??? 4464 4465 if Is_Class_Wide_Type (Parent_Type) then 4466 Error_Msg_N 4467 ("parent of type extension must not be a class-wide type", Indic); 4468 goto Leave; 4469 end if; 4470 4471 if (not Is_Package_Or_Generic_Package (Current_Scope) 4472 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration) 4473 or else In_Private_Part (Current_Scope) 4474 4475 then 4476 Error_Msg_N ("invalid context for private extension", N); 4477 end if; 4478 4479 -- Set common attributes 4480 4481 Set_Is_Pure (T, Is_Pure (Current_Scope)); 4482 Set_Scope (T, Current_Scope); 4483 Set_Ekind (T, E_Record_Type_With_Private); 4484 Init_Size_Align (T); 4485 Set_Default_SSO (T); 4486 4487 Set_Etype (T, Parent_Base); 4488 Set_Has_Task (T, Has_Task (Parent_Base)); 4489 Set_Has_Protected (T, Has_Task (Parent_Base)); 4490 4491 Set_Convention (T, Convention (Parent_Type)); 4492 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type)); 4493 Set_Is_First_Subtype (T); 4494 Make_Class_Wide_Type (T); 4495 4496 if Unknown_Discriminants_Present (N) then 4497 Set_Discriminant_Constraint (T, No_Elist); 4498 end if; 4499 4500 Build_Derived_Record_Type (N, Parent_Type, T); 4501 4502 -- Propagate inherited invariant information. The new type has 4503 -- invariants, if the parent type has inheritable invariants, 4504 -- and these invariants can in turn be inherited. 4505 4506 if Has_Inheritable_Invariants (Parent_Type) then 4507 Set_Has_Inheritable_Invariants (T); 4508 Set_Has_Invariants (T); 4509 end if; 4510 4511 -- Ada 2005 (AI-443): Synchronized private extension or a rewritten 4512 -- synchronized formal derived type. 4513 4514 if Ada_Version >= Ada_2005 and then Synchronized_Present (N) then 4515 Set_Is_Limited_Record (T); 4516 4517 -- Formal derived type case 4518 4519 if Is_Generic_Type (T) then 4520 4521 -- The parent must be a tagged limited type or a synchronized 4522 -- interface. 4523 4524 if (not Is_Tagged_Type (Parent_Type) 4525 or else not Is_Limited_Type (Parent_Type)) 4526 and then 4527 (not Is_Interface (Parent_Type) 4528 or else not Is_Synchronized_Interface (Parent_Type)) 4529 then 4530 Error_Msg_NE ("parent type of & must be tagged limited " & 4531 "or synchronized", N, T); 4532 end if; 4533 4534 -- The progenitors (if any) must be limited or synchronized 4535 -- interfaces. 4536 4537 if Present (Interfaces (T)) then 4538 declare 4539 Iface : Entity_Id; 4540 Iface_Elmt : Elmt_Id; 4541 4542 begin 4543 Iface_Elmt := First_Elmt (Interfaces (T)); 4544 while Present (Iface_Elmt) loop 4545 Iface := Node (Iface_Elmt); 4546 4547 if not Is_Limited_Interface (Iface) 4548 and then not Is_Synchronized_Interface (Iface) 4549 then 4550 Error_Msg_NE ("progenitor & must be limited " & 4551 "or synchronized", N, Iface); 4552 end if; 4553 4554 Next_Elmt (Iface_Elmt); 4555 end loop; 4556 end; 4557 end if; 4558 4559 -- Regular derived extension, the parent must be a limited or 4560 -- synchronized interface. 4561 4562 else 4563 if not Is_Interface (Parent_Type) 4564 or else (not Is_Limited_Interface (Parent_Type) 4565 and then not Is_Synchronized_Interface (Parent_Type)) 4566 then 4567 Error_Msg_NE 4568 ("parent type of & must be limited interface", N, T); 4569 end if; 4570 end if; 4571 4572 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private 4573 -- extension with a synchronized parent must be explicitly declared 4574 -- synchronized, because the full view will be a synchronized type. 4575 -- This must be checked before the check for limited types below, 4576 -- to ensure that types declared limited are not allowed to extend 4577 -- synchronized interfaces. 4578 4579 elsif Is_Interface (Parent_Type) 4580 and then Is_Synchronized_Interface (Parent_Type) 4581 and then not Synchronized_Present (N) 4582 then 4583 Error_Msg_NE 4584 ("private extension of& must be explicitly synchronized", 4585 N, Parent_Type); 4586 4587 elsif Limited_Present (N) then 4588 Set_Is_Limited_Record (T); 4589 4590 if not Is_Limited_Type (Parent_Type) 4591 and then 4592 (not Is_Interface (Parent_Type) 4593 or else not Is_Limited_Interface (Parent_Type)) 4594 then 4595 Error_Msg_NE ("parent type& of limited extension must be limited", 4596 N, Parent_Type); 4597 end if; 4598 end if; 4599 4600 <<Leave>> 4601 if Has_Aspects (N) then 4602 Analyze_Aspect_Specifications (N, T); 4603 end if; 4604 end Analyze_Private_Extension_Declaration; 4605 4606 --------------------------------- 4607 -- Analyze_Subtype_Declaration -- 4608 --------------------------------- 4609 4610 procedure Analyze_Subtype_Declaration 4611 (N : Node_Id; 4612 Skip : Boolean := False) 4613 is 4614 Id : constant Entity_Id := Defining_Identifier (N); 4615 T : Entity_Id; 4616 R_Checks : Check_Result; 4617 4618 begin 4619 -- The subtype declaration may be subject to pragma Ghost with policy 4620 -- Ignore. Set the mode now to ensure that any nodes generated during 4621 -- analysis and expansion are properly flagged as ignored Ghost. 4622 4623 Set_Ghost_Mode (N); 4624 4625 Generate_Definition (Id); 4626 Set_Is_Pure (Id, Is_Pure (Current_Scope)); 4627 Init_Size_Align (Id); 4628 4629 -- The following guard condition on Enter_Name is to handle cases where 4630 -- the defining identifier has already been entered into the scope but 4631 -- the declaration as a whole needs to be analyzed. 4632 4633 -- This case in particular happens for derived enumeration types. The 4634 -- derived enumeration type is processed as an inserted enumeration type 4635 -- declaration followed by a rewritten subtype declaration. The defining 4636 -- identifier, however, is entered into the name scope very early in the 4637 -- processing of the original type declaration and therefore needs to be 4638 -- avoided here, when the created subtype declaration is analyzed. (See 4639 -- Build_Derived_Types) 4640 4641 -- This also happens when the full view of a private type is derived 4642 -- type with constraints. In this case the entity has been introduced 4643 -- in the private declaration. 4644 4645 -- Finally this happens in some complex cases when validity checks are 4646 -- enabled, where the same subtype declaration may be analyzed twice. 4647 -- This can happen if the subtype is created by the pre-analysis of 4648 -- an attribute tht gives the range of a loop statement, and the loop 4649 -- itself appears within an if_statement that will be rewritten during 4650 -- expansion. 4651 4652 if Skip 4653 or else (Present (Etype (Id)) 4654 and then (Is_Private_Type (Etype (Id)) 4655 or else Is_Task_Type (Etype (Id)) 4656 or else Is_Rewrite_Substitution (N))) 4657 then 4658 null; 4659 4660 elsif Current_Entity (Id) = Id then 4661 null; 4662 4663 else 4664 Enter_Name (Id); 4665 end if; 4666 4667 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P'); 4668 4669 -- Class-wide equivalent types of records with unknown discriminants 4670 -- involve the generation of an itype which serves as the private view 4671 -- of a constrained record subtype. In such cases the base type of the 4672 -- current subtype we are processing is the private itype. Use the full 4673 -- of the private itype when decorating various attributes. 4674 4675 if Is_Itype (T) 4676 and then Is_Private_Type (T) 4677 and then Present (Full_View (T)) 4678 then 4679 T := Full_View (T); 4680 end if; 4681 4682 -- Inherit common attributes 4683 4684 Set_Is_Volatile (Id, Is_Volatile (T)); 4685 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T)); 4686 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T))); 4687 Set_Convention (Id, Convention (T)); 4688 4689 -- If ancestor has predicates then so does the subtype, and in addition 4690 -- we must delay the freeze to properly arrange predicate inheritance. 4691 4692 -- The Ancestor_Type test is really unpleasant, there seem to be cases 4693 -- in which T = ID, so the above tests and assignments do nothing??? 4694 4695 if Has_Predicates (T) 4696 or else (Present (Ancestor_Subtype (T)) 4697 and then Has_Predicates (Ancestor_Subtype (T))) 4698 then 4699 Set_Has_Predicates (Id); 4700 Set_Has_Delayed_Freeze (Id); 4701 end if; 4702 4703 -- Subtype of Boolean cannot have a constraint in SPARK 4704 4705 if Is_Boolean_Type (T) 4706 and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication 4707 then 4708 Check_SPARK_05_Restriction 4709 ("subtype of Boolean cannot have constraint", N); 4710 end if; 4711 4712 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then 4713 declare 4714 Cstr : constant Node_Id := Constraint (Subtype_Indication (N)); 4715 One_Cstr : Node_Id; 4716 Low : Node_Id; 4717 High : Node_Id; 4718 4719 begin 4720 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then 4721 One_Cstr := First (Constraints (Cstr)); 4722 while Present (One_Cstr) loop 4723 4724 -- Index or discriminant constraint in SPARK must be a 4725 -- subtype mark. 4726 4727 if not 4728 Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name) 4729 then 4730 Check_SPARK_05_Restriction 4731 ("subtype mark required", One_Cstr); 4732 4733 -- String subtype must have a lower bound of 1 in SPARK. 4734 -- Note that we do not need to test for the non-static case 4735 -- here, since that was already taken care of in 4736 -- Process_Range_Expr_In_Decl. 4737 4738 elsif Base_Type (T) = Standard_String then 4739 Get_Index_Bounds (One_Cstr, Low, High); 4740 4741 if Is_OK_Static_Expression (Low) 4742 and then Expr_Value (Low) /= 1 4743 then 4744 Check_SPARK_05_Restriction 4745 ("String subtype must have lower bound of 1", N); 4746 end if; 4747 end if; 4748 4749 Next (One_Cstr); 4750 end loop; 4751 end if; 4752 end; 4753 end if; 4754 4755 -- In the case where there is no constraint given in the subtype 4756 -- indication, Process_Subtype just returns the Subtype_Mark, so its 4757 -- semantic attributes must be established here. 4758 4759 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then 4760 Set_Etype (Id, Base_Type (T)); 4761 4762 -- Subtype of unconstrained array without constraint is not allowed 4763 -- in SPARK. 4764 4765 if Is_Array_Type (T) and then not Is_Constrained (T) then 4766 Check_SPARK_05_Restriction 4767 ("subtype of unconstrained array must have constraint", N); 4768 end if; 4769 4770 case Ekind (T) is 4771 when Array_Kind => 4772 Set_Ekind (Id, E_Array_Subtype); 4773 Copy_Array_Subtype_Attributes (Id, T); 4774 4775 when Decimal_Fixed_Point_Kind => 4776 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype); 4777 Set_Digits_Value (Id, Digits_Value (T)); 4778 Set_Delta_Value (Id, Delta_Value (T)); 4779 Set_Scale_Value (Id, Scale_Value (T)); 4780 Set_Small_Value (Id, Small_Value (T)); 4781 Set_Scalar_Range (Id, Scalar_Range (T)); 4782 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T)); 4783 Set_Is_Constrained (Id, Is_Constrained (T)); 4784 Set_Is_Known_Valid (Id, Is_Known_Valid (T)); 4785 Set_RM_Size (Id, RM_Size (T)); 4786 4787 when Enumeration_Kind => 4788 Set_Ekind (Id, E_Enumeration_Subtype); 4789 Set_First_Literal (Id, First_Literal (Base_Type (T))); 4790 Set_Scalar_Range (Id, Scalar_Range (T)); 4791 Set_Is_Character_Type (Id, Is_Character_Type (T)); 4792 Set_Is_Constrained (Id, Is_Constrained (T)); 4793 Set_Is_Known_Valid (Id, Is_Known_Valid (T)); 4794 Set_RM_Size (Id, RM_Size (T)); 4795 Inherit_Predicate_Flags (Id, T); 4796 4797 when Ordinary_Fixed_Point_Kind => 4798 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype); 4799 Set_Scalar_Range (Id, Scalar_Range (T)); 4800 Set_Small_Value (Id, Small_Value (T)); 4801 Set_Delta_Value (Id, Delta_Value (T)); 4802 Set_Is_Constrained (Id, Is_Constrained (T)); 4803 Set_Is_Known_Valid (Id, Is_Known_Valid (T)); 4804 Set_RM_Size (Id, RM_Size (T)); 4805 4806 when Float_Kind => 4807 Set_Ekind (Id, E_Floating_Point_Subtype); 4808 Set_Scalar_Range (Id, Scalar_Range (T)); 4809 Set_Digits_Value (Id, Digits_Value (T)); 4810 Set_Is_Constrained (Id, Is_Constrained (T)); 4811 4812 when Signed_Integer_Kind => 4813 Set_Ekind (Id, E_Signed_Integer_Subtype); 4814 Set_Scalar_Range (Id, Scalar_Range (T)); 4815 Set_Is_Constrained (Id, Is_Constrained (T)); 4816 Set_Is_Known_Valid (Id, Is_Known_Valid (T)); 4817 Set_RM_Size (Id, RM_Size (T)); 4818 Inherit_Predicate_Flags (Id, T); 4819 4820 when Modular_Integer_Kind => 4821 Set_Ekind (Id, E_Modular_Integer_Subtype); 4822 Set_Scalar_Range (Id, Scalar_Range (T)); 4823 Set_Is_Constrained (Id, Is_Constrained (T)); 4824 Set_Is_Known_Valid (Id, Is_Known_Valid (T)); 4825 Set_RM_Size (Id, RM_Size (T)); 4826 Inherit_Predicate_Flags (Id, T); 4827 4828 when Class_Wide_Kind => 4829 Set_Ekind (Id, E_Class_Wide_Subtype); 4830 Set_Class_Wide_Type (Id, Class_Wide_Type (T)); 4831 Set_Cloned_Subtype (Id, T); 4832 Set_Is_Tagged_Type (Id, True); 4833 Set_Has_Unknown_Discriminants 4834 (Id, True); 4835 Set_No_Tagged_Streams_Pragma 4836 (Id, No_Tagged_Streams_Pragma (T)); 4837 4838 if Ekind (T) = E_Class_Wide_Subtype then 4839 Set_Equivalent_Type (Id, Equivalent_Type (T)); 4840 end if; 4841 4842 when E_Record_Type | E_Record_Subtype => 4843 Set_Ekind (Id, E_Record_Subtype); 4844 4845 if Ekind (T) = E_Record_Subtype 4846 and then Present (Cloned_Subtype (T)) 4847 then 4848 Set_Cloned_Subtype (Id, Cloned_Subtype (T)); 4849 else 4850 Set_Cloned_Subtype (Id, T); 4851 end if; 4852 4853 Set_First_Entity (Id, First_Entity (T)); 4854 Set_Last_Entity (Id, Last_Entity (T)); 4855 Set_Has_Discriminants (Id, Has_Discriminants (T)); 4856 Set_Is_Constrained (Id, Is_Constrained (T)); 4857 Set_Is_Limited_Record (Id, Is_Limited_Record (T)); 4858 Set_Has_Implicit_Dereference 4859 (Id, Has_Implicit_Dereference (T)); 4860 Set_Has_Unknown_Discriminants 4861 (Id, Has_Unknown_Discriminants (T)); 4862 4863 if Has_Discriminants (T) then 4864 Set_Discriminant_Constraint 4865 (Id, Discriminant_Constraint (T)); 4866 Set_Stored_Constraint_From_Discriminant_Constraint (Id); 4867 4868 elsif Has_Unknown_Discriminants (Id) then 4869 Set_Discriminant_Constraint (Id, No_Elist); 4870 end if; 4871 4872 if Is_Tagged_Type (T) then 4873 Set_Is_Tagged_Type (Id, True); 4874 Set_No_Tagged_Streams_Pragma 4875 (Id, No_Tagged_Streams_Pragma (T)); 4876 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T)); 4877 Set_Direct_Primitive_Operations 4878 (Id, Direct_Primitive_Operations (T)); 4879 Set_Class_Wide_Type (Id, Class_Wide_Type (T)); 4880 4881 if Is_Interface (T) then 4882 Set_Is_Interface (Id); 4883 Set_Is_Limited_Interface (Id, Is_Limited_Interface (T)); 4884 end if; 4885 end if; 4886 4887 when Private_Kind => 4888 Set_Ekind (Id, Subtype_Kind (Ekind (T))); 4889 Set_Has_Discriminants (Id, Has_Discriminants (T)); 4890 Set_Is_Constrained (Id, Is_Constrained (T)); 4891 Set_First_Entity (Id, First_Entity (T)); 4892 Set_Last_Entity (Id, Last_Entity (T)); 4893 Set_Private_Dependents (Id, New_Elmt_List); 4894 Set_Is_Limited_Record (Id, Is_Limited_Record (T)); 4895 Set_Has_Implicit_Dereference 4896 (Id, Has_Implicit_Dereference (T)); 4897 Set_Has_Unknown_Discriminants 4898 (Id, Has_Unknown_Discriminants (T)); 4899 Set_Known_To_Have_Preelab_Init 4900 (Id, Known_To_Have_Preelab_Init (T)); 4901 4902 if Is_Tagged_Type (T) then 4903 Set_Is_Tagged_Type (Id); 4904 Set_No_Tagged_Streams_Pragma (Id, 4905 No_Tagged_Streams_Pragma (T)); 4906 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T)); 4907 Set_Class_Wide_Type (Id, Class_Wide_Type (T)); 4908 Set_Direct_Primitive_Operations (Id, 4909 Direct_Primitive_Operations (T)); 4910 end if; 4911 4912 -- In general the attributes of the subtype of a private type 4913 -- are the attributes of the partial view of parent. However, 4914 -- the full view may be a discriminated type, and the subtype 4915 -- must share the discriminant constraint to generate correct 4916 -- calls to initialization procedures. 4917 4918 if Has_Discriminants (T) then 4919 Set_Discriminant_Constraint 4920 (Id, Discriminant_Constraint (T)); 4921 Set_Stored_Constraint_From_Discriminant_Constraint (Id); 4922 4923 elsif Present (Full_View (T)) 4924 and then Has_Discriminants (Full_View (T)) 4925 then 4926 Set_Discriminant_Constraint 4927 (Id, Discriminant_Constraint (Full_View (T))); 4928 Set_Stored_Constraint_From_Discriminant_Constraint (Id); 4929 4930 -- This would seem semantically correct, but apparently 4931 -- generates spurious errors about missing components ??? 4932 4933 -- Set_Has_Discriminants (Id); 4934 end if; 4935 4936 Prepare_Private_Subtype_Completion (Id, N); 4937 4938 -- If this is the subtype of a constrained private type with 4939 -- discriminants that has got a full view and we also have 4940 -- built a completion just above, show that the completion 4941 -- is a clone of the full view to the back-end. 4942 4943 if Has_Discriminants (T) 4944 and then not Has_Unknown_Discriminants (T) 4945 and then not Is_Empty_Elmt_List (Discriminant_Constraint (T)) 4946 and then Present (Full_View (T)) 4947 and then Present (Full_View (Id)) 4948 then 4949 Set_Cloned_Subtype (Full_View (Id), Full_View (T)); 4950 end if; 4951 4952 when Access_Kind => 4953 Set_Ekind (Id, E_Access_Subtype); 4954 Set_Is_Constrained (Id, Is_Constrained (T)); 4955 Set_Is_Access_Constant 4956 (Id, Is_Access_Constant (T)); 4957 Set_Directly_Designated_Type 4958 (Id, Designated_Type (T)); 4959 Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T)); 4960 4961 -- A Pure library_item must not contain the declaration of a 4962 -- named access type, except within a subprogram, generic 4963 -- subprogram, task unit, or protected unit, or if it has 4964 -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)). 4965 4966 if Comes_From_Source (Id) 4967 and then In_Pure_Unit 4968 and then not In_Subprogram_Task_Protected_Unit 4969 and then not No_Pool_Assigned (Id) 4970 then 4971 Error_Msg_N 4972 ("named access types not allowed in pure unit", N); 4973 end if; 4974 4975 when Concurrent_Kind => 4976 Set_Ekind (Id, Subtype_Kind (Ekind (T))); 4977 Set_Corresponding_Record_Type (Id, 4978 Corresponding_Record_Type (T)); 4979 Set_First_Entity (Id, First_Entity (T)); 4980 Set_First_Private_Entity (Id, First_Private_Entity (T)); 4981 Set_Has_Discriminants (Id, Has_Discriminants (T)); 4982 Set_Is_Constrained (Id, Is_Constrained (T)); 4983 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T)); 4984 Set_Last_Entity (Id, Last_Entity (T)); 4985 4986 if Is_Tagged_Type (T) then 4987 Set_No_Tagged_Streams_Pragma 4988 (Id, No_Tagged_Streams_Pragma (T)); 4989 end if; 4990 4991 if Has_Discriminants (T) then 4992 Set_Discriminant_Constraint 4993 (Id, Discriminant_Constraint (T)); 4994 Set_Stored_Constraint_From_Discriminant_Constraint (Id); 4995 end if; 4996 4997 when Incomplete_Kind => 4998 if Ada_Version >= Ada_2005 then 4999 5000 -- In Ada 2005 an incomplete type can be explicitly tagged: 5001 -- propagate indication. Note that we also have to include 5002 -- subtypes for Ada 2012 extended use of incomplete types. 5003 5004 Set_Ekind (Id, E_Incomplete_Subtype); 5005 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T)); 5006 Set_Private_Dependents (Id, New_Elmt_List); 5007 5008 if Is_Tagged_Type (Id) then 5009 Set_No_Tagged_Streams_Pragma 5010 (Id, No_Tagged_Streams_Pragma (T)); 5011 Set_Direct_Primitive_Operations (Id, New_Elmt_List); 5012 end if; 5013 5014 -- Ada 2005 (AI-412): Decorate an incomplete subtype of an 5015 -- incomplete type visible through a limited with clause. 5016 5017 if From_Limited_With (T) 5018 and then Present (Non_Limited_View (T)) 5019 then 5020 Set_From_Limited_With (Id); 5021 Set_Non_Limited_View (Id, Non_Limited_View (T)); 5022 5023 -- Ada 2005 (AI-412): Add the regular incomplete subtype 5024 -- to the private dependents of the original incomplete 5025 -- type for future transformation. 5026 5027 else 5028 Append_Elmt (Id, Private_Dependents (T)); 5029 end if; 5030 5031 -- If the subtype name denotes an incomplete type an error 5032 -- was already reported by Process_Subtype. 5033 5034 else 5035 Set_Etype (Id, Any_Type); 5036 end if; 5037 5038 when others => 5039 raise Program_Error; 5040 end case; 5041 end if; 5042 5043 if Etype (Id) = Any_Type then 5044 goto Leave; 5045 end if; 5046 5047 -- Some common processing on all types 5048 5049 Set_Size_Info (Id, T); 5050 Set_First_Rep_Item (Id, First_Rep_Item (T)); 5051 5052 -- If the parent type is a generic actual, so is the subtype. This may 5053 -- happen in a nested instance. Why Comes_From_Source test??? 5054 5055 if not Comes_From_Source (N) then 5056 Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T)); 5057 end if; 5058 5059 T := Etype (Id); 5060 5061 Set_Is_Immediately_Visible (Id, True); 5062 Set_Depends_On_Private (Id, Has_Private_Component (T)); 5063 Set_Is_Descendent_Of_Address (Id, Is_Descendent_Of_Address (T)); 5064 5065 if Is_Interface (T) then 5066 Set_Is_Interface (Id); 5067 end if; 5068 5069 if Present (Generic_Parent_Type (N)) 5070 and then 5071 (Nkind (Parent (Generic_Parent_Type (N))) /= 5072 N_Formal_Type_Declaration 5073 or else Nkind (Formal_Type_Definition 5074 (Parent (Generic_Parent_Type (N)))) /= 5075 N_Formal_Private_Type_Definition) 5076 then 5077 if Is_Tagged_Type (Id) then 5078 5079 -- If this is a generic actual subtype for a synchronized type, 5080 -- the primitive operations are those of the corresponding record 5081 -- for which there is a separate subtype declaration. 5082 5083 if Is_Concurrent_Type (Id) then 5084 null; 5085 elsif Is_Class_Wide_Type (Id) then 5086 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T)); 5087 else 5088 Derive_Subprograms (Generic_Parent_Type (N), Id, T); 5089 end if; 5090 5091 elsif Scope (Etype (Id)) /= Standard_Standard then 5092 Derive_Subprograms (Generic_Parent_Type (N), Id); 5093 end if; 5094 end if; 5095 5096 if Is_Private_Type (T) and then Present (Full_View (T)) then 5097 Conditional_Delay (Id, Full_View (T)); 5098 5099 -- The subtypes of components or subcomponents of protected types 5100 -- do not need freeze nodes, which would otherwise appear in the 5101 -- wrong scope (before the freeze node for the protected type). The 5102 -- proper subtypes are those of the subcomponents of the corresponding 5103 -- record. 5104 5105 elsif Ekind (Scope (Id)) /= E_Protected_Type 5106 and then Present (Scope (Scope (Id))) -- error defense 5107 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type 5108 then 5109 Conditional_Delay (Id, T); 5110 end if; 5111 5112 -- Check that Constraint_Error is raised for a scalar subtype indication 5113 -- when the lower or upper bound of a non-null range lies outside the 5114 -- range of the type mark. 5115 5116 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then 5117 if Is_Scalar_Type (Etype (Id)) 5118 and then Scalar_Range (Id) /= 5119 Scalar_Range (Etype (Subtype_Mark 5120 (Subtype_Indication (N)))) 5121 then 5122 Apply_Range_Check 5123 (Scalar_Range (Id), 5124 Etype (Subtype_Mark (Subtype_Indication (N)))); 5125 5126 -- In the array case, check compatibility for each index 5127 5128 elsif Is_Array_Type (Etype (Id)) and then Present (First_Index (Id)) 5129 then 5130 -- This really should be a subprogram that finds the indications 5131 -- to check??? 5132 5133 declare 5134 Subt_Index : Node_Id := First_Index (Id); 5135 Target_Index : Node_Id := 5136 First_Index (Etype 5137 (Subtype_Mark (Subtype_Indication (N)))); 5138 Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N); 5139 5140 begin 5141 while Present (Subt_Index) loop 5142 if ((Nkind (Subt_Index) = N_Identifier 5143 and then Ekind (Entity (Subt_Index)) in Scalar_Kind) 5144 or else Nkind (Subt_Index) = N_Subtype_Indication) 5145 and then 5146 Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range 5147 then 5148 declare 5149 Target_Typ : constant Entity_Id := 5150 Etype (Target_Index); 5151 begin 5152 R_Checks := 5153 Get_Range_Checks 5154 (Scalar_Range (Etype (Subt_Index)), 5155 Target_Typ, 5156 Etype (Subt_Index), 5157 Defining_Identifier (N)); 5158 5159 -- Reset Has_Dynamic_Range_Check on the subtype to 5160 -- prevent elision of the index check due to a dynamic 5161 -- check generated for a preceding index (needed since 5162 -- Insert_Range_Checks tries to avoid generating 5163 -- redundant checks on a given declaration). 5164 5165 Set_Has_Dynamic_Range_Check (N, False); 5166 5167 Insert_Range_Checks 5168 (R_Checks, 5169 N, 5170 Target_Typ, 5171 Sloc (Defining_Identifier (N))); 5172 5173 -- Record whether this index involved a dynamic check 5174 5175 Has_Dyn_Chk := 5176 Has_Dyn_Chk or else Has_Dynamic_Range_Check (N); 5177 end; 5178 end if; 5179 5180 Next_Index (Subt_Index); 5181 Next_Index (Target_Index); 5182 end loop; 5183 5184 -- Finally, mark whether the subtype involves dynamic checks 5185 5186 Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk); 5187 end; 5188 end if; 5189 end if; 5190 5191 -- A type invariant applies to any subtype in its scope, in particular 5192 -- to a generic actual. 5193 5194 if Has_Invariants (T) and then In_Open_Scopes (Scope (T)) then 5195 Set_Has_Invariants (Id); 5196 Set_Invariant_Procedure (Id, Invariant_Procedure (T)); 5197 end if; 5198 5199 -- Make sure that generic actual types are properly frozen. The subtype 5200 -- is marked as a generic actual type when the enclosing instance is 5201 -- analyzed, so here we identify the subtype from the tree structure. 5202 5203 if Expander_Active 5204 and then Is_Generic_Actual_Type (Id) 5205 and then In_Instance 5206 and then not Comes_From_Source (N) 5207 and then Nkind (Subtype_Indication (N)) /= N_Subtype_Indication 5208 and then Is_Frozen (T) 5209 then 5210 Freeze_Before (N, Id); 5211 end if; 5212 5213 Set_Optimize_Alignment_Flags (Id); 5214 Check_Eliminated (Id); 5215 5216 <<Leave>> 5217 if Has_Aspects (N) then 5218 Analyze_Aspect_Specifications (N, Id); 5219 end if; 5220 5221 Analyze_Dimension (N); 5222 end Analyze_Subtype_Declaration; 5223 5224 -------------------------------- 5225 -- Analyze_Subtype_Indication -- 5226 -------------------------------- 5227 5228 procedure Analyze_Subtype_Indication (N : Node_Id) is 5229 T : constant Entity_Id := Subtype_Mark (N); 5230 R : constant Node_Id := Range_Expression (Constraint (N)); 5231 5232 begin 5233 Analyze (T); 5234 5235 if R /= Error then 5236 Analyze (R); 5237 Set_Etype (N, Etype (R)); 5238 Resolve (R, Entity (T)); 5239 else 5240 Set_Error_Posted (R); 5241 Set_Error_Posted (T); 5242 end if; 5243 end Analyze_Subtype_Indication; 5244 5245 -------------------------- 5246 -- Analyze_Variant_Part -- 5247 -------------------------- 5248 5249 procedure Analyze_Variant_Part (N : Node_Id) is 5250 Discr_Name : Node_Id; 5251 Discr_Type : Entity_Id; 5252 5253 procedure Process_Variant (A : Node_Id); 5254 -- Analyze declarations for a single variant 5255 5256 package Analyze_Variant_Choices is 5257 new Generic_Analyze_Choices (Process_Variant); 5258 use Analyze_Variant_Choices; 5259 5260 --------------------- 5261 -- Process_Variant -- 5262 --------------------- 5263 5264 procedure Process_Variant (A : Node_Id) is 5265 CL : constant Node_Id := Component_List (A); 5266 begin 5267 if not Null_Present (CL) then 5268 Analyze_Declarations (Component_Items (CL)); 5269 5270 if Present (Variant_Part (CL)) then 5271 Analyze (Variant_Part (CL)); 5272 end if; 5273 end if; 5274 end Process_Variant; 5275 5276 -- Start of processing for Analyze_Variant_Part 5277 5278 begin 5279 Discr_Name := Name (N); 5280 Analyze (Discr_Name); 5281 5282 -- If Discr_Name bad, get out (prevent cascaded errors) 5283 5284 if Etype (Discr_Name) = Any_Type then 5285 return; 5286 end if; 5287 5288 -- Check invalid discriminant in variant part 5289 5290 if Ekind (Entity (Discr_Name)) /= E_Discriminant then 5291 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name); 5292 end if; 5293 5294 Discr_Type := Etype (Entity (Discr_Name)); 5295 5296 if not Is_Discrete_Type (Discr_Type) then 5297 Error_Msg_N 5298 ("discriminant in a variant part must be of a discrete type", 5299 Name (N)); 5300 return; 5301 end if; 5302 5303 -- Now analyze the choices, which also analyzes the declarations that 5304 -- are associated with each choice. 5305 5306 Analyze_Choices (Variants (N), Discr_Type); 5307 5308 -- Note: we used to instantiate and call Check_Choices here to check 5309 -- that the choices covered the discriminant, but it's too early to do 5310 -- that because of statically predicated subtypes, whose analysis may 5311 -- be deferred to their freeze point which may be as late as the freeze 5312 -- point of the containing record. So this call is now to be found in 5313 -- Freeze_Record_Declaration. 5314 5315 end Analyze_Variant_Part; 5316 5317 ---------------------------- 5318 -- Array_Type_Declaration -- 5319 ---------------------------- 5320 5321 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is 5322 Component_Def : constant Node_Id := Component_Definition (Def); 5323 Component_Typ : constant Node_Id := Subtype_Indication (Component_Def); 5324 Element_Type : Entity_Id; 5325 Implicit_Base : Entity_Id; 5326 Index : Node_Id; 5327 Related_Id : Entity_Id := Empty; 5328 Nb_Index : Nat; 5329 P : constant Node_Id := Parent (Def); 5330 Priv : Entity_Id; 5331 5332 begin 5333 if Nkind (Def) = N_Constrained_Array_Definition then 5334 Index := First (Discrete_Subtype_Definitions (Def)); 5335 else 5336 Index := First (Subtype_Marks (Def)); 5337 end if; 5338 5339 -- Find proper names for the implicit types which may be public. In case 5340 -- of anonymous arrays we use the name of the first object of that type 5341 -- as prefix. 5342 5343 if No (T) then 5344 Related_Id := Defining_Identifier (P); 5345 else 5346 Related_Id := T; 5347 end if; 5348 5349 Nb_Index := 1; 5350 while Present (Index) loop 5351 Analyze (Index); 5352 5353 -- Test for odd case of trying to index a type by the type itself 5354 5355 if Is_Entity_Name (Index) and then Entity (Index) = T then 5356 Error_Msg_N ("type& cannot be indexed by itself", Index); 5357 Set_Entity (Index, Standard_Boolean); 5358 Set_Etype (Index, Standard_Boolean); 5359 end if; 5360 5361 -- Check SPARK restriction requiring a subtype mark 5362 5363 if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then 5364 Check_SPARK_05_Restriction ("subtype mark required", Index); 5365 end if; 5366 5367 -- Add a subtype declaration for each index of private array type 5368 -- declaration whose etype is also private. For example: 5369 5370 -- package Pkg is 5371 -- type Index is private; 5372 -- private 5373 -- type Table is array (Index) of ... 5374 -- end; 5375 5376 -- This is currently required by the expander for the internally 5377 -- generated equality subprogram of records with variant parts in 5378 -- which the etype of some component is such private type. 5379 5380 if Ekind (Current_Scope) = E_Package 5381 and then In_Private_Part (Current_Scope) 5382 and then Has_Private_Declaration (Etype (Index)) 5383 then 5384 declare 5385 Loc : constant Source_Ptr := Sloc (Def); 5386 New_E : Entity_Id; 5387 Decl : Entity_Id; 5388 5389 begin 5390 New_E := Make_Temporary (Loc, 'T'); 5391 Set_Is_Internal (New_E); 5392 5393 Decl := 5394 Make_Subtype_Declaration (Loc, 5395 Defining_Identifier => New_E, 5396 Subtype_Indication => 5397 New_Occurrence_Of (Etype (Index), Loc)); 5398 5399 Insert_Before (Parent (Def), Decl); 5400 Analyze (Decl); 5401 Set_Etype (Index, New_E); 5402 5403 -- If the index is a range the Entity attribute is not 5404 -- available. Example: 5405 5406 -- package Pkg is 5407 -- type T is private; 5408 -- private 5409 -- type T is new Natural; 5410 -- Table : array (T(1) .. T(10)) of Boolean; 5411 -- end Pkg; 5412 5413 if Nkind (Index) /= N_Range then 5414 Set_Entity (Index, New_E); 5415 end if; 5416 end; 5417 end if; 5418 5419 Make_Index (Index, P, Related_Id, Nb_Index); 5420 5421 -- Check error of subtype with predicate for index type 5422 5423 Bad_Predicated_Subtype_Use 5424 ("subtype& has predicate, not allowed as index subtype", 5425 Index, Etype (Index)); 5426 5427 -- Move to next index 5428 5429 Next_Index (Index); 5430 Nb_Index := Nb_Index + 1; 5431 end loop; 5432 5433 -- Process subtype indication if one is present 5434 5435 if Present (Component_Typ) then 5436 Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C'); 5437 5438 Set_Etype (Component_Typ, Element_Type); 5439 5440 if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then 5441 Check_SPARK_05_Restriction 5442 ("subtype mark required", Component_Typ); 5443 end if; 5444 5445 -- Ada 2005 (AI-230): Access Definition case 5446 5447 else pragma Assert (Present (Access_Definition (Component_Def))); 5448 5449 -- Indicate that the anonymous access type is created by the 5450 -- array type declaration. 5451 5452 Element_Type := Access_Definition 5453 (Related_Nod => P, 5454 N => Access_Definition (Component_Def)); 5455 Set_Is_Local_Anonymous_Access (Element_Type); 5456 5457 -- Propagate the parent. This field is needed if we have to generate 5458 -- the master_id associated with an anonymous access to task type 5459 -- component (see Expand_N_Full_Type_Declaration.Build_Master) 5460 5461 Set_Parent (Element_Type, Parent (T)); 5462 5463 -- Ada 2005 (AI-230): In case of components that are anonymous access 5464 -- types the level of accessibility depends on the enclosing type 5465 -- declaration 5466 5467 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230) 5468 5469 -- Ada 2005 (AI-254) 5470 5471 declare 5472 CD : constant Node_Id := 5473 Access_To_Subprogram_Definition 5474 (Access_Definition (Component_Def)); 5475 begin 5476 if Present (CD) and then Protected_Present (CD) then 5477 Element_Type := 5478 Replace_Anonymous_Access_To_Protected_Subprogram (Def); 5479 end if; 5480 end; 5481 end if; 5482 5483 -- Constrained array case 5484 5485 if No (T) then 5486 T := Create_Itype (E_Void, P, Related_Id, 'T'); 5487 end if; 5488 5489 if Nkind (Def) = N_Constrained_Array_Definition then 5490 5491 -- Establish Implicit_Base as unconstrained base type 5492 5493 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B'); 5494 5495 Set_Etype (Implicit_Base, Implicit_Base); 5496 Set_Scope (Implicit_Base, Current_Scope); 5497 Set_Has_Delayed_Freeze (Implicit_Base); 5498 Set_Default_SSO (Implicit_Base); 5499 5500 -- The constrained array type is a subtype of the unconstrained one 5501 5502 Set_Ekind (T, E_Array_Subtype); 5503 Init_Size_Align (T); 5504 Set_Etype (T, Implicit_Base); 5505 Set_Scope (T, Current_Scope); 5506 Set_Is_Constrained (T); 5507 Set_First_Index (T, 5508 First (Discrete_Subtype_Definitions (Def))); 5509 Set_Has_Delayed_Freeze (T); 5510 5511 -- Complete setup of implicit base type 5512 5513 Set_First_Index (Implicit_Base, First_Index (T)); 5514 Set_Component_Type (Implicit_Base, Element_Type); 5515 Set_Has_Task (Implicit_Base, Has_Task (Element_Type)); 5516 Set_Has_Protected (Implicit_Base, Has_Protected (Element_Type)); 5517 Set_Component_Size (Implicit_Base, Uint_0); 5518 Set_Packed_Array_Impl_Type (Implicit_Base, Empty); 5519 Set_Has_Controlled_Component (Implicit_Base, 5520 Has_Controlled_Component (Element_Type) 5521 or else Is_Controlled (Element_Type)); 5522 Set_Finalize_Storage_Only (Implicit_Base, 5523 Finalize_Storage_Only (Element_Type)); 5524 5525 -- Inherit the "ghostness" from the constrained array type 5526 5527 if Is_Ghost_Entity (T) or else Ghost_Mode > None then 5528 Set_Is_Ghost_Entity (Implicit_Base); 5529 end if; 5530 5531 -- Unconstrained array case 5532 5533 else 5534 Set_Ekind (T, E_Array_Type); 5535 Init_Size_Align (T); 5536 Set_Etype (T, T); 5537 Set_Scope (T, Current_Scope); 5538 Set_Component_Size (T, Uint_0); 5539 Set_Is_Constrained (T, False); 5540 Set_First_Index (T, First (Subtype_Marks (Def))); 5541 Set_Has_Delayed_Freeze (T, True); 5542 Set_Has_Task (T, Has_Task (Element_Type)); 5543 Set_Has_Protected (T, Has_Protected (Element_Type)); 5544 Set_Has_Controlled_Component (T, Has_Controlled_Component 5545 (Element_Type) 5546 or else 5547 Is_Controlled (Element_Type)); 5548 Set_Finalize_Storage_Only (T, Finalize_Storage_Only 5549 (Element_Type)); 5550 Set_Default_SSO (T); 5551 end if; 5552 5553 -- Common attributes for both cases 5554 5555 Set_Component_Type (Base_Type (T), Element_Type); 5556 Set_Packed_Array_Impl_Type (T, Empty); 5557 5558 if Aliased_Present (Component_Definition (Def)) then 5559 Check_SPARK_05_Restriction 5560 ("aliased is not allowed", Component_Definition (Def)); 5561 Set_Has_Aliased_Components (Etype (T)); 5562 end if; 5563 5564 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the 5565 -- array type to ensure that objects of this type are initialized. 5566 5567 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (Element_Type) then 5568 Set_Can_Never_Be_Null (T); 5569 5570 if Null_Exclusion_Present (Component_Definition (Def)) 5571 5572 -- No need to check itypes because in their case this check was 5573 -- done at their point of creation 5574 5575 and then not Is_Itype (Element_Type) 5576 then 5577 Error_Msg_N 5578 ("`NOT NULL` not allowed (null already excluded)", 5579 Subtype_Indication (Component_Definition (Def))); 5580 end if; 5581 end if; 5582 5583 Priv := Private_Component (Element_Type); 5584 5585 if Present (Priv) then 5586 5587 -- Check for circular definitions 5588 5589 if Priv = Any_Type then 5590 Set_Component_Type (Etype (T), Any_Type); 5591 5592 -- There is a gap in the visibility of operations on the composite 5593 -- type only if the component type is defined in a different scope. 5594 5595 elsif Scope (Priv) = Current_Scope then 5596 null; 5597 5598 elsif Is_Limited_Type (Priv) then 5599 Set_Is_Limited_Composite (Etype (T)); 5600 Set_Is_Limited_Composite (T); 5601 else 5602 Set_Is_Private_Composite (Etype (T)); 5603 Set_Is_Private_Composite (T); 5604 end if; 5605 end if; 5606 5607 -- A syntax error in the declaration itself may lead to an empty index 5608 -- list, in which case do a minimal patch. 5609 5610 if No (First_Index (T)) then 5611 Error_Msg_N ("missing index definition in array type declaration", T); 5612 5613 declare 5614 Indexes : constant List_Id := 5615 New_List (New_Occurrence_Of (Any_Id, Sloc (T))); 5616 begin 5617 Set_Discrete_Subtype_Definitions (Def, Indexes); 5618 Set_First_Index (T, First (Indexes)); 5619 return; 5620 end; 5621 end if; 5622 5623 -- Create a concatenation operator for the new type. Internal array 5624 -- types created for packed entities do not need such, they are 5625 -- compatible with the user-defined type. 5626 5627 if Number_Dimensions (T) = 1 5628 and then not Is_Packed_Array_Impl_Type (T) 5629 then 5630 New_Concatenation_Op (T); 5631 end if; 5632 5633 -- In the case of an unconstrained array the parser has already verified 5634 -- that all the indexes are unconstrained but we still need to make sure 5635 -- that the element type is constrained. 5636 5637 if Is_Indefinite_Subtype (Element_Type) then 5638 Error_Msg_N 5639 ("unconstrained element type in array declaration", 5640 Subtype_Indication (Component_Def)); 5641 5642 elsif Is_Abstract_Type (Element_Type) then 5643 Error_Msg_N 5644 ("the type of a component cannot be abstract", 5645 Subtype_Indication (Component_Def)); 5646 end if; 5647 5648 -- There may be an invariant declared for the component type, but 5649 -- the construction of the component invariant checking procedure 5650 -- takes place during expansion. 5651 end Array_Type_Declaration; 5652 5653 ------------------------------------------------------ 5654 -- Replace_Anonymous_Access_To_Protected_Subprogram -- 5655 ------------------------------------------------------ 5656 5657 function Replace_Anonymous_Access_To_Protected_Subprogram 5658 (N : Node_Id) return Entity_Id 5659 is 5660 Loc : constant Source_Ptr := Sloc (N); 5661 5662 Curr_Scope : constant Scope_Stack_Entry := 5663 Scope_Stack.Table (Scope_Stack.Last); 5664 5665 Anon : constant Entity_Id := Make_Temporary (Loc, 'S'); 5666 5667 Acc : Node_Id; 5668 -- Access definition in declaration 5669 5670 Comp : Node_Id; 5671 -- Object definition or formal definition with an access definition 5672 5673 Decl : Node_Id; 5674 -- Declaration of anonymous access to subprogram type 5675 5676 Spec : Node_Id; 5677 -- Original specification in access to subprogram 5678 5679 P : Node_Id; 5680 5681 begin 5682 Set_Is_Internal (Anon); 5683 5684 case Nkind (N) is 5685 when N_Component_Declaration | 5686 N_Unconstrained_Array_Definition | 5687 N_Constrained_Array_Definition => 5688 Comp := Component_Definition (N); 5689 Acc := Access_Definition (Comp); 5690 5691 when N_Discriminant_Specification => 5692 Comp := Discriminant_Type (N); 5693 Acc := Comp; 5694 5695 when N_Parameter_Specification => 5696 Comp := Parameter_Type (N); 5697 Acc := Comp; 5698 5699 when N_Access_Function_Definition => 5700 Comp := Result_Definition (N); 5701 Acc := Comp; 5702 5703 when N_Object_Declaration => 5704 Comp := Object_Definition (N); 5705 Acc := Comp; 5706 5707 when N_Function_Specification => 5708 Comp := Result_Definition (N); 5709 Acc := Comp; 5710 5711 when others => 5712 raise Program_Error; 5713 end case; 5714 5715 Spec := Access_To_Subprogram_Definition (Acc); 5716 5717 Decl := 5718 Make_Full_Type_Declaration (Loc, 5719 Defining_Identifier => Anon, 5720 Type_Definition => Copy_Separate_Tree (Spec)); 5721 5722 Mark_Rewrite_Insertion (Decl); 5723 5724 -- In ASIS mode, analyze the profile on the original node, because 5725 -- the separate copy does not provide enough links to recover the 5726 -- original tree. Analysis is limited to type annotations, within 5727 -- a temporary scope that serves as an anonymous subprogram to collect 5728 -- otherwise useless temporaries and itypes. 5729 5730 if ASIS_Mode then 5731 declare 5732 Typ : constant Entity_Id := Make_Temporary (Loc, 'S'); 5733 5734 begin 5735 if Nkind (Spec) = N_Access_Function_Definition then 5736 Set_Ekind (Typ, E_Function); 5737 else 5738 Set_Ekind (Typ, E_Procedure); 5739 end if; 5740 5741 Set_Parent (Typ, N); 5742 Set_Scope (Typ, Current_Scope); 5743 Push_Scope (Typ); 5744 5745 Process_Formals (Parameter_Specifications (Spec), Spec); 5746 5747 if Nkind (Spec) = N_Access_Function_Definition then 5748 declare 5749 Def : constant Node_Id := Result_Definition (Spec); 5750 5751 begin 5752 -- The result might itself be an anonymous access type, so 5753 -- have to recurse. 5754 5755 if Nkind (Def) = N_Access_Definition then 5756 if Present (Access_To_Subprogram_Definition (Def)) then 5757 Set_Etype 5758 (Def, 5759 Replace_Anonymous_Access_To_Protected_Subprogram 5760 (Spec)); 5761 else 5762 Find_Type (Subtype_Mark (Def)); 5763 end if; 5764 5765 else 5766 Find_Type (Def); 5767 end if; 5768 end; 5769 end if; 5770 5771 End_Scope; 5772 end; 5773 end if; 5774 5775 -- Insert the new declaration in the nearest enclosing scope. If the 5776 -- node is a body and N is its return type, the declaration belongs in 5777 -- the enclosing scope. 5778 5779 P := Parent (N); 5780 5781 if Nkind (P) = N_Subprogram_Body 5782 and then Nkind (N) = N_Function_Specification 5783 then 5784 P := Parent (P); 5785 end if; 5786 5787 while Present (P) and then not Has_Declarations (P) loop 5788 P := Parent (P); 5789 end loop; 5790 5791 pragma Assert (Present (P)); 5792 5793 if Nkind (P) = N_Package_Specification then 5794 Prepend (Decl, Visible_Declarations (P)); 5795 else 5796 Prepend (Decl, Declarations (P)); 5797 end if; 5798 5799 -- Replace the anonymous type with an occurrence of the new declaration. 5800 -- In all cases the rewritten node does not have the null-exclusion 5801 -- attribute because (if present) it was already inherited by the 5802 -- anonymous entity (Anon). Thus, in case of components we do not 5803 -- inherit this attribute. 5804 5805 if Nkind (N) = N_Parameter_Specification then 5806 Rewrite (Comp, New_Occurrence_Of (Anon, Loc)); 5807 Set_Etype (Defining_Identifier (N), Anon); 5808 Set_Null_Exclusion_Present (N, False); 5809 5810 elsif Nkind (N) = N_Object_Declaration then 5811 Rewrite (Comp, New_Occurrence_Of (Anon, Loc)); 5812 Set_Etype (Defining_Identifier (N), Anon); 5813 5814 elsif Nkind (N) = N_Access_Function_Definition then 5815 Rewrite (Comp, New_Occurrence_Of (Anon, Loc)); 5816 5817 elsif Nkind (N) = N_Function_Specification then 5818 Rewrite (Comp, New_Occurrence_Of (Anon, Loc)); 5819 Set_Etype (Defining_Unit_Name (N), Anon); 5820 5821 else 5822 Rewrite (Comp, 5823 Make_Component_Definition (Loc, 5824 Subtype_Indication => New_Occurrence_Of (Anon, Loc))); 5825 end if; 5826 5827 Mark_Rewrite_Insertion (Comp); 5828 5829 if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition) then 5830 Analyze (Decl); 5831 5832 else 5833 -- Temporarily remove the current scope (record or subprogram) from 5834 -- the stack to add the new declarations to the enclosing scope. 5835 5836 Scope_Stack.Decrement_Last; 5837 Analyze (Decl); 5838 Set_Is_Itype (Anon); 5839 Scope_Stack.Append (Curr_Scope); 5840 end if; 5841 5842 Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type); 5843 Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target); 5844 return Anon; 5845 end Replace_Anonymous_Access_To_Protected_Subprogram; 5846 5847 ------------------------------- 5848 -- Build_Derived_Access_Type -- 5849 ------------------------------- 5850 5851 procedure Build_Derived_Access_Type 5852 (N : Node_Id; 5853 Parent_Type : Entity_Id; 5854 Derived_Type : Entity_Id) 5855 is 5856 S : constant Node_Id := Subtype_Indication (Type_Definition (N)); 5857 5858 Desig_Type : Entity_Id; 5859 Discr : Entity_Id; 5860 Discr_Con_Elist : Elist_Id; 5861 Discr_Con_El : Elmt_Id; 5862 Subt : Entity_Id; 5863 5864 begin 5865 -- Set the designated type so it is available in case this is an access 5866 -- to a self-referential type, e.g. a standard list type with a next 5867 -- pointer. Will be reset after subtype is built. 5868 5869 Set_Directly_Designated_Type 5870 (Derived_Type, Designated_Type (Parent_Type)); 5871 5872 Subt := Process_Subtype (S, N); 5873 5874 if Nkind (S) /= N_Subtype_Indication 5875 and then Subt /= Base_Type (Subt) 5876 then 5877 Set_Ekind (Derived_Type, E_Access_Subtype); 5878 end if; 5879 5880 if Ekind (Derived_Type) = E_Access_Subtype then 5881 declare 5882 Pbase : constant Entity_Id := Base_Type (Parent_Type); 5883 Ibase : constant Entity_Id := 5884 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B'); 5885 Svg_Chars : constant Name_Id := Chars (Ibase); 5886 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase); 5887 5888 begin 5889 Copy_Node (Pbase, Ibase); 5890 5891 Set_Chars (Ibase, Svg_Chars); 5892 Set_Next_Entity (Ibase, Svg_Next_E); 5893 Set_Sloc (Ibase, Sloc (Derived_Type)); 5894 Set_Scope (Ibase, Scope (Derived_Type)); 5895 Set_Freeze_Node (Ibase, Empty); 5896 Set_Is_Frozen (Ibase, False); 5897 Set_Comes_From_Source (Ibase, False); 5898 Set_Is_First_Subtype (Ibase, False); 5899 5900 Set_Etype (Ibase, Pbase); 5901 Set_Etype (Derived_Type, Ibase); 5902 end; 5903 end if; 5904 5905 Set_Directly_Designated_Type 5906 (Derived_Type, Designated_Type (Subt)); 5907 5908 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt)); 5909 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type)); 5910 Set_Size_Info (Derived_Type, Parent_Type); 5911 Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); 5912 Set_Depends_On_Private (Derived_Type, 5913 Has_Private_Component (Derived_Type)); 5914 Conditional_Delay (Derived_Type, Subt); 5915 5916 -- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify 5917 -- that it is not redundant. 5918 5919 if Null_Exclusion_Present (Type_Definition (N)) then 5920 Set_Can_Never_Be_Null (Derived_Type); 5921 5922 -- What is with the "AND THEN FALSE" here ??? 5923 5924 if Can_Never_Be_Null (Parent_Type) 5925 and then False 5926 then 5927 Error_Msg_NE 5928 ("`NOT NULL` not allowed (& already excludes null)", 5929 N, Parent_Type); 5930 end if; 5931 5932 elsif Can_Never_Be_Null (Parent_Type) then 5933 Set_Can_Never_Be_Null (Derived_Type); 5934 end if; 5935 5936 -- Note: we do not copy the Storage_Size_Variable, since we always go to 5937 -- the root type for this information. 5938 5939 -- Apply range checks to discriminants for derived record case 5940 -- ??? THIS CODE SHOULD NOT BE HERE REALLY. 5941 5942 Desig_Type := Designated_Type (Derived_Type); 5943 if Is_Composite_Type (Desig_Type) 5944 and then (not Is_Array_Type (Desig_Type)) 5945 and then Has_Discriminants (Desig_Type) 5946 and then Base_Type (Desig_Type) /= Desig_Type 5947 then 5948 Discr_Con_Elist := Discriminant_Constraint (Desig_Type); 5949 Discr_Con_El := First_Elmt (Discr_Con_Elist); 5950 5951 Discr := First_Discriminant (Base_Type (Desig_Type)); 5952 while Present (Discr_Con_El) loop 5953 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr)); 5954 Next_Elmt (Discr_Con_El); 5955 Next_Discriminant (Discr); 5956 end loop; 5957 end if; 5958 end Build_Derived_Access_Type; 5959 5960 ------------------------------ 5961 -- Build_Derived_Array_Type -- 5962 ------------------------------ 5963 5964 procedure Build_Derived_Array_Type 5965 (N : Node_Id; 5966 Parent_Type : Entity_Id; 5967 Derived_Type : Entity_Id) 5968 is 5969 Loc : constant Source_Ptr := Sloc (N); 5970 Tdef : constant Node_Id := Type_Definition (N); 5971 Indic : constant Node_Id := Subtype_Indication (Tdef); 5972 Parent_Base : constant Entity_Id := Base_Type (Parent_Type); 5973 Implicit_Base : Entity_Id; 5974 New_Indic : Node_Id; 5975 5976 procedure Make_Implicit_Base; 5977 -- If the parent subtype is constrained, the derived type is a subtype 5978 -- of an implicit base type derived from the parent base. 5979 5980 ------------------------ 5981 -- Make_Implicit_Base -- 5982 ------------------------ 5983 5984 procedure Make_Implicit_Base is 5985 begin 5986 Implicit_Base := 5987 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B'); 5988 5989 Set_Ekind (Implicit_Base, Ekind (Parent_Base)); 5990 Set_Etype (Implicit_Base, Parent_Base); 5991 5992 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base); 5993 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base); 5994 5995 Set_Has_Delayed_Freeze (Implicit_Base, True); 5996 5997 -- Inherit the "ghostness" from the parent base type 5998 5999 if Is_Ghost_Entity (Parent_Base) or else Ghost_Mode > None then 6000 Set_Is_Ghost_Entity (Implicit_Base); 6001 end if; 6002 end Make_Implicit_Base; 6003 6004 -- Start of processing for Build_Derived_Array_Type 6005 6006 begin 6007 if not Is_Constrained (Parent_Type) then 6008 if Nkind (Indic) /= N_Subtype_Indication then 6009 Set_Ekind (Derived_Type, E_Array_Type); 6010 6011 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type); 6012 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type); 6013 6014 Set_Has_Delayed_Freeze (Derived_Type, True); 6015 6016 else 6017 Make_Implicit_Base; 6018 Set_Etype (Derived_Type, Implicit_Base); 6019 6020 New_Indic := 6021 Make_Subtype_Declaration (Loc, 6022 Defining_Identifier => Derived_Type, 6023 Subtype_Indication => 6024 Make_Subtype_Indication (Loc, 6025 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc), 6026 Constraint => Constraint (Indic))); 6027 6028 Rewrite (N, New_Indic); 6029 Analyze (N); 6030 end if; 6031 6032 else 6033 if Nkind (Indic) /= N_Subtype_Indication then 6034 Make_Implicit_Base; 6035 6036 Set_Ekind (Derived_Type, Ekind (Parent_Type)); 6037 Set_Etype (Derived_Type, Implicit_Base); 6038 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type); 6039 6040 else 6041 Error_Msg_N ("illegal constraint on constrained type", Indic); 6042 end if; 6043 end if; 6044 6045 -- If parent type is not a derived type itself, and is declared in 6046 -- closed scope (e.g. a subprogram), then we must explicitly introduce 6047 -- the new type's concatenation operator since Derive_Subprograms 6048 -- will not inherit the parent's operator. If the parent type is 6049 -- unconstrained, the operator is of the unconstrained base type. 6050 6051 if Number_Dimensions (Parent_Type) = 1 6052 and then not Is_Limited_Type (Parent_Type) 6053 and then not Is_Derived_Type (Parent_Type) 6054 and then not Is_Package_Or_Generic_Package 6055 (Scope (Base_Type (Parent_Type))) 6056 then 6057 if not Is_Constrained (Parent_Type) 6058 and then Is_Constrained (Derived_Type) 6059 then 6060 New_Concatenation_Op (Implicit_Base); 6061 else 6062 New_Concatenation_Op (Derived_Type); 6063 end if; 6064 end if; 6065 end Build_Derived_Array_Type; 6066 6067 ----------------------------------- 6068 -- Build_Derived_Concurrent_Type -- 6069 ----------------------------------- 6070 6071 procedure Build_Derived_Concurrent_Type 6072 (N : Node_Id; 6073 Parent_Type : Entity_Id; 6074 Derived_Type : Entity_Id) 6075 is 6076 Loc : constant Source_Ptr := Sloc (N); 6077 6078 Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C'); 6079 Corr_Decl : Node_Id; 6080 Corr_Decl_Needed : Boolean; 6081 -- If the derived type has fewer discriminants than its parent, the 6082 -- corresponding record is also a derived type, in order to account for 6083 -- the bound discriminants. We create a full type declaration for it in 6084 -- this case. 6085 6086 Constraint_Present : constant Boolean := 6087 Nkind (Subtype_Indication (Type_Definition (N))) = 6088 N_Subtype_Indication; 6089 6090 D_Constraint : Node_Id; 6091 New_Constraint : Elist_Id; 6092 Old_Disc : Entity_Id; 6093 New_Disc : Entity_Id; 6094 New_N : Node_Id; 6095 6096 begin 6097 Set_Stored_Constraint (Derived_Type, No_Elist); 6098 Corr_Decl_Needed := False; 6099 Old_Disc := Empty; 6100 6101 if Present (Discriminant_Specifications (N)) 6102 and then Constraint_Present 6103 then 6104 Old_Disc := First_Discriminant (Parent_Type); 6105 New_Disc := First (Discriminant_Specifications (N)); 6106 while Present (New_Disc) and then Present (Old_Disc) loop 6107 Next_Discriminant (Old_Disc); 6108 Next (New_Disc); 6109 end loop; 6110 end if; 6111 6112 if Present (Old_Disc) and then Expander_Active then 6113 6114 -- The new type has fewer discriminants, so we need to create a new 6115 -- corresponding record, which is derived from the corresponding 6116 -- record of the parent, and has a stored constraint that captures 6117 -- the values of the discriminant constraints. The corresponding 6118 -- record is needed only if expander is active and code generation is 6119 -- enabled. 6120 6121 -- The type declaration for the derived corresponding record has the 6122 -- same discriminant part and constraints as the current declaration. 6123 -- Copy the unanalyzed tree to build declaration. 6124 6125 Corr_Decl_Needed := True; 6126 New_N := Copy_Separate_Tree (N); 6127 6128 Corr_Decl := 6129 Make_Full_Type_Declaration (Loc, 6130 Defining_Identifier => Corr_Record, 6131 Discriminant_Specifications => 6132 Discriminant_Specifications (New_N), 6133 Type_Definition => 6134 Make_Derived_Type_Definition (Loc, 6135 Subtype_Indication => 6136 Make_Subtype_Indication (Loc, 6137 Subtype_Mark => 6138 New_Occurrence_Of 6139 (Corresponding_Record_Type (Parent_Type), Loc), 6140 Constraint => 6141 Constraint 6142 (Subtype_Indication (Type_Definition (New_N)))))); 6143 end if; 6144 6145 -- Copy Storage_Size and Relative_Deadline variables if task case 6146 6147 if Is_Task_Type (Parent_Type) then 6148 Set_Storage_Size_Variable (Derived_Type, 6149 Storage_Size_Variable (Parent_Type)); 6150 Set_Relative_Deadline_Variable (Derived_Type, 6151 Relative_Deadline_Variable (Parent_Type)); 6152 end if; 6153 6154 if Present (Discriminant_Specifications (N)) then 6155 Push_Scope (Derived_Type); 6156 Check_Or_Process_Discriminants (N, Derived_Type); 6157 6158 if Constraint_Present then 6159 New_Constraint := 6160 Expand_To_Stored_Constraint 6161 (Parent_Type, 6162 Build_Discriminant_Constraints 6163 (Parent_Type, 6164 Subtype_Indication (Type_Definition (N)), True)); 6165 end if; 6166 6167 End_Scope; 6168 6169 elsif Constraint_Present then 6170 6171 -- Build constrained subtype, copying the constraint, and derive 6172 -- from it to create a derived constrained type. 6173 6174 declare 6175 Loc : constant Source_Ptr := Sloc (N); 6176 Anon : constant Entity_Id := 6177 Make_Defining_Identifier (Loc, 6178 Chars => New_External_Name (Chars (Derived_Type), 'T')); 6179 Decl : Node_Id; 6180 6181 begin 6182 Decl := 6183 Make_Subtype_Declaration (Loc, 6184 Defining_Identifier => Anon, 6185 Subtype_Indication => 6186 New_Copy_Tree (Subtype_Indication (Type_Definition (N)))); 6187 Insert_Before (N, Decl); 6188 Analyze (Decl); 6189 6190 Rewrite (Subtype_Indication (Type_Definition (N)), 6191 New_Occurrence_Of (Anon, Loc)); 6192 Set_Analyzed (Derived_Type, False); 6193 Analyze (N); 6194 return; 6195 end; 6196 end if; 6197 6198 -- By default, operations and private data are inherited from parent. 6199 -- However, in the presence of bound discriminants, a new corresponding 6200 -- record will be created, see below. 6201 6202 Set_Has_Discriminants 6203 (Derived_Type, Has_Discriminants (Parent_Type)); 6204 Set_Corresponding_Record_Type 6205 (Derived_Type, Corresponding_Record_Type (Parent_Type)); 6206 6207 -- Is_Constrained is set according the parent subtype, but is set to 6208 -- False if the derived type is declared with new discriminants. 6209 6210 Set_Is_Constrained 6211 (Derived_Type, 6212 (Is_Constrained (Parent_Type) or else Constraint_Present) 6213 and then not Present (Discriminant_Specifications (N))); 6214 6215 if Constraint_Present then 6216 if not Has_Discriminants (Parent_Type) then 6217 Error_Msg_N ("untagged parent must have discriminants", N); 6218 6219 elsif Present (Discriminant_Specifications (N)) then 6220 6221 -- Verify that new discriminants are used to constrain old ones 6222 6223 D_Constraint := 6224 First 6225 (Constraints 6226 (Constraint (Subtype_Indication (Type_Definition (N))))); 6227 6228 Old_Disc := First_Discriminant (Parent_Type); 6229 6230 while Present (D_Constraint) loop 6231 if Nkind (D_Constraint) /= N_Discriminant_Association then 6232 6233 -- Positional constraint. If it is a reference to a new 6234 -- discriminant, it constrains the corresponding old one. 6235 6236 if Nkind (D_Constraint) = N_Identifier then 6237 New_Disc := First_Discriminant (Derived_Type); 6238 while Present (New_Disc) loop 6239 exit when Chars (New_Disc) = Chars (D_Constraint); 6240 Next_Discriminant (New_Disc); 6241 end loop; 6242 6243 if Present (New_Disc) then 6244 Set_Corresponding_Discriminant (New_Disc, Old_Disc); 6245 end if; 6246 end if; 6247 6248 Next_Discriminant (Old_Disc); 6249 6250 -- if this is a named constraint, search by name for the old 6251 -- discriminants constrained by the new one. 6252 6253 elsif Nkind (Expression (D_Constraint)) = N_Identifier then 6254 6255 -- Find new discriminant with that name 6256 6257 New_Disc := First_Discriminant (Derived_Type); 6258 while Present (New_Disc) loop 6259 exit when 6260 Chars (New_Disc) = Chars (Expression (D_Constraint)); 6261 Next_Discriminant (New_Disc); 6262 end loop; 6263 6264 if Present (New_Disc) then 6265 6266 -- Verify that new discriminant renames some discriminant 6267 -- of the parent type, and associate the new discriminant 6268 -- with one or more old ones that it renames. 6269 6270 declare 6271 Selector : Node_Id; 6272 6273 begin 6274 Selector := First (Selector_Names (D_Constraint)); 6275 while Present (Selector) loop 6276 Old_Disc := First_Discriminant (Parent_Type); 6277 while Present (Old_Disc) loop 6278 exit when Chars (Old_Disc) = Chars (Selector); 6279 Next_Discriminant (Old_Disc); 6280 end loop; 6281 6282 if Present (Old_Disc) then 6283 Set_Corresponding_Discriminant 6284 (New_Disc, Old_Disc); 6285 end if; 6286 6287 Next (Selector); 6288 end loop; 6289 end; 6290 end if; 6291 end if; 6292 6293 Next (D_Constraint); 6294 end loop; 6295 6296 New_Disc := First_Discriminant (Derived_Type); 6297 while Present (New_Disc) loop 6298 if No (Corresponding_Discriminant (New_Disc)) then 6299 Error_Msg_NE 6300 ("new discriminant& must constrain old one", N, New_Disc); 6301 6302 elsif not 6303 Subtypes_Statically_Compatible 6304 (Etype (New_Disc), 6305 Etype (Corresponding_Discriminant (New_Disc))) 6306 then 6307 Error_Msg_NE 6308 ("& not statically compatible with parent discriminant", 6309 N, New_Disc); 6310 end if; 6311 6312 Next_Discriminant (New_Disc); 6313 end loop; 6314 end if; 6315 6316 elsif Present (Discriminant_Specifications (N)) then 6317 Error_Msg_N 6318 ("missing discriminant constraint in untagged derivation", N); 6319 end if; 6320 6321 -- The entity chain of the derived type includes the new discriminants 6322 -- but shares operations with the parent. 6323 6324 if Present (Discriminant_Specifications (N)) then 6325 Old_Disc := First_Discriminant (Parent_Type); 6326 while Present (Old_Disc) loop 6327 if No (Next_Entity (Old_Disc)) 6328 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant 6329 then 6330 Set_Next_Entity 6331 (Last_Entity (Derived_Type), Next_Entity (Old_Disc)); 6332 exit; 6333 end if; 6334 6335 Next_Discriminant (Old_Disc); 6336 end loop; 6337 6338 else 6339 Set_First_Entity (Derived_Type, First_Entity (Parent_Type)); 6340 if Has_Discriminants (Parent_Type) then 6341 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); 6342 Set_Discriminant_Constraint ( 6343 Derived_Type, Discriminant_Constraint (Parent_Type)); 6344 end if; 6345 end if; 6346 6347 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type)); 6348 6349 Set_Has_Completion (Derived_Type); 6350 6351 if Corr_Decl_Needed then 6352 Set_Stored_Constraint (Derived_Type, New_Constraint); 6353 Insert_After (N, Corr_Decl); 6354 Analyze (Corr_Decl); 6355 Set_Corresponding_Record_Type (Derived_Type, Corr_Record); 6356 end if; 6357 end Build_Derived_Concurrent_Type; 6358 6359 ------------------------------------ 6360 -- Build_Derived_Enumeration_Type -- 6361 ------------------------------------ 6362 6363 procedure Build_Derived_Enumeration_Type 6364 (N : Node_Id; 6365 Parent_Type : Entity_Id; 6366 Derived_Type : Entity_Id) 6367 is 6368 Loc : constant Source_Ptr := Sloc (N); 6369 Def : constant Node_Id := Type_Definition (N); 6370 Indic : constant Node_Id := Subtype_Indication (Def); 6371 Implicit_Base : Entity_Id; 6372 Literal : Entity_Id; 6373 New_Lit : Entity_Id; 6374 Literals_List : List_Id; 6375 Type_Decl : Node_Id; 6376 Hi, Lo : Node_Id; 6377 Rang_Expr : Node_Id; 6378 6379 begin 6380 -- Since types Standard.Character and Standard.[Wide_]Wide_Character do 6381 -- not have explicit literals lists we need to process types derived 6382 -- from them specially. This is handled by Derived_Standard_Character. 6383 -- If the parent type is a generic type, there are no literals either, 6384 -- and we construct the same skeletal representation as for the generic 6385 -- parent type. 6386 6387 if Is_Standard_Character_Type (Parent_Type) then 6388 Derived_Standard_Character (N, Parent_Type, Derived_Type); 6389 6390 elsif Is_Generic_Type (Root_Type (Parent_Type)) then 6391 declare 6392 Lo : Node_Id; 6393 Hi : Node_Id; 6394 6395 begin 6396 if Nkind (Indic) /= N_Subtype_Indication then 6397 Lo := 6398 Make_Attribute_Reference (Loc, 6399 Attribute_Name => Name_First, 6400 Prefix => New_Occurrence_Of (Derived_Type, Loc)); 6401 Set_Etype (Lo, Derived_Type); 6402 6403 Hi := 6404 Make_Attribute_Reference (Loc, 6405 Attribute_Name => Name_Last, 6406 Prefix => New_Occurrence_Of (Derived_Type, Loc)); 6407 Set_Etype (Hi, Derived_Type); 6408 6409 Set_Scalar_Range (Derived_Type, 6410 Make_Range (Loc, 6411 Low_Bound => Lo, 6412 High_Bound => Hi)); 6413 else 6414 6415 -- Analyze subtype indication and verify compatibility 6416 -- with parent type. 6417 6418 if Base_Type (Process_Subtype (Indic, N)) /= 6419 Base_Type (Parent_Type) 6420 then 6421 Error_Msg_N 6422 ("illegal constraint for formal discrete type", N); 6423 end if; 6424 end if; 6425 end; 6426 6427 else 6428 -- If a constraint is present, analyze the bounds to catch 6429 -- premature usage of the derived literals. 6430 6431 if Nkind (Indic) = N_Subtype_Indication 6432 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range 6433 then 6434 Analyze (Low_Bound (Range_Expression (Constraint (Indic)))); 6435 Analyze (High_Bound (Range_Expression (Constraint (Indic)))); 6436 end if; 6437 6438 -- Introduce an implicit base type for the derived type even if there 6439 -- is no constraint attached to it, since this seems closer to the 6440 -- Ada semantics. Build a full type declaration tree for the derived 6441 -- type using the implicit base type as the defining identifier. The 6442 -- build a subtype declaration tree which applies the constraint (if 6443 -- any) have it replace the derived type declaration. 6444 6445 Literal := First_Literal (Parent_Type); 6446 Literals_List := New_List; 6447 while Present (Literal) 6448 and then Ekind (Literal) = E_Enumeration_Literal 6449 loop 6450 -- Literals of the derived type have the same representation as 6451 -- those of the parent type, but this representation can be 6452 -- overridden by an explicit representation clause. Indicate 6453 -- that there is no explicit representation given yet. These 6454 -- derived literals are implicit operations of the new type, 6455 -- and can be overridden by explicit ones. 6456 6457 if Nkind (Literal) = N_Defining_Character_Literal then 6458 New_Lit := 6459 Make_Defining_Character_Literal (Loc, Chars (Literal)); 6460 else 6461 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal)); 6462 end if; 6463 6464 Set_Ekind (New_Lit, E_Enumeration_Literal); 6465 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal)); 6466 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal)); 6467 Set_Enumeration_Rep_Expr (New_Lit, Empty); 6468 Set_Alias (New_Lit, Literal); 6469 Set_Is_Known_Valid (New_Lit, True); 6470 6471 Append (New_Lit, Literals_List); 6472 Next_Literal (Literal); 6473 end loop; 6474 6475 Implicit_Base := 6476 Make_Defining_Identifier (Sloc (Derived_Type), 6477 Chars => New_External_Name (Chars (Derived_Type), 'B')); 6478 6479 -- Indicate the proper nature of the derived type. This must be done 6480 -- before analysis of the literals, to recognize cases when a literal 6481 -- may be hidden by a previous explicit function definition (cf. 6482 -- c83031a). 6483 6484 Set_Ekind (Derived_Type, E_Enumeration_Subtype); 6485 Set_Etype (Derived_Type, Implicit_Base); 6486 6487 Type_Decl := 6488 Make_Full_Type_Declaration (Loc, 6489 Defining_Identifier => Implicit_Base, 6490 Discriminant_Specifications => No_List, 6491 Type_Definition => 6492 Make_Enumeration_Type_Definition (Loc, Literals_List)); 6493 6494 Mark_Rewrite_Insertion (Type_Decl); 6495 Insert_Before (N, Type_Decl); 6496 Analyze (Type_Decl); 6497 6498 -- After the implicit base is analyzed its Etype needs to be changed 6499 -- to reflect the fact that it is derived from the parent type which 6500 -- was ignored during analysis. We also set the size at this point. 6501 6502 Set_Etype (Implicit_Base, Parent_Type); 6503 6504 Set_Size_Info (Implicit_Base, Parent_Type); 6505 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type)); 6506 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type)); 6507 6508 -- Copy other flags from parent type 6509 6510 Set_Has_Non_Standard_Rep 6511 (Implicit_Base, Has_Non_Standard_Rep 6512 (Parent_Type)); 6513 Set_Has_Pragma_Ordered 6514 (Implicit_Base, Has_Pragma_Ordered 6515 (Parent_Type)); 6516 Set_Has_Delayed_Freeze (Implicit_Base); 6517 6518 -- Process the subtype indication including a validation check on the 6519 -- constraint, if any. If a constraint is given, its bounds must be 6520 -- implicitly converted to the new type. 6521 6522 if Nkind (Indic) = N_Subtype_Indication then 6523 declare 6524 R : constant Node_Id := 6525 Range_Expression (Constraint (Indic)); 6526 6527 begin 6528 if Nkind (R) = N_Range then 6529 Hi := Build_Scalar_Bound 6530 (High_Bound (R), Parent_Type, Implicit_Base); 6531 Lo := Build_Scalar_Bound 6532 (Low_Bound (R), Parent_Type, Implicit_Base); 6533 6534 else 6535 -- Constraint is a Range attribute. Replace with explicit 6536 -- mention of the bounds of the prefix, which must be a 6537 -- subtype. 6538 6539 Analyze (Prefix (R)); 6540 Hi := 6541 Convert_To (Implicit_Base, 6542 Make_Attribute_Reference (Loc, 6543 Attribute_Name => Name_Last, 6544 Prefix => 6545 New_Occurrence_Of (Entity (Prefix (R)), Loc))); 6546 6547 Lo := 6548 Convert_To (Implicit_Base, 6549 Make_Attribute_Reference (Loc, 6550 Attribute_Name => Name_First, 6551 Prefix => 6552 New_Occurrence_Of (Entity (Prefix (R)), Loc))); 6553 end if; 6554 end; 6555 6556 else 6557 Hi := 6558 Build_Scalar_Bound 6559 (Type_High_Bound (Parent_Type), 6560 Parent_Type, Implicit_Base); 6561 Lo := 6562 Build_Scalar_Bound 6563 (Type_Low_Bound (Parent_Type), 6564 Parent_Type, Implicit_Base); 6565 end if; 6566 6567 Rang_Expr := 6568 Make_Range (Loc, 6569 Low_Bound => Lo, 6570 High_Bound => Hi); 6571 6572 -- If we constructed a default range for the case where no range 6573 -- was given, then the expressions in the range must not freeze 6574 -- since they do not correspond to expressions in the source. 6575 6576 if Nkind (Indic) /= N_Subtype_Indication then 6577 Set_Must_Not_Freeze (Lo); 6578 Set_Must_Not_Freeze (Hi); 6579 Set_Must_Not_Freeze (Rang_Expr); 6580 end if; 6581 6582 Rewrite (N, 6583 Make_Subtype_Declaration (Loc, 6584 Defining_Identifier => Derived_Type, 6585 Subtype_Indication => 6586 Make_Subtype_Indication (Loc, 6587 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc), 6588 Constraint => 6589 Make_Range_Constraint (Loc, 6590 Range_Expression => Rang_Expr)))); 6591 6592 Analyze (N); 6593 6594 -- Propagate the aspects from the original type declaration to the 6595 -- declaration of the implicit base. 6596 6597 Move_Aspects (From => Original_Node (N), To => Type_Decl); 6598 6599 -- Apply a range check. Since this range expression doesn't have an 6600 -- Etype, we have to specifically pass the Source_Typ parameter. Is 6601 -- this right??? 6602 6603 if Nkind (Indic) = N_Subtype_Indication then 6604 Apply_Range_Check 6605 (Range_Expression (Constraint (Indic)), Parent_Type, 6606 Source_Typ => Entity (Subtype_Mark (Indic))); 6607 end if; 6608 end if; 6609 end Build_Derived_Enumeration_Type; 6610 6611 -------------------------------- 6612 -- Build_Derived_Numeric_Type -- 6613 -------------------------------- 6614 6615 procedure Build_Derived_Numeric_Type 6616 (N : Node_Id; 6617 Parent_Type : Entity_Id; 6618 Derived_Type : Entity_Id) 6619 is 6620 Loc : constant Source_Ptr := Sloc (N); 6621 Tdef : constant Node_Id := Type_Definition (N); 6622 Indic : constant Node_Id := Subtype_Indication (Tdef); 6623 Parent_Base : constant Entity_Id := Base_Type (Parent_Type); 6624 No_Constraint : constant Boolean := Nkind (Indic) /= 6625 N_Subtype_Indication; 6626 Implicit_Base : Entity_Id; 6627 6628 Lo : Node_Id; 6629 Hi : Node_Id; 6630 6631 begin 6632 -- Process the subtype indication including a validation check on 6633 -- the constraint if any. 6634 6635 Discard_Node (Process_Subtype (Indic, N)); 6636 6637 -- Introduce an implicit base type for the derived type even if there 6638 -- is no constraint attached to it, since this seems closer to the Ada 6639 -- semantics. 6640 6641 Implicit_Base := 6642 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B'); 6643 6644 Set_Etype (Implicit_Base, Parent_Base); 6645 Set_Ekind (Implicit_Base, Ekind (Parent_Base)); 6646 Set_Size_Info (Implicit_Base, Parent_Base); 6647 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base)); 6648 Set_Parent (Implicit_Base, Parent (Derived_Type)); 6649 Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base)); 6650 6651 -- Set RM Size for discrete type or decimal fixed-point type 6652 -- Ordinary fixed-point is excluded, why??? 6653 6654 if Is_Discrete_Type (Parent_Base) 6655 or else Is_Decimal_Fixed_Point_Type (Parent_Base) 6656 then 6657 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base)); 6658 end if; 6659 6660 Set_Has_Delayed_Freeze (Implicit_Base); 6661 6662 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base)); 6663 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base)); 6664 6665 Set_Scalar_Range (Implicit_Base, 6666 Make_Range (Loc, 6667 Low_Bound => Lo, 6668 High_Bound => Hi)); 6669 6670 if Has_Infinities (Parent_Base) then 6671 Set_Includes_Infinities (Scalar_Range (Implicit_Base)); 6672 end if; 6673 6674 -- The Derived_Type, which is the entity of the declaration, is a 6675 -- subtype of the implicit base. Its Ekind is a subtype, even in the 6676 -- absence of an explicit constraint. 6677 6678 Set_Etype (Derived_Type, Implicit_Base); 6679 6680 -- If we did not have a constraint, then the Ekind is set from the 6681 -- parent type (otherwise Process_Subtype has set the bounds) 6682 6683 if No_Constraint then 6684 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type))); 6685 end if; 6686 6687 -- If we did not have a range constraint, then set the range from the 6688 -- parent type. Otherwise, the Process_Subtype call has set the bounds. 6689 6690 if No_Constraint or else not Has_Range_Constraint (Indic) then 6691 Set_Scalar_Range (Derived_Type, 6692 Make_Range (Loc, 6693 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)), 6694 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type)))); 6695 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); 6696 6697 if Has_Infinities (Parent_Type) then 6698 Set_Includes_Infinities (Scalar_Range (Derived_Type)); 6699 end if; 6700 6701 Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type)); 6702 end if; 6703 6704 Set_Is_Descendent_Of_Address (Derived_Type, 6705 Is_Descendent_Of_Address (Parent_Type)); 6706 Set_Is_Descendent_Of_Address (Implicit_Base, 6707 Is_Descendent_Of_Address (Parent_Type)); 6708 6709 -- Set remaining type-specific fields, depending on numeric type 6710 6711 if Is_Modular_Integer_Type (Parent_Type) then 6712 Set_Modulus (Implicit_Base, Modulus (Parent_Base)); 6713 6714 Set_Non_Binary_Modulus 6715 (Implicit_Base, Non_Binary_Modulus (Parent_Base)); 6716 6717 Set_Is_Known_Valid 6718 (Implicit_Base, Is_Known_Valid (Parent_Base)); 6719 6720 elsif Is_Floating_Point_Type (Parent_Type) then 6721 6722 -- Digits of base type is always copied from the digits value of 6723 -- the parent base type, but the digits of the derived type will 6724 -- already have been set if there was a constraint present. 6725 6726 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base)); 6727 Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base)); 6728 6729 if No_Constraint then 6730 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type)); 6731 end if; 6732 6733 elsif Is_Fixed_Point_Type (Parent_Type) then 6734 6735 -- Small of base type and derived type are always copied from the 6736 -- parent base type, since smalls never change. The delta of the 6737 -- base type is also copied from the parent base type. However the 6738 -- delta of the derived type will have been set already if a 6739 -- constraint was present. 6740 6741 Set_Small_Value (Derived_Type, Small_Value (Parent_Base)); 6742 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base)); 6743 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base)); 6744 6745 if No_Constraint then 6746 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type)); 6747 end if; 6748 6749 -- The scale and machine radix in the decimal case are always 6750 -- copied from the parent base type. 6751 6752 if Is_Decimal_Fixed_Point_Type (Parent_Type) then 6753 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base)); 6754 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base)); 6755 6756 Set_Machine_Radix_10 6757 (Derived_Type, Machine_Radix_10 (Parent_Base)); 6758 Set_Machine_Radix_10 6759 (Implicit_Base, Machine_Radix_10 (Parent_Base)); 6760 6761 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base)); 6762 6763 if No_Constraint then 6764 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base)); 6765 6766 else 6767 -- the analysis of the subtype_indication sets the 6768 -- digits value of the derived type. 6769 6770 null; 6771 end if; 6772 end if; 6773 end if; 6774 6775 if Is_Integer_Type (Parent_Type) then 6776 Set_Has_Shift_Operator 6777 (Implicit_Base, Has_Shift_Operator (Parent_Type)); 6778 end if; 6779 6780 -- The type of the bounds is that of the parent type, and they 6781 -- must be converted to the derived type. 6782 6783 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc); 6784 6785 -- The implicit_base should be frozen when the derived type is frozen, 6786 -- but note that it is used in the conversions of the bounds. For fixed 6787 -- types we delay the determination of the bounds until the proper 6788 -- freezing point. For other numeric types this is rejected by GCC, for 6789 -- reasons that are currently unclear (???), so we choose to freeze the 6790 -- implicit base now. In the case of integers and floating point types 6791 -- this is harmless because subsequent representation clauses cannot 6792 -- affect anything, but it is still baffling that we cannot use the 6793 -- same mechanism for all derived numeric types. 6794 6795 -- There is a further complication: actually some representation 6796 -- clauses can affect the implicit base type. For example, attribute 6797 -- definition clauses for stream-oriented attributes need to set the 6798 -- corresponding TSS entries on the base type, and this normally 6799 -- cannot be done after the base type is frozen, so the circuitry in 6800 -- Sem_Ch13.New_Stream_Subprogram must account for this possibility 6801 -- and not use Set_TSS in this case. 6802 6803 -- There are also consequences for the case of delayed representation 6804 -- aspects for some cases. For example, a Size aspect is delayed and 6805 -- should not be evaluated to the freeze point. This early freezing 6806 -- means that the size attribute evaluation happens too early??? 6807 6808 if Is_Fixed_Point_Type (Parent_Type) then 6809 Conditional_Delay (Implicit_Base, Parent_Type); 6810 else 6811 Freeze_Before (N, Implicit_Base); 6812 end if; 6813 end Build_Derived_Numeric_Type; 6814 6815 -------------------------------- 6816 -- Build_Derived_Private_Type -- 6817 -------------------------------- 6818 6819 procedure Build_Derived_Private_Type 6820 (N : Node_Id; 6821 Parent_Type : Entity_Id; 6822 Derived_Type : Entity_Id; 6823 Is_Completion : Boolean; 6824 Derive_Subps : Boolean := True) 6825 is 6826 Loc : constant Source_Ptr := Sloc (N); 6827 Par_Base : constant Entity_Id := Base_Type (Parent_Type); 6828 Par_Scope : constant Entity_Id := Scope (Par_Base); 6829 Full_N : constant Node_Id := New_Copy_Tree (N); 6830 Full_Der : Entity_Id := New_Copy (Derived_Type); 6831 Full_P : Entity_Id; 6832 6833 procedure Build_Full_Derivation; 6834 -- Build full derivation, i.e. derive from the full view 6835 6836 procedure Copy_And_Build; 6837 -- Copy derived type declaration, replace parent with its full view, 6838 -- and build derivation 6839 6840 --------------------------- 6841 -- Build_Full_Derivation -- 6842 --------------------------- 6843 6844 procedure Build_Full_Derivation is 6845 begin 6846 -- If parent scope is not open, install the declarations 6847 6848 if not In_Open_Scopes (Par_Scope) then 6849 Install_Private_Declarations (Par_Scope); 6850 Install_Visible_Declarations (Par_Scope); 6851 Copy_And_Build; 6852 Uninstall_Declarations (Par_Scope); 6853 6854 -- If parent scope is open and in another unit, and parent has a 6855 -- completion, then the derivation is taking place in the visible 6856 -- part of a child unit. In that case retrieve the full view of 6857 -- the parent momentarily. 6858 6859 elsif not In_Same_Source_Unit (N, Parent_Type) then 6860 Full_P := Full_View (Parent_Type); 6861 Exchange_Declarations (Parent_Type); 6862 Copy_And_Build; 6863 Exchange_Declarations (Full_P); 6864 6865 -- Otherwise it is a local derivation 6866 6867 else 6868 Copy_And_Build; 6869 end if; 6870 end Build_Full_Derivation; 6871 6872 -------------------- 6873 -- Copy_And_Build -- 6874 -------------------- 6875 6876 procedure Copy_And_Build is 6877 Full_Parent : Entity_Id := Parent_Type; 6878 6879 begin 6880 -- If the parent is itself derived from another private type, 6881 -- installing the private declarations has not affected its 6882 -- privacy status, so use its own full view explicitly. 6883 6884 if Is_Private_Type (Full_Parent) 6885 and then Present (Full_View (Full_Parent)) 6886 then 6887 Full_Parent := Full_View (Full_Parent); 6888 end if; 6889 6890 -- And its underlying full view if necessary 6891 6892 if Is_Private_Type (Full_Parent) 6893 and then Present (Underlying_Full_View (Full_Parent)) 6894 then 6895 Full_Parent := Underlying_Full_View (Full_Parent); 6896 end if; 6897 6898 -- For record, access and most enumeration types, derivation from 6899 -- the full view requires a fully-fledged declaration. In the other 6900 -- cases, just use an itype. 6901 6902 if Ekind (Full_Parent) in Record_Kind 6903 or else Ekind (Full_Parent) in Access_Kind 6904 or else 6905 (Ekind (Full_Parent) in Enumeration_Kind 6906 and then not Is_Standard_Character_Type (Full_Parent) 6907 and then not Is_Generic_Type (Root_Type (Full_Parent))) 6908 then 6909 -- Copy and adjust declaration to provide a completion for what 6910 -- is originally a private declaration. Indicate that full view 6911 -- is internally generated. 6912 6913 Set_Comes_From_Source (Full_N, False); 6914 Set_Comes_From_Source (Full_Der, False); 6915 Set_Parent (Full_Der, Full_N); 6916 Set_Defining_Identifier (Full_N, Full_Der); 6917 6918 -- If there are no constraints, adjust the subtype mark 6919 6920 if Nkind (Subtype_Indication (Type_Definition (Full_N))) /= 6921 N_Subtype_Indication 6922 then 6923 Set_Subtype_Indication 6924 (Type_Definition (Full_N), 6925 New_Occurrence_Of (Full_Parent, Sloc (Full_N))); 6926 end if; 6927 6928 Insert_After (N, Full_N); 6929 6930 -- Build full view of derived type from full view of parent which 6931 -- is now installed. Subprograms have been derived on the partial 6932 -- view, the completion does not derive them anew. 6933 6934 if Ekind (Full_Parent) in Record_Kind then 6935 6936 -- If parent type is tagged, the completion inherits the proper 6937 -- primitive operations. 6938 6939 if Is_Tagged_Type (Parent_Type) then 6940 Build_Derived_Record_Type 6941 (Full_N, Full_Parent, Full_Der, Derive_Subps); 6942 else 6943 Build_Derived_Record_Type 6944 (Full_N, Full_Parent, Full_Der, Derive_Subps => False); 6945 end if; 6946 6947 else 6948 Build_Derived_Type 6949 (Full_N, Full_Parent, Full_Der, 6950 Is_Completion => False, Derive_Subps => False); 6951 end if; 6952 6953 -- The full declaration has been introduced into the tree and 6954 -- processed in the step above. It should not be analyzed again 6955 -- (when encountered later in the current list of declarations) 6956 -- to prevent spurious name conflicts. The full entity remains 6957 -- invisible. 6958 6959 Set_Analyzed (Full_N); 6960 6961 else 6962 Full_Der := 6963 Make_Defining_Identifier (Sloc (Derived_Type), 6964 Chars => Chars (Derived_Type)); 6965 Set_Is_Itype (Full_Der); 6966 Set_Associated_Node_For_Itype (Full_Der, N); 6967 Set_Parent (Full_Der, N); 6968 Build_Derived_Type 6969 (N, Full_Parent, Full_Der, 6970 Is_Completion => False, Derive_Subps => False); 6971 end if; 6972 6973 Set_Has_Private_Declaration (Full_Der); 6974 Set_Has_Private_Declaration (Derived_Type); 6975 6976 Set_Scope (Full_Der, Scope (Derived_Type)); 6977 Set_Is_First_Subtype (Full_Der, Is_First_Subtype (Derived_Type)); 6978 Set_Has_Size_Clause (Full_Der, False); 6979 Set_Has_Alignment_Clause (Full_Der, False); 6980 Set_Has_Delayed_Freeze (Full_Der); 6981 Set_Is_Frozen (Full_Der, False); 6982 Set_Freeze_Node (Full_Der, Empty); 6983 Set_Depends_On_Private (Full_Der, Has_Private_Component (Full_Der)); 6984 Set_Is_Public (Full_Der, Is_Public (Derived_Type)); 6985 6986 -- The convention on the base type may be set in the private part 6987 -- and not propagated to the subtype until later, so we obtain the 6988 -- convention from the base type of the parent. 6989 6990 Set_Convention (Full_Der, Convention (Base_Type (Full_Parent))); 6991 end Copy_And_Build; 6992 6993 -- Start of processing for Build_Derived_Private_Type 6994 6995 begin 6996 if Is_Tagged_Type (Parent_Type) then 6997 Full_P := Full_View (Parent_Type); 6998 6999 -- A type extension of a type with unknown discriminants is an 7000 -- indefinite type that the back-end cannot handle directly. 7001 -- We treat it as a private type, and build a completion that is 7002 -- derived from the full view of the parent, and hopefully has 7003 -- known discriminants. 7004 7005 -- If the full view of the parent type has an underlying record view, 7006 -- use it to generate the underlying record view of this derived type 7007 -- (required for chains of derivations with unknown discriminants). 7008 7009 -- Minor optimization: we avoid the generation of useless underlying 7010 -- record view entities if the private type declaration has unknown 7011 -- discriminants but its corresponding full view has no 7012 -- discriminants. 7013 7014 if Has_Unknown_Discriminants (Parent_Type) 7015 and then Present (Full_P) 7016 and then (Has_Discriminants (Full_P) 7017 or else Present (Underlying_Record_View (Full_P))) 7018 and then not In_Open_Scopes (Par_Scope) 7019 and then Expander_Active 7020 then 7021 declare 7022 Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T'); 7023 New_Ext : constant Node_Id := 7024 Copy_Separate_Tree 7025 (Record_Extension_Part (Type_Definition (N))); 7026 Decl : Node_Id; 7027 7028 begin 7029 Build_Derived_Record_Type 7030 (N, Parent_Type, Derived_Type, Derive_Subps); 7031 7032 -- Build anonymous completion, as a derivation from the full 7033 -- view of the parent. This is not a completion in the usual 7034 -- sense, because the current type is not private. 7035 7036 Decl := 7037 Make_Full_Type_Declaration (Loc, 7038 Defining_Identifier => Full_Der, 7039 Type_Definition => 7040 Make_Derived_Type_Definition (Loc, 7041 Subtype_Indication => 7042 New_Copy_Tree 7043 (Subtype_Indication (Type_Definition (N))), 7044 Record_Extension_Part => New_Ext)); 7045 7046 -- If the parent type has an underlying record view, use it 7047 -- here to build the new underlying record view. 7048 7049 if Present (Underlying_Record_View (Full_P)) then 7050 pragma Assert 7051 (Nkind (Subtype_Indication (Type_Definition (Decl))) 7052 = N_Identifier); 7053 Set_Entity (Subtype_Indication (Type_Definition (Decl)), 7054 Underlying_Record_View (Full_P)); 7055 end if; 7056 7057 Install_Private_Declarations (Par_Scope); 7058 Install_Visible_Declarations (Par_Scope); 7059 Insert_Before (N, Decl); 7060 7061 -- Mark entity as an underlying record view before analysis, 7062 -- to avoid generating the list of its primitive operations 7063 -- (which is not really required for this entity) and thus 7064 -- prevent spurious errors associated with missing overriding 7065 -- of abstract primitives (overridden only for Derived_Type). 7066 7067 Set_Ekind (Full_Der, E_Record_Type); 7068 Set_Is_Underlying_Record_View (Full_Der); 7069 Set_Default_SSO (Full_Der); 7070 7071 Analyze (Decl); 7072 7073 pragma Assert (Has_Discriminants (Full_Der) 7074 and then not Has_Unknown_Discriminants (Full_Der)); 7075 7076 Uninstall_Declarations (Par_Scope); 7077 7078 -- Freeze the underlying record view, to prevent generation of 7079 -- useless dispatching information, which is simply shared with 7080 -- the real derived type. 7081 7082 Set_Is_Frozen (Full_Der); 7083 7084 -- If the derived type has access discriminants, create 7085 -- references to their anonymous types now, to prevent 7086 -- back-end problems when their first use is in generated 7087 -- bodies of primitives. 7088 7089 declare 7090 E : Entity_Id; 7091 7092 begin 7093 E := First_Entity (Full_Der); 7094 7095 while Present (E) loop 7096 if Ekind (E) = E_Discriminant 7097 and then Ekind (Etype (E)) = E_Anonymous_Access_Type 7098 then 7099 Build_Itype_Reference (Etype (E), Decl); 7100 end if; 7101 7102 Next_Entity (E); 7103 end loop; 7104 end; 7105 7106 -- Set up links between real entity and underlying record view 7107 7108 Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der)); 7109 Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type); 7110 end; 7111 7112 -- If discriminants are known, build derived record 7113 7114 else 7115 Build_Derived_Record_Type 7116 (N, Parent_Type, Derived_Type, Derive_Subps); 7117 end if; 7118 7119 return; 7120 7121 elsif Has_Discriminants (Parent_Type) then 7122 7123 -- Build partial view of derived type from partial view of parent. 7124 -- This must be done before building the full derivation because the 7125 -- second derivation will modify the discriminants of the first and 7126 -- the discriminants are chained with the rest of the components in 7127 -- the full derivation. 7128 7129 Build_Derived_Record_Type 7130 (N, Parent_Type, Derived_Type, Derive_Subps); 7131 7132 -- Build the full derivation if this is not the anonymous derived 7133 -- base type created by Build_Derived_Record_Type in the constrained 7134 -- case (see point 5. of its head comment) since we build it for the 7135 -- derived subtype. And skip it for protected types altogether, as 7136 -- gigi does not use these types directly. 7137 7138 if Present (Full_View (Parent_Type)) 7139 and then not Is_Itype (Derived_Type) 7140 and then not (Ekind (Full_View (Parent_Type)) in Protected_Kind) 7141 then 7142 declare 7143 Der_Base : constant Entity_Id := Base_Type (Derived_Type); 7144 Discr : Entity_Id; 7145 Last_Discr : Entity_Id; 7146 7147 begin 7148 -- If this is not a completion, construct the implicit full 7149 -- view by deriving from the full view of the parent type. 7150 -- But if this is a completion, the derived private type 7151 -- being built is a full view and the full derivation can 7152 -- only be its underlying full view. 7153 7154 Build_Full_Derivation; 7155 7156 if not Is_Completion then 7157 Set_Full_View (Derived_Type, Full_Der); 7158 else 7159 Set_Underlying_Full_View (Derived_Type, Full_Der); 7160 end if; 7161 7162 if not Is_Base_Type (Derived_Type) then 7163 Set_Full_View (Der_Base, Base_Type (Full_Der)); 7164 end if; 7165 7166 -- Copy the discriminant list from full view to the partial 7167 -- view (base type and its subtype). Gigi requires that the 7168 -- partial and full views have the same discriminants. 7169 7170 -- Note that since the partial view points to discriminants 7171 -- in the full view, their scope will be that of the full 7172 -- view. This might cause some front end problems and need 7173 -- adjustment??? 7174 7175 Discr := First_Discriminant (Base_Type (Full_Der)); 7176 Set_First_Entity (Der_Base, Discr); 7177 7178 loop 7179 Last_Discr := Discr; 7180 Next_Discriminant (Discr); 7181 exit when No (Discr); 7182 end loop; 7183 7184 Set_Last_Entity (Der_Base, Last_Discr); 7185 Set_First_Entity (Derived_Type, First_Entity (Der_Base)); 7186 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base)); 7187 7188 Set_Stored_Constraint 7189 (Full_Der, Stored_Constraint (Derived_Type)); 7190 end; 7191 end if; 7192 7193 elsif Present (Full_View (Parent_Type)) 7194 and then Has_Discriminants (Full_View (Parent_Type)) 7195 then 7196 if Has_Unknown_Discriminants (Parent_Type) 7197 and then Nkind (Subtype_Indication (Type_Definition (N))) = 7198 N_Subtype_Indication 7199 then 7200 Error_Msg_N 7201 ("cannot constrain type with unknown discriminants", 7202 Subtype_Indication (Type_Definition (N))); 7203 return; 7204 end if; 7205 7206 -- If this is not a completion, construct the implicit full view by 7207 -- deriving from the full view of the parent type. But if this is a 7208 -- completion, the derived private type being built is a full view 7209 -- and the full derivation can only be its underlying full view. 7210 7211 Build_Full_Derivation; 7212 7213 if not Is_Completion then 7214 Set_Full_View (Derived_Type, Full_Der); 7215 else 7216 Set_Underlying_Full_View (Derived_Type, Full_Der); 7217 end if; 7218 7219 -- In any case, the primitive operations are inherited from the 7220 -- parent type, not from the internal full view. 7221 7222 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type)); 7223 7224 if Derive_Subps then 7225 Derive_Subprograms (Parent_Type, Derived_Type); 7226 end if; 7227 7228 Set_Stored_Constraint (Derived_Type, No_Elist); 7229 Set_Is_Constrained 7230 (Derived_Type, Is_Constrained (Full_View (Parent_Type))); 7231 7232 else 7233 -- Untagged type, No discriminants on either view 7234 7235 if Nkind (Subtype_Indication (Type_Definition (N))) = 7236 N_Subtype_Indication 7237 then 7238 Error_Msg_N 7239 ("illegal constraint on type without discriminants", N); 7240 end if; 7241 7242 if Present (Discriminant_Specifications (N)) 7243 and then Present (Full_View (Parent_Type)) 7244 and then not Is_Tagged_Type (Full_View (Parent_Type)) 7245 then 7246 Error_Msg_N ("cannot add discriminants to untagged type", N); 7247 end if; 7248 7249 Set_Stored_Constraint (Derived_Type, No_Elist); 7250 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); 7251 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type)); 7252 Set_Has_Controlled_Component 7253 (Derived_Type, Has_Controlled_Component 7254 (Parent_Type)); 7255 7256 -- Direct controlled types do not inherit Finalize_Storage_Only flag 7257 7258 if not Is_Controlled (Parent_Type) then 7259 Set_Finalize_Storage_Only 7260 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type)); 7261 end if; 7262 7263 -- If this is not a completion, construct the implicit full view by 7264 -- deriving from the full view of the parent type. 7265 7266 -- ??? If the parent is untagged private and its completion is 7267 -- tagged, this mechanism will not work because we cannot derive from 7268 -- the tagged full view unless we have an extension. 7269 7270 if Present (Full_View (Parent_Type)) 7271 and then not Is_Tagged_Type (Full_View (Parent_Type)) 7272 and then not Is_Completion 7273 then 7274 Build_Full_Derivation; 7275 Set_Full_View (Derived_Type, Full_Der); 7276 end if; 7277 end if; 7278 7279 Set_Has_Unknown_Discriminants (Derived_Type, 7280 Has_Unknown_Discriminants (Parent_Type)); 7281 7282 if Is_Private_Type (Derived_Type) then 7283 Set_Private_Dependents (Derived_Type, New_Elmt_List); 7284 end if; 7285 7286 -- If the parent base type is in scope, add the derived type to its 7287 -- list of private dependents, because its full view may become 7288 -- visible subsequently (in a nested private part, a body, or in a 7289 -- further child unit). 7290 7291 if Is_Private_Type (Par_Base) and then In_Open_Scopes (Par_Scope) then 7292 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type)); 7293 7294 -- Check for unusual case where a type completed by a private 7295 -- derivation occurs within a package nested in a child unit, and 7296 -- the parent is declared in an ancestor. 7297 7298 if Is_Child_Unit (Scope (Current_Scope)) 7299 and then Is_Completion 7300 and then In_Private_Part (Current_Scope) 7301 and then Scope (Parent_Type) /= Current_Scope 7302 7303 -- Note that if the parent has a completion in the private part, 7304 -- (which is itself a derivation from some other private type) 7305 -- it is that completion that is visible, there is no full view 7306 -- available, and no special processing is needed. 7307 7308 and then Present (Full_View (Parent_Type)) 7309 then 7310 -- In this case, the full view of the parent type will become 7311 -- visible in the body of the enclosing child, and only then will 7312 -- the current type be possibly non-private. Build an underlying 7313 -- full view that will be installed when the enclosing child body 7314 -- is compiled. 7315 7316 if Present (Underlying_Full_View (Derived_Type)) then 7317 Full_Der := Underlying_Full_View (Derived_Type); 7318 else 7319 Build_Full_Derivation; 7320 Set_Underlying_Full_View (Derived_Type, Full_Der); 7321 end if; 7322 7323 -- The full view will be used to swap entities on entry/exit to 7324 -- the body, and must appear in the entity list for the package. 7325 7326 Append_Entity (Full_Der, Scope (Derived_Type)); 7327 end if; 7328 end if; 7329 end Build_Derived_Private_Type; 7330 7331 ------------------------------- 7332 -- Build_Derived_Record_Type -- 7333 ------------------------------- 7334 7335 -- 1. INTRODUCTION 7336 7337 -- Ideally we would like to use the same model of type derivation for 7338 -- tagged and untagged record types. Unfortunately this is not quite 7339 -- possible because the semantics of representation clauses is different 7340 -- for tagged and untagged records under inheritance. Consider the 7341 -- following: 7342 7343 -- type R (...) is [tagged] record ... end record; 7344 -- type T (...) is new R (...) [with ...]; 7345 7346 -- The representation clauses for T can specify a completely different 7347 -- record layout from R's. Hence the same component can be placed in two 7348 -- very different positions in objects of type T and R. If R and T are 7349 -- tagged types, representation clauses for T can only specify the layout 7350 -- of non inherited components, thus components that are common in R and T 7351 -- have the same position in objects of type R and T. 7352 7353 -- This has two implications. The first is that the entire tree for R's 7354 -- declaration needs to be copied for T in the untagged case, so that T 7355 -- can be viewed as a record type of its own with its own representation 7356 -- clauses. The second implication is the way we handle discriminants. 7357 -- Specifically, in the untagged case we need a way to communicate to Gigi 7358 -- what are the real discriminants in the record, while for the semantics 7359 -- we need to consider those introduced by the user to rename the 7360 -- discriminants in the parent type. This is handled by introducing the 7361 -- notion of stored discriminants. See below for more. 7362 7363 -- Fortunately the way regular components are inherited can be handled in 7364 -- the same way in tagged and untagged types. 7365 7366 -- To complicate things a bit more the private view of a private extension 7367 -- cannot be handled in the same way as the full view (for one thing the 7368 -- semantic rules are somewhat different). We will explain what differs 7369 -- below. 7370 7371 -- 2. DISCRIMINANTS UNDER INHERITANCE 7372 7373 -- The semantic rules governing the discriminants of derived types are 7374 -- quite subtle. 7375 7376 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new 7377 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART] 7378 7379 -- If parent type has discriminants, then the discriminants that are 7380 -- declared in the derived type are [3.4 (11)]: 7381 7382 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if 7383 -- there is one; 7384 7385 -- o Otherwise, each discriminant of the parent type (implicitly declared 7386 -- in the same order with the same specifications). In this case, the 7387 -- discriminants are said to be "inherited", or if unknown in the parent 7388 -- are also unknown in the derived type. 7389 7390 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]: 7391 7392 -- o The parent subtype must be constrained; 7393 7394 -- o If the parent type is not a tagged type, then each discriminant of 7395 -- the derived type must be used in the constraint defining a parent 7396 -- subtype. [Implementation note: This ensures that the new discriminant 7397 -- can share storage with an existing discriminant.] 7398 7399 -- For the derived type each discriminant of the parent type is either 7400 -- inherited, constrained to equal some new discriminant of the derived 7401 -- type, or constrained to the value of an expression. 7402 7403 -- When inherited or constrained to equal some new discriminant, the 7404 -- parent discriminant and the discriminant of the derived type are said 7405 -- to "correspond". 7406 7407 -- If a discriminant of the parent type is constrained to a specific value 7408 -- in the derived type definition, then the discriminant is said to be 7409 -- "specified" by that derived type definition. 7410 7411 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES 7412 7413 -- We have spoken about stored discriminants in point 1 (introduction) 7414 -- above. There are two sort of stored discriminants: implicit and 7415 -- explicit. As long as the derived type inherits the same discriminants as 7416 -- the root record type, stored discriminants are the same as regular 7417 -- discriminants, and are said to be implicit. However, if any discriminant 7418 -- in the root type was renamed in the derived type, then the derived 7419 -- type will contain explicit stored discriminants. Explicit stored 7420 -- discriminants are discriminants in addition to the semantically visible 7421 -- discriminants defined for the derived type. Stored discriminants are 7422 -- used by Gigi to figure out what are the physical discriminants in 7423 -- objects of the derived type (see precise definition in einfo.ads). 7424 -- As an example, consider the following: 7425 7426 -- type R (D1, D2, D3 : Int) is record ... end record; 7427 -- type T1 is new R; 7428 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1); 7429 -- type T3 is new T2; 7430 -- type T4 (Y : Int) is new T3 (Y, 99); 7431 7432 -- The following table summarizes the discriminants and stored 7433 -- discriminants in R and T1 through T4. 7434 7435 -- Type Discrim Stored Discrim Comment 7436 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R 7437 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1 7438 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2 7439 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3 7440 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4 7441 7442 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to 7443 -- find the corresponding discriminant in the parent type, while 7444 -- Original_Record_Component (abbreviated ORC below), the actual physical 7445 -- component that is renamed. Finally the field Is_Completely_Hidden 7446 -- (abbreviated ICH below) is set for all explicit stored discriminants 7447 -- (see einfo.ads for more info). For the above example this gives: 7448 7449 -- Discrim CD ORC ICH 7450 -- ^^^^^^^ ^^ ^^^ ^^^ 7451 -- D1 in R empty itself no 7452 -- D2 in R empty itself no 7453 -- D3 in R empty itself no 7454 7455 -- D1 in T1 D1 in R itself no 7456 -- D2 in T1 D2 in R itself no 7457 -- D3 in T1 D3 in R itself no 7458 7459 -- X1 in T2 D3 in T1 D3 in T2 no 7460 -- X2 in T2 D1 in T1 D1 in T2 no 7461 -- D1 in T2 empty itself yes 7462 -- D2 in T2 empty itself yes 7463 -- D3 in T2 empty itself yes 7464 7465 -- X1 in T3 X1 in T2 D3 in T3 no 7466 -- X2 in T3 X2 in T2 D1 in T3 no 7467 -- D1 in T3 empty itself yes 7468 -- D2 in T3 empty itself yes 7469 -- D3 in T3 empty itself yes 7470 7471 -- Y in T4 X1 in T3 D3 in T3 no 7472 -- D1 in T3 empty itself yes 7473 -- D2 in T3 empty itself yes 7474 -- D3 in T3 empty itself yes 7475 7476 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES 7477 7478 -- Type derivation for tagged types is fairly straightforward. If no 7479 -- discriminants are specified by the derived type, these are inherited 7480 -- from the parent. No explicit stored discriminants are ever necessary. 7481 -- The only manipulation that is done to the tree is that of adding a 7482 -- _parent field with parent type and constrained to the same constraint 7483 -- specified for the parent in the derived type definition. For instance: 7484 7485 -- type R (D1, D2, D3 : Int) is tagged record ... end record; 7486 -- type T1 is new R with null record; 7487 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record; 7488 7489 -- are changed into: 7490 7491 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record 7492 -- _parent : R (D1, D2, D3); 7493 -- end record; 7494 7495 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record 7496 -- _parent : T1 (X2, 88, X1); 7497 -- end record; 7498 7499 -- The discriminants actually present in R, T1 and T2 as well as their CD, 7500 -- ORC and ICH fields are: 7501 7502 -- Discrim CD ORC ICH 7503 -- ^^^^^^^ ^^ ^^^ ^^^ 7504 -- D1 in R empty itself no 7505 -- D2 in R empty itself no 7506 -- D3 in R empty itself no 7507 7508 -- D1 in T1 D1 in R D1 in R no 7509 -- D2 in T1 D2 in R D2 in R no 7510 -- D3 in T1 D3 in R D3 in R no 7511 7512 -- X1 in T2 D3 in T1 D3 in R no 7513 -- X2 in T2 D1 in T1 D1 in R no 7514 7515 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS 7516 -- 7517 -- Regardless of whether we dealing with a tagged or untagged type 7518 -- we will transform all derived type declarations of the form 7519 -- 7520 -- type T is new R (...) [with ...]; 7521 -- or 7522 -- subtype S is R (...); 7523 -- type T is new S [with ...]; 7524 -- into 7525 -- type BT is new R [with ...]; 7526 -- subtype T is BT (...); 7527 -- 7528 -- That is, the base derived type is constrained only if it has no 7529 -- discriminants. The reason for doing this is that GNAT's semantic model 7530 -- assumes that a base type with discriminants is unconstrained. 7531 -- 7532 -- Note that, strictly speaking, the above transformation is not always 7533 -- correct. Consider for instance the following excerpt from ACVC b34011a: 7534 -- 7535 -- procedure B34011A is 7536 -- type REC (D : integer := 0) is record 7537 -- I : Integer; 7538 -- end record; 7539 7540 -- package P is 7541 -- type T6 is new Rec; 7542 -- function F return T6; 7543 -- end P; 7544 7545 -- use P; 7546 -- package Q6 is 7547 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F. 7548 -- end Q6; 7549 -- 7550 -- The definition of Q6.U is illegal. However transforming Q6.U into 7551 7552 -- type BaseU is new T6; 7553 -- subtype U is BaseU (Q6.F.I) 7554 7555 -- turns U into a legal subtype, which is incorrect. To avoid this problem 7556 -- we always analyze the constraint (in this case (Q6.F.I)) before applying 7557 -- the transformation described above. 7558 7559 -- There is another instance where the above transformation is incorrect. 7560 -- Consider: 7561 7562 -- package Pack is 7563 -- type Base (D : Integer) is tagged null record; 7564 -- procedure P (X : Base); 7565 7566 -- type Der is new Base (2) with null record; 7567 -- procedure P (X : Der); 7568 -- end Pack; 7569 7570 -- Then the above transformation turns this into 7571 7572 -- type Der_Base is new Base with null record; 7573 -- -- procedure P (X : Base) is implicitly inherited here 7574 -- -- as procedure P (X : Der_Base). 7575 7576 -- subtype Der is Der_Base (2); 7577 -- procedure P (X : Der); 7578 -- -- The overriding of P (X : Der_Base) is illegal since we 7579 -- -- have a parameter conformance problem. 7580 7581 -- To get around this problem, after having semantically processed Der_Base 7582 -- and the rewritten subtype declaration for Der, we copy Der_Base field 7583 -- Discriminant_Constraint from Der so that when parameter conformance is 7584 -- checked when P is overridden, no semantic errors are flagged. 7585 7586 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS 7587 7588 -- Regardless of whether we are dealing with a tagged or untagged type 7589 -- we will transform all derived type declarations of the form 7590 7591 -- type R (D1, .., Dn : ...) is [tagged] record ...; 7592 -- type T is new R [with ...]; 7593 -- into 7594 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...]; 7595 7596 -- The reason for such transformation is that it allows us to implement a 7597 -- very clean form of component inheritance as explained below. 7598 7599 -- Note that this transformation is not achieved by direct tree rewriting 7600 -- and manipulation, but rather by redoing the semantic actions that the 7601 -- above transformation will entail. This is done directly in routine 7602 -- Inherit_Components. 7603 7604 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE 7605 7606 -- In both tagged and untagged derived types, regular non discriminant 7607 -- components are inherited in the derived type from the parent type. In 7608 -- the absence of discriminants component, inheritance is straightforward 7609 -- as components can simply be copied from the parent. 7610 7611 -- If the parent has discriminants, inheriting components constrained with 7612 -- these discriminants requires caution. Consider the following example: 7613 7614 -- type R (D1, D2 : Positive) is [tagged] record 7615 -- S : String (D1 .. D2); 7616 -- end record; 7617 7618 -- type T1 is new R [with null record]; 7619 -- type T2 (X : positive) is new R (1, X) [with null record]; 7620 7621 -- As explained in 6. above, T1 is rewritten as 7622 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record]; 7623 -- which makes the treatment for T1 and T2 identical. 7624 7625 -- What we want when inheriting S, is that references to D1 and D2 in R are 7626 -- replaced with references to their correct constraints, i.e. D1 and D2 in 7627 -- T1 and 1 and X in T2. So all R's discriminant references are replaced 7628 -- with either discriminant references in the derived type or expressions. 7629 -- This replacement is achieved as follows: before inheriting R's 7630 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is 7631 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1 7632 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible). 7633 -- For T2, for instance, this has the effect of replacing String (D1 .. D2) 7634 -- by String (1 .. X). 7635 7636 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS 7637 7638 -- We explain here the rules governing private type extensions relevant to 7639 -- type derivation. These rules are explained on the following example: 7640 7641 -- type D [(...)] is new A [(...)] with private; <-- partial view 7642 -- type D [(...)] is new P [(...)] with null record; <-- full view 7643 7644 -- Type A is called the ancestor subtype of the private extension. 7645 -- Type P is the parent type of the full view of the private extension. It 7646 -- must be A or a type derived from A. 7647 7648 -- The rules concerning the discriminants of private type extensions are 7649 -- [7.3(10-13)]: 7650 7651 -- o If a private extension inherits known discriminants from the ancestor 7652 -- subtype, then the full view must also inherit its discriminants from 7653 -- the ancestor subtype and the parent subtype of the full view must be 7654 -- constrained if and only if the ancestor subtype is constrained. 7655 7656 -- o If a partial view has unknown discriminants, then the full view may 7657 -- define a definite or an indefinite subtype, with or without 7658 -- discriminants. 7659 7660 -- o If a partial view has neither known nor unknown discriminants, then 7661 -- the full view must define a definite subtype. 7662 7663 -- o If the ancestor subtype of a private extension has constrained 7664 -- discriminants, then the parent subtype of the full view must impose a 7665 -- statically matching constraint on those discriminants. 7666 7667 -- This means that only the following forms of private extensions are 7668 -- allowed: 7669 7670 -- type D is new A with private; <-- partial view 7671 -- type D is new P with null record; <-- full view 7672 7673 -- If A has no discriminants than P has no discriminants, otherwise P must 7674 -- inherit A's discriminants. 7675 7676 -- type D is new A (...) with private; <-- partial view 7677 -- type D is new P (:::) with null record; <-- full view 7678 7679 -- P must inherit A's discriminants and (...) and (:::) must statically 7680 -- match. 7681 7682 -- subtype A is R (...); 7683 -- type D is new A with private; <-- partial view 7684 -- type D is new P with null record; <-- full view 7685 7686 -- P must have inherited R's discriminants and must be derived from A or 7687 -- any of its subtypes. 7688 7689 -- type D (..) is new A with private; <-- partial view 7690 -- type D (..) is new P [(:::)] with null record; <-- full view 7691 7692 -- No specific constraints on P's discriminants or constraint (:::). 7693 -- Note that A can be unconstrained, but the parent subtype P must either 7694 -- be constrained or (:::) must be present. 7695 7696 -- type D (..) is new A [(...)] with private; <-- partial view 7697 -- type D (..) is new P [(:::)] with null record; <-- full view 7698 7699 -- P's constraints on A's discriminants must statically match those 7700 -- imposed by (...). 7701 7702 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS 7703 7704 -- The full view of a private extension is handled exactly as described 7705 -- above. The model chose for the private view of a private extension is 7706 -- the same for what concerns discriminants (i.e. they receive the same 7707 -- treatment as in the tagged case). However, the private view of the 7708 -- private extension always inherits the components of the parent base, 7709 -- without replacing any discriminant reference. Strictly speaking this is 7710 -- incorrect. However, Gigi never uses this view to generate code so this 7711 -- is a purely semantic issue. In theory, a set of transformations similar 7712 -- to those given in 5. and 6. above could be applied to private views of 7713 -- private extensions to have the same model of component inheritance as 7714 -- for non private extensions. However, this is not done because it would 7715 -- further complicate private type processing. Semantically speaking, this 7716 -- leaves us in an uncomfortable situation. As an example consider: 7717 7718 -- package Pack is 7719 -- type R (D : integer) is tagged record 7720 -- S : String (1 .. D); 7721 -- end record; 7722 -- procedure P (X : R); 7723 -- type T is new R (1) with private; 7724 -- private 7725 -- type T is new R (1) with null record; 7726 -- end; 7727 7728 -- This is transformed into: 7729 7730 -- package Pack is 7731 -- type R (D : integer) is tagged record 7732 -- S : String (1 .. D); 7733 -- end record; 7734 -- procedure P (X : R); 7735 -- type T is new R (1) with private; 7736 -- private 7737 -- type BaseT is new R with null record; 7738 -- subtype T is BaseT (1); 7739 -- end; 7740 7741 -- (strictly speaking the above is incorrect Ada) 7742 7743 -- From the semantic standpoint the private view of private extension T 7744 -- should be flagged as constrained since one can clearly have 7745 -- 7746 -- Obj : T; 7747 -- 7748 -- in a unit withing Pack. However, when deriving subprograms for the 7749 -- private view of private extension T, T must be seen as unconstrained 7750 -- since T has discriminants (this is a constraint of the current 7751 -- subprogram derivation model). Thus, when processing the private view of 7752 -- a private extension such as T, we first mark T as unconstrained, we 7753 -- process it, we perform program derivation and just before returning from 7754 -- Build_Derived_Record_Type we mark T as constrained. 7755 7756 -- ??? Are there are other uncomfortable cases that we will have to 7757 -- deal with. 7758 7759 -- 10. RECORD_TYPE_WITH_PRIVATE complications 7760 7761 -- Types that are derived from a visible record type and have a private 7762 -- extension present other peculiarities. They behave mostly like private 7763 -- types, but if they have primitive operations defined, these will not 7764 -- have the proper signatures for further inheritance, because other 7765 -- primitive operations will use the implicit base that we define for 7766 -- private derivations below. This affect subprogram inheritance (see 7767 -- Derive_Subprograms for details). We also derive the implicit base from 7768 -- the base type of the full view, so that the implicit base is a record 7769 -- type and not another private type, This avoids infinite loops. 7770 7771 procedure Build_Derived_Record_Type 7772 (N : Node_Id; 7773 Parent_Type : Entity_Id; 7774 Derived_Type : Entity_Id; 7775 Derive_Subps : Boolean := True) 7776 is 7777 Discriminant_Specs : constant Boolean := 7778 Present (Discriminant_Specifications (N)); 7779 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type); 7780 Loc : constant Source_Ptr := Sloc (N); 7781 Private_Extension : constant Boolean := 7782 Nkind (N) = N_Private_Extension_Declaration; 7783 Assoc_List : Elist_Id; 7784 Constraint_Present : Boolean; 7785 Constrs : Elist_Id; 7786 Discrim : Entity_Id; 7787 Indic : Node_Id; 7788 Inherit_Discrims : Boolean := False; 7789 Last_Discrim : Entity_Id; 7790 New_Base : Entity_Id; 7791 New_Decl : Node_Id; 7792 New_Discrs : Elist_Id; 7793 New_Indic : Node_Id; 7794 Parent_Base : Entity_Id; 7795 Save_Etype : Entity_Id; 7796 Save_Discr_Constr : Elist_Id; 7797 Save_Next_Entity : Entity_Id; 7798 Type_Def : Node_Id; 7799 7800 Discs : Elist_Id := New_Elmt_List; 7801 -- An empty Discs list means that there were no constraints in the 7802 -- subtype indication or that there was an error processing it. 7803 7804 begin 7805 if Ekind (Parent_Type) = E_Record_Type_With_Private 7806 and then Present (Full_View (Parent_Type)) 7807 and then Has_Discriminants (Parent_Type) 7808 then 7809 Parent_Base := Base_Type (Full_View (Parent_Type)); 7810 else 7811 Parent_Base := Base_Type (Parent_Type); 7812 end if; 7813 7814 -- AI05-0115 : if this is a derivation from a private type in some 7815 -- other scope that may lead to invisible components for the derived 7816 -- type, mark it accordingly. 7817 7818 if Is_Private_Type (Parent_Type) then 7819 if Scope (Parent_Type) = Scope (Derived_Type) then 7820 null; 7821 7822 elsif In_Open_Scopes (Scope (Parent_Type)) 7823 and then In_Private_Part (Scope (Parent_Type)) 7824 then 7825 null; 7826 7827 else 7828 Set_Has_Private_Ancestor (Derived_Type); 7829 end if; 7830 7831 else 7832 Set_Has_Private_Ancestor 7833 (Derived_Type, Has_Private_Ancestor (Parent_Type)); 7834 end if; 7835 7836 -- Before we start the previously documented transformations, here is 7837 -- little fix for size and alignment of tagged types. Normally when we 7838 -- derive type D from type P, we copy the size and alignment of P as the 7839 -- default for D, and in the absence of explicit representation clauses 7840 -- for D, the size and alignment are indeed the same as the parent. 7841 7842 -- But this is wrong for tagged types, since fields may be added, and 7843 -- the default size may need to be larger, and the default alignment may 7844 -- need to be larger. 7845 7846 -- We therefore reset the size and alignment fields in the tagged case. 7847 -- Note that the size and alignment will in any case be at least as 7848 -- large as the parent type (since the derived type has a copy of the 7849 -- parent type in the _parent field) 7850 7851 -- The type is also marked as being tagged here, which is needed when 7852 -- processing components with a self-referential anonymous access type 7853 -- in the call to Check_Anonymous_Access_Components below. Note that 7854 -- this flag is also set later on for completeness. 7855 7856 if Is_Tagged then 7857 Set_Is_Tagged_Type (Derived_Type); 7858 Init_Size_Align (Derived_Type); 7859 end if; 7860 7861 -- STEP 0a: figure out what kind of derived type declaration we have 7862 7863 if Private_Extension then 7864 Type_Def := N; 7865 Set_Ekind (Derived_Type, E_Record_Type_With_Private); 7866 Set_Default_SSO (Derived_Type); 7867 7868 else 7869 Type_Def := Type_Definition (N); 7870 7871 -- Ekind (Parent_Base) is not necessarily E_Record_Type since 7872 -- Parent_Base can be a private type or private extension. However, 7873 -- for tagged types with an extension the newly added fields are 7874 -- visible and hence the Derived_Type is always an E_Record_Type. 7875 -- (except that the parent may have its own private fields). 7876 -- For untagged types we preserve the Ekind of the Parent_Base. 7877 7878 if Present (Record_Extension_Part (Type_Def)) then 7879 Set_Ekind (Derived_Type, E_Record_Type); 7880 Set_Default_SSO (Derived_Type); 7881 7882 -- Create internal access types for components with anonymous 7883 -- access types. 7884 7885 if Ada_Version >= Ada_2005 then 7886 Check_Anonymous_Access_Components 7887 (N, Derived_Type, Derived_Type, 7888 Component_List (Record_Extension_Part (Type_Def))); 7889 end if; 7890 7891 else 7892 Set_Ekind (Derived_Type, Ekind (Parent_Base)); 7893 end if; 7894 end if; 7895 7896 -- Indic can either be an N_Identifier if the subtype indication 7897 -- contains no constraint or an N_Subtype_Indication if the subtype 7898 -- indication has a constraint. 7899 7900 Indic := Subtype_Indication (Type_Def); 7901 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication); 7902 7903 -- Check that the type has visible discriminants. The type may be 7904 -- a private type with unknown discriminants whose full view has 7905 -- discriminants which are invisible. 7906 7907 if Constraint_Present then 7908 if not Has_Discriminants (Parent_Base) 7909 or else 7910 (Has_Unknown_Discriminants (Parent_Base) 7911 and then Is_Private_Type (Parent_Base)) 7912 then 7913 Error_Msg_N 7914 ("invalid constraint: type has no discriminant", 7915 Constraint (Indic)); 7916 7917 Constraint_Present := False; 7918 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic))); 7919 7920 elsif Is_Constrained (Parent_Type) then 7921 Error_Msg_N 7922 ("invalid constraint: parent type is already constrained", 7923 Constraint (Indic)); 7924 7925 Constraint_Present := False; 7926 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic))); 7927 end if; 7928 end if; 7929 7930 -- STEP 0b: If needed, apply transformation given in point 5. above 7931 7932 if not Private_Extension 7933 and then Has_Discriminants (Parent_Type) 7934 and then not Discriminant_Specs 7935 and then (Is_Constrained (Parent_Type) or else Constraint_Present) 7936 then 7937 -- First, we must analyze the constraint (see comment in point 5.) 7938 -- The constraint may come from the subtype indication of the full 7939 -- declaration. 7940 7941 if Constraint_Present then 7942 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic); 7943 7944 -- If there is no explicit constraint, there might be one that is 7945 -- inherited from a constrained parent type. In that case verify that 7946 -- it conforms to the constraint in the partial view. In perverse 7947 -- cases the parent subtypes of the partial and full view can have 7948 -- different constraints. 7949 7950 elsif Present (Stored_Constraint (Parent_Type)) then 7951 New_Discrs := Stored_Constraint (Parent_Type); 7952 7953 else 7954 New_Discrs := No_Elist; 7955 end if; 7956 7957 if Has_Discriminants (Derived_Type) 7958 and then Has_Private_Declaration (Derived_Type) 7959 and then Present (Discriminant_Constraint (Derived_Type)) 7960 and then Present (New_Discrs) 7961 then 7962 -- Verify that constraints of the full view statically match 7963 -- those given in the partial view. 7964 7965 declare 7966 C1, C2 : Elmt_Id; 7967 7968 begin 7969 C1 := First_Elmt (New_Discrs); 7970 C2 := First_Elmt (Discriminant_Constraint (Derived_Type)); 7971 while Present (C1) and then Present (C2) loop 7972 if Fully_Conformant_Expressions (Node (C1), Node (C2)) 7973 or else 7974 (Is_OK_Static_Expression (Node (C1)) 7975 and then Is_OK_Static_Expression (Node (C2)) 7976 and then 7977 Expr_Value (Node (C1)) = Expr_Value (Node (C2))) 7978 then 7979 null; 7980 7981 else 7982 if Constraint_Present then 7983 Error_Msg_N 7984 ("constraint not conformant to previous declaration", 7985 Node (C1)); 7986 else 7987 Error_Msg_N 7988 ("constraint of full view is incompatible " 7989 & "with partial view", N); 7990 end if; 7991 end if; 7992 7993 Next_Elmt (C1); 7994 Next_Elmt (C2); 7995 end loop; 7996 end; 7997 end if; 7998 7999 -- Insert and analyze the declaration for the unconstrained base type 8000 8001 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B'); 8002 8003 New_Decl := 8004 Make_Full_Type_Declaration (Loc, 8005 Defining_Identifier => New_Base, 8006 Type_Definition => 8007 Make_Derived_Type_Definition (Loc, 8008 Abstract_Present => Abstract_Present (Type_Def), 8009 Limited_Present => Limited_Present (Type_Def), 8010 Subtype_Indication => 8011 New_Occurrence_Of (Parent_Base, Loc), 8012 Record_Extension_Part => 8013 Relocate_Node (Record_Extension_Part (Type_Def)), 8014 Interface_List => Interface_List (Type_Def))); 8015 8016 Set_Parent (New_Decl, Parent (N)); 8017 Mark_Rewrite_Insertion (New_Decl); 8018 Insert_Before (N, New_Decl); 8019 8020 -- In the extension case, make sure ancestor is frozen appropriately 8021 -- (see also non-discriminated case below). 8022 8023 if Present (Record_Extension_Part (Type_Def)) 8024 or else Is_Interface (Parent_Base) 8025 then 8026 Freeze_Before (New_Decl, Parent_Type); 8027 end if; 8028 8029 -- Note that this call passes False for the Derive_Subps parameter 8030 -- because subprogram derivation is deferred until after creating 8031 -- the subtype (see below). 8032 8033 Build_Derived_Type 8034 (New_Decl, Parent_Base, New_Base, 8035 Is_Completion => False, Derive_Subps => False); 8036 8037 -- ??? This needs re-examination to determine whether the 8038 -- above call can simply be replaced by a call to Analyze. 8039 8040 Set_Analyzed (New_Decl); 8041 8042 -- Insert and analyze the declaration for the constrained subtype 8043 8044 if Constraint_Present then 8045 New_Indic := 8046 Make_Subtype_Indication (Loc, 8047 Subtype_Mark => New_Occurrence_Of (New_Base, Loc), 8048 Constraint => Relocate_Node (Constraint (Indic))); 8049 8050 else 8051 declare 8052 Constr_List : constant List_Id := New_List; 8053 C : Elmt_Id; 8054 Expr : Node_Id; 8055 8056 begin 8057 C := First_Elmt (Discriminant_Constraint (Parent_Type)); 8058 while Present (C) loop 8059 Expr := Node (C); 8060 8061 -- It is safe here to call New_Copy_Tree since we called 8062 -- Force_Evaluation on each constraint previously 8063 -- in Build_Discriminant_Constraints. 8064 8065 Append (New_Copy_Tree (Expr), To => Constr_List); 8066 8067 Next_Elmt (C); 8068 end loop; 8069 8070 New_Indic := 8071 Make_Subtype_Indication (Loc, 8072 Subtype_Mark => New_Occurrence_Of (New_Base, Loc), 8073 Constraint => 8074 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List)); 8075 end; 8076 end if; 8077 8078 Rewrite (N, 8079 Make_Subtype_Declaration (Loc, 8080 Defining_Identifier => Derived_Type, 8081 Subtype_Indication => New_Indic)); 8082 8083 Analyze (N); 8084 8085 -- Derivation of subprograms must be delayed until the full subtype 8086 -- has been established, to ensure proper overriding of subprograms 8087 -- inherited by full types. If the derivations occurred as part of 8088 -- the call to Build_Derived_Type above, then the check for type 8089 -- conformance would fail because earlier primitive subprograms 8090 -- could still refer to the full type prior the change to the new 8091 -- subtype and hence would not match the new base type created here. 8092 -- Subprograms are not derived, however, when Derive_Subps is False 8093 -- (since otherwise there could be redundant derivations). 8094 8095 if Derive_Subps then 8096 Derive_Subprograms (Parent_Type, Derived_Type); 8097 end if; 8098 8099 -- For tagged types the Discriminant_Constraint of the new base itype 8100 -- is inherited from the first subtype so that no subtype conformance 8101 -- problem arise when the first subtype overrides primitive 8102 -- operations inherited by the implicit base type. 8103 8104 if Is_Tagged then 8105 Set_Discriminant_Constraint 8106 (New_Base, Discriminant_Constraint (Derived_Type)); 8107 end if; 8108 8109 return; 8110 end if; 8111 8112 -- If we get here Derived_Type will have no discriminants or it will be 8113 -- a discriminated unconstrained base type. 8114 8115 -- STEP 1a: perform preliminary actions/checks for derived tagged types 8116 8117 if Is_Tagged then 8118 8119 -- The parent type is frozen for non-private extensions (RM 13.14(7)) 8120 -- The declaration of a specific descendant of an interface type 8121 -- freezes the interface type (RM 13.14). 8122 8123 if not Private_Extension or else Is_Interface (Parent_Base) then 8124 Freeze_Before (N, Parent_Type); 8125 end if; 8126 8127 -- In Ada 2005 (AI-344), the restriction that a derived tagged type 8128 -- cannot be declared at a deeper level than its parent type is 8129 -- removed. The check on derivation within a generic body is also 8130 -- relaxed, but there's a restriction that a derived tagged type 8131 -- cannot be declared in a generic body if it's derived directly 8132 -- or indirectly from a formal type of that generic. 8133 8134 if Ada_Version >= Ada_2005 then 8135 if Present (Enclosing_Generic_Body (Derived_Type)) then 8136 declare 8137 Ancestor_Type : Entity_Id; 8138 8139 begin 8140 -- Check to see if any ancestor of the derived type is a 8141 -- formal type. 8142 8143 Ancestor_Type := Parent_Type; 8144 while not Is_Generic_Type (Ancestor_Type) 8145 and then Etype (Ancestor_Type) /= Ancestor_Type 8146 loop 8147 Ancestor_Type := Etype (Ancestor_Type); 8148 end loop; 8149 8150 -- If the derived type does have a formal type as an 8151 -- ancestor, then it's an error if the derived type is 8152 -- declared within the body of the generic unit that 8153 -- declares the formal type in its generic formal part. It's 8154 -- sufficient to check whether the ancestor type is declared 8155 -- inside the same generic body as the derived type (such as 8156 -- within a nested generic spec), in which case the 8157 -- derivation is legal. If the formal type is declared 8158 -- outside of that generic body, then it's guaranteed that 8159 -- the derived type is declared within the generic body of 8160 -- the generic unit declaring the formal type. 8161 8162 if Is_Generic_Type (Ancestor_Type) 8163 and then Enclosing_Generic_Body (Ancestor_Type) /= 8164 Enclosing_Generic_Body (Derived_Type) 8165 then 8166 Error_Msg_NE 8167 ("parent type of& must not be descendant of formal type" 8168 & " of an enclosing generic body", 8169 Indic, Derived_Type); 8170 end if; 8171 end; 8172 end if; 8173 8174 elsif Type_Access_Level (Derived_Type) /= 8175 Type_Access_Level (Parent_Type) 8176 and then not Is_Generic_Type (Derived_Type) 8177 then 8178 if Is_Controlled (Parent_Type) then 8179 Error_Msg_N 8180 ("controlled type must be declared at the library level", 8181 Indic); 8182 else 8183 Error_Msg_N 8184 ("type extension at deeper accessibility level than parent", 8185 Indic); 8186 end if; 8187 8188 else 8189 declare 8190 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type); 8191 begin 8192 if Present (GB) 8193 and then GB /= Enclosing_Generic_Body (Parent_Base) 8194 then 8195 Error_Msg_NE 8196 ("parent type of& must not be outside generic body" 8197 & " (RM 3.9.1(4))", 8198 Indic, Derived_Type); 8199 end if; 8200 end; 8201 end if; 8202 end if; 8203 8204 -- Ada 2005 (AI-251) 8205 8206 if Ada_Version >= Ada_2005 and then Is_Tagged then 8207 8208 -- "The declaration of a specific descendant of an interface type 8209 -- freezes the interface type" (RM 13.14). 8210 8211 declare 8212 Iface : Node_Id; 8213 begin 8214 if Is_Non_Empty_List (Interface_List (Type_Def)) then 8215 Iface := First (Interface_List (Type_Def)); 8216 while Present (Iface) loop 8217 Freeze_Before (N, Etype (Iface)); 8218 Next (Iface); 8219 end loop; 8220 end if; 8221 end; 8222 end if; 8223 8224 -- STEP 1b : preliminary cleanup of the full view of private types 8225 8226 -- If the type is already marked as having discriminants, then it's the 8227 -- completion of a private type or private extension and we need to 8228 -- retain the discriminants from the partial view if the current 8229 -- declaration has Discriminant_Specifications so that we can verify 8230 -- conformance. However, we must remove any existing components that 8231 -- were inherited from the parent (and attached in Copy_And_Swap) 8232 -- because the full type inherits all appropriate components anyway, and 8233 -- we do not want the partial view's components interfering. 8234 8235 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then 8236 Discrim := First_Discriminant (Derived_Type); 8237 loop 8238 Last_Discrim := Discrim; 8239 Next_Discriminant (Discrim); 8240 exit when No (Discrim); 8241 end loop; 8242 8243 Set_Last_Entity (Derived_Type, Last_Discrim); 8244 8245 -- In all other cases wipe out the list of inherited components (even 8246 -- inherited discriminants), it will be properly rebuilt here. 8247 8248 else 8249 Set_First_Entity (Derived_Type, Empty); 8250 Set_Last_Entity (Derived_Type, Empty); 8251 end if; 8252 8253 -- STEP 1c: Initialize some flags for the Derived_Type 8254 8255 -- The following flags must be initialized here so that 8256 -- Process_Discriminants can check that discriminants of tagged types do 8257 -- not have a default initial value and that access discriminants are 8258 -- only specified for limited records. For completeness, these flags are 8259 -- also initialized along with all the other flags below. 8260 8261 -- AI-419: Limitedness is not inherited from an interface parent, so to 8262 -- be limited in that case the type must be explicitly declared as 8263 -- limited. However, task and protected interfaces are always limited. 8264 8265 if Limited_Present (Type_Def) then 8266 Set_Is_Limited_Record (Derived_Type); 8267 8268 elsif Is_Limited_Record (Parent_Type) 8269 or else (Present (Full_View (Parent_Type)) 8270 and then Is_Limited_Record (Full_View (Parent_Type))) 8271 then 8272 if not Is_Interface (Parent_Type) 8273 or else Is_Synchronized_Interface (Parent_Type) 8274 or else Is_Protected_Interface (Parent_Type) 8275 or else Is_Task_Interface (Parent_Type) 8276 then 8277 Set_Is_Limited_Record (Derived_Type); 8278 end if; 8279 end if; 8280 8281 -- STEP 2a: process discriminants of derived type if any 8282 8283 Push_Scope (Derived_Type); 8284 8285 if Discriminant_Specs then 8286 Set_Has_Unknown_Discriminants (Derived_Type, False); 8287 8288 -- The following call initializes fields Has_Discriminants and 8289 -- Discriminant_Constraint, unless we are processing the completion 8290 -- of a private type declaration. 8291 8292 Check_Or_Process_Discriminants (N, Derived_Type); 8293 8294 -- For untagged types, the constraint on the Parent_Type must be 8295 -- present and is used to rename the discriminants. 8296 8297 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then 8298 Error_Msg_N ("untagged parent must have discriminants", Indic); 8299 8300 elsif not Is_Tagged and then not Constraint_Present then 8301 Error_Msg_N 8302 ("discriminant constraint needed for derived untagged records", 8303 Indic); 8304 8305 -- Otherwise the parent subtype must be constrained unless we have a 8306 -- private extension. 8307 8308 elsif not Constraint_Present 8309 and then not Private_Extension 8310 and then not Is_Constrained (Parent_Type) 8311 then 8312 Error_Msg_N 8313 ("unconstrained type not allowed in this context", Indic); 8314 8315 elsif Constraint_Present then 8316 -- The following call sets the field Corresponding_Discriminant 8317 -- for the discriminants in the Derived_Type. 8318 8319 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True); 8320 8321 -- For untagged types all new discriminants must rename 8322 -- discriminants in the parent. For private extensions new 8323 -- discriminants cannot rename old ones (implied by [7.3(13)]). 8324 8325 Discrim := First_Discriminant (Derived_Type); 8326 while Present (Discrim) loop 8327 if not Is_Tagged 8328 and then No (Corresponding_Discriminant (Discrim)) 8329 then 8330 Error_Msg_N 8331 ("new discriminants must constrain old ones", Discrim); 8332 8333 elsif Private_Extension 8334 and then Present (Corresponding_Discriminant (Discrim)) 8335 then 8336 Error_Msg_N 8337 ("only static constraints allowed for parent" 8338 & " discriminants in the partial view", Indic); 8339 exit; 8340 end if; 8341 8342 -- If a new discriminant is used in the constraint, then its 8343 -- subtype must be statically compatible with the parent 8344 -- discriminant's subtype (3.7(15)). 8345 8346 -- However, if the record contains an array constrained by 8347 -- the discriminant but with some different bound, the compiler 8348 -- attemps to create a smaller range for the discriminant type. 8349 -- (See exp_ch3.Adjust_Discriminants). In this case, where 8350 -- the discriminant type is a scalar type, the check must use 8351 -- the original discriminant type in the parent declaration. 8352 8353 declare 8354 Corr_Disc : constant Entity_Id := 8355 Corresponding_Discriminant (Discrim); 8356 Disc_Type : constant Entity_Id := Etype (Discrim); 8357 Corr_Type : Entity_Id; 8358 8359 begin 8360 if Present (Corr_Disc) then 8361 if Is_Scalar_Type (Disc_Type) then 8362 Corr_Type := 8363 Entity (Discriminant_Type (Parent (Corr_Disc))); 8364 else 8365 Corr_Type := Etype (Corr_Disc); 8366 end if; 8367 8368 if not 8369 Subtypes_Statically_Compatible (Disc_Type, Corr_Type) 8370 then 8371 Error_Msg_N 8372 ("subtype must be compatible " 8373 & "with parent discriminant", 8374 Discrim); 8375 end if; 8376 end if; 8377 end; 8378 8379 Next_Discriminant (Discrim); 8380 end loop; 8381 8382 -- Check whether the constraints of the full view statically 8383 -- match those imposed by the parent subtype [7.3(13)]. 8384 8385 if Present (Stored_Constraint (Derived_Type)) then 8386 declare 8387 C1, C2 : Elmt_Id; 8388 8389 begin 8390 C1 := First_Elmt (Discs); 8391 C2 := First_Elmt (Stored_Constraint (Derived_Type)); 8392 while Present (C1) and then Present (C2) loop 8393 if not 8394 Fully_Conformant_Expressions (Node (C1), Node (C2)) 8395 then 8396 Error_Msg_N 8397 ("not conformant with previous declaration", 8398 Node (C1)); 8399 end if; 8400 8401 Next_Elmt (C1); 8402 Next_Elmt (C2); 8403 end loop; 8404 end; 8405 end if; 8406 end if; 8407 8408 -- STEP 2b: No new discriminants, inherit discriminants if any 8409 8410 else 8411 if Private_Extension then 8412 Set_Has_Unknown_Discriminants 8413 (Derived_Type, 8414 Has_Unknown_Discriminants (Parent_Type) 8415 or else Unknown_Discriminants_Present (N)); 8416 8417 -- The partial view of the parent may have unknown discriminants, 8418 -- but if the full view has discriminants and the parent type is 8419 -- in scope they must be inherited. 8420 8421 elsif Has_Unknown_Discriminants (Parent_Type) 8422 and then 8423 (not Has_Discriminants (Parent_Type) 8424 or else not In_Open_Scopes (Scope (Parent_Type))) 8425 then 8426 Set_Has_Unknown_Discriminants (Derived_Type); 8427 end if; 8428 8429 if not Has_Unknown_Discriminants (Derived_Type) 8430 and then not Has_Unknown_Discriminants (Parent_Base) 8431 and then Has_Discriminants (Parent_Type) 8432 then 8433 Inherit_Discrims := True; 8434 Set_Has_Discriminants 8435 (Derived_Type, True); 8436 Set_Discriminant_Constraint 8437 (Derived_Type, Discriminant_Constraint (Parent_Base)); 8438 end if; 8439 8440 -- The following test is true for private types (remember 8441 -- transformation 5. is not applied to those) and in an error 8442 -- situation. 8443 8444 if Constraint_Present then 8445 Discs := Build_Discriminant_Constraints (Parent_Type, Indic); 8446 end if; 8447 8448 -- For now mark a new derived type as constrained only if it has no 8449 -- discriminants. At the end of Build_Derived_Record_Type we properly 8450 -- set this flag in the case of private extensions. See comments in 8451 -- point 9. just before body of Build_Derived_Record_Type. 8452 8453 Set_Is_Constrained 8454 (Derived_Type, 8455 not (Inherit_Discrims 8456 or else Has_Unknown_Discriminants (Derived_Type))); 8457 end if; 8458 8459 -- STEP 3: initialize fields of derived type 8460 8461 Set_Is_Tagged_Type (Derived_Type, Is_Tagged); 8462 Set_Stored_Constraint (Derived_Type, No_Elist); 8463 8464 -- Ada 2005 (AI-251): Private type-declarations can implement interfaces 8465 -- but cannot be interfaces 8466 8467 if not Private_Extension 8468 and then Ekind (Derived_Type) /= E_Private_Type 8469 and then Ekind (Derived_Type) /= E_Limited_Private_Type 8470 then 8471 if Interface_Present (Type_Def) then 8472 Analyze_Interface_Declaration (Derived_Type, Type_Def); 8473 end if; 8474 8475 Set_Interfaces (Derived_Type, No_Elist); 8476 end if; 8477 8478 -- Fields inherited from the Parent_Type 8479 8480 Set_Has_Specified_Layout 8481 (Derived_Type, Has_Specified_Layout (Parent_Type)); 8482 Set_Is_Limited_Composite 8483 (Derived_Type, Is_Limited_Composite (Parent_Type)); 8484 Set_Is_Private_Composite 8485 (Derived_Type, Is_Private_Composite (Parent_Type)); 8486 8487 if Is_Tagged_Type (Parent_Type) then 8488 Set_No_Tagged_Streams_Pragma 8489 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type)); 8490 end if; 8491 8492 -- Fields inherited from the Parent_Base 8493 8494 Set_Has_Controlled_Component 8495 (Derived_Type, Has_Controlled_Component (Parent_Base)); 8496 Set_Has_Non_Standard_Rep 8497 (Derived_Type, Has_Non_Standard_Rep (Parent_Base)); 8498 Set_Has_Primitive_Operations 8499 (Derived_Type, Has_Primitive_Operations (Parent_Base)); 8500 8501 -- Fields inherited from the Parent_Base in the non-private case 8502 8503 if Ekind (Derived_Type) = E_Record_Type then 8504 Set_Has_Complex_Representation 8505 (Derived_Type, Has_Complex_Representation (Parent_Base)); 8506 end if; 8507 8508 -- Fields inherited from the Parent_Base for record types 8509 8510 if Is_Record_Type (Derived_Type) then 8511 declare 8512 Parent_Full : Entity_Id; 8513 8514 begin 8515 -- Ekind (Parent_Base) is not necessarily E_Record_Type since 8516 -- Parent_Base can be a private type or private extension. Go 8517 -- to the full view here to get the E_Record_Type specific flags. 8518 8519 if Present (Full_View (Parent_Base)) then 8520 Parent_Full := Full_View (Parent_Base); 8521 else 8522 Parent_Full := Parent_Base; 8523 end if; 8524 8525 Set_OK_To_Reorder_Components 8526 (Derived_Type, OK_To_Reorder_Components (Parent_Full)); 8527 end; 8528 end if; 8529 8530 -- Set fields for private derived types 8531 8532 if Is_Private_Type (Derived_Type) then 8533 Set_Depends_On_Private (Derived_Type, True); 8534 Set_Private_Dependents (Derived_Type, New_Elmt_List); 8535 8536 -- Inherit fields from non private record types. If this is the 8537 -- completion of a derivation from a private type, the parent itself 8538 -- is private, and the attributes come from its full view, which must 8539 -- be present. 8540 8541 else 8542 if Is_Private_Type (Parent_Base) 8543 and then not Is_Record_Type (Parent_Base) 8544 then 8545 Set_Component_Alignment 8546 (Derived_Type, Component_Alignment (Full_View (Parent_Base))); 8547 Set_C_Pass_By_Copy 8548 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base))); 8549 else 8550 Set_Component_Alignment 8551 (Derived_Type, Component_Alignment (Parent_Base)); 8552 Set_C_Pass_By_Copy 8553 (Derived_Type, C_Pass_By_Copy (Parent_Base)); 8554 end if; 8555 end if; 8556 8557 -- Set fields for tagged types 8558 8559 if Is_Tagged then 8560 Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List); 8561 8562 -- All tagged types defined in Ada.Finalization are controlled 8563 8564 if Chars (Scope (Derived_Type)) = Name_Finalization 8565 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada 8566 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard 8567 then 8568 Set_Is_Controlled (Derived_Type); 8569 else 8570 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base)); 8571 end if; 8572 8573 -- Minor optimization: there is no need to generate the class-wide 8574 -- entity associated with an underlying record view. 8575 8576 if not Is_Underlying_Record_View (Derived_Type) then 8577 Make_Class_Wide_Type (Derived_Type); 8578 end if; 8579 8580 Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def)); 8581 8582 if Has_Discriminants (Derived_Type) 8583 and then Constraint_Present 8584 then 8585 Set_Stored_Constraint 8586 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs)); 8587 end if; 8588 8589 if Ada_Version >= Ada_2005 then 8590 declare 8591 Ifaces_List : Elist_Id; 8592 8593 begin 8594 -- Checks rules 3.9.4 (13/2 and 14/2) 8595 8596 if Comes_From_Source (Derived_Type) 8597 and then not Is_Private_Type (Derived_Type) 8598 and then Is_Interface (Parent_Type) 8599 and then not Is_Interface (Derived_Type) 8600 then 8601 if Is_Task_Interface (Parent_Type) then 8602 Error_Msg_N 8603 ("(Ada 2005) task type required (RM 3.9.4 (13.2))", 8604 Derived_Type); 8605 8606 elsif Is_Protected_Interface (Parent_Type) then 8607 Error_Msg_N 8608 ("(Ada 2005) protected type required (RM 3.9.4 (14.2))", 8609 Derived_Type); 8610 end if; 8611 end if; 8612 8613 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2) 8614 8615 Check_Interfaces (N, Type_Def); 8616 8617 -- Ada 2005 (AI-251): Collect the list of progenitors that are 8618 -- not already in the parents. 8619 8620 Collect_Interfaces 8621 (T => Derived_Type, 8622 Ifaces_List => Ifaces_List, 8623 Exclude_Parents => True); 8624 8625 Set_Interfaces (Derived_Type, Ifaces_List); 8626 8627 -- If the derived type is the anonymous type created for 8628 -- a declaration whose parent has a constraint, propagate 8629 -- the interface list to the source type. This must be done 8630 -- prior to the completion of the analysis of the source type 8631 -- because the components in the extension may contain current 8632 -- instances whose legality depends on some ancestor. 8633 8634 if Is_Itype (Derived_Type) then 8635 declare 8636 Def : constant Node_Id := 8637 Associated_Node_For_Itype (Derived_Type); 8638 begin 8639 if Present (Def) 8640 and then Nkind (Def) = N_Full_Type_Declaration 8641 then 8642 Set_Interfaces 8643 (Defining_Identifier (Def), Ifaces_List); 8644 end if; 8645 end; 8646 end if; 8647 8648 -- Propagate inherited invariant information of parents 8649 -- and progenitors 8650 8651 if Ada_Version >= Ada_2012 8652 and then not Is_Interface (Derived_Type) 8653 then 8654 if Has_Inheritable_Invariants (Parent_Type) then 8655 Set_Has_Invariants (Derived_Type); 8656 Set_Has_Inheritable_Invariants (Derived_Type); 8657 8658 elsif not Is_Empty_Elmt_List (Ifaces_List) then 8659 declare 8660 AI : Elmt_Id; 8661 8662 begin 8663 AI := First_Elmt (Ifaces_List); 8664 while Present (AI) loop 8665 if Has_Inheritable_Invariants (Node (AI)) then 8666 Set_Has_Invariants (Derived_Type); 8667 Set_Has_Inheritable_Invariants (Derived_Type); 8668 8669 exit; 8670 end if; 8671 8672 Next_Elmt (AI); 8673 end loop; 8674 end; 8675 end if; 8676 end if; 8677 8678 -- A type extension is automatically Ghost when one of its 8679 -- progenitors is Ghost (SPARK RM 6.9(9)). This property is 8680 -- also inherited when the parent type is Ghost, but this is 8681 -- done in Build_Derived_Type as the mechanism also handles 8682 -- untagged derivations. 8683 8684 if Implements_Ghost_Interface (Derived_Type) then 8685 Set_Is_Ghost_Entity (Derived_Type); 8686 end if; 8687 end; 8688 end if; 8689 8690 else 8691 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base)); 8692 Set_Has_Non_Standard_Rep 8693 (Derived_Type, Has_Non_Standard_Rep (Parent_Base)); 8694 end if; 8695 8696 -- STEP 4: Inherit components from the parent base and constrain them. 8697 -- Apply the second transformation described in point 6. above. 8698 8699 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims) 8700 or else not Has_Discriminants (Parent_Type) 8701 or else not Is_Constrained (Parent_Type) 8702 then 8703 Constrs := Discs; 8704 else 8705 Constrs := Discriminant_Constraint (Parent_Type); 8706 end if; 8707 8708 Assoc_List := 8709 Inherit_Components 8710 (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs); 8711 8712 -- STEP 5a: Copy the parent record declaration for untagged types 8713 8714 if not Is_Tagged then 8715 8716 -- Discriminant_Constraint (Derived_Type) has been properly 8717 -- constructed. Save it and temporarily set it to Empty because we 8718 -- do not want the call to New_Copy_Tree below to mess this list. 8719 8720 if Has_Discriminants (Derived_Type) then 8721 Save_Discr_Constr := Discriminant_Constraint (Derived_Type); 8722 Set_Discriminant_Constraint (Derived_Type, No_Elist); 8723 else 8724 Save_Discr_Constr := No_Elist; 8725 end if; 8726 8727 -- Save the Etype field of Derived_Type. It is correctly set now, 8728 -- but the call to New_Copy tree may remap it to point to itself, 8729 -- which is not what we want. Ditto for the Next_Entity field. 8730 8731 Save_Etype := Etype (Derived_Type); 8732 Save_Next_Entity := Next_Entity (Derived_Type); 8733 8734 -- Assoc_List maps all stored discriminants in the Parent_Base to 8735 -- stored discriminants in the Derived_Type. It is fundamental that 8736 -- no types or itypes with discriminants other than the stored 8737 -- discriminants appear in the entities declared inside 8738 -- Derived_Type, since the back end cannot deal with it. 8739 8740 New_Decl := 8741 New_Copy_Tree 8742 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc); 8743 8744 -- Restore the fields saved prior to the New_Copy_Tree call 8745 -- and compute the stored constraint. 8746 8747 Set_Etype (Derived_Type, Save_Etype); 8748 Set_Next_Entity (Derived_Type, Save_Next_Entity); 8749 8750 if Has_Discriminants (Derived_Type) then 8751 Set_Discriminant_Constraint 8752 (Derived_Type, Save_Discr_Constr); 8753 Set_Stored_Constraint 8754 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs)); 8755 Replace_Components (Derived_Type, New_Decl); 8756 Set_Has_Implicit_Dereference 8757 (Derived_Type, Has_Implicit_Dereference (Parent_Type)); 8758 end if; 8759 8760 -- Insert the new derived type declaration 8761 8762 Rewrite (N, New_Decl); 8763 8764 -- STEP 5b: Complete the processing for record extensions in generics 8765 8766 -- There is no completion for record extensions declared in the 8767 -- parameter part of a generic, so we need to complete processing for 8768 -- these generic record extensions here. The Record_Type_Definition call 8769 -- will change the Ekind of the components from E_Void to E_Component. 8770 8771 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then 8772 Record_Type_Definition (Empty, Derived_Type); 8773 8774 -- STEP 5c: Process the record extension for non private tagged types 8775 8776 elsif not Private_Extension then 8777 Expand_Record_Extension (Derived_Type, Type_Def); 8778 8779 -- Note : previously in ASIS mode we set the Parent_Subtype of the 8780 -- derived type to propagate some semantic information. This led 8781 -- to other ASIS failures and has been removed. 8782 8783 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the 8784 -- implemented interfaces if we are in expansion mode 8785 8786 if Expander_Active 8787 and then Has_Interfaces (Derived_Type) 8788 then 8789 Add_Interface_Tag_Components (N, Derived_Type); 8790 end if; 8791 8792 -- Analyze the record extension 8793 8794 Record_Type_Definition 8795 (Record_Extension_Part (Type_Def), Derived_Type); 8796 end if; 8797 8798 End_Scope; 8799 8800 -- Nothing else to do if there is an error in the derivation. 8801 -- An unusual case: the full view may be derived from a type in an 8802 -- instance, when the partial view was used illegally as an actual 8803 -- in that instance, leading to a circular definition. 8804 8805 if Etype (Derived_Type) = Any_Type 8806 or else Etype (Parent_Type) = Derived_Type 8807 then 8808 return; 8809 end if; 8810 8811 -- Set delayed freeze and then derive subprograms, we need to do 8812 -- this in this order so that derived subprograms inherit the 8813 -- derived freeze if necessary. 8814 8815 Set_Has_Delayed_Freeze (Derived_Type); 8816 8817 if Derive_Subps then 8818 Derive_Subprograms (Parent_Type, Derived_Type); 8819 end if; 8820 8821 -- If we have a private extension which defines a constrained derived 8822 -- type mark as constrained here after we have derived subprograms. See 8823 -- comment on point 9. just above the body of Build_Derived_Record_Type. 8824 8825 if Private_Extension and then Inherit_Discrims then 8826 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then 8827 Set_Is_Constrained (Derived_Type, True); 8828 Set_Discriminant_Constraint (Derived_Type, Discs); 8829 8830 elsif Is_Constrained (Parent_Type) then 8831 Set_Is_Constrained 8832 (Derived_Type, True); 8833 Set_Discriminant_Constraint 8834 (Derived_Type, Discriminant_Constraint (Parent_Type)); 8835 end if; 8836 end if; 8837 8838 -- Update the class-wide type, which shares the now-completed entity 8839 -- list with its specific type. In case of underlying record views, 8840 -- we do not generate the corresponding class wide entity. 8841 8842 if Is_Tagged 8843 and then not Is_Underlying_Record_View (Derived_Type) 8844 then 8845 Set_First_Entity 8846 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type)); 8847 Set_Last_Entity 8848 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type)); 8849 end if; 8850 8851 Check_Function_Writable_Actuals (N); 8852 end Build_Derived_Record_Type; 8853 8854 ------------------------ 8855 -- Build_Derived_Type -- 8856 ------------------------ 8857 8858 procedure Build_Derived_Type 8859 (N : Node_Id; 8860 Parent_Type : Entity_Id; 8861 Derived_Type : Entity_Id; 8862 Is_Completion : Boolean; 8863 Derive_Subps : Boolean := True) 8864 is 8865 Parent_Base : constant Entity_Id := Base_Type (Parent_Type); 8866 8867 begin 8868 -- Set common attributes 8869 8870 Set_Scope (Derived_Type, Current_Scope); 8871 8872 Set_Etype (Derived_Type, Parent_Base); 8873 Set_Ekind (Derived_Type, Ekind (Parent_Base)); 8874 Set_Has_Task (Derived_Type, Has_Task (Parent_Base)); 8875 Set_Has_Protected (Derived_Type, Has_Protected (Parent_Base)); 8876 8877 Set_Size_Info (Derived_Type, Parent_Type); 8878 Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); 8879 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type)); 8880 Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type)); 8881 Set_Is_Volatile (Derived_Type, Is_Volatile (Parent_Type)); 8882 8883 if Is_Tagged_Type (Derived_Type) then 8884 Set_No_Tagged_Streams_Pragma 8885 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type)); 8886 end if; 8887 8888 -- If the parent has primitive routines, set the derived type link 8889 8890 if Has_Primitive_Operations (Parent_Type) then 8891 Set_Derived_Type_Link (Parent_Base, Derived_Type); 8892 end if; 8893 8894 -- If the parent type is a private subtype, the convention on the base 8895 -- type may be set in the private part, and not propagated to the 8896 -- subtype until later, so we obtain the convention from the base type. 8897 8898 Set_Convention (Derived_Type, Convention (Parent_Base)); 8899 8900 -- Set SSO default for record or array type 8901 8902 if (Is_Array_Type (Derived_Type) or else Is_Record_Type (Derived_Type)) 8903 and then Is_Base_Type (Derived_Type) 8904 then 8905 Set_Default_SSO (Derived_Type); 8906 end if; 8907 8908 -- Propagate invariant information. The new type has invariants if 8909 -- they are inherited from the parent type, and these invariants can 8910 -- be further inherited, so both flags are set. 8911 8912 -- We similarly inherit predicates 8913 8914 if Has_Predicates (Parent_Type) then 8915 Set_Has_Predicates (Derived_Type); 8916 end if; 8917 8918 -- The derived type inherits the representation clauses of the parent 8919 8920 Inherit_Rep_Item_Chain (Derived_Type, Parent_Type); 8921 8922 -- Propagate the attributes related to pragma Default_Initial_Condition 8923 -- from the parent type to the private extension. A derived type always 8924 -- inherits the default initial condition flag from the parent type. If 8925 -- the derived type carries its own Default_Initial_Condition pragma, 8926 -- the flag is later reset in Analyze_Pragma. Note that both flags are 8927 -- mutually exclusive. 8928 8929 Propagate_Default_Init_Cond_Attributes 8930 (From_Typ => Parent_Type, 8931 To_Typ => Derived_Type, 8932 Parent_To_Derivation => True); 8933 8934 -- If the parent type has delayed rep aspects, then mark the derived 8935 -- type as possibly inheriting a delayed rep aspect. 8936 8937 if Has_Delayed_Rep_Aspects (Parent_Type) then 8938 Set_May_Inherit_Delayed_Rep_Aspects (Derived_Type); 8939 end if; 8940 8941 -- Propagate the attributes related to pragma Ghost from the parent type 8942 -- to the derived type or type extension (SPARK RM 6.9(9)). 8943 8944 if Is_Ghost_Entity (Parent_Type) then 8945 Set_Is_Ghost_Entity (Derived_Type); 8946 end if; 8947 8948 -- Type dependent processing 8949 8950 case Ekind (Parent_Type) is 8951 when Numeric_Kind => 8952 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type); 8953 8954 when Array_Kind => 8955 Build_Derived_Array_Type (N, Parent_Type, Derived_Type); 8956 8957 when E_Record_Type 8958 | E_Record_Subtype 8959 | Class_Wide_Kind => 8960 Build_Derived_Record_Type 8961 (N, Parent_Type, Derived_Type, Derive_Subps); 8962 return; 8963 8964 when Enumeration_Kind => 8965 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type); 8966 8967 when Access_Kind => 8968 Build_Derived_Access_Type (N, Parent_Type, Derived_Type); 8969 8970 when Incomplete_Or_Private_Kind => 8971 Build_Derived_Private_Type 8972 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps); 8973 8974 -- For discriminated types, the derivation includes deriving 8975 -- primitive operations. For others it is done below. 8976 8977 if Is_Tagged_Type (Parent_Type) 8978 or else Has_Discriminants (Parent_Type) 8979 or else (Present (Full_View (Parent_Type)) 8980 and then Has_Discriminants (Full_View (Parent_Type))) 8981 then 8982 return; 8983 end if; 8984 8985 when Concurrent_Kind => 8986 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type); 8987 8988 when others => 8989 raise Program_Error; 8990 end case; 8991 8992 -- Nothing more to do if some error occurred 8993 8994 if Etype (Derived_Type) = Any_Type then 8995 return; 8996 end if; 8997 8998 -- Set delayed freeze and then derive subprograms, we need to do this 8999 -- in this order so that derived subprograms inherit the derived freeze 9000 -- if necessary. 9001 9002 Set_Has_Delayed_Freeze (Derived_Type); 9003 9004 if Derive_Subps then 9005 Derive_Subprograms (Parent_Type, Derived_Type); 9006 end if; 9007 9008 Set_Has_Primitive_Operations 9009 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type)); 9010 end Build_Derived_Type; 9011 9012 ----------------------- 9013 -- Build_Discriminal -- 9014 ----------------------- 9015 9016 procedure Build_Discriminal (Discrim : Entity_Id) is 9017 D_Minal : Entity_Id; 9018 CR_Disc : Entity_Id; 9019 9020 begin 9021 -- A discriminal has the same name as the discriminant 9022 9023 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim)); 9024 9025 Set_Ekind (D_Minal, E_In_Parameter); 9026 Set_Mechanism (D_Minal, Default_Mechanism); 9027 Set_Etype (D_Minal, Etype (Discrim)); 9028 Set_Scope (D_Minal, Current_Scope); 9029 9030 Set_Discriminal (Discrim, D_Minal); 9031 Set_Discriminal_Link (D_Minal, Discrim); 9032 9033 -- For task types, build at once the discriminants of the corresponding 9034 -- record, which are needed if discriminants are used in entry defaults 9035 -- and in family bounds. 9036 9037 if Is_Concurrent_Type (Current_Scope) 9038 or else 9039 Is_Limited_Type (Current_Scope) 9040 then 9041 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim)); 9042 9043 Set_Ekind (CR_Disc, E_In_Parameter); 9044 Set_Mechanism (CR_Disc, Default_Mechanism); 9045 Set_Etype (CR_Disc, Etype (Discrim)); 9046 Set_Scope (CR_Disc, Current_Scope); 9047 Set_Discriminal_Link (CR_Disc, Discrim); 9048 Set_CR_Discriminant (Discrim, CR_Disc); 9049 end if; 9050 end Build_Discriminal; 9051 9052 ------------------------------------ 9053 -- Build_Discriminant_Constraints -- 9054 ------------------------------------ 9055 9056 function Build_Discriminant_Constraints 9057 (T : Entity_Id; 9058 Def : Node_Id; 9059 Derived_Def : Boolean := False) return Elist_Id 9060 is 9061 C : constant Node_Id := Constraint (Def); 9062 Nb_Discr : constant Nat := Number_Discriminants (T); 9063 9064 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty); 9065 -- Saves the expression corresponding to a given discriminant in T 9066 9067 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat; 9068 -- Return the Position number within array Discr_Expr of a discriminant 9069 -- D within the discriminant list of the discriminated type T. 9070 9071 procedure Process_Discriminant_Expression 9072 (Expr : Node_Id; 9073 D : Entity_Id); 9074 -- If this is a discriminant constraint on a partial view, do not 9075 -- generate an overflow check on the discriminant expression. The check 9076 -- will be generated when constraining the full view. Otherwise the 9077 -- backend creates duplicate symbols for the temporaries corresponding 9078 -- to the expressions to be checked, causing spurious assembler errors. 9079 9080 ------------------ 9081 -- Pos_Of_Discr -- 9082 ------------------ 9083 9084 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is 9085 Disc : Entity_Id; 9086 9087 begin 9088 Disc := First_Discriminant (T); 9089 for J in Discr_Expr'Range loop 9090 if Disc = D then 9091 return J; 9092 end if; 9093 9094 Next_Discriminant (Disc); 9095 end loop; 9096 9097 -- Note: Since this function is called on discriminants that are 9098 -- known to belong to the discriminated type, falling through the 9099 -- loop with no match signals an internal compiler error. 9100 9101 raise Program_Error; 9102 end Pos_Of_Discr; 9103 9104 ------------------------------------- 9105 -- Process_Discriminant_Expression -- 9106 ------------------------------------- 9107 9108 procedure Process_Discriminant_Expression 9109 (Expr : Node_Id; 9110 D : Entity_Id) 9111 is 9112 BDT : constant Entity_Id := Base_Type (Etype (D)); 9113 9114 begin 9115 -- If this is a discriminant constraint on a partial view, do 9116 -- not generate an overflow on the discriminant expression. The 9117 -- check will be generated when constraining the full view. 9118 9119 if Is_Private_Type (T) 9120 and then Present (Full_View (T)) 9121 then 9122 Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check); 9123 else 9124 Analyze_And_Resolve (Expr, BDT); 9125 end if; 9126 end Process_Discriminant_Expression; 9127 9128 -- Declarations local to Build_Discriminant_Constraints 9129 9130 Discr : Entity_Id; 9131 E : Entity_Id; 9132 Elist : constant Elist_Id := New_Elmt_List; 9133 9134 Constr : Node_Id; 9135 Expr : Node_Id; 9136 Id : Node_Id; 9137 Position : Nat; 9138 Found : Boolean; 9139 9140 Discrim_Present : Boolean := False; 9141 9142 -- Start of processing for Build_Discriminant_Constraints 9143 9144 begin 9145 -- The following loop will process positional associations only. 9146 -- For a positional association, the (single) discriminant is 9147 -- implicitly specified by position, in textual order (RM 3.7.2). 9148 9149 Discr := First_Discriminant (T); 9150 Constr := First (Constraints (C)); 9151 for D in Discr_Expr'Range loop 9152 exit when Nkind (Constr) = N_Discriminant_Association; 9153 9154 if No (Constr) then 9155 Error_Msg_N ("too few discriminants given in constraint", C); 9156 return New_Elmt_List; 9157 9158 elsif Nkind (Constr) = N_Range 9159 or else (Nkind (Constr) = N_Attribute_Reference 9160 and then Attribute_Name (Constr) = Name_Range) 9161 then 9162 Error_Msg_N 9163 ("a range is not a valid discriminant constraint", Constr); 9164 Discr_Expr (D) := Error; 9165 9166 else 9167 Process_Discriminant_Expression (Constr, Discr); 9168 Discr_Expr (D) := Constr; 9169 end if; 9170 9171 Next_Discriminant (Discr); 9172 Next (Constr); 9173 end loop; 9174 9175 if No (Discr) and then Present (Constr) then 9176 Error_Msg_N ("too many discriminants given in constraint", Constr); 9177 return New_Elmt_List; 9178 end if; 9179 9180 -- Named associations can be given in any order, but if both positional 9181 -- and named associations are used in the same discriminant constraint, 9182 -- then positional associations must occur first, at their normal 9183 -- position. Hence once a named association is used, the rest of the 9184 -- discriminant constraint must use only named associations. 9185 9186 while Present (Constr) loop 9187 9188 -- Positional association forbidden after a named association 9189 9190 if Nkind (Constr) /= N_Discriminant_Association then 9191 Error_Msg_N ("positional association follows named one", Constr); 9192 return New_Elmt_List; 9193 9194 -- Otherwise it is a named association 9195 9196 else 9197 -- E records the type of the discriminants in the named 9198 -- association. All the discriminants specified in the same name 9199 -- association must have the same type. 9200 9201 E := Empty; 9202 9203 -- Search the list of discriminants in T to see if the simple name 9204 -- given in the constraint matches any of them. 9205 9206 Id := First (Selector_Names (Constr)); 9207 while Present (Id) loop 9208 Found := False; 9209 9210 -- If Original_Discriminant is present, we are processing a 9211 -- generic instantiation and this is an instance node. We need 9212 -- to find the name of the corresponding discriminant in the 9213 -- actual record type T and not the name of the discriminant in 9214 -- the generic formal. Example: 9215 9216 -- generic 9217 -- type G (D : int) is private; 9218 -- package P is 9219 -- subtype W is G (D => 1); 9220 -- end package; 9221 -- type Rec (X : int) is record ... end record; 9222 -- package Q is new P (G => Rec); 9223 9224 -- At the point of the instantiation, formal type G is Rec 9225 -- and therefore when reanalyzing "subtype W is G (D => 1);" 9226 -- which really looks like "subtype W is Rec (D => 1);" at 9227 -- the point of instantiation, we want to find the discriminant 9228 -- that corresponds to D in Rec, i.e. X. 9229 9230 if Present (Original_Discriminant (Id)) 9231 and then In_Instance 9232 then 9233 Discr := Find_Corresponding_Discriminant (Id, T); 9234 Found := True; 9235 9236 else 9237 Discr := First_Discriminant (T); 9238 while Present (Discr) loop 9239 if Chars (Discr) = Chars (Id) then 9240 Found := True; 9241 exit; 9242 end if; 9243 9244 Next_Discriminant (Discr); 9245 end loop; 9246 9247 if not Found then 9248 Error_Msg_N ("& does not match any discriminant", Id); 9249 return New_Elmt_List; 9250 9251 -- If the parent type is a generic formal, preserve the 9252 -- name of the discriminant for subsequent instances. 9253 -- see comment at the beginning of this if statement. 9254 9255 elsif Is_Generic_Type (Root_Type (T)) then 9256 Set_Original_Discriminant (Id, Discr); 9257 end if; 9258 end if; 9259 9260 Position := Pos_Of_Discr (T, Discr); 9261 9262 if Present (Discr_Expr (Position)) then 9263 Error_Msg_N ("duplicate constraint for discriminant&", Id); 9264 9265 else 9266 -- Each discriminant specified in the same named association 9267 -- must be associated with a separate copy of the 9268 -- corresponding expression. 9269 9270 if Present (Next (Id)) then 9271 Expr := New_Copy_Tree (Expression (Constr)); 9272 Set_Parent (Expr, Parent (Expression (Constr))); 9273 else 9274 Expr := Expression (Constr); 9275 end if; 9276 9277 Discr_Expr (Position) := Expr; 9278 Process_Discriminant_Expression (Expr, Discr); 9279 end if; 9280 9281 -- A discriminant association with more than one discriminant 9282 -- name is only allowed if the named discriminants are all of 9283 -- the same type (RM 3.7.1(8)). 9284 9285 if E = Empty then 9286 E := Base_Type (Etype (Discr)); 9287 9288 elsif Base_Type (Etype (Discr)) /= E then 9289 Error_Msg_N 9290 ("all discriminants in an association " & 9291 "must have the same type", Id); 9292 end if; 9293 9294 Next (Id); 9295 end loop; 9296 end if; 9297 9298 Next (Constr); 9299 end loop; 9300 9301 -- A discriminant constraint must provide exactly one value for each 9302 -- discriminant of the type (RM 3.7.1(8)). 9303 9304 for J in Discr_Expr'Range loop 9305 if No (Discr_Expr (J)) then 9306 Error_Msg_N ("too few discriminants given in constraint", C); 9307 return New_Elmt_List; 9308 end if; 9309 end loop; 9310 9311 -- Determine if there are discriminant expressions in the constraint 9312 9313 for J in Discr_Expr'Range loop 9314 if Denotes_Discriminant 9315 (Discr_Expr (J), Check_Concurrent => True) 9316 then 9317 Discrim_Present := True; 9318 end if; 9319 end loop; 9320 9321 -- Build an element list consisting of the expressions given in the 9322 -- discriminant constraint and apply the appropriate checks. The list 9323 -- is constructed after resolving any named discriminant associations 9324 -- and therefore the expressions appear in the textual order of the 9325 -- discriminants. 9326 9327 Discr := First_Discriminant (T); 9328 for J in Discr_Expr'Range loop 9329 if Discr_Expr (J) /= Error then 9330 Append_Elmt (Discr_Expr (J), Elist); 9331 9332 -- If any of the discriminant constraints is given by a 9333 -- discriminant and we are in a derived type declaration we 9334 -- have a discriminant renaming. Establish link between new 9335 -- and old discriminant. 9336 9337 if Denotes_Discriminant (Discr_Expr (J)) then 9338 if Derived_Def then 9339 Set_Corresponding_Discriminant 9340 (Entity (Discr_Expr (J)), Discr); 9341 end if; 9342 9343 -- Force the evaluation of non-discriminant expressions. 9344 -- If we have found a discriminant in the constraint 3.4(26) 9345 -- and 3.8(18) demand that no range checks are performed are 9346 -- after evaluation. If the constraint is for a component 9347 -- definition that has a per-object constraint, expressions are 9348 -- evaluated but not checked either. In all other cases perform 9349 -- a range check. 9350 9351 else 9352 if Discrim_Present then 9353 null; 9354 9355 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration 9356 and then 9357 Has_Per_Object_Constraint 9358 (Defining_Identifier (Parent (Parent (Def)))) 9359 then 9360 null; 9361 9362 elsif Is_Access_Type (Etype (Discr)) then 9363 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr)); 9364 9365 else 9366 Apply_Range_Check (Discr_Expr (J), Etype (Discr)); 9367 end if; 9368 9369 Force_Evaluation (Discr_Expr (J)); 9370 end if; 9371 9372 -- Check that the designated type of an access discriminant's 9373 -- expression is not a class-wide type unless the discriminant's 9374 -- designated type is also class-wide. 9375 9376 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type 9377 and then not Is_Class_Wide_Type 9378 (Designated_Type (Etype (Discr))) 9379 and then Etype (Discr_Expr (J)) /= Any_Type 9380 and then Is_Class_Wide_Type 9381 (Designated_Type (Etype (Discr_Expr (J)))) 9382 then 9383 Wrong_Type (Discr_Expr (J), Etype (Discr)); 9384 9385 elsif Is_Access_Type (Etype (Discr)) 9386 and then not Is_Access_Constant (Etype (Discr)) 9387 and then Is_Access_Type (Etype (Discr_Expr (J))) 9388 and then Is_Access_Constant (Etype (Discr_Expr (J))) 9389 then 9390 Error_Msg_NE 9391 ("constraint for discriminant& must be access to variable", 9392 Def, Discr); 9393 end if; 9394 end if; 9395 9396 Next_Discriminant (Discr); 9397 end loop; 9398 9399 return Elist; 9400 end Build_Discriminant_Constraints; 9401 9402 --------------------------------- 9403 -- Build_Discriminated_Subtype -- 9404 --------------------------------- 9405 9406 procedure Build_Discriminated_Subtype 9407 (T : Entity_Id; 9408 Def_Id : Entity_Id; 9409 Elist : Elist_Id; 9410 Related_Nod : Node_Id; 9411 For_Access : Boolean := False) 9412 is 9413 Has_Discrs : constant Boolean := Has_Discriminants (T); 9414 Constrained : constant Boolean := 9415 (Has_Discrs 9416 and then not Is_Empty_Elmt_List (Elist) 9417 and then not Is_Class_Wide_Type (T)) 9418 or else Is_Constrained (T); 9419 9420 begin 9421 if Ekind (T) = E_Record_Type then 9422 if For_Access then 9423 Set_Ekind (Def_Id, E_Private_Subtype); 9424 Set_Is_For_Access_Subtype (Def_Id, True); 9425 else 9426 Set_Ekind (Def_Id, E_Record_Subtype); 9427 end if; 9428 9429 -- Inherit preelaboration flag from base, for types for which it 9430 -- may have been set: records, private types, protected types. 9431 9432 Set_Known_To_Have_Preelab_Init 9433 (Def_Id, Known_To_Have_Preelab_Init (T)); 9434 9435 elsif Ekind (T) = E_Task_Type then 9436 Set_Ekind (Def_Id, E_Task_Subtype); 9437 9438 elsif Ekind (T) = E_Protected_Type then 9439 Set_Ekind (Def_Id, E_Protected_Subtype); 9440 Set_Known_To_Have_Preelab_Init 9441 (Def_Id, Known_To_Have_Preelab_Init (T)); 9442 9443 elsif Is_Private_Type (T) then 9444 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T))); 9445 Set_Known_To_Have_Preelab_Init 9446 (Def_Id, Known_To_Have_Preelab_Init (T)); 9447 9448 -- Private subtypes may have private dependents 9449 9450 Set_Private_Dependents (Def_Id, New_Elmt_List); 9451 9452 elsif Is_Class_Wide_Type (T) then 9453 Set_Ekind (Def_Id, E_Class_Wide_Subtype); 9454 9455 else 9456 -- Incomplete type. Attach subtype to list of dependents, to be 9457 -- completed with full view of parent type, unless is it the 9458 -- designated subtype of a record component within an init_proc. 9459 -- This last case arises for a component of an access type whose 9460 -- designated type is incomplete (e.g. a Taft Amendment type). 9461 -- The designated subtype is within an inner scope, and needs no 9462 -- elaboration, because only the access type is needed in the 9463 -- initialization procedure. 9464 9465 Set_Ekind (Def_Id, Ekind (T)); 9466 9467 if For_Access and then Within_Init_Proc then 9468 null; 9469 else 9470 Append_Elmt (Def_Id, Private_Dependents (T)); 9471 end if; 9472 end if; 9473 9474 Set_Etype (Def_Id, T); 9475 Init_Size_Align (Def_Id); 9476 Set_Has_Discriminants (Def_Id, Has_Discrs); 9477 Set_Is_Constrained (Def_Id, Constrained); 9478 9479 Set_First_Entity (Def_Id, First_Entity (T)); 9480 Set_Last_Entity (Def_Id, Last_Entity (T)); 9481 Set_Has_Implicit_Dereference 9482 (Def_Id, Has_Implicit_Dereference (T)); 9483 9484 -- If the subtype is the completion of a private declaration, there may 9485 -- have been representation clauses for the partial view, and they must 9486 -- be preserved. Build_Derived_Type chains the inherited clauses with 9487 -- the ones appearing on the extension. If this comes from a subtype 9488 -- declaration, all clauses are inherited. 9489 9490 if No (First_Rep_Item (Def_Id)) then 9491 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 9492 end if; 9493 9494 if Is_Tagged_Type (T) then 9495 Set_Is_Tagged_Type (Def_Id); 9496 Set_No_Tagged_Streams_Pragma (Def_Id, No_Tagged_Streams_Pragma (T)); 9497 Make_Class_Wide_Type (Def_Id); 9498 end if; 9499 9500 Set_Stored_Constraint (Def_Id, No_Elist); 9501 9502 if Has_Discrs then 9503 Set_Discriminant_Constraint (Def_Id, Elist); 9504 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id); 9505 end if; 9506 9507 if Is_Tagged_Type (T) then 9508 9509 -- Ada 2005 (AI-251): In case of concurrent types we inherit the 9510 -- concurrent record type (which has the list of primitive 9511 -- operations). 9512 9513 if Ada_Version >= Ada_2005 9514 and then Is_Concurrent_Type (T) 9515 then 9516 Set_Corresponding_Record_Type (Def_Id, 9517 Corresponding_Record_Type (T)); 9518 else 9519 Set_Direct_Primitive_Operations (Def_Id, 9520 Direct_Primitive_Operations (T)); 9521 end if; 9522 9523 Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T)); 9524 end if; 9525 9526 -- Subtypes introduced by component declarations do not need to be 9527 -- marked as delayed, and do not get freeze nodes, because the semantics 9528 -- verifies that the parents of the subtypes are frozen before the 9529 -- enclosing record is frozen. 9530 9531 if not Is_Type (Scope (Def_Id)) then 9532 Set_Depends_On_Private (Def_Id, Depends_On_Private (T)); 9533 9534 if Is_Private_Type (T) 9535 and then Present (Full_View (T)) 9536 then 9537 Conditional_Delay (Def_Id, Full_View (T)); 9538 else 9539 Conditional_Delay (Def_Id, T); 9540 end if; 9541 end if; 9542 9543 if Is_Record_Type (T) then 9544 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T)); 9545 9546 if Has_Discrs 9547 and then not Is_Empty_Elmt_List (Elist) 9548 and then not For_Access 9549 then 9550 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist); 9551 elsif not For_Access then 9552 Set_Cloned_Subtype (Def_Id, T); 9553 end if; 9554 end if; 9555 end Build_Discriminated_Subtype; 9556 9557 --------------------------- 9558 -- Build_Itype_Reference -- 9559 --------------------------- 9560 9561 procedure Build_Itype_Reference 9562 (Ityp : Entity_Id; 9563 Nod : Node_Id) 9564 is 9565 IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod)); 9566 begin 9567 9568 -- Itype references are only created for use by the back-end 9569 9570 if Inside_A_Generic then 9571 return; 9572 else 9573 Set_Itype (IR, Ityp); 9574 Insert_After (Nod, IR); 9575 end if; 9576 end Build_Itype_Reference; 9577 9578 ------------------------ 9579 -- Build_Scalar_Bound -- 9580 ------------------------ 9581 9582 function Build_Scalar_Bound 9583 (Bound : Node_Id; 9584 Par_T : Entity_Id; 9585 Der_T : Entity_Id) return Node_Id 9586 is 9587 New_Bound : Entity_Id; 9588 9589 begin 9590 -- Note: not clear why this is needed, how can the original bound 9591 -- be unanalyzed at this point? and if it is, what business do we 9592 -- have messing around with it? and why is the base type of the 9593 -- parent type the right type for the resolution. It probably is 9594 -- not. It is OK for the new bound we are creating, but not for 9595 -- the old one??? Still if it never happens, no problem. 9596 9597 Analyze_And_Resolve (Bound, Base_Type (Par_T)); 9598 9599 if Nkind_In (Bound, N_Integer_Literal, N_Real_Literal) then 9600 New_Bound := New_Copy (Bound); 9601 Set_Etype (New_Bound, Der_T); 9602 Set_Analyzed (New_Bound); 9603 9604 elsif Is_Entity_Name (Bound) then 9605 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound)); 9606 9607 -- The following is almost certainly wrong. What business do we have 9608 -- relocating a node (Bound) that is presumably still attached to 9609 -- the tree elsewhere??? 9610 9611 else 9612 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound)); 9613 end if; 9614 9615 Set_Etype (New_Bound, Der_T); 9616 return New_Bound; 9617 end Build_Scalar_Bound; 9618 9619 -------------------------------- 9620 -- Build_Underlying_Full_View -- 9621 -------------------------------- 9622 9623 procedure Build_Underlying_Full_View 9624 (N : Node_Id; 9625 Typ : Entity_Id; 9626 Par : Entity_Id) 9627 is 9628 Loc : constant Source_Ptr := Sloc (N); 9629 Subt : constant Entity_Id := 9630 Make_Defining_Identifier 9631 (Loc, New_External_Name (Chars (Typ), 'S')); 9632 9633 Constr : Node_Id; 9634 Indic : Node_Id; 9635 C : Node_Id; 9636 Id : Node_Id; 9637 9638 procedure Set_Discriminant_Name (Id : Node_Id); 9639 -- If the derived type has discriminants, they may rename discriminants 9640 -- of the parent. When building the full view of the parent, we need to 9641 -- recover the names of the original discriminants if the constraint is 9642 -- given by named associations. 9643 9644 --------------------------- 9645 -- Set_Discriminant_Name -- 9646 --------------------------- 9647 9648 procedure Set_Discriminant_Name (Id : Node_Id) is 9649 Disc : Entity_Id; 9650 9651 begin 9652 Set_Original_Discriminant (Id, Empty); 9653 9654 if Has_Discriminants (Typ) then 9655 Disc := First_Discriminant (Typ); 9656 while Present (Disc) loop 9657 if Chars (Disc) = Chars (Id) 9658 and then Present (Corresponding_Discriminant (Disc)) 9659 then 9660 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc))); 9661 end if; 9662 Next_Discriminant (Disc); 9663 end loop; 9664 end if; 9665 end Set_Discriminant_Name; 9666 9667 -- Start of processing for Build_Underlying_Full_View 9668 9669 begin 9670 if Nkind (N) = N_Full_Type_Declaration then 9671 Constr := Constraint (Subtype_Indication (Type_Definition (N))); 9672 9673 elsif Nkind (N) = N_Subtype_Declaration then 9674 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N))); 9675 9676 elsif Nkind (N) = N_Component_Declaration then 9677 Constr := 9678 New_Copy_Tree 9679 (Constraint (Subtype_Indication (Component_Definition (N)))); 9680 9681 else 9682 raise Program_Error; 9683 end if; 9684 9685 C := First (Constraints (Constr)); 9686 while Present (C) loop 9687 if Nkind (C) = N_Discriminant_Association then 9688 Id := First (Selector_Names (C)); 9689 while Present (Id) loop 9690 Set_Discriminant_Name (Id); 9691 Next (Id); 9692 end loop; 9693 end if; 9694 9695 Next (C); 9696 end loop; 9697 9698 Indic := 9699 Make_Subtype_Declaration (Loc, 9700 Defining_Identifier => Subt, 9701 Subtype_Indication => 9702 Make_Subtype_Indication (Loc, 9703 Subtype_Mark => New_Occurrence_Of (Par, Loc), 9704 Constraint => New_Copy_Tree (Constr))); 9705 9706 -- If this is a component subtype for an outer itype, it is not 9707 -- a list member, so simply set the parent link for analysis: if 9708 -- the enclosing type does not need to be in a declarative list, 9709 -- neither do the components. 9710 9711 if Is_List_Member (N) 9712 and then Nkind (N) /= N_Component_Declaration 9713 then 9714 Insert_Before (N, Indic); 9715 else 9716 Set_Parent (Indic, Parent (N)); 9717 end if; 9718 9719 Analyze (Indic); 9720 Set_Underlying_Full_View (Typ, Full_View (Subt)); 9721 end Build_Underlying_Full_View; 9722 9723 ------------------------------- 9724 -- Check_Abstract_Overriding -- 9725 ------------------------------- 9726 9727 procedure Check_Abstract_Overriding (T : Entity_Id) is 9728 Alias_Subp : Entity_Id; 9729 Elmt : Elmt_Id; 9730 Op_List : Elist_Id; 9731 Subp : Entity_Id; 9732 Type_Def : Node_Id; 9733 9734 procedure Check_Pragma_Implemented (Subp : Entity_Id); 9735 -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine 9736 -- which has pragma Implemented already set. Check whether Subp's entity 9737 -- kind conforms to the implementation kind of the overridden routine. 9738 9739 procedure Check_Pragma_Implemented 9740 (Subp : Entity_Id; 9741 Iface_Subp : Entity_Id); 9742 -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine 9743 -- Iface_Subp and both entities have pragma Implemented already set on 9744 -- them. Check whether the two implementation kinds are conforming. 9745 9746 procedure Inherit_Pragma_Implemented 9747 (Subp : Entity_Id; 9748 Iface_Subp : Entity_Id); 9749 -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface 9750 -- subprogram Iface_Subp which has been marked by pragma Implemented. 9751 -- Propagate the implementation kind of Iface_Subp to Subp. 9752 9753 ------------------------------ 9754 -- Check_Pragma_Implemented -- 9755 ------------------------------ 9756 9757 procedure Check_Pragma_Implemented (Subp : Entity_Id) is 9758 Iface_Alias : constant Entity_Id := Interface_Alias (Subp); 9759 Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias); 9760 Subp_Alias : constant Entity_Id := Alias (Subp); 9761 Contr_Typ : Entity_Id; 9762 Impl_Subp : Entity_Id; 9763 9764 begin 9765 -- Subp must have an alias since it is a hidden entity used to link 9766 -- an interface subprogram to its overriding counterpart. 9767 9768 pragma Assert (Present (Subp_Alias)); 9769 9770 -- Handle aliases to synchronized wrappers 9771 9772 Impl_Subp := Subp_Alias; 9773 9774 if Is_Primitive_Wrapper (Impl_Subp) then 9775 Impl_Subp := Wrapped_Entity (Impl_Subp); 9776 end if; 9777 9778 -- Extract the type of the controlling formal 9779 9780 Contr_Typ := Etype (First_Formal (Subp_Alias)); 9781 9782 if Is_Concurrent_Record_Type (Contr_Typ) then 9783 Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ); 9784 end if; 9785 9786 -- An interface subprogram whose implementation kind is By_Entry must 9787 -- be implemented by an entry. 9788 9789 if Impl_Kind = Name_By_Entry 9790 and then Ekind (Impl_Subp) /= E_Entry 9791 then 9792 Error_Msg_Node_2 := Iface_Alias; 9793 Error_Msg_NE 9794 ("type & must implement abstract subprogram & with an entry", 9795 Subp_Alias, Contr_Typ); 9796 9797 elsif Impl_Kind = Name_By_Protected_Procedure then 9798 9799 -- An interface subprogram whose implementation kind is By_ 9800 -- Protected_Procedure cannot be implemented by a primitive 9801 -- procedure of a task type. 9802 9803 if Ekind (Contr_Typ) /= E_Protected_Type then 9804 Error_Msg_Node_2 := Contr_Typ; 9805 Error_Msg_NE 9806 ("interface subprogram & cannot be implemented by a " & 9807 "primitive procedure of task type &", Subp_Alias, 9808 Iface_Alias); 9809 9810 -- An interface subprogram whose implementation kind is By_ 9811 -- Protected_Procedure must be implemented by a procedure. 9812 9813 elsif Ekind (Impl_Subp) /= E_Procedure then 9814 Error_Msg_Node_2 := Iface_Alias; 9815 Error_Msg_NE 9816 ("type & must implement abstract subprogram & with a " & 9817 "procedure", Subp_Alias, Contr_Typ); 9818 9819 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented)) 9820 and then Implementation_Kind (Impl_Subp) /= Impl_Kind 9821 then 9822 Error_Msg_Name_1 := Impl_Kind; 9823 Error_Msg_N 9824 ("overriding operation& must have synchronization%", 9825 Subp_Alias); 9826 end if; 9827 9828 -- If primitive has Optional synchronization, overriding operation 9829 -- must match if it has an explicit synchronization.. 9830 9831 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented)) 9832 and then Implementation_Kind (Impl_Subp) /= Impl_Kind 9833 then 9834 Error_Msg_Name_1 := Impl_Kind; 9835 Error_Msg_N 9836 ("overriding operation& must have syncrhonization%", 9837 Subp_Alias); 9838 end if; 9839 end Check_Pragma_Implemented; 9840 9841 ------------------------------ 9842 -- Check_Pragma_Implemented -- 9843 ------------------------------ 9844 9845 procedure Check_Pragma_Implemented 9846 (Subp : Entity_Id; 9847 Iface_Subp : Entity_Id) 9848 is 9849 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp); 9850 Subp_Kind : constant Name_Id := Implementation_Kind (Subp); 9851 9852 begin 9853 -- Ada 2012 (AI05-0030): The implementation kinds of an overridden 9854 -- and overriding subprogram are different. In general this is an 9855 -- error except when the implementation kind of the overridden 9856 -- subprograms is By_Any or Optional. 9857 9858 if Iface_Kind /= Subp_Kind 9859 and then Iface_Kind /= Name_By_Any 9860 and then Iface_Kind /= Name_Optional 9861 then 9862 if Iface_Kind = Name_By_Entry then 9863 Error_Msg_N 9864 ("incompatible implementation kind, overridden subprogram " & 9865 "is marked By_Entry", Subp); 9866 else 9867 Error_Msg_N 9868 ("incompatible implementation kind, overridden subprogram " & 9869 "is marked By_Protected_Procedure", Subp); 9870 end if; 9871 end if; 9872 end Check_Pragma_Implemented; 9873 9874 -------------------------------- 9875 -- Inherit_Pragma_Implemented -- 9876 -------------------------------- 9877 9878 procedure Inherit_Pragma_Implemented 9879 (Subp : Entity_Id; 9880 Iface_Subp : Entity_Id) 9881 is 9882 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp); 9883 Loc : constant Source_Ptr := Sloc (Subp); 9884 Impl_Prag : Node_Id; 9885 9886 begin 9887 -- Since the implementation kind is stored as a representation item 9888 -- rather than a flag, create a pragma node. 9889 9890 Impl_Prag := 9891 Make_Pragma (Loc, 9892 Chars => Name_Implemented, 9893 Pragma_Argument_Associations => New_List ( 9894 Make_Pragma_Argument_Association (Loc, 9895 Expression => New_Occurrence_Of (Subp, Loc)), 9896 9897 Make_Pragma_Argument_Association (Loc, 9898 Expression => Make_Identifier (Loc, Iface_Kind)))); 9899 9900 -- The pragma doesn't need to be analyzed because it is internally 9901 -- built. It is safe to directly register it as a rep item since we 9902 -- are only interested in the characters of the implementation kind. 9903 9904 Record_Rep_Item (Subp, Impl_Prag); 9905 end Inherit_Pragma_Implemented; 9906 9907 -- Start of processing for Check_Abstract_Overriding 9908 9909 begin 9910 Op_List := Primitive_Operations (T); 9911 9912 -- Loop to check primitive operations 9913 9914 Elmt := First_Elmt (Op_List); 9915 while Present (Elmt) loop 9916 Subp := Node (Elmt); 9917 Alias_Subp := Alias (Subp); 9918 9919 -- Inherited subprograms are identified by the fact that they do not 9920 -- come from source, and the associated source location is the 9921 -- location of the first subtype of the derived type. 9922 9923 -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for 9924 -- subprograms that "require overriding". 9925 9926 -- Special exception, do not complain about failure to override the 9927 -- stream routines _Input and _Output, as well as the primitive 9928 -- operations used in dispatching selects since we always provide 9929 -- automatic overridings for these subprograms. 9930 9931 -- Also ignore this rule for convention CIL since .NET libraries 9932 -- do bizarre things with interfaces??? 9933 9934 -- The partial view of T may have been a private extension, for 9935 -- which inherited functions dispatching on result are abstract. 9936 -- If the full view is a null extension, there is no need for 9937 -- overriding in Ada 2005, but wrappers need to be built for them 9938 -- (see exp_ch3, Build_Controlling_Function_Wrappers). 9939 9940 if Is_Null_Extension (T) 9941 and then Has_Controlling_Result (Subp) 9942 and then Ada_Version >= Ada_2005 9943 and then Present (Alias_Subp) 9944 and then not Comes_From_Source (Subp) 9945 and then not Is_Abstract_Subprogram (Alias_Subp) 9946 and then not Is_Access_Type (Etype (Subp)) 9947 then 9948 null; 9949 9950 -- Ada 2005 (AI-251): Internal entities of interfaces need no 9951 -- processing because this check is done with the aliased 9952 -- entity 9953 9954 elsif Present (Interface_Alias (Subp)) then 9955 null; 9956 9957 elsif (Is_Abstract_Subprogram (Subp) 9958 or else Requires_Overriding (Subp) 9959 or else 9960 (Has_Controlling_Result (Subp) 9961 and then Present (Alias_Subp) 9962 and then not Comes_From_Source (Subp) 9963 and then Sloc (Subp) = Sloc (First_Subtype (T)))) 9964 and then not Is_TSS (Subp, TSS_Stream_Input) 9965 and then not Is_TSS (Subp, TSS_Stream_Output) 9966 and then not Is_Abstract_Type (T) 9967 and then Convention (T) /= Convention_CIL 9968 and then not Is_Predefined_Interface_Primitive (Subp) 9969 9970 -- Ada 2005 (AI-251): Do not consider hidden entities associated 9971 -- with abstract interface types because the check will be done 9972 -- with the aliased entity (otherwise we generate a duplicated 9973 -- error message). 9974 9975 and then not Present (Interface_Alias (Subp)) 9976 then 9977 if Present (Alias_Subp) then 9978 9979 -- Only perform the check for a derived subprogram when the 9980 -- type has an explicit record extension. This avoids incorrect 9981 -- flagging of abstract subprograms for the case of a type 9982 -- without an extension that is derived from a formal type 9983 -- with a tagged actual (can occur within a private part). 9984 9985 -- Ada 2005 (AI-391): In the case of an inherited function with 9986 -- a controlling result of the type, the rule does not apply if 9987 -- the type is a null extension (unless the parent function 9988 -- itself is abstract, in which case the function must still be 9989 -- be overridden). The expander will generate an overriding 9990 -- wrapper function calling the parent subprogram (see 9991 -- Exp_Ch3.Make_Controlling_Wrapper_Functions). 9992 9993 Type_Def := Type_Definition (Parent (T)); 9994 9995 if Nkind (Type_Def) = N_Derived_Type_Definition 9996 and then Present (Record_Extension_Part (Type_Def)) 9997 and then 9998 (Ada_Version < Ada_2005 9999 or else not Is_Null_Extension (T) 10000 or else Ekind (Subp) = E_Procedure 10001 or else not Has_Controlling_Result (Subp) 10002 or else Is_Abstract_Subprogram (Alias_Subp) 10003 or else Requires_Overriding (Subp) 10004 or else Is_Access_Type (Etype (Subp))) 10005 then 10006 -- Avoid reporting error in case of abstract predefined 10007 -- primitive inherited from interface type because the 10008 -- body of internally generated predefined primitives 10009 -- of tagged types are generated later by Freeze_Type 10010 10011 if Is_Interface (Root_Type (T)) 10012 and then Is_Abstract_Subprogram (Subp) 10013 and then Is_Predefined_Dispatching_Operation (Subp) 10014 and then not Comes_From_Source (Ultimate_Alias (Subp)) 10015 then 10016 null; 10017 10018 -- A null extension is not obliged to override an inherited 10019 -- procedure subject to pragma Extensions_Visible with value 10020 -- False and at least one controlling OUT parameter 10021 -- (SPARK RM 6.1.7(6)). 10022 10023 elsif Is_Null_Extension (T) 10024 and then Is_EVF_Procedure (Subp) 10025 then 10026 null; 10027 10028 else 10029 Error_Msg_NE 10030 ("type must be declared abstract or & overridden", 10031 T, Subp); 10032 10033 -- Traverse the whole chain of aliased subprograms to 10034 -- complete the error notification. This is especially 10035 -- useful for traceability of the chain of entities when 10036 -- the subprogram corresponds with an interface 10037 -- subprogram (which may be defined in another package). 10038 10039 if Present (Alias_Subp) then 10040 declare 10041 E : Entity_Id; 10042 10043 begin 10044 E := Subp; 10045 while Present (Alias (E)) loop 10046 10047 -- Avoid reporting redundant errors on entities 10048 -- inherited from interfaces 10049 10050 if Sloc (E) /= Sloc (T) then 10051 Error_Msg_Sloc := Sloc (E); 10052 Error_Msg_NE 10053 ("\& has been inherited #", T, Subp); 10054 end if; 10055 10056 E := Alias (E); 10057 end loop; 10058 10059 Error_Msg_Sloc := Sloc (E); 10060 10061 -- AI05-0068: report if there is an overriding 10062 -- non-abstract subprogram that is invisible. 10063 10064 if Is_Hidden (E) 10065 and then not Is_Abstract_Subprogram (E) 10066 then 10067 Error_Msg_NE 10068 ("\& subprogram# is not visible", 10069 T, Subp); 10070 10071 -- Clarify the case where a non-null extension must 10072 -- override inherited procedure subject to pragma 10073 -- Extensions_Visible with value False and at least 10074 -- one controlling OUT param. 10075 10076 elsif Is_EVF_Procedure (E) then 10077 Error_Msg_NE 10078 ("\& # is subject to Extensions_Visible False", 10079 T, Subp); 10080 10081 else 10082 Error_Msg_NE 10083 ("\& has been inherited from subprogram #", 10084 T, Subp); 10085 end if; 10086 end; 10087 end if; 10088 end if; 10089 10090 -- Ada 2005 (AI-345): Protected or task type implementing 10091 -- abstract interfaces. 10092 10093 elsif Is_Concurrent_Record_Type (T) 10094 and then Present (Interfaces (T)) 10095 then 10096 -- There is no need to check here RM 9.4(11.9/3) since we 10097 -- are processing the corresponding record type and the 10098 -- mode of the overriding subprograms was verified by 10099 -- Check_Conformance when the corresponding concurrent 10100 -- type declaration was analyzed. 10101 10102 Error_Msg_NE 10103 ("interface subprogram & must be overridden", T, Subp); 10104 10105 -- Examine primitive operations of synchronized type to find 10106 -- homonyms that have the wrong profile. 10107 10108 declare 10109 Prim : Entity_Id; 10110 10111 begin 10112 Prim := First_Entity (Corresponding_Concurrent_Type (T)); 10113 while Present (Prim) loop 10114 if Chars (Prim) = Chars (Subp) then 10115 Error_Msg_NE 10116 ("profile is not type conformant with prefixed " 10117 & "view profile of inherited operation&", 10118 Prim, Subp); 10119 end if; 10120 10121 Next_Entity (Prim); 10122 end loop; 10123 end; 10124 end if; 10125 10126 else 10127 Error_Msg_Node_2 := T; 10128 Error_Msg_N 10129 ("abstract subprogram& not allowed for type&", Subp); 10130 10131 -- Also post unconditional warning on the type (unconditional 10132 -- so that if there are more than one of these cases, we get 10133 -- them all, and not just the first one). 10134 10135 Error_Msg_Node_2 := Subp; 10136 Error_Msg_N ("nonabstract type& has abstract subprogram&!", T); 10137 end if; 10138 10139 -- A subprogram subject to pragma Extensions_Visible with value 10140 -- "True" cannot override a subprogram subject to the same pragma 10141 -- with value "False" (SPARK RM 6.1.7(5)). 10142 10143 elsif Extensions_Visible_Status (Subp) = Extensions_Visible_True 10144 and then Present (Overridden_Operation (Subp)) 10145 and then Extensions_Visible_Status (Overridden_Operation (Subp)) = 10146 Extensions_Visible_False 10147 then 10148 Error_Msg_Sloc := Sloc (Overridden_Operation (Subp)); 10149 Error_Msg_N 10150 ("subprogram & with Extensions_Visible True cannot override " 10151 & "subprogram # with Extensions_Visible False", Subp); 10152 end if; 10153 10154 -- Ada 2012 (AI05-0030): Perform checks related to pragma Implemented 10155 10156 -- Subp is an expander-generated procedure which maps an interface 10157 -- alias to a protected wrapper. The interface alias is flagged by 10158 -- pragma Implemented. Ensure that Subp is a procedure when the 10159 -- implementation kind is By_Protected_Procedure or an entry when 10160 -- By_Entry. 10161 10162 if Ada_Version >= Ada_2012 10163 and then Is_Hidden (Subp) 10164 and then Present (Interface_Alias (Subp)) 10165 and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented) 10166 then 10167 Check_Pragma_Implemented (Subp); 10168 end if; 10169 10170 -- Subp is an interface primitive which overrides another interface 10171 -- primitive marked with pragma Implemented. 10172 10173 if Ada_Version >= Ada_2012 10174 and then Present (Overridden_Operation (Subp)) 10175 and then Has_Rep_Pragma 10176 (Overridden_Operation (Subp), Name_Implemented) 10177 then 10178 -- If the overriding routine is also marked by Implemented, check 10179 -- that the two implementation kinds are conforming. 10180 10181 if Has_Rep_Pragma (Subp, Name_Implemented) then 10182 Check_Pragma_Implemented 10183 (Subp => Subp, 10184 Iface_Subp => Overridden_Operation (Subp)); 10185 10186 -- Otherwise the overriding routine inherits the implementation 10187 -- kind from the overridden subprogram. 10188 10189 else 10190 Inherit_Pragma_Implemented 10191 (Subp => Subp, 10192 Iface_Subp => Overridden_Operation (Subp)); 10193 end if; 10194 end if; 10195 10196 -- If the operation is a wrapper for a synchronized primitive, it 10197 -- may be called indirectly through a dispatching select. We assume 10198 -- that it will be referenced elsewhere indirectly, and suppress 10199 -- warnings about an unused entity. 10200 10201 if Is_Primitive_Wrapper (Subp) 10202 and then Present (Wrapped_Entity (Subp)) 10203 then 10204 Set_Referenced (Wrapped_Entity (Subp)); 10205 end if; 10206 10207 Next_Elmt (Elmt); 10208 end loop; 10209 end Check_Abstract_Overriding; 10210 10211 ------------------------------------------------ 10212 -- Check_Access_Discriminant_Requires_Limited -- 10213 ------------------------------------------------ 10214 10215 procedure Check_Access_Discriminant_Requires_Limited 10216 (D : Node_Id; 10217 Loc : Node_Id) 10218 is 10219 begin 10220 -- A discriminant_specification for an access discriminant shall appear 10221 -- only in the declaration for a task or protected type, or for a type 10222 -- with the reserved word 'limited' in its definition or in one of its 10223 -- ancestors (RM 3.7(10)). 10224 10225 -- AI-0063: The proper condition is that type must be immutably limited, 10226 -- or else be a partial view. 10227 10228 if Nkind (Discriminant_Type (D)) = N_Access_Definition then 10229 if Is_Limited_View (Current_Scope) 10230 or else 10231 (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration 10232 and then Limited_Present (Parent (Current_Scope))) 10233 then 10234 null; 10235 10236 else 10237 Error_Msg_N 10238 ("access discriminants allowed only for limited types", Loc); 10239 end if; 10240 end if; 10241 end Check_Access_Discriminant_Requires_Limited; 10242 10243 ----------------------------------- 10244 -- Check_Aliased_Component_Types -- 10245 ----------------------------------- 10246 10247 procedure Check_Aliased_Component_Types (T : Entity_Id) is 10248 C : Entity_Id; 10249 10250 begin 10251 -- ??? Also need to check components of record extensions, but not 10252 -- components of protected types (which are always limited). 10253 10254 -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such 10255 -- types to be unconstrained. This is safe because it is illegal to 10256 -- create access subtypes to such types with explicit discriminant 10257 -- constraints. 10258 10259 if not Is_Limited_Type (T) then 10260 if Ekind (T) = E_Record_Type then 10261 C := First_Component (T); 10262 while Present (C) loop 10263 if Is_Aliased (C) 10264 and then Has_Discriminants (Etype (C)) 10265 and then not Is_Constrained (Etype (C)) 10266 and then not In_Instance_Body 10267 and then Ada_Version < Ada_2005 10268 then 10269 Error_Msg_N 10270 ("aliased component must be constrained (RM 3.6(11))", 10271 C); 10272 end if; 10273 10274 Next_Component (C); 10275 end loop; 10276 10277 elsif Ekind (T) = E_Array_Type then 10278 if Has_Aliased_Components (T) 10279 and then Has_Discriminants (Component_Type (T)) 10280 and then not Is_Constrained (Component_Type (T)) 10281 and then not In_Instance_Body 10282 and then Ada_Version < Ada_2005 10283 then 10284 Error_Msg_N 10285 ("aliased component type must be constrained (RM 3.6(11))", 10286 T); 10287 end if; 10288 end if; 10289 end if; 10290 end Check_Aliased_Component_Types; 10291 10292 --------------------------------------- 10293 -- Check_Anonymous_Access_Components -- 10294 --------------------------------------- 10295 10296 procedure Check_Anonymous_Access_Components 10297 (Typ_Decl : Node_Id; 10298 Typ : Entity_Id; 10299 Prev : Entity_Id; 10300 Comp_List : Node_Id) 10301 is 10302 Loc : constant Source_Ptr := Sloc (Typ_Decl); 10303 Anon_Access : Entity_Id; 10304 Acc_Def : Node_Id; 10305 Comp : Node_Id; 10306 Comp_Def : Node_Id; 10307 Decl : Node_Id; 10308 Type_Def : Node_Id; 10309 10310 procedure Build_Incomplete_Type_Declaration; 10311 -- If the record type contains components that include an access to the 10312 -- current record, then create an incomplete type declaration for the 10313 -- record, to be used as the designated type of the anonymous access. 10314 -- This is done only once, and only if there is no previous partial 10315 -- view of the type. 10316 10317 function Designates_T (Subt : Node_Id) return Boolean; 10318 -- Check whether a node designates the enclosing record type, or 'Class 10319 -- of that type 10320 10321 function Mentions_T (Acc_Def : Node_Id) return Boolean; 10322 -- Check whether an access definition includes a reference to 10323 -- the enclosing record type. The reference can be a subtype mark 10324 -- in the access definition itself, a 'Class attribute reference, or 10325 -- recursively a reference appearing in a parameter specification 10326 -- or result definition of an access_to_subprogram definition. 10327 10328 -------------------------------------- 10329 -- Build_Incomplete_Type_Declaration -- 10330 -------------------------------------- 10331 10332 procedure Build_Incomplete_Type_Declaration is 10333 Decl : Node_Id; 10334 Inc_T : Entity_Id; 10335 H : Entity_Id; 10336 10337 -- Is_Tagged indicates whether the type is tagged. It is tagged if 10338 -- it's "is new ... with record" or else "is tagged record ...". 10339 10340 Is_Tagged : constant Boolean := 10341 (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition 10342 and then 10343 Present (Record_Extension_Part (Type_Definition (Typ_Decl)))) 10344 or else 10345 (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition 10346 and then Tagged_Present (Type_Definition (Typ_Decl))); 10347 10348 begin 10349 -- If there is a previous partial view, no need to create a new one 10350 -- If the partial view, given by Prev, is incomplete, If Prev is 10351 -- a private declaration, full declaration is flagged accordingly. 10352 10353 if Prev /= Typ then 10354 if Is_Tagged then 10355 Make_Class_Wide_Type (Prev); 10356 Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev)); 10357 Set_Etype (Class_Wide_Type (Typ), Typ); 10358 end if; 10359 10360 return; 10361 10362 elsif Has_Private_Declaration (Typ) then 10363 10364 -- If we refer to T'Class inside T, and T is the completion of a 10365 -- private type, then make sure the class-wide type exists. 10366 10367 if Is_Tagged then 10368 Make_Class_Wide_Type (Typ); 10369 end if; 10370 10371 return; 10372 10373 -- If there was a previous anonymous access type, the incomplete 10374 -- type declaration will have been created already. 10375 10376 elsif Present (Current_Entity (Typ)) 10377 and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type 10378 and then Full_View (Current_Entity (Typ)) = Typ 10379 then 10380 if Is_Tagged 10381 and then Comes_From_Source (Current_Entity (Typ)) 10382 and then not Is_Tagged_Type (Current_Entity (Typ)) 10383 then 10384 Make_Class_Wide_Type (Typ); 10385 Error_Msg_N 10386 ("incomplete view of tagged type should be declared tagged??", 10387 Parent (Current_Entity (Typ))); 10388 end if; 10389 return; 10390 10391 else 10392 Inc_T := Make_Defining_Identifier (Loc, Chars (Typ)); 10393 Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T); 10394 10395 -- Type has already been inserted into the current scope. Remove 10396 -- it, and add incomplete declaration for type, so that subsequent 10397 -- anonymous access types can use it. The entity is unchained from 10398 -- the homonym list and from immediate visibility. After analysis, 10399 -- the entity in the incomplete declaration becomes immediately 10400 -- visible in the record declaration that follows. 10401 10402 H := Current_Entity (Typ); 10403 10404 if H = Typ then 10405 Set_Name_Entity_Id (Chars (Typ), Homonym (Typ)); 10406 else 10407 while Present (H) 10408 and then Homonym (H) /= Typ 10409 loop 10410 H := Homonym (Typ); 10411 end loop; 10412 10413 Set_Homonym (H, Homonym (Typ)); 10414 end if; 10415 10416 Insert_Before (Typ_Decl, Decl); 10417 Analyze (Decl); 10418 Set_Full_View (Inc_T, Typ); 10419 10420 if Is_Tagged then 10421 10422 -- Create a common class-wide type for both views, and set the 10423 -- Etype of the class-wide type to the full view. 10424 10425 Make_Class_Wide_Type (Inc_T); 10426 Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T)); 10427 Set_Etype (Class_Wide_Type (Typ), Typ); 10428 end if; 10429 end if; 10430 end Build_Incomplete_Type_Declaration; 10431 10432 ------------------ 10433 -- Designates_T -- 10434 ------------------ 10435 10436 function Designates_T (Subt : Node_Id) return Boolean is 10437 Type_Id : constant Name_Id := Chars (Typ); 10438 10439 function Names_T (Nam : Node_Id) return Boolean; 10440 -- The record type has not been introduced in the current scope 10441 -- yet, so we must examine the name of the type itself, either 10442 -- an identifier T, or an expanded name of the form P.T, where 10443 -- P denotes the current scope. 10444 10445 ------------- 10446 -- Names_T -- 10447 ------------- 10448 10449 function Names_T (Nam : Node_Id) return Boolean is 10450 begin 10451 if Nkind (Nam) = N_Identifier then 10452 return Chars (Nam) = Type_Id; 10453 10454 elsif Nkind (Nam) = N_Selected_Component then 10455 if Chars (Selector_Name (Nam)) = Type_Id then 10456 if Nkind (Prefix (Nam)) = N_Identifier then 10457 return Chars (Prefix (Nam)) = Chars (Current_Scope); 10458 10459 elsif Nkind (Prefix (Nam)) = N_Selected_Component then 10460 return Chars (Selector_Name (Prefix (Nam))) = 10461 Chars (Current_Scope); 10462 else 10463 return False; 10464 end if; 10465 10466 else 10467 return False; 10468 end if; 10469 10470 else 10471 return False; 10472 end if; 10473 end Names_T; 10474 10475 -- Start of processing for Designates_T 10476 10477 begin 10478 if Nkind (Subt) = N_Identifier then 10479 return Chars (Subt) = Type_Id; 10480 10481 -- Reference can be through an expanded name which has not been 10482 -- analyzed yet, and which designates enclosing scopes. 10483 10484 elsif Nkind (Subt) = N_Selected_Component then 10485 if Names_T (Subt) then 10486 return True; 10487 10488 -- Otherwise it must denote an entity that is already visible. 10489 -- The access definition may name a subtype of the enclosing 10490 -- type, if there is a previous incomplete declaration for it. 10491 10492 else 10493 Find_Selected_Component (Subt); 10494 return 10495 Is_Entity_Name (Subt) 10496 and then Scope (Entity (Subt)) = Current_Scope 10497 and then 10498 (Chars (Base_Type (Entity (Subt))) = Type_Id 10499 or else 10500 (Is_Class_Wide_Type (Entity (Subt)) 10501 and then 10502 Chars (Etype (Base_Type (Entity (Subt)))) = 10503 Type_Id)); 10504 end if; 10505 10506 -- A reference to the current type may appear as the prefix of 10507 -- a 'Class attribute. 10508 10509 elsif Nkind (Subt) = N_Attribute_Reference 10510 and then Attribute_Name (Subt) = Name_Class 10511 then 10512 return Names_T (Prefix (Subt)); 10513 10514 else 10515 return False; 10516 end if; 10517 end Designates_T; 10518 10519 ---------------- 10520 -- Mentions_T -- 10521 ---------------- 10522 10523 function Mentions_T (Acc_Def : Node_Id) return Boolean is 10524 Param_Spec : Node_Id; 10525 10526 Acc_Subprg : constant Node_Id := 10527 Access_To_Subprogram_Definition (Acc_Def); 10528 10529 begin 10530 if No (Acc_Subprg) then 10531 return Designates_T (Subtype_Mark (Acc_Def)); 10532 end if; 10533 10534 -- Component is an access_to_subprogram: examine its formals, 10535 -- and result definition in the case of an access_to_function. 10536 10537 Param_Spec := First (Parameter_Specifications (Acc_Subprg)); 10538 while Present (Param_Spec) loop 10539 if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition 10540 and then Mentions_T (Parameter_Type (Param_Spec)) 10541 then 10542 return True; 10543 10544 elsif Designates_T (Parameter_Type (Param_Spec)) then 10545 return True; 10546 end if; 10547 10548 Next (Param_Spec); 10549 end loop; 10550 10551 if Nkind (Acc_Subprg) = N_Access_Function_Definition then 10552 if Nkind (Result_Definition (Acc_Subprg)) = 10553 N_Access_Definition 10554 then 10555 return Mentions_T (Result_Definition (Acc_Subprg)); 10556 else 10557 return Designates_T (Result_Definition (Acc_Subprg)); 10558 end if; 10559 end if; 10560 10561 return False; 10562 end Mentions_T; 10563 10564 -- Start of processing for Check_Anonymous_Access_Components 10565 10566 begin 10567 if No (Comp_List) then 10568 return; 10569 end if; 10570 10571 Comp := First (Component_Items (Comp_List)); 10572 while Present (Comp) loop 10573 if Nkind (Comp) = N_Component_Declaration 10574 and then Present 10575 (Access_Definition (Component_Definition (Comp))) 10576 and then 10577 Mentions_T (Access_Definition (Component_Definition (Comp))) 10578 then 10579 Comp_Def := Component_Definition (Comp); 10580 Acc_Def := 10581 Access_To_Subprogram_Definition (Access_Definition (Comp_Def)); 10582 10583 Build_Incomplete_Type_Declaration; 10584 Anon_Access := Make_Temporary (Loc, 'S'); 10585 10586 -- Create a declaration for the anonymous access type: either 10587 -- an access_to_object or an access_to_subprogram. 10588 10589 if Present (Acc_Def) then 10590 if Nkind (Acc_Def) = N_Access_Function_Definition then 10591 Type_Def := 10592 Make_Access_Function_Definition (Loc, 10593 Parameter_Specifications => 10594 Parameter_Specifications (Acc_Def), 10595 Result_Definition => Result_Definition (Acc_Def)); 10596 else 10597 Type_Def := 10598 Make_Access_Procedure_Definition (Loc, 10599 Parameter_Specifications => 10600 Parameter_Specifications (Acc_Def)); 10601 end if; 10602 10603 else 10604 Type_Def := 10605 Make_Access_To_Object_Definition (Loc, 10606 Subtype_Indication => 10607 Relocate_Node 10608 (Subtype_Mark (Access_Definition (Comp_Def)))); 10609 10610 Set_Constant_Present 10611 (Type_Def, Constant_Present (Access_Definition (Comp_Def))); 10612 Set_All_Present 10613 (Type_Def, All_Present (Access_Definition (Comp_Def))); 10614 end if; 10615 10616 Set_Null_Exclusion_Present 10617 (Type_Def, 10618 Null_Exclusion_Present (Access_Definition (Comp_Def))); 10619 10620 Decl := 10621 Make_Full_Type_Declaration (Loc, 10622 Defining_Identifier => Anon_Access, 10623 Type_Definition => Type_Def); 10624 10625 Insert_Before (Typ_Decl, Decl); 10626 Analyze (Decl); 10627 10628 -- If an access to subprogram, create the extra formals 10629 10630 if Present (Acc_Def) then 10631 Create_Extra_Formals (Designated_Type (Anon_Access)); 10632 10633 -- If an access to object, preserve entity of designated type, 10634 -- for ASIS use, before rewriting the component definition. 10635 10636 else 10637 declare 10638 Desig : Entity_Id; 10639 10640 begin 10641 Desig := Entity (Subtype_Indication (Type_Def)); 10642 10643 -- If the access definition is to the current record, 10644 -- the visible entity at this point is an incomplete 10645 -- type. Retrieve the full view to simplify ASIS queries 10646 10647 if Ekind (Desig) = E_Incomplete_Type then 10648 Desig := Full_View (Desig); 10649 end if; 10650 10651 Set_Entity 10652 (Subtype_Mark (Access_Definition (Comp_Def)), Desig); 10653 end; 10654 end if; 10655 10656 Rewrite (Comp_Def, 10657 Make_Component_Definition (Loc, 10658 Subtype_Indication => 10659 New_Occurrence_Of (Anon_Access, Loc))); 10660 10661 if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then 10662 Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type); 10663 else 10664 Set_Ekind (Anon_Access, E_Anonymous_Access_Type); 10665 end if; 10666 10667 Set_Is_Local_Anonymous_Access (Anon_Access); 10668 end if; 10669 10670 Next (Comp); 10671 end loop; 10672 10673 if Present (Variant_Part (Comp_List)) then 10674 declare 10675 V : Node_Id; 10676 begin 10677 V := First_Non_Pragma (Variants (Variant_Part (Comp_List))); 10678 while Present (V) loop 10679 Check_Anonymous_Access_Components 10680 (Typ_Decl, Typ, Prev, Component_List (V)); 10681 Next_Non_Pragma (V); 10682 end loop; 10683 end; 10684 end if; 10685 end Check_Anonymous_Access_Components; 10686 10687 ---------------------- 10688 -- Check_Completion -- 10689 ---------------------- 10690 10691 procedure Check_Completion (Body_Id : Node_Id := Empty) is 10692 E : Entity_Id; 10693 10694 procedure Post_Error; 10695 -- Post error message for lack of completion for entity E 10696 10697 ---------------- 10698 -- Post_Error -- 10699 ---------------- 10700 10701 procedure Post_Error is 10702 10703 procedure Missing_Body; 10704 -- Output missing body message 10705 10706 ------------------ 10707 -- Missing_Body -- 10708 ------------------ 10709 10710 procedure Missing_Body is 10711 begin 10712 -- Spec is in same unit, so we can post on spec 10713 10714 if In_Same_Source_Unit (Body_Id, E) then 10715 Error_Msg_N ("missing body for &", E); 10716 10717 -- Spec is in a separate unit, so we have to post on the body 10718 10719 else 10720 Error_Msg_NE ("missing body for & declared#!", Body_Id, E); 10721 end if; 10722 end Missing_Body; 10723 10724 -- Start of processing for Post_Error 10725 10726 begin 10727 if not Comes_From_Source (E) then 10728 10729 if Ekind_In (E, E_Task_Type, E_Protected_Type) then 10730 10731 -- It may be an anonymous protected type created for a 10732 -- single variable. Post error on variable, if present. 10733 10734 declare 10735 Var : Entity_Id; 10736 10737 begin 10738 Var := First_Entity (Current_Scope); 10739 while Present (Var) loop 10740 exit when Etype (Var) = E 10741 and then Comes_From_Source (Var); 10742 10743 Next_Entity (Var); 10744 end loop; 10745 10746 if Present (Var) then 10747 E := Var; 10748 end if; 10749 end; 10750 end if; 10751 end if; 10752 10753 -- If a generated entity has no completion, then either previous 10754 -- semantic errors have disabled the expansion phase, or else we had 10755 -- missing subunits, or else we are compiling without expansion, 10756 -- or else something is very wrong. 10757 10758 if not Comes_From_Source (E) then 10759 pragma Assert 10760 (Serious_Errors_Detected > 0 10761 or else Configurable_Run_Time_Violations > 0 10762 or else Subunits_Missing 10763 or else not Expander_Active); 10764 return; 10765 10766 -- Here for source entity 10767 10768 else 10769 -- Here if no body to post the error message, so we post the error 10770 -- on the declaration that has no completion. This is not really 10771 -- the right place to post it, think about this later ??? 10772 10773 if No (Body_Id) then 10774 if Is_Type (E) then 10775 Error_Msg_NE 10776 ("missing full declaration for }", Parent (E), E); 10777 else 10778 Error_Msg_NE ("missing body for &", Parent (E), E); 10779 end if; 10780 10781 -- Package body has no completion for a declaration that appears 10782 -- in the corresponding spec. Post error on the body, with a 10783 -- reference to the non-completed declaration. 10784 10785 else 10786 Error_Msg_Sloc := Sloc (E); 10787 10788 if Is_Type (E) then 10789 Error_Msg_NE ("missing full declaration for }!", Body_Id, E); 10790 10791 elsif Is_Overloadable (E) 10792 and then Current_Entity_In_Scope (E) /= E 10793 then 10794 -- It may be that the completion is mistyped and appears as 10795 -- a distinct overloading of the entity. 10796 10797 declare 10798 Candidate : constant Entity_Id := 10799 Current_Entity_In_Scope (E); 10800 Decl : constant Node_Id := 10801 Unit_Declaration_Node (Candidate); 10802 10803 begin 10804 if Is_Overloadable (Candidate) 10805 and then Ekind (Candidate) = Ekind (E) 10806 and then Nkind (Decl) = N_Subprogram_Body 10807 and then Acts_As_Spec (Decl) 10808 then 10809 Check_Type_Conformant (Candidate, E); 10810 10811 else 10812 Missing_Body; 10813 end if; 10814 end; 10815 10816 else 10817 Missing_Body; 10818 end if; 10819 end if; 10820 end if; 10821 end Post_Error; 10822 10823 -- Local variables 10824 10825 Pack_Id : constant Entity_Id := Current_Scope; 10826 10827 -- Start of processing for Check_Completion 10828 10829 begin 10830 E := First_Entity (Pack_Id); 10831 while Present (E) loop 10832 if Is_Intrinsic_Subprogram (E) then 10833 null; 10834 10835 -- A Ghost entity declared in a non-Ghost package does not force the 10836 -- need for a body (SPARK RM 6.9(11)). 10837 10838 elsif not Is_Ghost_Entity (Pack_Id) and then Is_Ghost_Entity (E) then 10839 null; 10840 10841 -- The following situation requires special handling: a child unit 10842 -- that appears in the context clause of the body of its parent: 10843 10844 -- procedure Parent.Child (...); 10845 10846 -- with Parent.Child; 10847 -- package body Parent is 10848 10849 -- Here Parent.Child appears as a local entity, but should not be 10850 -- flagged as requiring completion, because it is a compilation 10851 -- unit. 10852 10853 -- Ignore missing completion for a subprogram that does not come from 10854 -- source (including the _Call primitive operation of RAS types, 10855 -- which has to have the flag Comes_From_Source for other purposes): 10856 -- we assume that the expander will provide the missing completion. 10857 -- In case of previous errors, other expansion actions that provide 10858 -- bodies for null procedures with not be invoked, so inhibit message 10859 -- in those cases. 10860 10861 -- Note that E_Operator is not in the list that follows, because 10862 -- this kind is reserved for predefined operators, that are 10863 -- intrinsic and do not need completion. 10864 10865 elsif Ekind_In (E, E_Function, 10866 E_Procedure, 10867 E_Generic_Function, 10868 E_Generic_Procedure) 10869 then 10870 if Has_Completion (E) then 10871 null; 10872 10873 elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then 10874 null; 10875 10876 elsif Is_Subprogram (E) 10877 and then (not Comes_From_Source (E) 10878 or else Chars (E) = Name_uCall) 10879 then 10880 null; 10881 10882 elsif 10883 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit 10884 then 10885 null; 10886 10887 elsif Nkind (Parent (E)) = N_Procedure_Specification 10888 and then Null_Present (Parent (E)) 10889 and then Serious_Errors_Detected > 0 10890 then 10891 null; 10892 10893 else 10894 Post_Error; 10895 end if; 10896 10897 elsif Is_Entry (E) then 10898 if not Has_Completion (E) and then 10899 (Ekind (Scope (E)) = E_Protected_Object 10900 or else Ekind (Scope (E)) = E_Protected_Type) 10901 then 10902 Post_Error; 10903 end if; 10904 10905 elsif Is_Package_Or_Generic_Package (E) then 10906 if Unit_Requires_Body (E) then 10907 if not Has_Completion (E) 10908 and then Nkind (Parent (Unit_Declaration_Node (E))) /= 10909 N_Compilation_Unit 10910 then 10911 Post_Error; 10912 end if; 10913 10914 elsif not Is_Child_Unit (E) then 10915 May_Need_Implicit_Body (E); 10916 end if; 10917 10918 -- A formal incomplete type (Ada 2012) does not require a completion; 10919 -- other incomplete type declarations do. 10920 10921 elsif Ekind (E) = E_Incomplete_Type 10922 and then No (Underlying_Type (E)) 10923 and then not Is_Generic_Type (E) 10924 then 10925 Post_Error; 10926 10927 elsif Ekind_In (E, E_Task_Type, E_Protected_Type) 10928 and then not Has_Completion (E) 10929 then 10930 Post_Error; 10931 10932 -- A single task declared in the current scope is a constant, verify 10933 -- that the body of its anonymous type is in the same scope. If the 10934 -- task is defined elsewhere, this may be a renaming declaration for 10935 -- which no completion is needed. 10936 10937 elsif Ekind (E) = E_Constant 10938 and then Ekind (Etype (E)) = E_Task_Type 10939 and then not Has_Completion (Etype (E)) 10940 and then Scope (Etype (E)) = Current_Scope 10941 then 10942 Post_Error; 10943 10944 elsif Ekind (E) = E_Protected_Object 10945 and then not Has_Completion (Etype (E)) 10946 then 10947 Post_Error; 10948 10949 elsif Ekind (E) = E_Record_Type then 10950 if Is_Tagged_Type (E) then 10951 Check_Abstract_Overriding (E); 10952 Check_Conventions (E); 10953 end if; 10954 10955 Check_Aliased_Component_Types (E); 10956 10957 elsif Ekind (E) = E_Array_Type then 10958 Check_Aliased_Component_Types (E); 10959 10960 end if; 10961 10962 Next_Entity (E); 10963 end loop; 10964 end Check_Completion; 10965 10966 ------------------------------------ 10967 -- Check_CPP_Type_Has_No_Defaults -- 10968 ------------------------------------ 10969 10970 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is 10971 Tdef : constant Node_Id := Type_Definition (Declaration_Node (T)); 10972 Clist : Node_Id; 10973 Comp : Node_Id; 10974 10975 begin 10976 -- Obtain the component list 10977 10978 if Nkind (Tdef) = N_Record_Definition then 10979 Clist := Component_List (Tdef); 10980 else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition); 10981 Clist := Component_List (Record_Extension_Part (Tdef)); 10982 end if; 10983 10984 -- Check all components to ensure no default expressions 10985 10986 if Present (Clist) then 10987 Comp := First (Component_Items (Clist)); 10988 while Present (Comp) loop 10989 if Present (Expression (Comp)) then 10990 Error_Msg_N 10991 ("component of imported 'C'P'P type cannot have " 10992 & "default expression", Expression (Comp)); 10993 end if; 10994 10995 Next (Comp); 10996 end loop; 10997 end if; 10998 end Check_CPP_Type_Has_No_Defaults; 10999 11000 ---------------------------- 11001 -- Check_Delta_Expression -- 11002 ---------------------------- 11003 11004 procedure Check_Delta_Expression (E : Node_Id) is 11005 begin 11006 if not (Is_Real_Type (Etype (E))) then 11007 Wrong_Type (E, Any_Real); 11008 11009 elsif not Is_OK_Static_Expression (E) then 11010 Flag_Non_Static_Expr 11011 ("non-static expression used for delta value!", E); 11012 11013 elsif not UR_Is_Positive (Expr_Value_R (E)) then 11014 Error_Msg_N ("delta expression must be positive", E); 11015 11016 else 11017 return; 11018 end if; 11019 11020 -- If any of above errors occurred, then replace the incorrect 11021 -- expression by the real 0.1, which should prevent further errors. 11022 11023 Rewrite (E, 11024 Make_Real_Literal (Sloc (E), Ureal_Tenth)); 11025 Analyze_And_Resolve (E, Standard_Float); 11026 end Check_Delta_Expression; 11027 11028 ----------------------------- 11029 -- Check_Digits_Expression -- 11030 ----------------------------- 11031 11032 procedure Check_Digits_Expression (E : Node_Id) is 11033 begin 11034 if not (Is_Integer_Type (Etype (E))) then 11035 Wrong_Type (E, Any_Integer); 11036 11037 elsif not Is_OK_Static_Expression (E) then 11038 Flag_Non_Static_Expr 11039 ("non-static expression used for digits value!", E); 11040 11041 elsif Expr_Value (E) <= 0 then 11042 Error_Msg_N ("digits value must be greater than zero", E); 11043 11044 else 11045 return; 11046 end if; 11047 11048 -- If any of above errors occurred, then replace the incorrect 11049 -- expression by the integer 1, which should prevent further errors. 11050 11051 Rewrite (E, Make_Integer_Literal (Sloc (E), 1)); 11052 Analyze_And_Resolve (E, Standard_Integer); 11053 11054 end Check_Digits_Expression; 11055 11056 -------------------------- 11057 -- Check_Initialization -- 11058 -------------------------- 11059 11060 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is 11061 begin 11062 -- Special processing for limited types 11063 11064 if Is_Limited_Type (T) 11065 and then not In_Instance 11066 and then not In_Inlined_Body 11067 then 11068 if not OK_For_Limited_Init (T, Exp) then 11069 11070 -- In GNAT mode, this is just a warning, to allow it to be evilly 11071 -- turned off. Otherwise it is a real error. 11072 11073 if GNAT_Mode then 11074 Error_Msg_N 11075 ("??cannot initialize entities of limited type!", Exp); 11076 11077 elsif Ada_Version < Ada_2005 then 11078 11079 -- The side effect removal machinery may generate illegal Ada 11080 -- code to avoid the usage of access types and 'reference in 11081 -- SPARK mode. Since this is legal code with respect to theorem 11082 -- proving, do not emit the error. 11083 11084 if GNATprove_Mode 11085 and then Nkind (Exp) = N_Function_Call 11086 and then Nkind (Parent (Exp)) = N_Object_Declaration 11087 and then not Comes_From_Source 11088 (Defining_Identifier (Parent (Exp))) 11089 then 11090 null; 11091 11092 else 11093 Error_Msg_N 11094 ("cannot initialize entities of limited type", Exp); 11095 Explain_Limited_Type (T, Exp); 11096 end if; 11097 11098 else 11099 -- Specialize error message according to kind of illegal 11100 -- initial expression. 11101 11102 if Nkind (Exp) = N_Type_Conversion 11103 and then Nkind (Expression (Exp)) = N_Function_Call 11104 then 11105 Error_Msg_N 11106 ("illegal context for call" 11107 & " to function with limited result", Exp); 11108 11109 else 11110 Error_Msg_N 11111 ("initialization of limited object requires aggregate " 11112 & "or function call", Exp); 11113 end if; 11114 end if; 11115 end if; 11116 end if; 11117 11118 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag gets 11119 -- set unless we can be sure that no range check is required. 11120 11121 if (GNATprove_Mode or not Expander_Active) 11122 and then Is_Scalar_Type (T) 11123 and then not Is_In_Range (Exp, T, Assume_Valid => True) 11124 then 11125 Set_Do_Range_Check (Exp); 11126 end if; 11127 end Check_Initialization; 11128 11129 ---------------------- 11130 -- Check_Interfaces -- 11131 ---------------------- 11132 11133 procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is 11134 Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N)); 11135 11136 Iface : Node_Id; 11137 Iface_Def : Node_Id; 11138 Iface_Typ : Entity_Id; 11139 Parent_Node : Node_Id; 11140 11141 Is_Task : Boolean := False; 11142 -- Set True if parent type or any progenitor is a task interface 11143 11144 Is_Protected : Boolean := False; 11145 -- Set True if parent type or any progenitor is a protected interface 11146 11147 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id); 11148 -- Check that a progenitor is compatible with declaration. If an error 11149 -- message is output, it is posted on Error_Node. 11150 11151 ------------------ 11152 -- Check_Ifaces -- 11153 ------------------ 11154 11155 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is 11156 Iface_Id : constant Entity_Id := 11157 Defining_Identifier (Parent (Iface_Def)); 11158 Type_Def : Node_Id; 11159 11160 begin 11161 if Nkind (N) = N_Private_Extension_Declaration then 11162 Type_Def := N; 11163 else 11164 Type_Def := Type_Definition (N); 11165 end if; 11166 11167 if Is_Task_Interface (Iface_Id) then 11168 Is_Task := True; 11169 11170 elsif Is_Protected_Interface (Iface_Id) then 11171 Is_Protected := True; 11172 end if; 11173 11174 if Is_Synchronized_Interface (Iface_Id) then 11175 11176 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private 11177 -- extension derived from a synchronized interface must explicitly 11178 -- be declared synchronized, because the full view will be a 11179 -- synchronized type. 11180 11181 if Nkind (N) = N_Private_Extension_Declaration then 11182 if not Synchronized_Present (N) then 11183 Error_Msg_NE 11184 ("private extension of& must be explicitly synchronized", 11185 N, Iface_Id); 11186 end if; 11187 11188 -- However, by 3.9.4(16/2), a full type that is a record extension 11189 -- is never allowed to derive from a synchronized interface (note 11190 -- that interfaces must be excluded from this check, because those 11191 -- are represented by derived type definitions in some cases). 11192 11193 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition 11194 and then not Interface_Present (Type_Definition (N)) 11195 then 11196 Error_Msg_N ("record extension cannot derive from synchronized " 11197 & "interface", Error_Node); 11198 end if; 11199 end if; 11200 11201 -- Check that the characteristics of the progenitor are compatible 11202 -- with the explicit qualifier in the declaration. 11203 -- The check only applies to qualifiers that come from source. 11204 -- Limited_Present also appears in the declaration of corresponding 11205 -- records, and the check does not apply to them. 11206 11207 if Limited_Present (Type_Def) 11208 and then not 11209 Is_Concurrent_Record_Type (Defining_Identifier (N)) 11210 then 11211 if Is_Limited_Interface (Parent_Type) 11212 and then not Is_Limited_Interface (Iface_Id) 11213 then 11214 Error_Msg_NE 11215 ("progenitor & must be limited interface", 11216 Error_Node, Iface_Id); 11217 11218 elsif 11219 (Task_Present (Iface_Def) 11220 or else Protected_Present (Iface_Def) 11221 or else Synchronized_Present (Iface_Def)) 11222 and then Nkind (N) /= N_Private_Extension_Declaration 11223 and then not Error_Posted (N) 11224 then 11225 Error_Msg_NE 11226 ("progenitor & must be limited interface", 11227 Error_Node, Iface_Id); 11228 end if; 11229 11230 -- Protected interfaces can only inherit from limited, synchronized 11231 -- or protected interfaces. 11232 11233 elsif Nkind (N) = N_Full_Type_Declaration 11234 and then Protected_Present (Type_Def) 11235 then 11236 if Limited_Present (Iface_Def) 11237 or else Synchronized_Present (Iface_Def) 11238 or else Protected_Present (Iface_Def) 11239 then 11240 null; 11241 11242 elsif Task_Present (Iface_Def) then 11243 Error_Msg_N ("(Ada 2005) protected interface cannot inherit " 11244 & "from task interface", Error_Node); 11245 11246 else 11247 Error_Msg_N ("(Ada 2005) protected interface cannot inherit " 11248 & "from non-limited interface", Error_Node); 11249 end if; 11250 11251 -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from 11252 -- limited and synchronized. 11253 11254 elsif Synchronized_Present (Type_Def) then 11255 if Limited_Present (Iface_Def) 11256 or else Synchronized_Present (Iface_Def) 11257 then 11258 null; 11259 11260 elsif Protected_Present (Iface_Def) 11261 and then Nkind (N) /= N_Private_Extension_Declaration 11262 then 11263 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit " 11264 & "from protected interface", Error_Node); 11265 11266 elsif Task_Present (Iface_Def) 11267 and then Nkind (N) /= N_Private_Extension_Declaration 11268 then 11269 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit " 11270 & "from task interface", Error_Node); 11271 11272 elsif not Is_Limited_Interface (Iface_Id) then 11273 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit " 11274 & "from non-limited interface", Error_Node); 11275 end if; 11276 11277 -- Ada 2005 (AI-345): Task interfaces can only inherit from limited, 11278 -- synchronized or task interfaces. 11279 11280 elsif Nkind (N) = N_Full_Type_Declaration 11281 and then Task_Present (Type_Def) 11282 then 11283 if Limited_Present (Iface_Def) 11284 or else Synchronized_Present (Iface_Def) 11285 or else Task_Present (Iface_Def) 11286 then 11287 null; 11288 11289 elsif Protected_Present (Iface_Def) then 11290 Error_Msg_N ("(Ada 2005) task interface cannot inherit from " 11291 & "protected interface", Error_Node); 11292 11293 else 11294 Error_Msg_N ("(Ada 2005) task interface cannot inherit from " 11295 & "non-limited interface", Error_Node); 11296 end if; 11297 end if; 11298 end Check_Ifaces; 11299 11300 -- Start of processing for Check_Interfaces 11301 11302 begin 11303 if Is_Interface (Parent_Type) then 11304 if Is_Task_Interface (Parent_Type) then 11305 Is_Task := True; 11306 11307 elsif Is_Protected_Interface (Parent_Type) then 11308 Is_Protected := True; 11309 end if; 11310 end if; 11311 11312 if Nkind (N) = N_Private_Extension_Declaration then 11313 11314 -- Check that progenitors are compatible with declaration 11315 11316 Iface := First (Interface_List (Def)); 11317 while Present (Iface) loop 11318 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface); 11319 11320 Parent_Node := Parent (Base_Type (Iface_Typ)); 11321 Iface_Def := Type_Definition (Parent_Node); 11322 11323 if not Is_Interface (Iface_Typ) then 11324 Diagnose_Interface (Iface, Iface_Typ); 11325 else 11326 Check_Ifaces (Iface_Def, Iface); 11327 end if; 11328 11329 Next (Iface); 11330 end loop; 11331 11332 if Is_Task and Is_Protected then 11333 Error_Msg_N 11334 ("type cannot derive from task and protected interface", N); 11335 end if; 11336 11337 return; 11338 end if; 11339 11340 -- Full type declaration of derived type. 11341 -- Check compatibility with parent if it is interface type 11342 11343 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition 11344 and then Is_Interface (Parent_Type) 11345 then 11346 Parent_Node := Parent (Parent_Type); 11347 11348 -- More detailed checks for interface varieties 11349 11350 Check_Ifaces 11351 (Iface_Def => Type_Definition (Parent_Node), 11352 Error_Node => Subtype_Indication (Type_Definition (N))); 11353 end if; 11354 11355 Iface := First (Interface_List (Def)); 11356 while Present (Iface) loop 11357 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface); 11358 11359 Parent_Node := Parent (Base_Type (Iface_Typ)); 11360 Iface_Def := Type_Definition (Parent_Node); 11361 11362 if not Is_Interface (Iface_Typ) then 11363 Diagnose_Interface (Iface, Iface_Typ); 11364 11365 else 11366 -- "The declaration of a specific descendant of an interface 11367 -- type freezes the interface type" RM 13.14 11368 11369 Freeze_Before (N, Iface_Typ); 11370 Check_Ifaces (Iface_Def, Error_Node => Iface); 11371 end if; 11372 11373 Next (Iface); 11374 end loop; 11375 11376 if Is_Task and Is_Protected then 11377 Error_Msg_N 11378 ("type cannot derive from task and protected interface", N); 11379 end if; 11380 end Check_Interfaces; 11381 11382 ------------------------------------ 11383 -- Check_Or_Process_Discriminants -- 11384 ------------------------------------ 11385 11386 -- If an incomplete or private type declaration was already given for the 11387 -- type, the discriminants may have already been processed if they were 11388 -- present on the incomplete declaration. In this case a full conformance 11389 -- check has been performed in Find_Type_Name, and we then recheck here 11390 -- some properties that can't be checked on the partial view alone. 11391 -- Otherwise we call Process_Discriminants. 11392 11393 procedure Check_Or_Process_Discriminants 11394 (N : Node_Id; 11395 T : Entity_Id; 11396 Prev : Entity_Id := Empty) 11397 is 11398 begin 11399 if Has_Discriminants (T) then 11400 11401 -- Discriminants are already set on T if they were already present 11402 -- on the partial view. Make them visible to component declarations. 11403 11404 declare 11405 D : Entity_Id; 11406 -- Discriminant on T (full view) referencing expr on partial view 11407 11408 Prev_D : Entity_Id; 11409 -- Entity of corresponding discriminant on partial view 11410 11411 New_D : Node_Id; 11412 -- Discriminant specification for full view, expression is 11413 -- the syntactic copy on full view (which has been checked for 11414 -- conformance with partial view), only used here to post error 11415 -- message. 11416 11417 begin 11418 D := First_Discriminant (T); 11419 New_D := First (Discriminant_Specifications (N)); 11420 while Present (D) loop 11421 Prev_D := Current_Entity (D); 11422 Set_Current_Entity (D); 11423 Set_Is_Immediately_Visible (D); 11424 Set_Homonym (D, Prev_D); 11425 11426 -- Handle the case where there is an untagged partial view and 11427 -- the full view is tagged: must disallow discriminants with 11428 -- defaults, unless compiling for Ada 2012, which allows a 11429 -- limited tagged type to have defaulted discriminants (see 11430 -- AI05-0214). However, suppress error here if it was already 11431 -- reported on the default expression of the partial view. 11432 11433 if Is_Tagged_Type (T) 11434 and then Present (Expression (Parent (D))) 11435 and then (not Is_Limited_Type (Current_Scope) 11436 or else Ada_Version < Ada_2012) 11437 and then not Error_Posted (Expression (Parent (D))) 11438 then 11439 if Ada_Version >= Ada_2012 then 11440 Error_Msg_N 11441 ("discriminants of nonlimited tagged type cannot have " 11442 & "defaults", 11443 Expression (New_D)); 11444 else 11445 Error_Msg_N 11446 ("discriminants of tagged type cannot have defaults", 11447 Expression (New_D)); 11448 end if; 11449 end if; 11450 11451 -- Ada 2005 (AI-230): Access discriminant allowed in 11452 -- non-limited record types. 11453 11454 if Ada_Version < Ada_2005 then 11455 11456 -- This restriction gets applied to the full type here. It 11457 -- has already been applied earlier to the partial view. 11458 11459 Check_Access_Discriminant_Requires_Limited (Parent (D), N); 11460 end if; 11461 11462 Next_Discriminant (D); 11463 Next (New_D); 11464 end loop; 11465 end; 11466 11467 elsif Present (Discriminant_Specifications (N)) then 11468 Process_Discriminants (N, Prev); 11469 end if; 11470 end Check_Or_Process_Discriminants; 11471 11472 ---------------------- 11473 -- Check_Real_Bound -- 11474 ---------------------- 11475 11476 procedure Check_Real_Bound (Bound : Node_Id) is 11477 begin 11478 if not Is_Real_Type (Etype (Bound)) then 11479 Error_Msg_N 11480 ("bound in real type definition must be of real type", Bound); 11481 11482 elsif not Is_OK_Static_Expression (Bound) then 11483 Flag_Non_Static_Expr 11484 ("non-static expression used for real type bound!", Bound); 11485 11486 else 11487 return; 11488 end if; 11489 11490 Rewrite 11491 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0)); 11492 Analyze (Bound); 11493 Resolve (Bound, Standard_Float); 11494 end Check_Real_Bound; 11495 11496 ------------------------------ 11497 -- Complete_Private_Subtype -- 11498 ------------------------------ 11499 11500 procedure Complete_Private_Subtype 11501 (Priv : Entity_Id; 11502 Full : Entity_Id; 11503 Full_Base : Entity_Id; 11504 Related_Nod : Node_Id) 11505 is 11506 Save_Next_Entity : Entity_Id; 11507 Save_Homonym : Entity_Id; 11508 11509 begin 11510 -- Set semantic attributes for (implicit) private subtype completion. 11511 -- If the full type has no discriminants, then it is a copy of the 11512 -- full view of the base. Otherwise, it is a subtype of the base with 11513 -- a possible discriminant constraint. Save and restore the original 11514 -- Next_Entity field of full to ensure that the calls to Copy_Node do 11515 -- not corrupt the entity chain. 11516 11517 -- Note that the type of the full view is the same entity as the type 11518 -- of the partial view. In this fashion, the subtype has access to the 11519 -- correct view of the parent. 11520 11521 Save_Next_Entity := Next_Entity (Full); 11522 Save_Homonym := Homonym (Priv); 11523 11524 case Ekind (Full_Base) is 11525 when E_Record_Type | 11526 E_Record_Subtype | 11527 Class_Wide_Kind | 11528 Private_Kind | 11529 Task_Kind | 11530 Protected_Kind => 11531 Copy_Node (Priv, Full); 11532 11533 Set_Has_Discriminants 11534 (Full, Has_Discriminants (Full_Base)); 11535 Set_Has_Unknown_Discriminants 11536 (Full, Has_Unknown_Discriminants (Full_Base)); 11537 Set_First_Entity (Full, First_Entity (Full_Base)); 11538 Set_Last_Entity (Full, Last_Entity (Full_Base)); 11539 11540 -- If the underlying base type is constrained, we know that the 11541 -- full view of the subtype is constrained as well (the converse 11542 -- is not necessarily true). 11543 11544 if Is_Constrained (Full_Base) then 11545 Set_Is_Constrained (Full); 11546 end if; 11547 11548 when others => 11549 Copy_Node (Full_Base, Full); 11550 11551 Set_Chars (Full, Chars (Priv)); 11552 Conditional_Delay (Full, Priv); 11553 Set_Sloc (Full, Sloc (Priv)); 11554 end case; 11555 11556 Set_Next_Entity (Full, Save_Next_Entity); 11557 Set_Homonym (Full, Save_Homonym); 11558 Set_Associated_Node_For_Itype (Full, Related_Nod); 11559 11560 -- Set common attributes for all subtypes: kind, convention, etc. 11561 11562 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base))); 11563 Set_Convention (Full, Convention (Full_Base)); 11564 11565 -- The Etype of the full view is inconsistent. Gigi needs to see the 11566 -- structural full view, which is what the current scheme gives: the 11567 -- Etype of the full view is the etype of the full base. However, if the 11568 -- full base is a derived type, the full view then looks like a subtype 11569 -- of the parent, not a subtype of the full base. If instead we write: 11570 11571 -- Set_Etype (Full, Full_Base); 11572 11573 -- then we get inconsistencies in the front-end (confusion between 11574 -- views). Several outstanding bugs are related to this ??? 11575 11576 Set_Is_First_Subtype (Full, False); 11577 Set_Scope (Full, Scope (Priv)); 11578 Set_Size_Info (Full, Full_Base); 11579 Set_RM_Size (Full, RM_Size (Full_Base)); 11580 Set_Is_Itype (Full); 11581 11582 -- A subtype of a private-type-without-discriminants, whose full-view 11583 -- has discriminants with default expressions, is not constrained. 11584 11585 if not Has_Discriminants (Priv) then 11586 Set_Is_Constrained (Full, Is_Constrained (Full_Base)); 11587 11588 if Has_Discriminants (Full_Base) then 11589 Set_Discriminant_Constraint 11590 (Full, Discriminant_Constraint (Full_Base)); 11591 11592 -- The partial view may have been indefinite, the full view 11593 -- might not be. 11594 11595 Set_Has_Unknown_Discriminants 11596 (Full, Has_Unknown_Discriminants (Full_Base)); 11597 end if; 11598 end if; 11599 11600 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base)); 11601 Set_Depends_On_Private (Full, Has_Private_Component (Full)); 11602 11603 -- Freeze the private subtype entity if its parent is delayed, and not 11604 -- already frozen. We skip this processing if the type is an anonymous 11605 -- subtype of a record component, or is the corresponding record of a 11606 -- protected type, since ??? 11607 11608 if not Is_Type (Scope (Full)) then 11609 Set_Has_Delayed_Freeze (Full, 11610 Has_Delayed_Freeze (Full_Base) 11611 and then (not Is_Frozen (Full_Base))); 11612 end if; 11613 11614 Set_Freeze_Node (Full, Empty); 11615 Set_Is_Frozen (Full, False); 11616 Set_Full_View (Priv, Full); 11617 11618 if Has_Discriminants (Full) then 11619 Set_Stored_Constraint_From_Discriminant_Constraint (Full); 11620 Set_Stored_Constraint (Priv, Stored_Constraint (Full)); 11621 11622 if Has_Unknown_Discriminants (Full) then 11623 Set_Discriminant_Constraint (Full, No_Elist); 11624 end if; 11625 end if; 11626 11627 if Ekind (Full_Base) = E_Record_Type 11628 and then Has_Discriminants (Full_Base) 11629 and then Has_Discriminants (Priv) -- might not, if errors 11630 and then not Has_Unknown_Discriminants (Priv) 11631 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv)) 11632 then 11633 Create_Constrained_Components 11634 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv)); 11635 11636 -- If the full base is itself derived from private, build a congruent 11637 -- subtype of its underlying type, for use by the back end. For a 11638 -- constrained record component, the declaration cannot be placed on 11639 -- the component list, but it must nevertheless be built an analyzed, to 11640 -- supply enough information for Gigi to compute the size of component. 11641 11642 elsif Ekind (Full_Base) in Private_Kind 11643 and then Is_Derived_Type (Full_Base) 11644 and then Has_Discriminants (Full_Base) 11645 and then (Ekind (Current_Scope) /= E_Record_Subtype) 11646 then 11647 if not Is_Itype (Priv) 11648 and then 11649 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication 11650 then 11651 Build_Underlying_Full_View 11652 (Parent (Priv), Full, Etype (Full_Base)); 11653 11654 elsif Nkind (Related_Nod) = N_Component_Declaration then 11655 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base)); 11656 end if; 11657 11658 elsif Is_Record_Type (Full_Base) then 11659 11660 -- Show Full is simply a renaming of Full_Base 11661 11662 Set_Cloned_Subtype (Full, Full_Base); 11663 end if; 11664 11665 -- It is unsafe to share the bounds of a scalar type, because the Itype 11666 -- is elaborated on demand, and if a bound is non-static then different 11667 -- orders of elaboration in different units will lead to different 11668 -- external symbols. 11669 11670 if Is_Scalar_Type (Full_Base) then 11671 Set_Scalar_Range (Full, 11672 Make_Range (Sloc (Related_Nod), 11673 Low_Bound => 11674 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)), 11675 High_Bound => 11676 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base)))); 11677 11678 -- This completion inherits the bounds of the full parent, but if 11679 -- the parent is an unconstrained floating point type, so is the 11680 -- completion. 11681 11682 if Is_Floating_Point_Type (Full_Base) then 11683 Set_Includes_Infinities 11684 (Scalar_Range (Full), Has_Infinities (Full_Base)); 11685 end if; 11686 end if; 11687 11688 -- ??? It seems that a lot of fields are missing that should be copied 11689 -- from Full_Base to Full. Here are some that are introduced in a 11690 -- non-disruptive way but a cleanup is necessary. 11691 11692 if Is_Tagged_Type (Full_Base) then 11693 Set_Is_Tagged_Type (Full); 11694 Set_Direct_Primitive_Operations 11695 (Full, Direct_Primitive_Operations (Full_Base)); 11696 Set_No_Tagged_Streams_Pragma 11697 (Full, No_Tagged_Streams_Pragma (Full_Base)); 11698 11699 -- Inherit class_wide type of full_base in case the partial view was 11700 -- not tagged. Otherwise it has already been created when the private 11701 -- subtype was analyzed. 11702 11703 if No (Class_Wide_Type (Full)) then 11704 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base)); 11705 end if; 11706 11707 -- If this is a subtype of a protected or task type, constrain its 11708 -- corresponding record, unless this is a subtype without constraints, 11709 -- i.e. a simple renaming as with an actual subtype in an instance. 11710 11711 elsif Is_Concurrent_Type (Full_Base) then 11712 if Has_Discriminants (Full) 11713 and then Present (Corresponding_Record_Type (Full_Base)) 11714 and then 11715 not Is_Empty_Elmt_List (Discriminant_Constraint (Full)) 11716 then 11717 Set_Corresponding_Record_Type (Full, 11718 Constrain_Corresponding_Record 11719 (Full, Corresponding_Record_Type (Full_Base), Related_Nod)); 11720 11721 else 11722 Set_Corresponding_Record_Type (Full, 11723 Corresponding_Record_Type (Full_Base)); 11724 end if; 11725 end if; 11726 11727 -- Link rep item chain, and also setting of Has_Predicates from private 11728 -- subtype to full subtype, since we will need these on the full subtype 11729 -- to create the predicate function. Note that the full subtype may 11730 -- already have rep items, inherited from the full view of the base 11731 -- type, so we must be sure not to overwrite these entries. 11732 11733 declare 11734 Append : Boolean; 11735 Item : Node_Id; 11736 Next_Item : Node_Id; 11737 11738 begin 11739 Item := First_Rep_Item (Full); 11740 11741 -- If no existing rep items on full type, we can just link directly 11742 -- to the list of items on the private type, if any exist.. Same if 11743 -- the rep items are only those inherited from the base 11744 11745 if (No (Item) 11746 or else Nkind (Item) /= N_Aspect_Specification 11747 or else Entity (Item) = Full_Base) 11748 and then Present (First_Rep_Item (Priv)) 11749 then 11750 Set_First_Rep_Item (Full, First_Rep_Item (Priv)); 11751 11752 -- Otherwise, search to the end of items currently linked to the full 11753 -- subtype and append the private items to the end. However, if Priv 11754 -- and Full already have the same list of rep items, then the append 11755 -- is not done, as that would create a circularity. 11756 11757 elsif Item /= First_Rep_Item (Priv) then 11758 Append := True; 11759 loop 11760 Next_Item := Next_Rep_Item (Item); 11761 exit when No (Next_Item); 11762 Item := Next_Item; 11763 11764 -- If the private view has aspect specifications, the full view 11765 -- inherits them. Since these aspects may already have been 11766 -- attached to the full view during derivation, do not append 11767 -- them if already present. 11768 11769 if Item = First_Rep_Item (Priv) then 11770 Append := False; 11771 exit; 11772 end if; 11773 end loop; 11774 11775 -- And link the private type items at the end of the chain 11776 11777 if Append then 11778 Set_Next_Rep_Item (Item, First_Rep_Item (Priv)); 11779 end if; 11780 end if; 11781 end; 11782 11783 -- Make sure Has_Predicates is set on full type if it is set on the 11784 -- private type. Note that it may already be set on the full type and 11785 -- if so, we don't want to unset it. 11786 11787 if Has_Predicates (Priv) then 11788 Set_Has_Predicates (Full); 11789 end if; 11790 end Complete_Private_Subtype; 11791 11792 ---------------------------- 11793 -- Constant_Redeclaration -- 11794 ---------------------------- 11795 11796 procedure Constant_Redeclaration 11797 (Id : Entity_Id; 11798 N : Node_Id; 11799 T : out Entity_Id) 11800 is 11801 Prev : constant Entity_Id := Current_Entity_In_Scope (Id); 11802 Obj_Def : constant Node_Id := Object_Definition (N); 11803 New_T : Entity_Id; 11804 11805 procedure Check_Possible_Deferred_Completion 11806 (Prev_Id : Entity_Id; 11807 Prev_Obj_Def : Node_Id; 11808 Curr_Obj_Def : Node_Id); 11809 -- Determine whether the two object definitions describe the partial 11810 -- and the full view of a constrained deferred constant. Generate 11811 -- a subtype for the full view and verify that it statically matches 11812 -- the subtype of the partial view. 11813 11814 procedure Check_Recursive_Declaration (Typ : Entity_Id); 11815 -- If deferred constant is an access type initialized with an allocator, 11816 -- check whether there is an illegal recursion in the definition, 11817 -- through a default value of some record subcomponent. This is normally 11818 -- detected when generating init procs, but requires this additional 11819 -- mechanism when expansion is disabled. 11820 11821 ---------------------------------------- 11822 -- Check_Possible_Deferred_Completion -- 11823 ---------------------------------------- 11824 11825 procedure Check_Possible_Deferred_Completion 11826 (Prev_Id : Entity_Id; 11827 Prev_Obj_Def : Node_Id; 11828 Curr_Obj_Def : Node_Id) 11829 is 11830 begin 11831 if Nkind (Prev_Obj_Def) = N_Subtype_Indication 11832 and then Present (Constraint (Prev_Obj_Def)) 11833 and then Nkind (Curr_Obj_Def) = N_Subtype_Indication 11834 and then Present (Constraint (Curr_Obj_Def)) 11835 then 11836 declare 11837 Loc : constant Source_Ptr := Sloc (N); 11838 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S'); 11839 Decl : constant Node_Id := 11840 Make_Subtype_Declaration (Loc, 11841 Defining_Identifier => Def_Id, 11842 Subtype_Indication => 11843 Relocate_Node (Curr_Obj_Def)); 11844 11845 begin 11846 Insert_Before_And_Analyze (N, Decl); 11847 Set_Etype (Id, Def_Id); 11848 11849 if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then 11850 Error_Msg_Sloc := Sloc (Prev_Id); 11851 Error_Msg_N ("subtype does not statically match deferred " 11852 & "declaration #", N); 11853 end if; 11854 end; 11855 end if; 11856 end Check_Possible_Deferred_Completion; 11857 11858 --------------------------------- 11859 -- Check_Recursive_Declaration -- 11860 --------------------------------- 11861 11862 procedure Check_Recursive_Declaration (Typ : Entity_Id) is 11863 Comp : Entity_Id; 11864 11865 begin 11866 if Is_Record_Type (Typ) then 11867 Comp := First_Component (Typ); 11868 while Present (Comp) loop 11869 if Comes_From_Source (Comp) then 11870 if Present (Expression (Parent (Comp))) 11871 and then Is_Entity_Name (Expression (Parent (Comp))) 11872 and then Entity (Expression (Parent (Comp))) = Prev 11873 then 11874 Error_Msg_Sloc := Sloc (Parent (Comp)); 11875 Error_Msg_NE 11876 ("illegal circularity with declaration for & #", 11877 N, Comp); 11878 return; 11879 11880 elsif Is_Record_Type (Etype (Comp)) then 11881 Check_Recursive_Declaration (Etype (Comp)); 11882 end if; 11883 end if; 11884 11885 Next_Component (Comp); 11886 end loop; 11887 end if; 11888 end Check_Recursive_Declaration; 11889 11890 -- Start of processing for Constant_Redeclaration 11891 11892 begin 11893 if Nkind (Parent (Prev)) = N_Object_Declaration then 11894 if Nkind (Object_Definition 11895 (Parent (Prev))) = N_Subtype_Indication 11896 then 11897 -- Find type of new declaration. The constraints of the two 11898 -- views must match statically, but there is no point in 11899 -- creating an itype for the full view. 11900 11901 if Nkind (Obj_Def) = N_Subtype_Indication then 11902 Find_Type (Subtype_Mark (Obj_Def)); 11903 New_T := Entity (Subtype_Mark (Obj_Def)); 11904 11905 else 11906 Find_Type (Obj_Def); 11907 New_T := Entity (Obj_Def); 11908 end if; 11909 11910 T := Etype (Prev); 11911 11912 else 11913 -- The full view may impose a constraint, even if the partial 11914 -- view does not, so construct the subtype. 11915 11916 New_T := Find_Type_Of_Object (Obj_Def, N); 11917 T := New_T; 11918 end if; 11919 11920 else 11921 -- Current declaration is illegal, diagnosed below in Enter_Name 11922 11923 T := Empty; 11924 New_T := Any_Type; 11925 end if; 11926 11927 -- If previous full declaration or a renaming declaration exists, or if 11928 -- a homograph is present, let Enter_Name handle it, either with an 11929 -- error or with the removal of an overridden implicit subprogram. 11930 -- The previous one is a full declaration if it has an expression 11931 -- (which in the case of an aggregate is indicated by the Init flag). 11932 11933 if Ekind (Prev) /= E_Constant 11934 or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration 11935 or else Present (Expression (Parent (Prev))) 11936 or else Has_Init_Expression (Parent (Prev)) 11937 or else Present (Full_View (Prev)) 11938 then 11939 Enter_Name (Id); 11940 11941 -- Verify that types of both declarations match, or else that both types 11942 -- are anonymous access types whose designated subtypes statically match 11943 -- (as allowed in Ada 2005 by AI-385). 11944 11945 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) 11946 and then 11947 (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type 11948 or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type 11949 or else Is_Access_Constant (Etype (New_T)) /= 11950 Is_Access_Constant (Etype (Prev)) 11951 or else Can_Never_Be_Null (Etype (New_T)) /= 11952 Can_Never_Be_Null (Etype (Prev)) 11953 or else Null_Exclusion_Present (Parent (Prev)) /= 11954 Null_Exclusion_Present (Parent (Id)) 11955 or else not Subtypes_Statically_Match 11956 (Designated_Type (Etype (Prev)), 11957 Designated_Type (Etype (New_T)))) 11958 then 11959 Error_Msg_Sloc := Sloc (Prev); 11960 Error_Msg_N ("type does not match declaration#", N); 11961 Set_Full_View (Prev, Id); 11962 Set_Etype (Id, Any_Type); 11963 11964 -- A deferred constant whose type is an anonymous array is always 11965 -- illegal (unless imported). A detailed error message might be 11966 -- helpful for Ada beginners. 11967 11968 if Nkind (Object_Definition (Parent (Prev))) 11969 = N_Constrained_Array_Definition 11970 and then Nkind (Object_Definition (N)) 11971 = N_Constrained_Array_Definition 11972 then 11973 Error_Msg_N ("\each anonymous array is a distinct type", N); 11974 Error_Msg_N ("a deferred constant must have a named type", 11975 Object_Definition (Parent (Prev))); 11976 end if; 11977 11978 elsif 11979 Null_Exclusion_Present (Parent (Prev)) 11980 and then not Null_Exclusion_Present (N) 11981 then 11982 Error_Msg_Sloc := Sloc (Prev); 11983 Error_Msg_N ("null-exclusion does not match declaration#", N); 11984 Set_Full_View (Prev, Id); 11985 Set_Etype (Id, Any_Type); 11986 11987 -- If so, process the full constant declaration 11988 11989 else 11990 -- RM 7.4 (6): If the subtype defined by the subtype_indication in 11991 -- the deferred declaration is constrained, then the subtype defined 11992 -- by the subtype_indication in the full declaration shall match it 11993 -- statically. 11994 11995 Check_Possible_Deferred_Completion 11996 (Prev_Id => Prev, 11997 Prev_Obj_Def => Object_Definition (Parent (Prev)), 11998 Curr_Obj_Def => Obj_Def); 11999 12000 Set_Full_View (Prev, Id); 12001 Set_Is_Public (Id, Is_Public (Prev)); 12002 Set_Is_Internal (Id); 12003 Append_Entity (Id, Current_Scope); 12004 12005 -- Check ALIASED present if present before (RM 7.4(7)) 12006 12007 if Is_Aliased (Prev) 12008 and then not Aliased_Present (N) 12009 then 12010 Error_Msg_Sloc := Sloc (Prev); 12011 Error_Msg_N ("ALIASED required (see declaration #)", N); 12012 end if; 12013 12014 -- Check that placement is in private part and that the incomplete 12015 -- declaration appeared in the visible part. 12016 12017 if Ekind (Current_Scope) = E_Package 12018 and then not In_Private_Part (Current_Scope) 12019 then 12020 Error_Msg_Sloc := Sloc (Prev); 12021 Error_Msg_N 12022 ("full constant for declaration # must be in private part", N); 12023 12024 elsif Ekind (Current_Scope) = E_Package 12025 and then 12026 List_Containing (Parent (Prev)) /= 12027 Visible_Declarations (Package_Specification (Current_Scope)) 12028 then 12029 Error_Msg_N 12030 ("deferred constant must be declared in visible part", 12031 Parent (Prev)); 12032 end if; 12033 12034 if Is_Access_Type (T) 12035 and then Nkind (Expression (N)) = N_Allocator 12036 then 12037 Check_Recursive_Declaration (Designated_Type (T)); 12038 end if; 12039 12040 -- A deferred constant is a visible entity. If type has invariants, 12041 -- verify that the initial value satisfies them. 12042 12043 if Has_Invariants (T) and then Present (Invariant_Procedure (T)) then 12044 Insert_After (N, 12045 Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N)))); 12046 end if; 12047 end if; 12048 end Constant_Redeclaration; 12049 12050 ---------------------- 12051 -- Constrain_Access -- 12052 ---------------------- 12053 12054 procedure Constrain_Access 12055 (Def_Id : in out Entity_Id; 12056 S : Node_Id; 12057 Related_Nod : Node_Id) 12058 is 12059 T : constant Entity_Id := Entity (Subtype_Mark (S)); 12060 Desig_Type : constant Entity_Id := Designated_Type (T); 12061 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod); 12062 Constraint_OK : Boolean := True; 12063 12064 begin 12065 if Is_Array_Type (Desig_Type) then 12066 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P'); 12067 12068 elsif (Is_Record_Type (Desig_Type) 12069 or else Is_Incomplete_Or_Private_Type (Desig_Type)) 12070 and then not Is_Constrained (Desig_Type) 12071 then 12072 -- ??? The following code is a temporary bypass to ignore a 12073 -- discriminant constraint on access type if it is constraining 12074 -- the current record. Avoid creating the implicit subtype of the 12075 -- record we are currently compiling since right now, we cannot 12076 -- handle these. For now, just return the access type itself. 12077 12078 if Desig_Type = Current_Scope 12079 and then No (Def_Id) 12080 then 12081 Set_Ekind (Desig_Subtype, E_Record_Subtype); 12082 Def_Id := Entity (Subtype_Mark (S)); 12083 12084 -- This call added to ensure that the constraint is analyzed 12085 -- (needed for a B test). Note that we still return early from 12086 -- this procedure to avoid recursive processing. ??? 12087 12088 Constrain_Discriminated_Type 12089 (Desig_Subtype, S, Related_Nod, For_Access => True); 12090 return; 12091 end if; 12092 12093 -- Enforce rule that the constraint is illegal if there is an 12094 -- unconstrained view of the designated type. This means that the 12095 -- partial view (either a private type declaration or a derivation 12096 -- from a private type) has no discriminants. (Defect Report 12097 -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001). 12098 12099 -- Rule updated for Ada 2005: The private type is said to have 12100 -- a constrained partial view, given that objects of the type 12101 -- can be declared. Furthermore, the rule applies to all access 12102 -- types, unlike the rule concerning default discriminants (see 12103 -- RM 3.7.1(7/3)) 12104 12105 if (Ekind (T) = E_General_Access_Type or else Ada_Version >= Ada_2005) 12106 and then Has_Private_Declaration (Desig_Type) 12107 and then In_Open_Scopes (Scope (Desig_Type)) 12108 and then Has_Discriminants (Desig_Type) 12109 then 12110 declare 12111 Pack : constant Node_Id := 12112 Unit_Declaration_Node (Scope (Desig_Type)); 12113 Decls : List_Id; 12114 Decl : Node_Id; 12115 12116 begin 12117 if Nkind (Pack) = N_Package_Declaration then 12118 Decls := Visible_Declarations (Specification (Pack)); 12119 Decl := First (Decls); 12120 while Present (Decl) loop 12121 if (Nkind (Decl) = N_Private_Type_Declaration 12122 and then Chars (Defining_Identifier (Decl)) = 12123 Chars (Desig_Type)) 12124 12125 or else 12126 (Nkind (Decl) = N_Full_Type_Declaration 12127 and then 12128 Chars (Defining_Identifier (Decl)) = 12129 Chars (Desig_Type) 12130 and then Is_Derived_Type (Desig_Type) 12131 and then 12132 Has_Private_Declaration (Etype (Desig_Type))) 12133 then 12134 if No (Discriminant_Specifications (Decl)) then 12135 Error_Msg_N 12136 ("cannot constrain access type if designated " 12137 & "type has constrained partial view", S); 12138 end if; 12139 12140 exit; 12141 end if; 12142 12143 Next (Decl); 12144 end loop; 12145 end if; 12146 end; 12147 end if; 12148 12149 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod, 12150 For_Access => True); 12151 12152 elsif Is_Concurrent_Type (Desig_Type) 12153 and then not Is_Constrained (Desig_Type) 12154 then 12155 Constrain_Concurrent (Desig_Subtype, S, Related_Nod, Desig_Type, ' '); 12156 12157 else 12158 Error_Msg_N ("invalid constraint on access type", S); 12159 12160 -- We simply ignore an invalid constraint 12161 12162 Desig_Subtype := Desig_Type; 12163 Constraint_OK := False; 12164 end if; 12165 12166 if No (Def_Id) then 12167 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod); 12168 else 12169 Set_Ekind (Def_Id, E_Access_Subtype); 12170 end if; 12171 12172 if Constraint_OK then 12173 Set_Etype (Def_Id, Base_Type (T)); 12174 12175 if Is_Private_Type (Desig_Type) then 12176 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod); 12177 end if; 12178 else 12179 Set_Etype (Def_Id, Any_Type); 12180 end if; 12181 12182 Set_Size_Info (Def_Id, T); 12183 Set_Is_Constrained (Def_Id, Constraint_OK); 12184 Set_Directly_Designated_Type (Def_Id, Desig_Subtype); 12185 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); 12186 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T)); 12187 12188 Conditional_Delay (Def_Id, T); 12189 12190 -- AI-363 : Subtypes of general access types whose designated types have 12191 -- default discriminants are disallowed. In instances, the rule has to 12192 -- be checked against the actual, of which T is the subtype. In a 12193 -- generic body, the rule is checked assuming that the actual type has 12194 -- defaulted discriminants. 12195 12196 if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then 12197 if Ekind (Base_Type (T)) = E_General_Access_Type 12198 and then Has_Defaulted_Discriminants (Desig_Type) 12199 then 12200 if Ada_Version < Ada_2005 then 12201 Error_Msg_N 12202 ("access subtype of general access type would not " & 12203 "be allowed in Ada 2005?y?", S); 12204 else 12205 Error_Msg_N 12206 ("access subtype of general access type not allowed", S); 12207 end if; 12208 12209 Error_Msg_N ("\discriminants have defaults", S); 12210 12211 elsif Is_Access_Type (T) 12212 and then Is_Generic_Type (Desig_Type) 12213 and then Has_Discriminants (Desig_Type) 12214 and then In_Package_Body (Current_Scope) 12215 then 12216 if Ada_Version < Ada_2005 then 12217 Error_Msg_N 12218 ("access subtype would not be allowed in generic body " 12219 & "in Ada 2005?y?", S); 12220 else 12221 Error_Msg_N 12222 ("access subtype not allowed in generic body", S); 12223 end if; 12224 12225 Error_Msg_N 12226 ("\designated type is a discriminated formal", S); 12227 end if; 12228 end if; 12229 end Constrain_Access; 12230 12231 --------------------- 12232 -- Constrain_Array -- 12233 --------------------- 12234 12235 procedure Constrain_Array 12236 (Def_Id : in out Entity_Id; 12237 SI : Node_Id; 12238 Related_Nod : Node_Id; 12239 Related_Id : Entity_Id; 12240 Suffix : Character) 12241 is 12242 C : constant Node_Id := Constraint (SI); 12243 Number_Of_Constraints : Nat := 0; 12244 Index : Node_Id; 12245 S, T : Entity_Id; 12246 Constraint_OK : Boolean := True; 12247 12248 begin 12249 T := Entity (Subtype_Mark (SI)); 12250 12251 if Is_Access_Type (T) then 12252 T := Designated_Type (T); 12253 end if; 12254 12255 -- If an index constraint follows a subtype mark in a subtype indication 12256 -- then the type or subtype denoted by the subtype mark must not already 12257 -- impose an index constraint. The subtype mark must denote either an 12258 -- unconstrained array type or an access type whose designated type 12259 -- is such an array type... (RM 3.6.1) 12260 12261 if Is_Constrained (T) then 12262 Error_Msg_N ("array type is already constrained", Subtype_Mark (SI)); 12263 Constraint_OK := False; 12264 12265 else 12266 S := First (Constraints (C)); 12267 while Present (S) loop 12268 Number_Of_Constraints := Number_Of_Constraints + 1; 12269 Next (S); 12270 end loop; 12271 12272 -- In either case, the index constraint must provide a discrete 12273 -- range for each index of the array type and the type of each 12274 -- discrete range must be the same as that of the corresponding 12275 -- index. (RM 3.6.1) 12276 12277 if Number_Of_Constraints /= Number_Dimensions (T) then 12278 Error_Msg_NE ("incorrect number of index constraints for }", C, T); 12279 Constraint_OK := False; 12280 12281 else 12282 S := First (Constraints (C)); 12283 Index := First_Index (T); 12284 Analyze (Index); 12285 12286 -- Apply constraints to each index type 12287 12288 for J in 1 .. Number_Of_Constraints loop 12289 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J); 12290 Next (Index); 12291 Next (S); 12292 end loop; 12293 12294 end if; 12295 end if; 12296 12297 if No (Def_Id) then 12298 Def_Id := 12299 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix); 12300 Set_Parent (Def_Id, Related_Nod); 12301 12302 else 12303 Set_Ekind (Def_Id, E_Array_Subtype); 12304 end if; 12305 12306 Set_Size_Info (Def_Id, (T)); 12307 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 12308 Set_Etype (Def_Id, Base_Type (T)); 12309 12310 if Constraint_OK then 12311 Set_First_Index (Def_Id, First (Constraints (C))); 12312 else 12313 Set_First_Index (Def_Id, First_Index (T)); 12314 end if; 12315 12316 Set_Is_Constrained (Def_Id, True); 12317 Set_Is_Aliased (Def_Id, Is_Aliased (T)); 12318 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); 12319 12320 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T)); 12321 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T)); 12322 12323 -- A subtype does not inherit the Packed_Array_Impl_Type of is parent. 12324 -- We need to initialize the attribute because if Def_Id is previously 12325 -- analyzed through a limited_with clause, it will have the attributes 12326 -- of an incomplete type, one of which is an Elist that overlaps the 12327 -- Packed_Array_Impl_Type field. 12328 12329 Set_Packed_Array_Impl_Type (Def_Id, Empty); 12330 12331 -- Build a freeze node if parent still needs one. Also make sure that 12332 -- the Depends_On_Private status is set because the subtype will need 12333 -- reprocessing at the time the base type does, and also we must set a 12334 -- conditional delay. 12335 12336 Set_Depends_On_Private (Def_Id, Depends_On_Private (T)); 12337 Conditional_Delay (Def_Id, T); 12338 end Constrain_Array; 12339 12340 ------------------------------ 12341 -- Constrain_Component_Type -- 12342 ------------------------------ 12343 12344 function Constrain_Component_Type 12345 (Comp : Entity_Id; 12346 Constrained_Typ : Entity_Id; 12347 Related_Node : Node_Id; 12348 Typ : Entity_Id; 12349 Constraints : Elist_Id) return Entity_Id 12350 is 12351 Loc : constant Source_Ptr := Sloc (Constrained_Typ); 12352 Compon_Type : constant Entity_Id := Etype (Comp); 12353 12354 function Build_Constrained_Array_Type 12355 (Old_Type : Entity_Id) return Entity_Id; 12356 -- If Old_Type is an array type, one of whose indexes is constrained 12357 -- by a discriminant, build an Itype whose constraint replaces the 12358 -- discriminant with its value in the constraint. 12359 12360 function Build_Constrained_Discriminated_Type 12361 (Old_Type : Entity_Id) return Entity_Id; 12362 -- Ditto for record components 12363 12364 function Build_Constrained_Access_Type 12365 (Old_Type : Entity_Id) return Entity_Id; 12366 -- Ditto for access types. Makes use of previous two functions, to 12367 -- constrain designated type. 12368 12369 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id; 12370 -- T is an array or discriminated type, C is a list of constraints 12371 -- that apply to T. This routine builds the constrained subtype. 12372 12373 function Is_Discriminant (Expr : Node_Id) return Boolean; 12374 -- Returns True if Expr is a discriminant 12375 12376 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id; 12377 -- Find the value of discriminant Discrim in Constraint 12378 12379 ----------------------------------- 12380 -- Build_Constrained_Access_Type -- 12381 ----------------------------------- 12382 12383 function Build_Constrained_Access_Type 12384 (Old_Type : Entity_Id) return Entity_Id 12385 is 12386 Desig_Type : constant Entity_Id := Designated_Type (Old_Type); 12387 Itype : Entity_Id; 12388 Desig_Subtype : Entity_Id; 12389 Scop : Entity_Id; 12390 12391 begin 12392 -- if the original access type was not embedded in the enclosing 12393 -- type definition, there is no need to produce a new access 12394 -- subtype. In fact every access type with an explicit constraint 12395 -- generates an itype whose scope is the enclosing record. 12396 12397 if not Is_Type (Scope (Old_Type)) then 12398 return Old_Type; 12399 12400 elsif Is_Array_Type (Desig_Type) then 12401 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type); 12402 12403 elsif Has_Discriminants (Desig_Type) then 12404 12405 -- This may be an access type to an enclosing record type for 12406 -- which we are constructing the constrained components. Return 12407 -- the enclosing record subtype. This is not always correct, 12408 -- but avoids infinite recursion. ??? 12409 12410 Desig_Subtype := Any_Type; 12411 12412 for J in reverse 0 .. Scope_Stack.Last loop 12413 Scop := Scope_Stack.Table (J).Entity; 12414 12415 if Is_Type (Scop) 12416 and then Base_Type (Scop) = Base_Type (Desig_Type) 12417 then 12418 Desig_Subtype := Scop; 12419 end if; 12420 12421 exit when not Is_Type (Scop); 12422 end loop; 12423 12424 if Desig_Subtype = Any_Type then 12425 Desig_Subtype := 12426 Build_Constrained_Discriminated_Type (Desig_Type); 12427 end if; 12428 12429 else 12430 return Old_Type; 12431 end if; 12432 12433 if Desig_Subtype /= Desig_Type then 12434 12435 -- The Related_Node better be here or else we won't be able 12436 -- to attach new itypes to a node in the tree. 12437 12438 pragma Assert (Present (Related_Node)); 12439 12440 Itype := Create_Itype (E_Access_Subtype, Related_Node); 12441 12442 Set_Etype (Itype, Base_Type (Old_Type)); 12443 Set_Size_Info (Itype, (Old_Type)); 12444 Set_Directly_Designated_Type (Itype, Desig_Subtype); 12445 Set_Depends_On_Private (Itype, Has_Private_Component 12446 (Old_Type)); 12447 Set_Is_Access_Constant (Itype, Is_Access_Constant 12448 (Old_Type)); 12449 12450 -- The new itype needs freezing when it depends on a not frozen 12451 -- type and the enclosing subtype needs freezing. 12452 12453 if Has_Delayed_Freeze (Constrained_Typ) 12454 and then not Is_Frozen (Constrained_Typ) 12455 then 12456 Conditional_Delay (Itype, Base_Type (Old_Type)); 12457 end if; 12458 12459 return Itype; 12460 12461 else 12462 return Old_Type; 12463 end if; 12464 end Build_Constrained_Access_Type; 12465 12466 ---------------------------------- 12467 -- Build_Constrained_Array_Type -- 12468 ---------------------------------- 12469 12470 function Build_Constrained_Array_Type 12471 (Old_Type : Entity_Id) return Entity_Id 12472 is 12473 Lo_Expr : Node_Id; 12474 Hi_Expr : Node_Id; 12475 Old_Index : Node_Id; 12476 Range_Node : Node_Id; 12477 Constr_List : List_Id; 12478 12479 Need_To_Create_Itype : Boolean := False; 12480 12481 begin 12482 Old_Index := First_Index (Old_Type); 12483 while Present (Old_Index) loop 12484 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr); 12485 12486 if Is_Discriminant (Lo_Expr) 12487 or else 12488 Is_Discriminant (Hi_Expr) 12489 then 12490 Need_To_Create_Itype := True; 12491 end if; 12492 12493 Next_Index (Old_Index); 12494 end loop; 12495 12496 if Need_To_Create_Itype then 12497 Constr_List := New_List; 12498 12499 Old_Index := First_Index (Old_Type); 12500 while Present (Old_Index) loop 12501 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr); 12502 12503 if Is_Discriminant (Lo_Expr) then 12504 Lo_Expr := Get_Discr_Value (Lo_Expr); 12505 end if; 12506 12507 if Is_Discriminant (Hi_Expr) then 12508 Hi_Expr := Get_Discr_Value (Hi_Expr); 12509 end if; 12510 12511 Range_Node := 12512 Make_Range 12513 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr)); 12514 12515 Append (Range_Node, To => Constr_List); 12516 12517 Next_Index (Old_Index); 12518 end loop; 12519 12520 return Build_Subtype (Old_Type, Constr_List); 12521 12522 else 12523 return Old_Type; 12524 end if; 12525 end Build_Constrained_Array_Type; 12526 12527 ------------------------------------------ 12528 -- Build_Constrained_Discriminated_Type -- 12529 ------------------------------------------ 12530 12531 function Build_Constrained_Discriminated_Type 12532 (Old_Type : Entity_Id) return Entity_Id 12533 is 12534 Expr : Node_Id; 12535 Constr_List : List_Id; 12536 Old_Constraint : Elmt_Id; 12537 12538 Need_To_Create_Itype : Boolean := False; 12539 12540 begin 12541 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type)); 12542 while Present (Old_Constraint) loop 12543 Expr := Node (Old_Constraint); 12544 12545 if Is_Discriminant (Expr) then 12546 Need_To_Create_Itype := True; 12547 end if; 12548 12549 Next_Elmt (Old_Constraint); 12550 end loop; 12551 12552 if Need_To_Create_Itype then 12553 Constr_List := New_List; 12554 12555 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type)); 12556 while Present (Old_Constraint) loop 12557 Expr := Node (Old_Constraint); 12558 12559 if Is_Discriminant (Expr) then 12560 Expr := Get_Discr_Value (Expr); 12561 end if; 12562 12563 Append (New_Copy_Tree (Expr), To => Constr_List); 12564 12565 Next_Elmt (Old_Constraint); 12566 end loop; 12567 12568 return Build_Subtype (Old_Type, Constr_List); 12569 12570 else 12571 return Old_Type; 12572 end if; 12573 end Build_Constrained_Discriminated_Type; 12574 12575 ------------------- 12576 -- Build_Subtype -- 12577 ------------------- 12578 12579 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is 12580 Indic : Node_Id; 12581 Subtyp_Decl : Node_Id; 12582 Def_Id : Entity_Id; 12583 Btyp : Entity_Id := Base_Type (T); 12584 12585 begin 12586 -- The Related_Node better be here or else we won't be able to 12587 -- attach new itypes to a node in the tree. 12588 12589 pragma Assert (Present (Related_Node)); 12590 12591 -- If the view of the component's type is incomplete or private 12592 -- with unknown discriminants, then the constraint must be applied 12593 -- to the full type. 12594 12595 if Has_Unknown_Discriminants (Btyp) 12596 and then Present (Underlying_Type (Btyp)) 12597 then 12598 Btyp := Underlying_Type (Btyp); 12599 end if; 12600 12601 Indic := 12602 Make_Subtype_Indication (Loc, 12603 Subtype_Mark => New_Occurrence_Of (Btyp, Loc), 12604 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C)); 12605 12606 Def_Id := Create_Itype (Ekind (T), Related_Node); 12607 12608 Subtyp_Decl := 12609 Make_Subtype_Declaration (Loc, 12610 Defining_Identifier => Def_Id, 12611 Subtype_Indication => Indic); 12612 12613 Set_Parent (Subtyp_Decl, Parent (Related_Node)); 12614 12615 -- Itypes must be analyzed with checks off (see package Itypes) 12616 12617 Analyze (Subtyp_Decl, Suppress => All_Checks); 12618 12619 return Def_Id; 12620 end Build_Subtype; 12621 12622 --------------------- 12623 -- Get_Discr_Value -- 12624 --------------------- 12625 12626 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is 12627 D : Entity_Id; 12628 E : Elmt_Id; 12629 12630 begin 12631 -- The discriminant may be declared for the type, in which case we 12632 -- find it by iterating over the list of discriminants. If the 12633 -- discriminant is inherited from a parent type, it appears as the 12634 -- corresponding discriminant of the current type. This will be the 12635 -- case when constraining an inherited component whose constraint is 12636 -- given by a discriminant of the parent. 12637 12638 D := First_Discriminant (Typ); 12639 E := First_Elmt (Constraints); 12640 12641 while Present (D) loop 12642 if D = Entity (Discrim) 12643 or else D = CR_Discriminant (Entity (Discrim)) 12644 or else Corresponding_Discriminant (D) = Entity (Discrim) 12645 then 12646 return Node (E); 12647 end if; 12648 12649 Next_Discriminant (D); 12650 Next_Elmt (E); 12651 end loop; 12652 12653 -- The Corresponding_Discriminant mechanism is incomplete, because 12654 -- the correspondence between new and old discriminants is not one 12655 -- to one: one new discriminant can constrain several old ones. In 12656 -- that case, scan sequentially the stored_constraint, the list of 12657 -- discriminants of the parents, and the constraints. 12658 12659 -- Previous code checked for the present of the Stored_Constraint 12660 -- list for the derived type, but did not use it at all. Should it 12661 -- be present when the component is a discriminated task type? 12662 12663 if Is_Derived_Type (Typ) 12664 and then Scope (Entity (Discrim)) = Etype (Typ) 12665 then 12666 D := First_Discriminant (Etype (Typ)); 12667 E := First_Elmt (Constraints); 12668 while Present (D) loop 12669 if D = Entity (Discrim) then 12670 return Node (E); 12671 end if; 12672 12673 Next_Discriminant (D); 12674 Next_Elmt (E); 12675 end loop; 12676 end if; 12677 12678 -- Something is wrong if we did not find the value 12679 12680 raise Program_Error; 12681 end Get_Discr_Value; 12682 12683 --------------------- 12684 -- Is_Discriminant -- 12685 --------------------- 12686 12687 function Is_Discriminant (Expr : Node_Id) return Boolean is 12688 Discrim_Scope : Entity_Id; 12689 12690 begin 12691 if Denotes_Discriminant (Expr) then 12692 Discrim_Scope := Scope (Entity (Expr)); 12693 12694 -- Either we have a reference to one of Typ's discriminants, 12695 12696 pragma Assert (Discrim_Scope = Typ 12697 12698 -- or to the discriminants of the parent type, in the case 12699 -- of a derivation of a tagged type with variants. 12700 12701 or else Discrim_Scope = Etype (Typ) 12702 or else Full_View (Discrim_Scope) = Etype (Typ) 12703 12704 -- or same as above for the case where the discriminants 12705 -- were declared in Typ's private view. 12706 12707 or else (Is_Private_Type (Discrim_Scope) 12708 and then Chars (Discrim_Scope) = Chars (Typ)) 12709 12710 -- or else we are deriving from the full view and the 12711 -- discriminant is declared in the private entity. 12712 12713 or else (Is_Private_Type (Typ) 12714 and then Chars (Discrim_Scope) = Chars (Typ)) 12715 12716 -- Or we are constrained the corresponding record of a 12717 -- synchronized type that completes a private declaration. 12718 12719 or else (Is_Concurrent_Record_Type (Typ) 12720 and then 12721 Corresponding_Concurrent_Type (Typ) = Discrim_Scope) 12722 12723 -- or we have a class-wide type, in which case make sure the 12724 -- discriminant found belongs to the root type. 12725 12726 or else (Is_Class_Wide_Type (Typ) 12727 and then Etype (Typ) = Discrim_Scope)); 12728 12729 return True; 12730 end if; 12731 12732 -- In all other cases we have something wrong 12733 12734 return False; 12735 end Is_Discriminant; 12736 12737 -- Start of processing for Constrain_Component_Type 12738 12739 begin 12740 if Nkind (Parent (Comp)) = N_Component_Declaration 12741 and then Comes_From_Source (Parent (Comp)) 12742 and then Comes_From_Source 12743 (Subtype_Indication (Component_Definition (Parent (Comp)))) 12744 and then 12745 Is_Entity_Name 12746 (Subtype_Indication (Component_Definition (Parent (Comp)))) 12747 then 12748 return Compon_Type; 12749 12750 elsif Is_Array_Type (Compon_Type) then 12751 return Build_Constrained_Array_Type (Compon_Type); 12752 12753 elsif Has_Discriminants (Compon_Type) then 12754 return Build_Constrained_Discriminated_Type (Compon_Type); 12755 12756 elsif Is_Access_Type (Compon_Type) then 12757 return Build_Constrained_Access_Type (Compon_Type); 12758 12759 else 12760 return Compon_Type; 12761 end if; 12762 end Constrain_Component_Type; 12763 12764 -------------------------- 12765 -- Constrain_Concurrent -- 12766 -------------------------- 12767 12768 -- For concurrent types, the associated record value type carries the same 12769 -- discriminants, so when we constrain a concurrent type, we must constrain 12770 -- the corresponding record type as well. 12771 12772 procedure Constrain_Concurrent 12773 (Def_Id : in out Entity_Id; 12774 SI : Node_Id; 12775 Related_Nod : Node_Id; 12776 Related_Id : Entity_Id; 12777 Suffix : Character) 12778 is 12779 -- Retrieve Base_Type to ensure getting to the concurrent type in the 12780 -- case of a private subtype (needed when only doing semantic analysis). 12781 12782 T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI))); 12783 T_Val : Entity_Id; 12784 12785 begin 12786 if Is_Access_Type (T_Ent) then 12787 T_Ent := Designated_Type (T_Ent); 12788 end if; 12789 12790 T_Val := Corresponding_Record_Type (T_Ent); 12791 12792 if Present (T_Val) then 12793 12794 if No (Def_Id) then 12795 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); 12796 end if; 12797 12798 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod); 12799 12800 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); 12801 Set_Corresponding_Record_Type (Def_Id, 12802 Constrain_Corresponding_Record (Def_Id, T_Val, Related_Nod)); 12803 12804 else 12805 -- If there is no associated record, expansion is disabled and this 12806 -- is a generic context. Create a subtype in any case, so that 12807 -- semantic analysis can proceed. 12808 12809 if No (Def_Id) then 12810 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); 12811 end if; 12812 12813 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod); 12814 end if; 12815 end Constrain_Concurrent; 12816 12817 ------------------------------------ 12818 -- Constrain_Corresponding_Record -- 12819 ------------------------------------ 12820 12821 function Constrain_Corresponding_Record 12822 (Prot_Subt : Entity_Id; 12823 Corr_Rec : Entity_Id; 12824 Related_Nod : Node_Id) return Entity_Id 12825 is 12826 T_Sub : constant Entity_Id := 12827 Create_Itype (E_Record_Subtype, Related_Nod, Corr_Rec, 'C'); 12828 12829 begin 12830 Set_Etype (T_Sub, Corr_Rec); 12831 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt)); 12832 Set_Is_Constrained (T_Sub, True); 12833 Set_First_Entity (T_Sub, First_Entity (Corr_Rec)); 12834 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec)); 12835 12836 if Has_Discriminants (Prot_Subt) then -- False only if errors. 12837 Set_Discriminant_Constraint 12838 (T_Sub, Discriminant_Constraint (Prot_Subt)); 12839 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub); 12840 Create_Constrained_Components 12841 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub)); 12842 end if; 12843 12844 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub)); 12845 12846 if Ekind (Scope (Prot_Subt)) /= E_Record_Type then 12847 Conditional_Delay (T_Sub, Corr_Rec); 12848 12849 else 12850 -- This is a component subtype: it will be frozen in the context of 12851 -- the enclosing record's init_proc, so that discriminant references 12852 -- are resolved to discriminals. (Note: we used to skip freezing 12853 -- altogether in that case, which caused errors downstream for 12854 -- components of a bit packed array type). 12855 12856 Set_Has_Delayed_Freeze (T_Sub); 12857 end if; 12858 12859 return T_Sub; 12860 end Constrain_Corresponding_Record; 12861 12862 ----------------------- 12863 -- Constrain_Decimal -- 12864 ----------------------- 12865 12866 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is 12867 T : constant Entity_Id := Entity (Subtype_Mark (S)); 12868 C : constant Node_Id := Constraint (S); 12869 Loc : constant Source_Ptr := Sloc (C); 12870 Range_Expr : Node_Id; 12871 Digits_Expr : Node_Id; 12872 Digits_Val : Uint; 12873 Bound_Val : Ureal; 12874 12875 begin 12876 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype); 12877 12878 if Nkind (C) = N_Range_Constraint then 12879 Range_Expr := Range_Expression (C); 12880 Digits_Val := Digits_Value (T); 12881 12882 else 12883 pragma Assert (Nkind (C) = N_Digits_Constraint); 12884 12885 Check_SPARK_05_Restriction ("digits constraint is not allowed", S); 12886 12887 Digits_Expr := Digits_Expression (C); 12888 Analyze_And_Resolve (Digits_Expr, Any_Integer); 12889 12890 Check_Digits_Expression (Digits_Expr); 12891 Digits_Val := Expr_Value (Digits_Expr); 12892 12893 if Digits_Val > Digits_Value (T) then 12894 Error_Msg_N 12895 ("digits expression is incompatible with subtype", C); 12896 Digits_Val := Digits_Value (T); 12897 end if; 12898 12899 if Present (Range_Constraint (C)) then 12900 Range_Expr := Range_Expression (Range_Constraint (C)); 12901 else 12902 Range_Expr := Empty; 12903 end if; 12904 end if; 12905 12906 Set_Etype (Def_Id, Base_Type (T)); 12907 Set_Size_Info (Def_Id, (T)); 12908 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 12909 Set_Delta_Value (Def_Id, Delta_Value (T)); 12910 Set_Scale_Value (Def_Id, Scale_Value (T)); 12911 Set_Small_Value (Def_Id, Small_Value (T)); 12912 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T)); 12913 Set_Digits_Value (Def_Id, Digits_Val); 12914 12915 -- Manufacture range from given digits value if no range present 12916 12917 if No (Range_Expr) then 12918 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T); 12919 Range_Expr := 12920 Make_Range (Loc, 12921 Low_Bound => 12922 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))), 12923 High_Bound => 12924 Convert_To (T, Make_Real_Literal (Loc, Bound_Val))); 12925 end if; 12926 12927 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T); 12928 Set_Discrete_RM_Size (Def_Id); 12929 12930 -- Unconditionally delay the freeze, since we cannot set size 12931 -- information in all cases correctly until the freeze point. 12932 12933 Set_Has_Delayed_Freeze (Def_Id); 12934 end Constrain_Decimal; 12935 12936 ---------------------------------- 12937 -- Constrain_Discriminated_Type -- 12938 ---------------------------------- 12939 12940 procedure Constrain_Discriminated_Type 12941 (Def_Id : Entity_Id; 12942 S : Node_Id; 12943 Related_Nod : Node_Id; 12944 For_Access : Boolean := False) 12945 is 12946 E : constant Entity_Id := Entity (Subtype_Mark (S)); 12947 T : Entity_Id; 12948 C : Node_Id; 12949 Elist : Elist_Id := New_Elmt_List; 12950 12951 procedure Fixup_Bad_Constraint; 12952 -- This is called after finding a bad constraint, and after having 12953 -- posted an appropriate error message. The mission is to leave the 12954 -- entity T in as reasonable state as possible. 12955 12956 -------------------------- 12957 -- Fixup_Bad_Constraint -- 12958 -------------------------- 12959 12960 procedure Fixup_Bad_Constraint is 12961 begin 12962 -- Set a reasonable Ekind for the entity. For an incomplete type, 12963 -- we can't do much, but for other types, we can set the proper 12964 -- corresponding subtype kind. 12965 12966 if Ekind (T) = E_Incomplete_Type then 12967 Set_Ekind (Def_Id, Ekind (T)); 12968 else 12969 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T))); 12970 end if; 12971 12972 -- Set Etype to the known type, to reduce chances of cascaded errors 12973 12974 Set_Etype (Def_Id, E); 12975 Set_Error_Posted (Def_Id); 12976 end Fixup_Bad_Constraint; 12977 12978 -- Start of processing for Constrain_Discriminated_Type 12979 12980 begin 12981 C := Constraint (S); 12982 12983 -- A discriminant constraint is only allowed in a subtype indication, 12984 -- after a subtype mark. This subtype mark must denote either a type 12985 -- with discriminants, or an access type whose designated type is a 12986 -- type with discriminants. A discriminant constraint specifies the 12987 -- values of these discriminants (RM 3.7.2(5)). 12988 12989 T := Base_Type (Entity (Subtype_Mark (S))); 12990 12991 if Is_Access_Type (T) then 12992 T := Designated_Type (T); 12993 end if; 12994 12995 -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal. 12996 -- Avoid generating an error for access-to-incomplete subtypes. 12997 12998 if Ada_Version >= Ada_2005 12999 and then Ekind (T) = E_Incomplete_Type 13000 and then Nkind (Parent (S)) = N_Subtype_Declaration 13001 and then not Is_Itype (Def_Id) 13002 then 13003 -- A little sanity check, emit an error message if the type 13004 -- has discriminants to begin with. Type T may be a regular 13005 -- incomplete type or imported via a limited with clause. 13006 13007 if Has_Discriminants (T) 13008 or else (From_Limited_With (T) 13009 and then Present (Non_Limited_View (T)) 13010 and then Nkind (Parent (Non_Limited_View (T))) = 13011 N_Full_Type_Declaration 13012 and then Present (Discriminant_Specifications 13013 (Parent (Non_Limited_View (T))))) 13014 then 13015 Error_Msg_N 13016 ("(Ada 2005) incomplete subtype may not be constrained", C); 13017 else 13018 Error_Msg_N ("invalid constraint: type has no discriminant", C); 13019 end if; 13020 13021 Fixup_Bad_Constraint; 13022 return; 13023 13024 -- Check that the type has visible discriminants. The type may be 13025 -- a private type with unknown discriminants whose full view has 13026 -- discriminants which are invisible. 13027 13028 elsif not Has_Discriminants (T) 13029 or else 13030 (Has_Unknown_Discriminants (T) 13031 and then Is_Private_Type (T)) 13032 then 13033 Error_Msg_N ("invalid constraint: type has no discriminant", C); 13034 Fixup_Bad_Constraint; 13035 return; 13036 13037 elsif Is_Constrained (E) 13038 or else (Ekind (E) = E_Class_Wide_Subtype 13039 and then Present (Discriminant_Constraint (E))) 13040 then 13041 Error_Msg_N ("type is already constrained", Subtype_Mark (S)); 13042 Fixup_Bad_Constraint; 13043 return; 13044 end if; 13045 13046 -- T may be an unconstrained subtype (e.g. a generic actual). 13047 -- Constraint applies to the base type. 13048 13049 T := Base_Type (T); 13050 13051 Elist := Build_Discriminant_Constraints (T, S); 13052 13053 -- If the list returned was empty we had an error in building the 13054 -- discriminant constraint. We have also already signalled an error 13055 -- in the incomplete type case 13056 13057 if Is_Empty_Elmt_List (Elist) then 13058 Fixup_Bad_Constraint; 13059 return; 13060 end if; 13061 13062 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access); 13063 end Constrain_Discriminated_Type; 13064 13065 --------------------------- 13066 -- Constrain_Enumeration -- 13067 --------------------------- 13068 13069 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is 13070 T : constant Entity_Id := Entity (Subtype_Mark (S)); 13071 C : constant Node_Id := Constraint (S); 13072 13073 begin 13074 Set_Ekind (Def_Id, E_Enumeration_Subtype); 13075 13076 Set_First_Literal (Def_Id, First_Literal (Base_Type (T))); 13077 13078 Set_Etype (Def_Id, Base_Type (T)); 13079 Set_Size_Info (Def_Id, (T)); 13080 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 13081 Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); 13082 13083 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); 13084 13085 Set_Discrete_RM_Size (Def_Id); 13086 end Constrain_Enumeration; 13087 13088 ---------------------- 13089 -- Constrain_Float -- 13090 ---------------------- 13091 13092 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is 13093 T : constant Entity_Id := Entity (Subtype_Mark (S)); 13094 C : Node_Id; 13095 D : Node_Id; 13096 Rais : Node_Id; 13097 13098 begin 13099 Set_Ekind (Def_Id, E_Floating_Point_Subtype); 13100 13101 Set_Etype (Def_Id, Base_Type (T)); 13102 Set_Size_Info (Def_Id, (T)); 13103 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 13104 13105 -- Process the constraint 13106 13107 C := Constraint (S); 13108 13109 -- Digits constraint present 13110 13111 if Nkind (C) = N_Digits_Constraint then 13112 13113 Check_SPARK_05_Restriction ("digits constraint is not allowed", S); 13114 Check_Restriction (No_Obsolescent_Features, C); 13115 13116 if Warn_On_Obsolescent_Feature then 13117 Error_Msg_N 13118 ("subtype digits constraint is an " & 13119 "obsolescent feature (RM J.3(8))?j?", C); 13120 end if; 13121 13122 D := Digits_Expression (C); 13123 Analyze_And_Resolve (D, Any_Integer); 13124 Check_Digits_Expression (D); 13125 Set_Digits_Value (Def_Id, Expr_Value (D)); 13126 13127 -- Check that digits value is in range. Obviously we can do this 13128 -- at compile time, but it is strictly a runtime check, and of 13129 -- course there is an ACVC test that checks this. 13130 13131 if Digits_Value (Def_Id) > Digits_Value (T) then 13132 Error_Msg_Uint_1 := Digits_Value (T); 13133 Error_Msg_N ("??digits value is too large, maximum is ^", D); 13134 Rais := 13135 Make_Raise_Constraint_Error (Sloc (D), 13136 Reason => CE_Range_Check_Failed); 13137 Insert_Action (Declaration_Node (Def_Id), Rais); 13138 end if; 13139 13140 C := Range_Constraint (C); 13141 13142 -- No digits constraint present 13143 13144 else 13145 Set_Digits_Value (Def_Id, Digits_Value (T)); 13146 end if; 13147 13148 -- Range constraint present 13149 13150 if Nkind (C) = N_Range_Constraint then 13151 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); 13152 13153 -- No range constraint present 13154 13155 else 13156 pragma Assert (No (C)); 13157 Set_Scalar_Range (Def_Id, Scalar_Range (T)); 13158 end if; 13159 13160 Set_Is_Constrained (Def_Id); 13161 end Constrain_Float; 13162 13163 --------------------- 13164 -- Constrain_Index -- 13165 --------------------- 13166 13167 procedure Constrain_Index 13168 (Index : Node_Id; 13169 S : Node_Id; 13170 Related_Nod : Node_Id; 13171 Related_Id : Entity_Id; 13172 Suffix : Character; 13173 Suffix_Index : Nat) 13174 is 13175 Def_Id : Entity_Id; 13176 R : Node_Id := Empty; 13177 T : constant Entity_Id := Etype (Index); 13178 13179 begin 13180 Def_Id := 13181 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index); 13182 Set_Etype (Def_Id, Base_Type (T)); 13183 13184 if Nkind (S) = N_Range 13185 or else 13186 (Nkind (S) = N_Attribute_Reference 13187 and then Attribute_Name (S) = Name_Range) 13188 then 13189 -- A Range attribute will be transformed into N_Range by Resolve 13190 13191 Analyze (S); 13192 Set_Etype (S, T); 13193 R := S; 13194 13195 Process_Range_Expr_In_Decl (R, T); 13196 13197 if not Error_Posted (S) 13198 and then 13199 (Nkind (S) /= N_Range 13200 or else not Covers (T, (Etype (Low_Bound (S)))) 13201 or else not Covers (T, (Etype (High_Bound (S))))) 13202 then 13203 if Base_Type (T) /= Any_Type 13204 and then Etype (Low_Bound (S)) /= Any_Type 13205 and then Etype (High_Bound (S)) /= Any_Type 13206 then 13207 Error_Msg_N ("range expected", S); 13208 end if; 13209 end if; 13210 13211 elsif Nkind (S) = N_Subtype_Indication then 13212 13213 -- The parser has verified that this is a discrete indication 13214 13215 Resolve_Discrete_Subtype_Indication (S, T); 13216 Bad_Predicated_Subtype_Use 13217 ("subtype& has predicate, not allowed in index constraint", 13218 S, Entity (Subtype_Mark (S))); 13219 13220 R := Range_Expression (Constraint (S)); 13221 13222 -- Capture values of bounds and generate temporaries for them if 13223 -- needed, since checks may cause duplication of the expressions 13224 -- which must not be reevaluated. 13225 13226 -- The forced evaluation removes side effects from expressions, which 13227 -- should occur also in GNATprove mode. Otherwise, we end up with 13228 -- unexpected insertions of actions at places where this is not 13229 -- supposed to occur, e.g. on default parameters of a call. 13230 13231 if Expander_Active or GNATprove_Mode then 13232 Force_Evaluation 13233 (Low_Bound (R), Related_Id => Def_Id, Is_Low_Bound => True); 13234 Force_Evaluation 13235 (High_Bound (R), Related_Id => Def_Id, Is_High_Bound => True); 13236 end if; 13237 13238 elsif Nkind (S) = N_Discriminant_Association then 13239 13240 -- Syntactically valid in subtype indication 13241 13242 Error_Msg_N ("invalid index constraint", S); 13243 Rewrite (S, New_Occurrence_Of (T, Sloc (S))); 13244 return; 13245 13246 -- Subtype_Mark case, no anonymous subtypes to construct 13247 13248 else 13249 Analyze (S); 13250 13251 if Is_Entity_Name (S) then 13252 if not Is_Type (Entity (S)) then 13253 Error_Msg_N ("expect subtype mark for index constraint", S); 13254 13255 elsif Base_Type (Entity (S)) /= Base_Type (T) then 13256 Wrong_Type (S, Base_Type (T)); 13257 13258 -- Check error of subtype with predicate in index constraint 13259 13260 else 13261 Bad_Predicated_Subtype_Use 13262 ("subtype& has predicate, not allowed in index constraint", 13263 S, Entity (S)); 13264 end if; 13265 13266 return; 13267 13268 else 13269 Error_Msg_N ("invalid index constraint", S); 13270 Rewrite (S, New_Occurrence_Of (T, Sloc (S))); 13271 return; 13272 end if; 13273 end if; 13274 13275 -- Complete construction of the Itype 13276 13277 if Is_Modular_Integer_Type (T) then 13278 Set_Ekind (Def_Id, E_Modular_Integer_Subtype); 13279 13280 elsif Is_Integer_Type (T) then 13281 Set_Ekind (Def_Id, E_Signed_Integer_Subtype); 13282 13283 else 13284 Set_Ekind (Def_Id, E_Enumeration_Subtype); 13285 Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); 13286 Set_First_Literal (Def_Id, First_Literal (T)); 13287 end if; 13288 13289 Set_Size_Info (Def_Id, (T)); 13290 Set_RM_Size (Def_Id, RM_Size (T)); 13291 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 13292 13293 Set_Scalar_Range (Def_Id, R); 13294 13295 Set_Etype (S, Def_Id); 13296 Set_Discrete_RM_Size (Def_Id); 13297 end Constrain_Index; 13298 13299 ----------------------- 13300 -- Constrain_Integer -- 13301 ----------------------- 13302 13303 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is 13304 T : constant Entity_Id := Entity (Subtype_Mark (S)); 13305 C : constant Node_Id := Constraint (S); 13306 13307 begin 13308 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); 13309 13310 if Is_Modular_Integer_Type (T) then 13311 Set_Ekind (Def_Id, E_Modular_Integer_Subtype); 13312 else 13313 Set_Ekind (Def_Id, E_Signed_Integer_Subtype); 13314 end if; 13315 13316 Set_Etype (Def_Id, Base_Type (T)); 13317 Set_Size_Info (Def_Id, (T)); 13318 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 13319 Set_Discrete_RM_Size (Def_Id); 13320 end Constrain_Integer; 13321 13322 ------------------------------ 13323 -- Constrain_Ordinary_Fixed -- 13324 ------------------------------ 13325 13326 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is 13327 T : constant Entity_Id := Entity (Subtype_Mark (S)); 13328 C : Node_Id; 13329 D : Node_Id; 13330 Rais : Node_Id; 13331 13332 begin 13333 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype); 13334 Set_Etype (Def_Id, Base_Type (T)); 13335 Set_Size_Info (Def_Id, (T)); 13336 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 13337 Set_Small_Value (Def_Id, Small_Value (T)); 13338 13339 -- Process the constraint 13340 13341 C := Constraint (S); 13342 13343 -- Delta constraint present 13344 13345 if Nkind (C) = N_Delta_Constraint then 13346 13347 Check_SPARK_05_Restriction ("delta constraint is not allowed", S); 13348 Check_Restriction (No_Obsolescent_Features, C); 13349 13350 if Warn_On_Obsolescent_Feature then 13351 Error_Msg_S 13352 ("subtype delta constraint is an " & 13353 "obsolescent feature (RM J.3(7))?j?"); 13354 end if; 13355 13356 D := Delta_Expression (C); 13357 Analyze_And_Resolve (D, Any_Real); 13358 Check_Delta_Expression (D); 13359 Set_Delta_Value (Def_Id, Expr_Value_R (D)); 13360 13361 -- Check that delta value is in range. Obviously we can do this 13362 -- at compile time, but it is strictly a runtime check, and of 13363 -- course there is an ACVC test that checks this. 13364 13365 if Delta_Value (Def_Id) < Delta_Value (T) then 13366 Error_Msg_N ("??delta value is too small", D); 13367 Rais := 13368 Make_Raise_Constraint_Error (Sloc (D), 13369 Reason => CE_Range_Check_Failed); 13370 Insert_Action (Declaration_Node (Def_Id), Rais); 13371 end if; 13372 13373 C := Range_Constraint (C); 13374 13375 -- No delta constraint present 13376 13377 else 13378 Set_Delta_Value (Def_Id, Delta_Value (T)); 13379 end if; 13380 13381 -- Range constraint present 13382 13383 if Nkind (C) = N_Range_Constraint then 13384 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); 13385 13386 -- No range constraint present 13387 13388 else 13389 pragma Assert (No (C)); 13390 Set_Scalar_Range (Def_Id, Scalar_Range (T)); 13391 end if; 13392 13393 Set_Discrete_RM_Size (Def_Id); 13394 13395 -- Unconditionally delay the freeze, since we cannot set size 13396 -- information in all cases correctly until the freeze point. 13397 13398 Set_Has_Delayed_Freeze (Def_Id); 13399 end Constrain_Ordinary_Fixed; 13400 13401 ----------------------- 13402 -- Contain_Interface -- 13403 ----------------------- 13404 13405 function Contain_Interface 13406 (Iface : Entity_Id; 13407 Ifaces : Elist_Id) return Boolean 13408 is 13409 Iface_Elmt : Elmt_Id; 13410 13411 begin 13412 if Present (Ifaces) then 13413 Iface_Elmt := First_Elmt (Ifaces); 13414 while Present (Iface_Elmt) loop 13415 if Node (Iface_Elmt) = Iface then 13416 return True; 13417 end if; 13418 13419 Next_Elmt (Iface_Elmt); 13420 end loop; 13421 end if; 13422 13423 return False; 13424 end Contain_Interface; 13425 13426 --------------------------- 13427 -- Convert_Scalar_Bounds -- 13428 --------------------------- 13429 13430 procedure Convert_Scalar_Bounds 13431 (N : Node_Id; 13432 Parent_Type : Entity_Id; 13433 Derived_Type : Entity_Id; 13434 Loc : Source_Ptr) 13435 is 13436 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type); 13437 13438 Lo : Node_Id; 13439 Hi : Node_Id; 13440 Rng : Node_Id; 13441 13442 begin 13443 -- Defend against previous errors 13444 13445 if No (Scalar_Range (Derived_Type)) then 13446 Check_Error_Detected; 13447 return; 13448 end if; 13449 13450 Lo := Build_Scalar_Bound 13451 (Type_Low_Bound (Derived_Type), 13452 Parent_Type, Implicit_Base); 13453 13454 Hi := Build_Scalar_Bound 13455 (Type_High_Bound (Derived_Type), 13456 Parent_Type, Implicit_Base); 13457 13458 Rng := 13459 Make_Range (Loc, 13460 Low_Bound => Lo, 13461 High_Bound => Hi); 13462 13463 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type)); 13464 13465 Set_Parent (Rng, N); 13466 Set_Scalar_Range (Derived_Type, Rng); 13467 13468 -- Analyze the bounds 13469 13470 Analyze_And_Resolve (Lo, Implicit_Base); 13471 Analyze_And_Resolve (Hi, Implicit_Base); 13472 13473 -- Analyze the range itself, except that we do not analyze it if 13474 -- the bounds are real literals, and we have a fixed-point type. 13475 -- The reason for this is that we delay setting the bounds in this 13476 -- case till we know the final Small and Size values (see circuit 13477 -- in Freeze.Freeze_Fixed_Point_Type for further details). 13478 13479 if Is_Fixed_Point_Type (Parent_Type) 13480 and then Nkind (Lo) = N_Real_Literal 13481 and then Nkind (Hi) = N_Real_Literal 13482 then 13483 return; 13484 13485 -- Here we do the analysis of the range 13486 13487 -- Note: we do this manually, since if we do a normal Analyze and 13488 -- Resolve call, there are problems with the conversions used for 13489 -- the derived type range. 13490 13491 else 13492 Set_Etype (Rng, Implicit_Base); 13493 Set_Analyzed (Rng, True); 13494 end if; 13495 end Convert_Scalar_Bounds; 13496 13497 ------------------- 13498 -- Copy_And_Swap -- 13499 ------------------- 13500 13501 procedure Copy_And_Swap (Priv, Full : Entity_Id) is 13502 begin 13503 -- Initialize new full declaration entity by copying the pertinent 13504 -- fields of the corresponding private declaration entity. 13505 13506 -- We temporarily set Ekind to a value appropriate for a type to 13507 -- avoid assert failures in Einfo from checking for setting type 13508 -- attributes on something that is not a type. Ekind (Priv) is an 13509 -- appropriate choice, since it allowed the attributes to be set 13510 -- in the first place. This Ekind value will be modified later. 13511 13512 Set_Ekind (Full, Ekind (Priv)); 13513 13514 -- Also set Etype temporarily to Any_Type, again, in the absence 13515 -- of errors, it will be properly reset, and if there are errors, 13516 -- then we want a value of Any_Type to remain. 13517 13518 Set_Etype (Full, Any_Type); 13519 13520 -- Now start copying attributes 13521 13522 Set_Has_Discriminants (Full, Has_Discriminants (Priv)); 13523 13524 if Has_Discriminants (Full) then 13525 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv)); 13526 Set_Stored_Constraint (Full, Stored_Constraint (Priv)); 13527 end if; 13528 13529 Set_First_Rep_Item (Full, First_Rep_Item (Priv)); 13530 Set_Homonym (Full, Homonym (Priv)); 13531 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv)); 13532 Set_Is_Public (Full, Is_Public (Priv)); 13533 Set_Is_Pure (Full, Is_Pure (Priv)); 13534 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv)); 13535 Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv)); 13536 Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv)); 13537 Set_Has_Pragma_Unreferenced_Objects 13538 (Full, Has_Pragma_Unreferenced_Objects 13539 (Priv)); 13540 13541 Conditional_Delay (Full, Priv); 13542 13543 if Is_Tagged_Type (Full) then 13544 Set_Direct_Primitive_Operations 13545 (Full, Direct_Primitive_Operations (Priv)); 13546 Set_No_Tagged_Streams_Pragma 13547 (Full, No_Tagged_Streams_Pragma (Priv)); 13548 13549 if Is_Base_Type (Priv) then 13550 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv)); 13551 end if; 13552 end if; 13553 13554 Set_Is_Volatile (Full, Is_Volatile (Priv)); 13555 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv)); 13556 Set_Scope (Full, Scope (Priv)); 13557 Set_Next_Entity (Full, Next_Entity (Priv)); 13558 Set_First_Entity (Full, First_Entity (Priv)); 13559 Set_Last_Entity (Full, Last_Entity (Priv)); 13560 13561 -- If access types have been recorded for later handling, keep them in 13562 -- the full view so that they get handled when the full view freeze 13563 -- node is expanded. 13564 13565 if Present (Freeze_Node (Priv)) 13566 and then Present (Access_Types_To_Process (Freeze_Node (Priv))) 13567 then 13568 Ensure_Freeze_Node (Full); 13569 Set_Access_Types_To_Process 13570 (Freeze_Node (Full), 13571 Access_Types_To_Process (Freeze_Node (Priv))); 13572 end if; 13573 13574 -- Swap the two entities. Now Private is the full type entity and Full 13575 -- is the private one. They will be swapped back at the end of the 13576 -- private part. This swapping ensures that the entity that is visible 13577 -- in the private part is the full declaration. 13578 13579 Exchange_Entities (Priv, Full); 13580 Append_Entity (Full, Scope (Full)); 13581 end Copy_And_Swap; 13582 13583 ------------------------------------- 13584 -- Copy_Array_Base_Type_Attributes -- 13585 ------------------------------------- 13586 13587 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is 13588 begin 13589 Set_Component_Alignment (T1, Component_Alignment (T2)); 13590 Set_Component_Type (T1, Component_Type (T2)); 13591 Set_Component_Size (T1, Component_Size (T2)); 13592 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2)); 13593 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2)); 13594 Set_Has_Protected (T1, Has_Protected (T2)); 13595 Set_Has_Task (T1, Has_Task (T2)); 13596 Set_Is_Packed (T1, Is_Packed (T2)); 13597 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2)); 13598 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2)); 13599 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2)); 13600 end Copy_Array_Base_Type_Attributes; 13601 13602 ----------------------------------- 13603 -- Copy_Array_Subtype_Attributes -- 13604 ----------------------------------- 13605 13606 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is 13607 begin 13608 Set_Size_Info (T1, T2); 13609 13610 Set_First_Index (T1, First_Index (T2)); 13611 Set_Is_Aliased (T1, Is_Aliased (T2)); 13612 Set_Is_Volatile (T1, Is_Volatile (T2)); 13613 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2)); 13614 Set_Is_Constrained (T1, Is_Constrained (T2)); 13615 Set_Depends_On_Private (T1, Has_Private_Component (T2)); 13616 Inherit_Rep_Item_Chain (T1, T2); 13617 Set_Convention (T1, Convention (T2)); 13618 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2)); 13619 Set_Is_Private_Composite (T1, Is_Private_Composite (T2)); 13620 Set_Packed_Array_Impl_Type (T1, Packed_Array_Impl_Type (T2)); 13621 end Copy_Array_Subtype_Attributes; 13622 13623 ----------------------------------- 13624 -- Create_Constrained_Components -- 13625 ----------------------------------- 13626 13627 procedure Create_Constrained_Components 13628 (Subt : Entity_Id; 13629 Decl_Node : Node_Id; 13630 Typ : Entity_Id; 13631 Constraints : Elist_Id) 13632 is 13633 Loc : constant Source_Ptr := Sloc (Subt); 13634 Comp_List : constant Elist_Id := New_Elmt_List; 13635 Parent_Type : constant Entity_Id := Etype (Typ); 13636 Assoc_List : constant List_Id := New_List; 13637 Discr_Val : Elmt_Id; 13638 Errors : Boolean; 13639 New_C : Entity_Id; 13640 Old_C : Entity_Id; 13641 Is_Static : Boolean := True; 13642 13643 procedure Collect_Fixed_Components (Typ : Entity_Id); 13644 -- Collect parent type components that do not appear in a variant part 13645 13646 procedure Create_All_Components; 13647 -- Iterate over Comp_List to create the components of the subtype 13648 13649 function Create_Component (Old_Compon : Entity_Id) return Entity_Id; 13650 -- Creates a new component from Old_Compon, copying all the fields from 13651 -- it, including its Etype, inserts the new component in the Subt entity 13652 -- chain and returns the new component. 13653 13654 function Is_Variant_Record (T : Entity_Id) return Boolean; 13655 -- If true, and discriminants are static, collect only components from 13656 -- variants selected by discriminant values. 13657 13658 ------------------------------ 13659 -- Collect_Fixed_Components -- 13660 ------------------------------ 13661 13662 procedure Collect_Fixed_Components (Typ : Entity_Id) is 13663 begin 13664 -- Build association list for discriminants, and find components of the 13665 -- variant part selected by the values of the discriminants. 13666 13667 Old_C := First_Discriminant (Typ); 13668 Discr_Val := First_Elmt (Constraints); 13669 while Present (Old_C) loop 13670 Append_To (Assoc_List, 13671 Make_Component_Association (Loc, 13672 Choices => New_List (New_Occurrence_Of (Old_C, Loc)), 13673 Expression => New_Copy (Node (Discr_Val)))); 13674 13675 Next_Elmt (Discr_Val); 13676 Next_Discriminant (Old_C); 13677 end loop; 13678 13679 -- The tag and the possible parent component are unconditionally in 13680 -- the subtype. 13681 13682 if Is_Tagged_Type (Typ) or else Has_Controlled_Component (Typ) then 13683 Old_C := First_Component (Typ); 13684 while Present (Old_C) loop 13685 if Nam_In (Chars (Old_C), Name_uTag, Name_uParent) then 13686 Append_Elmt (Old_C, Comp_List); 13687 end if; 13688 13689 Next_Component (Old_C); 13690 end loop; 13691 end if; 13692 end Collect_Fixed_Components; 13693 13694 --------------------------- 13695 -- Create_All_Components -- 13696 --------------------------- 13697 13698 procedure Create_All_Components is 13699 Comp : Elmt_Id; 13700 13701 begin 13702 Comp := First_Elmt (Comp_List); 13703 while Present (Comp) loop 13704 Old_C := Node (Comp); 13705 New_C := Create_Component (Old_C); 13706 13707 Set_Etype 13708 (New_C, 13709 Constrain_Component_Type 13710 (Old_C, Subt, Decl_Node, Typ, Constraints)); 13711 Set_Is_Public (New_C, Is_Public (Subt)); 13712 13713 Next_Elmt (Comp); 13714 end loop; 13715 end Create_All_Components; 13716 13717 ---------------------- 13718 -- Create_Component -- 13719 ---------------------- 13720 13721 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is 13722 New_Compon : constant Entity_Id := New_Copy (Old_Compon); 13723 13724 begin 13725 if Ekind (Old_Compon) = E_Discriminant 13726 and then Is_Completely_Hidden (Old_Compon) 13727 then 13728 -- This is a shadow discriminant created for a discriminant of 13729 -- the parent type, which needs to be present in the subtype. 13730 -- Give the shadow discriminant an internal name that cannot 13731 -- conflict with that of visible components. 13732 13733 Set_Chars (New_Compon, New_Internal_Name ('C')); 13734 end if; 13735 13736 -- Set the parent so we have a proper link for freezing etc. This is 13737 -- not a real parent pointer, since of course our parent does not own 13738 -- up to us and reference us, we are an illegitimate child of the 13739 -- original parent. 13740 13741 Set_Parent (New_Compon, Parent (Old_Compon)); 13742 13743 -- If the old component's Esize was already determined and is a 13744 -- static value, then the new component simply inherits it. Otherwise 13745 -- the old component's size may require run-time determination, but 13746 -- the new component's size still might be statically determinable 13747 -- (if, for example it has a static constraint). In that case we want 13748 -- Layout_Type to recompute the component's size, so we reset its 13749 -- size and positional fields. 13750 13751 if Frontend_Layout_On_Target 13752 and then not Known_Static_Esize (Old_Compon) 13753 then 13754 Set_Esize (New_Compon, Uint_0); 13755 Init_Normalized_First_Bit (New_Compon); 13756 Init_Normalized_Position (New_Compon); 13757 Init_Normalized_Position_Max (New_Compon); 13758 end if; 13759 13760 -- We do not want this node marked as Comes_From_Source, since 13761 -- otherwise it would get first class status and a separate cross- 13762 -- reference line would be generated. Illegitimate children do not 13763 -- rate such recognition. 13764 13765 Set_Comes_From_Source (New_Compon, False); 13766 13767 -- But it is a real entity, and a birth certificate must be properly 13768 -- registered by entering it into the entity list. 13769 13770 Enter_Name (New_Compon); 13771 13772 return New_Compon; 13773 end Create_Component; 13774 13775 ----------------------- 13776 -- Is_Variant_Record -- 13777 ----------------------- 13778 13779 function Is_Variant_Record (T : Entity_Id) return Boolean is 13780 begin 13781 return Nkind (Parent (T)) = N_Full_Type_Declaration 13782 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition 13783 and then Present (Component_List (Type_Definition (Parent (T)))) 13784 and then 13785 Present 13786 (Variant_Part (Component_List (Type_Definition (Parent (T))))); 13787 end Is_Variant_Record; 13788 13789 -- Start of processing for Create_Constrained_Components 13790 13791 begin 13792 pragma Assert (Subt /= Base_Type (Subt)); 13793 pragma Assert (Typ = Base_Type (Typ)); 13794 13795 Set_First_Entity (Subt, Empty); 13796 Set_Last_Entity (Subt, Empty); 13797 13798 -- Check whether constraint is fully static, in which case we can 13799 -- optimize the list of components. 13800 13801 Discr_Val := First_Elmt (Constraints); 13802 while Present (Discr_Val) loop 13803 if not Is_OK_Static_Expression (Node (Discr_Val)) then 13804 Is_Static := False; 13805 exit; 13806 end if; 13807 13808 Next_Elmt (Discr_Val); 13809 end loop; 13810 13811 Set_Has_Static_Discriminants (Subt, Is_Static); 13812 13813 Push_Scope (Subt); 13814 13815 -- Inherit the discriminants of the parent type 13816 13817 Add_Discriminants : declare 13818 Num_Disc : Int; 13819 Num_Gird : Int; 13820 13821 begin 13822 Num_Disc := 0; 13823 Old_C := First_Discriminant (Typ); 13824 13825 while Present (Old_C) loop 13826 Num_Disc := Num_Disc + 1; 13827 New_C := Create_Component (Old_C); 13828 Set_Is_Public (New_C, Is_Public (Subt)); 13829 Next_Discriminant (Old_C); 13830 end loop; 13831 13832 -- For an untagged derived subtype, the number of discriminants may 13833 -- be smaller than the number of inherited discriminants, because 13834 -- several of them may be renamed by a single new discriminant or 13835 -- constrained. In this case, add the hidden discriminants back into 13836 -- the subtype, because they need to be present if the optimizer of 13837 -- the GCC 4.x back-end decides to break apart assignments between 13838 -- objects using the parent view into member-wise assignments. 13839 13840 Num_Gird := 0; 13841 13842 if Is_Derived_Type (Typ) 13843 and then not Is_Tagged_Type (Typ) 13844 then 13845 Old_C := First_Stored_Discriminant (Typ); 13846 13847 while Present (Old_C) loop 13848 Num_Gird := Num_Gird + 1; 13849 Next_Stored_Discriminant (Old_C); 13850 end loop; 13851 end if; 13852 13853 if Num_Gird > Num_Disc then 13854 13855 -- Find out multiple uses of new discriminants, and add hidden 13856 -- components for the extra renamed discriminants. We recognize 13857 -- multiple uses through the Corresponding_Discriminant of a 13858 -- new discriminant: if it constrains several old discriminants, 13859 -- this field points to the last one in the parent type. The 13860 -- stored discriminants of the derived type have the same name 13861 -- as those of the parent. 13862 13863 declare 13864 Constr : Elmt_Id; 13865 New_Discr : Entity_Id; 13866 Old_Discr : Entity_Id; 13867 13868 begin 13869 Constr := First_Elmt (Stored_Constraint (Typ)); 13870 Old_Discr := First_Stored_Discriminant (Typ); 13871 while Present (Constr) loop 13872 if Is_Entity_Name (Node (Constr)) 13873 and then Ekind (Entity (Node (Constr))) = E_Discriminant 13874 then 13875 New_Discr := Entity (Node (Constr)); 13876 13877 if Chars (Corresponding_Discriminant (New_Discr)) /= 13878 Chars (Old_Discr) 13879 then 13880 -- The new discriminant has been used to rename a 13881 -- subsequent old discriminant. Introduce a shadow 13882 -- component for the current old discriminant. 13883 13884 New_C := Create_Component (Old_Discr); 13885 Set_Original_Record_Component (New_C, Old_Discr); 13886 end if; 13887 13888 else 13889 -- The constraint has eliminated the old discriminant. 13890 -- Introduce a shadow component. 13891 13892 New_C := Create_Component (Old_Discr); 13893 Set_Original_Record_Component (New_C, Old_Discr); 13894 end if; 13895 13896 Next_Elmt (Constr); 13897 Next_Stored_Discriminant (Old_Discr); 13898 end loop; 13899 end; 13900 end if; 13901 end Add_Discriminants; 13902 13903 if Is_Static 13904 and then Is_Variant_Record (Typ) 13905 then 13906 Collect_Fixed_Components (Typ); 13907 13908 Gather_Components ( 13909 Typ, 13910 Component_List (Type_Definition (Parent (Typ))), 13911 Governed_By => Assoc_List, 13912 Into => Comp_List, 13913 Report_Errors => Errors); 13914 pragma Assert (not Errors); 13915 13916 Create_All_Components; 13917 13918 -- If the subtype declaration is created for a tagged type derivation 13919 -- with constraints, we retrieve the record definition of the parent 13920 -- type to select the components of the proper variant. 13921 13922 elsif Is_Static 13923 and then Is_Tagged_Type (Typ) 13924 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration 13925 and then 13926 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition 13927 and then Is_Variant_Record (Parent_Type) 13928 then 13929 Collect_Fixed_Components (Typ); 13930 13931 Gather_Components 13932 (Typ, 13933 Component_List (Type_Definition (Parent (Parent_Type))), 13934 Governed_By => Assoc_List, 13935 Into => Comp_List, 13936 Report_Errors => Errors); 13937 13938 -- Note: previously there was a check at this point that no errors 13939 -- were detected. As a consequence of AI05-220 there may be an error 13940 -- if an inherited discriminant that controls a variant has a non- 13941 -- static constraint. 13942 13943 -- If the tagged derivation has a type extension, collect all the 13944 -- new components therein. 13945 13946 if Present (Record_Extension_Part (Type_Definition (Parent (Typ)))) 13947 then 13948 Old_C := First_Component (Typ); 13949 while Present (Old_C) loop 13950 if Original_Record_Component (Old_C) = Old_C 13951 and then Chars (Old_C) /= Name_uTag 13952 and then Chars (Old_C) /= Name_uParent 13953 then 13954 Append_Elmt (Old_C, Comp_List); 13955 end if; 13956 13957 Next_Component (Old_C); 13958 end loop; 13959 end if; 13960 13961 Create_All_Components; 13962 13963 else 13964 -- If discriminants are not static, or if this is a multi-level type 13965 -- extension, we have to include all components of the parent type. 13966 13967 Old_C := First_Component (Typ); 13968 while Present (Old_C) loop 13969 New_C := Create_Component (Old_C); 13970 13971 Set_Etype 13972 (New_C, 13973 Constrain_Component_Type 13974 (Old_C, Subt, Decl_Node, Typ, Constraints)); 13975 Set_Is_Public (New_C, Is_Public (Subt)); 13976 13977 Next_Component (Old_C); 13978 end loop; 13979 end if; 13980 13981 End_Scope; 13982 end Create_Constrained_Components; 13983 13984 ------------------------------------------ 13985 -- Decimal_Fixed_Point_Type_Declaration -- 13986 ------------------------------------------ 13987 13988 procedure Decimal_Fixed_Point_Type_Declaration 13989 (T : Entity_Id; 13990 Def : Node_Id) 13991 is 13992 Loc : constant Source_Ptr := Sloc (Def); 13993 Digs_Expr : constant Node_Id := Digits_Expression (Def); 13994 Delta_Expr : constant Node_Id := Delta_Expression (Def); 13995 Implicit_Base : Entity_Id; 13996 Digs_Val : Uint; 13997 Delta_Val : Ureal; 13998 Scale_Val : Uint; 13999 Bound_Val : Ureal; 14000 14001 begin 14002 Check_SPARK_05_Restriction 14003 ("decimal fixed point type is not allowed", Def); 14004 Check_Restriction (No_Fixed_Point, Def); 14005 14006 -- Create implicit base type 14007 14008 Implicit_Base := 14009 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B'); 14010 Set_Etype (Implicit_Base, Implicit_Base); 14011 14012 -- Analyze and process delta expression 14013 14014 Analyze_And_Resolve (Delta_Expr, Universal_Real); 14015 14016 Check_Delta_Expression (Delta_Expr); 14017 Delta_Val := Expr_Value_R (Delta_Expr); 14018 14019 -- Check delta is power of 10, and determine scale value from it 14020 14021 declare 14022 Val : Ureal; 14023 14024 begin 14025 Scale_Val := Uint_0; 14026 Val := Delta_Val; 14027 14028 if Val < Ureal_1 then 14029 while Val < Ureal_1 loop 14030 Val := Val * Ureal_10; 14031 Scale_Val := Scale_Val + 1; 14032 end loop; 14033 14034 if Scale_Val > 18 then 14035 Error_Msg_N ("scale exceeds maximum value of 18", Def); 14036 Scale_Val := UI_From_Int (+18); 14037 end if; 14038 14039 else 14040 while Val > Ureal_1 loop 14041 Val := Val / Ureal_10; 14042 Scale_Val := Scale_Val - 1; 14043 end loop; 14044 14045 if Scale_Val < -18 then 14046 Error_Msg_N ("scale is less than minimum value of -18", Def); 14047 Scale_Val := UI_From_Int (-18); 14048 end if; 14049 end if; 14050 14051 if Val /= Ureal_1 then 14052 Error_Msg_N ("delta expression must be a power of 10", Def); 14053 Delta_Val := Ureal_10 ** (-Scale_Val); 14054 end if; 14055 end; 14056 14057 -- Set delta, scale and small (small = delta for decimal type) 14058 14059 Set_Delta_Value (Implicit_Base, Delta_Val); 14060 Set_Scale_Value (Implicit_Base, Scale_Val); 14061 Set_Small_Value (Implicit_Base, Delta_Val); 14062 14063 -- Analyze and process digits expression 14064 14065 Analyze_And_Resolve (Digs_Expr, Any_Integer); 14066 Check_Digits_Expression (Digs_Expr); 14067 Digs_Val := Expr_Value (Digs_Expr); 14068 14069 if Digs_Val > 18 then 14070 Digs_Val := UI_From_Int (+18); 14071 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr); 14072 end if; 14073 14074 Set_Digits_Value (Implicit_Base, Digs_Val); 14075 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val; 14076 14077 -- Set range of base type from digits value for now. This will be 14078 -- expanded to represent the true underlying base range by Freeze. 14079 14080 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val); 14081 14082 -- Note: We leave size as zero for now, size will be set at freeze 14083 -- time. We have to do this for ordinary fixed-point, because the size 14084 -- depends on the specified small, and we might as well do the same for 14085 -- decimal fixed-point. 14086 14087 pragma Assert (Esize (Implicit_Base) = Uint_0); 14088 14089 -- If there are bounds given in the declaration use them as the 14090 -- bounds of the first named subtype. 14091 14092 if Present (Real_Range_Specification (Def)) then 14093 declare 14094 RRS : constant Node_Id := Real_Range_Specification (Def); 14095 Low : constant Node_Id := Low_Bound (RRS); 14096 High : constant Node_Id := High_Bound (RRS); 14097 Low_Val : Ureal; 14098 High_Val : Ureal; 14099 14100 begin 14101 Analyze_And_Resolve (Low, Any_Real); 14102 Analyze_And_Resolve (High, Any_Real); 14103 Check_Real_Bound (Low); 14104 Check_Real_Bound (High); 14105 Low_Val := Expr_Value_R (Low); 14106 High_Val := Expr_Value_R (High); 14107 14108 if Low_Val < (-Bound_Val) then 14109 Error_Msg_N 14110 ("range low bound too small for digits value", Low); 14111 Low_Val := -Bound_Val; 14112 end if; 14113 14114 if High_Val > Bound_Val then 14115 Error_Msg_N 14116 ("range high bound too large for digits value", High); 14117 High_Val := Bound_Val; 14118 end if; 14119 14120 Set_Fixed_Range (T, Loc, Low_Val, High_Val); 14121 end; 14122 14123 -- If no explicit range, use range that corresponds to given 14124 -- digits value. This will end up as the final range for the 14125 -- first subtype. 14126 14127 else 14128 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val); 14129 end if; 14130 14131 -- Complete entity for first subtype. The inheritance of the rep item 14132 -- chain ensures that SPARK-related pragmas are not clobbered when the 14133 -- decimal fixed point type acts as a full view of a private type. 14134 14135 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype); 14136 Set_Etype (T, Implicit_Base); 14137 Set_Size_Info (T, Implicit_Base); 14138 Inherit_Rep_Item_Chain (T, Implicit_Base); 14139 Set_Digits_Value (T, Digs_Val); 14140 Set_Delta_Value (T, Delta_Val); 14141 Set_Small_Value (T, Delta_Val); 14142 Set_Scale_Value (T, Scale_Val); 14143 Set_Is_Constrained (T); 14144 end Decimal_Fixed_Point_Type_Declaration; 14145 14146 ----------------------------------- 14147 -- Derive_Progenitor_Subprograms -- 14148 ----------------------------------- 14149 14150 procedure Derive_Progenitor_Subprograms 14151 (Parent_Type : Entity_Id; 14152 Tagged_Type : Entity_Id) 14153 is 14154 E : Entity_Id; 14155 Elmt : Elmt_Id; 14156 Iface : Entity_Id; 14157 Iface_Elmt : Elmt_Id; 14158 Iface_Subp : Entity_Id; 14159 New_Subp : Entity_Id := Empty; 14160 Prim_Elmt : Elmt_Id; 14161 Subp : Entity_Id; 14162 Typ : Entity_Id; 14163 14164 begin 14165 pragma Assert (Ada_Version >= Ada_2005 14166 and then Is_Record_Type (Tagged_Type) 14167 and then Is_Tagged_Type (Tagged_Type) 14168 and then Has_Interfaces (Tagged_Type)); 14169 14170 -- Step 1: Transfer to the full-view primitives associated with the 14171 -- partial-view that cover interface primitives. Conceptually this 14172 -- work should be done later by Process_Full_View; done here to 14173 -- simplify its implementation at later stages. It can be safely 14174 -- done here because interfaces must be visible in the partial and 14175 -- private view (RM 7.3(7.3/2)). 14176 14177 -- Small optimization: This work is only required if the parent may 14178 -- have entities whose Alias attribute reference an interface primitive. 14179 -- Such a situation may occur if the parent is an abstract type and the 14180 -- primitive has not been yet overridden or if the parent is a generic 14181 -- formal type covering interfaces. 14182 14183 -- If the tagged type is not abstract, it cannot have abstract 14184 -- primitives (the only entities in the list of primitives of 14185 -- non-abstract tagged types that can reference abstract primitives 14186 -- through its Alias attribute are the internal entities that have 14187 -- attribute Interface_Alias, and these entities are generated later 14188 -- by Add_Internal_Interface_Entities). 14189 14190 if In_Private_Part (Current_Scope) 14191 and then (Is_Abstract_Type (Parent_Type) 14192 or else 14193 Is_Generic_Type (Parent_Type)) 14194 then 14195 Elmt := First_Elmt (Primitive_Operations (Tagged_Type)); 14196 while Present (Elmt) loop 14197 Subp := Node (Elmt); 14198 14199 -- At this stage it is not possible to have entities in the list 14200 -- of primitives that have attribute Interface_Alias. 14201 14202 pragma Assert (No (Interface_Alias (Subp))); 14203 14204 Typ := Find_Dispatching_Type (Ultimate_Alias (Subp)); 14205 14206 if Is_Interface (Typ) then 14207 E := Find_Primitive_Covering_Interface 14208 (Tagged_Type => Tagged_Type, 14209 Iface_Prim => Subp); 14210 14211 if Present (E) 14212 and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ 14213 then 14214 Replace_Elmt (Elmt, E); 14215 Remove_Homonym (Subp); 14216 end if; 14217 end if; 14218 14219 Next_Elmt (Elmt); 14220 end loop; 14221 end if; 14222 14223 -- Step 2: Add primitives of progenitors that are not implemented by 14224 -- parents of Tagged_Type. 14225 14226 if Present (Interfaces (Base_Type (Tagged_Type))) then 14227 Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type))); 14228 while Present (Iface_Elmt) loop 14229 Iface := Node (Iface_Elmt); 14230 14231 Prim_Elmt := First_Elmt (Primitive_Operations (Iface)); 14232 while Present (Prim_Elmt) loop 14233 Iface_Subp := Node (Prim_Elmt); 14234 14235 -- Exclude derivation of predefined primitives except those 14236 -- that come from source, or are inherited from one that comes 14237 -- from source. Required to catch declarations of equality 14238 -- operators of interfaces. For example: 14239 14240 -- type Iface is interface; 14241 -- function "=" (Left, Right : Iface) return Boolean; 14242 14243 if not Is_Predefined_Dispatching_Operation (Iface_Subp) 14244 or else Comes_From_Source (Ultimate_Alias (Iface_Subp)) 14245 then 14246 E := Find_Primitive_Covering_Interface 14247 (Tagged_Type => Tagged_Type, 14248 Iface_Prim => Iface_Subp); 14249 14250 -- If not found we derive a new primitive leaving its alias 14251 -- attribute referencing the interface primitive. 14252 14253 if No (E) then 14254 Derive_Subprogram 14255 (New_Subp, Iface_Subp, Tagged_Type, Iface); 14256 14257 -- Ada 2012 (AI05-0197): If the covering primitive's name 14258 -- differs from the name of the interface primitive then it 14259 -- is a private primitive inherited from a parent type. In 14260 -- such case, given that Tagged_Type covers the interface, 14261 -- the inherited private primitive becomes visible. For such 14262 -- purpose we add a new entity that renames the inherited 14263 -- private primitive. 14264 14265 elsif Chars (E) /= Chars (Iface_Subp) then 14266 pragma Assert (Has_Suffix (E, 'P')); 14267 Derive_Subprogram 14268 (New_Subp, Iface_Subp, Tagged_Type, Iface); 14269 Set_Alias (New_Subp, E); 14270 Set_Is_Abstract_Subprogram (New_Subp, 14271 Is_Abstract_Subprogram (E)); 14272 14273 -- Propagate to the full view interface entities associated 14274 -- with the partial view. 14275 14276 elsif In_Private_Part (Current_Scope) 14277 and then Present (Alias (E)) 14278 and then Alias (E) = Iface_Subp 14279 and then 14280 List_Containing (Parent (E)) /= 14281 Private_Declarations 14282 (Specification 14283 (Unit_Declaration_Node (Current_Scope))) 14284 then 14285 Append_Elmt (E, Primitive_Operations (Tagged_Type)); 14286 end if; 14287 end if; 14288 14289 Next_Elmt (Prim_Elmt); 14290 end loop; 14291 14292 Next_Elmt (Iface_Elmt); 14293 end loop; 14294 end if; 14295 end Derive_Progenitor_Subprograms; 14296 14297 ----------------------- 14298 -- Derive_Subprogram -- 14299 ----------------------- 14300 14301 procedure Derive_Subprogram 14302 (New_Subp : in out Entity_Id; 14303 Parent_Subp : Entity_Id; 14304 Derived_Type : Entity_Id; 14305 Parent_Type : Entity_Id; 14306 Actual_Subp : Entity_Id := Empty) 14307 is 14308 Formal : Entity_Id; 14309 -- Formal parameter of parent primitive operation 14310 14311 Formal_Of_Actual : Entity_Id; 14312 -- Formal parameter of actual operation, when the derivation is to 14313 -- create a renaming for a primitive operation of an actual in an 14314 -- instantiation. 14315 14316 New_Formal : Entity_Id; 14317 -- Formal of inherited operation 14318 14319 Visible_Subp : Entity_Id := Parent_Subp; 14320 14321 function Is_Private_Overriding return Boolean; 14322 -- If Subp is a private overriding of a visible operation, the inherited 14323 -- operation derives from the overridden op (even though its body is the 14324 -- overriding one) and the inherited operation is visible now. See 14325 -- sem_disp to see the full details of the handling of the overridden 14326 -- subprogram, which is removed from the list of primitive operations of 14327 -- the type. The overridden subprogram is saved locally in Visible_Subp, 14328 -- and used to diagnose abstract operations that need overriding in the 14329 -- derived type. 14330 14331 procedure Replace_Type (Id, New_Id : Entity_Id); 14332 -- When the type is an anonymous access type, create a new access type 14333 -- designating the derived type. 14334 14335 procedure Set_Derived_Name; 14336 -- This procedure sets the appropriate Chars name for New_Subp. This 14337 -- is normally just a copy of the parent name. An exception arises for 14338 -- type support subprograms, where the name is changed to reflect the 14339 -- name of the derived type, e.g. if type foo is derived from type bar, 14340 -- then a procedure barDA is derived with a name fooDA. 14341 14342 --------------------------- 14343 -- Is_Private_Overriding -- 14344 --------------------------- 14345 14346 function Is_Private_Overriding return Boolean is 14347 Prev : Entity_Id; 14348 14349 begin 14350 -- If the parent is not a dispatching operation there is no 14351 -- need to investigate overridings 14352 14353 if not Is_Dispatching_Operation (Parent_Subp) then 14354 return False; 14355 end if; 14356 14357 -- The visible operation that is overridden is a homonym of the 14358 -- parent subprogram. We scan the homonym chain to find the one 14359 -- whose alias is the subprogram we are deriving. 14360 14361 Prev := Current_Entity (Parent_Subp); 14362 while Present (Prev) loop 14363 if Ekind (Prev) = Ekind (Parent_Subp) 14364 and then Alias (Prev) = Parent_Subp 14365 and then Scope (Parent_Subp) = Scope (Prev) 14366 and then not Is_Hidden (Prev) 14367 then 14368 Visible_Subp := Prev; 14369 return True; 14370 end if; 14371 14372 Prev := Homonym (Prev); 14373 end loop; 14374 14375 return False; 14376 end Is_Private_Overriding; 14377 14378 ------------------ 14379 -- Replace_Type -- 14380 ------------------ 14381 14382 procedure Replace_Type (Id, New_Id : Entity_Id) is 14383 Id_Type : constant Entity_Id := Etype (Id); 14384 Acc_Type : Entity_Id; 14385 Par : constant Node_Id := Parent (Derived_Type); 14386 14387 begin 14388 -- When the type is an anonymous access type, create a new access 14389 -- type designating the derived type. This itype must be elaborated 14390 -- at the point of the derivation, not on subsequent calls that may 14391 -- be out of the proper scope for Gigi, so we insert a reference to 14392 -- it after the derivation. 14393 14394 if Ekind (Id_Type) = E_Anonymous_Access_Type then 14395 declare 14396 Desig_Typ : Entity_Id := Designated_Type (Id_Type); 14397 14398 begin 14399 if Ekind (Desig_Typ) = E_Record_Type_With_Private 14400 and then Present (Full_View (Desig_Typ)) 14401 and then not Is_Private_Type (Parent_Type) 14402 then 14403 Desig_Typ := Full_View (Desig_Typ); 14404 end if; 14405 14406 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) 14407 14408 -- Ada 2005 (AI-251): Handle also derivations of abstract 14409 -- interface primitives. 14410 14411 or else (Is_Interface (Desig_Typ) 14412 and then not Is_Class_Wide_Type (Desig_Typ)) 14413 then 14414 Acc_Type := New_Copy (Id_Type); 14415 Set_Etype (Acc_Type, Acc_Type); 14416 Set_Scope (Acc_Type, New_Subp); 14417 14418 -- Set size of anonymous access type. If we have an access 14419 -- to an unconstrained array, this is a fat pointer, so it 14420 -- is sizes at twice addtress size. 14421 14422 if Is_Array_Type (Desig_Typ) 14423 and then not Is_Constrained (Desig_Typ) 14424 then 14425 Init_Size (Acc_Type, 2 * System_Address_Size); 14426 14427 -- Other cases use a thin pointer 14428 14429 else 14430 Init_Size (Acc_Type, System_Address_Size); 14431 end if; 14432 14433 -- Set remaining characterstics of anonymous access type 14434 14435 Init_Alignment (Acc_Type); 14436 Set_Directly_Designated_Type (Acc_Type, Derived_Type); 14437 14438 Set_Etype (New_Id, Acc_Type); 14439 Set_Scope (New_Id, New_Subp); 14440 14441 -- Create a reference to it 14442 14443 Build_Itype_Reference (Acc_Type, Parent (Derived_Type)); 14444 14445 else 14446 Set_Etype (New_Id, Id_Type); 14447 end if; 14448 end; 14449 14450 -- In Ada2012, a formal may have an incomplete type but the type 14451 -- derivation that inherits the primitive follows the full view. 14452 14453 elsif Base_Type (Id_Type) = Base_Type (Parent_Type) 14454 or else 14455 (Ekind (Id_Type) = E_Record_Type_With_Private 14456 and then Present (Full_View (Id_Type)) 14457 and then 14458 Base_Type (Full_View (Id_Type)) = Base_Type (Parent_Type)) 14459 or else 14460 (Ada_Version >= Ada_2012 14461 and then Ekind (Id_Type) = E_Incomplete_Type 14462 and then Full_View (Id_Type) = Parent_Type) 14463 then 14464 -- Constraint checks on formals are generated during expansion, 14465 -- based on the signature of the original subprogram. The bounds 14466 -- of the derived type are not relevant, and thus we can use 14467 -- the base type for the formals. However, the return type may be 14468 -- used in a context that requires that the proper static bounds 14469 -- be used (a case statement, for example) and for those cases 14470 -- we must use the derived type (first subtype), not its base. 14471 14472 -- If the derived_type_definition has no constraints, we know that 14473 -- the derived type has the same constraints as the first subtype 14474 -- of the parent, and we can also use it rather than its base, 14475 -- which can lead to more efficient code. 14476 14477 if Etype (Id) = Parent_Type then 14478 if Is_Scalar_Type (Parent_Type) 14479 and then 14480 Subtypes_Statically_Compatible (Parent_Type, Derived_Type) 14481 then 14482 Set_Etype (New_Id, Derived_Type); 14483 14484 elsif Nkind (Par) = N_Full_Type_Declaration 14485 and then 14486 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition 14487 and then 14488 Is_Entity_Name 14489 (Subtype_Indication (Type_Definition (Par))) 14490 then 14491 Set_Etype (New_Id, Derived_Type); 14492 14493 else 14494 Set_Etype (New_Id, Base_Type (Derived_Type)); 14495 end if; 14496 14497 else 14498 Set_Etype (New_Id, Base_Type (Derived_Type)); 14499 end if; 14500 14501 else 14502 Set_Etype (New_Id, Etype (Id)); 14503 end if; 14504 end Replace_Type; 14505 14506 ---------------------- 14507 -- Set_Derived_Name -- 14508 ---------------------- 14509 14510 procedure Set_Derived_Name is 14511 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp); 14512 begin 14513 if Nm = TSS_Null then 14514 Set_Chars (New_Subp, Chars (Parent_Subp)); 14515 else 14516 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm)); 14517 end if; 14518 end Set_Derived_Name; 14519 14520 -- Start of processing for Derive_Subprogram 14521 14522 begin 14523 New_Subp := New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type)); 14524 Set_Ekind (New_Subp, Ekind (Parent_Subp)); 14525 14526 -- Check whether the inherited subprogram is a private operation that 14527 -- should be inherited but not yet made visible. Such subprograms can 14528 -- become visible at a later point (e.g., the private part of a public 14529 -- child unit) via Declare_Inherited_Private_Subprograms. If the 14530 -- following predicate is true, then this is not such a private 14531 -- operation and the subprogram simply inherits the name of the parent 14532 -- subprogram. Note the special check for the names of controlled 14533 -- operations, which are currently exempted from being inherited with 14534 -- a hidden name because they must be findable for generation of 14535 -- implicit run-time calls. 14536 14537 if not Is_Hidden (Parent_Subp) 14538 or else Is_Internal (Parent_Subp) 14539 or else Is_Private_Overriding 14540 or else Is_Internal_Name (Chars (Parent_Subp)) 14541 or else Nam_In (Chars (Parent_Subp), Name_Initialize, 14542 Name_Adjust, 14543 Name_Finalize) 14544 then 14545 Set_Derived_Name; 14546 14547 -- An inherited dispatching equality will be overridden by an internally 14548 -- generated one, or by an explicit one, so preserve its name and thus 14549 -- its entry in the dispatch table. Otherwise, if Parent_Subp is a 14550 -- private operation it may become invisible if the full view has 14551 -- progenitors, and the dispatch table will be malformed. 14552 -- We check that the type is limited to handle the anomalous declaration 14553 -- of Limited_Controlled, which is derived from a non-limited type, and 14554 -- which is handled specially elsewhere as well. 14555 14556 elsif Chars (Parent_Subp) = Name_Op_Eq 14557 and then Is_Dispatching_Operation (Parent_Subp) 14558 and then Etype (Parent_Subp) = Standard_Boolean 14559 and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp))) 14560 and then 14561 Etype (First_Formal (Parent_Subp)) = 14562 Etype (Next_Formal (First_Formal (Parent_Subp))) 14563 then 14564 Set_Derived_Name; 14565 14566 -- If parent is hidden, this can be a regular derivation if the 14567 -- parent is immediately visible in a non-instantiating context, 14568 -- or if we are in the private part of an instance. This test 14569 -- should still be refined ??? 14570 14571 -- The test for In_Instance_Not_Visible avoids inheriting the derived 14572 -- operation as a non-visible operation in cases where the parent 14573 -- subprogram might not be visible now, but was visible within the 14574 -- original generic, so it would be wrong to make the inherited 14575 -- subprogram non-visible now. (Not clear if this test is fully 14576 -- correct; are there any cases where we should declare the inherited 14577 -- operation as not visible to avoid it being overridden, e.g., when 14578 -- the parent type is a generic actual with private primitives ???) 14579 14580 -- (they should be treated the same as other private inherited 14581 -- subprograms, but it's not clear how to do this cleanly). ??? 14582 14583 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type))) 14584 and then Is_Immediately_Visible (Parent_Subp) 14585 and then not In_Instance) 14586 or else In_Instance_Not_Visible 14587 then 14588 Set_Derived_Name; 14589 14590 -- Ada 2005 (AI-251): Regular derivation if the parent subprogram 14591 -- overrides an interface primitive because interface primitives 14592 -- must be visible in the partial view of the parent (RM 7.3 (7.3/2)) 14593 14594 elsif Ada_Version >= Ada_2005 14595 and then Is_Dispatching_Operation (Parent_Subp) 14596 and then Covers_Some_Interface (Parent_Subp) 14597 then 14598 Set_Derived_Name; 14599 14600 -- Otherwise, the type is inheriting a private operation, so enter 14601 -- it with a special name so it can't be overridden. 14602 14603 else 14604 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P')); 14605 end if; 14606 14607 Set_Parent (New_Subp, Parent (Derived_Type)); 14608 14609 if Present (Actual_Subp) then 14610 Replace_Type (Actual_Subp, New_Subp); 14611 else 14612 Replace_Type (Parent_Subp, New_Subp); 14613 end if; 14614 14615 Conditional_Delay (New_Subp, Parent_Subp); 14616 14617 -- If we are creating a renaming for a primitive operation of an 14618 -- actual of a generic derived type, we must examine the signature 14619 -- of the actual primitive, not that of the generic formal, which for 14620 -- example may be an interface. However the name and initial value 14621 -- of the inherited operation are those of the formal primitive. 14622 14623 Formal := First_Formal (Parent_Subp); 14624 14625 if Present (Actual_Subp) then 14626 Formal_Of_Actual := First_Formal (Actual_Subp); 14627 else 14628 Formal_Of_Actual := Empty; 14629 end if; 14630 14631 while Present (Formal) loop 14632 New_Formal := New_Copy (Formal); 14633 14634 -- Normally we do not go copying parents, but in the case of 14635 -- formals, we need to link up to the declaration (which is the 14636 -- parameter specification), and it is fine to link up to the 14637 -- original formal's parameter specification in this case. 14638 14639 Set_Parent (New_Formal, Parent (Formal)); 14640 Append_Entity (New_Formal, New_Subp); 14641 14642 if Present (Formal_Of_Actual) then 14643 Replace_Type (Formal_Of_Actual, New_Formal); 14644 Next_Formal (Formal_Of_Actual); 14645 else 14646 Replace_Type (Formal, New_Formal); 14647 end if; 14648 14649 Next_Formal (Formal); 14650 end loop; 14651 14652 -- If this derivation corresponds to a tagged generic actual, then 14653 -- primitive operations rename those of the actual. Otherwise the 14654 -- primitive operations rename those of the parent type, If the parent 14655 -- renames an intrinsic operator, so does the new subprogram. We except 14656 -- concatenation, which is always properly typed, and does not get 14657 -- expanded as other intrinsic operations. 14658 14659 if No (Actual_Subp) then 14660 if Is_Intrinsic_Subprogram (Parent_Subp) then 14661 Set_Is_Intrinsic_Subprogram (New_Subp); 14662 14663 if Present (Alias (Parent_Subp)) 14664 and then Chars (Parent_Subp) /= Name_Op_Concat 14665 then 14666 Set_Alias (New_Subp, Alias (Parent_Subp)); 14667 else 14668 Set_Alias (New_Subp, Parent_Subp); 14669 end if; 14670 14671 else 14672 Set_Alias (New_Subp, Parent_Subp); 14673 end if; 14674 14675 else 14676 Set_Alias (New_Subp, Actual_Subp); 14677 end if; 14678 14679 -- Inherit the "ghostness" from the parent subprogram 14680 14681 if Is_Ghost_Entity (Alias (New_Subp)) then 14682 Set_Is_Ghost_Entity (New_Subp); 14683 end if; 14684 14685 -- Derived subprograms of a tagged type must inherit the convention 14686 -- of the parent subprogram (a requirement of AI-117). Derived 14687 -- subprograms of untagged types simply get convention Ada by default. 14688 14689 -- If the derived type is a tagged generic formal type with unknown 14690 -- discriminants, its convention is intrinsic (RM 6.3.1 (8)). 14691 14692 -- However, if the type is derived from a generic formal, the further 14693 -- inherited subprogram has the convention of the non-generic ancestor. 14694 -- Otherwise there would be no way to override the operation. 14695 -- (This is subject to forthcoming ARG discussions). 14696 14697 if Is_Tagged_Type (Derived_Type) then 14698 if Is_Generic_Type (Derived_Type) 14699 and then Has_Unknown_Discriminants (Derived_Type) 14700 then 14701 Set_Convention (New_Subp, Convention_Intrinsic); 14702 14703 else 14704 if Is_Generic_Type (Parent_Type) 14705 and then Has_Unknown_Discriminants (Parent_Type) 14706 then 14707 Set_Convention (New_Subp, Convention (Alias (Parent_Subp))); 14708 else 14709 Set_Convention (New_Subp, Convention (Parent_Subp)); 14710 end if; 14711 end if; 14712 end if; 14713 14714 -- Predefined controlled operations retain their name even if the parent 14715 -- is hidden (see above), but they are not primitive operations if the 14716 -- ancestor is not visible, for example if the parent is a private 14717 -- extension completed with a controlled extension. Note that a full 14718 -- type that is controlled can break privacy: the flag Is_Controlled is 14719 -- set on both views of the type. 14720 14721 if Is_Controlled (Parent_Type) 14722 and then Nam_In (Chars (Parent_Subp), Name_Initialize, 14723 Name_Adjust, 14724 Name_Finalize) 14725 and then Is_Hidden (Parent_Subp) 14726 and then not Is_Visibly_Controlled (Parent_Type) 14727 then 14728 Set_Is_Hidden (New_Subp); 14729 end if; 14730 14731 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp)); 14732 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp)); 14733 14734 if Ekind (Parent_Subp) = E_Procedure then 14735 Set_Is_Valued_Procedure 14736 (New_Subp, Is_Valued_Procedure (Parent_Subp)); 14737 else 14738 Set_Has_Controlling_Result 14739 (New_Subp, Has_Controlling_Result (Parent_Subp)); 14740 end if; 14741 14742 -- No_Return must be inherited properly. If this is overridden in the 14743 -- case of a dispatching operation, then a check is made in Sem_Disp 14744 -- that the overriding operation is also No_Return (no such check is 14745 -- required for the case of non-dispatching operation. 14746 14747 Set_No_Return (New_Subp, No_Return (Parent_Subp)); 14748 14749 -- A derived function with a controlling result is abstract. If the 14750 -- Derived_Type is a nonabstract formal generic derived type, then 14751 -- inherited operations are not abstract: the required check is done at 14752 -- instantiation time. If the derivation is for a generic actual, the 14753 -- function is not abstract unless the actual is. 14754 14755 if Is_Generic_Type (Derived_Type) 14756 and then not Is_Abstract_Type (Derived_Type) 14757 then 14758 null; 14759 14760 -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract" 14761 -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2). 14762 14763 -- A subprogram subject to pragma Extensions_Visible with value False 14764 -- requires overriding if the subprogram has at least one controlling 14765 -- OUT parameter (SPARK RM 6.1.7(6)). 14766 14767 elsif Ada_Version >= Ada_2005 14768 and then (Is_Abstract_Subprogram (Alias (New_Subp)) 14769 or else (Is_Tagged_Type (Derived_Type) 14770 and then Etype (New_Subp) = Derived_Type 14771 and then not Is_Null_Extension (Derived_Type)) 14772 or else (Is_Tagged_Type (Derived_Type) 14773 and then Ekind (Etype (New_Subp)) = 14774 E_Anonymous_Access_Type 14775 and then Designated_Type (Etype (New_Subp)) = 14776 Derived_Type 14777 and then not Is_Null_Extension (Derived_Type)) 14778 or else (Comes_From_Source (Alias (New_Subp)) 14779 and then Is_EVF_Procedure (Alias (New_Subp)))) 14780 and then No (Actual_Subp) 14781 then 14782 if not Is_Tagged_Type (Derived_Type) 14783 or else Is_Abstract_Type (Derived_Type) 14784 or else Is_Abstract_Subprogram (Alias (New_Subp)) 14785 then 14786 Set_Is_Abstract_Subprogram (New_Subp); 14787 else 14788 Set_Requires_Overriding (New_Subp); 14789 end if; 14790 14791 elsif Ada_Version < Ada_2005 14792 and then (Is_Abstract_Subprogram (Alias (New_Subp)) 14793 or else (Is_Tagged_Type (Derived_Type) 14794 and then Etype (New_Subp) = Derived_Type 14795 and then No (Actual_Subp))) 14796 then 14797 Set_Is_Abstract_Subprogram (New_Subp); 14798 14799 -- AI05-0097 : an inherited operation that dispatches on result is 14800 -- abstract if the derived type is abstract, even if the parent type 14801 -- is concrete and the derived type is a null extension. 14802 14803 elsif Has_Controlling_Result (Alias (New_Subp)) 14804 and then Is_Abstract_Type (Etype (New_Subp)) 14805 then 14806 Set_Is_Abstract_Subprogram (New_Subp); 14807 14808 -- Finally, if the parent type is abstract we must verify that all 14809 -- inherited operations are either non-abstract or overridden, or that 14810 -- the derived type itself is abstract (this check is performed at the 14811 -- end of a package declaration, in Check_Abstract_Overriding). A 14812 -- private overriding in the parent type will not be visible in the 14813 -- derivation if we are not in an inner package or in a child unit of 14814 -- the parent type, in which case the abstractness of the inherited 14815 -- operation is carried to the new subprogram. 14816 14817 elsif Is_Abstract_Type (Parent_Type) 14818 and then not In_Open_Scopes (Scope (Parent_Type)) 14819 and then Is_Private_Overriding 14820 and then Is_Abstract_Subprogram (Visible_Subp) 14821 then 14822 if No (Actual_Subp) then 14823 Set_Alias (New_Subp, Visible_Subp); 14824 Set_Is_Abstract_Subprogram (New_Subp, True); 14825 14826 else 14827 -- If this is a derivation for an instance of a formal derived 14828 -- type, abstractness comes from the primitive operation of the 14829 -- actual, not from the operation inherited from the ancestor. 14830 14831 Set_Is_Abstract_Subprogram 14832 (New_Subp, Is_Abstract_Subprogram (Actual_Subp)); 14833 end if; 14834 end if; 14835 14836 New_Overloaded_Entity (New_Subp, Derived_Type); 14837 14838 -- Check for case of a derived subprogram for the instantiation of a 14839 -- formal derived tagged type, if so mark the subprogram as dispatching 14840 -- and inherit the dispatching attributes of the actual subprogram. The 14841 -- derived subprogram is effectively renaming of the actual subprogram, 14842 -- so it needs to have the same attributes as the actual. 14843 14844 if Present (Actual_Subp) 14845 and then Is_Dispatching_Operation (Actual_Subp) 14846 then 14847 Set_Is_Dispatching_Operation (New_Subp); 14848 14849 if Present (DTC_Entity (Actual_Subp)) then 14850 Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp)); 14851 Set_DT_Position_Value (New_Subp, DT_Position (Actual_Subp)); 14852 end if; 14853 end if; 14854 14855 -- Indicate that a derived subprogram does not require a body and that 14856 -- it does not require processing of default expressions. 14857 14858 Set_Has_Completion (New_Subp); 14859 Set_Default_Expressions_Processed (New_Subp); 14860 14861 if Ekind (New_Subp) = E_Function then 14862 Set_Mechanism (New_Subp, Mechanism (Parent_Subp)); 14863 end if; 14864 end Derive_Subprogram; 14865 14866 ------------------------ 14867 -- Derive_Subprograms -- 14868 ------------------------ 14869 14870 procedure Derive_Subprograms 14871 (Parent_Type : Entity_Id; 14872 Derived_Type : Entity_Id; 14873 Generic_Actual : Entity_Id := Empty) 14874 is 14875 Op_List : constant Elist_Id := 14876 Collect_Primitive_Operations (Parent_Type); 14877 14878 function Check_Derived_Type return Boolean; 14879 -- Check that all the entities derived from Parent_Type are found in 14880 -- the list of primitives of Derived_Type exactly in the same order. 14881 14882 procedure Derive_Interface_Subprogram 14883 (New_Subp : in out Entity_Id; 14884 Subp : Entity_Id; 14885 Actual_Subp : Entity_Id); 14886 -- Derive New_Subp from the ultimate alias of the parent subprogram Subp 14887 -- (which is an interface primitive). If Generic_Actual is present then 14888 -- Actual_Subp is the actual subprogram corresponding with the generic 14889 -- subprogram Subp. 14890 14891 function Check_Derived_Type return Boolean is 14892 E : Entity_Id; 14893 Elmt : Elmt_Id; 14894 List : Elist_Id; 14895 New_Subp : Entity_Id; 14896 Op_Elmt : Elmt_Id; 14897 Subp : Entity_Id; 14898 14899 begin 14900 -- Traverse list of entities in the current scope searching for 14901 -- an incomplete type whose full-view is derived type 14902 14903 E := First_Entity (Scope (Derived_Type)); 14904 while Present (E) and then E /= Derived_Type loop 14905 if Ekind (E) = E_Incomplete_Type 14906 and then Present (Full_View (E)) 14907 and then Full_View (E) = Derived_Type 14908 then 14909 -- Disable this test if Derived_Type completes an incomplete 14910 -- type because in such case more primitives can be added 14911 -- later to the list of primitives of Derived_Type by routine 14912 -- Process_Incomplete_Dependents 14913 14914 return True; 14915 end if; 14916 14917 E := Next_Entity (E); 14918 end loop; 14919 14920 List := Collect_Primitive_Operations (Derived_Type); 14921 Elmt := First_Elmt (List); 14922 14923 Op_Elmt := First_Elmt (Op_List); 14924 while Present (Op_Elmt) loop 14925 Subp := Node (Op_Elmt); 14926 New_Subp := Node (Elmt); 14927 14928 -- At this early stage Derived_Type has no entities with attribute 14929 -- Interface_Alias. In addition, such primitives are always 14930 -- located at the end of the list of primitives of Parent_Type. 14931 -- Therefore, if found we can safely stop processing pending 14932 -- entities. 14933 14934 exit when Present (Interface_Alias (Subp)); 14935 14936 -- Handle hidden entities 14937 14938 if not Is_Predefined_Dispatching_Operation (Subp) 14939 and then Is_Hidden (Subp) 14940 then 14941 if Present (New_Subp) 14942 and then Primitive_Names_Match (Subp, New_Subp) 14943 then 14944 Next_Elmt (Elmt); 14945 end if; 14946 14947 else 14948 if not Present (New_Subp) 14949 or else Ekind (Subp) /= Ekind (New_Subp) 14950 or else not Primitive_Names_Match (Subp, New_Subp) 14951 then 14952 return False; 14953 end if; 14954 14955 Next_Elmt (Elmt); 14956 end if; 14957 14958 Next_Elmt (Op_Elmt); 14959 end loop; 14960 14961 return True; 14962 end Check_Derived_Type; 14963 14964 --------------------------------- 14965 -- Derive_Interface_Subprogram -- 14966 --------------------------------- 14967 14968 procedure Derive_Interface_Subprogram 14969 (New_Subp : in out Entity_Id; 14970 Subp : Entity_Id; 14971 Actual_Subp : Entity_Id) 14972 is 14973 Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp); 14974 Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp); 14975 14976 begin 14977 pragma Assert (Is_Interface (Iface_Type)); 14978 14979 Derive_Subprogram 14980 (New_Subp => New_Subp, 14981 Parent_Subp => Iface_Subp, 14982 Derived_Type => Derived_Type, 14983 Parent_Type => Iface_Type, 14984 Actual_Subp => Actual_Subp); 14985 14986 -- Given that this new interface entity corresponds with a primitive 14987 -- of the parent that was not overridden we must leave it associated 14988 -- with its parent primitive to ensure that it will share the same 14989 -- dispatch table slot when overridden. 14990 14991 if No (Actual_Subp) then 14992 Set_Alias (New_Subp, Subp); 14993 14994 -- For instantiations this is not needed since the previous call to 14995 -- Derive_Subprogram leaves the entity well decorated. 14996 14997 else 14998 pragma Assert (Alias (New_Subp) = Actual_Subp); 14999 null; 15000 end if; 15001 end Derive_Interface_Subprogram; 15002 15003 -- Local variables 15004 15005 Alias_Subp : Entity_Id; 15006 Act_List : Elist_Id; 15007 Act_Elmt : Elmt_Id; 15008 Act_Subp : Entity_Id := Empty; 15009 Elmt : Elmt_Id; 15010 Need_Search : Boolean := False; 15011 New_Subp : Entity_Id := Empty; 15012 Parent_Base : Entity_Id; 15013 Subp : Entity_Id; 15014 15015 -- Start of processing for Derive_Subprograms 15016 15017 begin 15018 if Ekind (Parent_Type) = E_Record_Type_With_Private 15019 and then Has_Discriminants (Parent_Type) 15020 and then Present (Full_View (Parent_Type)) 15021 then 15022 Parent_Base := Full_View (Parent_Type); 15023 else 15024 Parent_Base := Parent_Type; 15025 end if; 15026 15027 if Present (Generic_Actual) then 15028 Act_List := Collect_Primitive_Operations (Generic_Actual); 15029 Act_Elmt := First_Elmt (Act_List); 15030 else 15031 Act_List := No_Elist; 15032 Act_Elmt := No_Elmt; 15033 end if; 15034 15035 -- Derive primitives inherited from the parent. Note that if the generic 15036 -- actual is present, this is not really a type derivation, it is a 15037 -- completion within an instance. 15038 15039 -- Case 1: Derived_Type does not implement interfaces 15040 15041 if not Is_Tagged_Type (Derived_Type) 15042 or else (not Has_Interfaces (Derived_Type) 15043 and then not (Present (Generic_Actual) 15044 and then Has_Interfaces (Generic_Actual))) 15045 then 15046 Elmt := First_Elmt (Op_List); 15047 while Present (Elmt) loop 15048 Subp := Node (Elmt); 15049 15050 -- Literals are derived earlier in the process of building the 15051 -- derived type, and are skipped here. 15052 15053 if Ekind (Subp) = E_Enumeration_Literal then 15054 null; 15055 15056 -- The actual is a direct descendant and the common primitive 15057 -- operations appear in the same order. 15058 15059 -- If the generic parent type is present, the derived type is an 15060 -- instance of a formal derived type, and within the instance its 15061 -- operations are those of the actual. We derive from the formal 15062 -- type but make the inherited operations aliases of the 15063 -- corresponding operations of the actual. 15064 15065 else 15066 pragma Assert (No (Node (Act_Elmt)) 15067 or else (Primitive_Names_Match (Subp, Node (Act_Elmt)) 15068 and then 15069 Type_Conformant 15070 (Subp, Node (Act_Elmt), 15071 Skip_Controlling_Formals => True))); 15072 15073 Derive_Subprogram 15074 (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt)); 15075 15076 if Present (Act_Elmt) then 15077 Next_Elmt (Act_Elmt); 15078 end if; 15079 end if; 15080 15081 Next_Elmt (Elmt); 15082 end loop; 15083 15084 -- Case 2: Derived_Type implements interfaces 15085 15086 else 15087 -- If the parent type has no predefined primitives we remove 15088 -- predefined primitives from the list of primitives of generic 15089 -- actual to simplify the complexity of this algorithm. 15090 15091 if Present (Generic_Actual) then 15092 declare 15093 Has_Predefined_Primitives : Boolean := False; 15094 15095 begin 15096 -- Check if the parent type has predefined primitives 15097 15098 Elmt := First_Elmt (Op_List); 15099 while Present (Elmt) loop 15100 Subp := Node (Elmt); 15101 15102 if Is_Predefined_Dispatching_Operation (Subp) 15103 and then not Comes_From_Source (Ultimate_Alias (Subp)) 15104 then 15105 Has_Predefined_Primitives := True; 15106 exit; 15107 end if; 15108 15109 Next_Elmt (Elmt); 15110 end loop; 15111 15112 -- Remove predefined primitives of Generic_Actual. We must use 15113 -- an auxiliary list because in case of tagged types the value 15114 -- returned by Collect_Primitive_Operations is the value stored 15115 -- in its Primitive_Operations attribute (and we don't want to 15116 -- modify its current contents). 15117 15118 if not Has_Predefined_Primitives then 15119 declare 15120 Aux_List : constant Elist_Id := New_Elmt_List; 15121 15122 begin 15123 Elmt := First_Elmt (Act_List); 15124 while Present (Elmt) loop 15125 Subp := Node (Elmt); 15126 15127 if not Is_Predefined_Dispatching_Operation (Subp) 15128 or else Comes_From_Source (Subp) 15129 then 15130 Append_Elmt (Subp, Aux_List); 15131 end if; 15132 15133 Next_Elmt (Elmt); 15134 end loop; 15135 15136 Act_List := Aux_List; 15137 end; 15138 end if; 15139 15140 Act_Elmt := First_Elmt (Act_List); 15141 Act_Subp := Node (Act_Elmt); 15142 end; 15143 end if; 15144 15145 -- Stage 1: If the generic actual is not present we derive the 15146 -- primitives inherited from the parent type. If the generic parent 15147 -- type is present, the derived type is an instance of a formal 15148 -- derived type, and within the instance its operations are those of 15149 -- the actual. We derive from the formal type but make the inherited 15150 -- operations aliases of the corresponding operations of the actual. 15151 15152 Elmt := First_Elmt (Op_List); 15153 while Present (Elmt) loop 15154 Subp := Node (Elmt); 15155 Alias_Subp := Ultimate_Alias (Subp); 15156 15157 -- Do not derive internal entities of the parent that link 15158 -- interface primitives with their covering primitive. These 15159 -- entities will be added to this type when frozen. 15160 15161 if Present (Interface_Alias (Subp)) then 15162 goto Continue; 15163 end if; 15164 15165 -- If the generic actual is present find the corresponding 15166 -- operation in the generic actual. If the parent type is a 15167 -- direct ancestor of the derived type then, even if it is an 15168 -- interface, the operations are inherited from the primary 15169 -- dispatch table and are in the proper order. If we detect here 15170 -- that primitives are not in the same order we traverse the list 15171 -- of primitive operations of the actual to find the one that 15172 -- implements the interface primitive. 15173 15174 if Need_Search 15175 or else 15176 (Present (Generic_Actual) 15177 and then Present (Act_Subp) 15178 and then not 15179 (Primitive_Names_Match (Subp, Act_Subp) 15180 and then 15181 Type_Conformant (Subp, Act_Subp, 15182 Skip_Controlling_Formals => True))) 15183 then 15184 pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual, 15185 Use_Full_View => True)); 15186 15187 -- Remember that we need searching for all pending primitives 15188 15189 Need_Search := True; 15190 15191 -- Handle entities associated with interface primitives 15192 15193 if Present (Alias_Subp) 15194 and then Is_Interface (Find_Dispatching_Type (Alias_Subp)) 15195 and then not Is_Predefined_Dispatching_Operation (Subp) 15196 then 15197 -- Search for the primitive in the homonym chain 15198 15199 Act_Subp := 15200 Find_Primitive_Covering_Interface 15201 (Tagged_Type => Generic_Actual, 15202 Iface_Prim => Alias_Subp); 15203 15204 -- Previous search may not locate primitives covering 15205 -- interfaces defined in generics units or instantiations. 15206 -- (it fails if the covering primitive has formals whose 15207 -- type is also defined in generics or instantiations). 15208 -- In such case we search in the list of primitives of the 15209 -- generic actual for the internal entity that links the 15210 -- interface primitive and the covering primitive. 15211 15212 if No (Act_Subp) 15213 and then Is_Generic_Type (Parent_Type) 15214 then 15215 -- This code has been designed to handle only generic 15216 -- formals that implement interfaces that are defined 15217 -- in a generic unit or instantiation. If this code is 15218 -- needed for other cases we must review it because 15219 -- (given that it relies on Original_Location to locate 15220 -- the primitive of Generic_Actual that covers the 15221 -- interface) it could leave linked through attribute 15222 -- Alias entities of unrelated instantiations). 15223 15224 pragma Assert 15225 (Is_Generic_Unit 15226 (Scope (Find_Dispatching_Type (Alias_Subp))) 15227 or else 15228 Instantiation_Depth 15229 (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0); 15230 15231 declare 15232 Iface_Prim_Loc : constant Source_Ptr := 15233 Original_Location (Sloc (Alias_Subp)); 15234 15235 Elmt : Elmt_Id; 15236 Prim : Entity_Id; 15237 15238 begin 15239 Elmt := 15240 First_Elmt (Primitive_Operations (Generic_Actual)); 15241 15242 Search : while Present (Elmt) loop 15243 Prim := Node (Elmt); 15244 15245 if Present (Interface_Alias (Prim)) 15246 and then Original_Location 15247 (Sloc (Interface_Alias (Prim))) = 15248 Iface_Prim_Loc 15249 then 15250 Act_Subp := Alias (Prim); 15251 exit Search; 15252 end if; 15253 15254 Next_Elmt (Elmt); 15255 end loop Search; 15256 end; 15257 end if; 15258 15259 pragma Assert (Present (Act_Subp) 15260 or else Is_Abstract_Type (Generic_Actual) 15261 or else Serious_Errors_Detected > 0); 15262 15263 -- Handle predefined primitives plus the rest of user-defined 15264 -- primitives 15265 15266 else 15267 Act_Elmt := First_Elmt (Act_List); 15268 while Present (Act_Elmt) loop 15269 Act_Subp := Node (Act_Elmt); 15270 15271 exit when Primitive_Names_Match (Subp, Act_Subp) 15272 and then Type_Conformant 15273 (Subp, Act_Subp, 15274 Skip_Controlling_Formals => True) 15275 and then No (Interface_Alias (Act_Subp)); 15276 15277 Next_Elmt (Act_Elmt); 15278 end loop; 15279 15280 if No (Act_Elmt) then 15281 Act_Subp := Empty; 15282 end if; 15283 end if; 15284 end if; 15285 15286 -- Case 1: If the parent is a limited interface then it has the 15287 -- predefined primitives of synchronized interfaces. However, the 15288 -- actual type may be a non-limited type and hence it does not 15289 -- have such primitives. 15290 15291 if Present (Generic_Actual) 15292 and then not Present (Act_Subp) 15293 and then Is_Limited_Interface (Parent_Base) 15294 and then Is_Predefined_Interface_Primitive (Subp) 15295 then 15296 null; 15297 15298 -- Case 2: Inherit entities associated with interfaces that were 15299 -- not covered by the parent type. We exclude here null interface 15300 -- primitives because they do not need special management. 15301 15302 -- We also exclude interface operations that are renamings. If the 15303 -- subprogram is an explicit renaming of an interface primitive, 15304 -- it is a regular primitive operation, and the presence of its 15305 -- alias is not relevant: it has to be derived like any other 15306 -- primitive. 15307 15308 elsif Present (Alias (Subp)) 15309 and then Nkind (Unit_Declaration_Node (Subp)) /= 15310 N_Subprogram_Renaming_Declaration 15311 and then Is_Interface (Find_Dispatching_Type (Alias_Subp)) 15312 and then not 15313 (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification 15314 and then Null_Present (Parent (Alias_Subp))) 15315 then 15316 -- If this is an abstract private type then we transfer the 15317 -- derivation of the interface primitive from the partial view 15318 -- to the full view. This is safe because all the interfaces 15319 -- must be visible in the partial view. Done to avoid adding 15320 -- a new interface derivation to the private part of the 15321 -- enclosing package; otherwise this new derivation would be 15322 -- decorated as hidden when the analysis of the enclosing 15323 -- package completes. 15324 15325 if Is_Abstract_Type (Derived_Type) 15326 and then In_Private_Part (Current_Scope) 15327 and then Has_Private_Declaration (Derived_Type) 15328 then 15329 declare 15330 Partial_View : Entity_Id; 15331 Elmt : Elmt_Id; 15332 Ent : Entity_Id; 15333 15334 begin 15335 Partial_View := First_Entity (Current_Scope); 15336 loop 15337 exit when No (Partial_View) 15338 or else (Has_Private_Declaration (Partial_View) 15339 and then 15340 Full_View (Partial_View) = Derived_Type); 15341 15342 Next_Entity (Partial_View); 15343 end loop; 15344 15345 -- If the partial view was not found then the source code 15346 -- has errors and the derivation is not needed. 15347 15348 if Present (Partial_View) then 15349 Elmt := 15350 First_Elmt (Primitive_Operations (Partial_View)); 15351 while Present (Elmt) loop 15352 Ent := Node (Elmt); 15353 15354 if Present (Alias (Ent)) 15355 and then Ultimate_Alias (Ent) = Alias (Subp) 15356 then 15357 Append_Elmt 15358 (Ent, Primitive_Operations (Derived_Type)); 15359 exit; 15360 end if; 15361 15362 Next_Elmt (Elmt); 15363 end loop; 15364 15365 -- If the interface primitive was not found in the 15366 -- partial view then this interface primitive was 15367 -- overridden. We add a derivation to activate in 15368 -- Derive_Progenitor_Subprograms the machinery to 15369 -- search for it. 15370 15371 if No (Elmt) then 15372 Derive_Interface_Subprogram 15373 (New_Subp => New_Subp, 15374 Subp => Subp, 15375 Actual_Subp => Act_Subp); 15376 end if; 15377 end if; 15378 end; 15379 else 15380 Derive_Interface_Subprogram 15381 (New_Subp => New_Subp, 15382 Subp => Subp, 15383 Actual_Subp => Act_Subp); 15384 end if; 15385 15386 -- Case 3: Common derivation 15387 15388 else 15389 Derive_Subprogram 15390 (New_Subp => New_Subp, 15391 Parent_Subp => Subp, 15392 Derived_Type => Derived_Type, 15393 Parent_Type => Parent_Base, 15394 Actual_Subp => Act_Subp); 15395 end if; 15396 15397 -- No need to update Act_Elm if we must search for the 15398 -- corresponding operation in the generic actual 15399 15400 if not Need_Search 15401 and then Present (Act_Elmt) 15402 then 15403 Next_Elmt (Act_Elmt); 15404 Act_Subp := Node (Act_Elmt); 15405 end if; 15406 15407 <<Continue>> 15408 Next_Elmt (Elmt); 15409 end loop; 15410 15411 -- Inherit additional operations from progenitors. If the derived 15412 -- type is a generic actual, there are not new primitive operations 15413 -- for the type because it has those of the actual, and therefore 15414 -- nothing needs to be done. The renamings generated above are not 15415 -- primitive operations, and their purpose is simply to make the 15416 -- proper operations visible within an instantiation. 15417 15418 if No (Generic_Actual) then 15419 Derive_Progenitor_Subprograms (Parent_Base, Derived_Type); 15420 end if; 15421 end if; 15422 15423 -- Final check: Direct descendants must have their primitives in the 15424 -- same order. We exclude from this test untagged types and instances 15425 -- of formal derived types. We skip this test if we have already 15426 -- reported serious errors in the sources. 15427 15428 pragma Assert (not Is_Tagged_Type (Derived_Type) 15429 or else Present (Generic_Actual) 15430 or else Serious_Errors_Detected > 0 15431 or else Check_Derived_Type); 15432 end Derive_Subprograms; 15433 15434 -------------------------------- 15435 -- Derived_Standard_Character -- 15436 -------------------------------- 15437 15438 procedure Derived_Standard_Character 15439 (N : Node_Id; 15440 Parent_Type : Entity_Id; 15441 Derived_Type : Entity_Id) 15442 is 15443 Loc : constant Source_Ptr := Sloc (N); 15444 Def : constant Node_Id := Type_Definition (N); 15445 Indic : constant Node_Id := Subtype_Indication (Def); 15446 Parent_Base : constant Entity_Id := Base_Type (Parent_Type); 15447 Implicit_Base : constant Entity_Id := 15448 Create_Itype 15449 (E_Enumeration_Type, N, Derived_Type, 'B'); 15450 15451 Lo : Node_Id; 15452 Hi : Node_Id; 15453 15454 begin 15455 Discard_Node (Process_Subtype (Indic, N)); 15456 15457 Set_Etype (Implicit_Base, Parent_Base); 15458 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type)); 15459 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type))); 15460 15461 Set_Is_Character_Type (Implicit_Base, True); 15462 Set_Has_Delayed_Freeze (Implicit_Base); 15463 15464 -- The bounds of the implicit base are the bounds of the parent base. 15465 -- Note that their type is the parent base. 15466 15467 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base)); 15468 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base)); 15469 15470 Set_Scalar_Range (Implicit_Base, 15471 Make_Range (Loc, 15472 Low_Bound => Lo, 15473 High_Bound => Hi)); 15474 15475 Conditional_Delay (Derived_Type, Parent_Type); 15476 15477 Set_Ekind (Derived_Type, E_Enumeration_Subtype); 15478 Set_Etype (Derived_Type, Implicit_Base); 15479 Set_Size_Info (Derived_Type, Parent_Type); 15480 15481 if Unknown_RM_Size (Derived_Type) then 15482 Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); 15483 end if; 15484 15485 Set_Is_Character_Type (Derived_Type, True); 15486 15487 if Nkind (Indic) /= N_Subtype_Indication then 15488 15489 -- If no explicit constraint, the bounds are those 15490 -- of the parent type. 15491 15492 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type)); 15493 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type)); 15494 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi)); 15495 end if; 15496 15497 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc); 15498 15499 -- Because the implicit base is used in the conversion of the bounds, we 15500 -- have to freeze it now. This is similar to what is done for numeric 15501 -- types, and it equally suspicious, but otherwise a non-static bound 15502 -- will have a reference to an unfrozen type, which is rejected by Gigi 15503 -- (???). This requires specific care for definition of stream 15504 -- attributes. For details, see comments at the end of 15505 -- Build_Derived_Numeric_Type. 15506 15507 Freeze_Before (N, Implicit_Base); 15508 end Derived_Standard_Character; 15509 15510 ------------------------------ 15511 -- Derived_Type_Declaration -- 15512 ------------------------------ 15513 15514 procedure Derived_Type_Declaration 15515 (T : Entity_Id; 15516 N : Node_Id; 15517 Is_Completion : Boolean) 15518 is 15519 Parent_Type : Entity_Id; 15520 15521 function Comes_From_Generic (Typ : Entity_Id) return Boolean; 15522 -- Check whether the parent type is a generic formal, or derives 15523 -- directly or indirectly from one. 15524 15525 ------------------------ 15526 -- Comes_From_Generic -- 15527 ------------------------ 15528 15529 function Comes_From_Generic (Typ : Entity_Id) return Boolean is 15530 begin 15531 if Is_Generic_Type (Typ) then 15532 return True; 15533 15534 elsif Is_Generic_Type (Root_Type (Parent_Type)) then 15535 return True; 15536 15537 elsif Is_Private_Type (Typ) 15538 and then Present (Full_View (Typ)) 15539 and then Is_Generic_Type (Root_Type (Full_View (Typ))) 15540 then 15541 return True; 15542 15543 elsif Is_Generic_Actual_Type (Typ) then 15544 return True; 15545 15546 else 15547 return False; 15548 end if; 15549 end Comes_From_Generic; 15550 15551 -- Local variables 15552 15553 Def : constant Node_Id := Type_Definition (N); 15554 Iface_Def : Node_Id; 15555 Indic : constant Node_Id := Subtype_Indication (Def); 15556 Extension : constant Node_Id := Record_Extension_Part (Def); 15557 Parent_Node : Node_Id; 15558 Taggd : Boolean; 15559 15560 -- Start of processing for Derived_Type_Declaration 15561 15562 begin 15563 Parent_Type := Find_Type_Of_Subtype_Indic (Indic); 15564 15565 -- Ada 2005 (AI-251): In case of interface derivation check that the 15566 -- parent is also an interface. 15567 15568 if Interface_Present (Def) then 15569 Check_SPARK_05_Restriction ("interface is not allowed", Def); 15570 15571 if not Is_Interface (Parent_Type) then 15572 Diagnose_Interface (Indic, Parent_Type); 15573 15574 else 15575 Parent_Node := Parent (Base_Type (Parent_Type)); 15576 Iface_Def := Type_Definition (Parent_Node); 15577 15578 -- Ada 2005 (AI-251): Limited interfaces can only inherit from 15579 -- other limited interfaces. 15580 15581 if Limited_Present (Def) then 15582 if Limited_Present (Iface_Def) then 15583 null; 15584 15585 elsif Protected_Present (Iface_Def) then 15586 Error_Msg_NE 15587 ("descendant of& must be declared" 15588 & " as a protected interface", 15589 N, Parent_Type); 15590 15591 elsif Synchronized_Present (Iface_Def) then 15592 Error_Msg_NE 15593 ("descendant of& must be declared" 15594 & " as a synchronized interface", 15595 N, Parent_Type); 15596 15597 elsif Task_Present (Iface_Def) then 15598 Error_Msg_NE 15599 ("descendant of& must be declared as a task interface", 15600 N, Parent_Type); 15601 15602 else 15603 Error_Msg_N 15604 ("(Ada 2005) limited interface cannot " 15605 & "inherit from non-limited interface", Indic); 15606 end if; 15607 15608 -- Ada 2005 (AI-345): Non-limited interfaces can only inherit 15609 -- from non-limited or limited interfaces. 15610 15611 elsif not Protected_Present (Def) 15612 and then not Synchronized_Present (Def) 15613 and then not Task_Present (Def) 15614 then 15615 if Limited_Present (Iface_Def) then 15616 null; 15617 15618 elsif Protected_Present (Iface_Def) then 15619 Error_Msg_NE 15620 ("descendant of& must be declared" 15621 & " as a protected interface", 15622 N, Parent_Type); 15623 15624 elsif Synchronized_Present (Iface_Def) then 15625 Error_Msg_NE 15626 ("descendant of& must be declared" 15627 & " as a synchronized interface", 15628 N, Parent_Type); 15629 15630 elsif Task_Present (Iface_Def) then 15631 Error_Msg_NE 15632 ("descendant of& must be declared as a task interface", 15633 N, Parent_Type); 15634 else 15635 null; 15636 end if; 15637 end if; 15638 end if; 15639 end if; 15640 15641 if Is_Tagged_Type (Parent_Type) 15642 and then Is_Concurrent_Type (Parent_Type) 15643 and then not Is_Interface (Parent_Type) 15644 then 15645 Error_Msg_N 15646 ("parent type of a record extension cannot be " 15647 & "a synchronized tagged type (RM 3.9.1 (3/1))", N); 15648 Set_Etype (T, Any_Type); 15649 return; 15650 end if; 15651 15652 -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor 15653 -- interfaces 15654 15655 if Is_Tagged_Type (Parent_Type) 15656 and then Is_Non_Empty_List (Interface_List (Def)) 15657 then 15658 declare 15659 Intf : Node_Id; 15660 T : Entity_Id; 15661 15662 begin 15663 Intf := First (Interface_List (Def)); 15664 while Present (Intf) loop 15665 T := Find_Type_Of_Subtype_Indic (Intf); 15666 15667 if not Is_Interface (T) then 15668 Diagnose_Interface (Intf, T); 15669 15670 -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow 15671 -- a limited type from having a nonlimited progenitor. 15672 15673 elsif (Limited_Present (Def) 15674 or else (not Is_Interface (Parent_Type) 15675 and then Is_Limited_Type (Parent_Type))) 15676 and then not Is_Limited_Interface (T) 15677 then 15678 Error_Msg_NE 15679 ("progenitor interface& of limited type must be limited", 15680 N, T); 15681 end if; 15682 15683 Next (Intf); 15684 end loop; 15685 end; 15686 end if; 15687 15688 if Parent_Type = Any_Type 15689 or else Etype (Parent_Type) = Any_Type 15690 or else (Is_Class_Wide_Type (Parent_Type) 15691 and then Etype (Parent_Type) = T) 15692 then 15693 -- If Parent_Type is undefined or illegal, make new type into a 15694 -- subtype of Any_Type, and set a few attributes to prevent cascaded 15695 -- errors. If this is a self-definition, emit error now. 15696 15697 if T = Parent_Type or else T = Etype (Parent_Type) then 15698 Error_Msg_N ("type cannot be used in its own definition", Indic); 15699 end if; 15700 15701 Set_Ekind (T, Ekind (Parent_Type)); 15702 Set_Etype (T, Any_Type); 15703 Set_Scalar_Range (T, Scalar_Range (Any_Type)); 15704 15705 if Is_Tagged_Type (T) 15706 and then Is_Record_Type (T) 15707 then 15708 Set_Direct_Primitive_Operations (T, New_Elmt_List); 15709 end if; 15710 15711 return; 15712 end if; 15713 15714 -- Ada 2005 (AI-251): The case in which the parent of the full-view is 15715 -- an interface is special because the list of interfaces in the full 15716 -- view can be given in any order. For example: 15717 15718 -- type A is interface; 15719 -- type B is interface and A; 15720 -- type D is new B with private; 15721 -- private 15722 -- type D is new A and B with null record; -- 1 -- 15723 15724 -- In this case we perform the following transformation of -1-: 15725 15726 -- type D is new B and A with null record; 15727 15728 -- If the parent of the full-view covers the parent of the partial-view 15729 -- we have two possible cases: 15730 15731 -- 1) They have the same parent 15732 -- 2) The parent of the full-view implements some further interfaces 15733 15734 -- In both cases we do not need to perform the transformation. In the 15735 -- first case the source program is correct and the transformation is 15736 -- not needed; in the second case the source program does not fulfill 15737 -- the no-hidden interfaces rule (AI-396) and the error will be reported 15738 -- later. 15739 15740 -- This transformation not only simplifies the rest of the analysis of 15741 -- this type declaration but also simplifies the correct generation of 15742 -- the object layout to the expander. 15743 15744 if In_Private_Part (Current_Scope) 15745 and then Is_Interface (Parent_Type) 15746 then 15747 declare 15748 Iface : Node_Id; 15749 Partial_View : Entity_Id; 15750 Partial_View_Parent : Entity_Id; 15751 New_Iface : Node_Id; 15752 15753 begin 15754 -- Look for the associated private type declaration 15755 15756 Partial_View := First_Entity (Current_Scope); 15757 loop 15758 exit when No (Partial_View) 15759 or else (Has_Private_Declaration (Partial_View) 15760 and then Full_View (Partial_View) = T); 15761 15762 Next_Entity (Partial_View); 15763 end loop; 15764 15765 -- If the partial view was not found then the source code has 15766 -- errors and the transformation is not needed. 15767 15768 if Present (Partial_View) then 15769 Partial_View_Parent := Etype (Partial_View); 15770 15771 -- If the parent of the full-view covers the parent of the 15772 -- partial-view we have nothing else to do. 15773 15774 if Interface_Present_In_Ancestor 15775 (Parent_Type, Partial_View_Parent) 15776 then 15777 null; 15778 15779 -- Traverse the list of interfaces of the full-view to look 15780 -- for the parent of the partial-view and perform the tree 15781 -- transformation. 15782 15783 else 15784 Iface := First (Interface_List (Def)); 15785 while Present (Iface) loop 15786 if Etype (Iface) = Etype (Partial_View) then 15787 Rewrite (Subtype_Indication (Def), 15788 New_Copy (Subtype_Indication 15789 (Parent (Partial_View)))); 15790 15791 New_Iface := 15792 Make_Identifier (Sloc (N), Chars (Parent_Type)); 15793 Append (New_Iface, Interface_List (Def)); 15794 15795 -- Analyze the transformed code 15796 15797 Derived_Type_Declaration (T, N, Is_Completion); 15798 return; 15799 end if; 15800 15801 Next (Iface); 15802 end loop; 15803 end if; 15804 end if; 15805 end; 15806 end if; 15807 15808 -- Only composite types other than array types are allowed to have 15809 -- discriminants. 15810 15811 if Present (Discriminant_Specifications (N)) then 15812 if (Is_Elementary_Type (Parent_Type) 15813 or else 15814 Is_Array_Type (Parent_Type)) 15815 and then not Error_Posted (N) 15816 then 15817 Error_Msg_N 15818 ("elementary or array type cannot have discriminants", 15819 Defining_Identifier (First (Discriminant_Specifications (N)))); 15820 Set_Has_Discriminants (T, False); 15821 15822 -- The type is allowed to have discriminants 15823 15824 else 15825 Check_SPARK_05_Restriction ("discriminant type is not allowed", N); 15826 end if; 15827 end if; 15828 15829 -- In Ada 83, a derived type defined in a package specification cannot 15830 -- be used for further derivation until the end of its visible part. 15831 -- Note that derivation in the private part of the package is allowed. 15832 15833 if Ada_Version = Ada_83 15834 and then Is_Derived_Type (Parent_Type) 15835 and then In_Visible_Part (Scope (Parent_Type)) 15836 then 15837 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then 15838 Error_Msg_N 15839 ("(Ada 83): premature use of type for derivation", Indic); 15840 end if; 15841 end if; 15842 15843 -- Check for early use of incomplete or private type 15844 15845 if Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then 15846 Error_Msg_N ("premature derivation of incomplete type", Indic); 15847 return; 15848 15849 elsif (Is_Incomplete_Or_Private_Type (Parent_Type) 15850 and then not Comes_From_Generic (Parent_Type)) 15851 or else Has_Private_Component (Parent_Type) 15852 then 15853 -- The ancestor type of a formal type can be incomplete, in which 15854 -- case only the operations of the partial view are available in the 15855 -- generic. Subsequent checks may be required when the full view is 15856 -- analyzed to verify that a derivation from a tagged type has an 15857 -- extension. 15858 15859 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then 15860 null; 15861 15862 elsif No (Underlying_Type (Parent_Type)) 15863 or else Has_Private_Component (Parent_Type) 15864 then 15865 Error_Msg_N 15866 ("premature derivation of derived or private type", Indic); 15867 15868 -- Flag the type itself as being in error, this prevents some 15869 -- nasty problems with subsequent uses of the malformed type. 15870 15871 Set_Error_Posted (T); 15872 15873 -- Check that within the immediate scope of an untagged partial 15874 -- view it's illegal to derive from the partial view if the 15875 -- full view is tagged. (7.3(7)) 15876 15877 -- We verify that the Parent_Type is a partial view by checking 15878 -- that it is not a Full_Type_Declaration (i.e. a private type or 15879 -- private extension declaration), to distinguish a partial view 15880 -- from a derivation from a private type which also appears as 15881 -- E_Private_Type. If the parent base type is not declared in an 15882 -- enclosing scope there is no need to check. 15883 15884 elsif Present (Full_View (Parent_Type)) 15885 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration 15886 and then not Is_Tagged_Type (Parent_Type) 15887 and then Is_Tagged_Type (Full_View (Parent_Type)) 15888 and then In_Open_Scopes (Scope (Base_Type (Parent_Type))) 15889 then 15890 Error_Msg_N 15891 ("premature derivation from type with tagged full view", 15892 Indic); 15893 end if; 15894 end if; 15895 15896 -- Check that form of derivation is appropriate 15897 15898 Taggd := Is_Tagged_Type (Parent_Type); 15899 15900 -- Set the parent type to the class-wide type's specific type in this 15901 -- case to prevent cascading errors 15902 15903 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then 15904 Error_Msg_N ("parent type must not be a class-wide type", Indic); 15905 Set_Etype (T, Etype (Parent_Type)); 15906 return; 15907 end if; 15908 15909 if Present (Extension) and then not Taggd then 15910 Error_Msg_N 15911 ("type derived from untagged type cannot have extension", Indic); 15912 15913 elsif No (Extension) and then Taggd then 15914 15915 -- If this declaration is within a private part (or body) of a 15916 -- generic instantiation then the derivation is allowed (the parent 15917 -- type can only appear tagged in this case if it's a generic actual 15918 -- type, since it would otherwise have been rejected in the analysis 15919 -- of the generic template). 15920 15921 if not Is_Generic_Actual_Type (Parent_Type) 15922 or else In_Visible_Part (Scope (Parent_Type)) 15923 then 15924 if Is_Class_Wide_Type (Parent_Type) then 15925 Error_Msg_N 15926 ("parent type must not be a class-wide type", Indic); 15927 15928 -- Use specific type to prevent cascaded errors. 15929 15930 Parent_Type := Etype (Parent_Type); 15931 15932 else 15933 Error_Msg_N 15934 ("type derived from tagged type must have extension", Indic); 15935 end if; 15936 end if; 15937 end if; 15938 15939 -- AI-443: Synchronized formal derived types require a private 15940 -- extension. There is no point in checking the ancestor type or 15941 -- the progenitors since the construct is wrong to begin with. 15942 15943 if Ada_Version >= Ada_2005 15944 and then Is_Generic_Type (T) 15945 and then Present (Original_Node (N)) 15946 then 15947 declare 15948 Decl : constant Node_Id := Original_Node (N); 15949 15950 begin 15951 if Nkind (Decl) = N_Formal_Type_Declaration 15952 and then Nkind (Formal_Type_Definition (Decl)) = 15953 N_Formal_Derived_Type_Definition 15954 and then Synchronized_Present (Formal_Type_Definition (Decl)) 15955 and then No (Extension) 15956 15957 -- Avoid emitting a duplicate error message 15958 15959 and then not Error_Posted (Indic) 15960 then 15961 Error_Msg_N 15962 ("synchronized derived type must have extension", N); 15963 end if; 15964 end; 15965 end if; 15966 15967 if Null_Exclusion_Present (Def) 15968 and then not Is_Access_Type (Parent_Type) 15969 then 15970 Error_Msg_N ("null exclusion can only apply to an access type", N); 15971 end if; 15972 15973 -- Avoid deriving parent primitives of underlying record views 15974 15975 Build_Derived_Type (N, Parent_Type, T, Is_Completion, 15976 Derive_Subps => not Is_Underlying_Record_View (T)); 15977 15978 -- AI-419: The parent type of an explicitly limited derived type must 15979 -- be a limited type or a limited interface. 15980 15981 if Limited_Present (Def) then 15982 Set_Is_Limited_Record (T); 15983 15984 if Is_Interface (T) then 15985 Set_Is_Limited_Interface (T); 15986 end if; 15987 15988 if not Is_Limited_Type (Parent_Type) 15989 and then 15990 (not Is_Interface (Parent_Type) 15991 or else not Is_Limited_Interface (Parent_Type)) 15992 then 15993 -- AI05-0096: a derivation in the private part of an instance is 15994 -- legal if the generic formal is untagged limited, and the actual 15995 -- is non-limited. 15996 15997 if Is_Generic_Actual_Type (Parent_Type) 15998 and then In_Private_Part (Current_Scope) 15999 and then 16000 not Is_Tagged_Type 16001 (Generic_Parent_Type (Parent (Parent_Type))) 16002 then 16003 null; 16004 16005 else 16006 Error_Msg_NE 16007 ("parent type& of limited type must be limited", 16008 N, Parent_Type); 16009 end if; 16010 end if; 16011 end if; 16012 16013 -- In SPARK, there are no derived type definitions other than type 16014 -- extensions of tagged record types. 16015 16016 if No (Extension) then 16017 Check_SPARK_05_Restriction 16018 ("derived type is not allowed", Original_Node (N)); 16019 end if; 16020 end Derived_Type_Declaration; 16021 16022 ------------------------ 16023 -- Diagnose_Interface -- 16024 ------------------------ 16025 16026 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is 16027 begin 16028 if not Is_Interface (E) and then E /= Any_Type then 16029 Error_Msg_NE ("(Ada 2005) & must be an interface", N, E); 16030 end if; 16031 end Diagnose_Interface; 16032 16033 ---------------------------------- 16034 -- Enumeration_Type_Declaration -- 16035 ---------------------------------- 16036 16037 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is 16038 Ev : Uint; 16039 L : Node_Id; 16040 R_Node : Node_Id; 16041 B_Node : Node_Id; 16042 16043 begin 16044 -- Create identifier node representing lower bound 16045 16046 B_Node := New_Node (N_Identifier, Sloc (Def)); 16047 L := First (Literals (Def)); 16048 Set_Chars (B_Node, Chars (L)); 16049 Set_Entity (B_Node, L); 16050 Set_Etype (B_Node, T); 16051 Set_Is_Static_Expression (B_Node, True); 16052 16053 R_Node := New_Node (N_Range, Sloc (Def)); 16054 Set_Low_Bound (R_Node, B_Node); 16055 16056 Set_Ekind (T, E_Enumeration_Type); 16057 Set_First_Literal (T, L); 16058 Set_Etype (T, T); 16059 Set_Is_Constrained (T); 16060 16061 Ev := Uint_0; 16062 16063 -- Loop through literals of enumeration type setting pos and rep values 16064 -- except that if the Ekind is already set, then it means the literal 16065 -- was already constructed (case of a derived type declaration and we 16066 -- should not disturb the Pos and Rep values. 16067 16068 while Present (L) loop 16069 if Ekind (L) /= E_Enumeration_Literal then 16070 Set_Ekind (L, E_Enumeration_Literal); 16071 Set_Enumeration_Pos (L, Ev); 16072 Set_Enumeration_Rep (L, Ev); 16073 Set_Is_Known_Valid (L, True); 16074 end if; 16075 16076 Set_Etype (L, T); 16077 New_Overloaded_Entity (L); 16078 Generate_Definition (L); 16079 Set_Convention (L, Convention_Intrinsic); 16080 16081 -- Case of character literal 16082 16083 if Nkind (L) = N_Defining_Character_Literal then 16084 Set_Is_Character_Type (T, True); 16085 16086 -- Check violation of No_Wide_Characters 16087 16088 if Restriction_Check_Required (No_Wide_Characters) then 16089 Get_Name_String (Chars (L)); 16090 16091 if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then 16092 Check_Restriction (No_Wide_Characters, L); 16093 end if; 16094 end if; 16095 end if; 16096 16097 Ev := Ev + 1; 16098 Next (L); 16099 end loop; 16100 16101 -- Now create a node representing upper bound 16102 16103 B_Node := New_Node (N_Identifier, Sloc (Def)); 16104 Set_Chars (B_Node, Chars (Last (Literals (Def)))); 16105 Set_Entity (B_Node, Last (Literals (Def))); 16106 Set_Etype (B_Node, T); 16107 Set_Is_Static_Expression (B_Node, True); 16108 16109 Set_High_Bound (R_Node, B_Node); 16110 16111 -- Initialize various fields of the type. Some of this information 16112 -- may be overwritten later through rep.clauses. 16113 16114 Set_Scalar_Range (T, R_Node); 16115 Set_RM_Size (T, UI_From_Int (Minimum_Size (T))); 16116 Set_Enum_Esize (T); 16117 Set_Enum_Pos_To_Rep (T, Empty); 16118 16119 -- Set Discard_Names if configuration pragma set, or if there is 16120 -- a parameterless pragma in the current declarative region 16121 16122 if Global_Discard_Names or else Discard_Names (Scope (T)) then 16123 Set_Discard_Names (T); 16124 end if; 16125 16126 -- Process end label if there is one 16127 16128 if Present (Def) then 16129 Process_End_Label (Def, 'e', T); 16130 end if; 16131 end Enumeration_Type_Declaration; 16132 16133 --------------------------------- 16134 -- Expand_To_Stored_Constraint -- 16135 --------------------------------- 16136 16137 function Expand_To_Stored_Constraint 16138 (Typ : Entity_Id; 16139 Constraint : Elist_Id) return Elist_Id 16140 is 16141 Explicitly_Discriminated_Type : Entity_Id; 16142 Expansion : Elist_Id; 16143 Discriminant : Entity_Id; 16144 16145 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id; 16146 -- Find the nearest type that actually specifies discriminants 16147 16148 --------------------------------- 16149 -- Type_With_Explicit_Discrims -- 16150 --------------------------------- 16151 16152 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is 16153 Typ : constant E := Base_Type (Id); 16154 16155 begin 16156 if Ekind (Typ) in Incomplete_Or_Private_Kind then 16157 if Present (Full_View (Typ)) then 16158 return Type_With_Explicit_Discrims (Full_View (Typ)); 16159 end if; 16160 16161 else 16162 if Has_Discriminants (Typ) then 16163 return Typ; 16164 end if; 16165 end if; 16166 16167 if Etype (Typ) = Typ then 16168 return Empty; 16169 elsif Has_Discriminants (Typ) then 16170 return Typ; 16171 else 16172 return Type_With_Explicit_Discrims (Etype (Typ)); 16173 end if; 16174 16175 end Type_With_Explicit_Discrims; 16176 16177 -- Start of processing for Expand_To_Stored_Constraint 16178 16179 begin 16180 if No (Constraint) or else Is_Empty_Elmt_List (Constraint) then 16181 return No_Elist; 16182 end if; 16183 16184 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ); 16185 16186 if No (Explicitly_Discriminated_Type) then 16187 return No_Elist; 16188 end if; 16189 16190 Expansion := New_Elmt_List; 16191 16192 Discriminant := 16193 First_Stored_Discriminant (Explicitly_Discriminated_Type); 16194 while Present (Discriminant) loop 16195 Append_Elmt 16196 (Get_Discriminant_Value 16197 (Discriminant, Explicitly_Discriminated_Type, Constraint), 16198 To => Expansion); 16199 Next_Stored_Discriminant (Discriminant); 16200 end loop; 16201 16202 return Expansion; 16203 end Expand_To_Stored_Constraint; 16204 16205 --------------------------- 16206 -- Find_Hidden_Interface -- 16207 --------------------------- 16208 16209 function Find_Hidden_Interface 16210 (Src : Elist_Id; 16211 Dest : Elist_Id) return Entity_Id 16212 is 16213 Iface : Entity_Id; 16214 Iface_Elmt : Elmt_Id; 16215 16216 begin 16217 if Present (Src) and then Present (Dest) then 16218 Iface_Elmt := First_Elmt (Src); 16219 while Present (Iface_Elmt) loop 16220 Iface := Node (Iface_Elmt); 16221 16222 if Is_Interface (Iface) 16223 and then not Contain_Interface (Iface, Dest) 16224 then 16225 return Iface; 16226 end if; 16227 16228 Next_Elmt (Iface_Elmt); 16229 end loop; 16230 end if; 16231 16232 return Empty; 16233 end Find_Hidden_Interface; 16234 16235 -------------------- 16236 -- Find_Type_Name -- 16237 -------------------- 16238 16239 function Find_Type_Name (N : Node_Id) return Entity_Id is 16240 Id : constant Entity_Id := Defining_Identifier (N); 16241 Prev : Entity_Id; 16242 New_Id : Entity_Id; 16243 Prev_Par : Node_Id; 16244 16245 procedure Check_Duplicate_Aspects; 16246 -- Check that aspects specified in a completion have not been specified 16247 -- already in the partial view. Type_Invariant and others can be 16248 -- specified on either view but never on both. 16249 16250 procedure Tag_Mismatch; 16251 -- Diagnose a tagged partial view whose full view is untagged. 16252 -- We post the message on the full view, with a reference to 16253 -- the previous partial view. The partial view can be private 16254 -- or incomplete, and these are handled in a different manner, 16255 -- so we determine the position of the error message from the 16256 -- respective slocs of both. 16257 16258 ----------------------------- 16259 -- Check_Duplicate_Aspects -- 16260 ----------------------------- 16261 procedure Check_Duplicate_Aspects is 16262 Prev_Aspects : constant List_Id := Aspect_Specifications (Prev_Par); 16263 Full_Aspects : constant List_Id := Aspect_Specifications (N); 16264 F_Spec, P_Spec : Node_Id; 16265 16266 begin 16267 if Present (Prev_Aspects) and then Present (Full_Aspects) then 16268 F_Spec := First (Full_Aspects); 16269 while Present (F_Spec) loop 16270 P_Spec := First (Prev_Aspects); 16271 while Present (P_Spec) loop 16272 if Chars (Identifier (P_Spec)) = Chars (Identifier (F_Spec)) 16273 then 16274 Error_Msg_N 16275 ("aspect already specified in private declaration", 16276 F_Spec); 16277 Remove (F_Spec); 16278 return; 16279 end if; 16280 16281 Next (P_Spec); 16282 end loop; 16283 16284 Next (F_Spec); 16285 end loop; 16286 end if; 16287 end Check_Duplicate_Aspects; 16288 16289 ------------------ 16290 -- Tag_Mismatch -- 16291 ------------------ 16292 16293 procedure Tag_Mismatch is 16294 begin 16295 if Sloc (Prev) < Sloc (Id) then 16296 if Ada_Version >= Ada_2012 16297 and then Nkind (N) = N_Private_Type_Declaration 16298 then 16299 Error_Msg_NE 16300 ("declaration of private } must be a tagged type ", Id, Prev); 16301 else 16302 Error_Msg_NE 16303 ("full declaration of } must be a tagged type ", Id, Prev); 16304 end if; 16305 16306 else 16307 if Ada_Version >= Ada_2012 16308 and then Nkind (N) = N_Private_Type_Declaration 16309 then 16310 Error_Msg_NE 16311 ("declaration of private } must be a tagged type ", Prev, Id); 16312 else 16313 Error_Msg_NE 16314 ("full declaration of } must be a tagged type ", Prev, Id); 16315 end if; 16316 end if; 16317 end Tag_Mismatch; 16318 16319 -- Start of processing for Find_Type_Name 16320 16321 begin 16322 -- Find incomplete declaration, if one was given 16323 16324 Prev := Current_Entity_In_Scope (Id); 16325 16326 -- New type declaration 16327 16328 if No (Prev) then 16329 Enter_Name (Id); 16330 return Id; 16331 16332 -- Previous declaration exists 16333 16334 else 16335 Prev_Par := Parent (Prev); 16336 16337 -- Error if not incomplete/private case except if previous 16338 -- declaration is implicit, etc. Enter_Name will emit error if 16339 -- appropriate. 16340 16341 if not Is_Incomplete_Or_Private_Type (Prev) then 16342 Enter_Name (Id); 16343 New_Id := Id; 16344 16345 -- Check invalid completion of private or incomplete type 16346 16347 elsif not Nkind_In (N, N_Full_Type_Declaration, 16348 N_Task_Type_Declaration, 16349 N_Protected_Type_Declaration) 16350 and then 16351 (Ada_Version < Ada_2012 16352 or else not Is_Incomplete_Type (Prev) 16353 or else not Nkind_In (N, N_Private_Type_Declaration, 16354 N_Private_Extension_Declaration)) 16355 then 16356 -- Completion must be a full type declarations (RM 7.3(4)) 16357 16358 Error_Msg_Sloc := Sloc (Prev); 16359 Error_Msg_NE ("invalid completion of }", Id, Prev); 16360 16361 -- Set scope of Id to avoid cascaded errors. Entity is never 16362 -- examined again, except when saving globals in generics. 16363 16364 Set_Scope (Id, Current_Scope); 16365 New_Id := Id; 16366 16367 -- If this is a repeated incomplete declaration, no further 16368 -- checks are possible. 16369 16370 if Nkind (N) = N_Incomplete_Type_Declaration then 16371 return Prev; 16372 end if; 16373 16374 -- Case of full declaration of incomplete type 16375 16376 elsif Ekind (Prev) = E_Incomplete_Type 16377 and then (Ada_Version < Ada_2012 16378 or else No (Full_View (Prev)) 16379 or else not Is_Private_Type (Full_View (Prev))) 16380 then 16381 -- Indicate that the incomplete declaration has a matching full 16382 -- declaration. The defining occurrence of the incomplete 16383 -- declaration remains the visible one, and the procedure 16384 -- Get_Full_View dereferences it whenever the type is used. 16385 16386 if Present (Full_View (Prev)) then 16387 Error_Msg_NE ("invalid redeclaration of }", Id, Prev); 16388 end if; 16389 16390 Set_Full_View (Prev, Id); 16391 Append_Entity (Id, Current_Scope); 16392 Set_Is_Public (Id, Is_Public (Prev)); 16393 Set_Is_Internal (Id); 16394 New_Id := Prev; 16395 16396 -- If the incomplete view is tagged, a class_wide type has been 16397 -- created already. Use it for the private type as well, in order 16398 -- to prevent multiple incompatible class-wide types that may be 16399 -- created for self-referential anonymous access components. 16400 16401 if Is_Tagged_Type (Prev) 16402 and then Present (Class_Wide_Type (Prev)) 16403 then 16404 Set_Ekind (Id, Ekind (Prev)); -- will be reset later 16405 Set_Class_Wide_Type (Id, Class_Wide_Type (Prev)); 16406 16407 -- The type of the classwide type is the current Id. Previously 16408 -- this was not done for private declarations because of order- 16409 -- of elaboration issues in the back-end, but gigi now handles 16410 -- this properly. 16411 16412 Set_Etype (Class_Wide_Type (Id), Id); 16413 end if; 16414 16415 -- Case of full declaration of private type 16416 16417 else 16418 -- If the private type was a completion of an incomplete type then 16419 -- update Prev to reference the private type 16420 16421 if Ada_Version >= Ada_2012 16422 and then Ekind (Prev) = E_Incomplete_Type 16423 and then Present (Full_View (Prev)) 16424 and then Is_Private_Type (Full_View (Prev)) 16425 then 16426 Prev := Full_View (Prev); 16427 Prev_Par := Parent (Prev); 16428 end if; 16429 16430 if Nkind (N) = N_Full_Type_Declaration 16431 and then Nkind_In 16432 (Type_Definition (N), N_Record_Definition, 16433 N_Derived_Type_Definition) 16434 and then Interface_Present (Type_Definition (N)) 16435 then 16436 Error_Msg_N 16437 ("completion of private type cannot be an interface", N); 16438 end if; 16439 16440 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then 16441 if Etype (Prev) /= Prev then 16442 16443 -- Prev is a private subtype or a derived type, and needs 16444 -- no completion. 16445 16446 Error_Msg_NE ("invalid redeclaration of }", Id, Prev); 16447 New_Id := Id; 16448 16449 elsif Ekind (Prev) = E_Private_Type 16450 and then Nkind_In (N, N_Task_Type_Declaration, 16451 N_Protected_Type_Declaration) 16452 then 16453 Error_Msg_N 16454 ("completion of nonlimited type cannot be limited", N); 16455 16456 elsif Ekind (Prev) = E_Record_Type_With_Private 16457 and then Nkind_In (N, N_Task_Type_Declaration, 16458 N_Protected_Type_Declaration) 16459 then 16460 if not Is_Limited_Record (Prev) then 16461 Error_Msg_N 16462 ("completion of nonlimited type cannot be limited", N); 16463 16464 elsif No (Interface_List (N)) then 16465 Error_Msg_N 16466 ("completion of tagged private type must be tagged", 16467 N); 16468 end if; 16469 end if; 16470 16471 -- Ada 2005 (AI-251): Private extension declaration of a task 16472 -- type or a protected type. This case arises when covering 16473 -- interface types. 16474 16475 elsif Nkind_In (N, N_Task_Type_Declaration, 16476 N_Protected_Type_Declaration) 16477 then 16478 null; 16479 16480 elsif Nkind (N) /= N_Full_Type_Declaration 16481 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition 16482 then 16483 Error_Msg_N 16484 ("full view of private extension must be an extension", N); 16485 16486 elsif not (Abstract_Present (Parent (Prev))) 16487 and then Abstract_Present (Type_Definition (N)) 16488 then 16489 Error_Msg_N 16490 ("full view of non-abstract extension cannot be abstract", N); 16491 end if; 16492 16493 if not In_Private_Part (Current_Scope) then 16494 Error_Msg_N 16495 ("declaration of full view must appear in private part", N); 16496 end if; 16497 16498 if Ada_Version >= Ada_2012 then 16499 Check_Duplicate_Aspects; 16500 end if; 16501 16502 Copy_And_Swap (Prev, Id); 16503 Set_Has_Private_Declaration (Prev); 16504 Set_Has_Private_Declaration (Id); 16505 16506 -- AI12-0133: Indicate whether we have a partial view with 16507 -- unknown discriminants, in which case initialization of objects 16508 -- of the type do not receive an invariant check. 16509 16510 Set_Partial_View_Has_Unknown_Discr 16511 (Prev, Has_Unknown_Discriminants (Id)); 16512 16513 -- Preserve aspect and iterator flags that may have been set on 16514 -- the partial view. 16515 16516 Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id)); 16517 Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id)); 16518 16519 -- If no error, propagate freeze_node from private to full view. 16520 -- It may have been generated for an early operational item. 16521 16522 if Present (Freeze_Node (Id)) 16523 and then Serious_Errors_Detected = 0 16524 and then No (Full_View (Id)) 16525 then 16526 Set_Freeze_Node (Prev, Freeze_Node (Id)); 16527 Set_Freeze_Node (Id, Empty); 16528 Set_First_Rep_Item (Prev, First_Rep_Item (Id)); 16529 end if; 16530 16531 Set_Full_View (Id, Prev); 16532 New_Id := Prev; 16533 end if; 16534 16535 -- Verify that full declaration conforms to partial one 16536 16537 if Is_Incomplete_Or_Private_Type (Prev) 16538 and then Present (Discriminant_Specifications (Prev_Par)) 16539 then 16540 if Present (Discriminant_Specifications (N)) then 16541 if Ekind (Prev) = E_Incomplete_Type then 16542 Check_Discriminant_Conformance (N, Prev, Prev); 16543 else 16544 Check_Discriminant_Conformance (N, Prev, Id); 16545 end if; 16546 16547 else 16548 Error_Msg_N 16549 ("missing discriminants in full type declaration", N); 16550 16551 -- To avoid cascaded errors on subsequent use, share the 16552 -- discriminants of the partial view. 16553 16554 Set_Discriminant_Specifications (N, 16555 Discriminant_Specifications (Prev_Par)); 16556 end if; 16557 end if; 16558 16559 -- A prior untagged partial view can have an associated class-wide 16560 -- type due to use of the class attribute, and in this case the full 16561 -- type must also be tagged. This Ada 95 usage is deprecated in favor 16562 -- of incomplete tagged declarations, but we check for it. 16563 16564 if Is_Type (Prev) 16565 and then (Is_Tagged_Type (Prev) 16566 or else Present (Class_Wide_Type (Prev))) 16567 then 16568 -- Ada 2012 (AI05-0162): A private type may be the completion of 16569 -- an incomplete type. 16570 16571 if Ada_Version >= Ada_2012 16572 and then Is_Incomplete_Type (Prev) 16573 and then Nkind_In (N, N_Private_Type_Declaration, 16574 N_Private_Extension_Declaration) 16575 then 16576 -- No need to check private extensions since they are tagged 16577 16578 if Nkind (N) = N_Private_Type_Declaration 16579 and then not Tagged_Present (N) 16580 then 16581 Tag_Mismatch; 16582 end if; 16583 16584 -- The full declaration is either a tagged type (including 16585 -- a synchronized type that implements interfaces) or a 16586 -- type extension, otherwise this is an error. 16587 16588 elsif Nkind_In (N, N_Task_Type_Declaration, 16589 N_Protected_Type_Declaration) 16590 then 16591 if No (Interface_List (N)) and then not Error_Posted (N) then 16592 Tag_Mismatch; 16593 end if; 16594 16595 elsif Nkind (Type_Definition (N)) = N_Record_Definition then 16596 16597 -- Indicate that the previous declaration (tagged incomplete 16598 -- or private declaration) requires the same on the full one. 16599 16600 if not Tagged_Present (Type_Definition (N)) then 16601 Tag_Mismatch; 16602 Set_Is_Tagged_Type (Id); 16603 end if; 16604 16605 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then 16606 if No (Record_Extension_Part (Type_Definition (N))) then 16607 Error_Msg_NE 16608 ("full declaration of } must be a record extension", 16609 Prev, Id); 16610 16611 -- Set some attributes to produce a usable full view 16612 16613 Set_Is_Tagged_Type (Id); 16614 end if; 16615 16616 else 16617 Tag_Mismatch; 16618 end if; 16619 end if; 16620 16621 if Present (Prev) 16622 and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration 16623 and then Present (Premature_Use (Parent (Prev))) 16624 then 16625 Error_Msg_Sloc := Sloc (N); 16626 Error_Msg_N 16627 ("\full declaration #", Premature_Use (Parent (Prev))); 16628 end if; 16629 16630 return New_Id; 16631 end if; 16632 end Find_Type_Name; 16633 16634 ------------------------- 16635 -- Find_Type_Of_Object -- 16636 ------------------------- 16637 16638 function Find_Type_Of_Object 16639 (Obj_Def : Node_Id; 16640 Related_Nod : Node_Id) return Entity_Id 16641 is 16642 Def_Kind : constant Node_Kind := Nkind (Obj_Def); 16643 P : Node_Id := Parent (Obj_Def); 16644 T : Entity_Id; 16645 Nam : Name_Id; 16646 16647 begin 16648 -- If the parent is a component_definition node we climb to the 16649 -- component_declaration node 16650 16651 if Nkind (P) = N_Component_Definition then 16652 P := Parent (P); 16653 end if; 16654 16655 -- Case of an anonymous array subtype 16656 16657 if Nkind_In (Def_Kind, N_Constrained_Array_Definition, 16658 N_Unconstrained_Array_Definition) 16659 then 16660 T := Empty; 16661 Array_Type_Declaration (T, Obj_Def); 16662 16663 -- Create an explicit subtype whenever possible 16664 16665 elsif Nkind (P) /= N_Component_Declaration 16666 and then Def_Kind = N_Subtype_Indication 16667 then 16668 -- Base name of subtype on object name, which will be unique in 16669 -- the current scope. 16670 16671 -- If this is a duplicate declaration, return base type, to avoid 16672 -- generating duplicate anonymous types. 16673 16674 if Error_Posted (P) then 16675 Analyze (Subtype_Mark (Obj_Def)); 16676 return Entity (Subtype_Mark (Obj_Def)); 16677 end if; 16678 16679 Nam := 16680 New_External_Name 16681 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T'); 16682 16683 T := Make_Defining_Identifier (Sloc (P), Nam); 16684 16685 Insert_Action (Obj_Def, 16686 Make_Subtype_Declaration (Sloc (P), 16687 Defining_Identifier => T, 16688 Subtype_Indication => Relocate_Node (Obj_Def))); 16689 16690 -- This subtype may need freezing, and this will not be done 16691 -- automatically if the object declaration is not in declarative 16692 -- part. Since this is an object declaration, the type cannot always 16693 -- be frozen here. Deferred constants do not freeze their type 16694 -- (which often enough will be private). 16695 16696 if Nkind (P) = N_Object_Declaration 16697 and then Constant_Present (P) 16698 and then No (Expression (P)) 16699 then 16700 null; 16701 16702 -- Here we freeze the base type of object type to catch premature use 16703 -- of discriminated private type without a full view. 16704 16705 else 16706 Insert_Actions (Obj_Def, Freeze_Entity (Base_Type (T), P)); 16707 end if; 16708 16709 -- Ada 2005 AI-406: the object definition in an object declaration 16710 -- can be an access definition. 16711 16712 elsif Def_Kind = N_Access_Definition then 16713 T := Access_Definition (Related_Nod, Obj_Def); 16714 16715 Set_Is_Local_Anonymous_Access 16716 (T, 16717 V => (Ada_Version < Ada_2012) 16718 or else (Nkind (P) /= N_Object_Declaration) 16719 or else Is_Library_Level_Entity (Defining_Identifier (P))); 16720 16721 -- Otherwise, the object definition is just a subtype_mark 16722 16723 else 16724 T := Process_Subtype (Obj_Def, Related_Nod); 16725 16726 -- If expansion is disabled an object definition that is an aggregate 16727 -- will not get expanded and may lead to scoping problems in the back 16728 -- end, if the object is referenced in an inner scope. In that case 16729 -- create an itype reference for the object definition now. This 16730 -- may be redundant in some cases, but harmless. 16731 16732 if Is_Itype (T) 16733 and then Nkind (Related_Nod) = N_Object_Declaration 16734 and then ASIS_Mode 16735 then 16736 Build_Itype_Reference (T, Related_Nod); 16737 end if; 16738 end if; 16739 16740 return T; 16741 end Find_Type_Of_Object; 16742 16743 -------------------------------- 16744 -- Find_Type_Of_Subtype_Indic -- 16745 -------------------------------- 16746 16747 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is 16748 Typ : Entity_Id; 16749 16750 begin 16751 -- Case of subtype mark with a constraint 16752 16753 if Nkind (S) = N_Subtype_Indication then 16754 Find_Type (Subtype_Mark (S)); 16755 Typ := Entity (Subtype_Mark (S)); 16756 16757 if not 16758 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S))) 16759 then 16760 Error_Msg_N 16761 ("incorrect constraint for this kind of type", Constraint (S)); 16762 Rewrite (S, New_Copy_Tree (Subtype_Mark (S))); 16763 end if; 16764 16765 -- Otherwise we have a subtype mark without a constraint 16766 16767 elsif Error_Posted (S) then 16768 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S))); 16769 return Any_Type; 16770 16771 else 16772 Find_Type (S); 16773 Typ := Entity (S); 16774 end if; 16775 16776 -- Check No_Wide_Characters restriction 16777 16778 Check_Wide_Character_Restriction (Typ, S); 16779 16780 return Typ; 16781 end Find_Type_Of_Subtype_Indic; 16782 16783 ------------------------------------- 16784 -- Floating_Point_Type_Declaration -- 16785 ------------------------------------- 16786 16787 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is 16788 Digs : constant Node_Id := Digits_Expression (Def); 16789 Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float); 16790 Digs_Val : Uint; 16791 Base_Typ : Entity_Id; 16792 Implicit_Base : Entity_Id; 16793 Bound : Node_Id; 16794 16795 function Can_Derive_From (E : Entity_Id) return Boolean; 16796 -- Find if given digits value, and possibly a specified range, allows 16797 -- derivation from specified type 16798 16799 function Find_Base_Type return Entity_Id; 16800 -- Find a predefined base type that Def can derive from, or generate 16801 -- an error and substitute Long_Long_Float if none exists. 16802 16803 --------------------- 16804 -- Can_Derive_From -- 16805 --------------------- 16806 16807 function Can_Derive_From (E : Entity_Id) return Boolean is 16808 Spec : constant Entity_Id := Real_Range_Specification (Def); 16809 16810 begin 16811 -- Check specified "digits" constraint 16812 16813 if Digs_Val > Digits_Value (E) then 16814 return False; 16815 end if; 16816 16817 -- Check for matching range, if specified 16818 16819 if Present (Spec) then 16820 if Expr_Value_R (Type_Low_Bound (E)) > 16821 Expr_Value_R (Low_Bound (Spec)) 16822 then 16823 return False; 16824 end if; 16825 16826 if Expr_Value_R (Type_High_Bound (E)) < 16827 Expr_Value_R (High_Bound (Spec)) 16828 then 16829 return False; 16830 end if; 16831 end if; 16832 16833 return True; 16834 end Can_Derive_From; 16835 16836 -------------------- 16837 -- Find_Base_Type -- 16838 -------------------- 16839 16840 function Find_Base_Type return Entity_Id is 16841 Choice : Elmt_Id := First_Elmt (Predefined_Float_Types); 16842 16843 begin 16844 -- Iterate over the predefined types in order, returning the first 16845 -- one that Def can derive from. 16846 16847 while Present (Choice) loop 16848 if Can_Derive_From (Node (Choice)) then 16849 return Node (Choice); 16850 end if; 16851 16852 Next_Elmt (Choice); 16853 end loop; 16854 16855 -- If we can't derive from any existing type, use Long_Long_Float 16856 -- and give appropriate message explaining the problem. 16857 16858 if Digs_Val > Max_Digs_Val then 16859 -- It might be the case that there is a type with the requested 16860 -- range, just not the combination of digits and range. 16861 16862 Error_Msg_N 16863 ("no predefined type has requested range and precision", 16864 Real_Range_Specification (Def)); 16865 16866 else 16867 Error_Msg_N 16868 ("range too large for any predefined type", 16869 Real_Range_Specification (Def)); 16870 end if; 16871 16872 return Standard_Long_Long_Float; 16873 end Find_Base_Type; 16874 16875 -- Start of processing for Floating_Point_Type_Declaration 16876 16877 begin 16878 Check_Restriction (No_Floating_Point, Def); 16879 16880 -- Create an implicit base type 16881 16882 Implicit_Base := 16883 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B'); 16884 16885 -- Analyze and verify digits value 16886 16887 Analyze_And_Resolve (Digs, Any_Integer); 16888 Check_Digits_Expression (Digs); 16889 Digs_Val := Expr_Value (Digs); 16890 16891 -- Process possible range spec and find correct type to derive from 16892 16893 Process_Real_Range_Specification (Def); 16894 16895 -- Check that requested number of digits is not too high. 16896 16897 if Digs_Val > Max_Digs_Val then 16898 16899 -- The check for Max_Base_Digits may be somewhat expensive, as it 16900 -- requires reading System, so only do it when necessary. 16901 16902 declare 16903 Max_Base_Digits : constant Uint := 16904 Expr_Value 16905 (Expression 16906 (Parent (RTE (RE_Max_Base_Digits)))); 16907 16908 begin 16909 if Digs_Val > Max_Base_Digits then 16910 Error_Msg_Uint_1 := Max_Base_Digits; 16911 Error_Msg_N ("digits value out of range, maximum is ^", Digs); 16912 16913 elsif No (Real_Range_Specification (Def)) then 16914 Error_Msg_Uint_1 := Max_Digs_Val; 16915 Error_Msg_N ("types with more than ^ digits need range spec " 16916 & "(RM 3.5.7(6))", Digs); 16917 end if; 16918 end; 16919 end if; 16920 16921 -- Find a suitable type to derive from or complain and use a substitute 16922 16923 Base_Typ := Find_Base_Type; 16924 16925 -- If there are bounds given in the declaration use them as the bounds 16926 -- of the type, otherwise use the bounds of the predefined base type 16927 -- that was chosen based on the Digits value. 16928 16929 if Present (Real_Range_Specification (Def)) then 16930 Set_Scalar_Range (T, Real_Range_Specification (Def)); 16931 Set_Is_Constrained (T); 16932 16933 -- The bounds of this range must be converted to machine numbers 16934 -- in accordance with RM 4.9(38). 16935 16936 Bound := Type_Low_Bound (T); 16937 16938 if Nkind (Bound) = N_Real_Literal then 16939 Set_Realval 16940 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound)); 16941 Set_Is_Machine_Number (Bound); 16942 end if; 16943 16944 Bound := Type_High_Bound (T); 16945 16946 if Nkind (Bound) = N_Real_Literal then 16947 Set_Realval 16948 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound)); 16949 Set_Is_Machine_Number (Bound); 16950 end if; 16951 16952 else 16953 Set_Scalar_Range (T, Scalar_Range (Base_Typ)); 16954 end if; 16955 16956 -- Complete definition of implicit base and declared first subtype. The 16957 -- inheritance of the rep item chain ensures that SPARK-related pragmas 16958 -- are not clobbered when the floating point type acts as a full view of 16959 -- a private type. 16960 16961 Set_Etype (Implicit_Base, Base_Typ); 16962 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ)); 16963 Set_Size_Info (Implicit_Base, Base_Typ); 16964 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ)); 16965 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ)); 16966 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ)); 16967 Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ)); 16968 16969 Set_Ekind (T, E_Floating_Point_Subtype); 16970 Set_Etype (T, Implicit_Base); 16971 Set_Size_Info (T, Implicit_Base); 16972 Set_RM_Size (T, RM_Size (Implicit_Base)); 16973 Inherit_Rep_Item_Chain (T, Implicit_Base); 16974 Set_Digits_Value (T, Digs_Val); 16975 end Floating_Point_Type_Declaration; 16976 16977 ---------------------------- 16978 -- Get_Discriminant_Value -- 16979 ---------------------------- 16980 16981 -- This is the situation: 16982 16983 -- There is a non-derived type 16984 16985 -- type T0 (Dx, Dy, Dz...) 16986 16987 -- There are zero or more levels of derivation, with each derivation 16988 -- either purely inheriting the discriminants, or defining its own. 16989 16990 -- type Ti is new Ti-1 16991 -- or 16992 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y) 16993 -- or 16994 -- subtype Ti is ... 16995 16996 -- The subtype issue is avoided by the use of Original_Record_Component, 16997 -- and the fact that derived subtypes also derive the constraints. 16998 16999 -- This chain leads back from 17000 17001 -- Typ_For_Constraint 17002 17003 -- Typ_For_Constraint has discriminants, and the value for each 17004 -- discriminant is given by its corresponding Elmt of Constraints. 17005 17006 -- Discriminant is some discriminant in this hierarchy 17007 17008 -- We need to return its value 17009 17010 -- We do this by recursively searching each level, and looking for 17011 -- Discriminant. Once we get to the bottom, we start backing up 17012 -- returning the value for it which may in turn be a discriminant 17013 -- further up, so on the backup we continue the substitution. 17014 17015 function Get_Discriminant_Value 17016 (Discriminant : Entity_Id; 17017 Typ_For_Constraint : Entity_Id; 17018 Constraint : Elist_Id) return Node_Id 17019 is 17020 function Root_Corresponding_Discriminant 17021 (Discr : Entity_Id) return Entity_Id; 17022 -- Given a discriminant, traverse the chain of inherited discriminants 17023 -- and return the topmost discriminant. 17024 17025 function Search_Derivation_Levels 17026 (Ti : Entity_Id; 17027 Discrim_Values : Elist_Id; 17028 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id; 17029 -- This is the routine that performs the recursive search of levels 17030 -- as described above. 17031 17032 ------------------------------------- 17033 -- Root_Corresponding_Discriminant -- 17034 ------------------------------------- 17035 17036 function Root_Corresponding_Discriminant 17037 (Discr : Entity_Id) return Entity_Id 17038 is 17039 D : Entity_Id; 17040 17041 begin 17042 D := Discr; 17043 while Present (Corresponding_Discriminant (D)) loop 17044 D := Corresponding_Discriminant (D); 17045 end loop; 17046 17047 return D; 17048 end Root_Corresponding_Discriminant; 17049 17050 ------------------------------ 17051 -- Search_Derivation_Levels -- 17052 ------------------------------ 17053 17054 function Search_Derivation_Levels 17055 (Ti : Entity_Id; 17056 Discrim_Values : Elist_Id; 17057 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id 17058 is 17059 Assoc : Elmt_Id; 17060 Disc : Entity_Id; 17061 Result : Node_Or_Entity_Id; 17062 Result_Entity : Node_Id; 17063 17064 begin 17065 -- If inappropriate type, return Error, this happens only in 17066 -- cascaded error situations, and we want to avoid a blow up. 17067 17068 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then 17069 return Error; 17070 end if; 17071 17072 -- Look deeper if possible. Use Stored_Constraints only for 17073 -- untagged types. For tagged types use the given constraint. 17074 -- This asymmetry needs explanation??? 17075 17076 if not Stored_Discrim_Values 17077 and then Present (Stored_Constraint (Ti)) 17078 and then not Is_Tagged_Type (Ti) 17079 then 17080 Result := 17081 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True); 17082 else 17083 declare 17084 Td : constant Entity_Id := Etype (Ti); 17085 17086 begin 17087 if Td = Ti then 17088 Result := Discriminant; 17089 17090 else 17091 if Present (Stored_Constraint (Ti)) then 17092 Result := 17093 Search_Derivation_Levels 17094 (Td, Stored_Constraint (Ti), True); 17095 else 17096 Result := 17097 Search_Derivation_Levels 17098 (Td, Discrim_Values, Stored_Discrim_Values); 17099 end if; 17100 end if; 17101 end; 17102 end if; 17103 17104 -- Extra underlying places to search, if not found above. For 17105 -- concurrent types, the relevant discriminant appears in the 17106 -- corresponding record. For a type derived from a private type 17107 -- without discriminant, the full view inherits the discriminants 17108 -- of the full view of the parent. 17109 17110 if Result = Discriminant then 17111 if Is_Concurrent_Type (Ti) 17112 and then Present (Corresponding_Record_Type (Ti)) 17113 then 17114 Result := 17115 Search_Derivation_Levels ( 17116 Corresponding_Record_Type (Ti), 17117 Discrim_Values, 17118 Stored_Discrim_Values); 17119 17120 elsif Is_Private_Type (Ti) 17121 and then not Has_Discriminants (Ti) 17122 and then Present (Full_View (Ti)) 17123 and then Etype (Full_View (Ti)) /= Ti 17124 then 17125 Result := 17126 Search_Derivation_Levels ( 17127 Full_View (Ti), 17128 Discrim_Values, 17129 Stored_Discrim_Values); 17130 end if; 17131 end if; 17132 17133 -- If Result is not a (reference to a) discriminant, return it, 17134 -- otherwise set Result_Entity to the discriminant. 17135 17136 if Nkind (Result) = N_Defining_Identifier then 17137 pragma Assert (Result = Discriminant); 17138 Result_Entity := Result; 17139 17140 else 17141 if not Denotes_Discriminant (Result) then 17142 return Result; 17143 end if; 17144 17145 Result_Entity := Entity (Result); 17146 end if; 17147 17148 -- See if this level of derivation actually has discriminants because 17149 -- tagged derivations can add them, hence the lower levels need not 17150 -- have any. 17151 17152 if not Has_Discriminants (Ti) then 17153 return Result; 17154 end if; 17155 17156 -- Scan Ti's discriminants for Result_Entity, and return its 17157 -- corresponding value, if any. 17158 17159 Result_Entity := Original_Record_Component (Result_Entity); 17160 17161 Assoc := First_Elmt (Discrim_Values); 17162 17163 if Stored_Discrim_Values then 17164 Disc := First_Stored_Discriminant (Ti); 17165 else 17166 Disc := First_Discriminant (Ti); 17167 end if; 17168 17169 while Present (Disc) loop 17170 pragma Assert (Present (Assoc)); 17171 17172 if Original_Record_Component (Disc) = Result_Entity then 17173 return Node (Assoc); 17174 end if; 17175 17176 Next_Elmt (Assoc); 17177 17178 if Stored_Discrim_Values then 17179 Next_Stored_Discriminant (Disc); 17180 else 17181 Next_Discriminant (Disc); 17182 end if; 17183 end loop; 17184 17185 -- Could not find it 17186 17187 return Result; 17188 end Search_Derivation_Levels; 17189 17190 -- Local Variables 17191 17192 Result : Node_Or_Entity_Id; 17193 17194 -- Start of processing for Get_Discriminant_Value 17195 17196 begin 17197 -- ??? This routine is a gigantic mess and will be deleted. For the 17198 -- time being just test for the trivial case before calling recurse. 17199 17200 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then 17201 declare 17202 D : Entity_Id; 17203 E : Elmt_Id; 17204 17205 begin 17206 D := First_Discriminant (Typ_For_Constraint); 17207 E := First_Elmt (Constraint); 17208 while Present (D) loop 17209 if Chars (D) = Chars (Discriminant) then 17210 return Node (E); 17211 end if; 17212 17213 Next_Discriminant (D); 17214 Next_Elmt (E); 17215 end loop; 17216 end; 17217 end if; 17218 17219 Result := Search_Derivation_Levels 17220 (Typ_For_Constraint, Constraint, False); 17221 17222 -- ??? hack to disappear when this routine is gone 17223 17224 if Nkind (Result) = N_Defining_Identifier then 17225 declare 17226 D : Entity_Id; 17227 E : Elmt_Id; 17228 17229 begin 17230 D := First_Discriminant (Typ_For_Constraint); 17231 E := First_Elmt (Constraint); 17232 while Present (D) loop 17233 if Root_Corresponding_Discriminant (D) = Discriminant then 17234 return Node (E); 17235 end if; 17236 17237 Next_Discriminant (D); 17238 Next_Elmt (E); 17239 end loop; 17240 end; 17241 end if; 17242 17243 pragma Assert (Nkind (Result) /= N_Defining_Identifier); 17244 return Result; 17245 end Get_Discriminant_Value; 17246 17247 -------------------------- 17248 -- Has_Range_Constraint -- 17249 -------------------------- 17250 17251 function Has_Range_Constraint (N : Node_Id) return Boolean is 17252 C : constant Node_Id := Constraint (N); 17253 17254 begin 17255 if Nkind (C) = N_Range_Constraint then 17256 return True; 17257 17258 elsif Nkind (C) = N_Digits_Constraint then 17259 return 17260 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N))) 17261 or else Present (Range_Constraint (C)); 17262 17263 elsif Nkind (C) = N_Delta_Constraint then 17264 return Present (Range_Constraint (C)); 17265 17266 else 17267 return False; 17268 end if; 17269 end Has_Range_Constraint; 17270 17271 ------------------------ 17272 -- Inherit_Components -- 17273 ------------------------ 17274 17275 function Inherit_Components 17276 (N : Node_Id; 17277 Parent_Base : Entity_Id; 17278 Derived_Base : Entity_Id; 17279 Is_Tagged : Boolean; 17280 Inherit_Discr : Boolean; 17281 Discs : Elist_Id) return Elist_Id 17282 is 17283 Assoc_List : constant Elist_Id := New_Elmt_List; 17284 17285 procedure Inherit_Component 17286 (Old_C : Entity_Id; 17287 Plain_Discrim : Boolean := False; 17288 Stored_Discrim : Boolean := False); 17289 -- Inherits component Old_C from Parent_Base to the Derived_Base. If 17290 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is 17291 -- True, Old_C is a stored discriminant. If they are both false then 17292 -- Old_C is a regular component. 17293 17294 ----------------------- 17295 -- Inherit_Component -- 17296 ----------------------- 17297 17298 procedure Inherit_Component 17299 (Old_C : Entity_Id; 17300 Plain_Discrim : Boolean := False; 17301 Stored_Discrim : Boolean := False) 17302 is 17303 procedure Set_Anonymous_Type (Id : Entity_Id); 17304 -- Id denotes the entity of an access discriminant or anonymous 17305 -- access component. Set the type of Id to either the same type of 17306 -- Old_C or create a new one depending on whether the parent and 17307 -- the child types are in the same scope. 17308 17309 ------------------------ 17310 -- Set_Anonymous_Type -- 17311 ------------------------ 17312 17313 procedure Set_Anonymous_Type (Id : Entity_Id) is 17314 Old_Typ : constant Entity_Id := Etype (Old_C); 17315 17316 begin 17317 if Scope (Parent_Base) = Scope (Derived_Base) then 17318 Set_Etype (Id, Old_Typ); 17319 17320 -- The parent and the derived type are in two different scopes. 17321 -- Reuse the type of the original discriminant / component by 17322 -- copying it in order to preserve all attributes. 17323 17324 else 17325 declare 17326 Typ : constant Entity_Id := New_Copy (Old_Typ); 17327 17328 begin 17329 Set_Etype (Id, Typ); 17330 17331 -- Since we do not generate component declarations for 17332 -- inherited components, associate the itype with the 17333 -- derived type. 17334 17335 Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base)); 17336 Set_Scope (Typ, Derived_Base); 17337 end; 17338 end if; 17339 end Set_Anonymous_Type; 17340 17341 -- Local variables and constants 17342 17343 New_C : constant Entity_Id := New_Copy (Old_C); 17344 17345 Corr_Discrim : Entity_Id; 17346 Discrim : Entity_Id; 17347 17348 -- Start of processing for Inherit_Component 17349 17350 begin 17351 pragma Assert (not Is_Tagged or not Stored_Discrim); 17352 17353 Set_Parent (New_C, Parent (Old_C)); 17354 17355 -- Regular discriminants and components must be inserted in the scope 17356 -- of the Derived_Base. Do it here. 17357 17358 if not Stored_Discrim then 17359 Enter_Name (New_C); 17360 end if; 17361 17362 -- For tagged types the Original_Record_Component must point to 17363 -- whatever this field was pointing to in the parent type. This has 17364 -- already been achieved by the call to New_Copy above. 17365 17366 if not Is_Tagged then 17367 Set_Original_Record_Component (New_C, New_C); 17368 end if; 17369 17370 -- Set the proper type of an access discriminant 17371 17372 if Ekind (New_C) = E_Discriminant 17373 and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type 17374 then 17375 Set_Anonymous_Type (New_C); 17376 end if; 17377 17378 -- If we have inherited a component then see if its Etype contains 17379 -- references to Parent_Base discriminants. In this case, replace 17380 -- these references with the constraints given in Discs. We do not 17381 -- do this for the partial view of private types because this is 17382 -- not needed (only the components of the full view will be used 17383 -- for code generation) and cause problem. We also avoid this 17384 -- transformation in some error situations. 17385 17386 if Ekind (New_C) = E_Component then 17387 17388 -- Set the proper type of an anonymous access component 17389 17390 if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then 17391 Set_Anonymous_Type (New_C); 17392 17393 elsif (Is_Private_Type (Derived_Base) 17394 and then not Is_Generic_Type (Derived_Base)) 17395 or else (Is_Empty_Elmt_List (Discs) 17396 and then not Expander_Active) 17397 then 17398 Set_Etype (New_C, Etype (Old_C)); 17399 17400 else 17401 -- The current component introduces a circularity of the 17402 -- following kind: 17403 17404 -- limited with Pack_2; 17405 -- package Pack_1 is 17406 -- type T_1 is tagged record 17407 -- Comp : access Pack_2.T_2; 17408 -- ... 17409 -- end record; 17410 -- end Pack_1; 17411 17412 -- with Pack_1; 17413 -- package Pack_2 is 17414 -- type T_2 is new Pack_1.T_1 with ...; 17415 -- end Pack_2; 17416 17417 Set_Etype 17418 (New_C, 17419 Constrain_Component_Type 17420 (Old_C, Derived_Base, N, Parent_Base, Discs)); 17421 end if; 17422 end if; 17423 17424 -- In derived tagged types it is illegal to reference a non 17425 -- discriminant component in the parent type. To catch this, mark 17426 -- these components with an Ekind of E_Void. This will be reset in 17427 -- Record_Type_Definition after processing the record extension of 17428 -- the derived type. 17429 17430 -- If the declaration is a private extension, there is no further 17431 -- record extension to process, and the components retain their 17432 -- current kind, because they are visible at this point. 17433 17434 if Is_Tagged and then Ekind (New_C) = E_Component 17435 and then Nkind (N) /= N_Private_Extension_Declaration 17436 then 17437 Set_Ekind (New_C, E_Void); 17438 end if; 17439 17440 if Plain_Discrim then 17441 Set_Corresponding_Discriminant (New_C, Old_C); 17442 Build_Discriminal (New_C); 17443 17444 -- If we are explicitly inheriting a stored discriminant it will be 17445 -- completely hidden. 17446 17447 elsif Stored_Discrim then 17448 Set_Corresponding_Discriminant (New_C, Empty); 17449 Set_Discriminal (New_C, Empty); 17450 Set_Is_Completely_Hidden (New_C); 17451 17452 -- Set the Original_Record_Component of each discriminant in the 17453 -- derived base to point to the corresponding stored that we just 17454 -- created. 17455 17456 Discrim := First_Discriminant (Derived_Base); 17457 while Present (Discrim) loop 17458 Corr_Discrim := Corresponding_Discriminant (Discrim); 17459 17460 -- Corr_Discrim could be missing in an error situation 17461 17462 if Present (Corr_Discrim) 17463 and then Original_Record_Component (Corr_Discrim) = Old_C 17464 then 17465 Set_Original_Record_Component (Discrim, New_C); 17466 end if; 17467 17468 Next_Discriminant (Discrim); 17469 end loop; 17470 17471 Append_Entity (New_C, Derived_Base); 17472 end if; 17473 17474 if not Is_Tagged then 17475 Append_Elmt (Old_C, Assoc_List); 17476 Append_Elmt (New_C, Assoc_List); 17477 end if; 17478 end Inherit_Component; 17479 17480 -- Variables local to Inherit_Component 17481 17482 Loc : constant Source_Ptr := Sloc (N); 17483 17484 Parent_Discrim : Entity_Id; 17485 Stored_Discrim : Entity_Id; 17486 D : Entity_Id; 17487 Component : Entity_Id; 17488 17489 -- Start of processing for Inherit_Components 17490 17491 begin 17492 if not Is_Tagged then 17493 Append_Elmt (Parent_Base, Assoc_List); 17494 Append_Elmt (Derived_Base, Assoc_List); 17495 end if; 17496 17497 -- Inherit parent discriminants if needed 17498 17499 if Inherit_Discr then 17500 Parent_Discrim := First_Discriminant (Parent_Base); 17501 while Present (Parent_Discrim) loop 17502 Inherit_Component (Parent_Discrim, Plain_Discrim => True); 17503 Next_Discriminant (Parent_Discrim); 17504 end loop; 17505 end if; 17506 17507 -- Create explicit stored discrims for untagged types when necessary 17508 17509 if not Has_Unknown_Discriminants (Derived_Base) 17510 and then Has_Discriminants (Parent_Base) 17511 and then not Is_Tagged 17512 and then 17513 (not Inherit_Discr 17514 or else First_Discriminant (Parent_Base) /= 17515 First_Stored_Discriminant (Parent_Base)) 17516 then 17517 Stored_Discrim := First_Stored_Discriminant (Parent_Base); 17518 while Present (Stored_Discrim) loop 17519 Inherit_Component (Stored_Discrim, Stored_Discrim => True); 17520 Next_Stored_Discriminant (Stored_Discrim); 17521 end loop; 17522 end if; 17523 17524 -- See if we can apply the second transformation for derived types, as 17525 -- explained in point 6. in the comments above Build_Derived_Record_Type 17526 -- This is achieved by appending Derived_Base discriminants into Discs, 17527 -- which has the side effect of returning a non empty Discs list to the 17528 -- caller of Inherit_Components, which is what we want. This must be 17529 -- done for private derived types if there are explicit stored 17530 -- discriminants, to ensure that we can retrieve the values of the 17531 -- constraints provided in the ancestors. 17532 17533 if Inherit_Discr 17534 and then Is_Empty_Elmt_List (Discs) 17535 and then Present (First_Discriminant (Derived_Base)) 17536 and then 17537 (not Is_Private_Type (Derived_Base) 17538 or else Is_Completely_Hidden 17539 (First_Stored_Discriminant (Derived_Base)) 17540 or else Is_Generic_Type (Derived_Base)) 17541 then 17542 D := First_Discriminant (Derived_Base); 17543 while Present (D) loop 17544 Append_Elmt (New_Occurrence_Of (D, Loc), Discs); 17545 Next_Discriminant (D); 17546 end loop; 17547 end if; 17548 17549 -- Finally, inherit non-discriminant components unless they are not 17550 -- visible because defined or inherited from the full view of the 17551 -- parent. Don't inherit the _parent field of the parent type. 17552 17553 Component := First_Entity (Parent_Base); 17554 while Present (Component) loop 17555 17556 -- Ada 2005 (AI-251): Do not inherit components associated with 17557 -- secondary tags of the parent. 17558 17559 if Ekind (Component) = E_Component 17560 and then Present (Related_Type (Component)) 17561 then 17562 null; 17563 17564 elsif Ekind (Component) /= E_Component 17565 or else Chars (Component) = Name_uParent 17566 then 17567 null; 17568 17569 -- If the derived type is within the parent type's declarative 17570 -- region, then the components can still be inherited even though 17571 -- they aren't visible at this point. This can occur for cases 17572 -- such as within public child units where the components must 17573 -- become visible upon entering the child unit's private part. 17574 17575 elsif not Is_Visible_Component (Component) 17576 and then not In_Open_Scopes (Scope (Parent_Base)) 17577 then 17578 null; 17579 17580 elsif Ekind_In (Derived_Base, E_Private_Type, 17581 E_Limited_Private_Type) 17582 then 17583 null; 17584 17585 else 17586 Inherit_Component (Component); 17587 end if; 17588 17589 Next_Entity (Component); 17590 end loop; 17591 17592 -- For tagged derived types, inherited discriminants cannot be used in 17593 -- component declarations of the record extension part. To achieve this 17594 -- we mark the inherited discriminants as not visible. 17595 17596 if Is_Tagged and then Inherit_Discr then 17597 D := First_Discriminant (Derived_Base); 17598 while Present (D) loop 17599 Set_Is_Immediately_Visible (D, False); 17600 Next_Discriminant (D); 17601 end loop; 17602 end if; 17603 17604 return Assoc_List; 17605 end Inherit_Components; 17606 17607 ----------------------------- 17608 -- Inherit_Predicate_Flags -- 17609 ----------------------------- 17610 17611 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id) is 17612 begin 17613 Set_Has_Predicates (Subt, Has_Predicates (Par)); 17614 Set_Has_Static_Predicate_Aspect 17615 (Subt, Has_Static_Predicate_Aspect (Par)); 17616 Set_Has_Dynamic_Predicate_Aspect 17617 (Subt, Has_Dynamic_Predicate_Aspect (Par)); 17618 end Inherit_Predicate_Flags; 17619 17620 ---------------------- 17621 -- Is_EVF_Procedure -- 17622 ---------------------- 17623 17624 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean is 17625 Formal : Entity_Id; 17626 17627 begin 17628 -- Examine the formals of an Extensions_Visible False procedure looking 17629 -- for a controlling OUT parameter. 17630 17631 if Ekind (Subp) = E_Procedure 17632 and then Extensions_Visible_Status (Subp) = Extensions_Visible_False 17633 then 17634 Formal := First_Formal (Subp); 17635 while Present (Formal) loop 17636 if Ekind (Formal) = E_Out_Parameter 17637 and then Is_Controlling_Formal (Formal) 17638 then 17639 return True; 17640 end if; 17641 17642 Next_Formal (Formal); 17643 end loop; 17644 end if; 17645 17646 return False; 17647 end Is_EVF_Procedure; 17648 17649 ----------------------- 17650 -- Is_Null_Extension -- 17651 ----------------------- 17652 17653 function Is_Null_Extension (T : Entity_Id) return Boolean is 17654 Type_Decl : constant Node_Id := Parent (Base_Type (T)); 17655 Comp_List : Node_Id; 17656 Comp : Node_Id; 17657 17658 begin 17659 if Nkind (Type_Decl) /= N_Full_Type_Declaration 17660 or else not Is_Tagged_Type (T) 17661 or else Nkind (Type_Definition (Type_Decl)) /= 17662 N_Derived_Type_Definition 17663 or else No (Record_Extension_Part (Type_Definition (Type_Decl))) 17664 then 17665 return False; 17666 end if; 17667 17668 Comp_List := 17669 Component_List (Record_Extension_Part (Type_Definition (Type_Decl))); 17670 17671 if Present (Discriminant_Specifications (Type_Decl)) then 17672 return False; 17673 17674 elsif Present (Comp_List) 17675 and then Is_Non_Empty_List (Component_Items (Comp_List)) 17676 then 17677 Comp := First (Component_Items (Comp_List)); 17678 17679 -- Only user-defined components are relevant. The component list 17680 -- may also contain a parent component and internal components 17681 -- corresponding to secondary tags, but these do not determine 17682 -- whether this is a null extension. 17683 17684 while Present (Comp) loop 17685 if Comes_From_Source (Comp) then 17686 return False; 17687 end if; 17688 17689 Next (Comp); 17690 end loop; 17691 17692 return True; 17693 17694 else 17695 return True; 17696 end if; 17697 end Is_Null_Extension; 17698 17699 ------------------------------ 17700 -- Is_Valid_Constraint_Kind -- 17701 ------------------------------ 17702 17703 function Is_Valid_Constraint_Kind 17704 (T_Kind : Type_Kind; 17705 Constraint_Kind : Node_Kind) return Boolean 17706 is 17707 begin 17708 case T_Kind is 17709 when Enumeration_Kind | 17710 Integer_Kind => 17711 return Constraint_Kind = N_Range_Constraint; 17712 17713 when Decimal_Fixed_Point_Kind => 17714 return Nkind_In (Constraint_Kind, N_Digits_Constraint, 17715 N_Range_Constraint); 17716 17717 when Ordinary_Fixed_Point_Kind => 17718 return Nkind_In (Constraint_Kind, N_Delta_Constraint, 17719 N_Range_Constraint); 17720 17721 when Float_Kind => 17722 return Nkind_In (Constraint_Kind, N_Digits_Constraint, 17723 N_Range_Constraint); 17724 17725 when Access_Kind | 17726 Array_Kind | 17727 E_Record_Type | 17728 E_Record_Subtype | 17729 Class_Wide_Kind | 17730 E_Incomplete_Type | 17731 Private_Kind | 17732 Concurrent_Kind => 17733 return Constraint_Kind = N_Index_Or_Discriminant_Constraint; 17734 17735 when others => 17736 return True; -- Error will be detected later 17737 end case; 17738 end Is_Valid_Constraint_Kind; 17739 17740 -------------------------- 17741 -- Is_Visible_Component -- 17742 -------------------------- 17743 17744 function Is_Visible_Component 17745 (C : Entity_Id; 17746 N : Node_Id := Empty) return Boolean 17747 is 17748 Original_Comp : Entity_Id := Empty; 17749 Original_Scope : Entity_Id; 17750 Type_Scope : Entity_Id; 17751 17752 function Is_Local_Type (Typ : Entity_Id) return Boolean; 17753 -- Check whether parent type of inherited component is declared locally, 17754 -- possibly within a nested package or instance. The current scope is 17755 -- the derived record itself. 17756 17757 ------------------- 17758 -- Is_Local_Type -- 17759 ------------------- 17760 17761 function Is_Local_Type (Typ : Entity_Id) return Boolean is 17762 Scop : Entity_Id; 17763 17764 begin 17765 Scop := Scope (Typ); 17766 while Present (Scop) 17767 and then Scop /= Standard_Standard 17768 loop 17769 if Scop = Scope (Current_Scope) then 17770 return True; 17771 end if; 17772 17773 Scop := Scope (Scop); 17774 end loop; 17775 17776 return False; 17777 end Is_Local_Type; 17778 17779 -- Start of processing for Is_Visible_Component 17780 17781 begin 17782 if Ekind_In (C, E_Component, E_Discriminant) then 17783 Original_Comp := Original_Record_Component (C); 17784 end if; 17785 17786 if No (Original_Comp) then 17787 17788 -- Premature usage, or previous error 17789 17790 return False; 17791 17792 else 17793 Original_Scope := Scope (Original_Comp); 17794 Type_Scope := Scope (Base_Type (Scope (C))); 17795 end if; 17796 17797 -- This test only concerns tagged types 17798 17799 if not Is_Tagged_Type (Original_Scope) then 17800 return True; 17801 17802 -- If it is _Parent or _Tag, there is no visibility issue 17803 17804 elsif not Comes_From_Source (Original_Comp) then 17805 return True; 17806 17807 -- Discriminants are visible unless the (private) type has unknown 17808 -- discriminants. If the discriminant reference is inserted for a 17809 -- discriminant check on a full view it is also visible. 17810 17811 elsif Ekind (Original_Comp) = E_Discriminant 17812 and then 17813 (not Has_Unknown_Discriminants (Original_Scope) 17814 or else (Present (N) 17815 and then Nkind (N) = N_Selected_Component 17816 and then Nkind (Prefix (N)) = N_Type_Conversion 17817 and then not Comes_From_Source (Prefix (N)))) 17818 then 17819 return True; 17820 17821 -- In the body of an instantiation, no need to check for the visibility 17822 -- of a component. 17823 17824 elsif In_Instance_Body then 17825 return True; 17826 17827 -- If the component has been declared in an ancestor which is currently 17828 -- a private type, then it is not visible. The same applies if the 17829 -- component's containing type is not in an open scope and the original 17830 -- component's enclosing type is a visible full view of a private type 17831 -- (which can occur in cases where an attempt is being made to reference 17832 -- a component in a sibling package that is inherited from a visible 17833 -- component of a type in an ancestor package; the component in the 17834 -- sibling package should not be visible even though the component it 17835 -- inherited from is visible). This does not apply however in the case 17836 -- where the scope of the type is a private child unit, or when the 17837 -- parent comes from a local package in which the ancestor is currently 17838 -- visible. The latter suppression of visibility is needed for cases 17839 -- that are tested in B730006. 17840 17841 elsif Is_Private_Type (Original_Scope) 17842 or else 17843 (not Is_Private_Descendant (Type_Scope) 17844 and then not In_Open_Scopes (Type_Scope) 17845 and then Has_Private_Declaration (Original_Scope)) 17846 then 17847 -- If the type derives from an entity in a formal package, there 17848 -- are no additional visible components. 17849 17850 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) = 17851 N_Formal_Package_Declaration 17852 then 17853 return False; 17854 17855 -- if we are not in the private part of the current package, there 17856 -- are no additional visible components. 17857 17858 elsif Ekind (Scope (Current_Scope)) = E_Package 17859 and then not In_Private_Part (Scope (Current_Scope)) 17860 then 17861 return False; 17862 else 17863 return 17864 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit)) 17865 and then In_Open_Scopes (Scope (Original_Scope)) 17866 and then Is_Local_Type (Type_Scope); 17867 end if; 17868 17869 -- There is another weird way in which a component may be invisible when 17870 -- the private and the full view are not derived from the same ancestor. 17871 -- Here is an example : 17872 17873 -- type A1 is tagged record F1 : integer; end record; 17874 -- type A2 is new A1 with record F2 : integer; end record; 17875 -- type T is new A1 with private; 17876 -- private 17877 -- type T is new A2 with null record; 17878 17879 -- In this case, the full view of T inherits F1 and F2 but the private 17880 -- view inherits only F1 17881 17882 else 17883 declare 17884 Ancestor : Entity_Id := Scope (C); 17885 17886 begin 17887 loop 17888 if Ancestor = Original_Scope then 17889 return True; 17890 elsif Ancestor = Etype (Ancestor) then 17891 return False; 17892 end if; 17893 17894 Ancestor := Etype (Ancestor); 17895 end loop; 17896 end; 17897 end if; 17898 end Is_Visible_Component; 17899 17900 -------------------------- 17901 -- Make_Class_Wide_Type -- 17902 -------------------------- 17903 17904 procedure Make_Class_Wide_Type (T : Entity_Id) is 17905 CW_Type : Entity_Id; 17906 CW_Name : Name_Id; 17907 Next_E : Entity_Id; 17908 17909 begin 17910 if Present (Class_Wide_Type (T)) then 17911 17912 -- The class-wide type is a partially decorated entity created for a 17913 -- unanalyzed tagged type referenced through a limited with clause. 17914 -- When the tagged type is analyzed, its class-wide type needs to be 17915 -- redecorated. Note that we reuse the entity created by Decorate_ 17916 -- Tagged_Type in order to preserve all links. 17917 17918 if Materialize_Entity (Class_Wide_Type (T)) then 17919 CW_Type := Class_Wide_Type (T); 17920 Set_Materialize_Entity (CW_Type, False); 17921 17922 -- The class wide type can have been defined by the partial view, in 17923 -- which case everything is already done. 17924 17925 else 17926 return; 17927 end if; 17928 17929 -- Default case, we need to create a new class-wide type 17930 17931 else 17932 CW_Type := 17933 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T'); 17934 end if; 17935 17936 -- Inherit root type characteristics 17937 17938 CW_Name := Chars (CW_Type); 17939 Next_E := Next_Entity (CW_Type); 17940 Copy_Node (T, CW_Type); 17941 Set_Comes_From_Source (CW_Type, False); 17942 Set_Chars (CW_Type, CW_Name); 17943 Set_Parent (CW_Type, Parent (T)); 17944 Set_Next_Entity (CW_Type, Next_E); 17945 17946 -- Ensure we have a new freeze node for the class-wide type. The partial 17947 -- view may have freeze action of its own, requiring a proper freeze 17948 -- node, and the same freeze node cannot be shared between the two 17949 -- types. 17950 17951 Set_Has_Delayed_Freeze (CW_Type); 17952 Set_Freeze_Node (CW_Type, Empty); 17953 17954 -- Customize the class-wide type: It has no prim. op., it cannot be 17955 -- abstract and its Etype points back to the specific root type. 17956 17957 Set_Ekind (CW_Type, E_Class_Wide_Type); 17958 Set_Is_Tagged_Type (CW_Type, True); 17959 Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List); 17960 Set_Is_Abstract_Type (CW_Type, False); 17961 Set_Is_Constrained (CW_Type, False); 17962 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T)); 17963 Set_Default_SSO (CW_Type); 17964 17965 if Ekind (T) = E_Class_Wide_Subtype then 17966 Set_Etype (CW_Type, Etype (Base_Type (T))); 17967 else 17968 Set_Etype (CW_Type, T); 17969 end if; 17970 17971 Set_No_Tagged_Streams_Pragma (CW_Type, No_Tagged_Streams); 17972 17973 -- If this is the class_wide type of a constrained subtype, it does 17974 -- not have discriminants. 17975 17976 Set_Has_Discriminants (CW_Type, 17977 Has_Discriminants (T) and then not Is_Constrained (T)); 17978 17979 Set_Has_Unknown_Discriminants (CW_Type, True); 17980 Set_Class_Wide_Type (T, CW_Type); 17981 Set_Equivalent_Type (CW_Type, Empty); 17982 17983 -- The class-wide type of a class-wide type is itself (RM 3.9(14)) 17984 17985 Set_Class_Wide_Type (CW_Type, CW_Type); 17986 end Make_Class_Wide_Type; 17987 17988 ---------------- 17989 -- Make_Index -- 17990 ---------------- 17991 17992 procedure Make_Index 17993 (N : Node_Id; 17994 Related_Nod : Node_Id; 17995 Related_Id : Entity_Id := Empty; 17996 Suffix_Index : Nat := 1; 17997 In_Iter_Schm : Boolean := False) 17998 is 17999 R : Node_Id; 18000 T : Entity_Id; 18001 Def_Id : Entity_Id := Empty; 18002 Found : Boolean := False; 18003 18004 begin 18005 -- For a discrete range used in a constrained array definition and 18006 -- defined by a range, an implicit conversion to the predefined type 18007 -- INTEGER is assumed if each bound is either a numeric literal, a named 18008 -- number, or an attribute, and the type of both bounds (prior to the 18009 -- implicit conversion) is the type universal_integer. Otherwise, both 18010 -- bounds must be of the same discrete type, other than universal 18011 -- integer; this type must be determinable independently of the 18012 -- context, but using the fact that the type must be discrete and that 18013 -- both bounds must have the same type. 18014 18015 -- Character literals also have a universal type in the absence of 18016 -- of additional context, and are resolved to Standard_Character. 18017 18018 if Nkind (N) = N_Range then 18019 18020 -- The index is given by a range constraint. The bounds are known 18021 -- to be of a consistent type. 18022 18023 if not Is_Overloaded (N) then 18024 T := Etype (N); 18025 18026 -- For universal bounds, choose the specific predefined type 18027 18028 if T = Universal_Integer then 18029 T := Standard_Integer; 18030 18031 elsif T = Any_Character then 18032 Ambiguous_Character (Low_Bound (N)); 18033 18034 T := Standard_Character; 18035 end if; 18036 18037 -- The node may be overloaded because some user-defined operators 18038 -- are available, but if a universal interpretation exists it is 18039 -- also the selected one. 18040 18041 elsif Universal_Interpretation (N) = Universal_Integer then 18042 T := Standard_Integer; 18043 18044 else 18045 T := Any_Type; 18046 18047 declare 18048 Ind : Interp_Index; 18049 It : Interp; 18050 18051 begin 18052 Get_First_Interp (N, Ind, It); 18053 while Present (It.Typ) loop 18054 if Is_Discrete_Type (It.Typ) then 18055 18056 if Found 18057 and then not Covers (It.Typ, T) 18058 and then not Covers (T, It.Typ) 18059 then 18060 Error_Msg_N ("ambiguous bounds in discrete range", N); 18061 exit; 18062 else 18063 T := It.Typ; 18064 Found := True; 18065 end if; 18066 end if; 18067 18068 Get_Next_Interp (Ind, It); 18069 end loop; 18070 18071 if T = Any_Type then 18072 Error_Msg_N ("discrete type required for range", N); 18073 Set_Etype (N, Any_Type); 18074 return; 18075 18076 elsif T = Universal_Integer then 18077 T := Standard_Integer; 18078 end if; 18079 end; 18080 end if; 18081 18082 if not Is_Discrete_Type (T) then 18083 Error_Msg_N ("discrete type required for range", N); 18084 Set_Etype (N, Any_Type); 18085 return; 18086 end if; 18087 18088 if Nkind (Low_Bound (N)) = N_Attribute_Reference 18089 and then Attribute_Name (Low_Bound (N)) = Name_First 18090 and then Is_Entity_Name (Prefix (Low_Bound (N))) 18091 and then Is_Type (Entity (Prefix (Low_Bound (N)))) 18092 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (N)))) 18093 then 18094 -- The type of the index will be the type of the prefix, as long 18095 -- as the upper bound is 'Last of the same type. 18096 18097 Def_Id := Entity (Prefix (Low_Bound (N))); 18098 18099 if Nkind (High_Bound (N)) /= N_Attribute_Reference 18100 or else Attribute_Name (High_Bound (N)) /= Name_Last 18101 or else not Is_Entity_Name (Prefix (High_Bound (N))) 18102 or else Entity (Prefix (High_Bound (N))) /= Def_Id 18103 then 18104 Def_Id := Empty; 18105 end if; 18106 end if; 18107 18108 R := N; 18109 Process_Range_Expr_In_Decl (R, T, In_Iter_Schm => In_Iter_Schm); 18110 18111 elsif Nkind (N) = N_Subtype_Indication then 18112 18113 -- The index is given by a subtype with a range constraint 18114 18115 T := Base_Type (Entity (Subtype_Mark (N))); 18116 18117 if not Is_Discrete_Type (T) then 18118 Error_Msg_N ("discrete type required for range", N); 18119 Set_Etype (N, Any_Type); 18120 return; 18121 end if; 18122 18123 R := Range_Expression (Constraint (N)); 18124 18125 Resolve (R, T); 18126 Process_Range_Expr_In_Decl 18127 (R, Entity (Subtype_Mark (N)), In_Iter_Schm => In_Iter_Schm); 18128 18129 elsif Nkind (N) = N_Attribute_Reference then 18130 18131 -- Catch beginner's error (use of attribute other than 'Range) 18132 18133 if Attribute_Name (N) /= Name_Range then 18134 Error_Msg_N ("expect attribute ''Range", N); 18135 Set_Etype (N, Any_Type); 18136 return; 18137 end if; 18138 18139 -- If the node denotes the range of a type mark, that is also the 18140 -- resulting type, and we do not need to create an Itype for it. 18141 18142 if Is_Entity_Name (Prefix (N)) 18143 and then Comes_From_Source (N) 18144 and then Is_Type (Entity (Prefix (N))) 18145 and then Is_Discrete_Type (Entity (Prefix (N))) 18146 then 18147 Def_Id := Entity (Prefix (N)); 18148 end if; 18149 18150 Analyze_And_Resolve (N); 18151 T := Etype (N); 18152 R := N; 18153 18154 -- If none of the above, must be a subtype. We convert this to a 18155 -- range attribute reference because in the case of declared first 18156 -- named subtypes, the types in the range reference can be different 18157 -- from the type of the entity. A range attribute normalizes the 18158 -- reference and obtains the correct types for the bounds. 18159 18160 -- This transformation is in the nature of an expansion, is only 18161 -- done if expansion is active. In particular, it is not done on 18162 -- formal generic types, because we need to retain the name of the 18163 -- original index for instantiation purposes. 18164 18165 else 18166 if not Is_Entity_Name (N) or else not Is_Type (Entity (N)) then 18167 Error_Msg_N ("invalid subtype mark in discrete range ", N); 18168 Set_Etype (N, Any_Integer); 18169 return; 18170 18171 else 18172 -- The type mark may be that of an incomplete type. It is only 18173 -- now that we can get the full view, previous analysis does 18174 -- not look specifically for a type mark. 18175 18176 Set_Entity (N, Get_Full_View (Entity (N))); 18177 Set_Etype (N, Entity (N)); 18178 Def_Id := Entity (N); 18179 18180 if not Is_Discrete_Type (Def_Id) then 18181 Error_Msg_N ("discrete type required for index", N); 18182 Set_Etype (N, Any_Type); 18183 return; 18184 end if; 18185 end if; 18186 18187 if Expander_Active then 18188 Rewrite (N, 18189 Make_Attribute_Reference (Sloc (N), 18190 Attribute_Name => Name_Range, 18191 Prefix => Relocate_Node (N))); 18192 18193 -- The original was a subtype mark that does not freeze. This 18194 -- means that the rewritten version must not freeze either. 18195 18196 Set_Must_Not_Freeze (N); 18197 Set_Must_Not_Freeze (Prefix (N)); 18198 Analyze_And_Resolve (N); 18199 T := Etype (N); 18200 R := N; 18201 18202 -- If expander is inactive, type is legal, nothing else to construct 18203 18204 else 18205 return; 18206 end if; 18207 end if; 18208 18209 if not Is_Discrete_Type (T) then 18210 Error_Msg_N ("discrete type required for range", N); 18211 Set_Etype (N, Any_Type); 18212 return; 18213 18214 elsif T = Any_Type then 18215 Set_Etype (N, Any_Type); 18216 return; 18217 end if; 18218 18219 -- We will now create the appropriate Itype to describe the range, but 18220 -- first a check. If we originally had a subtype, then we just label 18221 -- the range with this subtype. Not only is there no need to construct 18222 -- a new subtype, but it is wrong to do so for two reasons: 18223 18224 -- 1. A legality concern, if we have a subtype, it must not freeze, 18225 -- and the Itype would cause freezing incorrectly 18226 18227 -- 2. An efficiency concern, if we created an Itype, it would not be 18228 -- recognized as the same type for the purposes of eliminating 18229 -- checks in some circumstances. 18230 18231 -- We signal this case by setting the subtype entity in Def_Id 18232 18233 if No (Def_Id) then 18234 Def_Id := 18235 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index); 18236 Set_Etype (Def_Id, Base_Type (T)); 18237 18238 if Is_Signed_Integer_Type (T) then 18239 Set_Ekind (Def_Id, E_Signed_Integer_Subtype); 18240 18241 elsif Is_Modular_Integer_Type (T) then 18242 Set_Ekind (Def_Id, E_Modular_Integer_Subtype); 18243 18244 else 18245 Set_Ekind (Def_Id, E_Enumeration_Subtype); 18246 Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); 18247 Set_First_Literal (Def_Id, First_Literal (T)); 18248 end if; 18249 18250 Set_Size_Info (Def_Id, (T)); 18251 Set_RM_Size (Def_Id, RM_Size (T)); 18252 Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); 18253 18254 Set_Scalar_Range (Def_Id, R); 18255 Conditional_Delay (Def_Id, T); 18256 18257 if Nkind (N) = N_Subtype_Indication then 18258 Inherit_Predicate_Flags (Def_Id, Entity (Subtype_Mark (N))); 18259 end if; 18260 18261 -- In the subtype indication case, if the immediate parent of the 18262 -- new subtype is non-static, then the subtype we create is non- 18263 -- static, even if its bounds are static. 18264 18265 if Nkind (N) = N_Subtype_Indication 18266 and then not Is_OK_Static_Subtype (Entity (Subtype_Mark (N))) 18267 then 18268 Set_Is_Non_Static_Subtype (Def_Id); 18269 end if; 18270 end if; 18271 18272 -- Final step is to label the index with this constructed type 18273 18274 Set_Etype (N, Def_Id); 18275 end Make_Index; 18276 18277 ------------------------------ 18278 -- Modular_Type_Declaration -- 18279 ------------------------------ 18280 18281 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is 18282 Mod_Expr : constant Node_Id := Expression (Def); 18283 M_Val : Uint; 18284 18285 procedure Set_Modular_Size (Bits : Int); 18286 -- Sets RM_Size to Bits, and Esize to normal word size above this 18287 18288 ---------------------- 18289 -- Set_Modular_Size -- 18290 ---------------------- 18291 18292 procedure Set_Modular_Size (Bits : Int) is 18293 begin 18294 Set_RM_Size (T, UI_From_Int (Bits)); 18295 18296 if Bits <= 8 then 18297 Init_Esize (T, 8); 18298 18299 elsif Bits <= 16 then 18300 Init_Esize (T, 16); 18301 18302 elsif Bits <= 32 then 18303 Init_Esize (T, 32); 18304 18305 else 18306 Init_Esize (T, System_Max_Binary_Modulus_Power); 18307 end if; 18308 18309 if not Non_Binary_Modulus (T) and then Esize (T) = RM_Size (T) then 18310 Set_Is_Known_Valid (T); 18311 end if; 18312 end Set_Modular_Size; 18313 18314 -- Start of processing for Modular_Type_Declaration 18315 18316 begin 18317 -- If the mod expression is (exactly) 2 * literal, where literal is 18318 -- 64 or less,then almost certainly the * was meant to be **. Warn. 18319 18320 if Warn_On_Suspicious_Modulus_Value 18321 and then Nkind (Mod_Expr) = N_Op_Multiply 18322 and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal 18323 and then Intval (Left_Opnd (Mod_Expr)) = Uint_2 18324 and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal 18325 and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64 18326 then 18327 Error_Msg_N 18328 ("suspicious MOD value, was '*'* intended'??M?", Mod_Expr); 18329 end if; 18330 18331 -- Proceed with analysis of mod expression 18332 18333 Analyze_And_Resolve (Mod_Expr, Any_Integer); 18334 Set_Etype (T, T); 18335 Set_Ekind (T, E_Modular_Integer_Type); 18336 Init_Alignment (T); 18337 Set_Is_Constrained (T); 18338 18339 if not Is_OK_Static_Expression (Mod_Expr) then 18340 Flag_Non_Static_Expr 18341 ("non-static expression used for modular type bound!", Mod_Expr); 18342 M_Val := 2 ** System_Max_Binary_Modulus_Power; 18343 else 18344 M_Val := Expr_Value (Mod_Expr); 18345 end if; 18346 18347 if M_Val < 1 then 18348 Error_Msg_N ("modulus value must be positive", Mod_Expr); 18349 M_Val := 2 ** System_Max_Binary_Modulus_Power; 18350 end if; 18351 18352 if M_Val > 2 ** Standard_Long_Integer_Size then 18353 Check_Restriction (No_Long_Long_Integers, Mod_Expr); 18354 end if; 18355 18356 Set_Modulus (T, M_Val); 18357 18358 -- Create bounds for the modular type based on the modulus given in 18359 -- the type declaration and then analyze and resolve those bounds. 18360 18361 Set_Scalar_Range (T, 18362 Make_Range (Sloc (Mod_Expr), 18363 Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0), 18364 High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1))); 18365 18366 -- Properly analyze the literals for the range. We do this manually 18367 -- because we can't go calling Resolve, since we are resolving these 18368 -- bounds with the type, and this type is certainly not complete yet. 18369 18370 Set_Etype (Low_Bound (Scalar_Range (T)), T); 18371 Set_Etype (High_Bound (Scalar_Range (T)), T); 18372 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T))); 18373 Set_Is_Static_Expression (High_Bound (Scalar_Range (T))); 18374 18375 -- Loop through powers of two to find number of bits required 18376 18377 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop 18378 18379 -- Binary case 18380 18381 if M_Val = 2 ** Bits then 18382 Set_Modular_Size (Bits); 18383 return; 18384 18385 -- Non-binary case 18386 18387 elsif M_Val < 2 ** Bits then 18388 Check_SPARK_05_Restriction ("modulus should be a power of 2", T); 18389 Set_Non_Binary_Modulus (T); 18390 18391 if Bits > System_Max_Nonbinary_Modulus_Power then 18392 Error_Msg_Uint_1 := 18393 UI_From_Int (System_Max_Nonbinary_Modulus_Power); 18394 Error_Msg_F 18395 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr); 18396 Set_Modular_Size (System_Max_Binary_Modulus_Power); 18397 return; 18398 18399 else 18400 -- In the non-binary case, set size as per RM 13.3(55) 18401 18402 Set_Modular_Size (Bits); 18403 return; 18404 end if; 18405 end if; 18406 18407 end loop; 18408 18409 -- If we fall through, then the size exceed System.Max_Binary_Modulus 18410 -- so we just signal an error and set the maximum size. 18411 18412 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power); 18413 Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr); 18414 18415 Set_Modular_Size (System_Max_Binary_Modulus_Power); 18416 Init_Alignment (T); 18417 18418 end Modular_Type_Declaration; 18419 18420 -------------------------- 18421 -- New_Concatenation_Op -- 18422 -------------------------- 18423 18424 procedure New_Concatenation_Op (Typ : Entity_Id) is 18425 Loc : constant Source_Ptr := Sloc (Typ); 18426 Op : Entity_Id; 18427 18428 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id; 18429 -- Create abbreviated declaration for the formal of a predefined 18430 -- Operator 'Op' of type 'Typ' 18431 18432 -------------------- 18433 -- Make_Op_Formal -- 18434 -------------------- 18435 18436 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is 18437 Formal : Entity_Id; 18438 begin 18439 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P'); 18440 Set_Etype (Formal, Typ); 18441 Set_Mechanism (Formal, Default_Mechanism); 18442 return Formal; 18443 end Make_Op_Formal; 18444 18445 -- Start of processing for New_Concatenation_Op 18446 18447 begin 18448 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat); 18449 18450 Set_Ekind (Op, E_Operator); 18451 Set_Scope (Op, Current_Scope); 18452 Set_Etype (Op, Typ); 18453 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat)); 18454 Set_Is_Immediately_Visible (Op); 18455 Set_Is_Intrinsic_Subprogram (Op); 18456 Set_Has_Completion (Op); 18457 Append_Entity (Op, Current_Scope); 18458 18459 Set_Name_Entity_Id (Name_Op_Concat, Op); 18460 18461 Append_Entity (Make_Op_Formal (Typ, Op), Op); 18462 Append_Entity (Make_Op_Formal (Typ, Op), Op); 18463 end New_Concatenation_Op; 18464 18465 ------------------------- 18466 -- OK_For_Limited_Init -- 18467 ------------------------- 18468 18469 -- ???Check all calls of this, and compare the conditions under which it's 18470 -- called. 18471 18472 function OK_For_Limited_Init 18473 (Typ : Entity_Id; 18474 Exp : Node_Id) return Boolean 18475 is 18476 begin 18477 return Is_CPP_Constructor_Call (Exp) 18478 or else (Ada_Version >= Ada_2005 18479 and then not Debug_Flag_Dot_L 18480 and then OK_For_Limited_Init_In_05 (Typ, Exp)); 18481 end OK_For_Limited_Init; 18482 18483 ------------------------------- 18484 -- OK_For_Limited_Init_In_05 -- 18485 ------------------------------- 18486 18487 function OK_For_Limited_Init_In_05 18488 (Typ : Entity_Id; 18489 Exp : Node_Id) return Boolean 18490 is 18491 begin 18492 -- An object of a limited interface type can be initialized with any 18493 -- expression of a nonlimited descendant type. 18494 18495 if Is_Class_Wide_Type (Typ) 18496 and then Is_Limited_Interface (Typ) 18497 and then not Is_Limited_Type (Etype (Exp)) 18498 then 18499 return True; 18500 end if; 18501 18502 -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in 18503 -- case of limited aggregates (including extension aggregates), and 18504 -- function calls. The function call may have been given in prefixed 18505 -- notation, in which case the original node is an indexed component. 18506 -- If the function is parameterless, the original node was an explicit 18507 -- dereference. The function may also be parameterless, in which case 18508 -- the source node is just an identifier. 18509 18510 case Nkind (Original_Node (Exp)) is 18511 when N_Aggregate | N_Extension_Aggregate | N_Function_Call | N_Op => 18512 return True; 18513 18514 when N_Identifier => 18515 return Present (Entity (Original_Node (Exp))) 18516 and then Ekind (Entity (Original_Node (Exp))) = E_Function; 18517 18518 when N_Qualified_Expression => 18519 return 18520 OK_For_Limited_Init_In_05 18521 (Typ, Expression (Original_Node (Exp))); 18522 18523 -- Ada 2005 (AI-251): If a class-wide interface object is initialized 18524 -- with a function call, the expander has rewritten the call into an 18525 -- N_Type_Conversion node to force displacement of the pointer to 18526 -- reference the component containing the secondary dispatch table. 18527 -- Otherwise a type conversion is not a legal context. 18528 -- A return statement for a build-in-place function returning a 18529 -- synchronized type also introduces an unchecked conversion. 18530 18531 when N_Type_Conversion | 18532 N_Unchecked_Type_Conversion => 18533 return not Comes_From_Source (Exp) 18534 and then 18535 OK_For_Limited_Init_In_05 18536 (Typ, Expression (Original_Node (Exp))); 18537 18538 when N_Indexed_Component | 18539 N_Selected_Component | 18540 N_Explicit_Dereference => 18541 return Nkind (Exp) = N_Function_Call; 18542 18543 -- A use of 'Input is a function call, hence allowed. Normally the 18544 -- attribute will be changed to a call, but the attribute by itself 18545 -- can occur with -gnatc. 18546 18547 when N_Attribute_Reference => 18548 return Attribute_Name (Original_Node (Exp)) = Name_Input; 18549 18550 -- For a case expression, all dependent expressions must be legal 18551 18552 when N_Case_Expression => 18553 declare 18554 Alt : Node_Id; 18555 18556 begin 18557 Alt := First (Alternatives (Original_Node (Exp))); 18558 while Present (Alt) loop 18559 if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then 18560 return False; 18561 end if; 18562 18563 Next (Alt); 18564 end loop; 18565 18566 return True; 18567 end; 18568 18569 -- For an if expression, all dependent expressions must be legal 18570 18571 when N_If_Expression => 18572 declare 18573 Then_Expr : constant Node_Id := 18574 Next (First (Expressions (Original_Node (Exp)))); 18575 Else_Expr : constant Node_Id := Next (Then_Expr); 18576 begin 18577 return OK_For_Limited_Init_In_05 (Typ, Then_Expr) 18578 and then 18579 OK_For_Limited_Init_In_05 (Typ, Else_Expr); 18580 end; 18581 18582 when others => 18583 return False; 18584 end case; 18585 end OK_For_Limited_Init_In_05; 18586 18587 ------------------------------------------- 18588 -- Ordinary_Fixed_Point_Type_Declaration -- 18589 ------------------------------------------- 18590 18591 procedure Ordinary_Fixed_Point_Type_Declaration 18592 (T : Entity_Id; 18593 Def : Node_Id) 18594 is 18595 Loc : constant Source_Ptr := Sloc (Def); 18596 Delta_Expr : constant Node_Id := Delta_Expression (Def); 18597 RRS : constant Node_Id := Real_Range_Specification (Def); 18598 Implicit_Base : Entity_Id; 18599 Delta_Val : Ureal; 18600 Small_Val : Ureal; 18601 Low_Val : Ureal; 18602 High_Val : Ureal; 18603 18604 begin 18605 Check_Restriction (No_Fixed_Point, Def); 18606 18607 -- Create implicit base type 18608 18609 Implicit_Base := 18610 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B'); 18611 Set_Etype (Implicit_Base, Implicit_Base); 18612 18613 -- Analyze and process delta expression 18614 18615 Analyze_And_Resolve (Delta_Expr, Any_Real); 18616 18617 Check_Delta_Expression (Delta_Expr); 18618 Delta_Val := Expr_Value_R (Delta_Expr); 18619 18620 Set_Delta_Value (Implicit_Base, Delta_Val); 18621 18622 -- Compute default small from given delta, which is the largest power 18623 -- of two that does not exceed the given delta value. 18624 18625 declare 18626 Tmp : Ureal; 18627 Scale : Int; 18628 18629 begin 18630 Tmp := Ureal_1; 18631 Scale := 0; 18632 18633 if Delta_Val < Ureal_1 then 18634 while Delta_Val < Tmp loop 18635 Tmp := Tmp / Ureal_2; 18636 Scale := Scale + 1; 18637 end loop; 18638 18639 else 18640 loop 18641 Tmp := Tmp * Ureal_2; 18642 exit when Tmp > Delta_Val; 18643 Scale := Scale - 1; 18644 end loop; 18645 end if; 18646 18647 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2); 18648 end; 18649 18650 Set_Small_Value (Implicit_Base, Small_Val); 18651 18652 -- If no range was given, set a dummy range 18653 18654 if RRS <= Empty_Or_Error then 18655 Low_Val := -Small_Val; 18656 High_Val := Small_Val; 18657 18658 -- Otherwise analyze and process given range 18659 18660 else 18661 declare 18662 Low : constant Node_Id := Low_Bound (RRS); 18663 High : constant Node_Id := High_Bound (RRS); 18664 18665 begin 18666 Analyze_And_Resolve (Low, Any_Real); 18667 Analyze_And_Resolve (High, Any_Real); 18668 Check_Real_Bound (Low); 18669 Check_Real_Bound (High); 18670 18671 -- Obtain and set the range 18672 18673 Low_Val := Expr_Value_R (Low); 18674 High_Val := Expr_Value_R (High); 18675 18676 if Low_Val > High_Val then 18677 Error_Msg_NE ("??fixed point type& has null range", Def, T); 18678 end if; 18679 end; 18680 end if; 18681 18682 -- The range for both the implicit base and the declared first subtype 18683 -- cannot be set yet, so we use the special routine Set_Fixed_Range to 18684 -- set a temporary range in place. Note that the bounds of the base 18685 -- type will be widened to be symmetrical and to fill the available 18686 -- bits when the type is frozen. 18687 18688 -- We could do this with all discrete types, and probably should, but 18689 -- we absolutely have to do it for fixed-point, since the end-points 18690 -- of the range and the size are determined by the small value, which 18691 -- could be reset before the freeze point. 18692 18693 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val); 18694 Set_Fixed_Range (T, Loc, Low_Val, High_Val); 18695 18696 -- Complete definition of first subtype. The inheritance of the rep item 18697 -- chain ensures that SPARK-related pragmas are not clobbered when the 18698 -- ordinary fixed point type acts as a full view of a private type. 18699 18700 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype); 18701 Set_Etype (T, Implicit_Base); 18702 Init_Size_Align (T); 18703 Inherit_Rep_Item_Chain (T, Implicit_Base); 18704 Set_Small_Value (T, Small_Val); 18705 Set_Delta_Value (T, Delta_Val); 18706 Set_Is_Constrained (T); 18707 end Ordinary_Fixed_Point_Type_Declaration; 18708 18709 ---------------------------------- 18710 -- Preanalyze_Assert_Expression -- 18711 ---------------------------------- 18712 18713 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is 18714 begin 18715 In_Assertion_Expr := In_Assertion_Expr + 1; 18716 Preanalyze_Spec_Expression (N, T); 18717 In_Assertion_Expr := In_Assertion_Expr - 1; 18718 end Preanalyze_Assert_Expression; 18719 18720 ----------------------------------- 18721 -- Preanalyze_Default_Expression -- 18722 ----------------------------------- 18723 18724 procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id) is 18725 Save_In_Default_Expr : constant Boolean := In_Default_Expr; 18726 begin 18727 In_Default_Expr := True; 18728 Preanalyze_Spec_Expression (N, T); 18729 In_Default_Expr := Save_In_Default_Expr; 18730 end Preanalyze_Default_Expression; 18731 18732 -------------------------------- 18733 -- Preanalyze_Spec_Expression -- 18734 -------------------------------- 18735 18736 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is 18737 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression; 18738 begin 18739 In_Spec_Expression := True; 18740 Preanalyze_And_Resolve (N, T); 18741 In_Spec_Expression := Save_In_Spec_Expression; 18742 end Preanalyze_Spec_Expression; 18743 18744 ---------------------------------------- 18745 -- Prepare_Private_Subtype_Completion -- 18746 ---------------------------------------- 18747 18748 procedure Prepare_Private_Subtype_Completion 18749 (Id : Entity_Id; 18750 Related_Nod : Node_Id) 18751 is 18752 Id_B : constant Entity_Id := Base_Type (Id); 18753 Full_B : Entity_Id := Full_View (Id_B); 18754 Full : Entity_Id; 18755 18756 begin 18757 if Present (Full_B) then 18758 18759 -- Get to the underlying full view if necessary 18760 18761 if Is_Private_Type (Full_B) 18762 and then Present (Underlying_Full_View (Full_B)) 18763 then 18764 Full_B := Underlying_Full_View (Full_B); 18765 end if; 18766 18767 -- The Base_Type is already completed, we can complete the subtype 18768 -- now. We have to create a new entity with the same name, Thus we 18769 -- can't use Create_Itype. 18770 18771 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id)); 18772 Set_Is_Itype (Full); 18773 Set_Associated_Node_For_Itype (Full, Related_Nod); 18774 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod); 18775 end if; 18776 18777 -- The parent subtype may be private, but the base might not, in some 18778 -- nested instances. In that case, the subtype does not need to be 18779 -- exchanged. It would still be nice to make private subtypes and their 18780 -- bases consistent at all times ??? 18781 18782 if Is_Private_Type (Id_B) then 18783 Append_Elmt (Id, Private_Dependents (Id_B)); 18784 end if; 18785 end Prepare_Private_Subtype_Completion; 18786 18787 --------------------------- 18788 -- Process_Discriminants -- 18789 --------------------------- 18790 18791 procedure Process_Discriminants 18792 (N : Node_Id; 18793 Prev : Entity_Id := Empty) 18794 is 18795 Elist : constant Elist_Id := New_Elmt_List; 18796 Id : Node_Id; 18797 Discr : Node_Id; 18798 Discr_Number : Uint; 18799 Discr_Type : Entity_Id; 18800 Default_Present : Boolean := False; 18801 Default_Not_Present : Boolean := False; 18802 18803 begin 18804 -- A composite type other than an array type can have discriminants. 18805 -- On entry, the current scope is the composite type. 18806 18807 -- The discriminants are initially entered into the scope of the type 18808 -- via Enter_Name with the default Ekind of E_Void to prevent premature 18809 -- use, as explained at the end of this procedure. 18810 18811 Discr := First (Discriminant_Specifications (N)); 18812 while Present (Discr) loop 18813 Enter_Name (Defining_Identifier (Discr)); 18814 18815 -- For navigation purposes we add a reference to the discriminant 18816 -- in the entity for the type. If the current declaration is a 18817 -- completion, place references on the partial view. Otherwise the 18818 -- type is the current scope. 18819 18820 if Present (Prev) then 18821 18822 -- The references go on the partial view, if present. If the 18823 -- partial view has discriminants, the references have been 18824 -- generated already. 18825 18826 if not Has_Discriminants (Prev) then 18827 Generate_Reference (Prev, Defining_Identifier (Discr), 'd'); 18828 end if; 18829 else 18830 Generate_Reference 18831 (Current_Scope, Defining_Identifier (Discr), 'd'); 18832 end if; 18833 18834 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then 18835 Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr)); 18836 18837 -- Ada 2005 (AI-254) 18838 18839 if Present (Access_To_Subprogram_Definition 18840 (Discriminant_Type (Discr))) 18841 and then Protected_Present (Access_To_Subprogram_Definition 18842 (Discriminant_Type (Discr))) 18843 then 18844 Discr_Type := 18845 Replace_Anonymous_Access_To_Protected_Subprogram (Discr); 18846 end if; 18847 18848 else 18849 Find_Type (Discriminant_Type (Discr)); 18850 Discr_Type := Etype (Discriminant_Type (Discr)); 18851 18852 if Error_Posted (Discriminant_Type (Discr)) then 18853 Discr_Type := Any_Type; 18854 end if; 18855 end if; 18856 18857 -- Handling of discriminants that are access types 18858 18859 if Is_Access_Type (Discr_Type) then 18860 18861 -- Ada 2005 (AI-230): Access discriminant allowed in non- 18862 -- limited record types 18863 18864 if Ada_Version < Ada_2005 then 18865 Check_Access_Discriminant_Requires_Limited 18866 (Discr, Discriminant_Type (Discr)); 18867 end if; 18868 18869 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then 18870 Error_Msg_N 18871 ("(Ada 83) access discriminant not allowed", Discr); 18872 end if; 18873 18874 -- If not access type, must be a discrete type 18875 18876 elsif not Is_Discrete_Type (Discr_Type) then 18877 Error_Msg_N 18878 ("discriminants must have a discrete or access type", 18879 Discriminant_Type (Discr)); 18880 end if; 18881 18882 Set_Etype (Defining_Identifier (Discr), Discr_Type); 18883 18884 -- If a discriminant specification includes the assignment compound 18885 -- delimiter followed by an expression, the expression is the default 18886 -- expression of the discriminant; the default expression must be of 18887 -- the type of the discriminant. (RM 3.7.1) Since this expression is 18888 -- a default expression, we do the special preanalysis, since this 18889 -- expression does not freeze (see section "Handling of Default and 18890 -- Per-Object Expressions" in spec of package Sem). 18891 18892 if Present (Expression (Discr)) then 18893 Preanalyze_Spec_Expression (Expression (Discr), Discr_Type); 18894 18895 -- Legaity checks 18896 18897 if Nkind (N) = N_Formal_Type_Declaration then 18898 Error_Msg_N 18899 ("discriminant defaults not allowed for formal type", 18900 Expression (Discr)); 18901 18902 -- Flag an error for a tagged type with defaulted discriminants, 18903 -- excluding limited tagged types when compiling for Ada 2012 18904 -- (see AI05-0214). 18905 18906 elsif Is_Tagged_Type (Current_Scope) 18907 and then (not Is_Limited_Type (Current_Scope) 18908 or else Ada_Version < Ada_2012) 18909 and then Comes_From_Source (N) 18910 then 18911 -- Note: see similar test in Check_Or_Process_Discriminants, to 18912 -- handle the (illegal) case of the completion of an untagged 18913 -- view with discriminants with defaults by a tagged full view. 18914 -- We skip the check if Discr does not come from source, to 18915 -- account for the case of an untagged derived type providing 18916 -- defaults for a renamed discriminant from a private untagged 18917 -- ancestor with a tagged full view (ACATS B460006). 18918 18919 if Ada_Version >= Ada_2012 then 18920 Error_Msg_N 18921 ("discriminants of nonlimited tagged type cannot have" 18922 & " defaults", 18923 Expression (Discr)); 18924 else 18925 Error_Msg_N 18926 ("discriminants of tagged type cannot have defaults", 18927 Expression (Discr)); 18928 end if; 18929 18930 else 18931 Default_Present := True; 18932 Append_Elmt (Expression (Discr), Elist); 18933 18934 -- Tag the defining identifiers for the discriminants with 18935 -- their corresponding default expressions from the tree. 18936 18937 Set_Discriminant_Default_Value 18938 (Defining_Identifier (Discr), Expression (Discr)); 18939 end if; 18940 18941 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag 18942 -- gets set unless we can be sure that no range check is required. 18943 18944 if (GNATprove_Mode or not Expander_Active) 18945 and then not 18946 Is_In_Range 18947 (Expression (Discr), Discr_Type, Assume_Valid => True) 18948 then 18949 Set_Do_Range_Check (Expression (Discr)); 18950 end if; 18951 18952 -- No default discriminant value given 18953 18954 else 18955 Default_Not_Present := True; 18956 end if; 18957 18958 -- Ada 2005 (AI-231): Create an Itype that is a duplicate of 18959 -- Discr_Type but with the null-exclusion attribute 18960 18961 if Ada_Version >= Ada_2005 then 18962 18963 -- Ada 2005 (AI-231): Static checks 18964 18965 if Can_Never_Be_Null (Discr_Type) then 18966 Null_Exclusion_Static_Checks (Discr); 18967 18968 elsif Is_Access_Type (Discr_Type) 18969 and then Null_Exclusion_Present (Discr) 18970 18971 -- No need to check itypes because in their case this check 18972 -- was done at their point of creation 18973 18974 and then not Is_Itype (Discr_Type) 18975 then 18976 if Can_Never_Be_Null (Discr_Type) then 18977 Error_Msg_NE 18978 ("`NOT NULL` not allowed (& already excludes null)", 18979 Discr, 18980 Discr_Type); 18981 end if; 18982 18983 Set_Etype (Defining_Identifier (Discr), 18984 Create_Null_Excluding_Itype 18985 (T => Discr_Type, 18986 Related_Nod => Discr)); 18987 18988 -- Check for improper null exclusion if the type is otherwise 18989 -- legal for a discriminant. 18990 18991 elsif Null_Exclusion_Present (Discr) 18992 and then Is_Discrete_Type (Discr_Type) 18993 then 18994 Error_Msg_N 18995 ("null exclusion can only apply to an access type", Discr); 18996 end if; 18997 18998 -- Ada 2005 (AI-402): access discriminants of nonlimited types 18999 -- can't have defaults. Synchronized types, or types that are 19000 -- explicitly limited are fine, but special tests apply to derived 19001 -- types in generics: in a generic body we have to assume the 19002 -- worst, and therefore defaults are not allowed if the parent is 19003 -- a generic formal private type (see ACATS B370001). 19004 19005 if Is_Access_Type (Discr_Type) and then Default_Present then 19006 if Ekind (Discr_Type) /= E_Anonymous_Access_Type 19007 or else Is_Limited_Record (Current_Scope) 19008 or else Is_Concurrent_Type (Current_Scope) 19009 or else Is_Concurrent_Record_Type (Current_Scope) 19010 or else Ekind (Current_Scope) = E_Limited_Private_Type 19011 then 19012 if not Is_Derived_Type (Current_Scope) 19013 or else not Is_Generic_Type (Etype (Current_Scope)) 19014 or else not In_Package_Body (Scope (Etype (Current_Scope))) 19015 or else Limited_Present 19016 (Type_Definition (Parent (Current_Scope))) 19017 then 19018 null; 19019 19020 else 19021 Error_Msg_N 19022 ("access discriminants of nonlimited types cannot " 19023 & "have defaults", Expression (Discr)); 19024 end if; 19025 19026 elsif Present (Expression (Discr)) then 19027 Error_Msg_N 19028 ("(Ada 2005) access discriminants of nonlimited types " 19029 & "cannot have defaults", Expression (Discr)); 19030 end if; 19031 end if; 19032 end if; 19033 19034 -- A discriminant cannot be effectively volatile. This check is only 19035 -- relevant when SPARK_Mode is on as it is not standard Ada legality 19036 -- rule (SPARK RM 7.1.3(6)). 19037 19038 if SPARK_Mode = On 19039 and then Is_Effectively_Volatile (Defining_Identifier (Discr)) 19040 then 19041 Error_Msg_N ("discriminant cannot be volatile", Discr); 19042 end if; 19043 19044 Next (Discr); 19045 end loop; 19046 19047 -- An element list consisting of the default expressions of the 19048 -- discriminants is constructed in the above loop and used to set 19049 -- the Discriminant_Constraint attribute for the type. If an object 19050 -- is declared of this (record or task) type without any explicit 19051 -- discriminant constraint given, this element list will form the 19052 -- actual parameters for the corresponding initialization procedure 19053 -- for the type. 19054 19055 Set_Discriminant_Constraint (Current_Scope, Elist); 19056 Set_Stored_Constraint (Current_Scope, No_Elist); 19057 19058 -- Default expressions must be provided either for all or for none 19059 -- of the discriminants of a discriminant part. (RM 3.7.1) 19060 19061 if Default_Present and then Default_Not_Present then 19062 Error_Msg_N 19063 ("incomplete specification of defaults for discriminants", N); 19064 end if; 19065 19066 -- The use of the name of a discriminant is not allowed in default 19067 -- expressions of a discriminant part if the specification of the 19068 -- discriminant is itself given in the discriminant part. (RM 3.7.1) 19069 19070 -- To detect this, the discriminant names are entered initially with an 19071 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any 19072 -- attempt to use a void entity (for example in an expression that is 19073 -- type-checked) produces the error message: premature usage. Now after 19074 -- completing the semantic analysis of the discriminant part, we can set 19075 -- the Ekind of all the discriminants appropriately. 19076 19077 Discr := First (Discriminant_Specifications (N)); 19078 Discr_Number := Uint_1; 19079 while Present (Discr) loop 19080 Id := Defining_Identifier (Discr); 19081 Set_Ekind (Id, E_Discriminant); 19082 Init_Component_Location (Id); 19083 Init_Esize (Id); 19084 Set_Discriminant_Number (Id, Discr_Number); 19085 19086 -- Make sure this is always set, even in illegal programs 19087 19088 Set_Corresponding_Discriminant (Id, Empty); 19089 19090 -- Initialize the Original_Record_Component to the entity itself. 19091 -- Inherit_Components will propagate the right value to 19092 -- discriminants in derived record types. 19093 19094 Set_Original_Record_Component (Id, Id); 19095 19096 -- Create the discriminal for the discriminant 19097 19098 Build_Discriminal (Id); 19099 19100 Next (Discr); 19101 Discr_Number := Discr_Number + 1; 19102 end loop; 19103 19104 Set_Has_Discriminants (Current_Scope); 19105 end Process_Discriminants; 19106 19107 ----------------------- 19108 -- Process_Full_View -- 19109 ----------------------- 19110 19111 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is 19112 procedure Collect_Implemented_Interfaces 19113 (Typ : Entity_Id; 19114 Ifaces : Elist_Id); 19115 -- Ada 2005: Gather all the interfaces that Typ directly or 19116 -- inherently implements. Duplicate entries are not added to 19117 -- the list Ifaces. 19118 19119 ------------------------------------ 19120 -- Collect_Implemented_Interfaces -- 19121 ------------------------------------ 19122 19123 procedure Collect_Implemented_Interfaces 19124 (Typ : Entity_Id; 19125 Ifaces : Elist_Id) 19126 is 19127 Iface : Entity_Id; 19128 Iface_Elmt : Elmt_Id; 19129 19130 begin 19131 -- Abstract interfaces are only associated with tagged record types 19132 19133 if not Is_Tagged_Type (Typ) or else not Is_Record_Type (Typ) then 19134 return; 19135 end if; 19136 19137 -- Recursively climb to the ancestors 19138 19139 if Etype (Typ) /= Typ 19140 19141 -- Protect the frontend against wrong cyclic declarations like: 19142 19143 -- type B is new A with private; 19144 -- type C is new A with private; 19145 -- private 19146 -- type B is new C with null record; 19147 -- type C is new B with null record; 19148 19149 and then Etype (Typ) /= Priv_T 19150 and then Etype (Typ) /= Full_T 19151 then 19152 -- Keep separate the management of private type declarations 19153 19154 if Ekind (Typ) = E_Record_Type_With_Private then 19155 19156 -- Handle the following illegal usage: 19157 -- type Private_Type is tagged private; 19158 -- private 19159 -- type Private_Type is new Type_Implementing_Iface; 19160 19161 if Present (Full_View (Typ)) 19162 and then Etype (Typ) /= Full_View (Typ) 19163 then 19164 if Is_Interface (Etype (Typ)) then 19165 Append_Unique_Elmt (Etype (Typ), Ifaces); 19166 end if; 19167 19168 Collect_Implemented_Interfaces (Etype (Typ), Ifaces); 19169 end if; 19170 19171 -- Non-private types 19172 19173 else 19174 if Is_Interface (Etype (Typ)) then 19175 Append_Unique_Elmt (Etype (Typ), Ifaces); 19176 end if; 19177 19178 Collect_Implemented_Interfaces (Etype (Typ), Ifaces); 19179 end if; 19180 end if; 19181 19182 -- Handle entities in the list of abstract interfaces 19183 19184 if Present (Interfaces (Typ)) then 19185 Iface_Elmt := First_Elmt (Interfaces (Typ)); 19186 while Present (Iface_Elmt) loop 19187 Iface := Node (Iface_Elmt); 19188 19189 pragma Assert (Is_Interface (Iface)); 19190 19191 if not Contain_Interface (Iface, Ifaces) then 19192 Append_Elmt (Iface, Ifaces); 19193 Collect_Implemented_Interfaces (Iface, Ifaces); 19194 end if; 19195 19196 Next_Elmt (Iface_Elmt); 19197 end loop; 19198 end if; 19199 end Collect_Implemented_Interfaces; 19200 19201 -- Local variables 19202 19203 Full_Indic : Node_Id; 19204 Full_Parent : Entity_Id; 19205 Priv_Parent : Entity_Id; 19206 19207 -- Start of processing for Process_Full_View 19208 19209 begin 19210 -- First some sanity checks that must be done after semantic 19211 -- decoration of the full view and thus cannot be placed with other 19212 -- similar checks in Find_Type_Name 19213 19214 if not Is_Limited_Type (Priv_T) 19215 and then (Is_Limited_Type (Full_T) 19216 or else Is_Limited_Composite (Full_T)) 19217 then 19218 if In_Instance then 19219 null; 19220 else 19221 Error_Msg_N 19222 ("completion of nonlimited type cannot be limited", Full_T); 19223 Explain_Limited_Type (Full_T, Full_T); 19224 end if; 19225 19226 elsif Is_Abstract_Type (Full_T) 19227 and then not Is_Abstract_Type (Priv_T) 19228 then 19229 Error_Msg_N 19230 ("completion of nonabstract type cannot be abstract", Full_T); 19231 19232 elsif Is_Tagged_Type (Priv_T) 19233 and then Is_Limited_Type (Priv_T) 19234 and then not Is_Limited_Type (Full_T) 19235 then 19236 -- If pragma CPP_Class was applied to the private declaration 19237 -- propagate the limitedness to the full-view 19238 19239 if Is_CPP_Class (Priv_T) then 19240 Set_Is_Limited_Record (Full_T); 19241 19242 -- GNAT allow its own definition of Limited_Controlled to disobey 19243 -- this rule in order in ease the implementation. This test is safe 19244 -- because Root_Controlled is defined in a child of System that 19245 -- normal programs are not supposed to use. 19246 19247 elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then 19248 Set_Is_Limited_Composite (Full_T); 19249 else 19250 Error_Msg_N 19251 ("completion of limited tagged type must be limited", Full_T); 19252 end if; 19253 19254 elsif Is_Generic_Type (Priv_T) then 19255 Error_Msg_N ("generic type cannot have a completion", Full_T); 19256 end if; 19257 19258 -- Check that ancestor interfaces of private and full views are 19259 -- consistent. We omit this check for synchronized types because 19260 -- they are performed on the corresponding record type when frozen. 19261 19262 if Ada_Version >= Ada_2005 19263 and then Is_Tagged_Type (Priv_T) 19264 and then Is_Tagged_Type (Full_T) 19265 and then not Is_Concurrent_Type (Full_T) 19266 then 19267 declare 19268 Iface : Entity_Id; 19269 Priv_T_Ifaces : constant Elist_Id := New_Elmt_List; 19270 Full_T_Ifaces : constant Elist_Id := New_Elmt_List; 19271 19272 begin 19273 Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces); 19274 Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces); 19275 19276 -- Ada 2005 (AI-251): The partial view shall be a descendant of 19277 -- an interface type if and only if the full type is descendant 19278 -- of the interface type (AARM 7.3 (7.3/2)). 19279 19280 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces); 19281 19282 if Present (Iface) then 19283 Error_Msg_NE 19284 ("interface in partial view& not implemented by full type " 19285 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface); 19286 end if; 19287 19288 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces); 19289 19290 if Present (Iface) then 19291 Error_Msg_NE 19292 ("interface & not implemented by partial view " 19293 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface); 19294 end if; 19295 end; 19296 end if; 19297 19298 if Is_Tagged_Type (Priv_T) 19299 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration 19300 and then Is_Derived_Type (Full_T) 19301 then 19302 Priv_Parent := Etype (Priv_T); 19303 19304 -- The full view of a private extension may have been transformed 19305 -- into an unconstrained derived type declaration and a subtype 19306 -- declaration (see build_derived_record_type for details). 19307 19308 if Nkind (N) = N_Subtype_Declaration then 19309 Full_Indic := Subtype_Indication (N); 19310 Full_Parent := Etype (Base_Type (Full_T)); 19311 else 19312 Full_Indic := Subtype_Indication (Type_Definition (N)); 19313 Full_Parent := Etype (Full_T); 19314 end if; 19315 19316 -- Check that the parent type of the full type is a descendant of 19317 -- the ancestor subtype given in the private extension. If either 19318 -- entity has an Etype equal to Any_Type then we had some previous 19319 -- error situation [7.3(8)]. 19320 19321 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then 19322 return; 19323 19324 -- Ada 2005 (AI-251): Interfaces in the full type can be given in 19325 -- any order. Therefore we don't have to check that its parent must 19326 -- be a descendant of the parent of the private type declaration. 19327 19328 elsif Is_Interface (Priv_Parent) 19329 and then Is_Interface (Full_Parent) 19330 then 19331 null; 19332 19333 -- Ada 2005 (AI-251): If the parent of the private type declaration 19334 -- is an interface there is no need to check that it is an ancestor 19335 -- of the associated full type declaration. The required tests for 19336 -- this case are performed by Build_Derived_Record_Type. 19337 19338 elsif not Is_Interface (Base_Type (Priv_Parent)) 19339 and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) 19340 then 19341 Error_Msg_N 19342 ("parent of full type must descend from parent" 19343 & " of private extension", Full_Indic); 19344 19345 -- First check a formal restriction, and then proceed with checking 19346 -- Ada rules. Since the formal restriction is not a serious error, we 19347 -- don't prevent further error detection for this check, hence the 19348 -- ELSE. 19349 19350 else 19351 -- In formal mode, when completing a private extension the type 19352 -- named in the private part must be exactly the same as that 19353 -- named in the visible part. 19354 19355 if Priv_Parent /= Full_Parent then 19356 Error_Msg_Name_1 := Chars (Priv_Parent); 19357 Check_SPARK_05_Restriction ("% expected", Full_Indic); 19358 end if; 19359 19360 -- Check the rules of 7.3(10): if the private extension inherits 19361 -- known discriminants, then the full type must also inherit those 19362 -- discriminants from the same (ancestor) type, and the parent 19363 -- subtype of the full type must be constrained if and only if 19364 -- the ancestor subtype of the private extension is constrained. 19365 19366 if No (Discriminant_Specifications (Parent (Priv_T))) 19367 and then not Has_Unknown_Discriminants (Priv_T) 19368 and then Has_Discriminants (Base_Type (Priv_Parent)) 19369 then 19370 declare 19371 Priv_Indic : constant Node_Id := 19372 Subtype_Indication (Parent (Priv_T)); 19373 19374 Priv_Constr : constant Boolean := 19375 Is_Constrained (Priv_Parent) 19376 or else 19377 Nkind (Priv_Indic) = N_Subtype_Indication 19378 or else 19379 Is_Constrained (Entity (Priv_Indic)); 19380 19381 Full_Constr : constant Boolean := 19382 Is_Constrained (Full_Parent) 19383 or else 19384 Nkind (Full_Indic) = N_Subtype_Indication 19385 or else 19386 Is_Constrained (Entity (Full_Indic)); 19387 19388 Priv_Discr : Entity_Id; 19389 Full_Discr : Entity_Id; 19390 19391 begin 19392 Priv_Discr := First_Discriminant (Priv_Parent); 19393 Full_Discr := First_Discriminant (Full_Parent); 19394 while Present (Priv_Discr) and then Present (Full_Discr) loop 19395 if Original_Record_Component (Priv_Discr) = 19396 Original_Record_Component (Full_Discr) 19397 or else 19398 Corresponding_Discriminant (Priv_Discr) = 19399 Corresponding_Discriminant (Full_Discr) 19400 then 19401 null; 19402 else 19403 exit; 19404 end if; 19405 19406 Next_Discriminant (Priv_Discr); 19407 Next_Discriminant (Full_Discr); 19408 end loop; 19409 19410 if Present (Priv_Discr) or else Present (Full_Discr) then 19411 Error_Msg_N 19412 ("full view must inherit discriminants of the parent" 19413 & " type used in the private extension", Full_Indic); 19414 19415 elsif Priv_Constr and then not Full_Constr then 19416 Error_Msg_N 19417 ("parent subtype of full type must be constrained", 19418 Full_Indic); 19419 19420 elsif Full_Constr and then not Priv_Constr then 19421 Error_Msg_N 19422 ("parent subtype of full type must be unconstrained", 19423 Full_Indic); 19424 end if; 19425 end; 19426 19427 -- Check the rules of 7.3(12): if a partial view has neither 19428 -- known or unknown discriminants, then the full type 19429 -- declaration shall define a definite subtype. 19430 19431 elsif not Has_Unknown_Discriminants (Priv_T) 19432 and then not Has_Discriminants (Priv_T) 19433 and then not Is_Constrained (Full_T) 19434 then 19435 Error_Msg_N 19436 ("full view must define a constrained type if partial view" 19437 & " has no discriminants", Full_T); 19438 end if; 19439 19440 -- ??????? Do we implement the following properly ????? 19441 -- If the ancestor subtype of a private extension has constrained 19442 -- discriminants, then the parent subtype of the full view shall 19443 -- impose a statically matching constraint on those discriminants 19444 -- [7.3(13)]. 19445 end if; 19446 19447 else 19448 -- For untagged types, verify that a type without discriminants is 19449 -- not completed with an unconstrained type. A separate error message 19450 -- is produced if the full type has defaulted discriminants. 19451 19452 if not Is_Indefinite_Subtype (Priv_T) 19453 and then Is_Indefinite_Subtype (Full_T) 19454 then 19455 Error_Msg_Sloc := Sloc (Parent (Priv_T)); 19456 Error_Msg_NE 19457 ("full view of& not compatible with declaration#", 19458 Full_T, Priv_T); 19459 19460 if not Is_Tagged_Type (Full_T) then 19461 Error_Msg_N 19462 ("\one is constrained, the other unconstrained", Full_T); 19463 end if; 19464 end if; 19465 end if; 19466 19467 -- AI-419: verify that the use of "limited" is consistent 19468 19469 declare 19470 Orig_Decl : constant Node_Id := Original_Node (N); 19471 19472 begin 19473 if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration 19474 and then Nkind (Orig_Decl) = N_Full_Type_Declaration 19475 and then Nkind 19476 (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition 19477 then 19478 if not Limited_Present (Parent (Priv_T)) 19479 and then not Synchronized_Present (Parent (Priv_T)) 19480 and then Limited_Present (Type_Definition (Orig_Decl)) 19481 then 19482 Error_Msg_N 19483 ("full view of non-limited extension cannot be limited", N); 19484 19485 -- Conversely, if the partial view carries the limited keyword, 19486 -- the full view must as well, even if it may be redundant. 19487 19488 elsif Limited_Present (Parent (Priv_T)) 19489 and then not Limited_Present (Type_Definition (Orig_Decl)) 19490 then 19491 Error_Msg_N 19492 ("full view of limited extension must be explicitly limited", 19493 N); 19494 end if; 19495 end if; 19496 end; 19497 19498 -- Ada 2005 (AI-443): A synchronized private extension must be 19499 -- completed by a task or protected type. 19500 19501 if Ada_Version >= Ada_2005 19502 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration 19503 and then Synchronized_Present (Parent (Priv_T)) 19504 and then not Is_Concurrent_Type (Full_T) 19505 then 19506 Error_Msg_N ("full view of synchronized extension must " & 19507 "be synchronized type", N); 19508 end if; 19509 19510 -- Ada 2005 AI-363: if the full view has discriminants with 19511 -- defaults, it is illegal to declare constrained access subtypes 19512 -- whose designated type is the current type. This allows objects 19513 -- of the type that are declared in the heap to be unconstrained. 19514 19515 if not Has_Unknown_Discriminants (Priv_T) 19516 and then not Has_Discriminants (Priv_T) 19517 and then Has_Discriminants (Full_T) 19518 and then 19519 Present (Discriminant_Default_Value (First_Discriminant (Full_T))) 19520 then 19521 Set_Has_Constrained_Partial_View (Full_T); 19522 Set_Has_Constrained_Partial_View (Priv_T); 19523 end if; 19524 19525 -- Create a full declaration for all its subtypes recorded in 19526 -- Private_Dependents and swap them similarly to the base type. These 19527 -- are subtypes that have been define before the full declaration of 19528 -- the private type. We also swap the entry in Private_Dependents list 19529 -- so we can properly restore the private view on exit from the scope. 19530 19531 declare 19532 Priv_Elmt : Elmt_Id; 19533 Priv_Scop : Entity_Id; 19534 Priv : Entity_Id; 19535 Full : Entity_Id; 19536 19537 begin 19538 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T)); 19539 while Present (Priv_Elmt) loop 19540 Priv := Node (Priv_Elmt); 19541 Priv_Scop := Scope (Priv); 19542 19543 if Ekind_In (Priv, E_Private_Subtype, 19544 E_Limited_Private_Subtype, 19545 E_Record_Subtype_With_Private) 19546 then 19547 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv)); 19548 Set_Is_Itype (Full); 19549 Set_Parent (Full, Parent (Priv)); 19550 Set_Associated_Node_For_Itype (Full, N); 19551 19552 -- Now we need to complete the private subtype, but since the 19553 -- base type has already been swapped, we must also swap the 19554 -- subtypes (and thus, reverse the arguments in the call to 19555 -- Complete_Private_Subtype). Also note that we may need to 19556 -- re-establish the scope of the private subtype. 19557 19558 Copy_And_Swap (Priv, Full); 19559 19560 if not In_Open_Scopes (Priv_Scop) then 19561 Push_Scope (Priv_Scop); 19562 19563 else 19564 -- Reset Priv_Scop to Empty to indicate no scope was pushed 19565 19566 Priv_Scop := Empty; 19567 end if; 19568 19569 Complete_Private_Subtype (Full, Priv, Full_T, N); 19570 19571 if Present (Priv_Scop) then 19572 Pop_Scope; 19573 end if; 19574 19575 Replace_Elmt (Priv_Elmt, Full); 19576 end if; 19577 19578 Next_Elmt (Priv_Elmt); 19579 end loop; 19580 end; 19581 19582 -- If the private view was tagged, copy the new primitive operations 19583 -- from the private view to the full view. 19584 19585 if Is_Tagged_Type (Full_T) then 19586 declare 19587 Disp_Typ : Entity_Id; 19588 Full_List : Elist_Id; 19589 Prim : Entity_Id; 19590 Prim_Elmt : Elmt_Id; 19591 Priv_List : Elist_Id; 19592 19593 function Contains 19594 (E : Entity_Id; 19595 L : Elist_Id) return Boolean; 19596 -- Determine whether list L contains element E 19597 19598 -------------- 19599 -- Contains -- 19600 -------------- 19601 19602 function Contains 19603 (E : Entity_Id; 19604 L : Elist_Id) return Boolean 19605 is 19606 List_Elmt : Elmt_Id; 19607 19608 begin 19609 List_Elmt := First_Elmt (L); 19610 while Present (List_Elmt) loop 19611 if Node (List_Elmt) = E then 19612 return True; 19613 end if; 19614 19615 Next_Elmt (List_Elmt); 19616 end loop; 19617 19618 return False; 19619 end Contains; 19620 19621 -- Start of processing 19622 19623 begin 19624 if Is_Tagged_Type (Priv_T) then 19625 Priv_List := Primitive_Operations (Priv_T); 19626 Prim_Elmt := First_Elmt (Priv_List); 19627 19628 -- In the case of a concurrent type completing a private tagged 19629 -- type, primitives may have been declared in between the two 19630 -- views. These subprograms need to be wrapped the same way 19631 -- entries and protected procedures are handled because they 19632 -- cannot be directly shared by the two views. 19633 19634 if Is_Concurrent_Type (Full_T) then 19635 declare 19636 Conc_Typ : constant Entity_Id := 19637 Corresponding_Record_Type (Full_T); 19638 Curr_Nod : Node_Id := Parent (Conc_Typ); 19639 Wrap_Spec : Node_Id; 19640 19641 begin 19642 while Present (Prim_Elmt) loop 19643 Prim := Node (Prim_Elmt); 19644 19645 if Comes_From_Source (Prim) 19646 and then not Is_Abstract_Subprogram (Prim) 19647 then 19648 Wrap_Spec := 19649 Make_Subprogram_Declaration (Sloc (Prim), 19650 Specification => 19651 Build_Wrapper_Spec 19652 (Subp_Id => Prim, 19653 Obj_Typ => Conc_Typ, 19654 Formals => 19655 Parameter_Specifications ( 19656 Parent (Prim)))); 19657 19658 Insert_After (Curr_Nod, Wrap_Spec); 19659 Curr_Nod := Wrap_Spec; 19660 19661 Analyze (Wrap_Spec); 19662 end if; 19663 19664 Next_Elmt (Prim_Elmt); 19665 end loop; 19666 19667 return; 19668 end; 19669 19670 -- For non-concurrent types, transfer explicit primitives, but 19671 -- omit those inherited from the parent of the private view 19672 -- since they will be re-inherited later on. 19673 19674 else 19675 Full_List := Primitive_Operations (Full_T); 19676 19677 while Present (Prim_Elmt) loop 19678 Prim := Node (Prim_Elmt); 19679 19680 if Comes_From_Source (Prim) 19681 and then not Contains (Prim, Full_List) 19682 then 19683 Append_Elmt (Prim, Full_List); 19684 end if; 19685 19686 Next_Elmt (Prim_Elmt); 19687 end loop; 19688 end if; 19689 19690 -- Untagged private view 19691 19692 else 19693 Full_List := Primitive_Operations (Full_T); 19694 19695 -- In this case the partial view is untagged, so here we locate 19696 -- all of the earlier primitives that need to be treated as 19697 -- dispatching (those that appear between the two views). Note 19698 -- that these additional operations must all be new operations 19699 -- (any earlier operations that override inherited operations 19700 -- of the full view will already have been inserted in the 19701 -- primitives list, marked by Check_Operation_From_Private_View 19702 -- as dispatching. Note that implicit "/=" operators are 19703 -- excluded from being added to the primitives list since they 19704 -- shouldn't be treated as dispatching (tagged "/=" is handled 19705 -- specially). 19706 19707 Prim := Next_Entity (Full_T); 19708 while Present (Prim) and then Prim /= Priv_T loop 19709 if Ekind_In (Prim, E_Procedure, E_Function) then 19710 Disp_Typ := Find_Dispatching_Type (Prim); 19711 19712 if Disp_Typ = Full_T 19713 and then (Chars (Prim) /= Name_Op_Ne 19714 or else Comes_From_Source (Prim)) 19715 then 19716 Check_Controlling_Formals (Full_T, Prim); 19717 19718 if not Is_Dispatching_Operation (Prim) then 19719 Append_Elmt (Prim, Full_List); 19720 Set_Is_Dispatching_Operation (Prim, True); 19721 Set_DT_Position_Value (Prim, No_Uint); 19722 end if; 19723 19724 elsif Is_Dispatching_Operation (Prim) 19725 and then Disp_Typ /= Full_T 19726 then 19727 19728 -- Verify that it is not otherwise controlled by a 19729 -- formal or a return value of type T. 19730 19731 Check_Controlling_Formals (Disp_Typ, Prim); 19732 end if; 19733 end if; 19734 19735 Next_Entity (Prim); 19736 end loop; 19737 end if; 19738 19739 -- For the tagged case, the two views can share the same primitive 19740 -- operations list and the same class-wide type. Update attributes 19741 -- of the class-wide type which depend on the full declaration. 19742 19743 if Is_Tagged_Type (Priv_T) then 19744 Set_Direct_Primitive_Operations (Priv_T, Full_List); 19745 Set_Class_Wide_Type 19746 (Base_Type (Full_T), Class_Wide_Type (Priv_T)); 19747 19748 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T)); 19749 Set_Has_Protected 19750 (Class_Wide_Type (Priv_T), Has_Protected (Full_T)); 19751 end if; 19752 end; 19753 end if; 19754 19755 -- Ada 2005 AI 161: Check preelaborable initialization consistency 19756 19757 if Known_To_Have_Preelab_Init (Priv_T) then 19758 19759 -- Case where there is a pragma Preelaborable_Initialization. We 19760 -- always allow this in predefined units, which is cheating a bit, 19761 -- but it means we don't have to struggle to meet the requirements in 19762 -- the RM for having Preelaborable Initialization. Otherwise we 19763 -- require that the type meets the RM rules. But we can't check that 19764 -- yet, because of the rule about overriding Initialize, so we simply 19765 -- set a flag that will be checked at freeze time. 19766 19767 if not In_Predefined_Unit (Full_T) then 19768 Set_Must_Have_Preelab_Init (Full_T); 19769 end if; 19770 end if; 19771 19772 -- If pragma CPP_Class was applied to the private type declaration, 19773 -- propagate it now to the full type declaration. 19774 19775 if Is_CPP_Class (Priv_T) then 19776 Set_Is_CPP_Class (Full_T); 19777 Set_Convention (Full_T, Convention_CPP); 19778 19779 -- Check that components of imported CPP types do not have default 19780 -- expressions. 19781 19782 Check_CPP_Type_Has_No_Defaults (Full_T); 19783 end if; 19784 19785 -- If the private view has user specified stream attributes, then so has 19786 -- the full view. 19787 19788 -- Why the test, how could these flags be already set in Full_T ??? 19789 19790 if Has_Specified_Stream_Read (Priv_T) then 19791 Set_Has_Specified_Stream_Read (Full_T); 19792 end if; 19793 19794 if Has_Specified_Stream_Write (Priv_T) then 19795 Set_Has_Specified_Stream_Write (Full_T); 19796 end if; 19797 19798 if Has_Specified_Stream_Input (Priv_T) then 19799 Set_Has_Specified_Stream_Input (Full_T); 19800 end if; 19801 19802 if Has_Specified_Stream_Output (Priv_T) then 19803 Set_Has_Specified_Stream_Output (Full_T); 19804 end if; 19805 19806 -- Propagate the attributes related to pragma Default_Initial_Condition 19807 -- from the private to the full view. Note that both flags are mutually 19808 -- exclusive. 19809 19810 if Has_Default_Init_Cond (Priv_T) 19811 or else Has_Inherited_Default_Init_Cond (Priv_T) 19812 then 19813 Propagate_Default_Init_Cond_Attributes 19814 (From_Typ => Priv_T, 19815 To_Typ => Full_T, 19816 Private_To_Full_View => True); 19817 19818 -- In the case where the full view is derived from another private type, 19819 -- the attributes related to pragma Default_Initial_Condition must be 19820 -- propagated from the full to the private view to maintain consistency 19821 -- of views. 19822 19823 -- package Pack is 19824 -- type Parent_Typ is private 19825 -- with Default_Initial_Condition ...; 19826 -- private 19827 -- type Parent_Typ is ...; 19828 -- end Pack; 19829 19830 -- with Pack; use Pack; 19831 -- package Pack_2 is 19832 -- type Deriv_Typ is private; -- must inherit 19833 -- private 19834 -- type Deriv_Typ is new Parent_Typ; -- must inherit 19835 -- end Pack_2; 19836 19837 elsif Has_Default_Init_Cond (Full_T) 19838 or else Has_Inherited_Default_Init_Cond (Full_T) 19839 then 19840 Propagate_Default_Init_Cond_Attributes 19841 (From_Typ => Full_T, 19842 To_Typ => Priv_T, 19843 Private_To_Full_View => True); 19844 end if; 19845 19846 -- Propagate the attributes related to pragma Ghost from the private to 19847 -- the full view. 19848 19849 if Is_Ghost_Entity (Priv_T) then 19850 Set_Is_Ghost_Entity (Full_T); 19851 19852 -- The Ghost policy in effect at the point of declaration and at the 19853 -- point of completion must match (SPARK RM 6.9(15)). 19854 19855 Check_Ghost_Completion (Priv_T, Full_T); 19856 19857 -- In the case where the private view of a tagged type lacks a parent 19858 -- type and is subject to pragma Ghost, ensure that the parent type 19859 -- specified by the full view is also Ghost (SPARK RM 6.9(9)). 19860 19861 if Is_Derived_Type (Full_T) then 19862 Check_Ghost_Derivation (Full_T); 19863 end if; 19864 end if; 19865 19866 -- Propagate invariants to full type 19867 19868 if Has_Invariants (Priv_T) then 19869 Set_Has_Invariants (Full_T); 19870 Set_Invariant_Procedure (Full_T, Invariant_Procedure (Priv_T)); 19871 end if; 19872 19873 if Has_Inheritable_Invariants (Priv_T) then 19874 Set_Has_Inheritable_Invariants (Full_T); 19875 end if; 19876 19877 -- Check hidden inheritance of class-wide type invariants 19878 19879 if Ada_Version >= Ada_2012 19880 and then not Has_Inheritable_Invariants (Full_T) 19881 and then In_Private_Part (Current_Scope) 19882 and then Has_Interfaces (Full_T) 19883 then 19884 declare 19885 Ifaces : Elist_Id; 19886 AI : Elmt_Id; 19887 19888 begin 19889 Collect_Interfaces (Full_T, Ifaces, Exclude_Parents => True); 19890 19891 AI := First_Elmt (Ifaces); 19892 while Present (AI) loop 19893 if Has_Inheritable_Invariants (Node (AI)) then 19894 Error_Msg_N 19895 ("hidden inheritance of class-wide type invariants " & 19896 "not allowed", N); 19897 exit; 19898 end if; 19899 19900 Next_Elmt (AI); 19901 end loop; 19902 end; 19903 end if; 19904 19905 -- Propagate predicates to full type, and predicate function if already 19906 -- defined. It is not clear that this can actually happen? the partial 19907 -- view cannot be frozen yet, and the predicate function has not been 19908 -- built. Still it is a cheap check and seems safer to make it. 19909 19910 if Has_Predicates (Priv_T) then 19911 if Present (Predicate_Function (Priv_T)) then 19912 Set_Predicate_Function (Full_T, Predicate_Function (Priv_T)); 19913 end if; 19914 19915 Set_Has_Predicates (Full_T); 19916 end if; 19917 end Process_Full_View; 19918 19919 ----------------------------------- 19920 -- Process_Incomplete_Dependents -- 19921 ----------------------------------- 19922 19923 procedure Process_Incomplete_Dependents 19924 (N : Node_Id; 19925 Full_T : Entity_Id; 19926 Inc_T : Entity_Id) 19927 is 19928 Inc_Elmt : Elmt_Id; 19929 Priv_Dep : Entity_Id; 19930 New_Subt : Entity_Id; 19931 19932 Disc_Constraint : Elist_Id; 19933 19934 begin 19935 if No (Private_Dependents (Inc_T)) then 19936 return; 19937 end if; 19938 19939 -- Itypes that may be generated by the completion of an incomplete 19940 -- subtype are not used by the back-end and not attached to the tree. 19941 -- They are created only for constraint-checking purposes. 19942 19943 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T)); 19944 while Present (Inc_Elmt) loop 19945 Priv_Dep := Node (Inc_Elmt); 19946 19947 if Ekind (Priv_Dep) = E_Subprogram_Type then 19948 19949 -- An Access_To_Subprogram type may have a return type or a 19950 -- parameter type that is incomplete. Replace with the full view. 19951 19952 if Etype (Priv_Dep) = Inc_T then 19953 Set_Etype (Priv_Dep, Full_T); 19954 end if; 19955 19956 declare 19957 Formal : Entity_Id; 19958 19959 begin 19960 Formal := First_Formal (Priv_Dep); 19961 while Present (Formal) loop 19962 if Etype (Formal) = Inc_T then 19963 Set_Etype (Formal, Full_T); 19964 end if; 19965 19966 Next_Formal (Formal); 19967 end loop; 19968 end; 19969 19970 elsif Is_Overloadable (Priv_Dep) then 19971 19972 -- If a subprogram in the incomplete dependents list is primitive 19973 -- for a tagged full type then mark it as a dispatching operation, 19974 -- check whether it overrides an inherited subprogram, and check 19975 -- restrictions on its controlling formals. Note that a protected 19976 -- operation is never dispatching: only its wrapper operation 19977 -- (which has convention Ada) is. 19978 19979 if Is_Tagged_Type (Full_T) 19980 and then Is_Primitive (Priv_Dep) 19981 and then Convention (Priv_Dep) /= Convention_Protected 19982 then 19983 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T); 19984 Set_Is_Dispatching_Operation (Priv_Dep); 19985 Check_Controlling_Formals (Full_T, Priv_Dep); 19986 end if; 19987 19988 elsif Ekind (Priv_Dep) = E_Subprogram_Body then 19989 19990 -- Can happen during processing of a body before the completion 19991 -- of a TA type. Ignore, because spec is also on dependent list. 19992 19993 return; 19994 19995 -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a 19996 -- corresponding subtype of the full view. 19997 19998 elsif Ekind (Priv_Dep) = E_Incomplete_Subtype then 19999 Set_Subtype_Indication 20000 (Parent (Priv_Dep), New_Occurrence_Of (Full_T, Sloc (Priv_Dep))); 20001 Set_Etype (Priv_Dep, Full_T); 20002 Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T))); 20003 Set_Analyzed (Parent (Priv_Dep), False); 20004 20005 -- Reanalyze the declaration, suppressing the call to 20006 -- Enter_Name to avoid duplicate names. 20007 20008 Analyze_Subtype_Declaration 20009 (N => Parent (Priv_Dep), 20010 Skip => True); 20011 20012 -- Dependent is a subtype 20013 20014 else 20015 -- We build a new subtype indication using the full view of the 20016 -- incomplete parent. The discriminant constraints have been 20017 -- elaborated already at the point of the subtype declaration. 20018 20019 New_Subt := Create_Itype (E_Void, N); 20020 20021 if Has_Discriminants (Full_T) then 20022 Disc_Constraint := Discriminant_Constraint (Priv_Dep); 20023 else 20024 Disc_Constraint := No_Elist; 20025 end if; 20026 20027 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N); 20028 Set_Full_View (Priv_Dep, New_Subt); 20029 end if; 20030 20031 Next_Elmt (Inc_Elmt); 20032 end loop; 20033 end Process_Incomplete_Dependents; 20034 20035 -------------------------------- 20036 -- Process_Range_Expr_In_Decl -- 20037 -------------------------------- 20038 20039 procedure Process_Range_Expr_In_Decl 20040 (R : Node_Id; 20041 T : Entity_Id; 20042 Subtyp : Entity_Id := Empty; 20043 Check_List : List_Id := Empty_List; 20044 R_Check_Off : Boolean := False; 20045 In_Iter_Schm : Boolean := False) 20046 is 20047 Lo, Hi : Node_Id; 20048 R_Checks : Check_Result; 20049 Insert_Node : Node_Id; 20050 Def_Id : Entity_Id; 20051 20052 begin 20053 Analyze_And_Resolve (R, Base_Type (T)); 20054 20055 if Nkind (R) = N_Range then 20056 20057 -- In SPARK, all ranges should be static, with the exception of the 20058 -- discrete type definition of a loop parameter specification. 20059 20060 if not In_Iter_Schm 20061 and then not Is_OK_Static_Range (R) 20062 then 20063 Check_SPARK_05_Restriction ("range should be static", R); 20064 end if; 20065 20066 Lo := Low_Bound (R); 20067 Hi := High_Bound (R); 20068 20069 -- Validity checks on the range of a quantified expression are 20070 -- delayed until the construct is transformed into a loop. 20071 20072 if Nkind (Parent (R)) = N_Loop_Parameter_Specification 20073 and then Nkind (Parent (Parent (R))) = N_Quantified_Expression 20074 then 20075 null; 20076 20077 -- We need to ensure validity of the bounds here, because if we 20078 -- go ahead and do the expansion, then the expanded code will get 20079 -- analyzed with range checks suppressed and we miss the check. 20080 20081 -- WARNING: The capture of the range bounds with xxx_FIRST/_LAST and 20082 -- the temporaries generated by routine Remove_Side_Effects by means 20083 -- of validity checks must use the same names. When a range appears 20084 -- in the parent of a generic, the range is processed with checks 20085 -- disabled as part of the generic context and with checks enabled 20086 -- for code generation purposes. This leads to link issues as the 20087 -- generic contains references to xxx_FIRST/_LAST, but the inlined 20088 -- template sees the temporaries generated by Remove_Side_Effects. 20089 20090 else 20091 Validity_Check_Range (R, Subtyp); 20092 end if; 20093 20094 -- If there were errors in the declaration, try and patch up some 20095 -- common mistakes in the bounds. The cases handled are literals 20096 -- which are Integer where the expected type is Real and vice versa. 20097 -- These corrections allow the compilation process to proceed further 20098 -- along since some basic assumptions of the format of the bounds 20099 -- are guaranteed. 20100 20101 if Etype (R) = Any_Type then 20102 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then 20103 Rewrite (Lo, 20104 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo)))); 20105 20106 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then 20107 Rewrite (Hi, 20108 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi)))); 20109 20110 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then 20111 Rewrite (Lo, 20112 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo)))); 20113 20114 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then 20115 Rewrite (Hi, 20116 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi)))); 20117 end if; 20118 20119 Set_Etype (Lo, T); 20120 Set_Etype (Hi, T); 20121 end if; 20122 20123 -- If the bounds of the range have been mistakenly given as string 20124 -- literals (perhaps in place of character literals), then an error 20125 -- has already been reported, but we rewrite the string literal as a 20126 -- bound of the range's type to avoid blowups in later processing 20127 -- that looks at static values. 20128 20129 if Nkind (Lo) = N_String_Literal then 20130 Rewrite (Lo, 20131 Make_Attribute_Reference (Sloc (Lo), 20132 Prefix => New_Occurrence_Of (T, Sloc (Lo)), 20133 Attribute_Name => Name_First)); 20134 Analyze_And_Resolve (Lo); 20135 end if; 20136 20137 if Nkind (Hi) = N_String_Literal then 20138 Rewrite (Hi, 20139 Make_Attribute_Reference (Sloc (Hi), 20140 Prefix => New_Occurrence_Of (T, Sloc (Hi)), 20141 Attribute_Name => Name_First)); 20142 Analyze_And_Resolve (Hi); 20143 end if; 20144 20145 -- If bounds aren't scalar at this point then exit, avoiding 20146 -- problems with further processing of the range in this procedure. 20147 20148 if not Is_Scalar_Type (Etype (Lo)) then 20149 return; 20150 end if; 20151 20152 -- Resolve (actually Sem_Eval) has checked that the bounds are in 20153 -- then range of the base type. Here we check whether the bounds 20154 -- are in the range of the subtype itself. Note that if the bounds 20155 -- represent the null range the Constraint_Error exception should 20156 -- not be raised. 20157 20158 -- ??? The following code should be cleaned up as follows 20159 20160 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it 20161 -- is done in the call to Range_Check (R, T); below 20162 20163 -- 2. The use of R_Check_Off should be investigated and possibly 20164 -- removed, this would clean up things a bit. 20165 20166 if Is_Null_Range (Lo, Hi) then 20167 null; 20168 20169 else 20170 -- Capture values of bounds and generate temporaries for them 20171 -- if needed, before applying checks, since checks may cause 20172 -- duplication of the expression without forcing evaluation. 20173 20174 -- The forced evaluation removes side effects from expressions, 20175 -- which should occur also in GNATprove mode. Otherwise, we end up 20176 -- with unexpected insertions of actions at places where this is 20177 -- not supposed to occur, e.g. on default parameters of a call. 20178 20179 if Expander_Active or GNATprove_Mode then 20180 20181 -- Call Force_Evaluation to create declarations as needed to 20182 -- deal with side effects, and also create typ_FIRST/LAST 20183 -- entities for bounds if we have a subtype name. 20184 20185 -- Note: we do this transformation even if expansion is not 20186 -- active if we are in GNATprove_Mode since the transformation 20187 -- is in general required to ensure that the resulting tree has 20188 -- proper Ada semantics. 20189 20190 Force_Evaluation 20191 (Lo, Related_Id => Subtyp, Is_Low_Bound => True); 20192 Force_Evaluation 20193 (Hi, Related_Id => Subtyp, Is_High_Bound => True); 20194 end if; 20195 20196 -- We use a flag here instead of suppressing checks on the type 20197 -- because the type we check against isn't necessarily the place 20198 -- where we put the check. 20199 20200 if not R_Check_Off then 20201 R_Checks := Get_Range_Checks (R, T); 20202 20203 -- Look up tree to find an appropriate insertion point. We 20204 -- can't just use insert_actions because later processing 20205 -- depends on the insertion node. Prior to Ada 2012 the 20206 -- insertion point could only be a declaration or a loop, but 20207 -- quantified expressions can appear within any context in an 20208 -- expression, and the insertion point can be any statement, 20209 -- pragma, or declaration. 20210 20211 Insert_Node := Parent (R); 20212 while Present (Insert_Node) loop 20213 exit when 20214 Nkind (Insert_Node) in N_Declaration 20215 and then 20216 not Nkind_In 20217 (Insert_Node, N_Component_Declaration, 20218 N_Loop_Parameter_Specification, 20219 N_Function_Specification, 20220 N_Procedure_Specification); 20221 20222 exit when Nkind (Insert_Node) in N_Later_Decl_Item 20223 or else Nkind (Insert_Node) in 20224 N_Statement_Other_Than_Procedure_Call 20225 or else Nkind_In (Insert_Node, N_Procedure_Call_Statement, 20226 N_Pragma); 20227 20228 Insert_Node := Parent (Insert_Node); 20229 end loop; 20230 20231 -- Why would Type_Decl not be present??? Without this test, 20232 -- short regression tests fail. 20233 20234 if Present (Insert_Node) then 20235 20236 -- Case of loop statement. Verify that the range is part 20237 -- of the subtype indication of the iteration scheme. 20238 20239 if Nkind (Insert_Node) = N_Loop_Statement then 20240 declare 20241 Indic : Node_Id; 20242 20243 begin 20244 Indic := Parent (R); 20245 while Present (Indic) 20246 and then Nkind (Indic) /= N_Subtype_Indication 20247 loop 20248 Indic := Parent (Indic); 20249 end loop; 20250 20251 if Present (Indic) then 20252 Def_Id := Etype (Subtype_Mark (Indic)); 20253 20254 Insert_Range_Checks 20255 (R_Checks, 20256 Insert_Node, 20257 Def_Id, 20258 Sloc (Insert_Node), 20259 R, 20260 Do_Before => True); 20261 end if; 20262 end; 20263 20264 -- Insertion before a declaration. If the declaration 20265 -- includes discriminants, the list of applicable checks 20266 -- is given by the caller. 20267 20268 elsif Nkind (Insert_Node) in N_Declaration then 20269 Def_Id := Defining_Identifier (Insert_Node); 20270 20271 if (Ekind (Def_Id) = E_Record_Type 20272 and then Depends_On_Discriminant (R)) 20273 or else 20274 (Ekind (Def_Id) = E_Protected_Type 20275 and then Has_Discriminants (Def_Id)) 20276 then 20277 Append_Range_Checks 20278 (R_Checks, 20279 Check_List, Def_Id, Sloc (Insert_Node), R); 20280 20281 else 20282 Insert_Range_Checks 20283 (R_Checks, 20284 Insert_Node, Def_Id, Sloc (Insert_Node), R); 20285 20286 end if; 20287 20288 -- Insertion before a statement. Range appears in the 20289 -- context of a quantified expression. Insertion will 20290 -- take place when expression is expanded. 20291 20292 else 20293 null; 20294 end if; 20295 end if; 20296 end if; 20297 end if; 20298 20299 -- Case of other than an explicit N_Range node 20300 20301 -- The forced evaluation removes side effects from expressions, which 20302 -- should occur also in GNATprove mode. Otherwise, we end up with 20303 -- unexpected insertions of actions at places where this is not 20304 -- supposed to occur, e.g. on default parameters of a call. 20305 20306 elsif Expander_Active or GNATprove_Mode then 20307 Get_Index_Bounds (R, Lo, Hi); 20308 Force_Evaluation (Lo); 20309 Force_Evaluation (Hi); 20310 end if; 20311 end Process_Range_Expr_In_Decl; 20312 20313 -------------------------------------- 20314 -- Process_Real_Range_Specification -- 20315 -------------------------------------- 20316 20317 procedure Process_Real_Range_Specification (Def : Node_Id) is 20318 Spec : constant Node_Id := Real_Range_Specification (Def); 20319 Lo : Node_Id; 20320 Hi : Node_Id; 20321 Err : Boolean := False; 20322 20323 procedure Analyze_Bound (N : Node_Id); 20324 -- Analyze and check one bound 20325 20326 ------------------- 20327 -- Analyze_Bound -- 20328 ------------------- 20329 20330 procedure Analyze_Bound (N : Node_Id) is 20331 begin 20332 Analyze_And_Resolve (N, Any_Real); 20333 20334 if not Is_OK_Static_Expression (N) then 20335 Flag_Non_Static_Expr 20336 ("bound in real type definition is not static!", N); 20337 Err := True; 20338 end if; 20339 end Analyze_Bound; 20340 20341 -- Start of processing for Process_Real_Range_Specification 20342 20343 begin 20344 if Present (Spec) then 20345 Lo := Low_Bound (Spec); 20346 Hi := High_Bound (Spec); 20347 Analyze_Bound (Lo); 20348 Analyze_Bound (Hi); 20349 20350 -- If error, clear away junk range specification 20351 20352 if Err then 20353 Set_Real_Range_Specification (Def, Empty); 20354 end if; 20355 end if; 20356 end Process_Real_Range_Specification; 20357 20358 --------------------- 20359 -- Process_Subtype -- 20360 --------------------- 20361 20362 function Process_Subtype 20363 (S : Node_Id; 20364 Related_Nod : Node_Id; 20365 Related_Id : Entity_Id := Empty; 20366 Suffix : Character := ' ') return Entity_Id 20367 is 20368 P : Node_Id; 20369 Def_Id : Entity_Id; 20370 Error_Node : Node_Id; 20371 Full_View_Id : Entity_Id; 20372 Subtype_Mark_Id : Entity_Id; 20373 20374 May_Have_Null_Exclusion : Boolean; 20375 20376 procedure Check_Incomplete (T : Entity_Id); 20377 -- Called to verify that an incomplete type is not used prematurely 20378 20379 ---------------------- 20380 -- Check_Incomplete -- 20381 ---------------------- 20382 20383 procedure Check_Incomplete (T : Entity_Id) is 20384 begin 20385 -- Ada 2005 (AI-412): Incomplete subtypes are legal 20386 20387 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type 20388 and then 20389 not (Ada_Version >= Ada_2005 20390 and then 20391 (Nkind (Parent (T)) = N_Subtype_Declaration 20392 or else (Nkind (Parent (T)) = N_Subtype_Indication 20393 and then Nkind (Parent (Parent (T))) = 20394 N_Subtype_Declaration))) 20395 then 20396 Error_Msg_N ("invalid use of type before its full declaration", T); 20397 end if; 20398 end Check_Incomplete; 20399 20400 -- Start of processing for Process_Subtype 20401 20402 begin 20403 -- Case of no constraints present 20404 20405 if Nkind (S) /= N_Subtype_Indication then 20406 Find_Type (S); 20407 Check_Incomplete (S); 20408 P := Parent (S); 20409 20410 -- Ada 2005 (AI-231): Static check 20411 20412 if Ada_Version >= Ada_2005 20413 and then Present (P) 20414 and then Null_Exclusion_Present (P) 20415 and then Nkind (P) /= N_Access_To_Object_Definition 20416 and then not Is_Access_Type (Entity (S)) 20417 then 20418 Error_Msg_N ("`NOT NULL` only allowed for an access type", S); 20419 end if; 20420 20421 -- The following is ugly, can't we have a range or even a flag??? 20422 20423 May_Have_Null_Exclusion := 20424 Nkind_In (P, N_Access_Definition, 20425 N_Access_Function_Definition, 20426 N_Access_Procedure_Definition, 20427 N_Access_To_Object_Definition, 20428 N_Allocator, 20429 N_Component_Definition) 20430 or else 20431 Nkind_In (P, N_Derived_Type_Definition, 20432 N_Discriminant_Specification, 20433 N_Formal_Object_Declaration, 20434 N_Object_Declaration, 20435 N_Object_Renaming_Declaration, 20436 N_Parameter_Specification, 20437 N_Subtype_Declaration); 20438 20439 -- Create an Itype that is a duplicate of Entity (S) but with the 20440 -- null-exclusion attribute. 20441 20442 if May_Have_Null_Exclusion 20443 and then Is_Access_Type (Entity (S)) 20444 and then Null_Exclusion_Present (P) 20445 20446 -- No need to check the case of an access to object definition. 20447 -- It is correct to define double not-null pointers. 20448 20449 -- Example: 20450 -- type Not_Null_Int_Ptr is not null access Integer; 20451 -- type Acc is not null access Not_Null_Int_Ptr; 20452 20453 and then Nkind (P) /= N_Access_To_Object_Definition 20454 then 20455 if Can_Never_Be_Null (Entity (S)) then 20456 case Nkind (Related_Nod) is 20457 when N_Full_Type_Declaration => 20458 if Nkind (Type_Definition (Related_Nod)) 20459 in N_Array_Type_Definition 20460 then 20461 Error_Node := 20462 Subtype_Indication 20463 (Component_Definition 20464 (Type_Definition (Related_Nod))); 20465 else 20466 Error_Node := 20467 Subtype_Indication (Type_Definition (Related_Nod)); 20468 end if; 20469 20470 when N_Subtype_Declaration => 20471 Error_Node := Subtype_Indication (Related_Nod); 20472 20473 when N_Object_Declaration => 20474 Error_Node := Object_Definition (Related_Nod); 20475 20476 when N_Component_Declaration => 20477 Error_Node := 20478 Subtype_Indication (Component_Definition (Related_Nod)); 20479 20480 when N_Allocator => 20481 Error_Node := Expression (Related_Nod); 20482 20483 when others => 20484 pragma Assert (False); 20485 Error_Node := Related_Nod; 20486 end case; 20487 20488 Error_Msg_NE 20489 ("`NOT NULL` not allowed (& already excludes null)", 20490 Error_Node, 20491 Entity (S)); 20492 end if; 20493 20494 Set_Etype (S, 20495 Create_Null_Excluding_Itype 20496 (T => Entity (S), 20497 Related_Nod => P)); 20498 Set_Entity (S, Etype (S)); 20499 end if; 20500 20501 return Entity (S); 20502 20503 -- Case of constraint present, so that we have an N_Subtype_Indication 20504 -- node (this node is created only if constraints are present). 20505 20506 else 20507 Find_Type (Subtype_Mark (S)); 20508 20509 if Nkind (Parent (S)) /= N_Access_To_Object_Definition 20510 and then not 20511 (Nkind (Parent (S)) = N_Subtype_Declaration 20512 and then Is_Itype (Defining_Identifier (Parent (S)))) 20513 then 20514 Check_Incomplete (Subtype_Mark (S)); 20515 end if; 20516 20517 P := Parent (S); 20518 Subtype_Mark_Id := Entity (Subtype_Mark (S)); 20519 20520 -- Explicit subtype declaration case 20521 20522 if Nkind (P) = N_Subtype_Declaration then 20523 Def_Id := Defining_Identifier (P); 20524 20525 -- Explicit derived type definition case 20526 20527 elsif Nkind (P) = N_Derived_Type_Definition then 20528 Def_Id := Defining_Identifier (Parent (P)); 20529 20530 -- Implicit case, the Def_Id must be created as an implicit type. 20531 -- The one exception arises in the case of concurrent types, array 20532 -- and access types, where other subsidiary implicit types may be 20533 -- created and must appear before the main implicit type. In these 20534 -- cases we leave Def_Id set to Empty as a signal that Create_Itype 20535 -- has not yet been called to create Def_Id. 20536 20537 else 20538 if Is_Array_Type (Subtype_Mark_Id) 20539 or else Is_Concurrent_Type (Subtype_Mark_Id) 20540 or else Is_Access_Type (Subtype_Mark_Id) 20541 then 20542 Def_Id := Empty; 20543 20544 -- For the other cases, we create a new unattached Itype, 20545 -- and set the indication to ensure it gets attached later. 20546 20547 else 20548 Def_Id := 20549 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); 20550 end if; 20551 end if; 20552 20553 -- If the kind of constraint is invalid for this kind of type, 20554 -- then give an error, and then pretend no constraint was given. 20555 20556 if not Is_Valid_Constraint_Kind 20557 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S))) 20558 then 20559 Error_Msg_N 20560 ("incorrect constraint for this kind of type", Constraint (S)); 20561 20562 Rewrite (S, New_Copy_Tree (Subtype_Mark (S))); 20563 20564 -- Set Ekind of orphan itype, to prevent cascaded errors 20565 20566 if Present (Def_Id) then 20567 Set_Ekind (Def_Id, Ekind (Any_Type)); 20568 end if; 20569 20570 -- Make recursive call, having got rid of the bogus constraint 20571 20572 return Process_Subtype (S, Related_Nod, Related_Id, Suffix); 20573 end if; 20574 20575 -- Remaining processing depends on type. Select on Base_Type kind to 20576 -- ensure getting to the concrete type kind in the case of a private 20577 -- subtype (needed when only doing semantic analysis). 20578 20579 case Ekind (Base_Type (Subtype_Mark_Id)) is 20580 when Access_Kind => 20581 20582 -- If this is a constraint on a class-wide type, discard it. 20583 -- There is currently no way to express a partial discriminant 20584 -- constraint on a type with unknown discriminants. This is 20585 -- a pathology that the ACATS wisely decides not to test. 20586 20587 if Is_Class_Wide_Type (Designated_Type (Subtype_Mark_Id)) then 20588 if Comes_From_Source (S) then 20589 Error_Msg_N 20590 ("constraint on class-wide type ignored??", 20591 Constraint (S)); 20592 end if; 20593 20594 if Nkind (P) = N_Subtype_Declaration then 20595 Set_Subtype_Indication (P, 20596 New_Occurrence_Of (Subtype_Mark_Id, Sloc (S))); 20597 end if; 20598 20599 return Subtype_Mark_Id; 20600 end if; 20601 20602 Constrain_Access (Def_Id, S, Related_Nod); 20603 20604 if Expander_Active 20605 and then Is_Itype (Designated_Type (Def_Id)) 20606 and then Nkind (Related_Nod) = N_Subtype_Declaration 20607 and then not Is_Incomplete_Type (Designated_Type (Def_Id)) 20608 then 20609 Build_Itype_Reference 20610 (Designated_Type (Def_Id), Related_Nod); 20611 end if; 20612 20613 when Array_Kind => 20614 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix); 20615 20616 when Decimal_Fixed_Point_Kind => 20617 Constrain_Decimal (Def_Id, S); 20618 20619 when Enumeration_Kind => 20620 Constrain_Enumeration (Def_Id, S); 20621 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id); 20622 20623 when Ordinary_Fixed_Point_Kind => 20624 Constrain_Ordinary_Fixed (Def_Id, S); 20625 20626 when Float_Kind => 20627 Constrain_Float (Def_Id, S); 20628 20629 when Integer_Kind => 20630 Constrain_Integer (Def_Id, S); 20631 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id); 20632 20633 when E_Record_Type | 20634 E_Record_Subtype | 20635 Class_Wide_Kind | 20636 E_Incomplete_Type => 20637 Constrain_Discriminated_Type (Def_Id, S, Related_Nod); 20638 20639 if Ekind (Def_Id) = E_Incomplete_Type then 20640 Set_Private_Dependents (Def_Id, New_Elmt_List); 20641 end if; 20642 20643 when Private_Kind => 20644 Constrain_Discriminated_Type (Def_Id, S, Related_Nod); 20645 Set_Private_Dependents (Def_Id, New_Elmt_List); 20646 20647 -- In case of an invalid constraint prevent further processing 20648 -- since the type constructed is missing expected fields. 20649 20650 if Etype (Def_Id) = Any_Type then 20651 return Def_Id; 20652 end if; 20653 20654 -- If the full view is that of a task with discriminants, 20655 -- we must constrain both the concurrent type and its 20656 -- corresponding record type. Otherwise we will just propagate 20657 -- the constraint to the full view, if available. 20658 20659 if Present (Full_View (Subtype_Mark_Id)) 20660 and then Has_Discriminants (Subtype_Mark_Id) 20661 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id)) 20662 then 20663 Full_View_Id := 20664 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); 20665 20666 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id)); 20667 Constrain_Concurrent (Full_View_Id, S, 20668 Related_Nod, Related_Id, Suffix); 20669 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id); 20670 Set_Full_View (Def_Id, Full_View_Id); 20671 20672 -- Introduce an explicit reference to the private subtype, 20673 -- to prevent scope anomalies in gigi if first use appears 20674 -- in a nested context, e.g. a later function body. 20675 -- Should this be generated in other contexts than a full 20676 -- type declaration? 20677 20678 if Is_Itype (Def_Id) 20679 and then 20680 Nkind (Parent (P)) = N_Full_Type_Declaration 20681 then 20682 Build_Itype_Reference (Def_Id, Parent (P)); 20683 end if; 20684 20685 else 20686 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod); 20687 end if; 20688 20689 when Concurrent_Kind => 20690 Constrain_Concurrent (Def_Id, S, 20691 Related_Nod, Related_Id, Suffix); 20692 20693 when others => 20694 Error_Msg_N ("invalid subtype mark in subtype indication", S); 20695 end case; 20696 20697 -- Size and Convention are always inherited from the base type 20698 20699 Set_Size_Info (Def_Id, (Subtype_Mark_Id)); 20700 Set_Convention (Def_Id, Convention (Subtype_Mark_Id)); 20701 20702 return Def_Id; 20703 end if; 20704 end Process_Subtype; 20705 20706 -------------------------------------------- 20707 -- Propagate_Default_Init_Cond_Attributes -- 20708 -------------------------------------------- 20709 20710 procedure Propagate_Default_Init_Cond_Attributes 20711 (From_Typ : Entity_Id; 20712 To_Typ : Entity_Id; 20713 Parent_To_Derivation : Boolean := False; 20714 Private_To_Full_View : Boolean := False) 20715 is 20716 procedure Remove_Default_Init_Cond_Procedure (Typ : Entity_Id); 20717 -- Remove the default initial procedure (if any) from the rep chain of 20718 -- type Typ. 20719 20720 ---------------------------------------- 20721 -- Remove_Default_Init_Cond_Procedure -- 20722 ---------------------------------------- 20723 20724 procedure Remove_Default_Init_Cond_Procedure (Typ : Entity_Id) is 20725 Found : Boolean := False; 20726 Prev : Entity_Id; 20727 Subp : Entity_Id; 20728 20729 begin 20730 Prev := Typ; 20731 Subp := Subprograms_For_Type (Typ); 20732 while Present (Subp) loop 20733 if Is_Default_Init_Cond_Procedure (Subp) then 20734 Found := True; 20735 exit; 20736 end if; 20737 20738 Prev := Subp; 20739 Subp := Subprograms_For_Type (Subp); 20740 end loop; 20741 20742 if Found then 20743 Set_Subprograms_For_Type (Prev, Subprograms_For_Type (Subp)); 20744 Set_Subprograms_For_Type (Subp, Empty); 20745 end if; 20746 end Remove_Default_Init_Cond_Procedure; 20747 20748 -- Local variables 20749 20750 Inherit_Procedure : Boolean := False; 20751 20752 -- Start of processing for Propagate_Default_Init_Cond_Attributes 20753 20754 begin 20755 if Has_Default_Init_Cond (From_Typ) then 20756 20757 -- A derived type inherits the attributes from its parent type 20758 20759 if Parent_To_Derivation then 20760 Set_Has_Inherited_Default_Init_Cond (To_Typ); 20761 20762 -- A full view shares the attributes with its private view 20763 20764 else 20765 Set_Has_Default_Init_Cond (To_Typ); 20766 end if; 20767 20768 Inherit_Procedure := True; 20769 20770 -- Due to the order of expansion, a derived private type is processed 20771 -- by two routines which both attempt to set the attributes related 20772 -- to pragma Default_Initial_Condition - Build_Derived_Type and then 20773 -- Process_Full_View. 20774 20775 -- package Pack is 20776 -- type Parent_Typ is private 20777 -- with Default_Initial_Condition ...; 20778 -- private 20779 -- type Parent_Typ is ...; 20780 -- end Pack; 20781 20782 -- with Pack; use Pack; 20783 -- package Pack_2 is 20784 -- type Deriv_Typ is private 20785 -- with Default_Initial_Condition ...; 20786 -- private 20787 -- type Deriv_Typ is new Parent_Typ; 20788 -- end Pack_2; 20789 20790 -- When Build_Derived_Type operates, it sets the attributes on the 20791 -- full view without taking into account that the private view may 20792 -- define its own default initial condition procedure. This becomes 20793 -- apparent in Process_Full_View which must undo some of the work by 20794 -- Build_Derived_Type and propagate the attributes from the private 20795 -- to the full view. 20796 20797 if Private_To_Full_View then 20798 Set_Has_Inherited_Default_Init_Cond (To_Typ, False); 20799 Remove_Default_Init_Cond_Procedure (To_Typ); 20800 end if; 20801 20802 -- A type must inherit the default initial condition procedure from a 20803 -- parent type when the parent itself is inheriting the procedure or 20804 -- when it is defining one. This circuitry is also used when dealing 20805 -- with the private / full view of a type. 20806 20807 elsif Has_Inherited_Default_Init_Cond (From_Typ) 20808 or (Parent_To_Derivation 20809 and Present (Get_Pragma 20810 (From_Typ, Pragma_Default_Initial_Condition))) 20811 then 20812 Set_Has_Inherited_Default_Init_Cond (To_Typ); 20813 Inherit_Procedure := True; 20814 end if; 20815 20816 if Inherit_Procedure 20817 and then No (Default_Init_Cond_Procedure (To_Typ)) 20818 then 20819 Set_Default_Init_Cond_Procedure 20820 (To_Typ, Default_Init_Cond_Procedure (From_Typ)); 20821 end if; 20822 end Propagate_Default_Init_Cond_Attributes; 20823 20824 ----------------------------- 20825 -- Record_Type_Declaration -- 20826 ----------------------------- 20827 20828 procedure Record_Type_Declaration 20829 (T : Entity_Id; 20830 N : Node_Id; 20831 Prev : Entity_Id) 20832 is 20833 Def : constant Node_Id := Type_Definition (N); 20834 Is_Tagged : Boolean; 20835 Tag_Comp : Entity_Id; 20836 20837 begin 20838 -- These flags must be initialized before calling Process_Discriminants 20839 -- because this routine makes use of them. 20840 20841 Set_Ekind (T, E_Record_Type); 20842 Set_Etype (T, T); 20843 Init_Size_Align (T); 20844 Set_Interfaces (T, No_Elist); 20845 Set_Stored_Constraint (T, No_Elist); 20846 Set_Default_SSO (T); 20847 20848 -- Normal case 20849 20850 if Ada_Version < Ada_2005 or else not Interface_Present (Def) then 20851 if Limited_Present (Def) then 20852 Check_SPARK_05_Restriction ("limited is not allowed", N); 20853 end if; 20854 20855 if Abstract_Present (Def) then 20856 Check_SPARK_05_Restriction ("abstract is not allowed", N); 20857 end if; 20858 20859 -- The flag Is_Tagged_Type might have already been set by 20860 -- Find_Type_Name if it detected an error for declaration T. This 20861 -- arises in the case of private tagged types where the full view 20862 -- omits the word tagged. 20863 20864 Is_Tagged := 20865 Tagged_Present (Def) 20866 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T)); 20867 20868 Set_Is_Limited_Record (T, Limited_Present (Def)); 20869 20870 if Is_Tagged then 20871 Set_Is_Tagged_Type (T, True); 20872 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams); 20873 end if; 20874 20875 -- Type is abstract if full declaration carries keyword, or if 20876 -- previous partial view did. 20877 20878 Set_Is_Abstract_Type (T, Is_Abstract_Type (T) 20879 or else Abstract_Present (Def)); 20880 20881 else 20882 Check_SPARK_05_Restriction ("interface is not allowed", N); 20883 20884 Is_Tagged := True; 20885 Analyze_Interface_Declaration (T, Def); 20886 20887 if Present (Discriminant_Specifications (N)) then 20888 Error_Msg_N 20889 ("interface types cannot have discriminants", 20890 Defining_Identifier 20891 (First (Discriminant_Specifications (N)))); 20892 end if; 20893 end if; 20894 20895 -- First pass: if there are self-referential access components, 20896 -- create the required anonymous access type declarations, and if 20897 -- need be an incomplete type declaration for T itself. 20898 20899 Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def)); 20900 20901 if Ada_Version >= Ada_2005 20902 and then Present (Interface_List (Def)) 20903 then 20904 Check_Interfaces (N, Def); 20905 20906 declare 20907 Ifaces_List : Elist_Id; 20908 20909 begin 20910 -- Ada 2005 (AI-251): Collect the list of progenitors that are not 20911 -- already in the parents. 20912 20913 Collect_Interfaces 20914 (T => T, 20915 Ifaces_List => Ifaces_List, 20916 Exclude_Parents => True); 20917 20918 Set_Interfaces (T, Ifaces_List); 20919 end; 20920 end if; 20921 20922 -- Records constitute a scope for the component declarations within. 20923 -- The scope is created prior to the processing of these declarations. 20924 -- Discriminants are processed first, so that they are visible when 20925 -- processing the other components. The Ekind of the record type itself 20926 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype). 20927 20928 -- Enter record scope 20929 20930 Push_Scope (T); 20931 20932 -- If an incomplete or private type declaration was already given for 20933 -- the type, then this scope already exists, and the discriminants have 20934 -- been declared within. We must verify that the full declaration 20935 -- matches the incomplete one. 20936 20937 Check_Or_Process_Discriminants (N, T, Prev); 20938 20939 Set_Is_Constrained (T, not Has_Discriminants (T)); 20940 Set_Has_Delayed_Freeze (T, True); 20941 20942 -- For tagged types add a manually analyzed component corresponding 20943 -- to the component _tag, the corresponding piece of tree will be 20944 -- expanded as part of the freezing actions if it is not a CPP_Class. 20945 20946 if Is_Tagged then 20947 20948 -- Do not add the tag unless we are in expansion mode 20949 20950 if Expander_Active then 20951 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag); 20952 Enter_Name (Tag_Comp); 20953 20954 Set_Ekind (Tag_Comp, E_Component); 20955 Set_Is_Tag (Tag_Comp); 20956 Set_Is_Aliased (Tag_Comp); 20957 Set_Etype (Tag_Comp, RTE (RE_Tag)); 20958 Set_DT_Entry_Count (Tag_Comp, No_Uint); 20959 Set_Original_Record_Component (Tag_Comp, Tag_Comp); 20960 Init_Component_Location (Tag_Comp); 20961 20962 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the 20963 -- implemented interfaces. 20964 20965 if Has_Interfaces (T) then 20966 Add_Interface_Tag_Components (N, T); 20967 end if; 20968 end if; 20969 20970 Make_Class_Wide_Type (T); 20971 Set_Direct_Primitive_Operations (T, New_Elmt_List); 20972 end if; 20973 20974 -- We must suppress range checks when processing record components in 20975 -- the presence of discriminants, since we don't want spurious checks to 20976 -- be generated during their analysis, but Suppress_Range_Checks flags 20977 -- must be reset the after processing the record definition. 20978 20979 -- Note: this is the only use of Kill_Range_Checks, and is a bit odd, 20980 -- couldn't we just use the normal range check suppression method here. 20981 -- That would seem cleaner ??? 20982 20983 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then 20984 Set_Kill_Range_Checks (T, True); 20985 Record_Type_Definition (Def, Prev); 20986 Set_Kill_Range_Checks (T, False); 20987 else 20988 Record_Type_Definition (Def, Prev); 20989 end if; 20990 20991 -- Exit from record scope 20992 20993 End_Scope; 20994 20995 -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all 20996 -- the implemented interfaces and associate them an aliased entity. 20997 20998 if Is_Tagged 20999 and then not Is_Empty_List (Interface_List (Def)) 21000 then 21001 Derive_Progenitor_Subprograms (T, T); 21002 end if; 21003 21004 Check_Function_Writable_Actuals (N); 21005 end Record_Type_Declaration; 21006 21007 ---------------------------- 21008 -- Record_Type_Definition -- 21009 ---------------------------- 21010 21011 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is 21012 Component : Entity_Id; 21013 Ctrl_Components : Boolean := False; 21014 Final_Storage_Only : Boolean; 21015 T : Entity_Id; 21016 21017 begin 21018 if Ekind (Prev_T) = E_Incomplete_Type then 21019 T := Full_View (Prev_T); 21020 else 21021 T := Prev_T; 21022 end if; 21023 21024 -- In SPARK, tagged types and type extensions may only be declared in 21025 -- the specification of library unit packages. 21026 21027 if Present (Def) and then Is_Tagged_Type (T) then 21028 declare 21029 Typ : Node_Id; 21030 Ctxt : Node_Id; 21031 21032 begin 21033 if Nkind (Parent (Def)) = N_Full_Type_Declaration then 21034 Typ := Parent (Def); 21035 else 21036 pragma Assert 21037 (Nkind (Parent (Def)) = N_Derived_Type_Definition); 21038 Typ := Parent (Parent (Def)); 21039 end if; 21040 21041 Ctxt := Parent (Typ); 21042 21043 if Nkind (Ctxt) = N_Package_Body 21044 and then Nkind (Parent (Ctxt)) = N_Compilation_Unit 21045 then 21046 Check_SPARK_05_Restriction 21047 ("type should be defined in package specification", Typ); 21048 21049 elsif Nkind (Ctxt) /= N_Package_Specification 21050 or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit 21051 then 21052 Check_SPARK_05_Restriction 21053 ("type should be defined in library unit package", Typ); 21054 end if; 21055 end; 21056 end if; 21057 21058 Final_Storage_Only := not Is_Controlled (T); 21059 21060 -- Ada 2005: Check whether an explicit Limited is present in a derived 21061 -- type declaration. 21062 21063 if Nkind (Parent (Def)) = N_Derived_Type_Definition 21064 and then Limited_Present (Parent (Def)) 21065 then 21066 Set_Is_Limited_Record (T); 21067 end if; 21068 21069 -- If the component list of a record type is defined by the reserved 21070 -- word null and there is no discriminant part, then the record type has 21071 -- no components and all records of the type are null records (RM 3.7) 21072 -- This procedure is also called to process the extension part of a 21073 -- record extension, in which case the current scope may have inherited 21074 -- components. 21075 21076 if No (Def) 21077 or else No (Component_List (Def)) 21078 or else Null_Present (Component_List (Def)) 21079 then 21080 if not Is_Tagged_Type (T) then 21081 Check_SPARK_05_Restriction ("untagged record cannot be null", Def); 21082 end if; 21083 21084 else 21085 Analyze_Declarations (Component_Items (Component_List (Def))); 21086 21087 if Present (Variant_Part (Component_List (Def))) then 21088 Check_SPARK_05_Restriction ("variant part is not allowed", Def); 21089 Analyze (Variant_Part (Component_List (Def))); 21090 end if; 21091 end if; 21092 21093 -- After completing the semantic analysis of the record definition, 21094 -- record components, both new and inherited, are accessible. Set their 21095 -- kind accordingly. Exclude malformed itypes from illegal declarations, 21096 -- whose Ekind may be void. 21097 21098 Component := First_Entity (Current_Scope); 21099 while Present (Component) loop 21100 if Ekind (Component) = E_Void 21101 and then not Is_Itype (Component) 21102 then 21103 Set_Ekind (Component, E_Component); 21104 Init_Component_Location (Component); 21105 end if; 21106 21107 if Has_Task (Etype (Component)) then 21108 Set_Has_Task (T); 21109 end if; 21110 21111 if Has_Protected (Etype (Component)) then 21112 Set_Has_Protected (T); 21113 end if; 21114 21115 if Ekind (Component) /= E_Component then 21116 null; 21117 21118 -- Do not set Has_Controlled_Component on a class-wide equivalent 21119 -- type. See Make_CW_Equivalent_Type. 21120 21121 elsif not Is_Class_Wide_Equivalent_Type (T) 21122 and then (Has_Controlled_Component (Etype (Component)) 21123 or else (Chars (Component) /= Name_uParent 21124 and then Is_Controlled (Etype (Component)))) 21125 then 21126 Set_Has_Controlled_Component (T, True); 21127 Final_Storage_Only := 21128 Final_Storage_Only 21129 and then Finalize_Storage_Only (Etype (Component)); 21130 Ctrl_Components := True; 21131 end if; 21132 21133 Next_Entity (Component); 21134 end loop; 21135 21136 -- A Type is Finalize_Storage_Only only if all its controlled components 21137 -- are also. 21138 21139 if Ctrl_Components then 21140 Set_Finalize_Storage_Only (T, Final_Storage_Only); 21141 end if; 21142 21143 -- Place reference to end record on the proper entity, which may 21144 -- be a partial view. 21145 21146 if Present (Def) then 21147 Process_End_Label (Def, 'e', Prev_T); 21148 end if; 21149 end Record_Type_Definition; 21150 21151 ------------------------ 21152 -- Replace_Components -- 21153 ------------------------ 21154 21155 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is 21156 function Process (N : Node_Id) return Traverse_Result; 21157 21158 ------------- 21159 -- Process -- 21160 ------------- 21161 21162 function Process (N : Node_Id) return Traverse_Result is 21163 Comp : Entity_Id; 21164 21165 begin 21166 if Nkind (N) = N_Discriminant_Specification then 21167 Comp := First_Discriminant (Typ); 21168 while Present (Comp) loop 21169 if Chars (Comp) = Chars (Defining_Identifier (N)) then 21170 Set_Defining_Identifier (N, Comp); 21171 exit; 21172 end if; 21173 21174 Next_Discriminant (Comp); 21175 end loop; 21176 21177 elsif Nkind (N) = N_Component_Declaration then 21178 Comp := First_Component (Typ); 21179 while Present (Comp) loop 21180 if Chars (Comp) = Chars (Defining_Identifier (N)) then 21181 Set_Defining_Identifier (N, Comp); 21182 exit; 21183 end if; 21184 21185 Next_Component (Comp); 21186 end loop; 21187 end if; 21188 21189 return OK; 21190 end Process; 21191 21192 procedure Replace is new Traverse_Proc (Process); 21193 21194 -- Start of processing for Replace_Components 21195 21196 begin 21197 Replace (Decl); 21198 end Replace_Components; 21199 21200 ------------------------------- 21201 -- Set_Completion_Referenced -- 21202 ------------------------------- 21203 21204 procedure Set_Completion_Referenced (E : Entity_Id) is 21205 begin 21206 -- If in main unit, mark entity that is a completion as referenced, 21207 -- warnings go on the partial view when needed. 21208 21209 if In_Extended_Main_Source_Unit (E) then 21210 Set_Referenced (E); 21211 end if; 21212 end Set_Completion_Referenced; 21213 21214 --------------------- 21215 -- Set_Default_SSO -- 21216 --------------------- 21217 21218 procedure Set_Default_SSO (T : Entity_Id) is 21219 begin 21220 case Opt.Default_SSO is 21221 when ' ' => 21222 null; 21223 when 'L' => 21224 Set_SSO_Set_Low_By_Default (T, True); 21225 when 'H' => 21226 Set_SSO_Set_High_By_Default (T, True); 21227 when others => 21228 raise Program_Error; 21229 end case; 21230 end Set_Default_SSO; 21231 21232 --------------------- 21233 -- Set_Fixed_Range -- 21234 --------------------- 21235 21236 -- The range for fixed-point types is complicated by the fact that we 21237 -- do not know the exact end points at the time of the declaration. This 21238 -- is true for three reasons: 21239 21240 -- A size clause may affect the fudging of the end-points. 21241 -- A small clause may affect the values of the end-points. 21242 -- We try to include the end-points if it does not affect the size. 21243 21244 -- This means that the actual end-points must be established at the 21245 -- point when the type is frozen. Meanwhile, we first narrow the range 21246 -- as permitted (so that it will fit if necessary in a small specified 21247 -- size), and then build a range subtree with these narrowed bounds. 21248 -- Set_Fixed_Range constructs the range from real literal values, and 21249 -- sets the range as the Scalar_Range of the given fixed-point type entity. 21250 21251 -- The parent of this range is set to point to the entity so that it is 21252 -- properly hooked into the tree (unlike normal Scalar_Range entries for 21253 -- other scalar types, which are just pointers to the range in the 21254 -- original tree, this would otherwise be an orphan). 21255 21256 -- The tree is left unanalyzed. When the type is frozen, the processing 21257 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not 21258 -- analyzed, and uses this as an indication that it should complete 21259 -- work on the range (it will know the final small and size values). 21260 21261 procedure Set_Fixed_Range 21262 (E : Entity_Id; 21263 Loc : Source_Ptr; 21264 Lo : Ureal; 21265 Hi : Ureal) 21266 is 21267 S : constant Node_Id := 21268 Make_Range (Loc, 21269 Low_Bound => Make_Real_Literal (Loc, Lo), 21270 High_Bound => Make_Real_Literal (Loc, Hi)); 21271 begin 21272 Set_Scalar_Range (E, S); 21273 Set_Parent (S, E); 21274 21275 -- Before the freeze point, the bounds of a fixed point are universal 21276 -- and carry the corresponding type. 21277 21278 Set_Etype (Low_Bound (S), Universal_Real); 21279 Set_Etype (High_Bound (S), Universal_Real); 21280 end Set_Fixed_Range; 21281 21282 ---------------------------------- 21283 -- Set_Scalar_Range_For_Subtype -- 21284 ---------------------------------- 21285 21286 procedure Set_Scalar_Range_For_Subtype 21287 (Def_Id : Entity_Id; 21288 R : Node_Id; 21289 Subt : Entity_Id) 21290 is 21291 Kind : constant Entity_Kind := Ekind (Def_Id); 21292 21293 begin 21294 -- Defend against previous error 21295 21296 if Nkind (R) = N_Error then 21297 return; 21298 end if; 21299 21300 Set_Scalar_Range (Def_Id, R); 21301 21302 -- We need to link the range into the tree before resolving it so 21303 -- that types that are referenced, including importantly the subtype 21304 -- itself, are properly frozen (Freeze_Expression requires that the 21305 -- expression be properly linked into the tree). Of course if it is 21306 -- already linked in, then we do not disturb the current link. 21307 21308 if No (Parent (R)) then 21309 Set_Parent (R, Def_Id); 21310 end if; 21311 21312 -- Reset the kind of the subtype during analysis of the range, to 21313 -- catch possible premature use in the bounds themselves. 21314 21315 Set_Ekind (Def_Id, E_Void); 21316 Process_Range_Expr_In_Decl (R, Subt, Subtyp => Def_Id); 21317 Set_Ekind (Def_Id, Kind); 21318 end Set_Scalar_Range_For_Subtype; 21319 21320 -------------------------------------------------------- 21321 -- Set_Stored_Constraint_From_Discriminant_Constraint -- 21322 -------------------------------------------------------- 21323 21324 procedure Set_Stored_Constraint_From_Discriminant_Constraint 21325 (E : Entity_Id) 21326 is 21327 begin 21328 -- Make sure set if encountered during Expand_To_Stored_Constraint 21329 21330 Set_Stored_Constraint (E, No_Elist); 21331 21332 -- Give it the right value 21333 21334 if Is_Constrained (E) and then Has_Discriminants (E) then 21335 Set_Stored_Constraint (E, 21336 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E))); 21337 end if; 21338 end Set_Stored_Constraint_From_Discriminant_Constraint; 21339 21340 ------------------------------------- 21341 -- Signed_Integer_Type_Declaration -- 21342 ------------------------------------- 21343 21344 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is 21345 Implicit_Base : Entity_Id; 21346 Base_Typ : Entity_Id; 21347 Lo_Val : Uint; 21348 Hi_Val : Uint; 21349 Errs : Boolean := False; 21350 Lo : Node_Id; 21351 Hi : Node_Id; 21352 21353 function Can_Derive_From (E : Entity_Id) return Boolean; 21354 -- Determine whether given bounds allow derivation from specified type 21355 21356 procedure Check_Bound (Expr : Node_Id); 21357 -- Check bound to make sure it is integral and static. If not, post 21358 -- appropriate error message and set Errs flag 21359 21360 --------------------- 21361 -- Can_Derive_From -- 21362 --------------------- 21363 21364 -- Note we check both bounds against both end values, to deal with 21365 -- strange types like ones with a range of 0 .. -12341234. 21366 21367 function Can_Derive_From (E : Entity_Id) return Boolean is 21368 Lo : constant Uint := Expr_Value (Type_Low_Bound (E)); 21369 Hi : constant Uint := Expr_Value (Type_High_Bound (E)); 21370 begin 21371 return Lo <= Lo_Val and then Lo_Val <= Hi 21372 and then 21373 Lo <= Hi_Val and then Hi_Val <= Hi; 21374 end Can_Derive_From; 21375 21376 ----------------- 21377 -- Check_Bound -- 21378 ----------------- 21379 21380 procedure Check_Bound (Expr : Node_Id) is 21381 begin 21382 -- If a range constraint is used as an integer type definition, each 21383 -- bound of the range must be defined by a static expression of some 21384 -- integer type, but the two bounds need not have the same integer 21385 -- type (Negative bounds are allowed.) (RM 3.5.4) 21386 21387 if not Is_Integer_Type (Etype (Expr)) then 21388 Error_Msg_N 21389 ("integer type definition bounds must be of integer type", Expr); 21390 Errs := True; 21391 21392 elsif not Is_OK_Static_Expression (Expr) then 21393 Flag_Non_Static_Expr 21394 ("non-static expression used for integer type bound!", Expr); 21395 Errs := True; 21396 21397 -- The bounds are folded into literals, and we set their type to be 21398 -- universal, to avoid typing difficulties: we cannot set the type 21399 -- of the literal to the new type, because this would be a forward 21400 -- reference for the back end, and if the original type is user- 21401 -- defined this can lead to spurious semantic errors (e.g. 2928-003). 21402 21403 else 21404 if Is_Entity_Name (Expr) then 21405 Fold_Uint (Expr, Expr_Value (Expr), True); 21406 end if; 21407 21408 Set_Etype (Expr, Universal_Integer); 21409 end if; 21410 end Check_Bound; 21411 21412 -- Start of processing for Signed_Integer_Type_Declaration 21413 21414 begin 21415 -- Create an anonymous base type 21416 21417 Implicit_Base := 21418 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B'); 21419 21420 -- Analyze and check the bounds, they can be of any integer type 21421 21422 Lo := Low_Bound (Def); 21423 Hi := High_Bound (Def); 21424 21425 -- Arbitrarily use Integer as the type if either bound had an error 21426 21427 if Hi = Error or else Lo = Error then 21428 Base_Typ := Any_Integer; 21429 Set_Error_Posted (T, True); 21430 21431 -- Here both bounds are OK expressions 21432 21433 else 21434 Analyze_And_Resolve (Lo, Any_Integer); 21435 Analyze_And_Resolve (Hi, Any_Integer); 21436 21437 Check_Bound (Lo); 21438 Check_Bound (Hi); 21439 21440 if Errs then 21441 Hi := Type_High_Bound (Standard_Long_Long_Integer); 21442 Lo := Type_Low_Bound (Standard_Long_Long_Integer); 21443 end if; 21444 21445 -- Find type to derive from 21446 21447 Lo_Val := Expr_Value (Lo); 21448 Hi_Val := Expr_Value (Hi); 21449 21450 if Can_Derive_From (Standard_Short_Short_Integer) then 21451 Base_Typ := Base_Type (Standard_Short_Short_Integer); 21452 21453 elsif Can_Derive_From (Standard_Short_Integer) then 21454 Base_Typ := Base_Type (Standard_Short_Integer); 21455 21456 elsif Can_Derive_From (Standard_Integer) then 21457 Base_Typ := Base_Type (Standard_Integer); 21458 21459 elsif Can_Derive_From (Standard_Long_Integer) then 21460 Base_Typ := Base_Type (Standard_Long_Integer); 21461 21462 elsif Can_Derive_From (Standard_Long_Long_Integer) then 21463 Check_Restriction (No_Long_Long_Integers, Def); 21464 Base_Typ := Base_Type (Standard_Long_Long_Integer); 21465 21466 else 21467 Base_Typ := Base_Type (Standard_Long_Long_Integer); 21468 Error_Msg_N ("integer type definition bounds out of range", Def); 21469 Hi := Type_High_Bound (Standard_Long_Long_Integer); 21470 Lo := Type_Low_Bound (Standard_Long_Long_Integer); 21471 end if; 21472 end if; 21473 21474 -- Complete both implicit base and declared first subtype entities. The 21475 -- inheritance of the rep item chain ensures that SPARK-related pragmas 21476 -- are not clobbered when the signed integer type acts as a full view of 21477 -- a private type. 21478 21479 Set_Etype (Implicit_Base, Base_Typ); 21480 Set_Size_Info (Implicit_Base, Base_Typ); 21481 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ)); 21482 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ)); 21483 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ)); 21484 21485 Set_Ekind (T, E_Signed_Integer_Subtype); 21486 Set_Etype (T, Implicit_Base); 21487 Set_Size_Info (T, Implicit_Base); 21488 Inherit_Rep_Item_Chain (T, Implicit_Base); 21489 Set_Scalar_Range (T, Def); 21490 Set_RM_Size (T, UI_From_Int (Minimum_Size (T))); 21491 Set_Is_Constrained (T); 21492 end Signed_Integer_Type_Declaration; 21493 21494end Sem_Ch3; 21495