1/* Process declarations and variables for C compiler. 2 Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 3 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2002110-1301, USA. */ 21 22/* $FreeBSD$ */ 23/* Merged C99 inline changes from gcc trunk 122565 2007-03-05 */ 24/* Fixed problems with compiling inline-25.c and inline-26.c */ 25/* XXX still fails inline-29.c, inline-31.c, and inline-32.c */ 26 27/* Process declarations and symbol lookup for C front end. 28 Also constructs types; the standard scalar types at initialization, 29 and structure, union, array and enum types when they are declared. */ 30 31/* ??? not all decl nodes are given the most useful possible 32 line numbers. For example, the CONST_DECLs for enum values. */ 33 34#include "config.h" 35#include "system.h" 36#include "coretypes.h" 37#include "input.h" 38#include "tm.h" 39#include "intl.h" 40#include "tree.h" 41#include "tree-inline.h" 42#include "rtl.h" 43#include "flags.h" 44#include "function.h" 45#include "output.h" 46#include "expr.h" 47#include "c-tree.h" 48#include "toplev.h" 49#include "ggc.h" 50#include "tm_p.h" 51#include "cpplib.h" 52#include "target.h" 53#include "debug.h" 54#include "opts.h" 55#include "timevar.h" 56#include "c-common.h" 57#include "c-pragma.h" 58#include "langhooks.h" 59#include "tree-mudflap.h" 60#include "tree-gimple.h" 61#include "diagnostic.h" 62#include "tree-dump.h" 63#include "cgraph.h" 64#include "hashtab.h" 65#include "libfuncs.h" 66#include "except.h" 67#include "langhooks-def.h" 68#include "pointer-set.h" 69 70/* In grokdeclarator, distinguish syntactic contexts of declarators. */ 71enum decl_context 72{ NORMAL, /* Ordinary declaration */ 73 FUNCDEF, /* Function definition */ 74 PARM, /* Declaration of parm before function body */ 75 FIELD, /* Declaration inside struct or union */ 76 TYPENAME}; /* Typename (inside cast or sizeof) */ 77 78 79/* Nonzero if we have seen an invalid cross reference 80 to a struct, union, or enum, but not yet printed the message. */ 81tree pending_invalid_xref; 82 83/* File and line to appear in the eventual error message. */ 84location_t pending_invalid_xref_location; 85 86/* True means we've initialized exception handling. */ 87bool c_eh_initialized_p; 88 89/* While defining an enum type, this is 1 plus the last enumerator 90 constant value. Note that will do not have to save this or `enum_overflow' 91 around nested function definition since such a definition could only 92 occur in an enum value expression and we don't use these variables in 93 that case. */ 94 95static tree enum_next_value; 96 97/* Nonzero means that there was overflow computing enum_next_value. */ 98 99static int enum_overflow; 100 101/* The file and line that the prototype came from if this is an 102 old-style definition; used for diagnostics in 103 store_parm_decls_oldstyle. */ 104 105static location_t current_function_prototype_locus; 106 107/* Whether this prototype was built-in. */ 108 109static bool current_function_prototype_built_in; 110 111/* The argument type information of this prototype. */ 112 113static tree current_function_prototype_arg_types; 114 115/* The argument information structure for the function currently being 116 defined. */ 117 118static struct c_arg_info *current_function_arg_info; 119 120/* The obstack on which parser and related data structures, which are 121 not live beyond their top-level declaration or definition, are 122 allocated. */ 123struct obstack parser_obstack; 124 125/* The current statement tree. */ 126 127static GTY(()) struct stmt_tree_s c_stmt_tree; 128 129/* State saving variables. */ 130tree c_break_label; 131tree c_cont_label; 132 133/* Linked list of TRANSLATION_UNIT_DECLS for the translation units 134 included in this invocation. Note that the current translation 135 unit is not included in this list. */ 136 137static GTY(()) tree all_translation_units; 138 139/* A list of decls to be made automatically visible in each file scope. */ 140static GTY(()) tree visible_builtins; 141 142/* Set to 0 at beginning of a function definition, set to 1 if 143 a return statement that specifies a return value is seen. */ 144 145int current_function_returns_value; 146 147/* Set to 0 at beginning of a function definition, set to 1 if 148 a return statement with no argument is seen. */ 149 150int current_function_returns_null; 151 152/* Set to 0 at beginning of a function definition, set to 1 if 153 a call to a noreturn function is seen. */ 154 155int current_function_returns_abnormally; 156 157/* Set to nonzero by `grokdeclarator' for a function 158 whose return type is defaulted, if warnings for this are desired. */ 159 160static int warn_about_return_type; 161 162/* Nonzero when the current toplevel function contains a declaration 163 of a nested function which is never defined. */ 164 165static bool undef_nested_function; 166 167/* True means global_bindings_p should return false even if the scope stack 168 says we are in file scope. */ 169bool c_override_global_bindings_to_false; 170 171 172/* Each c_binding structure describes one binding of an identifier to 173 a decl. All the decls in a scope - irrespective of namespace - are 174 chained together by the ->prev field, which (as the name implies) 175 runs in reverse order. All the decls in a given namespace bound to 176 a given identifier are chained by the ->shadowed field, which runs 177 from inner to outer scopes. 178 179 The ->decl field usually points to a DECL node, but there are two 180 exceptions. In the namespace of type tags, the bound entity is a 181 RECORD_TYPE, UNION_TYPE, or ENUMERAL_TYPE node. If an undeclared 182 identifier is encountered, it is bound to error_mark_node to 183 suppress further errors about that identifier in the current 184 function. 185 186 The ->type field stores the type of the declaration in this scope; 187 if NULL, the type is the type of the ->decl field. This is only of 188 relevance for objects with external or internal linkage which may 189 be redeclared in inner scopes, forming composite types that only 190 persist for the duration of those scopes. In the external scope, 191 this stores the composite of all the types declared for this 192 object, visible or not. The ->inner_comp field (used only at file 193 scope) stores whether an incomplete array type at file scope was 194 completed at an inner scope to an array size other than 1. 195 196 The depth field is copied from the scope structure that holds this 197 decl. It is used to preserve the proper ordering of the ->shadowed 198 field (see bind()) and also for a handful of special-case checks. 199 Finally, the invisible bit is true for a decl which should be 200 ignored for purposes of normal name lookup, and the nested bit is 201 true for a decl that's been bound a second time in an inner scope; 202 in all such cases, the binding in the outer scope will have its 203 invisible bit true. */ 204 205struct c_binding GTY((chain_next ("%h.prev"))) 206{ 207 tree decl; /* the decl bound */ 208 tree type; /* the type in this scope */ 209 tree id; /* the identifier it's bound to */ 210 struct c_binding *prev; /* the previous decl in this scope */ 211 struct c_binding *shadowed; /* the innermost decl shadowed by this one */ 212 unsigned int depth : 28; /* depth of this scope */ 213 BOOL_BITFIELD invisible : 1; /* normal lookup should ignore this binding */ 214 BOOL_BITFIELD nested : 1; /* do not set DECL_CONTEXT when popping */ 215 BOOL_BITFIELD inner_comp : 1; /* incomplete array completed in inner scope */ 216 /* one free bit */ 217}; 218#define B_IN_SCOPE(b1, b2) ((b1)->depth == (b2)->depth) 219#define B_IN_CURRENT_SCOPE(b) ((b)->depth == current_scope->depth) 220#define B_IN_FILE_SCOPE(b) ((b)->depth == 1 /*file_scope->depth*/) 221#define B_IN_EXTERNAL_SCOPE(b) ((b)->depth == 0 /*external_scope->depth*/) 222 223#define I_SYMBOL_BINDING(node) \ 224 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->symbol_binding) 225#define I_SYMBOL_DECL(node) \ 226 (I_SYMBOL_BINDING(node) ? I_SYMBOL_BINDING(node)->decl : 0) 227 228#define I_TAG_BINDING(node) \ 229 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->tag_binding) 230#define I_TAG_DECL(node) \ 231 (I_TAG_BINDING(node) ? I_TAG_BINDING(node)->decl : 0) 232 233#define I_LABEL_BINDING(node) \ 234 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->label_binding) 235#define I_LABEL_DECL(node) \ 236 (I_LABEL_BINDING(node) ? I_LABEL_BINDING(node)->decl : 0) 237 238/* Each C symbol points to three linked lists of c_binding structures. 239 These describe the values of the identifier in the three different 240 namespaces defined by the language. */ 241 242struct lang_identifier GTY(()) 243{ 244 struct c_common_identifier common_id; 245 struct c_binding *symbol_binding; /* vars, funcs, constants, typedefs */ 246 struct c_binding *tag_binding; /* struct/union/enum tags */ 247 struct c_binding *label_binding; /* labels */ 248}; 249 250/* Validate c-lang.c's assumptions. */ 251extern char C_SIZEOF_STRUCT_LANG_IDENTIFIER_isnt_accurate 252[(sizeof(struct lang_identifier) == C_SIZEOF_STRUCT_LANG_IDENTIFIER) ? 1 : -1]; 253 254/* The resulting tree type. */ 255 256union lang_tree_node 257 GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"), 258 chain_next ("TREE_CODE (&%h.generic) == INTEGER_TYPE ? (union lang_tree_node *) TYPE_NEXT_VARIANT (&%h.generic) : (union lang_tree_node *) TREE_CHAIN (&%h.generic)"))) 259{ 260 union tree_node GTY ((tag ("0"), 261 desc ("tree_node_structure (&%h)"))) 262 generic; 263 struct lang_identifier GTY ((tag ("1"))) identifier; 264}; 265 266/* Each c_scope structure describes the complete contents of one 267 scope. Four scopes are distinguished specially: the innermost or 268 current scope, the innermost function scope, the file scope (always 269 the second to outermost) and the outermost or external scope. 270 271 Most declarations are recorded in the current scope. 272 273 All normal label declarations are recorded in the innermost 274 function scope, as are bindings of undeclared identifiers to 275 error_mark_node. (GCC permits nested functions as an extension, 276 hence the 'innermost' qualifier.) Explicitly declared labels 277 (using the __label__ extension) appear in the current scope. 278 279 Being in the file scope (current_scope == file_scope) causes 280 special behavior in several places below. Also, under some 281 conditions the Objective-C front end records declarations in the 282 file scope even though that isn't the current scope. 283 284 All declarations with external linkage are recorded in the external 285 scope, even if they aren't visible there; this models the fact that 286 such declarations are visible to the entire program, and (with a 287 bit of cleverness, see pushdecl) allows diagnosis of some violations 288 of C99 6.2.2p7 and 6.2.7p2: 289 290 If, within the same translation unit, the same identifier appears 291 with both internal and external linkage, the behavior is 292 undefined. 293 294 All declarations that refer to the same object or function shall 295 have compatible type; otherwise, the behavior is undefined. 296 297 Initially only the built-in declarations, which describe compiler 298 intrinsic functions plus a subset of the standard library, are in 299 this scope. 300 301 The order of the blocks list matters, and it is frequently appended 302 to. To avoid having to walk all the way to the end of the list on 303 each insertion, or reverse the list later, we maintain a pointer to 304 the last list entry. (FIXME: It should be feasible to use a reversed 305 list here.) 306 307 The bindings list is strictly in reverse order of declarations; 308 pop_scope relies on this. */ 309 310 311struct c_scope GTY((chain_next ("%h.outer"))) 312{ 313 /* The scope containing this one. */ 314 struct c_scope *outer; 315 316 /* The next outermost function scope. */ 317 struct c_scope *outer_function; 318 319 /* All bindings in this scope. */ 320 struct c_binding *bindings; 321 322 /* For each scope (except the global one), a chain of BLOCK nodes 323 for all the scopes that were entered and exited one level down. */ 324 tree blocks; 325 tree blocks_last; 326 327 /* The depth of this scope. Used to keep the ->shadowed chain of 328 bindings sorted innermost to outermost. */ 329 unsigned int depth : 28; 330 331 /* True if we are currently filling this scope with parameter 332 declarations. */ 333 BOOL_BITFIELD parm_flag : 1; 334 335 /* True if we saw [*] in this scope. Used to give an error messages 336 if these appears in a function definition. */ 337 BOOL_BITFIELD had_vla_unspec : 1; 338 339 /* True if we already complained about forward parameter decls 340 in this scope. This prevents double warnings on 341 foo (int a; int b; ...) */ 342 BOOL_BITFIELD warned_forward_parm_decls : 1; 343 344 /* True if this is the outermost block scope of a function body. 345 This scope contains the parameters, the local variables declared 346 in the outermost block, and all the labels (except those in 347 nested functions, or declared at block scope with __label__). */ 348 BOOL_BITFIELD function_body : 1; 349 350 /* True means make a BLOCK for this scope no matter what. */ 351 BOOL_BITFIELD keep : 1; 352}; 353 354/* The scope currently in effect. */ 355 356static GTY(()) struct c_scope *current_scope; 357 358/* The innermost function scope. Ordinary (not explicitly declared) 359 labels, bindings to error_mark_node, and the lazily-created 360 bindings of __func__ and its friends get this scope. */ 361 362static GTY(()) struct c_scope *current_function_scope; 363 364/* The C file scope. This is reset for each input translation unit. */ 365 366static GTY(()) struct c_scope *file_scope; 367 368/* The outermost scope. This is used for all declarations with 369 external linkage, and only these, hence the name. */ 370 371static GTY(()) struct c_scope *external_scope; 372 373/* A chain of c_scope structures awaiting reuse. */ 374 375static GTY((deletable)) struct c_scope *scope_freelist; 376 377/* A chain of c_binding structures awaiting reuse. */ 378 379static GTY((deletable)) struct c_binding *binding_freelist; 380 381/* Append VAR to LIST in scope SCOPE. */ 382#define SCOPE_LIST_APPEND(scope, list, decl) do { \ 383 struct c_scope *s_ = (scope); \ 384 tree d_ = (decl); \ 385 if (s_->list##_last) \ 386 TREE_CHAIN (s_->list##_last) = d_; \ 387 else \ 388 s_->list = d_; \ 389 s_->list##_last = d_; \ 390} while (0) 391 392/* Concatenate FROM in scope FSCOPE onto TO in scope TSCOPE. */ 393#define SCOPE_LIST_CONCAT(tscope, to, fscope, from) do { \ 394 struct c_scope *t_ = (tscope); \ 395 struct c_scope *f_ = (fscope); \ 396 if (t_->to##_last) \ 397 TREE_CHAIN (t_->to##_last) = f_->from; \ 398 else \ 399 t_->to = f_->from; \ 400 t_->to##_last = f_->from##_last; \ 401} while (0) 402 403/* True means unconditionally make a BLOCK for the next scope pushed. */ 404 405static bool keep_next_level_flag; 406 407/* True means the next call to push_scope will be the outermost scope 408 of a function body, so do not push a new scope, merely cease 409 expecting parameter decls. */ 410 411static bool next_is_function_body; 412 413/* Functions called automatically at the beginning and end of execution. */ 414 415static GTY(()) tree static_ctors; 416static GTY(()) tree static_dtors; 417 418/* Forward declarations. */ 419static tree lookup_name_in_scope (tree, struct c_scope *); 420static tree c_make_fname_decl (tree, int); 421static tree grokdeclarator (const struct c_declarator *, 422 struct c_declspecs *, 423 enum decl_context, bool, tree *); 424static tree grokparms (struct c_arg_info *, bool); 425static void layout_array_type (tree); 426 427/* T is a statement. Add it to the statement-tree. This is the 428 C/ObjC version--C++ has a slightly different version of this 429 function. */ 430 431tree 432add_stmt (tree t) 433{ 434 enum tree_code code = TREE_CODE (t); 435 436 if (EXPR_P (t) && code != LABEL_EXPR) 437 { 438 if (!EXPR_HAS_LOCATION (t)) 439 SET_EXPR_LOCATION (t, input_location); 440 } 441 442 if (code == LABEL_EXPR || code == CASE_LABEL_EXPR) 443 STATEMENT_LIST_HAS_LABEL (cur_stmt_list) = 1; 444 445 /* Add T to the statement-tree. Non-side-effect statements need to be 446 recorded during statement expressions. */ 447 append_to_statement_list_force (t, &cur_stmt_list); 448 449 return t; 450} 451 452/* States indicating how grokdeclarator() should handle declspecs marked 453 with __attribute__((deprecated)). An object declared as 454 __attribute__((deprecated)) suppresses warnings of uses of other 455 deprecated items. */ 456 457enum deprecated_states { 458 DEPRECATED_NORMAL, 459 DEPRECATED_SUPPRESS 460}; 461 462static enum deprecated_states deprecated_state = DEPRECATED_NORMAL; 463 464void 465c_print_identifier (FILE *file, tree node, int indent) 466{ 467 print_node (file, "symbol", I_SYMBOL_DECL (node), indent + 4); 468 print_node (file, "tag", I_TAG_DECL (node), indent + 4); 469 print_node (file, "label", I_LABEL_DECL (node), indent + 4); 470 if (C_IS_RESERVED_WORD (node)) 471 { 472 tree rid = ridpointers[C_RID_CODE (node)]; 473 indent_to (file, indent + 4); 474 fprintf (file, "rid %p \"%s\"", 475 (void *) rid, IDENTIFIER_POINTER (rid)); 476 } 477} 478 479/* Establish a binding between NAME, an IDENTIFIER_NODE, and DECL, 480 which may be any of several kinds of DECL or TYPE or error_mark_node, 481 in the scope SCOPE. */ 482static void 483bind (tree name, tree decl, struct c_scope *scope, bool invisible, bool nested) 484{ 485 struct c_binding *b, **here; 486 487 if (binding_freelist) 488 { 489 b = binding_freelist; 490 binding_freelist = b->prev; 491 } 492 else 493 b = GGC_NEW (struct c_binding); 494 495 b->shadowed = 0; 496 b->decl = decl; 497 b->id = name; 498 b->depth = scope->depth; 499 b->invisible = invisible; 500 b->nested = nested; 501 b->inner_comp = 0; 502 503 b->type = 0; 504 505 b->prev = scope->bindings; 506 scope->bindings = b; 507 508 if (!name) 509 return; 510 511 switch (TREE_CODE (decl)) 512 { 513 case LABEL_DECL: here = &I_LABEL_BINDING (name); break; 514 case ENUMERAL_TYPE: 515 case UNION_TYPE: 516 case RECORD_TYPE: here = &I_TAG_BINDING (name); break; 517 case VAR_DECL: 518 case FUNCTION_DECL: 519 case TYPE_DECL: 520 case CONST_DECL: 521 case PARM_DECL: 522 case ERROR_MARK: here = &I_SYMBOL_BINDING (name); break; 523 524 default: 525 gcc_unreachable (); 526 } 527 528 /* Locate the appropriate place in the chain of shadowed decls 529 to insert this binding. Normally, scope == current_scope and 530 this does nothing. */ 531 while (*here && (*here)->depth > scope->depth) 532 here = &(*here)->shadowed; 533 534 b->shadowed = *here; 535 *here = b; 536} 537 538/* Clear the binding structure B, stick it on the binding_freelist, 539 and return the former value of b->prev. This is used by pop_scope 540 and get_parm_info to iterate destructively over all the bindings 541 from a given scope. */ 542static struct c_binding * 543free_binding_and_advance (struct c_binding *b) 544{ 545 struct c_binding *prev = b->prev; 546 547 memset (b, 0, sizeof (struct c_binding)); 548 b->prev = binding_freelist; 549 binding_freelist = b; 550 551 return prev; 552} 553 554 555/* Hook called at end of compilation to assume 1 elt 556 for a file-scope tentative array defn that wasn't complete before. */ 557 558void 559c_finish_incomplete_decl (tree decl) 560{ 561 if (TREE_CODE (decl) == VAR_DECL) 562 { 563 tree type = TREE_TYPE (decl); 564 if (type != error_mark_node 565 && TREE_CODE (type) == ARRAY_TYPE 566 && !DECL_EXTERNAL (decl) 567 && TYPE_DOMAIN (type) == 0) 568 { 569 warning (0, "array %q+D assumed to have one element", decl); 570 571 complete_array_type (&TREE_TYPE (decl), NULL_TREE, true); 572 573 layout_decl (decl, 0); 574 } 575 } 576} 577 578/* The Objective-C front-end often needs to determine the current scope. */ 579 580void * 581objc_get_current_scope (void) 582{ 583 return current_scope; 584} 585 586/* The following function is used only by Objective-C. It needs to live here 587 because it accesses the innards of c_scope. */ 588 589void 590objc_mark_locals_volatile (void *enclosing_blk) 591{ 592 struct c_scope *scope; 593 struct c_binding *b; 594 595 for (scope = current_scope; 596 scope && scope != enclosing_blk; 597 scope = scope->outer) 598 { 599 for (b = scope->bindings; b; b = b->prev) 600 objc_volatilize_decl (b->decl); 601 602 /* Do not climb up past the current function. */ 603 if (scope->function_body) 604 break; 605 } 606} 607 608/* Nonzero if we are currently in file scope. */ 609 610int 611global_bindings_p (void) 612{ 613 return current_scope == file_scope && !c_override_global_bindings_to_false; 614} 615 616void 617keep_next_level (void) 618{ 619 keep_next_level_flag = true; 620} 621 622/* Identify this scope as currently being filled with parameters. */ 623 624void 625declare_parm_level (void) 626{ 627 current_scope->parm_flag = true; 628} 629 630void 631push_scope (void) 632{ 633 if (next_is_function_body) 634 { 635 /* This is the transition from the parameters to the top level 636 of the function body. These are the same scope 637 (C99 6.2.1p4,6) so we do not push another scope structure. 638 next_is_function_body is set only by store_parm_decls, which 639 in turn is called when and only when we are about to 640 encounter the opening curly brace for the function body. 641 642 The outermost block of a function always gets a BLOCK node, 643 because the debugging output routines expect that each 644 function has at least one BLOCK. */ 645 current_scope->parm_flag = false; 646 current_scope->function_body = true; 647 current_scope->keep = true; 648 current_scope->outer_function = current_function_scope; 649 current_function_scope = current_scope; 650 651 keep_next_level_flag = false; 652 next_is_function_body = false; 653 } 654 else 655 { 656 struct c_scope *scope; 657 if (scope_freelist) 658 { 659 scope = scope_freelist; 660 scope_freelist = scope->outer; 661 } 662 else 663 scope = GGC_CNEW (struct c_scope); 664 665 scope->keep = keep_next_level_flag; 666 scope->outer = current_scope; 667 scope->depth = current_scope ? (current_scope->depth + 1) : 0; 668 669 /* Check for scope depth overflow. Unlikely (2^28 == 268,435,456) but 670 possible. */ 671 if (current_scope && scope->depth == 0) 672 { 673 scope->depth--; 674 sorry ("GCC supports only %u nested scopes", scope->depth); 675 } 676 677 current_scope = scope; 678 keep_next_level_flag = false; 679 } 680} 681 682/* Set the TYPE_CONTEXT of all of TYPE's variants to CONTEXT. */ 683 684static void 685set_type_context (tree type, tree context) 686{ 687 for (type = TYPE_MAIN_VARIANT (type); type; 688 type = TYPE_NEXT_VARIANT (type)) 689 TYPE_CONTEXT (type) = context; 690} 691 692/* Exit a scope. Restore the state of the identifier-decl mappings 693 that were in effect when this scope was entered. Return a BLOCK 694 node containing all the DECLs in this scope that are of interest 695 to debug info generation. */ 696 697tree 698pop_scope (void) 699{ 700 struct c_scope *scope = current_scope; 701 tree block, context, p; 702 struct c_binding *b; 703 704 bool functionbody = scope->function_body; 705 bool keep = functionbody || scope->keep || scope->bindings; 706 707 c_end_vm_scope (scope->depth); 708 709 /* If appropriate, create a BLOCK to record the decls for the life 710 of this function. */ 711 block = 0; 712 if (keep) 713 { 714 block = make_node (BLOCK); 715 BLOCK_SUBBLOCKS (block) = scope->blocks; 716 TREE_USED (block) = 1; 717 718 /* In each subblock, record that this is its superior. */ 719 for (p = scope->blocks; p; p = TREE_CHAIN (p)) 720 BLOCK_SUPERCONTEXT (p) = block; 721 722 BLOCK_VARS (block) = 0; 723 } 724 725 /* The TYPE_CONTEXTs for all of the tagged types belonging to this 726 scope must be set so that they point to the appropriate 727 construct, i.e. either to the current FUNCTION_DECL node, or 728 else to the BLOCK node we just constructed. 729 730 Note that for tagged types whose scope is just the formal 731 parameter list for some function type specification, we can't 732 properly set their TYPE_CONTEXTs here, because we don't have a 733 pointer to the appropriate FUNCTION_TYPE node readily available 734 to us. For those cases, the TYPE_CONTEXTs of the relevant tagged 735 type nodes get set in `grokdeclarator' as soon as we have created 736 the FUNCTION_TYPE node which will represent the "scope" for these 737 "parameter list local" tagged types. */ 738 if (scope->function_body) 739 context = current_function_decl; 740 else if (scope == file_scope) 741 { 742 tree file_decl = build_decl (TRANSLATION_UNIT_DECL, 0, 0); 743 TREE_CHAIN (file_decl) = all_translation_units; 744 all_translation_units = file_decl; 745 context = file_decl; 746 } 747 else 748 context = block; 749 750 /* Clear all bindings in this scope. */ 751 for (b = scope->bindings; b; b = free_binding_and_advance (b)) 752 { 753 p = b->decl; 754 switch (TREE_CODE (p)) 755 { 756 case LABEL_DECL: 757 /* Warnings for unused labels, errors for undefined labels. */ 758 if (TREE_USED (p) && !DECL_INITIAL (p)) 759 { 760 error ("label %q+D used but not defined", p); 761 DECL_INITIAL (p) = error_mark_node; 762 } 763 else if (!TREE_USED (p) && warn_unused_label) 764 { 765 if (DECL_INITIAL (p)) 766 warning (0, "label %q+D defined but not used", p); 767 else 768 warning (0, "label %q+D declared but not defined", p); 769 } 770 /* Labels go in BLOCK_VARS. */ 771 TREE_CHAIN (p) = BLOCK_VARS (block); 772 BLOCK_VARS (block) = p; 773 gcc_assert (I_LABEL_BINDING (b->id) == b); 774 I_LABEL_BINDING (b->id) = b->shadowed; 775 break; 776 777 case ENUMERAL_TYPE: 778 case UNION_TYPE: 779 case RECORD_TYPE: 780 set_type_context (p, context); 781 782 /* Types may not have tag-names, in which case the type 783 appears in the bindings list with b->id NULL. */ 784 if (b->id) 785 { 786 gcc_assert (I_TAG_BINDING (b->id) == b); 787 I_TAG_BINDING (b->id) = b->shadowed; 788 } 789 break; 790 791 case FUNCTION_DECL: 792 /* Propagate TREE_ADDRESSABLE from nested functions to their 793 containing functions. */ 794 if (!TREE_ASM_WRITTEN (p) 795 && DECL_INITIAL (p) != 0 796 && TREE_ADDRESSABLE (p) 797 && DECL_ABSTRACT_ORIGIN (p) != 0 798 && DECL_ABSTRACT_ORIGIN (p) != p) 799 TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (p)) = 1; 800 if (!DECL_EXTERNAL (p) 801 && DECL_INITIAL (p) == 0 802 && scope != file_scope 803 && scope != external_scope) 804 { 805 error ("nested function %q+D declared but never defined", p); 806 undef_nested_function = true; 807 } 808 /* C99 6.7.4p6: "a function with external linkage... declared 809 with an inline function specifier ... shall also be defined in the 810 same translation unit." */ 811 else if (DECL_DECLARED_INLINE_P (p) 812 && TREE_PUBLIC (p) 813 && !DECL_INITIAL (p) 814 && !flag_gnu89_inline) 815 pedwarn ("inline function %q+D declared but never defined", p); 816 817 goto common_symbol; 818 819 case VAR_DECL: 820 /* Warnings for unused variables. */ 821 if (!TREE_USED (p) 822 && !TREE_NO_WARNING (p) 823 && !DECL_IN_SYSTEM_HEADER (p) 824 && DECL_NAME (p) 825 && !DECL_ARTIFICIAL (p) 826 && scope != file_scope 827 && scope != external_scope) 828 warning (OPT_Wunused_variable, "unused variable %q+D", p); 829 830 if (b->inner_comp) 831 { 832 error ("type of array %q+D completed incompatibly with" 833 " implicit initialization", p); 834 } 835 836 /* Fall through. */ 837 case TYPE_DECL: 838 case CONST_DECL: 839 common_symbol: 840 /* All of these go in BLOCK_VARS, but only if this is the 841 binding in the home scope. */ 842 if (!b->nested) 843 { 844 TREE_CHAIN (p) = BLOCK_VARS (block); 845 BLOCK_VARS (block) = p; 846 } 847 /* If this is the file scope, and we are processing more 848 than one translation unit in this compilation, set 849 DECL_CONTEXT of each decl to the TRANSLATION_UNIT_DECL. 850 This makes same_translation_unit_p work, and causes 851 static declarations to be given disambiguating suffixes. */ 852 if (scope == file_scope && num_in_fnames > 1) 853 { 854 DECL_CONTEXT (p) = context; 855 if (TREE_CODE (p) == TYPE_DECL) 856 set_type_context (TREE_TYPE (p), context); 857 } 858 859 /* Fall through. */ 860 /* Parameters go in DECL_ARGUMENTS, not BLOCK_VARS, and have 861 already been put there by store_parm_decls. Unused- 862 parameter warnings are handled by function.c. 863 error_mark_node obviously does not go in BLOCK_VARS and 864 does not get unused-variable warnings. */ 865 case PARM_DECL: 866 case ERROR_MARK: 867 /* It is possible for a decl not to have a name. We get 868 here with b->id NULL in this case. */ 869 if (b->id) 870 { 871 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 872 I_SYMBOL_BINDING (b->id) = b->shadowed; 873 if (b->shadowed && b->shadowed->type) 874 TREE_TYPE (b->shadowed->decl) = b->shadowed->type; 875 } 876 break; 877 878 default: 879 gcc_unreachable (); 880 } 881 } 882 883 884 /* Dispose of the block that we just made inside some higher level. */ 885 if ((scope->function_body || scope == file_scope) && context) 886 { 887 DECL_INITIAL (context) = block; 888 BLOCK_SUPERCONTEXT (block) = context; 889 } 890 else if (scope->outer) 891 { 892 if (block) 893 SCOPE_LIST_APPEND (scope->outer, blocks, block); 894 /* If we did not make a block for the scope just exited, any 895 blocks made for inner scopes must be carried forward so they 896 will later become subblocks of something else. */ 897 else if (scope->blocks) 898 SCOPE_LIST_CONCAT (scope->outer, blocks, scope, blocks); 899 } 900 901 /* Pop the current scope, and free the structure for reuse. */ 902 current_scope = scope->outer; 903 if (scope->function_body) 904 current_function_scope = scope->outer_function; 905 906 memset (scope, 0, sizeof (struct c_scope)); 907 scope->outer = scope_freelist; 908 scope_freelist = scope; 909 910 return block; 911} 912 913void 914push_file_scope (void) 915{ 916 tree decl; 917 918 if (file_scope) 919 return; 920 921 push_scope (); 922 file_scope = current_scope; 923 924 start_fname_decls (); 925 926 for (decl = visible_builtins; decl; decl = TREE_CHAIN (decl)) 927 bind (DECL_NAME (decl), decl, file_scope, 928 /*invisible=*/false, /*nested=*/true); 929} 930 931void 932pop_file_scope (void) 933{ 934 /* In case there were missing closebraces, get us back to the global 935 binding level. */ 936 while (current_scope != file_scope) 937 pop_scope (); 938 939 /* __FUNCTION__ is defined at file scope (""). This 940 call may not be necessary as my tests indicate it 941 still works without it. */ 942 finish_fname_decls (); 943 944 /* This is the point to write out a PCH if we're doing that. 945 In that case we do not want to do anything else. */ 946 if (pch_file) 947 { 948 c_common_write_pch (); 949 return; 950 } 951 952 /* Pop off the file scope and close this translation unit. */ 953 pop_scope (); 954 file_scope = 0; 955 956 maybe_apply_pending_pragma_weaks (); 957 cgraph_finalize_compilation_unit (); 958} 959 960/* Insert BLOCK at the end of the list of subblocks of the current 961 scope. This is used when a BIND_EXPR is expanded, to handle the 962 BLOCK node inside the BIND_EXPR. */ 963 964void 965insert_block (tree block) 966{ 967 TREE_USED (block) = 1; 968 SCOPE_LIST_APPEND (current_scope, blocks, block); 969} 970 971/* Push a definition or a declaration of struct, union or enum tag "name". 972 "type" should be the type node. 973 We assume that the tag "name" is not already defined. 974 975 Note that the definition may really be just a forward reference. 976 In that case, the TYPE_SIZE will be zero. */ 977 978static void 979pushtag (tree name, tree type) 980{ 981 /* Record the identifier as the type's name if it has none. */ 982 if (name && !TYPE_NAME (type)) 983 TYPE_NAME (type) = name; 984 bind (name, type, current_scope, /*invisible=*/false, /*nested=*/false); 985 986 /* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the 987 tagged type we just added to the current scope. This fake 988 NULL-named TYPE_DECL node helps dwarfout.c to know when it needs 989 to output a representation of a tagged type, and it also gives 990 us a convenient place to record the "scope start" address for the 991 tagged type. */ 992 993 TYPE_STUB_DECL (type) = pushdecl (build_decl (TYPE_DECL, NULL_TREE, type)); 994 995 /* An approximation for now, so we can tell this is a function-scope tag. 996 This will be updated in pop_scope. */ 997 TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type)); 998} 999 1000/* Subroutine of compare_decls. Allow harmless mismatches in return 1001 and argument types provided that the type modes match. This function 1002 return a unified type given a suitable match, and 0 otherwise. */ 1003 1004static tree 1005match_builtin_function_types (tree newtype, tree oldtype) 1006{ 1007 tree newrettype, oldrettype; 1008 tree newargs, oldargs; 1009 tree trytype, tryargs; 1010 1011 /* Accept the return type of the new declaration if same modes. */ 1012 oldrettype = TREE_TYPE (oldtype); 1013 newrettype = TREE_TYPE (newtype); 1014 1015 if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype)) 1016 return 0; 1017 1018 oldargs = TYPE_ARG_TYPES (oldtype); 1019 newargs = TYPE_ARG_TYPES (newtype); 1020 tryargs = newargs; 1021 1022 while (oldargs || newargs) 1023 { 1024 if (!oldargs 1025 || !newargs 1026 || !TREE_VALUE (oldargs) 1027 || !TREE_VALUE (newargs) 1028 || TYPE_MODE (TREE_VALUE (oldargs)) 1029 != TYPE_MODE (TREE_VALUE (newargs))) 1030 return 0; 1031 1032 oldargs = TREE_CHAIN (oldargs); 1033 newargs = TREE_CHAIN (newargs); 1034 } 1035 1036 trytype = build_function_type (newrettype, tryargs); 1037 return build_type_attribute_variant (trytype, TYPE_ATTRIBUTES (oldtype)); 1038} 1039 1040/* Subroutine of diagnose_mismatched_decls. Check for function type 1041 mismatch involving an empty arglist vs a nonempty one and give clearer 1042 diagnostics. */ 1043static void 1044diagnose_arglist_conflict (tree newdecl, tree olddecl, 1045 tree newtype, tree oldtype) 1046{ 1047 tree t; 1048 1049 if (TREE_CODE (olddecl) != FUNCTION_DECL 1050 || !comptypes (TREE_TYPE (oldtype), TREE_TYPE (newtype)) 1051 || !((TYPE_ARG_TYPES (oldtype) == 0 && DECL_INITIAL (olddecl) == 0) 1052 || 1053 (TYPE_ARG_TYPES (newtype) == 0 && DECL_INITIAL (newdecl) == 0))) 1054 return; 1055 1056 t = TYPE_ARG_TYPES (oldtype); 1057 if (t == 0) 1058 t = TYPE_ARG_TYPES (newtype); 1059 for (; t; t = TREE_CHAIN (t)) 1060 { 1061 tree type = TREE_VALUE (t); 1062 1063 if (TREE_CHAIN (t) == 0 1064 && TYPE_MAIN_VARIANT (type) != void_type_node) 1065 { 1066 inform ("a parameter list with an ellipsis can%'t match " 1067 "an empty parameter name list declaration"); 1068 break; 1069 } 1070 1071 if (c_type_promotes_to (type) != type) 1072 { 1073 inform ("an argument type that has a default promotion can%'t match " 1074 "an empty parameter name list declaration"); 1075 break; 1076 } 1077 } 1078} 1079 1080/* Another subroutine of diagnose_mismatched_decls. OLDDECL is an 1081 old-style function definition, NEWDECL is a prototype declaration. 1082 Diagnose inconsistencies in the argument list. Returns TRUE if 1083 the prototype is compatible, FALSE if not. */ 1084static bool 1085validate_proto_after_old_defn (tree newdecl, tree newtype, tree oldtype) 1086{ 1087 tree newargs, oldargs; 1088 int i; 1089 1090#define END_OF_ARGLIST(t) ((t) == void_type_node) 1091 1092 oldargs = TYPE_ACTUAL_ARG_TYPES (oldtype); 1093 newargs = TYPE_ARG_TYPES (newtype); 1094 i = 1; 1095 1096 for (;;) 1097 { 1098 tree oldargtype = TREE_VALUE (oldargs); 1099 tree newargtype = TREE_VALUE (newargs); 1100 1101 if (oldargtype == error_mark_node || newargtype == error_mark_node) 1102 return false; 1103 1104 oldargtype = TYPE_MAIN_VARIANT (oldargtype); 1105 newargtype = TYPE_MAIN_VARIANT (newargtype); 1106 1107 if (END_OF_ARGLIST (oldargtype) && END_OF_ARGLIST (newargtype)) 1108 break; 1109 1110 /* Reaching the end of just one list means the two decls don't 1111 agree on the number of arguments. */ 1112 if (END_OF_ARGLIST (oldargtype)) 1113 { 1114 error ("prototype for %q+D declares more arguments " 1115 "than previous old-style definition", newdecl); 1116 return false; 1117 } 1118 else if (END_OF_ARGLIST (newargtype)) 1119 { 1120 error ("prototype for %q+D declares fewer arguments " 1121 "than previous old-style definition", newdecl); 1122 return false; 1123 } 1124 1125 /* Type for passing arg must be consistent with that declared 1126 for the arg. */ 1127 else if (!comptypes (oldargtype, newargtype)) 1128 { 1129 error ("prototype for %q+D declares argument %d" 1130 " with incompatible type", 1131 newdecl, i); 1132 return false; 1133 } 1134 1135 oldargs = TREE_CHAIN (oldargs); 1136 newargs = TREE_CHAIN (newargs); 1137 i++; 1138 } 1139 1140 /* If we get here, no errors were found, but do issue a warning 1141 for this poor-style construct. */ 1142 warning (0, "prototype for %q+D follows non-prototype definition", 1143 newdecl); 1144 return true; 1145#undef END_OF_ARGLIST 1146} 1147 1148/* Subroutine of diagnose_mismatched_decls. Report the location of DECL, 1149 first in a pair of mismatched declarations, using the diagnostic 1150 function DIAG. */ 1151static void 1152locate_old_decl (tree decl, void (*diag)(const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2)) 1153{ 1154 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) 1155 ; 1156 else if (DECL_INITIAL (decl)) 1157 diag (G_("previous definition of %q+D was here"), decl); 1158 else if (C_DECL_IMPLICIT (decl)) 1159 diag (G_("previous implicit declaration of %q+D was here"), decl); 1160 else 1161 diag (G_("previous declaration of %q+D was here"), decl); 1162} 1163 1164/* Subroutine of duplicate_decls. Compare NEWDECL to OLDDECL. 1165 Returns true if the caller should proceed to merge the two, false 1166 if OLDDECL should simply be discarded. As a side effect, issues 1167 all necessary diagnostics for invalid or poor-style combinations. 1168 If it returns true, writes the types of NEWDECL and OLDDECL to 1169 *NEWTYPEP and *OLDTYPEP - these may have been adjusted from 1170 TREE_TYPE (NEWDECL, OLDDECL) respectively. */ 1171 1172static bool 1173diagnose_mismatched_decls (tree newdecl, tree olddecl, 1174 tree *newtypep, tree *oldtypep) 1175{ 1176 tree newtype, oldtype; 1177 bool pedwarned = false; 1178 bool warned = false; 1179 bool retval = true; 1180 1181#define DECL_EXTERN_INLINE(DECL) (DECL_DECLARED_INLINE_P (DECL) \ 1182 && DECL_EXTERNAL (DECL)) 1183 1184 /* If we have error_mark_node for either decl or type, just discard 1185 the previous decl - we're in an error cascade already. */ 1186 if (olddecl == error_mark_node || newdecl == error_mark_node) 1187 return false; 1188 *oldtypep = oldtype = TREE_TYPE (olddecl); 1189 *newtypep = newtype = TREE_TYPE (newdecl); 1190 if (oldtype == error_mark_node || newtype == error_mark_node) 1191 return false; 1192 1193 /* Two different categories of symbol altogether. This is an error 1194 unless OLDDECL is a builtin. OLDDECL will be discarded in any case. */ 1195 if (TREE_CODE (olddecl) != TREE_CODE (newdecl)) 1196 { 1197 if (!(TREE_CODE (olddecl) == FUNCTION_DECL 1198 && DECL_BUILT_IN (olddecl) 1199 && !C_DECL_DECLARED_BUILTIN (olddecl))) 1200 { 1201 error ("%q+D redeclared as different kind of symbol", newdecl); 1202 locate_old_decl (olddecl, error); 1203 } 1204 else if (TREE_PUBLIC (newdecl)) 1205 warning (0, "built-in function %q+D declared as non-function", 1206 newdecl); 1207 else 1208 warning (OPT_Wshadow, "declaration of %q+D shadows " 1209 "a built-in function", newdecl); 1210 return false; 1211 } 1212 1213 /* Enumerators have no linkage, so may only be declared once in a 1214 given scope. */ 1215 if (TREE_CODE (olddecl) == CONST_DECL) 1216 { 1217 error ("redeclaration of enumerator %q+D", newdecl); 1218 locate_old_decl (olddecl, error); 1219 return false; 1220 } 1221 1222 if (!comptypes (oldtype, newtype)) 1223 { 1224 if (TREE_CODE (olddecl) == FUNCTION_DECL 1225 && DECL_BUILT_IN (olddecl) && !C_DECL_DECLARED_BUILTIN (olddecl)) 1226 { 1227 /* Accept harmless mismatch in function types. 1228 This is for the ffs and fprintf builtins. */ 1229 tree trytype = match_builtin_function_types (newtype, oldtype); 1230 1231 if (trytype && comptypes (newtype, trytype)) 1232 *oldtypep = oldtype = trytype; 1233 else 1234 { 1235 /* If types don't match for a built-in, throw away the 1236 built-in. No point in calling locate_old_decl here, it 1237 won't print anything. */ 1238 warning (0, "conflicting types for built-in function %q+D", 1239 newdecl); 1240 return false; 1241 } 1242 } 1243 else if (TREE_CODE (olddecl) == FUNCTION_DECL 1244 && DECL_IS_BUILTIN (olddecl)) 1245 { 1246 /* A conflicting function declaration for a predeclared 1247 function that isn't actually built in. Objective C uses 1248 these. The new declaration silently overrides everything 1249 but the volatility (i.e. noreturn) indication. See also 1250 below. FIXME: Make Objective C use normal builtins. */ 1251 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1252 return false; 1253 } 1254 /* Permit void foo (...) to match int foo (...) if the latter is 1255 the definition and implicit int was used. See 1256 c-torture/compile/920625-2.c. */ 1257 else if (TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl) 1258 && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == void_type_node 1259 && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == integer_type_node 1260 && C_FUNCTION_IMPLICIT_INT (newdecl) && !DECL_INITIAL (olddecl)) 1261 { 1262 pedwarn ("conflicting types for %q+D", newdecl); 1263 /* Make sure we keep void as the return type. */ 1264 TREE_TYPE (newdecl) = *newtypep = newtype = oldtype; 1265 C_FUNCTION_IMPLICIT_INT (newdecl) = 0; 1266 pedwarned = true; 1267 } 1268 /* Permit void foo (...) to match an earlier call to foo (...) with 1269 no declared type (thus, implicitly int). */ 1270 else if (TREE_CODE (newdecl) == FUNCTION_DECL 1271 && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == void_type_node 1272 && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == integer_type_node 1273 && C_DECL_IMPLICIT (olddecl) && !DECL_INITIAL (olddecl)) 1274 { 1275 pedwarn ("conflicting types for %q+D", newdecl); 1276 /* Make sure we keep void as the return type. */ 1277 TREE_TYPE (olddecl) = *oldtypep = oldtype = newtype; 1278 pedwarned = true; 1279 } 1280 else 1281 { 1282 if (TYPE_QUALS (newtype) != TYPE_QUALS (oldtype)) 1283 error ("conflicting type qualifiers for %q+D", newdecl); 1284 else 1285 error ("conflicting types for %q+D", newdecl); 1286 diagnose_arglist_conflict (newdecl, olddecl, newtype, oldtype); 1287 locate_old_decl (olddecl, error); 1288 return false; 1289 } 1290 } 1291 1292 /* Redeclaration of a type is a constraint violation (6.7.2.3p1), 1293 but silently ignore the redeclaration if either is in a system 1294 header. (Conflicting redeclarations were handled above.) */ 1295 if (TREE_CODE (newdecl) == TYPE_DECL) 1296 { 1297 if (DECL_IN_SYSTEM_HEADER (newdecl) || DECL_IN_SYSTEM_HEADER (olddecl)) 1298 return true; /* Allow OLDDECL to continue in use. */ 1299 1300 error ("redefinition of typedef %q+D", newdecl); 1301 locate_old_decl (olddecl, error); 1302 return false; 1303 } 1304 1305 /* Function declarations can either be 'static' or 'extern' (no 1306 qualifier is equivalent to 'extern' - C99 6.2.2p5) and therefore 1307 can never conflict with each other on account of linkage 1308 (6.2.2p4). Multiple definitions are not allowed (6.9p3,5) but 1309 gnu89 mode permits two definitions if one is 'extern inline' and 1310 one is not. The non- extern-inline definition supersedes the 1311 extern-inline definition. */ 1312 1313 else if (TREE_CODE (newdecl) == FUNCTION_DECL) 1314 { 1315 /* If you declare a built-in function name as static, or 1316 define the built-in with an old-style definition (so we 1317 can't validate the argument list) the built-in definition is 1318 overridden, but optionally warn this was a bad choice of name. */ 1319 if (DECL_BUILT_IN (olddecl) 1320 && !C_DECL_DECLARED_BUILTIN (olddecl) 1321 && (!TREE_PUBLIC (newdecl) 1322 || (DECL_INITIAL (newdecl) 1323 && !TYPE_ARG_TYPES (TREE_TYPE (newdecl))))) 1324 { 1325 warning (OPT_Wshadow, "declaration of %q+D shadows " 1326 "a built-in function", newdecl); 1327 /* Discard the old built-in function. */ 1328 return false; 1329 } 1330 1331 if (DECL_INITIAL (newdecl)) 1332 { 1333 if (DECL_INITIAL (olddecl)) 1334 { 1335 /* If both decls are in the same TU and the new declaration 1336 isn't overriding an extern inline reject the new decl. 1337 In c99, no overriding is allowed in the same translation 1338 unit. */ 1339 if ((!DECL_EXTERN_INLINE (olddecl) 1340 || DECL_EXTERN_INLINE (newdecl) 1341 || (!flag_gnu89_inline 1342 && (!DECL_DECLARED_INLINE_P (olddecl) 1343 || !lookup_attribute ("gnu_inline", 1344 DECL_ATTRIBUTES (olddecl))) 1345 && (!DECL_DECLARED_INLINE_P (newdecl) 1346 || !lookup_attribute ("gnu_inline", 1347 DECL_ATTRIBUTES (newdecl)))) 1348 ) 1349 && same_translation_unit_p (newdecl, olddecl)) 1350 { 1351 error ("redefinition of %q+D", newdecl); 1352 locate_old_decl (olddecl, error); 1353 return false; 1354 } 1355 } 1356 } 1357 /* If we have a prototype after an old-style function definition, 1358 the argument types must be checked specially. */ 1359 else if (DECL_INITIAL (olddecl) 1360 && !TYPE_ARG_TYPES (oldtype) && TYPE_ARG_TYPES (newtype) 1361 && TYPE_ACTUAL_ARG_TYPES (oldtype) 1362 && !validate_proto_after_old_defn (newdecl, newtype, oldtype)) 1363 { 1364 locate_old_decl (olddecl, error); 1365 return false; 1366 } 1367 /* A non-static declaration (even an "extern") followed by a 1368 static declaration is undefined behavior per C99 6.2.2p3-5,7. 1369 The same is true for a static forward declaration at block 1370 scope followed by a non-static declaration/definition at file 1371 scope. Static followed by non-static at the same scope is 1372 not undefined behavior, and is the most convenient way to get 1373 some effects (see e.g. what unwind-dw2-fde-glibc.c does to 1374 the definition of _Unwind_Find_FDE in unwind-dw2-fde.c), but 1375 we do diagnose it if -Wtraditional. */ 1376 if (TREE_PUBLIC (olddecl) && !TREE_PUBLIC (newdecl)) 1377 { 1378 /* Two exceptions to the rule. If olddecl is an extern 1379 inline, or a predeclared function that isn't actually 1380 built in, newdecl silently overrides olddecl. The latter 1381 occur only in Objective C; see also above. (FIXME: Make 1382 Objective C use normal builtins.) */ 1383 if (!DECL_IS_BUILTIN (olddecl) 1384 && !DECL_EXTERN_INLINE (olddecl)) 1385 { 1386 error ("static declaration of %q+D follows " 1387 "non-static declaration", newdecl); 1388 locate_old_decl (olddecl, error); 1389 } 1390 return false; 1391 } 1392 else if (TREE_PUBLIC (newdecl) && !TREE_PUBLIC (olddecl)) 1393 { 1394 if (DECL_CONTEXT (olddecl)) 1395 { 1396 error ("non-static declaration of %q+D follows " 1397 "static declaration", newdecl); 1398 locate_old_decl (olddecl, error); 1399 return false; 1400 } 1401 else if (warn_traditional) 1402 { 1403 warning (OPT_Wtraditional, "non-static declaration of %q+D " 1404 "follows static declaration", newdecl); 1405 warned = true; 1406 } 1407 } 1408 1409 /* Make sure gnu_inline attribute is either not present, or 1410 present on all inline decls. */ 1411 if (DECL_DECLARED_INLINE_P (olddecl) 1412 && DECL_DECLARED_INLINE_P (newdecl)) 1413 { 1414 bool newa = lookup_attribute ("gnu_inline", 1415 DECL_ATTRIBUTES (newdecl)) != NULL; 1416 bool olda = lookup_attribute ("gnu_inline", 1417 DECL_ATTRIBUTES (olddecl)) != NULL; 1418 if (newa != olda) 1419 { 1420 error ("%<gnu_inline%> attribute present on %q+D", 1421 newa ? newdecl : olddecl); 1422 error ("%Jbut not here", newa ? olddecl : newdecl); 1423 } 1424 } 1425 } 1426 else if (TREE_CODE (newdecl) == VAR_DECL) 1427 { 1428 /* Only variables can be thread-local, and all declarations must 1429 agree on this property. */ 1430 if (C_DECL_THREADPRIVATE_P (olddecl) && !DECL_THREAD_LOCAL_P (newdecl)) 1431 { 1432 /* Nothing to check. Since OLDDECL is marked threadprivate 1433 and NEWDECL does not have a thread-local attribute, we 1434 will merge the threadprivate attribute into NEWDECL. */ 1435 ; 1436 } 1437 else if (DECL_THREAD_LOCAL_P (newdecl) != DECL_THREAD_LOCAL_P (olddecl)) 1438 { 1439 if (DECL_THREAD_LOCAL_P (newdecl)) 1440 error ("thread-local declaration of %q+D follows " 1441 "non-thread-local declaration", newdecl); 1442 else 1443 error ("non-thread-local declaration of %q+D follows " 1444 "thread-local declaration", newdecl); 1445 1446 locate_old_decl (olddecl, error); 1447 return false; 1448 } 1449 1450 /* Multiple initialized definitions are not allowed (6.9p3,5). */ 1451 if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl)) 1452 { 1453 error ("redefinition of %q+D", newdecl); 1454 locate_old_decl (olddecl, error); 1455 return false; 1456 } 1457 1458 /* Objects declared at file scope: if the first declaration had 1459 external linkage (even if it was an external reference) the 1460 second must have external linkage as well, or the behavior is 1461 undefined. If the first declaration had internal linkage, then 1462 the second must too, or else be an external reference (in which 1463 case the composite declaration still has internal linkage). 1464 As for function declarations, we warn about the static-then- 1465 extern case only for -Wtraditional. See generally 6.2.2p3-5,7. */ 1466 if (DECL_FILE_SCOPE_P (newdecl) 1467 && TREE_PUBLIC (newdecl) != TREE_PUBLIC (olddecl)) 1468 { 1469 if (DECL_EXTERNAL (newdecl)) 1470 { 1471 if (!DECL_FILE_SCOPE_P (olddecl)) 1472 { 1473 error ("extern declaration of %q+D follows " 1474 "declaration with no linkage", newdecl); 1475 locate_old_decl (olddecl, error); 1476 return false; 1477 } 1478 else if (warn_traditional) 1479 { 1480 warning (OPT_Wtraditional, "non-static declaration of %q+D " 1481 "follows static declaration", newdecl); 1482 warned = true; 1483 } 1484 } 1485 else 1486 { 1487 if (TREE_PUBLIC (newdecl)) 1488 error ("non-static declaration of %q+D follows " 1489 "static declaration", newdecl); 1490 else 1491 error ("static declaration of %q+D follows " 1492 "non-static declaration", newdecl); 1493 1494 locate_old_decl (olddecl, error); 1495 return false; 1496 } 1497 } 1498 /* Two objects with the same name declared at the same block 1499 scope must both be external references (6.7p3). */ 1500 else if (!DECL_FILE_SCOPE_P (newdecl)) 1501 { 1502 if (DECL_EXTERNAL (newdecl)) 1503 { 1504 /* Extern with initializer at block scope, which will 1505 already have received an error. */ 1506 } 1507 else if (DECL_EXTERNAL (olddecl)) 1508 { 1509 error ("declaration of %q+D with no linkage follows " 1510 "extern declaration", newdecl); 1511 locate_old_decl (olddecl, error); 1512 } 1513 else 1514 { 1515 error ("redeclaration of %q+D with no linkage", newdecl); 1516 locate_old_decl (olddecl, error); 1517 } 1518 1519 return false; 1520 } 1521 } 1522 1523 /* warnings */ 1524 /* All decls must agree on a visibility. */ 1525 if (CODE_CONTAINS_STRUCT (TREE_CODE (newdecl), TS_DECL_WITH_VIS) 1526 && DECL_VISIBILITY_SPECIFIED (newdecl) && DECL_VISIBILITY_SPECIFIED (olddecl) 1527 && DECL_VISIBILITY (newdecl) != DECL_VISIBILITY (olddecl)) 1528 { 1529 warning (0, "redeclaration of %q+D with different visibility " 1530 "(old visibility preserved)", newdecl); 1531 warned = true; 1532 } 1533 1534 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1535 { 1536 /* Diagnose inline __attribute__ ((noinline)) which is silly. */ 1537 if (DECL_DECLARED_INLINE_P (newdecl) 1538 && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl))) 1539 { 1540 warning (OPT_Wattributes, "inline declaration of %qD follows " 1541 "declaration with attribute noinline", newdecl); 1542 warned = true; 1543 } 1544 else if (DECL_DECLARED_INLINE_P (olddecl) 1545 && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl))) 1546 { 1547 warning (OPT_Wattributes, "declaration of %q+D with attribute " 1548 "noinline follows inline declaration ", newdecl); 1549 warned = true; 1550 } 1551 1552 /* Inline declaration after use or definition. 1553 ??? Should we still warn about this now we have unit-at-a-time 1554 mode and can get it right? 1555 Definitely don't complain if the decls are in different translation 1556 units. 1557 C99 permits this, so don't warn in that case. (The function 1558 may not be inlined everywhere in function-at-a-time mode, but 1559 we still shouldn't warn.) */ 1560 if (DECL_DECLARED_INLINE_P (newdecl) && !DECL_DECLARED_INLINE_P (olddecl) 1561 && same_translation_unit_p (olddecl, newdecl) 1562 && flag_gnu89_inline) 1563 { 1564 if (TREE_USED (olddecl)) 1565 { 1566 warning (0, "%q+D declared inline after being called", olddecl); 1567 warned = true; 1568 } 1569 else if (DECL_INITIAL (olddecl)) 1570 { 1571 warning (0, "%q+D declared inline after its definition", olddecl); 1572 warned = true; 1573 } 1574 } 1575 } 1576 else /* PARM_DECL, VAR_DECL */ 1577 { 1578 /* Redeclaration of a parameter is a constraint violation (this is 1579 not explicitly stated, but follows from C99 6.7p3 [no more than 1580 one declaration of the same identifier with no linkage in the 1581 same scope, except type tags] and 6.2.2p6 [parameters have no 1582 linkage]). We must check for a forward parameter declaration, 1583 indicated by TREE_ASM_WRITTEN on the old declaration - this is 1584 an extension, the mandatory diagnostic for which is handled by 1585 mark_forward_parm_decls. */ 1586 1587 if (TREE_CODE (newdecl) == PARM_DECL 1588 && (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl))) 1589 { 1590 error ("redefinition of parameter %q+D", newdecl); 1591 locate_old_decl (olddecl, error); 1592 return false; 1593 } 1594 } 1595 1596 /* Optional warning for completely redundant decls. */ 1597 if (!warned && !pedwarned 1598 && warn_redundant_decls 1599 /* Don't warn about a function declaration followed by a 1600 definition. */ 1601 && !(TREE_CODE (newdecl) == FUNCTION_DECL 1602 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl)) 1603 /* Don't warn about redundant redeclarations of builtins. */ 1604 && !(TREE_CODE (newdecl) == FUNCTION_DECL 1605 && !DECL_BUILT_IN (newdecl) 1606 && DECL_BUILT_IN (olddecl) 1607 && !C_DECL_DECLARED_BUILTIN (olddecl)) 1608 /* Don't warn about an extern followed by a definition. */ 1609 && !(DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl)) 1610 /* Don't warn about forward parameter decls. */ 1611 && !(TREE_CODE (newdecl) == PARM_DECL 1612 && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl)) 1613 /* Don't warn about a variable definition following a declaration. */ 1614 && !(TREE_CODE (newdecl) == VAR_DECL 1615 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl))) 1616 { 1617 warning (OPT_Wredundant_decls, "redundant redeclaration of %q+D", 1618 newdecl); 1619 warned = true; 1620 } 1621 1622 /* Report location of previous decl/defn in a consistent manner. */ 1623 if (warned || pedwarned) 1624 locate_old_decl (olddecl, pedwarned ? pedwarn : warning0); 1625 1626#undef DECL_EXTERN_INLINE 1627 1628 return retval; 1629} 1630 1631/* Subroutine of duplicate_decls. NEWDECL has been found to be 1632 consistent with OLDDECL, but carries new information. Merge the 1633 new information into OLDDECL. This function issues no 1634 diagnostics. */ 1635 1636static void 1637merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype) 1638{ 1639 bool new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL 1640 && DECL_INITIAL (newdecl) != 0); 1641 bool new_is_prototype = (TREE_CODE (newdecl) == FUNCTION_DECL 1642 && TYPE_ARG_TYPES (TREE_TYPE (newdecl)) != 0); 1643 bool old_is_prototype = (TREE_CODE (olddecl) == FUNCTION_DECL 1644 && TYPE_ARG_TYPES (TREE_TYPE (olddecl)) != 0); 1645 bool extern_changed = false; 1646 1647 /* For real parm decl following a forward decl, rechain the old decl 1648 in its new location and clear TREE_ASM_WRITTEN (it's not a 1649 forward decl anymore). */ 1650 if (TREE_CODE (newdecl) == PARM_DECL 1651 && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl)) 1652 { 1653 struct c_binding *b, **here; 1654 1655 for (here = ¤t_scope->bindings; *here; here = &(*here)->prev) 1656 if ((*here)->decl == olddecl) 1657 goto found; 1658 gcc_unreachable (); 1659 1660 found: 1661 b = *here; 1662 *here = b->prev; 1663 b->prev = current_scope->bindings; 1664 current_scope->bindings = b; 1665 1666 TREE_ASM_WRITTEN (olddecl) = 0; 1667 } 1668 1669 DECL_ATTRIBUTES (newdecl) 1670 = targetm.merge_decl_attributes (olddecl, newdecl); 1671 1672 /* Merge the data types specified in the two decls. */ 1673 TREE_TYPE (newdecl) 1674 = TREE_TYPE (olddecl) 1675 = composite_type (newtype, oldtype); 1676 1677 /* Lay the type out, unless already done. */ 1678 if (!comptypes (oldtype, TREE_TYPE (newdecl))) 1679 { 1680 if (TREE_TYPE (newdecl) != error_mark_node) 1681 layout_type (TREE_TYPE (newdecl)); 1682 if (TREE_CODE (newdecl) != FUNCTION_DECL 1683 && TREE_CODE (newdecl) != TYPE_DECL 1684 && TREE_CODE (newdecl) != CONST_DECL) 1685 layout_decl (newdecl, 0); 1686 } 1687 else 1688 { 1689 /* Since the type is OLDDECL's, make OLDDECL's size go with. */ 1690 DECL_SIZE (newdecl) = DECL_SIZE (olddecl); 1691 DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl); 1692 DECL_MODE (newdecl) = DECL_MODE (olddecl); 1693 if (TREE_CODE (olddecl) != FUNCTION_DECL) 1694 if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl)) 1695 { 1696 DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl); 1697 DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl); 1698 } 1699 } 1700 1701 1702 /* Merge the type qualifiers. */ 1703 if (TREE_READONLY (newdecl)) 1704 TREE_READONLY (olddecl) = 1; 1705 1706 if (TREE_THIS_VOLATILE (newdecl)) 1707 TREE_THIS_VOLATILE (olddecl) = 1; 1708 1709 /* Merge deprecatedness. */ 1710 if (TREE_DEPRECATED (newdecl)) 1711 TREE_DEPRECATED (olddecl) = 1; 1712 1713 /* Keep source location of definition rather than declaration and of 1714 prototype rather than non-prototype unless that prototype is 1715 built-in. */ 1716 if ((DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0) 1717 || (old_is_prototype && !new_is_prototype 1718 && !C_DECL_BUILTIN_PROTOTYPE (olddecl))) 1719 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 1720 1721 /* Merge the initialization information. */ 1722 if (DECL_INITIAL (newdecl) == 0) 1723 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1724 1725 /* Merge the threadprivate attribute. */ 1726 if (TREE_CODE (olddecl) == VAR_DECL && C_DECL_THREADPRIVATE_P (olddecl)) 1727 { 1728 DECL_TLS_MODEL (newdecl) = DECL_TLS_MODEL (olddecl); 1729 C_DECL_THREADPRIVATE_P (newdecl) = 1; 1730 } 1731 1732 if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)) 1733 { 1734 /* Merge the unused-warning information. */ 1735 if (DECL_IN_SYSTEM_HEADER (olddecl)) 1736 DECL_IN_SYSTEM_HEADER (newdecl) = 1; 1737 else if (DECL_IN_SYSTEM_HEADER (newdecl)) 1738 DECL_IN_SYSTEM_HEADER (olddecl) = 1; 1739 1740 /* Merge the section attribute. 1741 We want to issue an error if the sections conflict but that 1742 must be done later in decl_attributes since we are called 1743 before attributes are assigned. */ 1744 if (DECL_SECTION_NAME (newdecl) == NULL_TREE) 1745 DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl); 1746 1747 /* Copy the assembler name. 1748 Currently, it can only be defined in the prototype. */ 1749 COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl); 1750 1751 /* Use visibility of whichever declaration had it specified */ 1752 if (DECL_VISIBILITY_SPECIFIED (olddecl)) 1753 { 1754 DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl); 1755 DECL_VISIBILITY_SPECIFIED (newdecl) = 1; 1756 } 1757 1758 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1759 { 1760 DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl); 1761 DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl); 1762 DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl); 1763 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl) 1764 |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl); 1765 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1766 TREE_READONLY (newdecl) |= TREE_READONLY (olddecl); 1767 DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl); 1768 DECL_IS_PURE (newdecl) |= DECL_IS_PURE (olddecl); 1769 DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl); 1770 } 1771 1772 /* Merge the storage class information. */ 1773 merge_weak (newdecl, olddecl); 1774 1775 /* For functions, static overrides non-static. */ 1776 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1777 { 1778 TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl); 1779 /* This is since we don't automatically 1780 copy the attributes of NEWDECL into OLDDECL. */ 1781 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1782 /* If this clears `static', clear it in the identifier too. */ 1783 if (!TREE_PUBLIC (olddecl)) 1784 TREE_PUBLIC (DECL_NAME (olddecl)) = 0; 1785 } 1786 } 1787 1788 /* In c99, 'extern' declaration before (or after) 'inline' means this 1789 function is not DECL_EXTERNAL, unless 'gnu_inline' attribute 1790 is present. */ 1791 if (TREE_CODE (newdecl) == FUNCTION_DECL 1792 && !flag_gnu89_inline 1793 && (DECL_DECLARED_INLINE_P (newdecl) 1794 || DECL_DECLARED_INLINE_P (olddecl)) 1795 && (!DECL_DECLARED_INLINE_P (newdecl) 1796 || !DECL_DECLARED_INLINE_P (olddecl) 1797 || !DECL_EXTERNAL (olddecl)) 1798 && DECL_EXTERNAL (newdecl) 1799 && !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl))) 1800 DECL_EXTERNAL (newdecl) = 0; 1801 1802 if (DECL_EXTERNAL (newdecl)) 1803 { 1804 TREE_STATIC (newdecl) = TREE_STATIC (olddecl); 1805 DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl); 1806 1807 /* An extern decl does not override previous storage class. */ 1808 TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl); 1809 if (!DECL_EXTERNAL (newdecl)) 1810 { 1811 DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl); 1812 DECL_COMMON (newdecl) = DECL_COMMON (olddecl); 1813 } 1814 } 1815 else 1816 { 1817 TREE_STATIC (olddecl) = TREE_STATIC (newdecl); 1818 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1819 } 1820 1821 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1822 { 1823 /* If we're redefining a function previously defined as extern 1824 inline, make sure we emit debug info for the inline before we 1825 throw it away, in case it was inlined into a function that 1826 hasn't been written out yet. */ 1827 if (new_is_definition && DECL_INITIAL (olddecl)) 1828 { 1829 if (TREE_USED (olddecl) 1830 /* In unit-at-a-time mode we never inline re-defined extern 1831 inline functions. */ 1832 && !flag_unit_at_a_time 1833 && cgraph_function_possibly_inlined_p (olddecl)) 1834 (*debug_hooks->outlining_inline_function) (olddecl); 1835 1836 /* The new defn must not be inline. */ 1837 DECL_INLINE (newdecl) = 0; 1838 DECL_UNINLINABLE (newdecl) = 1; 1839 } 1840 else 1841 { 1842 /* If either decl says `inline', this fn is inline, unless 1843 its definition was passed already. */ 1844 if (DECL_DECLARED_INLINE_P (newdecl) 1845 || DECL_DECLARED_INLINE_P (olddecl)) 1846 DECL_DECLARED_INLINE_P (newdecl) = 1; 1847 1848 DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl) 1849 = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)); 1850 } 1851 1852 if (DECL_BUILT_IN (olddecl)) 1853 { 1854 /* If redeclaring a builtin function, it stays built in. 1855 But it gets tagged as having been declared. */ 1856 DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl); 1857 DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl); 1858 C_DECL_DECLARED_BUILTIN (newdecl) = 1; 1859 if (new_is_prototype) 1860 C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0; 1861 else 1862 C_DECL_BUILTIN_PROTOTYPE (newdecl) 1863 = C_DECL_BUILTIN_PROTOTYPE (olddecl); 1864 } 1865 1866 /* Also preserve various other info from the definition. */ 1867 if (!new_is_definition) 1868 { 1869 DECL_RESULT (newdecl) = DECL_RESULT (olddecl); 1870 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1871 DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl); 1872 DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl); 1873 DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl); 1874 1875 /* Set DECL_INLINE on the declaration if we've got a body 1876 from which to instantiate. */ 1877 if (DECL_INLINE (olddecl) && !DECL_UNINLINABLE (newdecl)) 1878 { 1879 DECL_INLINE (newdecl) = 1; 1880 DECL_ABSTRACT_ORIGIN (newdecl) 1881 = DECL_ABSTRACT_ORIGIN (olddecl); 1882 } 1883 } 1884 else 1885 { 1886 /* If a previous declaration said inline, mark the 1887 definition as inlinable. */ 1888 if (DECL_DECLARED_INLINE_P (newdecl) 1889 && !DECL_UNINLINABLE (newdecl)) 1890 DECL_INLINE (newdecl) = 1; 1891 } 1892 } 1893 1894 extern_changed = DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl); 1895 1896 /* Copy most of the decl-specific fields of NEWDECL into OLDDECL. 1897 But preserve OLDDECL's DECL_UID and DECL_CONTEXT. */ 1898 { 1899 unsigned olddecl_uid = DECL_UID (olddecl); 1900 tree olddecl_context = DECL_CONTEXT (olddecl); 1901 1902 memcpy ((char *) olddecl + sizeof (struct tree_common), 1903 (char *) newdecl + sizeof (struct tree_common), 1904 sizeof (struct tree_decl_common) - sizeof (struct tree_common)); 1905 switch (TREE_CODE (olddecl)) 1906 { 1907 case FIELD_DECL: 1908 case VAR_DECL: 1909 case PARM_DECL: 1910 case LABEL_DECL: 1911 case RESULT_DECL: 1912 case CONST_DECL: 1913 case TYPE_DECL: 1914 case FUNCTION_DECL: 1915 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1916 (char *) newdecl + sizeof (struct tree_decl_common), 1917 tree_code_size (TREE_CODE (olddecl)) - sizeof (struct tree_decl_common)); 1918 break; 1919 1920 default: 1921 1922 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1923 (char *) newdecl + sizeof (struct tree_decl_common), 1924 sizeof (struct tree_decl_non_common) - sizeof (struct tree_decl_common)); 1925 } 1926 DECL_UID (olddecl) = olddecl_uid; 1927 DECL_CONTEXT (olddecl) = olddecl_context; 1928 } 1929 1930 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl 1931 so that encode_section_info has a chance to look at the new decl 1932 flags and attributes. */ 1933 if (DECL_RTL_SET_P (olddecl) 1934 && (TREE_CODE (olddecl) == FUNCTION_DECL 1935 || (TREE_CODE (olddecl) == VAR_DECL 1936 && TREE_STATIC (olddecl)))) 1937 make_decl_rtl (olddecl); 1938 1939 /* If we changed a function from DECL_EXTERNAL to !DECL_EXTERNAL, 1940 and the definition is coming from the old version, cgraph needs 1941 to be called again. */ 1942 if (extern_changed && !new_is_definition 1943 && TREE_CODE (olddecl) == FUNCTION_DECL && DECL_INITIAL (olddecl)) 1944 cgraph_finalize_function (olddecl, false); 1945} 1946 1947/* Handle when a new declaration NEWDECL has the same name as an old 1948 one OLDDECL in the same binding contour. Prints an error message 1949 if appropriate. 1950 1951 If safely possible, alter OLDDECL to look like NEWDECL, and return 1952 true. Otherwise, return false. */ 1953 1954static bool 1955duplicate_decls (tree newdecl, tree olddecl) 1956{ 1957 tree newtype = NULL, oldtype = NULL; 1958 1959 if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype)) 1960 { 1961 /* Avoid `unused variable' and other warnings warnings for OLDDECL. */ 1962 TREE_NO_WARNING (olddecl) = 1; 1963 return false; 1964 } 1965 1966 merge_decls (newdecl, olddecl, newtype, oldtype); 1967 return true; 1968} 1969 1970 1971/* Check whether decl-node NEW_DECL shadows an existing declaration. */ 1972static void 1973warn_if_shadowing (tree new_decl) 1974{ 1975 struct c_binding *b; 1976 1977 /* Shadow warnings wanted? */ 1978 if (!warn_shadow 1979 /* No shadow warnings for internally generated vars. */ 1980 || DECL_IS_BUILTIN (new_decl) 1981 /* No shadow warnings for vars made for inlining. */ 1982 || DECL_FROM_INLINE (new_decl)) 1983 return; 1984 1985 /* Is anything being shadowed? Invisible decls do not count. */ 1986 for (b = I_SYMBOL_BINDING (DECL_NAME (new_decl)); b; b = b->shadowed) 1987 if (b->decl && b->decl != new_decl && !b->invisible) 1988 { 1989 tree old_decl = b->decl; 1990 1991 if (old_decl == error_mark_node) 1992 { 1993 warning (OPT_Wshadow, "declaration of %q+D shadows previous " 1994 "non-variable", new_decl); 1995 break; 1996 } 1997 else if (TREE_CODE (old_decl) == PARM_DECL) 1998 warning (OPT_Wshadow, "declaration of %q+D shadows a parameter", 1999 new_decl); 2000 else if (DECL_FILE_SCOPE_P (old_decl)) 2001 warning (OPT_Wshadow, "declaration of %q+D shadows a global " 2002 "declaration", new_decl); 2003 else if (TREE_CODE (old_decl) == FUNCTION_DECL 2004 && DECL_BUILT_IN (old_decl)) 2005 { 2006 warning (OPT_Wshadow, "declaration of %q+D shadows " 2007 "a built-in function", new_decl); 2008 break; 2009 } 2010 else 2011 warning (OPT_Wshadow, "declaration of %q+D shadows a previous local", 2012 new_decl); 2013 2014 warning (OPT_Wshadow, "%Jshadowed declaration is here", old_decl); 2015 2016 break; 2017 } 2018} 2019 2020 2021/* Subroutine of pushdecl. 2022 2023 X is a TYPE_DECL for a typedef statement. Create a brand new 2024 ..._TYPE node (which will be just a variant of the existing 2025 ..._TYPE node with identical properties) and then install X 2026 as the TYPE_NAME of this brand new (duplicate) ..._TYPE node. 2027 2028 The whole point here is to end up with a situation where each 2029 and every ..._TYPE node the compiler creates will be uniquely 2030 associated with AT MOST one node representing a typedef name. 2031 This way, even though the compiler substitutes corresponding 2032 ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very 2033 early on, later parts of the compiler can always do the reverse 2034 translation and get back the corresponding typedef name. For 2035 example, given: 2036 2037 typedef struct S MY_TYPE; 2038 MY_TYPE object; 2039 2040 Later parts of the compiler might only know that `object' was of 2041 type `struct S' if it were not for code just below. With this 2042 code however, later parts of the compiler see something like: 2043 2044 struct S' == struct S 2045 typedef struct S' MY_TYPE; 2046 struct S' object; 2047 2048 And they can then deduce (from the node for type struct S') that 2049 the original object declaration was: 2050 2051 MY_TYPE object; 2052 2053 Being able to do this is important for proper support of protoize, 2054 and also for generating precise symbolic debugging information 2055 which takes full account of the programmer's (typedef) vocabulary. 2056 2057 Obviously, we don't want to generate a duplicate ..._TYPE node if 2058 the TYPE_DECL node that we are now processing really represents a 2059 standard built-in type. 2060 2061 Since all standard types are effectively declared at line zero 2062 in the source file, we can easily check to see if we are working 2063 on a standard type by checking the current value of lineno. */ 2064 2065static void 2066clone_underlying_type (tree x) 2067{ 2068 if (DECL_IS_BUILTIN (x)) 2069 { 2070 if (TYPE_NAME (TREE_TYPE (x)) == 0) 2071 TYPE_NAME (TREE_TYPE (x)) = x; 2072 } 2073 else if (TREE_TYPE (x) != error_mark_node 2074 && DECL_ORIGINAL_TYPE (x) == NULL_TREE) 2075 { 2076 tree tt = TREE_TYPE (x); 2077 DECL_ORIGINAL_TYPE (x) = tt; 2078 tt = build_variant_type_copy (tt); 2079 TYPE_NAME (tt) = x; 2080 TREE_USED (tt) = TREE_USED (x); 2081 TREE_TYPE (x) = tt; 2082 } 2083} 2084 2085/* Record a decl-node X as belonging to the current lexical scope. 2086 Check for errors (such as an incompatible declaration for the same 2087 name already seen in the same scope). 2088 2089 Returns either X or an old decl for the same name. 2090 If an old decl is returned, it may have been smashed 2091 to agree with what X says. */ 2092 2093tree 2094pushdecl (tree x) 2095{ 2096 tree name = DECL_NAME (x); 2097 struct c_scope *scope = current_scope; 2098 struct c_binding *b; 2099 bool nested = false; 2100 2101 /* Functions need the lang_decl data. */ 2102 if (TREE_CODE (x) == FUNCTION_DECL && !DECL_LANG_SPECIFIC (x)) 2103 DECL_LANG_SPECIFIC (x) = GGC_CNEW (struct lang_decl); 2104 2105 /* Must set DECL_CONTEXT for everything not at file scope or 2106 DECL_FILE_SCOPE_P won't work. Local externs don't count 2107 unless they have initializers (which generate code). */ 2108 if (current_function_decl 2109 && ((TREE_CODE (x) != FUNCTION_DECL && TREE_CODE (x) != VAR_DECL) 2110 || DECL_INITIAL (x) || !DECL_EXTERNAL (x))) 2111 DECL_CONTEXT (x) = current_function_decl; 2112 2113 /* If this is of variably modified type, prevent jumping into its 2114 scope. */ 2115 if ((TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == TYPE_DECL) 2116 && variably_modified_type_p (TREE_TYPE (x), NULL_TREE)) 2117 c_begin_vm_scope (scope->depth); 2118 2119 /* Anonymous decls are just inserted in the scope. */ 2120 if (!name) 2121 { 2122 bind (name, x, scope, /*invisible=*/false, /*nested=*/false); 2123 return x; 2124 } 2125 2126 /* First, see if there is another declaration with the same name in 2127 the current scope. If there is, duplicate_decls may do all the 2128 work for us. If duplicate_decls returns false, that indicates 2129 two incompatible decls in the same scope; we are to silently 2130 replace the old one (duplicate_decls has issued all appropriate 2131 diagnostics). In particular, we should not consider possible 2132 duplicates in the external scope, or shadowing. */ 2133 b = I_SYMBOL_BINDING (name); 2134 if (b && B_IN_SCOPE (b, scope)) 2135 { 2136 struct c_binding *b_ext, *b_use; 2137 tree type = TREE_TYPE (x); 2138 tree visdecl = b->decl; 2139 tree vistype = TREE_TYPE (visdecl); 2140 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 2141 && COMPLETE_TYPE_P (TREE_TYPE (x))) 2142 b->inner_comp = false; 2143 b_use = b; 2144 b_ext = b; 2145 /* If this is an external linkage declaration, we should check 2146 for compatibility with the type in the external scope before 2147 setting the type at this scope based on the visible 2148 information only. */ 2149 if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl)) 2150 { 2151 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 2152 b_ext = b_ext->shadowed; 2153 if (b_ext) 2154 { 2155 b_use = b_ext; 2156 if (b_use->type) 2157 TREE_TYPE (b_use->decl) = b_use->type; 2158 } 2159 } 2160 if (duplicate_decls (x, b_use->decl)) 2161 { 2162 if (b_use != b) 2163 { 2164 /* Save the updated type in the external scope and 2165 restore the proper type for this scope. */ 2166 tree thistype; 2167 if (comptypes (vistype, type)) 2168 thistype = composite_type (vistype, type); 2169 else 2170 thistype = TREE_TYPE (b_use->decl); 2171 b_use->type = TREE_TYPE (b_use->decl); 2172 if (TREE_CODE (b_use->decl) == FUNCTION_DECL 2173 && DECL_BUILT_IN (b_use->decl)) 2174 thistype 2175 = build_type_attribute_variant (thistype, 2176 TYPE_ATTRIBUTES 2177 (b_use->type)); 2178 TREE_TYPE (b_use->decl) = thistype; 2179 } 2180 return b_use->decl; 2181 } 2182 else 2183 goto skip_external_and_shadow_checks; 2184 } 2185 2186 /* All declarations with external linkage, and all external 2187 references, go in the external scope, no matter what scope is 2188 current. However, the binding in that scope is ignored for 2189 purposes of normal name lookup. A separate binding structure is 2190 created in the requested scope; this governs the normal 2191 visibility of the symbol. 2192 2193 The binding in the externals scope is used exclusively for 2194 detecting duplicate declarations of the same object, no matter 2195 what scope they are in; this is what we do here. (C99 6.2.7p2: 2196 All declarations that refer to the same object or function shall 2197 have compatible type; otherwise, the behavior is undefined.) */ 2198 if (DECL_EXTERNAL (x) || scope == file_scope) 2199 { 2200 tree type = TREE_TYPE (x); 2201 tree vistype = 0; 2202 tree visdecl = 0; 2203 bool type_saved = false; 2204 if (b && !B_IN_EXTERNAL_SCOPE (b) 2205 && (TREE_CODE (b->decl) == FUNCTION_DECL 2206 || TREE_CODE (b->decl) == VAR_DECL) 2207 && DECL_FILE_SCOPE_P (b->decl)) 2208 { 2209 visdecl = b->decl; 2210 vistype = TREE_TYPE (visdecl); 2211 } 2212 if (scope != file_scope 2213 && !DECL_IN_SYSTEM_HEADER (x)) 2214 warning (OPT_Wnested_externs, "nested extern declaration of %qD", x); 2215 2216 while (b && !B_IN_EXTERNAL_SCOPE (b)) 2217 { 2218 /* If this decl might be modified, save its type. This is 2219 done here rather than when the decl is first bound 2220 because the type may change after first binding, through 2221 being completed or through attributes being added. If we 2222 encounter multiple such decls, only the first should have 2223 its type saved; the others will already have had their 2224 proper types saved and the types will not have changed as 2225 their scopes will not have been re-entered. */ 2226 if (DECL_P (b->decl) && DECL_FILE_SCOPE_P (b->decl) && !type_saved) 2227 { 2228 b->type = TREE_TYPE (b->decl); 2229 type_saved = true; 2230 } 2231 if (B_IN_FILE_SCOPE (b) 2232 && TREE_CODE (b->decl) == VAR_DECL 2233 && TREE_STATIC (b->decl) 2234 && TREE_CODE (TREE_TYPE (b->decl)) == ARRAY_TYPE 2235 && !TYPE_DOMAIN (TREE_TYPE (b->decl)) 2236 && TREE_CODE (type) == ARRAY_TYPE 2237 && TYPE_DOMAIN (type) 2238 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) 2239 && !integer_zerop (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))) 2240 { 2241 /* Array type completed in inner scope, which should be 2242 diagnosed if the completion does not have size 1 and 2243 it does not get completed in the file scope. */ 2244 b->inner_comp = true; 2245 } 2246 b = b->shadowed; 2247 } 2248 2249 /* If a matching external declaration has been found, set its 2250 type to the composite of all the types of that declaration. 2251 After the consistency checks, it will be reset to the 2252 composite of the visible types only. */ 2253 if (b && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2254 && b->type) 2255 TREE_TYPE (b->decl) = b->type; 2256 2257 /* The point of the same_translation_unit_p check here is, 2258 we want to detect a duplicate decl for a construct like 2259 foo() { extern bar(); } ... static bar(); but not if 2260 they are in different translation units. In any case, 2261 the static does not go in the externals scope. */ 2262 if (b 2263 && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2264 && duplicate_decls (x, b->decl)) 2265 { 2266 tree thistype; 2267 if (vistype) 2268 { 2269 if (comptypes (vistype, type)) 2270 thistype = composite_type (vistype, type); 2271 else 2272 thistype = TREE_TYPE (b->decl); 2273 } 2274 else 2275 thistype = type; 2276 b->type = TREE_TYPE (b->decl); 2277 if (TREE_CODE (b->decl) == FUNCTION_DECL && DECL_BUILT_IN (b->decl)) 2278 thistype 2279 = build_type_attribute_variant (thistype, 2280 TYPE_ATTRIBUTES (b->type)); 2281 TREE_TYPE (b->decl) = thistype; 2282 bind (name, b->decl, scope, /*invisible=*/false, /*nested=*/true); 2283 return b->decl; 2284 } 2285 else if (TREE_PUBLIC (x)) 2286 { 2287 if (visdecl && !b && duplicate_decls (x, visdecl)) 2288 { 2289 /* An external declaration at block scope referring to a 2290 visible entity with internal linkage. The composite 2291 type will already be correct for this scope, so we 2292 just need to fall through to make the declaration in 2293 this scope. */ 2294 nested = true; 2295 x = visdecl; 2296 } 2297 else 2298 { 2299 bind (name, x, external_scope, /*invisible=*/true, 2300 /*nested=*/false); 2301 nested = true; 2302 } 2303 } 2304 } 2305 2306 if (TREE_CODE (x) != PARM_DECL) 2307 warn_if_shadowing (x); 2308 2309 skip_external_and_shadow_checks: 2310 if (TREE_CODE (x) == TYPE_DECL) 2311 clone_underlying_type (x); 2312 2313 bind (name, x, scope, /*invisible=*/false, nested); 2314 2315 /* If x's type is incomplete because it's based on a 2316 structure or union which has not yet been fully declared, 2317 attach it to that structure or union type, so we can go 2318 back and complete the variable declaration later, if the 2319 structure or union gets fully declared. 2320 2321 If the input is erroneous, we can have error_mark in the type 2322 slot (e.g. "f(void a, ...)") - that doesn't count as an 2323 incomplete type. */ 2324 if (TREE_TYPE (x) != error_mark_node 2325 && !COMPLETE_TYPE_P (TREE_TYPE (x))) 2326 { 2327 tree element = TREE_TYPE (x); 2328 2329 while (TREE_CODE (element) == ARRAY_TYPE) 2330 element = TREE_TYPE (element); 2331 element = TYPE_MAIN_VARIANT (element); 2332 2333 if ((TREE_CODE (element) == RECORD_TYPE 2334 || TREE_CODE (element) == UNION_TYPE) 2335 && (TREE_CODE (x) != TYPE_DECL 2336 || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE) 2337 && !COMPLETE_TYPE_P (element)) 2338 C_TYPE_INCOMPLETE_VARS (element) 2339 = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element)); 2340 } 2341 return x; 2342} 2343 2344/* Record X as belonging to file scope. 2345 This is used only internally by the Objective-C front end, 2346 and is limited to its needs. duplicate_decls is not called; 2347 if there is any preexisting decl for this identifier, it is an ICE. */ 2348 2349tree 2350pushdecl_top_level (tree x) 2351{ 2352 tree name; 2353 bool nested = false; 2354 gcc_assert (TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == CONST_DECL); 2355 2356 name = DECL_NAME (x); 2357 2358 gcc_assert (TREE_CODE (x) == CONST_DECL || !I_SYMBOL_BINDING (name)); 2359 2360 if (TREE_PUBLIC (x)) 2361 { 2362 bind (name, x, external_scope, /*invisible=*/true, /*nested=*/false); 2363 nested = true; 2364 } 2365 if (file_scope) 2366 bind (name, x, file_scope, /*invisible=*/false, nested); 2367 2368 return x; 2369} 2370 2371static void 2372implicit_decl_warning (tree id, tree olddecl) 2373{ 2374 void (*diag) (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2); 2375 switch (mesg_implicit_function_declaration) 2376 { 2377 case 0: return; 2378 case 1: diag = warning0; break; 2379 case 2: diag = error; break; 2380 default: gcc_unreachable (); 2381 } 2382 2383 diag (G_("implicit declaration of function %qE"), id); 2384 if (olddecl) 2385 locate_old_decl (olddecl, diag); 2386} 2387 2388/* Generate an implicit declaration for identifier FUNCTIONID as a 2389 function of type int (). */ 2390 2391tree 2392implicitly_declare (tree functionid) 2393{ 2394 struct c_binding *b; 2395 tree decl = 0; 2396 tree asmspec_tree; 2397 2398 for (b = I_SYMBOL_BINDING (functionid); b; b = b->shadowed) 2399 { 2400 if (B_IN_SCOPE (b, external_scope)) 2401 { 2402 decl = b->decl; 2403 break; 2404 } 2405 } 2406 2407 if (decl) 2408 { 2409 if (decl == error_mark_node) 2410 return decl; 2411 2412 /* FIXME: Objective-C has weird not-really-builtin functions 2413 which are supposed to be visible automatically. They wind up 2414 in the external scope because they're pushed before the file 2415 scope gets created. Catch this here and rebind them into the 2416 file scope. */ 2417 if (!DECL_BUILT_IN (decl) && DECL_IS_BUILTIN (decl)) 2418 { 2419 bind (functionid, decl, file_scope, 2420 /*invisible=*/false, /*nested=*/true); 2421 return decl; 2422 } 2423 else 2424 { 2425 tree newtype = default_function_type; 2426 if (b->type) 2427 TREE_TYPE (decl) = b->type; 2428 /* Implicit declaration of a function already declared 2429 (somehow) in a different scope, or as a built-in. 2430 If this is the first time this has happened, warn; 2431 then recycle the old declaration but with the new type. */ 2432 if (!C_DECL_IMPLICIT (decl)) 2433 { 2434 implicit_decl_warning (functionid, decl); 2435 C_DECL_IMPLICIT (decl) = 1; 2436 } 2437 if (DECL_BUILT_IN (decl)) 2438 { 2439 newtype = build_type_attribute_variant (newtype, 2440 TYPE_ATTRIBUTES 2441 (TREE_TYPE (decl))); 2442 if (!comptypes (newtype, TREE_TYPE (decl))) 2443 { 2444 warning (0, "incompatible implicit declaration of built-in" 2445 " function %qD", decl); 2446 newtype = TREE_TYPE (decl); 2447 } 2448 } 2449 else 2450 { 2451 if (!comptypes (newtype, TREE_TYPE (decl))) 2452 { 2453 error ("incompatible implicit declaration of function %qD", 2454 decl); 2455 locate_old_decl (decl, error); 2456 } 2457 } 2458 b->type = TREE_TYPE (decl); 2459 TREE_TYPE (decl) = newtype; 2460 bind (functionid, decl, current_scope, 2461 /*invisible=*/false, /*nested=*/true); 2462 return decl; 2463 } 2464 } 2465 2466 /* Not seen before. */ 2467 decl = build_decl (FUNCTION_DECL, functionid, default_function_type); 2468 DECL_EXTERNAL (decl) = 1; 2469 TREE_PUBLIC (decl) = 1; 2470 C_DECL_IMPLICIT (decl) = 1; 2471 implicit_decl_warning (functionid, 0); 2472 asmspec_tree = maybe_apply_renaming_pragma (decl, /*asmname=*/NULL); 2473 if (asmspec_tree) 2474 set_user_assembler_name (decl, TREE_STRING_POINTER (asmspec_tree)); 2475 2476 /* C89 says implicit declarations are in the innermost block. 2477 So we record the decl in the standard fashion. */ 2478 decl = pushdecl (decl); 2479 2480 /* No need to call objc_check_decl here - it's a function type. */ 2481 rest_of_decl_compilation (decl, 0, 0); 2482 2483 /* Write a record describing this implicit function declaration 2484 to the prototypes file (if requested). */ 2485 gen_aux_info_record (decl, 0, 1, 0); 2486 2487 /* Possibly apply some default attributes to this implicit declaration. */ 2488 decl_attributes (&decl, NULL_TREE, 0); 2489 2490 return decl; 2491} 2492 2493/* Issue an error message for a reference to an undeclared variable 2494 ID, including a reference to a builtin outside of function-call 2495 context. Establish a binding of the identifier to error_mark_node 2496 in an appropriate scope, which will suppress further errors for the 2497 same identifier. The error message should be given location LOC. */ 2498void 2499undeclared_variable (tree id, location_t loc) 2500{ 2501 static bool already = false; 2502 struct c_scope *scope; 2503 2504 if (current_function_decl == 0) 2505 { 2506 error ("%H%qE undeclared here (not in a function)", &loc, id); 2507 scope = current_scope; 2508 } 2509 else 2510 { 2511 error ("%H%qE undeclared (first use in this function)", &loc, id); 2512 2513 if (!already) 2514 { 2515 error ("%H(Each undeclared identifier is reported only once", &loc); 2516 error ("%Hfor each function it appears in.)", &loc); 2517 already = true; 2518 } 2519 2520 /* If we are parsing old-style parameter decls, current_function_decl 2521 will be nonnull but current_function_scope will be null. */ 2522 scope = current_function_scope ? current_function_scope : current_scope; 2523 } 2524 bind (id, error_mark_node, scope, /*invisible=*/false, /*nested=*/false); 2525} 2526 2527/* Subroutine of lookup_label, declare_label, define_label: construct a 2528 LABEL_DECL with all the proper frills. */ 2529 2530static tree 2531make_label (tree name, location_t location) 2532{ 2533 tree label = build_decl (LABEL_DECL, name, void_type_node); 2534 2535 DECL_CONTEXT (label) = current_function_decl; 2536 DECL_MODE (label) = VOIDmode; 2537 DECL_SOURCE_LOCATION (label) = location; 2538 2539 return label; 2540} 2541 2542/* Get the LABEL_DECL corresponding to identifier NAME as a label. 2543 Create one if none exists so far for the current function. 2544 This is called when a label is used in a goto expression or 2545 has its address taken. */ 2546 2547tree 2548lookup_label (tree name) 2549{ 2550 tree label; 2551 2552 if (current_function_decl == 0) 2553 { 2554 error ("label %qE referenced outside of any function", name); 2555 return 0; 2556 } 2557 2558 /* Use a label already defined or ref'd with this name, but not if 2559 it is inherited from a containing function and wasn't declared 2560 using __label__. */ 2561 label = I_LABEL_DECL (name); 2562 if (label && (DECL_CONTEXT (label) == current_function_decl 2563 || C_DECLARED_LABEL_FLAG (label))) 2564 { 2565 /* If the label has only been declared, update its apparent 2566 location to point here, for better diagnostics if it 2567 turns out not to have been defined. */ 2568 if (!TREE_USED (label)) 2569 DECL_SOURCE_LOCATION (label) = input_location; 2570 return label; 2571 } 2572 2573 /* No label binding for that identifier; make one. */ 2574 label = make_label (name, input_location); 2575 2576 /* Ordinary labels go in the current function scope. */ 2577 bind (name, label, current_function_scope, 2578 /*invisible=*/false, /*nested=*/false); 2579 return label; 2580} 2581 2582/* Make a label named NAME in the current function, shadowing silently 2583 any that may be inherited from containing functions or containing 2584 scopes. This is called for __label__ declarations. */ 2585 2586tree 2587declare_label (tree name) 2588{ 2589 struct c_binding *b = I_LABEL_BINDING (name); 2590 tree label; 2591 2592 /* Check to make sure that the label hasn't already been declared 2593 at this scope */ 2594 if (b && B_IN_CURRENT_SCOPE (b)) 2595 { 2596 error ("duplicate label declaration %qE", name); 2597 locate_old_decl (b->decl, error); 2598 2599 /* Just use the previous declaration. */ 2600 return b->decl; 2601 } 2602 2603 label = make_label (name, input_location); 2604 C_DECLARED_LABEL_FLAG (label) = 1; 2605 2606 /* Declared labels go in the current scope. */ 2607 bind (name, label, current_scope, 2608 /*invisible=*/false, /*nested=*/false); 2609 return label; 2610} 2611 2612/* Define a label, specifying the location in the source file. 2613 Return the LABEL_DECL node for the label, if the definition is valid. 2614 Otherwise return 0. */ 2615 2616tree 2617define_label (location_t location, tree name) 2618{ 2619 /* Find any preexisting label with this name. It is an error 2620 if that label has already been defined in this function, or 2621 if there is a containing function with a declared label with 2622 the same name. */ 2623 tree label = I_LABEL_DECL (name); 2624 struct c_label_list *nlist_se, *nlist_vm; 2625 2626 if (label 2627 && ((DECL_CONTEXT (label) == current_function_decl 2628 && DECL_INITIAL (label) != 0) 2629 || (DECL_CONTEXT (label) != current_function_decl 2630 && C_DECLARED_LABEL_FLAG (label)))) 2631 { 2632 error ("%Hduplicate label %qD", &location, label); 2633 locate_old_decl (label, error); 2634 return 0; 2635 } 2636 else if (label && DECL_CONTEXT (label) == current_function_decl) 2637 { 2638 /* The label has been used or declared already in this function, 2639 but not defined. Update its location to point to this 2640 definition. */ 2641 if (C_DECL_UNDEFINABLE_STMT_EXPR (label)) 2642 error ("%Jjump into statement expression", label); 2643 if (C_DECL_UNDEFINABLE_VM (label)) 2644 error ("%Jjump into scope of identifier with variably modified type", 2645 label); 2646 DECL_SOURCE_LOCATION (label) = location; 2647 } 2648 else 2649 { 2650 /* No label binding for that identifier; make one. */ 2651 label = make_label (name, location); 2652 2653 /* Ordinary labels go in the current function scope. */ 2654 bind (name, label, current_function_scope, 2655 /*invisible=*/false, /*nested=*/false); 2656 } 2657 2658 if (!in_system_header && lookup_name (name)) 2659 warning (OPT_Wtraditional, "%Htraditional C lacks a separate namespace " 2660 "for labels, identifier %qE conflicts", &location, name); 2661 2662 nlist_se = XOBNEW (&parser_obstack, struct c_label_list); 2663 nlist_se->next = label_context_stack_se->labels_def; 2664 nlist_se->label = label; 2665 label_context_stack_se->labels_def = nlist_se; 2666 2667 nlist_vm = XOBNEW (&parser_obstack, struct c_label_list); 2668 nlist_vm->next = label_context_stack_vm->labels_def; 2669 nlist_vm->label = label; 2670 label_context_stack_vm->labels_def = nlist_vm; 2671 2672 /* Mark label as having been defined. */ 2673 DECL_INITIAL (label) = error_mark_node; 2674 return label; 2675} 2676 2677/* Given NAME, an IDENTIFIER_NODE, 2678 return the structure (or union or enum) definition for that name. 2679 If THISLEVEL_ONLY is nonzero, searches only the current_scope. 2680 CODE says which kind of type the caller wants; 2681 it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE. 2682 If the wrong kind of type is found, an error is reported. */ 2683 2684static tree 2685lookup_tag (enum tree_code code, tree name, int thislevel_only) 2686{ 2687 struct c_binding *b = I_TAG_BINDING (name); 2688 int thislevel = 0; 2689 2690 if (!b || !b->decl) 2691 return 0; 2692 2693 /* We only care about whether it's in this level if 2694 thislevel_only was set or it might be a type clash. */ 2695 if (thislevel_only || TREE_CODE (b->decl) != code) 2696 { 2697 /* For our purposes, a tag in the external scope is the same as 2698 a tag in the file scope. (Primarily relevant to Objective-C 2699 and its builtin structure tags, which get pushed before the 2700 file scope is created.) */ 2701 if (B_IN_CURRENT_SCOPE (b) 2702 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 2703 thislevel = 1; 2704 } 2705 2706 if (thislevel_only && !thislevel) 2707 return 0; 2708 2709 if (TREE_CODE (b->decl) != code) 2710 { 2711 /* Definition isn't the kind we were looking for. */ 2712 pending_invalid_xref = name; 2713 pending_invalid_xref_location = input_location; 2714 2715 /* If in the same binding level as a declaration as a tag 2716 of a different type, this must not be allowed to 2717 shadow that tag, so give the error immediately. 2718 (For example, "struct foo; union foo;" is invalid.) */ 2719 if (thislevel) 2720 pending_xref_error (); 2721 } 2722 return b->decl; 2723} 2724 2725/* Print an error message now 2726 for a recent invalid struct, union or enum cross reference. 2727 We don't print them immediately because they are not invalid 2728 when used in the `struct foo;' construct for shadowing. */ 2729 2730void 2731pending_xref_error (void) 2732{ 2733 if (pending_invalid_xref != 0) 2734 error ("%H%qE defined as wrong kind of tag", 2735 &pending_invalid_xref_location, pending_invalid_xref); 2736 pending_invalid_xref = 0; 2737} 2738 2739 2740/* Look up NAME in the current scope and its superiors 2741 in the namespace of variables, functions and typedefs. 2742 Return a ..._DECL node of some kind representing its definition, 2743 or return 0 if it is undefined. */ 2744 2745tree 2746lookup_name (tree name) 2747{ 2748 struct c_binding *b = I_SYMBOL_BINDING (name); 2749 if (b && !b->invisible) 2750 return b->decl; 2751 return 0; 2752} 2753 2754/* Similar to `lookup_name' but look only at the indicated scope. */ 2755 2756static tree 2757lookup_name_in_scope (tree name, struct c_scope *scope) 2758{ 2759 struct c_binding *b; 2760 2761 for (b = I_SYMBOL_BINDING (name); b; b = b->shadowed) 2762 if (B_IN_SCOPE (b, scope)) 2763 return b->decl; 2764 return 0; 2765} 2766 2767/* Create the predefined scalar types of C, 2768 and some nodes representing standard constants (0, 1, (void *) 0). 2769 Initialize the global scope. 2770 Make definitions for built-in primitive functions. */ 2771 2772void 2773c_init_decl_processing (void) 2774{ 2775 location_t save_loc = input_location; 2776 2777 /* Initialize reserved words for parser. */ 2778 c_parse_init (); 2779 2780 current_function_decl = 0; 2781 2782 gcc_obstack_init (&parser_obstack); 2783 2784 /* Make the externals scope. */ 2785 push_scope (); 2786 external_scope = current_scope; 2787 2788 /* Declarations from c_common_nodes_and_builtins must not be associated 2789 with this input file, lest we get differences between using and not 2790 using preprocessed headers. */ 2791#ifdef USE_MAPPED_LOCATION 2792 input_location = BUILTINS_LOCATION; 2793#else 2794 input_location.file = "<built-in>"; 2795 input_location.line = 0; 2796#endif 2797 2798 build_common_tree_nodes (flag_signed_char, false); 2799 2800 c_common_nodes_and_builtins (); 2801 2802 /* In C, comparisons and TRUTH_* expressions have type int. */ 2803 truthvalue_type_node = integer_type_node; 2804 truthvalue_true_node = integer_one_node; 2805 truthvalue_false_node = integer_zero_node; 2806 2807 /* Even in C99, which has a real boolean type. */ 2808 pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"), 2809 boolean_type_node)); 2810 2811 input_location = save_loc; 2812 2813 pedantic_lvalues = true; 2814 2815 make_fname_decl = c_make_fname_decl; 2816 start_fname_decls (); 2817} 2818 2819/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the 2820 decl, NAME is the initialization string and TYPE_DEP indicates whether 2821 NAME depended on the type of the function. As we don't yet implement 2822 delayed emission of static data, we mark the decl as emitted 2823 so it is not placed in the output. Anything using it must therefore pull 2824 out the STRING_CST initializer directly. FIXME. */ 2825 2826static tree 2827c_make_fname_decl (tree id, int type_dep) 2828{ 2829 const char *name = fname_as_string (type_dep); 2830 tree decl, type, init; 2831 size_t length = strlen (name); 2832 2833 type = build_array_type (char_type_node, 2834 build_index_type (size_int (length))); 2835 type = c_build_qualified_type (type, TYPE_QUAL_CONST); 2836 2837 decl = build_decl (VAR_DECL, id, type); 2838 2839 TREE_STATIC (decl) = 1; 2840 TREE_READONLY (decl) = 1; 2841 DECL_ARTIFICIAL (decl) = 1; 2842 2843 init = build_string (length + 1, name); 2844 free ((char *) name); 2845 TREE_TYPE (init) = type; 2846 DECL_INITIAL (decl) = init; 2847 2848 TREE_USED (decl) = 1; 2849 2850 if (current_function_decl 2851 /* For invalid programs like this: 2852 2853 void foo() 2854 const char* p = __FUNCTION__; 2855 2856 the __FUNCTION__ is believed to appear in K&R style function 2857 parameter declarator. In that case we still don't have 2858 function_scope. */ 2859 && (!errorcount || current_function_scope)) 2860 { 2861 DECL_CONTEXT (decl) = current_function_decl; 2862 bind (id, decl, current_function_scope, 2863 /*invisible=*/false, /*nested=*/false); 2864 } 2865 2866 finish_decl (decl, init, NULL_TREE); 2867 2868 return decl; 2869} 2870 2871/* Return a definition for a builtin function named NAME and whose data type 2872 is TYPE. TYPE should be a function type with argument types. 2873 FUNCTION_CODE tells later passes how to compile calls to this function. 2874 See tree.h for its possible values. 2875 2876 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, 2877 the name to be called if we can't opencode the function. If 2878 ATTRS is nonzero, use that for the function's attribute list. */ 2879 2880tree 2881builtin_function (const char *name, tree type, int function_code, 2882 enum built_in_class cl, const char *library_name, 2883 tree attrs) 2884{ 2885 tree id = get_identifier (name); 2886 tree decl = build_decl (FUNCTION_DECL, id, type); 2887 TREE_PUBLIC (decl) = 1; 2888 DECL_EXTERNAL (decl) = 1; 2889 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 2890 DECL_BUILT_IN_CLASS (decl) = cl; 2891 DECL_FUNCTION_CODE (decl) = function_code; 2892 C_DECL_BUILTIN_PROTOTYPE (decl) = (TYPE_ARG_TYPES (type) != 0); 2893 if (library_name) 2894 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name)); 2895 2896 /* Should never be called on a symbol with a preexisting meaning. */ 2897 gcc_assert (!I_SYMBOL_BINDING (id)); 2898 2899 bind (id, decl, external_scope, /*invisible=*/true, /*nested=*/false); 2900 2901 /* Builtins in the implementation namespace are made visible without 2902 needing to be explicitly declared. See push_file_scope. */ 2903 if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1]))) 2904 { 2905 TREE_CHAIN (decl) = visible_builtins; 2906 visible_builtins = decl; 2907 } 2908 2909 /* Possibly apply some default attributes to this built-in function. */ 2910 if (attrs) 2911 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN); 2912 else 2913 decl_attributes (&decl, NULL_TREE, 0); 2914 2915 return decl; 2916} 2917 2918/* Called when a declaration is seen that contains no names to declare. 2919 If its type is a reference to a structure, union or enum inherited 2920 from a containing scope, shadow that tag name for the current scope 2921 with a forward reference. 2922 If its type defines a new named structure or union 2923 or defines an enum, it is valid but we need not do anything here. 2924 Otherwise, it is an error. */ 2925 2926void 2927shadow_tag (const struct c_declspecs *declspecs) 2928{ 2929 shadow_tag_warned (declspecs, 0); 2930} 2931 2932/* WARNED is 1 if we have done a pedwarn, 2 if we have done a warning, 2933 but no pedwarn. */ 2934void 2935shadow_tag_warned (const struct c_declspecs *declspecs, int warned) 2936{ 2937 bool found_tag = false; 2938 2939 if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p) 2940 { 2941 tree value = declspecs->type; 2942 enum tree_code code = TREE_CODE (value); 2943 2944 if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) 2945 /* Used to test also that TYPE_SIZE (value) != 0. 2946 That caused warning for `struct foo;' at top level in the file. */ 2947 { 2948 tree name = TYPE_NAME (value); 2949 tree t; 2950 2951 found_tag = true; 2952 2953 if (name == 0) 2954 { 2955 if (warned != 1 && code != ENUMERAL_TYPE) 2956 /* Empty unnamed enum OK */ 2957 { 2958 pedwarn ("unnamed struct/union that defines no instances"); 2959 warned = 1; 2960 } 2961 } 2962 else if (!declspecs->tag_defined_p 2963 && declspecs->storage_class != csc_none) 2964 { 2965 if (warned != 1) 2966 pedwarn ("empty declaration with storage class specifier " 2967 "does not redeclare tag"); 2968 warned = 1; 2969 pending_xref_error (); 2970 } 2971 else if (!declspecs->tag_defined_p 2972 && (declspecs->const_p 2973 || declspecs->volatile_p 2974 || declspecs->restrict_p)) 2975 { 2976 if (warned != 1) 2977 pedwarn ("empty declaration with type qualifier " 2978 "does not redeclare tag"); 2979 warned = 1; 2980 pending_xref_error (); 2981 } 2982 else 2983 { 2984 pending_invalid_xref = 0; 2985 t = lookup_tag (code, name, 1); 2986 2987 if (t == 0) 2988 { 2989 t = make_node (code); 2990 pushtag (name, t); 2991 } 2992 } 2993 } 2994 else 2995 { 2996 if (warned != 1 && !in_system_header) 2997 { 2998 pedwarn ("useless type name in empty declaration"); 2999 warned = 1; 3000 } 3001 } 3002 } 3003 else if (warned != 1 && !in_system_header && declspecs->typedef_p) 3004 { 3005 pedwarn ("useless type name in empty declaration"); 3006 warned = 1; 3007 } 3008 3009 pending_invalid_xref = 0; 3010 3011 if (declspecs->inline_p) 3012 { 3013 error ("%<inline%> in empty declaration"); 3014 warned = 1; 3015 } 3016 3017 if (current_scope == file_scope && declspecs->storage_class == csc_auto) 3018 { 3019 error ("%<auto%> in file-scope empty declaration"); 3020 warned = 1; 3021 } 3022 3023 if (current_scope == file_scope && declspecs->storage_class == csc_register) 3024 { 3025 error ("%<register%> in file-scope empty declaration"); 3026 warned = 1; 3027 } 3028 3029 if (!warned && !in_system_header && declspecs->storage_class != csc_none) 3030 { 3031 warning (0, "useless storage class specifier in empty declaration"); 3032 warned = 2; 3033 } 3034 3035 if (!warned && !in_system_header && declspecs->thread_p) 3036 { 3037 warning (0, "useless %<__thread%> in empty declaration"); 3038 warned = 2; 3039 } 3040 3041 if (!warned && !in_system_header && (declspecs->const_p 3042 || declspecs->volatile_p 3043 || declspecs->restrict_p)) 3044 { 3045 warning (0, "useless type qualifier in empty declaration"); 3046 warned = 2; 3047 } 3048 3049 if (warned != 1) 3050 { 3051 if (!found_tag) 3052 pedwarn ("empty declaration"); 3053 } 3054} 3055 3056 3057/* Return the qualifiers from SPECS as a bitwise OR of TYPE_QUAL_* 3058 bits. SPECS represents declaration specifiers that the grammar 3059 only permits to contain type qualifiers and attributes. */ 3060 3061int 3062quals_from_declspecs (const struct c_declspecs *specs) 3063{ 3064 int quals = ((specs->const_p ? TYPE_QUAL_CONST : 0) 3065 | (specs->volatile_p ? TYPE_QUAL_VOLATILE : 0) 3066 | (specs->restrict_p ? TYPE_QUAL_RESTRICT : 0)); 3067 gcc_assert (!specs->type 3068 && !specs->decl_attr 3069 && specs->typespec_word == cts_none 3070 && specs->storage_class == csc_none 3071 && !specs->typedef_p 3072 && !specs->explicit_signed_p 3073 && !specs->deprecated_p 3074 && !specs->long_p 3075 && !specs->long_long_p 3076 && !specs->short_p 3077 && !specs->signed_p 3078 && !specs->unsigned_p 3079 && !specs->complex_p 3080 && !specs->inline_p 3081 && !specs->thread_p); 3082 return quals; 3083} 3084 3085/* Construct an array declarator. EXPR is the expression inside [], 3086 or NULL_TREE. QUALS are the type qualifiers inside the [] (to be 3087 applied to the pointer to which a parameter array is converted). 3088 STATIC_P is true if "static" is inside the [], false otherwise. 3089 VLA_UNSPEC_P is true if the array is [*], a VLA of unspecified 3090 length which is nevertheless a complete type, false otherwise. The 3091 field for the contained declarator is left to be filled in by 3092 set_array_declarator_inner. */ 3093 3094struct c_declarator * 3095build_array_declarator (tree expr, struct c_declspecs *quals, bool static_p, 3096 bool vla_unspec_p) 3097{ 3098 struct c_declarator *declarator = XOBNEW (&parser_obstack, 3099 struct c_declarator); 3100 declarator->kind = cdk_array; 3101 declarator->declarator = 0; 3102 declarator->u.array.dimen = expr; 3103 if (quals) 3104 { 3105 declarator->u.array.attrs = quals->attrs; 3106 declarator->u.array.quals = quals_from_declspecs (quals); 3107 } 3108 else 3109 { 3110 declarator->u.array.attrs = NULL_TREE; 3111 declarator->u.array.quals = 0; 3112 } 3113 declarator->u.array.static_p = static_p; 3114 declarator->u.array.vla_unspec_p = vla_unspec_p; 3115 if (pedantic && !flag_isoc99) 3116 { 3117 if (static_p || quals != NULL) 3118 pedwarn ("ISO C90 does not support %<static%> or type " 3119 "qualifiers in parameter array declarators"); 3120 if (vla_unspec_p) 3121 pedwarn ("ISO C90 does not support %<[*]%> array declarators"); 3122 } 3123 if (vla_unspec_p) 3124 { 3125 if (!current_scope->parm_flag) 3126 { 3127 /* C99 6.7.5.2p4 */ 3128 error ("%<[*]%> not allowed in other than function prototype scope"); 3129 declarator->u.array.vla_unspec_p = false; 3130 return NULL; 3131 } 3132 current_scope->had_vla_unspec = true; 3133 } 3134 return declarator; 3135} 3136 3137/* Set the contained declarator of an array declarator. DECL is the 3138 declarator, as constructed by build_array_declarator; INNER is what 3139 appears on the left of the []. ABSTRACT_P is true if it is an 3140 abstract declarator, false otherwise; this is used to reject static 3141 and type qualifiers in abstract declarators, where they are not in 3142 the C99 grammar (subject to possible change in DR#289). */ 3143 3144struct c_declarator * 3145set_array_declarator_inner (struct c_declarator *decl, 3146 struct c_declarator *inner, bool abstract_p) 3147{ 3148 decl->declarator = inner; 3149 if (abstract_p && (decl->u.array.quals != TYPE_UNQUALIFIED 3150 || decl->u.array.attrs != NULL_TREE 3151 || decl->u.array.static_p)) 3152 error ("static or type qualifiers in abstract declarator"); 3153 return decl; 3154} 3155 3156/* INIT is a constructor that forms DECL's initializer. If the final 3157 element initializes a flexible array field, add the size of that 3158 initializer to DECL's size. */ 3159 3160static void 3161add_flexible_array_elts_to_size (tree decl, tree init) 3162{ 3163 tree elt, type; 3164 3165 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init))) 3166 return; 3167 3168 elt = VEC_last (constructor_elt, CONSTRUCTOR_ELTS (init))->value; 3169 type = TREE_TYPE (elt); 3170 if (TREE_CODE (type) == ARRAY_TYPE 3171 && TYPE_SIZE (type) == NULL_TREE 3172 && TYPE_DOMAIN (type) != NULL_TREE 3173 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL_TREE) 3174 { 3175 complete_array_type (&type, elt, false); 3176 DECL_SIZE (decl) 3177 = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type)); 3178 DECL_SIZE_UNIT (decl) 3179 = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type)); 3180 } 3181} 3182 3183/* Decode a "typename", such as "int **", returning a ..._TYPE node. */ 3184 3185tree 3186groktypename (struct c_type_name *type_name) 3187{ 3188 tree type; 3189 tree attrs = type_name->specs->attrs; 3190 3191 type_name->specs->attrs = NULL_TREE; 3192 3193 type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME, 3194 false, NULL); 3195 3196 /* Apply attributes. */ 3197 decl_attributes (&type, attrs, 0); 3198 3199 return type; 3200} 3201 3202/* Decode a declarator in an ordinary declaration or data definition. 3203 This is called as soon as the type information and variable name 3204 have been parsed, before parsing the initializer if any. 3205 Here we create the ..._DECL node, fill in its type, 3206 and put it on the list of decls for the current context. 3207 The ..._DECL node is returned as the value. 3208 3209 Exception: for arrays where the length is not specified, 3210 the type is left null, to be filled in by `finish_decl'. 3211 3212 Function definitions do not come here; they go to start_function 3213 instead. However, external and forward declarations of functions 3214 do go through here. Structure field declarations are done by 3215 grokfield and not through here. */ 3216 3217tree 3218start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, 3219 bool initialized, tree attributes) 3220{ 3221 tree decl; 3222 tree tem; 3223 3224 /* An object declared as __attribute__((deprecated)) suppresses 3225 warnings of uses of other deprecated items. */ 3226 if (lookup_attribute ("deprecated", attributes)) 3227 deprecated_state = DEPRECATED_SUPPRESS; 3228 3229 decl = grokdeclarator (declarator, declspecs, 3230 NORMAL, initialized, NULL); 3231 if (!decl) 3232 return 0; 3233 3234 deprecated_state = DEPRECATED_NORMAL; 3235 3236 if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL 3237 && MAIN_NAME_P (DECL_NAME (decl))) 3238 warning (OPT_Wmain, "%q+D is usually a function", decl); 3239 3240 if (initialized) 3241 /* Is it valid for this decl to have an initializer at all? 3242 If not, set INITIALIZED to zero, which will indirectly 3243 tell 'finish_decl' to ignore the initializer once it is parsed. */ 3244 switch (TREE_CODE (decl)) 3245 { 3246 case TYPE_DECL: 3247 error ("typedef %qD is initialized (use __typeof__ instead)", decl); 3248 initialized = 0; 3249 break; 3250 3251 case FUNCTION_DECL: 3252 error ("function %qD is initialized like a variable", decl); 3253 initialized = 0; 3254 break; 3255 3256 case PARM_DECL: 3257 /* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE. */ 3258 error ("parameter %qD is initialized", decl); 3259 initialized = 0; 3260 break; 3261 3262 default: 3263 /* Don't allow initializations for incomplete types except for 3264 arrays which might be completed by the initialization. */ 3265 3266 /* This can happen if the array size is an undefined macro. 3267 We already gave a warning, so we don't need another one. */ 3268 if (TREE_TYPE (decl) == error_mark_node) 3269 initialized = 0; 3270 else if (COMPLETE_TYPE_P (TREE_TYPE (decl))) 3271 { 3272 /* A complete type is ok if size is fixed. */ 3273 3274 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST 3275 || C_DECL_VARIABLE_SIZE (decl)) 3276 { 3277 error ("variable-sized object may not be initialized"); 3278 initialized = 0; 3279 } 3280 } 3281 else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE) 3282 { 3283 error ("variable %qD has initializer but incomplete type", decl); 3284 initialized = 0; 3285 } 3286 else if (C_DECL_VARIABLE_SIZE (decl)) 3287 { 3288 /* Although C99 is unclear about whether incomplete arrays 3289 of VLAs themselves count as VLAs, it does not make 3290 sense to permit them to be initialized given that 3291 ordinary VLAs may not be initialized. */ 3292 error ("variable-sized object may not be initialized"); 3293 initialized = 0; 3294 } 3295 } 3296 3297 if (initialized) 3298 { 3299 if (current_scope == file_scope) 3300 TREE_STATIC (decl) = 1; 3301 3302 /* Tell 'pushdecl' this is an initialized decl 3303 even though we don't yet have the initializer expression. 3304 Also tell 'finish_decl' it may store the real initializer. */ 3305 DECL_INITIAL (decl) = error_mark_node; 3306 } 3307 3308 /* If this is a function declaration, write a record describing it to the 3309 prototypes file (if requested). */ 3310 3311 if (TREE_CODE (decl) == FUNCTION_DECL) 3312 gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0); 3313 3314 /* ANSI specifies that a tentative definition which is not merged with 3315 a non-tentative definition behaves exactly like a definition with an 3316 initializer equal to zero. (Section 3.7.2) 3317 3318 -fno-common gives strict ANSI behavior, though this tends to break 3319 a large body of code that grew up without this rule. 3320 3321 Thread-local variables are never common, since there's no entrenched 3322 body of code to break, and it allows more efficient variable references 3323 in the presence of dynamic linking. */ 3324 3325 if (TREE_CODE (decl) == VAR_DECL 3326 && !initialized 3327 && TREE_PUBLIC (decl) 3328 && !DECL_THREAD_LOCAL_P (decl) 3329 && !flag_no_common) 3330 DECL_COMMON (decl) = 1; 3331 3332 /* Set attributes here so if duplicate decl, will have proper attributes. */ 3333 decl_attributes (&decl, attributes, 0); 3334 3335 /* Handle gnu_inline attribute. */ 3336 if (declspecs->inline_p 3337 && !flag_gnu89_inline 3338 && TREE_CODE (decl) == FUNCTION_DECL 3339 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl))) 3340 { 3341 if (declspecs->storage_class == csc_auto && current_scope != file_scope) 3342 ; 3343 else if (declspecs->storage_class != csc_static) 3344 DECL_EXTERNAL (decl) = !DECL_EXTERNAL (decl); 3345 } 3346 3347 if (TREE_CODE (decl) == FUNCTION_DECL 3348 && targetm.calls.promote_prototypes (TREE_TYPE (decl))) 3349 { 3350 struct c_declarator *ce = declarator; 3351 3352 if (ce->kind == cdk_pointer) 3353 ce = declarator->declarator; 3354 if (ce->kind == cdk_function) 3355 { 3356 tree args = ce->u.arg_info->parms; 3357 for (; args; args = TREE_CHAIN (args)) 3358 { 3359 tree type = TREE_TYPE (args); 3360 if (type && INTEGRAL_TYPE_P (type) 3361 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 3362 DECL_ARG_TYPE (args) = integer_type_node; 3363 } 3364 } 3365 } 3366 3367 if (TREE_CODE (decl) == FUNCTION_DECL 3368 && DECL_DECLARED_INLINE_P (decl) 3369 && DECL_UNINLINABLE (decl) 3370 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl))) 3371 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 3372 decl); 3373 3374 /* C99 6.7.4p3: An inline definition of a function with external 3375 linkage shall not contain a definition of a modifiable object 3376 with static storage duration... */ 3377 if (TREE_CODE (decl) == VAR_DECL 3378 && current_scope != file_scope 3379 && TREE_STATIC (decl) 3380 && !TREE_READONLY (decl) 3381 && DECL_DECLARED_INLINE_P (current_function_decl) 3382 && DECL_EXTERNAL (current_function_decl)) 3383 pedwarn ("%q+D is static but declared in inline function %qD " 3384 "which is not static", decl, current_function_decl); 3385 3386 /* Add this decl to the current scope. 3387 TEM may equal DECL or it may be a previous decl of the same name. */ 3388 tem = pushdecl (decl); 3389 3390 if (initialized && DECL_EXTERNAL (tem)) 3391 { 3392 DECL_EXTERNAL (tem) = 0; 3393 TREE_STATIC (tem) = 1; 3394 } 3395 3396 return tem; 3397} 3398 3399/* Initialize EH if not initialized yet and exceptions are enabled. */ 3400 3401void 3402c_maybe_initialize_eh (void) 3403{ 3404 if (!flag_exceptions || c_eh_initialized_p) 3405 return; 3406 3407 c_eh_initialized_p = true; 3408 eh_personality_libfunc 3409 = init_one_libfunc (USING_SJLJ_EXCEPTIONS 3410 ? "__gcc_personality_sj0" 3411 : "__gcc_personality_v0"); 3412 default_init_unwind_resume_libfunc (); 3413 using_eh_for_cleanups (); 3414} 3415 3416/* Finish processing of a declaration; 3417 install its initial value. 3418 If the length of an array type is not known before, 3419 it must be determined now, from the initial value, or it is an error. */ 3420 3421void 3422finish_decl (tree decl, tree init, tree asmspec_tree) 3423{ 3424 tree type; 3425 int was_incomplete = (DECL_SIZE (decl) == 0); 3426 const char *asmspec = 0; 3427 3428 /* If a name was specified, get the string. */ 3429 if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL) 3430 && DECL_FILE_SCOPE_P (decl)) 3431 asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree); 3432 if (asmspec_tree) 3433 asmspec = TREE_STRING_POINTER (asmspec_tree); 3434 3435 /* If `start_decl' didn't like having an initialization, ignore it now. */ 3436 if (init != 0 && DECL_INITIAL (decl) == 0) 3437 init = 0; 3438 3439 /* Don't crash if parm is initialized. */ 3440 if (TREE_CODE (decl) == PARM_DECL) 3441 init = 0; 3442 3443 if (init) 3444 store_init_value (decl, init); 3445 3446 if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL 3447 || TREE_CODE (decl) == FUNCTION_DECL 3448 || TREE_CODE (decl) == FIELD_DECL)) 3449 objc_check_decl (decl); 3450 3451 type = TREE_TYPE (decl); 3452 3453 /* Deduce size of array from initialization, if not already known. */ 3454 if (TREE_CODE (type) == ARRAY_TYPE 3455 && TYPE_DOMAIN (type) == 0 3456 && TREE_CODE (decl) != TYPE_DECL) 3457 { 3458 bool do_default 3459 = (TREE_STATIC (decl) 3460 /* Even if pedantic, an external linkage array 3461 may have incomplete type at first. */ 3462 ? pedantic && !TREE_PUBLIC (decl) 3463 : !DECL_EXTERNAL (decl)); 3464 int failure 3465 = complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl), 3466 do_default); 3467 3468 /* Get the completed type made by complete_array_type. */ 3469 type = TREE_TYPE (decl); 3470 3471 switch (failure) 3472 { 3473 case 1: 3474 error ("initializer fails to determine size of %q+D", decl); 3475 break; 3476 3477 case 2: 3478 if (do_default) 3479 error ("array size missing in %q+D", decl); 3480 /* If a `static' var's size isn't known, 3481 make it extern as well as static, so it does not get 3482 allocated. 3483 If it is not `static', then do not mark extern; 3484 finish_incomplete_decl will give it a default size 3485 and it will get allocated. */ 3486 else if (!pedantic && TREE_STATIC (decl) && !TREE_PUBLIC (decl)) 3487 DECL_EXTERNAL (decl) = 1; 3488 break; 3489 3490 case 3: 3491 error ("zero or negative size array %q+D", decl); 3492 break; 3493 3494 case 0: 3495 /* For global variables, update the copy of the type that 3496 exists in the binding. */ 3497 if (TREE_PUBLIC (decl)) 3498 { 3499 struct c_binding *b_ext = I_SYMBOL_BINDING (DECL_NAME (decl)); 3500 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 3501 b_ext = b_ext->shadowed; 3502 if (b_ext) 3503 { 3504 if (b_ext->type) 3505 b_ext->type = composite_type (b_ext->type, type); 3506 else 3507 b_ext->type = type; 3508 } 3509 } 3510 break; 3511 3512 default: 3513 gcc_unreachable (); 3514 } 3515 3516 if (DECL_INITIAL (decl)) 3517 TREE_TYPE (DECL_INITIAL (decl)) = type; 3518 3519 layout_decl (decl, 0); 3520 } 3521 3522 if (TREE_CODE (decl) == VAR_DECL) 3523 { 3524 if (init && TREE_CODE (init) == CONSTRUCTOR) 3525 add_flexible_array_elts_to_size (decl, init); 3526 3527 if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node 3528 && COMPLETE_TYPE_P (TREE_TYPE (decl))) 3529 layout_decl (decl, 0); 3530 3531 if (DECL_SIZE (decl) == 0 3532 /* Don't give an error if we already gave one earlier. */ 3533 && TREE_TYPE (decl) != error_mark_node 3534 && (TREE_STATIC (decl) 3535 /* A static variable with an incomplete type 3536 is an error if it is initialized. 3537 Also if it is not file scope. 3538 Otherwise, let it through, but if it is not `extern' 3539 then it may cause an error message later. */ 3540 ? (DECL_INITIAL (decl) != 0 3541 || !DECL_FILE_SCOPE_P (decl)) 3542 /* An automatic variable with an incomplete type 3543 is an error. */ 3544 : !DECL_EXTERNAL (decl))) 3545 { 3546 error ("storage size of %q+D isn%'t known", decl); 3547 TREE_TYPE (decl) = error_mark_node; 3548 } 3549 3550 if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl)) 3551 && DECL_SIZE (decl) != 0) 3552 { 3553 if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) 3554 constant_expression_warning (DECL_SIZE (decl)); 3555 else 3556 error ("storage size of %q+D isn%'t constant", decl); 3557 } 3558 3559 if (TREE_USED (type)) 3560 TREE_USED (decl) = 1; 3561 } 3562 3563 /* If this is a function and an assembler name is specified, reset DECL_RTL 3564 so we can give it its new name. Also, update built_in_decls if it 3565 was a normal built-in. */ 3566 if (TREE_CODE (decl) == FUNCTION_DECL && asmspec) 3567 { 3568 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) 3569 set_builtin_user_assembler_name (decl, asmspec); 3570 set_user_assembler_name (decl, asmspec); 3571 } 3572 3573 /* If #pragma weak was used, mark the decl weak now. */ 3574 maybe_apply_pragma_weak (decl); 3575 3576 /* Output the assembler code and/or RTL code for variables and functions, 3577 unless the type is an undefined structure or union. 3578 If not, it will get done when the type is completed. */ 3579 3580 if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL) 3581 { 3582 /* Determine the ELF visibility. */ 3583 if (TREE_PUBLIC (decl)) 3584 c_determine_visibility (decl); 3585 3586 /* This is a no-op in c-lang.c or something real in objc-act.c. */ 3587 if (c_dialect_objc ()) 3588 objc_check_decl (decl); 3589 3590 if (asmspec) 3591 { 3592 /* If this is not a static variable, issue a warning. 3593 It doesn't make any sense to give an ASMSPEC for an 3594 ordinary, non-register local variable. Historically, 3595 GCC has accepted -- but ignored -- the ASMSPEC in 3596 this case. */ 3597 if (!DECL_FILE_SCOPE_P (decl) 3598 && TREE_CODE (decl) == VAR_DECL 3599 && !C_DECL_REGISTER (decl) 3600 && !TREE_STATIC (decl)) 3601 warning (0, "ignoring asm-specifier for non-static local " 3602 "variable %q+D", decl); 3603 else 3604 set_user_assembler_name (decl, asmspec); 3605 } 3606 3607 if (DECL_FILE_SCOPE_P (decl)) 3608 { 3609 if (DECL_INITIAL (decl) == NULL_TREE 3610 || DECL_INITIAL (decl) == error_mark_node) 3611 /* Don't output anything 3612 when a tentative file-scope definition is seen. 3613 But at end of compilation, do output code for them. */ 3614 DECL_DEFER_OUTPUT (decl) = 1; 3615 rest_of_decl_compilation (decl, true, 0); 3616 } 3617 else 3618 { 3619 /* In conjunction with an ASMSPEC, the `register' 3620 keyword indicates that we should place the variable 3621 in a particular register. */ 3622 if (asmspec && C_DECL_REGISTER (decl)) 3623 { 3624 DECL_HARD_REGISTER (decl) = 1; 3625 /* This cannot be done for a structure with volatile 3626 fields, on which DECL_REGISTER will have been 3627 reset. */ 3628 if (!DECL_REGISTER (decl)) 3629 error ("cannot put object with volatile field into register"); 3630 } 3631 3632 if (TREE_CODE (decl) != FUNCTION_DECL) 3633 { 3634 /* If we're building a variable sized type, and we might be 3635 reachable other than via the top of the current binding 3636 level, then create a new BIND_EXPR so that we deallocate 3637 the object at the right time. */ 3638 /* Note that DECL_SIZE can be null due to errors. */ 3639 if (DECL_SIZE (decl) 3640 && !TREE_CONSTANT (DECL_SIZE (decl)) 3641 && STATEMENT_LIST_HAS_LABEL (cur_stmt_list)) 3642 { 3643 tree bind; 3644 bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL); 3645 TREE_SIDE_EFFECTS (bind) = 1; 3646 add_stmt (bind); 3647 BIND_EXPR_BODY (bind) = push_stmt_list (); 3648 } 3649 add_stmt (build_stmt (DECL_EXPR, decl)); 3650 } 3651 } 3652 3653 3654 if (!DECL_FILE_SCOPE_P (decl)) 3655 { 3656 /* Recompute the RTL of a local array now 3657 if it used to be an incomplete type. */ 3658 if (was_incomplete 3659 && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) 3660 { 3661 /* If we used it already as memory, it must stay in memory. */ 3662 TREE_ADDRESSABLE (decl) = TREE_USED (decl); 3663 /* If it's still incomplete now, no init will save it. */ 3664 if (DECL_SIZE (decl) == 0) 3665 DECL_INITIAL (decl) = 0; 3666 } 3667 } 3668 } 3669 3670 /* If this was marked 'used', be sure it will be output. */ 3671 if (!flag_unit_at_a_time && lookup_attribute ("used", DECL_ATTRIBUTES (decl))) 3672 mark_decl_referenced (decl); 3673 3674 if (TREE_CODE (decl) == TYPE_DECL) 3675 { 3676 if (!DECL_FILE_SCOPE_P (decl) 3677 && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 3678 add_stmt (build_stmt (DECL_EXPR, decl)); 3679 3680 rest_of_decl_compilation (decl, DECL_FILE_SCOPE_P (decl), 0); 3681 } 3682 3683 /* At the end of a declaration, throw away any variable type sizes 3684 of types defined inside that declaration. There is no use 3685 computing them in the following function definition. */ 3686 if (current_scope == file_scope) 3687 get_pending_sizes (); 3688 3689 /* Install a cleanup (aka destructor) if one was given. */ 3690 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 3691 { 3692 tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl)); 3693 if (attr) 3694 { 3695 tree cleanup_id = TREE_VALUE (TREE_VALUE (attr)); 3696 tree cleanup_decl = lookup_name (cleanup_id); 3697 tree cleanup; 3698 3699 /* Build "cleanup(&decl)" for the destructor. */ 3700 cleanup = build_unary_op (ADDR_EXPR, decl, 0); 3701 cleanup = build_tree_list (NULL_TREE, cleanup); 3702 cleanup = build_function_call (cleanup_decl, cleanup); 3703 3704 /* Don't warn about decl unused; the cleanup uses it. */ 3705 TREE_USED (decl) = 1; 3706 TREE_USED (cleanup_decl) = 1; 3707 3708 /* Initialize EH, if we've been told to do so. */ 3709 c_maybe_initialize_eh (); 3710 3711 push_cleanup (decl, cleanup, false); 3712 } 3713 } 3714} 3715 3716/* Given a parsed parameter declaration, decode it into a PARM_DECL. */ 3717 3718tree 3719grokparm (const struct c_parm *parm) 3720{ 3721 tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, 3722 NULL); 3723 3724 decl_attributes (&decl, parm->attrs, 0); 3725 3726 return decl; 3727} 3728 3729/* Given a parsed parameter declaration, decode it into a PARM_DECL 3730 and push that on the current scope. */ 3731 3732void 3733push_parm_decl (const struct c_parm *parm) 3734{ 3735 tree decl; 3736 3737 decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL); 3738 decl_attributes (&decl, parm->attrs, 0); 3739 3740 decl = pushdecl (decl); 3741 3742 finish_decl (decl, NULL_TREE, NULL_TREE); 3743} 3744 3745/* Mark all the parameter declarations to date as forward decls. 3746 Also diagnose use of this extension. */ 3747 3748void 3749mark_forward_parm_decls (void) 3750{ 3751 struct c_binding *b; 3752 3753 if (pedantic && !current_scope->warned_forward_parm_decls) 3754 { 3755 pedwarn ("ISO C forbids forward parameter declarations"); 3756 current_scope->warned_forward_parm_decls = true; 3757 } 3758 3759 for (b = current_scope->bindings; b; b = b->prev) 3760 if (TREE_CODE (b->decl) == PARM_DECL) 3761 TREE_ASM_WRITTEN (b->decl) = 1; 3762} 3763 3764/* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound 3765 literal, which may be an incomplete array type completed by the 3766 initializer; INIT is a CONSTRUCTOR that initializes the compound 3767 literal. */ 3768 3769tree 3770build_compound_literal (tree type, tree init) 3771{ 3772 /* We do not use start_decl here because we have a type, not a declarator; 3773 and do not use finish_decl because the decl should be stored inside 3774 the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_EXPR. */ 3775 tree decl; 3776 tree complit; 3777 tree stmt; 3778 3779 if (type == error_mark_node) 3780 return error_mark_node; 3781 3782 decl = build_decl (VAR_DECL, NULL_TREE, type); 3783 DECL_EXTERNAL (decl) = 0; 3784 TREE_PUBLIC (decl) = 0; 3785 TREE_STATIC (decl) = (current_scope == file_scope); 3786 DECL_CONTEXT (decl) = current_function_decl; 3787 TREE_USED (decl) = 1; 3788 TREE_TYPE (decl) = type; 3789 TREE_READONLY (decl) = TYPE_READONLY (type); 3790 store_init_value (decl, init); 3791 3792 if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type)) 3793 { 3794 int failure = complete_array_type (&TREE_TYPE (decl), 3795 DECL_INITIAL (decl), true); 3796 gcc_assert (!failure); 3797 3798 type = TREE_TYPE (decl); 3799 TREE_TYPE (DECL_INITIAL (decl)) = type; 3800 } 3801 3802 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 3803 return error_mark_node; 3804 3805 stmt = build_stmt (DECL_EXPR, decl); 3806 complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt); 3807 TREE_SIDE_EFFECTS (complit) = 1; 3808 3809 layout_decl (decl, 0); 3810 3811 if (TREE_STATIC (decl)) 3812 { 3813 /* This decl needs a name for the assembler output. */ 3814 set_compound_literal_name (decl); 3815 DECL_DEFER_OUTPUT (decl) = 1; 3816 DECL_COMDAT (decl) = 1; 3817 DECL_ARTIFICIAL (decl) = 1; 3818 DECL_IGNORED_P (decl) = 1; 3819 pushdecl (decl); 3820 rest_of_decl_compilation (decl, 1, 0); 3821 } 3822 3823 return complit; 3824} 3825 3826/* Determine whether TYPE is a structure with a flexible array member, 3827 or a union containing such a structure (possibly recursively). */ 3828 3829static bool 3830flexible_array_type_p (tree type) 3831{ 3832 tree x; 3833 switch (TREE_CODE (type)) 3834 { 3835 case RECORD_TYPE: 3836 x = TYPE_FIELDS (type); 3837 if (x == NULL_TREE) 3838 return false; 3839 while (TREE_CHAIN (x) != NULL_TREE) 3840 x = TREE_CHAIN (x); 3841 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 3842 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 3843 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 3844 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 3845 return true; 3846 return false; 3847 case UNION_TYPE: 3848 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x)) 3849 { 3850 if (flexible_array_type_p (TREE_TYPE (x))) 3851 return true; 3852 } 3853 return false; 3854 default: 3855 return false; 3856 } 3857} 3858 3859/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 3860 replacing with appropriate values if they are invalid. */ 3861static void 3862check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name) 3863{ 3864 tree type_mv; 3865 unsigned int max_width; 3866 unsigned HOST_WIDE_INT w; 3867 const char *name = orig_name ? orig_name: _("<anonymous>"); 3868 3869 /* Detect and ignore out of range field width and process valid 3870 field widths. */ 3871 if (!INTEGRAL_TYPE_P (TREE_TYPE (*width)) 3872 || TREE_CODE (*width) != INTEGER_CST) 3873 { 3874 error ("bit-field %qs width not an integer constant", name); 3875 *width = integer_one_node; 3876 } 3877 else 3878 { 3879 constant_expression_warning (*width); 3880 if (tree_int_cst_sgn (*width) < 0) 3881 { 3882 error ("negative width in bit-field %qs", name); 3883 *width = integer_one_node; 3884 } 3885 else if (integer_zerop (*width) && orig_name) 3886 { 3887 error ("zero width for bit-field %qs", name); 3888 *width = integer_one_node; 3889 } 3890 } 3891 3892 /* Detect invalid bit-field type. */ 3893 if (TREE_CODE (*type) != INTEGER_TYPE 3894 && TREE_CODE (*type) != BOOLEAN_TYPE 3895 && TREE_CODE (*type) != ENUMERAL_TYPE) 3896 { 3897 error ("bit-field %qs has invalid type", name); 3898 *type = unsigned_type_node; 3899 } 3900 3901 type_mv = TYPE_MAIN_VARIANT (*type); 3902 if (pedantic 3903 && !in_system_header 3904 && type_mv != integer_type_node 3905 && type_mv != unsigned_type_node 3906 && type_mv != boolean_type_node) 3907 pedwarn ("type of bit-field %qs is a GCC extension", name); 3908 3909 if (type_mv == boolean_type_node) 3910 max_width = CHAR_TYPE_SIZE; 3911 else 3912 max_width = TYPE_PRECISION (*type); 3913 3914 if (0 < compare_tree_int (*width, max_width)) 3915 { 3916 error ("width of %qs exceeds its type", name); 3917 w = max_width; 3918 *width = build_int_cst (NULL_TREE, w); 3919 } 3920 else 3921 w = tree_low_cst (*width, 1); 3922 3923 if (TREE_CODE (*type) == ENUMERAL_TYPE) 3924 { 3925 struct lang_type *lt = TYPE_LANG_SPECIFIC (*type); 3926 if (!lt 3927 || w < min_precision (lt->enum_min, TYPE_UNSIGNED (*type)) 3928 || w < min_precision (lt->enum_max, TYPE_UNSIGNED (*type))) 3929 warning (0, "%qs is narrower than values of its type", name); 3930 } 3931} 3932 3933 3934/* Given declspecs and a declarator, 3935 determine the name and type of the object declared 3936 and construct a ..._DECL node for it. 3937 (In one case we can return a ..._TYPE node instead. 3938 For invalid input we sometimes return 0.) 3939 3940 DECLSPECS is a c_declspecs structure for the declaration specifiers. 3941 3942 DECL_CONTEXT says which syntactic context this declaration is in: 3943 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 3944 FUNCDEF for a function definition. Like NORMAL but a few different 3945 error messages in each case. Return value may be zero meaning 3946 this definition is too screwy to try to parse. 3947 PARM for a parameter declaration (either within a function prototype 3948 or before a function body). Make a PARM_DECL, or return void_type_node. 3949 TYPENAME if for a typename (in a cast or sizeof). 3950 Don't make a DECL node; just return the ..._TYPE node. 3951 FIELD for a struct or union field; make a FIELD_DECL. 3952 INITIALIZED is true if the decl has an initializer. 3953 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 3954 representing the width of the bit-field. 3955 3956 In the TYPENAME case, DECLARATOR is really an absolute declarator. 3957 It may also be so in the PARM case, for a prototype where the 3958 argument type is specified but not the name. 3959 3960 This function is where the complicated C meanings of `static' 3961 and `extern' are interpreted. */ 3962 3963static tree 3964grokdeclarator (const struct c_declarator *declarator, 3965 struct c_declspecs *declspecs, 3966 enum decl_context decl_context, bool initialized, tree *width) 3967{ 3968 tree type = declspecs->type; 3969 bool threadp = declspecs->thread_p; 3970 enum c_storage_class storage_class = declspecs->storage_class; 3971 int constp; 3972 int restrictp; 3973 int volatilep; 3974 int type_quals = TYPE_UNQUALIFIED; 3975 const char *name, *orig_name; 3976 tree typedef_type = 0; 3977 bool funcdef_flag = false; 3978 bool funcdef_syntax = false; 3979 int size_varies = 0; 3980 tree decl_attr = declspecs->decl_attr; 3981 int array_ptr_quals = TYPE_UNQUALIFIED; 3982 tree array_ptr_attrs = NULL_TREE; 3983 int array_parm_static = 0; 3984 bool array_parm_vla_unspec_p = false; 3985 tree returned_attrs = NULL_TREE; 3986 bool bitfield = width != NULL; 3987 tree element_type; 3988 struct c_arg_info *arg_info = 0; 3989 3990 if (decl_context == FUNCDEF) 3991 funcdef_flag = true, decl_context = NORMAL; 3992 3993 /* Look inside a declarator for the name being declared 3994 and get it as a string, for an error message. */ 3995 { 3996 const struct c_declarator *decl = declarator; 3997 name = 0; 3998 3999 while (decl) 4000 switch (decl->kind) 4001 { 4002 case cdk_function: 4003 case cdk_array: 4004 case cdk_pointer: 4005 funcdef_syntax = (decl->kind == cdk_function); 4006 decl = decl->declarator; 4007 break; 4008 4009 case cdk_attrs: 4010 decl = decl->declarator; 4011 break; 4012 4013 case cdk_id: 4014 if (decl->u.id) 4015 name = IDENTIFIER_POINTER (decl->u.id); 4016 decl = 0; 4017 break; 4018 4019 default: 4020 gcc_unreachable (); 4021 } 4022 orig_name = name; 4023 if (name == 0) 4024 name = "type name"; 4025 } 4026 4027 /* A function definition's declarator must have the form of 4028 a function declarator. */ 4029 4030 if (funcdef_flag && !funcdef_syntax) 4031 return 0; 4032 4033 /* If this looks like a function definition, make it one, 4034 even if it occurs where parms are expected. 4035 Then store_parm_decls will reject it and not use it as a parm. */ 4036 if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag) 4037 decl_context = PARM; 4038 4039 if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS) 4040 warn_deprecated_use (declspecs->type); 4041 4042 if ((decl_context == NORMAL || decl_context == FIELD) 4043 && current_scope == file_scope 4044 && variably_modified_type_p (type, NULL_TREE)) 4045 { 4046 error ("variably modified %qs at file scope", name); 4047 type = integer_type_node; 4048 } 4049 4050 typedef_type = type; 4051 size_varies = C_TYPE_VARIABLE_SIZE (type); 4052 4053 /* Diagnose defaulting to "int". */ 4054 4055 if (declspecs->default_int_p && !in_system_header) 4056 { 4057 /* Issue a warning if this is an ISO C 99 program or if 4058 -Wreturn-type and this is a function, or if -Wimplicit; 4059 prefer the former warning since it is more explicit. */ 4060 if ((warn_implicit_int || warn_return_type || flag_isoc99) 4061 && funcdef_flag) 4062 warn_about_return_type = 1; 4063 else if (warn_implicit_int || flag_isoc99) 4064 pedwarn_c99 ("type defaults to %<int%> in declaration of %qs", name); 4065 } 4066 4067 /* Adjust the type if a bit-field is being declared, 4068 -funsigned-bitfields applied and the type is not explicitly 4069 "signed". */ 4070 if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p 4071 && TREE_CODE (type) == INTEGER_TYPE) 4072 type = c_common_unsigned_type (type); 4073 4074 /* Figure out the type qualifiers for the declaration. There are 4075 two ways a declaration can become qualified. One is something 4076 like `const int i' where the `const' is explicit. Another is 4077 something like `typedef const int CI; CI i' where the type of the 4078 declaration contains the `const'. A third possibility is that 4079 there is a type qualifier on the element type of a typedefed 4080 array type, in which case we should extract that qualifier so 4081 that c_apply_type_quals_to_decls receives the full list of 4082 qualifiers to work with (C90 is not entirely clear about whether 4083 duplicate qualifiers should be diagnosed in this case, but it 4084 seems most appropriate to do so). */ 4085 element_type = strip_array_types (type); 4086 constp = declspecs->const_p + TYPE_READONLY (element_type); 4087 restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type); 4088 volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type); 4089 if (pedantic && !flag_isoc99) 4090 { 4091 if (constp > 1) 4092 pedwarn ("duplicate %<const%>"); 4093 if (restrictp > 1) 4094 pedwarn ("duplicate %<restrict%>"); 4095 if (volatilep > 1) 4096 pedwarn ("duplicate %<volatile%>"); 4097 } 4098 if (!flag_gen_aux_info && (TYPE_QUALS (element_type))) 4099 type = TYPE_MAIN_VARIANT (type); 4100 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 4101 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 4102 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 4103 4104 /* Warn about storage classes that are invalid for certain 4105 kinds of declarations (parameters, typenames, etc.). */ 4106 4107 if (funcdef_flag 4108 && (threadp 4109 || storage_class == csc_auto 4110 || storage_class == csc_register 4111 || storage_class == csc_typedef)) 4112 { 4113 if (storage_class == csc_auto 4114 && (pedantic || current_scope == file_scope)) 4115 pedwarn ("function definition declared %<auto%>"); 4116 if (storage_class == csc_register) 4117 error ("function definition declared %<register%>"); 4118 if (storage_class == csc_typedef) 4119 error ("function definition declared %<typedef%>"); 4120 if (threadp) 4121 error ("function definition declared %<__thread%>"); 4122 threadp = false; 4123 if (storage_class == csc_auto 4124 || storage_class == csc_register 4125 || storage_class == csc_typedef) 4126 storage_class = csc_none; 4127 } 4128 else if (decl_context != NORMAL && (storage_class != csc_none || threadp)) 4129 { 4130 if (decl_context == PARM && storage_class == csc_register) 4131 ; 4132 else 4133 { 4134 switch (decl_context) 4135 { 4136 case FIELD: 4137 error ("storage class specified for structure field %qs", 4138 name); 4139 break; 4140 case PARM: 4141 error ("storage class specified for parameter %qs", name); 4142 break; 4143 default: 4144 error ("storage class specified for typename"); 4145 break; 4146 } 4147 storage_class = csc_none; 4148 threadp = false; 4149 } 4150 } 4151 else if (storage_class == csc_extern 4152 && initialized 4153 && !funcdef_flag) 4154 { 4155 /* 'extern' with initialization is invalid if not at file scope. */ 4156 if (current_scope == file_scope) 4157 { 4158 /* It is fine to have 'extern const' when compiling at C 4159 and C++ intersection. */ 4160 if (!(warn_cxx_compat && constp)) 4161 warning (0, "%qs initialized and declared %<extern%>", name); 4162 } 4163 else 4164 error ("%qs has both %<extern%> and initializer", name); 4165 } 4166 else if (current_scope == file_scope) 4167 { 4168 if (storage_class == csc_auto) 4169 error ("file-scope declaration of %qs specifies %<auto%>", name); 4170 if (pedantic && storage_class == csc_register) 4171 pedwarn ("file-scope declaration of %qs specifies %<register%>", name); 4172 } 4173 else 4174 { 4175 if (storage_class == csc_extern && funcdef_flag) 4176 error ("nested function %qs declared %<extern%>", name); 4177 else if (threadp && storage_class == csc_none) 4178 { 4179 error ("function-scope %qs implicitly auto and declared " 4180 "%<__thread%>", 4181 name); 4182 threadp = false; 4183 } 4184 } 4185 4186 /* Now figure out the structure of the declarator proper. 4187 Descend through it, creating more complex types, until we reach 4188 the declared identifier (or NULL_TREE, in an absolute declarator). 4189 At each stage we maintain an unqualified version of the type 4190 together with any qualifiers that should be applied to it with 4191 c_build_qualified_type; this way, array types including 4192 multidimensional array types are first built up in unqualified 4193 form and then the qualified form is created with 4194 TYPE_MAIN_VARIANT pointing to the unqualified form. */ 4195 4196 while (declarator && declarator->kind != cdk_id) 4197 { 4198 if (type == error_mark_node) 4199 { 4200 declarator = declarator->declarator; 4201 continue; 4202 } 4203 4204 /* Each level of DECLARATOR is either a cdk_array (for ...[..]), 4205 a cdk_pointer (for *...), 4206 a cdk_function (for ...(...)), 4207 a cdk_attrs (for nested attributes), 4208 or a cdk_id (for the name being declared 4209 or the place in an absolute declarator 4210 where the name was omitted). 4211 For the last case, we have just exited the loop. 4212 4213 At this point, TYPE is the type of elements of an array, 4214 or for a function to return, or for a pointer to point to. 4215 After this sequence of ifs, TYPE is the type of the 4216 array or function or pointer, and DECLARATOR has had its 4217 outermost layer removed. */ 4218 4219 if (array_ptr_quals != TYPE_UNQUALIFIED 4220 || array_ptr_attrs != NULL_TREE 4221 || array_parm_static) 4222 { 4223 /* Only the innermost declarator (making a parameter be of 4224 array type which is converted to pointer type) 4225 may have static or type qualifiers. */ 4226 error ("static or type qualifiers in non-parameter array declarator"); 4227 array_ptr_quals = TYPE_UNQUALIFIED; 4228 array_ptr_attrs = NULL_TREE; 4229 array_parm_static = 0; 4230 } 4231 4232 switch (declarator->kind) 4233 { 4234 case cdk_attrs: 4235 { 4236 /* A declarator with embedded attributes. */ 4237 tree attrs = declarator->u.attrs; 4238 const struct c_declarator *inner_decl; 4239 int attr_flags = 0; 4240 declarator = declarator->declarator; 4241 inner_decl = declarator; 4242 while (inner_decl->kind == cdk_attrs) 4243 inner_decl = inner_decl->declarator; 4244 if (inner_decl->kind == cdk_id) 4245 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 4246 else if (inner_decl->kind == cdk_function) 4247 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 4248 else if (inner_decl->kind == cdk_array) 4249 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 4250 returned_attrs = decl_attributes (&type, 4251 chainon (returned_attrs, attrs), 4252 attr_flags); 4253 break; 4254 } 4255 case cdk_array: 4256 { 4257 tree itype = NULL_TREE; 4258 tree size = declarator->u.array.dimen; 4259 /* The index is a signed object `sizetype' bits wide. */ 4260 tree index_type = c_common_signed_type (sizetype); 4261 4262 array_ptr_quals = declarator->u.array.quals; 4263 array_ptr_attrs = declarator->u.array.attrs; 4264 array_parm_static = declarator->u.array.static_p; 4265 array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p; 4266 4267 declarator = declarator->declarator; 4268 4269 /* Check for some types that there cannot be arrays of. */ 4270 4271 if (VOID_TYPE_P (type)) 4272 { 4273 error ("declaration of %qs as array of voids", name); 4274 type = error_mark_node; 4275 } 4276 4277 if (TREE_CODE (type) == FUNCTION_TYPE) 4278 { 4279 error ("declaration of %qs as array of functions", name); 4280 type = error_mark_node; 4281 } 4282 4283 if (pedantic && !in_system_header && flexible_array_type_p (type)) 4284 pedwarn ("invalid use of structure with flexible array member"); 4285 4286 if (size == error_mark_node) 4287 type = error_mark_node; 4288 4289 if (type == error_mark_node) 4290 continue; 4291 4292 /* If size was specified, set ITYPE to a range-type for 4293 that size. Otherwise, ITYPE remains null. finish_decl 4294 may figure it out from an initial value. */ 4295 4296 if (size) 4297 { 4298 /* Strip NON_LVALUE_EXPRs since we aren't using as an 4299 lvalue. */ 4300 STRIP_TYPE_NOPS (size); 4301 4302 if (!INTEGRAL_TYPE_P (TREE_TYPE (size))) 4303 { 4304 error ("size of array %qs has non-integer type", name); 4305 size = integer_one_node; 4306 } 4307 4308 if (pedantic && integer_zerop (size)) 4309 pedwarn ("ISO C forbids zero-size array %qs", name); 4310 4311 if (TREE_CODE (size) == INTEGER_CST) 4312 { 4313 constant_expression_warning (size); 4314 if (tree_int_cst_sgn (size) < 0) 4315 { 4316 error ("size of array %qs is negative", name); 4317 size = integer_one_node; 4318 } 4319 } 4320 else if ((decl_context == NORMAL || decl_context == FIELD) 4321 && current_scope == file_scope) 4322 { 4323 error ("variably modified %qs at file scope", name); 4324 size = integer_one_node; 4325 } 4326 else 4327 { 4328 /* Make sure the array size remains visibly 4329 nonconstant even if it is (eg) a const variable 4330 with known value. */ 4331 size_varies = 1; 4332 4333 if (!flag_isoc99 && pedantic) 4334 { 4335 if (TREE_CONSTANT (size)) 4336 pedwarn ("ISO C90 forbids array %qs whose size " 4337 "can%'t be evaluated", 4338 name); 4339 else 4340 pedwarn ("ISO C90 forbids variable-size array %qs", 4341 name); 4342 } 4343 if (warn_variable_decl) 4344 warning (0, "variable-sized array %qs", name); 4345 } 4346 4347 if (integer_zerop (size)) 4348 { 4349 /* A zero-length array cannot be represented with 4350 an unsigned index type, which is what we'll 4351 get with build_index_type. Create an 4352 open-ended range instead. */ 4353 itype = build_range_type (sizetype, size, NULL_TREE); 4354 } 4355 else 4356 { 4357 /* Arrange for the SAVE_EXPR on the inside of the 4358 MINUS_EXPR, which allows the -1 to get folded 4359 with the +1 that happens when building TYPE_SIZE. */ 4360 if (size_varies) 4361 size = variable_size (size); 4362 4363 /* Compute the maximum valid index, that is, size 4364 - 1. Do the calculation in index_type, so that 4365 if it is a variable the computations will be 4366 done in the proper mode. */ 4367 itype = fold_build2 (MINUS_EXPR, index_type, 4368 convert (index_type, size), 4369 convert (index_type, 4370 size_one_node)); 4371 4372 /* If that overflowed, the array is too big. ??? 4373 While a size of INT_MAX+1 technically shouldn't 4374 cause an overflow (because we subtract 1), the 4375 overflow is recorded during the conversion to 4376 index_type, before the subtraction. Handling 4377 this case seems like an unnecessary 4378 complication. */ 4379 if (TREE_CODE (itype) == INTEGER_CST 4380 && TREE_OVERFLOW (itype)) 4381 { 4382 error ("size of array %qs is too large", name); 4383 type = error_mark_node; 4384 continue; 4385 } 4386 4387 itype = build_index_type (itype); 4388 } 4389 } 4390 else if (decl_context == FIELD) 4391 { 4392 if (pedantic && !flag_isoc99 && !in_system_header) 4393 pedwarn ("ISO C90 does not support flexible array members"); 4394 4395 /* ISO C99 Flexible array members are effectively 4396 identical to GCC's zero-length array extension. */ 4397 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4398 } 4399 else if (decl_context == PARM) 4400 { 4401 if (array_parm_vla_unspec_p) 4402 { 4403 if (! orig_name) 4404 { 4405 /* C99 6.7.5.2p4 */ 4406 error ("%<[*]%> not allowed in other than a declaration"); 4407 } 4408 4409 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4410 size_varies = 1; 4411 } 4412 } 4413 else if (decl_context == TYPENAME) 4414 { 4415 if (array_parm_vla_unspec_p) 4416 { 4417 /* The error is printed elsewhere. We use this to 4418 avoid messing up with incomplete array types of 4419 the same type, that would otherwise be modified 4420 below. */ 4421 itype = build_range_type (sizetype, size_zero_node, 4422 NULL_TREE); 4423 } 4424 } 4425 4426 /* Complain about arrays of incomplete types. */ 4427 if (!COMPLETE_TYPE_P (type)) 4428 { 4429 error ("array type has incomplete element type"); 4430 type = error_mark_node; 4431 } 4432 else 4433 /* When itype is NULL, a shared incomplete array type is 4434 returned for all array of a given type. Elsewhere we 4435 make sure we don't complete that type before copying 4436 it, but here we want to make sure we don't ever 4437 modify the shared type, so we gcc_assert (itype) 4438 below. */ 4439 type = build_array_type (type, itype); 4440 4441 if (type != error_mark_node) 4442 { 4443 if (size_varies) 4444 { 4445 /* It is ok to modify type here even if itype is 4446 NULL: if size_varies, we're in a 4447 multi-dimensional array and the inner type has 4448 variable size, so the enclosing shared array type 4449 must too. */ 4450 if (size && TREE_CODE (size) == INTEGER_CST) 4451 type 4452 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4453 C_TYPE_VARIABLE_SIZE (type) = 1; 4454 } 4455 4456 /* The GCC extension for zero-length arrays differs from 4457 ISO flexible array members in that sizeof yields 4458 zero. */ 4459 if (size && integer_zerop (size)) 4460 { 4461 gcc_assert (itype); 4462 TYPE_SIZE (type) = bitsize_zero_node; 4463 TYPE_SIZE_UNIT (type) = size_zero_node; 4464 } 4465 if (array_parm_vla_unspec_p) 4466 { 4467 gcc_assert (itype); 4468 /* The type is complete. C99 6.7.5.2p4 */ 4469 TYPE_SIZE (type) = bitsize_zero_node; 4470 TYPE_SIZE_UNIT (type) = size_zero_node; 4471 } 4472 } 4473 4474 if (decl_context != PARM 4475 && (array_ptr_quals != TYPE_UNQUALIFIED 4476 || array_ptr_attrs != NULL_TREE 4477 || array_parm_static)) 4478 { 4479 error ("static or type qualifiers in non-parameter array declarator"); 4480 array_ptr_quals = TYPE_UNQUALIFIED; 4481 array_ptr_attrs = NULL_TREE; 4482 array_parm_static = 0; 4483 } 4484 break; 4485 } 4486 case cdk_function: 4487 { 4488 /* Say it's a definition only for the declarator closest 4489 to the identifier, apart possibly from some 4490 attributes. */ 4491 bool really_funcdef = false; 4492 tree arg_types; 4493 if (funcdef_flag) 4494 { 4495 const struct c_declarator *t = declarator->declarator; 4496 while (t->kind == cdk_attrs) 4497 t = t->declarator; 4498 really_funcdef = (t->kind == cdk_id); 4499 } 4500 4501 /* Declaring a function type. Make sure we have a valid 4502 type for the function to return. */ 4503 if (type == error_mark_node) 4504 continue; 4505 4506 size_varies = 0; 4507 4508 /* Warn about some types functions can't return. */ 4509 if (TREE_CODE (type) == FUNCTION_TYPE) 4510 { 4511 error ("%qs declared as function returning a function", name); 4512 type = integer_type_node; 4513 } 4514 if (TREE_CODE (type) == ARRAY_TYPE) 4515 { 4516 error ("%qs declared as function returning an array", name); 4517 type = integer_type_node; 4518 } 4519 4520 /* Construct the function type and go to the next 4521 inner layer of declarator. */ 4522 arg_info = declarator->u.arg_info; 4523 arg_types = grokparms (arg_info, really_funcdef); 4524 if (really_funcdef) 4525 put_pending_sizes (arg_info->pending_sizes); 4526 4527 /* Type qualifiers before the return type of the function 4528 qualify the return type, not the function type. */ 4529 if (type_quals) 4530 { 4531 /* Type qualifiers on a function return type are 4532 normally permitted by the standard but have no 4533 effect, so give a warning at -Wreturn-type. 4534 Qualifiers on a void return type are banned on 4535 function definitions in ISO C; GCC used to used 4536 them for noreturn functions. */ 4537 if (VOID_TYPE_P (type) && really_funcdef) 4538 pedwarn ("function definition has qualified void return type"); 4539 else 4540 warning (OPT_Wreturn_type, 4541 "type qualifiers ignored on function return type"); 4542 4543 type = c_build_qualified_type (type, type_quals); 4544 } 4545 type_quals = TYPE_UNQUALIFIED; 4546 4547 type = build_function_type (type, arg_types); 4548 declarator = declarator->declarator; 4549 4550 /* Set the TYPE_CONTEXTs for each tagged type which is local to 4551 the formal parameter list of this FUNCTION_TYPE to point to 4552 the FUNCTION_TYPE node itself. */ 4553 { 4554 tree link; 4555 4556 for (link = arg_info->tags; 4557 link; 4558 link = TREE_CHAIN (link)) 4559 TYPE_CONTEXT (TREE_VALUE (link)) = type; 4560 } 4561 break; 4562 } 4563 case cdk_pointer: 4564 { 4565 /* Merge any constancy or volatility into the target type 4566 for the pointer. */ 4567 4568 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4569 && type_quals) 4570 pedwarn ("ISO C forbids qualified function types"); 4571 if (type_quals) 4572 type = c_build_qualified_type (type, type_quals); 4573 size_varies = 0; 4574 4575 /* When the pointed-to type involves components of variable size, 4576 care must be taken to ensure that the size evaluation code is 4577 emitted early enough to dominate all the possible later uses 4578 and late enough for the variables on which it depends to have 4579 been assigned. 4580 4581 This is expected to happen automatically when the pointed-to 4582 type has a name/declaration of it's own, but special attention 4583 is required if the type is anonymous. 4584 4585 We handle the NORMAL and FIELD contexts here by attaching an 4586 artificial TYPE_DECL to such pointed-to type. This forces the 4587 sizes evaluation at a safe point and ensures it is not deferred 4588 until e.g. within a deeper conditional context. 4589 4590 We expect nothing to be needed here for PARM or TYPENAME. 4591 Pushing a TYPE_DECL at this point for TYPENAME would actually 4592 be incorrect, as we might be in the middle of an expression 4593 with side effects on the pointed-to type size "arguments" prior 4594 to the pointer declaration point and the fake TYPE_DECL in the 4595 enclosing context would force the size evaluation prior to the 4596 side effects. */ 4597 4598 if (!TYPE_NAME (type) 4599 && (decl_context == NORMAL || decl_context == FIELD) 4600 && variably_modified_type_p (type, NULL_TREE)) 4601 { 4602 tree decl = build_decl (TYPE_DECL, NULL_TREE, type); 4603 DECL_ARTIFICIAL (decl) = 1; 4604 pushdecl (decl); 4605 finish_decl (decl, NULL_TREE, NULL_TREE); 4606 TYPE_NAME (type) = decl; 4607 } 4608 4609 type = build_pointer_type (type); 4610 4611 /* Process type qualifiers (such as const or volatile) 4612 that were given inside the `*'. */ 4613 type_quals = declarator->u.pointer_quals; 4614 4615 declarator = declarator->declarator; 4616 break; 4617 } 4618 default: 4619 gcc_unreachable (); 4620 } 4621 } 4622 4623 /* Now TYPE has the actual type, apart from any qualifiers in 4624 TYPE_QUALS. */ 4625 4626 /* Check the type and width of a bit-field. */ 4627 if (bitfield) 4628 check_bitfield_type_and_width (&type, width, orig_name); 4629 4630 /* Did array size calculations overflow? */ 4631 4632 if (TREE_CODE (type) == ARRAY_TYPE 4633 && COMPLETE_TYPE_P (type) 4634 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 4635 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 4636 { 4637 error ("size of array %qs is too large", name); 4638 /* If we proceed with the array type as it is, we'll eventually 4639 crash in tree_low_cst(). */ 4640 type = error_mark_node; 4641 } 4642 4643 /* If this is declaring a typedef name, return a TYPE_DECL. */ 4644 4645 if (storage_class == csc_typedef) 4646 { 4647 tree decl; 4648 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4649 && type_quals) 4650 pedwarn ("ISO C forbids qualified function types"); 4651 if (type_quals) 4652 type = c_build_qualified_type (type, type_quals); 4653 decl = build_decl (TYPE_DECL, declarator->u.id, type); 4654 if (declspecs->explicit_signed_p) 4655 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 4656 decl_attributes (&decl, returned_attrs, 0); 4657 if (declspecs->inline_p) 4658 pedwarn ("typedef %q+D declared %<inline%>", decl); 4659 return decl; 4660 } 4661 4662 /* If this is a type name (such as, in a cast or sizeof), 4663 compute the type and return it now. */ 4664 4665 if (decl_context == TYPENAME) 4666 { 4667 /* Note that the grammar rejects storage classes in typenames 4668 and fields. */ 4669 gcc_assert (storage_class == csc_none && !threadp 4670 && !declspecs->inline_p); 4671 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4672 && type_quals) 4673 pedwarn ("ISO C forbids const or volatile function types"); 4674 if (type_quals) 4675 type = c_build_qualified_type (type, type_quals); 4676 decl_attributes (&type, returned_attrs, 0); 4677 return type; 4678 } 4679 4680 if (pedantic && decl_context == FIELD 4681 && variably_modified_type_p (type, NULL_TREE)) 4682 { 4683 /* C99 6.7.2.1p8 */ 4684 pedwarn ("a member of a structure or union cannot have a variably modified type"); 4685 } 4686 4687 /* Aside from typedefs and type names (handle above), 4688 `void' at top level (not within pointer) 4689 is allowed only in public variables. 4690 We don't complain about parms either, but that is because 4691 a better error message can be made later. */ 4692 4693 if (VOID_TYPE_P (type) && decl_context != PARM 4694 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 4695 && (storage_class == csc_extern 4696 || (current_scope == file_scope 4697 && !(storage_class == csc_static 4698 || storage_class == csc_register))))) 4699 { 4700 error ("variable or field %qs declared void", name); 4701 type = integer_type_node; 4702 } 4703 4704 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 4705 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 4706 4707 { 4708 tree decl; 4709 4710 if (decl_context == PARM) 4711 { 4712 tree type_as_written; 4713 tree promoted_type; 4714 4715 /* A parameter declared as an array of T is really a pointer to T. 4716 One declared as a function is really a pointer to a function. */ 4717 4718 if (TREE_CODE (type) == ARRAY_TYPE) 4719 { 4720 /* Transfer const-ness of array into that of type pointed to. */ 4721 type = TREE_TYPE (type); 4722 if (type_quals) 4723 type = c_build_qualified_type (type, type_quals); 4724 type = build_pointer_type (type); 4725 type_quals = array_ptr_quals; 4726 4727 /* We don't yet implement attributes in this context. */ 4728 if (array_ptr_attrs != NULL_TREE) 4729 warning (OPT_Wattributes, 4730 "attributes in parameter array declarator ignored"); 4731 4732 size_varies = 0; 4733 } 4734 else if (TREE_CODE (type) == FUNCTION_TYPE) 4735 { 4736 if (pedantic && type_quals) 4737 pedwarn ("ISO C forbids qualified function types"); 4738 if (type_quals) 4739 type = c_build_qualified_type (type, type_quals); 4740 type = build_pointer_type (type); 4741 type_quals = TYPE_UNQUALIFIED; 4742 } 4743 else if (type_quals) 4744 type = c_build_qualified_type (type, type_quals); 4745 4746 type_as_written = type; 4747 4748 decl = build_decl (PARM_DECL, declarator->u.id, type); 4749 if (size_varies) 4750 C_DECL_VARIABLE_SIZE (decl) = 1; 4751 4752 /* Compute the type actually passed in the parmlist, 4753 for the case where there is no prototype. 4754 (For example, shorts and chars are passed as ints.) 4755 When there is a prototype, this is overridden later. */ 4756 4757 if (type == error_mark_node) 4758 promoted_type = type; 4759 else 4760 promoted_type = c_type_promotes_to (type); 4761 4762 DECL_ARG_TYPE (decl) = promoted_type; 4763 if (declspecs->inline_p) 4764 pedwarn ("parameter %q+D declared %<inline%>", decl); 4765 } 4766 else if (decl_context == FIELD) 4767 { 4768 /* Note that the grammar rejects storage classes in typenames 4769 and fields. */ 4770 gcc_assert (storage_class == csc_none && !threadp 4771 && !declspecs->inline_p); 4772 4773 /* Structure field. It may not be a function. */ 4774 4775 if (TREE_CODE (type) == FUNCTION_TYPE) 4776 { 4777 error ("field %qs declared as a function", name); 4778 type = build_pointer_type (type); 4779 } 4780 else if (TREE_CODE (type) != ERROR_MARK 4781 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 4782 { 4783 error ("field %qs has incomplete type", name); 4784 type = error_mark_node; 4785 } 4786 type = c_build_qualified_type (type, type_quals); 4787 decl = build_decl (FIELD_DECL, declarator->u.id, type); 4788 DECL_NONADDRESSABLE_P (decl) = bitfield; 4789 4790 if (size_varies) 4791 C_DECL_VARIABLE_SIZE (decl) = 1; 4792 } 4793 else if (TREE_CODE (type) == FUNCTION_TYPE) 4794 { 4795 if (storage_class == csc_register || threadp) 4796 { 4797 error ("invalid storage class for function %qs", name); 4798 } 4799 else if (current_scope != file_scope) 4800 { 4801 /* Function declaration not at file scope. Storage 4802 classes other than `extern' are not allowed, C99 4803 6.7.1p5, and `extern' makes no difference. However, 4804 GCC allows 'auto', perhaps with 'inline', to support 4805 nested functions. */ 4806 if (storage_class == csc_auto) 4807 { 4808 if (pedantic) 4809 pedwarn ("invalid storage class for function %qs", name); 4810 } 4811 else if (storage_class == csc_static) 4812 { 4813 error ("invalid storage class for function %qs", name); 4814 if (funcdef_flag) 4815 storage_class = declspecs->storage_class = csc_none; 4816 else 4817 return 0; 4818 } 4819 } 4820 4821 decl = build_decl (FUNCTION_DECL, declarator->u.id, type); 4822 decl = build_decl_attribute_variant (decl, decl_attr); 4823 4824 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 4825 4826 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 4827 pedwarn ("ISO C forbids qualified function types"); 4828 4829 /* GNU C interprets a volatile-qualified function type to indicate 4830 that the function does not return. */ 4831 if ((type_quals & TYPE_QUAL_VOLATILE) 4832 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 4833 warning (0, "%<noreturn%> function returns non-void value"); 4834 4835 /* Every function declaration is an external reference 4836 (DECL_EXTERNAL) except for those which are not at file 4837 scope and are explicitly declared "auto". This is 4838 forbidden by standard C (C99 6.7.1p5) and is interpreted by 4839 GCC to signify a forward declaration of a nested function. */ 4840 if (storage_class == csc_auto && current_scope != file_scope) 4841 DECL_EXTERNAL (decl) = 0; 4842 /* In C99, a function which is declared 'inline' with 'extern' 4843 is not an external reference (which is confusing). It 4844 means that the later definition of the function must be output 4845 in this file, C99 6.7.4p6. In GNU C89, a function declared 4846 'extern inline' is an external reference. */ 4847 else if (declspecs->inline_p && storage_class != csc_static) 4848 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 4849 == flag_gnu89_inline); 4850 else 4851 DECL_EXTERNAL (decl) = !initialized; 4852 4853 /* Record absence of global scope for `static' or `auto'. */ 4854 TREE_PUBLIC (decl) 4855 = !(storage_class == csc_static || storage_class == csc_auto); 4856 4857 /* For a function definition, record the argument information 4858 block where store_parm_decls will look for it. */ 4859 if (funcdef_flag) 4860 current_function_arg_info = arg_info; 4861 4862 if (declspecs->default_int_p) 4863 C_FUNCTION_IMPLICIT_INT (decl) = 1; 4864 4865 /* Record presence of `inline', if it is reasonable. */ 4866 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 4867 { 4868 if (declspecs->inline_p) 4869 pedwarn ("cannot inline function %<main%>"); 4870 } 4871 else if (declspecs->inline_p) 4872 { 4873 /* Record that the function is declared `inline'. */ 4874 DECL_DECLARED_INLINE_P (decl) = 1; 4875 4876 /* Do not mark bare declarations as DECL_INLINE. Doing so 4877 in the presence of multiple declarations can result in 4878 the abstract origin pointing between the declarations, 4879 which will confuse dwarf2out. */ 4880 if (initialized) 4881 DECL_INLINE (decl) = 1; 4882 } 4883 /* If -finline-functions, assume it can be inlined. This does 4884 two things: let the function be deferred until it is actually 4885 needed, and let dwarf2 know that the function is inlinable. */ 4886 else if (flag_inline_trees == 2 && initialized) 4887 DECL_INLINE (decl) = 1; 4888 } 4889 else 4890 { 4891 /* It's a variable. */ 4892 /* An uninitialized decl with `extern' is a reference. */ 4893 int extern_ref = !initialized && storage_class == csc_extern; 4894 4895 type = c_build_qualified_type (type, type_quals); 4896 4897 /* C99 6.2.2p7: It is invalid (compile-time undefined 4898 behavior) to create an 'extern' declaration for a 4899 variable if there is a global declaration that is 4900 'static' and the global declaration is not visible. 4901 (If the static declaration _is_ currently visible, 4902 the 'extern' declaration is taken to refer to that decl.) */ 4903 if (extern_ref && current_scope != file_scope) 4904 { 4905 tree global_decl = identifier_global_value (declarator->u.id); 4906 tree visible_decl = lookup_name (declarator->u.id); 4907 4908 if (global_decl 4909 && global_decl != visible_decl 4910 && TREE_CODE (global_decl) == VAR_DECL 4911 && !TREE_PUBLIC (global_decl)) 4912 error ("variable previously declared %<static%> redeclared " 4913 "%<extern%>"); 4914 } 4915 4916 decl = build_decl (VAR_DECL, declarator->u.id, type); 4917 DECL_SOURCE_LOCATION (decl) = declarator->id_loc; 4918 if (size_varies) 4919 C_DECL_VARIABLE_SIZE (decl) = 1; 4920 4921 if (declspecs->inline_p) 4922 pedwarn ("variable %q+D declared %<inline%>", decl); 4923 4924 /* At file scope, an initialized extern declaration may follow 4925 a static declaration. In that case, DECL_EXTERNAL will be 4926 reset later in start_decl. */ 4927 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 4928 4929 /* At file scope, the presence of a `static' or `register' storage 4930 class specifier, or the absence of all storage class specifiers 4931 makes this declaration a definition (perhaps tentative). Also, 4932 the absence of `static' makes it public. */ 4933 if (current_scope == file_scope) 4934 { 4935 TREE_PUBLIC (decl) = storage_class != csc_static; 4936 TREE_STATIC (decl) = !extern_ref; 4937 } 4938 /* Not at file scope, only `static' makes a static definition. */ 4939 else 4940 { 4941 TREE_STATIC (decl) = (storage_class == csc_static); 4942 TREE_PUBLIC (decl) = extern_ref; 4943 } 4944 4945 if (threadp) 4946 { 4947 if (targetm.have_tls) 4948 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 4949 else 4950 /* A mere warning is sure to result in improper semantics 4951 at runtime. Don't bother to allow this to compile. */ 4952 error ("thread-local storage not supported for this target"); 4953 } 4954 } 4955 4956 if (storage_class == csc_extern 4957 && variably_modified_type_p (type, NULL_TREE)) 4958 { 4959 /* C99 6.7.5.2p2 */ 4960 error ("object with variably modified type must have no linkage"); 4961 } 4962 4963 /* Record `register' declaration for warnings on & 4964 and in case doing stupid register allocation. */ 4965 4966 if (storage_class == csc_register) 4967 { 4968 C_DECL_REGISTER (decl) = 1; 4969 DECL_REGISTER (decl) = 1; 4970 } 4971 4972 /* Record constancy and volatility. */ 4973 c_apply_type_quals_to_decl (type_quals, decl); 4974 4975 /* If a type has volatile components, it should be stored in memory. 4976 Otherwise, the fact that those components are volatile 4977 will be ignored, and would even crash the compiler. 4978 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 4979 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 4980 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 4981 || TREE_CODE (decl) == RESULT_DECL)) 4982 { 4983 /* It is not an error for a structure with volatile fields to 4984 be declared register, but reset DECL_REGISTER since it 4985 cannot actually go in a register. */ 4986 int was_reg = C_DECL_REGISTER (decl); 4987 C_DECL_REGISTER (decl) = 0; 4988 DECL_REGISTER (decl) = 0; 4989 c_mark_addressable (decl); 4990 C_DECL_REGISTER (decl) = was_reg; 4991 } 4992 4993 /* This is the earliest point at which we might know the assembler 4994 name of a variable. Thus, if it's known before this, die horribly. */ 4995 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 4996 4997 decl_attributes (&decl, returned_attrs, 0); 4998 4999 return decl; 5000 } 5001} 5002 5003/* Decode the parameter-list info for a function type or function definition. 5004 The argument is the value returned by `get_parm_info' (or made in c-parse.c 5005 if there is an identifier list instead of a parameter decl list). 5006 These two functions are separate because when a function returns 5007 or receives functions then each is called multiple times but the order 5008 of calls is different. The last call to `grokparms' is always the one 5009 that contains the formal parameter names of a function definition. 5010 5011 Return a list of arg types to use in the FUNCTION_TYPE for this function. 5012 5013 FUNCDEF_FLAG is true for a function definition, false for 5014 a mere declaration. A nonempty identifier-list gets an error message 5015 when FUNCDEF_FLAG is false. */ 5016 5017static tree 5018grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 5019{ 5020 tree arg_types = arg_info->types; 5021 5022 if (funcdef_flag && arg_info->had_vla_unspec) 5023 { 5024 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 5025 /* C99 6.7.5.2p4 */ 5026 error ("%<[*]%> not allowed in other than function prototype scope"); 5027 } 5028 5029 if (arg_types == 0 && !funcdef_flag && !in_system_header) 5030 warning (OPT_Wstrict_prototypes, 5031 "function declaration isn%'t a prototype"); 5032 5033 if (arg_types == error_mark_node) 5034 return 0; /* don't set TYPE_ARG_TYPES in this case */ 5035 5036 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 5037 { 5038 if (!funcdef_flag) 5039 pedwarn ("parameter names (without types) in function declaration"); 5040 5041 arg_info->parms = arg_info->types; 5042 arg_info->types = 0; 5043 return 0; 5044 } 5045 else 5046 { 5047 tree parm, type, typelt; 5048 unsigned int parmno; 5049 5050 /* If there is a parameter of incomplete type in a definition, 5051 this is an error. In a declaration this is valid, and a 5052 struct or union type may be completed later, before any calls 5053 or definition of the function. In the case where the tag was 5054 first declared within the parameter list, a warning has 5055 already been given. If a parameter has void type, then 5056 however the function cannot be defined or called, so 5057 warn. */ 5058 5059 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 5060 parm; 5061 parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 5062 { 5063 type = TREE_VALUE (typelt); 5064 if (type == error_mark_node) 5065 continue; 5066 5067 if (!COMPLETE_TYPE_P (type)) 5068 { 5069 if (funcdef_flag) 5070 { 5071 if (DECL_NAME (parm)) 5072 error ("parameter %u (%q+D) has incomplete type", 5073 parmno, parm); 5074 else 5075 error ("%Jparameter %u has incomplete type", 5076 parm, parmno); 5077 5078 TREE_VALUE (typelt) = error_mark_node; 5079 TREE_TYPE (parm) = error_mark_node; 5080 } 5081 else if (VOID_TYPE_P (type)) 5082 { 5083 if (DECL_NAME (parm)) 5084 warning (0, "parameter %u (%q+D) has void type", 5085 parmno, parm); 5086 else 5087 warning (0, "%Jparameter %u has void type", 5088 parm, parmno); 5089 } 5090 } 5091 5092 if (DECL_NAME (parm) && TREE_USED (parm)) 5093 warn_if_shadowing (parm); 5094 } 5095 return arg_types; 5096 } 5097} 5098 5099/* Take apart the current scope and return a c_arg_info structure with 5100 info on a parameter list just parsed. 5101 5102 This structure is later fed to 'grokparms' and 'store_parm_decls'. 5103 5104 ELLIPSIS being true means the argument list ended in '...' so don't 5105 append a sentinel (void_list_node) to the end of the type-list. */ 5106 5107struct c_arg_info * 5108get_parm_info (bool ellipsis) 5109{ 5110 struct c_binding *b = current_scope->bindings; 5111 struct c_arg_info *arg_info = XOBNEW (&parser_obstack, 5112 struct c_arg_info); 5113 tree parms = 0; 5114 tree tags = 0; 5115 tree types = 0; 5116 tree others = 0; 5117 5118 static bool explained_incomplete_types = false; 5119 bool gave_void_only_once_err = false; 5120 5121 arg_info->parms = 0; 5122 arg_info->tags = 0; 5123 arg_info->types = 0; 5124 arg_info->others = 0; 5125 arg_info->pending_sizes = 0; 5126 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 5127 5128 /* The bindings in this scope must not get put into a block. 5129 We will take care of deleting the binding nodes. */ 5130 current_scope->bindings = 0; 5131 5132 /* This function is only called if there was *something* on the 5133 parameter list. */ 5134 gcc_assert (b); 5135 5136 /* A parameter list consisting solely of 'void' indicates that the 5137 function takes no arguments. But if the 'void' is qualified 5138 (by 'const' or 'volatile'), or has a storage class specifier 5139 ('register'), then the behavior is undefined; issue an error. 5140 Typedefs for 'void' are OK (see DR#157). */ 5141 if (b->prev == 0 /* one binding */ 5142 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 5143 && !DECL_NAME (b->decl) /* anonymous */ 5144 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 5145 { 5146 if (TREE_THIS_VOLATILE (b->decl) 5147 || TREE_READONLY (b->decl) 5148 || C_DECL_REGISTER (b->decl)) 5149 error ("%<void%> as only parameter may not be qualified"); 5150 5151 /* There cannot be an ellipsis. */ 5152 if (ellipsis) 5153 error ("%<void%> must be the only parameter"); 5154 5155 arg_info->types = void_list_node; 5156 return arg_info; 5157 } 5158 5159 if (!ellipsis) 5160 types = void_list_node; 5161 5162 /* Break up the bindings list into parms, tags, types, and others; 5163 apply sanity checks; purge the name-to-decl bindings. */ 5164 while (b) 5165 { 5166 tree decl = b->decl; 5167 tree type = TREE_TYPE (decl); 5168 const char *keyword; 5169 5170 switch (TREE_CODE (decl)) 5171 { 5172 case PARM_DECL: 5173 if (b->id) 5174 { 5175 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5176 I_SYMBOL_BINDING (b->id) = b->shadowed; 5177 } 5178 5179 /* Check for forward decls that never got their actual decl. */ 5180 if (TREE_ASM_WRITTEN (decl)) 5181 error ("parameter %q+D has just a forward declaration", decl); 5182 /* Check for (..., void, ...) and issue an error. */ 5183 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 5184 { 5185 if (!gave_void_only_once_err) 5186 { 5187 error ("%<void%> must be the only parameter"); 5188 gave_void_only_once_err = true; 5189 } 5190 } 5191 else 5192 { 5193 /* Valid parameter, add it to the list. */ 5194 TREE_CHAIN (decl) = parms; 5195 parms = decl; 5196 5197 /* Since there is a prototype, args are passed in their 5198 declared types. The back end may override this later. */ 5199 DECL_ARG_TYPE (decl) = type; 5200 types = tree_cons (0, type, types); 5201 } 5202 break; 5203 5204 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 5205 case UNION_TYPE: keyword = "union"; goto tag; 5206 case RECORD_TYPE: keyword = "struct"; goto tag; 5207 tag: 5208 /* Types may not have tag-names, in which case the type 5209 appears in the bindings list with b->id NULL. */ 5210 if (b->id) 5211 { 5212 gcc_assert (I_TAG_BINDING (b->id) == b); 5213 I_TAG_BINDING (b->id) = b->shadowed; 5214 } 5215 5216 /* Warn about any struct, union or enum tags defined in a 5217 parameter list. The scope of such types is limited to 5218 the parameter list, which is rarely if ever desirable 5219 (it's impossible to call such a function with type- 5220 correct arguments). An anonymous union parm type is 5221 meaningful as a GNU extension, so don't warn for that. */ 5222 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 5223 { 5224 if (b->id) 5225 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5226 warning (0, "%<%s %E%> declared inside parameter list", 5227 keyword, b->id); 5228 else 5229 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5230 warning (0, "anonymous %s declared inside parameter list", 5231 keyword); 5232 5233 if (!explained_incomplete_types) 5234 { 5235 warning (0, "its scope is only this definition or declaration," 5236 " which is probably not what you want"); 5237 explained_incomplete_types = true; 5238 } 5239 } 5240 5241 tags = tree_cons (b->id, decl, tags); 5242 break; 5243 5244 case CONST_DECL: 5245 case TYPE_DECL: 5246 case FUNCTION_DECL: 5247 /* CONST_DECLs appear here when we have an embedded enum, 5248 and TYPE_DECLs appear here when we have an embedded struct 5249 or union. No warnings for this - we already warned about the 5250 type itself. FUNCTION_DECLs appear when there is an implicit 5251 function declaration in the parameter list. */ 5252 5253 TREE_CHAIN (decl) = others; 5254 others = decl; 5255 /* fall through */ 5256 5257 case ERROR_MARK: 5258 /* error_mark_node appears here when we have an undeclared 5259 variable. Just throw it away. */ 5260 if (b->id) 5261 { 5262 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5263 I_SYMBOL_BINDING (b->id) = b->shadowed; 5264 } 5265 break; 5266 5267 /* Other things that might be encountered. */ 5268 case LABEL_DECL: 5269 case VAR_DECL: 5270 default: 5271 gcc_unreachable (); 5272 } 5273 5274 b = free_binding_and_advance (b); 5275 } 5276 5277 arg_info->parms = parms; 5278 arg_info->tags = tags; 5279 arg_info->types = types; 5280 arg_info->others = others; 5281 arg_info->pending_sizes = get_pending_sizes (); 5282 return arg_info; 5283} 5284 5285/* Get the struct, enum or union (CODE says which) with tag NAME. 5286 Define the tag as a forward-reference if it is not defined. 5287 Return a c_typespec structure for the type specifier. */ 5288 5289struct c_typespec 5290parser_xref_tag (enum tree_code code, tree name) 5291{ 5292 struct c_typespec ret; 5293 /* If a cross reference is requested, look up the type 5294 already defined for this tag and return it. */ 5295 5296 tree ref = lookup_tag (code, name, 0); 5297 /* If this is the right type of tag, return what we found. 5298 (This reference will be shadowed by shadow_tag later if appropriate.) 5299 If this is the wrong type of tag, do not return it. If it was the 5300 wrong type in the same scope, we will have had an error 5301 message already; if in a different scope and declaring 5302 a name, pending_xref_error will give an error message; but if in a 5303 different scope and not declaring a name, this tag should 5304 shadow the previous declaration of a different type of tag, and 5305 this would not work properly if we return the reference found. 5306 (For example, with "struct foo" in an outer scope, "union foo;" 5307 must shadow that tag with a new one of union type.) */ 5308 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 5309 if (ref && TREE_CODE (ref) == code) 5310 { 5311 ret.spec = ref; 5312 return ret; 5313 } 5314 5315 /* If no such tag is yet defined, create a forward-reference node 5316 and record it as the "definition". 5317 When a real declaration of this type is found, 5318 the forward-reference will be altered into a real type. */ 5319 5320 ref = make_node (code); 5321 if (code == ENUMERAL_TYPE) 5322 { 5323 /* Give the type a default layout like unsigned int 5324 to avoid crashing if it does not get defined. */ 5325 TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node); 5326 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 5327 TYPE_USER_ALIGN (ref) = 0; 5328 TYPE_UNSIGNED (ref) = 1; 5329 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 5330 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 5331 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 5332 } 5333 5334 pushtag (name, ref); 5335 5336 ret.spec = ref; 5337 return ret; 5338} 5339 5340/* Get the struct, enum or union (CODE says which) with tag NAME. 5341 Define the tag as a forward-reference if it is not defined. 5342 Return a tree for the type. */ 5343 5344tree 5345xref_tag (enum tree_code code, tree name) 5346{ 5347 return parser_xref_tag (code, name).spec; 5348} 5349 5350/* Make sure that the tag NAME is defined *in the current scope* 5351 at least as a forward reference. 5352 CODE says which kind of tag NAME ought to be. */ 5353 5354tree 5355start_struct (enum tree_code code, tree name) 5356{ 5357 /* If there is already a tag defined at this scope 5358 (as a forward reference), just return it. */ 5359 5360 tree ref = 0; 5361 5362 if (name != 0) 5363 ref = lookup_tag (code, name, 1); 5364 if (ref && TREE_CODE (ref) == code) 5365 { 5366 if (TYPE_SIZE (ref)) 5367 { 5368 if (code == UNION_TYPE) 5369 error ("redefinition of %<union %E%>", name); 5370 else 5371 error ("redefinition of %<struct %E%>", name); 5372 } 5373 else if (C_TYPE_BEING_DEFINED (ref)) 5374 { 5375 if (code == UNION_TYPE) 5376 error ("nested redefinition of %<union %E%>", name); 5377 else 5378 error ("nested redefinition of %<struct %E%>", name); 5379 /* Don't create structures that contain themselves. */ 5380 ref = NULL_TREE; 5381 } 5382 } 5383 5384 /* Otherwise create a forward-reference just so the tag is in scope. */ 5385 5386 if (ref == NULL_TREE || TREE_CODE (ref) != code) 5387 { 5388 ref = make_node (code); 5389 pushtag (name, ref); 5390 } 5391 5392 C_TYPE_BEING_DEFINED (ref) = 1; 5393 TYPE_PACKED (ref) = flag_pack_struct; 5394 return ref; 5395} 5396 5397/* Process the specs, declarator and width (NULL if omitted) 5398 of a structure component, returning a FIELD_DECL node. 5399 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 5400 5401 This is done during the parsing of the struct declaration. 5402 The FIELD_DECL nodes are chained together and the lot of them 5403 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 5404 5405tree 5406grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs, 5407 tree width) 5408{ 5409 tree value; 5410 5411 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 5412 && width == NULL_TREE) 5413 { 5414 /* This is an unnamed decl. 5415 5416 If we have something of the form "union { list } ;" then this 5417 is the anonymous union extension. Similarly for struct. 5418 5419 If this is something of the form "struct foo;", then 5420 If MS extensions are enabled, this is handled as an 5421 anonymous struct. 5422 Otherwise this is a forward declaration of a structure tag. 5423 5424 If this is something of the form "foo;" and foo is a TYPE_DECL, then 5425 If MS extensions are enabled and foo names a structure, then 5426 again this is an anonymous struct. 5427 Otherwise this is an error. 5428 5429 Oh what a horrid tangled web we weave. I wonder if MS consciously 5430 took this from Plan 9 or if it was an accident of implementation 5431 that took root before someone noticed the bug... */ 5432 5433 tree type = declspecs->type; 5434 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 5435 || TREE_CODE (type) == UNION_TYPE); 5436 bool ok = false; 5437 5438 if (type_ok 5439 && (flag_ms_extensions || !declspecs->typedef_p)) 5440 { 5441 if (flag_ms_extensions) 5442 ok = true; 5443 else if (flag_iso) 5444 ok = false; 5445 else if (TYPE_NAME (type) == NULL) 5446 ok = true; 5447 else 5448 ok = false; 5449 } 5450 if (!ok) 5451 { 5452 pedwarn ("declaration does not declare anything"); 5453 return NULL_TREE; 5454 } 5455 if (pedantic) 5456 pedwarn ("ISO C doesn%'t support unnamed structs/unions"); 5457 } 5458 5459 value = grokdeclarator (declarator, declspecs, FIELD, false, 5460 width ? &width : NULL); 5461 5462 finish_decl (value, NULL_TREE, NULL_TREE); 5463 DECL_INITIAL (value) = width; 5464 5465 return value; 5466} 5467 5468/* Generate an error for any duplicate field names in FIELDLIST. Munge 5469 the list such that this does not present a problem later. */ 5470 5471static void 5472detect_field_duplicates (tree fieldlist) 5473{ 5474 tree x, y; 5475 int timeout = 10; 5476 5477 /* First, see if there are more than "a few" fields. 5478 This is trivially true if there are zero or one fields. */ 5479 if (!fieldlist) 5480 return; 5481 x = TREE_CHAIN (fieldlist); 5482 if (!x) 5483 return; 5484 do { 5485 timeout--; 5486 x = TREE_CHAIN (x); 5487 } while (timeout > 0 && x); 5488 5489 /* If there were "few" fields, avoid the overhead of allocating 5490 a hash table. Instead just do the nested traversal thing. */ 5491 if (timeout > 0) 5492 { 5493 for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x)) 5494 if (DECL_NAME (x)) 5495 { 5496 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 5497 if (DECL_NAME (y) == DECL_NAME (x)) 5498 { 5499 error ("duplicate member %q+D", x); 5500 DECL_NAME (x) = NULL_TREE; 5501 } 5502 } 5503 } 5504 else 5505 { 5506 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 5507 void **slot; 5508 5509 for (x = fieldlist; x ; x = TREE_CHAIN (x)) 5510 if ((y = DECL_NAME (x)) != 0) 5511 { 5512 slot = htab_find_slot (htab, y, INSERT); 5513 if (*slot) 5514 { 5515 error ("duplicate member %q+D", x); 5516 DECL_NAME (x) = NULL_TREE; 5517 } 5518 *slot = y; 5519 } 5520 5521 htab_delete (htab); 5522 } 5523} 5524 5525/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 5526 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 5527 ATTRIBUTES are attributes to be applied to the structure. */ 5528 5529tree 5530finish_struct (tree t, tree fieldlist, tree attributes) 5531{ 5532 tree x; 5533 bool toplevel = file_scope == current_scope; 5534 int saw_named_field; 5535 5536 /* If this type was previously laid out as a forward reference, 5537 make sure we lay it out again. */ 5538 5539 TYPE_SIZE (t) = 0; 5540 5541 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5542 5543 if (pedantic) 5544 { 5545 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5546 if (DECL_NAME (x) != 0) 5547 break; 5548 5549 if (x == 0) 5550 { 5551 if (TREE_CODE (t) == UNION_TYPE) 5552 { 5553 if (fieldlist) 5554 pedwarn ("union has no named members"); 5555 else 5556 pedwarn ("union has no members"); 5557 } 5558 else 5559 { 5560 if (fieldlist) 5561 pedwarn ("struct has no named members"); 5562 else 5563 pedwarn ("struct has no members"); 5564 } 5565 } 5566 } 5567 5568 /* Install struct as DECL_CONTEXT of each field decl. 5569 Also process specified field sizes, found in the DECL_INITIAL, 5570 storing 0 there after the type has been changed to precision equal 5571 to its width, rather than the precision of the specified standard 5572 type. (Correct layout requires the original type to have been preserved 5573 until now.) */ 5574 5575 saw_named_field = 0; 5576 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5577 { 5578 if (TREE_TYPE (x) == error_mark_node) 5579 continue; 5580 5581 DECL_CONTEXT (x) = t; 5582 5583 if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 5584 DECL_PACKED (x) = 1; 5585 5586 /* If any field is const, the structure type is pseudo-const. */ 5587 if (TREE_READONLY (x)) 5588 C_TYPE_FIELDS_READONLY (t) = 1; 5589 else 5590 { 5591 /* A field that is pseudo-const makes the structure likewise. */ 5592 tree t1 = TREE_TYPE (x); 5593 while (TREE_CODE (t1) == ARRAY_TYPE) 5594 t1 = TREE_TYPE (t1); 5595 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 5596 && C_TYPE_FIELDS_READONLY (t1)) 5597 C_TYPE_FIELDS_READONLY (t) = 1; 5598 } 5599 5600 /* Any field that is volatile means variables of this type must be 5601 treated in some ways as volatile. */ 5602 if (TREE_THIS_VOLATILE (x)) 5603 C_TYPE_FIELDS_VOLATILE (t) = 1; 5604 5605 /* Any field of nominal variable size implies structure is too. */ 5606 if (C_DECL_VARIABLE_SIZE (x)) 5607 C_TYPE_VARIABLE_SIZE (t) = 1; 5608 5609 if (DECL_INITIAL (x)) 5610 { 5611 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 5612 DECL_SIZE (x) = bitsize_int (width); 5613 DECL_BIT_FIELD (x) = 1; 5614 SET_DECL_C_BIT_FIELD (x); 5615 } 5616 5617 /* Detect flexible array member in an invalid context. */ 5618 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 5619 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 5620 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 5621 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 5622 { 5623 if (TREE_CODE (t) == UNION_TYPE) 5624 { 5625 error ("%Jflexible array member in union", x); 5626 TREE_TYPE (x) = error_mark_node; 5627 } 5628 else if (TREE_CHAIN (x) != NULL_TREE) 5629 { 5630 error ("%Jflexible array member not at end of struct", x); 5631 TREE_TYPE (x) = error_mark_node; 5632 } 5633 else if (!saw_named_field) 5634 { 5635 error ("%Jflexible array member in otherwise empty struct", x); 5636 TREE_TYPE (x) = error_mark_node; 5637 } 5638 } 5639 5640 if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE 5641 && flexible_array_type_p (TREE_TYPE (x))) 5642 pedwarn ("%Jinvalid use of structure with flexible array member", x); 5643 5644 if (DECL_NAME (x)) 5645 saw_named_field = 1; 5646 } 5647 5648 detect_field_duplicates (fieldlist); 5649 5650 /* Now we have the nearly final fieldlist. Record it, 5651 then lay out the structure or union (including the fields). */ 5652 5653 TYPE_FIELDS (t) = fieldlist; 5654 5655 layout_type (t); 5656 5657 /* Give bit-fields their proper types. */ 5658 { 5659 tree *fieldlistp = &fieldlist; 5660 while (*fieldlistp) 5661 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 5662 && TREE_TYPE (*fieldlistp) != error_mark_node) 5663 { 5664 unsigned HOST_WIDE_INT width 5665 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 5666 tree type = TREE_TYPE (*fieldlistp); 5667 if (width != TYPE_PRECISION (type)) 5668 { 5669 TREE_TYPE (*fieldlistp) 5670 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 5671 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 5672 } 5673 DECL_INITIAL (*fieldlistp) = 0; 5674 } 5675 else 5676 fieldlistp = &TREE_CHAIN (*fieldlistp); 5677 } 5678 5679 /* Now we have the truly final field list. 5680 Store it in this type and in the variants. */ 5681 5682 TYPE_FIELDS (t) = fieldlist; 5683 5684 /* If there are lots of fields, sort so we can look through them fast. 5685 We arbitrarily consider 16 or more elts to be "a lot". */ 5686 5687 { 5688 int len = 0; 5689 5690 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5691 { 5692 if (len > 15 || DECL_NAME (x) == NULL) 5693 break; 5694 len += 1; 5695 } 5696 5697 if (len > 15) 5698 { 5699 tree *field_array; 5700 struct lang_type *space; 5701 struct sorted_fields_type *space2; 5702 5703 len += list_length (x); 5704 5705 /* Use the same allocation policy here that make_node uses, to 5706 ensure that this lives as long as the rest of the struct decl. 5707 All decls in an inline function need to be saved. */ 5708 5709 space = GGC_CNEW (struct lang_type); 5710 space2 = GGC_NEWVAR (struct sorted_fields_type, 5711 sizeof (struct sorted_fields_type) + len * sizeof (tree)); 5712 5713 len = 0; 5714 space->s = space2; 5715 field_array = &space2->elts[0]; 5716 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5717 { 5718 field_array[len++] = x; 5719 5720 /* If there is anonymous struct or union, break out of the loop. */ 5721 if (DECL_NAME (x) == NULL) 5722 break; 5723 } 5724 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 5725 if (x == NULL) 5726 { 5727 TYPE_LANG_SPECIFIC (t) = space; 5728 TYPE_LANG_SPECIFIC (t)->s->len = len; 5729 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 5730 qsort (field_array, len, sizeof (tree), field_decl_cmp); 5731 } 5732 } 5733 } 5734 5735 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 5736 { 5737 TYPE_FIELDS (x) = TYPE_FIELDS (t); 5738 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 5739 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 5740 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 5741 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 5742 } 5743 5744 /* If this was supposed to be a transparent union, but we can't 5745 make it one, warn and turn off the flag. */ 5746 if (TREE_CODE (t) == UNION_TYPE 5747 && TYPE_TRANSPARENT_UNION (t) 5748 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 5749 { 5750 TYPE_TRANSPARENT_UNION (t) = 0; 5751 warning (0, "union cannot be made transparent"); 5752 } 5753 5754 /* If this structure or union completes the type of any previous 5755 variable declaration, lay it out and output its rtl. */ 5756 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 5757 x; 5758 x = TREE_CHAIN (x)) 5759 { 5760 tree decl = TREE_VALUE (x); 5761 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 5762 layout_array_type (TREE_TYPE (decl)); 5763 if (TREE_CODE (decl) != TYPE_DECL) 5764 { 5765 layout_decl (decl, 0); 5766 if (c_dialect_objc ()) 5767 objc_check_decl (decl); 5768 rest_of_decl_compilation (decl, toplevel, 0); 5769 if (!toplevel) 5770 expand_decl (decl); 5771 } 5772 } 5773 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 5774 5775 /* Finish debugging output for this type. */ 5776 rest_of_type_compilation (t, toplevel); 5777 5778 /* If we're inside a function proper, i.e. not file-scope and not still 5779 parsing parameters, then arrange for the size of a variable sized type 5780 to be bound now. */ 5781 if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE)) 5782 add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t))); 5783 5784 return t; 5785} 5786 5787/* Lay out the type T, and its element type, and so on. */ 5788 5789static void 5790layout_array_type (tree t) 5791{ 5792 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 5793 layout_array_type (TREE_TYPE (t)); 5794 layout_type (t); 5795} 5796 5797/* Begin compiling the definition of an enumeration type. 5798 NAME is its name (or null if anonymous). 5799 Returns the type object, as yet incomplete. 5800 Also records info about it so that build_enumerator 5801 may be used to declare the individual values as they are read. */ 5802 5803tree 5804start_enum (tree name) 5805{ 5806 tree enumtype = 0; 5807 5808 /* If this is the real definition for a previous forward reference, 5809 fill in the contents in the same object that used to be the 5810 forward reference. */ 5811 5812 if (name != 0) 5813 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1); 5814 5815 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 5816 { 5817 enumtype = make_node (ENUMERAL_TYPE); 5818 pushtag (name, enumtype); 5819 } 5820 5821 if (C_TYPE_BEING_DEFINED (enumtype)) 5822 error ("nested redefinition of %<enum %E%>", name); 5823 5824 C_TYPE_BEING_DEFINED (enumtype) = 1; 5825 5826 if (TYPE_VALUES (enumtype) != 0) 5827 { 5828 /* This enum is a named one that has been declared already. */ 5829 error ("redeclaration of %<enum %E%>", name); 5830 5831 /* Completely replace its old definition. 5832 The old enumerators remain defined, however. */ 5833 TYPE_VALUES (enumtype) = 0; 5834 } 5835 5836 enum_next_value = integer_zero_node; 5837 enum_overflow = 0; 5838 5839 if (flag_short_enums) 5840 TYPE_PACKED (enumtype) = 1; 5841 5842 return enumtype; 5843} 5844 5845/* After processing and defining all the values of an enumeration type, 5846 install their decls in the enumeration type and finish it off. 5847 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 5848 and ATTRIBUTES are the specified attributes. 5849 Returns ENUMTYPE. */ 5850 5851tree 5852finish_enum (tree enumtype, tree values, tree attributes) 5853{ 5854 tree pair, tem; 5855 tree minnode = 0, maxnode = 0; 5856 int precision, unsign; 5857 bool toplevel = (file_scope == current_scope); 5858 struct lang_type *lt; 5859 5860 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5861 5862 /* Calculate the maximum value of any enumerator in this type. */ 5863 5864 if (values == error_mark_node) 5865 minnode = maxnode = integer_zero_node; 5866 else 5867 { 5868 minnode = maxnode = TREE_VALUE (values); 5869 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 5870 { 5871 tree value = TREE_VALUE (pair); 5872 if (tree_int_cst_lt (maxnode, value)) 5873 maxnode = value; 5874 if (tree_int_cst_lt (value, minnode)) 5875 minnode = value; 5876 } 5877 } 5878 5879 /* Construct the final type of this enumeration. It is the same 5880 as one of the integral types - the narrowest one that fits, except 5881 that normally we only go as narrow as int - and signed iff any of 5882 the values are negative. */ 5883 unsign = (tree_int_cst_sgn (minnode) >= 0); 5884 precision = MAX (min_precision (minnode, unsign), 5885 min_precision (maxnode, unsign)); 5886 5887 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 5888 { 5889 tem = c_common_type_for_size (precision, unsign); 5890 if (tem == NULL) 5891 { 5892 warning (0, "enumeration values exceed range of largest integer"); 5893 tem = long_long_integer_type_node; 5894 } 5895 } 5896 else 5897 tem = unsign ? unsigned_type_node : integer_type_node; 5898 5899 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 5900 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 5901 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 5902 TYPE_SIZE (enumtype) = 0; 5903 5904 /* If the precision of the type was specific with an attribute and it 5905 was too small, give an error. Otherwise, use it. */ 5906 if (TYPE_PRECISION (enumtype)) 5907 { 5908 if (precision > TYPE_PRECISION (enumtype)) 5909 error ("specified mode too small for enumeral values"); 5910 } 5911 else 5912 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 5913 5914 layout_type (enumtype); 5915 5916 if (values != error_mark_node) 5917 { 5918 /* Change the type of the enumerators to be the enum type. We 5919 need to do this irrespective of the size of the enum, for 5920 proper type checking. Replace the DECL_INITIALs of the 5921 enumerators, and the value slots of the list, with copies 5922 that have the enum type; they cannot be modified in place 5923 because they may be shared (e.g. integer_zero_node) Finally, 5924 change the purpose slots to point to the names of the decls. */ 5925 for (pair = values; pair; pair = TREE_CHAIN (pair)) 5926 { 5927 tree enu = TREE_PURPOSE (pair); 5928 tree ini = DECL_INITIAL (enu); 5929 5930 TREE_TYPE (enu) = enumtype; 5931 5932 /* The ISO C Standard mandates enumerators to have type int, 5933 even though the underlying type of an enum type is 5934 unspecified. Here we convert any enumerators that fit in 5935 an int to type int, to avoid promotions to unsigned types 5936 when comparing integers with enumerators that fit in the 5937 int range. When -pedantic is given, build_enumerator() 5938 would have already taken care of those that don't fit. */ 5939 if (int_fits_type_p (ini, integer_type_node)) 5940 tem = integer_type_node; 5941 else 5942 tem = enumtype; 5943 ini = convert (tem, ini); 5944 5945 DECL_INITIAL (enu) = ini; 5946 TREE_PURPOSE (pair) = DECL_NAME (enu); 5947 TREE_VALUE (pair) = ini; 5948 } 5949 5950 TYPE_VALUES (enumtype) = values; 5951 } 5952 5953 /* Record the min/max values so that we can warn about bit-field 5954 enumerations that are too small for the values. */ 5955 lt = GGC_CNEW (struct lang_type); 5956 lt->enum_min = minnode; 5957 lt->enum_max = maxnode; 5958 TYPE_LANG_SPECIFIC (enumtype) = lt; 5959 5960 /* Fix up all variant types of this enum type. */ 5961 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 5962 { 5963 if (tem == enumtype) 5964 continue; 5965 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 5966 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 5967 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 5968 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 5969 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 5970 TYPE_MODE (tem) = TYPE_MODE (enumtype); 5971 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 5972 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 5973 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 5974 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 5975 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 5976 } 5977 5978 /* Finish debugging output for this type. */ 5979 rest_of_type_compilation (enumtype, toplevel); 5980 5981 return enumtype; 5982} 5983 5984/* Build and install a CONST_DECL for one value of the 5985 current enumeration type (one that was begun with start_enum). 5986 Return a tree-list containing the CONST_DECL and its value. 5987 Assignment of sequential values by default is handled here. */ 5988 5989tree 5990build_enumerator (tree name, tree value) 5991{ 5992 tree decl, type; 5993 5994 /* Validate and default VALUE. */ 5995 5996 if (value != 0) 5997 { 5998 /* Don't issue more errors for error_mark_node (i.e. an 5999 undeclared identifier) - just ignore the value expression. */ 6000 if (value == error_mark_node) 6001 value = 0; 6002 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value)) 6003 || TREE_CODE (value) != INTEGER_CST) 6004 { 6005 error ("enumerator value for %qE is not an integer constant", name); 6006 value = 0; 6007 } 6008 else 6009 { 6010 value = default_conversion (value); 6011 constant_expression_warning (value); 6012 } 6013 } 6014 6015 /* Default based on previous value. */ 6016 /* It should no longer be possible to have NON_LVALUE_EXPR 6017 in the default. */ 6018 if (value == 0) 6019 { 6020 value = enum_next_value; 6021 if (enum_overflow) 6022 error ("overflow in enumeration values"); 6023 } 6024 6025 if (pedantic && !int_fits_type_p (value, integer_type_node)) 6026 { 6027 pedwarn ("ISO C restricts enumerator values to range of %<int%>"); 6028 /* XXX This causes -pedantic to change the meaning of the program. 6029 Remove? -zw 2004-03-15 */ 6030 value = convert (integer_type_node, value); 6031 } 6032 6033 /* Set basis for default for next value. */ 6034 enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0); 6035 enum_overflow = tree_int_cst_lt (enum_next_value, value); 6036 6037 /* Now create a declaration for the enum value name. */ 6038 6039 type = TREE_TYPE (value); 6040 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 6041 TYPE_PRECISION (integer_type_node)), 6042 (TYPE_PRECISION (type) 6043 >= TYPE_PRECISION (integer_type_node) 6044 && TYPE_UNSIGNED (type))); 6045 6046 decl = build_decl (CONST_DECL, name, type); 6047 DECL_INITIAL (decl) = convert (type, value); 6048 pushdecl (decl); 6049 6050 return tree_cons (decl, value, NULL_TREE); 6051} 6052 6053 6054/* Create the FUNCTION_DECL for a function definition. 6055 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 6056 the declaration; they describe the function's name and the type it returns, 6057 but twisted together in a fashion that parallels the syntax of C. 6058 6059 This function creates a binding context for the function body 6060 as well as setting up the FUNCTION_DECL in current_function_decl. 6061 6062 Returns 1 on success. If the DECLARATOR is not suitable for a function 6063 (it defines a datum instead), we return 0, which tells 6064 yyparse to report a parse error. */ 6065 6066int 6067start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 6068 tree attributes) 6069{ 6070 tree decl1, old_decl; 6071 tree restype, resdecl; 6072 struct c_label_context_se *nstack_se; 6073 struct c_label_context_vm *nstack_vm; 6074 6075 current_function_returns_value = 0; /* Assume, until we see it does. */ 6076 current_function_returns_null = 0; 6077 current_function_returns_abnormally = 0; 6078 warn_about_return_type = 0; 6079 c_switch_stack = NULL; 6080 6081 nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se); 6082 nstack_se->labels_def = NULL; 6083 nstack_se->labels_used = NULL; 6084 nstack_se->next = label_context_stack_se; 6085 label_context_stack_se = nstack_se; 6086 6087 nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm); 6088 nstack_vm->labels_def = NULL; 6089 nstack_vm->labels_used = NULL; 6090 nstack_vm->scope = 0; 6091 nstack_vm->next = label_context_stack_vm; 6092 label_context_stack_vm = nstack_vm; 6093 6094 /* Indicate no valid break/continue context by setting these variables 6095 to some non-null, non-label value. We'll notice and emit the proper 6096 error message in c_finish_bc_stmt. */ 6097 c_break_label = c_cont_label = size_zero_node; 6098 6099 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL); 6100 6101 /* If the declarator is not suitable for a function definition, 6102 cause a syntax error. */ 6103 if (decl1 == 0) 6104 { 6105 label_context_stack_se = label_context_stack_se->next; 6106 label_context_stack_vm = label_context_stack_vm->next; 6107 return 0; 6108 } 6109 6110 decl_attributes (&decl1, attributes, 0); 6111 6112 if (DECL_DECLARED_INLINE_P (decl1) 6113 && DECL_UNINLINABLE (decl1) 6114 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 6115 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 6116 decl1); 6117 6118 /* Handle gnu_inline attribute. */ 6119 if (declspecs->inline_p 6120 && !flag_gnu89_inline 6121 && TREE_CODE (decl1) == FUNCTION_DECL 6122 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1))) 6123 { 6124 if (declspecs->storage_class != csc_static) 6125 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 6126 } 6127 6128 announce_function (decl1); 6129 6130 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 6131 { 6132 error ("return type is an incomplete type"); 6133 /* Make it return void instead. */ 6134 TREE_TYPE (decl1) 6135 = build_function_type (void_type_node, 6136 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 6137 } 6138 6139 if (warn_about_return_type) 6140 pedwarn_c99 ("return type defaults to %<int%>"); 6141 6142 /* Make the init_value nonzero so pushdecl knows this is not tentative. 6143 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 6144 DECL_INITIAL (decl1) = error_mark_node; 6145 6146 /* If this definition isn't a prototype and we had a prototype declaration 6147 before, copy the arg type info from that prototype. */ 6148 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 6149 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 6150 old_decl = 0; 6151 current_function_prototype_locus = UNKNOWN_LOCATION; 6152 current_function_prototype_built_in = false; 6153 current_function_prototype_arg_types = NULL_TREE; 6154 if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0) 6155 { 6156 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 6157 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6158 TREE_TYPE (TREE_TYPE (old_decl)))) 6159 { 6160 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 6161 TREE_TYPE (decl1)); 6162 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 6163 current_function_prototype_built_in 6164 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 6165 current_function_prototype_arg_types 6166 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 6167 } 6168 if (TREE_PUBLIC (decl1)) 6169 { 6170 /* If there is an external prototype declaration of this 6171 function, record its location but do not copy information 6172 to this decl. This may be an invisible declaration 6173 (built-in or in a scope which has finished) or simply 6174 have more refined argument types than any declaration 6175 found above. */ 6176 struct c_binding *b; 6177 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 6178 if (B_IN_SCOPE (b, external_scope)) 6179 break; 6180 if (b) 6181 { 6182 tree ext_decl, ext_type; 6183 ext_decl = b->decl; 6184 ext_type = b->type ? b->type : TREE_TYPE (ext_decl); 6185 if (TREE_CODE (ext_type) == FUNCTION_TYPE 6186 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6187 TREE_TYPE (ext_type))) 6188 { 6189 current_function_prototype_locus 6190 = DECL_SOURCE_LOCATION (ext_decl); 6191 current_function_prototype_built_in 6192 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 6193 current_function_prototype_arg_types 6194 = TYPE_ARG_TYPES (ext_type); 6195 } 6196 } 6197 } 6198 } 6199 6200 /* Optionally warn of old-fashioned def with no previous prototype. */ 6201 if (warn_strict_prototypes 6202 && old_decl != error_mark_node 6203 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0 6204 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6205 warning (OPT_Wstrict_prototypes, 6206 "function declaration isn%'t a prototype"); 6207 /* Optionally warn of any global def with no previous prototype. */ 6208 else if (warn_missing_prototypes 6209 && old_decl != error_mark_node 6210 && TREE_PUBLIC (decl1) 6211 && !MAIN_NAME_P (DECL_NAME (decl1)) 6212 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6213 warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1); 6214 /* Optionally warn of any def with no previous prototype 6215 if the function has already been used. */ 6216 else if (warn_missing_prototypes 6217 && old_decl != 0 6218 && old_decl != error_mark_node 6219 && TREE_USED (old_decl) 6220 && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0) 6221 warning (OPT_Wmissing_prototypes, 6222 "%q+D was used with no prototype before its definition", decl1); 6223 /* Optionally warn of any global def with no previous declaration. */ 6224 else if (warn_missing_declarations 6225 && TREE_PUBLIC (decl1) 6226 && old_decl == 0 6227 && !MAIN_NAME_P (DECL_NAME (decl1))) 6228 warning (OPT_Wmissing_declarations, "no previous declaration for %q+D", 6229 decl1); 6230 /* Optionally warn of any def with no previous declaration 6231 if the function has already been used. */ 6232 else if (warn_missing_declarations 6233 && old_decl != 0 6234 && old_decl != error_mark_node 6235 && TREE_USED (old_decl) 6236 && C_DECL_IMPLICIT (old_decl)) 6237 warning (OPT_Wmissing_declarations, 6238 "%q+D was used with no declaration before its definition", decl1); 6239 6240 /* This function exists in static storage. 6241 (This does not mean `static' in the C sense!) */ 6242 TREE_STATIC (decl1) = 1; 6243 6244 /* A nested function is not global. */ 6245 if (current_function_decl != 0) 6246 TREE_PUBLIC (decl1) = 0; 6247 6248 /* This is the earliest point at which we might know the assembler 6249 name of the function. Thus, if it's set before this, die horribly. */ 6250 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 6251 6252 /* If #pragma weak was used, mark the decl weak now. */ 6253 if (current_scope == file_scope) 6254 maybe_apply_pragma_weak (decl1); 6255 6256 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 6257 if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1))) 6258 { 6259 tree args; 6260 int argct = 0; 6261 6262 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 6263 != integer_type_node) 6264 pedwarn ("return type of %q+D is not %<int%>", decl1); 6265 6266 for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args; 6267 args = TREE_CHAIN (args)) 6268 { 6269 tree type = args ? TREE_VALUE (args) : 0; 6270 6271 if (type == void_type_node) 6272 break; 6273 6274 ++argct; 6275 switch (argct) 6276 { 6277 case 1: 6278 if (TYPE_MAIN_VARIANT (type) != integer_type_node) 6279 pedwarn ("first argument of %q+D should be %<int%>", decl1); 6280 break; 6281 6282 case 2: 6283 if (TREE_CODE (type) != POINTER_TYPE 6284 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6285 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6286 != char_type_node)) 6287 pedwarn ("second argument of %q+D should be %<char **%>", 6288 decl1); 6289 break; 6290 6291 case 3: 6292 if (TREE_CODE (type) != POINTER_TYPE 6293 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6294 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6295 != char_type_node)) 6296 pedwarn ("third argument of %q+D should probably be " 6297 "%<char **%>", decl1); 6298 break; 6299 } 6300 } 6301 6302 /* It is intentional that this message does not mention the third 6303 argument because it's only mentioned in an appendix of the 6304 standard. */ 6305 if (argct > 0 && (argct < 2 || argct > 3)) 6306 pedwarn ("%q+D takes only zero or two arguments", decl1); 6307 6308 if (!TREE_PUBLIC (decl1)) 6309 pedwarn ("%q+D is normally a non-static function", decl1); 6310 } 6311 6312 /* Record the decl so that the function name is defined. 6313 If we already have a decl for this name, and it is a FUNCTION_DECL, 6314 use the old decl. */ 6315 6316 current_function_decl = pushdecl (decl1); 6317 6318 push_scope (); 6319 declare_parm_level (); 6320 6321 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6322 /* Promote the value to int before returning it. */ 6323 if (c_promoting_integer_type_p (restype)) 6324 { 6325 /* It retains unsignedness if not really getting wider. */ 6326 if (TYPE_UNSIGNED (restype) 6327 && (TYPE_PRECISION (restype) 6328 == TYPE_PRECISION (integer_type_node))) 6329 restype = unsigned_type_node; 6330 else 6331 restype = integer_type_node; 6332 } 6333 6334 resdecl = build_decl (RESULT_DECL, NULL_TREE, restype); 6335 DECL_ARTIFICIAL (resdecl) = 1; 6336 DECL_IGNORED_P (resdecl) = 1; 6337 DECL_RESULT (current_function_decl) = resdecl; 6338 6339 start_fname_decls (); 6340 6341 return 1; 6342} 6343 6344/* Subroutine of store_parm_decls which handles new-style function 6345 definitions (prototype format). The parms already have decls, so we 6346 need only record them as in effect and complain if any redundant 6347 old-style parm decls were written. */ 6348static void 6349store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 6350{ 6351 tree decl; 6352 6353 if (current_scope->bindings) 6354 { 6355 error ("%Jold-style parameter declarations in prototyped " 6356 "function definition", fndecl); 6357 6358 /* Get rid of the old-style declarations. */ 6359 pop_scope (); 6360 push_scope (); 6361 } 6362 /* Don't issue this warning for nested functions, and don't issue this 6363 warning if we got here because ARG_INFO_TYPES was error_mark_node 6364 (this happens when a function definition has just an ellipsis in 6365 its parameter list). */ 6366 else if (!in_system_header && !current_function_scope 6367 && arg_info->types != error_mark_node) 6368 warning (OPT_Wtraditional, 6369 "%Jtraditional C rejects ISO C style function definitions", 6370 fndecl); 6371 6372 /* Now make all the parameter declarations visible in the function body. 6373 We can bypass most of the grunt work of pushdecl. */ 6374 for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl)) 6375 { 6376 DECL_CONTEXT (decl) = current_function_decl; 6377 if (DECL_NAME (decl)) 6378 { 6379 bind (DECL_NAME (decl), decl, current_scope, 6380 /*invisible=*/false, /*nested=*/false); 6381 if (!TREE_USED (decl)) 6382 warn_if_shadowing (decl); 6383 } 6384 else 6385 error ("%Jparameter name omitted", decl); 6386 } 6387 6388 /* Record the parameter list in the function declaration. */ 6389 DECL_ARGUMENTS (fndecl) = arg_info->parms; 6390 6391 /* Now make all the ancillary declarations visible, likewise. */ 6392 for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl)) 6393 { 6394 DECL_CONTEXT (decl) = current_function_decl; 6395 if (DECL_NAME (decl)) 6396 bind (DECL_NAME (decl), decl, current_scope, 6397 /*invisible=*/false, /*nested=*/false); 6398 } 6399 6400 /* And all the tag declarations. */ 6401 for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl)) 6402 if (TREE_PURPOSE (decl)) 6403 bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope, 6404 /*invisible=*/false, /*nested=*/false); 6405} 6406 6407/* Subroutine of store_parm_decls which handles old-style function 6408 definitions (separate parameter list and declarations). */ 6409 6410static void 6411store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 6412{ 6413 struct c_binding *b; 6414 tree parm, decl, last; 6415 tree parmids = arg_info->parms; 6416 struct pointer_set_t *seen_args = pointer_set_create (); 6417 6418 if (!in_system_header) 6419 warning (OPT_Wold_style_definition, "%Jold-style function definition", 6420 fndecl); 6421 6422 /* Match each formal parameter name with its declaration. Save each 6423 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 6424 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6425 { 6426 if (TREE_VALUE (parm) == 0) 6427 { 6428 error ("%Jparameter name missing from parameter list", fndecl); 6429 TREE_PURPOSE (parm) = 0; 6430 continue; 6431 } 6432 6433 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 6434 if (b && B_IN_CURRENT_SCOPE (b)) 6435 { 6436 decl = b->decl; 6437 /* If we got something other than a PARM_DECL it is an error. */ 6438 if (TREE_CODE (decl) != PARM_DECL) 6439 error ("%q+D declared as a non-parameter", decl); 6440 /* If the declaration is already marked, we have a duplicate 6441 name. Complain and ignore the duplicate. */ 6442 else if (pointer_set_contains (seen_args, decl)) 6443 { 6444 error ("multiple parameters named %q+D", decl); 6445 TREE_PURPOSE (parm) = 0; 6446 continue; 6447 } 6448 /* If the declaration says "void", complain and turn it into 6449 an int. */ 6450 else if (VOID_TYPE_P (TREE_TYPE (decl))) 6451 { 6452 error ("parameter %q+D declared with void type", decl); 6453 TREE_TYPE (decl) = integer_type_node; 6454 DECL_ARG_TYPE (decl) = integer_type_node; 6455 layout_decl (decl, 0); 6456 } 6457 warn_if_shadowing (decl); 6458 } 6459 /* If no declaration found, default to int. */ 6460 else 6461 { 6462 decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node); 6463 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 6464 DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl); 6465 pushdecl (decl); 6466 warn_if_shadowing (decl); 6467 6468 if (flag_isoc99) 6469 pedwarn ("type of %q+D defaults to %<int%>", decl); 6470 else if (extra_warnings) 6471 warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl); 6472 } 6473 6474 TREE_PURPOSE (parm) = decl; 6475 pointer_set_insert (seen_args, decl); 6476 } 6477 6478 /* Now examine the parms chain for incomplete declarations 6479 and declarations with no corresponding names. */ 6480 6481 for (b = current_scope->bindings; b; b = b->prev) 6482 { 6483 parm = b->decl; 6484 if (TREE_CODE (parm) != PARM_DECL) 6485 continue; 6486 6487 if (TREE_TYPE (parm) != error_mark_node 6488 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 6489 { 6490 error ("parameter %q+D has incomplete type", parm); 6491 TREE_TYPE (parm) = error_mark_node; 6492 } 6493 6494 if (!pointer_set_contains (seen_args, parm)) 6495 { 6496 error ("declaration for parameter %q+D but no such parameter", parm); 6497 6498 /* Pretend the parameter was not missing. 6499 This gets us to a standard state and minimizes 6500 further error messages. */ 6501 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 6502 } 6503 } 6504 6505 /* Chain the declarations together in the order of the list of 6506 names. Store that chain in the function decl, replacing the 6507 list of names. Update the current scope to match. */ 6508 DECL_ARGUMENTS (fndecl) = 0; 6509 6510 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6511 if (TREE_PURPOSE (parm)) 6512 break; 6513 if (parm && TREE_PURPOSE (parm)) 6514 { 6515 last = TREE_PURPOSE (parm); 6516 DECL_ARGUMENTS (fndecl) = last; 6517 6518 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 6519 if (TREE_PURPOSE (parm)) 6520 { 6521 TREE_CHAIN (last) = TREE_PURPOSE (parm); 6522 last = TREE_PURPOSE (parm); 6523 } 6524 TREE_CHAIN (last) = 0; 6525 } 6526 6527 pointer_set_destroy (seen_args); 6528 6529 /* If there was a previous prototype, 6530 set the DECL_ARG_TYPE of each argument according to 6531 the type previously specified, and report any mismatches. */ 6532 6533 if (current_function_prototype_arg_types) 6534 { 6535 tree type; 6536 for (parm = DECL_ARGUMENTS (fndecl), 6537 type = current_function_prototype_arg_types; 6538 parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) 6539 != void_type_node)); 6540 parm = TREE_CHAIN (parm), type = TREE_CHAIN (type)) 6541 { 6542 if (parm == 0 || type == 0 6543 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 6544 { 6545 if (current_function_prototype_built_in) 6546 warning (0, "number of arguments doesn%'t match " 6547 "built-in prototype"); 6548 else 6549 { 6550 error ("number of arguments doesn%'t match prototype"); 6551 error ("%Hprototype declaration", 6552 ¤t_function_prototype_locus); 6553 } 6554 break; 6555 } 6556 /* Type for passing arg must be consistent with that 6557 declared for the arg. ISO C says we take the unqualified 6558 type for parameters declared with qualified type. */ 6559 if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 6560 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 6561 { 6562 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 6563 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 6564 { 6565 /* Adjust argument to match prototype. E.g. a previous 6566 `int foo(float);' prototype causes 6567 `int foo(x) float x; {...}' to be treated like 6568 `int foo(float x) {...}'. This is particularly 6569 useful for argument types like uid_t. */ 6570 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 6571 6572 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 6573 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 6574 && TYPE_PRECISION (TREE_TYPE (parm)) 6575 < TYPE_PRECISION (integer_type_node)) 6576 DECL_ARG_TYPE (parm) = integer_type_node; 6577 6578 if (pedantic) 6579 { 6580 /* ??? Is it possible to get here with a 6581 built-in prototype or will it always have 6582 been diagnosed as conflicting with an 6583 old-style definition and discarded? */ 6584 if (current_function_prototype_built_in) 6585 warning (0, "promoted argument %qD " 6586 "doesn%'t match built-in prototype", parm); 6587 else 6588 { 6589 pedwarn ("promoted argument %qD " 6590 "doesn%'t match prototype", parm); 6591 pedwarn ("%Hprototype declaration", 6592 ¤t_function_prototype_locus); 6593 } 6594 } 6595 } 6596 else 6597 { 6598 if (current_function_prototype_built_in) 6599 warning (0, "argument %qD doesn%'t match " 6600 "built-in prototype", parm); 6601 else 6602 { 6603 error ("argument %qD doesn%'t match prototype", parm); 6604 error ("%Hprototype declaration", 6605 ¤t_function_prototype_locus); 6606 } 6607 } 6608 } 6609 } 6610 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 6611 } 6612 6613 /* Otherwise, create a prototype that would match. */ 6614 6615 else 6616 { 6617 tree actual = 0, last = 0, type; 6618 6619 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm)) 6620 { 6621 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 6622 if (last) 6623 TREE_CHAIN (last) = type; 6624 else 6625 actual = type; 6626 last = type; 6627 } 6628 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 6629 if (last) 6630 TREE_CHAIN (last) = type; 6631 else 6632 actual = type; 6633 6634 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 6635 of the type of this function, but we need to avoid having this 6636 affect the types of other similarly-typed functions, so we must 6637 first force the generation of an identical (but separate) type 6638 node for the relevant function type. The new node we create 6639 will be a variant of the main variant of the original function 6640 type. */ 6641 6642 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 6643 6644 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 6645 } 6646} 6647 6648/* Store parameter declarations passed in ARG_INFO into the current 6649 function declaration. */ 6650 6651void 6652store_parm_decls_from (struct c_arg_info *arg_info) 6653{ 6654 current_function_arg_info = arg_info; 6655 store_parm_decls (); 6656} 6657 6658/* Store the parameter declarations into the current function declaration. 6659 This is called after parsing the parameter declarations, before 6660 digesting the body of the function. 6661 6662 For an old-style definition, construct a prototype out of the old-style 6663 parameter declarations and inject it into the function's type. */ 6664 6665void 6666store_parm_decls (void) 6667{ 6668 tree fndecl = current_function_decl; 6669 bool proto; 6670 6671 /* The argument information block for FNDECL. */ 6672 struct c_arg_info *arg_info = current_function_arg_info; 6673 current_function_arg_info = 0; 6674 6675 /* True if this definition is written with a prototype. Note: 6676 despite C99 6.7.5.3p14, we can *not* treat an empty argument 6677 list in a function definition as equivalent to (void) -- an 6678 empty argument list specifies the function has no parameters, 6679 but only (void) sets up a prototype for future calls. */ 6680 proto = arg_info->types != 0; 6681 6682 if (proto) 6683 store_parm_decls_newstyle (fndecl, arg_info); 6684 else 6685 store_parm_decls_oldstyle (fndecl, arg_info); 6686 6687 /* The next call to push_scope will be a function body. */ 6688 6689 next_is_function_body = true; 6690 6691 /* Write a record describing this function definition to the prototypes 6692 file (if requested). */ 6693 6694 gen_aux_info_record (fndecl, 1, 0, proto); 6695 6696 /* Initialize the RTL code for the function. */ 6697 allocate_struct_function (fndecl); 6698 6699 /* Begin the statement tree for this function. */ 6700 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 6701 6702 /* ??? Insert the contents of the pending sizes list into the function 6703 to be evaluated. The only reason left to have this is 6704 void foo(int n, int array[n++]) 6705 because we throw away the array type in favor of a pointer type, and 6706 thus won't naturally see the SAVE_EXPR containing the increment. All 6707 other pending sizes would be handled by gimplify_parameters. */ 6708 { 6709 tree t; 6710 for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t)) 6711 add_stmt (TREE_VALUE (t)); 6712 } 6713 6714 /* Even though we're inside a function body, we still don't want to 6715 call expand_expr to calculate the size of a variable-sized array. 6716 We haven't necessarily assigned RTL to all variables yet, so it's 6717 not safe to try to expand expressions involving them. */ 6718 cfun->x_dont_save_pending_sizes_p = 1; 6719} 6720 6721/* Emit diagnostics that require gimple input for detection. Operate on 6722 FNDECL and all its nested functions. */ 6723 6724static void 6725c_gimple_diagnostics_recursively (tree fndecl) 6726{ 6727 struct cgraph_node *cgn; 6728 6729 /* Handle attribute((warn_unused_result)). Relies on gimple input. */ 6730 c_warn_unused_result (&DECL_SAVED_TREE (fndecl)); 6731 6732 /* Notice when OpenMP structured block constraints are violated. */ 6733 if (flag_openmp) 6734 diagnose_omp_structured_block_errors (fndecl); 6735 6736 /* Finalize all nested functions now. */ 6737 cgn = cgraph_node (fndecl); 6738 for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) 6739 c_gimple_diagnostics_recursively (cgn->decl); 6740} 6741 6742/* Finish up a function declaration and compile that function 6743 all the way to assembler language output. The free the storage 6744 for the function definition. 6745 6746 This is called after parsing the body of the function definition. */ 6747 6748void 6749finish_function (void) 6750{ 6751 tree fndecl = current_function_decl; 6752 6753 label_context_stack_se = label_context_stack_se->next; 6754 label_context_stack_vm = label_context_stack_vm->next; 6755 6756 if (TREE_CODE (fndecl) == FUNCTION_DECL 6757 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 6758 { 6759 tree args = DECL_ARGUMENTS (fndecl); 6760 for (; args; args = TREE_CHAIN (args)) 6761 { 6762 tree type = TREE_TYPE (args); 6763 if (INTEGRAL_TYPE_P (type) 6764 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 6765 DECL_ARG_TYPE (args) = integer_type_node; 6766 } 6767 } 6768 6769 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6770 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 6771 6772 /* Must mark the RESULT_DECL as being in this function. */ 6773 6774 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 6775 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 6776 6777 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted) 6778 { 6779 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 6780 != integer_type_node) 6781 { 6782 /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned. 6783 If warn_main is -1 (-Wno-main) we don't want to be warned. */ 6784 if (!warn_main) 6785 pedwarn ("return type of %q+D is not %<int%>", fndecl); 6786 } 6787 else 6788 { 6789 if (flag_isoc99) 6790 { 6791 tree stmt = c_finish_return (integer_zero_node); 6792#ifdef USE_MAPPED_LOCATION 6793 /* Hack. We don't want the middle-end to warn that this return 6794 is unreachable, so we mark its location as special. Using 6795 UNKNOWN_LOCATION has the problem that it gets clobbered in 6796 annotate_one_with_locus. A cleaner solution might be to 6797 ensure ! should_carry_locus_p (stmt), but that needs a flag. 6798 */ 6799 SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION); 6800#else 6801 /* Hack. We don't want the middle-end to warn that this 6802 return is unreachable, so put the statement on the 6803 special line 0. */ 6804 annotate_with_file_line (stmt, input_filename, 0); 6805#endif 6806 } 6807 } 6808 } 6809 6810 /* Tie off the statement tree for this function. */ 6811 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 6812 6813 finish_fname_decls (); 6814 6815 /* Complain if there's just no return statement. */ 6816 if (warn_return_type 6817 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 6818 && !current_function_returns_value && !current_function_returns_null 6819 /* Don't complain if we are no-return. */ 6820 && !current_function_returns_abnormally 6821 /* Don't warn for main(). */ 6822 && !MAIN_NAME_P (DECL_NAME (fndecl)) 6823 /* Or if they didn't actually specify a return type. */ 6824 && !C_FUNCTION_IMPLICIT_INT (fndecl) 6825 /* Normally, with -Wreturn-type, flow will complain. Unless we're an 6826 inline function, as we might never be compiled separately. */ 6827 && DECL_INLINE (fndecl)) 6828 { 6829 warning (OPT_Wreturn_type, 6830 "no return statement in function returning non-void"); 6831 TREE_NO_WARNING (fndecl) = 1; 6832 } 6833 6834 /* With just -Wextra, complain only if function returns both with 6835 and without a value. */ 6836 if (extra_warnings 6837 && current_function_returns_value 6838 && current_function_returns_null) 6839 warning (OPT_Wextra, "this function may return with or without a value"); 6840 6841 /* Store the end of the function, so that we get good line number 6842 info for the epilogue. */ 6843 cfun->function_end_locus = input_location; 6844 6845 /* If we don't have ctors/dtors sections, and this is a static 6846 constructor or destructor, it must be recorded now. */ 6847 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6848 && !targetm.have_ctors_dtors) 6849 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors); 6850 if (DECL_STATIC_DESTRUCTOR (fndecl) 6851 && !targetm.have_ctors_dtors) 6852 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors); 6853 6854 /* Finalize the ELF visibility for the function. */ 6855 c_determine_visibility (fndecl); 6856 6857 /* Genericize before inlining. Delay genericizing nested functions 6858 until their parent function is genericized. Since finalizing 6859 requires GENERIC, delay that as well. */ 6860 6861 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 6862 && !undef_nested_function) 6863 { 6864 if (!decl_function_context (fndecl)) 6865 { 6866 c_genericize (fndecl); 6867 c_gimple_diagnostics_recursively (fndecl); 6868 6869 /* ??? Objc emits functions after finalizing the compilation unit. 6870 This should be cleaned up later and this conditional removed. */ 6871 if (cgraph_global_info_ready) 6872 { 6873 c_expand_body (fndecl); 6874 return; 6875 } 6876 6877 cgraph_finalize_function (fndecl, false); 6878 } 6879 else 6880 { 6881 /* Register this function with cgraph just far enough to get it 6882 added to our parent's nested function list. Handy, since the 6883 C front end doesn't have such a list. */ 6884 (void) cgraph_node (fndecl); 6885 } 6886 } 6887 6888 if (!decl_function_context (fndecl)) 6889 undef_nested_function = false; 6890 6891 /* We're leaving the context of this function, so zap cfun. 6892 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 6893 tree_rest_of_compilation. */ 6894 cfun = NULL; 6895 current_function_decl = NULL; 6896} 6897 6898/* Generate the RTL for the body of FNDECL. */ 6899 6900void 6901c_expand_body (tree fndecl) 6902{ 6903 6904 if (!DECL_INITIAL (fndecl) 6905 || DECL_INITIAL (fndecl) == error_mark_node) 6906 return; 6907 6908 tree_rest_of_compilation (fndecl); 6909 6910 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6911 && targetm.have_ctors_dtors) 6912 targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0), 6913 DEFAULT_INIT_PRIORITY); 6914 if (DECL_STATIC_DESTRUCTOR (fndecl) 6915 && targetm.have_ctors_dtors) 6916 targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0), 6917 DEFAULT_INIT_PRIORITY); 6918} 6919 6920/* Check the declarations given in a for-loop for satisfying the C99 6921 constraints. If exactly one such decl is found, return it. */ 6922 6923tree 6924check_for_loop_decls (void) 6925{ 6926 struct c_binding *b; 6927 tree one_decl = NULL_TREE; 6928 int n_decls = 0; 6929 6930 6931 if (!flag_isoc99) 6932 { 6933 /* If we get here, declarations have been used in a for loop without 6934 the C99 for loop scope. This doesn't make much sense, so don't 6935 allow it. */ 6936 error ("%<for%> loop initial declaration used outside C99 mode"); 6937 return NULL_TREE; 6938 } 6939 /* C99 subclause 6.8.5 paragraph 3: 6940 6941 [#3] The declaration part of a for statement shall only 6942 declare identifiers for objects having storage class auto or 6943 register. 6944 6945 It isn't clear whether, in this sentence, "identifiers" binds to 6946 "shall only declare" or to "objects" - that is, whether all identifiers 6947 declared must be identifiers for objects, or whether the restriction 6948 only applies to those that are. (A question on this in comp.std.c 6949 in November 2000 received no answer.) We implement the strictest 6950 interpretation, to avoid creating an extension which later causes 6951 problems. */ 6952 6953 for (b = current_scope->bindings; b; b = b->prev) 6954 { 6955 tree id = b->id; 6956 tree decl = b->decl; 6957 6958 if (!id) 6959 continue; 6960 6961 switch (TREE_CODE (decl)) 6962 { 6963 case VAR_DECL: 6964 if (TREE_STATIC (decl)) 6965 error ("declaration of static variable %q+D in %<for%> loop " 6966 "initial declaration", decl); 6967 else if (DECL_EXTERNAL (decl)) 6968 error ("declaration of %<extern%> variable %q+D in %<for%> loop " 6969 "initial declaration", decl); 6970 break; 6971 6972 case RECORD_TYPE: 6973 error ("%<struct %E%> declared in %<for%> loop initial declaration", 6974 id); 6975 break; 6976 case UNION_TYPE: 6977 error ("%<union %E%> declared in %<for%> loop initial declaration", 6978 id); 6979 break; 6980 case ENUMERAL_TYPE: 6981 error ("%<enum %E%> declared in %<for%> loop initial declaration", 6982 id); 6983 break; 6984 default: 6985 error ("declaration of non-variable %q+D in %<for%> loop " 6986 "initial declaration", decl); 6987 } 6988 6989 n_decls++; 6990 one_decl = decl; 6991 } 6992 6993 return n_decls == 1 ? one_decl : NULL_TREE; 6994} 6995 6996/* Save and reinitialize the variables 6997 used during compilation of a C function. */ 6998 6999void 7000c_push_function_context (struct function *f) 7001{ 7002 struct language_function *p; 7003 p = GGC_NEW (struct language_function); 7004 f->language = p; 7005 7006 p->base.x_stmt_tree = c_stmt_tree; 7007 p->x_break_label = c_break_label; 7008 p->x_cont_label = c_cont_label; 7009 p->x_switch_stack = c_switch_stack; 7010 p->arg_info = current_function_arg_info; 7011 p->returns_value = current_function_returns_value; 7012 p->returns_null = current_function_returns_null; 7013 p->returns_abnormally = current_function_returns_abnormally; 7014 p->warn_about_return_type = warn_about_return_type; 7015} 7016 7017/* Restore the variables used during compilation of a C function. */ 7018 7019void 7020c_pop_function_context (struct function *f) 7021{ 7022 struct language_function *p = f->language; 7023 7024 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 7025 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 7026 { 7027 /* Stop pointing to the local nodes about to be freed. */ 7028 /* But DECL_INITIAL must remain nonzero so we know this 7029 was an actual function definition. */ 7030 DECL_INITIAL (current_function_decl) = error_mark_node; 7031 DECL_ARGUMENTS (current_function_decl) = 0; 7032 } 7033 7034 c_stmt_tree = p->base.x_stmt_tree; 7035 c_break_label = p->x_break_label; 7036 c_cont_label = p->x_cont_label; 7037 c_switch_stack = p->x_switch_stack; 7038 current_function_arg_info = p->arg_info; 7039 current_function_returns_value = p->returns_value; 7040 current_function_returns_null = p->returns_null; 7041 current_function_returns_abnormally = p->returns_abnormally; 7042 warn_about_return_type = p->warn_about_return_type; 7043 7044 f->language = NULL; 7045} 7046 7047/* Copy the DECL_LANG_SPECIFIC data associated with DECL. */ 7048 7049void 7050c_dup_lang_specific_decl (tree decl) 7051{ 7052 struct lang_decl *ld; 7053 7054 if (!DECL_LANG_SPECIFIC (decl)) 7055 return; 7056 7057 ld = GGC_NEW (struct lang_decl); 7058 memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl)); 7059 DECL_LANG_SPECIFIC (decl) = ld; 7060} 7061 7062/* The functions below are required for functionality of doing 7063 function at once processing in the C front end. Currently these 7064 functions are not called from anywhere in the C front end, but as 7065 these changes continue, that will change. */ 7066 7067/* Returns the stmt_tree (if any) to which statements are currently 7068 being added. If there is no active statement-tree, NULL is 7069 returned. */ 7070 7071stmt_tree 7072current_stmt_tree (void) 7073{ 7074 return &c_stmt_tree; 7075} 7076 7077/* Nonzero if TYPE is an anonymous union or struct type. Always 0 in 7078 C. */ 7079 7080int 7081anon_aggr_type_p (tree ARG_UNUSED (node)) 7082{ 7083 return 0; 7084} 7085 7086/* Return the global value of T as a symbol. */ 7087 7088tree 7089identifier_global_value (tree t) 7090{ 7091 struct c_binding *b; 7092 7093 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 7094 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 7095 return b->decl; 7096 7097 return 0; 7098} 7099 7100/* Record a builtin type for C. If NAME is non-NULL, it is the name used; 7101 otherwise the name is found in ridpointers from RID_INDEX. */ 7102 7103void 7104record_builtin_type (enum rid rid_index, const char *name, tree type) 7105{ 7106 tree id, decl; 7107 if (name == 0) 7108 id = ridpointers[(int) rid_index]; 7109 else 7110 id = get_identifier (name); 7111 decl = build_decl (TYPE_DECL, id, type); 7112 pushdecl (decl); 7113 if (debug_hooks->type_decl) 7114 debug_hooks->type_decl (decl, false); 7115} 7116 7117/* Build the void_list_node (void_type_node having been created). */ 7118tree 7119build_void_list_node (void) 7120{ 7121 tree t = build_tree_list (NULL_TREE, void_type_node); 7122 return t; 7123} 7124 7125/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 7126 7127struct c_parm * 7128build_c_parm (struct c_declspecs *specs, tree attrs, 7129 struct c_declarator *declarator) 7130{ 7131 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 7132 ret->specs = specs; 7133 ret->attrs = attrs; 7134 ret->declarator = declarator; 7135 return ret; 7136} 7137 7138/* Return a declarator with nested attributes. TARGET is the inner 7139 declarator to which these attributes apply. ATTRS are the 7140 attributes. */ 7141 7142struct c_declarator * 7143build_attrs_declarator (tree attrs, struct c_declarator *target) 7144{ 7145 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7146 ret->kind = cdk_attrs; 7147 ret->declarator = target; 7148 ret->u.attrs = attrs; 7149 return ret; 7150} 7151 7152/* Return a declarator for a function with arguments specified by ARGS 7153 and return type specified by TARGET. */ 7154 7155struct c_declarator * 7156build_function_declarator (struct c_arg_info *args, 7157 struct c_declarator *target) 7158{ 7159 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7160 ret->kind = cdk_function; 7161 ret->declarator = target; 7162 ret->u.arg_info = args; 7163 return ret; 7164} 7165 7166/* Return a declarator for the identifier IDENT (which may be 7167 NULL_TREE for an abstract declarator). */ 7168 7169struct c_declarator * 7170build_id_declarator (tree ident) 7171{ 7172 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7173 ret->kind = cdk_id; 7174 ret->declarator = 0; 7175 ret->u.id = ident; 7176 /* Default value - may get reset to a more precise location. */ 7177 ret->id_loc = input_location; 7178 return ret; 7179} 7180 7181/* Return something to represent absolute declarators containing a *. 7182 TARGET is the absolute declarator that the * contains. 7183 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 7184 to apply to the pointer type. */ 7185 7186struct c_declarator * 7187make_pointer_declarator (struct c_declspecs *type_quals_attrs, 7188 struct c_declarator *target) 7189{ 7190 tree attrs; 7191 int quals = 0; 7192 struct c_declarator *itarget = target; 7193 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7194 if (type_quals_attrs) 7195 { 7196 attrs = type_quals_attrs->attrs; 7197 quals = quals_from_declspecs (type_quals_attrs); 7198 if (attrs != NULL_TREE) 7199 itarget = build_attrs_declarator (attrs, target); 7200 } 7201 ret->kind = cdk_pointer; 7202 ret->declarator = itarget; 7203 ret->u.pointer_quals = quals; 7204 return ret; 7205} 7206 7207/* Return a pointer to a structure for an empty list of declaration 7208 specifiers. */ 7209 7210struct c_declspecs * 7211build_null_declspecs (void) 7212{ 7213 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 7214 ret->type = 0; 7215 ret->decl_attr = 0; 7216 ret->attrs = 0; 7217 ret->typespec_word = cts_none; 7218 ret->storage_class = csc_none; 7219 ret->declspecs_seen_p = false; 7220 ret->type_seen_p = false; 7221 ret->non_sc_seen_p = false; 7222 ret->typedef_p = false; 7223 ret->tag_defined_p = false; 7224 ret->explicit_signed_p = false; 7225 ret->deprecated_p = false; 7226 ret->default_int_p = false; 7227 ret->long_p = false; 7228 ret->long_long_p = false; 7229 ret->short_p = false; 7230 ret->signed_p = false; 7231 ret->unsigned_p = false; 7232 ret->complex_p = false; 7233 ret->inline_p = false; 7234 ret->thread_p = false; 7235 ret->const_p = false; 7236 ret->volatile_p = false; 7237 ret->restrict_p = false; 7238 return ret; 7239} 7240 7241/* Add the type qualifier QUAL to the declaration specifiers SPECS, 7242 returning SPECS. */ 7243 7244struct c_declspecs * 7245declspecs_add_qual (struct c_declspecs *specs, tree qual) 7246{ 7247 enum rid i; 7248 bool dupe = false; 7249 specs->non_sc_seen_p = true; 7250 specs->declspecs_seen_p = true; 7251 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 7252 && C_IS_RESERVED_WORD (qual)); 7253 i = C_RID_CODE (qual); 7254 switch (i) 7255 { 7256 case RID_CONST: 7257 dupe = specs->const_p; 7258 specs->const_p = true; 7259 break; 7260 case RID_VOLATILE: 7261 dupe = specs->volatile_p; 7262 specs->volatile_p = true; 7263 break; 7264 case RID_RESTRICT: 7265 dupe = specs->restrict_p; 7266 specs->restrict_p = true; 7267 break; 7268 default: 7269 gcc_unreachable (); 7270 } 7271 if (dupe && pedantic && !flag_isoc99) 7272 pedwarn ("duplicate %qE", qual); 7273 return specs; 7274} 7275 7276/* Add the type specifier TYPE to the declaration specifiers SPECS, 7277 returning SPECS. */ 7278 7279struct c_declspecs * 7280declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec) 7281{ 7282 tree type = spec.spec; 7283 specs->non_sc_seen_p = true; 7284 specs->declspecs_seen_p = true; 7285 specs->type_seen_p = true; 7286 if (TREE_DEPRECATED (type)) 7287 specs->deprecated_p = true; 7288 7289 /* Handle type specifier keywords. */ 7290 if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type)) 7291 { 7292 enum rid i = C_RID_CODE (type); 7293 if (specs->type) 7294 { 7295 error ("two or more data types in declaration specifiers"); 7296 return specs; 7297 } 7298 if ((int) i <= (int) RID_LAST_MODIFIER) 7299 { 7300 /* "long", "short", "signed", "unsigned" or "_Complex". */ 7301 bool dupe = false; 7302 switch (i) 7303 { 7304 case RID_LONG: 7305 if (specs->long_long_p) 7306 { 7307 error ("%<long long long%> is too long for GCC"); 7308 break; 7309 } 7310 if (specs->long_p) 7311 { 7312 if (specs->typespec_word == cts_double) 7313 { 7314 error ("both %<long long%> and %<double%> in " 7315 "declaration specifiers"); 7316 break; 7317 } 7318 if (pedantic && !flag_isoc99 && !in_system_header 7319 && warn_long_long) 7320 pedwarn ("ISO C90 does not support %<long long%>"); 7321 specs->long_long_p = 1; 7322 break; 7323 } 7324 if (specs->short_p) 7325 error ("both %<long%> and %<short%> in " 7326 "declaration specifiers"); 7327 else if (specs->typespec_word == cts_void) 7328 error ("both %<long%> and %<void%> in " 7329 "declaration specifiers"); 7330 else if (specs->typespec_word == cts_bool) 7331 error ("both %<long%> and %<_Bool%> in " 7332 "declaration specifiers"); 7333 else if (specs->typespec_word == cts_char) 7334 error ("both %<long%> and %<char%> in " 7335 "declaration specifiers"); 7336 else if (specs->typespec_word == cts_float) 7337 error ("both %<long%> and %<float%> in " 7338 "declaration specifiers"); 7339 else if (specs->typespec_word == cts_dfloat32) 7340 error ("both %<long%> and %<_Decimal32%> in " 7341 "declaration specifiers"); 7342 else if (specs->typespec_word == cts_dfloat64) 7343 error ("both %<long%> and %<_Decimal64%> in " 7344 "declaration specifiers"); 7345 else if (specs->typespec_word == cts_dfloat128) 7346 error ("both %<long%> and %<_Decimal128%> in " 7347 "declaration specifiers"); 7348 else 7349 specs->long_p = true; 7350 break; 7351 case RID_SHORT: 7352 dupe = specs->short_p; 7353 if (specs->long_p) 7354 error ("both %<long%> and %<short%> in " 7355 "declaration specifiers"); 7356 else if (specs->typespec_word == cts_void) 7357 error ("both %<short%> and %<void%> in " 7358 "declaration specifiers"); 7359 else if (specs->typespec_word == cts_bool) 7360 error ("both %<short%> and %<_Bool%> in " 7361 "declaration specifiers"); 7362 else if (specs->typespec_word == cts_char) 7363 error ("both %<short%> and %<char%> in " 7364 "declaration specifiers"); 7365 else if (specs->typespec_word == cts_float) 7366 error ("both %<short%> and %<float%> in " 7367 "declaration specifiers"); 7368 else if (specs->typespec_word == cts_double) 7369 error ("both %<short%> and %<double%> in " 7370 "declaration specifiers"); 7371 else if (specs->typespec_word == cts_dfloat32) 7372 error ("both %<short%> and %<_Decimal32%> in " 7373 "declaration specifiers"); 7374 else if (specs->typespec_word == cts_dfloat64) 7375 error ("both %<short%> and %<_Decimal64%> in " 7376 "declaration specifiers"); 7377 else if (specs->typespec_word == cts_dfloat128) 7378 error ("both %<short%> and %<_Decimal128%> in " 7379 "declaration specifiers"); 7380 else 7381 specs->short_p = true; 7382 break; 7383 case RID_SIGNED: 7384 dupe = specs->signed_p; 7385 if (specs->unsigned_p) 7386 error ("both %<signed%> and %<unsigned%> in " 7387 "declaration specifiers"); 7388 else if (specs->typespec_word == cts_void) 7389 error ("both %<signed%> and %<void%> in " 7390 "declaration specifiers"); 7391 else if (specs->typespec_word == cts_bool) 7392 error ("both %<signed%> and %<_Bool%> in " 7393 "declaration specifiers"); 7394 else if (specs->typespec_word == cts_float) 7395 error ("both %<signed%> and %<float%> in " 7396 "declaration specifiers"); 7397 else if (specs->typespec_word == cts_double) 7398 error ("both %<signed%> and %<double%> in " 7399 "declaration specifiers"); 7400 else if (specs->typespec_word == cts_dfloat32) 7401 error ("both %<signed%> and %<_Decimal32%> in " 7402 "declaration specifiers"); 7403 else if (specs->typespec_word == cts_dfloat64) 7404 error ("both %<signed%> and %<_Decimal64%> in " 7405 "declaration specifiers"); 7406 else if (specs->typespec_word == cts_dfloat128) 7407 error ("both %<signed%> and %<_Decimal128%> in " 7408 "declaration specifiers"); 7409 else 7410 specs->signed_p = true; 7411 break; 7412 case RID_UNSIGNED: 7413 dupe = specs->unsigned_p; 7414 if (specs->signed_p) 7415 error ("both %<signed%> and %<unsigned%> in " 7416 "declaration specifiers"); 7417 else if (specs->typespec_word == cts_void) 7418 error ("both %<unsigned%> and %<void%> in " 7419 "declaration specifiers"); 7420 else if (specs->typespec_word == cts_bool) 7421 error ("both %<unsigned%> and %<_Bool%> in " 7422 "declaration specifiers"); 7423 else if (specs->typespec_word == cts_float) 7424 error ("both %<unsigned%> and %<float%> in " 7425 "declaration specifiers"); 7426 else if (specs->typespec_word == cts_double) 7427 error ("both %<unsigned%> and %<double%> in " 7428 "declaration specifiers"); 7429 else if (specs->typespec_word == cts_dfloat32) 7430 error ("both %<unsigned%> and %<_Decimal32%> in " 7431 "declaration specifiers"); 7432 else if (specs->typespec_word == cts_dfloat64) 7433 error ("both %<unsigned%> and %<_Decimal64%> in " 7434 "declaration specifiers"); 7435 else if (specs->typespec_word == cts_dfloat128) 7436 error ("both %<unsigned%> and %<_Decimal128%> in " 7437 "declaration specifiers"); 7438 else 7439 specs->unsigned_p = true; 7440 break; 7441 case RID_COMPLEX: 7442 dupe = specs->complex_p; 7443 if (pedantic && !flag_isoc99 && !in_system_header) 7444 pedwarn ("ISO C90 does not support complex types"); 7445 if (specs->typespec_word == cts_void) 7446 error ("both %<complex%> and %<void%> in " 7447 "declaration specifiers"); 7448 else if (specs->typespec_word == cts_bool) 7449 error ("both %<complex%> and %<_Bool%> in " 7450 "declaration specifiers"); 7451 else if (specs->typespec_word == cts_dfloat32) 7452 error ("both %<complex%> and %<_Decimal32%> in " 7453 "declaration specifiers"); 7454 else if (specs->typespec_word == cts_dfloat64) 7455 error ("both %<complex%> and %<_Decimal64%> in " 7456 "declaration specifiers"); 7457 else if (specs->typespec_word == cts_dfloat128) 7458 error ("both %<complex%> and %<_Decimal128%> in " 7459 "declaration specifiers"); 7460 else 7461 specs->complex_p = true; 7462 break; 7463 default: 7464 gcc_unreachable (); 7465 } 7466 7467 if (dupe) 7468 error ("duplicate %qE", type); 7469 7470 return specs; 7471 } 7472 else 7473 { 7474 /* "void", "_Bool", "char", "int", "float" or "double". */ 7475 if (specs->typespec_word != cts_none) 7476 { 7477 error ("two or more data types in declaration specifiers"); 7478 return specs; 7479 } 7480 switch (i) 7481 { 7482 case RID_VOID: 7483 if (specs->long_p) 7484 error ("both %<long%> and %<void%> in " 7485 "declaration specifiers"); 7486 else if (specs->short_p) 7487 error ("both %<short%> and %<void%> in " 7488 "declaration specifiers"); 7489 else if (specs->signed_p) 7490 error ("both %<signed%> and %<void%> in " 7491 "declaration specifiers"); 7492 else if (specs->unsigned_p) 7493 error ("both %<unsigned%> and %<void%> in " 7494 "declaration specifiers"); 7495 else if (specs->complex_p) 7496 error ("both %<complex%> and %<void%> in " 7497 "declaration specifiers"); 7498 else 7499 specs->typespec_word = cts_void; 7500 return specs; 7501 case RID_BOOL: 7502 if (specs->long_p) 7503 error ("both %<long%> and %<_Bool%> in " 7504 "declaration specifiers"); 7505 else if (specs->short_p) 7506 error ("both %<short%> and %<_Bool%> in " 7507 "declaration specifiers"); 7508 else if (specs->signed_p) 7509 error ("both %<signed%> and %<_Bool%> in " 7510 "declaration specifiers"); 7511 else if (specs->unsigned_p) 7512 error ("both %<unsigned%> and %<_Bool%> in " 7513 "declaration specifiers"); 7514 else if (specs->complex_p) 7515 error ("both %<complex%> and %<_Bool%> in " 7516 "declaration specifiers"); 7517 else 7518 specs->typespec_word = cts_bool; 7519 return specs; 7520 case RID_CHAR: 7521 if (specs->long_p) 7522 error ("both %<long%> and %<char%> in " 7523 "declaration specifiers"); 7524 else if (specs->short_p) 7525 error ("both %<short%> and %<char%> in " 7526 "declaration specifiers"); 7527 else 7528 specs->typespec_word = cts_char; 7529 return specs; 7530 case RID_INT: 7531 specs->typespec_word = cts_int; 7532 return specs; 7533 case RID_FLOAT: 7534 if (specs->long_p) 7535 error ("both %<long%> and %<float%> in " 7536 "declaration specifiers"); 7537 else if (specs->short_p) 7538 error ("both %<short%> and %<float%> in " 7539 "declaration specifiers"); 7540 else if (specs->signed_p) 7541 error ("both %<signed%> and %<float%> in " 7542 "declaration specifiers"); 7543 else if (specs->unsigned_p) 7544 error ("both %<unsigned%> and %<float%> in " 7545 "declaration specifiers"); 7546 else 7547 specs->typespec_word = cts_float; 7548 return specs; 7549 case RID_DOUBLE: 7550 if (specs->long_long_p) 7551 error ("both %<long long%> and %<double%> in " 7552 "declaration specifiers"); 7553 else if (specs->short_p) 7554 error ("both %<short%> and %<double%> in " 7555 "declaration specifiers"); 7556 else if (specs->signed_p) 7557 error ("both %<signed%> and %<double%> in " 7558 "declaration specifiers"); 7559 else if (specs->unsigned_p) 7560 error ("both %<unsigned%> and %<double%> in " 7561 "declaration specifiers"); 7562 else 7563 specs->typespec_word = cts_double; 7564 return specs; 7565 case RID_DFLOAT32: 7566 case RID_DFLOAT64: 7567 case RID_DFLOAT128: 7568 { 7569 const char *str; 7570 if (i == RID_DFLOAT32) 7571 str = "_Decimal32"; 7572 else if (i == RID_DFLOAT64) 7573 str = "_Decimal64"; 7574 else 7575 str = "_Decimal128"; 7576 if (specs->long_long_p) 7577 error ("both %<long long%> and %<%s%> in " 7578 "declaration specifiers", str); 7579 if (specs->long_p) 7580 error ("both %<long%> and %<%s%> in " 7581 "declaration specifiers", str); 7582 else if (specs->short_p) 7583 error ("both %<short%> and %<%s%> in " 7584 "declaration specifiers", str); 7585 else if (specs->signed_p) 7586 error ("both %<signed%> and %<%s%> in " 7587 "declaration specifiers", str); 7588 else if (specs->unsigned_p) 7589 error ("both %<unsigned%> and %<%s%> in " 7590 "declaration specifiers", str); 7591 else if (specs->complex_p) 7592 error ("both %<complex%> and %<%s%> in " 7593 "declaration specifiers", str); 7594 else if (i == RID_DFLOAT32) 7595 specs->typespec_word = cts_dfloat32; 7596 else if (i == RID_DFLOAT64) 7597 specs->typespec_word = cts_dfloat64; 7598 else 7599 specs->typespec_word = cts_dfloat128; 7600 } 7601 if (!targetm.decimal_float_supported_p ()) 7602 error ("decimal floating point not supported for this target"); 7603 if (pedantic) 7604 pedwarn ("ISO C does not support decimal floating point"); 7605 return specs; 7606 default: 7607 /* ObjC reserved word "id", handled below. */ 7608 break; 7609 } 7610 } 7611 } 7612 7613 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 7614 form of ObjC type, cases such as "int" and "long" being handled 7615 above), a TYPE (struct, union, enum and typeof specifiers) or an 7616 ERROR_MARK. In none of these cases may there have previously 7617 been any type specifiers. */ 7618 if (specs->type || specs->typespec_word != cts_none 7619 || specs->long_p || specs->short_p || specs->signed_p 7620 || specs->unsigned_p || specs->complex_p) 7621 error ("two or more data types in declaration specifiers"); 7622 else if (TREE_CODE (type) == TYPE_DECL) 7623 { 7624 if (TREE_TYPE (type) == error_mark_node) 7625 ; /* Allow the type to default to int to avoid cascading errors. */ 7626 else 7627 { 7628 specs->type = TREE_TYPE (type); 7629 specs->decl_attr = DECL_ATTRIBUTES (type); 7630 specs->typedef_p = true; 7631 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 7632 } 7633 } 7634 else if (TREE_CODE (type) == IDENTIFIER_NODE) 7635 { 7636 tree t = lookup_name (type); 7637 if (!t || TREE_CODE (t) != TYPE_DECL) 7638 error ("%qE fails to be a typedef or built in type", type); 7639 else if (TREE_TYPE (t) == error_mark_node) 7640 ; 7641 else 7642 specs->type = TREE_TYPE (t); 7643 } 7644 else if (TREE_CODE (type) != ERROR_MARK) 7645 { 7646 if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref) 7647 specs->tag_defined_p = true; 7648 if (spec.kind == ctsk_typeof) 7649 specs->typedef_p = true; 7650 specs->type = type; 7651 } 7652 7653 return specs; 7654} 7655 7656/* Add the storage class specifier or function specifier SCSPEC to the 7657 declaration specifiers SPECS, returning SPECS. */ 7658 7659struct c_declspecs * 7660declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 7661{ 7662 enum rid i; 7663 enum c_storage_class n = csc_none; 7664 bool dupe = false; 7665 specs->declspecs_seen_p = true; 7666 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 7667 && C_IS_RESERVED_WORD (scspec)); 7668 i = C_RID_CODE (scspec); 7669 if (extra_warnings && specs->non_sc_seen_p) 7670 warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec); 7671 switch (i) 7672 { 7673 case RID_INLINE: 7674 /* C99 permits duplicate inline. Although of doubtful utility, 7675 it seems simplest to permit it in gnu89 mode as well, as 7676 there is also little utility in maintaining this as a 7677 difference between gnu89 and C99 inline. */ 7678 dupe = false; 7679 specs->inline_p = true; 7680 break; 7681 case RID_THREAD: 7682 dupe = specs->thread_p; 7683 if (specs->storage_class == csc_auto) 7684 error ("%<__thread%> used with %<auto%>"); 7685 else if (specs->storage_class == csc_register) 7686 error ("%<__thread%> used with %<register%>"); 7687 else if (specs->storage_class == csc_typedef) 7688 error ("%<__thread%> used with %<typedef%>"); 7689 else 7690 specs->thread_p = true; 7691 break; 7692 case RID_AUTO: 7693 n = csc_auto; 7694 break; 7695 case RID_EXTERN: 7696 n = csc_extern; 7697 /* Diagnose "__thread extern". */ 7698 if (specs->thread_p) 7699 error ("%<__thread%> before %<extern%>"); 7700 break; 7701 case RID_REGISTER: 7702 n = csc_register; 7703 break; 7704 case RID_STATIC: 7705 n = csc_static; 7706 /* Diagnose "__thread static". */ 7707 if (specs->thread_p) 7708 error ("%<__thread%> before %<static%>"); 7709 break; 7710 case RID_TYPEDEF: 7711 n = csc_typedef; 7712 break; 7713 default: 7714 gcc_unreachable (); 7715 } 7716 if (n != csc_none && n == specs->storage_class) 7717 dupe = true; 7718 if (dupe) 7719 error ("duplicate %qE", scspec); 7720 if (n != csc_none) 7721 { 7722 if (specs->storage_class != csc_none && n != specs->storage_class) 7723 { 7724 error ("multiple storage classes in declaration specifiers"); 7725 } 7726 else 7727 { 7728 specs->storage_class = n; 7729 if (n != csc_extern && n != csc_static && specs->thread_p) 7730 { 7731 error ("%<__thread%> used with %qE", scspec); 7732 specs->thread_p = false; 7733 } 7734 } 7735 } 7736 return specs; 7737} 7738 7739/* Add the attributes ATTRS to the declaration specifiers SPECS, 7740 returning SPECS. */ 7741 7742struct c_declspecs * 7743declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 7744{ 7745 specs->attrs = chainon (attrs, specs->attrs); 7746 specs->declspecs_seen_p = true; 7747 return specs; 7748} 7749 7750/* Combine "long", "short", "signed", "unsigned" and "_Complex" type 7751 specifiers with any other type specifier to determine the resulting 7752 type. This is where ISO C checks on complex types are made, since 7753 "_Complex long" is a prefix of the valid ISO C type "_Complex long 7754 double". */ 7755 7756struct c_declspecs * 7757finish_declspecs (struct c_declspecs *specs) 7758{ 7759 /* If a type was specified as a whole, we have no modifiers and are 7760 done. */ 7761 if (specs->type != NULL_TREE) 7762 { 7763 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7764 && !specs->signed_p && !specs->unsigned_p 7765 && !specs->complex_p); 7766 return specs; 7767 } 7768 7769 /* If none of "void", "_Bool", "char", "int", "float" or "double" 7770 has been specified, treat it as "int" unless "_Complex" is 7771 present and there are no other specifiers. If we just have 7772 "_Complex", it is equivalent to "_Complex double", but e.g. 7773 "_Complex short" is equivalent to "_Complex short int". */ 7774 if (specs->typespec_word == cts_none) 7775 { 7776 if (specs->long_p || specs->short_p 7777 || specs->signed_p || specs->unsigned_p) 7778 { 7779 specs->typespec_word = cts_int; 7780 } 7781 else if (specs->complex_p) 7782 { 7783 specs->typespec_word = cts_double; 7784 if (pedantic) 7785 pedwarn ("ISO C does not support plain %<complex%> meaning " 7786 "%<double complex%>"); 7787 } 7788 else 7789 { 7790 specs->typespec_word = cts_int; 7791 specs->default_int_p = true; 7792 /* We don't diagnose this here because grokdeclarator will 7793 give more specific diagnostics according to whether it is 7794 a function definition. */ 7795 } 7796 } 7797 7798 /* If "signed" was specified, record this to distinguish "int" and 7799 "signed int" in the case of a bit-field with 7800 -funsigned-bitfields. */ 7801 specs->explicit_signed_p = specs->signed_p; 7802 7803 /* Now compute the actual type. */ 7804 switch (specs->typespec_word) 7805 { 7806 case cts_void: 7807 gcc_assert (!specs->long_p && !specs->short_p 7808 && !specs->signed_p && !specs->unsigned_p 7809 && !specs->complex_p); 7810 specs->type = void_type_node; 7811 break; 7812 case cts_bool: 7813 gcc_assert (!specs->long_p && !specs->short_p 7814 && !specs->signed_p && !specs->unsigned_p 7815 && !specs->complex_p); 7816 specs->type = boolean_type_node; 7817 break; 7818 case cts_char: 7819 gcc_assert (!specs->long_p && !specs->short_p); 7820 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7821 if (specs->signed_p) 7822 specs->type = signed_char_type_node; 7823 else if (specs->unsigned_p) 7824 specs->type = unsigned_char_type_node; 7825 else 7826 specs->type = char_type_node; 7827 if (specs->complex_p) 7828 { 7829 if (pedantic) 7830 pedwarn ("ISO C does not support complex integer types"); 7831 specs->type = build_complex_type (specs->type); 7832 } 7833 break; 7834 case cts_int: 7835 gcc_assert (!(specs->long_p && specs->short_p)); 7836 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7837 if (specs->long_long_p) 7838 specs->type = (specs->unsigned_p 7839 ? long_long_unsigned_type_node 7840 : long_long_integer_type_node); 7841 else if (specs->long_p) 7842 specs->type = (specs->unsigned_p 7843 ? long_unsigned_type_node 7844 : long_integer_type_node); 7845 else if (specs->short_p) 7846 specs->type = (specs->unsigned_p 7847 ? short_unsigned_type_node 7848 : short_integer_type_node); 7849 else 7850 specs->type = (specs->unsigned_p 7851 ? unsigned_type_node 7852 : integer_type_node); 7853 if (specs->complex_p) 7854 { 7855 if (pedantic) 7856 pedwarn ("ISO C does not support complex integer types"); 7857 specs->type = build_complex_type (specs->type); 7858 } 7859 break; 7860 case cts_float: 7861 gcc_assert (!specs->long_p && !specs->short_p 7862 && !specs->signed_p && !specs->unsigned_p); 7863 specs->type = (specs->complex_p 7864 ? complex_float_type_node 7865 : float_type_node); 7866 break; 7867 case cts_double: 7868 gcc_assert (!specs->long_long_p && !specs->short_p 7869 && !specs->signed_p && !specs->unsigned_p); 7870 if (specs->long_p) 7871 { 7872 specs->type = (specs->complex_p 7873 ? complex_long_double_type_node 7874 : long_double_type_node); 7875 } 7876 else 7877 { 7878 specs->type = (specs->complex_p 7879 ? complex_double_type_node 7880 : double_type_node); 7881 } 7882 break; 7883 case cts_dfloat32: 7884 case cts_dfloat64: 7885 case cts_dfloat128: 7886 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7887 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 7888 if (specs->typespec_word == cts_dfloat32) 7889 specs->type = dfloat32_type_node; 7890 else if (specs->typespec_word == cts_dfloat64) 7891 specs->type = dfloat64_type_node; 7892 else 7893 specs->type = dfloat128_type_node; 7894 break; 7895 default: 7896 gcc_unreachable (); 7897 } 7898 7899 return specs; 7900} 7901 7902/* Synthesize a function which calls all the global ctors or global 7903 dtors in this file. This is only used for targets which do not 7904 support .ctors/.dtors sections. FIXME: Migrate into cgraph. */ 7905static void 7906build_cdtor (int method_type, tree cdtors) 7907{ 7908 tree body = 0; 7909 7910 if (!cdtors) 7911 return; 7912 7913 for (; cdtors; cdtors = TREE_CHAIN (cdtors)) 7914 append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0), 7915 &body); 7916 7917 cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY); 7918} 7919 7920/* A subroutine of c_write_global_declarations. Perform final processing 7921 on one file scope's declarations (or the external scope's declarations), 7922 GLOBALS. */ 7923 7924static void 7925c_write_global_declarations_1 (tree globals) 7926{ 7927 tree decl; 7928 bool reconsider; 7929 7930 /* Process the decls in the order they were written. */ 7931 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7932 { 7933 /* Check for used but undefined static functions using the C 7934 standard's definition of "used", and set TREE_NO_WARNING so 7935 that check_global_declarations doesn't repeat the check. */ 7936 if (TREE_CODE (decl) == FUNCTION_DECL 7937 && DECL_INITIAL (decl) == 0 7938 && DECL_EXTERNAL (decl) 7939 && !TREE_PUBLIC (decl) 7940 && C_DECL_USED (decl)) 7941 { 7942 pedwarn ("%q+F used but never defined", decl); 7943 TREE_NO_WARNING (decl) = 1; 7944 } 7945 7946 wrapup_global_declaration_1 (decl); 7947 } 7948 7949 do 7950 { 7951 reconsider = false; 7952 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7953 reconsider |= wrapup_global_declaration_2 (decl); 7954 } 7955 while (reconsider); 7956 7957 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7958 check_global_declaration_1 (decl); 7959} 7960 7961/* A subroutine of c_write_global_declarations Emit debug information for each 7962 of the declarations in GLOBALS. */ 7963 7964static void 7965c_write_global_declarations_2 (tree globals) 7966{ 7967 tree decl; 7968 7969 for (decl = globals; decl ; decl = TREE_CHAIN (decl)) 7970 debug_hooks->global_decl (decl); 7971} 7972 7973/* Preserve the external declarations scope across a garbage collect. */ 7974static GTY(()) tree ext_block; 7975 7976void 7977c_write_global_declarations (void) 7978{ 7979 tree t; 7980 7981 /* We don't want to do this if generating a PCH. */ 7982 if (pch_file) 7983 return; 7984 7985 /* Don't waste time on further processing if -fsyntax-only or we've 7986 encountered errors. */ 7987 if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in)) 7988 return; 7989 7990 /* Close the external scope. */ 7991 ext_block = pop_scope (); 7992 external_scope = 0; 7993 gcc_assert (!current_scope); 7994 7995 if (ext_block) 7996 { 7997 tree tmp = BLOCK_VARS (ext_block); 7998 int flags; 7999 FILE * stream = dump_begin (TDI_tu, &flags); 8000 if (stream && tmp) 8001 { 8002 dump_node (tmp, flags & ~TDF_SLIM, stream); 8003 dump_end (TDI_tu, stream); 8004 } 8005 } 8006 8007 /* Process all file scopes in this compilation, and the external_scope, 8008 through wrapup_global_declarations and check_global_declarations. */ 8009 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8010 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 8011 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 8012 8013 /* Generate functions to call static constructors and destructors 8014 for targets that do not support .ctors/.dtors sections. These 8015 functions have magic names which are detected by collect2. */ 8016 build_cdtor ('I', static_ctors); static_ctors = 0; 8017 build_cdtor ('D', static_dtors); static_dtors = 0; 8018 8019 /* We're done parsing; proceed to optimize and emit assembly. 8020 FIXME: shouldn't be the front end's responsibility to call this. */ 8021 cgraph_optimize (); 8022 8023 /* After cgraph has had a chance to emit everything that's going to 8024 be emitted, output debug information for globals. */ 8025 if (errorcount == 0 && sorrycount == 0) 8026 { 8027 timevar_push (TV_SYMOUT); 8028 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8029 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 8030 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 8031 timevar_pop (TV_SYMOUT); 8032 } 8033 8034 ext_block = NULL; 8035} 8036 8037#include "gt-c-decl.h" 8038