c-decl.c revision 190404
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: head/contrib/gcc/c-decl.c 190404 2009-03-25 05:10:32Z das $ */ 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 } 4344 4345 if (integer_zerop (size)) 4346 { 4347 /* A zero-length array cannot be represented with 4348 an unsigned index type, which is what we'll 4349 get with build_index_type. Create an 4350 open-ended range instead. */ 4351 itype = build_range_type (sizetype, size, NULL_TREE); 4352 } 4353 else 4354 { 4355 /* Arrange for the SAVE_EXPR on the inside of the 4356 MINUS_EXPR, which allows the -1 to get folded 4357 with the +1 that happens when building TYPE_SIZE. */ 4358 if (size_varies) 4359 size = variable_size (size); 4360 4361 /* Compute the maximum valid index, that is, size 4362 - 1. Do the calculation in index_type, so that 4363 if it is a variable the computations will be 4364 done in the proper mode. */ 4365 itype = fold_build2 (MINUS_EXPR, index_type, 4366 convert (index_type, size), 4367 convert (index_type, 4368 size_one_node)); 4369 4370 /* If that overflowed, the array is too big. ??? 4371 While a size of INT_MAX+1 technically shouldn't 4372 cause an overflow (because we subtract 1), the 4373 overflow is recorded during the conversion to 4374 index_type, before the subtraction. Handling 4375 this case seems like an unnecessary 4376 complication. */ 4377 if (TREE_CODE (itype) == INTEGER_CST 4378 && TREE_OVERFLOW (itype)) 4379 { 4380 error ("size of array %qs is too large", name); 4381 type = error_mark_node; 4382 continue; 4383 } 4384 4385 itype = build_index_type (itype); 4386 } 4387 } 4388 else if (decl_context == FIELD) 4389 { 4390 if (pedantic && !flag_isoc99 && !in_system_header) 4391 pedwarn ("ISO C90 does not support flexible array members"); 4392 4393 /* ISO C99 Flexible array members are effectively 4394 identical to GCC's zero-length array extension. */ 4395 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4396 } 4397 else if (decl_context == PARM) 4398 { 4399 if (array_parm_vla_unspec_p) 4400 { 4401 if (! orig_name) 4402 { 4403 /* C99 6.7.5.2p4 */ 4404 error ("%<[*]%> not allowed in other than a declaration"); 4405 } 4406 4407 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4408 size_varies = 1; 4409 } 4410 } 4411 else if (decl_context == TYPENAME) 4412 { 4413 if (array_parm_vla_unspec_p) 4414 { 4415 /* The error is printed elsewhere. We use this to 4416 avoid messing up with incomplete array types of 4417 the same type, that would otherwise be modified 4418 below. */ 4419 itype = build_range_type (sizetype, size_zero_node, 4420 NULL_TREE); 4421 } 4422 } 4423 4424 /* Complain about arrays of incomplete types. */ 4425 if (!COMPLETE_TYPE_P (type)) 4426 { 4427 error ("array type has incomplete element type"); 4428 type = error_mark_node; 4429 } 4430 else 4431 /* When itype is NULL, a shared incomplete array type is 4432 returned for all array of a given type. Elsewhere we 4433 make sure we don't complete that type before copying 4434 it, but here we want to make sure we don't ever 4435 modify the shared type, so we gcc_assert (itype) 4436 below. */ 4437 type = build_array_type (type, itype); 4438 4439 if (type != error_mark_node) 4440 { 4441 if (size_varies) 4442 { 4443 /* It is ok to modify type here even if itype is 4444 NULL: if size_varies, we're in a 4445 multi-dimensional array and the inner type has 4446 variable size, so the enclosing shared array type 4447 must too. */ 4448 if (size && TREE_CODE (size) == INTEGER_CST) 4449 type 4450 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4451 C_TYPE_VARIABLE_SIZE (type) = 1; 4452 } 4453 4454 /* The GCC extension for zero-length arrays differs from 4455 ISO flexible array members in that sizeof yields 4456 zero. */ 4457 if (size && integer_zerop (size)) 4458 { 4459 gcc_assert (itype); 4460 TYPE_SIZE (type) = bitsize_zero_node; 4461 TYPE_SIZE_UNIT (type) = size_zero_node; 4462 } 4463 if (array_parm_vla_unspec_p) 4464 { 4465 gcc_assert (itype); 4466 /* The type is complete. C99 6.7.5.2p4 */ 4467 TYPE_SIZE (type) = bitsize_zero_node; 4468 TYPE_SIZE_UNIT (type) = size_zero_node; 4469 } 4470 } 4471 4472 if (decl_context != PARM 4473 && (array_ptr_quals != TYPE_UNQUALIFIED 4474 || array_ptr_attrs != NULL_TREE 4475 || array_parm_static)) 4476 { 4477 error ("static or type qualifiers in non-parameter array declarator"); 4478 array_ptr_quals = TYPE_UNQUALIFIED; 4479 array_ptr_attrs = NULL_TREE; 4480 array_parm_static = 0; 4481 } 4482 break; 4483 } 4484 case cdk_function: 4485 { 4486 /* Say it's a definition only for the declarator closest 4487 to the identifier, apart possibly from some 4488 attributes. */ 4489 bool really_funcdef = false; 4490 tree arg_types; 4491 if (funcdef_flag) 4492 { 4493 const struct c_declarator *t = declarator->declarator; 4494 while (t->kind == cdk_attrs) 4495 t = t->declarator; 4496 really_funcdef = (t->kind == cdk_id); 4497 } 4498 4499 /* Declaring a function type. Make sure we have a valid 4500 type for the function to return. */ 4501 if (type == error_mark_node) 4502 continue; 4503 4504 size_varies = 0; 4505 4506 /* Warn about some types functions can't return. */ 4507 if (TREE_CODE (type) == FUNCTION_TYPE) 4508 { 4509 error ("%qs declared as function returning a function", name); 4510 type = integer_type_node; 4511 } 4512 if (TREE_CODE (type) == ARRAY_TYPE) 4513 { 4514 error ("%qs declared as function returning an array", name); 4515 type = integer_type_node; 4516 } 4517 4518 /* Construct the function type and go to the next 4519 inner layer of declarator. */ 4520 arg_info = declarator->u.arg_info; 4521 arg_types = grokparms (arg_info, really_funcdef); 4522 if (really_funcdef) 4523 put_pending_sizes (arg_info->pending_sizes); 4524 4525 /* Type qualifiers before the return type of the function 4526 qualify the return type, not the function type. */ 4527 if (type_quals) 4528 { 4529 /* Type qualifiers on a function return type are 4530 normally permitted by the standard but have no 4531 effect, so give a warning at -Wreturn-type. 4532 Qualifiers on a void return type are banned on 4533 function definitions in ISO C; GCC used to used 4534 them for noreturn functions. */ 4535 if (VOID_TYPE_P (type) && really_funcdef) 4536 pedwarn ("function definition has qualified void return type"); 4537 else 4538 warning (OPT_Wreturn_type, 4539 "type qualifiers ignored on function return type"); 4540 4541 type = c_build_qualified_type (type, type_quals); 4542 } 4543 type_quals = TYPE_UNQUALIFIED; 4544 4545 type = build_function_type (type, arg_types); 4546 declarator = declarator->declarator; 4547 4548 /* Set the TYPE_CONTEXTs for each tagged type which is local to 4549 the formal parameter list of this FUNCTION_TYPE to point to 4550 the FUNCTION_TYPE node itself. */ 4551 { 4552 tree link; 4553 4554 for (link = arg_info->tags; 4555 link; 4556 link = TREE_CHAIN (link)) 4557 TYPE_CONTEXT (TREE_VALUE (link)) = type; 4558 } 4559 break; 4560 } 4561 case cdk_pointer: 4562 { 4563 /* Merge any constancy or volatility into the target type 4564 for the pointer. */ 4565 4566 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4567 && type_quals) 4568 pedwarn ("ISO C forbids qualified function types"); 4569 if (type_quals) 4570 type = c_build_qualified_type (type, type_quals); 4571 size_varies = 0; 4572 4573 /* When the pointed-to type involves components of variable size, 4574 care must be taken to ensure that the size evaluation code is 4575 emitted early enough to dominate all the possible later uses 4576 and late enough for the variables on which it depends to have 4577 been assigned. 4578 4579 This is expected to happen automatically when the pointed-to 4580 type has a name/declaration of it's own, but special attention 4581 is required if the type is anonymous. 4582 4583 We handle the NORMAL and FIELD contexts here by attaching an 4584 artificial TYPE_DECL to such pointed-to type. This forces the 4585 sizes evaluation at a safe point and ensures it is not deferred 4586 until e.g. within a deeper conditional context. 4587 4588 We expect nothing to be needed here for PARM or TYPENAME. 4589 Pushing a TYPE_DECL at this point for TYPENAME would actually 4590 be incorrect, as we might be in the middle of an expression 4591 with side effects on the pointed-to type size "arguments" prior 4592 to the pointer declaration point and the fake TYPE_DECL in the 4593 enclosing context would force the size evaluation prior to the 4594 side effects. */ 4595 4596 if (!TYPE_NAME (type) 4597 && (decl_context == NORMAL || decl_context == FIELD) 4598 && variably_modified_type_p (type, NULL_TREE)) 4599 { 4600 tree decl = build_decl (TYPE_DECL, NULL_TREE, type); 4601 DECL_ARTIFICIAL (decl) = 1; 4602 pushdecl (decl); 4603 finish_decl (decl, NULL_TREE, NULL_TREE); 4604 TYPE_NAME (type) = decl; 4605 } 4606 4607 type = build_pointer_type (type); 4608 4609 /* Process type qualifiers (such as const or volatile) 4610 that were given inside the `*'. */ 4611 type_quals = declarator->u.pointer_quals; 4612 4613 declarator = declarator->declarator; 4614 break; 4615 } 4616 default: 4617 gcc_unreachable (); 4618 } 4619 } 4620 4621 /* Now TYPE has the actual type, apart from any qualifiers in 4622 TYPE_QUALS. */ 4623 4624 /* Check the type and width of a bit-field. */ 4625 if (bitfield) 4626 check_bitfield_type_and_width (&type, width, orig_name); 4627 4628 /* Did array size calculations overflow? */ 4629 4630 if (TREE_CODE (type) == ARRAY_TYPE 4631 && COMPLETE_TYPE_P (type) 4632 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 4633 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 4634 { 4635 error ("size of array %qs is too large", name); 4636 /* If we proceed with the array type as it is, we'll eventually 4637 crash in tree_low_cst(). */ 4638 type = error_mark_node; 4639 } 4640 4641 /* If this is declaring a typedef name, return a TYPE_DECL. */ 4642 4643 if (storage_class == csc_typedef) 4644 { 4645 tree decl; 4646 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4647 && type_quals) 4648 pedwarn ("ISO C forbids qualified function types"); 4649 if (type_quals) 4650 type = c_build_qualified_type (type, type_quals); 4651 decl = build_decl (TYPE_DECL, declarator->u.id, type); 4652 if (declspecs->explicit_signed_p) 4653 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 4654 decl_attributes (&decl, returned_attrs, 0); 4655 if (declspecs->inline_p) 4656 pedwarn ("typedef %q+D declared %<inline%>", decl); 4657 return decl; 4658 } 4659 4660 /* If this is a type name (such as, in a cast or sizeof), 4661 compute the type and return it now. */ 4662 4663 if (decl_context == TYPENAME) 4664 { 4665 /* Note that the grammar rejects storage classes in typenames 4666 and fields. */ 4667 gcc_assert (storage_class == csc_none && !threadp 4668 && !declspecs->inline_p); 4669 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4670 && type_quals) 4671 pedwarn ("ISO C forbids const or volatile function types"); 4672 if (type_quals) 4673 type = c_build_qualified_type (type, type_quals); 4674 decl_attributes (&type, returned_attrs, 0); 4675 return type; 4676 } 4677 4678 if (pedantic && decl_context == FIELD 4679 && variably_modified_type_p (type, NULL_TREE)) 4680 { 4681 /* C99 6.7.2.1p8 */ 4682 pedwarn ("a member of a structure or union cannot have a variably modified type"); 4683 } 4684 4685 /* Aside from typedefs and type names (handle above), 4686 `void' at top level (not within pointer) 4687 is allowed only in public variables. 4688 We don't complain about parms either, but that is because 4689 a better error message can be made later. */ 4690 4691 if (VOID_TYPE_P (type) && decl_context != PARM 4692 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 4693 && (storage_class == csc_extern 4694 || (current_scope == file_scope 4695 && !(storage_class == csc_static 4696 || storage_class == csc_register))))) 4697 { 4698 error ("variable or field %qs declared void", name); 4699 type = integer_type_node; 4700 } 4701 4702 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 4703 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 4704 4705 { 4706 tree decl; 4707 4708 if (decl_context == PARM) 4709 { 4710 tree type_as_written; 4711 tree promoted_type; 4712 4713 /* A parameter declared as an array of T is really a pointer to T. 4714 One declared as a function is really a pointer to a function. */ 4715 4716 if (TREE_CODE (type) == ARRAY_TYPE) 4717 { 4718 /* Transfer const-ness of array into that of type pointed to. */ 4719 type = TREE_TYPE (type); 4720 if (type_quals) 4721 type = c_build_qualified_type (type, type_quals); 4722 type = build_pointer_type (type); 4723 type_quals = array_ptr_quals; 4724 4725 /* We don't yet implement attributes in this context. */ 4726 if (array_ptr_attrs != NULL_TREE) 4727 warning (OPT_Wattributes, 4728 "attributes in parameter array declarator ignored"); 4729 4730 size_varies = 0; 4731 } 4732 else if (TREE_CODE (type) == FUNCTION_TYPE) 4733 { 4734 if (pedantic && type_quals) 4735 pedwarn ("ISO C forbids qualified function types"); 4736 if (type_quals) 4737 type = c_build_qualified_type (type, type_quals); 4738 type = build_pointer_type (type); 4739 type_quals = TYPE_UNQUALIFIED; 4740 } 4741 else if (type_quals) 4742 type = c_build_qualified_type (type, type_quals); 4743 4744 type_as_written = type; 4745 4746 decl = build_decl (PARM_DECL, declarator->u.id, type); 4747 if (size_varies) 4748 C_DECL_VARIABLE_SIZE (decl) = 1; 4749 4750 /* Compute the type actually passed in the parmlist, 4751 for the case where there is no prototype. 4752 (For example, shorts and chars are passed as ints.) 4753 When there is a prototype, this is overridden later. */ 4754 4755 if (type == error_mark_node) 4756 promoted_type = type; 4757 else 4758 promoted_type = c_type_promotes_to (type); 4759 4760 DECL_ARG_TYPE (decl) = promoted_type; 4761 if (declspecs->inline_p) 4762 pedwarn ("parameter %q+D declared %<inline%>", decl); 4763 } 4764 else if (decl_context == FIELD) 4765 { 4766 /* Note that the grammar rejects storage classes in typenames 4767 and fields. */ 4768 gcc_assert (storage_class == csc_none && !threadp 4769 && !declspecs->inline_p); 4770 4771 /* Structure field. It may not be a function. */ 4772 4773 if (TREE_CODE (type) == FUNCTION_TYPE) 4774 { 4775 error ("field %qs declared as a function", name); 4776 type = build_pointer_type (type); 4777 } 4778 else if (TREE_CODE (type) != ERROR_MARK 4779 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 4780 { 4781 error ("field %qs has incomplete type", name); 4782 type = error_mark_node; 4783 } 4784 type = c_build_qualified_type (type, type_quals); 4785 decl = build_decl (FIELD_DECL, declarator->u.id, type); 4786 DECL_NONADDRESSABLE_P (decl) = bitfield; 4787 4788 if (size_varies) 4789 C_DECL_VARIABLE_SIZE (decl) = 1; 4790 } 4791 else if (TREE_CODE (type) == FUNCTION_TYPE) 4792 { 4793 if (storage_class == csc_register || threadp) 4794 { 4795 error ("invalid storage class for function %qs", name); 4796 } 4797 else if (current_scope != file_scope) 4798 { 4799 /* Function declaration not at file scope. Storage 4800 classes other than `extern' are not allowed, C99 4801 6.7.1p5, and `extern' makes no difference. However, 4802 GCC allows 'auto', perhaps with 'inline', to support 4803 nested functions. */ 4804 if (storage_class == csc_auto) 4805 { 4806 if (pedantic) 4807 pedwarn ("invalid storage class for function %qs", name); 4808 } 4809 else if (storage_class == csc_static) 4810 { 4811 error ("invalid storage class for function %qs", name); 4812 if (funcdef_flag) 4813 storage_class = declspecs->storage_class = csc_none; 4814 else 4815 return 0; 4816 } 4817 } 4818 4819 decl = build_decl (FUNCTION_DECL, declarator->u.id, type); 4820 decl = build_decl_attribute_variant (decl, decl_attr); 4821 4822 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 4823 4824 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 4825 pedwarn ("ISO C forbids qualified function types"); 4826 4827 /* GNU C interprets a volatile-qualified function type to indicate 4828 that the function does not return. */ 4829 if ((type_quals & TYPE_QUAL_VOLATILE) 4830 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 4831 warning (0, "%<noreturn%> function returns non-void value"); 4832 4833 /* Every function declaration is an external reference 4834 (DECL_EXTERNAL) except for those which are not at file 4835 scope and are explicitly declared "auto". This is 4836 forbidden by standard C (C99 6.7.1p5) and is interpreted by 4837 GCC to signify a forward declaration of a nested function. */ 4838 if (storage_class == csc_auto && current_scope != file_scope) 4839 DECL_EXTERNAL (decl) = 0; 4840 /* In C99, a function which is declared 'inline' with 'extern' 4841 is not an external reference (which is confusing). It 4842 means that the later definition of the function must be output 4843 in this file, C99 6.7.4p6. In GNU C89, a function declared 4844 'extern inline' is an external reference. */ 4845 else if (declspecs->inline_p && storage_class != csc_static) 4846 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 4847 == flag_gnu89_inline); 4848 else 4849 DECL_EXTERNAL (decl) = !initialized; 4850 4851 /* Record absence of global scope for `static' or `auto'. */ 4852 TREE_PUBLIC (decl) 4853 = !(storage_class == csc_static || storage_class == csc_auto); 4854 4855 /* For a function definition, record the argument information 4856 block where store_parm_decls will look for it. */ 4857 if (funcdef_flag) 4858 current_function_arg_info = arg_info; 4859 4860 if (declspecs->default_int_p) 4861 C_FUNCTION_IMPLICIT_INT (decl) = 1; 4862 4863 /* Record presence of `inline', if it is reasonable. */ 4864 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 4865 { 4866 if (declspecs->inline_p) 4867 pedwarn ("cannot inline function %<main%>"); 4868 } 4869 else if (declspecs->inline_p) 4870 { 4871 /* Record that the function is declared `inline'. */ 4872 DECL_DECLARED_INLINE_P (decl) = 1; 4873 4874 /* Do not mark bare declarations as DECL_INLINE. Doing so 4875 in the presence of multiple declarations can result in 4876 the abstract origin pointing between the declarations, 4877 which will confuse dwarf2out. */ 4878 if (initialized) 4879 DECL_INLINE (decl) = 1; 4880 } 4881 /* If -finline-functions, assume it can be inlined. This does 4882 two things: let the function be deferred until it is actually 4883 needed, and let dwarf2 know that the function is inlinable. */ 4884 else if (flag_inline_trees == 2 && initialized) 4885 DECL_INLINE (decl) = 1; 4886 } 4887 else 4888 { 4889 /* It's a variable. */ 4890 /* An uninitialized decl with `extern' is a reference. */ 4891 int extern_ref = !initialized && storage_class == csc_extern; 4892 4893 type = c_build_qualified_type (type, type_quals); 4894 4895 /* C99 6.2.2p7: It is invalid (compile-time undefined 4896 behavior) to create an 'extern' declaration for a 4897 variable if there is a global declaration that is 4898 'static' and the global declaration is not visible. 4899 (If the static declaration _is_ currently visible, 4900 the 'extern' declaration is taken to refer to that decl.) */ 4901 if (extern_ref && current_scope != file_scope) 4902 { 4903 tree global_decl = identifier_global_value (declarator->u.id); 4904 tree visible_decl = lookup_name (declarator->u.id); 4905 4906 if (global_decl 4907 && global_decl != visible_decl 4908 && TREE_CODE (global_decl) == VAR_DECL 4909 && !TREE_PUBLIC (global_decl)) 4910 error ("variable previously declared %<static%> redeclared " 4911 "%<extern%>"); 4912 } 4913 4914 decl = build_decl (VAR_DECL, declarator->u.id, type); 4915 DECL_SOURCE_LOCATION (decl) = declarator->id_loc; 4916 if (size_varies) 4917 C_DECL_VARIABLE_SIZE (decl) = 1; 4918 4919 if (declspecs->inline_p) 4920 pedwarn ("variable %q+D declared %<inline%>", decl); 4921 4922 /* At file scope, an initialized extern declaration may follow 4923 a static declaration. In that case, DECL_EXTERNAL will be 4924 reset later in start_decl. */ 4925 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 4926 4927 /* At file scope, the presence of a `static' or `register' storage 4928 class specifier, or the absence of all storage class specifiers 4929 makes this declaration a definition (perhaps tentative). Also, 4930 the absence of `static' makes it public. */ 4931 if (current_scope == file_scope) 4932 { 4933 TREE_PUBLIC (decl) = storage_class != csc_static; 4934 TREE_STATIC (decl) = !extern_ref; 4935 } 4936 /* Not at file scope, only `static' makes a static definition. */ 4937 else 4938 { 4939 TREE_STATIC (decl) = (storage_class == csc_static); 4940 TREE_PUBLIC (decl) = extern_ref; 4941 } 4942 4943 if (threadp) 4944 { 4945 if (targetm.have_tls) 4946 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 4947 else 4948 /* A mere warning is sure to result in improper semantics 4949 at runtime. Don't bother to allow this to compile. */ 4950 error ("thread-local storage not supported for this target"); 4951 } 4952 } 4953 4954 if (storage_class == csc_extern 4955 && variably_modified_type_p (type, NULL_TREE)) 4956 { 4957 /* C99 6.7.5.2p2 */ 4958 error ("object with variably modified type must have no linkage"); 4959 } 4960 4961 /* Record `register' declaration for warnings on & 4962 and in case doing stupid register allocation. */ 4963 4964 if (storage_class == csc_register) 4965 { 4966 C_DECL_REGISTER (decl) = 1; 4967 DECL_REGISTER (decl) = 1; 4968 } 4969 4970 /* Record constancy and volatility. */ 4971 c_apply_type_quals_to_decl (type_quals, decl); 4972 4973 /* If a type has volatile components, it should be stored in memory. 4974 Otherwise, the fact that those components are volatile 4975 will be ignored, and would even crash the compiler. 4976 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 4977 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 4978 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 4979 || TREE_CODE (decl) == RESULT_DECL)) 4980 { 4981 /* It is not an error for a structure with volatile fields to 4982 be declared register, but reset DECL_REGISTER since it 4983 cannot actually go in a register. */ 4984 int was_reg = C_DECL_REGISTER (decl); 4985 C_DECL_REGISTER (decl) = 0; 4986 DECL_REGISTER (decl) = 0; 4987 c_mark_addressable (decl); 4988 C_DECL_REGISTER (decl) = was_reg; 4989 } 4990 4991 /* This is the earliest point at which we might know the assembler 4992 name of a variable. Thus, if it's known before this, die horribly. */ 4993 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 4994 4995 decl_attributes (&decl, returned_attrs, 0); 4996 4997 return decl; 4998 } 4999} 5000 5001/* Decode the parameter-list info for a function type or function definition. 5002 The argument is the value returned by `get_parm_info' (or made in c-parse.c 5003 if there is an identifier list instead of a parameter decl list). 5004 These two functions are separate because when a function returns 5005 or receives functions then each is called multiple times but the order 5006 of calls is different. The last call to `grokparms' is always the one 5007 that contains the formal parameter names of a function definition. 5008 5009 Return a list of arg types to use in the FUNCTION_TYPE for this function. 5010 5011 FUNCDEF_FLAG is true for a function definition, false for 5012 a mere declaration. A nonempty identifier-list gets an error message 5013 when FUNCDEF_FLAG is false. */ 5014 5015static tree 5016grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 5017{ 5018 tree arg_types = arg_info->types; 5019 5020 if (funcdef_flag && arg_info->had_vla_unspec) 5021 { 5022 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 5023 /* C99 6.7.5.2p4 */ 5024 error ("%<[*]%> not allowed in other than function prototype scope"); 5025 } 5026 5027 if (arg_types == 0 && !funcdef_flag && !in_system_header) 5028 warning (OPT_Wstrict_prototypes, 5029 "function declaration isn%'t a prototype"); 5030 5031 if (arg_types == error_mark_node) 5032 return 0; /* don't set TYPE_ARG_TYPES in this case */ 5033 5034 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 5035 { 5036 if (!funcdef_flag) 5037 pedwarn ("parameter names (without types) in function declaration"); 5038 5039 arg_info->parms = arg_info->types; 5040 arg_info->types = 0; 5041 return 0; 5042 } 5043 else 5044 { 5045 tree parm, type, typelt; 5046 unsigned int parmno; 5047 5048 /* If there is a parameter of incomplete type in a definition, 5049 this is an error. In a declaration this is valid, and a 5050 struct or union type may be completed later, before any calls 5051 or definition of the function. In the case where the tag was 5052 first declared within the parameter list, a warning has 5053 already been given. If a parameter has void type, then 5054 however the function cannot be defined or called, so 5055 warn. */ 5056 5057 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 5058 parm; 5059 parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 5060 { 5061 type = TREE_VALUE (typelt); 5062 if (type == error_mark_node) 5063 continue; 5064 5065 if (!COMPLETE_TYPE_P (type)) 5066 { 5067 if (funcdef_flag) 5068 { 5069 if (DECL_NAME (parm)) 5070 error ("parameter %u (%q+D) has incomplete type", 5071 parmno, parm); 5072 else 5073 error ("%Jparameter %u has incomplete type", 5074 parm, parmno); 5075 5076 TREE_VALUE (typelt) = error_mark_node; 5077 TREE_TYPE (parm) = error_mark_node; 5078 } 5079 else if (VOID_TYPE_P (type)) 5080 { 5081 if (DECL_NAME (parm)) 5082 warning (0, "parameter %u (%q+D) has void type", 5083 parmno, parm); 5084 else 5085 warning (0, "%Jparameter %u has void type", 5086 parm, parmno); 5087 } 5088 } 5089 5090 if (DECL_NAME (parm) && TREE_USED (parm)) 5091 warn_if_shadowing (parm); 5092 } 5093 return arg_types; 5094 } 5095} 5096 5097/* Take apart the current scope and return a c_arg_info structure with 5098 info on a parameter list just parsed. 5099 5100 This structure is later fed to 'grokparms' and 'store_parm_decls'. 5101 5102 ELLIPSIS being true means the argument list ended in '...' so don't 5103 append a sentinel (void_list_node) to the end of the type-list. */ 5104 5105struct c_arg_info * 5106get_parm_info (bool ellipsis) 5107{ 5108 struct c_binding *b = current_scope->bindings; 5109 struct c_arg_info *arg_info = XOBNEW (&parser_obstack, 5110 struct c_arg_info); 5111 tree parms = 0; 5112 tree tags = 0; 5113 tree types = 0; 5114 tree others = 0; 5115 5116 static bool explained_incomplete_types = false; 5117 bool gave_void_only_once_err = false; 5118 5119 arg_info->parms = 0; 5120 arg_info->tags = 0; 5121 arg_info->types = 0; 5122 arg_info->others = 0; 5123 arg_info->pending_sizes = 0; 5124 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 5125 5126 /* The bindings in this scope must not get put into a block. 5127 We will take care of deleting the binding nodes. */ 5128 current_scope->bindings = 0; 5129 5130 /* This function is only called if there was *something* on the 5131 parameter list. */ 5132 gcc_assert (b); 5133 5134 /* A parameter list consisting solely of 'void' indicates that the 5135 function takes no arguments. But if the 'void' is qualified 5136 (by 'const' or 'volatile'), or has a storage class specifier 5137 ('register'), then the behavior is undefined; issue an error. 5138 Typedefs for 'void' are OK (see DR#157). */ 5139 if (b->prev == 0 /* one binding */ 5140 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 5141 && !DECL_NAME (b->decl) /* anonymous */ 5142 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 5143 { 5144 if (TREE_THIS_VOLATILE (b->decl) 5145 || TREE_READONLY (b->decl) 5146 || C_DECL_REGISTER (b->decl)) 5147 error ("%<void%> as only parameter may not be qualified"); 5148 5149 /* There cannot be an ellipsis. */ 5150 if (ellipsis) 5151 error ("%<void%> must be the only parameter"); 5152 5153 arg_info->types = void_list_node; 5154 return arg_info; 5155 } 5156 5157 if (!ellipsis) 5158 types = void_list_node; 5159 5160 /* Break up the bindings list into parms, tags, types, and others; 5161 apply sanity checks; purge the name-to-decl bindings. */ 5162 while (b) 5163 { 5164 tree decl = b->decl; 5165 tree type = TREE_TYPE (decl); 5166 const char *keyword; 5167 5168 switch (TREE_CODE (decl)) 5169 { 5170 case PARM_DECL: 5171 if (b->id) 5172 { 5173 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5174 I_SYMBOL_BINDING (b->id) = b->shadowed; 5175 } 5176 5177 /* Check for forward decls that never got their actual decl. */ 5178 if (TREE_ASM_WRITTEN (decl)) 5179 error ("parameter %q+D has just a forward declaration", decl); 5180 /* Check for (..., void, ...) and issue an error. */ 5181 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 5182 { 5183 if (!gave_void_only_once_err) 5184 { 5185 error ("%<void%> must be the only parameter"); 5186 gave_void_only_once_err = true; 5187 } 5188 } 5189 else 5190 { 5191 /* Valid parameter, add it to the list. */ 5192 TREE_CHAIN (decl) = parms; 5193 parms = decl; 5194 5195 /* Since there is a prototype, args are passed in their 5196 declared types. The back end may override this later. */ 5197 DECL_ARG_TYPE (decl) = type; 5198 types = tree_cons (0, type, types); 5199 } 5200 break; 5201 5202 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 5203 case UNION_TYPE: keyword = "union"; goto tag; 5204 case RECORD_TYPE: keyword = "struct"; goto tag; 5205 tag: 5206 /* Types may not have tag-names, in which case the type 5207 appears in the bindings list with b->id NULL. */ 5208 if (b->id) 5209 { 5210 gcc_assert (I_TAG_BINDING (b->id) == b); 5211 I_TAG_BINDING (b->id) = b->shadowed; 5212 } 5213 5214 /* Warn about any struct, union or enum tags defined in a 5215 parameter list. The scope of such types is limited to 5216 the parameter list, which is rarely if ever desirable 5217 (it's impossible to call such a function with type- 5218 correct arguments). An anonymous union parm type is 5219 meaningful as a GNU extension, so don't warn for that. */ 5220 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 5221 { 5222 if (b->id) 5223 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5224 warning (0, "%<%s %E%> declared inside parameter list", 5225 keyword, b->id); 5226 else 5227 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5228 warning (0, "anonymous %s declared inside parameter list", 5229 keyword); 5230 5231 if (!explained_incomplete_types) 5232 { 5233 warning (0, "its scope is only this definition or declaration," 5234 " which is probably not what you want"); 5235 explained_incomplete_types = true; 5236 } 5237 } 5238 5239 tags = tree_cons (b->id, decl, tags); 5240 break; 5241 5242 case CONST_DECL: 5243 case TYPE_DECL: 5244 case FUNCTION_DECL: 5245 /* CONST_DECLs appear here when we have an embedded enum, 5246 and TYPE_DECLs appear here when we have an embedded struct 5247 or union. No warnings for this - we already warned about the 5248 type itself. FUNCTION_DECLs appear when there is an implicit 5249 function declaration in the parameter list. */ 5250 5251 TREE_CHAIN (decl) = others; 5252 others = decl; 5253 /* fall through */ 5254 5255 case ERROR_MARK: 5256 /* error_mark_node appears here when we have an undeclared 5257 variable. Just throw it away. */ 5258 if (b->id) 5259 { 5260 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5261 I_SYMBOL_BINDING (b->id) = b->shadowed; 5262 } 5263 break; 5264 5265 /* Other things that might be encountered. */ 5266 case LABEL_DECL: 5267 case VAR_DECL: 5268 default: 5269 gcc_unreachable (); 5270 } 5271 5272 b = free_binding_and_advance (b); 5273 } 5274 5275 arg_info->parms = parms; 5276 arg_info->tags = tags; 5277 arg_info->types = types; 5278 arg_info->others = others; 5279 arg_info->pending_sizes = get_pending_sizes (); 5280 return arg_info; 5281} 5282 5283/* Get the struct, enum or union (CODE says which) with tag NAME. 5284 Define the tag as a forward-reference if it is not defined. 5285 Return a c_typespec structure for the type specifier. */ 5286 5287struct c_typespec 5288parser_xref_tag (enum tree_code code, tree name) 5289{ 5290 struct c_typespec ret; 5291 /* If a cross reference is requested, look up the type 5292 already defined for this tag and return it. */ 5293 5294 tree ref = lookup_tag (code, name, 0); 5295 /* If this is the right type of tag, return what we found. 5296 (This reference will be shadowed by shadow_tag later if appropriate.) 5297 If this is the wrong type of tag, do not return it. If it was the 5298 wrong type in the same scope, we will have had an error 5299 message already; if in a different scope and declaring 5300 a name, pending_xref_error will give an error message; but if in a 5301 different scope and not declaring a name, this tag should 5302 shadow the previous declaration of a different type of tag, and 5303 this would not work properly if we return the reference found. 5304 (For example, with "struct foo" in an outer scope, "union foo;" 5305 must shadow that tag with a new one of union type.) */ 5306 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 5307 if (ref && TREE_CODE (ref) == code) 5308 { 5309 ret.spec = ref; 5310 return ret; 5311 } 5312 5313 /* If no such tag is yet defined, create a forward-reference node 5314 and record it as the "definition". 5315 When a real declaration of this type is found, 5316 the forward-reference will be altered into a real type. */ 5317 5318 ref = make_node (code); 5319 if (code == ENUMERAL_TYPE) 5320 { 5321 /* Give the type a default layout like unsigned int 5322 to avoid crashing if it does not get defined. */ 5323 TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node); 5324 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 5325 TYPE_USER_ALIGN (ref) = 0; 5326 TYPE_UNSIGNED (ref) = 1; 5327 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 5328 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 5329 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 5330 } 5331 5332 pushtag (name, ref); 5333 5334 ret.spec = ref; 5335 return ret; 5336} 5337 5338/* Get the struct, enum or union (CODE says which) with tag NAME. 5339 Define the tag as a forward-reference if it is not defined. 5340 Return a tree for the type. */ 5341 5342tree 5343xref_tag (enum tree_code code, tree name) 5344{ 5345 return parser_xref_tag (code, name).spec; 5346} 5347 5348/* Make sure that the tag NAME is defined *in the current scope* 5349 at least as a forward reference. 5350 CODE says which kind of tag NAME ought to be. */ 5351 5352tree 5353start_struct (enum tree_code code, tree name) 5354{ 5355 /* If there is already a tag defined at this scope 5356 (as a forward reference), just return it. */ 5357 5358 tree ref = 0; 5359 5360 if (name != 0) 5361 ref = lookup_tag (code, name, 1); 5362 if (ref && TREE_CODE (ref) == code) 5363 { 5364 if (TYPE_SIZE (ref)) 5365 { 5366 if (code == UNION_TYPE) 5367 error ("redefinition of %<union %E%>", name); 5368 else 5369 error ("redefinition of %<struct %E%>", name); 5370 } 5371 else if (C_TYPE_BEING_DEFINED (ref)) 5372 { 5373 if (code == UNION_TYPE) 5374 error ("nested redefinition of %<union %E%>", name); 5375 else 5376 error ("nested redefinition of %<struct %E%>", name); 5377 /* Don't create structures that contain themselves. */ 5378 ref = NULL_TREE; 5379 } 5380 } 5381 5382 /* Otherwise create a forward-reference just so the tag is in scope. */ 5383 5384 if (ref == NULL_TREE || TREE_CODE (ref) != code) 5385 { 5386 ref = make_node (code); 5387 pushtag (name, ref); 5388 } 5389 5390 C_TYPE_BEING_DEFINED (ref) = 1; 5391 TYPE_PACKED (ref) = flag_pack_struct; 5392 return ref; 5393} 5394 5395/* Process the specs, declarator and width (NULL if omitted) 5396 of a structure component, returning a FIELD_DECL node. 5397 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 5398 5399 This is done during the parsing of the struct declaration. 5400 The FIELD_DECL nodes are chained together and the lot of them 5401 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 5402 5403tree 5404grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs, 5405 tree width) 5406{ 5407 tree value; 5408 5409 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 5410 && width == NULL_TREE) 5411 { 5412 /* This is an unnamed decl. 5413 5414 If we have something of the form "union { list } ;" then this 5415 is the anonymous union extension. Similarly for struct. 5416 5417 If this is something of the form "struct foo;", then 5418 If MS extensions are enabled, this is handled as an 5419 anonymous struct. 5420 Otherwise this is a forward declaration of a structure tag. 5421 5422 If this is something of the form "foo;" and foo is a TYPE_DECL, then 5423 If MS extensions are enabled and foo names a structure, then 5424 again this is an anonymous struct. 5425 Otherwise this is an error. 5426 5427 Oh what a horrid tangled web we weave. I wonder if MS consciously 5428 took this from Plan 9 or if it was an accident of implementation 5429 that took root before someone noticed the bug... */ 5430 5431 tree type = declspecs->type; 5432 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 5433 || TREE_CODE (type) == UNION_TYPE); 5434 bool ok = false; 5435 5436 if (type_ok 5437 && (flag_ms_extensions || !declspecs->typedef_p)) 5438 { 5439 if (flag_ms_extensions) 5440 ok = true; 5441 else if (flag_iso) 5442 ok = false; 5443 else if (TYPE_NAME (type) == NULL) 5444 ok = true; 5445 else 5446 ok = false; 5447 } 5448 if (!ok) 5449 { 5450 pedwarn ("declaration does not declare anything"); 5451 return NULL_TREE; 5452 } 5453 if (pedantic) 5454 pedwarn ("ISO C doesn%'t support unnamed structs/unions"); 5455 } 5456 5457 value = grokdeclarator (declarator, declspecs, FIELD, false, 5458 width ? &width : NULL); 5459 5460 finish_decl (value, NULL_TREE, NULL_TREE); 5461 DECL_INITIAL (value) = width; 5462 5463 return value; 5464} 5465 5466/* Generate an error for any duplicate field names in FIELDLIST. Munge 5467 the list such that this does not present a problem later. */ 5468 5469static void 5470detect_field_duplicates (tree fieldlist) 5471{ 5472 tree x, y; 5473 int timeout = 10; 5474 5475 /* First, see if there are more than "a few" fields. 5476 This is trivially true if there are zero or one fields. */ 5477 if (!fieldlist) 5478 return; 5479 x = TREE_CHAIN (fieldlist); 5480 if (!x) 5481 return; 5482 do { 5483 timeout--; 5484 x = TREE_CHAIN (x); 5485 } while (timeout > 0 && x); 5486 5487 /* If there were "few" fields, avoid the overhead of allocating 5488 a hash table. Instead just do the nested traversal thing. */ 5489 if (timeout > 0) 5490 { 5491 for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x)) 5492 if (DECL_NAME (x)) 5493 { 5494 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 5495 if (DECL_NAME (y) == DECL_NAME (x)) 5496 { 5497 error ("duplicate member %q+D", x); 5498 DECL_NAME (x) = NULL_TREE; 5499 } 5500 } 5501 } 5502 else 5503 { 5504 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 5505 void **slot; 5506 5507 for (x = fieldlist; x ; x = TREE_CHAIN (x)) 5508 if ((y = DECL_NAME (x)) != 0) 5509 { 5510 slot = htab_find_slot (htab, y, INSERT); 5511 if (*slot) 5512 { 5513 error ("duplicate member %q+D", x); 5514 DECL_NAME (x) = NULL_TREE; 5515 } 5516 *slot = y; 5517 } 5518 5519 htab_delete (htab); 5520 } 5521} 5522 5523/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 5524 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 5525 ATTRIBUTES are attributes to be applied to the structure. */ 5526 5527tree 5528finish_struct (tree t, tree fieldlist, tree attributes) 5529{ 5530 tree x; 5531 bool toplevel = file_scope == current_scope; 5532 int saw_named_field; 5533 5534 /* If this type was previously laid out as a forward reference, 5535 make sure we lay it out again. */ 5536 5537 TYPE_SIZE (t) = 0; 5538 5539 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5540 5541 if (pedantic) 5542 { 5543 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5544 if (DECL_NAME (x) != 0) 5545 break; 5546 5547 if (x == 0) 5548 { 5549 if (TREE_CODE (t) == UNION_TYPE) 5550 { 5551 if (fieldlist) 5552 pedwarn ("union has no named members"); 5553 else 5554 pedwarn ("union has no members"); 5555 } 5556 else 5557 { 5558 if (fieldlist) 5559 pedwarn ("struct has no named members"); 5560 else 5561 pedwarn ("struct has no members"); 5562 } 5563 } 5564 } 5565 5566 /* Install struct as DECL_CONTEXT of each field decl. 5567 Also process specified field sizes, found in the DECL_INITIAL, 5568 storing 0 there after the type has been changed to precision equal 5569 to its width, rather than the precision of the specified standard 5570 type. (Correct layout requires the original type to have been preserved 5571 until now.) */ 5572 5573 saw_named_field = 0; 5574 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5575 { 5576 if (TREE_TYPE (x) == error_mark_node) 5577 continue; 5578 5579 DECL_CONTEXT (x) = t; 5580 5581 if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 5582 DECL_PACKED (x) = 1; 5583 5584 /* If any field is const, the structure type is pseudo-const. */ 5585 if (TREE_READONLY (x)) 5586 C_TYPE_FIELDS_READONLY (t) = 1; 5587 else 5588 { 5589 /* A field that is pseudo-const makes the structure likewise. */ 5590 tree t1 = TREE_TYPE (x); 5591 while (TREE_CODE (t1) == ARRAY_TYPE) 5592 t1 = TREE_TYPE (t1); 5593 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 5594 && C_TYPE_FIELDS_READONLY (t1)) 5595 C_TYPE_FIELDS_READONLY (t) = 1; 5596 } 5597 5598 /* Any field that is volatile means variables of this type must be 5599 treated in some ways as volatile. */ 5600 if (TREE_THIS_VOLATILE (x)) 5601 C_TYPE_FIELDS_VOLATILE (t) = 1; 5602 5603 /* Any field of nominal variable size implies structure is too. */ 5604 if (C_DECL_VARIABLE_SIZE (x)) 5605 C_TYPE_VARIABLE_SIZE (t) = 1; 5606 5607 if (DECL_INITIAL (x)) 5608 { 5609 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 5610 DECL_SIZE (x) = bitsize_int (width); 5611 DECL_BIT_FIELD (x) = 1; 5612 SET_DECL_C_BIT_FIELD (x); 5613 } 5614 5615 /* Detect flexible array member in an invalid context. */ 5616 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 5617 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 5618 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 5619 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 5620 { 5621 if (TREE_CODE (t) == UNION_TYPE) 5622 { 5623 error ("%Jflexible array member in union", x); 5624 TREE_TYPE (x) = error_mark_node; 5625 } 5626 else if (TREE_CHAIN (x) != NULL_TREE) 5627 { 5628 error ("%Jflexible array member not at end of struct", x); 5629 TREE_TYPE (x) = error_mark_node; 5630 } 5631 else if (!saw_named_field) 5632 { 5633 error ("%Jflexible array member in otherwise empty struct", x); 5634 TREE_TYPE (x) = error_mark_node; 5635 } 5636 } 5637 5638 if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE 5639 && flexible_array_type_p (TREE_TYPE (x))) 5640 pedwarn ("%Jinvalid use of structure with flexible array member", x); 5641 5642 if (DECL_NAME (x)) 5643 saw_named_field = 1; 5644 } 5645 5646 detect_field_duplicates (fieldlist); 5647 5648 /* Now we have the nearly final fieldlist. Record it, 5649 then lay out the structure or union (including the fields). */ 5650 5651 TYPE_FIELDS (t) = fieldlist; 5652 5653 layout_type (t); 5654 5655 /* Give bit-fields their proper types. */ 5656 { 5657 tree *fieldlistp = &fieldlist; 5658 while (*fieldlistp) 5659 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 5660 && TREE_TYPE (*fieldlistp) != error_mark_node) 5661 { 5662 unsigned HOST_WIDE_INT width 5663 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 5664 tree type = TREE_TYPE (*fieldlistp); 5665 if (width != TYPE_PRECISION (type)) 5666 { 5667 TREE_TYPE (*fieldlistp) 5668 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 5669 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 5670 } 5671 DECL_INITIAL (*fieldlistp) = 0; 5672 } 5673 else 5674 fieldlistp = &TREE_CHAIN (*fieldlistp); 5675 } 5676 5677 /* Now we have the truly final field list. 5678 Store it in this type and in the variants. */ 5679 5680 TYPE_FIELDS (t) = fieldlist; 5681 5682 /* If there are lots of fields, sort so we can look through them fast. 5683 We arbitrarily consider 16 or more elts to be "a lot". */ 5684 5685 { 5686 int len = 0; 5687 5688 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5689 { 5690 if (len > 15 || DECL_NAME (x) == NULL) 5691 break; 5692 len += 1; 5693 } 5694 5695 if (len > 15) 5696 { 5697 tree *field_array; 5698 struct lang_type *space; 5699 struct sorted_fields_type *space2; 5700 5701 len += list_length (x); 5702 5703 /* Use the same allocation policy here that make_node uses, to 5704 ensure that this lives as long as the rest of the struct decl. 5705 All decls in an inline function need to be saved. */ 5706 5707 space = GGC_CNEW (struct lang_type); 5708 space2 = GGC_NEWVAR (struct sorted_fields_type, 5709 sizeof (struct sorted_fields_type) + len * sizeof (tree)); 5710 5711 len = 0; 5712 space->s = space2; 5713 field_array = &space2->elts[0]; 5714 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5715 { 5716 field_array[len++] = x; 5717 5718 /* If there is anonymous struct or union, break out of the loop. */ 5719 if (DECL_NAME (x) == NULL) 5720 break; 5721 } 5722 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 5723 if (x == NULL) 5724 { 5725 TYPE_LANG_SPECIFIC (t) = space; 5726 TYPE_LANG_SPECIFIC (t)->s->len = len; 5727 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 5728 qsort (field_array, len, sizeof (tree), field_decl_cmp); 5729 } 5730 } 5731 } 5732 5733 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 5734 { 5735 TYPE_FIELDS (x) = TYPE_FIELDS (t); 5736 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 5737 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 5738 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 5739 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 5740 } 5741 5742 /* If this was supposed to be a transparent union, but we can't 5743 make it one, warn and turn off the flag. */ 5744 if (TREE_CODE (t) == UNION_TYPE 5745 && TYPE_TRANSPARENT_UNION (t) 5746 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 5747 { 5748 TYPE_TRANSPARENT_UNION (t) = 0; 5749 warning (0, "union cannot be made transparent"); 5750 } 5751 5752 /* If this structure or union completes the type of any previous 5753 variable declaration, lay it out and output its rtl. */ 5754 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 5755 x; 5756 x = TREE_CHAIN (x)) 5757 { 5758 tree decl = TREE_VALUE (x); 5759 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 5760 layout_array_type (TREE_TYPE (decl)); 5761 if (TREE_CODE (decl) != TYPE_DECL) 5762 { 5763 layout_decl (decl, 0); 5764 if (c_dialect_objc ()) 5765 objc_check_decl (decl); 5766 rest_of_decl_compilation (decl, toplevel, 0); 5767 if (!toplevel) 5768 expand_decl (decl); 5769 } 5770 } 5771 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 5772 5773 /* Finish debugging output for this type. */ 5774 rest_of_type_compilation (t, toplevel); 5775 5776 /* If we're inside a function proper, i.e. not file-scope and not still 5777 parsing parameters, then arrange for the size of a variable sized type 5778 to be bound now. */ 5779 if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE)) 5780 add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t))); 5781 5782 return t; 5783} 5784 5785/* Lay out the type T, and its element type, and so on. */ 5786 5787static void 5788layout_array_type (tree t) 5789{ 5790 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 5791 layout_array_type (TREE_TYPE (t)); 5792 layout_type (t); 5793} 5794 5795/* Begin compiling the definition of an enumeration type. 5796 NAME is its name (or null if anonymous). 5797 Returns the type object, as yet incomplete. 5798 Also records info about it so that build_enumerator 5799 may be used to declare the individual values as they are read. */ 5800 5801tree 5802start_enum (tree name) 5803{ 5804 tree enumtype = 0; 5805 5806 /* If this is the real definition for a previous forward reference, 5807 fill in the contents in the same object that used to be the 5808 forward reference. */ 5809 5810 if (name != 0) 5811 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1); 5812 5813 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 5814 { 5815 enumtype = make_node (ENUMERAL_TYPE); 5816 pushtag (name, enumtype); 5817 } 5818 5819 if (C_TYPE_BEING_DEFINED (enumtype)) 5820 error ("nested redefinition of %<enum %E%>", name); 5821 5822 C_TYPE_BEING_DEFINED (enumtype) = 1; 5823 5824 if (TYPE_VALUES (enumtype) != 0) 5825 { 5826 /* This enum is a named one that has been declared already. */ 5827 error ("redeclaration of %<enum %E%>", name); 5828 5829 /* Completely replace its old definition. 5830 The old enumerators remain defined, however. */ 5831 TYPE_VALUES (enumtype) = 0; 5832 } 5833 5834 enum_next_value = integer_zero_node; 5835 enum_overflow = 0; 5836 5837 if (flag_short_enums) 5838 TYPE_PACKED (enumtype) = 1; 5839 5840 return enumtype; 5841} 5842 5843/* After processing and defining all the values of an enumeration type, 5844 install their decls in the enumeration type and finish it off. 5845 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 5846 and ATTRIBUTES are the specified attributes. 5847 Returns ENUMTYPE. */ 5848 5849tree 5850finish_enum (tree enumtype, tree values, tree attributes) 5851{ 5852 tree pair, tem; 5853 tree minnode = 0, maxnode = 0; 5854 int precision, unsign; 5855 bool toplevel = (file_scope == current_scope); 5856 struct lang_type *lt; 5857 5858 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5859 5860 /* Calculate the maximum value of any enumerator in this type. */ 5861 5862 if (values == error_mark_node) 5863 minnode = maxnode = integer_zero_node; 5864 else 5865 { 5866 minnode = maxnode = TREE_VALUE (values); 5867 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 5868 { 5869 tree value = TREE_VALUE (pair); 5870 if (tree_int_cst_lt (maxnode, value)) 5871 maxnode = value; 5872 if (tree_int_cst_lt (value, minnode)) 5873 minnode = value; 5874 } 5875 } 5876 5877 /* Construct the final type of this enumeration. It is the same 5878 as one of the integral types - the narrowest one that fits, except 5879 that normally we only go as narrow as int - and signed iff any of 5880 the values are negative. */ 5881 unsign = (tree_int_cst_sgn (minnode) >= 0); 5882 precision = MAX (min_precision (minnode, unsign), 5883 min_precision (maxnode, unsign)); 5884 5885 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 5886 { 5887 tem = c_common_type_for_size (precision, unsign); 5888 if (tem == NULL) 5889 { 5890 warning (0, "enumeration values exceed range of largest integer"); 5891 tem = long_long_integer_type_node; 5892 } 5893 } 5894 else 5895 tem = unsign ? unsigned_type_node : integer_type_node; 5896 5897 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 5898 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 5899 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 5900 TYPE_SIZE (enumtype) = 0; 5901 5902 /* If the precision of the type was specific with an attribute and it 5903 was too small, give an error. Otherwise, use it. */ 5904 if (TYPE_PRECISION (enumtype)) 5905 { 5906 if (precision > TYPE_PRECISION (enumtype)) 5907 error ("specified mode too small for enumeral values"); 5908 } 5909 else 5910 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 5911 5912 layout_type (enumtype); 5913 5914 if (values != error_mark_node) 5915 { 5916 /* Change the type of the enumerators to be the enum type. We 5917 need to do this irrespective of the size of the enum, for 5918 proper type checking. Replace the DECL_INITIALs of the 5919 enumerators, and the value slots of the list, with copies 5920 that have the enum type; they cannot be modified in place 5921 because they may be shared (e.g. integer_zero_node) Finally, 5922 change the purpose slots to point to the names of the decls. */ 5923 for (pair = values; pair; pair = TREE_CHAIN (pair)) 5924 { 5925 tree enu = TREE_PURPOSE (pair); 5926 tree ini = DECL_INITIAL (enu); 5927 5928 TREE_TYPE (enu) = enumtype; 5929 5930 /* The ISO C Standard mandates enumerators to have type int, 5931 even though the underlying type of an enum type is 5932 unspecified. Here we convert any enumerators that fit in 5933 an int to type int, to avoid promotions to unsigned types 5934 when comparing integers with enumerators that fit in the 5935 int range. When -pedantic is given, build_enumerator() 5936 would have already taken care of those that don't fit. */ 5937 if (int_fits_type_p (ini, integer_type_node)) 5938 tem = integer_type_node; 5939 else 5940 tem = enumtype; 5941 ini = convert (tem, ini); 5942 5943 DECL_INITIAL (enu) = ini; 5944 TREE_PURPOSE (pair) = DECL_NAME (enu); 5945 TREE_VALUE (pair) = ini; 5946 } 5947 5948 TYPE_VALUES (enumtype) = values; 5949 } 5950 5951 /* Record the min/max values so that we can warn about bit-field 5952 enumerations that are too small for the values. */ 5953 lt = GGC_CNEW (struct lang_type); 5954 lt->enum_min = minnode; 5955 lt->enum_max = maxnode; 5956 TYPE_LANG_SPECIFIC (enumtype) = lt; 5957 5958 /* Fix up all variant types of this enum type. */ 5959 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 5960 { 5961 if (tem == enumtype) 5962 continue; 5963 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 5964 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 5965 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 5966 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 5967 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 5968 TYPE_MODE (tem) = TYPE_MODE (enumtype); 5969 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 5970 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 5971 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 5972 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 5973 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 5974 } 5975 5976 /* Finish debugging output for this type. */ 5977 rest_of_type_compilation (enumtype, toplevel); 5978 5979 return enumtype; 5980} 5981 5982/* Build and install a CONST_DECL for one value of the 5983 current enumeration type (one that was begun with start_enum). 5984 Return a tree-list containing the CONST_DECL and its value. 5985 Assignment of sequential values by default is handled here. */ 5986 5987tree 5988build_enumerator (tree name, tree value) 5989{ 5990 tree decl, type; 5991 5992 /* Validate and default VALUE. */ 5993 5994 if (value != 0) 5995 { 5996 /* Don't issue more errors for error_mark_node (i.e. an 5997 undeclared identifier) - just ignore the value expression. */ 5998 if (value == error_mark_node) 5999 value = 0; 6000 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value)) 6001 || TREE_CODE (value) != INTEGER_CST) 6002 { 6003 error ("enumerator value for %qE is not an integer constant", name); 6004 value = 0; 6005 } 6006 else 6007 { 6008 value = default_conversion (value); 6009 constant_expression_warning (value); 6010 } 6011 } 6012 6013 /* Default based on previous value. */ 6014 /* It should no longer be possible to have NON_LVALUE_EXPR 6015 in the default. */ 6016 if (value == 0) 6017 { 6018 value = enum_next_value; 6019 if (enum_overflow) 6020 error ("overflow in enumeration values"); 6021 } 6022 6023 if (pedantic && !int_fits_type_p (value, integer_type_node)) 6024 { 6025 pedwarn ("ISO C restricts enumerator values to range of %<int%>"); 6026 /* XXX This causes -pedantic to change the meaning of the program. 6027 Remove? -zw 2004-03-15 */ 6028 value = convert (integer_type_node, value); 6029 } 6030 6031 /* Set basis for default for next value. */ 6032 enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0); 6033 enum_overflow = tree_int_cst_lt (enum_next_value, value); 6034 6035 /* Now create a declaration for the enum value name. */ 6036 6037 type = TREE_TYPE (value); 6038 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 6039 TYPE_PRECISION (integer_type_node)), 6040 (TYPE_PRECISION (type) 6041 >= TYPE_PRECISION (integer_type_node) 6042 && TYPE_UNSIGNED (type))); 6043 6044 decl = build_decl (CONST_DECL, name, type); 6045 DECL_INITIAL (decl) = convert (type, value); 6046 pushdecl (decl); 6047 6048 return tree_cons (decl, value, NULL_TREE); 6049} 6050 6051 6052/* Create the FUNCTION_DECL for a function definition. 6053 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 6054 the declaration; they describe the function's name and the type it returns, 6055 but twisted together in a fashion that parallels the syntax of C. 6056 6057 This function creates a binding context for the function body 6058 as well as setting up the FUNCTION_DECL in current_function_decl. 6059 6060 Returns 1 on success. If the DECLARATOR is not suitable for a function 6061 (it defines a datum instead), we return 0, which tells 6062 yyparse to report a parse error. */ 6063 6064int 6065start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 6066 tree attributes) 6067{ 6068 tree decl1, old_decl; 6069 tree restype, resdecl; 6070 struct c_label_context_se *nstack_se; 6071 struct c_label_context_vm *nstack_vm; 6072 6073 current_function_returns_value = 0; /* Assume, until we see it does. */ 6074 current_function_returns_null = 0; 6075 current_function_returns_abnormally = 0; 6076 warn_about_return_type = 0; 6077 c_switch_stack = NULL; 6078 6079 nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se); 6080 nstack_se->labels_def = NULL; 6081 nstack_se->labels_used = NULL; 6082 nstack_se->next = label_context_stack_se; 6083 label_context_stack_se = nstack_se; 6084 6085 nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm); 6086 nstack_vm->labels_def = NULL; 6087 nstack_vm->labels_used = NULL; 6088 nstack_vm->scope = 0; 6089 nstack_vm->next = label_context_stack_vm; 6090 label_context_stack_vm = nstack_vm; 6091 6092 /* Indicate no valid break/continue context by setting these variables 6093 to some non-null, non-label value. We'll notice and emit the proper 6094 error message in c_finish_bc_stmt. */ 6095 c_break_label = c_cont_label = size_zero_node; 6096 6097 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL); 6098 6099 /* If the declarator is not suitable for a function definition, 6100 cause a syntax error. */ 6101 if (decl1 == 0) 6102 { 6103 label_context_stack_se = label_context_stack_se->next; 6104 label_context_stack_vm = label_context_stack_vm->next; 6105 return 0; 6106 } 6107 6108 decl_attributes (&decl1, attributes, 0); 6109 6110 if (DECL_DECLARED_INLINE_P (decl1) 6111 && DECL_UNINLINABLE (decl1) 6112 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 6113 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 6114 decl1); 6115 6116 /* Handle gnu_inline attribute. */ 6117 if (declspecs->inline_p 6118 && !flag_gnu89_inline 6119 && TREE_CODE (decl1) == FUNCTION_DECL 6120 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1))) 6121 { 6122 if (declspecs->storage_class != csc_static) 6123 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 6124 } 6125 6126 announce_function (decl1); 6127 6128 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 6129 { 6130 error ("return type is an incomplete type"); 6131 /* Make it return void instead. */ 6132 TREE_TYPE (decl1) 6133 = build_function_type (void_type_node, 6134 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 6135 } 6136 6137 if (warn_about_return_type) 6138 pedwarn_c99 ("return type defaults to %<int%>"); 6139 6140 /* Make the init_value nonzero so pushdecl knows this is not tentative. 6141 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 6142 DECL_INITIAL (decl1) = error_mark_node; 6143 6144 /* If this definition isn't a prototype and we had a prototype declaration 6145 before, copy the arg type info from that prototype. */ 6146 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 6147 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 6148 old_decl = 0; 6149 current_function_prototype_locus = UNKNOWN_LOCATION; 6150 current_function_prototype_built_in = false; 6151 current_function_prototype_arg_types = NULL_TREE; 6152 if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0) 6153 { 6154 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 6155 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6156 TREE_TYPE (TREE_TYPE (old_decl)))) 6157 { 6158 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 6159 TREE_TYPE (decl1)); 6160 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 6161 current_function_prototype_built_in 6162 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 6163 current_function_prototype_arg_types 6164 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 6165 } 6166 if (TREE_PUBLIC (decl1)) 6167 { 6168 /* If there is an external prototype declaration of this 6169 function, record its location but do not copy information 6170 to this decl. This may be an invisible declaration 6171 (built-in or in a scope which has finished) or simply 6172 have more refined argument types than any declaration 6173 found above. */ 6174 struct c_binding *b; 6175 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 6176 if (B_IN_SCOPE (b, external_scope)) 6177 break; 6178 if (b) 6179 { 6180 tree ext_decl, ext_type; 6181 ext_decl = b->decl; 6182 ext_type = b->type ? b->type : TREE_TYPE (ext_decl); 6183 if (TREE_CODE (ext_type) == FUNCTION_TYPE 6184 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6185 TREE_TYPE (ext_type))) 6186 { 6187 current_function_prototype_locus 6188 = DECL_SOURCE_LOCATION (ext_decl); 6189 current_function_prototype_built_in 6190 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 6191 current_function_prototype_arg_types 6192 = TYPE_ARG_TYPES (ext_type); 6193 } 6194 } 6195 } 6196 } 6197 6198 /* Optionally warn of old-fashioned def with no previous prototype. */ 6199 if (warn_strict_prototypes 6200 && old_decl != error_mark_node 6201 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0 6202 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6203 warning (OPT_Wstrict_prototypes, 6204 "function declaration isn%'t a prototype"); 6205 /* Optionally warn of any global def with no previous prototype. */ 6206 else if (warn_missing_prototypes 6207 && old_decl != error_mark_node 6208 && TREE_PUBLIC (decl1) 6209 && !MAIN_NAME_P (DECL_NAME (decl1)) 6210 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6211 warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1); 6212 /* Optionally warn of any def with no previous prototype 6213 if the function has already been used. */ 6214 else if (warn_missing_prototypes 6215 && old_decl != 0 6216 && old_decl != error_mark_node 6217 && TREE_USED (old_decl) 6218 && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0) 6219 warning (OPT_Wmissing_prototypes, 6220 "%q+D was used with no prototype before its definition", decl1); 6221 /* Optionally warn of any global def with no previous declaration. */ 6222 else if (warn_missing_declarations 6223 && TREE_PUBLIC (decl1) 6224 && old_decl == 0 6225 && !MAIN_NAME_P (DECL_NAME (decl1))) 6226 warning (OPT_Wmissing_declarations, "no previous declaration for %q+D", 6227 decl1); 6228 /* Optionally warn of any def with no previous declaration 6229 if the function has already been used. */ 6230 else if (warn_missing_declarations 6231 && old_decl != 0 6232 && old_decl != error_mark_node 6233 && TREE_USED (old_decl) 6234 && C_DECL_IMPLICIT (old_decl)) 6235 warning (OPT_Wmissing_declarations, 6236 "%q+D was used with no declaration before its definition", decl1); 6237 6238 /* This function exists in static storage. 6239 (This does not mean `static' in the C sense!) */ 6240 TREE_STATIC (decl1) = 1; 6241 6242 /* A nested function is not global. */ 6243 if (current_function_decl != 0) 6244 TREE_PUBLIC (decl1) = 0; 6245 6246 /* This is the earliest point at which we might know the assembler 6247 name of the function. Thus, if it's set before this, die horribly. */ 6248 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 6249 6250 /* If #pragma weak was used, mark the decl weak now. */ 6251 if (current_scope == file_scope) 6252 maybe_apply_pragma_weak (decl1); 6253 6254 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 6255 if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1))) 6256 { 6257 tree args; 6258 int argct = 0; 6259 6260 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 6261 != integer_type_node) 6262 pedwarn ("return type of %q+D is not %<int%>", decl1); 6263 6264 for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args; 6265 args = TREE_CHAIN (args)) 6266 { 6267 tree type = args ? TREE_VALUE (args) : 0; 6268 6269 if (type == void_type_node) 6270 break; 6271 6272 ++argct; 6273 switch (argct) 6274 { 6275 case 1: 6276 if (TYPE_MAIN_VARIANT (type) != integer_type_node) 6277 pedwarn ("first argument of %q+D should be %<int%>", decl1); 6278 break; 6279 6280 case 2: 6281 if (TREE_CODE (type) != POINTER_TYPE 6282 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6283 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6284 != char_type_node)) 6285 pedwarn ("second argument of %q+D should be %<char **%>", 6286 decl1); 6287 break; 6288 6289 case 3: 6290 if (TREE_CODE (type) != POINTER_TYPE 6291 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6292 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6293 != char_type_node)) 6294 pedwarn ("third argument of %q+D should probably be " 6295 "%<char **%>", decl1); 6296 break; 6297 } 6298 } 6299 6300 /* It is intentional that this message does not mention the third 6301 argument because it's only mentioned in an appendix of the 6302 standard. */ 6303 if (argct > 0 && (argct < 2 || argct > 3)) 6304 pedwarn ("%q+D takes only zero or two arguments", decl1); 6305 6306 if (!TREE_PUBLIC (decl1)) 6307 pedwarn ("%q+D is normally a non-static function", decl1); 6308 } 6309 6310 /* Record the decl so that the function name is defined. 6311 If we already have a decl for this name, and it is a FUNCTION_DECL, 6312 use the old decl. */ 6313 6314 current_function_decl = pushdecl (decl1); 6315 6316 push_scope (); 6317 declare_parm_level (); 6318 6319 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6320 /* Promote the value to int before returning it. */ 6321 if (c_promoting_integer_type_p (restype)) 6322 { 6323 /* It retains unsignedness if not really getting wider. */ 6324 if (TYPE_UNSIGNED (restype) 6325 && (TYPE_PRECISION (restype) 6326 == TYPE_PRECISION (integer_type_node))) 6327 restype = unsigned_type_node; 6328 else 6329 restype = integer_type_node; 6330 } 6331 6332 resdecl = build_decl (RESULT_DECL, NULL_TREE, restype); 6333 DECL_ARTIFICIAL (resdecl) = 1; 6334 DECL_IGNORED_P (resdecl) = 1; 6335 DECL_RESULT (current_function_decl) = resdecl; 6336 6337 start_fname_decls (); 6338 6339 return 1; 6340} 6341 6342/* Subroutine of store_parm_decls which handles new-style function 6343 definitions (prototype format). The parms already have decls, so we 6344 need only record them as in effect and complain if any redundant 6345 old-style parm decls were written. */ 6346static void 6347store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 6348{ 6349 tree decl; 6350 6351 if (current_scope->bindings) 6352 { 6353 error ("%Jold-style parameter declarations in prototyped " 6354 "function definition", fndecl); 6355 6356 /* Get rid of the old-style declarations. */ 6357 pop_scope (); 6358 push_scope (); 6359 } 6360 /* Don't issue this warning for nested functions, and don't issue this 6361 warning if we got here because ARG_INFO_TYPES was error_mark_node 6362 (this happens when a function definition has just an ellipsis in 6363 its parameter list). */ 6364 else if (!in_system_header && !current_function_scope 6365 && arg_info->types != error_mark_node) 6366 warning (OPT_Wtraditional, 6367 "%Jtraditional C rejects ISO C style function definitions", 6368 fndecl); 6369 6370 /* Now make all the parameter declarations visible in the function body. 6371 We can bypass most of the grunt work of pushdecl. */ 6372 for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl)) 6373 { 6374 DECL_CONTEXT (decl) = current_function_decl; 6375 if (DECL_NAME (decl)) 6376 { 6377 bind (DECL_NAME (decl), decl, current_scope, 6378 /*invisible=*/false, /*nested=*/false); 6379 if (!TREE_USED (decl)) 6380 warn_if_shadowing (decl); 6381 } 6382 else 6383 error ("%Jparameter name omitted", decl); 6384 } 6385 6386 /* Record the parameter list in the function declaration. */ 6387 DECL_ARGUMENTS (fndecl) = arg_info->parms; 6388 6389 /* Now make all the ancillary declarations visible, likewise. */ 6390 for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl)) 6391 { 6392 DECL_CONTEXT (decl) = current_function_decl; 6393 if (DECL_NAME (decl)) 6394 bind (DECL_NAME (decl), decl, current_scope, 6395 /*invisible=*/false, /*nested=*/false); 6396 } 6397 6398 /* And all the tag declarations. */ 6399 for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl)) 6400 if (TREE_PURPOSE (decl)) 6401 bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope, 6402 /*invisible=*/false, /*nested=*/false); 6403} 6404 6405/* Subroutine of store_parm_decls which handles old-style function 6406 definitions (separate parameter list and declarations). */ 6407 6408static void 6409store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 6410{ 6411 struct c_binding *b; 6412 tree parm, decl, last; 6413 tree parmids = arg_info->parms; 6414 struct pointer_set_t *seen_args = pointer_set_create (); 6415 6416 if (!in_system_header) 6417 warning (OPT_Wold_style_definition, "%Jold-style function definition", 6418 fndecl); 6419 6420 /* Match each formal parameter name with its declaration. Save each 6421 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 6422 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6423 { 6424 if (TREE_VALUE (parm) == 0) 6425 { 6426 error ("%Jparameter name missing from parameter list", fndecl); 6427 TREE_PURPOSE (parm) = 0; 6428 continue; 6429 } 6430 6431 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 6432 if (b && B_IN_CURRENT_SCOPE (b)) 6433 { 6434 decl = b->decl; 6435 /* If we got something other than a PARM_DECL it is an error. */ 6436 if (TREE_CODE (decl) != PARM_DECL) 6437 error ("%q+D declared as a non-parameter", decl); 6438 /* If the declaration is already marked, we have a duplicate 6439 name. Complain and ignore the duplicate. */ 6440 else if (pointer_set_contains (seen_args, decl)) 6441 { 6442 error ("multiple parameters named %q+D", decl); 6443 TREE_PURPOSE (parm) = 0; 6444 continue; 6445 } 6446 /* If the declaration says "void", complain and turn it into 6447 an int. */ 6448 else if (VOID_TYPE_P (TREE_TYPE (decl))) 6449 { 6450 error ("parameter %q+D declared with void type", decl); 6451 TREE_TYPE (decl) = integer_type_node; 6452 DECL_ARG_TYPE (decl) = integer_type_node; 6453 layout_decl (decl, 0); 6454 } 6455 warn_if_shadowing (decl); 6456 } 6457 /* If no declaration found, default to int. */ 6458 else 6459 { 6460 decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node); 6461 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 6462 DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl); 6463 pushdecl (decl); 6464 warn_if_shadowing (decl); 6465 6466 if (flag_isoc99) 6467 pedwarn ("type of %q+D defaults to %<int%>", decl); 6468 else if (extra_warnings) 6469 warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl); 6470 } 6471 6472 TREE_PURPOSE (parm) = decl; 6473 pointer_set_insert (seen_args, decl); 6474 } 6475 6476 /* Now examine the parms chain for incomplete declarations 6477 and declarations with no corresponding names. */ 6478 6479 for (b = current_scope->bindings; b; b = b->prev) 6480 { 6481 parm = b->decl; 6482 if (TREE_CODE (parm) != PARM_DECL) 6483 continue; 6484 6485 if (TREE_TYPE (parm) != error_mark_node 6486 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 6487 { 6488 error ("parameter %q+D has incomplete type", parm); 6489 TREE_TYPE (parm) = error_mark_node; 6490 } 6491 6492 if (!pointer_set_contains (seen_args, parm)) 6493 { 6494 error ("declaration for parameter %q+D but no such parameter", parm); 6495 6496 /* Pretend the parameter was not missing. 6497 This gets us to a standard state and minimizes 6498 further error messages. */ 6499 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 6500 } 6501 } 6502 6503 /* Chain the declarations together in the order of the list of 6504 names. Store that chain in the function decl, replacing the 6505 list of names. Update the current scope to match. */ 6506 DECL_ARGUMENTS (fndecl) = 0; 6507 6508 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6509 if (TREE_PURPOSE (parm)) 6510 break; 6511 if (parm && TREE_PURPOSE (parm)) 6512 { 6513 last = TREE_PURPOSE (parm); 6514 DECL_ARGUMENTS (fndecl) = last; 6515 6516 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 6517 if (TREE_PURPOSE (parm)) 6518 { 6519 TREE_CHAIN (last) = TREE_PURPOSE (parm); 6520 last = TREE_PURPOSE (parm); 6521 } 6522 TREE_CHAIN (last) = 0; 6523 } 6524 6525 pointer_set_destroy (seen_args); 6526 6527 /* If there was a previous prototype, 6528 set the DECL_ARG_TYPE of each argument according to 6529 the type previously specified, and report any mismatches. */ 6530 6531 if (current_function_prototype_arg_types) 6532 { 6533 tree type; 6534 for (parm = DECL_ARGUMENTS (fndecl), 6535 type = current_function_prototype_arg_types; 6536 parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) 6537 != void_type_node)); 6538 parm = TREE_CHAIN (parm), type = TREE_CHAIN (type)) 6539 { 6540 if (parm == 0 || type == 0 6541 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 6542 { 6543 if (current_function_prototype_built_in) 6544 warning (0, "number of arguments doesn%'t match " 6545 "built-in prototype"); 6546 else 6547 { 6548 error ("number of arguments doesn%'t match prototype"); 6549 error ("%Hprototype declaration", 6550 ¤t_function_prototype_locus); 6551 } 6552 break; 6553 } 6554 /* Type for passing arg must be consistent with that 6555 declared for the arg. ISO C says we take the unqualified 6556 type for parameters declared with qualified type. */ 6557 if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 6558 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 6559 { 6560 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 6561 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 6562 { 6563 /* Adjust argument to match prototype. E.g. a previous 6564 `int foo(float);' prototype causes 6565 `int foo(x) float x; {...}' to be treated like 6566 `int foo(float x) {...}'. This is particularly 6567 useful for argument types like uid_t. */ 6568 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 6569 6570 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 6571 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 6572 && TYPE_PRECISION (TREE_TYPE (parm)) 6573 < TYPE_PRECISION (integer_type_node)) 6574 DECL_ARG_TYPE (parm) = integer_type_node; 6575 6576 if (pedantic) 6577 { 6578 /* ??? Is it possible to get here with a 6579 built-in prototype or will it always have 6580 been diagnosed as conflicting with an 6581 old-style definition and discarded? */ 6582 if (current_function_prototype_built_in) 6583 warning (0, "promoted argument %qD " 6584 "doesn%'t match built-in prototype", parm); 6585 else 6586 { 6587 pedwarn ("promoted argument %qD " 6588 "doesn%'t match prototype", parm); 6589 pedwarn ("%Hprototype declaration", 6590 ¤t_function_prototype_locus); 6591 } 6592 } 6593 } 6594 else 6595 { 6596 if (current_function_prototype_built_in) 6597 warning (0, "argument %qD doesn%'t match " 6598 "built-in prototype", parm); 6599 else 6600 { 6601 error ("argument %qD doesn%'t match prototype", parm); 6602 error ("%Hprototype declaration", 6603 ¤t_function_prototype_locus); 6604 } 6605 } 6606 } 6607 } 6608 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 6609 } 6610 6611 /* Otherwise, create a prototype that would match. */ 6612 6613 else 6614 { 6615 tree actual = 0, last = 0, type; 6616 6617 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm)) 6618 { 6619 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 6620 if (last) 6621 TREE_CHAIN (last) = type; 6622 else 6623 actual = type; 6624 last = type; 6625 } 6626 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 6627 if (last) 6628 TREE_CHAIN (last) = type; 6629 else 6630 actual = type; 6631 6632 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 6633 of the type of this function, but we need to avoid having this 6634 affect the types of other similarly-typed functions, so we must 6635 first force the generation of an identical (but separate) type 6636 node for the relevant function type. The new node we create 6637 will be a variant of the main variant of the original function 6638 type. */ 6639 6640 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 6641 6642 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 6643 } 6644} 6645 6646/* Store parameter declarations passed in ARG_INFO into the current 6647 function declaration. */ 6648 6649void 6650store_parm_decls_from (struct c_arg_info *arg_info) 6651{ 6652 current_function_arg_info = arg_info; 6653 store_parm_decls (); 6654} 6655 6656/* Store the parameter declarations into the current function declaration. 6657 This is called after parsing the parameter declarations, before 6658 digesting the body of the function. 6659 6660 For an old-style definition, construct a prototype out of the old-style 6661 parameter declarations and inject it into the function's type. */ 6662 6663void 6664store_parm_decls (void) 6665{ 6666 tree fndecl = current_function_decl; 6667 bool proto; 6668 6669 /* The argument information block for FNDECL. */ 6670 struct c_arg_info *arg_info = current_function_arg_info; 6671 current_function_arg_info = 0; 6672 6673 /* True if this definition is written with a prototype. Note: 6674 despite C99 6.7.5.3p14, we can *not* treat an empty argument 6675 list in a function definition as equivalent to (void) -- an 6676 empty argument list specifies the function has no parameters, 6677 but only (void) sets up a prototype for future calls. */ 6678 proto = arg_info->types != 0; 6679 6680 if (proto) 6681 store_parm_decls_newstyle (fndecl, arg_info); 6682 else 6683 store_parm_decls_oldstyle (fndecl, arg_info); 6684 6685 /* The next call to push_scope will be a function body. */ 6686 6687 next_is_function_body = true; 6688 6689 /* Write a record describing this function definition to the prototypes 6690 file (if requested). */ 6691 6692 gen_aux_info_record (fndecl, 1, 0, proto); 6693 6694 /* Initialize the RTL code for the function. */ 6695 allocate_struct_function (fndecl); 6696 6697 /* Begin the statement tree for this function. */ 6698 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 6699 6700 /* ??? Insert the contents of the pending sizes list into the function 6701 to be evaluated. The only reason left to have this is 6702 void foo(int n, int array[n++]) 6703 because we throw away the array type in favor of a pointer type, and 6704 thus won't naturally see the SAVE_EXPR containing the increment. All 6705 other pending sizes would be handled by gimplify_parameters. */ 6706 { 6707 tree t; 6708 for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t)) 6709 add_stmt (TREE_VALUE (t)); 6710 } 6711 6712 /* Even though we're inside a function body, we still don't want to 6713 call expand_expr to calculate the size of a variable-sized array. 6714 We haven't necessarily assigned RTL to all variables yet, so it's 6715 not safe to try to expand expressions involving them. */ 6716 cfun->x_dont_save_pending_sizes_p = 1; 6717} 6718 6719/* Emit diagnostics that require gimple input for detection. Operate on 6720 FNDECL and all its nested functions. */ 6721 6722static void 6723c_gimple_diagnostics_recursively (tree fndecl) 6724{ 6725 struct cgraph_node *cgn; 6726 6727 /* Handle attribute((warn_unused_result)). Relies on gimple input. */ 6728 c_warn_unused_result (&DECL_SAVED_TREE (fndecl)); 6729 6730 /* Notice when OpenMP structured block constraints are violated. */ 6731 if (flag_openmp) 6732 diagnose_omp_structured_block_errors (fndecl); 6733 6734 /* Finalize all nested functions now. */ 6735 cgn = cgraph_node (fndecl); 6736 for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) 6737 c_gimple_diagnostics_recursively (cgn->decl); 6738} 6739 6740/* Finish up a function declaration and compile that function 6741 all the way to assembler language output. The free the storage 6742 for the function definition. 6743 6744 This is called after parsing the body of the function definition. */ 6745 6746void 6747finish_function (void) 6748{ 6749 tree fndecl = current_function_decl; 6750 6751 label_context_stack_se = label_context_stack_se->next; 6752 label_context_stack_vm = label_context_stack_vm->next; 6753 6754 if (TREE_CODE (fndecl) == FUNCTION_DECL 6755 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 6756 { 6757 tree args = DECL_ARGUMENTS (fndecl); 6758 for (; args; args = TREE_CHAIN (args)) 6759 { 6760 tree type = TREE_TYPE (args); 6761 if (INTEGRAL_TYPE_P (type) 6762 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 6763 DECL_ARG_TYPE (args) = integer_type_node; 6764 } 6765 } 6766 6767 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6768 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 6769 6770 /* Must mark the RESULT_DECL as being in this function. */ 6771 6772 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 6773 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 6774 6775 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted) 6776 { 6777 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 6778 != integer_type_node) 6779 { 6780 /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned. 6781 If warn_main is -1 (-Wno-main) we don't want to be warned. */ 6782 if (!warn_main) 6783 pedwarn ("return type of %q+D is not %<int%>", fndecl); 6784 } 6785 else 6786 { 6787 if (flag_isoc99) 6788 { 6789 tree stmt = c_finish_return (integer_zero_node); 6790#ifdef USE_MAPPED_LOCATION 6791 /* Hack. We don't want the middle-end to warn that this return 6792 is unreachable, so we mark its location as special. Using 6793 UNKNOWN_LOCATION has the problem that it gets clobbered in 6794 annotate_one_with_locus. A cleaner solution might be to 6795 ensure ! should_carry_locus_p (stmt), but that needs a flag. 6796 */ 6797 SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION); 6798#else 6799 /* Hack. We don't want the middle-end to warn that this 6800 return is unreachable, so put the statement on the 6801 special line 0. */ 6802 annotate_with_file_line (stmt, input_filename, 0); 6803#endif 6804 } 6805 } 6806 } 6807 6808 /* Tie off the statement tree for this function. */ 6809 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 6810 6811 finish_fname_decls (); 6812 6813 /* Complain if there's just no return statement. */ 6814 if (warn_return_type 6815 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 6816 && !current_function_returns_value && !current_function_returns_null 6817 /* Don't complain if we are no-return. */ 6818 && !current_function_returns_abnormally 6819 /* Don't warn for main(). */ 6820 && !MAIN_NAME_P (DECL_NAME (fndecl)) 6821 /* Or if they didn't actually specify a return type. */ 6822 && !C_FUNCTION_IMPLICIT_INT (fndecl) 6823 /* Normally, with -Wreturn-type, flow will complain. Unless we're an 6824 inline function, as we might never be compiled separately. */ 6825 && DECL_INLINE (fndecl)) 6826 { 6827 warning (OPT_Wreturn_type, 6828 "no return statement in function returning non-void"); 6829 TREE_NO_WARNING (fndecl) = 1; 6830 } 6831 6832 /* With just -Wextra, complain only if function returns both with 6833 and without a value. */ 6834 if (extra_warnings 6835 && current_function_returns_value 6836 && current_function_returns_null) 6837 warning (OPT_Wextra, "this function may return with or without a value"); 6838 6839 /* Store the end of the function, so that we get good line number 6840 info for the epilogue. */ 6841 cfun->function_end_locus = input_location; 6842 6843 /* If we don't have ctors/dtors sections, and this is a static 6844 constructor or destructor, it must be recorded now. */ 6845 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6846 && !targetm.have_ctors_dtors) 6847 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors); 6848 if (DECL_STATIC_DESTRUCTOR (fndecl) 6849 && !targetm.have_ctors_dtors) 6850 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors); 6851 6852 /* Finalize the ELF visibility for the function. */ 6853 c_determine_visibility (fndecl); 6854 6855 /* Genericize before inlining. Delay genericizing nested functions 6856 until their parent function is genericized. Since finalizing 6857 requires GENERIC, delay that as well. */ 6858 6859 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 6860 && !undef_nested_function) 6861 { 6862 if (!decl_function_context (fndecl)) 6863 { 6864 c_genericize (fndecl); 6865 c_gimple_diagnostics_recursively (fndecl); 6866 6867 /* ??? Objc emits functions after finalizing the compilation unit. 6868 This should be cleaned up later and this conditional removed. */ 6869 if (cgraph_global_info_ready) 6870 { 6871 c_expand_body (fndecl); 6872 return; 6873 } 6874 6875 cgraph_finalize_function (fndecl, false); 6876 } 6877 else 6878 { 6879 /* Register this function with cgraph just far enough to get it 6880 added to our parent's nested function list. Handy, since the 6881 C front end doesn't have such a list. */ 6882 (void) cgraph_node (fndecl); 6883 } 6884 } 6885 6886 if (!decl_function_context (fndecl)) 6887 undef_nested_function = false; 6888 6889 /* We're leaving the context of this function, so zap cfun. 6890 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 6891 tree_rest_of_compilation. */ 6892 cfun = NULL; 6893 current_function_decl = NULL; 6894} 6895 6896/* Generate the RTL for the body of FNDECL. */ 6897 6898void 6899c_expand_body (tree fndecl) 6900{ 6901 6902 if (!DECL_INITIAL (fndecl) 6903 || DECL_INITIAL (fndecl) == error_mark_node) 6904 return; 6905 6906 tree_rest_of_compilation (fndecl); 6907 6908 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6909 && targetm.have_ctors_dtors) 6910 targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0), 6911 DEFAULT_INIT_PRIORITY); 6912 if (DECL_STATIC_DESTRUCTOR (fndecl) 6913 && targetm.have_ctors_dtors) 6914 targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0), 6915 DEFAULT_INIT_PRIORITY); 6916} 6917 6918/* Check the declarations given in a for-loop for satisfying the C99 6919 constraints. If exactly one such decl is found, return it. */ 6920 6921tree 6922check_for_loop_decls (void) 6923{ 6924 struct c_binding *b; 6925 tree one_decl = NULL_TREE; 6926 int n_decls = 0; 6927 6928 6929 if (!flag_isoc99) 6930 { 6931 /* If we get here, declarations have been used in a for loop without 6932 the C99 for loop scope. This doesn't make much sense, so don't 6933 allow it. */ 6934 error ("%<for%> loop initial declaration used outside C99 mode"); 6935 return NULL_TREE; 6936 } 6937 /* C99 subclause 6.8.5 paragraph 3: 6938 6939 [#3] The declaration part of a for statement shall only 6940 declare identifiers for objects having storage class auto or 6941 register. 6942 6943 It isn't clear whether, in this sentence, "identifiers" binds to 6944 "shall only declare" or to "objects" - that is, whether all identifiers 6945 declared must be identifiers for objects, or whether the restriction 6946 only applies to those that are. (A question on this in comp.std.c 6947 in November 2000 received no answer.) We implement the strictest 6948 interpretation, to avoid creating an extension which later causes 6949 problems. */ 6950 6951 for (b = current_scope->bindings; b; b = b->prev) 6952 { 6953 tree id = b->id; 6954 tree decl = b->decl; 6955 6956 if (!id) 6957 continue; 6958 6959 switch (TREE_CODE (decl)) 6960 { 6961 case VAR_DECL: 6962 if (TREE_STATIC (decl)) 6963 error ("declaration of static variable %q+D in %<for%> loop " 6964 "initial declaration", decl); 6965 else if (DECL_EXTERNAL (decl)) 6966 error ("declaration of %<extern%> variable %q+D in %<for%> loop " 6967 "initial declaration", decl); 6968 break; 6969 6970 case RECORD_TYPE: 6971 error ("%<struct %E%> declared in %<for%> loop initial declaration", 6972 id); 6973 break; 6974 case UNION_TYPE: 6975 error ("%<union %E%> declared in %<for%> loop initial declaration", 6976 id); 6977 break; 6978 case ENUMERAL_TYPE: 6979 error ("%<enum %E%> declared in %<for%> loop initial declaration", 6980 id); 6981 break; 6982 default: 6983 error ("declaration of non-variable %q+D in %<for%> loop " 6984 "initial declaration", decl); 6985 } 6986 6987 n_decls++; 6988 one_decl = decl; 6989 } 6990 6991 return n_decls == 1 ? one_decl : NULL_TREE; 6992} 6993 6994/* Save and reinitialize the variables 6995 used during compilation of a C function. */ 6996 6997void 6998c_push_function_context (struct function *f) 6999{ 7000 struct language_function *p; 7001 p = GGC_NEW (struct language_function); 7002 f->language = p; 7003 7004 p->base.x_stmt_tree = c_stmt_tree; 7005 p->x_break_label = c_break_label; 7006 p->x_cont_label = c_cont_label; 7007 p->x_switch_stack = c_switch_stack; 7008 p->arg_info = current_function_arg_info; 7009 p->returns_value = current_function_returns_value; 7010 p->returns_null = current_function_returns_null; 7011 p->returns_abnormally = current_function_returns_abnormally; 7012 p->warn_about_return_type = warn_about_return_type; 7013} 7014 7015/* Restore the variables used during compilation of a C function. */ 7016 7017void 7018c_pop_function_context (struct function *f) 7019{ 7020 struct language_function *p = f->language; 7021 7022 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 7023 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 7024 { 7025 /* Stop pointing to the local nodes about to be freed. */ 7026 /* But DECL_INITIAL must remain nonzero so we know this 7027 was an actual function definition. */ 7028 DECL_INITIAL (current_function_decl) = error_mark_node; 7029 DECL_ARGUMENTS (current_function_decl) = 0; 7030 } 7031 7032 c_stmt_tree = p->base.x_stmt_tree; 7033 c_break_label = p->x_break_label; 7034 c_cont_label = p->x_cont_label; 7035 c_switch_stack = p->x_switch_stack; 7036 current_function_arg_info = p->arg_info; 7037 current_function_returns_value = p->returns_value; 7038 current_function_returns_null = p->returns_null; 7039 current_function_returns_abnormally = p->returns_abnormally; 7040 warn_about_return_type = p->warn_about_return_type; 7041 7042 f->language = NULL; 7043} 7044 7045/* Copy the DECL_LANG_SPECIFIC data associated with DECL. */ 7046 7047void 7048c_dup_lang_specific_decl (tree decl) 7049{ 7050 struct lang_decl *ld; 7051 7052 if (!DECL_LANG_SPECIFIC (decl)) 7053 return; 7054 7055 ld = GGC_NEW (struct lang_decl); 7056 memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl)); 7057 DECL_LANG_SPECIFIC (decl) = ld; 7058} 7059 7060/* The functions below are required for functionality of doing 7061 function at once processing in the C front end. Currently these 7062 functions are not called from anywhere in the C front end, but as 7063 these changes continue, that will change. */ 7064 7065/* Returns the stmt_tree (if any) to which statements are currently 7066 being added. If there is no active statement-tree, NULL is 7067 returned. */ 7068 7069stmt_tree 7070current_stmt_tree (void) 7071{ 7072 return &c_stmt_tree; 7073} 7074 7075/* Nonzero if TYPE is an anonymous union or struct type. Always 0 in 7076 C. */ 7077 7078int 7079anon_aggr_type_p (tree ARG_UNUSED (node)) 7080{ 7081 return 0; 7082} 7083 7084/* Return the global value of T as a symbol. */ 7085 7086tree 7087identifier_global_value (tree t) 7088{ 7089 struct c_binding *b; 7090 7091 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 7092 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 7093 return b->decl; 7094 7095 return 0; 7096} 7097 7098/* Record a builtin type for C. If NAME is non-NULL, it is the name used; 7099 otherwise the name is found in ridpointers from RID_INDEX. */ 7100 7101void 7102record_builtin_type (enum rid rid_index, const char *name, tree type) 7103{ 7104 tree id, decl; 7105 if (name == 0) 7106 id = ridpointers[(int) rid_index]; 7107 else 7108 id = get_identifier (name); 7109 decl = build_decl (TYPE_DECL, id, type); 7110 pushdecl (decl); 7111 if (debug_hooks->type_decl) 7112 debug_hooks->type_decl (decl, false); 7113} 7114 7115/* Build the void_list_node (void_type_node having been created). */ 7116tree 7117build_void_list_node (void) 7118{ 7119 tree t = build_tree_list (NULL_TREE, void_type_node); 7120 return t; 7121} 7122 7123/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 7124 7125struct c_parm * 7126build_c_parm (struct c_declspecs *specs, tree attrs, 7127 struct c_declarator *declarator) 7128{ 7129 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 7130 ret->specs = specs; 7131 ret->attrs = attrs; 7132 ret->declarator = declarator; 7133 return ret; 7134} 7135 7136/* Return a declarator with nested attributes. TARGET is the inner 7137 declarator to which these attributes apply. ATTRS are the 7138 attributes. */ 7139 7140struct c_declarator * 7141build_attrs_declarator (tree attrs, struct c_declarator *target) 7142{ 7143 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7144 ret->kind = cdk_attrs; 7145 ret->declarator = target; 7146 ret->u.attrs = attrs; 7147 return ret; 7148} 7149 7150/* Return a declarator for a function with arguments specified by ARGS 7151 and return type specified by TARGET. */ 7152 7153struct c_declarator * 7154build_function_declarator (struct c_arg_info *args, 7155 struct c_declarator *target) 7156{ 7157 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7158 ret->kind = cdk_function; 7159 ret->declarator = target; 7160 ret->u.arg_info = args; 7161 return ret; 7162} 7163 7164/* Return a declarator for the identifier IDENT (which may be 7165 NULL_TREE for an abstract declarator). */ 7166 7167struct c_declarator * 7168build_id_declarator (tree ident) 7169{ 7170 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7171 ret->kind = cdk_id; 7172 ret->declarator = 0; 7173 ret->u.id = ident; 7174 /* Default value - may get reset to a more precise location. */ 7175 ret->id_loc = input_location; 7176 return ret; 7177} 7178 7179/* Return something to represent absolute declarators containing a *. 7180 TARGET is the absolute declarator that the * contains. 7181 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 7182 to apply to the pointer type. */ 7183 7184struct c_declarator * 7185make_pointer_declarator (struct c_declspecs *type_quals_attrs, 7186 struct c_declarator *target) 7187{ 7188 tree attrs; 7189 int quals = 0; 7190 struct c_declarator *itarget = target; 7191 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7192 if (type_quals_attrs) 7193 { 7194 attrs = type_quals_attrs->attrs; 7195 quals = quals_from_declspecs (type_quals_attrs); 7196 if (attrs != NULL_TREE) 7197 itarget = build_attrs_declarator (attrs, target); 7198 } 7199 ret->kind = cdk_pointer; 7200 ret->declarator = itarget; 7201 ret->u.pointer_quals = quals; 7202 return ret; 7203} 7204 7205/* Return a pointer to a structure for an empty list of declaration 7206 specifiers. */ 7207 7208struct c_declspecs * 7209build_null_declspecs (void) 7210{ 7211 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 7212 ret->type = 0; 7213 ret->decl_attr = 0; 7214 ret->attrs = 0; 7215 ret->typespec_word = cts_none; 7216 ret->storage_class = csc_none; 7217 ret->declspecs_seen_p = false; 7218 ret->type_seen_p = false; 7219 ret->non_sc_seen_p = false; 7220 ret->typedef_p = false; 7221 ret->tag_defined_p = false; 7222 ret->explicit_signed_p = false; 7223 ret->deprecated_p = false; 7224 ret->default_int_p = false; 7225 ret->long_p = false; 7226 ret->long_long_p = false; 7227 ret->short_p = false; 7228 ret->signed_p = false; 7229 ret->unsigned_p = false; 7230 ret->complex_p = false; 7231 ret->inline_p = false; 7232 ret->thread_p = false; 7233 ret->const_p = false; 7234 ret->volatile_p = false; 7235 ret->restrict_p = false; 7236 return ret; 7237} 7238 7239/* Add the type qualifier QUAL to the declaration specifiers SPECS, 7240 returning SPECS. */ 7241 7242struct c_declspecs * 7243declspecs_add_qual (struct c_declspecs *specs, tree qual) 7244{ 7245 enum rid i; 7246 bool dupe = false; 7247 specs->non_sc_seen_p = true; 7248 specs->declspecs_seen_p = true; 7249 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 7250 && C_IS_RESERVED_WORD (qual)); 7251 i = C_RID_CODE (qual); 7252 switch (i) 7253 { 7254 case RID_CONST: 7255 dupe = specs->const_p; 7256 specs->const_p = true; 7257 break; 7258 case RID_VOLATILE: 7259 dupe = specs->volatile_p; 7260 specs->volatile_p = true; 7261 break; 7262 case RID_RESTRICT: 7263 dupe = specs->restrict_p; 7264 specs->restrict_p = true; 7265 break; 7266 default: 7267 gcc_unreachable (); 7268 } 7269 if (dupe && pedantic && !flag_isoc99) 7270 pedwarn ("duplicate %qE", qual); 7271 return specs; 7272} 7273 7274/* Add the type specifier TYPE to the declaration specifiers SPECS, 7275 returning SPECS. */ 7276 7277struct c_declspecs * 7278declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec) 7279{ 7280 tree type = spec.spec; 7281 specs->non_sc_seen_p = true; 7282 specs->declspecs_seen_p = true; 7283 specs->type_seen_p = true; 7284 if (TREE_DEPRECATED (type)) 7285 specs->deprecated_p = true; 7286 7287 /* Handle type specifier keywords. */ 7288 if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type)) 7289 { 7290 enum rid i = C_RID_CODE (type); 7291 if (specs->type) 7292 { 7293 error ("two or more data types in declaration specifiers"); 7294 return specs; 7295 } 7296 if ((int) i <= (int) RID_LAST_MODIFIER) 7297 { 7298 /* "long", "short", "signed", "unsigned" or "_Complex". */ 7299 bool dupe = false; 7300 switch (i) 7301 { 7302 case RID_LONG: 7303 if (specs->long_long_p) 7304 { 7305 error ("%<long long long%> is too long for GCC"); 7306 break; 7307 } 7308 if (specs->long_p) 7309 { 7310 if (specs->typespec_word == cts_double) 7311 { 7312 error ("both %<long long%> and %<double%> in " 7313 "declaration specifiers"); 7314 break; 7315 } 7316 if (pedantic && !flag_isoc99 && !in_system_header 7317 && warn_long_long) 7318 pedwarn ("ISO C90 does not support %<long long%>"); 7319 specs->long_long_p = 1; 7320 break; 7321 } 7322 if (specs->short_p) 7323 error ("both %<long%> and %<short%> in " 7324 "declaration specifiers"); 7325 else if (specs->typespec_word == cts_void) 7326 error ("both %<long%> and %<void%> in " 7327 "declaration specifiers"); 7328 else if (specs->typespec_word == cts_bool) 7329 error ("both %<long%> and %<_Bool%> in " 7330 "declaration specifiers"); 7331 else if (specs->typespec_word == cts_char) 7332 error ("both %<long%> and %<char%> in " 7333 "declaration specifiers"); 7334 else if (specs->typespec_word == cts_float) 7335 error ("both %<long%> and %<float%> in " 7336 "declaration specifiers"); 7337 else if (specs->typespec_word == cts_dfloat32) 7338 error ("both %<long%> and %<_Decimal32%> in " 7339 "declaration specifiers"); 7340 else if (specs->typespec_word == cts_dfloat64) 7341 error ("both %<long%> and %<_Decimal64%> in " 7342 "declaration specifiers"); 7343 else if (specs->typespec_word == cts_dfloat128) 7344 error ("both %<long%> and %<_Decimal128%> in " 7345 "declaration specifiers"); 7346 else 7347 specs->long_p = true; 7348 break; 7349 case RID_SHORT: 7350 dupe = specs->short_p; 7351 if (specs->long_p) 7352 error ("both %<long%> and %<short%> in " 7353 "declaration specifiers"); 7354 else if (specs->typespec_word == cts_void) 7355 error ("both %<short%> and %<void%> in " 7356 "declaration specifiers"); 7357 else if (specs->typespec_word == cts_bool) 7358 error ("both %<short%> and %<_Bool%> in " 7359 "declaration specifiers"); 7360 else if (specs->typespec_word == cts_char) 7361 error ("both %<short%> and %<char%> in " 7362 "declaration specifiers"); 7363 else if (specs->typespec_word == cts_float) 7364 error ("both %<short%> and %<float%> in " 7365 "declaration specifiers"); 7366 else if (specs->typespec_word == cts_double) 7367 error ("both %<short%> and %<double%> in " 7368 "declaration specifiers"); 7369 else if (specs->typespec_word == cts_dfloat32) 7370 error ("both %<short%> and %<_Decimal32%> in " 7371 "declaration specifiers"); 7372 else if (specs->typespec_word == cts_dfloat64) 7373 error ("both %<short%> and %<_Decimal64%> in " 7374 "declaration specifiers"); 7375 else if (specs->typespec_word == cts_dfloat128) 7376 error ("both %<short%> and %<_Decimal128%> in " 7377 "declaration specifiers"); 7378 else 7379 specs->short_p = true; 7380 break; 7381 case RID_SIGNED: 7382 dupe = specs->signed_p; 7383 if (specs->unsigned_p) 7384 error ("both %<signed%> and %<unsigned%> in " 7385 "declaration specifiers"); 7386 else if (specs->typespec_word == cts_void) 7387 error ("both %<signed%> and %<void%> in " 7388 "declaration specifiers"); 7389 else if (specs->typespec_word == cts_bool) 7390 error ("both %<signed%> and %<_Bool%> in " 7391 "declaration specifiers"); 7392 else if (specs->typespec_word == cts_float) 7393 error ("both %<signed%> and %<float%> in " 7394 "declaration specifiers"); 7395 else if (specs->typespec_word == cts_double) 7396 error ("both %<signed%> and %<double%> in " 7397 "declaration specifiers"); 7398 else if (specs->typespec_word == cts_dfloat32) 7399 error ("both %<signed%> and %<_Decimal32%> in " 7400 "declaration specifiers"); 7401 else if (specs->typespec_word == cts_dfloat64) 7402 error ("both %<signed%> and %<_Decimal64%> in " 7403 "declaration specifiers"); 7404 else if (specs->typespec_word == cts_dfloat128) 7405 error ("both %<signed%> and %<_Decimal128%> in " 7406 "declaration specifiers"); 7407 else 7408 specs->signed_p = true; 7409 break; 7410 case RID_UNSIGNED: 7411 dupe = specs->unsigned_p; 7412 if (specs->signed_p) 7413 error ("both %<signed%> and %<unsigned%> in " 7414 "declaration specifiers"); 7415 else if (specs->typespec_word == cts_void) 7416 error ("both %<unsigned%> and %<void%> in " 7417 "declaration specifiers"); 7418 else if (specs->typespec_word == cts_bool) 7419 error ("both %<unsigned%> and %<_Bool%> in " 7420 "declaration specifiers"); 7421 else if (specs->typespec_word == cts_float) 7422 error ("both %<unsigned%> and %<float%> in " 7423 "declaration specifiers"); 7424 else if (specs->typespec_word == cts_double) 7425 error ("both %<unsigned%> and %<double%> in " 7426 "declaration specifiers"); 7427 else if (specs->typespec_word == cts_dfloat32) 7428 error ("both %<unsigned%> and %<_Decimal32%> in " 7429 "declaration specifiers"); 7430 else if (specs->typespec_word == cts_dfloat64) 7431 error ("both %<unsigned%> and %<_Decimal64%> in " 7432 "declaration specifiers"); 7433 else if (specs->typespec_word == cts_dfloat128) 7434 error ("both %<unsigned%> and %<_Decimal128%> in " 7435 "declaration specifiers"); 7436 else 7437 specs->unsigned_p = true; 7438 break; 7439 case RID_COMPLEX: 7440 dupe = specs->complex_p; 7441 if (pedantic && !flag_isoc99 && !in_system_header) 7442 pedwarn ("ISO C90 does not support complex types"); 7443 if (specs->typespec_word == cts_void) 7444 error ("both %<complex%> and %<void%> in " 7445 "declaration specifiers"); 7446 else if (specs->typespec_word == cts_bool) 7447 error ("both %<complex%> and %<_Bool%> in " 7448 "declaration specifiers"); 7449 else if (specs->typespec_word == cts_dfloat32) 7450 error ("both %<complex%> and %<_Decimal32%> in " 7451 "declaration specifiers"); 7452 else if (specs->typespec_word == cts_dfloat64) 7453 error ("both %<complex%> and %<_Decimal64%> in " 7454 "declaration specifiers"); 7455 else if (specs->typespec_word == cts_dfloat128) 7456 error ("both %<complex%> and %<_Decimal128%> in " 7457 "declaration specifiers"); 7458 else 7459 specs->complex_p = true; 7460 break; 7461 default: 7462 gcc_unreachable (); 7463 } 7464 7465 if (dupe) 7466 error ("duplicate %qE", type); 7467 7468 return specs; 7469 } 7470 else 7471 { 7472 /* "void", "_Bool", "char", "int", "float" or "double". */ 7473 if (specs->typespec_word != cts_none) 7474 { 7475 error ("two or more data types in declaration specifiers"); 7476 return specs; 7477 } 7478 switch (i) 7479 { 7480 case RID_VOID: 7481 if (specs->long_p) 7482 error ("both %<long%> and %<void%> in " 7483 "declaration specifiers"); 7484 else if (specs->short_p) 7485 error ("both %<short%> and %<void%> in " 7486 "declaration specifiers"); 7487 else if (specs->signed_p) 7488 error ("both %<signed%> and %<void%> in " 7489 "declaration specifiers"); 7490 else if (specs->unsigned_p) 7491 error ("both %<unsigned%> and %<void%> in " 7492 "declaration specifiers"); 7493 else if (specs->complex_p) 7494 error ("both %<complex%> and %<void%> in " 7495 "declaration specifiers"); 7496 else 7497 specs->typespec_word = cts_void; 7498 return specs; 7499 case RID_BOOL: 7500 if (specs->long_p) 7501 error ("both %<long%> and %<_Bool%> in " 7502 "declaration specifiers"); 7503 else if (specs->short_p) 7504 error ("both %<short%> and %<_Bool%> in " 7505 "declaration specifiers"); 7506 else if (specs->signed_p) 7507 error ("both %<signed%> and %<_Bool%> in " 7508 "declaration specifiers"); 7509 else if (specs->unsigned_p) 7510 error ("both %<unsigned%> and %<_Bool%> in " 7511 "declaration specifiers"); 7512 else if (specs->complex_p) 7513 error ("both %<complex%> and %<_Bool%> in " 7514 "declaration specifiers"); 7515 else 7516 specs->typespec_word = cts_bool; 7517 return specs; 7518 case RID_CHAR: 7519 if (specs->long_p) 7520 error ("both %<long%> and %<char%> in " 7521 "declaration specifiers"); 7522 else if (specs->short_p) 7523 error ("both %<short%> and %<char%> in " 7524 "declaration specifiers"); 7525 else 7526 specs->typespec_word = cts_char; 7527 return specs; 7528 case RID_INT: 7529 specs->typespec_word = cts_int; 7530 return specs; 7531 case RID_FLOAT: 7532 if (specs->long_p) 7533 error ("both %<long%> and %<float%> in " 7534 "declaration specifiers"); 7535 else if (specs->short_p) 7536 error ("both %<short%> and %<float%> in " 7537 "declaration specifiers"); 7538 else if (specs->signed_p) 7539 error ("both %<signed%> and %<float%> in " 7540 "declaration specifiers"); 7541 else if (specs->unsigned_p) 7542 error ("both %<unsigned%> and %<float%> in " 7543 "declaration specifiers"); 7544 else 7545 specs->typespec_word = cts_float; 7546 return specs; 7547 case RID_DOUBLE: 7548 if (specs->long_long_p) 7549 error ("both %<long long%> and %<double%> in " 7550 "declaration specifiers"); 7551 else if (specs->short_p) 7552 error ("both %<short%> and %<double%> in " 7553 "declaration specifiers"); 7554 else if (specs->signed_p) 7555 error ("both %<signed%> and %<double%> in " 7556 "declaration specifiers"); 7557 else if (specs->unsigned_p) 7558 error ("both %<unsigned%> and %<double%> in " 7559 "declaration specifiers"); 7560 else 7561 specs->typespec_word = cts_double; 7562 return specs; 7563 case RID_DFLOAT32: 7564 case RID_DFLOAT64: 7565 case RID_DFLOAT128: 7566 { 7567 const char *str; 7568 if (i == RID_DFLOAT32) 7569 str = "_Decimal32"; 7570 else if (i == RID_DFLOAT64) 7571 str = "_Decimal64"; 7572 else 7573 str = "_Decimal128"; 7574 if (specs->long_long_p) 7575 error ("both %<long long%> and %<%s%> in " 7576 "declaration specifiers", str); 7577 if (specs->long_p) 7578 error ("both %<long%> and %<%s%> in " 7579 "declaration specifiers", str); 7580 else if (specs->short_p) 7581 error ("both %<short%> and %<%s%> in " 7582 "declaration specifiers", str); 7583 else if (specs->signed_p) 7584 error ("both %<signed%> and %<%s%> in " 7585 "declaration specifiers", str); 7586 else if (specs->unsigned_p) 7587 error ("both %<unsigned%> and %<%s%> in " 7588 "declaration specifiers", str); 7589 else if (specs->complex_p) 7590 error ("both %<complex%> and %<%s%> in " 7591 "declaration specifiers", str); 7592 else if (i == RID_DFLOAT32) 7593 specs->typespec_word = cts_dfloat32; 7594 else if (i == RID_DFLOAT64) 7595 specs->typespec_word = cts_dfloat64; 7596 else 7597 specs->typespec_word = cts_dfloat128; 7598 } 7599 if (!targetm.decimal_float_supported_p ()) 7600 error ("decimal floating point not supported for this target"); 7601 if (pedantic) 7602 pedwarn ("ISO C does not support decimal floating point"); 7603 return specs; 7604 default: 7605 /* ObjC reserved word "id", handled below. */ 7606 break; 7607 } 7608 } 7609 } 7610 7611 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 7612 form of ObjC type, cases such as "int" and "long" being handled 7613 above), a TYPE (struct, union, enum and typeof specifiers) or an 7614 ERROR_MARK. In none of these cases may there have previously 7615 been any type specifiers. */ 7616 if (specs->type || specs->typespec_word != cts_none 7617 || specs->long_p || specs->short_p || specs->signed_p 7618 || specs->unsigned_p || specs->complex_p) 7619 error ("two or more data types in declaration specifiers"); 7620 else if (TREE_CODE (type) == TYPE_DECL) 7621 { 7622 if (TREE_TYPE (type) == error_mark_node) 7623 ; /* Allow the type to default to int to avoid cascading errors. */ 7624 else 7625 { 7626 specs->type = TREE_TYPE (type); 7627 specs->decl_attr = DECL_ATTRIBUTES (type); 7628 specs->typedef_p = true; 7629 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 7630 } 7631 } 7632 else if (TREE_CODE (type) == IDENTIFIER_NODE) 7633 { 7634 tree t = lookup_name (type); 7635 if (!t || TREE_CODE (t) != TYPE_DECL) 7636 error ("%qE fails to be a typedef or built in type", type); 7637 else if (TREE_TYPE (t) == error_mark_node) 7638 ; 7639 else 7640 specs->type = TREE_TYPE (t); 7641 } 7642 else if (TREE_CODE (type) != ERROR_MARK) 7643 { 7644 if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref) 7645 specs->tag_defined_p = true; 7646 if (spec.kind == ctsk_typeof) 7647 specs->typedef_p = true; 7648 specs->type = type; 7649 } 7650 7651 return specs; 7652} 7653 7654/* Add the storage class specifier or function specifier SCSPEC to the 7655 declaration specifiers SPECS, returning SPECS. */ 7656 7657struct c_declspecs * 7658declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 7659{ 7660 enum rid i; 7661 enum c_storage_class n = csc_none; 7662 bool dupe = false; 7663 specs->declspecs_seen_p = true; 7664 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 7665 && C_IS_RESERVED_WORD (scspec)); 7666 i = C_RID_CODE (scspec); 7667 if (extra_warnings && specs->non_sc_seen_p) 7668 warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec); 7669 switch (i) 7670 { 7671 case RID_INLINE: 7672 /* C99 permits duplicate inline. Although of doubtful utility, 7673 it seems simplest to permit it in gnu89 mode as well, as 7674 there is also little utility in maintaining this as a 7675 difference between gnu89 and C99 inline. */ 7676 dupe = false; 7677 specs->inline_p = true; 7678 break; 7679 case RID_THREAD: 7680 dupe = specs->thread_p; 7681 if (specs->storage_class == csc_auto) 7682 error ("%<__thread%> used with %<auto%>"); 7683 else if (specs->storage_class == csc_register) 7684 error ("%<__thread%> used with %<register%>"); 7685 else if (specs->storage_class == csc_typedef) 7686 error ("%<__thread%> used with %<typedef%>"); 7687 else 7688 specs->thread_p = true; 7689 break; 7690 case RID_AUTO: 7691 n = csc_auto; 7692 break; 7693 case RID_EXTERN: 7694 n = csc_extern; 7695 /* Diagnose "__thread extern". */ 7696 if (specs->thread_p) 7697 error ("%<__thread%> before %<extern%>"); 7698 break; 7699 case RID_REGISTER: 7700 n = csc_register; 7701 break; 7702 case RID_STATIC: 7703 n = csc_static; 7704 /* Diagnose "__thread static". */ 7705 if (specs->thread_p) 7706 error ("%<__thread%> before %<static%>"); 7707 break; 7708 case RID_TYPEDEF: 7709 n = csc_typedef; 7710 break; 7711 default: 7712 gcc_unreachable (); 7713 } 7714 if (n != csc_none && n == specs->storage_class) 7715 dupe = true; 7716 if (dupe) 7717 error ("duplicate %qE", scspec); 7718 if (n != csc_none) 7719 { 7720 if (specs->storage_class != csc_none && n != specs->storage_class) 7721 { 7722 error ("multiple storage classes in declaration specifiers"); 7723 } 7724 else 7725 { 7726 specs->storage_class = n; 7727 if (n != csc_extern && n != csc_static && specs->thread_p) 7728 { 7729 error ("%<__thread%> used with %qE", scspec); 7730 specs->thread_p = false; 7731 } 7732 } 7733 } 7734 return specs; 7735} 7736 7737/* Add the attributes ATTRS to the declaration specifiers SPECS, 7738 returning SPECS. */ 7739 7740struct c_declspecs * 7741declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 7742{ 7743 specs->attrs = chainon (attrs, specs->attrs); 7744 specs->declspecs_seen_p = true; 7745 return specs; 7746} 7747 7748/* Combine "long", "short", "signed", "unsigned" and "_Complex" type 7749 specifiers with any other type specifier to determine the resulting 7750 type. This is where ISO C checks on complex types are made, since 7751 "_Complex long" is a prefix of the valid ISO C type "_Complex long 7752 double". */ 7753 7754struct c_declspecs * 7755finish_declspecs (struct c_declspecs *specs) 7756{ 7757 /* If a type was specified as a whole, we have no modifiers and are 7758 done. */ 7759 if (specs->type != NULL_TREE) 7760 { 7761 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7762 && !specs->signed_p && !specs->unsigned_p 7763 && !specs->complex_p); 7764 return specs; 7765 } 7766 7767 /* If none of "void", "_Bool", "char", "int", "float" or "double" 7768 has been specified, treat it as "int" unless "_Complex" is 7769 present and there are no other specifiers. If we just have 7770 "_Complex", it is equivalent to "_Complex double", but e.g. 7771 "_Complex short" is equivalent to "_Complex short int". */ 7772 if (specs->typespec_word == cts_none) 7773 { 7774 if (specs->long_p || specs->short_p 7775 || specs->signed_p || specs->unsigned_p) 7776 { 7777 specs->typespec_word = cts_int; 7778 } 7779 else if (specs->complex_p) 7780 { 7781 specs->typespec_word = cts_double; 7782 if (pedantic) 7783 pedwarn ("ISO C does not support plain %<complex%> meaning " 7784 "%<double complex%>"); 7785 } 7786 else 7787 { 7788 specs->typespec_word = cts_int; 7789 specs->default_int_p = true; 7790 /* We don't diagnose this here because grokdeclarator will 7791 give more specific diagnostics according to whether it is 7792 a function definition. */ 7793 } 7794 } 7795 7796 /* If "signed" was specified, record this to distinguish "int" and 7797 "signed int" in the case of a bit-field with 7798 -funsigned-bitfields. */ 7799 specs->explicit_signed_p = specs->signed_p; 7800 7801 /* Now compute the actual type. */ 7802 switch (specs->typespec_word) 7803 { 7804 case cts_void: 7805 gcc_assert (!specs->long_p && !specs->short_p 7806 && !specs->signed_p && !specs->unsigned_p 7807 && !specs->complex_p); 7808 specs->type = void_type_node; 7809 break; 7810 case cts_bool: 7811 gcc_assert (!specs->long_p && !specs->short_p 7812 && !specs->signed_p && !specs->unsigned_p 7813 && !specs->complex_p); 7814 specs->type = boolean_type_node; 7815 break; 7816 case cts_char: 7817 gcc_assert (!specs->long_p && !specs->short_p); 7818 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7819 if (specs->signed_p) 7820 specs->type = signed_char_type_node; 7821 else if (specs->unsigned_p) 7822 specs->type = unsigned_char_type_node; 7823 else 7824 specs->type = char_type_node; 7825 if (specs->complex_p) 7826 { 7827 if (pedantic) 7828 pedwarn ("ISO C does not support complex integer types"); 7829 specs->type = build_complex_type (specs->type); 7830 } 7831 break; 7832 case cts_int: 7833 gcc_assert (!(specs->long_p && specs->short_p)); 7834 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7835 if (specs->long_long_p) 7836 specs->type = (specs->unsigned_p 7837 ? long_long_unsigned_type_node 7838 : long_long_integer_type_node); 7839 else if (specs->long_p) 7840 specs->type = (specs->unsigned_p 7841 ? long_unsigned_type_node 7842 : long_integer_type_node); 7843 else if (specs->short_p) 7844 specs->type = (specs->unsigned_p 7845 ? short_unsigned_type_node 7846 : short_integer_type_node); 7847 else 7848 specs->type = (specs->unsigned_p 7849 ? unsigned_type_node 7850 : integer_type_node); 7851 if (specs->complex_p) 7852 { 7853 if (pedantic) 7854 pedwarn ("ISO C does not support complex integer types"); 7855 specs->type = build_complex_type (specs->type); 7856 } 7857 break; 7858 case cts_float: 7859 gcc_assert (!specs->long_p && !specs->short_p 7860 && !specs->signed_p && !specs->unsigned_p); 7861 specs->type = (specs->complex_p 7862 ? complex_float_type_node 7863 : float_type_node); 7864 break; 7865 case cts_double: 7866 gcc_assert (!specs->long_long_p && !specs->short_p 7867 && !specs->signed_p && !specs->unsigned_p); 7868 if (specs->long_p) 7869 { 7870 specs->type = (specs->complex_p 7871 ? complex_long_double_type_node 7872 : long_double_type_node); 7873 } 7874 else 7875 { 7876 specs->type = (specs->complex_p 7877 ? complex_double_type_node 7878 : double_type_node); 7879 } 7880 break; 7881 case cts_dfloat32: 7882 case cts_dfloat64: 7883 case cts_dfloat128: 7884 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7885 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 7886 if (specs->typespec_word == cts_dfloat32) 7887 specs->type = dfloat32_type_node; 7888 else if (specs->typespec_word == cts_dfloat64) 7889 specs->type = dfloat64_type_node; 7890 else 7891 specs->type = dfloat128_type_node; 7892 break; 7893 default: 7894 gcc_unreachable (); 7895 } 7896 7897 return specs; 7898} 7899 7900/* Synthesize a function which calls all the global ctors or global 7901 dtors in this file. This is only used for targets which do not 7902 support .ctors/.dtors sections. FIXME: Migrate into cgraph. */ 7903static void 7904build_cdtor (int method_type, tree cdtors) 7905{ 7906 tree body = 0; 7907 7908 if (!cdtors) 7909 return; 7910 7911 for (; cdtors; cdtors = TREE_CHAIN (cdtors)) 7912 append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0), 7913 &body); 7914 7915 cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY); 7916} 7917 7918/* A subroutine of c_write_global_declarations. Perform final processing 7919 on one file scope's declarations (or the external scope's declarations), 7920 GLOBALS. */ 7921 7922static void 7923c_write_global_declarations_1 (tree globals) 7924{ 7925 tree decl; 7926 bool reconsider; 7927 7928 /* Process the decls in the order they were written. */ 7929 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7930 { 7931 /* Check for used but undefined static functions using the C 7932 standard's definition of "used", and set TREE_NO_WARNING so 7933 that check_global_declarations doesn't repeat the check. */ 7934 if (TREE_CODE (decl) == FUNCTION_DECL 7935 && DECL_INITIAL (decl) == 0 7936 && DECL_EXTERNAL (decl) 7937 && !TREE_PUBLIC (decl) 7938 && C_DECL_USED (decl)) 7939 { 7940 pedwarn ("%q+F used but never defined", decl); 7941 TREE_NO_WARNING (decl) = 1; 7942 } 7943 7944 wrapup_global_declaration_1 (decl); 7945 } 7946 7947 do 7948 { 7949 reconsider = false; 7950 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7951 reconsider |= wrapup_global_declaration_2 (decl); 7952 } 7953 while (reconsider); 7954 7955 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7956 check_global_declaration_1 (decl); 7957} 7958 7959/* A subroutine of c_write_global_declarations Emit debug information for each 7960 of the declarations in GLOBALS. */ 7961 7962static void 7963c_write_global_declarations_2 (tree globals) 7964{ 7965 tree decl; 7966 7967 for (decl = globals; decl ; decl = TREE_CHAIN (decl)) 7968 debug_hooks->global_decl (decl); 7969} 7970 7971/* Preserve the external declarations scope across a garbage collect. */ 7972static GTY(()) tree ext_block; 7973 7974void 7975c_write_global_declarations (void) 7976{ 7977 tree t; 7978 7979 /* We don't want to do this if generating a PCH. */ 7980 if (pch_file) 7981 return; 7982 7983 /* Don't waste time on further processing if -fsyntax-only or we've 7984 encountered errors. */ 7985 if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in)) 7986 return; 7987 7988 /* Close the external scope. */ 7989 ext_block = pop_scope (); 7990 external_scope = 0; 7991 gcc_assert (!current_scope); 7992 7993 if (ext_block) 7994 { 7995 tree tmp = BLOCK_VARS (ext_block); 7996 int flags; 7997 FILE * stream = dump_begin (TDI_tu, &flags); 7998 if (stream && tmp) 7999 { 8000 dump_node (tmp, flags & ~TDF_SLIM, stream); 8001 dump_end (TDI_tu, stream); 8002 } 8003 } 8004 8005 /* Process all file scopes in this compilation, and the external_scope, 8006 through wrapup_global_declarations and check_global_declarations. */ 8007 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8008 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 8009 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 8010 8011 /* Generate functions to call static constructors and destructors 8012 for targets that do not support .ctors/.dtors sections. These 8013 functions have magic names which are detected by collect2. */ 8014 build_cdtor ('I', static_ctors); static_ctors = 0; 8015 build_cdtor ('D', static_dtors); static_dtors = 0; 8016 8017 /* We're done parsing; proceed to optimize and emit assembly. 8018 FIXME: shouldn't be the front end's responsibility to call this. */ 8019 cgraph_optimize (); 8020 8021 /* After cgraph has had a chance to emit everything that's going to 8022 be emitted, output debug information for globals. */ 8023 if (errorcount == 0 && sorrycount == 0) 8024 { 8025 timevar_push (TV_SYMOUT); 8026 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8027 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 8028 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 8029 timevar_pop (TV_SYMOUT); 8030 } 8031 8032 ext_block = NULL; 8033} 8034 8035#include "gt-c-decl.h" 8036