1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ C H 4 -- 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 Debug; use Debug; 29with Einfo; use Einfo; 30with Elists; use Elists; 31with Errout; use Errout; 32with Exp_Util; use Exp_Util; 33with Fname; use Fname; 34with Itypes; use Itypes; 35with Lib; use Lib; 36with Lib.Xref; use Lib.Xref; 37with Namet; use Namet; 38with Namet.Sp; use Namet.Sp; 39with Nlists; use Nlists; 40with Nmake; use Nmake; 41with Opt; use Opt; 42with Output; use Output; 43with Restrict; use Restrict; 44with Rident; use Rident; 45with Sem; use Sem; 46with Sem_Aux; use Sem_Aux; 47with Sem_Case; use Sem_Case; 48with Sem_Cat; use Sem_Cat; 49with Sem_Ch3; use Sem_Ch3; 50with Sem_Ch6; use Sem_Ch6; 51with Sem_Ch8; use Sem_Ch8; 52with Sem_Dim; use Sem_Dim; 53with Sem_Disp; use Sem_Disp; 54with Sem_Dist; use Sem_Dist; 55with Sem_Eval; use Sem_Eval; 56with Sem_Res; use Sem_Res; 57with Sem_Type; use Sem_Type; 58with Sem_Util; use Sem_Util; 59with Sem_Warn; use Sem_Warn; 60with Stand; use Stand; 61with Sinfo; use Sinfo; 62with Snames; use Snames; 63with Tbuild; use Tbuild; 64with Uintp; use Uintp; 65 66package body Sem_Ch4 is 67 68 ----------------------- 69 -- Local Subprograms -- 70 ----------------------- 71 72 procedure Analyze_Concatenation_Rest (N : Node_Id); 73 -- Does the "rest" of the work of Analyze_Concatenation, after the left 74 -- operand has been analyzed. See Analyze_Concatenation for details. 75 76 procedure Analyze_Expression (N : Node_Id); 77 -- For expressions that are not names, this is just a call to analyze. If 78 -- the expression is a name, it may be a call to a parameterless function, 79 -- and if so must be converted into an explicit call node and analyzed as 80 -- such. This deproceduring must be done during the first pass of overload 81 -- resolution, because otherwise a procedure call with overloaded actuals 82 -- may fail to resolve. 83 84 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id); 85 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call is an 86 -- operator name or an expanded name whose selector is an operator name, 87 -- and one possible interpretation is as a predefined operator. 88 89 procedure Analyze_Overloaded_Selected_Component (N : Node_Id); 90 -- If the prefix of a selected_component is overloaded, the proper 91 -- interpretation that yields a record type with the proper selector 92 -- name must be selected. 93 94 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id); 95 -- Procedure to analyze a user defined binary operator, which is resolved 96 -- like a function, but instead of a list of actuals it is presented 97 -- with the left and right operands of an operator node. 98 99 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id); 100 -- Procedure to analyze a user defined unary operator, which is resolved 101 -- like a function, but instead of a list of actuals, it is presented with 102 -- the operand of the operator node. 103 104 procedure Ambiguous_Operands (N : Node_Id); 105 -- For equality, membership, and comparison operators with overloaded 106 -- arguments, list possible interpretations. 107 108 procedure Analyze_One_Call 109 (N : Node_Id; 110 Nam : Entity_Id; 111 Report : Boolean; 112 Success : out Boolean; 113 Skip_First : Boolean := False); 114 -- Check one interpretation of an overloaded subprogram name for 115 -- compatibility with the types of the actuals in a call. If there is a 116 -- single interpretation which does not match, post error if Report is 117 -- set to True. 118 -- 119 -- Nam is the entity that provides the formals against which the actuals 120 -- are checked. Nam is either the name of a subprogram, or the internal 121 -- subprogram type constructed for an access_to_subprogram. If the actuals 122 -- are compatible with Nam, then Nam is added to the list of candidate 123 -- interpretations for N, and Success is set to True. 124 -- 125 -- The flag Skip_First is used when analyzing a call that was rewritten 126 -- from object notation. In this case the first actual may have to receive 127 -- an explicit dereference, depending on the first formal of the operation 128 -- being called. The caller will have verified that the object is legal 129 -- for the call. If the remaining parameters match, the first parameter 130 -- will rewritten as a dereference if needed, prior to completing analysis. 131 132 procedure Check_Misspelled_Selector 133 (Prefix : Entity_Id; 134 Sel : Node_Id); 135 -- Give possible misspelling message if Sel seems likely to be a mis- 136 -- spelling of one of the selectors of the Prefix. This is called by 137 -- Analyze_Selected_Component after producing an invalid selector error 138 -- message. 139 140 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean; 141 -- Verify that type T is declared in scope S. Used to find interpretations 142 -- for operators given by expanded names. This is abstracted as a separate 143 -- function to handle extensions to System, where S is System, but T is 144 -- declared in the extension. 145 146 procedure Find_Arithmetic_Types 147 (L, R : Node_Id; 148 Op_Id : Entity_Id; 149 N : Node_Id); 150 -- L and R are the operands of an arithmetic operator. Find consistent 151 -- pairs of interpretations for L and R that have a numeric type consistent 152 -- with the semantics of the operator. 153 154 procedure Find_Comparison_Types 155 (L, R : Node_Id; 156 Op_Id : Entity_Id; 157 N : Node_Id); 158 -- L and R are operands of a comparison operator. Find consistent pairs of 159 -- interpretations for L and R. 160 161 procedure Find_Concatenation_Types 162 (L, R : Node_Id; 163 Op_Id : Entity_Id; 164 N : Node_Id); 165 -- For the four varieties of concatenation 166 167 procedure Find_Equality_Types 168 (L, R : Node_Id; 169 Op_Id : Entity_Id; 170 N : Node_Id); 171 -- Ditto for equality operators 172 173 procedure Find_Boolean_Types 174 (L, R : Node_Id; 175 Op_Id : Entity_Id; 176 N : Node_Id); 177 -- Ditto for binary logical operations 178 179 procedure Find_Negation_Types 180 (R : Node_Id; 181 Op_Id : Entity_Id; 182 N : Node_Id); 183 -- Find consistent interpretation for operand of negation operator 184 185 procedure Find_Non_Universal_Interpretations 186 (N : Node_Id; 187 R : Node_Id; 188 Op_Id : Entity_Id; 189 T1 : Entity_Id); 190 -- For equality and comparison operators, the result is always boolean, 191 -- and the legality of the operation is determined from the visibility 192 -- of the operand types. If one of the operands has a universal interpre- 193 -- tation, the legality check uses some compatible non-universal 194 -- interpretation of the other operand. N can be an operator node, or 195 -- a function call whose name is an operator designator. Any_Access, which 196 -- is the initial type of the literal NULL, is a universal type for the 197 -- purpose of this routine. 198 199 function Find_Primitive_Operation (N : Node_Id) return Boolean; 200 -- Find candidate interpretations for the name Obj.Proc when it appears 201 -- in a subprogram renaming declaration. 202 203 procedure Find_Unary_Types 204 (R : Node_Id; 205 Op_Id : Entity_Id; 206 N : Node_Id); 207 -- Unary arithmetic types: plus, minus, abs 208 209 procedure Check_Arithmetic_Pair 210 (T1, T2 : Entity_Id; 211 Op_Id : Entity_Id; 212 N : Node_Id); 213 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid 214 -- types for left and right operand. Determine whether they constitute 215 -- a valid pair for the given operator, and record the corresponding 216 -- interpretation of the operator node. The node N may be an operator 217 -- node (the usual case) or a function call whose prefix is an operator 218 -- designator. In both cases Op_Id is the operator name itself. 219 220 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id); 221 -- Give detailed information on overloaded call where none of the 222 -- interpretations match. N is the call node, Nam the designator for 223 -- the overloaded entity being called. 224 225 function Junk_Operand (N : Node_Id) return Boolean; 226 -- Test for an operand that is an inappropriate entity (e.g. a package 227 -- name or a label). If so, issue an error message and return True. If 228 -- the operand is not an inappropriate entity kind, return False. 229 230 procedure Operator_Check (N : Node_Id); 231 -- Verify that an operator has received some valid interpretation. If none 232 -- was found, determine whether a use clause would make the operation 233 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for 234 -- every type compatible with the operator, even if the operator for the 235 -- type is not directly visible. The routine uses this type to emit a more 236 -- informative message. 237 238 function Process_Implicit_Dereference_Prefix 239 (E : Entity_Id; 240 P : Node_Id) return Entity_Id; 241 -- Called when P is the prefix of an implicit dereference, denoting an 242 -- object E. The function returns the designated type of the prefix, taking 243 -- into account that the designated type of an anonymous access type may be 244 -- a limited view, when the non-limited view is visible. 245 -- If in semantics only mode (-gnatc or generic), the function also records 246 -- that the prefix is a reference to E, if any. Normally, such a reference 247 -- is generated only when the implicit dereference is expanded into an 248 -- explicit one, but for consistency we must generate the reference when 249 -- expansion is disabled as well. 250 251 procedure Remove_Abstract_Operations (N : Node_Id); 252 -- Ada 2005: implementation of AI-310. An abstract non-dispatching 253 -- operation is not a candidate interpretation. 254 255 function Try_Container_Indexing 256 (N : Node_Id; 257 Prefix : Node_Id; 258 Exprs : List_Id) return Boolean; 259 -- AI05-0139: Generalized indexing to support iterators over containers 260 261 function Try_Indexed_Call 262 (N : Node_Id; 263 Nam : Entity_Id; 264 Typ : Entity_Id; 265 Skip_First : Boolean) return Boolean; 266 -- If a function has defaults for all its actuals, a call to it may in fact 267 -- be an indexing on the result of the call. Try_Indexed_Call attempts the 268 -- interpretation as an indexing, prior to analysis as a call. If both are 269 -- possible, the node is overloaded with both interpretations (same symbol 270 -- but two different types). If the call is written in prefix form, the 271 -- prefix becomes the first parameter in the call, and only the remaining 272 -- actuals must be checked for the presence of defaults. 273 274 function Try_Indirect_Call 275 (N : Node_Id; 276 Nam : Entity_Id; 277 Typ : Entity_Id) return Boolean; 278 -- Similarly, a function F that needs no actuals can return an access to a 279 -- subprogram, and the call F (X) interpreted as F.all (X). In this case 280 -- the call may be overloaded with both interpretations. 281 282 function Try_Object_Operation 283 (N : Node_Id; 284 CW_Test_Only : Boolean := False) return Boolean; 285 -- Ada 2005 (AI-252): Support the object.operation notation. If node N 286 -- is a call in this notation, it is transformed into a normal subprogram 287 -- call where the prefix is a parameter, and True is returned. If node 288 -- N is not of this form, it is unchanged, and False is returned. if 289 -- CW_Test_Only is true then N is an N_Selected_Component node which 290 -- is part of a call to an entry or procedure of a tagged concurrent 291 -- type and this routine is invoked to search for class-wide subprograms 292 -- conflicting with the target entity. 293 294 procedure wpo (T : Entity_Id); 295 pragma Warnings (Off, wpo); 296 -- Used for debugging: obtain list of primitive operations even if 297 -- type is not frozen and dispatch table is not built yet. 298 299 ------------------------ 300 -- Ambiguous_Operands -- 301 ------------------------ 302 303 procedure Ambiguous_Operands (N : Node_Id) is 304 procedure List_Operand_Interps (Opnd : Node_Id); 305 306 -------------------------- 307 -- List_Operand_Interps -- 308 -------------------------- 309 310 procedure List_Operand_Interps (Opnd : Node_Id) is 311 Nam : Node_Id; 312 Err : Node_Id := N; 313 314 begin 315 if Is_Overloaded (Opnd) then 316 if Nkind (Opnd) in N_Op then 317 Nam := Opnd; 318 elsif Nkind (Opnd) = N_Function_Call then 319 Nam := Name (Opnd); 320 elsif Ada_Version >= Ada_2012 then 321 declare 322 It : Interp; 323 I : Interp_Index; 324 325 begin 326 Get_First_Interp (Opnd, I, It); 327 while Present (It.Nam) loop 328 if Has_Implicit_Dereference (It.Typ) then 329 Error_Msg_N 330 ("can be interpreted as implicit dereference", Opnd); 331 return; 332 end if; 333 334 Get_Next_Interp (I, It); 335 end loop; 336 end; 337 338 return; 339 end if; 340 341 else 342 return; 343 end if; 344 345 if Opnd = Left_Opnd (N) then 346 Error_Msg_N ("\left operand has the following interpretations", N); 347 else 348 Error_Msg_N 349 ("\right operand has the following interpretations", N); 350 Err := Opnd; 351 end if; 352 353 List_Interps (Nam, Err); 354 end List_Operand_Interps; 355 356 -- Start of processing for Ambiguous_Operands 357 358 begin 359 if Nkind (N) in N_Membership_Test then 360 Error_Msg_N ("ambiguous operands for membership", N); 361 362 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then 363 Error_Msg_N ("ambiguous operands for equality", N); 364 365 else 366 Error_Msg_N ("ambiguous operands for comparison", N); 367 end if; 368 369 if All_Errors_Mode then 370 List_Operand_Interps (Left_Opnd (N)); 371 List_Operand_Interps (Right_Opnd (N)); 372 else 373 Error_Msg_N ("\use -gnatf switch for details", N); 374 end if; 375 end Ambiguous_Operands; 376 377 ----------------------- 378 -- Analyze_Aggregate -- 379 ----------------------- 380 381 -- Most of the analysis of Aggregates requires that the type be known, 382 -- and is therefore put off until resolution. 383 384 procedure Analyze_Aggregate (N : Node_Id) is 385 begin 386 if No (Etype (N)) then 387 Set_Etype (N, Any_Composite); 388 end if; 389 end Analyze_Aggregate; 390 391 ----------------------- 392 -- Analyze_Allocator -- 393 ----------------------- 394 395 procedure Analyze_Allocator (N : Node_Id) is 396 Loc : constant Source_Ptr := Sloc (N); 397 Sav_Errs : constant Nat := Serious_Errors_Detected; 398 E : Node_Id := Expression (N); 399 Acc_Type : Entity_Id; 400 Type_Id : Entity_Id; 401 P : Node_Id; 402 C : Node_Id; 403 Onode : Node_Id; 404 405 begin 406 Check_SPARK_05_Restriction ("allocator is not allowed", N); 407 408 -- Deal with allocator restrictions 409 410 -- In accordance with H.4(7), the No_Allocators restriction only applies 411 -- to user-written allocators. The same consideration applies to the 412 -- No_Standard_Allocators_Before_Elaboration restriction. 413 414 if Comes_From_Source (N) then 415 Check_Restriction (No_Allocators, N); 416 417 -- Processing for No_Standard_Allocators_After_Elaboration, loop to 418 -- look at enclosing context, checking task/main subprogram case. 419 420 C := N; 421 P := Parent (C); 422 while Present (P) loop 423 424 -- For the task case we need a handled sequence of statements, 425 -- where the occurrence of the allocator is within the statements 426 -- and the parent is a task body 427 428 if Nkind (P) = N_Handled_Sequence_Of_Statements 429 and then Is_List_Member (C) 430 and then List_Containing (C) = Statements (P) 431 then 432 Onode := Original_Node (Parent (P)); 433 434 -- Check for allocator within task body, this is a definite 435 -- violation of No_Allocators_After_Elaboration we can detect 436 -- at compile time. 437 438 if Nkind (Onode) = N_Task_Body then 439 Check_Restriction 440 (No_Standard_Allocators_After_Elaboration, N); 441 exit; 442 end if; 443 end if; 444 445 -- The other case is appearance in a subprogram body. This is 446 -- a violation if this is a library level subprogram with no 447 -- parameters. Note that this is now a static error even if the 448 -- subprogram is not the main program (this is a change, in an 449 -- earlier version only the main program was affected, and the 450 -- check had to be done in the binder. 451 452 if Nkind (P) = N_Subprogram_Body 453 and then Nkind (Parent (P)) = N_Compilation_Unit 454 and then No (Parameter_Specifications (Specification (P))) 455 then 456 Check_Restriction 457 (No_Standard_Allocators_After_Elaboration, N); 458 end if; 459 460 C := P; 461 P := Parent (C); 462 end loop; 463 end if; 464 465 -- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if 466 -- any. The expected type for the name is any type. A non-overloading 467 -- rule then requires it to be of a type descended from 468 -- System.Storage_Pools.Subpools.Subpool_Handle. 469 470 -- This isn't exactly what the AI says, but it seems to be the right 471 -- rule. The AI should be fixed.??? 472 473 declare 474 Subpool : constant Node_Id := Subpool_Handle_Name (N); 475 476 begin 477 if Present (Subpool) then 478 Analyze (Subpool); 479 480 if Is_Overloaded (Subpool) then 481 Error_Msg_N ("ambiguous subpool handle", Subpool); 482 end if; 483 484 -- Check that Etype (Subpool) is descended from Subpool_Handle 485 486 Resolve (Subpool); 487 end if; 488 end; 489 490 -- Analyze the qualified expression or subtype indication 491 492 if Nkind (E) = N_Qualified_Expression then 493 Acc_Type := Create_Itype (E_Allocator_Type, N); 494 Set_Etype (Acc_Type, Acc_Type); 495 Find_Type (Subtype_Mark (E)); 496 497 -- Analyze the qualified expression, and apply the name resolution 498 -- rule given in 4.7(3). 499 500 Analyze (E); 501 Type_Id := Etype (E); 502 Set_Directly_Designated_Type (Acc_Type, Type_Id); 503 504 -- Allocators generated by the build-in-place expansion mechanism 505 -- are explicitly marked as coming from source but do not need to be 506 -- checked for limited initialization. To exclude this case, ensure 507 -- that the parent of the allocator is a source node. 508 509 if Is_Limited_Type (Type_Id) 510 and then Comes_From_Source (N) 511 and then Comes_From_Source (Parent (N)) 512 and then not In_Instance_Body 513 then 514 if not OK_For_Limited_Init (Type_Id, Expression (E)) then 515 Error_Msg_N ("initialization not allowed for limited types", N); 516 Explain_Limited_Type (Type_Id, N); 517 end if; 518 end if; 519 520 -- A qualified expression requires an exact match of the type, 521 -- class-wide matching is not allowed. 522 523 -- if Is_Class_Wide_Type (Type_Id) 524 -- and then Base_Type 525 -- (Etype (Expression (E))) /= Base_Type (Type_Id) 526 -- then 527 -- Wrong_Type (Expression (E), Type_Id); 528 -- end if; 529 530 -- We don't analyze the qualified expression itself because it's 531 -- part of the allocator. It is fully analyzed and resolved when 532 -- the allocator is resolved with the context type. 533 534 Set_Etype (E, Type_Id); 535 536 -- Case where allocator has a subtype indication 537 538 else 539 declare 540 Def_Id : Entity_Id; 541 Base_Typ : Entity_Id; 542 543 begin 544 -- If the allocator includes a N_Subtype_Indication then a 545 -- constraint is present, otherwise the node is a subtype mark. 546 -- Introduce an explicit subtype declaration into the tree 547 -- defining some anonymous subtype and rewrite the allocator to 548 -- use this subtype rather than the subtype indication. 549 550 -- It is important to introduce the explicit subtype declaration 551 -- so that the bounds of the subtype indication are attached to 552 -- the tree in case the allocator is inside a generic unit. 553 554 if Nkind (E) = N_Subtype_Indication then 555 556 -- A constraint is only allowed for a composite type in Ada 557 -- 95. In Ada 83, a constraint is also allowed for an 558 -- access-to-composite type, but the constraint is ignored. 559 560 Find_Type (Subtype_Mark (E)); 561 Base_Typ := Entity (Subtype_Mark (E)); 562 563 if Is_Elementary_Type (Base_Typ) then 564 if not (Ada_Version = Ada_83 565 and then Is_Access_Type (Base_Typ)) 566 then 567 Error_Msg_N ("constraint not allowed here", E); 568 569 if Nkind (Constraint (E)) = 570 N_Index_Or_Discriminant_Constraint 571 then 572 Error_Msg_N -- CODEFIX 573 ("\if qualified expression was meant, " & 574 "use apostrophe", Constraint (E)); 575 end if; 576 end if; 577 578 -- Get rid of the bogus constraint: 579 580 Rewrite (E, New_Copy_Tree (Subtype_Mark (E))); 581 Analyze_Allocator (N); 582 return; 583 end if; 584 585 if Expander_Active then 586 Def_Id := Make_Temporary (Loc, 'S'); 587 588 Insert_Action (E, 589 Make_Subtype_Declaration (Loc, 590 Defining_Identifier => Def_Id, 591 Subtype_Indication => Relocate_Node (E))); 592 593 if Sav_Errs /= Serious_Errors_Detected 594 and then Nkind (Constraint (E)) = 595 N_Index_Or_Discriminant_Constraint 596 then 597 Error_Msg_N -- CODEFIX 598 ("if qualified expression was meant, " 599 & "use apostrophe!", Constraint (E)); 600 end if; 601 602 E := New_Occurrence_Of (Def_Id, Loc); 603 Rewrite (Expression (N), E); 604 end if; 605 end if; 606 607 Type_Id := Process_Subtype (E, N); 608 Acc_Type := Create_Itype (E_Allocator_Type, N); 609 Set_Etype (Acc_Type, Acc_Type); 610 Set_Directly_Designated_Type (Acc_Type, Type_Id); 611 Check_Fully_Declared (Type_Id, N); 612 613 -- Ada 2005 (AI-231): If the designated type is itself an access 614 -- type that excludes null, its default initialization will 615 -- be a null object, and we can insert an unconditional raise 616 -- before the allocator. 617 618 -- Ada 2012 (AI-104): A not null indication here is altogether 619 -- illegal. 620 621 if Can_Never_Be_Null (Type_Id) then 622 declare 623 Not_Null_Check : constant Node_Id := 624 Make_Raise_Constraint_Error (Sloc (E), 625 Reason => CE_Null_Not_Allowed); 626 627 begin 628 if Expander_Active then 629 Insert_Action (N, Not_Null_Check); 630 Analyze (Not_Null_Check); 631 632 elsif Warn_On_Ada_2012_Compatibility then 633 Error_Msg_N 634 ("null value not allowed here in Ada 2012?y?", E); 635 end if; 636 end; 637 end if; 638 639 -- Check for missing initialization. Skip this check if we already 640 -- had errors on analyzing the allocator, since in that case these 641 -- are probably cascaded errors. 642 643 if Is_Indefinite_Subtype (Type_Id) 644 and then Serious_Errors_Detected = Sav_Errs 645 then 646 -- The build-in-place machinery may produce an allocator when 647 -- the designated type is indefinite but the underlying type is 648 -- not. In this case the unknown discriminants are meaningless 649 -- and should not trigger error messages. Check the parent node 650 -- because the allocator is marked as coming from source. 651 652 if Present (Underlying_Type (Type_Id)) 653 and then not Is_Indefinite_Subtype (Underlying_Type (Type_Id)) 654 and then not Comes_From_Source (Parent (N)) 655 then 656 null; 657 658 elsif Is_Class_Wide_Type (Type_Id) then 659 Error_Msg_N 660 ("initialization required in class-wide allocation", N); 661 662 else 663 if Ada_Version < Ada_2005 664 and then Is_Limited_Type (Type_Id) 665 then 666 Error_Msg_N ("unconstrained allocation not allowed", N); 667 668 if Is_Array_Type (Type_Id) then 669 Error_Msg_N 670 ("\constraint with array bounds required", N); 671 672 elsif Has_Unknown_Discriminants (Type_Id) then 673 null; 674 675 else pragma Assert (Has_Discriminants (Type_Id)); 676 Error_Msg_N 677 ("\constraint with discriminant values required", N); 678 end if; 679 680 -- Limited Ada 2005 and general non-limited case 681 682 else 683 Error_Msg_N 684 ("uninitialized unconstrained allocation not allowed", 685 N); 686 687 if Is_Array_Type (Type_Id) then 688 Error_Msg_N 689 ("\qualified expression or constraint with " & 690 "array bounds required", N); 691 692 elsif Has_Unknown_Discriminants (Type_Id) then 693 Error_Msg_N ("\qualified expression required", N); 694 695 else pragma Assert (Has_Discriminants (Type_Id)); 696 Error_Msg_N 697 ("\qualified expression or constraint with " & 698 "discriminant values required", N); 699 end if; 700 end if; 701 end if; 702 end if; 703 end; 704 end if; 705 706 if Is_Abstract_Type (Type_Id) then 707 Error_Msg_N ("cannot allocate abstract object", E); 708 end if; 709 710 if Has_Task (Designated_Type (Acc_Type)) then 711 Check_Restriction (No_Tasking, N); 712 Check_Restriction (Max_Tasks, N); 713 Check_Restriction (No_Task_Allocators, N); 714 end if; 715 716 -- Check restriction against dynamically allocated protected objects 717 718 if Has_Protected (Designated_Type (Acc_Type)) then 719 Check_Restriction (No_Protected_Type_Allocators, N); 720 end if; 721 722 -- AI05-0013-1: No_Nested_Finalization forbids allocators if the access 723 -- type is nested, and the designated type needs finalization. The rule 724 -- is conservative in that class-wide types need finalization. 725 726 if Needs_Finalization (Designated_Type (Acc_Type)) 727 and then not Is_Library_Level_Entity (Acc_Type) 728 then 729 Check_Restriction (No_Nested_Finalization, N); 730 end if; 731 732 -- Check that an allocator of a nested access type doesn't create a 733 -- protected object when restriction No_Local_Protected_Objects applies. 734 735 if Has_Protected (Designated_Type (Acc_Type)) 736 and then not Is_Library_Level_Entity (Acc_Type) 737 then 738 Check_Restriction (No_Local_Protected_Objects, N); 739 end if; 740 741 -- If the No_Streams restriction is set, check that the type of the 742 -- object is not, and does not contain, any subtype derived from 743 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to 744 -- Has_Stream just for efficiency reasons. There is no point in 745 -- spending time on a Has_Stream check if the restriction is not set. 746 747 if Restriction_Check_Required (No_Streams) then 748 if Has_Stream (Designated_Type (Acc_Type)) then 749 Check_Restriction (No_Streams, N); 750 end if; 751 end if; 752 753 Set_Etype (N, Acc_Type); 754 755 if not Is_Library_Level_Entity (Acc_Type) then 756 Check_Restriction (No_Local_Allocators, N); 757 end if; 758 759 if Serious_Errors_Detected > Sav_Errs then 760 Set_Error_Posted (N); 761 Set_Etype (N, Any_Type); 762 end if; 763 end Analyze_Allocator; 764 765 --------------------------- 766 -- Analyze_Arithmetic_Op -- 767 --------------------------- 768 769 procedure Analyze_Arithmetic_Op (N : Node_Id) is 770 L : constant Node_Id := Left_Opnd (N); 771 R : constant Node_Id := Right_Opnd (N); 772 Op_Id : Entity_Id; 773 774 begin 775 Candidate_Type := Empty; 776 Analyze_Expression (L); 777 Analyze_Expression (R); 778 779 -- If the entity is already set, the node is the instantiation of a 780 -- generic node with a non-local reference, or was manufactured by a 781 -- call to Make_Op_xxx. In either case the entity is known to be valid, 782 -- and we do not need to collect interpretations, instead we just get 783 -- the single possible interpretation. 784 785 Op_Id := Entity (N); 786 787 if Present (Op_Id) then 788 if Ekind (Op_Id) = E_Operator then 789 790 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem) 791 and then Treat_Fixed_As_Integer (N) 792 then 793 null; 794 else 795 Set_Etype (N, Any_Type); 796 Find_Arithmetic_Types (L, R, Op_Id, N); 797 end if; 798 799 else 800 Set_Etype (N, Any_Type); 801 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 802 end if; 803 804 -- Entity is not already set, so we do need to collect interpretations 805 806 else 807 Op_Id := Get_Name_Entity_Id (Chars (N)); 808 Set_Etype (N, Any_Type); 809 810 while Present (Op_Id) loop 811 if Ekind (Op_Id) = E_Operator 812 and then Present (Next_Entity (First_Entity (Op_Id))) 813 then 814 Find_Arithmetic_Types (L, R, Op_Id, N); 815 816 -- The following may seem superfluous, because an operator cannot 817 -- be generic, but this ignores the cleverness of the author of 818 -- ACVC bc1013a. 819 820 elsif Is_Overloadable (Op_Id) then 821 Analyze_User_Defined_Binary_Op (N, Op_Id); 822 end if; 823 824 Op_Id := Homonym (Op_Id); 825 end loop; 826 end if; 827 828 Operator_Check (N); 829 end Analyze_Arithmetic_Op; 830 831 ------------------ 832 -- Analyze_Call -- 833 ------------------ 834 835 -- Function, procedure, and entry calls are checked here. The Name in 836 -- the call may be overloaded. The actuals have been analyzed and may 837 -- themselves be overloaded. On exit from this procedure, the node N 838 -- may have zero, one or more interpretations. In the first case an 839 -- error message is produced. In the last case, the node is flagged 840 -- as overloaded and the interpretations are collected in All_Interp. 841 842 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but 843 -- the type-checking is similar to that of other calls. 844 845 procedure Analyze_Call (N : Node_Id) is 846 Actuals : constant List_Id := Parameter_Associations (N); 847 Nam : Node_Id; 848 X : Interp_Index; 849 It : Interp; 850 Nam_Ent : Entity_Id; 851 Success : Boolean := False; 852 853 Deref : Boolean := False; 854 -- Flag indicates whether an interpretation of the prefix is a 855 -- parameterless call that returns an access_to_subprogram. 856 857 procedure Check_Mixed_Parameter_And_Named_Associations; 858 -- Check that parameter and named associations are not mixed. This is 859 -- a restriction in SPARK mode. 860 861 function Name_Denotes_Function return Boolean; 862 -- If the type of the name is an access to subprogram, this may be the 863 -- type of a name, or the return type of the function being called. If 864 -- the name is not an entity then it can denote a protected function. 865 -- Until we distinguish Etype from Return_Type, we must use this routine 866 -- to resolve the meaning of the name in the call. 867 868 procedure No_Interpretation; 869 -- Output error message when no valid interpretation exists 870 871 -------------------------------------------------- 872 -- Check_Mixed_Parameter_And_Named_Associations -- 873 -------------------------------------------------- 874 875 procedure Check_Mixed_Parameter_And_Named_Associations is 876 Actual : Node_Id; 877 Named_Seen : Boolean; 878 879 begin 880 Named_Seen := False; 881 882 Actual := First (Actuals); 883 while Present (Actual) loop 884 case Nkind (Actual) is 885 when N_Parameter_Association => 886 if Named_Seen then 887 Check_SPARK_05_Restriction 888 ("named association cannot follow positional one", 889 Actual); 890 exit; 891 end if; 892 when others => 893 Named_Seen := True; 894 end case; 895 896 Next (Actual); 897 end loop; 898 end Check_Mixed_Parameter_And_Named_Associations; 899 900 --------------------------- 901 -- Name_Denotes_Function -- 902 --------------------------- 903 904 function Name_Denotes_Function return Boolean is 905 begin 906 if Is_Entity_Name (Nam) then 907 return Ekind (Entity (Nam)) = E_Function; 908 909 elsif Nkind (Nam) = N_Selected_Component then 910 return Ekind (Entity (Selector_Name (Nam))) = E_Function; 911 912 else 913 return False; 914 end if; 915 end Name_Denotes_Function; 916 917 ----------------------- 918 -- No_Interpretation -- 919 ----------------------- 920 921 procedure No_Interpretation is 922 L : constant Boolean := Is_List_Member (N); 923 K : constant Node_Kind := Nkind (Parent (N)); 924 925 begin 926 -- If the node is in a list whose parent is not an expression then it 927 -- must be an attempted procedure call. 928 929 if L and then K not in N_Subexpr then 930 if Ekind (Entity (Nam)) = E_Generic_Procedure then 931 Error_Msg_NE 932 ("must instantiate generic procedure& before call", 933 Nam, Entity (Nam)); 934 else 935 Error_Msg_N 936 ("procedure or entry name expected", Nam); 937 end if; 938 939 -- Check for tasking cases where only an entry call will do 940 941 elsif not L 942 and then Nkind_In (K, N_Entry_Call_Alternative, 943 N_Triggering_Alternative) 944 then 945 Error_Msg_N ("entry name expected", Nam); 946 947 -- Otherwise give general error message 948 949 else 950 Error_Msg_N ("invalid prefix in call", Nam); 951 end if; 952 end No_Interpretation; 953 954 -- Start of processing for Analyze_Call 955 956 begin 957 if Restriction_Check_Required (SPARK_05) then 958 Check_Mixed_Parameter_And_Named_Associations; 959 end if; 960 961 -- Initialize the type of the result of the call to the error type, 962 -- which will be reset if the type is successfully resolved. 963 964 Set_Etype (N, Any_Type); 965 966 Nam := Name (N); 967 968 if not Is_Overloaded (Nam) then 969 970 -- Only one interpretation to check 971 972 if Ekind (Etype (Nam)) = E_Subprogram_Type then 973 Nam_Ent := Etype (Nam); 974 975 -- If the prefix is an access_to_subprogram, this may be an indirect 976 -- call. This is the case if the name in the call is not an entity 977 -- name, or if it is a function name in the context of a procedure 978 -- call. In this latter case, we have a call to a parameterless 979 -- function that returns a pointer_to_procedure which is the entity 980 -- being called. Finally, F (X) may be a call to a parameterless 981 -- function that returns a pointer to a function with parameters. 982 -- Note that if F returns an access-to-subprogram whose designated 983 -- type is an array, F (X) cannot be interpreted as an indirect call 984 -- through the result of the call to F. 985 986 elsif Is_Access_Type (Etype (Nam)) 987 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type 988 and then 989 (not Name_Denotes_Function 990 or else Nkind (N) = N_Procedure_Call_Statement 991 or else 992 (Nkind (Parent (N)) /= N_Explicit_Dereference 993 and then Is_Entity_Name (Nam) 994 and then No (First_Formal (Entity (Nam))) 995 and then not 996 Is_Array_Type (Etype (Designated_Type (Etype (Nam)))) 997 and then Present (Actuals))) 998 then 999 Nam_Ent := Designated_Type (Etype (Nam)); 1000 Insert_Explicit_Dereference (Nam); 1001 1002 -- Selected component case. Simple entry or protected operation, 1003 -- where the entry name is given by the selector name. 1004 1005 elsif Nkind (Nam) = N_Selected_Component then 1006 Nam_Ent := Entity (Selector_Name (Nam)); 1007 1008 if not Ekind_In (Nam_Ent, E_Entry, 1009 E_Entry_Family, 1010 E_Function, 1011 E_Procedure) 1012 then 1013 Error_Msg_N ("name in call is not a callable entity", Nam); 1014 Set_Etype (N, Any_Type); 1015 return; 1016 end if; 1017 1018 -- If the name is an Indexed component, it can be a call to a member 1019 -- of an entry family. The prefix must be a selected component whose 1020 -- selector is the entry. Analyze_Procedure_Call normalizes several 1021 -- kinds of call into this form. 1022 1023 elsif Nkind (Nam) = N_Indexed_Component then 1024 if Nkind (Prefix (Nam)) = N_Selected_Component then 1025 Nam_Ent := Entity (Selector_Name (Prefix (Nam))); 1026 else 1027 Error_Msg_N ("name in call is not a callable entity", Nam); 1028 Set_Etype (N, Any_Type); 1029 return; 1030 end if; 1031 1032 elsif not Is_Entity_Name (Nam) then 1033 Error_Msg_N ("name in call is not a callable entity", Nam); 1034 Set_Etype (N, Any_Type); 1035 return; 1036 1037 else 1038 Nam_Ent := Entity (Nam); 1039 1040 -- If not overloadable, this may be a generalized indexing 1041 -- operation with named associations. Rewrite again as an 1042 -- indexed component and analyze as container indexing. 1043 1044 if not Is_Overloadable (Nam_Ent) then 1045 if Present 1046 (Find_Value_Of_Aspect 1047 (Etype (Nam_Ent), Aspect_Constant_Indexing)) 1048 then 1049 Replace (N, 1050 Make_Indexed_Component (Sloc (N), 1051 Prefix => Nam, 1052 Expressions => Parameter_Associations (N))); 1053 1054 if Try_Container_Indexing (N, Nam, Expressions (N)) then 1055 return; 1056 else 1057 No_Interpretation; 1058 end if; 1059 1060 else 1061 No_Interpretation; 1062 end if; 1063 1064 return; 1065 end if; 1066 end if; 1067 1068 -- Operations generated for RACW stub types are called only through 1069 -- dispatching, and can never be the static interpretation of a call. 1070 1071 if Is_RACW_Stub_Type_Operation (Nam_Ent) then 1072 No_Interpretation; 1073 return; 1074 end if; 1075 1076 Analyze_One_Call (N, Nam_Ent, True, Success); 1077 1078 -- If this is an indirect call, the return type of the access_to 1079 -- subprogram may be an incomplete type. At the point of the call, 1080 -- use the full type if available, and at the same time update the 1081 -- return type of the access_to_subprogram. 1082 1083 if Success 1084 and then Nkind (Nam) = N_Explicit_Dereference 1085 and then Ekind (Etype (N)) = E_Incomplete_Type 1086 and then Present (Full_View (Etype (N))) 1087 then 1088 Set_Etype (N, Full_View (Etype (N))); 1089 Set_Etype (Nam_Ent, Etype (N)); 1090 end if; 1091 1092 -- Overloaded call 1093 1094 else 1095 -- An overloaded selected component must denote overloaded operations 1096 -- of a concurrent type. The interpretations are attached to the 1097 -- simple name of those operations. 1098 1099 if Nkind (Nam) = N_Selected_Component then 1100 Nam := Selector_Name (Nam); 1101 end if; 1102 1103 Get_First_Interp (Nam, X, It); 1104 1105 while Present (It.Nam) loop 1106 Nam_Ent := It.Nam; 1107 Deref := False; 1108 1109 -- Name may be call that returns an access to subprogram, or more 1110 -- generally an overloaded expression one of whose interpretations 1111 -- yields an access to subprogram. If the name is an entity, we do 1112 -- not dereference, because the node is a call that returns the 1113 -- access type: note difference between f(x), where the call may 1114 -- return an access subprogram type, and f(x)(y), where the type 1115 -- returned by the call to f is implicitly dereferenced to analyze 1116 -- the outer call. 1117 1118 if Is_Access_Type (Nam_Ent) then 1119 Nam_Ent := Designated_Type (Nam_Ent); 1120 1121 elsif Is_Access_Type (Etype (Nam_Ent)) 1122 and then 1123 (not Is_Entity_Name (Nam) 1124 or else Nkind (N) = N_Procedure_Call_Statement) 1125 and then Ekind (Designated_Type (Etype (Nam_Ent))) 1126 = E_Subprogram_Type 1127 then 1128 Nam_Ent := Designated_Type (Etype (Nam_Ent)); 1129 1130 if Is_Entity_Name (Nam) then 1131 Deref := True; 1132 end if; 1133 end if; 1134 1135 -- If the call has been rewritten from a prefixed call, the first 1136 -- parameter has been analyzed, but may need a subsequent 1137 -- dereference, so skip its analysis now. 1138 1139 if N /= Original_Node (N) 1140 and then Nkind (Original_Node (N)) = Nkind (N) 1141 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N))) 1142 and then Present (Parameter_Associations (N)) 1143 and then Present (Etype (First (Parameter_Associations (N)))) 1144 then 1145 Analyze_One_Call 1146 (N, Nam_Ent, False, Success, Skip_First => True); 1147 else 1148 Analyze_One_Call (N, Nam_Ent, False, Success); 1149 end if; 1150 1151 -- If the interpretation succeeds, mark the proper type of the 1152 -- prefix (any valid candidate will do). If not, remove the 1153 -- candidate interpretation. This only needs to be done for 1154 -- overloaded protected operations, for other entities disambi- 1155 -- guation is done directly in Resolve. 1156 1157 if Success then 1158 if Deref 1159 and then Nkind (Parent (N)) /= N_Explicit_Dereference 1160 then 1161 Set_Entity (Nam, It.Nam); 1162 Insert_Explicit_Dereference (Nam); 1163 Set_Etype (Nam, Nam_Ent); 1164 1165 else 1166 Set_Etype (Nam, It.Typ); 1167 end if; 1168 1169 elsif Nkind_In (Name (N), N_Selected_Component, 1170 N_Function_Call) 1171 then 1172 Remove_Interp (X); 1173 end if; 1174 1175 Get_Next_Interp (X, It); 1176 end loop; 1177 1178 -- If the name is the result of a function call, it can only be a 1179 -- call to a function returning an access to subprogram. Insert 1180 -- explicit dereference. 1181 1182 if Nkind (Nam) = N_Function_Call then 1183 Insert_Explicit_Dereference (Nam); 1184 end if; 1185 1186 if Etype (N) = Any_Type then 1187 1188 -- None of the interpretations is compatible with the actuals 1189 1190 Diagnose_Call (N, Nam); 1191 1192 -- Special checks for uninstantiated put routines 1193 1194 if Nkind (N) = N_Procedure_Call_Statement 1195 and then Is_Entity_Name (Nam) 1196 and then Chars (Nam) = Name_Put 1197 and then List_Length (Actuals) = 1 1198 then 1199 declare 1200 Arg : constant Node_Id := First (Actuals); 1201 Typ : Entity_Id; 1202 1203 begin 1204 if Nkind (Arg) = N_Parameter_Association then 1205 Typ := Etype (Explicit_Actual_Parameter (Arg)); 1206 else 1207 Typ := Etype (Arg); 1208 end if; 1209 1210 if Is_Signed_Integer_Type (Typ) then 1211 Error_Msg_N 1212 ("possible missing instantiation of " 1213 & "'Text_'I'O.'Integer_'I'O!", Nam); 1214 1215 elsif Is_Modular_Integer_Type (Typ) then 1216 Error_Msg_N 1217 ("possible missing instantiation of " 1218 & "'Text_'I'O.'Modular_'I'O!", Nam); 1219 1220 elsif Is_Floating_Point_Type (Typ) then 1221 Error_Msg_N 1222 ("possible missing instantiation of " 1223 & "'Text_'I'O.'Float_'I'O!", Nam); 1224 1225 elsif Is_Ordinary_Fixed_Point_Type (Typ) then 1226 Error_Msg_N 1227 ("possible missing instantiation of " 1228 & "'Text_'I'O.'Fixed_'I'O!", Nam); 1229 1230 elsif Is_Decimal_Fixed_Point_Type (Typ) then 1231 Error_Msg_N 1232 ("possible missing instantiation of " 1233 & "'Text_'I'O.'Decimal_'I'O!", Nam); 1234 1235 elsif Is_Enumeration_Type (Typ) then 1236 Error_Msg_N 1237 ("possible missing instantiation of " 1238 & "'Text_'I'O.'Enumeration_'I'O!", Nam); 1239 end if; 1240 end; 1241 end if; 1242 1243 elsif not Is_Overloaded (N) 1244 and then Is_Entity_Name (Nam) 1245 then 1246 -- Resolution yields a single interpretation. Verify that the 1247 -- reference has capitalization consistent with the declaration. 1248 1249 Set_Entity_With_Checks (Nam, Entity (Nam)); 1250 Generate_Reference (Entity (Nam), Nam); 1251 1252 Set_Etype (Nam, Etype (Entity (Nam))); 1253 else 1254 Remove_Abstract_Operations (N); 1255 end if; 1256 1257 End_Interp_List; 1258 end if; 1259 end Analyze_Call; 1260 1261 ----------------------------- 1262 -- Analyze_Case_Expression -- 1263 ----------------------------- 1264 1265 procedure Analyze_Case_Expression (N : Node_Id) is 1266 procedure Non_Static_Choice_Error (Choice : Node_Id); 1267 -- Error routine invoked by the generic instantiation below when 1268 -- the case expression has a non static choice. 1269 1270 package Case_Choices_Analysis is new 1271 Generic_Analyze_Choices 1272 (Process_Associated_Node => No_OP); 1273 use Case_Choices_Analysis; 1274 1275 package Case_Choices_Checking is new 1276 Generic_Check_Choices 1277 (Process_Empty_Choice => No_OP, 1278 Process_Non_Static_Choice => Non_Static_Choice_Error, 1279 Process_Associated_Node => No_OP); 1280 use Case_Choices_Checking; 1281 1282 ----------------------------- 1283 -- Non_Static_Choice_Error -- 1284 ----------------------------- 1285 1286 procedure Non_Static_Choice_Error (Choice : Node_Id) is 1287 begin 1288 Flag_Non_Static_Expr 1289 ("choice given in case expression is not static!", Choice); 1290 end Non_Static_Choice_Error; 1291 1292 -- Local variables 1293 1294 Expr : constant Node_Id := Expression (N); 1295 Alt : Node_Id; 1296 Exp_Type : Entity_Id; 1297 Exp_Btype : Entity_Id; 1298 1299 FirstX : Node_Id := Empty; 1300 -- First expression in the case for which there is some type information 1301 -- available, i.e. it is not Any_Type, which can happen because of some 1302 -- error, or from the use of e.g. raise Constraint_Error. 1303 1304 Others_Present : Boolean; 1305 -- Indicates if Others was present 1306 1307 Wrong_Alt : Node_Id; 1308 -- For error reporting 1309 1310 -- Start of processing for Analyze_Case_Expression 1311 1312 begin 1313 if Comes_From_Source (N) then 1314 Check_Compiler_Unit ("case expression", N); 1315 end if; 1316 1317 Analyze_And_Resolve (Expr, Any_Discrete); 1318 Check_Unset_Reference (Expr); 1319 Exp_Type := Etype (Expr); 1320 Exp_Btype := Base_Type (Exp_Type); 1321 1322 Alt := First (Alternatives (N)); 1323 while Present (Alt) loop 1324 Analyze (Expression (Alt)); 1325 1326 if No (FirstX) and then Etype (Expression (Alt)) /= Any_Type then 1327 FirstX := Expression (Alt); 1328 end if; 1329 1330 Next (Alt); 1331 end loop; 1332 1333 -- Get our initial type from the first expression for which we got some 1334 -- useful type information from the expression. 1335 1336 if not Is_Overloaded (FirstX) then 1337 Set_Etype (N, Etype (FirstX)); 1338 1339 else 1340 declare 1341 I : Interp_Index; 1342 It : Interp; 1343 1344 begin 1345 Set_Etype (N, Any_Type); 1346 1347 Get_First_Interp (FirstX, I, It); 1348 while Present (It.Nam) loop 1349 1350 -- For each interpretation of the first expression, we only 1351 -- add the interpretation if every other expression in the 1352 -- case expression alternatives has a compatible type. 1353 1354 Alt := Next (First (Alternatives (N))); 1355 while Present (Alt) loop 1356 exit when not Has_Compatible_Type (Expression (Alt), It.Typ); 1357 Next (Alt); 1358 end loop; 1359 1360 if No (Alt) then 1361 Add_One_Interp (N, It.Typ, It.Typ); 1362 1363 else 1364 Wrong_Alt := Alt; 1365 end if; 1366 1367 Get_Next_Interp (I, It); 1368 end loop; 1369 end; 1370 end if; 1371 1372 Exp_Btype := Base_Type (Exp_Type); 1373 1374 -- The expression must be of a discrete type which must be determinable 1375 -- independently of the context in which the expression occurs, but 1376 -- using the fact that the expression must be of a discrete type. 1377 -- Moreover, the type this expression must not be a character literal 1378 -- (which is always ambiguous). 1379 1380 -- If error already reported by Resolve, nothing more to do 1381 1382 if Exp_Btype = Any_Discrete or else Exp_Btype = Any_Type then 1383 return; 1384 1385 -- Special casee message for character literal 1386 1387 elsif Exp_Btype = Any_Character then 1388 Error_Msg_N 1389 ("character literal as case expression is ambiguous", Expr); 1390 return; 1391 end if; 1392 1393 if Etype (N) = Any_Type and then Present (Wrong_Alt) then 1394 Error_Msg_N 1395 ("type incompatible with that of previous alternatives", 1396 Expression (Wrong_Alt)); 1397 return; 1398 end if; 1399 1400 -- If the case expression is a formal object of mode in out, then 1401 -- treat it as having a nonstatic subtype by forcing use of the base 1402 -- type (which has to get passed to Check_Case_Choices below). Also 1403 -- use base type when the case expression is parenthesized. 1404 1405 if Paren_Count (Expr) > 0 1406 or else (Is_Entity_Name (Expr) 1407 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter) 1408 then 1409 Exp_Type := Exp_Btype; 1410 end if; 1411 1412 -- The case expression alternatives cover the range of a static subtype 1413 -- subject to aspect Static_Predicate. Do not check the choices when the 1414 -- case expression has not been fully analyzed yet because this may lead 1415 -- to bogus errors. 1416 1417 if Is_OK_Static_Subtype (Exp_Type) 1418 and then Has_Static_Predicate_Aspect (Exp_Type) 1419 and then In_Spec_Expression 1420 then 1421 null; 1422 1423 -- Call Analyze_Choices and Check_Choices to do the rest of the work 1424 1425 else 1426 Analyze_Choices (Alternatives (N), Exp_Type); 1427 Check_Choices (N, Alternatives (N), Exp_Type, Others_Present); 1428 end if; 1429 1430 if Exp_Type = Universal_Integer and then not Others_Present then 1431 Error_Msg_N 1432 ("case on universal integer requires OTHERS choice", Expr); 1433 end if; 1434 end Analyze_Case_Expression; 1435 1436 --------------------------- 1437 -- Analyze_Comparison_Op -- 1438 --------------------------- 1439 1440 procedure Analyze_Comparison_Op (N : Node_Id) is 1441 L : constant Node_Id := Left_Opnd (N); 1442 R : constant Node_Id := Right_Opnd (N); 1443 Op_Id : Entity_Id := Entity (N); 1444 1445 begin 1446 Set_Etype (N, Any_Type); 1447 Candidate_Type := Empty; 1448 1449 Analyze_Expression (L); 1450 Analyze_Expression (R); 1451 1452 if Present (Op_Id) then 1453 if Ekind (Op_Id) = E_Operator then 1454 Find_Comparison_Types (L, R, Op_Id, N); 1455 else 1456 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 1457 end if; 1458 1459 if Is_Overloaded (L) then 1460 Set_Etype (L, Intersect_Types (L, R)); 1461 end if; 1462 1463 else 1464 Op_Id := Get_Name_Entity_Id (Chars (N)); 1465 while Present (Op_Id) loop 1466 if Ekind (Op_Id) = E_Operator then 1467 Find_Comparison_Types (L, R, Op_Id, N); 1468 else 1469 Analyze_User_Defined_Binary_Op (N, Op_Id); 1470 end if; 1471 1472 Op_Id := Homonym (Op_Id); 1473 end loop; 1474 end if; 1475 1476 Operator_Check (N); 1477 end Analyze_Comparison_Op; 1478 1479 --------------------------- 1480 -- Analyze_Concatenation -- 1481 --------------------------- 1482 1483 procedure Analyze_Concatenation (N : Node_Id) is 1484 1485 -- We wish to avoid deep recursion, because concatenations are often 1486 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left 1487 -- operands nonrecursively until we find something that is not a 1488 -- concatenation (A in this case), or has already been analyzed. We 1489 -- analyze that, and then walk back up the tree following Parent 1490 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the 1491 -- work at each level. The Parent pointers allow us to avoid recursion, 1492 -- and thus avoid running out of memory. 1493 1494 NN : Node_Id := N; 1495 L : Node_Id; 1496 1497 begin 1498 Candidate_Type := Empty; 1499 1500 -- The following code is equivalent to: 1501 1502 -- Set_Etype (N, Any_Type); 1503 -- Analyze_Expression (Left_Opnd (N)); 1504 -- Analyze_Concatenation_Rest (N); 1505 1506 -- where the Analyze_Expression call recurses back here if the left 1507 -- operand is a concatenation. 1508 1509 -- Walk down left operands 1510 1511 loop 1512 Set_Etype (NN, Any_Type); 1513 L := Left_Opnd (NN); 1514 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L); 1515 NN := L; 1516 end loop; 1517 1518 -- Now (given the above example) NN is A&B and L is A 1519 1520 -- First analyze L ... 1521 1522 Analyze_Expression (L); 1523 1524 -- ... then walk NN back up until we reach N (where we started), calling 1525 -- Analyze_Concatenation_Rest along the way. 1526 1527 loop 1528 Analyze_Concatenation_Rest (NN); 1529 exit when NN = N; 1530 NN := Parent (NN); 1531 end loop; 1532 end Analyze_Concatenation; 1533 1534 -------------------------------- 1535 -- Analyze_Concatenation_Rest -- 1536 -------------------------------- 1537 1538 -- If the only one-dimensional array type in scope is String, 1539 -- this is the resulting type of the operation. Otherwise there 1540 -- will be a concatenation operation defined for each user-defined 1541 -- one-dimensional array. 1542 1543 procedure Analyze_Concatenation_Rest (N : Node_Id) is 1544 L : constant Node_Id := Left_Opnd (N); 1545 R : constant Node_Id := Right_Opnd (N); 1546 Op_Id : Entity_Id := Entity (N); 1547 LT : Entity_Id; 1548 RT : Entity_Id; 1549 1550 begin 1551 Analyze_Expression (R); 1552 1553 -- If the entity is present, the node appears in an instance, and 1554 -- denotes a predefined concatenation operation. The resulting type is 1555 -- obtained from the arguments when possible. If the arguments are 1556 -- aggregates, the array type and the concatenation type must be 1557 -- visible. 1558 1559 if Present (Op_Id) then 1560 if Ekind (Op_Id) = E_Operator then 1561 LT := Base_Type (Etype (L)); 1562 RT := Base_Type (Etype (R)); 1563 1564 if Is_Array_Type (LT) 1565 and then (RT = LT or else RT = Base_Type (Component_Type (LT))) 1566 then 1567 Add_One_Interp (N, Op_Id, LT); 1568 1569 elsif Is_Array_Type (RT) 1570 and then LT = Base_Type (Component_Type (RT)) 1571 then 1572 Add_One_Interp (N, Op_Id, RT); 1573 1574 -- If one operand is a string type or a user-defined array type, 1575 -- and the other is a literal, result is of the specific type. 1576 1577 elsif 1578 (Root_Type (LT) = Standard_String 1579 or else Scope (LT) /= Standard_Standard) 1580 and then Etype (R) = Any_String 1581 then 1582 Add_One_Interp (N, Op_Id, LT); 1583 1584 elsif 1585 (Root_Type (RT) = Standard_String 1586 or else Scope (RT) /= Standard_Standard) 1587 and then Etype (L) = Any_String 1588 then 1589 Add_One_Interp (N, Op_Id, RT); 1590 1591 elsif not Is_Generic_Type (Etype (Op_Id)) then 1592 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 1593 1594 else 1595 -- Type and its operations must be visible 1596 1597 Set_Entity (N, Empty); 1598 Analyze_Concatenation (N); 1599 end if; 1600 1601 else 1602 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 1603 end if; 1604 1605 else 1606 Op_Id := Get_Name_Entity_Id (Name_Op_Concat); 1607 while Present (Op_Id) loop 1608 if Ekind (Op_Id) = E_Operator then 1609 1610 -- Do not consider operators declared in dead code, they can 1611 -- not be part of the resolution. 1612 1613 if Is_Eliminated (Op_Id) then 1614 null; 1615 else 1616 Find_Concatenation_Types (L, R, Op_Id, N); 1617 end if; 1618 1619 else 1620 Analyze_User_Defined_Binary_Op (N, Op_Id); 1621 end if; 1622 1623 Op_Id := Homonym (Op_Id); 1624 end loop; 1625 end if; 1626 1627 Operator_Check (N); 1628 end Analyze_Concatenation_Rest; 1629 1630 ------------------------- 1631 -- Analyze_Equality_Op -- 1632 ------------------------- 1633 1634 procedure Analyze_Equality_Op (N : Node_Id) is 1635 Loc : constant Source_Ptr := Sloc (N); 1636 L : constant Node_Id := Left_Opnd (N); 1637 R : constant Node_Id := Right_Opnd (N); 1638 Op_Id : Entity_Id; 1639 1640 begin 1641 Set_Etype (N, Any_Type); 1642 Candidate_Type := Empty; 1643 1644 Analyze_Expression (L); 1645 Analyze_Expression (R); 1646 1647 -- If the entity is set, the node is a generic instance with a non-local 1648 -- reference to the predefined operator or to a user-defined function. 1649 -- It can also be an inequality that is expanded into the negation of a 1650 -- call to a user-defined equality operator. 1651 1652 -- For the predefined case, the result is Boolean, regardless of the 1653 -- type of the operands. The operands may even be limited, if they are 1654 -- generic actuals. If they are overloaded, label the left argument with 1655 -- the common type that must be present, or with the type of the formal 1656 -- of the user-defined function. 1657 1658 if Present (Entity (N)) then 1659 Op_Id := Entity (N); 1660 1661 if Ekind (Op_Id) = E_Operator then 1662 Add_One_Interp (N, Op_Id, Standard_Boolean); 1663 else 1664 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 1665 end if; 1666 1667 if Is_Overloaded (L) then 1668 if Ekind (Op_Id) = E_Operator then 1669 Set_Etype (L, Intersect_Types (L, R)); 1670 else 1671 Set_Etype (L, Etype (First_Formal (Op_Id))); 1672 end if; 1673 end if; 1674 1675 else 1676 Op_Id := Get_Name_Entity_Id (Chars (N)); 1677 while Present (Op_Id) loop 1678 if Ekind (Op_Id) = E_Operator then 1679 Find_Equality_Types (L, R, Op_Id, N); 1680 else 1681 Analyze_User_Defined_Binary_Op (N, Op_Id); 1682 end if; 1683 1684 Op_Id := Homonym (Op_Id); 1685 end loop; 1686 end if; 1687 1688 -- If there was no match, and the operator is inequality, this may 1689 -- be a case where inequality has not been made explicit, as for 1690 -- tagged types. Analyze the node as the negation of an equality 1691 -- operation. This cannot be done earlier, because before analysis 1692 -- we cannot rule out the presence of an explicit inequality. 1693 1694 if Etype (N) = Any_Type 1695 and then Nkind (N) = N_Op_Ne 1696 then 1697 Op_Id := Get_Name_Entity_Id (Name_Op_Eq); 1698 while Present (Op_Id) loop 1699 if Ekind (Op_Id) = E_Operator then 1700 Find_Equality_Types (L, R, Op_Id, N); 1701 else 1702 Analyze_User_Defined_Binary_Op (N, Op_Id); 1703 end if; 1704 1705 Op_Id := Homonym (Op_Id); 1706 end loop; 1707 1708 if Etype (N) /= Any_Type then 1709 Op_Id := Entity (N); 1710 1711 Rewrite (N, 1712 Make_Op_Not (Loc, 1713 Right_Opnd => 1714 Make_Op_Eq (Loc, 1715 Left_Opnd => Left_Opnd (N), 1716 Right_Opnd => Right_Opnd (N)))); 1717 1718 Set_Entity (Right_Opnd (N), Op_Id); 1719 Analyze (N); 1720 end if; 1721 end if; 1722 1723 Operator_Check (N); 1724 end Analyze_Equality_Op; 1725 1726 ---------------------------------- 1727 -- Analyze_Explicit_Dereference -- 1728 ---------------------------------- 1729 1730 procedure Analyze_Explicit_Dereference (N : Node_Id) is 1731 Loc : constant Source_Ptr := Sloc (N); 1732 P : constant Node_Id := Prefix (N); 1733 T : Entity_Id; 1734 I : Interp_Index; 1735 It : Interp; 1736 New_N : Node_Id; 1737 1738 function Is_Function_Type return Boolean; 1739 -- Check whether node may be interpreted as an implicit function call 1740 1741 ---------------------- 1742 -- Is_Function_Type -- 1743 ---------------------- 1744 1745 function Is_Function_Type return Boolean is 1746 I : Interp_Index; 1747 It : Interp; 1748 1749 begin 1750 if not Is_Overloaded (N) then 1751 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type 1752 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type; 1753 1754 else 1755 Get_First_Interp (N, I, It); 1756 while Present (It.Nam) loop 1757 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type 1758 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type 1759 then 1760 return False; 1761 end if; 1762 1763 Get_Next_Interp (I, It); 1764 end loop; 1765 1766 return True; 1767 end if; 1768 end Is_Function_Type; 1769 1770 -- Start of processing for Analyze_Explicit_Dereference 1771 1772 begin 1773 -- If source node, check SPARK restriction. We guard this with the 1774 -- source node check, because ??? 1775 1776 if Comes_From_Source (N) then 1777 Check_SPARK_05_Restriction ("explicit dereference is not allowed", N); 1778 end if; 1779 1780 -- In formal verification mode, keep track of all reads and writes 1781 -- through explicit dereferences. 1782 1783 if GNATprove_Mode then 1784 SPARK_Specific.Generate_Dereference (N); 1785 end if; 1786 1787 Analyze (P); 1788 Set_Etype (N, Any_Type); 1789 1790 -- Test for remote access to subprogram type, and if so return 1791 -- after rewriting the original tree. 1792 1793 if Remote_AST_E_Dereference (P) then 1794 return; 1795 end if; 1796 1797 -- Normal processing for other than remote access to subprogram type 1798 1799 if not Is_Overloaded (P) then 1800 if Is_Access_Type (Etype (P)) then 1801 1802 -- Set the Etype. We need to go through Is_For_Access_Subtypes to 1803 -- avoid other problems caused by the Private_Subtype and it is 1804 -- safe to go to the Base_Type because this is the same as 1805 -- converting the access value to its Base_Type. 1806 1807 declare 1808 DT : Entity_Id := Designated_Type (Etype (P)); 1809 1810 begin 1811 if Ekind (DT) = E_Private_Subtype 1812 and then Is_For_Access_Subtype (DT) 1813 then 1814 DT := Base_Type (DT); 1815 end if; 1816 1817 -- An explicit dereference is a legal occurrence of an 1818 -- incomplete type imported through a limited_with clause, 1819 -- if the full view is visible. 1820 1821 if From_Limited_With (DT) 1822 and then not From_Limited_With (Scope (DT)) 1823 and then 1824 (Is_Immediately_Visible (Scope (DT)) 1825 or else 1826 (Is_Child_Unit (Scope (DT)) 1827 and then Is_Visible_Lib_Unit (Scope (DT)))) 1828 then 1829 Set_Etype (N, Available_View (DT)); 1830 1831 else 1832 Set_Etype (N, DT); 1833 end if; 1834 end; 1835 1836 elsif Etype (P) /= Any_Type then 1837 Error_Msg_N ("prefix of dereference must be an access type", N); 1838 return; 1839 end if; 1840 1841 else 1842 Get_First_Interp (P, I, It); 1843 while Present (It.Nam) loop 1844 T := It.Typ; 1845 1846 if Is_Access_Type (T) then 1847 Add_One_Interp (N, Designated_Type (T), Designated_Type (T)); 1848 end if; 1849 1850 Get_Next_Interp (I, It); 1851 end loop; 1852 1853 -- Error if no interpretation of the prefix has an access type 1854 1855 if Etype (N) = Any_Type then 1856 Error_Msg_N 1857 ("access type required in prefix of explicit dereference", P); 1858 Set_Etype (N, Any_Type); 1859 return; 1860 end if; 1861 end if; 1862 1863 if Is_Function_Type 1864 and then Nkind (Parent (N)) /= N_Indexed_Component 1865 1866 and then (Nkind (Parent (N)) /= N_Function_Call 1867 or else N /= Name (Parent (N))) 1868 1869 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement 1870 or else N /= Name (Parent (N))) 1871 1872 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration 1873 and then (Nkind (Parent (N)) /= N_Attribute_Reference 1874 or else 1875 (Attribute_Name (Parent (N)) /= Name_Address 1876 and then 1877 Attribute_Name (Parent (N)) /= Name_Access)) 1878 then 1879 -- Name is a function call with no actuals, in a context that 1880 -- requires deproceduring (including as an actual in an enclosing 1881 -- function or procedure call). There are some pathological cases 1882 -- where the prefix might include functions that return access to 1883 -- subprograms and others that return a regular type. Disambiguation 1884 -- of those has to take place in Resolve. 1885 1886 New_N := 1887 Make_Function_Call (Loc, 1888 Name => Make_Explicit_Dereference (Loc, P), 1889 Parameter_Associations => New_List); 1890 1891 -- If the prefix is overloaded, remove operations that have formals, 1892 -- we know that this is a parameterless call. 1893 1894 if Is_Overloaded (P) then 1895 Get_First_Interp (P, I, It); 1896 while Present (It.Nam) loop 1897 T := It.Typ; 1898 1899 if No (First_Formal (Base_Type (Designated_Type (T)))) then 1900 Set_Etype (P, T); 1901 else 1902 Remove_Interp (I); 1903 end if; 1904 1905 Get_Next_Interp (I, It); 1906 end loop; 1907 end if; 1908 1909 Rewrite (N, New_N); 1910 Analyze (N); 1911 1912 elsif not Is_Function_Type 1913 and then Is_Overloaded (N) 1914 then 1915 -- The prefix may include access to subprograms and other access 1916 -- types. If the context selects the interpretation that is a 1917 -- function call (not a procedure call) we cannot rewrite the node 1918 -- yet, but we include the result of the call interpretation. 1919 1920 Get_First_Interp (N, I, It); 1921 while Present (It.Nam) loop 1922 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type 1923 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type 1924 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement 1925 then 1926 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ)); 1927 end if; 1928 1929 Get_Next_Interp (I, It); 1930 end loop; 1931 end if; 1932 1933 -- A value of remote access-to-class-wide must not be dereferenced 1934 -- (RM E.2.2(16)). 1935 1936 Validate_Remote_Access_To_Class_Wide_Type (N); 1937 end Analyze_Explicit_Dereference; 1938 1939 ------------------------ 1940 -- Analyze_Expression -- 1941 ------------------------ 1942 1943 procedure Analyze_Expression (N : Node_Id) is 1944 begin 1945 1946 -- If the expression is an indexed component that will be rewritten 1947 -- as a container indexing, it has already been analyzed. 1948 1949 if Nkind (N) = N_Indexed_Component 1950 and then Present (Generalized_Indexing (N)) 1951 then 1952 null; 1953 1954 else 1955 Analyze (N); 1956 Check_Parameterless_Call (N); 1957 end if; 1958 end Analyze_Expression; 1959 1960 ------------------------------------- 1961 -- Analyze_Expression_With_Actions -- 1962 ------------------------------------- 1963 1964 procedure Analyze_Expression_With_Actions (N : Node_Id) is 1965 A : Node_Id; 1966 1967 begin 1968 A := First (Actions (N)); 1969 while Present (A) loop 1970 Analyze (A); 1971 Next (A); 1972 end loop; 1973 1974 Analyze_Expression (Expression (N)); 1975 Set_Etype (N, Etype (Expression (N))); 1976 end Analyze_Expression_With_Actions; 1977 1978 --------------------------- 1979 -- Analyze_If_Expression -- 1980 --------------------------- 1981 1982 procedure Analyze_If_Expression (N : Node_Id) is 1983 Condition : constant Node_Id := First (Expressions (N)); 1984 Then_Expr : constant Node_Id := Next (Condition); 1985 Else_Expr : Node_Id; 1986 1987 begin 1988 -- Defend against error of missing expressions from previous error 1989 1990 if No (Then_Expr) then 1991 Check_Error_Detected; 1992 return; 1993 end if; 1994 1995 if Comes_From_Source (N) then 1996 Check_SPARK_05_Restriction ("if expression is not allowed", N); 1997 end if; 1998 1999 Else_Expr := Next (Then_Expr); 2000 2001 if Comes_From_Source (N) then 2002 Check_Compiler_Unit ("if expression", N); 2003 end if; 2004 2005 -- Analyze and resolve the condition. We need to resolve this now so 2006 -- that it gets folded to True/False if possible, before we analyze 2007 -- the THEN/ELSE branches, because when analyzing these branches, we 2008 -- may call Is_Statically_Unevaluated, which expects the condition of 2009 -- an enclosing IF to have been analyze/resolved/evaluated. 2010 2011 Analyze_Expression (Condition); 2012 Resolve (Condition, Any_Boolean); 2013 2014 -- Analyze THEN expression and (if present) ELSE expression. For those 2015 -- we delay resolution in the normal manner, because of overloading etc. 2016 2017 Analyze_Expression (Then_Expr); 2018 2019 if Present (Else_Expr) then 2020 Analyze_Expression (Else_Expr); 2021 end if; 2022 2023 -- If then expression not overloaded, then that decides the type 2024 2025 if not Is_Overloaded (Then_Expr) then 2026 Set_Etype (N, Etype (Then_Expr)); 2027 2028 -- Case where then expression is overloaded 2029 2030 else 2031 declare 2032 I : Interp_Index; 2033 It : Interp; 2034 2035 begin 2036 Set_Etype (N, Any_Type); 2037 2038 -- Loop through intepretations of Then_Expr 2039 2040 Get_First_Interp (Then_Expr, I, It); 2041 while Present (It.Nam) loop 2042 2043 -- Add possible intepretation of Then_Expr if no Else_Expr, 2044 -- or Else_Expr is present and has a compatible type. 2045 2046 if No (Else_Expr) 2047 or else Has_Compatible_Type (Else_Expr, It.Typ) 2048 then 2049 Add_One_Interp (N, It.Typ, It.Typ); 2050 end if; 2051 2052 Get_Next_Interp (I, It); 2053 end loop; 2054 end; 2055 end if; 2056 end Analyze_If_Expression; 2057 2058 ------------------------------------ 2059 -- Analyze_Indexed_Component_Form -- 2060 ------------------------------------ 2061 2062 procedure Analyze_Indexed_Component_Form (N : Node_Id) is 2063 P : constant Node_Id := Prefix (N); 2064 Exprs : constant List_Id := Expressions (N); 2065 Exp : Node_Id; 2066 P_T : Entity_Id; 2067 E : Node_Id; 2068 U_N : Entity_Id; 2069 2070 procedure Process_Function_Call; 2071 -- Prefix in indexed component form is an overloadable entity, 2072 -- so the node is a function call. Reformat it as such. 2073 2074 procedure Process_Indexed_Component; 2075 -- Prefix in indexed component form is actually an indexed component. 2076 -- This routine processes it, knowing that the prefix is already 2077 -- resolved. 2078 2079 procedure Process_Indexed_Component_Or_Slice; 2080 -- An indexed component with a single index may designate a slice if 2081 -- the index is a subtype mark. This routine disambiguates these two 2082 -- cases by resolving the prefix to see if it is a subtype mark. 2083 2084 procedure Process_Overloaded_Indexed_Component; 2085 -- If the prefix of an indexed component is overloaded, the proper 2086 -- interpretation is selected by the index types and the context. 2087 2088 --------------------------- 2089 -- Process_Function_Call -- 2090 --------------------------- 2091 2092 procedure Process_Function_Call is 2093 Loc : constant Source_Ptr := Sloc (N); 2094 Actual : Node_Id; 2095 2096 begin 2097 Change_Node (N, N_Function_Call); 2098 Set_Name (N, P); 2099 Set_Parameter_Associations (N, Exprs); 2100 2101 -- Analyze actuals prior to analyzing the call itself 2102 2103 Actual := First (Parameter_Associations (N)); 2104 while Present (Actual) loop 2105 Analyze (Actual); 2106 Check_Parameterless_Call (Actual); 2107 2108 -- Move to next actual. Note that we use Next, not Next_Actual 2109 -- here. The reason for this is a bit subtle. If a function call 2110 -- includes named associations, the parser recognizes the node as 2111 -- a call, and it is analyzed as such. If all associations are 2112 -- positional, the parser builds an indexed_component node, and 2113 -- it is only after analysis of the prefix that the construct 2114 -- is recognized as a call, in which case Process_Function_Call 2115 -- rewrites the node and analyzes the actuals. If the list of 2116 -- actuals is malformed, the parser may leave the node as an 2117 -- indexed component (despite the presence of named associations). 2118 -- The iterator Next_Actual is equivalent to Next if the list is 2119 -- positional, but follows the normalized chain of actuals when 2120 -- named associations are present. In this case normalization has 2121 -- not taken place, and actuals remain unanalyzed, which leads to 2122 -- subsequent crashes or loops if there is an attempt to continue 2123 -- analysis of the program. 2124 2125 -- IF there is a single actual and it is a type name, the node 2126 -- can only be interpreted as a slice of a parameterless call. 2127 -- Rebuild the node as such and analyze. 2128 2129 if No (Next (Actual)) 2130 and then Is_Entity_Name (Actual) 2131 and then Is_Type (Entity (Actual)) 2132 and then Is_Discrete_Type (Entity (Actual)) 2133 then 2134 Replace (N, 2135 Make_Slice (Loc, 2136 Prefix => P, 2137 Discrete_Range => 2138 New_Occurrence_Of (Entity (Actual), Loc))); 2139 Analyze (N); 2140 return; 2141 2142 else 2143 Next (Actual); 2144 end if; 2145 end loop; 2146 2147 Analyze_Call (N); 2148 end Process_Function_Call; 2149 2150 ------------------------------- 2151 -- Process_Indexed_Component -- 2152 ------------------------------- 2153 2154 procedure Process_Indexed_Component is 2155 Exp : Node_Id; 2156 Array_Type : Entity_Id; 2157 Index : Node_Id; 2158 Pent : Entity_Id := Empty; 2159 2160 begin 2161 Exp := First (Exprs); 2162 2163 if Is_Overloaded (P) then 2164 Process_Overloaded_Indexed_Component; 2165 2166 else 2167 Array_Type := Etype (P); 2168 2169 if Is_Entity_Name (P) then 2170 Pent := Entity (P); 2171 elsif Nkind (P) = N_Selected_Component 2172 and then Is_Entity_Name (Selector_Name (P)) 2173 then 2174 Pent := Entity (Selector_Name (P)); 2175 end if; 2176 2177 -- Prefix must be appropriate for an array type, taking into 2178 -- account a possible implicit dereference. 2179 2180 if Is_Access_Type (Array_Type) then 2181 Error_Msg_NW 2182 (Warn_On_Dereference, "?d?implicit dereference", N); 2183 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P); 2184 end if; 2185 2186 if Is_Array_Type (Array_Type) then 2187 null; 2188 2189 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then 2190 Analyze (Exp); 2191 Set_Etype (N, Any_Type); 2192 2193 if not Has_Compatible_Type 2194 (Exp, Entry_Index_Type (Pent)) 2195 then 2196 Error_Msg_N ("invalid index type in entry name", N); 2197 2198 elsif Present (Next (Exp)) then 2199 Error_Msg_N ("too many subscripts in entry reference", N); 2200 2201 else 2202 Set_Etype (N, Etype (P)); 2203 end if; 2204 2205 return; 2206 2207 elsif Is_Record_Type (Array_Type) 2208 and then Remote_AST_I_Dereference (P) 2209 then 2210 return; 2211 2212 elsif Try_Container_Indexing (N, P, Exprs) then 2213 return; 2214 2215 elsif Array_Type = Any_Type then 2216 Set_Etype (N, Any_Type); 2217 2218 -- In most cases the analysis of the prefix will have emitted 2219 -- an error already, but if the prefix may be interpreted as a 2220 -- call in prefixed notation, the report is left to the caller. 2221 -- To prevent cascaded errors, report only if no previous ones. 2222 2223 if Serious_Errors_Detected = 0 then 2224 Error_Msg_N ("invalid prefix in indexed component", P); 2225 2226 if Nkind (P) = N_Expanded_Name then 2227 Error_Msg_NE ("\& is not visible", P, Selector_Name (P)); 2228 end if; 2229 end if; 2230 2231 return; 2232 2233 -- Here we definitely have a bad indexing 2234 2235 else 2236 if Nkind (Parent (N)) = N_Requeue_Statement 2237 and then Present (Pent) and then Ekind (Pent) = E_Entry 2238 then 2239 Error_Msg_N 2240 ("REQUEUE does not permit parameters", First (Exprs)); 2241 2242 elsif Is_Entity_Name (P) 2243 and then Etype (P) = Standard_Void_Type 2244 then 2245 Error_Msg_NE ("incorrect use of&", P, Entity (P)); 2246 2247 else 2248 Error_Msg_N ("array type required in indexed component", P); 2249 end if; 2250 2251 Set_Etype (N, Any_Type); 2252 return; 2253 end if; 2254 2255 Index := First_Index (Array_Type); 2256 while Present (Index) and then Present (Exp) loop 2257 if not Has_Compatible_Type (Exp, Etype (Index)) then 2258 Wrong_Type (Exp, Etype (Index)); 2259 Set_Etype (N, Any_Type); 2260 return; 2261 end if; 2262 2263 Next_Index (Index); 2264 Next (Exp); 2265 end loop; 2266 2267 Set_Etype (N, Component_Type (Array_Type)); 2268 Check_Implicit_Dereference (N, Etype (N)); 2269 2270 if Present (Index) then 2271 Error_Msg_N 2272 ("too few subscripts in array reference", First (Exprs)); 2273 2274 elsif Present (Exp) then 2275 Error_Msg_N ("too many subscripts in array reference", Exp); 2276 end if; 2277 end if; 2278 end Process_Indexed_Component; 2279 2280 ---------------------------------------- 2281 -- Process_Indexed_Component_Or_Slice -- 2282 ---------------------------------------- 2283 2284 procedure Process_Indexed_Component_Or_Slice is 2285 begin 2286 Exp := First (Exprs); 2287 while Present (Exp) loop 2288 Analyze_Expression (Exp); 2289 Next (Exp); 2290 end loop; 2291 2292 Exp := First (Exprs); 2293 2294 -- If one index is present, and it is a subtype name, then the 2295 -- node denotes a slice (note that the case of an explicit range 2296 -- for a slice was already built as an N_Slice node in the first 2297 -- place, so that case is not handled here). 2298 2299 -- We use a replace rather than a rewrite here because this is one 2300 -- of the cases in which the tree built by the parser is plain wrong. 2301 2302 if No (Next (Exp)) 2303 and then Is_Entity_Name (Exp) 2304 and then Is_Type (Entity (Exp)) 2305 then 2306 Replace (N, 2307 Make_Slice (Sloc (N), 2308 Prefix => P, 2309 Discrete_Range => New_Copy (Exp))); 2310 Analyze (N); 2311 2312 -- Otherwise (more than one index present, or single index is not 2313 -- a subtype name), then we have the indexed component case. 2314 2315 else 2316 Process_Indexed_Component; 2317 end if; 2318 end Process_Indexed_Component_Or_Slice; 2319 2320 ------------------------------------------ 2321 -- Process_Overloaded_Indexed_Component -- 2322 ------------------------------------------ 2323 2324 procedure Process_Overloaded_Indexed_Component is 2325 Exp : Node_Id; 2326 I : Interp_Index; 2327 It : Interp; 2328 Typ : Entity_Id; 2329 Index : Node_Id; 2330 Found : Boolean; 2331 2332 begin 2333 Set_Etype (N, Any_Type); 2334 2335 Get_First_Interp (P, I, It); 2336 while Present (It.Nam) loop 2337 Typ := It.Typ; 2338 2339 if Is_Access_Type (Typ) then 2340 Typ := Designated_Type (Typ); 2341 Error_Msg_NW 2342 (Warn_On_Dereference, "?d?implicit dereference", N); 2343 end if; 2344 2345 if Is_Array_Type (Typ) then 2346 2347 -- Got a candidate: verify that index types are compatible 2348 2349 Index := First_Index (Typ); 2350 Found := True; 2351 Exp := First (Exprs); 2352 while Present (Index) and then Present (Exp) loop 2353 if Has_Compatible_Type (Exp, Etype (Index)) then 2354 null; 2355 else 2356 Found := False; 2357 Remove_Interp (I); 2358 exit; 2359 end if; 2360 2361 Next_Index (Index); 2362 Next (Exp); 2363 end loop; 2364 2365 if Found and then No (Index) and then No (Exp) then 2366 declare 2367 CT : constant Entity_Id := 2368 Base_Type (Component_Type (Typ)); 2369 begin 2370 Add_One_Interp (N, CT, CT); 2371 Check_Implicit_Dereference (N, CT); 2372 end; 2373 end if; 2374 2375 elsif Try_Container_Indexing (N, P, Exprs) then 2376 return; 2377 2378 end if; 2379 2380 Get_Next_Interp (I, It); 2381 end loop; 2382 2383 if Etype (N) = Any_Type then 2384 Error_Msg_N ("no legal interpretation for indexed component", N); 2385 Set_Is_Overloaded (N, False); 2386 end if; 2387 2388 End_Interp_List; 2389 end Process_Overloaded_Indexed_Component; 2390 2391 -- Start of processing for Analyze_Indexed_Component_Form 2392 2393 begin 2394 -- Get name of array, function or type 2395 2396 Analyze (P); 2397 2398 -- If P is an explicit dereference whose prefix is of a remote access- 2399 -- to-subprogram type, then N has already been rewritten as a subprogram 2400 -- call and analyzed. 2401 2402 if Nkind (N) in N_Subprogram_Call then 2403 return; 2404 2405 -- When the prefix is attribute 'Loop_Entry and the sole expression of 2406 -- the indexed component denotes a loop name, the indexed form is turned 2407 -- into an attribute reference. 2408 2409 elsif Nkind (N) = N_Attribute_Reference 2410 and then Attribute_Name (N) = Name_Loop_Entry 2411 then 2412 return; 2413 end if; 2414 2415 pragma Assert (Nkind (N) = N_Indexed_Component); 2416 2417 P_T := Base_Type (Etype (P)); 2418 2419 if Is_Entity_Name (P) and then Present (Entity (P)) then 2420 U_N := Entity (P); 2421 2422 if Is_Type (U_N) then 2423 2424 -- Reformat node as a type conversion 2425 2426 E := Remove_Head (Exprs); 2427 2428 if Present (First (Exprs)) then 2429 Error_Msg_N 2430 ("argument of type conversion must be single expression", N); 2431 end if; 2432 2433 Change_Node (N, N_Type_Conversion); 2434 Set_Subtype_Mark (N, P); 2435 Set_Etype (N, U_N); 2436 Set_Expression (N, E); 2437 2438 -- After changing the node, call for the specific Analysis 2439 -- routine directly, to avoid a double call to the expander. 2440 2441 Analyze_Type_Conversion (N); 2442 return; 2443 end if; 2444 2445 if Is_Overloadable (U_N) then 2446 Process_Function_Call; 2447 2448 elsif Ekind (Etype (P)) = E_Subprogram_Type 2449 or else (Is_Access_Type (Etype (P)) 2450 and then 2451 Ekind (Designated_Type (Etype (P))) = 2452 E_Subprogram_Type) 2453 then 2454 -- Call to access_to-subprogram with possible implicit dereference 2455 2456 Process_Function_Call; 2457 2458 elsif Is_Generic_Subprogram (U_N) then 2459 2460 -- A common beginner's (or C++ templates fan) error 2461 2462 Error_Msg_N ("generic subprogram cannot be called", N); 2463 Set_Etype (N, Any_Type); 2464 return; 2465 2466 else 2467 Process_Indexed_Component_Or_Slice; 2468 end if; 2469 2470 -- If not an entity name, prefix is an expression that may denote 2471 -- an array or an access-to-subprogram. 2472 2473 else 2474 if Ekind (P_T) = E_Subprogram_Type 2475 or else (Is_Access_Type (P_T) 2476 and then 2477 Ekind (Designated_Type (P_T)) = E_Subprogram_Type) 2478 then 2479 Process_Function_Call; 2480 2481 elsif Nkind (P) = N_Selected_Component 2482 and then Present (Entity (Selector_Name (P))) 2483 and then Is_Overloadable (Entity (Selector_Name (P))) 2484 then 2485 Process_Function_Call; 2486 2487 -- In ASIS mode within a generic, a prefixed call is analyzed and 2488 -- partially rewritten but the original indexed component has not 2489 -- yet been rewritten as a call. Perform the replacement now. 2490 2491 elsif Nkind (P) = N_Selected_Component 2492 and then Nkind (Parent (P)) = N_Function_Call 2493 and then ASIS_Mode 2494 then 2495 Rewrite (N, Parent (P)); 2496 Analyze (N); 2497 2498 else 2499 -- Indexed component, slice, or a call to a member of a family 2500 -- entry, which will be converted to an entry call later. 2501 2502 Process_Indexed_Component_Or_Slice; 2503 end if; 2504 end if; 2505 2506 Analyze_Dimension (N); 2507 end Analyze_Indexed_Component_Form; 2508 2509 ------------------------ 2510 -- Analyze_Logical_Op -- 2511 ------------------------ 2512 2513 procedure Analyze_Logical_Op (N : Node_Id) is 2514 L : constant Node_Id := Left_Opnd (N); 2515 R : constant Node_Id := Right_Opnd (N); 2516 Op_Id : Entity_Id := Entity (N); 2517 2518 begin 2519 Set_Etype (N, Any_Type); 2520 Candidate_Type := Empty; 2521 2522 Analyze_Expression (L); 2523 Analyze_Expression (R); 2524 2525 if Present (Op_Id) then 2526 2527 if Ekind (Op_Id) = E_Operator then 2528 Find_Boolean_Types (L, R, Op_Id, N); 2529 else 2530 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 2531 end if; 2532 2533 else 2534 Op_Id := Get_Name_Entity_Id (Chars (N)); 2535 while Present (Op_Id) loop 2536 if Ekind (Op_Id) = E_Operator then 2537 Find_Boolean_Types (L, R, Op_Id, N); 2538 else 2539 Analyze_User_Defined_Binary_Op (N, Op_Id); 2540 end if; 2541 2542 Op_Id := Homonym (Op_Id); 2543 end loop; 2544 end if; 2545 2546 Operator_Check (N); 2547 end Analyze_Logical_Op; 2548 2549 --------------------------- 2550 -- Analyze_Membership_Op -- 2551 --------------------------- 2552 2553 procedure Analyze_Membership_Op (N : Node_Id) is 2554 Loc : constant Source_Ptr := Sloc (N); 2555 L : constant Node_Id := Left_Opnd (N); 2556 R : constant Node_Id := Right_Opnd (N); 2557 2558 Index : Interp_Index; 2559 It : Interp; 2560 Found : Boolean := False; 2561 I_F : Interp_Index; 2562 T_F : Entity_Id; 2563 2564 procedure Try_One_Interp (T1 : Entity_Id); 2565 -- Routine to try one proposed interpretation. Note that the context 2566 -- of the operation plays no role in resolving the arguments, so that 2567 -- if there is more than one interpretation of the operands that is 2568 -- compatible with a membership test, the operation is ambiguous. 2569 2570 -------------------- 2571 -- Try_One_Interp -- 2572 -------------------- 2573 2574 procedure Try_One_Interp (T1 : Entity_Id) is 2575 begin 2576 if Has_Compatible_Type (R, T1) then 2577 if Found 2578 and then Base_Type (T1) /= Base_Type (T_F) 2579 then 2580 It := Disambiguate (L, I_F, Index, Any_Type); 2581 2582 if It = No_Interp then 2583 Ambiguous_Operands (N); 2584 Set_Etype (L, Any_Type); 2585 return; 2586 2587 else 2588 T_F := It.Typ; 2589 end if; 2590 2591 else 2592 Found := True; 2593 T_F := T1; 2594 I_F := Index; 2595 end if; 2596 2597 Set_Etype (L, T_F); 2598 end if; 2599 end Try_One_Interp; 2600 2601 procedure Analyze_Set_Membership; 2602 -- If a set of alternatives is present, analyze each and find the 2603 -- common type to which they must all resolve. 2604 2605 ---------------------------- 2606 -- Analyze_Set_Membership -- 2607 ---------------------------- 2608 2609 procedure Analyze_Set_Membership is 2610 Alt : Node_Id; 2611 Index : Interp_Index; 2612 It : Interp; 2613 Candidate_Interps : Node_Id; 2614 Common_Type : Entity_Id := Empty; 2615 2616 begin 2617 if Comes_From_Source (N) then 2618 Check_Compiler_Unit ("set membership", N); 2619 end if; 2620 2621 Analyze (L); 2622 Candidate_Interps := L; 2623 2624 if not Is_Overloaded (L) then 2625 Common_Type := Etype (L); 2626 2627 Alt := First (Alternatives (N)); 2628 while Present (Alt) loop 2629 Analyze (Alt); 2630 2631 if not Has_Compatible_Type (Alt, Common_Type) then 2632 Wrong_Type (Alt, Common_Type); 2633 end if; 2634 2635 Next (Alt); 2636 end loop; 2637 2638 else 2639 Alt := First (Alternatives (N)); 2640 while Present (Alt) loop 2641 Analyze (Alt); 2642 if not Is_Overloaded (Alt) then 2643 Common_Type := Etype (Alt); 2644 2645 else 2646 Get_First_Interp (Alt, Index, It); 2647 while Present (It.Typ) loop 2648 if not 2649 Has_Compatible_Type (Candidate_Interps, It.Typ) 2650 then 2651 Remove_Interp (Index); 2652 end if; 2653 2654 Get_Next_Interp (Index, It); 2655 end loop; 2656 2657 Get_First_Interp (Alt, Index, It); 2658 2659 if No (It.Typ) then 2660 Error_Msg_N ("alternative has no legal type", Alt); 2661 return; 2662 end if; 2663 2664 -- If alternative is not overloaded, we have a unique type 2665 -- for all of them. 2666 2667 Set_Etype (Alt, It.Typ); 2668 Get_Next_Interp (Index, It); 2669 2670 if No (It.Typ) then 2671 Set_Is_Overloaded (Alt, False); 2672 Common_Type := Etype (Alt); 2673 end if; 2674 2675 Candidate_Interps := Alt; 2676 end if; 2677 2678 Next (Alt); 2679 end loop; 2680 end if; 2681 2682 Set_Etype (N, Standard_Boolean); 2683 2684 if Present (Common_Type) then 2685 Set_Etype (L, Common_Type); 2686 2687 -- The left operand may still be overloaded, to be resolved using 2688 -- the Common_Type. 2689 2690 else 2691 Error_Msg_N ("cannot resolve membership operation", N); 2692 end if; 2693 end Analyze_Set_Membership; 2694 2695 -- Start of processing for Analyze_Membership_Op 2696 2697 begin 2698 Analyze_Expression (L); 2699 2700 if No (R) and then Ada_Version >= Ada_2012 then 2701 Analyze_Set_Membership; 2702 return; 2703 end if; 2704 2705 if Nkind (R) = N_Range 2706 or else (Nkind (R) = N_Attribute_Reference 2707 and then Attribute_Name (R) = Name_Range) 2708 then 2709 Analyze (R); 2710 2711 if not Is_Overloaded (L) then 2712 Try_One_Interp (Etype (L)); 2713 2714 else 2715 Get_First_Interp (L, Index, It); 2716 while Present (It.Typ) loop 2717 Try_One_Interp (It.Typ); 2718 Get_Next_Interp (Index, It); 2719 end loop; 2720 end if; 2721 2722 -- If not a range, it can be a subtype mark, or else it is a degenerate 2723 -- membership test with a singleton value, i.e. a test for equality, 2724 -- if the types are compatible. 2725 2726 else 2727 Analyze (R); 2728 2729 if Is_Entity_Name (R) 2730 and then Is_Type (Entity (R)) 2731 then 2732 Find_Type (R); 2733 Check_Fully_Declared (Entity (R), R); 2734 2735 elsif Ada_Version >= Ada_2012 2736 and then Has_Compatible_Type (R, Etype (L)) 2737 then 2738 if Nkind (N) = N_In then 2739 Rewrite (N, 2740 Make_Op_Eq (Loc, 2741 Left_Opnd => L, 2742 Right_Opnd => R)); 2743 else 2744 Rewrite (N, 2745 Make_Op_Ne (Loc, 2746 Left_Opnd => L, 2747 Right_Opnd => R)); 2748 end if; 2749 2750 Analyze (N); 2751 return; 2752 2753 else 2754 -- In all versions of the language, if we reach this point there 2755 -- is a previous error that will be diagnosed below. 2756 2757 Find_Type (R); 2758 end if; 2759 end if; 2760 2761 -- Compatibility between expression and subtype mark or range is 2762 -- checked during resolution. The result of the operation is Boolean 2763 -- in any case. 2764 2765 Set_Etype (N, Standard_Boolean); 2766 2767 if Comes_From_Source (N) 2768 and then Present (Right_Opnd (N)) 2769 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N)))) 2770 then 2771 Error_Msg_N ("membership test not applicable to cpp-class types", N); 2772 end if; 2773 end Analyze_Membership_Op; 2774 2775 ----------------- 2776 -- Analyze_Mod -- 2777 ----------------- 2778 2779 procedure Analyze_Mod (N : Node_Id) is 2780 begin 2781 -- A special warning check, if we have an expression of the form: 2782 -- expr mod 2 * literal 2783 -- where literal is 64 or less, then probably what was meant was 2784 -- expr mod 2 ** literal 2785 -- so issue an appropriate warning. 2786 2787 if Warn_On_Suspicious_Modulus_Value 2788 and then Nkind (Right_Opnd (N)) = N_Integer_Literal 2789 and then Intval (Right_Opnd (N)) = Uint_2 2790 and then Nkind (Parent (N)) = N_Op_Multiply 2791 and then Nkind (Right_Opnd (Parent (N))) = N_Integer_Literal 2792 and then Intval (Right_Opnd (Parent (N))) <= Uint_64 2793 then 2794 Error_Msg_N 2795 ("suspicious MOD value, was '*'* intended'??M?", Parent (N)); 2796 end if; 2797 2798 -- Remaining processing is same as for other arithmetic operators 2799 2800 Analyze_Arithmetic_Op (N); 2801 end Analyze_Mod; 2802 2803 ---------------------- 2804 -- Analyze_Negation -- 2805 ---------------------- 2806 2807 procedure Analyze_Negation (N : Node_Id) is 2808 R : constant Node_Id := Right_Opnd (N); 2809 Op_Id : Entity_Id := Entity (N); 2810 2811 begin 2812 Set_Etype (N, Any_Type); 2813 Candidate_Type := Empty; 2814 2815 Analyze_Expression (R); 2816 2817 if Present (Op_Id) then 2818 if Ekind (Op_Id) = E_Operator then 2819 Find_Negation_Types (R, Op_Id, N); 2820 else 2821 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 2822 end if; 2823 2824 else 2825 Op_Id := Get_Name_Entity_Id (Chars (N)); 2826 while Present (Op_Id) loop 2827 if Ekind (Op_Id) = E_Operator then 2828 Find_Negation_Types (R, Op_Id, N); 2829 else 2830 Analyze_User_Defined_Unary_Op (N, Op_Id); 2831 end if; 2832 2833 Op_Id := Homonym (Op_Id); 2834 end loop; 2835 end if; 2836 2837 Operator_Check (N); 2838 end Analyze_Negation; 2839 2840 ------------------ 2841 -- Analyze_Null -- 2842 ------------------ 2843 2844 procedure Analyze_Null (N : Node_Id) is 2845 begin 2846 Check_SPARK_05_Restriction ("null is not allowed", N); 2847 2848 Set_Etype (N, Any_Access); 2849 end Analyze_Null; 2850 2851 ---------------------- 2852 -- Analyze_One_Call -- 2853 ---------------------- 2854 2855 procedure Analyze_One_Call 2856 (N : Node_Id; 2857 Nam : Entity_Id; 2858 Report : Boolean; 2859 Success : out Boolean; 2860 Skip_First : Boolean := False) 2861 is 2862 Actuals : constant List_Id := Parameter_Associations (N); 2863 Prev_T : constant Entity_Id := Etype (N); 2864 2865 Must_Skip : constant Boolean := Skip_First 2866 or else Nkind (Original_Node (N)) = N_Selected_Component 2867 or else 2868 (Nkind (Original_Node (N)) = N_Indexed_Component 2869 and then Nkind (Prefix (Original_Node (N))) 2870 = N_Selected_Component); 2871 -- The first formal must be omitted from the match when trying to find 2872 -- a primitive operation that is a possible interpretation, and also 2873 -- after the call has been rewritten, because the corresponding actual 2874 -- is already known to be compatible, and because this may be an 2875 -- indexing of a call with default parameters. 2876 2877 Formal : Entity_Id; 2878 Actual : Node_Id; 2879 Is_Indexed : Boolean := False; 2880 Is_Indirect : Boolean := False; 2881 Subp_Type : constant Entity_Id := Etype (Nam); 2882 Norm_OK : Boolean; 2883 2884 function Operator_Hidden_By (Fun : Entity_Id) return Boolean; 2885 -- There may be a user-defined operator that hides the current 2886 -- interpretation. We must check for this independently of the 2887 -- analysis of the call with the user-defined operation, because 2888 -- the parameter names may be wrong and yet the hiding takes place. 2889 -- This fixes a problem with ACATS test B34014O. 2890 -- 2891 -- When the type Address is a visible integer type, and the DEC 2892 -- system extension is visible, the predefined operator may be 2893 -- hidden as well, by one of the address operations in auxdec. 2894 -- Finally, The abstract operations on address do not hide the 2895 -- predefined operator (this is the purpose of making them abstract). 2896 2897 procedure Indicate_Name_And_Type; 2898 -- If candidate interpretation matches, indicate name and type of 2899 -- result on call node. 2900 2901 ---------------------------- 2902 -- Indicate_Name_And_Type -- 2903 ---------------------------- 2904 2905 procedure Indicate_Name_And_Type is 2906 begin 2907 Add_One_Interp (N, Nam, Etype (Nam)); 2908 Check_Implicit_Dereference (N, Etype (Nam)); 2909 Success := True; 2910 2911 -- If the prefix of the call is a name, indicate the entity 2912 -- being called. If it is not a name, it is an expression that 2913 -- denotes an access to subprogram or else an entry or family. In 2914 -- the latter case, the name is a selected component, and the entity 2915 -- being called is noted on the selector. 2916 2917 if not Is_Type (Nam) then 2918 if Is_Entity_Name (Name (N)) then 2919 Set_Entity (Name (N), Nam); 2920 2921 elsif Nkind (Name (N)) = N_Selected_Component then 2922 Set_Entity (Selector_Name (Name (N)), Nam); 2923 end if; 2924 end if; 2925 2926 if Debug_Flag_E and not Report then 2927 Write_Str (" Overloaded call "); 2928 Write_Int (Int (N)); 2929 Write_Str (" compatible with "); 2930 Write_Int (Int (Nam)); 2931 Write_Eol; 2932 end if; 2933 end Indicate_Name_And_Type; 2934 2935 ------------------------ 2936 -- Operator_Hidden_By -- 2937 ------------------------ 2938 2939 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is 2940 Act1 : constant Node_Id := First_Actual (N); 2941 Act2 : constant Node_Id := Next_Actual (Act1); 2942 Form1 : constant Entity_Id := First_Formal (Fun); 2943 Form2 : constant Entity_Id := Next_Formal (Form1); 2944 2945 begin 2946 if Ekind (Fun) /= E_Function or else Is_Abstract_Subprogram (Fun) then 2947 return False; 2948 2949 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then 2950 return False; 2951 2952 elsif Present (Form2) then 2953 if No (Act2) 2954 or else not Has_Compatible_Type (Act2, Etype (Form2)) 2955 then 2956 return False; 2957 end if; 2958 2959 elsif Present (Act2) then 2960 return False; 2961 end if; 2962 2963 -- Now we know that the arity of the operator matches the function, 2964 -- and the function call is a valid interpretation. The function 2965 -- hides the operator if it has the right signature, or if one of 2966 -- its operands is a non-abstract operation on Address when this is 2967 -- a visible integer type. 2968 2969 return Hides_Op (Fun, Nam) 2970 or else Is_Descendent_Of_Address (Etype (Form1)) 2971 or else 2972 (Present (Form2) 2973 and then Is_Descendent_Of_Address (Etype (Form2))); 2974 end Operator_Hidden_By; 2975 2976 -- Start of processing for Analyze_One_Call 2977 2978 begin 2979 Success := False; 2980 2981 -- If the subprogram has no formals or if all the formals have defaults, 2982 -- and the return type is an array type, the node may denote an indexing 2983 -- of the result of a parameterless call. In Ada 2005, the subprogram 2984 -- may have one non-defaulted formal, and the call may have been written 2985 -- in prefix notation, so that the rebuilt parameter list has more than 2986 -- one actual. 2987 2988 if not Is_Overloadable (Nam) 2989 and then Ekind (Nam) /= E_Subprogram_Type 2990 and then Ekind (Nam) /= E_Entry_Family 2991 then 2992 return; 2993 end if; 2994 2995 -- An indexing requires at least one actual. The name of the call cannot 2996 -- be an implicit indirect call, so it cannot be a generated explicit 2997 -- dereference. 2998 2999 if not Is_Empty_List (Actuals) 3000 and then 3001 (Needs_No_Actuals (Nam) 3002 or else 3003 (Needs_One_Actual (Nam) 3004 and then Present (Next_Actual (First (Actuals))))) 3005 then 3006 if Is_Array_Type (Subp_Type) 3007 and then 3008 (Nkind (Name (N)) /= N_Explicit_Dereference 3009 or else Comes_From_Source (Name (N))) 3010 then 3011 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip); 3012 3013 elsif Is_Access_Type (Subp_Type) 3014 and then Is_Array_Type (Designated_Type (Subp_Type)) 3015 then 3016 Is_Indexed := 3017 Try_Indexed_Call 3018 (N, Nam, Designated_Type (Subp_Type), Must_Skip); 3019 3020 -- The prefix can also be a parameterless function that returns an 3021 -- access to subprogram, in which case this is an indirect call. 3022 -- If this succeeds, an explicit dereference is added later on, 3023 -- in Analyze_Call or Resolve_Call. 3024 3025 elsif Is_Access_Type (Subp_Type) 3026 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type 3027 then 3028 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type); 3029 end if; 3030 3031 end if; 3032 3033 -- If the call has been transformed into a slice, it is of the form 3034 -- F (Subtype) where F is parameterless. The node has been rewritten in 3035 -- Try_Indexed_Call and there is nothing else to do. 3036 3037 if Is_Indexed 3038 and then Nkind (N) = N_Slice 3039 then 3040 return; 3041 end if; 3042 3043 Normalize_Actuals 3044 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK); 3045 3046 if not Norm_OK then 3047 3048 -- If an indirect call is a possible interpretation, indicate 3049 -- success to the caller. This may be an indexing of an explicit 3050 -- dereference of a call that returns an access type (see above). 3051 3052 if Is_Indirect 3053 or else (Is_Indexed 3054 and then Nkind (Name (N)) = N_Explicit_Dereference 3055 and then Comes_From_Source (Name (N))) 3056 then 3057 Success := True; 3058 return; 3059 3060 -- Mismatch in number or names of parameters 3061 3062 elsif Debug_Flag_E then 3063 Write_Str (" normalization fails in call "); 3064 Write_Int (Int (N)); 3065 Write_Str (" with subprogram "); 3066 Write_Int (Int (Nam)); 3067 Write_Eol; 3068 end if; 3069 3070 -- If the context expects a function call, discard any interpretation 3071 -- that is a procedure. If the node is not overloaded, leave as is for 3072 -- better error reporting when type mismatch is found. 3073 3074 elsif Nkind (N) = N_Function_Call 3075 and then Is_Overloaded (Name (N)) 3076 and then Ekind (Nam) = E_Procedure 3077 then 3078 return; 3079 3080 -- Ditto for function calls in a procedure context 3081 3082 elsif Nkind (N) = N_Procedure_Call_Statement 3083 and then Is_Overloaded (Name (N)) 3084 and then Etype (Nam) /= Standard_Void_Type 3085 then 3086 return; 3087 3088 elsif No (Actuals) then 3089 3090 -- If Normalize succeeds, then there are default parameters for 3091 -- all formals. 3092 3093 Indicate_Name_And_Type; 3094 3095 elsif Ekind (Nam) = E_Operator then 3096 if Nkind (N) = N_Procedure_Call_Statement then 3097 return; 3098 end if; 3099 3100 -- This can occur when the prefix of the call is an operator 3101 -- name or an expanded name whose selector is an operator name. 3102 3103 Analyze_Operator_Call (N, Nam); 3104 3105 if Etype (N) /= Prev_T then 3106 3107 -- Check that operator is not hidden by a function interpretation 3108 3109 if Is_Overloaded (Name (N)) then 3110 declare 3111 I : Interp_Index; 3112 It : Interp; 3113 3114 begin 3115 Get_First_Interp (Name (N), I, It); 3116 while Present (It.Nam) loop 3117 if Operator_Hidden_By (It.Nam) then 3118 Set_Etype (N, Prev_T); 3119 return; 3120 end if; 3121 3122 Get_Next_Interp (I, It); 3123 end loop; 3124 end; 3125 end if; 3126 3127 -- If operator matches formals, record its name on the call. 3128 -- If the operator is overloaded, Resolve will select the 3129 -- correct one from the list of interpretations. The call 3130 -- node itself carries the first candidate. 3131 3132 Set_Entity (Name (N), Nam); 3133 Success := True; 3134 3135 elsif Report and then Etype (N) = Any_Type then 3136 Error_Msg_N ("incompatible arguments for operator", N); 3137 end if; 3138 3139 else 3140 -- Normalize_Actuals has chained the named associations in the 3141 -- correct order of the formals. 3142 3143 Actual := First_Actual (N); 3144 Formal := First_Formal (Nam); 3145 3146 -- If we are analyzing a call rewritten from object notation, skip 3147 -- first actual, which may be rewritten later as an explicit 3148 -- dereference. 3149 3150 if Must_Skip then 3151 Next_Actual (Actual); 3152 Next_Formal (Formal); 3153 end if; 3154 3155 while Present (Actual) and then Present (Formal) loop 3156 if Nkind (Parent (Actual)) /= N_Parameter_Association 3157 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal) 3158 then 3159 -- The actual can be compatible with the formal, but we must 3160 -- also check that the context is not an address type that is 3161 -- visibly an integer type. In this case the use of literals is 3162 -- illegal, except in the body of descendents of system, where 3163 -- arithmetic operations on address are of course used. 3164 3165 if Has_Compatible_Type (Actual, Etype (Formal)) 3166 and then 3167 (Etype (Actual) /= Universal_Integer 3168 or else not Is_Descendent_Of_Address (Etype (Formal)) 3169 or else 3170 Is_Predefined_File_Name 3171 (Unit_File_Name (Get_Source_Unit (N)))) 3172 then 3173 Next_Actual (Actual); 3174 Next_Formal (Formal); 3175 3176 -- In Allow_Integer_Address mode, we allow an actual integer to 3177 -- match a formal address type and vice versa. We only do this 3178 -- if we are certain that an error will otherwise be issued 3179 3180 elsif Address_Integer_Convert_OK 3181 (Etype (Actual), Etype (Formal)) 3182 and then (Report and not Is_Indexed and not Is_Indirect) 3183 then 3184 -- Handle this case by introducing an unchecked conversion 3185 3186 Rewrite (Actual, 3187 Unchecked_Convert_To (Etype (Formal), 3188 Relocate_Node (Actual))); 3189 Analyze_And_Resolve (Actual, Etype (Formal)); 3190 Next_Actual (Actual); 3191 Next_Formal (Formal); 3192 3193 -- For an Ada 2012 predicate or invariant, a call may mention 3194 -- an incomplete type, while resolution of the corresponding 3195 -- predicate function may see the full view, as a consequence 3196 -- of the delayed resolution of the corresponding expressions. 3197 3198 elsif Ekind (Etype (Formal)) = E_Incomplete_Type 3199 and then Full_View (Etype (Formal)) = Etype (Actual) 3200 then 3201 Set_Etype (Formal, Etype (Actual)); 3202 Next_Actual (Actual); 3203 Next_Formal (Formal); 3204 3205 else 3206 if Debug_Flag_E then 3207 Write_Str (" type checking fails in call "); 3208 Write_Int (Int (N)); 3209 Write_Str (" with formal "); 3210 Write_Int (Int (Formal)); 3211 Write_Str (" in subprogram "); 3212 Write_Int (Int (Nam)); 3213 Write_Eol; 3214 end if; 3215 3216 -- Comment needed on the following test??? 3217 3218 if Report and not Is_Indexed and not Is_Indirect then 3219 3220 -- Ada 2005 (AI-251): Complete the error notification 3221 -- to help new Ada 2005 users. 3222 3223 if Is_Class_Wide_Type (Etype (Formal)) 3224 and then Is_Interface (Etype (Etype (Formal))) 3225 and then not Interface_Present_In_Ancestor 3226 (Typ => Etype (Actual), 3227 Iface => Etype (Etype (Formal))) 3228 then 3229 Error_Msg_NE 3230 ("(Ada 2005) does not implement interface }", 3231 Actual, Etype (Etype (Formal))); 3232 end if; 3233 3234 Wrong_Type (Actual, Etype (Formal)); 3235 3236 if Nkind (Actual) = N_Op_Eq 3237 and then Nkind (Left_Opnd (Actual)) = N_Identifier 3238 then 3239 Formal := First_Formal (Nam); 3240 while Present (Formal) loop 3241 if Chars (Left_Opnd (Actual)) = Chars (Formal) then 3242 Error_Msg_N -- CODEFIX 3243 ("possible misspelling of `='>`!", Actual); 3244 exit; 3245 end if; 3246 3247 Next_Formal (Formal); 3248 end loop; 3249 end if; 3250 3251 if All_Errors_Mode then 3252 Error_Msg_Sloc := Sloc (Nam); 3253 3254 if Etype (Formal) = Any_Type then 3255 Error_Msg_N 3256 ("there is no legal actual parameter", Actual); 3257 end if; 3258 3259 if Is_Overloadable (Nam) 3260 and then Present (Alias (Nam)) 3261 and then not Comes_From_Source (Nam) 3262 then 3263 Error_Msg_NE 3264 ("\\ =='> in call to inherited operation & #!", 3265 Actual, Nam); 3266 3267 elsif Ekind (Nam) = E_Subprogram_Type then 3268 declare 3269 Access_To_Subprogram_Typ : 3270 constant Entity_Id := 3271 Defining_Identifier 3272 (Associated_Node_For_Itype (Nam)); 3273 begin 3274 Error_Msg_NE 3275 ("\\ =='> in call to dereference of &#!", 3276 Actual, Access_To_Subprogram_Typ); 3277 end; 3278 3279 else 3280 Error_Msg_NE 3281 ("\\ =='> in call to &#!", Actual, Nam); 3282 3283 end if; 3284 end if; 3285 end if; 3286 3287 return; 3288 end if; 3289 3290 else 3291 -- Normalize_Actuals has verified that a default value exists 3292 -- for this formal. Current actual names a subsequent formal. 3293 3294 Next_Formal (Formal); 3295 end if; 3296 end loop; 3297 3298 -- On exit, all actuals match 3299 3300 Indicate_Name_And_Type; 3301 end if; 3302 end Analyze_One_Call; 3303 3304 --------------------------- 3305 -- Analyze_Operator_Call -- 3306 --------------------------- 3307 3308 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is 3309 Op_Name : constant Name_Id := Chars (Op_Id); 3310 Act1 : constant Node_Id := First_Actual (N); 3311 Act2 : constant Node_Id := Next_Actual (Act1); 3312 3313 begin 3314 -- Binary operator case 3315 3316 if Present (Act2) then 3317 3318 -- If more than two operands, then not binary operator after all 3319 3320 if Present (Next_Actual (Act2)) then 3321 return; 3322 end if; 3323 3324 -- Otherwise action depends on operator 3325 3326 case Op_Name is 3327 when Name_Op_Add | 3328 Name_Op_Subtract | 3329 Name_Op_Multiply | 3330 Name_Op_Divide | 3331 Name_Op_Mod | 3332 Name_Op_Rem | 3333 Name_Op_Expon => 3334 Find_Arithmetic_Types (Act1, Act2, Op_Id, N); 3335 3336 when Name_Op_And | 3337 Name_Op_Or | 3338 Name_Op_Xor => 3339 Find_Boolean_Types (Act1, Act2, Op_Id, N); 3340 3341 when Name_Op_Lt | 3342 Name_Op_Le | 3343 Name_Op_Gt | 3344 Name_Op_Ge => 3345 Find_Comparison_Types (Act1, Act2, Op_Id, N); 3346 3347 when Name_Op_Eq | 3348 Name_Op_Ne => 3349 Find_Equality_Types (Act1, Act2, Op_Id, N); 3350 3351 when Name_Op_Concat => 3352 Find_Concatenation_Types (Act1, Act2, Op_Id, N); 3353 3354 -- Is this when others, or should it be an abort??? 3355 3356 when others => 3357 null; 3358 end case; 3359 3360 -- Unary operator case 3361 3362 else 3363 case Op_Name is 3364 when Name_Op_Subtract | 3365 Name_Op_Add | 3366 Name_Op_Abs => 3367 Find_Unary_Types (Act1, Op_Id, N); 3368 3369 when Name_Op_Not => 3370 Find_Negation_Types (Act1, Op_Id, N); 3371 3372 -- Is this when others correct, or should it be an abort??? 3373 3374 when others => 3375 null; 3376 end case; 3377 end if; 3378 end Analyze_Operator_Call; 3379 3380 ------------------------------------------- 3381 -- Analyze_Overloaded_Selected_Component -- 3382 ------------------------------------------- 3383 3384 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is 3385 Nam : constant Node_Id := Prefix (N); 3386 Sel : constant Node_Id := Selector_Name (N); 3387 Comp : Entity_Id; 3388 I : Interp_Index; 3389 It : Interp; 3390 T : Entity_Id; 3391 3392 begin 3393 Set_Etype (Sel, Any_Type); 3394 3395 Get_First_Interp (Nam, I, It); 3396 while Present (It.Typ) loop 3397 if Is_Access_Type (It.Typ) then 3398 T := Designated_Type (It.Typ); 3399 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N); 3400 else 3401 T := It.Typ; 3402 end if; 3403 3404 -- Locate the component. For a private prefix the selector can denote 3405 -- a discriminant. 3406 3407 if Is_Record_Type (T) or else Is_Private_Type (T) then 3408 3409 -- If the prefix is a class-wide type, the visible components are 3410 -- those of the base type. 3411 3412 if Is_Class_Wide_Type (T) then 3413 T := Etype (T); 3414 end if; 3415 3416 Comp := First_Entity (T); 3417 while Present (Comp) loop 3418 if Chars (Comp) = Chars (Sel) 3419 and then Is_Visible_Component (Comp) 3420 then 3421 3422 -- AI05-105: if the context is an object renaming with 3423 -- an anonymous access type, the expected type of the 3424 -- object must be anonymous. This is a name resolution rule. 3425 3426 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration 3427 or else No (Access_Definition (Parent (N))) 3428 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type 3429 or else 3430 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type 3431 then 3432 Set_Entity (Sel, Comp); 3433 Set_Etype (Sel, Etype (Comp)); 3434 Add_One_Interp (N, Etype (Comp), Etype (Comp)); 3435 Check_Implicit_Dereference (N, Etype (Comp)); 3436 3437 -- This also specifies a candidate to resolve the name. 3438 -- Further overloading will be resolved from context. 3439 -- The selector name itself does not carry overloading 3440 -- information. 3441 3442 Set_Etype (Nam, It.Typ); 3443 3444 else 3445 -- Named access type in the context of a renaming 3446 -- declaration with an access definition. Remove 3447 -- inapplicable candidate. 3448 3449 Remove_Interp (I); 3450 end if; 3451 end if; 3452 3453 Next_Entity (Comp); 3454 end loop; 3455 3456 elsif Is_Concurrent_Type (T) then 3457 Comp := First_Entity (T); 3458 while Present (Comp) 3459 and then Comp /= First_Private_Entity (T) 3460 loop 3461 if Chars (Comp) = Chars (Sel) then 3462 if Is_Overloadable (Comp) then 3463 Add_One_Interp (Sel, Comp, Etype (Comp)); 3464 else 3465 Set_Entity_With_Checks (Sel, Comp); 3466 Generate_Reference (Comp, Sel); 3467 end if; 3468 3469 Set_Etype (Sel, Etype (Comp)); 3470 Set_Etype (N, Etype (Comp)); 3471 Set_Etype (Nam, It.Typ); 3472 3473 -- For access type case, introduce explicit dereference for 3474 -- more uniform treatment of entry calls. Do this only once 3475 -- if several interpretations yield an access type. 3476 3477 if Is_Access_Type (Etype (Nam)) 3478 and then Nkind (Nam) /= N_Explicit_Dereference 3479 then 3480 Insert_Explicit_Dereference (Nam); 3481 Error_Msg_NW 3482 (Warn_On_Dereference, "?d?implicit dereference", N); 3483 end if; 3484 end if; 3485 3486 Next_Entity (Comp); 3487 end loop; 3488 3489 Set_Is_Overloaded (N, Is_Overloaded (Sel)); 3490 end if; 3491 3492 Get_Next_Interp (I, It); 3493 end loop; 3494 3495 if Etype (N) = Any_Type 3496 and then not Try_Object_Operation (N) 3497 then 3498 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel); 3499 Set_Entity (Sel, Any_Id); 3500 Set_Etype (Sel, Any_Type); 3501 end if; 3502 end Analyze_Overloaded_Selected_Component; 3503 3504 ---------------------------------- 3505 -- Analyze_Qualified_Expression -- 3506 ---------------------------------- 3507 3508 procedure Analyze_Qualified_Expression (N : Node_Id) is 3509 Mark : constant Entity_Id := Subtype_Mark (N); 3510 Expr : constant Node_Id := Expression (N); 3511 I : Interp_Index; 3512 It : Interp; 3513 T : Entity_Id; 3514 3515 begin 3516 Analyze_Expression (Expr); 3517 3518 Set_Etype (N, Any_Type); 3519 Find_Type (Mark); 3520 T := Entity (Mark); 3521 Set_Etype (N, T); 3522 3523 if T = Any_Type then 3524 return; 3525 end if; 3526 3527 Check_Fully_Declared (T, N); 3528 3529 -- If expected type is class-wide, check for exact match before 3530 -- expansion, because if the expression is a dispatching call it 3531 -- may be rewritten as explicit dereference with class-wide result. 3532 -- If expression is overloaded, retain only interpretations that 3533 -- will yield exact matches. 3534 3535 if Is_Class_Wide_Type (T) then 3536 if not Is_Overloaded (Expr) then 3537 if Base_Type (Etype (Expr)) /= Base_Type (T) then 3538 if Nkind (Expr) = N_Aggregate then 3539 Error_Msg_N ("type of aggregate cannot be class-wide", Expr); 3540 else 3541 Wrong_Type (Expr, T); 3542 end if; 3543 end if; 3544 3545 else 3546 Get_First_Interp (Expr, I, It); 3547 3548 while Present (It.Nam) loop 3549 if Base_Type (It.Typ) /= Base_Type (T) then 3550 Remove_Interp (I); 3551 end if; 3552 3553 Get_Next_Interp (I, It); 3554 end loop; 3555 end if; 3556 end if; 3557 3558 Set_Etype (N, T); 3559 end Analyze_Qualified_Expression; 3560 3561 ----------------------------------- 3562 -- Analyze_Quantified_Expression -- 3563 ----------------------------------- 3564 3565 procedure Analyze_Quantified_Expression (N : Node_Id) is 3566 function Is_Empty_Range (Typ : Entity_Id) return Boolean; 3567 -- If the iterator is part of a quantified expression, and the range is 3568 -- known to be statically empty, emit a warning and replace expression 3569 -- with its static value. Returns True if the replacement occurs. 3570 3571 function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean; 3572 -- Determine whether if expression If_Expr lacks an else part or if it 3573 -- has one, it evaluates to True. 3574 3575 -------------------- 3576 -- Is_Empty_Range -- 3577 -------------------- 3578 3579 function Is_Empty_Range (Typ : Entity_Id) return Boolean is 3580 Loc : constant Source_Ptr := Sloc (N); 3581 3582 begin 3583 if Is_Array_Type (Typ) 3584 and then Compile_Time_Known_Bounds (Typ) 3585 and then 3586 (Expr_Value (Type_Low_Bound (Etype (First_Index (Typ)))) > 3587 Expr_Value (Type_High_Bound (Etype (First_Index (Typ))))) 3588 then 3589 Preanalyze_And_Resolve (Condition (N), Standard_Boolean); 3590 3591 if All_Present (N) then 3592 Error_Msg_N 3593 ("??quantified expression with ALL " 3594 & "over a null range has value True", N); 3595 Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); 3596 3597 else 3598 Error_Msg_N 3599 ("??quantified expression with SOME " 3600 & "over a null range has value False", N); 3601 Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); 3602 end if; 3603 3604 Analyze (N); 3605 return True; 3606 3607 else 3608 return False; 3609 end if; 3610 end Is_Empty_Range; 3611 3612 ----------------------------- 3613 -- No_Else_Or_Trivial_True -- 3614 ----------------------------- 3615 3616 function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean is 3617 Else_Expr : constant Node_Id := 3618 Next (Next (First (Expressions (If_Expr)))); 3619 begin 3620 return 3621 No (Else_Expr) 3622 or else (Compile_Time_Known_Value (Else_Expr) 3623 and then Is_True (Expr_Value (Else_Expr))); 3624 end No_Else_Or_Trivial_True; 3625 3626 -- Local variables 3627 3628 Cond : constant Node_Id := Condition (N); 3629 Loop_Id : Entity_Id; 3630 QE_Scop : Entity_Id; 3631 3632 -- Start of processing for Analyze_Quantified_Expression 3633 3634 begin 3635 Check_SPARK_05_Restriction ("quantified expression is not allowed", N); 3636 3637 -- Create a scope to emulate the loop-like behavior of the quantified 3638 -- expression. The scope is needed to provide proper visibility of the 3639 -- loop variable. 3640 3641 QE_Scop := New_Internal_Entity (E_Loop, Current_Scope, Sloc (N), 'L'); 3642 Set_Etype (QE_Scop, Standard_Void_Type); 3643 Set_Scope (QE_Scop, Current_Scope); 3644 Set_Parent (QE_Scop, N); 3645 3646 Push_Scope (QE_Scop); 3647 3648 -- All constituents are preanalyzed and resolved to avoid untimely 3649 -- generation of various temporaries and types. Full analysis and 3650 -- expansion is carried out when the quantified expression is 3651 -- transformed into an expression with actions. 3652 3653 if Present (Iterator_Specification (N)) then 3654 Preanalyze (Iterator_Specification (N)); 3655 3656 -- Do not proceed with the analysis when the range of iteration is 3657 -- empty. The appropriate error is issued by Is_Empty_Range. 3658 3659 if Is_Entity_Name (Name (Iterator_Specification (N))) 3660 and then Is_Empty_Range (Etype (Name (Iterator_Specification (N)))) 3661 then 3662 return; 3663 end if; 3664 3665 else pragma Assert (Present (Loop_Parameter_Specification (N))); 3666 declare 3667 Loop_Par : constant Node_Id := Loop_Parameter_Specification (N); 3668 3669 begin 3670 Preanalyze (Loop_Par); 3671 3672 if Nkind (Discrete_Subtype_Definition (Loop_Par)) = N_Function_Call 3673 and then Parent (Loop_Par) /= N 3674 then 3675 -- The parser cannot distinguish between a loop specification 3676 -- and an iterator specification. If after pre-analysis the 3677 -- proper form has been recognized, rewrite the expression to 3678 -- reflect the right kind. This is needed for proper ASIS 3679 -- navigation. If expansion is enabled, the transformation is 3680 -- performed when the expression is rewritten as a loop. 3681 3682 Set_Iterator_Specification (N, 3683 New_Copy_Tree (Iterator_Specification (Parent (Loop_Par)))); 3684 3685 Set_Defining_Identifier (Iterator_Specification (N), 3686 Relocate_Node (Defining_Identifier (Loop_Par))); 3687 Set_Name (Iterator_Specification (N), 3688 Relocate_Node (Discrete_Subtype_Definition (Loop_Par))); 3689 Set_Comes_From_Source (Iterator_Specification (N), 3690 Comes_From_Source (Loop_Parameter_Specification (N))); 3691 Set_Loop_Parameter_Specification (N, Empty); 3692 end if; 3693 end; 3694 end if; 3695 3696 Preanalyze_And_Resolve (Cond, Standard_Boolean); 3697 3698 End_Scope; 3699 Set_Etype (N, Standard_Boolean); 3700 3701 -- Verify that the loop variable is used within the condition of the 3702 -- quantified expression. 3703 3704 if Present (Iterator_Specification (N)) then 3705 Loop_Id := Defining_Identifier (Iterator_Specification (N)); 3706 else 3707 Loop_Id := Defining_Identifier (Loop_Parameter_Specification (N)); 3708 end if; 3709 3710 if Warn_On_Suspicious_Contract 3711 and then not Referenced (Loop_Id, Cond) 3712 then 3713 Error_Msg_N ("?T?unused variable &", Loop_Id); 3714 end if; 3715 3716 -- Diagnose a possible misuse of the SOME existential quantifier. When 3717 -- we have a quantified expression of the form: 3718 3719 -- for some X => (if P then Q [else True]) 3720 3721 -- any value for X that makes P False results in the if expression being 3722 -- trivially True, and so also results in the the quantified expression 3723 -- being trivially True. 3724 3725 if Warn_On_Suspicious_Contract 3726 and then not All_Present (N) 3727 and then Nkind (Cond) = N_If_Expression 3728 and then No_Else_Or_Trivial_True (Cond) 3729 then 3730 Error_Msg_N ("?T?suspicious expression", N); 3731 Error_Msg_N ("\\did you mean (for all X ='> (if P then Q))", N); 3732 Error_Msg_N ("\\or (for some X ='> P and then Q) instead'?", N); 3733 end if; 3734 end Analyze_Quantified_Expression; 3735 3736 ------------------- 3737 -- Analyze_Range -- 3738 ------------------- 3739 3740 procedure Analyze_Range (N : Node_Id) is 3741 L : constant Node_Id := Low_Bound (N); 3742 H : constant Node_Id := High_Bound (N); 3743 I1, I2 : Interp_Index; 3744 It1, It2 : Interp; 3745 3746 procedure Check_Common_Type (T1, T2 : Entity_Id); 3747 -- Verify the compatibility of two types, and choose the 3748 -- non universal one if the other is universal. 3749 3750 procedure Check_High_Bound (T : Entity_Id); 3751 -- Test one interpretation of the low bound against all those 3752 -- of the high bound. 3753 3754 procedure Check_Universal_Expression (N : Node_Id); 3755 -- In Ada 83, reject bounds of a universal range that are not literals 3756 -- or entity names. 3757 3758 ----------------------- 3759 -- Check_Common_Type -- 3760 ----------------------- 3761 3762 procedure Check_Common_Type (T1, T2 : Entity_Id) is 3763 begin 3764 if Covers (T1 => T1, T2 => T2) 3765 or else 3766 Covers (T1 => T2, T2 => T1) 3767 then 3768 if T1 = Universal_Integer 3769 or else T1 = Universal_Real 3770 or else T1 = Any_Character 3771 then 3772 Add_One_Interp (N, Base_Type (T2), Base_Type (T2)); 3773 3774 elsif T1 = T2 then 3775 Add_One_Interp (N, T1, T1); 3776 3777 else 3778 Add_One_Interp (N, Base_Type (T1), Base_Type (T1)); 3779 end if; 3780 end if; 3781 end Check_Common_Type; 3782 3783 ---------------------- 3784 -- Check_High_Bound -- 3785 ---------------------- 3786 3787 procedure Check_High_Bound (T : Entity_Id) is 3788 begin 3789 if not Is_Overloaded (H) then 3790 Check_Common_Type (T, Etype (H)); 3791 else 3792 Get_First_Interp (H, I2, It2); 3793 while Present (It2.Typ) loop 3794 Check_Common_Type (T, It2.Typ); 3795 Get_Next_Interp (I2, It2); 3796 end loop; 3797 end if; 3798 end Check_High_Bound; 3799 3800 ----------------------------- 3801 -- Is_Universal_Expression -- 3802 ----------------------------- 3803 3804 procedure Check_Universal_Expression (N : Node_Id) is 3805 begin 3806 if Etype (N) = Universal_Integer 3807 and then Nkind (N) /= N_Integer_Literal 3808 and then not Is_Entity_Name (N) 3809 and then Nkind (N) /= N_Attribute_Reference 3810 then 3811 Error_Msg_N ("illegal bound in discrete range", N); 3812 end if; 3813 end Check_Universal_Expression; 3814 3815 -- Start of processing for Analyze_Range 3816 3817 begin 3818 Set_Etype (N, Any_Type); 3819 Analyze_Expression (L); 3820 Analyze_Expression (H); 3821 3822 if Etype (L) = Any_Type or else Etype (H) = Any_Type then 3823 return; 3824 3825 else 3826 if not Is_Overloaded (L) then 3827 Check_High_Bound (Etype (L)); 3828 else 3829 Get_First_Interp (L, I1, It1); 3830 while Present (It1.Typ) loop 3831 Check_High_Bound (It1.Typ); 3832 Get_Next_Interp (I1, It1); 3833 end loop; 3834 end if; 3835 3836 -- If result is Any_Type, then we did not find a compatible pair 3837 3838 if Etype (N) = Any_Type then 3839 Error_Msg_N ("incompatible types in range ", N); 3840 end if; 3841 end if; 3842 3843 if Ada_Version = Ada_83 3844 and then 3845 (Nkind (Parent (N)) = N_Loop_Parameter_Specification 3846 or else Nkind (Parent (N)) = N_Constrained_Array_Definition) 3847 then 3848 Check_Universal_Expression (L); 3849 Check_Universal_Expression (H); 3850 end if; 3851 3852 Check_Function_Writable_Actuals (N); 3853 end Analyze_Range; 3854 3855 ----------------------- 3856 -- Analyze_Reference -- 3857 ----------------------- 3858 3859 procedure Analyze_Reference (N : Node_Id) is 3860 P : constant Node_Id := Prefix (N); 3861 E : Entity_Id; 3862 T : Entity_Id; 3863 Acc_Type : Entity_Id; 3864 3865 begin 3866 Analyze (P); 3867 3868 -- An interesting error check, if we take the 'Reference of an object 3869 -- for which a pragma Atomic or Volatile has been given, and the type 3870 -- of the object is not Atomic or Volatile, then we are in trouble. The 3871 -- problem is that no trace of the atomic/volatile status will remain 3872 -- for the backend to respect when it deals with the resulting pointer, 3873 -- since the pointer type will not be marked atomic (it is a pointer to 3874 -- the base type of the object). 3875 3876 -- It is not clear if that can ever occur, but in case it does, we will 3877 -- generate an error message. Not clear if this message can ever be 3878 -- generated, and pretty clear that it represents a bug if it is, still 3879 -- seems worth checking, except in CodePeer mode where we do not really 3880 -- care and don't want to bother the user. 3881 3882 T := Etype (P); 3883 3884 if Is_Entity_Name (P) 3885 and then Is_Object_Reference (P) 3886 and then not CodePeer_Mode 3887 then 3888 E := Entity (P); 3889 T := Etype (P); 3890 3891 if (Has_Atomic_Components (E) 3892 and then not Has_Atomic_Components (T)) 3893 or else 3894 (Has_Volatile_Components (E) 3895 and then not Has_Volatile_Components (T)) 3896 or else (Is_Atomic (E) and then not Is_Atomic (T)) 3897 or else (Is_Volatile (E) and then not Is_Volatile (T)) 3898 then 3899 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N); 3900 end if; 3901 end if; 3902 3903 -- Carry on with normal processing 3904 3905 Acc_Type := Create_Itype (E_Allocator_Type, N); 3906 Set_Etype (Acc_Type, Acc_Type); 3907 Set_Directly_Designated_Type (Acc_Type, Etype (P)); 3908 Set_Etype (N, Acc_Type); 3909 end Analyze_Reference; 3910 3911 -------------------------------- 3912 -- Analyze_Selected_Component -- 3913 -------------------------------- 3914 3915 -- Prefix is a record type or a task or protected type. In the latter case, 3916 -- the selector must denote a visible entry. 3917 3918 procedure Analyze_Selected_Component (N : Node_Id) is 3919 Name : constant Node_Id := Prefix (N); 3920 Sel : constant Node_Id := Selector_Name (N); 3921 Act_Decl : Node_Id; 3922 Comp : Entity_Id; 3923 Has_Candidate : Boolean := False; 3924 In_Scope : Boolean; 3925 Parent_N : Node_Id; 3926 Pent : Entity_Id := Empty; 3927 Prefix_Type : Entity_Id; 3928 3929 Type_To_Use : Entity_Id; 3930 -- In most cases this is the Prefix_Type, but if the Prefix_Type is 3931 -- a class-wide type, we use its root type, whose components are 3932 -- present in the class-wide type. 3933 3934 Is_Single_Concurrent_Object : Boolean; 3935 -- Set True if the prefix is a single task or a single protected object 3936 3937 procedure Find_Component_In_Instance (Rec : Entity_Id); 3938 -- In an instance, a component of a private extension may not be visible 3939 -- while it was visible in the generic. Search candidate scope for a 3940 -- component with the proper identifier. This is only done if all other 3941 -- searches have failed. If a match is found, the Etype of both N and 3942 -- Sel are set from this component, and the entity of Sel is set to 3943 -- reference this component. If no match is found, Entity (Sel) remains 3944 -- unset. 3945 3946 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean; 3947 -- It is known that the parent of N denotes a subprogram call. Comp 3948 -- is an overloadable component of the concurrent type of the prefix. 3949 -- Determine whether all formals of the parent of N and Comp are mode 3950 -- conformant. If the parent node is not analyzed yet it may be an 3951 -- indexed component rather than a function call. 3952 3953 -------------------------------- 3954 -- Find_Component_In_Instance -- 3955 -------------------------------- 3956 3957 procedure Find_Component_In_Instance (Rec : Entity_Id) is 3958 Comp : Entity_Id; 3959 3960 begin 3961 Comp := First_Component (Rec); 3962 while Present (Comp) loop 3963 if Chars (Comp) = Chars (Sel) then 3964 Set_Entity_With_Checks (Sel, Comp); 3965 Set_Etype (Sel, Etype (Comp)); 3966 Set_Etype (N, Etype (Comp)); 3967 return; 3968 end if; 3969 3970 Next_Component (Comp); 3971 end loop; 3972 3973 -- If we fall through, no match, so no changes made 3974 3975 return; 3976 end Find_Component_In_Instance; 3977 3978 ------------------------------ 3979 -- Has_Mode_Conformant_Spec -- 3980 ------------------------------ 3981 3982 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is 3983 Comp_Param : Entity_Id; 3984 Param : Node_Id; 3985 Param_Typ : Entity_Id; 3986 3987 begin 3988 Comp_Param := First_Formal (Comp); 3989 3990 if Nkind (Parent (N)) = N_Indexed_Component then 3991 Param := First (Expressions (Parent (N))); 3992 else 3993 Param := First (Parameter_Associations (Parent (N))); 3994 end if; 3995 3996 while Present (Comp_Param) 3997 and then Present (Param) 3998 loop 3999 Param_Typ := Find_Parameter_Type (Param); 4000 4001 if Present (Param_Typ) 4002 and then 4003 not Conforming_Types 4004 (Etype (Comp_Param), Param_Typ, Mode_Conformant) 4005 then 4006 return False; 4007 end if; 4008 4009 Next_Formal (Comp_Param); 4010 Next (Param); 4011 end loop; 4012 4013 -- One of the specs has additional formals; there is no match, unless 4014 -- this may be an indexing of a parameterless call. 4015 4016 -- Note that when expansion is disabled, the corresponding record 4017 -- type of synchronized types is not constructed, so that there is 4018 -- no point is attempting an interpretation as a prefixed call, as 4019 -- this is bound to fail because the primitive operations will not 4020 -- be properly located. 4021 4022 if Present (Comp_Param) or else Present (Param) then 4023 if Needs_No_Actuals (Comp) 4024 and then Is_Array_Type (Etype (Comp)) 4025 and then not Expander_Active 4026 then 4027 return True; 4028 else 4029 return False; 4030 end if; 4031 end if; 4032 4033 return True; 4034 end Has_Mode_Conformant_Spec; 4035 4036 -- Start of processing for Analyze_Selected_Component 4037 4038 begin 4039 Set_Etype (N, Any_Type); 4040 4041 if Is_Overloaded (Name) then 4042 Analyze_Overloaded_Selected_Component (N); 4043 return; 4044 4045 elsif Etype (Name) = Any_Type then 4046 Set_Entity (Sel, Any_Id); 4047 Set_Etype (Sel, Any_Type); 4048 return; 4049 4050 else 4051 Prefix_Type := Etype (Name); 4052 end if; 4053 4054 if Is_Access_Type (Prefix_Type) then 4055 4056 -- A RACW object can never be used as prefix of a selected component 4057 -- since that means it is dereferenced without being a controlling 4058 -- operand of a dispatching operation (RM E.2.2(16/1)). Before 4059 -- reporting an error, we must check whether this is actually a 4060 -- dispatching call in prefix form. 4061 4062 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type) 4063 and then Comes_From_Source (N) 4064 then 4065 if Try_Object_Operation (N) then 4066 return; 4067 else 4068 Error_Msg_N 4069 ("invalid dereference of a remote access-to-class-wide value", 4070 N); 4071 end if; 4072 4073 -- Normal case of selected component applied to access type 4074 4075 else 4076 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N); 4077 4078 if Is_Entity_Name (Name) then 4079 Pent := Entity (Name); 4080 elsif Nkind (Name) = N_Selected_Component 4081 and then Is_Entity_Name (Selector_Name (Name)) 4082 then 4083 Pent := Entity (Selector_Name (Name)); 4084 end if; 4085 4086 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name); 4087 end if; 4088 4089 -- If we have an explicit dereference of a remote access-to-class-wide 4090 -- value, then issue an error (see RM-E.2.2(16/1)). However we first 4091 -- have to check for the case of a prefix that is a controlling operand 4092 -- of a prefixed dispatching call, as the dereference is legal in that 4093 -- case. Normally this condition is checked in Validate_Remote_Access_ 4094 -- To_Class_Wide_Type, but we have to defer the checking for selected 4095 -- component prefixes because of the prefixed dispatching call case. 4096 -- Note that implicit dereferences are checked for this just above. 4097 4098 elsif Nkind (Name) = N_Explicit_Dereference 4099 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name))) 4100 and then Comes_From_Source (N) 4101 then 4102 if Try_Object_Operation (N) then 4103 return; 4104 else 4105 Error_Msg_N 4106 ("invalid dereference of a remote access-to-class-wide value", 4107 N); 4108 end if; 4109 end if; 4110 4111 -- (Ada 2005): if the prefix is the limited view of a type, and 4112 -- the context already includes the full view, use the full view 4113 -- in what follows, either to retrieve a component of to find 4114 -- a primitive operation. If the prefix is an explicit dereference, 4115 -- set the type of the prefix to reflect this transformation. 4116 -- If the non-limited view is itself an incomplete type, get the 4117 -- full view if available. 4118 4119 if Is_Incomplete_Type (Prefix_Type) 4120 and then From_Limited_With (Prefix_Type) 4121 and then Present (Non_Limited_View (Prefix_Type)) 4122 then 4123 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type)); 4124 4125 if Nkind (N) = N_Explicit_Dereference then 4126 Set_Etype (Prefix (N), Prefix_Type); 4127 end if; 4128 4129 elsif Ekind (Prefix_Type) = E_Class_Wide_Type 4130 and then From_Limited_With (Prefix_Type) 4131 and then Present (Non_Limited_View (Etype (Prefix_Type))) 4132 then 4133 Prefix_Type := 4134 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type))); 4135 4136 if Nkind (N) = N_Explicit_Dereference then 4137 Set_Etype (Prefix (N), Prefix_Type); 4138 end if; 4139 end if; 4140 4141 if Ekind (Prefix_Type) = E_Private_Subtype then 4142 Prefix_Type := Base_Type (Prefix_Type); 4143 end if; 4144 4145 Type_To_Use := Prefix_Type; 4146 4147 -- For class-wide types, use the entity list of the root type. This 4148 -- indirection is specially important for private extensions because 4149 -- only the root type get switched (not the class-wide type). 4150 4151 if Is_Class_Wide_Type (Prefix_Type) then 4152 Type_To_Use := Root_Type (Prefix_Type); 4153 end if; 4154 4155 -- If the prefix is a single concurrent object, use its name in error 4156 -- messages, rather than that of its anonymous type. 4157 4158 Is_Single_Concurrent_Object := 4159 Is_Concurrent_Type (Prefix_Type) 4160 and then Is_Internal_Name (Chars (Prefix_Type)) 4161 and then not Is_Derived_Type (Prefix_Type) 4162 and then Is_Entity_Name (Name); 4163 4164 Comp := First_Entity (Type_To_Use); 4165 4166 -- If the selector has an original discriminant, the node appears in 4167 -- an instance. Replace the discriminant with the corresponding one 4168 -- in the current discriminated type. For nested generics, this must 4169 -- be done transitively, so note the new original discriminant. 4170 4171 if Nkind (Sel) = N_Identifier 4172 and then In_Instance 4173 and then Present (Original_Discriminant (Sel)) 4174 then 4175 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type); 4176 4177 -- Mark entity before rewriting, for completeness and because 4178 -- subsequent semantic checks might examine the original node. 4179 4180 Set_Entity (Sel, Comp); 4181 Rewrite (Selector_Name (N), New_Occurrence_Of (Comp, Sloc (N))); 4182 Set_Original_Discriminant (Selector_Name (N), Comp); 4183 Set_Etype (N, Etype (Comp)); 4184 Check_Implicit_Dereference (N, Etype (Comp)); 4185 4186 if Is_Access_Type (Etype (Name)) then 4187 Insert_Explicit_Dereference (Name); 4188 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N); 4189 end if; 4190 4191 elsif Is_Record_Type (Prefix_Type) then 4192 4193 -- Find component with given name. In an instance, if the node is 4194 -- known as a prefixed call, do not examine components whose 4195 -- visibility may be accidental. 4196 4197 while Present (Comp) and then not Is_Prefixed_Call (N) loop 4198 if Chars (Comp) = Chars (Sel) 4199 and then Is_Visible_Component (Comp, N) 4200 then 4201 Set_Entity_With_Checks (Sel, Comp); 4202 Set_Etype (Sel, Etype (Comp)); 4203 4204 if Ekind (Comp) = E_Discriminant then 4205 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then 4206 Error_Msg_N 4207 ("cannot reference discriminant of unchecked union", 4208 Sel); 4209 end if; 4210 4211 if Is_Generic_Type (Prefix_Type) 4212 or else 4213 Is_Generic_Type (Root_Type (Prefix_Type)) 4214 then 4215 Set_Original_Discriminant (Sel, Comp); 4216 end if; 4217 end if; 4218 4219 -- Resolve the prefix early otherwise it is not possible to 4220 -- build the actual subtype of the component: it may need 4221 -- to duplicate this prefix and duplication is only allowed 4222 -- on fully resolved expressions. 4223 4224 Resolve (Name); 4225 4226 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or 4227 -- subtypes in a package specification. 4228 -- Example: 4229 4230 -- limited with Pkg; 4231 -- package Pkg is 4232 -- type Acc_Inc is access Pkg.T; 4233 -- X : Acc_Inc; 4234 -- N : Natural := X.all.Comp; -- ERROR, limited view 4235 -- end Pkg; -- Comp is not visible 4236 4237 if Nkind (Name) = N_Explicit_Dereference 4238 and then From_Limited_With (Etype (Prefix (Name))) 4239 and then not Is_Potentially_Use_Visible (Etype (Name)) 4240 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) = 4241 N_Package_Specification 4242 then 4243 Error_Msg_NE 4244 ("premature usage of incomplete}", Prefix (Name), 4245 Etype (Prefix (Name))); 4246 end if; 4247 4248 -- We never need an actual subtype for the case of a selection 4249 -- for a indexed component of a non-packed array, since in 4250 -- this case gigi generates all the checks and can find the 4251 -- necessary bounds information. 4252 4253 -- We also do not need an actual subtype for the case of a 4254 -- first, last, length, or range attribute applied to a 4255 -- non-packed array, since gigi can again get the bounds in 4256 -- these cases (gigi cannot handle the packed case, since it 4257 -- has the bounds of the packed array type, not the original 4258 -- bounds of the type). However, if the prefix is itself a 4259 -- selected component, as in a.b.c (i), gigi may regard a.b.c 4260 -- as a dynamic-sized temporary, so we do generate an actual 4261 -- subtype for this case. 4262 4263 Parent_N := Parent (N); 4264 4265 if not Is_Packed (Etype (Comp)) 4266 and then 4267 ((Nkind (Parent_N) = N_Indexed_Component 4268 and then Nkind (Name) /= N_Selected_Component) 4269 or else 4270 (Nkind (Parent_N) = N_Attribute_Reference 4271 and then 4272 Nam_In (Attribute_Name (Parent_N), Name_First, 4273 Name_Last, 4274 Name_Length, 4275 Name_Range))) 4276 then 4277 Set_Etype (N, Etype (Comp)); 4278 4279 -- If full analysis is not enabled, we do not generate an 4280 -- actual subtype, because in the absence of expansion 4281 -- reference to a formal of a protected type, for example, 4282 -- will not be properly transformed, and will lead to 4283 -- out-of-scope references in gigi. 4284 4285 -- In all other cases, we currently build an actual subtype. 4286 -- It seems likely that many of these cases can be avoided, 4287 -- but right now, the front end makes direct references to the 4288 -- bounds (e.g. in generating a length check), and if we do 4289 -- not make an actual subtype, we end up getting a direct 4290 -- reference to a discriminant, which will not do. 4291 4292 elsif Full_Analysis then 4293 Act_Decl := 4294 Build_Actual_Subtype_Of_Component (Etype (Comp), N); 4295 Insert_Action (N, Act_Decl); 4296 4297 if No (Act_Decl) then 4298 Set_Etype (N, Etype (Comp)); 4299 4300 else 4301 -- Component type depends on discriminants. Enter the 4302 -- main attributes of the subtype. 4303 4304 declare 4305 Subt : constant Entity_Id := 4306 Defining_Identifier (Act_Decl); 4307 4308 begin 4309 Set_Etype (Subt, Base_Type (Etype (Comp))); 4310 Set_Ekind (Subt, Ekind (Etype (Comp))); 4311 Set_Etype (N, Subt); 4312 end; 4313 end if; 4314 4315 -- If Full_Analysis not enabled, just set the Etype 4316 4317 else 4318 Set_Etype (N, Etype (Comp)); 4319 end if; 4320 4321 Check_Implicit_Dereference (N, Etype (N)); 4322 return; 4323 end if; 4324 4325 -- If the prefix is a private extension, check only the visible 4326 -- components of the partial view. This must include the tag, 4327 -- which can appear in expanded code in a tag check. 4328 4329 if Ekind (Type_To_Use) = E_Record_Type_With_Private 4330 and then Chars (Selector_Name (N)) /= Name_uTag 4331 then 4332 exit when Comp = Last_Entity (Type_To_Use); 4333 end if; 4334 4335 Next_Entity (Comp); 4336 end loop; 4337 4338 -- Ada 2005 (AI-252): The selected component can be interpreted as 4339 -- a prefixed view of a subprogram. Depending on the context, this is 4340 -- either a name that can appear in a renaming declaration, or part 4341 -- of an enclosing call given in prefix form. 4342 4343 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the 4344 -- selected component should resolve to a name. 4345 4346 if Ada_Version >= Ada_2005 4347 and then Is_Tagged_Type (Prefix_Type) 4348 and then not Is_Concurrent_Type (Prefix_Type) 4349 then 4350 if Nkind (Parent (N)) = N_Generic_Association 4351 or else Nkind (Parent (N)) = N_Requeue_Statement 4352 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration 4353 then 4354 if Find_Primitive_Operation (N) then 4355 return; 4356 end if; 4357 4358 elsif Try_Object_Operation (N) then 4359 return; 4360 end if; 4361 4362 -- If the transformation fails, it will be necessary to redo the 4363 -- analysis with all errors enabled, to indicate candidate 4364 -- interpretations and reasons for each failure ??? 4365 4366 end if; 4367 4368 elsif Is_Private_Type (Prefix_Type) then 4369 4370 -- Allow access only to discriminants of the type. If the type has 4371 -- no full view, gigi uses the parent type for the components, so we 4372 -- do the same here. 4373 4374 if No (Full_View (Prefix_Type)) then 4375 Type_To_Use := Root_Type (Base_Type (Prefix_Type)); 4376 Comp := First_Entity (Type_To_Use); 4377 end if; 4378 4379 while Present (Comp) loop 4380 if Chars (Comp) = Chars (Sel) then 4381 if Ekind (Comp) = E_Discriminant then 4382 Set_Entity_With_Checks (Sel, Comp); 4383 Generate_Reference (Comp, Sel); 4384 4385 Set_Etype (Sel, Etype (Comp)); 4386 Set_Etype (N, Etype (Comp)); 4387 Check_Implicit_Dereference (N, Etype (N)); 4388 4389 if Is_Generic_Type (Prefix_Type) 4390 or else Is_Generic_Type (Root_Type (Prefix_Type)) 4391 then 4392 Set_Original_Discriminant (Sel, Comp); 4393 end if; 4394 4395 -- Before declaring an error, check whether this is tagged 4396 -- private type and a call to a primitive operation. 4397 4398 elsif Ada_Version >= Ada_2005 4399 and then Is_Tagged_Type (Prefix_Type) 4400 and then Try_Object_Operation (N) 4401 then 4402 return; 4403 4404 else 4405 Error_Msg_Node_2 := First_Subtype (Prefix_Type); 4406 Error_Msg_NE ("invisible selector& for }", N, Sel); 4407 Set_Entity (Sel, Any_Id); 4408 Set_Etype (N, Any_Type); 4409 end if; 4410 4411 return; 4412 end if; 4413 4414 Next_Entity (Comp); 4415 end loop; 4416 4417 elsif Is_Concurrent_Type (Prefix_Type) then 4418 4419 -- Find visible operation with given name. For a protected type, 4420 -- the possible candidates are discriminants, entries or protected 4421 -- procedures. For a task type, the set can only include entries or 4422 -- discriminants if the task type is not an enclosing scope. If it 4423 -- is an enclosing scope (e.g. in an inner task) then all entities 4424 -- are visible, but the prefix must denote the enclosing scope, i.e. 4425 -- can only be a direct name or an expanded name. 4426 4427 Set_Etype (Sel, Any_Type); 4428 In_Scope := In_Open_Scopes (Prefix_Type); 4429 4430 while Present (Comp) loop 4431 if Chars (Comp) = Chars (Sel) then 4432 if Is_Overloadable (Comp) then 4433 Add_One_Interp (Sel, Comp, Etype (Comp)); 4434 4435 -- If the prefix is tagged, the correct interpretation may 4436 -- lie in the primitive or class-wide operations of the 4437 -- type. Perform a simple conformance check to determine 4438 -- whether Try_Object_Operation should be invoked even if 4439 -- a visible entity is found. 4440 4441 if Is_Tagged_Type (Prefix_Type) 4442 and then 4443 Nkind_In (Parent (N), N_Procedure_Call_Statement, 4444 N_Function_Call, 4445 N_Indexed_Component) 4446 and then Has_Mode_Conformant_Spec (Comp) 4447 then 4448 Has_Candidate := True; 4449 end if; 4450 4451 -- Note: a selected component may not denote a component of a 4452 -- protected type (4.1.3(7)). 4453 4454 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family) 4455 or else (In_Scope 4456 and then not Is_Protected_Type (Prefix_Type) 4457 and then Is_Entity_Name (Name)) 4458 then 4459 Set_Entity_With_Checks (Sel, Comp); 4460 Generate_Reference (Comp, Sel); 4461 4462 -- The selector is not overloadable, so we have a candidate 4463 -- interpretation. 4464 4465 Has_Candidate := True; 4466 4467 else 4468 goto Next_Comp; 4469 end if; 4470 4471 Set_Etype (Sel, Etype (Comp)); 4472 Set_Etype (N, Etype (Comp)); 4473 4474 if Ekind (Comp) = E_Discriminant then 4475 Set_Original_Discriminant (Sel, Comp); 4476 end if; 4477 4478 -- For access type case, introduce explicit dereference for 4479 -- more uniform treatment of entry calls. 4480 4481 if Is_Access_Type (Etype (Name)) then 4482 Insert_Explicit_Dereference (Name); 4483 Error_Msg_NW 4484 (Warn_On_Dereference, "?d?implicit dereference", N); 4485 end if; 4486 end if; 4487 4488 <<Next_Comp>> 4489 Next_Entity (Comp); 4490 exit when not In_Scope 4491 and then 4492 Comp = First_Private_Entity (Base_Type (Prefix_Type)); 4493 end loop; 4494 4495 -- If there is no visible entity with the given name or none of the 4496 -- visible entities are plausible interpretations, check whether 4497 -- there is some other primitive operation with that name. 4498 4499 if Ada_Version >= Ada_2005 4500 and then Is_Tagged_Type (Prefix_Type) 4501 then 4502 if (Etype (N) = Any_Type 4503 or else not Has_Candidate) 4504 and then Try_Object_Operation (N) 4505 then 4506 return; 4507 4508 -- If the context is not syntactically a procedure call, it 4509 -- may be a call to a primitive function declared outside of 4510 -- the synchronized type. 4511 4512 -- If the context is a procedure call, there might still be 4513 -- an overloading between an entry and a primitive procedure 4514 -- declared outside of the synchronized type, called in prefix 4515 -- notation. This is harder to disambiguate because in one case 4516 -- the controlling formal is implicit ??? 4517 4518 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement 4519 and then Nkind (Parent (N)) /= N_Indexed_Component 4520 and then Try_Object_Operation (N) 4521 then 4522 return; 4523 end if; 4524 4525 -- Ada 2012 (AI05-0090-1): If we found a candidate of a call to an 4526 -- entry or procedure of a tagged concurrent type we must check 4527 -- if there are class-wide subprograms covering the primitive. If 4528 -- true then Try_Object_Operation reports the error. 4529 4530 if Has_Candidate 4531 and then Is_Concurrent_Type (Prefix_Type) 4532 and then Nkind (Parent (N)) = N_Procedure_Call_Statement 4533 4534 -- Duplicate the call. This is required to avoid problems with 4535 -- the tree transformations performed by Try_Object_Operation. 4536 -- Set properly the parent of the copied call, because it is 4537 -- about to be reanalyzed. 4538 4539 then 4540 declare 4541 Par : constant Node_Id := New_Copy_Tree (Parent (N)); 4542 4543 begin 4544 Set_Parent (Par, Parent (Parent (N))); 4545 4546 if Try_Object_Operation 4547 (Sinfo.Name (Par), CW_Test_Only => True) 4548 then 4549 return; 4550 end if; 4551 end; 4552 end if; 4553 end if; 4554 4555 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then 4556 4557 -- Case of a prefix of a protected type: selector might denote 4558 -- an invisible private component. 4559 4560 Comp := First_Private_Entity (Base_Type (Prefix_Type)); 4561 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop 4562 Next_Entity (Comp); 4563 end loop; 4564 4565 if Present (Comp) then 4566 if Is_Single_Concurrent_Object then 4567 Error_Msg_Node_2 := Entity (Name); 4568 Error_Msg_NE ("invisible selector& for &", N, Sel); 4569 4570 else 4571 Error_Msg_Node_2 := First_Subtype (Prefix_Type); 4572 Error_Msg_NE ("invisible selector& for }", N, Sel); 4573 end if; 4574 return; 4575 end if; 4576 end if; 4577 4578 Set_Is_Overloaded (N, Is_Overloaded (Sel)); 4579 4580 else 4581 -- Invalid prefix 4582 4583 Error_Msg_NE ("invalid prefix in selected component&", N, Sel); 4584 end if; 4585 4586 -- If N still has no type, the component is not defined in the prefix 4587 4588 if Etype (N) = Any_Type then 4589 4590 if Is_Single_Concurrent_Object then 4591 Error_Msg_Node_2 := Entity (Name); 4592 Error_Msg_NE ("no selector& for&", N, Sel); 4593 4594 Check_Misspelled_Selector (Type_To_Use, Sel); 4595 4596 -- If this is a derived formal type, the parent may have different 4597 -- visibility at this point. Try for an inherited component before 4598 -- reporting an error. 4599 4600 elsif Is_Generic_Type (Prefix_Type) 4601 and then Ekind (Prefix_Type) = E_Record_Type_With_Private 4602 and then Prefix_Type /= Etype (Prefix_Type) 4603 and then Is_Record_Type (Etype (Prefix_Type)) 4604 then 4605 Set_Etype (Prefix (N), Etype (Prefix_Type)); 4606 Analyze_Selected_Component (N); 4607 return; 4608 4609 -- Similarly, if this is the actual for a formal derived type, or 4610 -- a derived type thereof, the component inherited from the generic 4611 -- parent may not be visible in the actual, but the selected 4612 -- component is legal. Climb up the derivation chain of the generic 4613 -- parent type until we find the proper ancestor type. 4614 4615 elsif In_Instance and then Is_Tagged_Type (Prefix_Type) then 4616 declare 4617 Par : Entity_Id := Prefix_Type; 4618 begin 4619 -- Climb up derivation chain to generic actual subtype 4620 4621 while not Is_Generic_Actual_Type (Par) loop 4622 if Ekind (Par) = E_Record_Type then 4623 Par := Parent_Subtype (Par); 4624 exit when No (Par); 4625 else 4626 exit when Par = Etype (Par); 4627 Par := Etype (Par); 4628 end if; 4629 end loop; 4630 4631 if Present (Par) and then Is_Generic_Actual_Type (Par) then 4632 4633 -- Now look for component in ancestor types 4634 4635 Par := Generic_Parent_Type (Declaration_Node (Par)); 4636 loop 4637 Find_Component_In_Instance (Par); 4638 exit when Present (Entity (Sel)) 4639 or else Par = Etype (Par); 4640 Par := Etype (Par); 4641 end loop; 4642 4643 -- In ASIS mode the generic parent type may be absent. Examine 4644 -- the parent type directly for a component that may have been 4645 -- visible in a parent generic unit. 4646 4647 elsif Is_Derived_Type (Prefix_Type) then 4648 Par := Etype (Prefix_Type); 4649 Find_Component_In_Instance (Par); 4650 end if; 4651 end; 4652 4653 -- The search above must have eventually succeeded, since the 4654 -- selected component was legal in the generic. 4655 4656 if No (Entity (Sel)) then 4657 raise Program_Error; 4658 end if; 4659 4660 return; 4661 4662 -- Component not found, specialize error message when appropriate 4663 4664 else 4665 if Ekind (Prefix_Type) = E_Record_Subtype then 4666 4667 -- Check whether this is a component of the base type which 4668 -- is absent from a statically constrained subtype. This will 4669 -- raise constraint error at run time, but is not a compile- 4670 -- time error. When the selector is illegal for base type as 4671 -- well fall through and generate a compilation error anyway. 4672 4673 Comp := First_Component (Base_Type (Prefix_Type)); 4674 while Present (Comp) loop 4675 if Chars (Comp) = Chars (Sel) 4676 and then Is_Visible_Component (Comp) 4677 then 4678 Set_Entity_With_Checks (Sel, Comp); 4679 Generate_Reference (Comp, Sel); 4680 Set_Etype (Sel, Etype (Comp)); 4681 Set_Etype (N, Etype (Comp)); 4682 4683 -- Emit appropriate message. The node will be replaced 4684 -- by an appropriate raise statement. 4685 4686 -- Note that in SPARK mode, as with all calls to apply a 4687 -- compile time constraint error, this will be made into 4688 -- an error to simplify the processing of the formal 4689 -- verification backend. 4690 4691 Apply_Compile_Time_Constraint_Error 4692 (N, "component not present in }??", 4693 CE_Discriminant_Check_Failed, 4694 Ent => Prefix_Type, Rep => False); 4695 4696 Set_Raises_Constraint_Error (N); 4697 return; 4698 end if; 4699 4700 Next_Component (Comp); 4701 end loop; 4702 4703 end if; 4704 4705 Error_Msg_Node_2 := First_Subtype (Prefix_Type); 4706 Error_Msg_NE ("no selector& for}", N, Sel); 4707 4708 -- Add information in the case of an incomplete prefix 4709 4710 if Is_Incomplete_Type (Type_To_Use) then 4711 declare 4712 Inc : constant Entity_Id := First_Subtype (Type_To_Use); 4713 4714 begin 4715 if From_Limited_With (Scope (Type_To_Use)) then 4716 Error_Msg_NE 4717 ("\limited view of& has no components", N, Inc); 4718 4719 else 4720 Error_Msg_NE 4721 ("\premature usage of incomplete type&", N, Inc); 4722 4723 if Nkind (Parent (Inc)) = 4724 N_Incomplete_Type_Declaration 4725 then 4726 -- Record location of premature use in entity so that 4727 -- a continuation message is generated when the 4728 -- completion is seen. 4729 4730 Set_Premature_Use (Parent (Inc), N); 4731 end if; 4732 end if; 4733 end; 4734 end if; 4735 4736 Check_Misspelled_Selector (Type_To_Use, Sel); 4737 end if; 4738 4739 Set_Entity (Sel, Any_Id); 4740 Set_Etype (Sel, Any_Type); 4741 end if; 4742 end Analyze_Selected_Component; 4743 4744 --------------------------- 4745 -- Analyze_Short_Circuit -- 4746 --------------------------- 4747 4748 procedure Analyze_Short_Circuit (N : Node_Id) is 4749 L : constant Node_Id := Left_Opnd (N); 4750 R : constant Node_Id := Right_Opnd (N); 4751 Ind : Interp_Index; 4752 It : Interp; 4753 4754 begin 4755 Analyze_Expression (L); 4756 Analyze_Expression (R); 4757 Set_Etype (N, Any_Type); 4758 4759 if not Is_Overloaded (L) then 4760 if Root_Type (Etype (L)) = Standard_Boolean 4761 and then Has_Compatible_Type (R, Etype (L)) 4762 then 4763 Add_One_Interp (N, Etype (L), Etype (L)); 4764 end if; 4765 4766 else 4767 Get_First_Interp (L, Ind, It); 4768 while Present (It.Typ) loop 4769 if Root_Type (It.Typ) = Standard_Boolean 4770 and then Has_Compatible_Type (R, It.Typ) 4771 then 4772 Add_One_Interp (N, It.Typ, It.Typ); 4773 end if; 4774 4775 Get_Next_Interp (Ind, It); 4776 end loop; 4777 end if; 4778 4779 -- Here we have failed to find an interpretation. Clearly we know that 4780 -- it is not the case that both operands can have an interpretation of 4781 -- Boolean, but this is by far the most likely intended interpretation. 4782 -- So we simply resolve both operands as Booleans, and at least one of 4783 -- these resolutions will generate an error message, and we do not need 4784 -- to give another error message on the short circuit operation itself. 4785 4786 if Etype (N) = Any_Type then 4787 Resolve (L, Standard_Boolean); 4788 Resolve (R, Standard_Boolean); 4789 Set_Etype (N, Standard_Boolean); 4790 end if; 4791 end Analyze_Short_Circuit; 4792 4793 ------------------- 4794 -- Analyze_Slice -- 4795 ------------------- 4796 4797 procedure Analyze_Slice (N : Node_Id) is 4798 D : constant Node_Id := Discrete_Range (N); 4799 P : constant Node_Id := Prefix (N); 4800 Array_Type : Entity_Id; 4801 Index_Type : Entity_Id; 4802 4803 procedure Analyze_Overloaded_Slice; 4804 -- If the prefix is overloaded, select those interpretations that 4805 -- yield a one-dimensional array type. 4806 4807 ------------------------------ 4808 -- Analyze_Overloaded_Slice -- 4809 ------------------------------ 4810 4811 procedure Analyze_Overloaded_Slice is 4812 I : Interp_Index; 4813 It : Interp; 4814 Typ : Entity_Id; 4815 4816 begin 4817 Set_Etype (N, Any_Type); 4818 4819 Get_First_Interp (P, I, It); 4820 while Present (It.Nam) loop 4821 Typ := It.Typ; 4822 4823 if Is_Access_Type (Typ) then 4824 Typ := Designated_Type (Typ); 4825 Error_Msg_NW 4826 (Warn_On_Dereference, "?d?implicit dereference", N); 4827 end if; 4828 4829 if Is_Array_Type (Typ) 4830 and then Number_Dimensions (Typ) = 1 4831 and then Has_Compatible_Type (D, Etype (First_Index (Typ))) 4832 then 4833 Add_One_Interp (N, Typ, Typ); 4834 end if; 4835 4836 Get_Next_Interp (I, It); 4837 end loop; 4838 4839 if Etype (N) = Any_Type then 4840 Error_Msg_N ("expect array type in prefix of slice", N); 4841 end if; 4842 end Analyze_Overloaded_Slice; 4843 4844 -- Start of processing for Analyze_Slice 4845 4846 begin 4847 if Comes_From_Source (N) then 4848 Check_SPARK_05_Restriction ("slice is not allowed", N); 4849 end if; 4850 4851 Analyze (P); 4852 Analyze (D); 4853 4854 if Is_Overloaded (P) then 4855 Analyze_Overloaded_Slice; 4856 4857 else 4858 Array_Type := Etype (P); 4859 Set_Etype (N, Any_Type); 4860 4861 if Is_Access_Type (Array_Type) then 4862 Array_Type := Designated_Type (Array_Type); 4863 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N); 4864 end if; 4865 4866 if not Is_Array_Type (Array_Type) then 4867 Wrong_Type (P, Any_Array); 4868 4869 elsif Number_Dimensions (Array_Type) > 1 then 4870 Error_Msg_N 4871 ("type is not one-dimensional array in slice prefix", N); 4872 4873 else 4874 if Ekind (Array_Type) = E_String_Literal_Subtype then 4875 Index_Type := Etype (String_Literal_Low_Bound (Array_Type)); 4876 else 4877 Index_Type := Etype (First_Index (Array_Type)); 4878 end if; 4879 4880 if not Has_Compatible_Type (D, Index_Type) then 4881 Wrong_Type (D, Index_Type); 4882 else 4883 Set_Etype (N, Array_Type); 4884 end if; 4885 end if; 4886 end if; 4887 end Analyze_Slice; 4888 4889 ----------------------------- 4890 -- Analyze_Type_Conversion -- 4891 ----------------------------- 4892 4893 procedure Analyze_Type_Conversion (N : Node_Id) is 4894 Expr : constant Node_Id := Expression (N); 4895 Typ : Entity_Id; 4896 4897 begin 4898 -- If Conversion_OK is set, then the Etype is already set, and the only 4899 -- processing required is to analyze the expression. This is used to 4900 -- construct certain "illegal" conversions which are not allowed by Ada 4901 -- semantics, but can be handled by Gigi, see Sinfo for further details. 4902 4903 if Conversion_OK (N) then 4904 Analyze (Expr); 4905 return; 4906 end if; 4907 4908 -- Otherwise full type analysis is required, as well as some semantic 4909 -- checks to make sure the argument of the conversion is appropriate. 4910 4911 Find_Type (Subtype_Mark (N)); 4912 Typ := Entity (Subtype_Mark (N)); 4913 Set_Etype (N, Typ); 4914 Check_Fully_Declared (Typ, N); 4915 Analyze_Expression (Expr); 4916 Validate_Remote_Type_Type_Conversion (N); 4917 4918 -- Only remaining step is validity checks on the argument. These 4919 -- are skipped if the conversion does not come from the source. 4920 4921 if not Comes_From_Source (N) then 4922 return; 4923 4924 -- If there was an error in a generic unit, no need to replicate the 4925 -- error message. Conversely, constant-folding in the generic may 4926 -- transform the argument of a conversion into a string literal, which 4927 -- is legal. Therefore the following tests are not performed in an 4928 -- instance. The same applies to an inlined body. 4929 4930 elsif In_Instance or In_Inlined_Body then 4931 return; 4932 4933 elsif Nkind (Expr) = N_Null then 4934 Error_Msg_N ("argument of conversion cannot be null", N); 4935 Error_Msg_N ("\use qualified expression instead", N); 4936 Set_Etype (N, Any_Type); 4937 4938 elsif Nkind (Expr) = N_Aggregate then 4939 Error_Msg_N ("argument of conversion cannot be aggregate", N); 4940 Error_Msg_N ("\use qualified expression instead", N); 4941 4942 elsif Nkind (Expr) = N_Allocator then 4943 Error_Msg_N ("argument of conversion cannot be an allocator", N); 4944 Error_Msg_N ("\use qualified expression instead", N); 4945 4946 elsif Nkind (Expr) = N_String_Literal then 4947 Error_Msg_N ("argument of conversion cannot be string literal", N); 4948 Error_Msg_N ("\use qualified expression instead", N); 4949 4950 elsif Nkind (Expr) = N_Character_Literal then 4951 if Ada_Version = Ada_83 then 4952 Resolve (Expr, Typ); 4953 else 4954 Error_Msg_N ("argument of conversion cannot be character literal", 4955 N); 4956 Error_Msg_N ("\use qualified expression instead", N); 4957 end if; 4958 4959 elsif Nkind (Expr) = N_Attribute_Reference 4960 and then Nam_In (Attribute_Name (Expr), Name_Access, 4961 Name_Unchecked_Access, 4962 Name_Unrestricted_Access) 4963 then 4964 Error_Msg_N ("argument of conversion cannot be access", N); 4965 Error_Msg_N ("\use qualified expression instead", N); 4966 end if; 4967 4968 -- A formal parameter of a specific tagged type whose related subprogram 4969 -- is subject to pragma Extensions_Visible with value "False" cannot 4970 -- appear in a class-wide conversion (SPARK RM 6.1.7(3)). 4971 4972 if Is_Class_Wide_Type (Typ) and then Is_EVF_Expression (Expr) then 4973 Error_Msg_N 4974 ("formal parameter with Extensions_Visible False cannot be " 4975 & "converted to class-wide type", Expr); 4976 end if; 4977 end Analyze_Type_Conversion; 4978 4979 ---------------------- 4980 -- Analyze_Unary_Op -- 4981 ---------------------- 4982 4983 procedure Analyze_Unary_Op (N : Node_Id) is 4984 R : constant Node_Id := Right_Opnd (N); 4985 Op_Id : Entity_Id := Entity (N); 4986 4987 begin 4988 Set_Etype (N, Any_Type); 4989 Candidate_Type := Empty; 4990 4991 Analyze_Expression (R); 4992 4993 if Present (Op_Id) then 4994 if Ekind (Op_Id) = E_Operator then 4995 Find_Unary_Types (R, Op_Id, N); 4996 else 4997 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 4998 end if; 4999 5000 else 5001 Op_Id := Get_Name_Entity_Id (Chars (N)); 5002 while Present (Op_Id) loop 5003 if Ekind (Op_Id) = E_Operator then 5004 if No (Next_Entity (First_Entity (Op_Id))) then 5005 Find_Unary_Types (R, Op_Id, N); 5006 end if; 5007 5008 elsif Is_Overloadable (Op_Id) then 5009 Analyze_User_Defined_Unary_Op (N, Op_Id); 5010 end if; 5011 5012 Op_Id := Homonym (Op_Id); 5013 end loop; 5014 end if; 5015 5016 Operator_Check (N); 5017 end Analyze_Unary_Op; 5018 5019 ---------------------------------- 5020 -- Analyze_Unchecked_Expression -- 5021 ---------------------------------- 5022 5023 procedure Analyze_Unchecked_Expression (N : Node_Id) is 5024 begin 5025 Analyze (Expression (N), Suppress => All_Checks); 5026 Set_Etype (N, Etype (Expression (N))); 5027 Save_Interps (Expression (N), N); 5028 end Analyze_Unchecked_Expression; 5029 5030 --------------------------------------- 5031 -- Analyze_Unchecked_Type_Conversion -- 5032 --------------------------------------- 5033 5034 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is 5035 begin 5036 Find_Type (Subtype_Mark (N)); 5037 Analyze_Expression (Expression (N)); 5038 Set_Etype (N, Entity (Subtype_Mark (N))); 5039 end Analyze_Unchecked_Type_Conversion; 5040 5041 ------------------------------------ 5042 -- Analyze_User_Defined_Binary_Op -- 5043 ------------------------------------ 5044 5045 procedure Analyze_User_Defined_Binary_Op 5046 (N : Node_Id; 5047 Op_Id : Entity_Id) 5048 is 5049 begin 5050 -- Only do analysis if the operator Comes_From_Source, since otherwise 5051 -- the operator was generated by the expander, and all such operators 5052 -- always refer to the operators in package Standard. 5053 5054 if Comes_From_Source (N) then 5055 declare 5056 F1 : constant Entity_Id := First_Formal (Op_Id); 5057 F2 : constant Entity_Id := Next_Formal (F1); 5058 5059 begin 5060 -- Verify that Op_Id is a visible binary function. Note that since 5061 -- we know Op_Id is overloaded, potentially use visible means use 5062 -- visible for sure (RM 9.4(11)). 5063 5064 if Ekind (Op_Id) = E_Function 5065 and then Present (F2) 5066 and then (Is_Immediately_Visible (Op_Id) 5067 or else Is_Potentially_Use_Visible (Op_Id)) 5068 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1)) 5069 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2)) 5070 then 5071 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 5072 5073 -- If the left operand is overloaded, indicate that the current 5074 -- type is a viable candidate. This is redundant in most cases, 5075 -- but for equality and comparison operators where the context 5076 -- does not impose a type on the operands, setting the proper 5077 -- type is necessary to avoid subsequent ambiguities during 5078 -- resolution, when both user-defined and predefined operators 5079 -- may be candidates. 5080 5081 if Is_Overloaded (Left_Opnd (N)) then 5082 Set_Etype (Left_Opnd (N), Etype (F1)); 5083 end if; 5084 5085 if Debug_Flag_E then 5086 Write_Str ("user defined operator "); 5087 Write_Name (Chars (Op_Id)); 5088 Write_Str (" on node "); 5089 Write_Int (Int (N)); 5090 Write_Eol; 5091 end if; 5092 end if; 5093 end; 5094 end if; 5095 end Analyze_User_Defined_Binary_Op; 5096 5097 ----------------------------------- 5098 -- Analyze_User_Defined_Unary_Op -- 5099 ----------------------------------- 5100 5101 procedure Analyze_User_Defined_Unary_Op 5102 (N : Node_Id; 5103 Op_Id : Entity_Id) 5104 is 5105 begin 5106 -- Only do analysis if the operator Comes_From_Source, since otherwise 5107 -- the operator was generated by the expander, and all such operators 5108 -- always refer to the operators in package Standard. 5109 5110 if Comes_From_Source (N) then 5111 declare 5112 F : constant Entity_Id := First_Formal (Op_Id); 5113 5114 begin 5115 -- Verify that Op_Id is a visible unary function. Note that since 5116 -- we know Op_Id is overloaded, potentially use visible means use 5117 -- visible for sure (RM 9.4(11)). 5118 5119 if Ekind (Op_Id) = E_Function 5120 and then No (Next_Formal (F)) 5121 and then (Is_Immediately_Visible (Op_Id) 5122 or else Is_Potentially_Use_Visible (Op_Id)) 5123 and then Has_Compatible_Type (Right_Opnd (N), Etype (F)) 5124 then 5125 Add_One_Interp (N, Op_Id, Etype (Op_Id)); 5126 end if; 5127 end; 5128 end if; 5129 end Analyze_User_Defined_Unary_Op; 5130 5131 --------------------------- 5132 -- Check_Arithmetic_Pair -- 5133 --------------------------- 5134 5135 procedure Check_Arithmetic_Pair 5136 (T1, T2 : Entity_Id; 5137 Op_Id : Entity_Id; 5138 N : Node_Id) 5139 is 5140 Op_Name : constant Name_Id := Chars (Op_Id); 5141 5142 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean; 5143 -- Check whether the fixed-point type Typ has a user-defined operator 5144 -- (multiplication or division) that should hide the corresponding 5145 -- predefined operator. Used to implement Ada 2005 AI-264, to make 5146 -- such operators more visible and therefore useful. 5147 -- 5148 -- If the name of the operation is an expanded name with prefix 5149 -- Standard, the predefined universal fixed operator is available, 5150 -- as specified by AI-420 (RM 4.5.5 (19.1/2)). 5151 5152 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id; 5153 -- Get specific type (i.e. non-universal type if there is one) 5154 5155 ------------------ 5156 -- Has_Fixed_Op -- 5157 ------------------ 5158 5159 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is 5160 Bas : constant Entity_Id := Base_Type (Typ); 5161 Ent : Entity_Id; 5162 F1 : Entity_Id; 5163 F2 : Entity_Id; 5164 5165 begin 5166 -- If the universal_fixed operation is given explicitly the rule 5167 -- concerning primitive operations of the type do not apply. 5168 5169 if Nkind (N) = N_Function_Call 5170 and then Nkind (Name (N)) = N_Expanded_Name 5171 and then Entity (Prefix (Name (N))) = Standard_Standard 5172 then 5173 return False; 5174 end if; 5175 5176 -- The operation is treated as primitive if it is declared in the 5177 -- same scope as the type, and therefore on the same entity chain. 5178 5179 Ent := Next_Entity (Typ); 5180 while Present (Ent) loop 5181 if Chars (Ent) = Chars (Op) then 5182 F1 := First_Formal (Ent); 5183 F2 := Next_Formal (F1); 5184 5185 -- The operation counts as primitive if either operand or 5186 -- result are of the given base type, and both operands are 5187 -- fixed point types. 5188 5189 if (Base_Type (Etype (F1)) = Bas 5190 and then Is_Fixed_Point_Type (Etype (F2))) 5191 5192 or else 5193 (Base_Type (Etype (F2)) = Bas 5194 and then Is_Fixed_Point_Type (Etype (F1))) 5195 5196 or else 5197 (Base_Type (Etype (Ent)) = Bas 5198 and then Is_Fixed_Point_Type (Etype (F1)) 5199 and then Is_Fixed_Point_Type (Etype (F2))) 5200 then 5201 return True; 5202 end if; 5203 end if; 5204 5205 Next_Entity (Ent); 5206 end loop; 5207 5208 return False; 5209 end Has_Fixed_Op; 5210 5211 ------------------- 5212 -- Specific_Type -- 5213 ------------------- 5214 5215 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is 5216 begin 5217 if T1 = Universal_Integer or else T1 = Universal_Real then 5218 return Base_Type (T2); 5219 else 5220 return Base_Type (T1); 5221 end if; 5222 end Specific_Type; 5223 5224 -- Start of processing for Check_Arithmetic_Pair 5225 5226 begin 5227 if Nam_In (Op_Name, Name_Op_Add, Name_Op_Subtract) then 5228 if Is_Numeric_Type (T1) 5229 and then Is_Numeric_Type (T2) 5230 and then (Covers (T1 => T1, T2 => T2) 5231 or else 5232 Covers (T1 => T2, T2 => T1)) 5233 then 5234 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); 5235 end if; 5236 5237 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide) then 5238 if Is_Fixed_Point_Type (T1) 5239 and then (Is_Fixed_Point_Type (T2) or else T2 = Universal_Real) 5240 then 5241 -- If Treat_Fixed_As_Integer is set then the Etype is already set 5242 -- and no further processing is required (this is the case of an 5243 -- operator constructed by Exp_Fixd for a fixed point operation) 5244 -- Otherwise add one interpretation with universal fixed result 5245 -- If the operator is given in functional notation, it comes 5246 -- from source and Fixed_As_Integer cannot apply. 5247 5248 if (Nkind (N) not in N_Op 5249 or else not Treat_Fixed_As_Integer (N)) 5250 and then 5251 (not Has_Fixed_Op (T1, Op_Id) 5252 or else Nkind (Parent (N)) = N_Type_Conversion) 5253 then 5254 Add_One_Interp (N, Op_Id, Universal_Fixed); 5255 end if; 5256 5257 elsif Is_Fixed_Point_Type (T2) 5258 and then (Nkind (N) not in N_Op 5259 or else not Treat_Fixed_As_Integer (N)) 5260 and then T1 = Universal_Real 5261 and then 5262 (not Has_Fixed_Op (T1, Op_Id) 5263 or else Nkind (Parent (N)) = N_Type_Conversion) 5264 then 5265 Add_One_Interp (N, Op_Id, Universal_Fixed); 5266 5267 elsif Is_Numeric_Type (T1) 5268 and then Is_Numeric_Type (T2) 5269 and then (Covers (T1 => T1, T2 => T2) 5270 or else 5271 Covers (T1 => T2, T2 => T1)) 5272 then 5273 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); 5274 5275 elsif Is_Fixed_Point_Type (T1) 5276 and then (Base_Type (T2) = Base_Type (Standard_Integer) 5277 or else T2 = Universal_Integer) 5278 then 5279 Add_One_Interp (N, Op_Id, T1); 5280 5281 elsif T2 = Universal_Real 5282 and then Base_Type (T1) = Base_Type (Standard_Integer) 5283 and then Op_Name = Name_Op_Multiply 5284 then 5285 Add_One_Interp (N, Op_Id, Any_Fixed); 5286 5287 elsif T1 = Universal_Real 5288 and then Base_Type (T2) = Base_Type (Standard_Integer) 5289 then 5290 Add_One_Interp (N, Op_Id, Any_Fixed); 5291 5292 elsif Is_Fixed_Point_Type (T2) 5293 and then (Base_Type (T1) = Base_Type (Standard_Integer) 5294 or else T1 = Universal_Integer) 5295 and then Op_Name = Name_Op_Multiply 5296 then 5297 Add_One_Interp (N, Op_Id, T2); 5298 5299 elsif T1 = Universal_Real and then T2 = Universal_Integer then 5300 Add_One_Interp (N, Op_Id, T1); 5301 5302 elsif T2 = Universal_Real 5303 and then T1 = Universal_Integer 5304 and then Op_Name = Name_Op_Multiply 5305 then 5306 Add_One_Interp (N, Op_Id, T2); 5307 end if; 5308 5309 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then 5310 5311 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer 5312 -- set does not require any special processing, since the Etype is 5313 -- already set (case of operation constructed by Exp_Fixed). 5314 5315 if Is_Integer_Type (T1) 5316 and then (Covers (T1 => T1, T2 => T2) 5317 or else 5318 Covers (T1 => T2, T2 => T1)) 5319 then 5320 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); 5321 end if; 5322 5323 elsif Op_Name = Name_Op_Expon then 5324 if Is_Numeric_Type (T1) 5325 and then not Is_Fixed_Point_Type (T1) 5326 and then (Base_Type (T2) = Base_Type (Standard_Integer) 5327 or else T2 = Universal_Integer) 5328 then 5329 Add_One_Interp (N, Op_Id, Base_Type (T1)); 5330 end if; 5331 5332 else pragma Assert (Nkind (N) in N_Op_Shift); 5333 5334 -- If not one of the predefined operators, the node may be one 5335 -- of the intrinsic functions. Its kind is always specific, and 5336 -- we can use it directly, rather than the name of the operation. 5337 5338 if Is_Integer_Type (T1) 5339 and then (Base_Type (T2) = Base_Type (Standard_Integer) 5340 or else T2 = Universal_Integer) 5341 then 5342 Add_One_Interp (N, Op_Id, Base_Type (T1)); 5343 end if; 5344 end if; 5345 end Check_Arithmetic_Pair; 5346 5347 ------------------------------- 5348 -- Check_Misspelled_Selector -- 5349 ------------------------------- 5350 5351 procedure Check_Misspelled_Selector 5352 (Prefix : Entity_Id; 5353 Sel : Node_Id) 5354 is 5355 Max_Suggestions : constant := 2; 5356 Nr_Of_Suggestions : Natural := 0; 5357 5358 Suggestion_1 : Entity_Id := Empty; 5359 Suggestion_2 : Entity_Id := Empty; 5360 5361 Comp : Entity_Id; 5362 5363 begin 5364 -- All the components of the prefix of selector Sel are matched against 5365 -- Sel and a count is maintained of possible misspellings. When at 5366 -- the end of the analysis there are one or two (not more) possible 5367 -- misspellings, these misspellings will be suggested as possible 5368 -- correction. 5369 5370 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then 5371 5372 -- Concurrent types should be handled as well ??? 5373 5374 return; 5375 end if; 5376 5377 Comp := First_Entity (Prefix); 5378 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop 5379 if Is_Visible_Component (Comp) then 5380 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then 5381 Nr_Of_Suggestions := Nr_Of_Suggestions + 1; 5382 5383 case Nr_Of_Suggestions is 5384 when 1 => Suggestion_1 := Comp; 5385 when 2 => Suggestion_2 := Comp; 5386 when others => exit; 5387 end case; 5388 end if; 5389 end if; 5390 5391 Comp := Next_Entity (Comp); 5392 end loop; 5393 5394 -- Report at most two suggestions 5395 5396 if Nr_Of_Suggestions = 1 then 5397 Error_Msg_NE -- CODEFIX 5398 ("\possible misspelling of&", Sel, Suggestion_1); 5399 5400 elsif Nr_Of_Suggestions = 2 then 5401 Error_Msg_Node_2 := Suggestion_2; 5402 Error_Msg_NE -- CODEFIX 5403 ("\possible misspelling of& or&", Sel, Suggestion_1); 5404 end if; 5405 end Check_Misspelled_Selector; 5406 5407 ---------------------- 5408 -- Defined_In_Scope -- 5409 ---------------------- 5410 5411 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean 5412 is 5413 S1 : constant Entity_Id := Scope (Base_Type (T)); 5414 begin 5415 return S1 = S 5416 or else (S1 = System_Aux_Id and then S = Scope (S1)); 5417 end Defined_In_Scope; 5418 5419 ------------------- 5420 -- Diagnose_Call -- 5421 ------------------- 5422 5423 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is 5424 Actual : Node_Id; 5425 X : Interp_Index; 5426 It : Interp; 5427 Err_Mode : Boolean; 5428 New_Nam : Node_Id; 5429 Void_Interp_Seen : Boolean := False; 5430 5431 Success : Boolean; 5432 pragma Warnings (Off, Boolean); 5433 5434 begin 5435 if Ada_Version >= Ada_2005 then 5436 Actual := First_Actual (N); 5437 while Present (Actual) loop 5438 5439 -- Ada 2005 (AI-50217): Post an error in case of premature 5440 -- usage of an entity from the limited view. 5441 5442 if not Analyzed (Etype (Actual)) 5443 and then From_Limited_With (Etype (Actual)) 5444 then 5445 Error_Msg_Qual_Level := 1; 5446 Error_Msg_NE 5447 ("missing with_clause for scope of imported type&", 5448 Actual, Etype (Actual)); 5449 Error_Msg_Qual_Level := 0; 5450 end if; 5451 5452 Next_Actual (Actual); 5453 end loop; 5454 end if; 5455 5456 -- Analyze each candidate call again, with full error reporting 5457 -- for each. 5458 5459 Error_Msg_N 5460 ("no candidate interpretations match the actuals:!", Nam); 5461 Err_Mode := All_Errors_Mode; 5462 All_Errors_Mode := True; 5463 5464 -- If this is a call to an operation of a concurrent type, 5465 -- the failed interpretations have been removed from the 5466 -- name. Recover them to provide full diagnostics. 5467 5468 if Nkind (Parent (Nam)) = N_Selected_Component then 5469 Set_Entity (Nam, Empty); 5470 New_Nam := New_Copy_Tree (Parent (Nam)); 5471 Set_Is_Overloaded (New_Nam, False); 5472 Set_Is_Overloaded (Selector_Name (New_Nam), False); 5473 Set_Parent (New_Nam, Parent (Parent (Nam))); 5474 Analyze_Selected_Component (New_Nam); 5475 Get_First_Interp (Selector_Name (New_Nam), X, It); 5476 else 5477 Get_First_Interp (Nam, X, It); 5478 end if; 5479 5480 while Present (It.Nam) loop 5481 if Etype (It.Nam) = Standard_Void_Type then 5482 Void_Interp_Seen := True; 5483 end if; 5484 5485 Analyze_One_Call (N, It.Nam, True, Success); 5486 Get_Next_Interp (X, It); 5487 end loop; 5488 5489 if Nkind (N) = N_Function_Call then 5490 Get_First_Interp (Nam, X, It); 5491 while Present (It.Nam) loop 5492 if Ekind_In (It.Nam, E_Function, E_Operator) then 5493 return; 5494 else 5495 Get_Next_Interp (X, It); 5496 end if; 5497 end loop; 5498 5499 -- If all interpretations are procedures, this deserves a 5500 -- more precise message. Ditto if this appears as the prefix 5501 -- of a selected component, which may be a lexical error. 5502 5503 Error_Msg_N 5504 ("\context requires function call, found procedure name", Nam); 5505 5506 if Nkind (Parent (N)) = N_Selected_Component 5507 and then N = Prefix (Parent (N)) 5508 then 5509 Error_Msg_N -- CODEFIX 5510 ("\period should probably be semicolon", Parent (N)); 5511 end if; 5512 5513 elsif Nkind (N) = N_Procedure_Call_Statement 5514 and then not Void_Interp_Seen 5515 then 5516 Error_Msg_N ( 5517 "\function name found in procedure call", Nam); 5518 end if; 5519 5520 All_Errors_Mode := Err_Mode; 5521 end Diagnose_Call; 5522 5523 --------------------------- 5524 -- Find_Arithmetic_Types -- 5525 --------------------------- 5526 5527 procedure Find_Arithmetic_Types 5528 (L, R : Node_Id; 5529 Op_Id : Entity_Id; 5530 N : Node_Id) 5531 is 5532 Index1 : Interp_Index; 5533 Index2 : Interp_Index; 5534 It1 : Interp; 5535 It2 : Interp; 5536 5537 procedure Check_Right_Argument (T : Entity_Id); 5538 -- Check right operand of operator 5539 5540 -------------------------- 5541 -- Check_Right_Argument -- 5542 -------------------------- 5543 5544 procedure Check_Right_Argument (T : Entity_Id) is 5545 begin 5546 if not Is_Overloaded (R) then 5547 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N); 5548 else 5549 Get_First_Interp (R, Index2, It2); 5550 while Present (It2.Typ) loop 5551 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N); 5552 Get_Next_Interp (Index2, It2); 5553 end loop; 5554 end if; 5555 end Check_Right_Argument; 5556 5557 -- Start of processing for Find_Arithmetic_Types 5558 5559 begin 5560 if not Is_Overloaded (L) then 5561 Check_Right_Argument (Etype (L)); 5562 5563 else 5564 Get_First_Interp (L, Index1, It1); 5565 while Present (It1.Typ) loop 5566 Check_Right_Argument (It1.Typ); 5567 Get_Next_Interp (Index1, It1); 5568 end loop; 5569 end if; 5570 5571 end Find_Arithmetic_Types; 5572 5573 ------------------------ 5574 -- Find_Boolean_Types -- 5575 ------------------------ 5576 5577 procedure Find_Boolean_Types 5578 (L, R : Node_Id; 5579 Op_Id : Entity_Id; 5580 N : Node_Id) 5581 is 5582 Index : Interp_Index; 5583 It : Interp; 5584 5585 procedure Check_Numeric_Argument (T : Entity_Id); 5586 -- Special case for logical operations one of whose operands is an 5587 -- integer literal. If both are literal the result is any modular type. 5588 5589 ---------------------------- 5590 -- Check_Numeric_Argument -- 5591 ---------------------------- 5592 5593 procedure Check_Numeric_Argument (T : Entity_Id) is 5594 begin 5595 if T = Universal_Integer then 5596 Add_One_Interp (N, Op_Id, Any_Modular); 5597 5598 elsif Is_Modular_Integer_Type (T) then 5599 Add_One_Interp (N, Op_Id, T); 5600 end if; 5601 end Check_Numeric_Argument; 5602 5603 -- Start of processing for Find_Boolean_Types 5604 5605 begin 5606 if not Is_Overloaded (L) then 5607 if Etype (L) = Universal_Integer 5608 or else Etype (L) = Any_Modular 5609 then 5610 if not Is_Overloaded (R) then 5611 Check_Numeric_Argument (Etype (R)); 5612 5613 else 5614 Get_First_Interp (R, Index, It); 5615 while Present (It.Typ) loop 5616 Check_Numeric_Argument (It.Typ); 5617 Get_Next_Interp (Index, It); 5618 end loop; 5619 end if; 5620 5621 -- If operands are aggregates, we must assume that they may be 5622 -- boolean arrays, and leave disambiguation for the second pass. 5623 -- If only one is an aggregate, verify that the other one has an 5624 -- interpretation as a boolean array 5625 5626 elsif Nkind (L) = N_Aggregate then 5627 if Nkind (R) = N_Aggregate then 5628 Add_One_Interp (N, Op_Id, Etype (L)); 5629 5630 elsif not Is_Overloaded (R) then 5631 if Valid_Boolean_Arg (Etype (R)) then 5632 Add_One_Interp (N, Op_Id, Etype (R)); 5633 end if; 5634 5635 else 5636 Get_First_Interp (R, Index, It); 5637 while Present (It.Typ) loop 5638 if Valid_Boolean_Arg (It.Typ) then 5639 Add_One_Interp (N, Op_Id, It.Typ); 5640 end if; 5641 5642 Get_Next_Interp (Index, It); 5643 end loop; 5644 end if; 5645 5646 elsif Valid_Boolean_Arg (Etype (L)) 5647 and then Has_Compatible_Type (R, Etype (L)) 5648 then 5649 Add_One_Interp (N, Op_Id, Etype (L)); 5650 end if; 5651 5652 else 5653 Get_First_Interp (L, Index, It); 5654 while Present (It.Typ) loop 5655 if Valid_Boolean_Arg (It.Typ) 5656 and then Has_Compatible_Type (R, It.Typ) 5657 then 5658 Add_One_Interp (N, Op_Id, It.Typ); 5659 end if; 5660 5661 Get_Next_Interp (Index, It); 5662 end loop; 5663 end if; 5664 end Find_Boolean_Types; 5665 5666 --------------------------- 5667 -- Find_Comparison_Types -- 5668 --------------------------- 5669 5670 procedure Find_Comparison_Types 5671 (L, R : Node_Id; 5672 Op_Id : Entity_Id; 5673 N : Node_Id) 5674 is 5675 Index : Interp_Index; 5676 It : Interp; 5677 Found : Boolean := False; 5678 I_F : Interp_Index; 5679 T_F : Entity_Id; 5680 Scop : Entity_Id := Empty; 5681 5682 procedure Try_One_Interp (T1 : Entity_Id); 5683 -- Routine to try one proposed interpretation. Note that the context 5684 -- of the operator plays no role in resolving the arguments, so that 5685 -- if there is more than one interpretation of the operands that is 5686 -- compatible with comparison, the operation is ambiguous. 5687 5688 -------------------- 5689 -- Try_One_Interp -- 5690 -------------------- 5691 5692 procedure Try_One_Interp (T1 : Entity_Id) is 5693 begin 5694 5695 -- If the operator is an expanded name, then the type of the operand 5696 -- must be defined in the corresponding scope. If the type is 5697 -- universal, the context will impose the correct type. 5698 5699 if Present (Scop) 5700 and then not Defined_In_Scope (T1, Scop) 5701 and then T1 /= Universal_Integer 5702 and then T1 /= Universal_Real 5703 and then T1 /= Any_String 5704 and then T1 /= Any_Composite 5705 then 5706 return; 5707 end if; 5708 5709 if Valid_Comparison_Arg (T1) and then Has_Compatible_Type (R, T1) then 5710 if Found and then Base_Type (T1) /= Base_Type (T_F) then 5711 It := Disambiguate (L, I_F, Index, Any_Type); 5712 5713 if It = No_Interp then 5714 Ambiguous_Operands (N); 5715 Set_Etype (L, Any_Type); 5716 return; 5717 5718 else 5719 T_F := It.Typ; 5720 end if; 5721 5722 else 5723 Found := True; 5724 T_F := T1; 5725 I_F := Index; 5726 end if; 5727 5728 Set_Etype (L, T_F); 5729 Find_Non_Universal_Interpretations (N, R, Op_Id, T1); 5730 5731 end if; 5732 end Try_One_Interp; 5733 5734 -- Start of processing for Find_Comparison_Types 5735 5736 begin 5737 -- If left operand is aggregate, the right operand has to 5738 -- provide a usable type for it. 5739 5740 if Nkind (L) = N_Aggregate and then Nkind (R) /= N_Aggregate then 5741 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N); 5742 return; 5743 end if; 5744 5745 if Nkind (N) = N_Function_Call 5746 and then Nkind (Name (N)) = N_Expanded_Name 5747 then 5748 Scop := Entity (Prefix (Name (N))); 5749 5750 -- The prefix may be a package renaming, and the subsequent test 5751 -- requires the original package. 5752 5753 if Ekind (Scop) = E_Package 5754 and then Present (Renamed_Entity (Scop)) 5755 then 5756 Scop := Renamed_Entity (Scop); 5757 Set_Entity (Prefix (Name (N)), Scop); 5758 end if; 5759 end if; 5760 5761 if not Is_Overloaded (L) then 5762 Try_One_Interp (Etype (L)); 5763 5764 else 5765 Get_First_Interp (L, Index, It); 5766 while Present (It.Typ) loop 5767 Try_One_Interp (It.Typ); 5768 Get_Next_Interp (Index, It); 5769 end loop; 5770 end if; 5771 end Find_Comparison_Types; 5772 5773 ---------------------------------------- 5774 -- Find_Non_Universal_Interpretations -- 5775 ---------------------------------------- 5776 5777 procedure Find_Non_Universal_Interpretations 5778 (N : Node_Id; 5779 R : Node_Id; 5780 Op_Id : Entity_Id; 5781 T1 : Entity_Id) 5782 is 5783 Index : Interp_Index; 5784 It : Interp; 5785 5786 begin 5787 if T1 = Universal_Integer or else T1 = Universal_Real 5788 5789 -- If the left operand of an equality operator is null, the visibility 5790 -- of the operator must be determined from the interpretation of the 5791 -- right operand. This processing must be done for Any_Access, which 5792 -- is the internal representation of the type of the literal null. 5793 5794 or else T1 = Any_Access 5795 then 5796 if not Is_Overloaded (R) then 5797 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (Etype (R))); 5798 else 5799 Get_First_Interp (R, Index, It); 5800 while Present (It.Typ) loop 5801 if Covers (It.Typ, T1) then 5802 Add_One_Interp 5803 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ)); 5804 end if; 5805 5806 Get_Next_Interp (Index, It); 5807 end loop; 5808 end if; 5809 else 5810 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1)); 5811 end if; 5812 end Find_Non_Universal_Interpretations; 5813 5814 ------------------------------ 5815 -- Find_Concatenation_Types -- 5816 ------------------------------ 5817 5818 procedure Find_Concatenation_Types 5819 (L, R : Node_Id; 5820 Op_Id : Entity_Id; 5821 N : Node_Id) 5822 is 5823 Op_Type : constant Entity_Id := Etype (Op_Id); 5824 5825 begin 5826 if Is_Array_Type (Op_Type) 5827 and then not Is_Limited_Type (Op_Type) 5828 5829 and then (Has_Compatible_Type (L, Op_Type) 5830 or else 5831 Has_Compatible_Type (L, Component_Type (Op_Type))) 5832 5833 and then (Has_Compatible_Type (R, Op_Type) 5834 or else 5835 Has_Compatible_Type (R, Component_Type (Op_Type))) 5836 then 5837 Add_One_Interp (N, Op_Id, Op_Type); 5838 end if; 5839 end Find_Concatenation_Types; 5840 5841 ------------------------- 5842 -- Find_Equality_Types -- 5843 ------------------------- 5844 5845 procedure Find_Equality_Types 5846 (L, R : Node_Id; 5847 Op_Id : Entity_Id; 5848 N : Node_Id) 5849 is 5850 Index : Interp_Index; 5851 It : Interp; 5852 Found : Boolean := False; 5853 I_F : Interp_Index; 5854 T_F : Entity_Id; 5855 Scop : Entity_Id := Empty; 5856 5857 procedure Try_One_Interp (T1 : Entity_Id); 5858 -- The context of the equality operator plays no role in resolving the 5859 -- arguments, so that if there is more than one interpretation of the 5860 -- operands that is compatible with equality, the construct is ambiguous 5861 -- and an error can be emitted now, after trying to disambiguate, i.e. 5862 -- applying preference rules. 5863 5864 -------------------- 5865 -- Try_One_Interp -- 5866 -------------------- 5867 5868 procedure Try_One_Interp (T1 : Entity_Id) is 5869 Bas : constant Entity_Id := Base_Type (T1); 5870 5871 begin 5872 -- If the operator is an expanded name, then the type of the operand 5873 -- must be defined in the corresponding scope. If the type is 5874 -- universal, the context will impose the correct type. An anonymous 5875 -- type for a 'Access reference is also universal in this sense, as 5876 -- the actual type is obtained from context. 5877 5878 -- In Ada 2005, the equality operator for anonymous access types 5879 -- is declared in Standard, and preference rules apply to it. 5880 5881 if Present (Scop) then 5882 if Defined_In_Scope (T1, Scop) 5883 or else T1 = Universal_Integer 5884 or else T1 = Universal_Real 5885 or else T1 = Any_Access 5886 or else T1 = Any_String 5887 or else T1 = Any_Composite 5888 or else (Ekind (T1) = E_Access_Subprogram_Type 5889 and then not Comes_From_Source (T1)) 5890 then 5891 null; 5892 5893 elsif Ekind (T1) = E_Anonymous_Access_Type 5894 and then Scop = Standard_Standard 5895 then 5896 null; 5897 5898 else 5899 -- The scope does not contain an operator for the type 5900 5901 return; 5902 end if; 5903 5904 -- If we have infix notation, the operator must be usable. Within 5905 -- an instance, if the type is already established we know it is 5906 -- correct. If an operand is universal it is compatible with any 5907 -- numeric type. 5908 5909 elsif In_Open_Scopes (Scope (Bas)) 5910 or else Is_Potentially_Use_Visible (Bas) 5911 or else In_Use (Bas) 5912 or else (In_Use (Scope (Bas)) and then not Is_Hidden (Bas)) 5913 5914 -- In an instance, the type may have been immediately visible. 5915 -- Either the types are compatible, or one operand is universal 5916 -- (numeric or null). 5917 5918 or else (In_Instance 5919 and then 5920 (First_Subtype (T1) = First_Subtype (Etype (R)) 5921 or else Nkind (R) = N_Null 5922 or else 5923 (Is_Numeric_Type (T1) 5924 and then Is_Universal_Numeric_Type (Etype (R))))) 5925 5926 -- In Ada 2005, the equality on anonymous access types is declared 5927 -- in Standard, and is always visible. 5928 5929 or else Ekind (T1) = E_Anonymous_Access_Type 5930 then 5931 null; 5932 5933 else 5934 -- Save candidate type for subsequent error message, if any 5935 5936 if not Is_Limited_Type (T1) then 5937 Candidate_Type := T1; 5938 end if; 5939 5940 return; 5941 end if; 5942 5943 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95: 5944 -- Do not allow anonymous access types in equality operators. 5945 5946 if Ada_Version < Ada_2005 5947 and then Ekind (T1) = E_Anonymous_Access_Type 5948 then 5949 return; 5950 end if; 5951 5952 -- If the right operand has a type compatible with T1, check for an 5953 -- acceptable interpretation, unless T1 is limited (no predefined 5954 -- equality available), or this is use of a "/=" for a tagged type. 5955 -- In the latter case, possible interpretations of equality need 5956 -- to be considered, we don't want the default inequality declared 5957 -- in Standard to be chosen, and the "/=" will be rewritten as a 5958 -- negation of "=" (see the end of Analyze_Equality_Op). This ensures 5959 -- that that rewriting happens during analysis rather than being 5960 -- delayed until expansion (this is needed for ASIS, which only sees 5961 -- the unexpanded tree). Note that if the node is N_Op_Ne, but Op_Id 5962 -- is Name_Op_Eq then we still proceed with the interpretation, 5963 -- because that indicates the potential rewriting case where the 5964 -- interpretation to consider is actually "=" and the node may be 5965 -- about to be rewritten by Analyze_Equality_Op. 5966 5967 if T1 /= Standard_Void_Type 5968 and then Has_Compatible_Type (R, T1) 5969 5970 and then 5971 ((not Is_Limited_Type (T1) 5972 and then not Is_Limited_Composite (T1)) 5973 5974 or else 5975 (Is_Array_Type (T1) 5976 and then not Is_Limited_Type (Component_Type (T1)) 5977 and then Available_Full_View_Of_Component (T1))) 5978 5979 and then 5980 (Nkind (N) /= N_Op_Ne 5981 or else not Is_Tagged_Type (T1) 5982 or else Chars (Op_Id) = Name_Op_Eq) 5983 then 5984 if Found 5985 and then Base_Type (T1) /= Base_Type (T_F) 5986 then 5987 It := Disambiguate (L, I_F, Index, Any_Type); 5988 5989 if It = No_Interp then 5990 Ambiguous_Operands (N); 5991 Set_Etype (L, Any_Type); 5992 return; 5993 5994 else 5995 T_F := It.Typ; 5996 end if; 5997 5998 else 5999 Found := True; 6000 T_F := T1; 6001 I_F := Index; 6002 end if; 6003 6004 if not Analyzed (L) then 6005 Set_Etype (L, T_F); 6006 end if; 6007 6008 Find_Non_Universal_Interpretations (N, R, Op_Id, T1); 6009 6010 -- Case of operator was not visible, Etype still set to Any_Type 6011 6012 if Etype (N) = Any_Type then 6013 Found := False; 6014 end if; 6015 6016 elsif Scop = Standard_Standard 6017 and then Ekind (T1) = E_Anonymous_Access_Type 6018 then 6019 Found := True; 6020 end if; 6021 end Try_One_Interp; 6022 6023 -- Start of processing for Find_Equality_Types 6024 6025 begin 6026 -- If left operand is aggregate, the right operand has to 6027 -- provide a usable type for it. 6028 6029 if Nkind (L) = N_Aggregate 6030 and then Nkind (R) /= N_Aggregate 6031 then 6032 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N); 6033 return; 6034 end if; 6035 6036 if Nkind (N) = N_Function_Call 6037 and then Nkind (Name (N)) = N_Expanded_Name 6038 then 6039 Scop := Entity (Prefix (Name (N))); 6040 6041 -- The prefix may be a package renaming, and the subsequent test 6042 -- requires the original package. 6043 6044 if Ekind (Scop) = E_Package 6045 and then Present (Renamed_Entity (Scop)) 6046 then 6047 Scop := Renamed_Entity (Scop); 6048 Set_Entity (Prefix (Name (N)), Scop); 6049 end if; 6050 end if; 6051 6052 if not Is_Overloaded (L) then 6053 Try_One_Interp (Etype (L)); 6054 6055 else 6056 Get_First_Interp (L, Index, It); 6057 while Present (It.Typ) loop 6058 Try_One_Interp (It.Typ); 6059 Get_Next_Interp (Index, It); 6060 end loop; 6061 end if; 6062 end Find_Equality_Types; 6063 6064 ------------------------- 6065 -- Find_Negation_Types -- 6066 ------------------------- 6067 6068 procedure Find_Negation_Types 6069 (R : Node_Id; 6070 Op_Id : Entity_Id; 6071 N : Node_Id) 6072 is 6073 Index : Interp_Index; 6074 It : Interp; 6075 6076 begin 6077 if not Is_Overloaded (R) then 6078 if Etype (R) = Universal_Integer then 6079 Add_One_Interp (N, Op_Id, Any_Modular); 6080 elsif Valid_Boolean_Arg (Etype (R)) then 6081 Add_One_Interp (N, Op_Id, Etype (R)); 6082 end if; 6083 6084 else 6085 Get_First_Interp (R, Index, It); 6086 while Present (It.Typ) loop 6087 if Valid_Boolean_Arg (It.Typ) then 6088 Add_One_Interp (N, Op_Id, It.Typ); 6089 end if; 6090 6091 Get_Next_Interp (Index, It); 6092 end loop; 6093 end if; 6094 end Find_Negation_Types; 6095 6096 ------------------------------ 6097 -- Find_Primitive_Operation -- 6098 ------------------------------ 6099 6100 function Find_Primitive_Operation (N : Node_Id) return Boolean is 6101 Obj : constant Node_Id := Prefix (N); 6102 Op : constant Node_Id := Selector_Name (N); 6103 6104 Prim : Elmt_Id; 6105 Prims : Elist_Id; 6106 Typ : Entity_Id; 6107 6108 begin 6109 Set_Etype (Op, Any_Type); 6110 6111 if Is_Access_Type (Etype (Obj)) then 6112 Typ := Designated_Type (Etype (Obj)); 6113 else 6114 Typ := Etype (Obj); 6115 end if; 6116 6117 if Is_Class_Wide_Type (Typ) then 6118 Typ := Root_Type (Typ); 6119 end if; 6120 6121 Prims := Primitive_Operations (Typ); 6122 6123 Prim := First_Elmt (Prims); 6124 while Present (Prim) loop 6125 if Chars (Node (Prim)) = Chars (Op) then 6126 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim))); 6127 Set_Etype (N, Etype (Node (Prim))); 6128 end if; 6129 6130 Next_Elmt (Prim); 6131 end loop; 6132 6133 -- Now look for class-wide operations of the type or any of its 6134 -- ancestors by iterating over the homonyms of the selector. 6135 6136 declare 6137 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ); 6138 Hom : Entity_Id; 6139 6140 begin 6141 Hom := Current_Entity (Op); 6142 while Present (Hom) loop 6143 if (Ekind (Hom) = E_Procedure 6144 or else 6145 Ekind (Hom) = E_Function) 6146 and then Scope (Hom) = Scope (Typ) 6147 and then Present (First_Formal (Hom)) 6148 and then 6149 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type 6150 or else 6151 (Is_Access_Type (Etype (First_Formal (Hom))) 6152 and then 6153 Ekind (Etype (First_Formal (Hom))) = 6154 E_Anonymous_Access_Type 6155 and then 6156 Base_Type 6157 (Designated_Type (Etype (First_Formal (Hom)))) = 6158 Cls_Type)) 6159 then 6160 Add_One_Interp (Op, Hom, Etype (Hom)); 6161 Set_Etype (N, Etype (Hom)); 6162 end if; 6163 6164 Hom := Homonym (Hom); 6165 end loop; 6166 end; 6167 6168 return Etype (Op) /= Any_Type; 6169 end Find_Primitive_Operation; 6170 6171 ---------------------- 6172 -- Find_Unary_Types -- 6173 ---------------------- 6174 6175 procedure Find_Unary_Types 6176 (R : Node_Id; 6177 Op_Id : Entity_Id; 6178 N : Node_Id) 6179 is 6180 Index : Interp_Index; 6181 It : Interp; 6182 6183 begin 6184 if not Is_Overloaded (R) then 6185 if Is_Numeric_Type (Etype (R)) then 6186 6187 -- In an instance a generic actual may be a numeric type even if 6188 -- the formal in the generic unit was not. In that case, the 6189 -- predefined operator was not a possible interpretation in the 6190 -- generic, and cannot be one in the instance, unless the operator 6191 -- is an actual of an instance. 6192 6193 if In_Instance 6194 and then 6195 not Is_Numeric_Type (Corresponding_Generic_Type (Etype (R))) 6196 then 6197 null; 6198 else 6199 Add_One_Interp (N, Op_Id, Base_Type (Etype (R))); 6200 end if; 6201 end if; 6202 6203 else 6204 Get_First_Interp (R, Index, It); 6205 while Present (It.Typ) loop 6206 if Is_Numeric_Type (It.Typ) then 6207 if In_Instance 6208 and then 6209 not Is_Numeric_Type 6210 (Corresponding_Generic_Type (Etype (It.Typ))) 6211 then 6212 null; 6213 6214 else 6215 Add_One_Interp (N, Op_Id, Base_Type (It.Typ)); 6216 end if; 6217 end if; 6218 6219 Get_Next_Interp (Index, It); 6220 end loop; 6221 end if; 6222 end Find_Unary_Types; 6223 6224 ------------------ 6225 -- Junk_Operand -- 6226 ------------------ 6227 6228 function Junk_Operand (N : Node_Id) return Boolean is 6229 Enode : Node_Id; 6230 6231 begin 6232 if Error_Posted (N) then 6233 return False; 6234 end if; 6235 6236 -- Get entity to be tested 6237 6238 if Is_Entity_Name (N) 6239 and then Present (Entity (N)) 6240 then 6241 Enode := N; 6242 6243 -- An odd case, a procedure name gets converted to a very peculiar 6244 -- function call, and here is where we detect this happening. 6245 6246 elsif Nkind (N) = N_Function_Call 6247 and then Is_Entity_Name (Name (N)) 6248 and then Present (Entity (Name (N))) 6249 then 6250 Enode := Name (N); 6251 6252 -- Another odd case, there are at least some cases of selected 6253 -- components where the selected component is not marked as having 6254 -- an entity, even though the selector does have an entity 6255 6256 elsif Nkind (N) = N_Selected_Component 6257 and then Present (Entity (Selector_Name (N))) 6258 then 6259 Enode := Selector_Name (N); 6260 6261 else 6262 return False; 6263 end if; 6264 6265 -- Now test the entity we got to see if it is a bad case 6266 6267 case Ekind (Entity (Enode)) is 6268 6269 when E_Package => 6270 Error_Msg_N 6271 ("package name cannot be used as operand", Enode); 6272 6273 when Generic_Unit_Kind => 6274 Error_Msg_N 6275 ("generic unit name cannot be used as operand", Enode); 6276 6277 when Type_Kind => 6278 Error_Msg_N 6279 ("subtype name cannot be used as operand", Enode); 6280 6281 when Entry_Kind => 6282 Error_Msg_N 6283 ("entry name cannot be used as operand", Enode); 6284 6285 when E_Procedure => 6286 Error_Msg_N 6287 ("procedure name cannot be used as operand", Enode); 6288 6289 when E_Exception => 6290 Error_Msg_N 6291 ("exception name cannot be used as operand", Enode); 6292 6293 when E_Block | E_Label | E_Loop => 6294 Error_Msg_N 6295 ("label name cannot be used as operand", Enode); 6296 6297 when others => 6298 return False; 6299 6300 end case; 6301 6302 return True; 6303 end Junk_Operand; 6304 6305 -------------------- 6306 -- Operator_Check -- 6307 -------------------- 6308 6309 procedure Operator_Check (N : Node_Id) is 6310 begin 6311 Remove_Abstract_Operations (N); 6312 6313 -- Test for case of no interpretation found for operator 6314 6315 if Etype (N) = Any_Type then 6316 declare 6317 L : Node_Id; 6318 R : Node_Id; 6319 Op_Id : Entity_Id := Empty; 6320 6321 begin 6322 R := Right_Opnd (N); 6323 6324 if Nkind (N) in N_Binary_Op then 6325 L := Left_Opnd (N); 6326 else 6327 L := Empty; 6328 end if; 6329 6330 -- If either operand has no type, then don't complain further, 6331 -- since this simply means that we have a propagated error. 6332 6333 if R = Error 6334 or else Etype (R) = Any_Type 6335 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type) 6336 then 6337 -- For the rather unusual case where one of the operands is 6338 -- a Raise_Expression, whose initial type is Any_Type, use 6339 -- the type of the other operand. 6340 6341 if Nkind (L) = N_Raise_Expression then 6342 Set_Etype (L, Etype (R)); 6343 Set_Etype (N, Etype (R)); 6344 6345 elsif Nkind (R) = N_Raise_Expression then 6346 Set_Etype (R, Etype (L)); 6347 Set_Etype (N, Etype (L)); 6348 end if; 6349 6350 return; 6351 6352 -- We explicitly check for the case of concatenation of component 6353 -- with component to avoid reporting spurious matching array types 6354 -- that might happen to be lurking in distant packages (such as 6355 -- run-time packages). This also prevents inconsistencies in the 6356 -- messages for certain ACVC B tests, which can vary depending on 6357 -- types declared in run-time interfaces. Another improvement when 6358 -- aggregates are present is to look for a well-typed operand. 6359 6360 elsif Present (Candidate_Type) 6361 and then (Nkind (N) /= N_Op_Concat 6362 or else Is_Array_Type (Etype (L)) 6363 or else Is_Array_Type (Etype (R))) 6364 then 6365 if Nkind (N) = N_Op_Concat then 6366 if Etype (L) /= Any_Composite 6367 and then Is_Array_Type (Etype (L)) 6368 then 6369 Candidate_Type := Etype (L); 6370 6371 elsif Etype (R) /= Any_Composite 6372 and then Is_Array_Type (Etype (R)) 6373 then 6374 Candidate_Type := Etype (R); 6375 end if; 6376 end if; 6377 6378 Error_Msg_NE -- CODEFIX 6379 ("operator for} is not directly visible!", 6380 N, First_Subtype (Candidate_Type)); 6381 6382 declare 6383 U : constant Node_Id := 6384 Cunit (Get_Source_Unit (Candidate_Type)); 6385 begin 6386 if Unit_Is_Visible (U) then 6387 Error_Msg_N -- CODEFIX 6388 ("use clause would make operation legal!", N); 6389 else 6390 Error_Msg_NE -- CODEFIX 6391 ("add with_clause and use_clause for&!", 6392 N, Defining_Entity (Unit (U))); 6393 end if; 6394 end; 6395 return; 6396 6397 -- If either operand is a junk operand (e.g. package name), then 6398 -- post appropriate error messages, but do not complain further. 6399 6400 -- Note that the use of OR in this test instead of OR ELSE is 6401 -- quite deliberate, we may as well check both operands in the 6402 -- binary operator case. 6403 6404 elsif Junk_Operand (R) 6405 or -- really mean OR here and not OR ELSE, see above 6406 (Nkind (N) in N_Binary_Op and then Junk_Operand (L)) 6407 then 6408 return; 6409 6410 -- If we have a logical operator, one of whose operands is 6411 -- Boolean, then we know that the other operand cannot resolve to 6412 -- Boolean (since we got no interpretations), but in that case we 6413 -- pretty much know that the other operand should be Boolean, so 6414 -- resolve it that way (generating an error) 6415 6416 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then 6417 if Etype (L) = Standard_Boolean then 6418 Resolve (R, Standard_Boolean); 6419 return; 6420 elsif Etype (R) = Standard_Boolean then 6421 Resolve (L, Standard_Boolean); 6422 return; 6423 end if; 6424 6425 -- For an arithmetic operator or comparison operator, if one 6426 -- of the operands is numeric, then we know the other operand 6427 -- is not the same numeric type. If it is a non-numeric type, 6428 -- then probably it is intended to match the other operand. 6429 6430 elsif Nkind_In (N, N_Op_Add, 6431 N_Op_Divide, 6432 N_Op_Ge, 6433 N_Op_Gt, 6434 N_Op_Le) 6435 or else 6436 Nkind_In (N, N_Op_Lt, 6437 N_Op_Mod, 6438 N_Op_Multiply, 6439 N_Op_Rem, 6440 N_Op_Subtract) 6441 then 6442 -- If Allow_Integer_Address is active, check whether the 6443 -- operation becomes legal after converting an operand. 6444 6445 if Is_Numeric_Type (Etype (L)) 6446 and then not Is_Numeric_Type (Etype (R)) 6447 then 6448 if Address_Integer_Convert_OK (Etype (R), Etype (L)) then 6449 Rewrite (R, 6450 Unchecked_Convert_To (Etype (L), Relocate_Node (R))); 6451 6452 if Nkind_In (N, N_Op_Ge, N_Op_Gt, N_Op_Le, N_Op_Lt) then 6453 Analyze_Comparison_Op (N); 6454 else 6455 Analyze_Arithmetic_Op (N); 6456 end if; 6457 else 6458 Resolve (R, Etype (L)); 6459 end if; 6460 6461 return; 6462 6463 elsif Is_Numeric_Type (Etype (R)) 6464 and then not Is_Numeric_Type (Etype (L)) 6465 then 6466 if Address_Integer_Convert_OK (Etype (L), Etype (R)) then 6467 Rewrite (L, 6468 Unchecked_Convert_To (Etype (R), Relocate_Node (L))); 6469 6470 if Nkind_In (N, N_Op_Ge, N_Op_Gt, N_Op_Le, N_Op_Lt) then 6471 Analyze_Comparison_Op (N); 6472 else 6473 Analyze_Arithmetic_Op (N); 6474 end if; 6475 6476 return; 6477 6478 else 6479 Resolve (L, Etype (R)); 6480 end if; 6481 6482 return; 6483 6484 elsif Allow_Integer_Address 6485 and then Is_Descendent_Of_Address (Etype (L)) 6486 and then Is_Descendent_Of_Address (Etype (R)) 6487 and then not Error_Posted (N) 6488 then 6489 declare 6490 Addr_Type : constant Entity_Id := Etype (L); 6491 6492 begin 6493 Rewrite (L, 6494 Unchecked_Convert_To ( 6495 Standard_Integer, Relocate_Node (L))); 6496 Rewrite (R, 6497 Unchecked_Convert_To ( 6498 Standard_Integer, Relocate_Node (R))); 6499 6500 if Nkind_In (N, N_Op_Ge, N_Op_Gt, N_Op_Le, N_Op_Lt) then 6501 Analyze_Comparison_Op (N); 6502 else 6503 Analyze_Arithmetic_Op (N); 6504 end if; 6505 6506 -- If this is an operand in an enclosing arithmetic 6507 -- operation, Convert the result as an address so that 6508 -- arithmetic folding of address can continue. 6509 6510 if Nkind (Parent (N)) in N_Op then 6511 Rewrite (N, 6512 Unchecked_Convert_To (Addr_Type, Relocate_Node (N))); 6513 end if; 6514 6515 return; 6516 end; 6517 end if; 6518 6519 -- Comparisons on A'Access are common enough to deserve a 6520 -- special message. 6521 6522 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) 6523 and then Ekind (Etype (L)) = E_Access_Attribute_Type 6524 and then Ekind (Etype (R)) = E_Access_Attribute_Type 6525 then 6526 Error_Msg_N 6527 ("two access attributes cannot be compared directly", N); 6528 Error_Msg_N 6529 ("\use qualified expression for one of the operands", 6530 N); 6531 return; 6532 6533 -- Another one for C programmers 6534 6535 elsif Nkind (N) = N_Op_Concat 6536 and then Valid_Boolean_Arg (Etype (L)) 6537 and then Valid_Boolean_Arg (Etype (R)) 6538 then 6539 Error_Msg_N ("invalid operands for concatenation", N); 6540 Error_Msg_N -- CODEFIX 6541 ("\maybe AND was meant", N); 6542 return; 6543 6544 -- A special case for comparison of access parameter with null 6545 6546 elsif Nkind (N) = N_Op_Eq 6547 and then Is_Entity_Name (L) 6548 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification 6549 and then Nkind (Parameter_Type (Parent (Entity (L)))) = 6550 N_Access_Definition 6551 and then Nkind (R) = N_Null 6552 then 6553 Error_Msg_N ("access parameter is not allowed to be null", L); 6554 Error_Msg_N ("\(call would raise Constraint_Error)", L); 6555 return; 6556 6557 -- Another special case for exponentiation, where the right 6558 -- operand must be Natural, independently of the base. 6559 6560 elsif Nkind (N) = N_Op_Expon 6561 and then Is_Numeric_Type (Etype (L)) 6562 and then not Is_Overloaded (R) 6563 and then 6564 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer 6565 and then Base_Type (Etype (R)) /= Universal_Integer 6566 then 6567 if Ada_Version >= Ada_2012 6568 and then Has_Dimension_System (Etype (L)) 6569 then 6570 Error_Msg_NE 6571 ("exponent for dimensioned type must be a rational" & 6572 ", found}", R, Etype (R)); 6573 else 6574 Error_Msg_NE 6575 ("exponent must be of type Natural, found}", R, Etype (R)); 6576 end if; 6577 6578 return; 6579 6580 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then 6581 if Address_Integer_Convert_OK (Etype (R), Etype (L)) then 6582 Rewrite (R, 6583 Unchecked_Convert_To (Etype (L), Relocate_Node (R))); 6584 Analyze_Equality_Op (N); 6585 return; 6586 end if; 6587 end if; 6588 6589 -- If we fall through then just give general message. Note that in 6590 -- the following messages, if the operand is overloaded we choose 6591 -- an arbitrary type to complain about, but that is probably more 6592 -- useful than not giving a type at all. 6593 6594 if Nkind (N) in N_Unary_Op then 6595 Error_Msg_Node_2 := Etype (R); 6596 Error_Msg_N ("operator& not defined for}", N); 6597 return; 6598 6599 else 6600 if Nkind (N) in N_Binary_Op then 6601 if not Is_Overloaded (L) 6602 and then not Is_Overloaded (R) 6603 and then Base_Type (Etype (L)) = Base_Type (Etype (R)) 6604 then 6605 Error_Msg_Node_2 := First_Subtype (Etype (R)); 6606 Error_Msg_N ("there is no applicable operator& for}", N); 6607 6608 else 6609 -- Another attempt to find a fix: one of the candidate 6610 -- interpretations may not be use-visible. This has 6611 -- already been checked for predefined operators, so 6612 -- we examine only user-defined functions. 6613 6614 Op_Id := Get_Name_Entity_Id (Chars (N)); 6615 6616 while Present (Op_Id) loop 6617 if Ekind (Op_Id) /= E_Operator 6618 and then Is_Overloadable (Op_Id) 6619 then 6620 if not Is_Immediately_Visible (Op_Id) 6621 and then not In_Use (Scope (Op_Id)) 6622 and then not Is_Abstract_Subprogram (Op_Id) 6623 and then not Is_Hidden (Op_Id) 6624 and then Ekind (Scope (Op_Id)) = E_Package 6625 and then 6626 Has_Compatible_Type 6627 (L, Etype (First_Formal (Op_Id))) 6628 and then Present 6629 (Next_Formal (First_Formal (Op_Id))) 6630 and then 6631 Has_Compatible_Type 6632 (R, 6633 Etype (Next_Formal (First_Formal (Op_Id)))) 6634 then 6635 Error_Msg_N 6636 ("No legal interpretation for operator&", N); 6637 Error_Msg_NE 6638 ("\use clause on& would make operation legal", 6639 N, Scope (Op_Id)); 6640 exit; 6641 end if; 6642 end if; 6643 6644 Op_Id := Homonym (Op_Id); 6645 end loop; 6646 6647 if No (Op_Id) then 6648 Error_Msg_N ("invalid operand types for operator&", N); 6649 6650 if Nkind (N) /= N_Op_Concat then 6651 Error_Msg_NE ("\left operand has}!", N, Etype (L)); 6652 Error_Msg_NE ("\right operand has}!", N, Etype (R)); 6653 6654 -- For concatenation operators it is more difficult to 6655 -- determine which is the wrong operand. It is worth 6656 -- flagging explicitly an access type, for those who 6657 -- might think that a dereference happens here. 6658 6659 elsif Is_Access_Type (Etype (L)) then 6660 Error_Msg_N ("\left operand is access type", N); 6661 6662 elsif Is_Access_Type (Etype (R)) then 6663 Error_Msg_N ("\right operand is access type", N); 6664 end if; 6665 end if; 6666 end if; 6667 end if; 6668 end if; 6669 end; 6670 end if; 6671 end Operator_Check; 6672 6673 ----------------------------------------- 6674 -- Process_Implicit_Dereference_Prefix -- 6675 ----------------------------------------- 6676 6677 function Process_Implicit_Dereference_Prefix 6678 (E : Entity_Id; 6679 P : Entity_Id) return Entity_Id 6680 is 6681 Ref : Node_Id; 6682 Typ : constant Entity_Id := Designated_Type (Etype (P)); 6683 6684 begin 6685 if Present (E) 6686 and then (Operating_Mode = Check_Semantics or else not Expander_Active) 6687 then 6688 -- We create a dummy reference to E to ensure that the reference is 6689 -- not considered as part of an assignment (an implicit dereference 6690 -- can never assign to its prefix). The Comes_From_Source attribute 6691 -- needs to be propagated for accurate warnings. 6692 6693 Ref := New_Occurrence_Of (E, Sloc (P)); 6694 Set_Comes_From_Source (Ref, Comes_From_Source (P)); 6695 Generate_Reference (E, Ref); 6696 end if; 6697 6698 -- An implicit dereference is a legal occurrence of an incomplete type 6699 -- imported through a limited_with clause, if the full view is visible. 6700 6701 if From_Limited_With (Typ) 6702 and then not From_Limited_With (Scope (Typ)) 6703 and then 6704 (Is_Immediately_Visible (Scope (Typ)) 6705 or else 6706 (Is_Child_Unit (Scope (Typ)) 6707 and then Is_Visible_Lib_Unit (Scope (Typ)))) 6708 then 6709 return Available_View (Typ); 6710 else 6711 return Typ; 6712 end if; 6713 end Process_Implicit_Dereference_Prefix; 6714 6715 -------------------------------- 6716 -- Remove_Abstract_Operations -- 6717 -------------------------------- 6718 6719 procedure Remove_Abstract_Operations (N : Node_Id) is 6720 Abstract_Op : Entity_Id := Empty; 6721 Address_Descendent : Boolean := False; 6722 I : Interp_Index; 6723 It : Interp; 6724 6725 -- AI-310: If overloaded, remove abstract non-dispatching operations. We 6726 -- activate this if either extensions are enabled, or if the abstract 6727 -- operation in question comes from a predefined file. This latter test 6728 -- allows us to use abstract to make operations invisible to users. In 6729 -- particular, if type Address is non-private and abstract subprograms 6730 -- are used to hide its operators, they will be truly hidden. 6731 6732 type Operand_Position is (First_Op, Second_Op); 6733 Univ_Type : constant Entity_Id := Universal_Interpretation (N); 6734 6735 procedure Remove_Address_Interpretations (Op : Operand_Position); 6736 -- Ambiguities may arise when the operands are literal and the address 6737 -- operations in s-auxdec are visible. In that case, remove the 6738 -- interpretation of a literal as Address, to retain the semantics 6739 -- of Address as a private type. 6740 6741 ------------------------------------ 6742 -- Remove_Address_Interpretations -- 6743 ------------------------------------ 6744 6745 procedure Remove_Address_Interpretations (Op : Operand_Position) is 6746 Formal : Entity_Id; 6747 6748 begin 6749 if Is_Overloaded (N) then 6750 Get_First_Interp (N, I, It); 6751 while Present (It.Nam) loop 6752 Formal := First_Entity (It.Nam); 6753 6754 if Op = Second_Op then 6755 Formal := Next_Entity (Formal); 6756 end if; 6757 6758 if Is_Descendent_Of_Address (Etype (Formal)) then 6759 Address_Descendent := True; 6760 Remove_Interp (I); 6761 end if; 6762 6763 Get_Next_Interp (I, It); 6764 end loop; 6765 end if; 6766 end Remove_Address_Interpretations; 6767 6768 -- Start of processing for Remove_Abstract_Operations 6769 6770 begin 6771 if Is_Overloaded (N) then 6772 if Debug_Flag_V then 6773 Write_Str ("Remove_Abstract_Operations: "); 6774 Write_Overloads (N); 6775 end if; 6776 6777 Get_First_Interp (N, I, It); 6778 6779 while Present (It.Nam) loop 6780 if Is_Overloadable (It.Nam) 6781 and then Is_Abstract_Subprogram (It.Nam) 6782 and then not Is_Dispatching_Operation (It.Nam) 6783 then 6784 Abstract_Op := It.Nam; 6785 6786 if Is_Descendent_Of_Address (It.Typ) then 6787 Address_Descendent := True; 6788 Remove_Interp (I); 6789 exit; 6790 6791 -- In Ada 2005, this operation does not participate in overload 6792 -- resolution. If the operation is defined in a predefined 6793 -- unit, it is one of the operations declared abstract in some 6794 -- variants of System, and it must be removed as well. 6795 6796 elsif Ada_Version >= Ada_2005 6797 or else Is_Predefined_File_Name 6798 (Unit_File_Name (Get_Source_Unit (It.Nam))) 6799 then 6800 Remove_Interp (I); 6801 exit; 6802 end if; 6803 end if; 6804 6805 Get_Next_Interp (I, It); 6806 end loop; 6807 6808 if No (Abstract_Op) then 6809 6810 -- If some interpretation yields an integer type, it is still 6811 -- possible that there are address interpretations. Remove them 6812 -- if one operand is a literal, to avoid spurious ambiguities 6813 -- on systems where Address is a visible integer type. 6814 6815 if Is_Overloaded (N) 6816 and then Nkind (N) in N_Op 6817 and then Is_Integer_Type (Etype (N)) 6818 then 6819 if Nkind (N) in N_Binary_Op then 6820 if Nkind (Right_Opnd (N)) = N_Integer_Literal then 6821 Remove_Address_Interpretations (Second_Op); 6822 6823 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then 6824 Remove_Address_Interpretations (First_Op); 6825 end if; 6826 end if; 6827 end if; 6828 6829 elsif Nkind (N) in N_Op then 6830 6831 -- Remove interpretations that treat literals as addresses. This 6832 -- is never appropriate, even when Address is defined as a visible 6833 -- Integer type. The reason is that we would really prefer Address 6834 -- to behave as a private type, even in this case. If Address is a 6835 -- visible integer type, we get lots of overload ambiguities. 6836 6837 if Nkind (N) in N_Binary_Op then 6838 declare 6839 U1 : constant Boolean := 6840 Present (Universal_Interpretation (Right_Opnd (N))); 6841 U2 : constant Boolean := 6842 Present (Universal_Interpretation (Left_Opnd (N))); 6843 6844 begin 6845 if U1 then 6846 Remove_Address_Interpretations (Second_Op); 6847 end if; 6848 6849 if U2 then 6850 Remove_Address_Interpretations (First_Op); 6851 end if; 6852 6853 if not (U1 and U2) then 6854 6855 -- Remove corresponding predefined operator, which is 6856 -- always added to the overload set. 6857 6858 Get_First_Interp (N, I, It); 6859 while Present (It.Nam) loop 6860 if Scope (It.Nam) = Standard_Standard 6861 and then Base_Type (It.Typ) = 6862 Base_Type (Etype (Abstract_Op)) 6863 then 6864 Remove_Interp (I); 6865 end if; 6866 6867 Get_Next_Interp (I, It); 6868 end loop; 6869 6870 elsif Is_Overloaded (N) 6871 and then Present (Univ_Type) 6872 then 6873 -- If both operands have a universal interpretation, 6874 -- it is still necessary to remove interpretations that 6875 -- yield Address. Any remaining ambiguities will be 6876 -- removed in Disambiguate. 6877 6878 Get_First_Interp (N, I, It); 6879 while Present (It.Nam) loop 6880 if Is_Descendent_Of_Address (It.Typ) then 6881 Remove_Interp (I); 6882 6883 elsif not Is_Type (It.Nam) then 6884 Set_Entity (N, It.Nam); 6885 end if; 6886 6887 Get_Next_Interp (I, It); 6888 end loop; 6889 end if; 6890 end; 6891 end if; 6892 6893 elsif Nkind (N) = N_Function_Call 6894 and then 6895 (Nkind (Name (N)) = N_Operator_Symbol 6896 or else 6897 (Nkind (Name (N)) = N_Expanded_Name 6898 and then 6899 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol)) 6900 then 6901 6902 declare 6903 Arg1 : constant Node_Id := First (Parameter_Associations (N)); 6904 U1 : constant Boolean := 6905 Present (Universal_Interpretation (Arg1)); 6906 U2 : constant Boolean := 6907 Present (Next (Arg1)) and then 6908 Present (Universal_Interpretation (Next (Arg1))); 6909 6910 begin 6911 if U1 then 6912 Remove_Address_Interpretations (First_Op); 6913 end if; 6914 6915 if U2 then 6916 Remove_Address_Interpretations (Second_Op); 6917 end if; 6918 6919 if not (U1 and U2) then 6920 Get_First_Interp (N, I, It); 6921 while Present (It.Nam) loop 6922 if Scope (It.Nam) = Standard_Standard 6923 and then It.Typ = Base_Type (Etype (Abstract_Op)) 6924 then 6925 Remove_Interp (I); 6926 end if; 6927 6928 Get_Next_Interp (I, It); 6929 end loop; 6930 end if; 6931 end; 6932 end if; 6933 6934 -- If the removal has left no valid interpretations, emit an error 6935 -- message now and label node as illegal. 6936 6937 if Present (Abstract_Op) then 6938 Get_First_Interp (N, I, It); 6939 6940 if No (It.Nam) then 6941 6942 -- Removal of abstract operation left no viable candidate 6943 6944 Set_Etype (N, Any_Type); 6945 Error_Msg_Sloc := Sloc (Abstract_Op); 6946 Error_Msg_NE 6947 ("cannot call abstract operation& declared#", N, Abstract_Op); 6948 6949 -- In Ada 2005, an abstract operation may disable predefined 6950 -- operators. Since the context is not yet known, we mark the 6951 -- predefined operators as potentially hidden. Do not include 6952 -- predefined operators when addresses are involved since this 6953 -- case is handled separately. 6954 6955 elsif Ada_Version >= Ada_2005 and then not Address_Descendent then 6956 while Present (It.Nam) loop 6957 if Is_Numeric_Type (It.Typ) 6958 and then Scope (It.Typ) = Standard_Standard 6959 then 6960 Set_Abstract_Op (I, Abstract_Op); 6961 end if; 6962 6963 Get_Next_Interp (I, It); 6964 end loop; 6965 end if; 6966 end if; 6967 6968 if Debug_Flag_V then 6969 Write_Str ("Remove_Abstract_Operations done: "); 6970 Write_Overloads (N); 6971 end if; 6972 end if; 6973 end Remove_Abstract_Operations; 6974 6975 ---------------------------- 6976 -- Try_Container_Indexing -- 6977 ---------------------------- 6978 6979 function Try_Container_Indexing 6980 (N : Node_Id; 6981 Prefix : Node_Id; 6982 Exprs : List_Id) return Boolean 6983 is 6984 Loc : constant Source_Ptr := Sloc (N); 6985 C_Type : Entity_Id; 6986 Assoc : List_Id; 6987 Func : Entity_Id; 6988 Func_Name : Node_Id; 6989 Indexing : Node_Id; 6990 6991 begin 6992 C_Type := Etype (Prefix); 6993 6994 -- If indexing a class-wide container, obtain indexing primitive 6995 -- from specific type. 6996 6997 if Is_Class_Wide_Type (C_Type) then 6998 C_Type := Etype (Base_Type (C_Type)); 6999 end if; 7000 7001 -- Check whether type has a specified indexing aspect 7002 7003 Func_Name := Empty; 7004 7005 if Is_Variable (Prefix) then 7006 Func_Name := 7007 Find_Value_Of_Aspect (Etype (Prefix), Aspect_Variable_Indexing); 7008 end if; 7009 7010 if No (Func_Name) then 7011 Func_Name := 7012 Find_Value_Of_Aspect (Etype (Prefix), Aspect_Constant_Indexing); 7013 end if; 7014 7015 -- If aspect does not exist the expression is illegal. Error is 7016 -- diagnosed in caller. 7017 7018 if No (Func_Name) then 7019 7020 -- The prefix itself may be an indexing of a container: rewrite 7021 -- as such and re-analyze. 7022 7023 if Has_Implicit_Dereference (Etype (Prefix)) then 7024 Build_Explicit_Dereference 7025 (Prefix, First_Discriminant (Etype (Prefix))); 7026 return Try_Container_Indexing (N, Prefix, Exprs); 7027 7028 else 7029 return False; 7030 end if; 7031 7032 -- If the container type is derived from another container type, the 7033 -- value of the inherited aspect is the Reference operation declared 7034 -- for the parent type. 7035 7036 -- However, Reference is also a primitive operation of the type, and 7037 -- the inherited operation has a different signature. We retrieve the 7038 -- right one from the list of primitive operations of the derived type. 7039 7040 -- Note that predefined containers are typically all derived from one 7041 -- of the Controlled types. The code below is motivated by containers 7042 -- that are derived from other types with a Reference aspect. 7043 7044 -- Additional machinery may be needed for types that have several user- 7045 -- defined Reference operations with different signatures ??? 7046 7047 elsif Is_Derived_Type (C_Type) 7048 and then Etype (First_Formal (Entity (Func_Name))) /= Etype (Prefix) 7049 then 7050 Func := Find_Prim_Op (C_Type, Chars (Func_Name)); 7051 Func_Name := New_Occurrence_Of (Func, Loc); 7052 end if; 7053 7054 Assoc := New_List (Relocate_Node (Prefix)); 7055 7056 -- A generalized indexing may have nore than one index expression, so 7057 -- transfer all of them to the argument list to be used in the call. 7058 -- Note that there may be named associations, in which case the node 7059 -- was rewritten earlier as a call, and has been transformed back into 7060 -- an indexed expression to share the following processing. 7061 7062 -- The generalized indexing node is the one on which analysis and 7063 -- resolution take place. Before expansion the original node is replaced 7064 -- with the generalized indexing node, which is a call, possibly with 7065 -- a dereference operation. 7066 7067 if Comes_From_Source (N) then 7068 Check_Compiler_Unit ("generalized indexing", N); 7069 end if; 7070 7071 declare 7072 Arg : Node_Id; 7073 begin 7074 Arg := First (Exprs); 7075 while Present (Arg) loop 7076 Append (Relocate_Node (Arg), Assoc); 7077 Next (Arg); 7078 end loop; 7079 end; 7080 7081 if not Is_Overloaded (Func_Name) then 7082 Func := Entity (Func_Name); 7083 Indexing := 7084 Make_Function_Call (Loc, 7085 Name => New_Occurrence_Of (Func, Loc), 7086 Parameter_Associations => Assoc); 7087 Set_Parent (Indexing, Parent (N)); 7088 Set_Generalized_Indexing (N, Indexing); 7089 Analyze (Indexing); 7090 Set_Etype (N, Etype (Indexing)); 7091 7092 -- If the return type of the indexing function is a reference type, 7093 -- add the dereference as a possible interpretation. Note that the 7094 -- indexing aspect may be a function that returns the element type 7095 -- with no intervening implicit dereference, and that the reference 7096 -- discriminant is not the first discriminant. 7097 7098 if Has_Discriminants (Etype (Func)) then 7099 Check_Implicit_Dereference (N, Etype (Func)); 7100 end if; 7101 7102 else 7103 Indexing := 7104 Make_Function_Call (Loc, 7105 Name => Make_Identifier (Loc, Chars (Func_Name)), 7106 Parameter_Associations => Assoc); 7107 7108 Set_Parent (Indexing, Parent (N)); 7109 Set_Generalized_Indexing (N, Indexing); 7110 7111 declare 7112 I : Interp_Index; 7113 It : Interp; 7114 Success : Boolean; 7115 7116 begin 7117 Get_First_Interp (Func_Name, I, It); 7118 Set_Etype (Indexing, Any_Type); 7119 while Present (It.Nam) loop 7120 Analyze_One_Call (Indexing, It.Nam, False, Success); 7121 7122 if Success then 7123 Set_Etype (Name (Indexing), It.Typ); 7124 Set_Entity (Name (Indexing), It.Nam); 7125 Set_Etype (N, Etype (Indexing)); 7126 7127 -- Add implicit dereference interpretation 7128 7129 if Has_Discriminants (Etype (It.Nam)) then 7130 Check_Implicit_Dereference (N, Etype (It.Nam)); 7131 end if; 7132 7133 exit; 7134 end if; 7135 7136 Get_Next_Interp (I, It); 7137 end loop; 7138 end; 7139 end if; 7140 7141 if Etype (Indexing) = Any_Type then 7142 Error_Msg_NE 7143 ("container cannot be indexed with&", N, Etype (First (Exprs))); 7144 Rewrite (N, New_Occurrence_Of (Any_Id, Loc)); 7145 end if; 7146 7147 return True; 7148 end Try_Container_Indexing; 7149 7150 ----------------------- 7151 -- Try_Indirect_Call -- 7152 ----------------------- 7153 7154 function Try_Indirect_Call 7155 (N : Node_Id; 7156 Nam : Entity_Id; 7157 Typ : Entity_Id) return Boolean 7158 is 7159 Actual : Node_Id; 7160 Formal : Entity_Id; 7161 7162 Call_OK : Boolean; 7163 pragma Warnings (Off, Call_OK); 7164 7165 begin 7166 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK); 7167 7168 Actual := First_Actual (N); 7169 Formal := First_Formal (Designated_Type (Typ)); 7170 while Present (Actual) and then Present (Formal) loop 7171 if not Has_Compatible_Type (Actual, Etype (Formal)) then 7172 return False; 7173 end if; 7174 7175 Next (Actual); 7176 Next_Formal (Formal); 7177 end loop; 7178 7179 if No (Actual) and then No (Formal) then 7180 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ))); 7181 7182 -- Nam is a candidate interpretation for the name in the call, 7183 -- if it is not an indirect call. 7184 7185 if not Is_Type (Nam) 7186 and then Is_Entity_Name (Name (N)) 7187 then 7188 Set_Entity (Name (N), Nam); 7189 end if; 7190 7191 return True; 7192 7193 else 7194 return False; 7195 end if; 7196 end Try_Indirect_Call; 7197 7198 ---------------------- 7199 -- Try_Indexed_Call -- 7200 ---------------------- 7201 7202 function Try_Indexed_Call 7203 (N : Node_Id; 7204 Nam : Entity_Id; 7205 Typ : Entity_Id; 7206 Skip_First : Boolean) return Boolean 7207 is 7208 Loc : constant Source_Ptr := Sloc (N); 7209 Actuals : constant List_Id := Parameter_Associations (N); 7210 Actual : Node_Id; 7211 Index : Entity_Id; 7212 7213 begin 7214 Actual := First (Actuals); 7215 7216 -- If the call was originally written in prefix form, skip the first 7217 -- actual, which is obviously not defaulted. 7218 7219 if Skip_First then 7220 Next (Actual); 7221 end if; 7222 7223 Index := First_Index (Typ); 7224 while Present (Actual) and then Present (Index) loop 7225 7226 -- If the parameter list has a named association, the expression 7227 -- is definitely a call and not an indexed component. 7228 7229 if Nkind (Actual) = N_Parameter_Association then 7230 return False; 7231 end if; 7232 7233 if Is_Entity_Name (Actual) 7234 and then Is_Type (Entity (Actual)) 7235 and then No (Next (Actual)) 7236 then 7237 -- A single actual that is a type name indicates a slice if the 7238 -- type is discrete, and an error otherwise. 7239 7240 if Is_Discrete_Type (Entity (Actual)) then 7241 Rewrite (N, 7242 Make_Slice (Loc, 7243 Prefix => 7244 Make_Function_Call (Loc, 7245 Name => Relocate_Node (Name (N))), 7246 Discrete_Range => 7247 New_Occurrence_Of (Entity (Actual), Sloc (Actual)))); 7248 7249 Analyze (N); 7250 7251 else 7252 Error_Msg_N ("invalid use of type in expression", Actual); 7253 Set_Etype (N, Any_Type); 7254 end if; 7255 7256 return True; 7257 7258 elsif not Has_Compatible_Type (Actual, Etype (Index)) then 7259 return False; 7260 end if; 7261 7262 Next (Actual); 7263 Next_Index (Index); 7264 end loop; 7265 7266 if No (Actual) and then No (Index) then 7267 Add_One_Interp (N, Nam, Component_Type (Typ)); 7268 7269 -- Nam is a candidate interpretation for the name in the call, 7270 -- if it is not an indirect call. 7271 7272 if not Is_Type (Nam) 7273 and then Is_Entity_Name (Name (N)) 7274 then 7275 Set_Entity (Name (N), Nam); 7276 end if; 7277 7278 return True; 7279 else 7280 return False; 7281 end if; 7282 end Try_Indexed_Call; 7283 7284 -------------------------- 7285 -- Try_Object_Operation -- 7286 -------------------------- 7287 7288 function Try_Object_Operation 7289 (N : Node_Id; CW_Test_Only : Boolean := False) return Boolean 7290 is 7291 K : constant Node_Kind := Nkind (Parent (N)); 7292 Is_Subprg_Call : constant Boolean := K in N_Subprogram_Call; 7293 Loc : constant Source_Ptr := Sloc (N); 7294 Obj : constant Node_Id := Prefix (N); 7295 7296 Subprog : constant Node_Id := 7297 Make_Identifier (Sloc (Selector_Name (N)), 7298 Chars => Chars (Selector_Name (N))); 7299 -- Identifier on which possible interpretations will be collected 7300 7301 Report_Error : Boolean := False; 7302 -- If no candidate interpretation matches the context, redo analysis 7303 -- with Report_Error True to provide additional information. 7304 7305 Actual : Node_Id; 7306 Candidate : Entity_Id := Empty; 7307 New_Call_Node : Node_Id := Empty; 7308 Node_To_Replace : Node_Id; 7309 Obj_Type : Entity_Id := Etype (Obj); 7310 Success : Boolean := False; 7311 7312 function Valid_Candidate 7313 (Success : Boolean; 7314 Call : Node_Id; 7315 Subp : Entity_Id) return Entity_Id; 7316 -- If the subprogram is a valid interpretation, record it, and add 7317 -- to the list of interpretations of Subprog. Otherwise return Empty. 7318 7319 procedure Complete_Object_Operation 7320 (Call_Node : Node_Id; 7321 Node_To_Replace : Node_Id); 7322 -- Make Subprog the name of Call_Node, replace Node_To_Replace with 7323 -- Call_Node, insert the object (or its dereference) as the first actual 7324 -- in the call, and complete the analysis of the call. 7325 7326 procedure Report_Ambiguity (Op : Entity_Id); 7327 -- If a prefixed procedure call is ambiguous, indicate whether the 7328 -- call includes an implicit dereference or an implicit 'Access. 7329 7330 procedure Transform_Object_Operation 7331 (Call_Node : out Node_Id; 7332 Node_To_Replace : out Node_Id); 7333 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..) 7334 -- Call_Node is the resulting subprogram call, Node_To_Replace is 7335 -- either N or the parent of N, and Subprog is a reference to the 7336 -- subprogram we are trying to match. 7337 7338 function Try_Class_Wide_Operation 7339 (Call_Node : Node_Id; 7340 Node_To_Replace : Node_Id) return Boolean; 7341 -- Traverse all ancestor types looking for a class-wide subprogram 7342 -- for which the current operation is a valid non-dispatching call. 7343 7344 procedure Try_One_Prefix_Interpretation (T : Entity_Id); 7345 -- If prefix is overloaded, its interpretation may include different 7346 -- tagged types, and we must examine the primitive operations and 7347 -- the class-wide operations of each in order to find candidate 7348 -- interpretations for the call as a whole. 7349 7350 function Try_Primitive_Operation 7351 (Call_Node : Node_Id; 7352 Node_To_Replace : Node_Id) return Boolean; 7353 -- Traverse the list of primitive subprograms looking for a dispatching 7354 -- operation for which the current node is a valid call . 7355 7356 --------------------- 7357 -- Valid_Candidate -- 7358 --------------------- 7359 7360 function Valid_Candidate 7361 (Success : Boolean; 7362 Call : Node_Id; 7363 Subp : Entity_Id) return Entity_Id 7364 is 7365 Arr_Type : Entity_Id; 7366 Comp_Type : Entity_Id; 7367 7368 begin 7369 -- If the subprogram is a valid interpretation, record it in global 7370 -- variable Subprog, to collect all possible overloadings. 7371 7372 if Success then 7373 if Subp /= Entity (Subprog) then 7374 Add_One_Interp (Subprog, Subp, Etype (Subp)); 7375 end if; 7376 end if; 7377 7378 -- If the call may be an indexed call, retrieve component type of 7379 -- resulting expression, and add possible interpretation. 7380 7381 Arr_Type := Empty; 7382 Comp_Type := Empty; 7383 7384 if Nkind (Call) = N_Function_Call 7385 and then Nkind (Parent (N)) = N_Indexed_Component 7386 and then Needs_One_Actual (Subp) 7387 then 7388 if Is_Array_Type (Etype (Subp)) then 7389 Arr_Type := Etype (Subp); 7390 7391 elsif Is_Access_Type (Etype (Subp)) 7392 and then Is_Array_Type (Designated_Type (Etype (Subp))) 7393 then 7394 Arr_Type := Designated_Type (Etype (Subp)); 7395 end if; 7396 end if; 7397 7398 if Present (Arr_Type) then 7399 7400 -- Verify that the actuals (excluding the object) match the types 7401 -- of the indexes. 7402 7403 declare 7404 Actual : Node_Id; 7405 Index : Node_Id; 7406 7407 begin 7408 Actual := Next (First_Actual (Call)); 7409 Index := First_Index (Arr_Type); 7410 while Present (Actual) and then Present (Index) loop 7411 if not Has_Compatible_Type (Actual, Etype (Index)) then 7412 Arr_Type := Empty; 7413 exit; 7414 end if; 7415 7416 Next_Actual (Actual); 7417 Next_Index (Index); 7418 end loop; 7419 7420 if No (Actual) 7421 and then No (Index) 7422 and then Present (Arr_Type) 7423 then 7424 Comp_Type := Component_Type (Arr_Type); 7425 end if; 7426 end; 7427 7428 if Present (Comp_Type) 7429 and then Etype (Subprog) /= Comp_Type 7430 then 7431 Add_One_Interp (Subprog, Subp, Comp_Type); 7432 end if; 7433 end if; 7434 7435 if Etype (Call) /= Any_Type then 7436 return Subp; 7437 else 7438 return Empty; 7439 end if; 7440 end Valid_Candidate; 7441 7442 ------------------------------- 7443 -- Complete_Object_Operation -- 7444 ------------------------------- 7445 7446 procedure Complete_Object_Operation 7447 (Call_Node : Node_Id; 7448 Node_To_Replace : Node_Id) 7449 is 7450 Control : constant Entity_Id := First_Formal (Entity (Subprog)); 7451 Formal_Type : constant Entity_Id := Etype (Control); 7452 First_Actual : Node_Id; 7453 7454 begin 7455 -- Place the name of the operation, with its interpretations, 7456 -- on the rewritten call. 7457 7458 Set_Name (Call_Node, Subprog); 7459 7460 First_Actual := First (Parameter_Associations (Call_Node)); 7461 7462 -- For cross-reference purposes, treat the new node as being in the 7463 -- source if the original one is. Set entity and type, even though 7464 -- they may be overwritten during resolution if overloaded. 7465 7466 Set_Comes_From_Source (Subprog, Comes_From_Source (N)); 7467 Set_Comes_From_Source (Call_Node, Comes_From_Source (N)); 7468 7469 if Nkind (N) = N_Selected_Component 7470 and then not Inside_A_Generic 7471 then 7472 Set_Entity (Selector_Name (N), Entity (Subprog)); 7473 Set_Etype (Selector_Name (N), Etype (Entity (Subprog))); 7474 end if; 7475 7476 -- If need be, rewrite first actual as an explicit dereference. If 7477 -- the call is overloaded, the rewriting can only be done once the 7478 -- primitive operation is identified. 7479 7480 if Is_Overloaded (Subprog) then 7481 7482 -- The prefix itself may be overloaded, and its interpretations 7483 -- must be propagated to the new actual in the call. 7484 7485 if Is_Overloaded (Obj) then 7486 Save_Interps (Obj, First_Actual); 7487 end if; 7488 7489 Rewrite (First_Actual, Obj); 7490 7491 elsif not Is_Access_Type (Formal_Type) 7492 and then Is_Access_Type (Etype (Obj)) 7493 then 7494 Rewrite (First_Actual, 7495 Make_Explicit_Dereference (Sloc (Obj), Obj)); 7496 Analyze (First_Actual); 7497 7498 -- If we need to introduce an explicit dereference, verify that 7499 -- the resulting actual is compatible with the mode of the formal. 7500 7501 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter 7502 and then Is_Access_Constant (Etype (Obj)) 7503 then 7504 Error_Msg_NE 7505 ("expect variable in call to&", Prefix (N), Entity (Subprog)); 7506 end if; 7507 7508 -- Conversely, if the formal is an access parameter and the object 7509 -- is not, replace the actual with a 'Access reference. Its analysis 7510 -- will check that the object is aliased. 7511 7512 elsif Is_Access_Type (Formal_Type) 7513 and then not Is_Access_Type (Etype (Obj)) 7514 then 7515 -- A special case: A.all'access is illegal if A is an access to a 7516 -- constant and the context requires an access to a variable. 7517 7518 if not Is_Access_Constant (Formal_Type) then 7519 if (Nkind (Obj) = N_Explicit_Dereference 7520 and then Is_Access_Constant (Etype (Prefix (Obj)))) 7521 or else not Is_Variable (Obj) 7522 then 7523 Error_Msg_NE 7524 ("actual for & must be a variable", Obj, Control); 7525 end if; 7526 end if; 7527 7528 Rewrite (First_Actual, 7529 Make_Attribute_Reference (Loc, 7530 Attribute_Name => Name_Access, 7531 Prefix => Relocate_Node (Obj))); 7532 7533 if not Is_Aliased_View (Obj) then 7534 Error_Msg_NE 7535 ("object in prefixed call to & must be aliased " 7536 & "(RM 4.1.3 (13 1/2))", Prefix (First_Actual), Subprog); 7537 end if; 7538 7539 Analyze (First_Actual); 7540 7541 else 7542 if Is_Overloaded (Obj) then 7543 Save_Interps (Obj, First_Actual); 7544 end if; 7545 7546 Rewrite (First_Actual, Obj); 7547 end if; 7548 7549 -- The operation is obtained from the dispatch table and not by 7550 -- visibility, and may be declared in a unit that is not explicitly 7551 -- referenced in the source, but is nevertheless required in the 7552 -- context of the current unit. Indicate that operation and its scope 7553 -- are referenced, to prevent spurious and misleading warnings. If 7554 -- the operation is overloaded, all primitives are in the same scope 7555 -- and we can use any of them. 7556 7557 Set_Referenced (Entity (Subprog), True); 7558 Set_Referenced (Scope (Entity (Subprog)), True); 7559 7560 Rewrite (Node_To_Replace, Call_Node); 7561 7562 -- Propagate the interpretations collected in subprog to the new 7563 -- function call node, to be resolved from context. 7564 7565 if Is_Overloaded (Subprog) then 7566 Save_Interps (Subprog, Node_To_Replace); 7567 7568 else 7569 -- The type of the subprogram may be a limited view obtained 7570 -- transitively from another unit. If full view is available, 7571 -- use it to analyze call. 7572 7573 declare 7574 T : constant Entity_Id := Etype (Subprog); 7575 begin 7576 if From_Limited_With (T) then 7577 Set_Etype (Entity (Subprog), Available_View (T)); 7578 end if; 7579 end; 7580 7581 Analyze (Node_To_Replace); 7582 7583 -- If the operation has been rewritten into a call, which may get 7584 -- subsequently an explicit dereference, preserve the type on the 7585 -- original node (selected component or indexed component) for 7586 -- subsequent legality tests, e.g. Is_Variable. which examines 7587 -- the original node. 7588 7589 if Nkind (Node_To_Replace) = N_Function_Call then 7590 Set_Etype 7591 (Original_Node (Node_To_Replace), Etype (Node_To_Replace)); 7592 end if; 7593 end if; 7594 end Complete_Object_Operation; 7595 7596 ---------------------- 7597 -- Report_Ambiguity -- 7598 ---------------------- 7599 7600 procedure Report_Ambiguity (Op : Entity_Id) is 7601 Access_Actual : constant Boolean := 7602 Is_Access_Type (Etype (Prefix (N))); 7603 Access_Formal : Boolean := False; 7604 7605 begin 7606 Error_Msg_Sloc := Sloc (Op); 7607 7608 if Present (First_Formal (Op)) then 7609 Access_Formal := Is_Access_Type (Etype (First_Formal (Op))); 7610 end if; 7611 7612 if Access_Formal and then not Access_Actual then 7613 if Nkind (Parent (Op)) = N_Full_Type_Declaration then 7614 Error_Msg_N 7615 ("\possible interpretation " 7616 & "(inherited, with implicit 'Access) #", N); 7617 else 7618 Error_Msg_N 7619 ("\possible interpretation (with implicit 'Access) #", N); 7620 end if; 7621 7622 elsif not Access_Formal and then Access_Actual then 7623 if Nkind (Parent (Op)) = N_Full_Type_Declaration then 7624 Error_Msg_N 7625 ("\possible interpretation " 7626 & "(inherited, with implicit dereference) #", N); 7627 else 7628 Error_Msg_N 7629 ("\possible interpretation (with implicit dereference) #", N); 7630 end if; 7631 7632 else 7633 if Nkind (Parent (Op)) = N_Full_Type_Declaration then 7634 Error_Msg_N ("\possible interpretation (inherited)#", N); 7635 else 7636 Error_Msg_N -- CODEFIX 7637 ("\possible interpretation#", N); 7638 end if; 7639 end if; 7640 end Report_Ambiguity; 7641 7642 -------------------------------- 7643 -- Transform_Object_Operation -- 7644 -------------------------------- 7645 7646 procedure Transform_Object_Operation 7647 (Call_Node : out Node_Id; 7648 Node_To_Replace : out Node_Id) 7649 is 7650 Dummy : constant Node_Id := New_Copy (Obj); 7651 -- Placeholder used as a first parameter in the call, replaced 7652 -- eventually by the proper object. 7653 7654 Parent_Node : constant Node_Id := Parent (N); 7655 7656 Actual : Node_Id; 7657 Actuals : List_Id; 7658 7659 begin 7660 -- Common case covering 1) Call to a procedure and 2) Call to a 7661 -- function that has some additional actuals. 7662 7663 if Nkind (Parent_Node) in N_Subprogram_Call 7664 7665 -- N is a selected component node containing the name of the 7666 -- subprogram. If N is not the name of the parent node we must 7667 -- not replace the parent node by the new construct. This case 7668 -- occurs when N is a parameterless call to a subprogram that 7669 -- is an actual parameter of a call to another subprogram. For 7670 -- example: 7671 -- Some_Subprogram (..., Obj.Operation, ...) 7672 7673 and then Name (Parent_Node) = N 7674 then 7675 Node_To_Replace := Parent_Node; 7676 7677 Actuals := Parameter_Associations (Parent_Node); 7678 7679 if Present (Actuals) then 7680 Prepend (Dummy, Actuals); 7681 else 7682 Actuals := New_List (Dummy); 7683 end if; 7684 7685 if Nkind (Parent_Node) = N_Procedure_Call_Statement then 7686 Call_Node := 7687 Make_Procedure_Call_Statement (Loc, 7688 Name => New_Copy (Subprog), 7689 Parameter_Associations => Actuals); 7690 7691 else 7692 Call_Node := 7693 Make_Function_Call (Loc, 7694 Name => New_Copy (Subprog), 7695 Parameter_Associations => Actuals); 7696 end if; 7697 7698 -- Before analysis, a function call appears as an indexed component 7699 -- if there are no named associations. 7700 7701 elsif Nkind (Parent_Node) = N_Indexed_Component 7702 and then N = Prefix (Parent_Node) 7703 then 7704 Node_To_Replace := Parent_Node; 7705 Actuals := Expressions (Parent_Node); 7706 7707 Actual := First (Actuals); 7708 while Present (Actual) loop 7709 Analyze (Actual); 7710 Next (Actual); 7711 end loop; 7712 7713 Prepend (Dummy, Actuals); 7714 7715 Call_Node := 7716 Make_Function_Call (Loc, 7717 Name => New_Copy (Subprog), 7718 Parameter_Associations => Actuals); 7719 7720 -- Parameterless call: Obj.F is rewritten as F (Obj) 7721 7722 else 7723 Node_To_Replace := N; 7724 7725 Call_Node := 7726 Make_Function_Call (Loc, 7727 Name => New_Copy (Subprog), 7728 Parameter_Associations => New_List (Dummy)); 7729 end if; 7730 end Transform_Object_Operation; 7731 7732 ------------------------------ 7733 -- Try_Class_Wide_Operation -- 7734 ------------------------------ 7735 7736 function Try_Class_Wide_Operation 7737 (Call_Node : Node_Id; 7738 Node_To_Replace : Node_Id) return Boolean 7739 is 7740 Anc_Type : Entity_Id; 7741 Matching_Op : Entity_Id := Empty; 7742 Error : Boolean; 7743 7744 procedure Traverse_Homonyms 7745 (Anc_Type : Entity_Id; 7746 Error : out Boolean); 7747 -- Traverse the homonym chain of the subprogram searching for those 7748 -- homonyms whose first formal has the Anc_Type's class-wide type, 7749 -- or an anonymous access type designating the class-wide type. If 7750 -- an ambiguity is detected, then Error is set to True. 7751 7752 procedure Traverse_Interfaces 7753 (Anc_Type : Entity_Id; 7754 Error : out Boolean); 7755 -- Traverse the list of interfaces, if any, associated with Anc_Type 7756 -- and search for acceptable class-wide homonyms associated with each 7757 -- interface. If an ambiguity is detected, then Error is set to True. 7758 7759 ----------------------- 7760 -- Traverse_Homonyms -- 7761 ----------------------- 7762 7763 procedure Traverse_Homonyms 7764 (Anc_Type : Entity_Id; 7765 Error : out Boolean) 7766 is 7767 Cls_Type : Entity_Id; 7768 Hom : Entity_Id; 7769 Hom_Ref : Node_Id; 7770 Success : Boolean; 7771 7772 begin 7773 Error := False; 7774 7775 Cls_Type := Class_Wide_Type (Anc_Type); 7776 7777 Hom := Current_Entity (Subprog); 7778 7779 -- Find a non-hidden operation whose first parameter is of the 7780 -- class-wide type, a subtype thereof, or an anonymous access 7781 -- to same. If in an instance, the operation can be considered 7782 -- even if hidden (it may be hidden because the instantiation 7783 -- is expanded after the containing package has been analyzed). 7784 7785 while Present (Hom) loop 7786 if Ekind_In (Hom, E_Procedure, E_Function) 7787 and then (not Is_Hidden (Hom) or else In_Instance) 7788 and then Scope (Hom) = Scope (Anc_Type) 7789 and then Present (First_Formal (Hom)) 7790 and then 7791 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type 7792 or else 7793 (Is_Access_Type (Etype (First_Formal (Hom))) 7794 and then 7795 Ekind (Etype (First_Formal (Hom))) = 7796 E_Anonymous_Access_Type 7797 and then 7798 Base_Type 7799 (Designated_Type (Etype (First_Formal (Hom)))) = 7800 Cls_Type)) 7801 then 7802 -- If the context is a procedure call, ignore functions 7803 -- in the name of the call. 7804 7805 if Ekind (Hom) = E_Function 7806 and then Nkind (Parent (N)) = N_Procedure_Call_Statement 7807 and then N = Name (Parent (N)) 7808 then 7809 goto Next_Hom; 7810 7811 -- If the context is a function call, ignore procedures 7812 -- in the name of the call. 7813 7814 elsif Ekind (Hom) = E_Procedure 7815 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement 7816 then 7817 goto Next_Hom; 7818 end if; 7819 7820 Set_Etype (Call_Node, Any_Type); 7821 Set_Is_Overloaded (Call_Node, False); 7822 Success := False; 7823 7824 if No (Matching_Op) then 7825 Hom_Ref := New_Occurrence_Of (Hom, Sloc (Subprog)); 7826 Set_Etype (Call_Node, Any_Type); 7827 Set_Parent (Call_Node, Parent (Node_To_Replace)); 7828 7829 Set_Name (Call_Node, Hom_Ref); 7830 7831 Analyze_One_Call 7832 (N => Call_Node, 7833 Nam => Hom, 7834 Report => Report_Error, 7835 Success => Success, 7836 Skip_First => True); 7837 7838 Matching_Op := 7839 Valid_Candidate (Success, Call_Node, Hom); 7840 7841 else 7842 Analyze_One_Call 7843 (N => Call_Node, 7844 Nam => Hom, 7845 Report => Report_Error, 7846 Success => Success, 7847 Skip_First => True); 7848 7849 if Present (Valid_Candidate (Success, Call_Node, Hom)) 7850 and then Nkind (Call_Node) /= N_Function_Call 7851 then 7852 Error_Msg_NE ("ambiguous call to&", N, Hom); 7853 Report_Ambiguity (Matching_Op); 7854 Report_Ambiguity (Hom); 7855 Error := True; 7856 return; 7857 end if; 7858 end if; 7859 end if; 7860 7861 <<Next_Hom>> 7862 Hom := Homonym (Hom); 7863 end loop; 7864 end Traverse_Homonyms; 7865 7866 ------------------------- 7867 -- Traverse_Interfaces -- 7868 ------------------------- 7869 7870 procedure Traverse_Interfaces 7871 (Anc_Type : Entity_Id; 7872 Error : out Boolean) 7873 is 7874 Intface_List : constant List_Id := 7875 Abstract_Interface_List (Anc_Type); 7876 Intface : Node_Id; 7877 7878 begin 7879 Error := False; 7880 7881 if Is_Non_Empty_List (Intface_List) then 7882 Intface := First (Intface_List); 7883 while Present (Intface) loop 7884 7885 -- Look for acceptable class-wide homonyms associated with 7886 -- the interface. 7887 7888 Traverse_Homonyms (Etype (Intface), Error); 7889 7890 if Error then 7891 return; 7892 end if; 7893 7894 -- Continue the search by looking at each of the interface's 7895 -- associated interface ancestors. 7896 7897 Traverse_Interfaces (Etype (Intface), Error); 7898 7899 if Error then 7900 return; 7901 end if; 7902 7903 Next (Intface); 7904 end loop; 7905 end if; 7906 end Traverse_Interfaces; 7907 7908 -- Start of processing for Try_Class_Wide_Operation 7909 7910 begin 7911 -- If we are searching only for conflicting class-wide subprograms 7912 -- then initialize directly Matching_Op with the target entity. 7913 7914 if CW_Test_Only then 7915 Matching_Op := Entity (Selector_Name (N)); 7916 end if; 7917 7918 -- Loop through ancestor types (including interfaces), traversing 7919 -- the homonym chain of the subprogram, trying out those homonyms 7920 -- whose first formal has the class-wide type of the ancestor, or 7921 -- an anonymous access type designating the class-wide type. 7922 7923 Anc_Type := Obj_Type; 7924 loop 7925 -- Look for a match among homonyms associated with the ancestor 7926 7927 Traverse_Homonyms (Anc_Type, Error); 7928 7929 if Error then 7930 return True; 7931 end if; 7932 7933 -- Continue the search for matches among homonyms associated with 7934 -- any interfaces implemented by the ancestor. 7935 7936 Traverse_Interfaces (Anc_Type, Error); 7937 7938 if Error then 7939 return True; 7940 end if; 7941 7942 exit when Etype (Anc_Type) = Anc_Type; 7943 Anc_Type := Etype (Anc_Type); 7944 end loop; 7945 7946 if Present (Matching_Op) then 7947 Set_Etype (Call_Node, Etype (Matching_Op)); 7948 end if; 7949 7950 return Present (Matching_Op); 7951 end Try_Class_Wide_Operation; 7952 7953 ----------------------------------- 7954 -- Try_One_Prefix_Interpretation -- 7955 ----------------------------------- 7956 7957 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is 7958 begin 7959 Obj_Type := T; 7960 7961 if Is_Access_Type (Obj_Type) then 7962 Obj_Type := Designated_Type (Obj_Type); 7963 end if; 7964 7965 if Ekind (Obj_Type) = E_Private_Subtype then 7966 Obj_Type := Base_Type (Obj_Type); 7967 end if; 7968 7969 if Is_Class_Wide_Type (Obj_Type) then 7970 Obj_Type := Etype (Class_Wide_Type (Obj_Type)); 7971 end if; 7972 7973 -- The type may have be obtained through a limited_with clause, 7974 -- in which case the primitive operations are available on its 7975 -- non-limited view. If still incomplete, retrieve full view. 7976 7977 if Ekind (Obj_Type) = E_Incomplete_Type 7978 and then From_Limited_With (Obj_Type) 7979 then 7980 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type)); 7981 end if; 7982 7983 -- If the object is not tagged, or the type is still an incomplete 7984 -- type, this is not a prefixed call. 7985 7986 if not Is_Tagged_Type (Obj_Type) 7987 or else Is_Incomplete_Type (Obj_Type) 7988 then 7989 return; 7990 end if; 7991 7992 declare 7993 Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node); 7994 CW_Result : Boolean; 7995 Prim_Result : Boolean; 7996 pragma Unreferenced (CW_Result); 7997 7998 begin 7999 if not CW_Test_Only then 8000 Prim_Result := 8001 Try_Primitive_Operation 8002 (Call_Node => New_Call_Node, 8003 Node_To_Replace => Node_To_Replace); 8004 end if; 8005 8006 -- Check if there is a class-wide subprogram covering the 8007 -- primitive. This check must be done even if a candidate 8008 -- was found in order to report ambiguous calls. 8009 8010 if not (Prim_Result) then 8011 CW_Result := 8012 Try_Class_Wide_Operation 8013 (Call_Node => New_Call_Node, 8014 Node_To_Replace => Node_To_Replace); 8015 8016 -- If we found a primitive we search for class-wide subprograms 8017 -- using a duplicate of the call node (done to avoid missing its 8018 -- decoration if there is no ambiguity). 8019 8020 else 8021 CW_Result := 8022 Try_Class_Wide_Operation 8023 (Call_Node => Dup_Call_Node, 8024 Node_To_Replace => Node_To_Replace); 8025 end if; 8026 end; 8027 end Try_One_Prefix_Interpretation; 8028 8029 ----------------------------- 8030 -- Try_Primitive_Operation -- 8031 ----------------------------- 8032 8033 function Try_Primitive_Operation 8034 (Call_Node : Node_Id; 8035 Node_To_Replace : Node_Id) return Boolean 8036 is 8037 Elmt : Elmt_Id; 8038 Prim_Op : Entity_Id; 8039 Matching_Op : Entity_Id := Empty; 8040 Prim_Op_Ref : Node_Id := Empty; 8041 8042 Corr_Type : Entity_Id := Empty; 8043 -- If the prefix is a synchronized type, the controlling type of 8044 -- the primitive operation is the corresponding record type, else 8045 -- this is the object type itself. 8046 8047 Success : Boolean := False; 8048 8049 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id; 8050 -- For tagged types the candidate interpretations are found in 8051 -- the list of primitive operations of the type and its ancestors. 8052 -- For formal tagged types we have to find the operations declared 8053 -- in the same scope as the type (including in the generic formal 8054 -- part) because the type itself carries no primitive operations, 8055 -- except for formal derived types that inherit the operations of 8056 -- the parent and progenitors. 8057 -- 8058 -- If the context is a generic subprogram body, the generic formals 8059 -- are visible by name, but are not in the entity list of the 8060 -- subprogram because that list starts with the subprogram formals. 8061 -- We retrieve the candidate operations from the generic declaration. 8062 8063 function Is_Private_Overriding (Op : Entity_Id) return Boolean; 8064 -- An operation that overrides an inherited operation in the private 8065 -- part of its package may be hidden, but if the inherited operation 8066 -- is visible a direct call to it will dispatch to the private one, 8067 -- which is therefore a valid candidate. 8068 8069 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean; 8070 -- Verify that the prefix, dereferenced if need be, is a valid 8071 -- controlling argument in a call to Op. The remaining actuals 8072 -- are checked in the subsequent call to Analyze_One_Call. 8073 8074 ------------------------------ 8075 -- Collect_Generic_Type_Ops -- 8076 ------------------------------ 8077 8078 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is 8079 Bas : constant Entity_Id := Base_Type (T); 8080 Candidates : constant Elist_Id := New_Elmt_List; 8081 Subp : Entity_Id; 8082 Formal : Entity_Id; 8083 8084 procedure Check_Candidate; 8085 -- The operation is a candidate if its first parameter is a 8086 -- controlling operand of the desired type. 8087 8088 ----------------------- 8089 -- Check_Candidate; -- 8090 ----------------------- 8091 8092 procedure Check_Candidate is 8093 begin 8094 Formal := First_Formal (Subp); 8095 8096 if Present (Formal) 8097 and then Is_Controlling_Formal (Formal) 8098 and then 8099 (Base_Type (Etype (Formal)) = Bas 8100 or else 8101 (Is_Access_Type (Etype (Formal)) 8102 and then Designated_Type (Etype (Formal)) = Bas)) 8103 then 8104 Append_Elmt (Subp, Candidates); 8105 end if; 8106 end Check_Candidate; 8107 8108 -- Start of processing for Collect_Generic_Type_Ops 8109 8110 begin 8111 if Is_Derived_Type (T) then 8112 return Primitive_Operations (T); 8113 8114 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then 8115 8116 -- Scan the list of generic formals to find subprograms 8117 -- that may have a first controlling formal of the type. 8118 8119 if Nkind (Unit_Declaration_Node (Scope (T))) = 8120 N_Generic_Subprogram_Declaration 8121 then 8122 declare 8123 Decl : Node_Id; 8124 8125 begin 8126 Decl := 8127 First (Generic_Formal_Declarations 8128 (Unit_Declaration_Node (Scope (T)))); 8129 while Present (Decl) loop 8130 if Nkind (Decl) in N_Formal_Subprogram_Declaration then 8131 Subp := Defining_Entity (Decl); 8132 Check_Candidate; 8133 end if; 8134 8135 Next (Decl); 8136 end loop; 8137 end; 8138 end if; 8139 return Candidates; 8140 8141 else 8142 -- Scan the list of entities declared in the same scope as 8143 -- the type. In general this will be an open scope, given that 8144 -- the call we are analyzing can only appear within a generic 8145 -- declaration or body (either the one that declares T, or a 8146 -- child unit). 8147 8148 -- For a subtype representing a generic actual type, go to the 8149 -- base type. 8150 8151 if Is_Generic_Actual_Type (T) then 8152 Subp := First_Entity (Scope (Base_Type (T))); 8153 else 8154 Subp := First_Entity (Scope (T)); 8155 end if; 8156 8157 while Present (Subp) loop 8158 if Is_Overloadable (Subp) then 8159 Check_Candidate; 8160 end if; 8161 8162 Next_Entity (Subp); 8163 end loop; 8164 8165 return Candidates; 8166 end if; 8167 end Collect_Generic_Type_Ops; 8168 8169 --------------------------- 8170 -- Is_Private_Overriding -- 8171 --------------------------- 8172 8173 function Is_Private_Overriding (Op : Entity_Id) return Boolean is 8174 Visible_Op : constant Entity_Id := Homonym (Op); 8175 8176 begin 8177 return Present (Visible_Op) 8178 and then Scope (Op) = Scope (Visible_Op) 8179 and then not Comes_From_Source (Visible_Op) 8180 and then Alias (Visible_Op) = Op 8181 and then not Is_Hidden (Visible_Op); 8182 end Is_Private_Overriding; 8183 8184 ----------------------------- 8185 -- Valid_First_Argument_Of -- 8186 ----------------------------- 8187 8188 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is 8189 Typ : Entity_Id := Etype (First_Formal (Op)); 8190 8191 begin 8192 if Is_Concurrent_Type (Typ) 8193 and then Present (Corresponding_Record_Type (Typ)) 8194 then 8195 Typ := Corresponding_Record_Type (Typ); 8196 end if; 8197 8198 -- Simple case. Object may be a subtype of the tagged type or 8199 -- may be the corresponding record of a synchronized type. 8200 8201 return Obj_Type = Typ 8202 or else Base_Type (Obj_Type) = Typ 8203 or else Corr_Type = Typ 8204 8205 -- Prefix can be dereferenced 8206 8207 or else 8208 (Is_Access_Type (Corr_Type) 8209 and then Designated_Type (Corr_Type) = Typ) 8210 8211 -- Formal is an access parameter, for which the object 8212 -- can provide an access. 8213 8214 or else 8215 (Ekind (Typ) = E_Anonymous_Access_Type 8216 and then 8217 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type)); 8218 end Valid_First_Argument_Of; 8219 8220 -- Start of processing for Try_Primitive_Operation 8221 8222 begin 8223 -- Look for subprograms in the list of primitive operations. The name 8224 -- must be identical, and the kind of call indicates the expected 8225 -- kind of operation (function or procedure). If the type is a 8226 -- (tagged) synchronized type, the primitive ops are attached to the 8227 -- corresponding record (base) type. 8228 8229 if Is_Concurrent_Type (Obj_Type) then 8230 if Present (Corresponding_Record_Type (Obj_Type)) then 8231 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type)); 8232 Elmt := First_Elmt (Primitive_Operations (Corr_Type)); 8233 else 8234 Corr_Type := Obj_Type; 8235 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type)); 8236 end if; 8237 8238 elsif not Is_Generic_Type (Obj_Type) then 8239 Corr_Type := Obj_Type; 8240 Elmt := First_Elmt (Primitive_Operations (Obj_Type)); 8241 8242 else 8243 Corr_Type := Obj_Type; 8244 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type)); 8245 end if; 8246 8247 while Present (Elmt) loop 8248 Prim_Op := Node (Elmt); 8249 8250 if Chars (Prim_Op) = Chars (Subprog) 8251 and then Present (First_Formal (Prim_Op)) 8252 and then Valid_First_Argument_Of (Prim_Op) 8253 and then 8254 (Nkind (Call_Node) = N_Function_Call) 8255 = 8256 (Ekind (Prim_Op) = E_Function) 8257 then 8258 -- Ada 2005 (AI-251): If this primitive operation corresponds 8259 -- to an immediate ancestor interface there is no need to add 8260 -- it to the list of interpretations; the corresponding aliased 8261 -- primitive is also in this list of primitive operations and 8262 -- will be used instead. 8263 8264 if (Present (Interface_Alias (Prim_Op)) 8265 and then Is_Ancestor (Find_Dispatching_Type 8266 (Alias (Prim_Op)), Corr_Type)) 8267 8268 -- Do not consider hidden primitives unless the type is in an 8269 -- open scope or we are within an instance, where visibility 8270 -- is known to be correct, or else if this is an overriding 8271 -- operation in the private part for an inherited operation. 8272 8273 or else (Is_Hidden (Prim_Op) 8274 and then not Is_Immediately_Visible (Obj_Type) 8275 and then not In_Instance 8276 and then not Is_Private_Overriding (Prim_Op)) 8277 then 8278 goto Continue; 8279 end if; 8280 8281 Set_Etype (Call_Node, Any_Type); 8282 Set_Is_Overloaded (Call_Node, False); 8283 8284 if No (Matching_Op) then 8285 Prim_Op_Ref := New_Occurrence_Of (Prim_Op, Sloc (Subprog)); 8286 Candidate := Prim_Op; 8287 8288 Set_Parent (Call_Node, Parent (Node_To_Replace)); 8289 8290 Set_Name (Call_Node, Prim_Op_Ref); 8291 Success := False; 8292 8293 Analyze_One_Call 8294 (N => Call_Node, 8295 Nam => Prim_Op, 8296 Report => Report_Error, 8297 Success => Success, 8298 Skip_First => True); 8299 8300 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op); 8301 8302 -- More than one interpretation, collect for subsequent 8303 -- disambiguation. If this is a procedure call and there 8304 -- is another match, report ambiguity now. 8305 8306 else 8307 Analyze_One_Call 8308 (N => Call_Node, 8309 Nam => Prim_Op, 8310 Report => Report_Error, 8311 Success => Success, 8312 Skip_First => True); 8313 8314 if Present (Valid_Candidate (Success, Call_Node, Prim_Op)) 8315 and then Nkind (Call_Node) /= N_Function_Call 8316 then 8317 Error_Msg_NE ("ambiguous call to&", N, Prim_Op); 8318 Report_Ambiguity (Matching_Op); 8319 Report_Ambiguity (Prim_Op); 8320 return True; 8321 end if; 8322 end if; 8323 end if; 8324 8325 <<Continue>> 8326 Next_Elmt (Elmt); 8327 end loop; 8328 8329 if Present (Matching_Op) then 8330 Set_Etype (Call_Node, Etype (Matching_Op)); 8331 end if; 8332 8333 return Present (Matching_Op); 8334 end Try_Primitive_Operation; 8335 8336 -- Start of processing for Try_Object_Operation 8337 8338 begin 8339 Analyze_Expression (Obj); 8340 8341 -- Analyze the actuals if node is known to be a subprogram call 8342 8343 if Is_Subprg_Call and then N = Name (Parent (N)) then 8344 Actual := First (Parameter_Associations (Parent (N))); 8345 while Present (Actual) loop 8346 Analyze_Expression (Actual); 8347 Next (Actual); 8348 end loop; 8349 end if; 8350 8351 -- Build a subprogram call node, using a copy of Obj as its first 8352 -- actual. This is a placeholder, to be replaced by an explicit 8353 -- dereference when needed. 8354 8355 Transform_Object_Operation 8356 (Call_Node => New_Call_Node, 8357 Node_To_Replace => Node_To_Replace); 8358 8359 Set_Etype (New_Call_Node, Any_Type); 8360 Set_Etype (Subprog, Any_Type); 8361 Set_Parent (New_Call_Node, Parent (Node_To_Replace)); 8362 8363 if not Is_Overloaded (Obj) then 8364 Try_One_Prefix_Interpretation (Obj_Type); 8365 8366 else 8367 declare 8368 I : Interp_Index; 8369 It : Interp; 8370 begin 8371 Get_First_Interp (Obj, I, It); 8372 while Present (It.Nam) loop 8373 Try_One_Prefix_Interpretation (It.Typ); 8374 Get_Next_Interp (I, It); 8375 end loop; 8376 end; 8377 end if; 8378 8379 if Etype (New_Call_Node) /= Any_Type then 8380 8381 -- No need to complete the tree transformations if we are only 8382 -- searching for conflicting class-wide subprograms 8383 8384 if CW_Test_Only then 8385 return False; 8386 else 8387 Complete_Object_Operation 8388 (Call_Node => New_Call_Node, 8389 Node_To_Replace => Node_To_Replace); 8390 return True; 8391 end if; 8392 8393 elsif Present (Candidate) then 8394 8395 -- The argument list is not type correct. Re-analyze with error 8396 -- reporting enabled, and use one of the possible candidates. 8397 -- In All_Errors_Mode, re-analyze all failed interpretations. 8398 8399 if All_Errors_Mode then 8400 Report_Error := True; 8401 if Try_Primitive_Operation 8402 (Call_Node => New_Call_Node, 8403 Node_To_Replace => Node_To_Replace) 8404 8405 or else 8406 Try_Class_Wide_Operation 8407 (Call_Node => New_Call_Node, 8408 Node_To_Replace => Node_To_Replace) 8409 then 8410 null; 8411 end if; 8412 8413 else 8414 Analyze_One_Call 8415 (N => New_Call_Node, 8416 Nam => Candidate, 8417 Report => True, 8418 Success => Success, 8419 Skip_First => True); 8420 end if; 8421 8422 -- No need for further errors 8423 8424 return True; 8425 8426 else 8427 -- There was no candidate operation, so report it as an error 8428 -- in the caller: Analyze_Selected_Component. 8429 8430 return False; 8431 end if; 8432 end Try_Object_Operation; 8433 8434 --------- 8435 -- wpo -- 8436 --------- 8437 8438 procedure wpo (T : Entity_Id) is 8439 Op : Entity_Id; 8440 E : Elmt_Id; 8441 8442 begin 8443 if not Is_Tagged_Type (T) then 8444 return; 8445 end if; 8446 8447 E := First_Elmt (Primitive_Operations (Base_Type (T))); 8448 while Present (E) loop 8449 Op := Node (E); 8450 Write_Int (Int (Op)); 8451 Write_Str (" === "); 8452 Write_Name (Chars (Op)); 8453 Write_Str (" in "); 8454 Write_Name (Chars (Scope (Op))); 8455 Next_Elmt (E); 8456 Write_Eol; 8457 end loop; 8458 end wpo; 8459 8460end Sem_Ch4; 8461