c-decl.c revision 258748
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 258748 2013-11-29 18:46:02Z pfg $ */ 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 (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl)) 1694 { 1695 DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl); 1696 DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl); 1697 } 1698 } 1699 1700 1701 /* Merge the type qualifiers. */ 1702 if (TREE_READONLY (newdecl)) 1703 TREE_READONLY (olddecl) = 1; 1704 1705 if (TREE_THIS_VOLATILE (newdecl)) 1706 TREE_THIS_VOLATILE (olddecl) = 1; 1707 1708 /* Merge deprecatedness. */ 1709 if (TREE_DEPRECATED (newdecl)) 1710 TREE_DEPRECATED (olddecl) = 1; 1711 1712 /* Keep source location of definition rather than declaration and of 1713 prototype rather than non-prototype unless that prototype is 1714 built-in. */ 1715 if ((DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0) 1716 || (old_is_prototype && !new_is_prototype 1717 && !C_DECL_BUILTIN_PROTOTYPE (olddecl))) 1718 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 1719 1720 /* Merge the initialization information. */ 1721 if (DECL_INITIAL (newdecl) == 0) 1722 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1723 1724 /* Merge the threadprivate attribute. */ 1725 if (TREE_CODE (olddecl) == VAR_DECL && C_DECL_THREADPRIVATE_P (olddecl)) 1726 { 1727 DECL_TLS_MODEL (newdecl) = DECL_TLS_MODEL (olddecl); 1728 C_DECL_THREADPRIVATE_P (newdecl) = 1; 1729 } 1730 1731 if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)) 1732 { 1733 /* Merge the unused-warning information. */ 1734 if (DECL_IN_SYSTEM_HEADER (olddecl)) 1735 DECL_IN_SYSTEM_HEADER (newdecl) = 1; 1736 else if (DECL_IN_SYSTEM_HEADER (newdecl)) 1737 DECL_IN_SYSTEM_HEADER (olddecl) = 1; 1738 1739 /* Merge the section attribute. 1740 We want to issue an error if the sections conflict but that 1741 must be done later in decl_attributes since we are called 1742 before attributes are assigned. */ 1743 if (DECL_SECTION_NAME (newdecl) == NULL_TREE) 1744 DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl); 1745 1746 /* Copy the assembler name. 1747 Currently, it can only be defined in the prototype. */ 1748 COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl); 1749 1750 /* Use visibility of whichever declaration had it specified */ 1751 if (DECL_VISIBILITY_SPECIFIED (olddecl)) 1752 { 1753 DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl); 1754 DECL_VISIBILITY_SPECIFIED (newdecl) = 1; 1755 } 1756 1757 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1758 { 1759 DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl); 1760 DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl); 1761 DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl); 1762 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl) 1763 |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl); 1764 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1765 TREE_READONLY (newdecl) |= TREE_READONLY (olddecl); 1766 DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl); 1767 DECL_IS_PURE (newdecl) |= DECL_IS_PURE (olddecl); 1768 DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl); 1769 } 1770 1771 /* Merge the storage class information. */ 1772 merge_weak (newdecl, olddecl); 1773 1774 /* For functions, static overrides non-static. */ 1775 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1776 { 1777 TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl); 1778 /* This is since we don't automatically 1779 copy the attributes of NEWDECL into OLDDECL. */ 1780 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1781 /* If this clears `static', clear it in the identifier too. */ 1782 if (!TREE_PUBLIC (olddecl)) 1783 TREE_PUBLIC (DECL_NAME (olddecl)) = 0; 1784 } 1785 } 1786 1787 /* In c99, 'extern' declaration before (or after) 'inline' means this 1788 function is not DECL_EXTERNAL, unless 'gnu_inline' attribute 1789 is present. */ 1790 if (TREE_CODE (newdecl) == FUNCTION_DECL 1791 && !flag_gnu89_inline 1792 && (DECL_DECLARED_INLINE_P (newdecl) 1793 || DECL_DECLARED_INLINE_P (olddecl)) 1794 && (!DECL_DECLARED_INLINE_P (newdecl) 1795 || !DECL_DECLARED_INLINE_P (olddecl) 1796 || !DECL_EXTERNAL (olddecl)) 1797 && DECL_EXTERNAL (newdecl) 1798 && !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl))) 1799 DECL_EXTERNAL (newdecl) = 0; 1800 1801 if (DECL_EXTERNAL (newdecl)) 1802 { 1803 TREE_STATIC (newdecl) = TREE_STATIC (olddecl); 1804 DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl); 1805 1806 /* An extern decl does not override previous storage class. */ 1807 TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl); 1808 if (!DECL_EXTERNAL (newdecl)) 1809 { 1810 DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl); 1811 DECL_COMMON (newdecl) = DECL_COMMON (olddecl); 1812 } 1813 } 1814 else 1815 { 1816 TREE_STATIC (olddecl) = TREE_STATIC (newdecl); 1817 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1818 } 1819 1820 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1821 { 1822 /* If we're redefining a function previously defined as extern 1823 inline, make sure we emit debug info for the inline before we 1824 throw it away, in case it was inlined into a function that 1825 hasn't been written out yet. */ 1826 if (new_is_definition && DECL_INITIAL (olddecl)) 1827 { 1828 if (TREE_USED (olddecl) 1829 /* In unit-at-a-time mode we never inline re-defined extern 1830 inline functions. */ 1831 && !flag_unit_at_a_time 1832 && cgraph_function_possibly_inlined_p (olddecl)) 1833 (*debug_hooks->outlining_inline_function) (olddecl); 1834 1835 /* The new defn must not be inline. */ 1836 DECL_INLINE (newdecl) = 0; 1837 DECL_UNINLINABLE (newdecl) = 1; 1838 } 1839 else 1840 { 1841 /* If either decl says `inline', this fn is inline, unless 1842 its definition was passed already. */ 1843 if (DECL_DECLARED_INLINE_P (newdecl) 1844 || DECL_DECLARED_INLINE_P (olddecl)) 1845 DECL_DECLARED_INLINE_P (newdecl) = 1; 1846 1847 DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl) 1848 = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)); 1849 } 1850 1851 if (DECL_BUILT_IN (olddecl)) 1852 { 1853 /* If redeclaring a builtin function, it stays built in. 1854 But it gets tagged as having been declared. */ 1855 DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl); 1856 DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl); 1857 C_DECL_DECLARED_BUILTIN (newdecl) = 1; 1858 if (new_is_prototype) 1859 C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0; 1860 else 1861 C_DECL_BUILTIN_PROTOTYPE (newdecl) 1862 = C_DECL_BUILTIN_PROTOTYPE (olddecl); 1863 } 1864 1865 /* Also preserve various other info from the definition. */ 1866 if (!new_is_definition) 1867 { 1868 DECL_RESULT (newdecl) = DECL_RESULT (olddecl); 1869 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1870 DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl); 1871 DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl); 1872 DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl); 1873 1874 /* Set DECL_INLINE on the declaration if we've got a body 1875 from which to instantiate. */ 1876 if (DECL_INLINE (olddecl) && !DECL_UNINLINABLE (newdecl)) 1877 { 1878 DECL_INLINE (newdecl) = 1; 1879 DECL_ABSTRACT_ORIGIN (newdecl) 1880 = DECL_ABSTRACT_ORIGIN (olddecl); 1881 } 1882 } 1883 else 1884 { 1885 /* If a previous declaration said inline, mark the 1886 definition as inlinable. */ 1887 if (DECL_DECLARED_INLINE_P (newdecl) 1888 && !DECL_UNINLINABLE (newdecl)) 1889 DECL_INLINE (newdecl) = 1; 1890 } 1891 } 1892 1893 extern_changed = DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl); 1894 1895 /* Copy most of the decl-specific fields of NEWDECL into OLDDECL. 1896 But preserve OLDDECL's DECL_UID and DECL_CONTEXT. */ 1897 { 1898 unsigned olddecl_uid = DECL_UID (olddecl); 1899 tree olddecl_context = DECL_CONTEXT (olddecl); 1900 1901 memcpy ((char *) olddecl + sizeof (struct tree_common), 1902 (char *) newdecl + sizeof (struct tree_common), 1903 sizeof (struct tree_decl_common) - sizeof (struct tree_common)); 1904 switch (TREE_CODE (olddecl)) 1905 { 1906 case FIELD_DECL: 1907 case VAR_DECL: 1908 case PARM_DECL: 1909 case LABEL_DECL: 1910 case RESULT_DECL: 1911 case CONST_DECL: 1912 case TYPE_DECL: 1913 case FUNCTION_DECL: 1914 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1915 (char *) newdecl + sizeof (struct tree_decl_common), 1916 tree_code_size (TREE_CODE (olddecl)) - sizeof (struct tree_decl_common)); 1917 break; 1918 1919 default: 1920 1921 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1922 (char *) newdecl + sizeof (struct tree_decl_common), 1923 sizeof (struct tree_decl_non_common) - sizeof (struct tree_decl_common)); 1924 } 1925 DECL_UID (olddecl) = olddecl_uid; 1926 DECL_CONTEXT (olddecl) = olddecl_context; 1927 } 1928 1929 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl 1930 so that encode_section_info has a chance to look at the new decl 1931 flags and attributes. */ 1932 if (DECL_RTL_SET_P (olddecl) 1933 && (TREE_CODE (olddecl) == FUNCTION_DECL 1934 || (TREE_CODE (olddecl) == VAR_DECL 1935 && TREE_STATIC (olddecl)))) 1936 make_decl_rtl (olddecl); 1937 1938 /* If we changed a function from DECL_EXTERNAL to !DECL_EXTERNAL, 1939 and the definition is coming from the old version, cgraph needs 1940 to be called again. */ 1941 if (extern_changed && !new_is_definition 1942 && TREE_CODE (olddecl) == FUNCTION_DECL && DECL_INITIAL (olddecl)) 1943 cgraph_finalize_function (olddecl, false); 1944} 1945 1946/* Handle when a new declaration NEWDECL has the same name as an old 1947 one OLDDECL in the same binding contour. Prints an error message 1948 if appropriate. 1949 1950 If safely possible, alter OLDDECL to look like NEWDECL, and return 1951 true. Otherwise, return false. */ 1952 1953static bool 1954duplicate_decls (tree newdecl, tree olddecl) 1955{ 1956 tree newtype = NULL, oldtype = NULL; 1957 1958 if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype)) 1959 { 1960 /* Avoid `unused variable' and other warnings warnings for OLDDECL. */ 1961 TREE_NO_WARNING (olddecl) = 1; 1962 return false; 1963 } 1964 1965 merge_decls (newdecl, olddecl, newtype, oldtype); 1966 return true; 1967} 1968 1969 1970/* Check whether decl-node NEW_DECL shadows an existing declaration. */ 1971static void 1972warn_if_shadowing (tree new_decl) 1973{ 1974 struct c_binding *b; 1975 1976 /* Shadow warnings wanted? */ 1977 if (!warn_shadow 1978 /* No shadow warnings for internally generated vars. */ 1979 || DECL_IS_BUILTIN (new_decl) 1980 /* No shadow warnings for vars made for inlining. */ 1981 || DECL_FROM_INLINE (new_decl)) 1982 return; 1983 1984 /* Is anything being shadowed? Invisible decls do not count. */ 1985 for (b = I_SYMBOL_BINDING (DECL_NAME (new_decl)); b; b = b->shadowed) 1986 if (b->decl && b->decl != new_decl && !b->invisible) 1987 { 1988 tree old_decl = b->decl; 1989 1990 if (old_decl == error_mark_node) 1991 { 1992 warning (OPT_Wshadow, "declaration of %q+D shadows previous " 1993 "non-variable", new_decl); 1994 break; 1995 } 1996 else if (TREE_CODE (old_decl) == PARM_DECL) 1997 warning (OPT_Wshadow, "declaration of %q+D shadows a parameter", 1998 new_decl); 1999 else if (DECL_FILE_SCOPE_P (old_decl)) 2000 warning (OPT_Wshadow, "declaration of %q+D shadows a global " 2001 "declaration", new_decl); 2002 else if (TREE_CODE (old_decl) == FUNCTION_DECL 2003 && DECL_BUILT_IN (old_decl)) 2004 { 2005 warning (OPT_Wshadow, "declaration of %q+D shadows " 2006 "a built-in function", new_decl); 2007 break; 2008 } 2009 else 2010 warning (OPT_Wshadow, "declaration of %q+D shadows a previous local", 2011 new_decl); 2012 2013 warning (OPT_Wshadow, "%Jshadowed declaration is here", old_decl); 2014 2015 break; 2016 } 2017} 2018 2019 2020/* Subroutine of pushdecl. 2021 2022 X is a TYPE_DECL for a typedef statement. Create a brand new 2023 ..._TYPE node (which will be just a variant of the existing 2024 ..._TYPE node with identical properties) and then install X 2025 as the TYPE_NAME of this brand new (duplicate) ..._TYPE node. 2026 2027 The whole point here is to end up with a situation where each 2028 and every ..._TYPE node the compiler creates will be uniquely 2029 associated with AT MOST one node representing a typedef name. 2030 This way, even though the compiler substitutes corresponding 2031 ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very 2032 early on, later parts of the compiler can always do the reverse 2033 translation and get back the corresponding typedef name. For 2034 example, given: 2035 2036 typedef struct S MY_TYPE; 2037 MY_TYPE object; 2038 2039 Later parts of the compiler might only know that `object' was of 2040 type `struct S' if it were not for code just below. With this 2041 code however, later parts of the compiler see something like: 2042 2043 struct S' == struct S 2044 typedef struct S' MY_TYPE; 2045 struct S' object; 2046 2047 And they can then deduce (from the node for type struct S') that 2048 the original object declaration was: 2049 2050 MY_TYPE object; 2051 2052 Being able to do this is important for proper support of protoize, 2053 and also for generating precise symbolic debugging information 2054 which takes full account of the programmer's (typedef) vocabulary. 2055 2056 Obviously, we don't want to generate a duplicate ..._TYPE node if 2057 the TYPE_DECL node that we are now processing really represents a 2058 standard built-in type. 2059 2060 Since all standard types are effectively declared at line zero 2061 in the source file, we can easily check to see if we are working 2062 on a standard type by checking the current value of lineno. */ 2063 2064static void 2065clone_underlying_type (tree x) 2066{ 2067 if (DECL_IS_BUILTIN (x)) 2068 { 2069 if (TYPE_NAME (TREE_TYPE (x)) == 0) 2070 TYPE_NAME (TREE_TYPE (x)) = x; 2071 } 2072 else if (TREE_TYPE (x) != error_mark_node 2073 && DECL_ORIGINAL_TYPE (x) == NULL_TREE) 2074 { 2075 tree tt = TREE_TYPE (x); 2076 DECL_ORIGINAL_TYPE (x) = tt; 2077 tt = build_variant_type_copy (tt); 2078 TYPE_NAME (tt) = x; 2079 TREE_USED (tt) = TREE_USED (x); 2080 TREE_TYPE (x) = tt; 2081 } 2082} 2083 2084/* Record a decl-node X as belonging to the current lexical scope. 2085 Check for errors (such as an incompatible declaration for the same 2086 name already seen in the same scope). 2087 2088 Returns either X or an old decl for the same name. 2089 If an old decl is returned, it may have been smashed 2090 to agree with what X says. */ 2091 2092tree 2093pushdecl (tree x) 2094{ 2095 tree name = DECL_NAME (x); 2096 struct c_scope *scope = current_scope; 2097 struct c_binding *b; 2098 bool nested = false; 2099 2100 /* Functions need the lang_decl data. */ 2101 if (TREE_CODE (x) == FUNCTION_DECL && !DECL_LANG_SPECIFIC (x)) 2102 DECL_LANG_SPECIFIC (x) = GGC_CNEW (struct lang_decl); 2103 2104 /* Must set DECL_CONTEXT for everything not at file scope or 2105 DECL_FILE_SCOPE_P won't work. Local externs don't count 2106 unless they have initializers (which generate code). */ 2107 if (current_function_decl 2108 && ((TREE_CODE (x) != FUNCTION_DECL && TREE_CODE (x) != VAR_DECL) 2109 || DECL_INITIAL (x) || !DECL_EXTERNAL (x))) 2110 DECL_CONTEXT (x) = current_function_decl; 2111 2112 /* If this is of variably modified type, prevent jumping into its 2113 scope. */ 2114 if ((TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == TYPE_DECL) 2115 && variably_modified_type_p (TREE_TYPE (x), NULL_TREE)) 2116 c_begin_vm_scope (scope->depth); 2117 2118 /* Anonymous decls are just inserted in the scope. */ 2119 if (!name) 2120 { 2121 bind (name, x, scope, /*invisible=*/false, /*nested=*/false); 2122 return x; 2123 } 2124 2125 /* First, see if there is another declaration with the same name in 2126 the current scope. If there is, duplicate_decls may do all the 2127 work for us. If duplicate_decls returns false, that indicates 2128 two incompatible decls in the same scope; we are to silently 2129 replace the old one (duplicate_decls has issued all appropriate 2130 diagnostics). In particular, we should not consider possible 2131 duplicates in the external scope, or shadowing. */ 2132 b = I_SYMBOL_BINDING (name); 2133 if (b && B_IN_SCOPE (b, scope)) 2134 { 2135 struct c_binding *b_ext, *b_use; 2136 tree type = TREE_TYPE (x); 2137 tree visdecl = b->decl; 2138 tree vistype = TREE_TYPE (visdecl); 2139 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 2140 && COMPLETE_TYPE_P (TREE_TYPE (x))) 2141 b->inner_comp = false; 2142 b_use = b; 2143 b_ext = b; 2144 /* If this is an external linkage declaration, we should check 2145 for compatibility with the type in the external scope before 2146 setting the type at this scope based on the visible 2147 information only. */ 2148 if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl)) 2149 { 2150 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 2151 b_ext = b_ext->shadowed; 2152 if (b_ext) 2153 { 2154 b_use = b_ext; 2155 if (b_use->type) 2156 TREE_TYPE (b_use->decl) = b_use->type; 2157 } 2158 } 2159 if (duplicate_decls (x, b_use->decl)) 2160 { 2161 if (b_use != b) 2162 { 2163 /* Save the updated type in the external scope and 2164 restore the proper type for this scope. */ 2165 tree thistype; 2166 if (comptypes (vistype, type)) 2167 thistype = composite_type (vistype, type); 2168 else 2169 thistype = TREE_TYPE (b_use->decl); 2170 b_use->type = TREE_TYPE (b_use->decl); 2171 if (TREE_CODE (b_use->decl) == FUNCTION_DECL 2172 && DECL_BUILT_IN (b_use->decl)) 2173 thistype 2174 = build_type_attribute_variant (thistype, 2175 TYPE_ATTRIBUTES 2176 (b_use->type)); 2177 TREE_TYPE (b_use->decl) = thistype; 2178 } 2179 return b_use->decl; 2180 } 2181 else 2182 goto skip_external_and_shadow_checks; 2183 } 2184 2185 /* All declarations with external linkage, and all external 2186 references, go in the external scope, no matter what scope is 2187 current. However, the binding in that scope is ignored for 2188 purposes of normal name lookup. A separate binding structure is 2189 created in the requested scope; this governs the normal 2190 visibility of the symbol. 2191 2192 The binding in the externals scope is used exclusively for 2193 detecting duplicate declarations of the same object, no matter 2194 what scope they are in; this is what we do here. (C99 6.2.7p2: 2195 All declarations that refer to the same object or function shall 2196 have compatible type; otherwise, the behavior is undefined.) */ 2197 if (DECL_EXTERNAL (x) || scope == file_scope) 2198 { 2199 tree type = TREE_TYPE (x); 2200 tree vistype = 0; 2201 tree visdecl = 0; 2202 bool type_saved = false; 2203 if (b && !B_IN_EXTERNAL_SCOPE (b) 2204 && (TREE_CODE (b->decl) == FUNCTION_DECL 2205 || TREE_CODE (b->decl) == VAR_DECL) 2206 && DECL_FILE_SCOPE_P (b->decl)) 2207 { 2208 visdecl = b->decl; 2209 vistype = TREE_TYPE (visdecl); 2210 } 2211 if (scope != file_scope 2212 && !DECL_IN_SYSTEM_HEADER (x)) 2213 warning (OPT_Wnested_externs, "nested extern declaration of %qD", x); 2214 2215 while (b && !B_IN_EXTERNAL_SCOPE (b)) 2216 { 2217 /* If this decl might be modified, save its type. This is 2218 done here rather than when the decl is first bound 2219 because the type may change after first binding, through 2220 being completed or through attributes being added. If we 2221 encounter multiple such decls, only the first should have 2222 its type saved; the others will already have had their 2223 proper types saved and the types will not have changed as 2224 their scopes will not have been re-entered. */ 2225 if (DECL_P (b->decl) && DECL_FILE_SCOPE_P (b->decl) && !type_saved) 2226 { 2227 b->type = TREE_TYPE (b->decl); 2228 type_saved = true; 2229 } 2230 if (B_IN_FILE_SCOPE (b) 2231 && TREE_CODE (b->decl) == VAR_DECL 2232 && TREE_STATIC (b->decl) 2233 && TREE_CODE (TREE_TYPE (b->decl)) == ARRAY_TYPE 2234 && !TYPE_DOMAIN (TREE_TYPE (b->decl)) 2235 && TREE_CODE (type) == ARRAY_TYPE 2236 && TYPE_DOMAIN (type) 2237 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) 2238 && !integer_zerop (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))) 2239 { 2240 /* Array type completed in inner scope, which should be 2241 diagnosed if the completion does not have size 1 and 2242 it does not get completed in the file scope. */ 2243 b->inner_comp = true; 2244 } 2245 b = b->shadowed; 2246 } 2247 2248 /* If a matching external declaration has been found, set its 2249 type to the composite of all the types of that declaration. 2250 After the consistency checks, it will be reset to the 2251 composite of the visible types only. */ 2252 if (b && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2253 && b->type) 2254 TREE_TYPE (b->decl) = b->type; 2255 2256 /* The point of the same_translation_unit_p check here is, 2257 we want to detect a duplicate decl for a construct like 2258 foo() { extern bar(); } ... static bar(); but not if 2259 they are in different translation units. In any case, 2260 the static does not go in the externals scope. */ 2261 if (b 2262 && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2263 && duplicate_decls (x, b->decl)) 2264 { 2265 tree thistype; 2266 if (vistype) 2267 { 2268 if (comptypes (vistype, type)) 2269 thistype = composite_type (vistype, type); 2270 else 2271 thistype = TREE_TYPE (b->decl); 2272 } 2273 else 2274 thistype = type; 2275 b->type = TREE_TYPE (b->decl); 2276 if (TREE_CODE (b->decl) == FUNCTION_DECL && DECL_BUILT_IN (b->decl)) 2277 thistype 2278 = build_type_attribute_variant (thistype, 2279 TYPE_ATTRIBUTES (b->type)); 2280 TREE_TYPE (b->decl) = thistype; 2281 bind (name, b->decl, scope, /*invisible=*/false, /*nested=*/true); 2282 return b->decl; 2283 } 2284 else if (TREE_PUBLIC (x)) 2285 { 2286 if (visdecl && !b && duplicate_decls (x, visdecl)) 2287 { 2288 /* An external declaration at block scope referring to a 2289 visible entity with internal linkage. The composite 2290 type will already be correct for this scope, so we 2291 just need to fall through to make the declaration in 2292 this scope. */ 2293 nested = true; 2294 x = visdecl; 2295 } 2296 else 2297 { 2298 bind (name, x, external_scope, /*invisible=*/true, 2299 /*nested=*/false); 2300 nested = true; 2301 } 2302 } 2303 } 2304 2305 if (TREE_CODE (x) != PARM_DECL) 2306 warn_if_shadowing (x); 2307 2308 skip_external_and_shadow_checks: 2309 if (TREE_CODE (x) == TYPE_DECL) 2310 clone_underlying_type (x); 2311 2312 bind (name, x, scope, /*invisible=*/false, nested); 2313 2314 /* If x's type is incomplete because it's based on a 2315 structure or union which has not yet been fully declared, 2316 attach it to that structure or union type, so we can go 2317 back and complete the variable declaration later, if the 2318 structure or union gets fully declared. 2319 2320 If the input is erroneous, we can have error_mark in the type 2321 slot (e.g. "f(void a, ...)") - that doesn't count as an 2322 incomplete type. */ 2323 if (TREE_TYPE (x) != error_mark_node 2324 && !COMPLETE_TYPE_P (TREE_TYPE (x))) 2325 { 2326 tree element = TREE_TYPE (x); 2327 2328 while (TREE_CODE (element) == ARRAY_TYPE) 2329 element = TREE_TYPE (element); 2330 element = TYPE_MAIN_VARIANT (element); 2331 2332 if ((TREE_CODE (element) == RECORD_TYPE 2333 || TREE_CODE (element) == UNION_TYPE) 2334 && (TREE_CODE (x) != TYPE_DECL 2335 || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE) 2336 && !COMPLETE_TYPE_P (element)) 2337 C_TYPE_INCOMPLETE_VARS (element) 2338 = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element)); 2339 } 2340 return x; 2341} 2342 2343/* Record X as belonging to file scope. 2344 This is used only internally by the Objective-C front end, 2345 and is limited to its needs. duplicate_decls is not called; 2346 if there is any preexisting decl for this identifier, it is an ICE. */ 2347 2348tree 2349pushdecl_top_level (tree x) 2350{ 2351 tree name; 2352 bool nested = false; 2353 gcc_assert (TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == CONST_DECL); 2354 2355 name = DECL_NAME (x); 2356 2357 gcc_assert (TREE_CODE (x) == CONST_DECL || !I_SYMBOL_BINDING (name)); 2358 2359 if (TREE_PUBLIC (x)) 2360 { 2361 bind (name, x, external_scope, /*invisible=*/true, /*nested=*/false); 2362 nested = true; 2363 } 2364 if (file_scope) 2365 bind (name, x, file_scope, /*invisible=*/false, nested); 2366 2367 return x; 2368} 2369 2370static void 2371implicit_decl_warning (tree id, tree olddecl) 2372{ 2373 void (*diag) (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2); 2374 switch (mesg_implicit_function_declaration) 2375 { 2376 case 0: return; 2377 case 1: diag = warning0; break; 2378 case 2: diag = error; break; 2379 default: gcc_unreachable (); 2380 } 2381 2382 diag (G_("implicit declaration of function %qE"), id); 2383 if (olddecl) 2384 locate_old_decl (olddecl, diag); 2385} 2386 2387/* Generate an implicit declaration for identifier FUNCTIONID as a 2388 function of type int (). */ 2389 2390tree 2391implicitly_declare (tree functionid) 2392{ 2393 struct c_binding *b; 2394 tree decl = 0; 2395 tree asmspec_tree; 2396 2397 for (b = I_SYMBOL_BINDING (functionid); b; b = b->shadowed) 2398 { 2399 if (B_IN_SCOPE (b, external_scope)) 2400 { 2401 decl = b->decl; 2402 break; 2403 } 2404 } 2405 2406 if (decl) 2407 { 2408 if (decl == error_mark_node) 2409 return decl; 2410 2411 /* FIXME: Objective-C has weird not-really-builtin functions 2412 which are supposed to be visible automatically. They wind up 2413 in the external scope because they're pushed before the file 2414 scope gets created. Catch this here and rebind them into the 2415 file scope. */ 2416 if (!DECL_BUILT_IN (decl) && DECL_IS_BUILTIN (decl)) 2417 { 2418 bind (functionid, decl, file_scope, 2419 /*invisible=*/false, /*nested=*/true); 2420 return decl; 2421 } 2422 else 2423 { 2424 tree newtype = default_function_type; 2425 if (b->type) 2426 TREE_TYPE (decl) = b->type; 2427 /* Implicit declaration of a function already declared 2428 (somehow) in a different scope, or as a built-in. 2429 If this is the first time this has happened, warn; 2430 then recycle the old declaration but with the new type. */ 2431 if (!C_DECL_IMPLICIT (decl)) 2432 { 2433 implicit_decl_warning (functionid, decl); 2434 C_DECL_IMPLICIT (decl) = 1; 2435 } 2436 if (DECL_BUILT_IN (decl)) 2437 { 2438 newtype = build_type_attribute_variant (newtype, 2439 TYPE_ATTRIBUTES 2440 (TREE_TYPE (decl))); 2441 if (!comptypes (newtype, TREE_TYPE (decl))) 2442 { 2443 warning (0, "incompatible implicit declaration of built-in" 2444 " function %qD", decl); 2445 newtype = TREE_TYPE (decl); 2446 } 2447 } 2448 else 2449 { 2450 if (!comptypes (newtype, TREE_TYPE (decl))) 2451 { 2452 error ("incompatible implicit declaration of function %qD", 2453 decl); 2454 locate_old_decl (decl, error); 2455 } 2456 } 2457 b->type = TREE_TYPE (decl); 2458 TREE_TYPE (decl) = newtype; 2459 bind (functionid, decl, current_scope, 2460 /*invisible=*/false, /*nested=*/true); 2461 return decl; 2462 } 2463 } 2464 2465 /* Not seen before. */ 2466 decl = build_decl (FUNCTION_DECL, functionid, default_function_type); 2467 DECL_EXTERNAL (decl) = 1; 2468 TREE_PUBLIC (decl) = 1; 2469 C_DECL_IMPLICIT (decl) = 1; 2470 implicit_decl_warning (functionid, 0); 2471 asmspec_tree = maybe_apply_renaming_pragma (decl, /*asmname=*/NULL); 2472 if (asmspec_tree) 2473 set_user_assembler_name (decl, TREE_STRING_POINTER (asmspec_tree)); 2474 2475 /* C89 says implicit declarations are in the innermost block. 2476 So we record the decl in the standard fashion. */ 2477 decl = pushdecl (decl); 2478 2479 /* No need to call objc_check_decl here - it's a function type. */ 2480 rest_of_decl_compilation (decl, 0, 0); 2481 2482 /* Write a record describing this implicit function declaration 2483 to the prototypes file (if requested). */ 2484 gen_aux_info_record (decl, 0, 1, 0); 2485 2486 /* Possibly apply some default attributes to this implicit declaration. */ 2487 decl_attributes (&decl, NULL_TREE, 0); 2488 2489 return decl; 2490} 2491 2492/* Issue an error message for a reference to an undeclared variable 2493 ID, including a reference to a builtin outside of function-call 2494 context. Establish a binding of the identifier to error_mark_node 2495 in an appropriate scope, which will suppress further errors for the 2496 same identifier. The error message should be given location LOC. */ 2497void 2498undeclared_variable (tree id, location_t loc) 2499{ 2500 static bool already = false; 2501 struct c_scope *scope; 2502 2503 if (current_function_decl == 0) 2504 { 2505 error ("%H%qE undeclared here (not in a function)", &loc, id); 2506 scope = current_scope; 2507 } 2508 else 2509 { 2510 error ("%H%qE undeclared (first use in this function)", &loc, id); 2511 2512 if (!already) 2513 { 2514 error ("%H(Each undeclared identifier is reported only once", &loc); 2515 error ("%Hfor each function it appears in.)", &loc); 2516 already = true; 2517 } 2518 2519 /* If we are parsing old-style parameter decls, current_function_decl 2520 will be nonnull but current_function_scope will be null. */ 2521 scope = current_function_scope ? current_function_scope : current_scope; 2522 } 2523 bind (id, error_mark_node, scope, /*invisible=*/false, /*nested=*/false); 2524} 2525 2526/* Subroutine of lookup_label, declare_label, define_label: construct a 2527 LABEL_DECL with all the proper frills. */ 2528 2529static tree 2530make_label (tree name, location_t location) 2531{ 2532 tree label = build_decl (LABEL_DECL, name, void_type_node); 2533 2534 DECL_CONTEXT (label) = current_function_decl; 2535 DECL_MODE (label) = VOIDmode; 2536 DECL_SOURCE_LOCATION (label) = location; 2537 2538 return label; 2539} 2540 2541/* Get the LABEL_DECL corresponding to identifier NAME as a label. 2542 Create one if none exists so far for the current function. 2543 This is called when a label is used in a goto expression or 2544 has its address taken. */ 2545 2546tree 2547lookup_label (tree name) 2548{ 2549 tree label; 2550 2551 if (current_function_decl == 0) 2552 { 2553 error ("label %qE referenced outside of any function", name); 2554 return 0; 2555 } 2556 2557 /* Use a label already defined or ref'd with this name, but not if 2558 it is inherited from a containing function and wasn't declared 2559 using __label__. */ 2560 label = I_LABEL_DECL (name); 2561 if (label && (DECL_CONTEXT (label) == current_function_decl 2562 || C_DECLARED_LABEL_FLAG (label))) 2563 { 2564 /* If the label has only been declared, update its apparent 2565 location to point here, for better diagnostics if it 2566 turns out not to have been defined. */ 2567 if (!TREE_USED (label)) 2568 DECL_SOURCE_LOCATION (label) = input_location; 2569 return label; 2570 } 2571 2572 /* No label binding for that identifier; make one. */ 2573 label = make_label (name, input_location); 2574 2575 /* Ordinary labels go in the current function scope. */ 2576 bind (name, label, current_function_scope, 2577 /*invisible=*/false, /*nested=*/false); 2578 return label; 2579} 2580 2581/* Make a label named NAME in the current function, shadowing silently 2582 any that may be inherited from containing functions or containing 2583 scopes. This is called for __label__ declarations. */ 2584 2585tree 2586declare_label (tree name) 2587{ 2588 struct c_binding *b = I_LABEL_BINDING (name); 2589 tree label; 2590 2591 /* Check to make sure that the label hasn't already been declared 2592 at this scope */ 2593 if (b && B_IN_CURRENT_SCOPE (b)) 2594 { 2595 error ("duplicate label declaration %qE", name); 2596 locate_old_decl (b->decl, error); 2597 2598 /* Just use the previous declaration. */ 2599 return b->decl; 2600 } 2601 2602 label = make_label (name, input_location); 2603 C_DECLARED_LABEL_FLAG (label) = 1; 2604 2605 /* Declared labels go in the current scope. */ 2606 bind (name, label, current_scope, 2607 /*invisible=*/false, /*nested=*/false); 2608 return label; 2609} 2610 2611/* Define a label, specifying the location in the source file. 2612 Return the LABEL_DECL node for the label, if the definition is valid. 2613 Otherwise return 0. */ 2614 2615tree 2616define_label (location_t location, tree name) 2617{ 2618 /* Find any preexisting label with this name. It is an error 2619 if that label has already been defined in this function, or 2620 if there is a containing function with a declared label with 2621 the same name. */ 2622 tree label = I_LABEL_DECL (name); 2623 struct c_label_list *nlist_se, *nlist_vm; 2624 2625 if (label 2626 && ((DECL_CONTEXT (label) == current_function_decl 2627 && DECL_INITIAL (label) != 0) 2628 || (DECL_CONTEXT (label) != current_function_decl 2629 && C_DECLARED_LABEL_FLAG (label)))) 2630 { 2631 error ("%Hduplicate label %qD", &location, label); 2632 locate_old_decl (label, error); 2633 return 0; 2634 } 2635 else if (label && DECL_CONTEXT (label) == current_function_decl) 2636 { 2637 /* The label has been used or declared already in this function, 2638 but not defined. Update its location to point to this 2639 definition. */ 2640 if (C_DECL_UNDEFINABLE_STMT_EXPR (label)) 2641 error ("%Jjump into statement expression", label); 2642 if (C_DECL_UNDEFINABLE_VM (label)) 2643 error ("%Jjump into scope of identifier with variably modified type", 2644 label); 2645 DECL_SOURCE_LOCATION (label) = location; 2646 } 2647 else 2648 { 2649 /* No label binding for that identifier; make one. */ 2650 label = make_label (name, location); 2651 2652 /* Ordinary labels go in the current function scope. */ 2653 bind (name, label, current_function_scope, 2654 /*invisible=*/false, /*nested=*/false); 2655 } 2656 2657 if (!in_system_header && lookup_name (name)) 2658 warning (OPT_Wtraditional, "%Htraditional C lacks a separate namespace " 2659 "for labels, identifier %qE conflicts", &location, name); 2660 2661 nlist_se = XOBNEW (&parser_obstack, struct c_label_list); 2662 nlist_se->next = label_context_stack_se->labels_def; 2663 nlist_se->label = label; 2664 label_context_stack_se->labels_def = nlist_se; 2665 2666 nlist_vm = XOBNEW (&parser_obstack, struct c_label_list); 2667 nlist_vm->next = label_context_stack_vm->labels_def; 2668 nlist_vm->label = label; 2669 label_context_stack_vm->labels_def = nlist_vm; 2670 2671 /* Mark label as having been defined. */ 2672 DECL_INITIAL (label) = error_mark_node; 2673 return label; 2674} 2675 2676/* Given NAME, an IDENTIFIER_NODE, 2677 return the structure (or union or enum) definition for that name. 2678 If THISLEVEL_ONLY is nonzero, searches only the current_scope. 2679 CODE says which kind of type the caller wants; 2680 it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE. 2681 If the wrong kind of type is found, an error is reported. */ 2682 2683static tree 2684lookup_tag (enum tree_code code, tree name, int thislevel_only) 2685{ 2686 struct c_binding *b = I_TAG_BINDING (name); 2687 int thislevel = 0; 2688 2689 if (!b || !b->decl) 2690 return 0; 2691 2692 /* We only care about whether it's in this level if 2693 thislevel_only was set or it might be a type clash. */ 2694 if (thislevel_only || TREE_CODE (b->decl) != code) 2695 { 2696 /* For our purposes, a tag in the external scope is the same as 2697 a tag in the file scope. (Primarily relevant to Objective-C 2698 and its builtin structure tags, which get pushed before the 2699 file scope is created.) */ 2700 if (B_IN_CURRENT_SCOPE (b) 2701 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 2702 thislevel = 1; 2703 } 2704 2705 if (thislevel_only && !thislevel) 2706 return 0; 2707 2708 if (TREE_CODE (b->decl) != code) 2709 { 2710 /* Definition isn't the kind we were looking for. */ 2711 pending_invalid_xref = name; 2712 pending_invalid_xref_location = input_location; 2713 2714 /* If in the same binding level as a declaration as a tag 2715 of a different type, this must not be allowed to 2716 shadow that tag, so give the error immediately. 2717 (For example, "struct foo; union foo;" is invalid.) */ 2718 if (thislevel) 2719 pending_xref_error (); 2720 } 2721 return b->decl; 2722} 2723 2724/* Print an error message now 2725 for a recent invalid struct, union or enum cross reference. 2726 We don't print them immediately because they are not invalid 2727 when used in the `struct foo;' construct for shadowing. */ 2728 2729void 2730pending_xref_error (void) 2731{ 2732 if (pending_invalid_xref != 0) 2733 error ("%H%qE defined as wrong kind of tag", 2734 &pending_invalid_xref_location, pending_invalid_xref); 2735 pending_invalid_xref = 0; 2736} 2737 2738 2739/* Look up NAME in the current scope and its superiors 2740 in the namespace of variables, functions and typedefs. 2741 Return a ..._DECL node of some kind representing its definition, 2742 or return 0 if it is undefined. */ 2743 2744tree 2745lookup_name (tree name) 2746{ 2747 struct c_binding *b = I_SYMBOL_BINDING (name); 2748 if (b && !b->invisible) 2749 return b->decl; 2750 return 0; 2751} 2752 2753/* Similar to `lookup_name' but look only at the indicated scope. */ 2754 2755static tree 2756lookup_name_in_scope (tree name, struct c_scope *scope) 2757{ 2758 struct c_binding *b; 2759 2760 for (b = I_SYMBOL_BINDING (name); b; b = b->shadowed) 2761 if (B_IN_SCOPE (b, scope)) 2762 return b->decl; 2763 return 0; 2764} 2765 2766/* Create the predefined scalar types of C, 2767 and some nodes representing standard constants (0, 1, (void *) 0). 2768 Initialize the global scope. 2769 Make definitions for built-in primitive functions. */ 2770 2771void 2772c_init_decl_processing (void) 2773{ 2774 location_t save_loc = input_location; 2775 2776 /* Initialize reserved words for parser. */ 2777 c_parse_init (); 2778 2779 current_function_decl = 0; 2780 2781 gcc_obstack_init (&parser_obstack); 2782 2783 /* Make the externals scope. */ 2784 push_scope (); 2785 external_scope = current_scope; 2786 2787 /* Declarations from c_common_nodes_and_builtins must not be associated 2788 with this input file, lest we get differences between using and not 2789 using preprocessed headers. */ 2790#ifdef USE_MAPPED_LOCATION 2791 input_location = BUILTINS_LOCATION; 2792#else 2793 input_location.file = "<built-in>"; 2794 input_location.line = 0; 2795#endif 2796 2797 build_common_tree_nodes (flag_signed_char, false); 2798 2799 c_common_nodes_and_builtins (); 2800 2801 /* In C, comparisons and TRUTH_* expressions have type int. */ 2802 truthvalue_type_node = integer_type_node; 2803 truthvalue_true_node = integer_one_node; 2804 truthvalue_false_node = integer_zero_node; 2805 2806 /* Even in C99, which has a real boolean type. */ 2807 pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"), 2808 boolean_type_node)); 2809 2810 input_location = save_loc; 2811 2812 pedantic_lvalues = true; 2813 2814 make_fname_decl = c_make_fname_decl; 2815 start_fname_decls (); 2816} 2817 2818/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the 2819 decl, NAME is the initialization string and TYPE_DEP indicates whether 2820 NAME depended on the type of the function. As we don't yet implement 2821 delayed emission of static data, we mark the decl as emitted 2822 so it is not placed in the output. Anything using it must therefore pull 2823 out the STRING_CST initializer directly. FIXME. */ 2824 2825static tree 2826c_make_fname_decl (tree id, int type_dep) 2827{ 2828 const char *name = fname_as_string (type_dep); 2829 tree decl, type, init; 2830 size_t length = strlen (name); 2831 2832 type = build_array_type (char_type_node, 2833 build_index_type (size_int (length))); 2834 type = c_build_qualified_type (type, TYPE_QUAL_CONST); 2835 2836 decl = build_decl (VAR_DECL, id, type); 2837 2838 TREE_STATIC (decl) = 1; 2839 TREE_READONLY (decl) = 1; 2840 DECL_ARTIFICIAL (decl) = 1; 2841 2842 init = build_string (length + 1, name); 2843 free ((char *) name); 2844 TREE_TYPE (init) = type; 2845 DECL_INITIAL (decl) = init; 2846 2847 TREE_USED (decl) = 1; 2848 2849 if (current_function_decl 2850 /* For invalid programs like this: 2851 2852 void foo() 2853 const char* p = __FUNCTION__; 2854 2855 the __FUNCTION__ is believed to appear in K&R style function 2856 parameter declarator. In that case we still don't have 2857 function_scope. */ 2858 && (!errorcount || current_function_scope)) 2859 { 2860 DECL_CONTEXT (decl) = current_function_decl; 2861 bind (id, decl, current_function_scope, 2862 /*invisible=*/false, /*nested=*/false); 2863 } 2864 2865 finish_decl (decl, init, NULL_TREE); 2866 2867 return decl; 2868} 2869 2870/* Return a definition for a builtin function named NAME and whose data type 2871 is TYPE. TYPE should be a function type with argument types. 2872 FUNCTION_CODE tells later passes how to compile calls to this function. 2873 See tree.h for its possible values. 2874 2875 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, 2876 the name to be called if we can't opencode the function. If 2877 ATTRS is nonzero, use that for the function's attribute list. */ 2878 2879tree 2880builtin_function (const char *name, tree type, int function_code, 2881 enum built_in_class cl, const char *library_name, 2882 tree attrs) 2883{ 2884 tree id = get_identifier (name); 2885 tree decl = build_decl (FUNCTION_DECL, id, type); 2886 TREE_PUBLIC (decl) = 1; 2887 DECL_EXTERNAL (decl) = 1; 2888 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 2889 DECL_BUILT_IN_CLASS (decl) = cl; 2890 DECL_FUNCTION_CODE (decl) = function_code; 2891 C_DECL_BUILTIN_PROTOTYPE (decl) = (TYPE_ARG_TYPES (type) != 0); 2892 if (library_name) 2893 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name)); 2894 2895 /* Should never be called on a symbol with a preexisting meaning. */ 2896 gcc_assert (!I_SYMBOL_BINDING (id)); 2897 2898 bind (id, decl, external_scope, /*invisible=*/true, /*nested=*/false); 2899 2900 /* Builtins in the implementation namespace are made visible without 2901 needing to be explicitly declared. See push_file_scope. */ 2902 if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1]))) 2903 { 2904 TREE_CHAIN (decl) = visible_builtins; 2905 visible_builtins = decl; 2906 } 2907 2908 /* Possibly apply some default attributes to this built-in function. */ 2909 if (attrs) 2910 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN); 2911 else 2912 decl_attributes (&decl, NULL_TREE, 0); 2913 2914 return decl; 2915} 2916 2917/* Called when a declaration is seen that contains no names to declare. 2918 If its type is a reference to a structure, union or enum inherited 2919 from a containing scope, shadow that tag name for the current scope 2920 with a forward reference. 2921 If its type defines a new named structure or union 2922 or defines an enum, it is valid but we need not do anything here. 2923 Otherwise, it is an error. */ 2924 2925void 2926shadow_tag (const struct c_declspecs *declspecs) 2927{ 2928 shadow_tag_warned (declspecs, 0); 2929} 2930 2931/* WARNED is 1 if we have done a pedwarn, 2 if we have done a warning, 2932 but no pedwarn. */ 2933void 2934shadow_tag_warned (const struct c_declspecs *declspecs, int warned) 2935{ 2936 bool found_tag = false; 2937 2938 if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p) 2939 { 2940 tree value = declspecs->type; 2941 enum tree_code code = TREE_CODE (value); 2942 2943 if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) 2944 /* Used to test also that TYPE_SIZE (value) != 0. 2945 That caused warning for `struct foo;' at top level in the file. */ 2946 { 2947 tree name = TYPE_NAME (value); 2948 tree t; 2949 2950 found_tag = true; 2951 2952 if (name == 0) 2953 { 2954 if (warned != 1 && code != ENUMERAL_TYPE) 2955 /* Empty unnamed enum OK */ 2956 { 2957 pedwarn ("unnamed struct/union that defines no instances"); 2958 warned = 1; 2959 } 2960 } 2961 else if (!declspecs->tag_defined_p 2962 && declspecs->storage_class != csc_none) 2963 { 2964 if (warned != 1) 2965 pedwarn ("empty declaration with storage class specifier " 2966 "does not redeclare tag"); 2967 warned = 1; 2968 pending_xref_error (); 2969 } 2970 else if (!declspecs->tag_defined_p 2971 && (declspecs->const_p 2972 || declspecs->volatile_p 2973 || declspecs->restrict_p)) 2974 { 2975 if (warned != 1) 2976 pedwarn ("empty declaration with type qualifier " 2977 "does not redeclare tag"); 2978 warned = 1; 2979 pending_xref_error (); 2980 } 2981 else 2982 { 2983 pending_invalid_xref = 0; 2984 t = lookup_tag (code, name, 1); 2985 2986 if (t == 0) 2987 { 2988 t = make_node (code); 2989 pushtag (name, t); 2990 } 2991 } 2992 } 2993 else 2994 { 2995 if (warned != 1 && !in_system_header) 2996 { 2997 pedwarn ("useless type name in empty declaration"); 2998 warned = 1; 2999 } 3000 } 3001 } 3002 else if (warned != 1 && !in_system_header && declspecs->typedef_p) 3003 { 3004 pedwarn ("useless type name in empty declaration"); 3005 warned = 1; 3006 } 3007 3008 pending_invalid_xref = 0; 3009 3010 if (declspecs->inline_p) 3011 { 3012 error ("%<inline%> in empty declaration"); 3013 warned = 1; 3014 } 3015 3016 if (current_scope == file_scope && declspecs->storage_class == csc_auto) 3017 { 3018 error ("%<auto%> in file-scope empty declaration"); 3019 warned = 1; 3020 } 3021 3022 if (current_scope == file_scope && declspecs->storage_class == csc_register) 3023 { 3024 error ("%<register%> in file-scope empty declaration"); 3025 warned = 1; 3026 } 3027 3028 if (!warned && !in_system_header && declspecs->storage_class != csc_none) 3029 { 3030 warning (0, "useless storage class specifier in empty declaration"); 3031 warned = 2; 3032 } 3033 3034 if (!warned && !in_system_header && declspecs->thread_p) 3035 { 3036 warning (0, "useless %<__thread%> in empty declaration"); 3037 warned = 2; 3038 } 3039 3040 if (!warned && !in_system_header && (declspecs->const_p 3041 || declspecs->volatile_p 3042 || declspecs->restrict_p)) 3043 { 3044 warning (0, "useless type qualifier in empty declaration"); 3045 warned = 2; 3046 } 3047 3048 if (warned != 1) 3049 { 3050 if (!found_tag) 3051 pedwarn ("empty declaration"); 3052 } 3053} 3054 3055 3056/* Return the qualifiers from SPECS as a bitwise OR of TYPE_QUAL_* 3057 bits. SPECS represents declaration specifiers that the grammar 3058 only permits to contain type qualifiers and attributes. */ 3059 3060int 3061quals_from_declspecs (const struct c_declspecs *specs) 3062{ 3063 int quals = ((specs->const_p ? TYPE_QUAL_CONST : 0) 3064 | (specs->volatile_p ? TYPE_QUAL_VOLATILE : 0) 3065 | (specs->restrict_p ? TYPE_QUAL_RESTRICT : 0)); 3066 gcc_assert (!specs->type 3067 && !specs->decl_attr 3068 && specs->typespec_word == cts_none 3069 && specs->storage_class == csc_none 3070 && !specs->typedef_p 3071 && !specs->explicit_signed_p 3072 && !specs->deprecated_p 3073 && !specs->long_p 3074 && !specs->long_long_p 3075 && !specs->short_p 3076 && !specs->signed_p 3077 && !specs->unsigned_p 3078 && !specs->complex_p 3079 && !specs->inline_p 3080 && !specs->thread_p); 3081 return quals; 3082} 3083 3084/* Construct an array declarator. EXPR is the expression inside [], 3085 or NULL_TREE. QUALS are the type qualifiers inside the [] (to be 3086 applied to the pointer to which a parameter array is converted). 3087 STATIC_P is true if "static" is inside the [], false otherwise. 3088 VLA_UNSPEC_P is true if the array is [*], a VLA of unspecified 3089 length which is nevertheless a complete type, false otherwise. The 3090 field for the contained declarator is left to be filled in by 3091 set_array_declarator_inner. */ 3092 3093struct c_declarator * 3094build_array_declarator (tree expr, struct c_declspecs *quals, bool static_p, 3095 bool vla_unspec_p) 3096{ 3097 struct c_declarator *declarator = XOBNEW (&parser_obstack, 3098 struct c_declarator); 3099 declarator->kind = cdk_array; 3100 declarator->declarator = 0; 3101 declarator->u.array.dimen = expr; 3102 if (quals) 3103 { 3104 declarator->u.array.attrs = quals->attrs; 3105 declarator->u.array.quals = quals_from_declspecs (quals); 3106 } 3107 else 3108 { 3109 declarator->u.array.attrs = NULL_TREE; 3110 declarator->u.array.quals = 0; 3111 } 3112 declarator->u.array.static_p = static_p; 3113 declarator->u.array.vla_unspec_p = vla_unspec_p; 3114 if (pedantic && !flag_isoc99) 3115 { 3116 if (static_p || quals != NULL) 3117 pedwarn ("ISO C90 does not support %<static%> or type " 3118 "qualifiers in parameter array declarators"); 3119 if (vla_unspec_p) 3120 pedwarn ("ISO C90 does not support %<[*]%> array declarators"); 3121 } 3122 if (vla_unspec_p) 3123 { 3124 if (!current_scope->parm_flag) 3125 { 3126 /* C99 6.7.5.2p4 */ 3127 error ("%<[*]%> not allowed in other than function prototype scope"); 3128 declarator->u.array.vla_unspec_p = false; 3129 return NULL; 3130 } 3131 current_scope->had_vla_unspec = true; 3132 } 3133 return declarator; 3134} 3135 3136/* Set the contained declarator of an array declarator. DECL is the 3137 declarator, as constructed by build_array_declarator; INNER is what 3138 appears on the left of the []. ABSTRACT_P is true if it is an 3139 abstract declarator, false otherwise; this is used to reject static 3140 and type qualifiers in abstract declarators, where they are not in 3141 the C99 grammar (subject to possible change in DR#289). */ 3142 3143struct c_declarator * 3144set_array_declarator_inner (struct c_declarator *decl, 3145 struct c_declarator *inner, bool abstract_p) 3146{ 3147 decl->declarator = inner; 3148 if (abstract_p && (decl->u.array.quals != TYPE_UNQUALIFIED 3149 || decl->u.array.attrs != NULL_TREE 3150 || decl->u.array.static_p)) 3151 error ("static or type qualifiers in abstract declarator"); 3152 return decl; 3153} 3154 3155/* INIT is a constructor that forms DECL's initializer. If the final 3156 element initializes a flexible array field, add the size of that 3157 initializer to DECL's size. */ 3158 3159static void 3160add_flexible_array_elts_to_size (tree decl, tree init) 3161{ 3162 tree elt, type; 3163 3164 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init))) 3165 return; 3166 3167 elt = VEC_last (constructor_elt, CONSTRUCTOR_ELTS (init))->value; 3168 type = TREE_TYPE (elt); 3169 if (TREE_CODE (type) == ARRAY_TYPE 3170 && TYPE_SIZE (type) == NULL_TREE 3171 && TYPE_DOMAIN (type) != NULL_TREE 3172 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL_TREE) 3173 { 3174 complete_array_type (&type, elt, false); 3175 DECL_SIZE (decl) 3176 = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type)); 3177 DECL_SIZE_UNIT (decl) 3178 = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type)); 3179 } 3180} 3181 3182/* Decode a "typename", such as "int **", returning a ..._TYPE node. */ 3183 3184tree 3185groktypename (struct c_type_name *type_name) 3186{ 3187 tree type; 3188 tree attrs = type_name->specs->attrs; 3189 3190 type_name->specs->attrs = NULL_TREE; 3191 3192 type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME, 3193 false, NULL); 3194 3195 /* Apply attributes. */ 3196 decl_attributes (&type, attrs, 0); 3197 3198 return type; 3199} 3200 3201/* Decode a declarator in an ordinary declaration or data definition. 3202 This is called as soon as the type information and variable name 3203 have been parsed, before parsing the initializer if any. 3204 Here we create the ..._DECL node, fill in its type, 3205 and put it on the list of decls for the current context. 3206 The ..._DECL node is returned as the value. 3207 3208 Exception: for arrays where the length is not specified, 3209 the type is left null, to be filled in by `finish_decl'. 3210 3211 Function definitions do not come here; they go to start_function 3212 instead. However, external and forward declarations of functions 3213 do go through here. Structure field declarations are done by 3214 grokfield and not through here. */ 3215 3216tree 3217start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, 3218 bool initialized, tree attributes) 3219{ 3220 tree decl; 3221 tree tem; 3222 3223 /* An object declared as __attribute__((deprecated)) suppresses 3224 warnings of uses of other deprecated items. */ 3225 if (lookup_attribute ("deprecated", attributes)) 3226 deprecated_state = DEPRECATED_SUPPRESS; 3227 3228 decl = grokdeclarator (declarator, declspecs, 3229 NORMAL, initialized, NULL); 3230 if (!decl) 3231 return 0; 3232 3233 deprecated_state = DEPRECATED_NORMAL; 3234 3235 if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL 3236 && MAIN_NAME_P (DECL_NAME (decl))) 3237 warning (OPT_Wmain, "%q+D is usually a function", decl); 3238 3239 if (initialized) 3240 /* Is it valid for this decl to have an initializer at all? 3241 If not, set INITIALIZED to zero, which will indirectly 3242 tell 'finish_decl' to ignore the initializer once it is parsed. */ 3243 switch (TREE_CODE (decl)) 3244 { 3245 case TYPE_DECL: 3246 error ("typedef %qD is initialized (use __typeof__ instead)", decl); 3247 initialized = 0; 3248 break; 3249 3250 case FUNCTION_DECL: 3251 error ("function %qD is initialized like a variable", decl); 3252 initialized = 0; 3253 break; 3254 3255 case PARM_DECL: 3256 /* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE. */ 3257 error ("parameter %qD is initialized", decl); 3258 initialized = 0; 3259 break; 3260 3261 default: 3262 /* Don't allow initializations for incomplete types except for 3263 arrays which might be completed by the initialization. */ 3264 3265 /* This can happen if the array size is an undefined macro. 3266 We already gave a warning, so we don't need another one. */ 3267 if (TREE_TYPE (decl) == error_mark_node) 3268 initialized = 0; 3269 else if (COMPLETE_TYPE_P (TREE_TYPE (decl))) 3270 { 3271 /* A complete type is ok if size is fixed. */ 3272 3273 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST 3274 || C_DECL_VARIABLE_SIZE (decl)) 3275 { 3276 error ("variable-sized object may not be initialized"); 3277 initialized = 0; 3278 } 3279 } 3280 else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE) 3281 { 3282 error ("variable %qD has initializer but incomplete type", decl); 3283 initialized = 0; 3284 } 3285 else if (C_DECL_VARIABLE_SIZE (decl)) 3286 { 3287 /* Although C99 is unclear about whether incomplete arrays 3288 of VLAs themselves count as VLAs, it does not make 3289 sense to permit them to be initialized given that 3290 ordinary VLAs may not be initialized. */ 3291 error ("variable-sized object may not be initialized"); 3292 initialized = 0; 3293 } 3294 } 3295 3296 if (initialized) 3297 { 3298 if (current_scope == file_scope) 3299 TREE_STATIC (decl) = 1; 3300 3301 /* Tell 'pushdecl' this is an initialized decl 3302 even though we don't yet have the initializer expression. 3303 Also tell 'finish_decl' it may store the real initializer. */ 3304 DECL_INITIAL (decl) = error_mark_node; 3305 } 3306 3307 /* If this is a function declaration, write a record describing it to the 3308 prototypes file (if requested). */ 3309 3310 if (TREE_CODE (decl) == FUNCTION_DECL) 3311 gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0); 3312 3313 /* ANSI specifies that a tentative definition which is not merged with 3314 a non-tentative definition behaves exactly like a definition with an 3315 initializer equal to zero. (Section 3.7.2) 3316 3317 -fno-common gives strict ANSI behavior, though this tends to break 3318 a large body of code that grew up without this rule. 3319 3320 Thread-local variables are never common, since there's no entrenched 3321 body of code to break, and it allows more efficient variable references 3322 in the presence of dynamic linking. */ 3323 3324 if (TREE_CODE (decl) == VAR_DECL 3325 && !initialized 3326 && TREE_PUBLIC (decl) 3327 && !DECL_THREAD_LOCAL_P (decl) 3328 && !flag_no_common) 3329 DECL_COMMON (decl) = 1; 3330 3331 /* Set attributes here so if duplicate decl, will have proper attributes. */ 3332 decl_attributes (&decl, attributes, 0); 3333 3334 /* Handle gnu_inline attribute. */ 3335 if (declspecs->inline_p 3336 && !flag_gnu89_inline 3337 && TREE_CODE (decl) == FUNCTION_DECL 3338 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl))) 3339 { 3340 if (declspecs->storage_class == csc_auto && current_scope != file_scope) 3341 ; 3342 else if (declspecs->storage_class != csc_static) 3343 DECL_EXTERNAL (decl) = !DECL_EXTERNAL (decl); 3344 } 3345 3346 if (TREE_CODE (decl) == FUNCTION_DECL 3347 && targetm.calls.promote_prototypes (TREE_TYPE (decl))) 3348 { 3349 struct c_declarator *ce = declarator; 3350 3351 if (ce->kind == cdk_pointer) 3352 ce = declarator->declarator; 3353 if (ce->kind == cdk_function) 3354 { 3355 tree args = ce->u.arg_info->parms; 3356 for (; args; args = TREE_CHAIN (args)) 3357 { 3358 tree type = TREE_TYPE (args); 3359 if (type && INTEGRAL_TYPE_P (type) 3360 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 3361 DECL_ARG_TYPE (args) = integer_type_node; 3362 } 3363 } 3364 } 3365 3366 if (TREE_CODE (decl) == FUNCTION_DECL 3367 && DECL_DECLARED_INLINE_P (decl) 3368 && DECL_UNINLINABLE (decl) 3369 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl))) 3370 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 3371 decl); 3372 3373 /* C99 6.7.4p3: An inline definition of a function with external 3374 linkage shall not contain a definition of a modifiable object 3375 with static storage duration... */ 3376 if (TREE_CODE (decl) == VAR_DECL 3377 && current_scope != file_scope 3378 && TREE_STATIC (decl) 3379 && !TREE_READONLY (decl) 3380 && DECL_DECLARED_INLINE_P (current_function_decl) 3381 && DECL_EXTERNAL (current_function_decl)) 3382 pedwarn ("%q+D is static but declared in inline function %qD " 3383 "which is not static", decl, current_function_decl); 3384 3385 /* Add this decl to the current scope. 3386 TEM may equal DECL or it may be a previous decl of the same name. */ 3387 tem = pushdecl (decl); 3388 3389 if (initialized && DECL_EXTERNAL (tem)) 3390 { 3391 DECL_EXTERNAL (tem) = 0; 3392 TREE_STATIC (tem) = 1; 3393 } 3394 3395 return tem; 3396} 3397 3398/* Initialize EH if not initialized yet and exceptions are enabled. */ 3399 3400void 3401c_maybe_initialize_eh (void) 3402{ 3403 if (!flag_exceptions || c_eh_initialized_p) 3404 return; 3405 3406 c_eh_initialized_p = true; 3407 eh_personality_libfunc 3408 = init_one_libfunc (USING_SJLJ_EXCEPTIONS 3409 ? "__gcc_personality_sj0" 3410 : "__gcc_personality_v0"); 3411 default_init_unwind_resume_libfunc (); 3412 using_eh_for_cleanups (); 3413} 3414 3415/* Finish processing of a declaration; 3416 install its initial value. 3417 If the length of an array type is not known before, 3418 it must be determined now, from the initial value, or it is an error. */ 3419 3420void 3421finish_decl (tree decl, tree init, tree asmspec_tree) 3422{ 3423 tree type; 3424 int was_incomplete = (DECL_SIZE (decl) == 0); 3425 const char *asmspec = 0; 3426 3427 /* If a name was specified, get the string. */ 3428 if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL) 3429 && DECL_FILE_SCOPE_P (decl)) 3430 asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree); 3431 if (asmspec_tree) 3432 asmspec = TREE_STRING_POINTER (asmspec_tree); 3433 3434 /* If `start_decl' didn't like having an initialization, ignore it now. */ 3435 if (init != 0 && DECL_INITIAL (decl) == 0) 3436 init = 0; 3437 3438 /* Don't crash if parm is initialized. */ 3439 if (TREE_CODE (decl) == PARM_DECL) 3440 init = 0; 3441 3442 if (init) 3443 store_init_value (decl, init); 3444 3445 if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL 3446 || TREE_CODE (decl) == FUNCTION_DECL 3447 || TREE_CODE (decl) == FIELD_DECL)) 3448 objc_check_decl (decl); 3449 3450 type = TREE_TYPE (decl); 3451 3452 /* Deduce size of array from initialization, if not already known. */ 3453 if (TREE_CODE (type) == ARRAY_TYPE 3454 && TYPE_DOMAIN (type) == 0 3455 && TREE_CODE (decl) != TYPE_DECL) 3456 { 3457 bool do_default 3458 = (TREE_STATIC (decl) 3459 /* Even if pedantic, an external linkage array 3460 may have incomplete type at first. */ 3461 ? pedantic && !TREE_PUBLIC (decl) 3462 : !DECL_EXTERNAL (decl)); 3463 int failure 3464 = complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl), 3465 do_default); 3466 3467 /* Get the completed type made by complete_array_type. */ 3468 type = TREE_TYPE (decl); 3469 3470 switch (failure) 3471 { 3472 case 1: 3473 error ("initializer fails to determine size of %q+D", decl); 3474 break; 3475 3476 case 2: 3477 if (do_default) 3478 error ("array size missing in %q+D", decl); 3479 /* If a `static' var's size isn't known, 3480 make it extern as well as static, so it does not get 3481 allocated. 3482 If it is not `static', then do not mark extern; 3483 finish_incomplete_decl will give it a default size 3484 and it will get allocated. */ 3485 else if (!pedantic && TREE_STATIC (decl) && !TREE_PUBLIC (decl)) 3486 DECL_EXTERNAL (decl) = 1; 3487 break; 3488 3489 case 3: 3490 error ("zero or negative size array %q+D", decl); 3491 break; 3492 3493 case 0: 3494 /* For global variables, update the copy of the type that 3495 exists in the binding. */ 3496 if (TREE_PUBLIC (decl)) 3497 { 3498 struct c_binding *b_ext = I_SYMBOL_BINDING (DECL_NAME (decl)); 3499 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 3500 b_ext = b_ext->shadowed; 3501 if (b_ext) 3502 { 3503 if (b_ext->type) 3504 b_ext->type = composite_type (b_ext->type, type); 3505 else 3506 b_ext->type = type; 3507 } 3508 } 3509 break; 3510 3511 default: 3512 gcc_unreachable (); 3513 } 3514 3515 if (DECL_INITIAL (decl)) 3516 TREE_TYPE (DECL_INITIAL (decl)) = type; 3517 3518 layout_decl (decl, 0); 3519 } 3520 3521 if (TREE_CODE (decl) == VAR_DECL) 3522 { 3523 if (init && TREE_CODE (init) == CONSTRUCTOR) 3524 add_flexible_array_elts_to_size (decl, init); 3525 3526 if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node 3527 && COMPLETE_TYPE_P (TREE_TYPE (decl))) 3528 layout_decl (decl, 0); 3529 3530 if (DECL_SIZE (decl) == 0 3531 /* Don't give an error if we already gave one earlier. */ 3532 && TREE_TYPE (decl) != error_mark_node 3533 && (TREE_STATIC (decl) 3534 /* A static variable with an incomplete type 3535 is an error if it is initialized. 3536 Also if it is not file scope. 3537 Otherwise, let it through, but if it is not `extern' 3538 then it may cause an error message later. */ 3539 ? (DECL_INITIAL (decl) != 0 3540 || !DECL_FILE_SCOPE_P (decl)) 3541 /* An automatic variable with an incomplete type 3542 is an error. */ 3543 : !DECL_EXTERNAL (decl))) 3544 { 3545 error ("storage size of %q+D isn%'t known", decl); 3546 TREE_TYPE (decl) = error_mark_node; 3547 } 3548 3549 if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl)) 3550 && DECL_SIZE (decl) != 0) 3551 { 3552 if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) 3553 constant_expression_warning (DECL_SIZE (decl)); 3554 else 3555 error ("storage size of %q+D isn%'t constant", decl); 3556 } 3557 3558 if (TREE_USED (type)) 3559 TREE_USED (decl) = 1; 3560 } 3561 3562 /* If this is a function and an assembler name is specified, reset DECL_RTL 3563 so we can give it its new name. Also, update built_in_decls if it 3564 was a normal built-in. */ 3565 if (TREE_CODE (decl) == FUNCTION_DECL && asmspec) 3566 { 3567 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) 3568 set_builtin_user_assembler_name (decl, asmspec); 3569 set_user_assembler_name (decl, asmspec); 3570 } 3571 3572 /* If #pragma weak was used, mark the decl weak now. */ 3573 maybe_apply_pragma_weak (decl); 3574 3575 /* Output the assembler code and/or RTL code for variables and functions, 3576 unless the type is an undefined structure or union. 3577 If not, it will get done when the type is completed. */ 3578 3579 if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL) 3580 { 3581 /* Determine the ELF visibility. */ 3582 if (TREE_PUBLIC (decl)) 3583 c_determine_visibility (decl); 3584 3585 /* This is a no-op in c-lang.c or something real in objc-act.c. */ 3586 if (c_dialect_objc ()) 3587 objc_check_decl (decl); 3588 3589 if (asmspec) 3590 { 3591 /* If this is not a static variable, issue a warning. 3592 It doesn't make any sense to give an ASMSPEC for an 3593 ordinary, non-register local variable. Historically, 3594 GCC has accepted -- but ignored -- the ASMSPEC in 3595 this case. */ 3596 if (!DECL_FILE_SCOPE_P (decl) 3597 && TREE_CODE (decl) == VAR_DECL 3598 && !C_DECL_REGISTER (decl) 3599 && !TREE_STATIC (decl)) 3600 warning (0, "ignoring asm-specifier for non-static local " 3601 "variable %q+D", decl); 3602 else 3603 set_user_assembler_name (decl, asmspec); 3604 } 3605 3606 if (DECL_FILE_SCOPE_P (decl)) 3607 { 3608 if (DECL_INITIAL (decl) == NULL_TREE 3609 || DECL_INITIAL (decl) == error_mark_node) 3610 /* Don't output anything 3611 when a tentative file-scope definition is seen. 3612 But at end of compilation, do output code for them. */ 3613 DECL_DEFER_OUTPUT (decl) = 1; 3614 rest_of_decl_compilation (decl, true, 0); 3615 } 3616 else 3617 { 3618 /* In conjunction with an ASMSPEC, the `register' 3619 keyword indicates that we should place the variable 3620 in a particular register. */ 3621 if (asmspec && C_DECL_REGISTER (decl)) 3622 { 3623 DECL_HARD_REGISTER (decl) = 1; 3624 /* This cannot be done for a structure with volatile 3625 fields, on which DECL_REGISTER will have been 3626 reset. */ 3627 if (!DECL_REGISTER (decl)) 3628 error ("cannot put object with volatile field into register"); 3629 } 3630 3631 if (TREE_CODE (decl) != FUNCTION_DECL) 3632 { 3633 /* If we're building a variable sized type, and we might be 3634 reachable other than via the top of the current binding 3635 level, then create a new BIND_EXPR so that we deallocate 3636 the object at the right time. */ 3637 /* Note that DECL_SIZE can be null due to errors. */ 3638 if (DECL_SIZE (decl) 3639 && !TREE_CONSTANT (DECL_SIZE (decl)) 3640 && STATEMENT_LIST_HAS_LABEL (cur_stmt_list)) 3641 { 3642 tree bind; 3643 bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL); 3644 TREE_SIDE_EFFECTS (bind) = 1; 3645 add_stmt (bind); 3646 BIND_EXPR_BODY (bind) = push_stmt_list (); 3647 } 3648 add_stmt (build_stmt (DECL_EXPR, decl)); 3649 } 3650 } 3651 3652 3653 if (!DECL_FILE_SCOPE_P (decl)) 3654 { 3655 /* Recompute the RTL of a local array now 3656 if it used to be an incomplete type. */ 3657 if (was_incomplete 3658 && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) 3659 { 3660 /* If we used it already as memory, it must stay in memory. */ 3661 TREE_ADDRESSABLE (decl) = TREE_USED (decl); 3662 /* If it's still incomplete now, no init will save it. */ 3663 if (DECL_SIZE (decl) == 0) 3664 DECL_INITIAL (decl) = 0; 3665 } 3666 } 3667 } 3668 3669 /* If this was marked 'used', be sure it will be output. */ 3670 if (!flag_unit_at_a_time && lookup_attribute ("used", DECL_ATTRIBUTES (decl))) 3671 mark_decl_referenced (decl); 3672 3673 if (TREE_CODE (decl) == TYPE_DECL) 3674 { 3675 if (!DECL_FILE_SCOPE_P (decl) 3676 && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 3677 add_stmt (build_stmt (DECL_EXPR, decl)); 3678 3679 rest_of_decl_compilation (decl, DECL_FILE_SCOPE_P (decl), 0); 3680 } 3681 3682 /* At the end of a declaration, throw away any variable type sizes 3683 of types defined inside that declaration. There is no use 3684 computing them in the following function definition. */ 3685 if (current_scope == file_scope) 3686 get_pending_sizes (); 3687 3688 /* Install a cleanup (aka destructor) if one was given. */ 3689 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 3690 { 3691 tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl)); 3692 if (attr) 3693 { 3694 tree cleanup_id = TREE_VALUE (TREE_VALUE (attr)); 3695 tree cleanup_decl = lookup_name (cleanup_id); 3696 tree cleanup; 3697 3698 /* Build "cleanup(&decl)" for the destructor. */ 3699 cleanup = build_unary_op (ADDR_EXPR, decl, 0); 3700 cleanup = build_tree_list (NULL_TREE, cleanup); 3701 cleanup = build_function_call (cleanup_decl, cleanup); 3702 3703 /* Don't warn about decl unused; the cleanup uses it. */ 3704 TREE_USED (decl) = 1; 3705 TREE_USED (cleanup_decl) = 1; 3706 3707 /* Initialize EH, if we've been told to do so. */ 3708 c_maybe_initialize_eh (); 3709 3710 push_cleanup (decl, cleanup, false); 3711 } 3712 } 3713} 3714 3715/* Given a parsed parameter declaration, decode it into a PARM_DECL. */ 3716 3717tree 3718grokparm (const struct c_parm *parm) 3719{ 3720 tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, 3721 NULL); 3722 3723 decl_attributes (&decl, parm->attrs, 0); 3724 3725 return decl; 3726} 3727 3728/* Given a parsed parameter declaration, decode it into a PARM_DECL 3729 and push that on the current scope. */ 3730 3731void 3732push_parm_decl (const struct c_parm *parm) 3733{ 3734 tree decl; 3735 3736 decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL); 3737 decl_attributes (&decl, parm->attrs, 0); 3738 3739 decl = pushdecl (decl); 3740 3741 finish_decl (decl, NULL_TREE, NULL_TREE); 3742} 3743 3744/* Mark all the parameter declarations to date as forward decls. 3745 Also diagnose use of this extension. */ 3746 3747void 3748mark_forward_parm_decls (void) 3749{ 3750 struct c_binding *b; 3751 3752 if (pedantic && !current_scope->warned_forward_parm_decls) 3753 { 3754 pedwarn ("ISO C forbids forward parameter declarations"); 3755 current_scope->warned_forward_parm_decls = true; 3756 } 3757 3758 for (b = current_scope->bindings; b; b = b->prev) 3759 if (TREE_CODE (b->decl) == PARM_DECL) 3760 TREE_ASM_WRITTEN (b->decl) = 1; 3761} 3762 3763/* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound 3764 literal, which may be an incomplete array type completed by the 3765 initializer; INIT is a CONSTRUCTOR that initializes the compound 3766 literal. */ 3767 3768tree 3769build_compound_literal (tree type, tree init) 3770{ 3771 /* We do not use start_decl here because we have a type, not a declarator; 3772 and do not use finish_decl because the decl should be stored inside 3773 the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_EXPR. */ 3774 tree decl; 3775 tree complit; 3776 tree stmt; 3777 3778 if (type == error_mark_node) 3779 return error_mark_node; 3780 3781 decl = build_decl (VAR_DECL, NULL_TREE, type); 3782 DECL_EXTERNAL (decl) = 0; 3783 TREE_PUBLIC (decl) = 0; 3784 TREE_STATIC (decl) = (current_scope == file_scope); 3785 DECL_CONTEXT (decl) = current_function_decl; 3786 TREE_USED (decl) = 1; 3787 TREE_TYPE (decl) = type; 3788 TREE_READONLY (decl) = TYPE_READONLY (type); 3789 store_init_value (decl, init); 3790 3791 if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type)) 3792 { 3793 int failure = complete_array_type (&TREE_TYPE (decl), 3794 DECL_INITIAL (decl), true); 3795 gcc_assert (!failure); 3796 3797 type = TREE_TYPE (decl); 3798 TREE_TYPE (DECL_INITIAL (decl)) = type; 3799 } 3800 3801 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 3802 return error_mark_node; 3803 3804 stmt = build_stmt (DECL_EXPR, decl); 3805 complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt); 3806 TREE_SIDE_EFFECTS (complit) = 1; 3807 3808 layout_decl (decl, 0); 3809 3810 if (TREE_STATIC (decl)) 3811 { 3812 /* This decl needs a name for the assembler output. */ 3813 set_compound_literal_name (decl); 3814 DECL_DEFER_OUTPUT (decl) = 1; 3815 DECL_COMDAT (decl) = 1; 3816 DECL_ARTIFICIAL (decl) = 1; 3817 DECL_IGNORED_P (decl) = 1; 3818 pushdecl (decl); 3819 rest_of_decl_compilation (decl, 1, 0); 3820 } 3821 3822 return complit; 3823} 3824 3825/* Determine whether TYPE is a structure with a flexible array member, 3826 or a union containing such a structure (possibly recursively). */ 3827 3828static bool 3829flexible_array_type_p (tree type) 3830{ 3831 tree x; 3832 switch (TREE_CODE (type)) 3833 { 3834 case RECORD_TYPE: 3835 x = TYPE_FIELDS (type); 3836 if (x == NULL_TREE) 3837 return false; 3838 while (TREE_CHAIN (x) != NULL_TREE) 3839 x = TREE_CHAIN (x); 3840 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 3841 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 3842 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 3843 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 3844 return true; 3845 return false; 3846 case UNION_TYPE: 3847 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x)) 3848 { 3849 if (flexible_array_type_p (TREE_TYPE (x))) 3850 return true; 3851 } 3852 return false; 3853 default: 3854 return false; 3855 } 3856} 3857 3858/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 3859 replacing with appropriate values if they are invalid. */ 3860static void 3861check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name) 3862{ 3863 tree type_mv; 3864 unsigned int max_width; 3865 unsigned HOST_WIDE_INT w; 3866 const char *name = orig_name ? orig_name: _("<anonymous>"); 3867 3868 /* Detect and ignore out of range field width and process valid 3869 field widths. */ 3870 if (!INTEGRAL_TYPE_P (TREE_TYPE (*width)) 3871 || TREE_CODE (*width) != INTEGER_CST) 3872 { 3873 error ("bit-field %qs width not an integer constant", name); 3874 *width = integer_one_node; 3875 } 3876 else 3877 { 3878 constant_expression_warning (*width); 3879 if (tree_int_cst_sgn (*width) < 0) 3880 { 3881 error ("negative width in bit-field %qs", name); 3882 *width = integer_one_node; 3883 } 3884 else if (integer_zerop (*width) && orig_name) 3885 { 3886 error ("zero width for bit-field %qs", name); 3887 *width = integer_one_node; 3888 } 3889 } 3890 3891 /* Detect invalid bit-field type. */ 3892 if (TREE_CODE (*type) != INTEGER_TYPE 3893 && TREE_CODE (*type) != BOOLEAN_TYPE 3894 && TREE_CODE (*type) != ENUMERAL_TYPE) 3895 { 3896 error ("bit-field %qs has invalid type", name); 3897 *type = unsigned_type_node; 3898 } 3899 3900 type_mv = TYPE_MAIN_VARIANT (*type); 3901 if (pedantic 3902 && !in_system_header 3903 && type_mv != integer_type_node 3904 && type_mv != unsigned_type_node 3905 && type_mv != boolean_type_node) 3906 pedwarn ("type of bit-field %qs is a GCC extension", name); 3907 3908 if (type_mv == boolean_type_node) 3909 max_width = CHAR_TYPE_SIZE; 3910 else 3911 max_width = TYPE_PRECISION (*type); 3912 3913 if (0 < compare_tree_int (*width, max_width)) 3914 { 3915 error ("width of %qs exceeds its type", name); 3916 w = max_width; 3917 *width = build_int_cst (NULL_TREE, w); 3918 } 3919 else 3920 w = tree_low_cst (*width, 1); 3921 3922 if (TREE_CODE (*type) == ENUMERAL_TYPE) 3923 { 3924 struct lang_type *lt = TYPE_LANG_SPECIFIC (*type); 3925 if (!lt 3926 || w < min_precision (lt->enum_min, TYPE_UNSIGNED (*type)) 3927 || w < min_precision (lt->enum_max, TYPE_UNSIGNED (*type))) 3928 warning (0, "%qs is narrower than values of its type", name); 3929 } 3930} 3931 3932 3933 3934/* Print warning about variable length array if necessary. */ 3935 3936static void 3937warn_variable_length_array (const char *name, tree size) 3938{ 3939 int ped = !flag_isoc99 && pedantic && warn_vla != 0; 3940 int const_size = TREE_CONSTANT (size); 3941 3942 if (ped) 3943 { 3944 if (const_size) 3945 { 3946 if (name) 3947 pedwarn ("ISO C90 forbids array %qs whose size " 3948 "can%'t be evaluated", 3949 name); 3950 else 3951 pedwarn ("ISO C90 forbids array whose size " 3952 "can%'t be evaluated"); 3953 } 3954 else 3955 { 3956 if (name) 3957 pedwarn ("ISO C90 forbids variable length array %qs", 3958 name); 3959 else 3960 pedwarn ("ISO C90 forbids variable length array"); 3961 } 3962 } 3963 else if (warn_vla > 0) 3964 { 3965 if (const_size) 3966 { 3967 if (name) 3968 warning (OPT_Wvla, 3969 "the size of array %qs can" 3970 "%'t be evaluated", name); 3971 else 3972 warning (OPT_Wvla, 3973 "the size of array can %'t be evaluated"); 3974 } 3975 else 3976 { 3977 if (name) 3978 warning (OPT_Wvla, 3979 "variable length array %qs is used", 3980 name); 3981 else 3982 warning (OPT_Wvla, 3983 "variable length array is used"); 3984 } 3985 } 3986} 3987 3988/* Given declspecs and a declarator, 3989 determine the name and type of the object declared 3990 and construct a ..._DECL node for it. 3991 (In one case we can return a ..._TYPE node instead. 3992 For invalid input we sometimes return 0.) 3993 3994 DECLSPECS is a c_declspecs structure for the declaration specifiers. 3995 3996 DECL_CONTEXT says which syntactic context this declaration is in: 3997 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 3998 FUNCDEF for a function definition. Like NORMAL but a few different 3999 error messages in each case. Return value may be zero meaning 4000 this definition is too screwy to try to parse. 4001 PARM for a parameter declaration (either within a function prototype 4002 or before a function body). Make a PARM_DECL, or return void_type_node. 4003 TYPENAME if for a typename (in a cast or sizeof). 4004 Don't make a DECL node; just return the ..._TYPE node. 4005 FIELD for a struct or union field; make a FIELD_DECL. 4006 INITIALIZED is true if the decl has an initializer. 4007 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 4008 representing the width of the bit-field. 4009 4010 In the TYPENAME case, DECLARATOR is really an absolute declarator. 4011 It may also be so in the PARM case, for a prototype where the 4012 argument type is specified but not the name. 4013 4014 This function is where the complicated C meanings of `static' 4015 and `extern' are interpreted. */ 4016 4017static tree 4018grokdeclarator (const struct c_declarator *declarator, 4019 struct c_declspecs *declspecs, 4020 enum decl_context decl_context, bool initialized, tree *width) 4021{ 4022 tree type = declspecs->type; 4023 bool threadp = declspecs->thread_p; 4024 enum c_storage_class storage_class = declspecs->storage_class; 4025 int constp; 4026 int restrictp; 4027 int volatilep; 4028 int type_quals = TYPE_UNQUALIFIED; 4029 const char *name, *orig_name; 4030 tree typedef_type = 0; 4031 bool funcdef_flag = false; 4032 bool funcdef_syntax = false; 4033 int size_varies = 0; 4034 tree decl_attr = declspecs->decl_attr; 4035 int array_ptr_quals = TYPE_UNQUALIFIED; 4036 tree array_ptr_attrs = NULL_TREE; 4037 int array_parm_static = 0; 4038 bool array_parm_vla_unspec_p = false; 4039 tree returned_attrs = NULL_TREE; 4040 bool bitfield = width != NULL; 4041 tree element_type; 4042 struct c_arg_info *arg_info = 0; 4043 4044 if (decl_context == FUNCDEF) 4045 funcdef_flag = true, decl_context = NORMAL; 4046 4047 /* Look inside a declarator for the name being declared 4048 and get it as a string, for an error message. */ 4049 { 4050 const struct c_declarator *decl = declarator; 4051 name = 0; 4052 4053 while (decl) 4054 switch (decl->kind) 4055 { 4056 case cdk_function: 4057 case cdk_array: 4058 case cdk_pointer: 4059 funcdef_syntax = (decl->kind == cdk_function); 4060 decl = decl->declarator; 4061 break; 4062 4063 case cdk_attrs: 4064 decl = decl->declarator; 4065 break; 4066 4067 case cdk_id: 4068 if (decl->u.id) 4069 name = IDENTIFIER_POINTER (decl->u.id); 4070 decl = 0; 4071 break; 4072 4073 default: 4074 gcc_unreachable (); 4075 } 4076 orig_name = name; 4077 if (name == 0) 4078 name = "type name"; 4079 } 4080 4081 /* A function definition's declarator must have the form of 4082 a function declarator. */ 4083 4084 if (funcdef_flag && !funcdef_syntax) 4085 return 0; 4086 4087 /* If this looks like a function definition, make it one, 4088 even if it occurs where parms are expected. 4089 Then store_parm_decls will reject it and not use it as a parm. */ 4090 if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag) 4091 decl_context = PARM; 4092 4093 if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS) 4094 warn_deprecated_use (declspecs->type); 4095 4096 if ((decl_context == NORMAL || decl_context == FIELD) 4097 && current_scope == file_scope 4098 && variably_modified_type_p (type, NULL_TREE)) 4099 { 4100 error ("variably modified %qs at file scope", name); 4101 type = integer_type_node; 4102 } 4103 4104 typedef_type = type; 4105 size_varies = C_TYPE_VARIABLE_SIZE (type); 4106 4107 /* Diagnose defaulting to "int". */ 4108 4109 if (declspecs->default_int_p && !in_system_header) 4110 { 4111 /* Issue a warning if this is an ISO C 99 program or if 4112 -Wreturn-type and this is a function, or if -Wimplicit; 4113 prefer the former warning since it is more explicit. */ 4114 if ((warn_implicit_int || warn_return_type || flag_isoc99) 4115 && funcdef_flag) 4116 warn_about_return_type = 1; 4117 else if (warn_implicit_int || flag_isoc99) 4118 pedwarn_c99 ("type defaults to %<int%> in declaration of %qs", name); 4119 } 4120 4121 /* Adjust the type if a bit-field is being declared, 4122 -funsigned-bitfields applied and the type is not explicitly 4123 "signed". */ 4124 if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p 4125 && TREE_CODE (type) == INTEGER_TYPE) 4126 type = c_common_unsigned_type (type); 4127 4128 /* Figure out the type qualifiers for the declaration. There are 4129 two ways a declaration can become qualified. One is something 4130 like `const int i' where the `const' is explicit. Another is 4131 something like `typedef const int CI; CI i' where the type of the 4132 declaration contains the `const'. A third possibility is that 4133 there is a type qualifier on the element type of a typedefed 4134 array type, in which case we should extract that qualifier so 4135 that c_apply_type_quals_to_decls receives the full list of 4136 qualifiers to work with (C90 is not entirely clear about whether 4137 duplicate qualifiers should be diagnosed in this case, but it 4138 seems most appropriate to do so). */ 4139 element_type = strip_array_types (type); 4140 constp = declspecs->const_p + TYPE_READONLY (element_type); 4141 restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type); 4142 volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type); 4143 if (pedantic && !flag_isoc99) 4144 { 4145 if (constp > 1) 4146 pedwarn ("duplicate %<const%>"); 4147 if (restrictp > 1) 4148 pedwarn ("duplicate %<restrict%>"); 4149 if (volatilep > 1) 4150 pedwarn ("duplicate %<volatile%>"); 4151 } 4152 if (!flag_gen_aux_info && (TYPE_QUALS (element_type))) 4153 type = TYPE_MAIN_VARIANT (type); 4154 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 4155 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 4156 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 4157 4158 /* Warn about storage classes that are invalid for certain 4159 kinds of declarations (parameters, typenames, etc.). */ 4160 4161 if (funcdef_flag 4162 && (threadp 4163 || storage_class == csc_auto 4164 || storage_class == csc_register 4165 || storage_class == csc_typedef)) 4166 { 4167 if (storage_class == csc_auto 4168 && (pedantic || current_scope == file_scope)) 4169 pedwarn ("function definition declared %<auto%>"); 4170 if (storage_class == csc_register) 4171 error ("function definition declared %<register%>"); 4172 if (storage_class == csc_typedef) 4173 error ("function definition declared %<typedef%>"); 4174 if (threadp) 4175 error ("function definition declared %<__thread%>"); 4176 threadp = false; 4177 if (storage_class == csc_auto 4178 || storage_class == csc_register 4179 || storage_class == csc_typedef) 4180 storage_class = csc_none; 4181 } 4182 else if (decl_context != NORMAL && (storage_class != csc_none || threadp)) 4183 { 4184 if (decl_context == PARM && storage_class == csc_register) 4185 ; 4186 else 4187 { 4188 switch (decl_context) 4189 { 4190 case FIELD: 4191 error ("storage class specified for structure field %qs", 4192 name); 4193 break; 4194 case PARM: 4195 error ("storage class specified for parameter %qs", name); 4196 break; 4197 default: 4198 error ("storage class specified for typename"); 4199 break; 4200 } 4201 storage_class = csc_none; 4202 threadp = false; 4203 } 4204 } 4205 else if (storage_class == csc_extern 4206 && initialized 4207 && !funcdef_flag) 4208 { 4209 /* 'extern' with initialization is invalid if not at file scope. */ 4210 if (current_scope == file_scope) 4211 { 4212 /* It is fine to have 'extern const' when compiling at C 4213 and C++ intersection. */ 4214 if (!(warn_cxx_compat && constp)) 4215 warning (0, "%qs initialized and declared %<extern%>", name); 4216 } 4217 else 4218 error ("%qs has both %<extern%> and initializer", name); 4219 } 4220 else if (current_scope == file_scope) 4221 { 4222 if (storage_class == csc_auto) 4223 error ("file-scope declaration of %qs specifies %<auto%>", name); 4224 if (pedantic && storage_class == csc_register) 4225 pedwarn ("file-scope declaration of %qs specifies %<register%>", name); 4226 } 4227 else 4228 { 4229 if (storage_class == csc_extern && funcdef_flag) 4230 error ("nested function %qs declared %<extern%>", name); 4231 else if (threadp && storage_class == csc_none) 4232 { 4233 error ("function-scope %qs implicitly auto and declared " 4234 "%<__thread%>", 4235 name); 4236 threadp = false; 4237 } 4238 } 4239 4240 /* Now figure out the structure of the declarator proper. 4241 Descend through it, creating more complex types, until we reach 4242 the declared identifier (or NULL_TREE, in an absolute declarator). 4243 At each stage we maintain an unqualified version of the type 4244 together with any qualifiers that should be applied to it with 4245 c_build_qualified_type; this way, array types including 4246 multidimensional array types are first built up in unqualified 4247 form and then the qualified form is created with 4248 TYPE_MAIN_VARIANT pointing to the unqualified form. */ 4249 4250 while (declarator && declarator->kind != cdk_id) 4251 { 4252 if (type == error_mark_node) 4253 { 4254 declarator = declarator->declarator; 4255 continue; 4256 } 4257 4258 /* Each level of DECLARATOR is either a cdk_array (for ...[..]), 4259 a cdk_pointer (for *...), 4260 a cdk_function (for ...(...)), 4261 a cdk_attrs (for nested attributes), 4262 or a cdk_id (for the name being declared 4263 or the place in an absolute declarator 4264 where the name was omitted). 4265 For the last case, we have just exited the loop. 4266 4267 At this point, TYPE is the type of elements of an array, 4268 or for a function to return, or for a pointer to point to. 4269 After this sequence of ifs, TYPE is the type of the 4270 array or function or pointer, and DECLARATOR has had its 4271 outermost layer removed. */ 4272 4273 if (array_ptr_quals != TYPE_UNQUALIFIED 4274 || array_ptr_attrs != NULL_TREE 4275 || array_parm_static) 4276 { 4277 /* Only the innermost declarator (making a parameter be of 4278 array type which is converted to pointer type) 4279 may have static or type qualifiers. */ 4280 error ("static or type qualifiers in non-parameter array declarator"); 4281 array_ptr_quals = TYPE_UNQUALIFIED; 4282 array_ptr_attrs = NULL_TREE; 4283 array_parm_static = 0; 4284 } 4285 4286 switch (declarator->kind) 4287 { 4288 case cdk_attrs: 4289 { 4290 /* A declarator with embedded attributes. */ 4291 tree attrs = declarator->u.attrs; 4292 const struct c_declarator *inner_decl; 4293 int attr_flags = 0; 4294 declarator = declarator->declarator; 4295 inner_decl = declarator; 4296 while (inner_decl->kind == cdk_attrs) 4297 inner_decl = inner_decl->declarator; 4298 if (inner_decl->kind == cdk_id) 4299 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 4300 else if (inner_decl->kind == cdk_function) 4301 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 4302 else if (inner_decl->kind == cdk_array) 4303 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 4304 returned_attrs = decl_attributes (&type, 4305 chainon (returned_attrs, attrs), 4306 attr_flags); 4307 break; 4308 } 4309 case cdk_array: 4310 { 4311 tree itype = NULL_TREE; 4312 tree size = declarator->u.array.dimen; 4313 /* The index is a signed object `sizetype' bits wide. */ 4314 tree index_type = c_common_signed_type (sizetype); 4315 4316 array_ptr_quals = declarator->u.array.quals; 4317 array_ptr_attrs = declarator->u.array.attrs; 4318 array_parm_static = declarator->u.array.static_p; 4319 array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p; 4320 4321 declarator = declarator->declarator; 4322 4323 /* Check for some types that there cannot be arrays of. */ 4324 4325 if (VOID_TYPE_P (type)) 4326 { 4327 error ("declaration of %qs as array of voids", name); 4328 type = error_mark_node; 4329 } 4330 4331 if (TREE_CODE (type) == FUNCTION_TYPE) 4332 { 4333 error ("declaration of %qs as array of functions", name); 4334 type = error_mark_node; 4335 } 4336 4337 if (pedantic && !in_system_header && flexible_array_type_p (type)) 4338 pedwarn ("invalid use of structure with flexible array member"); 4339 4340 if (size == error_mark_node) 4341 type = error_mark_node; 4342 4343 if (type == error_mark_node) 4344 continue; 4345 4346 /* If size was specified, set ITYPE to a range-type for 4347 that size. Otherwise, ITYPE remains null. finish_decl 4348 may figure it out from an initial value. */ 4349 4350 if (size) 4351 { 4352 /* Strip NON_LVALUE_EXPRs since we aren't using as an 4353 lvalue. */ 4354 STRIP_TYPE_NOPS (size); 4355 4356 if (!INTEGRAL_TYPE_P (TREE_TYPE (size))) 4357 { 4358 error ("size of array %qs has non-integer type", name); 4359 size = integer_one_node; 4360 } 4361 4362 if (pedantic && integer_zerop (size)) 4363 pedwarn ("ISO C forbids zero-size array %qs", name); 4364 4365 if (TREE_CODE (size) == INTEGER_CST) 4366 { 4367 constant_expression_warning (size); 4368 if (tree_int_cst_sgn (size) < 0) 4369 { 4370 error ("size of array %qs is negative", name); 4371 size = integer_one_node; 4372 } 4373 } 4374 else if ((decl_context == NORMAL || decl_context == FIELD) 4375 && current_scope == file_scope) 4376 { 4377 error ("variably modified %qs at file scope", name); 4378 size = integer_one_node; 4379 } 4380 else 4381 { 4382 /* Make sure the array size remains visibly 4383 nonconstant even if it is (eg) a const variable 4384 with known value. */ 4385 size_varies = 1; 4386 warn_variable_length_array (orig_name, size); 4387 if (warn_variable_decl) 4388 warning (0, "variable-sized array %qs", name); 4389 } 4390 4391 if (integer_zerop (size)) 4392 { 4393 /* A zero-length array cannot be represented with 4394 an unsigned index type, which is what we'll 4395 get with build_index_type. Create an 4396 open-ended range instead. */ 4397 itype = build_range_type (sizetype, size, NULL_TREE); 4398 } 4399 else 4400 { 4401 /* Arrange for the SAVE_EXPR on the inside of the 4402 MINUS_EXPR, which allows the -1 to get folded 4403 with the +1 that happens when building TYPE_SIZE. */ 4404 if (size_varies) 4405 size = variable_size (size); 4406 4407 /* Compute the maximum valid index, that is, size 4408 - 1. Do the calculation in index_type, so that 4409 if it is a variable the computations will be 4410 done in the proper mode. */ 4411 itype = fold_build2 (MINUS_EXPR, index_type, 4412 convert (index_type, size), 4413 convert (index_type, 4414 size_one_node)); 4415 4416 /* If that overflowed, the array is too big. ??? 4417 While a size of INT_MAX+1 technically shouldn't 4418 cause an overflow (because we subtract 1), the 4419 overflow is recorded during the conversion to 4420 index_type, before the subtraction. Handling 4421 this case seems like an unnecessary 4422 complication. */ 4423 if (TREE_CODE (itype) == INTEGER_CST 4424 && TREE_OVERFLOW (itype)) 4425 { 4426 error ("size of array %qs is too large", name); 4427 type = error_mark_node; 4428 continue; 4429 } 4430 4431 itype = build_index_type (itype); 4432 } 4433 } 4434 else if (decl_context == FIELD) 4435 { 4436 if (pedantic && !flag_isoc99 && !in_system_header) 4437 pedwarn ("ISO C90 does not support flexible array members"); 4438 4439 /* ISO C99 Flexible array members are effectively 4440 identical to GCC's zero-length array extension. */ 4441 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4442 } 4443 else if (decl_context == PARM) 4444 { 4445 if (array_parm_vla_unspec_p) 4446 { 4447 if (! orig_name) 4448 { 4449 /* C99 6.7.5.2p4 */ 4450 error ("%<[*]%> not allowed in other than a declaration"); 4451 } 4452 4453 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4454 size_varies = 1; 4455 } 4456 } 4457 else if (decl_context == TYPENAME) 4458 { 4459 if (array_parm_vla_unspec_p) 4460 { 4461 /* The error is printed elsewhere. We use this to 4462 avoid messing up with incomplete array types of 4463 the same type, that would otherwise be modified 4464 below. */ 4465 itype = build_range_type (sizetype, size_zero_node, 4466 NULL_TREE); 4467 } 4468 } 4469 4470 /* Complain about arrays of incomplete types. */ 4471 if (!COMPLETE_TYPE_P (type)) 4472 { 4473 error ("array type has incomplete element type"); 4474 type = error_mark_node; 4475 } 4476 else 4477 /* When itype is NULL, a shared incomplete array type is 4478 returned for all array of a given type. Elsewhere we 4479 make sure we don't complete that type before copying 4480 it, but here we want to make sure we don't ever 4481 modify the shared type, so we gcc_assert (itype) 4482 below. */ 4483 type = build_array_type (type, itype); 4484 4485 if (type != error_mark_node) 4486 { 4487 if (size_varies) 4488 { 4489 /* It is ok to modify type here even if itype is 4490 NULL: if size_varies, we're in a 4491 multi-dimensional array and the inner type has 4492 variable size, so the enclosing shared array type 4493 must too. */ 4494 if (size && TREE_CODE (size) == INTEGER_CST) 4495 type 4496 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4497 C_TYPE_VARIABLE_SIZE (type) = 1; 4498 } 4499 4500 /* The GCC extension for zero-length arrays differs from 4501 ISO flexible array members in that sizeof yields 4502 zero. */ 4503 if (size && integer_zerop (size)) 4504 { 4505 gcc_assert (itype); 4506 TYPE_SIZE (type) = bitsize_zero_node; 4507 TYPE_SIZE_UNIT (type) = size_zero_node; 4508 } 4509 if (array_parm_vla_unspec_p) 4510 { 4511 gcc_assert (itype); 4512 /* The type is complete. C99 6.7.5.2p4 */ 4513 TYPE_SIZE (type) = bitsize_zero_node; 4514 TYPE_SIZE_UNIT (type) = size_zero_node; 4515 } 4516 } 4517 4518 if (decl_context != PARM 4519 && (array_ptr_quals != TYPE_UNQUALIFIED 4520 || array_ptr_attrs != NULL_TREE 4521 || array_parm_static)) 4522 { 4523 error ("static or type qualifiers in non-parameter array declarator"); 4524 array_ptr_quals = TYPE_UNQUALIFIED; 4525 array_ptr_attrs = NULL_TREE; 4526 array_parm_static = 0; 4527 } 4528 break; 4529 } 4530 case cdk_function: 4531 { 4532 /* Say it's a definition only for the declarator closest 4533 to the identifier, apart possibly from some 4534 attributes. */ 4535 bool really_funcdef = false; 4536 tree arg_types; 4537 if (funcdef_flag) 4538 { 4539 const struct c_declarator *t = declarator->declarator; 4540 while (t->kind == cdk_attrs) 4541 t = t->declarator; 4542 really_funcdef = (t->kind == cdk_id); 4543 } 4544 4545 /* Declaring a function type. Make sure we have a valid 4546 type for the function to return. */ 4547 if (type == error_mark_node) 4548 continue; 4549 4550 size_varies = 0; 4551 4552 /* Warn about some types functions can't return. */ 4553 if (TREE_CODE (type) == FUNCTION_TYPE) 4554 { 4555 error ("%qs declared as function returning a function", name); 4556 type = integer_type_node; 4557 } 4558 if (TREE_CODE (type) == ARRAY_TYPE) 4559 { 4560 error ("%qs declared as function returning an array", name); 4561 type = integer_type_node; 4562 } 4563 4564 /* Construct the function type and go to the next 4565 inner layer of declarator. */ 4566 arg_info = declarator->u.arg_info; 4567 arg_types = grokparms (arg_info, really_funcdef); 4568 if (really_funcdef) 4569 put_pending_sizes (arg_info->pending_sizes); 4570 4571 /* Type qualifiers before the return type of the function 4572 qualify the return type, not the function type. */ 4573 if (type_quals) 4574 { 4575 /* Type qualifiers on a function return type are 4576 normally permitted by the standard but have no 4577 effect, so give a warning at -Wreturn-type. 4578 Qualifiers on a void return type are banned on 4579 function definitions in ISO C; GCC used to used 4580 them for noreturn functions. */ 4581 if (VOID_TYPE_P (type) && really_funcdef) 4582 pedwarn ("function definition has qualified void return type"); 4583 else 4584 warning (OPT_Wreturn_type, 4585 "type qualifiers ignored on function return type"); 4586 4587 type = c_build_qualified_type (type, type_quals); 4588 } 4589 type_quals = TYPE_UNQUALIFIED; 4590 4591 type = build_function_type (type, arg_types); 4592 declarator = declarator->declarator; 4593 4594 /* Set the TYPE_CONTEXTs for each tagged type which is local to 4595 the formal parameter list of this FUNCTION_TYPE to point to 4596 the FUNCTION_TYPE node itself. */ 4597 { 4598 tree link; 4599 4600 for (link = arg_info->tags; 4601 link; 4602 link = TREE_CHAIN (link)) 4603 TYPE_CONTEXT (TREE_VALUE (link)) = type; 4604 } 4605 break; 4606 } 4607 case cdk_pointer: 4608 { 4609 /* Merge any constancy or volatility into the target type 4610 for the pointer. */ 4611 4612 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4613 && type_quals) 4614 pedwarn ("ISO C forbids qualified function types"); 4615 if (type_quals) 4616 type = c_build_qualified_type (type, type_quals); 4617 size_varies = 0; 4618 4619 /* When the pointed-to type involves components of variable size, 4620 care must be taken to ensure that the size evaluation code is 4621 emitted early enough to dominate all the possible later uses 4622 and late enough for the variables on which it depends to have 4623 been assigned. 4624 4625 This is expected to happen automatically when the pointed-to 4626 type has a name/declaration of it's own, but special attention 4627 is required if the type is anonymous. 4628 4629 We handle the NORMAL and FIELD contexts here by attaching an 4630 artificial TYPE_DECL to such pointed-to type. This forces the 4631 sizes evaluation at a safe point and ensures it is not deferred 4632 until e.g. within a deeper conditional context. 4633 4634 We expect nothing to be needed here for PARM or TYPENAME. 4635 Pushing a TYPE_DECL at this point for TYPENAME would actually 4636 be incorrect, as we might be in the middle of an expression 4637 with side effects on the pointed-to type size "arguments" prior 4638 to the pointer declaration point and the fake TYPE_DECL in the 4639 enclosing context would force the size evaluation prior to the 4640 side effects. */ 4641 4642 if (!TYPE_NAME (type) 4643 && (decl_context == NORMAL || decl_context == FIELD) 4644 && variably_modified_type_p (type, NULL_TREE)) 4645 { 4646 tree decl = build_decl (TYPE_DECL, NULL_TREE, type); 4647 DECL_ARTIFICIAL (decl) = 1; 4648 pushdecl (decl); 4649 finish_decl (decl, NULL_TREE, NULL_TREE); 4650 TYPE_NAME (type) = decl; 4651 } 4652 4653 type = build_pointer_type (type); 4654 4655 /* Process type qualifiers (such as const or volatile) 4656 that were given inside the `*'. */ 4657 type_quals = declarator->u.pointer_quals; 4658 4659 declarator = declarator->declarator; 4660 break; 4661 } 4662 default: 4663 gcc_unreachable (); 4664 } 4665 } 4666 4667 /* Now TYPE has the actual type, apart from any qualifiers in 4668 TYPE_QUALS. */ 4669 4670 /* Check the type and width of a bit-field. */ 4671 if (bitfield) 4672 check_bitfield_type_and_width (&type, width, orig_name); 4673 4674 /* Did array size calculations overflow? */ 4675 4676 if (TREE_CODE (type) == ARRAY_TYPE 4677 && COMPLETE_TYPE_P (type) 4678 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 4679 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 4680 { 4681 error ("size of array %qs is too large", name); 4682 /* If we proceed with the array type as it is, we'll eventually 4683 crash in tree_low_cst(). */ 4684 type = error_mark_node; 4685 } 4686 4687 /* If this is declaring a typedef name, return a TYPE_DECL. */ 4688 4689 if (storage_class == csc_typedef) 4690 { 4691 tree decl; 4692 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4693 && type_quals) 4694 pedwarn ("ISO C forbids qualified function types"); 4695 if (type_quals) 4696 type = c_build_qualified_type (type, type_quals); 4697 decl = build_decl (TYPE_DECL, declarator->u.id, type); 4698 if (declspecs->explicit_signed_p) 4699 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 4700 decl_attributes (&decl, returned_attrs, 0); 4701 if (declspecs->inline_p) 4702 pedwarn ("typedef %q+D declared %<inline%>", decl); 4703 return decl; 4704 } 4705 4706 /* If this is a type name (such as, in a cast or sizeof), 4707 compute the type and return it now. */ 4708 4709 if (decl_context == TYPENAME) 4710 { 4711 /* Note that the grammar rejects storage classes in typenames 4712 and fields. */ 4713 gcc_assert (storage_class == csc_none && !threadp 4714 && !declspecs->inline_p); 4715 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4716 && type_quals) 4717 pedwarn ("ISO C forbids const or volatile function types"); 4718 if (type_quals) 4719 type = c_build_qualified_type (type, type_quals); 4720 decl_attributes (&type, returned_attrs, 0); 4721 return type; 4722 } 4723 4724 if (pedantic && decl_context == FIELD 4725 && variably_modified_type_p (type, NULL_TREE)) 4726 { 4727 /* C99 6.7.2.1p8 */ 4728 pedwarn ("a member of a structure or union cannot have a variably modified type"); 4729 } 4730 4731 /* Aside from typedefs and type names (handle above), 4732 `void' at top level (not within pointer) 4733 is allowed only in public variables. 4734 We don't complain about parms either, but that is because 4735 a better error message can be made later. */ 4736 4737 if (VOID_TYPE_P (type) && decl_context != PARM 4738 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 4739 && (storage_class == csc_extern 4740 || (current_scope == file_scope 4741 && !(storage_class == csc_static 4742 || storage_class == csc_register))))) 4743 { 4744 error ("variable or field %qs declared void", name); 4745 type = integer_type_node; 4746 } 4747 4748 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 4749 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 4750 4751 { 4752 tree decl; 4753 4754 if (decl_context == PARM) 4755 { 4756 tree type_as_written; 4757 tree promoted_type; 4758 4759 /* A parameter declared as an array of T is really a pointer to T. 4760 One declared as a function is really a pointer to a function. */ 4761 4762 if (TREE_CODE (type) == ARRAY_TYPE) 4763 { 4764 /* Transfer const-ness of array into that of type pointed to. */ 4765 type = TREE_TYPE (type); 4766 if (type_quals) 4767 type = c_build_qualified_type (type, type_quals); 4768 type = build_pointer_type (type); 4769 type_quals = array_ptr_quals; 4770 4771 /* We don't yet implement attributes in this context. */ 4772 if (array_ptr_attrs != NULL_TREE) 4773 warning (OPT_Wattributes, 4774 "attributes in parameter array declarator ignored"); 4775 4776 size_varies = 0; 4777 } 4778 else if (TREE_CODE (type) == FUNCTION_TYPE) 4779 { 4780 if (pedantic && type_quals) 4781 pedwarn ("ISO C forbids qualified function types"); 4782 if (type_quals) 4783 type = c_build_qualified_type (type, type_quals); 4784 type = build_pointer_type (type); 4785 type_quals = TYPE_UNQUALIFIED; 4786 } 4787 else if (type_quals) 4788 type = c_build_qualified_type (type, type_quals); 4789 4790 type_as_written = type; 4791 4792 decl = build_decl (PARM_DECL, declarator->u.id, type); 4793 if (size_varies) 4794 C_DECL_VARIABLE_SIZE (decl) = 1; 4795 4796 /* Compute the type actually passed in the parmlist, 4797 for the case where there is no prototype. 4798 (For example, shorts and chars are passed as ints.) 4799 When there is a prototype, this is overridden later. */ 4800 4801 if (type == error_mark_node) 4802 promoted_type = type; 4803 else 4804 promoted_type = c_type_promotes_to (type); 4805 4806 DECL_ARG_TYPE (decl) = promoted_type; 4807 if (declspecs->inline_p) 4808 pedwarn ("parameter %q+D declared %<inline%>", decl); 4809 } 4810 else if (decl_context == FIELD) 4811 { 4812 /* Note that the grammar rejects storage classes in typenames 4813 and fields. */ 4814 gcc_assert (storage_class == csc_none && !threadp 4815 && !declspecs->inline_p); 4816 4817 /* Structure field. It may not be a function. */ 4818 4819 if (TREE_CODE (type) == FUNCTION_TYPE) 4820 { 4821 error ("field %qs declared as a function", name); 4822 type = build_pointer_type (type); 4823 } 4824 else if (TREE_CODE (type) != ERROR_MARK 4825 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 4826 { 4827 error ("field %qs has incomplete type", name); 4828 type = error_mark_node; 4829 } 4830 type = c_build_qualified_type (type, type_quals); 4831 decl = build_decl (FIELD_DECL, declarator->u.id, type); 4832 DECL_NONADDRESSABLE_P (decl) = bitfield; 4833 4834 if (size_varies) 4835 C_DECL_VARIABLE_SIZE (decl) = 1; 4836 } 4837 else if (TREE_CODE (type) == FUNCTION_TYPE) 4838 { 4839 if (storage_class == csc_register || threadp) 4840 { 4841 error ("invalid storage class for function %qs", name); 4842 } 4843 else if (current_scope != file_scope) 4844 { 4845 /* Function declaration not at file scope. Storage 4846 classes other than `extern' are not allowed, C99 4847 6.7.1p5, and `extern' makes no difference. However, 4848 GCC allows 'auto', perhaps with 'inline', to support 4849 nested functions. */ 4850 if (storage_class == csc_auto) 4851 { 4852 if (pedantic) 4853 pedwarn ("invalid storage class for function %qs", name); 4854 } 4855 else if (storage_class == csc_static) 4856 { 4857 error ("invalid storage class for function %qs", name); 4858 if (funcdef_flag) 4859 storage_class = declspecs->storage_class = csc_none; 4860 else 4861 return 0; 4862 } 4863 } 4864 4865 decl = build_decl (FUNCTION_DECL, declarator->u.id, type); 4866 decl = build_decl_attribute_variant (decl, decl_attr); 4867 4868 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 4869 4870 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 4871 pedwarn ("ISO C forbids qualified function types"); 4872 4873 /* GNU C interprets a volatile-qualified function type to indicate 4874 that the function does not return. */ 4875 if ((type_quals & TYPE_QUAL_VOLATILE) 4876 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 4877 warning (0, "%<noreturn%> function returns non-void value"); 4878 4879 /* Every function declaration is an external reference 4880 (DECL_EXTERNAL) except for those which are not at file 4881 scope and are explicitly declared "auto". This is 4882 forbidden by standard C (C99 6.7.1p5) and is interpreted by 4883 GCC to signify a forward declaration of a nested function. */ 4884 if (storage_class == csc_auto && current_scope != file_scope) 4885 DECL_EXTERNAL (decl) = 0; 4886 /* In C99, a function which is declared 'inline' with 'extern' 4887 is not an external reference (which is confusing). It 4888 means that the later definition of the function must be output 4889 in this file, C99 6.7.4p6. In GNU C89, a function declared 4890 'extern inline' is an external reference. */ 4891 else if (declspecs->inline_p && storage_class != csc_static) 4892 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 4893 == flag_gnu89_inline); 4894 else 4895 DECL_EXTERNAL (decl) = !initialized; 4896 4897 /* Record absence of global scope for `static' or `auto'. */ 4898 TREE_PUBLIC (decl) 4899 = !(storage_class == csc_static || storage_class == csc_auto); 4900 4901 /* For a function definition, record the argument information 4902 block where store_parm_decls will look for it. */ 4903 if (funcdef_flag) 4904 current_function_arg_info = arg_info; 4905 4906 if (declspecs->default_int_p) 4907 C_FUNCTION_IMPLICIT_INT (decl) = 1; 4908 4909 /* Record presence of `inline', if it is reasonable. */ 4910 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 4911 { 4912 if (declspecs->inline_p) 4913 pedwarn ("cannot inline function %<main%>"); 4914 } 4915 else if (declspecs->inline_p) 4916 { 4917 /* Record that the function is declared `inline'. */ 4918 DECL_DECLARED_INLINE_P (decl) = 1; 4919 4920 /* Do not mark bare declarations as DECL_INLINE. Doing so 4921 in the presence of multiple declarations can result in 4922 the abstract origin pointing between the declarations, 4923 which will confuse dwarf2out. */ 4924 if (initialized) 4925 DECL_INLINE (decl) = 1; 4926 } 4927 /* If -finline-functions, assume it can be inlined. This does 4928 two things: let the function be deferred until it is actually 4929 needed, and let dwarf2 know that the function is inlinable. */ 4930 else if (flag_inline_trees == 2 && initialized) 4931 DECL_INLINE (decl) = 1; 4932 } 4933 else 4934 { 4935 /* It's a variable. */ 4936 /* An uninitialized decl with `extern' is a reference. */ 4937 int extern_ref = !initialized && storage_class == csc_extern; 4938 4939 type = c_build_qualified_type (type, type_quals); 4940 4941 /* C99 6.2.2p7: It is invalid (compile-time undefined 4942 behavior) to create an 'extern' declaration for a 4943 variable if there is a global declaration that is 4944 'static' and the global declaration is not visible. 4945 (If the static declaration _is_ currently visible, 4946 the 'extern' declaration is taken to refer to that decl.) */ 4947 if (extern_ref && current_scope != file_scope) 4948 { 4949 tree global_decl = identifier_global_value (declarator->u.id); 4950 tree visible_decl = lookup_name (declarator->u.id); 4951 4952 if (global_decl 4953 && global_decl != visible_decl 4954 && TREE_CODE (global_decl) == VAR_DECL 4955 && !TREE_PUBLIC (global_decl)) 4956 error ("variable previously declared %<static%> redeclared " 4957 "%<extern%>"); 4958 } 4959 4960 decl = build_decl (VAR_DECL, declarator->u.id, type); 4961 DECL_SOURCE_LOCATION (decl) = declarator->id_loc; 4962 if (size_varies) 4963 C_DECL_VARIABLE_SIZE (decl) = 1; 4964 4965 if (declspecs->inline_p) 4966 pedwarn ("variable %q+D declared %<inline%>", decl); 4967 4968 /* At file scope, an initialized extern declaration may follow 4969 a static declaration. In that case, DECL_EXTERNAL will be 4970 reset later in start_decl. */ 4971 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 4972 4973 /* At file scope, the presence of a `static' or `register' storage 4974 class specifier, or the absence of all storage class specifiers 4975 makes this declaration a definition (perhaps tentative). Also, 4976 the absence of `static' makes it public. */ 4977 if (current_scope == file_scope) 4978 { 4979 TREE_PUBLIC (decl) = storage_class != csc_static; 4980 TREE_STATIC (decl) = !extern_ref; 4981 } 4982 /* Not at file scope, only `static' makes a static definition. */ 4983 else 4984 { 4985 TREE_STATIC (decl) = (storage_class == csc_static); 4986 TREE_PUBLIC (decl) = extern_ref; 4987 } 4988 4989 if (threadp) 4990 { 4991 if (targetm.have_tls) 4992 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 4993 else 4994 /* A mere warning is sure to result in improper semantics 4995 at runtime. Don't bother to allow this to compile. */ 4996 error ("thread-local storage not supported for this target"); 4997 } 4998 } 4999 5000 if (storage_class == csc_extern 5001 && variably_modified_type_p (type, NULL_TREE)) 5002 { 5003 /* C99 6.7.5.2p2 */ 5004 error ("object with variably modified type must have no linkage"); 5005 } 5006 5007 /* Record `register' declaration for warnings on & 5008 and in case doing stupid register allocation. */ 5009 5010 if (storage_class == csc_register) 5011 { 5012 C_DECL_REGISTER (decl) = 1; 5013 DECL_REGISTER (decl) = 1; 5014 } 5015 5016 /* Record constancy and volatility. */ 5017 c_apply_type_quals_to_decl (type_quals, decl); 5018 5019 /* If a type has volatile components, it should be stored in memory. 5020 Otherwise, the fact that those components are volatile 5021 will be ignored, and would even crash the compiler. 5022 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 5023 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 5024 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 5025 || TREE_CODE (decl) == RESULT_DECL)) 5026 { 5027 /* It is not an error for a structure with volatile fields to 5028 be declared register, but reset DECL_REGISTER since it 5029 cannot actually go in a register. */ 5030 int was_reg = C_DECL_REGISTER (decl); 5031 C_DECL_REGISTER (decl) = 0; 5032 DECL_REGISTER (decl) = 0; 5033 c_mark_addressable (decl); 5034 C_DECL_REGISTER (decl) = was_reg; 5035 } 5036 5037 /* This is the earliest point at which we might know the assembler 5038 name of a variable. Thus, if it's known before this, die horribly. */ 5039 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 5040 5041 decl_attributes (&decl, returned_attrs, 0); 5042 5043 return decl; 5044 } 5045} 5046 5047/* Decode the parameter-list info for a function type or function definition. 5048 The argument is the value returned by `get_parm_info' (or made in c-parse.c 5049 if there is an identifier list instead of a parameter decl list). 5050 These two functions are separate because when a function returns 5051 or receives functions then each is called multiple times but the order 5052 of calls is different. The last call to `grokparms' is always the one 5053 that contains the formal parameter names of a function definition. 5054 5055 Return a list of arg types to use in the FUNCTION_TYPE for this function. 5056 5057 FUNCDEF_FLAG is true for a function definition, false for 5058 a mere declaration. A nonempty identifier-list gets an error message 5059 when FUNCDEF_FLAG is false. */ 5060 5061static tree 5062grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 5063{ 5064 tree arg_types = arg_info->types; 5065 5066 if (funcdef_flag && arg_info->had_vla_unspec) 5067 { 5068 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 5069 /* C99 6.7.5.2p4 */ 5070 error ("%<[*]%> not allowed in other than function prototype scope"); 5071 } 5072 5073 if (arg_types == 0 && !funcdef_flag && !in_system_header) 5074 warning (OPT_Wstrict_prototypes, 5075 "function declaration isn%'t a prototype"); 5076 5077 if (arg_types == error_mark_node) 5078 return 0; /* don't set TYPE_ARG_TYPES in this case */ 5079 5080 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 5081 { 5082 if (!funcdef_flag) 5083 pedwarn ("parameter names (without types) in function declaration"); 5084 5085 arg_info->parms = arg_info->types; 5086 arg_info->types = 0; 5087 return 0; 5088 } 5089 else 5090 { 5091 tree parm, type, typelt; 5092 unsigned int parmno; 5093 5094 /* If there is a parameter of incomplete type in a definition, 5095 this is an error. In a declaration this is valid, and a 5096 struct or union type may be completed later, before any calls 5097 or definition of the function. In the case where the tag was 5098 first declared within the parameter list, a warning has 5099 already been given. If a parameter has void type, then 5100 however the function cannot be defined or called, so 5101 warn. */ 5102 5103 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 5104 parm; 5105 parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 5106 { 5107 type = TREE_VALUE (typelt); 5108 if (type == error_mark_node) 5109 continue; 5110 5111 if (!COMPLETE_TYPE_P (type)) 5112 { 5113 if (funcdef_flag) 5114 { 5115 if (DECL_NAME (parm)) 5116 error ("parameter %u (%q+D) has incomplete type", 5117 parmno, parm); 5118 else 5119 error ("%Jparameter %u has incomplete type", 5120 parm, parmno); 5121 5122 TREE_VALUE (typelt) = error_mark_node; 5123 TREE_TYPE (parm) = error_mark_node; 5124 } 5125 else if (VOID_TYPE_P (type)) 5126 { 5127 if (DECL_NAME (parm)) 5128 warning (0, "parameter %u (%q+D) has void type", 5129 parmno, parm); 5130 else 5131 warning (0, "%Jparameter %u has void type", 5132 parm, parmno); 5133 } 5134 } 5135 5136 if (DECL_NAME (parm) && TREE_USED (parm)) 5137 warn_if_shadowing (parm); 5138 } 5139 return arg_types; 5140 } 5141} 5142 5143/* Take apart the current scope and return a c_arg_info structure with 5144 info on a parameter list just parsed. 5145 5146 This structure is later fed to 'grokparms' and 'store_parm_decls'. 5147 5148 ELLIPSIS being true means the argument list ended in '...' so don't 5149 append a sentinel (void_list_node) to the end of the type-list. */ 5150 5151struct c_arg_info * 5152get_parm_info (bool ellipsis) 5153{ 5154 struct c_binding *b = current_scope->bindings; 5155 struct c_arg_info *arg_info = XOBNEW (&parser_obstack, 5156 struct c_arg_info); 5157 tree parms = 0; 5158 tree tags = 0; 5159 tree types = 0; 5160 tree others = 0; 5161 5162 static bool explained_incomplete_types = false; 5163 bool gave_void_only_once_err = false; 5164 5165 arg_info->parms = 0; 5166 arg_info->tags = 0; 5167 arg_info->types = 0; 5168 arg_info->others = 0; 5169 arg_info->pending_sizes = 0; 5170 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 5171 5172 /* The bindings in this scope must not get put into a block. 5173 We will take care of deleting the binding nodes. */ 5174 current_scope->bindings = 0; 5175 5176 /* This function is only called if there was *something* on the 5177 parameter list. */ 5178 gcc_assert (b); 5179 5180 /* A parameter list consisting solely of 'void' indicates that the 5181 function takes no arguments. But if the 'void' is qualified 5182 (by 'const' or 'volatile'), or has a storage class specifier 5183 ('register'), then the behavior is undefined; issue an error. 5184 Typedefs for 'void' are OK (see DR#157). */ 5185 if (b->prev == 0 /* one binding */ 5186 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 5187 && !DECL_NAME (b->decl) /* anonymous */ 5188 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 5189 { 5190 if (TREE_THIS_VOLATILE (b->decl) 5191 || TREE_READONLY (b->decl) 5192 || C_DECL_REGISTER (b->decl)) 5193 error ("%<void%> as only parameter may not be qualified"); 5194 5195 /* There cannot be an ellipsis. */ 5196 if (ellipsis) 5197 error ("%<void%> must be the only parameter"); 5198 5199 arg_info->types = void_list_node; 5200 return arg_info; 5201 } 5202 5203 if (!ellipsis) 5204 types = void_list_node; 5205 5206 /* Break up the bindings list into parms, tags, types, and others; 5207 apply sanity checks; purge the name-to-decl bindings. */ 5208 while (b) 5209 { 5210 tree decl = b->decl; 5211 tree type = TREE_TYPE (decl); 5212 const char *keyword; 5213 5214 switch (TREE_CODE (decl)) 5215 { 5216 case PARM_DECL: 5217 if (b->id) 5218 { 5219 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5220 I_SYMBOL_BINDING (b->id) = b->shadowed; 5221 } 5222 5223 /* Check for forward decls that never got their actual decl. */ 5224 if (TREE_ASM_WRITTEN (decl)) 5225 error ("parameter %q+D has just a forward declaration", decl); 5226 /* Check for (..., void, ...) and issue an error. */ 5227 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 5228 { 5229 if (!gave_void_only_once_err) 5230 { 5231 error ("%<void%> must be the only parameter"); 5232 gave_void_only_once_err = true; 5233 } 5234 } 5235 else 5236 { 5237 /* Valid parameter, add it to the list. */ 5238 TREE_CHAIN (decl) = parms; 5239 parms = decl; 5240 5241 /* Since there is a prototype, args are passed in their 5242 declared types. The back end may override this later. */ 5243 DECL_ARG_TYPE (decl) = type; 5244 types = tree_cons (0, type, types); 5245 } 5246 break; 5247 5248 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 5249 case UNION_TYPE: keyword = "union"; goto tag; 5250 case RECORD_TYPE: keyword = "struct"; goto tag; 5251 tag: 5252 /* Types may not have tag-names, in which case the type 5253 appears in the bindings list with b->id NULL. */ 5254 if (b->id) 5255 { 5256 gcc_assert (I_TAG_BINDING (b->id) == b); 5257 I_TAG_BINDING (b->id) = b->shadowed; 5258 } 5259 5260 /* Warn about any struct, union or enum tags defined in a 5261 parameter list. The scope of such types is limited to 5262 the parameter list, which is rarely if ever desirable 5263 (it's impossible to call such a function with type- 5264 correct arguments). An anonymous union parm type is 5265 meaningful as a GNU extension, so don't warn for that. */ 5266 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 5267 { 5268 if (b->id) 5269 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5270 warning (0, "%<%s %E%> declared inside parameter list", 5271 keyword, b->id); 5272 else 5273 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5274 warning (0, "anonymous %s declared inside parameter list", 5275 keyword); 5276 5277 if (!explained_incomplete_types) 5278 { 5279 warning (0, "its scope is only this definition or declaration," 5280 " which is probably not what you want"); 5281 explained_incomplete_types = true; 5282 } 5283 } 5284 5285 tags = tree_cons (b->id, decl, tags); 5286 break; 5287 5288 case CONST_DECL: 5289 case TYPE_DECL: 5290 case FUNCTION_DECL: 5291 /* CONST_DECLs appear here when we have an embedded enum, 5292 and TYPE_DECLs appear here when we have an embedded struct 5293 or union. No warnings for this - we already warned about the 5294 type itself. FUNCTION_DECLs appear when there is an implicit 5295 function declaration in the parameter list. */ 5296 5297 TREE_CHAIN (decl) = others; 5298 others = decl; 5299 /* fall through */ 5300 5301 case ERROR_MARK: 5302 /* error_mark_node appears here when we have an undeclared 5303 variable. Just throw it away. */ 5304 if (b->id) 5305 { 5306 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5307 I_SYMBOL_BINDING (b->id) = b->shadowed; 5308 } 5309 break; 5310 5311 /* Other things that might be encountered. */ 5312 case LABEL_DECL: 5313 case VAR_DECL: 5314 default: 5315 gcc_unreachable (); 5316 } 5317 5318 b = free_binding_and_advance (b); 5319 } 5320 5321 arg_info->parms = parms; 5322 arg_info->tags = tags; 5323 arg_info->types = types; 5324 arg_info->others = others; 5325 arg_info->pending_sizes = get_pending_sizes (); 5326 return arg_info; 5327} 5328 5329/* Get the struct, enum or union (CODE says which) with tag NAME. 5330 Define the tag as a forward-reference if it is not defined. 5331 Return a c_typespec structure for the type specifier. */ 5332 5333struct c_typespec 5334parser_xref_tag (enum tree_code code, tree name) 5335{ 5336 struct c_typespec ret; 5337 /* If a cross reference is requested, look up the type 5338 already defined for this tag and return it. */ 5339 5340 tree ref = lookup_tag (code, name, 0); 5341 /* If this is the right type of tag, return what we found. 5342 (This reference will be shadowed by shadow_tag later if appropriate.) 5343 If this is the wrong type of tag, do not return it. If it was the 5344 wrong type in the same scope, we will have had an error 5345 message already; if in a different scope and declaring 5346 a name, pending_xref_error will give an error message; but if in a 5347 different scope and not declaring a name, this tag should 5348 shadow the previous declaration of a different type of tag, and 5349 this would not work properly if we return the reference found. 5350 (For example, with "struct foo" in an outer scope, "union foo;" 5351 must shadow that tag with a new one of union type.) */ 5352 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 5353 if (ref && TREE_CODE (ref) == code) 5354 { 5355 ret.spec = ref; 5356 return ret; 5357 } 5358 5359 /* If no such tag is yet defined, create a forward-reference node 5360 and record it as the "definition". 5361 When a real declaration of this type is found, 5362 the forward-reference will be altered into a real type. */ 5363 5364 ref = make_node (code); 5365 if (code == ENUMERAL_TYPE) 5366 { 5367 /* Give the type a default layout like unsigned int 5368 to avoid crashing if it does not get defined. */ 5369 TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node); 5370 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 5371 TYPE_USER_ALIGN (ref) = 0; 5372 TYPE_UNSIGNED (ref) = 1; 5373 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 5374 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 5375 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 5376 } 5377 5378 pushtag (name, ref); 5379 5380 ret.spec = ref; 5381 return ret; 5382} 5383 5384/* Get the struct, enum or union (CODE says which) with tag NAME. 5385 Define the tag as a forward-reference if it is not defined. 5386 Return a tree for the type. */ 5387 5388tree 5389xref_tag (enum tree_code code, tree name) 5390{ 5391 return parser_xref_tag (code, name).spec; 5392} 5393 5394/* Make sure that the tag NAME is defined *in the current scope* 5395 at least as a forward reference. 5396 CODE says which kind of tag NAME ought to be. */ 5397 5398tree 5399start_struct (enum tree_code code, tree name) 5400{ 5401 /* If there is already a tag defined at this scope 5402 (as a forward reference), just return it. */ 5403 5404 tree ref = 0; 5405 5406 if (name != 0) 5407 ref = lookup_tag (code, name, 1); 5408 if (ref && TREE_CODE (ref) == code) 5409 { 5410 if (TYPE_SIZE (ref)) 5411 { 5412 if (code == UNION_TYPE) 5413 error ("redefinition of %<union %E%>", name); 5414 else 5415 error ("redefinition of %<struct %E%>", name); 5416 } 5417 else if (C_TYPE_BEING_DEFINED (ref)) 5418 { 5419 if (code == UNION_TYPE) 5420 error ("nested redefinition of %<union %E%>", name); 5421 else 5422 error ("nested redefinition of %<struct %E%>", name); 5423 /* Don't create structures that contain themselves. */ 5424 ref = NULL_TREE; 5425 } 5426 } 5427 5428 /* Otherwise create a forward-reference just so the tag is in scope. */ 5429 5430 if (ref == NULL_TREE || TREE_CODE (ref) != code) 5431 { 5432 ref = make_node (code); 5433 pushtag (name, ref); 5434 } 5435 5436 C_TYPE_BEING_DEFINED (ref) = 1; 5437 TYPE_PACKED (ref) = flag_pack_struct; 5438 return ref; 5439} 5440 5441/* Process the specs, declarator and width (NULL if omitted) 5442 of a structure component, returning a FIELD_DECL node. 5443 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 5444 5445 This is done during the parsing of the struct declaration. 5446 The FIELD_DECL nodes are chained together and the lot of them 5447 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 5448 5449tree 5450grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs, 5451 tree width) 5452{ 5453 tree value; 5454 5455 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 5456 && width == NULL_TREE) 5457 { 5458 /* This is an unnamed decl. 5459 5460 If we have something of the form "union { list } ;" then this 5461 is the anonymous union extension. Similarly for struct. 5462 5463 If this is something of the form "struct foo;", then 5464 If MS extensions are enabled, this is handled as an 5465 anonymous struct. 5466 Otherwise this is a forward declaration of a structure tag. 5467 5468 If this is something of the form "foo;" and foo is a TYPE_DECL, then 5469 If MS extensions are enabled and foo names a structure, then 5470 again this is an anonymous struct. 5471 Otherwise this is an error. 5472 5473 Oh what a horrid tangled web we weave. I wonder if MS consciously 5474 took this from Plan 9 or if it was an accident of implementation 5475 that took root before someone noticed the bug... */ 5476 5477 tree type = declspecs->type; 5478 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 5479 || TREE_CODE (type) == UNION_TYPE); 5480 bool ok = false; 5481 5482 if (type_ok 5483 && (flag_ms_extensions || !declspecs->typedef_p)) 5484 { 5485 if (flag_ms_extensions) 5486 ok = true; 5487 else if (flag_iso) 5488 ok = false; 5489 else if (TYPE_NAME (type) == NULL) 5490 ok = true; 5491 else 5492 ok = false; 5493 } 5494 if (!ok) 5495 { 5496 pedwarn ("declaration does not declare anything"); 5497 return NULL_TREE; 5498 } 5499 if (pedantic) 5500 pedwarn ("ISO C doesn%'t support unnamed structs/unions"); 5501 } 5502 5503 value = grokdeclarator (declarator, declspecs, FIELD, false, 5504 width ? &width : NULL); 5505 5506 finish_decl (value, NULL_TREE, NULL_TREE); 5507 DECL_INITIAL (value) = width; 5508 5509 return value; 5510} 5511 5512/* Generate an error for any duplicate field names in FIELDLIST. Munge 5513 the list such that this does not present a problem later. */ 5514 5515static void 5516detect_field_duplicates (tree fieldlist) 5517{ 5518 tree x, y; 5519 int timeout = 10; 5520 5521 /* First, see if there are more than "a few" fields. 5522 This is trivially true if there are zero or one fields. */ 5523 if (!fieldlist) 5524 return; 5525 x = TREE_CHAIN (fieldlist); 5526 if (!x) 5527 return; 5528 do { 5529 timeout--; 5530 x = TREE_CHAIN (x); 5531 } while (timeout > 0 && x); 5532 5533 /* If there were "few" fields, avoid the overhead of allocating 5534 a hash table. Instead just do the nested traversal thing. */ 5535 if (timeout > 0) 5536 { 5537 for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x)) 5538 if (DECL_NAME (x)) 5539 { 5540 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 5541 if (DECL_NAME (y) == DECL_NAME (x)) 5542 { 5543 error ("duplicate member %q+D", x); 5544 DECL_NAME (x) = NULL_TREE; 5545 } 5546 } 5547 } 5548 else 5549 { 5550 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 5551 void **slot; 5552 5553 for (x = fieldlist; x ; x = TREE_CHAIN (x)) 5554 if ((y = DECL_NAME (x)) != 0) 5555 { 5556 slot = htab_find_slot (htab, y, INSERT); 5557 if (*slot) 5558 { 5559 error ("duplicate member %q+D", x); 5560 DECL_NAME (x) = NULL_TREE; 5561 } 5562 *slot = y; 5563 } 5564 5565 htab_delete (htab); 5566 } 5567} 5568 5569/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 5570 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 5571 ATTRIBUTES are attributes to be applied to the structure. */ 5572 5573tree 5574finish_struct (tree t, tree fieldlist, tree attributes) 5575{ 5576 tree x; 5577 bool toplevel = file_scope == current_scope; 5578 int saw_named_field; 5579 5580 /* If this type was previously laid out as a forward reference, 5581 make sure we lay it out again. */ 5582 5583 TYPE_SIZE (t) = 0; 5584 5585 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5586 5587 if (pedantic) 5588 { 5589 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5590 if (DECL_NAME (x) != 0) 5591 break; 5592 5593 if (x == 0) 5594 { 5595 if (TREE_CODE (t) == UNION_TYPE) 5596 { 5597 if (fieldlist) 5598 pedwarn ("union has no named members"); 5599 else 5600 pedwarn ("union has no members"); 5601 } 5602 else 5603 { 5604 if (fieldlist) 5605 pedwarn ("struct has no named members"); 5606 else 5607 pedwarn ("struct has no members"); 5608 } 5609 } 5610 } 5611 5612 /* Install struct as DECL_CONTEXT of each field decl. 5613 Also process specified field sizes, found in the DECL_INITIAL, 5614 storing 0 there after the type has been changed to precision equal 5615 to its width, rather than the precision of the specified standard 5616 type. (Correct layout requires the original type to have been preserved 5617 until now.) */ 5618 5619 saw_named_field = 0; 5620 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5621 { 5622 if (TREE_TYPE (x) == error_mark_node) 5623 continue; 5624 5625 DECL_CONTEXT (x) = t; 5626 5627 if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 5628 DECL_PACKED (x) = 1; 5629 5630 /* If any field is const, the structure type is pseudo-const. */ 5631 if (TREE_READONLY (x)) 5632 C_TYPE_FIELDS_READONLY (t) = 1; 5633 else 5634 { 5635 /* A field that is pseudo-const makes the structure likewise. */ 5636 tree t1 = TREE_TYPE (x); 5637 while (TREE_CODE (t1) == ARRAY_TYPE) 5638 t1 = TREE_TYPE (t1); 5639 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 5640 && C_TYPE_FIELDS_READONLY (t1)) 5641 C_TYPE_FIELDS_READONLY (t) = 1; 5642 } 5643 5644 /* Any field that is volatile means variables of this type must be 5645 treated in some ways as volatile. */ 5646 if (TREE_THIS_VOLATILE (x)) 5647 C_TYPE_FIELDS_VOLATILE (t) = 1; 5648 5649 /* Any field of nominal variable size implies structure is too. */ 5650 if (C_DECL_VARIABLE_SIZE (x)) 5651 C_TYPE_VARIABLE_SIZE (t) = 1; 5652 5653 if (DECL_INITIAL (x)) 5654 { 5655 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 5656 DECL_SIZE (x) = bitsize_int (width); 5657 DECL_BIT_FIELD (x) = 1; 5658 SET_DECL_C_BIT_FIELD (x); 5659 } 5660 5661 /* Detect flexible array member in an invalid context. */ 5662 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 5663 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 5664 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 5665 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 5666 { 5667 if (TREE_CODE (t) == UNION_TYPE) 5668 { 5669 error ("%Jflexible array member in union", x); 5670 TREE_TYPE (x) = error_mark_node; 5671 } 5672 else if (TREE_CHAIN (x) != NULL_TREE) 5673 { 5674 error ("%Jflexible array member not at end of struct", x); 5675 TREE_TYPE (x) = error_mark_node; 5676 } 5677 else if (!saw_named_field) 5678 { 5679 error ("%Jflexible array member in otherwise empty struct", x); 5680 TREE_TYPE (x) = error_mark_node; 5681 } 5682 } 5683 5684 if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE 5685 && flexible_array_type_p (TREE_TYPE (x))) 5686 pedwarn ("%Jinvalid use of structure with flexible array member", x); 5687 5688 if (DECL_NAME (x)) 5689 saw_named_field = 1; 5690 } 5691 5692 detect_field_duplicates (fieldlist); 5693 5694 /* Now we have the nearly final fieldlist. Record it, 5695 then lay out the structure or union (including the fields). */ 5696 5697 TYPE_FIELDS (t) = fieldlist; 5698 5699 layout_type (t); 5700 5701 /* Give bit-fields their proper types. */ 5702 { 5703 tree *fieldlistp = &fieldlist; 5704 while (*fieldlistp) 5705 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 5706 && TREE_TYPE (*fieldlistp) != error_mark_node) 5707 { 5708 unsigned HOST_WIDE_INT width 5709 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 5710 tree type = TREE_TYPE (*fieldlistp); 5711 if (width != TYPE_PRECISION (type)) 5712 { 5713 TREE_TYPE (*fieldlistp) 5714 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 5715 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 5716 } 5717 DECL_INITIAL (*fieldlistp) = 0; 5718 } 5719 else 5720 fieldlistp = &TREE_CHAIN (*fieldlistp); 5721 } 5722 5723 /* Now we have the truly final field list. 5724 Store it in this type and in the variants. */ 5725 5726 TYPE_FIELDS (t) = fieldlist; 5727 5728 /* If there are lots of fields, sort so we can look through them fast. 5729 We arbitrarily consider 16 or more elts to be "a lot". */ 5730 5731 { 5732 int len = 0; 5733 5734 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5735 { 5736 if (len > 15 || DECL_NAME (x) == NULL) 5737 break; 5738 len += 1; 5739 } 5740 5741 if (len > 15) 5742 { 5743 tree *field_array; 5744 struct lang_type *space; 5745 struct sorted_fields_type *space2; 5746 5747 len += list_length (x); 5748 5749 /* Use the same allocation policy here that make_node uses, to 5750 ensure that this lives as long as the rest of the struct decl. 5751 All decls in an inline function need to be saved. */ 5752 5753 space = GGC_CNEW (struct lang_type); 5754 space2 = GGC_NEWVAR (struct sorted_fields_type, 5755 sizeof (struct sorted_fields_type) + len * sizeof (tree)); 5756 5757 len = 0; 5758 space->s = space2; 5759 field_array = &space2->elts[0]; 5760 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5761 { 5762 field_array[len++] = x; 5763 5764 /* If there is anonymous struct or union, break out of the loop. */ 5765 if (DECL_NAME (x) == NULL) 5766 break; 5767 } 5768 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 5769 if (x == NULL) 5770 { 5771 TYPE_LANG_SPECIFIC (t) = space; 5772 TYPE_LANG_SPECIFIC (t)->s->len = len; 5773 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 5774 qsort (field_array, len, sizeof (tree), field_decl_cmp); 5775 } 5776 } 5777 } 5778 5779 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 5780 { 5781 TYPE_FIELDS (x) = TYPE_FIELDS (t); 5782 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 5783 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 5784 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 5785 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 5786 } 5787 5788 /* If this was supposed to be a transparent union, but we can't 5789 make it one, warn and turn off the flag. */ 5790 if (TREE_CODE (t) == UNION_TYPE 5791 && TYPE_TRANSPARENT_UNION (t) 5792 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 5793 { 5794 TYPE_TRANSPARENT_UNION (t) = 0; 5795 warning (0, "union cannot be made transparent"); 5796 } 5797 5798 /* If this structure or union completes the type of any previous 5799 variable declaration, lay it out and output its rtl. */ 5800 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 5801 x; 5802 x = TREE_CHAIN (x)) 5803 { 5804 tree decl = TREE_VALUE (x); 5805 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 5806 layout_array_type (TREE_TYPE (decl)); 5807 if (TREE_CODE (decl) != TYPE_DECL) 5808 { 5809 layout_decl (decl, 0); 5810 if (c_dialect_objc ()) 5811 objc_check_decl (decl); 5812 rest_of_decl_compilation (decl, toplevel, 0); 5813 if (!toplevel) 5814 expand_decl (decl); 5815 } 5816 } 5817 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 5818 5819 /* Finish debugging output for this type. */ 5820 rest_of_type_compilation (t, toplevel); 5821 5822 /* If we're inside a function proper, i.e. not file-scope and not still 5823 parsing parameters, then arrange for the size of a variable sized type 5824 to be bound now. */ 5825 if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE)) 5826 add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t))); 5827 5828 return t; 5829} 5830 5831/* Lay out the type T, and its element type, and so on. */ 5832 5833static void 5834layout_array_type (tree t) 5835{ 5836 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 5837 layout_array_type (TREE_TYPE (t)); 5838 layout_type (t); 5839} 5840 5841/* Begin compiling the definition of an enumeration type. 5842 NAME is its name (or null if anonymous). 5843 Returns the type object, as yet incomplete. 5844 Also records info about it so that build_enumerator 5845 may be used to declare the individual values as they are read. */ 5846 5847tree 5848start_enum (tree name) 5849{ 5850 tree enumtype = 0; 5851 5852 /* If this is the real definition for a previous forward reference, 5853 fill in the contents in the same object that used to be the 5854 forward reference. */ 5855 5856 if (name != 0) 5857 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1); 5858 5859 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 5860 { 5861 enumtype = make_node (ENUMERAL_TYPE); 5862 pushtag (name, enumtype); 5863 } 5864 5865 if (C_TYPE_BEING_DEFINED (enumtype)) 5866 error ("nested redefinition of %<enum %E%>", name); 5867 5868 C_TYPE_BEING_DEFINED (enumtype) = 1; 5869 5870 if (TYPE_VALUES (enumtype) != 0) 5871 { 5872 /* This enum is a named one that has been declared already. */ 5873 error ("redeclaration of %<enum %E%>", name); 5874 5875 /* Completely replace its old definition. 5876 The old enumerators remain defined, however. */ 5877 TYPE_VALUES (enumtype) = 0; 5878 } 5879 5880 enum_next_value = integer_zero_node; 5881 enum_overflow = 0; 5882 5883 if (flag_short_enums) 5884 TYPE_PACKED (enumtype) = 1; 5885 5886 return enumtype; 5887} 5888 5889/* After processing and defining all the values of an enumeration type, 5890 install their decls in the enumeration type and finish it off. 5891 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 5892 and ATTRIBUTES are the specified attributes. 5893 Returns ENUMTYPE. */ 5894 5895tree 5896finish_enum (tree enumtype, tree values, tree attributes) 5897{ 5898 tree pair, tem; 5899 tree minnode = 0, maxnode = 0; 5900 int precision, unsign; 5901 bool toplevel = (file_scope == current_scope); 5902 struct lang_type *lt; 5903 5904 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5905 5906 /* Calculate the maximum value of any enumerator in this type. */ 5907 5908 if (values == error_mark_node) 5909 minnode = maxnode = integer_zero_node; 5910 else 5911 { 5912 minnode = maxnode = TREE_VALUE (values); 5913 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 5914 { 5915 tree value = TREE_VALUE (pair); 5916 if (tree_int_cst_lt (maxnode, value)) 5917 maxnode = value; 5918 if (tree_int_cst_lt (value, minnode)) 5919 minnode = value; 5920 } 5921 } 5922 5923 /* Construct the final type of this enumeration. It is the same 5924 as one of the integral types - the narrowest one that fits, except 5925 that normally we only go as narrow as int - and signed iff any of 5926 the values are negative. */ 5927 unsign = (tree_int_cst_sgn (minnode) >= 0); 5928 precision = MAX (min_precision (minnode, unsign), 5929 min_precision (maxnode, unsign)); 5930 5931 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 5932 { 5933 tem = c_common_type_for_size (precision, unsign); 5934 if (tem == NULL) 5935 { 5936 warning (0, "enumeration values exceed range of largest integer"); 5937 tem = long_long_integer_type_node; 5938 } 5939 } 5940 else 5941 tem = unsign ? unsigned_type_node : integer_type_node; 5942 5943 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 5944 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 5945 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 5946 TYPE_SIZE (enumtype) = 0; 5947 5948 /* If the precision of the type was specific with an attribute and it 5949 was too small, give an error. Otherwise, use it. */ 5950 if (TYPE_PRECISION (enumtype)) 5951 { 5952 if (precision > TYPE_PRECISION (enumtype)) 5953 error ("specified mode too small for enumeral values"); 5954 } 5955 else 5956 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 5957 5958 layout_type (enumtype); 5959 5960 if (values != error_mark_node) 5961 { 5962 /* Change the type of the enumerators to be the enum type. We 5963 need to do this irrespective of the size of the enum, for 5964 proper type checking. Replace the DECL_INITIALs of the 5965 enumerators, and the value slots of the list, with copies 5966 that have the enum type; they cannot be modified in place 5967 because they may be shared (e.g. integer_zero_node) Finally, 5968 change the purpose slots to point to the names of the decls. */ 5969 for (pair = values; pair; pair = TREE_CHAIN (pair)) 5970 { 5971 tree enu = TREE_PURPOSE (pair); 5972 tree ini = DECL_INITIAL (enu); 5973 5974 TREE_TYPE (enu) = enumtype; 5975 5976 /* The ISO C Standard mandates enumerators to have type int, 5977 even though the underlying type of an enum type is 5978 unspecified. Here we convert any enumerators that fit in 5979 an int to type int, to avoid promotions to unsigned types 5980 when comparing integers with enumerators that fit in the 5981 int range. When -pedantic is given, build_enumerator() 5982 would have already taken care of those that don't fit. */ 5983 if (int_fits_type_p (ini, integer_type_node)) 5984 tem = integer_type_node; 5985 else 5986 tem = enumtype; 5987 ini = convert (tem, ini); 5988 5989 DECL_INITIAL (enu) = ini; 5990 TREE_PURPOSE (pair) = DECL_NAME (enu); 5991 TREE_VALUE (pair) = ini; 5992 } 5993 5994 TYPE_VALUES (enumtype) = values; 5995 } 5996 5997 /* Record the min/max values so that we can warn about bit-field 5998 enumerations that are too small for the values. */ 5999 lt = GGC_CNEW (struct lang_type); 6000 lt->enum_min = minnode; 6001 lt->enum_max = maxnode; 6002 TYPE_LANG_SPECIFIC (enumtype) = lt; 6003 6004 /* Fix up all variant types of this enum type. */ 6005 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 6006 { 6007 if (tem == enumtype) 6008 continue; 6009 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 6010 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 6011 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 6012 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 6013 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 6014 TYPE_MODE (tem) = TYPE_MODE (enumtype); 6015 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 6016 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 6017 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 6018 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 6019 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 6020 } 6021 6022 /* Finish debugging output for this type. */ 6023 rest_of_type_compilation (enumtype, toplevel); 6024 6025 return enumtype; 6026} 6027 6028/* Build and install a CONST_DECL for one value of the 6029 current enumeration type (one that was begun with start_enum). 6030 Return a tree-list containing the CONST_DECL and its value. 6031 Assignment of sequential values by default is handled here. */ 6032 6033tree 6034build_enumerator (tree name, tree value) 6035{ 6036 tree decl, type; 6037 6038 /* Validate and default VALUE. */ 6039 6040 if (value != 0) 6041 { 6042 /* Don't issue more errors for error_mark_node (i.e. an 6043 undeclared identifier) - just ignore the value expression. */ 6044 if (value == error_mark_node) 6045 value = 0; 6046 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value)) 6047 || TREE_CODE (value) != INTEGER_CST) 6048 { 6049 error ("enumerator value for %qE is not an integer constant", name); 6050 value = 0; 6051 } 6052 else 6053 { 6054 value = default_conversion (value); 6055 constant_expression_warning (value); 6056 } 6057 } 6058 6059 /* Default based on previous value. */ 6060 /* It should no longer be possible to have NON_LVALUE_EXPR 6061 in the default. */ 6062 if (value == 0) 6063 { 6064 value = enum_next_value; 6065 if (enum_overflow) 6066 error ("overflow in enumeration values"); 6067 } 6068 6069 if (pedantic && !int_fits_type_p (value, integer_type_node)) 6070 { 6071 pedwarn ("ISO C restricts enumerator values to range of %<int%>"); 6072 /* XXX This causes -pedantic to change the meaning of the program. 6073 Remove? -zw 2004-03-15 */ 6074 value = convert (integer_type_node, value); 6075 } 6076 6077 /* Set basis for default for next value. */ 6078 enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0); 6079 enum_overflow = tree_int_cst_lt (enum_next_value, value); 6080 6081 /* Now create a declaration for the enum value name. */ 6082 6083 type = TREE_TYPE (value); 6084 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 6085 TYPE_PRECISION (integer_type_node)), 6086 (TYPE_PRECISION (type) 6087 >= TYPE_PRECISION (integer_type_node) 6088 && TYPE_UNSIGNED (type))); 6089 6090 decl = build_decl (CONST_DECL, name, type); 6091 DECL_INITIAL (decl) = convert (type, value); 6092 pushdecl (decl); 6093 6094 return tree_cons (decl, value, NULL_TREE); 6095} 6096 6097 6098/* Create the FUNCTION_DECL for a function definition. 6099 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 6100 the declaration; they describe the function's name and the type it returns, 6101 but twisted together in a fashion that parallels the syntax of C. 6102 6103 This function creates a binding context for the function body 6104 as well as setting up the FUNCTION_DECL in current_function_decl. 6105 6106 Returns 1 on success. If the DECLARATOR is not suitable for a function 6107 (it defines a datum instead), we return 0, which tells 6108 yyparse to report a parse error. */ 6109 6110int 6111start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 6112 tree attributes) 6113{ 6114 tree decl1, old_decl; 6115 tree restype, resdecl; 6116 struct c_label_context_se *nstack_se; 6117 struct c_label_context_vm *nstack_vm; 6118 6119 current_function_returns_value = 0; /* Assume, until we see it does. */ 6120 current_function_returns_null = 0; 6121 current_function_returns_abnormally = 0; 6122 warn_about_return_type = 0; 6123 c_switch_stack = NULL; 6124 6125 nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se); 6126 nstack_se->labels_def = NULL; 6127 nstack_se->labels_used = NULL; 6128 nstack_se->next = label_context_stack_se; 6129 label_context_stack_se = nstack_se; 6130 6131 nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm); 6132 nstack_vm->labels_def = NULL; 6133 nstack_vm->labels_used = NULL; 6134 nstack_vm->scope = 0; 6135 nstack_vm->next = label_context_stack_vm; 6136 label_context_stack_vm = nstack_vm; 6137 6138 /* Indicate no valid break/continue context by setting these variables 6139 to some non-null, non-label value. We'll notice and emit the proper 6140 error message in c_finish_bc_stmt. */ 6141 c_break_label = c_cont_label = size_zero_node; 6142 6143 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL); 6144 6145 /* If the declarator is not suitable for a function definition, 6146 cause a syntax error. */ 6147 if (decl1 == 0) 6148 { 6149 label_context_stack_se = label_context_stack_se->next; 6150 label_context_stack_vm = label_context_stack_vm->next; 6151 return 0; 6152 } 6153 6154 decl_attributes (&decl1, attributes, 0); 6155 6156 if (DECL_DECLARED_INLINE_P (decl1) 6157 && DECL_UNINLINABLE (decl1) 6158 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 6159 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 6160 decl1); 6161 6162 /* Handle gnu_inline attribute. */ 6163 if (declspecs->inline_p 6164 && !flag_gnu89_inline 6165 && TREE_CODE (decl1) == FUNCTION_DECL 6166 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1))) 6167 { 6168 if (declspecs->storage_class != csc_static) 6169 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 6170 } 6171 6172 announce_function (decl1); 6173 6174 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 6175 { 6176 error ("return type is an incomplete type"); 6177 /* Make it return void instead. */ 6178 TREE_TYPE (decl1) 6179 = build_function_type (void_type_node, 6180 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 6181 } 6182 6183 if (warn_about_return_type) 6184 pedwarn_c99 ("return type defaults to %<int%>"); 6185 6186 /* Make the init_value nonzero so pushdecl knows this is not tentative. 6187 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 6188 DECL_INITIAL (decl1) = error_mark_node; 6189 6190 /* If this definition isn't a prototype and we had a prototype declaration 6191 before, copy the arg type info from that prototype. */ 6192 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 6193 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 6194 old_decl = 0; 6195 current_function_prototype_locus = UNKNOWN_LOCATION; 6196 current_function_prototype_built_in = false; 6197 current_function_prototype_arg_types = NULL_TREE; 6198 if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0) 6199 { 6200 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 6201 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6202 TREE_TYPE (TREE_TYPE (old_decl)))) 6203 { 6204 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 6205 TREE_TYPE (decl1)); 6206 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 6207 current_function_prototype_built_in 6208 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 6209 current_function_prototype_arg_types 6210 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 6211 } 6212 if (TREE_PUBLIC (decl1)) 6213 { 6214 /* If there is an external prototype declaration of this 6215 function, record its location but do not copy information 6216 to this decl. This may be an invisible declaration 6217 (built-in or in a scope which has finished) or simply 6218 have more refined argument types than any declaration 6219 found above. */ 6220 struct c_binding *b; 6221 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 6222 if (B_IN_SCOPE (b, external_scope)) 6223 break; 6224 if (b) 6225 { 6226 tree ext_decl, ext_type; 6227 ext_decl = b->decl; 6228 ext_type = b->type ? b->type : TREE_TYPE (ext_decl); 6229 if (TREE_CODE (ext_type) == FUNCTION_TYPE 6230 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6231 TREE_TYPE (ext_type))) 6232 { 6233 current_function_prototype_locus 6234 = DECL_SOURCE_LOCATION (ext_decl); 6235 current_function_prototype_built_in 6236 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 6237 current_function_prototype_arg_types 6238 = TYPE_ARG_TYPES (ext_type); 6239 } 6240 } 6241 } 6242 } 6243 6244 /* Optionally warn of old-fashioned def with no previous prototype. */ 6245 if (warn_strict_prototypes 6246 && old_decl != error_mark_node 6247 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0 6248 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6249 warning (OPT_Wstrict_prototypes, 6250 "function declaration isn%'t a prototype"); 6251 /* Optionally warn of any global def with no previous prototype. */ 6252 else if (warn_missing_prototypes 6253 && old_decl != error_mark_node 6254 && TREE_PUBLIC (decl1) 6255 && !MAIN_NAME_P (DECL_NAME (decl1)) 6256 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6257 warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1); 6258 /* Optionally warn of any def with no previous prototype 6259 if the function has already been used. */ 6260 else if (warn_missing_prototypes 6261 && old_decl != 0 6262 && old_decl != error_mark_node 6263 && TREE_USED (old_decl) 6264 && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0) 6265 warning (OPT_Wmissing_prototypes, 6266 "%q+D was used with no prototype before its definition", decl1); 6267 /* Optionally warn of any global def with no previous declaration. */ 6268 else if (warn_missing_declarations 6269 && TREE_PUBLIC (decl1) 6270 && old_decl == 0 6271 && !MAIN_NAME_P (DECL_NAME (decl1))) 6272 warning (OPT_Wmissing_declarations, "no previous declaration for %q+D", 6273 decl1); 6274 /* Optionally warn of any def with no previous declaration 6275 if the function has already been used. */ 6276 else if (warn_missing_declarations 6277 && old_decl != 0 6278 && old_decl != error_mark_node 6279 && TREE_USED (old_decl) 6280 && C_DECL_IMPLICIT (old_decl)) 6281 warning (OPT_Wmissing_declarations, 6282 "%q+D was used with no declaration before its definition", decl1); 6283 6284 /* This function exists in static storage. 6285 (This does not mean `static' in the C sense!) */ 6286 TREE_STATIC (decl1) = 1; 6287 6288 /* A nested function is not global. */ 6289 if (current_function_decl != 0) 6290 TREE_PUBLIC (decl1) = 0; 6291 6292 /* This is the earliest point at which we might know the assembler 6293 name of the function. Thus, if it's set before this, die horribly. */ 6294 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 6295 6296 /* If #pragma weak was used, mark the decl weak now. */ 6297 if (current_scope == file_scope) 6298 maybe_apply_pragma_weak (decl1); 6299 6300 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 6301 if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1))) 6302 { 6303 tree args; 6304 int argct = 0; 6305 6306 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 6307 != integer_type_node) 6308 pedwarn ("return type of %q+D is not %<int%>", decl1); 6309 6310 for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args; 6311 args = TREE_CHAIN (args)) 6312 { 6313 tree type = args ? TREE_VALUE (args) : 0; 6314 6315 if (type == void_type_node) 6316 break; 6317 6318 ++argct; 6319 switch (argct) 6320 { 6321 case 1: 6322 if (TYPE_MAIN_VARIANT (type) != integer_type_node) 6323 pedwarn ("first argument of %q+D should be %<int%>", decl1); 6324 break; 6325 6326 case 2: 6327 if (TREE_CODE (type) != POINTER_TYPE 6328 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6329 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6330 != char_type_node)) 6331 pedwarn ("second argument of %q+D should be %<char **%>", 6332 decl1); 6333 break; 6334 6335 case 3: 6336 if (TREE_CODE (type) != POINTER_TYPE 6337 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6338 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6339 != char_type_node)) 6340 pedwarn ("third argument of %q+D should probably be " 6341 "%<char **%>", decl1); 6342 break; 6343 } 6344 } 6345 6346 /* It is intentional that this message does not mention the third 6347 argument because it's only mentioned in an appendix of the 6348 standard. */ 6349 if (argct > 0 && (argct < 2 || argct > 3)) 6350 pedwarn ("%q+D takes only zero or two arguments", decl1); 6351 6352 if (!TREE_PUBLIC (decl1)) 6353 pedwarn ("%q+D is normally a non-static function", decl1); 6354 } 6355 6356 /* Record the decl so that the function name is defined. 6357 If we already have a decl for this name, and it is a FUNCTION_DECL, 6358 use the old decl. */ 6359 6360 current_function_decl = pushdecl (decl1); 6361 6362 push_scope (); 6363 declare_parm_level (); 6364 6365 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6366 /* Promote the value to int before returning it. */ 6367 if (c_promoting_integer_type_p (restype)) 6368 { 6369 /* It retains unsignedness if not really getting wider. */ 6370 if (TYPE_UNSIGNED (restype) 6371 && (TYPE_PRECISION (restype) 6372 == TYPE_PRECISION (integer_type_node))) 6373 restype = unsigned_type_node; 6374 else 6375 restype = integer_type_node; 6376 } 6377 6378 resdecl = build_decl (RESULT_DECL, NULL_TREE, restype); 6379 DECL_ARTIFICIAL (resdecl) = 1; 6380 DECL_IGNORED_P (resdecl) = 1; 6381 DECL_RESULT (current_function_decl) = resdecl; 6382 6383 start_fname_decls (); 6384 6385 return 1; 6386} 6387 6388/* Subroutine of store_parm_decls which handles new-style function 6389 definitions (prototype format). The parms already have decls, so we 6390 need only record them as in effect and complain if any redundant 6391 old-style parm decls were written. */ 6392static void 6393store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 6394{ 6395 tree decl; 6396 6397 if (current_scope->bindings) 6398 { 6399 error ("%Jold-style parameter declarations in prototyped " 6400 "function definition", fndecl); 6401 6402 /* Get rid of the old-style declarations. */ 6403 pop_scope (); 6404 push_scope (); 6405 } 6406 /* Don't issue this warning for nested functions, and don't issue this 6407 warning if we got here because ARG_INFO_TYPES was error_mark_node 6408 (this happens when a function definition has just an ellipsis in 6409 its parameter list). */ 6410 else if (!in_system_header && !current_function_scope 6411 && arg_info->types != error_mark_node) 6412 warning (OPT_Wtraditional, 6413 "%Jtraditional C rejects ISO C style function definitions", 6414 fndecl); 6415 6416 /* Now make all the parameter declarations visible in the function body. 6417 We can bypass most of the grunt work of pushdecl. */ 6418 for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl)) 6419 { 6420 DECL_CONTEXT (decl) = current_function_decl; 6421 if (DECL_NAME (decl)) 6422 { 6423 bind (DECL_NAME (decl), decl, current_scope, 6424 /*invisible=*/false, /*nested=*/false); 6425 if (!TREE_USED (decl)) 6426 warn_if_shadowing (decl); 6427 } 6428 else 6429 error ("%Jparameter name omitted", decl); 6430 } 6431 6432 /* Record the parameter list in the function declaration. */ 6433 DECL_ARGUMENTS (fndecl) = arg_info->parms; 6434 6435 /* Now make all the ancillary declarations visible, likewise. */ 6436 for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl)) 6437 { 6438 DECL_CONTEXT (decl) = current_function_decl; 6439 if (DECL_NAME (decl)) 6440 bind (DECL_NAME (decl), decl, current_scope, 6441 /*invisible=*/false, /*nested=*/false); 6442 } 6443 6444 /* And all the tag declarations. */ 6445 for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl)) 6446 if (TREE_PURPOSE (decl)) 6447 bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope, 6448 /*invisible=*/false, /*nested=*/false); 6449} 6450 6451/* Subroutine of store_parm_decls which handles old-style function 6452 definitions (separate parameter list and declarations). */ 6453 6454static void 6455store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 6456{ 6457 struct c_binding *b; 6458 tree parm, decl, last; 6459 tree parmids = arg_info->parms; 6460 struct pointer_set_t *seen_args = pointer_set_create (); 6461 6462 if (!in_system_header) 6463 warning (OPT_Wold_style_definition, "%Jold-style function definition", 6464 fndecl); 6465 6466 /* Match each formal parameter name with its declaration. Save each 6467 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 6468 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6469 { 6470 if (TREE_VALUE (parm) == 0) 6471 { 6472 error ("%Jparameter name missing from parameter list", fndecl); 6473 TREE_PURPOSE (parm) = 0; 6474 continue; 6475 } 6476 6477 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 6478 if (b && B_IN_CURRENT_SCOPE (b)) 6479 { 6480 decl = b->decl; 6481 /* If we got something other than a PARM_DECL it is an error. */ 6482 if (TREE_CODE (decl) != PARM_DECL) 6483 error ("%q+D declared as a non-parameter", decl); 6484 /* If the declaration is already marked, we have a duplicate 6485 name. Complain and ignore the duplicate. */ 6486 else if (pointer_set_contains (seen_args, decl)) 6487 { 6488 error ("multiple parameters named %q+D", decl); 6489 TREE_PURPOSE (parm) = 0; 6490 continue; 6491 } 6492 /* If the declaration says "void", complain and turn it into 6493 an int. */ 6494 else if (VOID_TYPE_P (TREE_TYPE (decl))) 6495 { 6496 error ("parameter %q+D declared with void type", decl); 6497 TREE_TYPE (decl) = integer_type_node; 6498 DECL_ARG_TYPE (decl) = integer_type_node; 6499 layout_decl (decl, 0); 6500 } 6501 warn_if_shadowing (decl); 6502 } 6503 /* If no declaration found, default to int. */ 6504 else 6505 { 6506 decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node); 6507 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 6508 DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl); 6509 pushdecl (decl); 6510 warn_if_shadowing (decl); 6511 6512 if (flag_isoc99) 6513 pedwarn ("type of %q+D defaults to %<int%>", decl); 6514 else if (extra_warnings) 6515 warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl); 6516 } 6517 6518 TREE_PURPOSE (parm) = decl; 6519 pointer_set_insert (seen_args, decl); 6520 } 6521 6522 /* Now examine the parms chain for incomplete declarations 6523 and declarations with no corresponding names. */ 6524 6525 for (b = current_scope->bindings; b; b = b->prev) 6526 { 6527 parm = b->decl; 6528 if (TREE_CODE (parm) != PARM_DECL) 6529 continue; 6530 6531 if (TREE_TYPE (parm) != error_mark_node 6532 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 6533 { 6534 error ("parameter %q+D has incomplete type", parm); 6535 TREE_TYPE (parm) = error_mark_node; 6536 } 6537 6538 if (!pointer_set_contains (seen_args, parm)) 6539 { 6540 error ("declaration for parameter %q+D but no such parameter", parm); 6541 6542 /* Pretend the parameter was not missing. 6543 This gets us to a standard state and minimizes 6544 further error messages. */ 6545 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 6546 } 6547 } 6548 6549 /* Chain the declarations together in the order of the list of 6550 names. Store that chain in the function decl, replacing the 6551 list of names. Update the current scope to match. */ 6552 DECL_ARGUMENTS (fndecl) = 0; 6553 6554 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6555 if (TREE_PURPOSE (parm)) 6556 break; 6557 if (parm && TREE_PURPOSE (parm)) 6558 { 6559 last = TREE_PURPOSE (parm); 6560 DECL_ARGUMENTS (fndecl) = last; 6561 6562 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 6563 if (TREE_PURPOSE (parm)) 6564 { 6565 TREE_CHAIN (last) = TREE_PURPOSE (parm); 6566 last = TREE_PURPOSE (parm); 6567 } 6568 TREE_CHAIN (last) = 0; 6569 } 6570 6571 pointer_set_destroy (seen_args); 6572 6573 /* If there was a previous prototype, 6574 set the DECL_ARG_TYPE of each argument according to 6575 the type previously specified, and report any mismatches. */ 6576 6577 if (current_function_prototype_arg_types) 6578 { 6579 tree type; 6580 for (parm = DECL_ARGUMENTS (fndecl), 6581 type = current_function_prototype_arg_types; 6582 parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) 6583 != void_type_node)); 6584 parm = TREE_CHAIN (parm), type = TREE_CHAIN (type)) 6585 { 6586 if (parm == 0 || type == 0 6587 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 6588 { 6589 if (current_function_prototype_built_in) 6590 warning (0, "number of arguments doesn%'t match " 6591 "built-in prototype"); 6592 else 6593 { 6594 error ("number of arguments doesn%'t match prototype"); 6595 error ("%Hprototype declaration", 6596 ¤t_function_prototype_locus); 6597 } 6598 break; 6599 } 6600 /* Type for passing arg must be consistent with that 6601 declared for the arg. ISO C says we take the unqualified 6602 type for parameters declared with qualified type. */ 6603 if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 6604 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 6605 { 6606 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 6607 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 6608 { 6609 /* Adjust argument to match prototype. E.g. a previous 6610 `int foo(float);' prototype causes 6611 `int foo(x) float x; {...}' to be treated like 6612 `int foo(float x) {...}'. This is particularly 6613 useful for argument types like uid_t. */ 6614 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 6615 6616 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 6617 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 6618 && TYPE_PRECISION (TREE_TYPE (parm)) 6619 < TYPE_PRECISION (integer_type_node)) 6620 DECL_ARG_TYPE (parm) = integer_type_node; 6621 6622 if (pedantic) 6623 { 6624 /* ??? Is it possible to get here with a 6625 built-in prototype or will it always have 6626 been diagnosed as conflicting with an 6627 old-style definition and discarded? */ 6628 if (current_function_prototype_built_in) 6629 warning (0, "promoted argument %qD " 6630 "doesn%'t match built-in prototype", parm); 6631 else 6632 { 6633 pedwarn ("promoted argument %qD " 6634 "doesn%'t match prototype", parm); 6635 pedwarn ("%Hprototype declaration", 6636 ¤t_function_prototype_locus); 6637 } 6638 } 6639 } 6640 else 6641 { 6642 if (current_function_prototype_built_in) 6643 warning (0, "argument %qD doesn%'t match " 6644 "built-in prototype", parm); 6645 else 6646 { 6647 error ("argument %qD doesn%'t match prototype", parm); 6648 error ("%Hprototype declaration", 6649 ¤t_function_prototype_locus); 6650 } 6651 } 6652 } 6653 } 6654 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 6655 } 6656 6657 /* Otherwise, create a prototype that would match. */ 6658 6659 else 6660 { 6661 tree actual = 0, last = 0, type; 6662 6663 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm)) 6664 { 6665 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 6666 if (last) 6667 TREE_CHAIN (last) = type; 6668 else 6669 actual = type; 6670 last = type; 6671 } 6672 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 6673 if (last) 6674 TREE_CHAIN (last) = type; 6675 else 6676 actual = type; 6677 6678 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 6679 of the type of this function, but we need to avoid having this 6680 affect the types of other similarly-typed functions, so we must 6681 first force the generation of an identical (but separate) type 6682 node for the relevant function type. The new node we create 6683 will be a variant of the main variant of the original function 6684 type. */ 6685 6686 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 6687 6688 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 6689 } 6690} 6691 6692/* Store parameter declarations passed in ARG_INFO into the current 6693 function declaration. */ 6694 6695void 6696store_parm_decls_from (struct c_arg_info *arg_info) 6697{ 6698 current_function_arg_info = arg_info; 6699 store_parm_decls (); 6700} 6701 6702/* Store the parameter declarations into the current function declaration. 6703 This is called after parsing the parameter declarations, before 6704 digesting the body of the function. 6705 6706 For an old-style definition, construct a prototype out of the old-style 6707 parameter declarations and inject it into the function's type. */ 6708 6709void 6710store_parm_decls (void) 6711{ 6712 tree fndecl = current_function_decl; 6713 bool proto; 6714 6715 /* The argument information block for FNDECL. */ 6716 struct c_arg_info *arg_info = current_function_arg_info; 6717 current_function_arg_info = 0; 6718 6719 /* True if this definition is written with a prototype. Note: 6720 despite C99 6.7.5.3p14, we can *not* treat an empty argument 6721 list in a function definition as equivalent to (void) -- an 6722 empty argument list specifies the function has no parameters, 6723 but only (void) sets up a prototype for future calls. */ 6724 proto = arg_info->types != 0; 6725 6726 if (proto) 6727 store_parm_decls_newstyle (fndecl, arg_info); 6728 else 6729 store_parm_decls_oldstyle (fndecl, arg_info); 6730 6731 /* The next call to push_scope will be a function body. */ 6732 6733 next_is_function_body = true; 6734 6735 /* Write a record describing this function definition to the prototypes 6736 file (if requested). */ 6737 6738 gen_aux_info_record (fndecl, 1, 0, proto); 6739 6740 /* Initialize the RTL code for the function. */ 6741 allocate_struct_function (fndecl); 6742 6743 /* Begin the statement tree for this function. */ 6744 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 6745 6746 /* ??? Insert the contents of the pending sizes list into the function 6747 to be evaluated. The only reason left to have this is 6748 void foo(int n, int array[n++]) 6749 because we throw away the array type in favor of a pointer type, and 6750 thus won't naturally see the SAVE_EXPR containing the increment. All 6751 other pending sizes would be handled by gimplify_parameters. */ 6752 { 6753 tree t; 6754 for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t)) 6755 add_stmt (TREE_VALUE (t)); 6756 } 6757 6758 /* Even though we're inside a function body, we still don't want to 6759 call expand_expr to calculate the size of a variable-sized array. 6760 We haven't necessarily assigned RTL to all variables yet, so it's 6761 not safe to try to expand expressions involving them. */ 6762 cfun->x_dont_save_pending_sizes_p = 1; 6763} 6764 6765/* Emit diagnostics that require gimple input for detection. Operate on 6766 FNDECL and all its nested functions. */ 6767 6768static void 6769c_gimple_diagnostics_recursively (tree fndecl) 6770{ 6771 struct cgraph_node *cgn; 6772 6773 /* Handle attribute((warn_unused_result)). Relies on gimple input. */ 6774 c_warn_unused_result (&DECL_SAVED_TREE (fndecl)); 6775 6776 /* Notice when OpenMP structured block constraints are violated. */ 6777 if (flag_openmp) 6778 diagnose_omp_structured_block_errors (fndecl); 6779 6780 /* Finalize all nested functions now. */ 6781 cgn = cgraph_node (fndecl); 6782 for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) 6783 c_gimple_diagnostics_recursively (cgn->decl); 6784} 6785 6786/* Finish up a function declaration and compile that function 6787 all the way to assembler language output. The free the storage 6788 for the function definition. 6789 6790 This is called after parsing the body of the function definition. */ 6791 6792void 6793finish_function (void) 6794{ 6795 tree fndecl = current_function_decl; 6796 6797 label_context_stack_se = label_context_stack_se->next; 6798 label_context_stack_vm = label_context_stack_vm->next; 6799 6800 if (TREE_CODE (fndecl) == FUNCTION_DECL 6801 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 6802 { 6803 tree args = DECL_ARGUMENTS (fndecl); 6804 for (; args; args = TREE_CHAIN (args)) 6805 { 6806 tree type = TREE_TYPE (args); 6807 if (INTEGRAL_TYPE_P (type) 6808 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 6809 DECL_ARG_TYPE (args) = integer_type_node; 6810 } 6811 } 6812 6813 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6814 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 6815 6816 /* Must mark the RESULT_DECL as being in this function. */ 6817 6818 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 6819 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 6820 6821 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted) 6822 { 6823 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 6824 != integer_type_node) 6825 { 6826 /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned. 6827 If warn_main is -1 (-Wno-main) we don't want to be warned. */ 6828 if (!warn_main) 6829 pedwarn ("return type of %q+D is not %<int%>", fndecl); 6830 } 6831 else 6832 { 6833 if (flag_isoc99) 6834 { 6835 tree stmt = c_finish_return (integer_zero_node); 6836#ifdef USE_MAPPED_LOCATION 6837 /* Hack. We don't want the middle-end to warn that this return 6838 is unreachable, so we mark its location as special. Using 6839 UNKNOWN_LOCATION has the problem that it gets clobbered in 6840 annotate_one_with_locus. A cleaner solution might be to 6841 ensure ! should_carry_locus_p (stmt), but that needs a flag. 6842 */ 6843 SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION); 6844#else 6845 /* Hack. We don't want the middle-end to warn that this 6846 return is unreachable, so put the statement on the 6847 special line 0. */ 6848 annotate_with_file_line (stmt, input_filename, 0); 6849#endif 6850 } 6851 } 6852 } 6853 6854 /* Tie off the statement tree for this function. */ 6855 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 6856 6857 finish_fname_decls (); 6858 6859 /* Complain if there's just no return statement. */ 6860 if (warn_return_type 6861 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 6862 && !current_function_returns_value && !current_function_returns_null 6863 /* Don't complain if we are no-return. */ 6864 && !current_function_returns_abnormally 6865 /* Don't warn for main(). */ 6866 && !MAIN_NAME_P (DECL_NAME (fndecl)) 6867 /* Or if they didn't actually specify a return type. */ 6868 && !C_FUNCTION_IMPLICIT_INT (fndecl) 6869 /* Normally, with -Wreturn-type, flow will complain. Unless we're an 6870 inline function, as we might never be compiled separately. */ 6871 && DECL_INLINE (fndecl)) 6872 { 6873 warning (OPT_Wreturn_type, 6874 "no return statement in function returning non-void"); 6875 TREE_NO_WARNING (fndecl) = 1; 6876 } 6877 6878 /* With just -Wextra, complain only if function returns both with 6879 and without a value. */ 6880 if (extra_warnings 6881 && current_function_returns_value 6882 && current_function_returns_null) 6883 warning (OPT_Wextra, "this function may return with or without a value"); 6884 6885 /* Store the end of the function, so that we get good line number 6886 info for the epilogue. */ 6887 cfun->function_end_locus = input_location; 6888 6889 /* If we don't have ctors/dtors sections, and this is a static 6890 constructor or destructor, it must be recorded now. */ 6891 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6892 && !targetm.have_ctors_dtors) 6893 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors); 6894 if (DECL_STATIC_DESTRUCTOR (fndecl) 6895 && !targetm.have_ctors_dtors) 6896 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors); 6897 6898 /* Finalize the ELF visibility for the function. */ 6899 c_determine_visibility (fndecl); 6900 6901 /* Genericize before inlining. Delay genericizing nested functions 6902 until their parent function is genericized. Since finalizing 6903 requires GENERIC, delay that as well. */ 6904 6905 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 6906 && !undef_nested_function) 6907 { 6908 if (!decl_function_context (fndecl)) 6909 { 6910 c_genericize (fndecl); 6911 c_gimple_diagnostics_recursively (fndecl); 6912 6913 /* ??? Objc emits functions after finalizing the compilation unit. 6914 This should be cleaned up later and this conditional removed. */ 6915 if (cgraph_global_info_ready) 6916 { 6917 c_expand_body (fndecl); 6918 return; 6919 } 6920 6921 cgraph_finalize_function (fndecl, false); 6922 } 6923 else 6924 { 6925 /* Register this function with cgraph just far enough to get it 6926 added to our parent's nested function list. Handy, since the 6927 C front end doesn't have such a list. */ 6928 (void) cgraph_node (fndecl); 6929 } 6930 } 6931 6932 if (!decl_function_context (fndecl)) 6933 undef_nested_function = false; 6934 6935 /* We're leaving the context of this function, so zap cfun. 6936 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 6937 tree_rest_of_compilation. */ 6938 cfun = NULL; 6939 current_function_decl = NULL; 6940} 6941 6942/* Generate the RTL for the body of FNDECL. */ 6943 6944void 6945c_expand_body (tree fndecl) 6946{ 6947 6948 if (!DECL_INITIAL (fndecl) 6949 || DECL_INITIAL (fndecl) == error_mark_node) 6950 return; 6951 6952 tree_rest_of_compilation (fndecl); 6953 6954 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6955 && targetm.have_ctors_dtors) 6956 targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0), 6957 DEFAULT_INIT_PRIORITY); 6958 if (DECL_STATIC_DESTRUCTOR (fndecl) 6959 && targetm.have_ctors_dtors) 6960 targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0), 6961 DEFAULT_INIT_PRIORITY); 6962} 6963 6964/* Check the declarations given in a for-loop for satisfying the C99 6965 constraints. If exactly one such decl is found, return it. */ 6966 6967tree 6968check_for_loop_decls (void) 6969{ 6970 struct c_binding *b; 6971 tree one_decl = NULL_TREE; 6972 int n_decls = 0; 6973 6974 6975 if (!flag_isoc99) 6976 { 6977 /* If we get here, declarations have been used in a for loop without 6978 the C99 for loop scope. This doesn't make much sense, so don't 6979 allow it. */ 6980 error ("%<for%> loop initial declaration used outside C99 mode"); 6981 return NULL_TREE; 6982 } 6983 /* C99 subclause 6.8.5 paragraph 3: 6984 6985 [#3] The declaration part of a for statement shall only 6986 declare identifiers for objects having storage class auto or 6987 register. 6988 6989 It isn't clear whether, in this sentence, "identifiers" binds to 6990 "shall only declare" or to "objects" - that is, whether all identifiers 6991 declared must be identifiers for objects, or whether the restriction 6992 only applies to those that are. (A question on this in comp.std.c 6993 in November 2000 received no answer.) We implement the strictest 6994 interpretation, to avoid creating an extension which later causes 6995 problems. */ 6996 6997 for (b = current_scope->bindings; b; b = b->prev) 6998 { 6999 tree id = b->id; 7000 tree decl = b->decl; 7001 7002 if (!id) 7003 continue; 7004 7005 switch (TREE_CODE (decl)) 7006 { 7007 case VAR_DECL: 7008 if (TREE_STATIC (decl)) 7009 error ("declaration of static variable %q+D in %<for%> loop " 7010 "initial declaration", decl); 7011 else if (DECL_EXTERNAL (decl)) 7012 error ("declaration of %<extern%> variable %q+D in %<for%> loop " 7013 "initial declaration", decl); 7014 break; 7015 7016 case RECORD_TYPE: 7017 error ("%<struct %E%> declared in %<for%> loop initial declaration", 7018 id); 7019 break; 7020 case UNION_TYPE: 7021 error ("%<union %E%> declared in %<for%> loop initial declaration", 7022 id); 7023 break; 7024 case ENUMERAL_TYPE: 7025 error ("%<enum %E%> declared in %<for%> loop initial declaration", 7026 id); 7027 break; 7028 default: 7029 error ("declaration of non-variable %q+D in %<for%> loop " 7030 "initial declaration", decl); 7031 } 7032 7033 n_decls++; 7034 one_decl = decl; 7035 } 7036 7037 return n_decls == 1 ? one_decl : NULL_TREE; 7038} 7039 7040/* Save and reinitialize the variables 7041 used during compilation of a C function. */ 7042 7043void 7044c_push_function_context (struct function *f) 7045{ 7046 struct language_function *p; 7047 p = GGC_NEW (struct language_function); 7048 f->language = p; 7049 7050 p->base.x_stmt_tree = c_stmt_tree; 7051 p->x_break_label = c_break_label; 7052 p->x_cont_label = c_cont_label; 7053 p->x_switch_stack = c_switch_stack; 7054 p->arg_info = current_function_arg_info; 7055 p->returns_value = current_function_returns_value; 7056 p->returns_null = current_function_returns_null; 7057 p->returns_abnormally = current_function_returns_abnormally; 7058 p->warn_about_return_type = warn_about_return_type; 7059} 7060 7061/* Restore the variables used during compilation of a C function. */ 7062 7063void 7064c_pop_function_context (struct function *f) 7065{ 7066 struct language_function *p = f->language; 7067 7068 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 7069 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 7070 { 7071 /* Stop pointing to the local nodes about to be freed. */ 7072 /* But DECL_INITIAL must remain nonzero so we know this 7073 was an actual function definition. */ 7074 DECL_INITIAL (current_function_decl) = error_mark_node; 7075 DECL_ARGUMENTS (current_function_decl) = 0; 7076 } 7077 7078 c_stmt_tree = p->base.x_stmt_tree; 7079 c_break_label = p->x_break_label; 7080 c_cont_label = p->x_cont_label; 7081 c_switch_stack = p->x_switch_stack; 7082 current_function_arg_info = p->arg_info; 7083 current_function_returns_value = p->returns_value; 7084 current_function_returns_null = p->returns_null; 7085 current_function_returns_abnormally = p->returns_abnormally; 7086 warn_about_return_type = p->warn_about_return_type; 7087 7088 f->language = NULL; 7089} 7090 7091/* Copy the DECL_LANG_SPECIFIC data associated with DECL. */ 7092 7093void 7094c_dup_lang_specific_decl (tree decl) 7095{ 7096 struct lang_decl *ld; 7097 7098 if (!DECL_LANG_SPECIFIC (decl)) 7099 return; 7100 7101 ld = GGC_NEW (struct lang_decl); 7102 memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl)); 7103 DECL_LANG_SPECIFIC (decl) = ld; 7104} 7105 7106/* The functions below are required for functionality of doing 7107 function at once processing in the C front end. Currently these 7108 functions are not called from anywhere in the C front end, but as 7109 these changes continue, that will change. */ 7110 7111/* Returns the stmt_tree (if any) to which statements are currently 7112 being added. If there is no active statement-tree, NULL is 7113 returned. */ 7114 7115stmt_tree 7116current_stmt_tree (void) 7117{ 7118 return &c_stmt_tree; 7119} 7120 7121/* Nonzero if TYPE is an anonymous union or struct type. Always 0 in 7122 C. */ 7123 7124int 7125anon_aggr_type_p (tree ARG_UNUSED (node)) 7126{ 7127 return 0; 7128} 7129 7130/* Return the global value of T as a symbol. */ 7131 7132tree 7133identifier_global_value (tree t) 7134{ 7135 struct c_binding *b; 7136 7137 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 7138 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 7139 return b->decl; 7140 7141 return 0; 7142} 7143 7144/* Record a builtin type for C. If NAME is non-NULL, it is the name used; 7145 otherwise the name is found in ridpointers from RID_INDEX. */ 7146 7147void 7148record_builtin_type (enum rid rid_index, const char *name, tree type) 7149{ 7150 tree id, decl; 7151 if (name == 0) 7152 id = ridpointers[(int) rid_index]; 7153 else 7154 id = get_identifier (name); 7155 decl = build_decl (TYPE_DECL, id, type); 7156 pushdecl (decl); 7157 if (debug_hooks->type_decl) 7158 debug_hooks->type_decl (decl, false); 7159} 7160 7161/* Build the void_list_node (void_type_node having been created). */ 7162tree 7163build_void_list_node (void) 7164{ 7165 tree t = build_tree_list (NULL_TREE, void_type_node); 7166 return t; 7167} 7168 7169/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 7170 7171struct c_parm * 7172build_c_parm (struct c_declspecs *specs, tree attrs, 7173 struct c_declarator *declarator) 7174{ 7175 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 7176 ret->specs = specs; 7177 ret->attrs = attrs; 7178 ret->declarator = declarator; 7179 return ret; 7180} 7181 7182/* Return a declarator with nested attributes. TARGET is the inner 7183 declarator to which these attributes apply. ATTRS are the 7184 attributes. */ 7185 7186struct c_declarator * 7187build_attrs_declarator (tree attrs, struct c_declarator *target) 7188{ 7189 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7190 ret->kind = cdk_attrs; 7191 ret->declarator = target; 7192 ret->u.attrs = attrs; 7193 return ret; 7194} 7195 7196/* Return a declarator for a function with arguments specified by ARGS 7197 and return type specified by TARGET. */ 7198 7199struct c_declarator * 7200build_function_declarator (struct c_arg_info *args, 7201 struct c_declarator *target) 7202{ 7203 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7204 ret->kind = cdk_function; 7205 ret->declarator = target; 7206 ret->u.arg_info = args; 7207 return ret; 7208} 7209 7210/* Return a declarator for the identifier IDENT (which may be 7211 NULL_TREE for an abstract declarator). */ 7212 7213struct c_declarator * 7214build_id_declarator (tree ident) 7215{ 7216 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7217 ret->kind = cdk_id; 7218 ret->declarator = 0; 7219 ret->u.id = ident; 7220 /* Default value - may get reset to a more precise location. */ 7221 ret->id_loc = input_location; 7222 return ret; 7223} 7224 7225/* Return something to represent absolute declarators containing a *. 7226 TARGET is the absolute declarator that the * contains. 7227 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 7228 to apply to the pointer type. */ 7229 7230struct c_declarator * 7231make_pointer_declarator (struct c_declspecs *type_quals_attrs, 7232 struct c_declarator *target) 7233{ 7234 tree attrs; 7235 int quals = 0; 7236 struct c_declarator *itarget = target; 7237 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7238 if (type_quals_attrs) 7239 { 7240 attrs = type_quals_attrs->attrs; 7241 quals = quals_from_declspecs (type_quals_attrs); 7242 if (attrs != NULL_TREE) 7243 itarget = build_attrs_declarator (attrs, target); 7244 } 7245 ret->kind = cdk_pointer; 7246 ret->declarator = itarget; 7247 ret->u.pointer_quals = quals; 7248 return ret; 7249} 7250 7251/* Return a pointer to a structure for an empty list of declaration 7252 specifiers. */ 7253 7254struct c_declspecs * 7255build_null_declspecs (void) 7256{ 7257 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 7258 ret->type = 0; 7259 ret->decl_attr = 0; 7260 ret->attrs = 0; 7261 ret->typespec_word = cts_none; 7262 ret->storage_class = csc_none; 7263 ret->declspecs_seen_p = false; 7264 ret->type_seen_p = false; 7265 ret->non_sc_seen_p = false; 7266 ret->typedef_p = false; 7267 ret->tag_defined_p = false; 7268 ret->explicit_signed_p = false; 7269 ret->deprecated_p = false; 7270 ret->default_int_p = false; 7271 ret->long_p = false; 7272 ret->long_long_p = false; 7273 ret->short_p = false; 7274 ret->signed_p = false; 7275 ret->unsigned_p = false; 7276 ret->complex_p = false; 7277 ret->inline_p = false; 7278 ret->thread_p = false; 7279 ret->const_p = false; 7280 ret->volatile_p = false; 7281 ret->restrict_p = false; 7282 return ret; 7283} 7284 7285/* Add the type qualifier QUAL to the declaration specifiers SPECS, 7286 returning SPECS. */ 7287 7288struct c_declspecs * 7289declspecs_add_qual (struct c_declspecs *specs, tree qual) 7290{ 7291 enum rid i; 7292 bool dupe = false; 7293 specs->non_sc_seen_p = true; 7294 specs->declspecs_seen_p = true; 7295 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 7296 && C_IS_RESERVED_WORD (qual)); 7297 i = C_RID_CODE (qual); 7298 switch (i) 7299 { 7300 case RID_CONST: 7301 dupe = specs->const_p; 7302 specs->const_p = true; 7303 break; 7304 case RID_VOLATILE: 7305 dupe = specs->volatile_p; 7306 specs->volatile_p = true; 7307 break; 7308 case RID_RESTRICT: 7309 dupe = specs->restrict_p; 7310 specs->restrict_p = true; 7311 break; 7312 default: 7313 gcc_unreachable (); 7314 } 7315 if (dupe && pedantic && !flag_isoc99) 7316 pedwarn ("duplicate %qE", qual); 7317 return specs; 7318} 7319 7320/* Add the type specifier TYPE to the declaration specifiers SPECS, 7321 returning SPECS. */ 7322 7323struct c_declspecs * 7324declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec) 7325{ 7326 tree type = spec.spec; 7327 specs->non_sc_seen_p = true; 7328 specs->declspecs_seen_p = true; 7329 specs->type_seen_p = true; 7330 if (TREE_DEPRECATED (type)) 7331 specs->deprecated_p = true; 7332 7333 /* Handle type specifier keywords. */ 7334 if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type)) 7335 { 7336 enum rid i = C_RID_CODE (type); 7337 if (specs->type) 7338 { 7339 error ("two or more data types in declaration specifiers"); 7340 return specs; 7341 } 7342 if ((int) i <= (int) RID_LAST_MODIFIER) 7343 { 7344 /* "long", "short", "signed", "unsigned" or "_Complex". */ 7345 bool dupe = false; 7346 switch (i) 7347 { 7348 case RID_LONG: 7349 if (specs->long_long_p) 7350 { 7351 error ("%<long long long%> is too long for GCC"); 7352 break; 7353 } 7354 if (specs->long_p) 7355 { 7356 if (specs->typespec_word == cts_double) 7357 { 7358 error ("both %<long long%> and %<double%> in " 7359 "declaration specifiers"); 7360 break; 7361 } 7362 if (pedantic && !flag_isoc99 && !in_system_header 7363 && warn_long_long) 7364 pedwarn ("ISO C90 does not support %<long long%>"); 7365 specs->long_long_p = 1; 7366 break; 7367 } 7368 if (specs->short_p) 7369 error ("both %<long%> and %<short%> in " 7370 "declaration specifiers"); 7371 else if (specs->typespec_word == cts_void) 7372 error ("both %<long%> and %<void%> in " 7373 "declaration specifiers"); 7374 else if (specs->typespec_word == cts_bool) 7375 error ("both %<long%> and %<_Bool%> in " 7376 "declaration specifiers"); 7377 else if (specs->typespec_word == cts_char) 7378 error ("both %<long%> and %<char%> in " 7379 "declaration specifiers"); 7380 else if (specs->typespec_word == cts_float) 7381 error ("both %<long%> and %<float%> in " 7382 "declaration specifiers"); 7383 else if (specs->typespec_word == cts_dfloat32) 7384 error ("both %<long%> and %<_Decimal32%> in " 7385 "declaration specifiers"); 7386 else if (specs->typespec_word == cts_dfloat64) 7387 error ("both %<long%> and %<_Decimal64%> in " 7388 "declaration specifiers"); 7389 else if (specs->typespec_word == cts_dfloat128) 7390 error ("both %<long%> and %<_Decimal128%> in " 7391 "declaration specifiers"); 7392 else 7393 specs->long_p = true; 7394 break; 7395 case RID_SHORT: 7396 dupe = specs->short_p; 7397 if (specs->long_p) 7398 error ("both %<long%> and %<short%> in " 7399 "declaration specifiers"); 7400 else if (specs->typespec_word == cts_void) 7401 error ("both %<short%> and %<void%> in " 7402 "declaration specifiers"); 7403 else if (specs->typespec_word == cts_bool) 7404 error ("both %<short%> and %<_Bool%> in " 7405 "declaration specifiers"); 7406 else if (specs->typespec_word == cts_char) 7407 error ("both %<short%> and %<char%> in " 7408 "declaration specifiers"); 7409 else if (specs->typespec_word == cts_float) 7410 error ("both %<short%> and %<float%> in " 7411 "declaration specifiers"); 7412 else if (specs->typespec_word == cts_double) 7413 error ("both %<short%> and %<double%> in " 7414 "declaration specifiers"); 7415 else if (specs->typespec_word == cts_dfloat32) 7416 error ("both %<short%> and %<_Decimal32%> in " 7417 "declaration specifiers"); 7418 else if (specs->typespec_word == cts_dfloat64) 7419 error ("both %<short%> and %<_Decimal64%> in " 7420 "declaration specifiers"); 7421 else if (specs->typespec_word == cts_dfloat128) 7422 error ("both %<short%> and %<_Decimal128%> in " 7423 "declaration specifiers"); 7424 else 7425 specs->short_p = true; 7426 break; 7427 case RID_SIGNED: 7428 dupe = specs->signed_p; 7429 if (specs->unsigned_p) 7430 error ("both %<signed%> and %<unsigned%> in " 7431 "declaration specifiers"); 7432 else if (specs->typespec_word == cts_void) 7433 error ("both %<signed%> and %<void%> in " 7434 "declaration specifiers"); 7435 else if (specs->typespec_word == cts_bool) 7436 error ("both %<signed%> and %<_Bool%> in " 7437 "declaration specifiers"); 7438 else if (specs->typespec_word == cts_float) 7439 error ("both %<signed%> and %<float%> in " 7440 "declaration specifiers"); 7441 else if (specs->typespec_word == cts_double) 7442 error ("both %<signed%> and %<double%> in " 7443 "declaration specifiers"); 7444 else if (specs->typespec_word == cts_dfloat32) 7445 error ("both %<signed%> and %<_Decimal32%> in " 7446 "declaration specifiers"); 7447 else if (specs->typespec_word == cts_dfloat64) 7448 error ("both %<signed%> and %<_Decimal64%> in " 7449 "declaration specifiers"); 7450 else if (specs->typespec_word == cts_dfloat128) 7451 error ("both %<signed%> and %<_Decimal128%> in " 7452 "declaration specifiers"); 7453 else 7454 specs->signed_p = true; 7455 break; 7456 case RID_UNSIGNED: 7457 dupe = specs->unsigned_p; 7458 if (specs->signed_p) 7459 error ("both %<signed%> and %<unsigned%> in " 7460 "declaration specifiers"); 7461 else if (specs->typespec_word == cts_void) 7462 error ("both %<unsigned%> and %<void%> in " 7463 "declaration specifiers"); 7464 else if (specs->typespec_word == cts_bool) 7465 error ("both %<unsigned%> and %<_Bool%> in " 7466 "declaration specifiers"); 7467 else if (specs->typespec_word == cts_float) 7468 error ("both %<unsigned%> and %<float%> in " 7469 "declaration specifiers"); 7470 else if (specs->typespec_word == cts_double) 7471 error ("both %<unsigned%> and %<double%> in " 7472 "declaration specifiers"); 7473 else if (specs->typespec_word == cts_dfloat32) 7474 error ("both %<unsigned%> and %<_Decimal32%> in " 7475 "declaration specifiers"); 7476 else if (specs->typespec_word == cts_dfloat64) 7477 error ("both %<unsigned%> and %<_Decimal64%> in " 7478 "declaration specifiers"); 7479 else if (specs->typespec_word == cts_dfloat128) 7480 error ("both %<unsigned%> and %<_Decimal128%> in " 7481 "declaration specifiers"); 7482 else 7483 specs->unsigned_p = true; 7484 break; 7485 case RID_COMPLEX: 7486 dupe = specs->complex_p; 7487 if (pedantic && !flag_isoc99 && !in_system_header) 7488 pedwarn ("ISO C90 does not support complex types"); 7489 if (specs->typespec_word == cts_void) 7490 error ("both %<complex%> and %<void%> in " 7491 "declaration specifiers"); 7492 else if (specs->typespec_word == cts_bool) 7493 error ("both %<complex%> and %<_Bool%> in " 7494 "declaration specifiers"); 7495 else if (specs->typespec_word == cts_dfloat32) 7496 error ("both %<complex%> and %<_Decimal32%> in " 7497 "declaration specifiers"); 7498 else if (specs->typespec_word == cts_dfloat64) 7499 error ("both %<complex%> and %<_Decimal64%> in " 7500 "declaration specifiers"); 7501 else if (specs->typespec_word == cts_dfloat128) 7502 error ("both %<complex%> and %<_Decimal128%> in " 7503 "declaration specifiers"); 7504 else 7505 specs->complex_p = true; 7506 break; 7507 default: 7508 gcc_unreachable (); 7509 } 7510 7511 if (dupe) 7512 error ("duplicate %qE", type); 7513 7514 return specs; 7515 } 7516 else 7517 { 7518 /* "void", "_Bool", "char", "int", "float" or "double". */ 7519 if (specs->typespec_word != cts_none) 7520 { 7521 error ("two or more data types in declaration specifiers"); 7522 return specs; 7523 } 7524 switch (i) 7525 { 7526 case RID_VOID: 7527 if (specs->long_p) 7528 error ("both %<long%> and %<void%> in " 7529 "declaration specifiers"); 7530 else if (specs->short_p) 7531 error ("both %<short%> and %<void%> in " 7532 "declaration specifiers"); 7533 else if (specs->signed_p) 7534 error ("both %<signed%> and %<void%> in " 7535 "declaration specifiers"); 7536 else if (specs->unsigned_p) 7537 error ("both %<unsigned%> and %<void%> in " 7538 "declaration specifiers"); 7539 else if (specs->complex_p) 7540 error ("both %<complex%> and %<void%> in " 7541 "declaration specifiers"); 7542 else 7543 specs->typespec_word = cts_void; 7544 return specs; 7545 case RID_BOOL: 7546 if (specs->long_p) 7547 error ("both %<long%> and %<_Bool%> in " 7548 "declaration specifiers"); 7549 else if (specs->short_p) 7550 error ("both %<short%> and %<_Bool%> in " 7551 "declaration specifiers"); 7552 else if (specs->signed_p) 7553 error ("both %<signed%> and %<_Bool%> in " 7554 "declaration specifiers"); 7555 else if (specs->unsigned_p) 7556 error ("both %<unsigned%> and %<_Bool%> in " 7557 "declaration specifiers"); 7558 else if (specs->complex_p) 7559 error ("both %<complex%> and %<_Bool%> in " 7560 "declaration specifiers"); 7561 else 7562 specs->typespec_word = cts_bool; 7563 return specs; 7564 case RID_CHAR: 7565 if (specs->long_p) 7566 error ("both %<long%> and %<char%> in " 7567 "declaration specifiers"); 7568 else if (specs->short_p) 7569 error ("both %<short%> and %<char%> in " 7570 "declaration specifiers"); 7571 else 7572 specs->typespec_word = cts_char; 7573 return specs; 7574 case RID_INT: 7575 specs->typespec_word = cts_int; 7576 return specs; 7577 case RID_FLOAT: 7578 if (specs->long_p) 7579 error ("both %<long%> and %<float%> in " 7580 "declaration specifiers"); 7581 else if (specs->short_p) 7582 error ("both %<short%> and %<float%> in " 7583 "declaration specifiers"); 7584 else if (specs->signed_p) 7585 error ("both %<signed%> and %<float%> in " 7586 "declaration specifiers"); 7587 else if (specs->unsigned_p) 7588 error ("both %<unsigned%> and %<float%> in " 7589 "declaration specifiers"); 7590 else 7591 specs->typespec_word = cts_float; 7592 return specs; 7593 case RID_DOUBLE: 7594 if (specs->long_long_p) 7595 error ("both %<long long%> and %<double%> in " 7596 "declaration specifiers"); 7597 else if (specs->short_p) 7598 error ("both %<short%> and %<double%> in " 7599 "declaration specifiers"); 7600 else if (specs->signed_p) 7601 error ("both %<signed%> and %<double%> in " 7602 "declaration specifiers"); 7603 else if (specs->unsigned_p) 7604 error ("both %<unsigned%> and %<double%> in " 7605 "declaration specifiers"); 7606 else 7607 specs->typespec_word = cts_double; 7608 return specs; 7609 case RID_DFLOAT32: 7610 case RID_DFLOAT64: 7611 case RID_DFLOAT128: 7612 { 7613 const char *str; 7614 if (i == RID_DFLOAT32) 7615 str = "_Decimal32"; 7616 else if (i == RID_DFLOAT64) 7617 str = "_Decimal64"; 7618 else 7619 str = "_Decimal128"; 7620 if (specs->long_long_p) 7621 error ("both %<long long%> and %<%s%> in " 7622 "declaration specifiers", str); 7623 if (specs->long_p) 7624 error ("both %<long%> and %<%s%> in " 7625 "declaration specifiers", str); 7626 else if (specs->short_p) 7627 error ("both %<short%> and %<%s%> in " 7628 "declaration specifiers", str); 7629 else if (specs->signed_p) 7630 error ("both %<signed%> and %<%s%> in " 7631 "declaration specifiers", str); 7632 else if (specs->unsigned_p) 7633 error ("both %<unsigned%> and %<%s%> in " 7634 "declaration specifiers", str); 7635 else if (specs->complex_p) 7636 error ("both %<complex%> and %<%s%> in " 7637 "declaration specifiers", str); 7638 else if (i == RID_DFLOAT32) 7639 specs->typespec_word = cts_dfloat32; 7640 else if (i == RID_DFLOAT64) 7641 specs->typespec_word = cts_dfloat64; 7642 else 7643 specs->typespec_word = cts_dfloat128; 7644 } 7645 if (!targetm.decimal_float_supported_p ()) 7646 error ("decimal floating point not supported for this target"); 7647 if (pedantic) 7648 pedwarn ("ISO C does not support decimal floating point"); 7649 return specs; 7650 default: 7651 /* ObjC reserved word "id", handled below. */ 7652 break; 7653 } 7654 } 7655 } 7656 7657 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 7658 form of ObjC type, cases such as "int" and "long" being handled 7659 above), a TYPE (struct, union, enum and typeof specifiers) or an 7660 ERROR_MARK. In none of these cases may there have previously 7661 been any type specifiers. */ 7662 if (specs->type || specs->typespec_word != cts_none 7663 || specs->long_p || specs->short_p || specs->signed_p 7664 || specs->unsigned_p || specs->complex_p) 7665 error ("two or more data types in declaration specifiers"); 7666 else if (TREE_CODE (type) == TYPE_DECL) 7667 { 7668 if (TREE_TYPE (type) == error_mark_node) 7669 ; /* Allow the type to default to int to avoid cascading errors. */ 7670 else 7671 { 7672 specs->type = TREE_TYPE (type); 7673 specs->decl_attr = DECL_ATTRIBUTES (type); 7674 specs->typedef_p = true; 7675 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 7676 } 7677 } 7678 else if (TREE_CODE (type) == IDENTIFIER_NODE) 7679 { 7680 tree t = lookup_name (type); 7681 if (!t || TREE_CODE (t) != TYPE_DECL) 7682 error ("%qE fails to be a typedef or built in type", type); 7683 else if (TREE_TYPE (t) == error_mark_node) 7684 ; 7685 else 7686 specs->type = TREE_TYPE (t); 7687 } 7688 else if (TREE_CODE (type) != ERROR_MARK) 7689 { 7690 if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref) 7691 specs->tag_defined_p = true; 7692 if (spec.kind == ctsk_typeof) 7693 specs->typedef_p = true; 7694 specs->type = type; 7695 } 7696 7697 return specs; 7698} 7699 7700/* Add the storage class specifier or function specifier SCSPEC to the 7701 declaration specifiers SPECS, returning SPECS. */ 7702 7703struct c_declspecs * 7704declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 7705{ 7706 enum rid i; 7707 enum c_storage_class n = csc_none; 7708 bool dupe = false; 7709 specs->declspecs_seen_p = true; 7710 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 7711 && C_IS_RESERVED_WORD (scspec)); 7712 i = C_RID_CODE (scspec); 7713 if (extra_warnings && specs->non_sc_seen_p) 7714 warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec); 7715 switch (i) 7716 { 7717 case RID_INLINE: 7718 /* C99 permits duplicate inline. Although of doubtful utility, 7719 it seems simplest to permit it in gnu89 mode as well, as 7720 there is also little utility in maintaining this as a 7721 difference between gnu89 and C99 inline. */ 7722 dupe = false; 7723 specs->inline_p = true; 7724 break; 7725 case RID_THREAD: 7726 dupe = specs->thread_p; 7727 if (specs->storage_class == csc_auto) 7728 error ("%<__thread%> used with %<auto%>"); 7729 else if (specs->storage_class == csc_register) 7730 error ("%<__thread%> used with %<register%>"); 7731 else if (specs->storage_class == csc_typedef) 7732 error ("%<__thread%> used with %<typedef%>"); 7733 else 7734 specs->thread_p = true; 7735 break; 7736 case RID_AUTO: 7737 n = csc_auto; 7738 break; 7739 case RID_EXTERN: 7740 n = csc_extern; 7741 /* Diagnose "__thread extern". */ 7742 if (specs->thread_p) 7743 error ("%<__thread%> before %<extern%>"); 7744 break; 7745 case RID_REGISTER: 7746 n = csc_register; 7747 break; 7748 case RID_STATIC: 7749 n = csc_static; 7750 /* Diagnose "__thread static". */ 7751 if (specs->thread_p) 7752 error ("%<__thread%> before %<static%>"); 7753 break; 7754 case RID_TYPEDEF: 7755 n = csc_typedef; 7756 break; 7757 default: 7758 gcc_unreachable (); 7759 } 7760 if (n != csc_none && n == specs->storage_class) 7761 dupe = true; 7762 if (dupe) 7763 error ("duplicate %qE", scspec); 7764 if (n != csc_none) 7765 { 7766 if (specs->storage_class != csc_none && n != specs->storage_class) 7767 { 7768 error ("multiple storage classes in declaration specifiers"); 7769 } 7770 else 7771 { 7772 specs->storage_class = n; 7773 if (n != csc_extern && n != csc_static && specs->thread_p) 7774 { 7775 error ("%<__thread%> used with %qE", scspec); 7776 specs->thread_p = false; 7777 } 7778 } 7779 } 7780 return specs; 7781} 7782 7783/* Add the attributes ATTRS to the declaration specifiers SPECS, 7784 returning SPECS. */ 7785 7786struct c_declspecs * 7787declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 7788{ 7789 specs->attrs = chainon (attrs, specs->attrs); 7790 specs->declspecs_seen_p = true; 7791 return specs; 7792} 7793 7794/* Combine "long", "short", "signed", "unsigned" and "_Complex" type 7795 specifiers with any other type specifier to determine the resulting 7796 type. This is where ISO C checks on complex types are made, since 7797 "_Complex long" is a prefix of the valid ISO C type "_Complex long 7798 double". */ 7799 7800struct c_declspecs * 7801finish_declspecs (struct c_declspecs *specs) 7802{ 7803 /* If a type was specified as a whole, we have no modifiers and are 7804 done. */ 7805 if (specs->type != NULL_TREE) 7806 { 7807 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7808 && !specs->signed_p && !specs->unsigned_p 7809 && !specs->complex_p); 7810 return specs; 7811 } 7812 7813 /* If none of "void", "_Bool", "char", "int", "float" or "double" 7814 has been specified, treat it as "int" unless "_Complex" is 7815 present and there are no other specifiers. If we just have 7816 "_Complex", it is equivalent to "_Complex double", but e.g. 7817 "_Complex short" is equivalent to "_Complex short int". */ 7818 if (specs->typespec_word == cts_none) 7819 { 7820 if (specs->long_p || specs->short_p 7821 || specs->signed_p || specs->unsigned_p) 7822 { 7823 specs->typespec_word = cts_int; 7824 } 7825 else if (specs->complex_p) 7826 { 7827 specs->typespec_word = cts_double; 7828 if (pedantic) 7829 pedwarn ("ISO C does not support plain %<complex%> meaning " 7830 "%<double complex%>"); 7831 } 7832 else 7833 { 7834 specs->typespec_word = cts_int; 7835 specs->default_int_p = true; 7836 /* We don't diagnose this here because grokdeclarator will 7837 give more specific diagnostics according to whether it is 7838 a function definition. */ 7839 } 7840 } 7841 7842 /* If "signed" was specified, record this to distinguish "int" and 7843 "signed int" in the case of a bit-field with 7844 -funsigned-bitfields. */ 7845 specs->explicit_signed_p = specs->signed_p; 7846 7847 /* Now compute the actual type. */ 7848 switch (specs->typespec_word) 7849 { 7850 case cts_void: 7851 gcc_assert (!specs->long_p && !specs->short_p 7852 && !specs->signed_p && !specs->unsigned_p 7853 && !specs->complex_p); 7854 specs->type = void_type_node; 7855 break; 7856 case cts_bool: 7857 gcc_assert (!specs->long_p && !specs->short_p 7858 && !specs->signed_p && !specs->unsigned_p 7859 && !specs->complex_p); 7860 specs->type = boolean_type_node; 7861 break; 7862 case cts_char: 7863 gcc_assert (!specs->long_p && !specs->short_p); 7864 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7865 if (specs->signed_p) 7866 specs->type = signed_char_type_node; 7867 else if (specs->unsigned_p) 7868 specs->type = unsigned_char_type_node; 7869 else 7870 specs->type = char_type_node; 7871 if (specs->complex_p) 7872 { 7873 if (pedantic) 7874 pedwarn ("ISO C does not support complex integer types"); 7875 specs->type = build_complex_type (specs->type); 7876 } 7877 break; 7878 case cts_int: 7879 gcc_assert (!(specs->long_p && specs->short_p)); 7880 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7881 if (specs->long_long_p) 7882 specs->type = (specs->unsigned_p 7883 ? long_long_unsigned_type_node 7884 : long_long_integer_type_node); 7885 else if (specs->long_p) 7886 specs->type = (specs->unsigned_p 7887 ? long_unsigned_type_node 7888 : long_integer_type_node); 7889 else if (specs->short_p) 7890 specs->type = (specs->unsigned_p 7891 ? short_unsigned_type_node 7892 : short_integer_type_node); 7893 else 7894 specs->type = (specs->unsigned_p 7895 ? unsigned_type_node 7896 : integer_type_node); 7897 if (specs->complex_p) 7898 { 7899 if (pedantic) 7900 pedwarn ("ISO C does not support complex integer types"); 7901 specs->type = build_complex_type (specs->type); 7902 } 7903 break; 7904 case cts_float: 7905 gcc_assert (!specs->long_p && !specs->short_p 7906 && !specs->signed_p && !specs->unsigned_p); 7907 specs->type = (specs->complex_p 7908 ? complex_float_type_node 7909 : float_type_node); 7910 break; 7911 case cts_double: 7912 gcc_assert (!specs->long_long_p && !specs->short_p 7913 && !specs->signed_p && !specs->unsigned_p); 7914 if (specs->long_p) 7915 { 7916 specs->type = (specs->complex_p 7917 ? complex_long_double_type_node 7918 : long_double_type_node); 7919 } 7920 else 7921 { 7922 specs->type = (specs->complex_p 7923 ? complex_double_type_node 7924 : double_type_node); 7925 } 7926 break; 7927 case cts_dfloat32: 7928 case cts_dfloat64: 7929 case cts_dfloat128: 7930 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7931 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 7932 if (specs->typespec_word == cts_dfloat32) 7933 specs->type = dfloat32_type_node; 7934 else if (specs->typespec_word == cts_dfloat64) 7935 specs->type = dfloat64_type_node; 7936 else 7937 specs->type = dfloat128_type_node; 7938 break; 7939 default: 7940 gcc_unreachable (); 7941 } 7942 7943 return specs; 7944} 7945 7946/* Synthesize a function which calls all the global ctors or global 7947 dtors in this file. This is only used for targets which do not 7948 support .ctors/.dtors sections. FIXME: Migrate into cgraph. */ 7949static void 7950build_cdtor (int method_type, tree cdtors) 7951{ 7952 tree body = 0; 7953 7954 if (!cdtors) 7955 return; 7956 7957 for (; cdtors; cdtors = TREE_CHAIN (cdtors)) 7958 append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0), 7959 &body); 7960 7961 cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY); 7962} 7963 7964/* A subroutine of c_write_global_declarations. Perform final processing 7965 on one file scope's declarations (or the external scope's declarations), 7966 GLOBALS. */ 7967 7968static void 7969c_write_global_declarations_1 (tree globals) 7970{ 7971 tree decl; 7972 bool reconsider; 7973 7974 /* Process the decls in the order they were written. */ 7975 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7976 { 7977 /* Check for used but undefined static functions using the C 7978 standard's definition of "used", and set TREE_NO_WARNING so 7979 that check_global_declarations doesn't repeat the check. */ 7980 if (TREE_CODE (decl) == FUNCTION_DECL 7981 && DECL_INITIAL (decl) == 0 7982 && DECL_EXTERNAL (decl) 7983 && !TREE_PUBLIC (decl) 7984 && C_DECL_USED (decl)) 7985 { 7986 pedwarn ("%q+F used but never defined", decl); 7987 TREE_NO_WARNING (decl) = 1; 7988 } 7989 7990 wrapup_global_declaration_1 (decl); 7991 } 7992 7993 do 7994 { 7995 reconsider = false; 7996 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7997 reconsider |= wrapup_global_declaration_2 (decl); 7998 } 7999 while (reconsider); 8000 8001 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 8002 check_global_declaration_1 (decl); 8003} 8004 8005/* A subroutine of c_write_global_declarations Emit debug information for each 8006 of the declarations in GLOBALS. */ 8007 8008static void 8009c_write_global_declarations_2 (tree globals) 8010{ 8011 tree decl; 8012 8013 for (decl = globals; decl ; decl = TREE_CHAIN (decl)) 8014 debug_hooks->global_decl (decl); 8015} 8016 8017/* Preserve the external declarations scope across a garbage collect. */ 8018static GTY(()) tree ext_block; 8019 8020void 8021c_write_global_declarations (void) 8022{ 8023 tree t; 8024 8025 /* We don't want to do this if generating a PCH. */ 8026 if (pch_file) 8027 return; 8028 8029 /* Don't waste time on further processing if -fsyntax-only or we've 8030 encountered errors. */ 8031 if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in)) 8032 return; 8033 8034 /* Close the external scope. */ 8035 ext_block = pop_scope (); 8036 external_scope = 0; 8037 gcc_assert (!current_scope); 8038 8039 if (ext_block) 8040 { 8041 tree tmp = BLOCK_VARS (ext_block); 8042 int flags; 8043 FILE * stream = dump_begin (TDI_tu, &flags); 8044 if (stream && tmp) 8045 { 8046 dump_node (tmp, flags & ~TDF_SLIM, stream); 8047 dump_end (TDI_tu, stream); 8048 } 8049 } 8050 8051 /* Process all file scopes in this compilation, and the external_scope, 8052 through wrapup_global_declarations and check_global_declarations. */ 8053 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8054 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 8055 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 8056 8057 /* Generate functions to call static constructors and destructors 8058 for targets that do not support .ctors/.dtors sections. These 8059 functions have magic names which are detected by collect2. */ 8060 build_cdtor ('I', static_ctors); static_ctors = 0; 8061 build_cdtor ('D', static_dtors); static_dtors = 0; 8062 8063 /* We're done parsing; proceed to optimize and emit assembly. 8064 FIXME: shouldn't be the front end's responsibility to call this. */ 8065 cgraph_optimize (); 8066 8067 /* After cgraph has had a chance to emit everything that's going to 8068 be emitted, output debug information for globals. */ 8069 if (errorcount == 0 && sorrycount == 0) 8070 { 8071 timevar_push (TV_SYMOUT); 8072 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8073 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 8074 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 8075 timevar_pop (TV_SYMOUT); 8076 } 8077 8078 ext_block = NULL; 8079} 8080 8081#include "gt-c-decl.h" 8082