c-decl.c revision 259269
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: stable/9/contrib/gcc/c-decl.c 259269 2013-12-12 18:16:46Z 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 (TREE_CODE (olddecl) != FUNCTION_DECL) 1694 if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl)) 1695 { 1696 DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl); 1697 DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl); 1698 } 1699 } 1700 1701 1702 /* Merge the type qualifiers. */ 1703 if (TREE_READONLY (newdecl)) 1704 TREE_READONLY (olddecl) = 1; 1705 1706 if (TREE_THIS_VOLATILE (newdecl)) 1707 TREE_THIS_VOLATILE (olddecl) = 1; 1708 1709 /* Merge deprecatedness. */ 1710 if (TREE_DEPRECATED (newdecl)) 1711 TREE_DEPRECATED (olddecl) = 1; 1712 1713 /* Keep source location of definition rather than declaration and of 1714 prototype rather than non-prototype unless that prototype is 1715 built-in. */ 1716 if ((DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0) 1717 || (old_is_prototype && !new_is_prototype 1718 && !C_DECL_BUILTIN_PROTOTYPE (olddecl))) 1719 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 1720 1721 /* Merge the initialization information. */ 1722 if (DECL_INITIAL (newdecl) == 0) 1723 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1724 1725 /* Merge the threadprivate attribute. */ 1726 if (TREE_CODE (olddecl) == VAR_DECL && C_DECL_THREADPRIVATE_P (olddecl)) 1727 { 1728 DECL_TLS_MODEL (newdecl) = DECL_TLS_MODEL (olddecl); 1729 C_DECL_THREADPRIVATE_P (newdecl) = 1; 1730 } 1731 1732 if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)) 1733 { 1734 /* Merge the unused-warning information. */ 1735 if (DECL_IN_SYSTEM_HEADER (olddecl)) 1736 DECL_IN_SYSTEM_HEADER (newdecl) = 1; 1737 else if (DECL_IN_SYSTEM_HEADER (newdecl)) 1738 DECL_IN_SYSTEM_HEADER (olddecl) = 1; 1739 1740 /* Merge the section attribute. 1741 We want to issue an error if the sections conflict but that 1742 must be done later in decl_attributes since we are called 1743 before attributes are assigned. */ 1744 if (DECL_SECTION_NAME (newdecl) == NULL_TREE) 1745 DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl); 1746 1747 /* Copy the assembler name. 1748 Currently, it can only be defined in the prototype. */ 1749 COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl); 1750 1751 /* Use visibility of whichever declaration had it specified */ 1752 if (DECL_VISIBILITY_SPECIFIED (olddecl)) 1753 { 1754 DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl); 1755 DECL_VISIBILITY_SPECIFIED (newdecl) = 1; 1756 } 1757 1758 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1759 { 1760 DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl); 1761 DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl); 1762 DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl); 1763 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl) 1764 |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl); 1765 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1766 TREE_READONLY (newdecl) |= TREE_READONLY (olddecl); 1767 DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl); 1768 DECL_IS_PURE (newdecl) |= DECL_IS_PURE (olddecl); 1769 DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl); 1770 } 1771 1772 /* Merge the storage class information. */ 1773 merge_weak (newdecl, olddecl); 1774 1775 /* For functions, static overrides non-static. */ 1776 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1777 { 1778 TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl); 1779 /* This is since we don't automatically 1780 copy the attributes of NEWDECL into OLDDECL. */ 1781 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1782 /* If this clears `static', clear it in the identifier too. */ 1783 if (!TREE_PUBLIC (olddecl)) 1784 TREE_PUBLIC (DECL_NAME (olddecl)) = 0; 1785 } 1786 } 1787 1788 /* In c99, 'extern' declaration before (or after) 'inline' means this 1789 function is not DECL_EXTERNAL, unless 'gnu_inline' attribute 1790 is present. */ 1791 if (TREE_CODE (newdecl) == FUNCTION_DECL 1792 && !flag_gnu89_inline 1793 && (DECL_DECLARED_INLINE_P (newdecl) 1794 || DECL_DECLARED_INLINE_P (olddecl)) 1795 && (!DECL_DECLARED_INLINE_P (newdecl) 1796 || !DECL_DECLARED_INLINE_P (olddecl) 1797 || !DECL_EXTERNAL (olddecl)) 1798 && DECL_EXTERNAL (newdecl) 1799 && !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl))) 1800 DECL_EXTERNAL (newdecl) = 0; 1801 1802 if (DECL_EXTERNAL (newdecl)) 1803 { 1804 TREE_STATIC (newdecl) = TREE_STATIC (olddecl); 1805 DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl); 1806 1807 /* An extern decl does not override previous storage class. */ 1808 TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl); 1809 if (!DECL_EXTERNAL (newdecl)) 1810 { 1811 DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl); 1812 DECL_COMMON (newdecl) = DECL_COMMON (olddecl); 1813 } 1814 } 1815 else 1816 { 1817 TREE_STATIC (olddecl) = TREE_STATIC (newdecl); 1818 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1819 } 1820 1821 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1822 { 1823 /* If we're redefining a function previously defined as extern 1824 inline, make sure we emit debug info for the inline before we 1825 throw it away, in case it was inlined into a function that 1826 hasn't been written out yet. */ 1827 if (new_is_definition && DECL_INITIAL (olddecl)) 1828 { 1829 if (TREE_USED (olddecl) 1830 /* In unit-at-a-time mode we never inline re-defined extern 1831 inline functions. */ 1832 && !flag_unit_at_a_time 1833 && cgraph_function_possibly_inlined_p (olddecl)) 1834 (*debug_hooks->outlining_inline_function) (olddecl); 1835 1836 /* The new defn must not be inline. */ 1837 DECL_INLINE (newdecl) = 0; 1838 DECL_UNINLINABLE (newdecl) = 1; 1839 } 1840 else 1841 { 1842 /* If either decl says `inline', this fn is inline, unless 1843 its definition was passed already. */ 1844 if (DECL_DECLARED_INLINE_P (newdecl) 1845 || DECL_DECLARED_INLINE_P (olddecl)) 1846 DECL_DECLARED_INLINE_P (newdecl) = 1; 1847 1848 DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl) 1849 = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)); 1850 } 1851 1852 if (DECL_BUILT_IN (olddecl)) 1853 { 1854 /* If redeclaring a builtin function, it stays built in. 1855 But it gets tagged as having been declared. */ 1856 DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl); 1857 DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl); 1858 C_DECL_DECLARED_BUILTIN (newdecl) = 1; 1859 if (new_is_prototype) 1860 C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0; 1861 else 1862 C_DECL_BUILTIN_PROTOTYPE (newdecl) 1863 = C_DECL_BUILTIN_PROTOTYPE (olddecl); 1864 } 1865 1866 /* Also preserve various other info from the definition. */ 1867 if (!new_is_definition) 1868 { 1869 DECL_RESULT (newdecl) = DECL_RESULT (olddecl); 1870 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1871 DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl); 1872 DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl); 1873 DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl); 1874 1875 /* Set DECL_INLINE on the declaration if we've got a body 1876 from which to instantiate. */ 1877 if (DECL_INLINE (olddecl) && !DECL_UNINLINABLE (newdecl)) 1878 { 1879 DECL_INLINE (newdecl) = 1; 1880 DECL_ABSTRACT_ORIGIN (newdecl) 1881 = DECL_ABSTRACT_ORIGIN (olddecl); 1882 } 1883 } 1884 else 1885 { 1886 /* If a previous declaration said inline, mark the 1887 definition as inlinable. */ 1888 if (DECL_DECLARED_INLINE_P (newdecl) 1889 && !DECL_UNINLINABLE (newdecl)) 1890 DECL_INLINE (newdecl) = 1; 1891 } 1892 } 1893 1894 extern_changed = DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl); 1895 1896 /* Copy most of the decl-specific fields of NEWDECL into OLDDECL. 1897 But preserve OLDDECL's DECL_UID and DECL_CONTEXT. */ 1898 { 1899 unsigned olddecl_uid = DECL_UID (olddecl); 1900 tree olddecl_context = DECL_CONTEXT (olddecl); 1901 1902 memcpy ((char *) olddecl + sizeof (struct tree_common), 1903 (char *) newdecl + sizeof (struct tree_common), 1904 sizeof (struct tree_decl_common) - sizeof (struct tree_common)); 1905 switch (TREE_CODE (olddecl)) 1906 { 1907 case FIELD_DECL: 1908 case VAR_DECL: 1909 case PARM_DECL: 1910 case LABEL_DECL: 1911 case RESULT_DECL: 1912 case CONST_DECL: 1913 case TYPE_DECL: 1914 case FUNCTION_DECL: 1915 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1916 (char *) newdecl + sizeof (struct tree_decl_common), 1917 tree_code_size (TREE_CODE (olddecl)) - sizeof (struct tree_decl_common)); 1918 break; 1919 1920 default: 1921 1922 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 1923 (char *) newdecl + sizeof (struct tree_decl_common), 1924 sizeof (struct tree_decl_non_common) - sizeof (struct tree_decl_common)); 1925 } 1926 DECL_UID (olddecl) = olddecl_uid; 1927 DECL_CONTEXT (olddecl) = olddecl_context; 1928 } 1929 1930 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl 1931 so that encode_section_info has a chance to look at the new decl 1932 flags and attributes. */ 1933 if (DECL_RTL_SET_P (olddecl) 1934 && (TREE_CODE (olddecl) == FUNCTION_DECL 1935 || (TREE_CODE (olddecl) == VAR_DECL 1936 && TREE_STATIC (olddecl)))) 1937 make_decl_rtl (olddecl); 1938 1939 /* If we changed a function from DECL_EXTERNAL to !DECL_EXTERNAL, 1940 and the definition is coming from the old version, cgraph needs 1941 to be called again. */ 1942 if (extern_changed && !new_is_definition 1943 && TREE_CODE (olddecl) == FUNCTION_DECL && DECL_INITIAL (olddecl)) 1944 cgraph_finalize_function (olddecl, false); 1945} 1946 1947/* Handle when a new declaration NEWDECL has the same name as an old 1948 one OLDDECL in the same binding contour. Prints an error message 1949 if appropriate. 1950 1951 If safely possible, alter OLDDECL to look like NEWDECL, and return 1952 true. Otherwise, return false. */ 1953 1954static bool 1955duplicate_decls (tree newdecl, tree olddecl) 1956{ 1957 tree newtype = NULL, oldtype = NULL; 1958 1959 if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype)) 1960 { 1961 /* Avoid `unused variable' and other warnings warnings for OLDDECL. */ 1962 TREE_NO_WARNING (olddecl) = 1; 1963 return false; 1964 } 1965 1966 merge_decls (newdecl, olddecl, newtype, oldtype); 1967 return true; 1968} 1969 1970 1971/* Check whether decl-node NEW_DECL shadows an existing declaration. */ 1972static void 1973warn_if_shadowing (tree new_decl) 1974{ 1975 struct c_binding *b; 1976 1977 /* Shadow warnings wanted? */ 1978 if (!warn_shadow 1979 /* No shadow warnings for internally generated vars. */ 1980 || DECL_IS_BUILTIN (new_decl) 1981 /* No shadow warnings for vars made for inlining. */ 1982 || DECL_FROM_INLINE (new_decl)) 1983 return; 1984 1985 /* Is anything being shadowed? Invisible decls do not count. */ 1986 for (b = I_SYMBOL_BINDING (DECL_NAME (new_decl)); b; b = b->shadowed) 1987 if (b->decl && b->decl != new_decl && !b->invisible) 1988 { 1989 tree old_decl = b->decl; 1990 1991 if (old_decl == error_mark_node) 1992 { 1993 warning (OPT_Wshadow, "declaration of %q+D shadows previous " 1994 "non-variable", new_decl); 1995 break; 1996 } 1997 else if (TREE_CODE (old_decl) == PARM_DECL) 1998 warning (OPT_Wshadow, "declaration of %q+D shadows a parameter", 1999 new_decl); 2000 else if (DECL_FILE_SCOPE_P (old_decl)) 2001 warning (OPT_Wshadow, "declaration of %q+D shadows a global " 2002 "declaration", new_decl); 2003 else if (TREE_CODE (old_decl) == FUNCTION_DECL 2004 && DECL_BUILT_IN (old_decl)) 2005 { 2006 warning (OPT_Wshadow, "declaration of %q+D shadows " 2007 "a built-in function", new_decl); 2008 break; 2009 } 2010 else 2011 warning (OPT_Wshadow, "declaration of %q+D shadows a previous local", 2012 new_decl); 2013 2014 warning (OPT_Wshadow, "%Jshadowed declaration is here", old_decl); 2015 2016 break; 2017 } 2018} 2019 2020 2021/* Subroutine of pushdecl. 2022 2023 X is a TYPE_DECL for a typedef statement. Create a brand new 2024 ..._TYPE node (which will be just a variant of the existing 2025 ..._TYPE node with identical properties) and then install X 2026 as the TYPE_NAME of this brand new (duplicate) ..._TYPE node. 2027 2028 The whole point here is to end up with a situation where each 2029 and every ..._TYPE node the compiler creates will be uniquely 2030 associated with AT MOST one node representing a typedef name. 2031 This way, even though the compiler substitutes corresponding 2032 ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very 2033 early on, later parts of the compiler can always do the reverse 2034 translation and get back the corresponding typedef name. For 2035 example, given: 2036 2037 typedef struct S MY_TYPE; 2038 MY_TYPE object; 2039 2040 Later parts of the compiler might only know that `object' was of 2041 type `struct S' if it were not for code just below. With this 2042 code however, later parts of the compiler see something like: 2043 2044 struct S' == struct S 2045 typedef struct S' MY_TYPE; 2046 struct S' object; 2047 2048 And they can then deduce (from the node for type struct S') that 2049 the original object declaration was: 2050 2051 MY_TYPE object; 2052 2053 Being able to do this is important for proper support of protoize, 2054 and also for generating precise symbolic debugging information 2055 which takes full account of the programmer's (typedef) vocabulary. 2056 2057 Obviously, we don't want to generate a duplicate ..._TYPE node if 2058 the TYPE_DECL node that we are now processing really represents a 2059 standard built-in type. 2060 2061 Since all standard types are effectively declared at line zero 2062 in the source file, we can easily check to see if we are working 2063 on a standard type by checking the current value of lineno. */ 2064 2065static void 2066clone_underlying_type (tree x) 2067{ 2068 if (DECL_IS_BUILTIN (x)) 2069 { 2070 if (TYPE_NAME (TREE_TYPE (x)) == 0) 2071 TYPE_NAME (TREE_TYPE (x)) = x; 2072 } 2073 else if (TREE_TYPE (x) != error_mark_node 2074 && DECL_ORIGINAL_TYPE (x) == NULL_TREE) 2075 { 2076 tree tt = TREE_TYPE (x); 2077 DECL_ORIGINAL_TYPE (x) = tt; 2078 tt = build_variant_type_copy (tt); 2079 TYPE_NAME (tt) = x; 2080 TREE_USED (tt) = TREE_USED (x); 2081 TREE_TYPE (x) = tt; 2082 } 2083} 2084 2085/* Record a decl-node X as belonging to the current lexical scope. 2086 Check for errors (such as an incompatible declaration for the same 2087 name already seen in the same scope). 2088 2089 Returns either X or an old decl for the same name. 2090 If an old decl is returned, it may have been smashed 2091 to agree with what X says. */ 2092 2093tree 2094pushdecl (tree x) 2095{ 2096 tree name = DECL_NAME (x); 2097 struct c_scope *scope = current_scope; 2098 struct c_binding *b; 2099 bool nested = false; 2100 2101 /* Functions need the lang_decl data. */ 2102 if (TREE_CODE (x) == FUNCTION_DECL && !DECL_LANG_SPECIFIC (x)) 2103 DECL_LANG_SPECIFIC (x) = GGC_CNEW (struct lang_decl); 2104 2105 /* Must set DECL_CONTEXT for everything not at file scope or 2106 DECL_FILE_SCOPE_P won't work. Local externs don't count 2107 unless they have initializers (which generate code). */ 2108 if (current_function_decl 2109 && ((TREE_CODE (x) != FUNCTION_DECL && TREE_CODE (x) != VAR_DECL) 2110 || DECL_INITIAL (x) || !DECL_EXTERNAL (x))) 2111 DECL_CONTEXT (x) = current_function_decl; 2112 2113 /* If this is of variably modified type, prevent jumping into its 2114 scope. */ 2115 if ((TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == TYPE_DECL) 2116 && variably_modified_type_p (TREE_TYPE (x), NULL_TREE)) 2117 c_begin_vm_scope (scope->depth); 2118 2119 /* Anonymous decls are just inserted in the scope. */ 2120 if (!name) 2121 { 2122 bind (name, x, scope, /*invisible=*/false, /*nested=*/false); 2123 return x; 2124 } 2125 2126 /* First, see if there is another declaration with the same name in 2127 the current scope. If there is, duplicate_decls may do all the 2128 work for us. If duplicate_decls returns false, that indicates 2129 two incompatible decls in the same scope; we are to silently 2130 replace the old one (duplicate_decls has issued all appropriate 2131 diagnostics). In particular, we should not consider possible 2132 duplicates in the external scope, or shadowing. */ 2133 b = I_SYMBOL_BINDING (name); 2134 if (b && B_IN_SCOPE (b, scope)) 2135 { 2136 struct c_binding *b_ext, *b_use; 2137 tree type = TREE_TYPE (x); 2138 tree visdecl = b->decl; 2139 tree vistype = TREE_TYPE (visdecl); 2140 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 2141 && COMPLETE_TYPE_P (TREE_TYPE (x))) 2142 b->inner_comp = false; 2143 b_use = b; 2144 b_ext = b; 2145 /* If this is an external linkage declaration, we should check 2146 for compatibility with the type in the external scope before 2147 setting the type at this scope based on the visible 2148 information only. */ 2149 if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl)) 2150 { 2151 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 2152 b_ext = b_ext->shadowed; 2153 if (b_ext) 2154 { 2155 b_use = b_ext; 2156 if (b_use->type) 2157 TREE_TYPE (b_use->decl) = b_use->type; 2158 } 2159 } 2160 if (duplicate_decls (x, b_use->decl)) 2161 { 2162 if (b_use != b) 2163 { 2164 /* Save the updated type in the external scope and 2165 restore the proper type for this scope. */ 2166 tree thistype; 2167 if (comptypes (vistype, type)) 2168 thistype = composite_type (vistype, type); 2169 else 2170 thistype = TREE_TYPE (b_use->decl); 2171 b_use->type = TREE_TYPE (b_use->decl); 2172 if (TREE_CODE (b_use->decl) == FUNCTION_DECL 2173 && DECL_BUILT_IN (b_use->decl)) 2174 thistype 2175 = build_type_attribute_variant (thistype, 2176 TYPE_ATTRIBUTES 2177 (b_use->type)); 2178 TREE_TYPE (b_use->decl) = thistype; 2179 } 2180 return b_use->decl; 2181 } 2182 else 2183 goto skip_external_and_shadow_checks; 2184 } 2185 2186 /* All declarations with external linkage, and all external 2187 references, go in the external scope, no matter what scope is 2188 current. However, the binding in that scope is ignored for 2189 purposes of normal name lookup. A separate binding structure is 2190 created in the requested scope; this governs the normal 2191 visibility of the symbol. 2192 2193 The binding in the externals scope is used exclusively for 2194 detecting duplicate declarations of the same object, no matter 2195 what scope they are in; this is what we do here. (C99 6.2.7p2: 2196 All declarations that refer to the same object or function shall 2197 have compatible type; otherwise, the behavior is undefined.) */ 2198 if (DECL_EXTERNAL (x) || scope == file_scope) 2199 { 2200 tree type = TREE_TYPE (x); 2201 tree vistype = 0; 2202 tree visdecl = 0; 2203 bool type_saved = false; 2204 if (b && !B_IN_EXTERNAL_SCOPE (b) 2205 && (TREE_CODE (b->decl) == FUNCTION_DECL 2206 || TREE_CODE (b->decl) == VAR_DECL) 2207 && DECL_FILE_SCOPE_P (b->decl)) 2208 { 2209 visdecl = b->decl; 2210 vistype = TREE_TYPE (visdecl); 2211 } 2212 if (scope != file_scope 2213 && !DECL_IN_SYSTEM_HEADER (x)) 2214 warning (OPT_Wnested_externs, "nested extern declaration of %qD", x); 2215 2216 while (b && !B_IN_EXTERNAL_SCOPE (b)) 2217 { 2218 /* If this decl might be modified, save its type. This is 2219 done here rather than when the decl is first bound 2220 because the type may change after first binding, through 2221 being completed or through attributes being added. If we 2222 encounter multiple such decls, only the first should have 2223 its type saved; the others will already have had their 2224 proper types saved and the types will not have changed as 2225 their scopes will not have been re-entered. */ 2226 if (DECL_P (b->decl) && DECL_FILE_SCOPE_P (b->decl) && !type_saved) 2227 { 2228 b->type = TREE_TYPE (b->decl); 2229 type_saved = true; 2230 } 2231 if (B_IN_FILE_SCOPE (b) 2232 && TREE_CODE (b->decl) == VAR_DECL 2233 && TREE_STATIC (b->decl) 2234 && TREE_CODE (TREE_TYPE (b->decl)) == ARRAY_TYPE 2235 && !TYPE_DOMAIN (TREE_TYPE (b->decl)) 2236 && TREE_CODE (type) == ARRAY_TYPE 2237 && TYPE_DOMAIN (type) 2238 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) 2239 && !integer_zerop (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))) 2240 { 2241 /* Array type completed in inner scope, which should be 2242 diagnosed if the completion does not have size 1 and 2243 it does not get completed in the file scope. */ 2244 b->inner_comp = true; 2245 } 2246 b = b->shadowed; 2247 } 2248 2249 /* If a matching external declaration has been found, set its 2250 type to the composite of all the types of that declaration. 2251 After the consistency checks, it will be reset to the 2252 composite of the visible types only. */ 2253 if (b && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2254 && b->type) 2255 TREE_TYPE (b->decl) = b->type; 2256 2257 /* The point of the same_translation_unit_p check here is, 2258 we want to detect a duplicate decl for a construct like 2259 foo() { extern bar(); } ... static bar(); but not if 2260 they are in different translation units. In any case, 2261 the static does not go in the externals scope. */ 2262 if (b 2263 && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2264 && duplicate_decls (x, b->decl)) 2265 { 2266 tree thistype; 2267 if (vistype) 2268 { 2269 if (comptypes (vistype, type)) 2270 thistype = composite_type (vistype, type); 2271 else 2272 thistype = TREE_TYPE (b->decl); 2273 } 2274 else 2275 thistype = type; 2276 b->type = TREE_TYPE (b->decl); 2277 if (TREE_CODE (b->decl) == FUNCTION_DECL && DECL_BUILT_IN (b->decl)) 2278 thistype 2279 = build_type_attribute_variant (thistype, 2280 TYPE_ATTRIBUTES (b->type)); 2281 TREE_TYPE (b->decl) = thistype; 2282 bind (name, b->decl, scope, /*invisible=*/false, /*nested=*/true); 2283 return b->decl; 2284 } 2285 else if (TREE_PUBLIC (x)) 2286 { 2287 if (visdecl && !b && duplicate_decls (x, visdecl)) 2288 { 2289 /* An external declaration at block scope referring to a 2290 visible entity with internal linkage. The composite 2291 type will already be correct for this scope, so we 2292 just need to fall through to make the declaration in 2293 this scope. */ 2294 nested = true; 2295 x = visdecl; 2296 } 2297 else 2298 { 2299 bind (name, x, external_scope, /*invisible=*/true, 2300 /*nested=*/false); 2301 nested = true; 2302 } 2303 } 2304 } 2305 2306 if (TREE_CODE (x) != PARM_DECL) 2307 warn_if_shadowing (x); 2308 2309 skip_external_and_shadow_checks: 2310 if (TREE_CODE (x) == TYPE_DECL) 2311 clone_underlying_type (x); 2312 2313 bind (name, x, scope, /*invisible=*/false, nested); 2314 2315 /* If x's type is incomplete because it's based on a 2316 structure or union which has not yet been fully declared, 2317 attach it to that structure or union type, so we can go 2318 back and complete the variable declaration later, if the 2319 structure or union gets fully declared. 2320 2321 If the input is erroneous, we can have error_mark in the type 2322 slot (e.g. "f(void a, ...)") - that doesn't count as an 2323 incomplete type. */ 2324 if (TREE_TYPE (x) != error_mark_node 2325 && !COMPLETE_TYPE_P (TREE_TYPE (x))) 2326 { 2327 tree element = TREE_TYPE (x); 2328 2329 while (TREE_CODE (element) == ARRAY_TYPE) 2330 element = TREE_TYPE (element); 2331 element = TYPE_MAIN_VARIANT (element); 2332 2333 if ((TREE_CODE (element) == RECORD_TYPE 2334 || TREE_CODE (element) == UNION_TYPE) 2335 && (TREE_CODE (x) != TYPE_DECL 2336 || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE) 2337 && !COMPLETE_TYPE_P (element)) 2338 C_TYPE_INCOMPLETE_VARS (element) 2339 = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element)); 2340 } 2341 return x; 2342} 2343 2344/* Record X as belonging to file scope. 2345 This is used only internally by the Objective-C front end, 2346 and is limited to its needs. duplicate_decls is not called; 2347 if there is any preexisting decl for this identifier, it is an ICE. */ 2348 2349tree 2350pushdecl_top_level (tree x) 2351{ 2352 tree name; 2353 bool nested = false; 2354 gcc_assert (TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == CONST_DECL); 2355 2356 name = DECL_NAME (x); 2357 2358 gcc_assert (TREE_CODE (x) == CONST_DECL || !I_SYMBOL_BINDING (name)); 2359 2360 if (TREE_PUBLIC (x)) 2361 { 2362 bind (name, x, external_scope, /*invisible=*/true, /*nested=*/false); 2363 nested = true; 2364 } 2365 if (file_scope) 2366 bind (name, x, file_scope, /*invisible=*/false, nested); 2367 2368 return x; 2369} 2370 2371static void 2372implicit_decl_warning (tree id, tree olddecl) 2373{ 2374 void (*diag) (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2); 2375 switch (mesg_implicit_function_declaration) 2376 { 2377 case 0: return; 2378 case 1: diag = warning0; break; 2379 case 2: diag = error; break; 2380 default: gcc_unreachable (); 2381 } 2382 2383 diag (G_("implicit declaration of function %qE"), id); 2384 if (olddecl) 2385 locate_old_decl (olddecl, diag); 2386} 2387 2388/* Generate an implicit declaration for identifier FUNCTIONID as a 2389 function of type int (). */ 2390 2391tree 2392implicitly_declare (tree functionid) 2393{ 2394 struct c_binding *b; 2395 tree decl = 0; 2396 tree asmspec_tree; 2397 2398 for (b = I_SYMBOL_BINDING (functionid); b; b = b->shadowed) 2399 { 2400 if (B_IN_SCOPE (b, external_scope)) 2401 { 2402 decl = b->decl; 2403 break; 2404 } 2405 } 2406 2407 if (decl) 2408 { 2409 if (decl == error_mark_node) 2410 return decl; 2411 2412 /* FIXME: Objective-C has weird not-really-builtin functions 2413 which are supposed to be visible automatically. They wind up 2414 in the external scope because they're pushed before the file 2415 scope gets created. Catch this here and rebind them into the 2416 file scope. */ 2417 if (!DECL_BUILT_IN (decl) && DECL_IS_BUILTIN (decl)) 2418 { 2419 bind (functionid, decl, file_scope, 2420 /*invisible=*/false, /*nested=*/true); 2421 return decl; 2422 } 2423 else 2424 { 2425 tree newtype = default_function_type; 2426 if (b->type) 2427 TREE_TYPE (decl) = b->type; 2428 /* Implicit declaration of a function already declared 2429 (somehow) in a different scope, or as a built-in. 2430 If this is the first time this has happened, warn; 2431 then recycle the old declaration but with the new type. */ 2432 if (!C_DECL_IMPLICIT (decl)) 2433 { 2434 implicit_decl_warning (functionid, decl); 2435 C_DECL_IMPLICIT (decl) = 1; 2436 } 2437 if (DECL_BUILT_IN (decl)) 2438 { 2439 newtype = build_type_attribute_variant (newtype, 2440 TYPE_ATTRIBUTES 2441 (TREE_TYPE (decl))); 2442 if (!comptypes (newtype, TREE_TYPE (decl))) 2443 { 2444 warning (0, "incompatible implicit declaration of built-in" 2445 " function %qD", decl); 2446 newtype = TREE_TYPE (decl); 2447 } 2448 } 2449 else 2450 { 2451 if (!comptypes (newtype, TREE_TYPE (decl))) 2452 { 2453 error ("incompatible implicit declaration of function %qD", 2454 decl); 2455 locate_old_decl (decl, error); 2456 } 2457 } 2458 b->type = TREE_TYPE (decl); 2459 TREE_TYPE (decl) = newtype; 2460 bind (functionid, decl, current_scope, 2461 /*invisible=*/false, /*nested=*/true); 2462 return decl; 2463 } 2464 } 2465 2466 /* Not seen before. */ 2467 decl = build_decl (FUNCTION_DECL, functionid, default_function_type); 2468 DECL_EXTERNAL (decl) = 1; 2469 TREE_PUBLIC (decl) = 1; 2470 C_DECL_IMPLICIT (decl) = 1; 2471 implicit_decl_warning (functionid, 0); 2472 asmspec_tree = maybe_apply_renaming_pragma (decl, /*asmname=*/NULL); 2473 if (asmspec_tree) 2474 set_user_assembler_name (decl, TREE_STRING_POINTER (asmspec_tree)); 2475 2476 /* C89 says implicit declarations are in the innermost block. 2477 So we record the decl in the standard fashion. */ 2478 decl = pushdecl (decl); 2479 2480 /* No need to call objc_check_decl here - it's a function type. */ 2481 rest_of_decl_compilation (decl, 0, 0); 2482 2483 /* Write a record describing this implicit function declaration 2484 to the prototypes file (if requested). */ 2485 gen_aux_info_record (decl, 0, 1, 0); 2486 2487 /* Possibly apply some default attributes to this implicit declaration. */ 2488 decl_attributes (&decl, NULL_TREE, 0); 2489 2490 return decl; 2491} 2492 2493/* Issue an error message for a reference to an undeclared variable 2494 ID, including a reference to a builtin outside of function-call 2495 context. Establish a binding of the identifier to error_mark_node 2496 in an appropriate scope, which will suppress further errors for the 2497 same identifier. The error message should be given location LOC. */ 2498void 2499undeclared_variable (tree id, location_t loc) 2500{ 2501 static bool already = false; 2502 struct c_scope *scope; 2503 2504 if (current_function_decl == 0) 2505 { 2506 error ("%H%qE undeclared here (not in a function)", &loc, id); 2507 scope = current_scope; 2508 } 2509 else 2510 { 2511 error ("%H%qE undeclared (first use in this function)", &loc, id); 2512 2513 if (!already) 2514 { 2515 error ("%H(Each undeclared identifier is reported only once", &loc); 2516 error ("%Hfor each function it appears in.)", &loc); 2517 already = true; 2518 } 2519 2520 /* If we are parsing old-style parameter decls, current_function_decl 2521 will be nonnull but current_function_scope will be null. */ 2522 scope = current_function_scope ? current_function_scope : current_scope; 2523 } 2524 bind (id, error_mark_node, scope, /*invisible=*/false, /*nested=*/false); 2525} 2526 2527/* Subroutine of lookup_label, declare_label, define_label: construct a 2528 LABEL_DECL with all the proper frills. */ 2529 2530static tree 2531make_label (tree name, location_t location) 2532{ 2533 tree label = build_decl (LABEL_DECL, name, void_type_node); 2534 2535 DECL_CONTEXT (label) = current_function_decl; 2536 DECL_MODE (label) = VOIDmode; 2537 DECL_SOURCE_LOCATION (label) = location; 2538 2539 return label; 2540} 2541 2542/* Get the LABEL_DECL corresponding to identifier NAME as a label. 2543 Create one if none exists so far for the current function. 2544 This is called when a label is used in a goto expression or 2545 has its address taken. */ 2546 2547tree 2548lookup_label (tree name) 2549{ 2550 tree label; 2551 2552 if (current_function_decl == 0) 2553 { 2554 error ("label %qE referenced outside of any function", name); 2555 return 0; 2556 } 2557 2558 /* Use a label already defined or ref'd with this name, but not if 2559 it is inherited from a containing function and wasn't declared 2560 using __label__. */ 2561 label = I_LABEL_DECL (name); 2562 if (label && (DECL_CONTEXT (label) == current_function_decl 2563 || C_DECLARED_LABEL_FLAG (label))) 2564 { 2565 /* If the label has only been declared, update its apparent 2566 location to point here, for better diagnostics if it 2567 turns out not to have been defined. */ 2568 if (!TREE_USED (label)) 2569 DECL_SOURCE_LOCATION (label) = input_location; 2570 return label; 2571 } 2572 2573 /* No label binding for that identifier; make one. */ 2574 label = make_label (name, input_location); 2575 2576 /* Ordinary labels go in the current function scope. */ 2577 bind (name, label, current_function_scope, 2578 /*invisible=*/false, /*nested=*/false); 2579 return label; 2580} 2581 2582/* Make a label named NAME in the current function, shadowing silently 2583 any that may be inherited from containing functions or containing 2584 scopes. This is called for __label__ declarations. */ 2585 2586tree 2587declare_label (tree name) 2588{ 2589 struct c_binding *b = I_LABEL_BINDING (name); 2590 tree label; 2591 2592 /* Check to make sure that the label hasn't already been declared 2593 at this scope */ 2594 if (b && B_IN_CURRENT_SCOPE (b)) 2595 { 2596 error ("duplicate label declaration %qE", name); 2597 locate_old_decl (b->decl, error); 2598 2599 /* Just use the previous declaration. */ 2600 return b->decl; 2601 } 2602 2603 label = make_label (name, input_location); 2604 C_DECLARED_LABEL_FLAG (label) = 1; 2605 2606 /* Declared labels go in the current scope. */ 2607 bind (name, label, current_scope, 2608 /*invisible=*/false, /*nested=*/false); 2609 return label; 2610} 2611 2612/* Define a label, specifying the location in the source file. 2613 Return the LABEL_DECL node for the label, if the definition is valid. 2614 Otherwise return 0. */ 2615 2616tree 2617define_label (location_t location, tree name) 2618{ 2619 /* Find any preexisting label with this name. It is an error 2620 if that label has already been defined in this function, or 2621 if there is a containing function with a declared label with 2622 the same name. */ 2623 tree label = I_LABEL_DECL (name); 2624 struct c_label_list *nlist_se, *nlist_vm; 2625 2626 if (label 2627 && ((DECL_CONTEXT (label) == current_function_decl 2628 && DECL_INITIAL (label) != 0) 2629 || (DECL_CONTEXT (label) != current_function_decl 2630 && C_DECLARED_LABEL_FLAG (label)))) 2631 { 2632 error ("%Hduplicate label %qD", &location, label); 2633 locate_old_decl (label, error); 2634 return 0; 2635 } 2636 else if (label && DECL_CONTEXT (label) == current_function_decl) 2637 { 2638 /* The label has been used or declared already in this function, 2639 but not defined. Update its location to point to this 2640 definition. */ 2641 if (C_DECL_UNDEFINABLE_STMT_EXPR (label)) 2642 error ("%Jjump into statement expression", label); 2643 if (C_DECL_UNDEFINABLE_VM (label)) 2644 error ("%Jjump into scope of identifier with variably modified type", 2645 label); 2646 DECL_SOURCE_LOCATION (label) = location; 2647 } 2648 else 2649 { 2650 /* No label binding for that identifier; make one. */ 2651 label = make_label (name, location); 2652 2653 /* Ordinary labels go in the current function scope. */ 2654 bind (name, label, current_function_scope, 2655 /*invisible=*/false, /*nested=*/false); 2656 } 2657 2658 if (!in_system_header && lookup_name (name)) 2659 warning (OPT_Wtraditional, "%Htraditional C lacks a separate namespace " 2660 "for labels, identifier %qE conflicts", &location, name); 2661 2662 nlist_se = XOBNEW (&parser_obstack, struct c_label_list); 2663 nlist_se->next = label_context_stack_se->labels_def; 2664 nlist_se->label = label; 2665 label_context_stack_se->labels_def = nlist_se; 2666 2667 nlist_vm = XOBNEW (&parser_obstack, struct c_label_list); 2668 nlist_vm->next = label_context_stack_vm->labels_def; 2669 nlist_vm->label = label; 2670 label_context_stack_vm->labels_def = nlist_vm; 2671 2672 /* Mark label as having been defined. */ 2673 DECL_INITIAL (label) = error_mark_node; 2674 return label; 2675} 2676 2677/* Given NAME, an IDENTIFIER_NODE, 2678 return the structure (or union or enum) definition for that name. 2679 If THISLEVEL_ONLY is nonzero, searches only the current_scope. 2680 CODE says which kind of type the caller wants; 2681 it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE. 2682 If the wrong kind of type is found, an error is reported. */ 2683 2684static tree 2685lookup_tag (enum tree_code code, tree name, int thislevel_only) 2686{ 2687 struct c_binding *b = I_TAG_BINDING (name); 2688 int thislevel = 0; 2689 2690 if (!b || !b->decl) 2691 return 0; 2692 2693 /* We only care about whether it's in this level if 2694 thislevel_only was set or it might be a type clash. */ 2695 if (thislevel_only || TREE_CODE (b->decl) != code) 2696 { 2697 /* For our purposes, a tag in the external scope is the same as 2698 a tag in the file scope. (Primarily relevant to Objective-C 2699 and its builtin structure tags, which get pushed before the 2700 file scope is created.) */ 2701 if (B_IN_CURRENT_SCOPE (b) 2702 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 2703 thislevel = 1; 2704 } 2705 2706 if (thislevel_only && !thislevel) 2707 return 0; 2708 2709 if (TREE_CODE (b->decl) != code) 2710 { 2711 /* Definition isn't the kind we were looking for. */ 2712 pending_invalid_xref = name; 2713 pending_invalid_xref_location = input_location; 2714 2715 /* If in the same binding level as a declaration as a tag 2716 of a different type, this must not be allowed to 2717 shadow that tag, so give the error immediately. 2718 (For example, "struct foo; union foo;" is invalid.) */ 2719 if (thislevel) 2720 pending_xref_error (); 2721 } 2722 return b->decl; 2723} 2724 2725/* Print an error message now 2726 for a recent invalid struct, union or enum cross reference. 2727 We don't print them immediately because they are not invalid 2728 when used in the `struct foo;' construct for shadowing. */ 2729 2730void 2731pending_xref_error (void) 2732{ 2733 if (pending_invalid_xref != 0) 2734 error ("%H%qE defined as wrong kind of tag", 2735 &pending_invalid_xref_location, pending_invalid_xref); 2736 pending_invalid_xref = 0; 2737} 2738 2739 2740/* Look up NAME in the current scope and its superiors 2741 in the namespace of variables, functions and typedefs. 2742 Return a ..._DECL node of some kind representing its definition, 2743 or return 0 if it is undefined. */ 2744 2745tree 2746lookup_name (tree name) 2747{ 2748 struct c_binding *b = I_SYMBOL_BINDING (name); 2749 if (b && !b->invisible) 2750 return b->decl; 2751 return 0; 2752} 2753 2754/* Similar to `lookup_name' but look only at the indicated scope. */ 2755 2756static tree 2757lookup_name_in_scope (tree name, struct c_scope *scope) 2758{ 2759 struct c_binding *b; 2760 2761 for (b = I_SYMBOL_BINDING (name); b; b = b->shadowed) 2762 if (B_IN_SCOPE (b, scope)) 2763 return b->decl; 2764 return 0; 2765} 2766 2767/* Create the predefined scalar types of C, 2768 and some nodes representing standard constants (0, 1, (void *) 0). 2769 Initialize the global scope. 2770 Make definitions for built-in primitive functions. */ 2771 2772void 2773c_init_decl_processing (void) 2774{ 2775 location_t save_loc = input_location; 2776 2777 /* Initialize reserved words for parser. */ 2778 c_parse_init (); 2779 2780 current_function_decl = 0; 2781 2782 gcc_obstack_init (&parser_obstack); 2783 2784 /* Make the externals scope. */ 2785 push_scope (); 2786 external_scope = current_scope; 2787 2788 /* Declarations from c_common_nodes_and_builtins must not be associated 2789 with this input file, lest we get differences between using and not 2790 using preprocessed headers. */ 2791#ifdef USE_MAPPED_LOCATION 2792 input_location = BUILTINS_LOCATION; 2793#else 2794 input_location.file = "<built-in>"; 2795 input_location.line = 0; 2796#endif 2797 2798 build_common_tree_nodes (flag_signed_char, false); 2799 2800 c_common_nodes_and_builtins (); 2801 2802 /* In C, comparisons and TRUTH_* expressions have type int. */ 2803 truthvalue_type_node = integer_type_node; 2804 truthvalue_true_node = integer_one_node; 2805 truthvalue_false_node = integer_zero_node; 2806 2807 /* Even in C99, which has a real boolean type. */ 2808 pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"), 2809 boolean_type_node)); 2810 2811 input_location = save_loc; 2812 2813 pedantic_lvalues = true; 2814 2815 make_fname_decl = c_make_fname_decl; 2816 start_fname_decls (); 2817} 2818 2819/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the 2820 decl, NAME is the initialization string and TYPE_DEP indicates whether 2821 NAME depended on the type of the function. As we don't yet implement 2822 delayed emission of static data, we mark the decl as emitted 2823 so it is not placed in the output. Anything using it must therefore pull 2824 out the STRING_CST initializer directly. FIXME. */ 2825 2826static tree 2827c_make_fname_decl (tree id, int type_dep) 2828{ 2829 const char *name = fname_as_string (type_dep); 2830 tree decl, type, init; 2831 size_t length = strlen (name); 2832 2833 type = build_array_type (char_type_node, 2834 build_index_type (size_int (length))); 2835 type = c_build_qualified_type (type, TYPE_QUAL_CONST); 2836 2837 decl = build_decl (VAR_DECL, id, type); 2838 2839 TREE_STATIC (decl) = 1; 2840 TREE_READONLY (decl) = 1; 2841 DECL_ARTIFICIAL (decl) = 1; 2842 2843 init = build_string (length + 1, name); 2844 free ((char *) name); 2845 TREE_TYPE (init) = type; 2846 DECL_INITIAL (decl) = init; 2847 2848 TREE_USED (decl) = 1; 2849 2850 if (current_function_decl 2851 /* For invalid programs like this: 2852 2853 void foo() 2854 const char* p = __FUNCTION__; 2855 2856 the __FUNCTION__ is believed to appear in K&R style function 2857 parameter declarator. In that case we still don't have 2858 function_scope. */ 2859 && (!errorcount || current_function_scope)) 2860 { 2861 DECL_CONTEXT (decl) = current_function_decl; 2862 bind (id, decl, current_function_scope, 2863 /*invisible=*/false, /*nested=*/false); 2864 } 2865 2866 finish_decl (decl, init, NULL_TREE); 2867 2868 return decl; 2869} 2870 2871/* Return a definition for a builtin function named NAME and whose data type 2872 is TYPE. TYPE should be a function type with argument types. 2873 FUNCTION_CODE tells later passes how to compile calls to this function. 2874 See tree.h for its possible values. 2875 2876 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, 2877 the name to be called if we can't opencode the function. If 2878 ATTRS is nonzero, use that for the function's attribute list. */ 2879 2880tree 2881builtin_function (const char *name, tree type, int function_code, 2882 enum built_in_class cl, const char *library_name, 2883 tree attrs) 2884{ 2885 tree id = get_identifier (name); 2886 tree decl = build_decl (FUNCTION_DECL, id, type); 2887 TREE_PUBLIC (decl) = 1; 2888 DECL_EXTERNAL (decl) = 1; 2889 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 2890 DECL_BUILT_IN_CLASS (decl) = cl; 2891 DECL_FUNCTION_CODE (decl) = function_code; 2892 C_DECL_BUILTIN_PROTOTYPE (decl) = (TYPE_ARG_TYPES (type) != 0); 2893 if (library_name) 2894 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name)); 2895 2896 /* Should never be called on a symbol with a preexisting meaning. */ 2897 gcc_assert (!I_SYMBOL_BINDING (id)); 2898 2899 bind (id, decl, external_scope, /*invisible=*/true, /*nested=*/false); 2900 2901 /* Builtins in the implementation namespace are made visible without 2902 needing to be explicitly declared. See push_file_scope. */ 2903 if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1]))) 2904 { 2905 TREE_CHAIN (decl) = visible_builtins; 2906 visible_builtins = decl; 2907 } 2908 2909 /* Possibly apply some default attributes to this built-in function. */ 2910 if (attrs) 2911 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN); 2912 else 2913 decl_attributes (&decl, NULL_TREE, 0); 2914 2915 return decl; 2916} 2917 2918/* Called when a declaration is seen that contains no names to declare. 2919 If its type is a reference to a structure, union or enum inherited 2920 from a containing scope, shadow that tag name for the current scope 2921 with a forward reference. 2922 If its type defines a new named structure or union 2923 or defines an enum, it is valid but we need not do anything here. 2924 Otherwise, it is an error. */ 2925 2926void 2927shadow_tag (const struct c_declspecs *declspecs) 2928{ 2929 shadow_tag_warned (declspecs, 0); 2930} 2931 2932/* WARNED is 1 if we have done a pedwarn, 2 if we have done a warning, 2933 but no pedwarn. */ 2934void 2935shadow_tag_warned (const struct c_declspecs *declspecs, int warned) 2936{ 2937 bool found_tag = false; 2938 2939 if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p) 2940 { 2941 tree value = declspecs->type; 2942 enum tree_code code = TREE_CODE (value); 2943 2944 if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) 2945 /* Used to test also that TYPE_SIZE (value) != 0. 2946 That caused warning for `struct foo;' at top level in the file. */ 2947 { 2948 tree name = TYPE_NAME (value); 2949 tree t; 2950 2951 found_tag = true; 2952 2953 if (name == 0) 2954 { 2955 if (warned != 1 && code != ENUMERAL_TYPE) 2956 /* Empty unnamed enum OK */ 2957 { 2958 pedwarn ("unnamed struct/union that defines no instances"); 2959 warned = 1; 2960 } 2961 } 2962 else if (!declspecs->tag_defined_p 2963 && declspecs->storage_class != csc_none) 2964 { 2965 if (warned != 1) 2966 pedwarn ("empty declaration with storage class specifier " 2967 "does not redeclare tag"); 2968 warned = 1; 2969 pending_xref_error (); 2970 } 2971 else if (!declspecs->tag_defined_p 2972 && (declspecs->const_p 2973 || declspecs->volatile_p 2974 || declspecs->restrict_p)) 2975 { 2976 if (warned != 1) 2977 pedwarn ("empty declaration with type qualifier " 2978 "does not redeclare tag"); 2979 warned = 1; 2980 pending_xref_error (); 2981 } 2982 else 2983 { 2984 pending_invalid_xref = 0; 2985 t = lookup_tag (code, name, 1); 2986 2987 if (t == 0) 2988 { 2989 t = make_node (code); 2990 pushtag (name, t); 2991 } 2992 } 2993 } 2994 else 2995 { 2996 if (warned != 1 && !in_system_header) 2997 { 2998 pedwarn ("useless type name in empty declaration"); 2999 warned = 1; 3000 } 3001 } 3002 } 3003 else if (warned != 1 && !in_system_header && declspecs->typedef_p) 3004 { 3005 pedwarn ("useless type name in empty declaration"); 3006 warned = 1; 3007 } 3008 3009 pending_invalid_xref = 0; 3010 3011 if (declspecs->inline_p) 3012 { 3013 error ("%<inline%> in empty declaration"); 3014 warned = 1; 3015 } 3016 3017 if (current_scope == file_scope && declspecs->storage_class == csc_auto) 3018 { 3019 error ("%<auto%> in file-scope empty declaration"); 3020 warned = 1; 3021 } 3022 3023 if (current_scope == file_scope && declspecs->storage_class == csc_register) 3024 { 3025 error ("%<register%> in file-scope empty declaration"); 3026 warned = 1; 3027 } 3028 3029 if (!warned && !in_system_header && declspecs->storage_class != csc_none) 3030 { 3031 warning (0, "useless storage class specifier in empty declaration"); 3032 warned = 2; 3033 } 3034 3035 if (!warned && !in_system_header && declspecs->thread_p) 3036 { 3037 warning (0, "useless %<__thread%> in empty declaration"); 3038 warned = 2; 3039 } 3040 3041 if (!warned && !in_system_header && (declspecs->const_p 3042 || declspecs->volatile_p 3043 || declspecs->restrict_p)) 3044 { 3045 warning (0, "useless type qualifier in empty declaration"); 3046 warned = 2; 3047 } 3048 3049 if (warned != 1) 3050 { 3051 if (!found_tag) 3052 pedwarn ("empty declaration"); 3053 } 3054} 3055 3056 3057/* Return the qualifiers from SPECS as a bitwise OR of TYPE_QUAL_* 3058 bits. SPECS represents declaration specifiers that the grammar 3059 only permits to contain type qualifiers and attributes. */ 3060 3061int 3062quals_from_declspecs (const struct c_declspecs *specs) 3063{ 3064 int quals = ((specs->const_p ? TYPE_QUAL_CONST : 0) 3065 | (specs->volatile_p ? TYPE_QUAL_VOLATILE : 0) 3066 | (specs->restrict_p ? TYPE_QUAL_RESTRICT : 0)); 3067 gcc_assert (!specs->type 3068 && !specs->decl_attr 3069 && specs->typespec_word == cts_none 3070 && specs->storage_class == csc_none 3071 && !specs->typedef_p 3072 && !specs->explicit_signed_p 3073 && !specs->deprecated_p 3074 && !specs->long_p 3075 && !specs->long_long_p 3076 && !specs->short_p 3077 && !specs->signed_p 3078 && !specs->unsigned_p 3079 && !specs->complex_p 3080 && !specs->inline_p 3081 && !specs->thread_p); 3082 return quals; 3083} 3084 3085/* Construct an array declarator. EXPR is the expression inside [], 3086 or NULL_TREE. QUALS are the type qualifiers inside the [] (to be 3087 applied to the pointer to which a parameter array is converted). 3088 STATIC_P is true if "static" is inside the [], false otherwise. 3089 VLA_UNSPEC_P is true if the array is [*], a VLA of unspecified 3090 length which is nevertheless a complete type, false otherwise. The 3091 field for the contained declarator is left to be filled in by 3092 set_array_declarator_inner. */ 3093 3094struct c_declarator * 3095build_array_declarator (tree expr, struct c_declspecs *quals, bool static_p, 3096 bool vla_unspec_p) 3097{ 3098 struct c_declarator *declarator = XOBNEW (&parser_obstack, 3099 struct c_declarator); 3100 declarator->kind = cdk_array; 3101 declarator->declarator = 0; 3102 declarator->u.array.dimen = expr; 3103 if (quals) 3104 { 3105 declarator->u.array.attrs = quals->attrs; 3106 declarator->u.array.quals = quals_from_declspecs (quals); 3107 } 3108 else 3109 { 3110 declarator->u.array.attrs = NULL_TREE; 3111 declarator->u.array.quals = 0; 3112 } 3113 declarator->u.array.static_p = static_p; 3114 declarator->u.array.vla_unspec_p = vla_unspec_p; 3115 if (pedantic && !flag_isoc99) 3116 { 3117 if (static_p || quals != NULL) 3118 pedwarn ("ISO C90 does not support %<static%> or type " 3119 "qualifiers in parameter array declarators"); 3120 if (vla_unspec_p) 3121 pedwarn ("ISO C90 does not support %<[*]%> array declarators"); 3122 } 3123 if (vla_unspec_p) 3124 { 3125 if (!current_scope->parm_flag) 3126 { 3127 /* C99 6.7.5.2p4 */ 3128 error ("%<[*]%> not allowed in other than function prototype scope"); 3129 declarator->u.array.vla_unspec_p = false; 3130 return NULL; 3131 } 3132 current_scope->had_vla_unspec = true; 3133 } 3134 return declarator; 3135} 3136 3137/* Set the contained declarator of an array declarator. DECL is the 3138 declarator, as constructed by build_array_declarator; INNER is what 3139 appears on the left of the []. ABSTRACT_P is true if it is an 3140 abstract declarator, false otherwise; this is used to reject static 3141 and type qualifiers in abstract declarators, where they are not in 3142 the C99 grammar (subject to possible change in DR#289). */ 3143 3144struct c_declarator * 3145set_array_declarator_inner (struct c_declarator *decl, 3146 struct c_declarator *inner, bool abstract_p) 3147{ 3148 decl->declarator = inner; 3149 if (abstract_p && (decl->u.array.quals != TYPE_UNQUALIFIED 3150 || decl->u.array.attrs != NULL_TREE 3151 || decl->u.array.static_p)) 3152 error ("static or type qualifiers in abstract declarator"); 3153 return decl; 3154} 3155 3156/* INIT is a constructor that forms DECL's initializer. If the final 3157 element initializes a flexible array field, add the size of that 3158 initializer to DECL's size. */ 3159 3160static void 3161add_flexible_array_elts_to_size (tree decl, tree init) 3162{ 3163 tree elt, type; 3164 3165 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init))) 3166 return; 3167 3168 elt = VEC_last (constructor_elt, CONSTRUCTOR_ELTS (init))->value; 3169 type = TREE_TYPE (elt); 3170 if (TREE_CODE (type) == ARRAY_TYPE 3171 && TYPE_SIZE (type) == NULL_TREE 3172 && TYPE_DOMAIN (type) != NULL_TREE 3173 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL_TREE) 3174 { 3175 complete_array_type (&type, elt, false); 3176 DECL_SIZE (decl) 3177 = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type)); 3178 DECL_SIZE_UNIT (decl) 3179 = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type)); 3180 } 3181} 3182 3183/* Decode a "typename", such as "int **", returning a ..._TYPE node. */ 3184 3185tree 3186groktypename (struct c_type_name *type_name) 3187{ 3188 tree type; 3189 tree attrs = type_name->specs->attrs; 3190 3191 type_name->specs->attrs = NULL_TREE; 3192 3193 type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME, 3194 false, NULL); 3195 3196 /* Apply attributes. */ 3197 decl_attributes (&type, attrs, 0); 3198 3199 return type; 3200} 3201 3202/* Decode a declarator in an ordinary declaration or data definition. 3203 This is called as soon as the type information and variable name 3204 have been parsed, before parsing the initializer if any. 3205 Here we create the ..._DECL node, fill in its type, 3206 and put it on the list of decls for the current context. 3207 The ..._DECL node is returned as the value. 3208 3209 Exception: for arrays where the length is not specified, 3210 the type is left null, to be filled in by `finish_decl'. 3211 3212 Function definitions do not come here; they go to start_function 3213 instead. However, external and forward declarations of functions 3214 do go through here. Structure field declarations are done by 3215 grokfield and not through here. */ 3216 3217tree 3218start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, 3219 bool initialized, tree attributes) 3220{ 3221 tree decl; 3222 tree tem; 3223 3224 /* An object declared as __attribute__((deprecated)) suppresses 3225 warnings of uses of other deprecated items. */ 3226 if (lookup_attribute ("deprecated", attributes)) 3227 deprecated_state = DEPRECATED_SUPPRESS; 3228 3229 decl = grokdeclarator (declarator, declspecs, 3230 NORMAL, initialized, NULL); 3231 if (!decl) 3232 return 0; 3233 3234 deprecated_state = DEPRECATED_NORMAL; 3235 3236 if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL 3237 && MAIN_NAME_P (DECL_NAME (decl))) 3238 warning (OPT_Wmain, "%q+D is usually a function", decl); 3239 3240 if (initialized) 3241 /* Is it valid for this decl to have an initializer at all? 3242 If not, set INITIALIZED to zero, which will indirectly 3243 tell 'finish_decl' to ignore the initializer once it is parsed. */ 3244 switch (TREE_CODE (decl)) 3245 { 3246 case TYPE_DECL: 3247 error ("typedef %qD is initialized (use __typeof__ instead)", decl); 3248 initialized = 0; 3249 break; 3250 3251 case FUNCTION_DECL: 3252 error ("function %qD is initialized like a variable", decl); 3253 initialized = 0; 3254 break; 3255 3256 case PARM_DECL: 3257 /* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE. */ 3258 error ("parameter %qD is initialized", decl); 3259 initialized = 0; 3260 break; 3261 3262 default: 3263 /* Don't allow initializations for incomplete types except for 3264 arrays which might be completed by the initialization. */ 3265 3266 /* This can happen if the array size is an undefined macro. 3267 We already gave a warning, so we don't need another one. */ 3268 if (TREE_TYPE (decl) == error_mark_node) 3269 initialized = 0; 3270 else if (COMPLETE_TYPE_P (TREE_TYPE (decl))) 3271 { 3272 /* A complete type is ok if size is fixed. */ 3273 3274 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST 3275 || C_DECL_VARIABLE_SIZE (decl)) 3276 { 3277 error ("variable-sized object may not be initialized"); 3278 initialized = 0; 3279 } 3280 } 3281 else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE) 3282 { 3283 error ("variable %qD has initializer but incomplete type", decl); 3284 initialized = 0; 3285 } 3286 else if (C_DECL_VARIABLE_SIZE (decl)) 3287 { 3288 /* Although C99 is unclear about whether incomplete arrays 3289 of VLAs themselves count as VLAs, it does not make 3290 sense to permit them to be initialized given that 3291 ordinary VLAs may not be initialized. */ 3292 error ("variable-sized object may not be initialized"); 3293 initialized = 0; 3294 } 3295 } 3296 3297 if (initialized) 3298 { 3299 if (current_scope == file_scope) 3300 TREE_STATIC (decl) = 1; 3301 3302 /* Tell 'pushdecl' this is an initialized decl 3303 even though we don't yet have the initializer expression. 3304 Also tell 'finish_decl' it may store the real initializer. */ 3305 DECL_INITIAL (decl) = error_mark_node; 3306 } 3307 3308 /* If this is a function declaration, write a record describing it to the 3309 prototypes file (if requested). */ 3310 3311 if (TREE_CODE (decl) == FUNCTION_DECL) 3312 gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0); 3313 3314 /* ANSI specifies that a tentative definition which is not merged with 3315 a non-tentative definition behaves exactly like a definition with an 3316 initializer equal to zero. (Section 3.7.2) 3317 3318 -fno-common gives strict ANSI behavior, though this tends to break 3319 a large body of code that grew up without this rule. 3320 3321 Thread-local variables are never common, since there's no entrenched 3322 body of code to break, and it allows more efficient variable references 3323 in the presence of dynamic linking. */ 3324 3325 if (TREE_CODE (decl) == VAR_DECL 3326 && !initialized 3327 && TREE_PUBLIC (decl) 3328 && !DECL_THREAD_LOCAL_P (decl) 3329 && !flag_no_common) 3330 DECL_COMMON (decl) = 1; 3331 3332 /* Set attributes here so if duplicate decl, will have proper attributes. */ 3333 decl_attributes (&decl, attributes, 0); 3334 3335 /* Handle gnu_inline attribute. */ 3336 if (declspecs->inline_p 3337 && !flag_gnu89_inline 3338 && TREE_CODE (decl) == FUNCTION_DECL 3339 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl))) 3340 { 3341 if (declspecs->storage_class == csc_auto && current_scope != file_scope) 3342 ; 3343 else if (declspecs->storage_class != csc_static) 3344 DECL_EXTERNAL (decl) = !DECL_EXTERNAL (decl); 3345 } 3346 3347 if (TREE_CODE (decl) == FUNCTION_DECL 3348 && targetm.calls.promote_prototypes (TREE_TYPE (decl))) 3349 { 3350 struct c_declarator *ce = declarator; 3351 3352 if (ce->kind == cdk_pointer) 3353 ce = declarator->declarator; 3354 if (ce->kind == cdk_function) 3355 { 3356 tree args = ce->u.arg_info->parms; 3357 for (; args; args = TREE_CHAIN (args)) 3358 { 3359 tree type = TREE_TYPE (args); 3360 if (type && INTEGRAL_TYPE_P (type) 3361 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 3362 DECL_ARG_TYPE (args) = integer_type_node; 3363 } 3364 } 3365 } 3366 3367 if (TREE_CODE (decl) == FUNCTION_DECL 3368 && DECL_DECLARED_INLINE_P (decl) 3369 && DECL_UNINLINABLE (decl) 3370 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl))) 3371 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 3372 decl); 3373 3374 /* C99 6.7.4p3: An inline definition of a function with external 3375 linkage shall not contain a definition of a modifiable object 3376 with static storage duration... */ 3377 if (TREE_CODE (decl) == VAR_DECL 3378 && current_scope != file_scope 3379 && TREE_STATIC (decl) 3380 && !TREE_READONLY (decl) 3381 && DECL_DECLARED_INLINE_P (current_function_decl) 3382 && DECL_EXTERNAL (current_function_decl)) 3383 pedwarn ("%q+D is static but declared in inline function %qD " 3384 "which is not static", decl, current_function_decl); 3385 3386 /* Add this decl to the current scope. 3387 TEM may equal DECL or it may be a previous decl of the same name. */ 3388 tem = pushdecl (decl); 3389 3390 if (initialized && DECL_EXTERNAL (tem)) 3391 { 3392 DECL_EXTERNAL (tem) = 0; 3393 TREE_STATIC (tem) = 1; 3394 } 3395 3396 return tem; 3397} 3398 3399/* Initialize EH if not initialized yet and exceptions are enabled. */ 3400 3401void 3402c_maybe_initialize_eh (void) 3403{ 3404 if (!flag_exceptions || c_eh_initialized_p) 3405 return; 3406 3407 c_eh_initialized_p = true; 3408 eh_personality_libfunc 3409 = init_one_libfunc (USING_SJLJ_EXCEPTIONS 3410 ? "__gcc_personality_sj0" 3411 : "__gcc_personality_v0"); 3412 default_init_unwind_resume_libfunc (); 3413 using_eh_for_cleanups (); 3414} 3415 3416/* Finish processing of a declaration; 3417 install its initial value. 3418 If the length of an array type is not known before, 3419 it must be determined now, from the initial value, or it is an error. */ 3420 3421void 3422finish_decl (tree decl, tree init, tree asmspec_tree) 3423{ 3424 tree type; 3425 int was_incomplete = (DECL_SIZE (decl) == 0); 3426 const char *asmspec = 0; 3427 3428 /* If a name was specified, get the string. */ 3429 if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL) 3430 && DECL_FILE_SCOPE_P (decl)) 3431 asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree); 3432 if (asmspec_tree) 3433 asmspec = TREE_STRING_POINTER (asmspec_tree); 3434 3435 /* If `start_decl' didn't like having an initialization, ignore it now. */ 3436 if (init != 0 && DECL_INITIAL (decl) == 0) 3437 init = 0; 3438 3439 /* Don't crash if parm is initialized. */ 3440 if (TREE_CODE (decl) == PARM_DECL) 3441 init = 0; 3442 3443 if (init) 3444 store_init_value (decl, init); 3445 3446 if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL 3447 || TREE_CODE (decl) == FUNCTION_DECL 3448 || TREE_CODE (decl) == FIELD_DECL)) 3449 objc_check_decl (decl); 3450 3451 type = TREE_TYPE (decl); 3452 3453 /* Deduce size of array from initialization, if not already known. */ 3454 if (TREE_CODE (type) == ARRAY_TYPE 3455 && TYPE_DOMAIN (type) == 0 3456 && TREE_CODE (decl) != TYPE_DECL) 3457 { 3458 bool do_default 3459 = (TREE_STATIC (decl) 3460 /* Even if pedantic, an external linkage array 3461 may have incomplete type at first. */ 3462 ? pedantic && !TREE_PUBLIC (decl) 3463 : !DECL_EXTERNAL (decl)); 3464 int failure 3465 = complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl), 3466 do_default); 3467 3468 /* Get the completed type made by complete_array_type. */ 3469 type = TREE_TYPE (decl); 3470 3471 switch (failure) 3472 { 3473 case 1: 3474 error ("initializer fails to determine size of %q+D", decl); 3475 break; 3476 3477 case 2: 3478 if (do_default) 3479 error ("array size missing in %q+D", decl); 3480 /* If a `static' var's size isn't known, 3481 make it extern as well as static, so it does not get 3482 allocated. 3483 If it is not `static', then do not mark extern; 3484 finish_incomplete_decl will give it a default size 3485 and it will get allocated. */ 3486 else if (!pedantic && TREE_STATIC (decl) && !TREE_PUBLIC (decl)) 3487 DECL_EXTERNAL (decl) = 1; 3488 break; 3489 3490 case 3: 3491 error ("zero or negative size array %q+D", decl); 3492 break; 3493 3494 case 0: 3495 /* For global variables, update the copy of the type that 3496 exists in the binding. */ 3497 if (TREE_PUBLIC (decl)) 3498 { 3499 struct c_binding *b_ext = I_SYMBOL_BINDING (DECL_NAME (decl)); 3500 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 3501 b_ext = b_ext->shadowed; 3502 if (b_ext) 3503 { 3504 if (b_ext->type) 3505 b_ext->type = composite_type (b_ext->type, type); 3506 else 3507 b_ext->type = type; 3508 } 3509 } 3510 break; 3511 3512 default: 3513 gcc_unreachable (); 3514 } 3515 3516 if (DECL_INITIAL (decl)) 3517 TREE_TYPE (DECL_INITIAL (decl)) = type; 3518 3519 layout_decl (decl, 0); 3520 } 3521 3522 if (TREE_CODE (decl) == VAR_DECL) 3523 { 3524 if (init && TREE_CODE (init) == CONSTRUCTOR) 3525 add_flexible_array_elts_to_size (decl, init); 3526 3527 if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node 3528 && COMPLETE_TYPE_P (TREE_TYPE (decl))) 3529 layout_decl (decl, 0); 3530 3531 if (DECL_SIZE (decl) == 0 3532 /* Don't give an error if we already gave one earlier. */ 3533 && TREE_TYPE (decl) != error_mark_node 3534 && (TREE_STATIC (decl) 3535 /* A static variable with an incomplete type 3536 is an error if it is initialized. 3537 Also if it is not file scope. 3538 Otherwise, let it through, but if it is not `extern' 3539 then it may cause an error message later. */ 3540 ? (DECL_INITIAL (decl) != 0 3541 || !DECL_FILE_SCOPE_P (decl)) 3542 /* An automatic variable with an incomplete type 3543 is an error. */ 3544 : !DECL_EXTERNAL (decl))) 3545 { 3546 error ("storage size of %q+D isn%'t known", decl); 3547 TREE_TYPE (decl) = error_mark_node; 3548 } 3549 3550 if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl)) 3551 && DECL_SIZE (decl) != 0) 3552 { 3553 if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) 3554 constant_expression_warning (DECL_SIZE (decl)); 3555 else 3556 error ("storage size of %q+D isn%'t constant", decl); 3557 } 3558 3559 if (TREE_USED (type)) 3560 TREE_USED (decl) = 1; 3561 } 3562 3563 /* If this is a function and an assembler name is specified, reset DECL_RTL 3564 so we can give it its new name. Also, update built_in_decls if it 3565 was a normal built-in. */ 3566 if (TREE_CODE (decl) == FUNCTION_DECL && asmspec) 3567 { 3568 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) 3569 set_builtin_user_assembler_name (decl, asmspec); 3570 set_user_assembler_name (decl, asmspec); 3571 } 3572 3573 /* If #pragma weak was used, mark the decl weak now. */ 3574 maybe_apply_pragma_weak (decl); 3575 3576 /* Output the assembler code and/or RTL code for variables and functions, 3577 unless the type is an undefined structure or union. 3578 If not, it will get done when the type is completed. */ 3579 3580 if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL) 3581 { 3582 /* Determine the ELF visibility. */ 3583 if (TREE_PUBLIC (decl)) 3584 c_determine_visibility (decl); 3585 3586 /* This is a no-op in c-lang.c or something real in objc-act.c. */ 3587 if (c_dialect_objc ()) 3588 objc_check_decl (decl); 3589 3590 if (asmspec) 3591 { 3592 /* If this is not a static variable, issue a warning. 3593 It doesn't make any sense to give an ASMSPEC for an 3594 ordinary, non-register local variable. Historically, 3595 GCC has accepted -- but ignored -- the ASMSPEC in 3596 this case. */ 3597 if (!DECL_FILE_SCOPE_P (decl) 3598 && TREE_CODE (decl) == VAR_DECL 3599 && !C_DECL_REGISTER (decl) 3600 && !TREE_STATIC (decl)) 3601 warning (0, "ignoring asm-specifier for non-static local " 3602 "variable %q+D", decl); 3603 else 3604 set_user_assembler_name (decl, asmspec); 3605 } 3606 3607 if (DECL_FILE_SCOPE_P (decl)) 3608 { 3609 if (DECL_INITIAL (decl) == NULL_TREE 3610 || DECL_INITIAL (decl) == error_mark_node) 3611 /* Don't output anything 3612 when a tentative file-scope definition is seen. 3613 But at end of compilation, do output code for them. */ 3614 DECL_DEFER_OUTPUT (decl) = 1; 3615 rest_of_decl_compilation (decl, true, 0); 3616 } 3617 else 3618 { 3619 /* In conjunction with an ASMSPEC, the `register' 3620 keyword indicates that we should place the variable 3621 in a particular register. */ 3622 if (asmspec && C_DECL_REGISTER (decl)) 3623 { 3624 DECL_HARD_REGISTER (decl) = 1; 3625 /* This cannot be done for a structure with volatile 3626 fields, on which DECL_REGISTER will have been 3627 reset. */ 3628 if (!DECL_REGISTER (decl)) 3629 error ("cannot put object with volatile field into register"); 3630 } 3631 3632 if (TREE_CODE (decl) != FUNCTION_DECL) 3633 { 3634 /* If we're building a variable sized type, and we might be 3635 reachable other than via the top of the current binding 3636 level, then create a new BIND_EXPR so that we deallocate 3637 the object at the right time. */ 3638 /* Note that DECL_SIZE can be null due to errors. */ 3639 if (DECL_SIZE (decl) 3640 && !TREE_CONSTANT (DECL_SIZE (decl)) 3641 && STATEMENT_LIST_HAS_LABEL (cur_stmt_list)) 3642 { 3643 tree bind; 3644 bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL); 3645 TREE_SIDE_EFFECTS (bind) = 1; 3646 add_stmt (bind); 3647 BIND_EXPR_BODY (bind) = push_stmt_list (); 3648 } 3649 add_stmt (build_stmt (DECL_EXPR, decl)); 3650 } 3651 } 3652 3653 3654 if (!DECL_FILE_SCOPE_P (decl)) 3655 { 3656 /* Recompute the RTL of a local array now 3657 if it used to be an incomplete type. */ 3658 if (was_incomplete 3659 && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) 3660 { 3661 /* If we used it already as memory, it must stay in memory. */ 3662 TREE_ADDRESSABLE (decl) = TREE_USED (decl); 3663 /* If it's still incomplete now, no init will save it. */ 3664 if (DECL_SIZE (decl) == 0) 3665 DECL_INITIAL (decl) = 0; 3666 } 3667 } 3668 } 3669 3670 /* If this was marked 'used', be sure it will be output. */ 3671 if (!flag_unit_at_a_time && lookup_attribute ("used", DECL_ATTRIBUTES (decl))) 3672 mark_decl_referenced (decl); 3673 3674 if (TREE_CODE (decl) == TYPE_DECL) 3675 { 3676 if (!DECL_FILE_SCOPE_P (decl) 3677 && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 3678 add_stmt (build_stmt (DECL_EXPR, decl)); 3679 3680 rest_of_decl_compilation (decl, DECL_FILE_SCOPE_P (decl), 0); 3681 } 3682 3683 /* At the end of a declaration, throw away any variable type sizes 3684 of types defined inside that declaration. There is no use 3685 computing them in the following function definition. */ 3686 if (current_scope == file_scope) 3687 get_pending_sizes (); 3688 3689 /* Install a cleanup (aka destructor) if one was given. */ 3690 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 3691 { 3692 tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl)); 3693 if (attr) 3694 { 3695 tree cleanup_id = TREE_VALUE (TREE_VALUE (attr)); 3696 tree cleanup_decl = lookup_name (cleanup_id); 3697 tree cleanup; 3698 3699 /* Build "cleanup(&decl)" for the destructor. */ 3700 cleanup = build_unary_op (ADDR_EXPR, decl, 0); 3701 cleanup = build_tree_list (NULL_TREE, cleanup); 3702 cleanup = build_function_call (cleanup_decl, cleanup); 3703 3704 /* Don't warn about decl unused; the cleanup uses it. */ 3705 TREE_USED (decl) = 1; 3706 TREE_USED (cleanup_decl) = 1; 3707 3708 /* Initialize EH, if we've been told to do so. */ 3709 c_maybe_initialize_eh (); 3710 3711 push_cleanup (decl, cleanup, false); 3712 } 3713 } 3714} 3715 3716/* Given a parsed parameter declaration, decode it into a PARM_DECL. */ 3717 3718tree 3719grokparm (const struct c_parm *parm) 3720{ 3721 tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, 3722 NULL); 3723 3724 decl_attributes (&decl, parm->attrs, 0); 3725 3726 return decl; 3727} 3728 3729/* Given a parsed parameter declaration, decode it into a PARM_DECL 3730 and push that on the current scope. */ 3731 3732void 3733push_parm_decl (const struct c_parm *parm) 3734{ 3735 tree decl; 3736 3737 decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL); 3738 decl_attributes (&decl, parm->attrs, 0); 3739 3740 decl = pushdecl (decl); 3741 3742 finish_decl (decl, NULL_TREE, NULL_TREE); 3743} 3744 3745/* Mark all the parameter declarations to date as forward decls. 3746 Also diagnose use of this extension. */ 3747 3748void 3749mark_forward_parm_decls (void) 3750{ 3751 struct c_binding *b; 3752 3753 if (pedantic && !current_scope->warned_forward_parm_decls) 3754 { 3755 pedwarn ("ISO C forbids forward parameter declarations"); 3756 current_scope->warned_forward_parm_decls = true; 3757 } 3758 3759 for (b = current_scope->bindings; b; b = b->prev) 3760 if (TREE_CODE (b->decl) == PARM_DECL) 3761 TREE_ASM_WRITTEN (b->decl) = 1; 3762} 3763 3764/* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound 3765 literal, which may be an incomplete array type completed by the 3766 initializer; INIT is a CONSTRUCTOR that initializes the compound 3767 literal. */ 3768 3769tree 3770build_compound_literal (tree type, tree init) 3771{ 3772 /* We do not use start_decl here because we have a type, not a declarator; 3773 and do not use finish_decl because the decl should be stored inside 3774 the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_EXPR. */ 3775 tree decl; 3776 tree complit; 3777 tree stmt; 3778 3779 if (type == error_mark_node) 3780 return error_mark_node; 3781 3782 decl = build_decl (VAR_DECL, NULL_TREE, type); 3783 DECL_EXTERNAL (decl) = 0; 3784 TREE_PUBLIC (decl) = 0; 3785 TREE_STATIC (decl) = (current_scope == file_scope); 3786 DECL_CONTEXT (decl) = current_function_decl; 3787 TREE_USED (decl) = 1; 3788 TREE_TYPE (decl) = type; 3789 TREE_READONLY (decl) = TYPE_READONLY (type); 3790 store_init_value (decl, init); 3791 3792 if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type)) 3793 { 3794 int failure = complete_array_type (&TREE_TYPE (decl), 3795 DECL_INITIAL (decl), true); 3796 gcc_assert (!failure); 3797 3798 type = TREE_TYPE (decl); 3799 TREE_TYPE (DECL_INITIAL (decl)) = type; 3800 } 3801 3802 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 3803 return error_mark_node; 3804 3805 stmt = build_stmt (DECL_EXPR, decl); 3806 complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt); 3807 TREE_SIDE_EFFECTS (complit) = 1; 3808 3809 layout_decl (decl, 0); 3810 3811 if (TREE_STATIC (decl)) 3812 { 3813 /* This decl needs a name for the assembler output. */ 3814 set_compound_literal_name (decl); 3815 DECL_DEFER_OUTPUT (decl) = 1; 3816 DECL_COMDAT (decl) = 1; 3817 DECL_ARTIFICIAL (decl) = 1; 3818 DECL_IGNORED_P (decl) = 1; 3819 pushdecl (decl); 3820 rest_of_decl_compilation (decl, 1, 0); 3821 } 3822 3823 return complit; 3824} 3825 3826/* Determine whether TYPE is a structure with a flexible array member, 3827 or a union containing such a structure (possibly recursively). */ 3828 3829static bool 3830flexible_array_type_p (tree type) 3831{ 3832 tree x; 3833 switch (TREE_CODE (type)) 3834 { 3835 case RECORD_TYPE: 3836 x = TYPE_FIELDS (type); 3837 if (x == NULL_TREE) 3838 return false; 3839 while (TREE_CHAIN (x) != NULL_TREE) 3840 x = TREE_CHAIN (x); 3841 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 3842 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 3843 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 3844 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 3845 return true; 3846 return false; 3847 case UNION_TYPE: 3848 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x)) 3849 { 3850 if (flexible_array_type_p (TREE_TYPE (x))) 3851 return true; 3852 } 3853 return false; 3854 default: 3855 return false; 3856 } 3857} 3858 3859/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 3860 replacing with appropriate values if they are invalid. */ 3861static void 3862check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name) 3863{ 3864 tree type_mv; 3865 unsigned int max_width; 3866 unsigned HOST_WIDE_INT w; 3867 const char *name = orig_name ? orig_name: _("<anonymous>"); 3868 3869 /* Detect and ignore out of range field width and process valid 3870 field widths. */ 3871 if (!INTEGRAL_TYPE_P (TREE_TYPE (*width)) 3872 || TREE_CODE (*width) != INTEGER_CST) 3873 { 3874 error ("bit-field %qs width not an integer constant", name); 3875 *width = integer_one_node; 3876 } 3877 else 3878 { 3879 constant_expression_warning (*width); 3880 if (tree_int_cst_sgn (*width) < 0) 3881 { 3882 error ("negative width in bit-field %qs", name); 3883 *width = integer_one_node; 3884 } 3885 else if (integer_zerop (*width) && orig_name) 3886 { 3887 error ("zero width for bit-field %qs", name); 3888 *width = integer_one_node; 3889 } 3890 } 3891 3892 /* Detect invalid bit-field type. */ 3893 if (TREE_CODE (*type) != INTEGER_TYPE 3894 && TREE_CODE (*type) != BOOLEAN_TYPE 3895 && TREE_CODE (*type) != ENUMERAL_TYPE) 3896 { 3897 error ("bit-field %qs has invalid type", name); 3898 *type = unsigned_type_node; 3899 } 3900 3901 type_mv = TYPE_MAIN_VARIANT (*type); 3902 if (pedantic 3903 && !in_system_header 3904 && type_mv != integer_type_node 3905 && type_mv != unsigned_type_node 3906 && type_mv != boolean_type_node) 3907 pedwarn ("type of bit-field %qs is a GCC extension", name); 3908 3909 if (type_mv == boolean_type_node) 3910 max_width = CHAR_TYPE_SIZE; 3911 else 3912 max_width = TYPE_PRECISION (*type); 3913 3914 if (0 < compare_tree_int (*width, max_width)) 3915 { 3916 error ("width of %qs exceeds its type", name); 3917 w = max_width; 3918 *width = build_int_cst (NULL_TREE, w); 3919 } 3920 else 3921 w = tree_low_cst (*width, 1); 3922 3923 if (TREE_CODE (*type) == ENUMERAL_TYPE) 3924 { 3925 struct lang_type *lt = TYPE_LANG_SPECIFIC (*type); 3926 if (!lt 3927 || w < min_precision (lt->enum_min, TYPE_UNSIGNED (*type)) 3928 || w < min_precision (lt->enum_max, TYPE_UNSIGNED (*type))) 3929 warning (0, "%qs is narrower than values of its type", name); 3930 } 3931} 3932 3933 3934 3935/* Print warning about variable length array if necessary. */ 3936 3937static void 3938warn_variable_length_array (const char *name, tree size) 3939{ 3940 int ped = !flag_isoc99 && pedantic && warn_vla != 0; 3941 int const_size = TREE_CONSTANT (size); 3942 3943 if (ped) 3944 { 3945 if (const_size) 3946 { 3947 if (name) 3948 pedwarn ("ISO C90 forbids array %qs whose size " 3949 "can%'t be evaluated", 3950 name); 3951 else 3952 pedwarn ("ISO C90 forbids array whose size " 3953 "can%'t be evaluated"); 3954 } 3955 else 3956 { 3957 if (name) 3958 pedwarn ("ISO C90 forbids variable length array %qs", 3959 name); 3960 else 3961 pedwarn ("ISO C90 forbids variable length array"); 3962 } 3963 } 3964 else if (warn_vla > 0) 3965 { 3966 if (const_size) 3967 { 3968 if (name) 3969 warning (OPT_Wvla, 3970 "the size of array %qs can" 3971 "%'t be evaluated", name); 3972 else 3973 warning (OPT_Wvla, 3974 "the size of array can %'t be evaluated"); 3975 } 3976 else 3977 { 3978 if (name) 3979 warning (OPT_Wvla, 3980 "variable length array %qs is used", 3981 name); 3982 else 3983 warning (OPT_Wvla, 3984 "variable length array is used"); 3985 } 3986 } 3987} 3988 3989/* Given declspecs and a declarator, 3990 determine the name and type of the object declared 3991 and construct a ..._DECL node for it. 3992 (In one case we can return a ..._TYPE node instead. 3993 For invalid input we sometimes return 0.) 3994 3995 DECLSPECS is a c_declspecs structure for the declaration specifiers. 3996 3997 DECL_CONTEXT says which syntactic context this declaration is in: 3998 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 3999 FUNCDEF for a function definition. Like NORMAL but a few different 4000 error messages in each case. Return value may be zero meaning 4001 this definition is too screwy to try to parse. 4002 PARM for a parameter declaration (either within a function prototype 4003 or before a function body). Make a PARM_DECL, or return void_type_node. 4004 TYPENAME if for a typename (in a cast or sizeof). 4005 Don't make a DECL node; just return the ..._TYPE node. 4006 FIELD for a struct or union field; make a FIELD_DECL. 4007 INITIALIZED is true if the decl has an initializer. 4008 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 4009 representing the width of the bit-field. 4010 4011 In the TYPENAME case, DECLARATOR is really an absolute declarator. 4012 It may also be so in the PARM case, for a prototype where the 4013 argument type is specified but not the name. 4014 4015 This function is where the complicated C meanings of `static' 4016 and `extern' are interpreted. */ 4017 4018static tree 4019grokdeclarator (const struct c_declarator *declarator, 4020 struct c_declspecs *declspecs, 4021 enum decl_context decl_context, bool initialized, tree *width) 4022{ 4023 tree type = declspecs->type; 4024 bool threadp = declspecs->thread_p; 4025 enum c_storage_class storage_class = declspecs->storage_class; 4026 int constp; 4027 int restrictp; 4028 int volatilep; 4029 int type_quals = TYPE_UNQUALIFIED; 4030 const char *name, *orig_name; 4031 tree typedef_type = 0; 4032 bool funcdef_flag = false; 4033 bool funcdef_syntax = false; 4034 int size_varies = 0; 4035 tree decl_attr = declspecs->decl_attr; 4036 int array_ptr_quals = TYPE_UNQUALIFIED; 4037 tree array_ptr_attrs = NULL_TREE; 4038 int array_parm_static = 0; 4039 bool array_parm_vla_unspec_p = false; 4040 tree returned_attrs = NULL_TREE; 4041 bool bitfield = width != NULL; 4042 tree element_type; 4043 struct c_arg_info *arg_info = 0; 4044 4045 if (decl_context == FUNCDEF) 4046 funcdef_flag = true, decl_context = NORMAL; 4047 4048 /* Look inside a declarator for the name being declared 4049 and get it as a string, for an error message. */ 4050 { 4051 const struct c_declarator *decl = declarator; 4052 name = 0; 4053 4054 while (decl) 4055 switch (decl->kind) 4056 { 4057 case cdk_function: 4058 case cdk_array: 4059 case cdk_pointer: 4060 funcdef_syntax = (decl->kind == cdk_function); 4061 decl = decl->declarator; 4062 break; 4063 4064 case cdk_attrs: 4065 decl = decl->declarator; 4066 break; 4067 4068 case cdk_id: 4069 if (decl->u.id) 4070 name = IDENTIFIER_POINTER (decl->u.id); 4071 decl = 0; 4072 break; 4073 4074 default: 4075 gcc_unreachable (); 4076 } 4077 orig_name = name; 4078 if (name == 0) 4079 name = "type name"; 4080 } 4081 4082 /* A function definition's declarator must have the form of 4083 a function declarator. */ 4084 4085 if (funcdef_flag && !funcdef_syntax) 4086 return 0; 4087 4088 /* If this looks like a function definition, make it one, 4089 even if it occurs where parms are expected. 4090 Then store_parm_decls will reject it and not use it as a parm. */ 4091 if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag) 4092 decl_context = PARM; 4093 4094 if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS) 4095 warn_deprecated_use (declspecs->type); 4096 4097 if ((decl_context == NORMAL || decl_context == FIELD) 4098 && current_scope == file_scope 4099 && variably_modified_type_p (type, NULL_TREE)) 4100 { 4101 error ("variably modified %qs at file scope", name); 4102 type = integer_type_node; 4103 } 4104 4105 typedef_type = type; 4106 size_varies = C_TYPE_VARIABLE_SIZE (type); 4107 4108 /* Diagnose defaulting to "int". */ 4109 4110 if (declspecs->default_int_p && !in_system_header) 4111 { 4112 /* Issue a warning if this is an ISO C 99 program or if 4113 -Wreturn-type and this is a function, or if -Wimplicit; 4114 prefer the former warning since it is more explicit. */ 4115 if ((warn_implicit_int || warn_return_type || flag_isoc99) 4116 && funcdef_flag) 4117 warn_about_return_type = 1; 4118 else if (warn_implicit_int || flag_isoc99) 4119 pedwarn_c99 ("type defaults to %<int%> in declaration of %qs", name); 4120 } 4121 4122 /* Adjust the type if a bit-field is being declared, 4123 -funsigned-bitfields applied and the type is not explicitly 4124 "signed". */ 4125 if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p 4126 && TREE_CODE (type) == INTEGER_TYPE) 4127 type = c_common_unsigned_type (type); 4128 4129 /* Figure out the type qualifiers for the declaration. There are 4130 two ways a declaration can become qualified. One is something 4131 like `const int i' where the `const' is explicit. Another is 4132 something like `typedef const int CI; CI i' where the type of the 4133 declaration contains the `const'. A third possibility is that 4134 there is a type qualifier on the element type of a typedefed 4135 array type, in which case we should extract that qualifier so 4136 that c_apply_type_quals_to_decls receives the full list of 4137 qualifiers to work with (C90 is not entirely clear about whether 4138 duplicate qualifiers should be diagnosed in this case, but it 4139 seems most appropriate to do so). */ 4140 element_type = strip_array_types (type); 4141 constp = declspecs->const_p + TYPE_READONLY (element_type); 4142 restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type); 4143 volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type); 4144 if (pedantic && !flag_isoc99) 4145 { 4146 if (constp > 1) 4147 pedwarn ("duplicate %<const%>"); 4148 if (restrictp > 1) 4149 pedwarn ("duplicate %<restrict%>"); 4150 if (volatilep > 1) 4151 pedwarn ("duplicate %<volatile%>"); 4152 } 4153 if (!flag_gen_aux_info && (TYPE_QUALS (element_type))) 4154 type = TYPE_MAIN_VARIANT (type); 4155 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 4156 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 4157 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 4158 4159 /* Warn about storage classes that are invalid for certain 4160 kinds of declarations (parameters, typenames, etc.). */ 4161 4162 if (funcdef_flag 4163 && (threadp 4164 || storage_class == csc_auto 4165 || storage_class == csc_register 4166 || storage_class == csc_typedef)) 4167 { 4168 if (storage_class == csc_auto 4169 && (pedantic || current_scope == file_scope)) 4170 pedwarn ("function definition declared %<auto%>"); 4171 if (storage_class == csc_register) 4172 error ("function definition declared %<register%>"); 4173 if (storage_class == csc_typedef) 4174 error ("function definition declared %<typedef%>"); 4175 if (threadp) 4176 error ("function definition declared %<__thread%>"); 4177 threadp = false; 4178 if (storage_class == csc_auto 4179 || storage_class == csc_register 4180 || storage_class == csc_typedef) 4181 storage_class = csc_none; 4182 } 4183 else if (decl_context != NORMAL && (storage_class != csc_none || threadp)) 4184 { 4185 if (decl_context == PARM && storage_class == csc_register) 4186 ; 4187 else 4188 { 4189 switch (decl_context) 4190 { 4191 case FIELD: 4192 error ("storage class specified for structure field %qs", 4193 name); 4194 break; 4195 case PARM: 4196 error ("storage class specified for parameter %qs", name); 4197 break; 4198 default: 4199 error ("storage class specified for typename"); 4200 break; 4201 } 4202 storage_class = csc_none; 4203 threadp = false; 4204 } 4205 } 4206 else if (storage_class == csc_extern 4207 && initialized 4208 && !funcdef_flag) 4209 { 4210 /* 'extern' with initialization is invalid if not at file scope. */ 4211 if (current_scope == file_scope) 4212 { 4213 /* It is fine to have 'extern const' when compiling at C 4214 and C++ intersection. */ 4215 if (!(warn_cxx_compat && constp)) 4216 warning (0, "%qs initialized and declared %<extern%>", name); 4217 } 4218 else 4219 error ("%qs has both %<extern%> and initializer", name); 4220 } 4221 else if (current_scope == file_scope) 4222 { 4223 if (storage_class == csc_auto) 4224 error ("file-scope declaration of %qs specifies %<auto%>", name); 4225 if (pedantic && storage_class == csc_register) 4226 pedwarn ("file-scope declaration of %qs specifies %<register%>", name); 4227 } 4228 else 4229 { 4230 if (storage_class == csc_extern && funcdef_flag) 4231 error ("nested function %qs declared %<extern%>", name); 4232 else if (threadp && storage_class == csc_none) 4233 { 4234 error ("function-scope %qs implicitly auto and declared " 4235 "%<__thread%>", 4236 name); 4237 threadp = false; 4238 } 4239 } 4240 4241 /* Now figure out the structure of the declarator proper. 4242 Descend through it, creating more complex types, until we reach 4243 the declared identifier (or NULL_TREE, in an absolute declarator). 4244 At each stage we maintain an unqualified version of the type 4245 together with any qualifiers that should be applied to it with 4246 c_build_qualified_type; this way, array types including 4247 multidimensional array types are first built up in unqualified 4248 form and then the qualified form is created with 4249 TYPE_MAIN_VARIANT pointing to the unqualified form. */ 4250 4251 while (declarator && declarator->kind != cdk_id) 4252 { 4253 if (type == error_mark_node) 4254 { 4255 declarator = declarator->declarator; 4256 continue; 4257 } 4258 4259 /* Each level of DECLARATOR is either a cdk_array (for ...[..]), 4260 a cdk_pointer (for *...), 4261 a cdk_function (for ...(...)), 4262 a cdk_attrs (for nested attributes), 4263 or a cdk_id (for the name being declared 4264 or the place in an absolute declarator 4265 where the name was omitted). 4266 For the last case, we have just exited the loop. 4267 4268 At this point, TYPE is the type of elements of an array, 4269 or for a function to return, or for a pointer to point to. 4270 After this sequence of ifs, TYPE is the type of the 4271 array or function or pointer, and DECLARATOR has had its 4272 outermost layer removed. */ 4273 4274 if (array_ptr_quals != TYPE_UNQUALIFIED 4275 || array_ptr_attrs != NULL_TREE 4276 || array_parm_static) 4277 { 4278 /* Only the innermost declarator (making a parameter be of 4279 array type which is converted to pointer type) 4280 may have static or type qualifiers. */ 4281 error ("static or type qualifiers in non-parameter array declarator"); 4282 array_ptr_quals = TYPE_UNQUALIFIED; 4283 array_ptr_attrs = NULL_TREE; 4284 array_parm_static = 0; 4285 } 4286 4287 switch (declarator->kind) 4288 { 4289 case cdk_attrs: 4290 { 4291 /* A declarator with embedded attributes. */ 4292 tree attrs = declarator->u.attrs; 4293 const struct c_declarator *inner_decl; 4294 int attr_flags = 0; 4295 declarator = declarator->declarator; 4296 inner_decl = declarator; 4297 while (inner_decl->kind == cdk_attrs) 4298 inner_decl = inner_decl->declarator; 4299 if (inner_decl->kind == cdk_id) 4300 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 4301 else if (inner_decl->kind == cdk_function) 4302 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 4303 else if (inner_decl->kind == cdk_array) 4304 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 4305 returned_attrs = decl_attributes (&type, 4306 chainon (returned_attrs, attrs), 4307 attr_flags); 4308 break; 4309 } 4310 case cdk_array: 4311 { 4312 tree itype = NULL_TREE; 4313 tree size = declarator->u.array.dimen; 4314 /* The index is a signed object `sizetype' bits wide. */ 4315 tree index_type = c_common_signed_type (sizetype); 4316 4317 array_ptr_quals = declarator->u.array.quals; 4318 array_ptr_attrs = declarator->u.array.attrs; 4319 array_parm_static = declarator->u.array.static_p; 4320 array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p; 4321 4322 declarator = declarator->declarator; 4323 4324 /* Check for some types that there cannot be arrays of. */ 4325 4326 if (VOID_TYPE_P (type)) 4327 { 4328 error ("declaration of %qs as array of voids", name); 4329 type = error_mark_node; 4330 } 4331 4332 if (TREE_CODE (type) == FUNCTION_TYPE) 4333 { 4334 error ("declaration of %qs as array of functions", name); 4335 type = error_mark_node; 4336 } 4337 4338 if (pedantic && !in_system_header && flexible_array_type_p (type)) 4339 pedwarn ("invalid use of structure with flexible array member"); 4340 4341 if (size == error_mark_node) 4342 type = error_mark_node; 4343 4344 if (type == error_mark_node) 4345 continue; 4346 4347 /* If size was specified, set ITYPE to a range-type for 4348 that size. Otherwise, ITYPE remains null. finish_decl 4349 may figure it out from an initial value. */ 4350 4351 if (size) 4352 { 4353 /* Strip NON_LVALUE_EXPRs since we aren't using as an 4354 lvalue. */ 4355 STRIP_TYPE_NOPS (size); 4356 4357 if (!INTEGRAL_TYPE_P (TREE_TYPE (size))) 4358 { 4359 error ("size of array %qs has non-integer type", name); 4360 size = integer_one_node; 4361 } 4362 4363 if (pedantic && integer_zerop (size)) 4364 pedwarn ("ISO C forbids zero-size array %qs", name); 4365 4366 if (TREE_CODE (size) == INTEGER_CST) 4367 { 4368 constant_expression_warning (size); 4369 if (tree_int_cst_sgn (size) < 0) 4370 { 4371 error ("size of array %qs is negative", name); 4372 size = integer_one_node; 4373 } 4374 } 4375 else if ((decl_context == NORMAL || decl_context == FIELD) 4376 && current_scope == file_scope) 4377 { 4378 error ("variably modified %qs at file scope", name); 4379 size = integer_one_node; 4380 } 4381 else 4382 { 4383 /* Make sure the array size remains visibly 4384 nonconstant even if it is (eg) a const variable 4385 with known value. */ 4386 size_varies = 1; 4387 warn_variable_length_array (orig_name, size); 4388 if (warn_variable_decl) 4389 warning (0, "variable-sized array %qs", name); 4390 } 4391 4392 if (integer_zerop (size)) 4393 { 4394 /* A zero-length array cannot be represented with 4395 an unsigned index type, which is what we'll 4396 get with build_index_type. Create an 4397 open-ended range instead. */ 4398 itype = build_range_type (sizetype, size, NULL_TREE); 4399 } 4400 else 4401 { 4402 /* Arrange for the SAVE_EXPR on the inside of the 4403 MINUS_EXPR, which allows the -1 to get folded 4404 with the +1 that happens when building TYPE_SIZE. */ 4405 if (size_varies) 4406 size = variable_size (size); 4407 4408 /* Compute the maximum valid index, that is, size 4409 - 1. Do the calculation in index_type, so that 4410 if it is a variable the computations will be 4411 done in the proper mode. */ 4412 itype = fold_build2 (MINUS_EXPR, index_type, 4413 convert (index_type, size), 4414 convert (index_type, 4415 size_one_node)); 4416 4417 /* If that overflowed, the array is too big. ??? 4418 While a size of INT_MAX+1 technically shouldn't 4419 cause an overflow (because we subtract 1), the 4420 overflow is recorded during the conversion to 4421 index_type, before the subtraction. Handling 4422 this case seems like an unnecessary 4423 complication. */ 4424 if (TREE_CODE (itype) == INTEGER_CST 4425 && TREE_OVERFLOW (itype)) 4426 { 4427 error ("size of array %qs is too large", name); 4428 type = error_mark_node; 4429 continue; 4430 } 4431 4432 itype = build_index_type (itype); 4433 } 4434 } 4435 else if (decl_context == FIELD) 4436 { 4437 if (pedantic && !flag_isoc99 && !in_system_header) 4438 pedwarn ("ISO C90 does not support flexible array members"); 4439 4440 /* ISO C99 Flexible array members are effectively 4441 identical to GCC's zero-length array extension. */ 4442 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4443 } 4444 else if (decl_context == PARM) 4445 { 4446 if (array_parm_vla_unspec_p) 4447 { 4448 if (! orig_name) 4449 { 4450 /* C99 6.7.5.2p4 */ 4451 error ("%<[*]%> not allowed in other than a declaration"); 4452 } 4453 4454 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 4455 size_varies = 1; 4456 } 4457 } 4458 else if (decl_context == TYPENAME) 4459 { 4460 if (array_parm_vla_unspec_p) 4461 { 4462 /* The error is printed elsewhere. We use this to 4463 avoid messing up with incomplete array types of 4464 the same type, that would otherwise be modified 4465 below. */ 4466 itype = build_range_type (sizetype, size_zero_node, 4467 NULL_TREE); 4468 } 4469 } 4470 4471 /* Complain about arrays of incomplete types. */ 4472 if (!COMPLETE_TYPE_P (type)) 4473 { 4474 error ("array type has incomplete element type"); 4475 type = error_mark_node; 4476 } 4477 else 4478 /* When itype is NULL, a shared incomplete array type is 4479 returned for all array of a given type. Elsewhere we 4480 make sure we don't complete that type before copying 4481 it, but here we want to make sure we don't ever 4482 modify the shared type, so we gcc_assert (itype) 4483 below. */ 4484 type = build_array_type (type, itype); 4485 4486 if (type != error_mark_node) 4487 { 4488 if (size_varies) 4489 { 4490 /* It is ok to modify type here even if itype is 4491 NULL: if size_varies, we're in a 4492 multi-dimensional array and the inner type has 4493 variable size, so the enclosing shared array type 4494 must too. */ 4495 if (size && TREE_CODE (size) == INTEGER_CST) 4496 type 4497 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4498 C_TYPE_VARIABLE_SIZE (type) = 1; 4499 } 4500 4501 /* The GCC extension for zero-length arrays differs from 4502 ISO flexible array members in that sizeof yields 4503 zero. */ 4504 if (size && integer_zerop (size)) 4505 { 4506 gcc_assert (itype); 4507 TYPE_SIZE (type) = bitsize_zero_node; 4508 TYPE_SIZE_UNIT (type) = size_zero_node; 4509 } 4510 if (array_parm_vla_unspec_p) 4511 { 4512 gcc_assert (itype); 4513 /* The type is complete. C99 6.7.5.2p4 */ 4514 TYPE_SIZE (type) = bitsize_zero_node; 4515 TYPE_SIZE_UNIT (type) = size_zero_node; 4516 } 4517 } 4518 4519 if (decl_context != PARM 4520 && (array_ptr_quals != TYPE_UNQUALIFIED 4521 || array_ptr_attrs != NULL_TREE 4522 || array_parm_static)) 4523 { 4524 error ("static or type qualifiers in non-parameter array declarator"); 4525 array_ptr_quals = TYPE_UNQUALIFIED; 4526 array_ptr_attrs = NULL_TREE; 4527 array_parm_static = 0; 4528 } 4529 break; 4530 } 4531 case cdk_function: 4532 { 4533 /* Say it's a definition only for the declarator closest 4534 to the identifier, apart possibly from some 4535 attributes. */ 4536 bool really_funcdef = false; 4537 tree arg_types; 4538 if (funcdef_flag) 4539 { 4540 const struct c_declarator *t = declarator->declarator; 4541 while (t->kind == cdk_attrs) 4542 t = t->declarator; 4543 really_funcdef = (t->kind == cdk_id); 4544 } 4545 4546 /* Declaring a function type. Make sure we have a valid 4547 type for the function to return. */ 4548 if (type == error_mark_node) 4549 continue; 4550 4551 size_varies = 0; 4552 4553 /* Warn about some types functions can't return. */ 4554 if (TREE_CODE (type) == FUNCTION_TYPE) 4555 { 4556 error ("%qs declared as function returning a function", name); 4557 type = integer_type_node; 4558 } 4559 if (TREE_CODE (type) == ARRAY_TYPE) 4560 { 4561 error ("%qs declared as function returning an array", name); 4562 type = integer_type_node; 4563 } 4564 4565 /* Construct the function type and go to the next 4566 inner layer of declarator. */ 4567 arg_info = declarator->u.arg_info; 4568 arg_types = grokparms (arg_info, really_funcdef); 4569 if (really_funcdef) 4570 put_pending_sizes (arg_info->pending_sizes); 4571 4572 /* Type qualifiers before the return type of the function 4573 qualify the return type, not the function type. */ 4574 if (type_quals) 4575 { 4576 /* Type qualifiers on a function return type are 4577 normally permitted by the standard but have no 4578 effect, so give a warning at -Wreturn-type. 4579 Qualifiers on a void return type are banned on 4580 function definitions in ISO C; GCC used to used 4581 them for noreturn functions. */ 4582 if (VOID_TYPE_P (type) && really_funcdef) 4583 pedwarn ("function definition has qualified void return type"); 4584 else 4585 warning (OPT_Wreturn_type, 4586 "type qualifiers ignored on function return type"); 4587 4588 type = c_build_qualified_type (type, type_quals); 4589 } 4590 type_quals = TYPE_UNQUALIFIED; 4591 4592 type = build_function_type (type, arg_types); 4593 declarator = declarator->declarator; 4594 4595 /* Set the TYPE_CONTEXTs for each tagged type which is local to 4596 the formal parameter list of this FUNCTION_TYPE to point to 4597 the FUNCTION_TYPE node itself. */ 4598 { 4599 tree link; 4600 4601 for (link = arg_info->tags; 4602 link; 4603 link = TREE_CHAIN (link)) 4604 TYPE_CONTEXT (TREE_VALUE (link)) = type; 4605 } 4606 break; 4607 } 4608 case cdk_pointer: 4609 { 4610 /* Merge any constancy or volatility into the target type 4611 for the pointer. */ 4612 4613 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4614 && type_quals) 4615 pedwarn ("ISO C forbids qualified function types"); 4616 if (type_quals) 4617 type = c_build_qualified_type (type, type_quals); 4618 size_varies = 0; 4619 4620 /* When the pointed-to type involves components of variable size, 4621 care must be taken to ensure that the size evaluation code is 4622 emitted early enough to dominate all the possible later uses 4623 and late enough for the variables on which it depends to have 4624 been assigned. 4625 4626 This is expected to happen automatically when the pointed-to 4627 type has a name/declaration of it's own, but special attention 4628 is required if the type is anonymous. 4629 4630 We handle the NORMAL and FIELD contexts here by attaching an 4631 artificial TYPE_DECL to such pointed-to type. This forces the 4632 sizes evaluation at a safe point and ensures it is not deferred 4633 until e.g. within a deeper conditional context. 4634 4635 We expect nothing to be needed here for PARM or TYPENAME. 4636 Pushing a TYPE_DECL at this point for TYPENAME would actually 4637 be incorrect, as we might be in the middle of an expression 4638 with side effects on the pointed-to type size "arguments" prior 4639 to the pointer declaration point and the fake TYPE_DECL in the 4640 enclosing context would force the size evaluation prior to the 4641 side effects. */ 4642 4643 if (!TYPE_NAME (type) 4644 && (decl_context == NORMAL || decl_context == FIELD) 4645 && variably_modified_type_p (type, NULL_TREE)) 4646 { 4647 tree decl = build_decl (TYPE_DECL, NULL_TREE, type); 4648 DECL_ARTIFICIAL (decl) = 1; 4649 pushdecl (decl); 4650 finish_decl (decl, NULL_TREE, NULL_TREE); 4651 TYPE_NAME (type) = decl; 4652 } 4653 4654 type = build_pointer_type (type); 4655 4656 /* Process type qualifiers (such as const or volatile) 4657 that were given inside the `*'. */ 4658 type_quals = declarator->u.pointer_quals; 4659 4660 declarator = declarator->declarator; 4661 break; 4662 } 4663 default: 4664 gcc_unreachable (); 4665 } 4666 } 4667 4668 /* Now TYPE has the actual type, apart from any qualifiers in 4669 TYPE_QUALS. */ 4670 4671 /* Check the type and width of a bit-field. */ 4672 if (bitfield) 4673 check_bitfield_type_and_width (&type, width, orig_name); 4674 4675 /* Did array size calculations overflow? */ 4676 4677 if (TREE_CODE (type) == ARRAY_TYPE 4678 && COMPLETE_TYPE_P (type) 4679 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 4680 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 4681 { 4682 error ("size of array %qs is too large", name); 4683 /* If we proceed with the array type as it is, we'll eventually 4684 crash in tree_low_cst(). */ 4685 type = error_mark_node; 4686 } 4687 4688 /* If this is declaring a typedef name, return a TYPE_DECL. */ 4689 4690 if (storage_class == csc_typedef) 4691 { 4692 tree decl; 4693 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4694 && type_quals) 4695 pedwarn ("ISO C forbids qualified function types"); 4696 if (type_quals) 4697 type = c_build_qualified_type (type, type_quals); 4698 decl = build_decl (TYPE_DECL, declarator->u.id, type); 4699 if (declspecs->explicit_signed_p) 4700 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 4701 decl_attributes (&decl, returned_attrs, 0); 4702 if (declspecs->inline_p) 4703 pedwarn ("typedef %q+D declared %<inline%>", decl); 4704 return decl; 4705 } 4706 4707 /* If this is a type name (such as, in a cast or sizeof), 4708 compute the type and return it now. */ 4709 4710 if (decl_context == TYPENAME) 4711 { 4712 /* Note that the grammar rejects storage classes in typenames 4713 and fields. */ 4714 gcc_assert (storage_class == csc_none && !threadp 4715 && !declspecs->inline_p); 4716 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4717 && type_quals) 4718 pedwarn ("ISO C forbids const or volatile function types"); 4719 if (type_quals) 4720 type = c_build_qualified_type (type, type_quals); 4721 decl_attributes (&type, returned_attrs, 0); 4722 return type; 4723 } 4724 4725 if (pedantic && decl_context == FIELD 4726 && variably_modified_type_p (type, NULL_TREE)) 4727 { 4728 /* C99 6.7.2.1p8 */ 4729 pedwarn ("a member of a structure or union cannot have a variably modified type"); 4730 } 4731 4732 /* Aside from typedefs and type names (handle above), 4733 `void' at top level (not within pointer) 4734 is allowed only in public variables. 4735 We don't complain about parms either, but that is because 4736 a better error message can be made later. */ 4737 4738 if (VOID_TYPE_P (type) && decl_context != PARM 4739 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 4740 && (storage_class == csc_extern 4741 || (current_scope == file_scope 4742 && !(storage_class == csc_static 4743 || storage_class == csc_register))))) 4744 { 4745 error ("variable or field %qs declared void", name); 4746 type = integer_type_node; 4747 } 4748 4749 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 4750 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 4751 4752 { 4753 tree decl; 4754 4755 if (decl_context == PARM) 4756 { 4757 tree type_as_written; 4758 tree promoted_type; 4759 4760 /* A parameter declared as an array of T is really a pointer to T. 4761 One declared as a function is really a pointer to a function. */ 4762 4763 if (TREE_CODE (type) == ARRAY_TYPE) 4764 { 4765 /* Transfer const-ness of array into that of type pointed to. */ 4766 type = TREE_TYPE (type); 4767 if (type_quals) 4768 type = c_build_qualified_type (type, type_quals); 4769 type = build_pointer_type (type); 4770 type_quals = array_ptr_quals; 4771 4772 /* We don't yet implement attributes in this context. */ 4773 if (array_ptr_attrs != NULL_TREE) 4774 warning (OPT_Wattributes, 4775 "attributes in parameter array declarator ignored"); 4776 4777 size_varies = 0; 4778 } 4779 else if (TREE_CODE (type) == FUNCTION_TYPE) 4780 { 4781 if (pedantic && type_quals) 4782 pedwarn ("ISO C forbids qualified function types"); 4783 if (type_quals) 4784 type = c_build_qualified_type (type, type_quals); 4785 type = build_pointer_type (type); 4786 type_quals = TYPE_UNQUALIFIED; 4787 } 4788 else if (type_quals) 4789 type = c_build_qualified_type (type, type_quals); 4790 4791 type_as_written = type; 4792 4793 decl = build_decl (PARM_DECL, declarator->u.id, type); 4794 if (size_varies) 4795 C_DECL_VARIABLE_SIZE (decl) = 1; 4796 4797 /* Compute the type actually passed in the parmlist, 4798 for the case where there is no prototype. 4799 (For example, shorts and chars are passed as ints.) 4800 When there is a prototype, this is overridden later. */ 4801 4802 if (type == error_mark_node) 4803 promoted_type = type; 4804 else 4805 promoted_type = c_type_promotes_to (type); 4806 4807 DECL_ARG_TYPE (decl) = promoted_type; 4808 if (declspecs->inline_p) 4809 pedwarn ("parameter %q+D declared %<inline%>", decl); 4810 } 4811 else if (decl_context == FIELD) 4812 { 4813 /* Note that the grammar rejects storage classes in typenames 4814 and fields. */ 4815 gcc_assert (storage_class == csc_none && !threadp 4816 && !declspecs->inline_p); 4817 4818 /* Structure field. It may not be a function. */ 4819 4820 if (TREE_CODE (type) == FUNCTION_TYPE) 4821 { 4822 error ("field %qs declared as a function", name); 4823 type = build_pointer_type (type); 4824 } 4825 else if (TREE_CODE (type) != ERROR_MARK 4826 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 4827 { 4828 error ("field %qs has incomplete type", name); 4829 type = error_mark_node; 4830 } 4831 type = c_build_qualified_type (type, type_quals); 4832 decl = build_decl (FIELD_DECL, declarator->u.id, type); 4833 DECL_NONADDRESSABLE_P (decl) = bitfield; 4834 4835 if (size_varies) 4836 C_DECL_VARIABLE_SIZE (decl) = 1; 4837 } 4838 else if (TREE_CODE (type) == FUNCTION_TYPE) 4839 { 4840 if (storage_class == csc_register || threadp) 4841 { 4842 error ("invalid storage class for function %qs", name); 4843 } 4844 else if (current_scope != file_scope) 4845 { 4846 /* Function declaration not at file scope. Storage 4847 classes other than `extern' are not allowed, C99 4848 6.7.1p5, and `extern' makes no difference. However, 4849 GCC allows 'auto', perhaps with 'inline', to support 4850 nested functions. */ 4851 if (storage_class == csc_auto) 4852 { 4853 if (pedantic) 4854 pedwarn ("invalid storage class for function %qs", name); 4855 } 4856 else if (storage_class == csc_static) 4857 { 4858 error ("invalid storage class for function %qs", name); 4859 if (funcdef_flag) 4860 storage_class = declspecs->storage_class = csc_none; 4861 else 4862 return 0; 4863 } 4864 } 4865 4866 decl = build_decl (FUNCTION_DECL, declarator->u.id, type); 4867 decl = build_decl_attribute_variant (decl, decl_attr); 4868 4869 DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl); 4870 4871 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 4872 pedwarn ("ISO C forbids qualified function types"); 4873 4874 /* GNU C interprets a volatile-qualified function type to indicate 4875 that the function does not return. */ 4876 if ((type_quals & TYPE_QUAL_VOLATILE) 4877 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 4878 warning (0, "%<noreturn%> function returns non-void value"); 4879 4880 /* Every function declaration is an external reference 4881 (DECL_EXTERNAL) except for those which are not at file 4882 scope and are explicitly declared "auto". This is 4883 forbidden by standard C (C99 6.7.1p5) and is interpreted by 4884 GCC to signify a forward declaration of a nested function. */ 4885 if (storage_class == csc_auto && current_scope != file_scope) 4886 DECL_EXTERNAL (decl) = 0; 4887 /* In C99, a function which is declared 'inline' with 'extern' 4888 is not an external reference (which is confusing). It 4889 means that the later definition of the function must be output 4890 in this file, C99 6.7.4p6. In GNU C89, a function declared 4891 'extern inline' is an external reference. */ 4892 else if (declspecs->inline_p && storage_class != csc_static) 4893 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 4894 == flag_gnu89_inline); 4895 else 4896 DECL_EXTERNAL (decl) = !initialized; 4897 4898 /* Record absence of global scope for `static' or `auto'. */ 4899 TREE_PUBLIC (decl) 4900 = !(storage_class == csc_static || storage_class == csc_auto); 4901 4902 /* For a function definition, record the argument information 4903 block where store_parm_decls will look for it. */ 4904 if (funcdef_flag) 4905 current_function_arg_info = arg_info; 4906 4907 if (declspecs->default_int_p) 4908 C_FUNCTION_IMPLICIT_INT (decl) = 1; 4909 4910 /* Record presence of `inline', if it is reasonable. */ 4911 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 4912 { 4913 if (declspecs->inline_p) 4914 pedwarn ("cannot inline function %<main%>"); 4915 } 4916 else if (declspecs->inline_p) 4917 { 4918 /* Record that the function is declared `inline'. */ 4919 DECL_DECLARED_INLINE_P (decl) = 1; 4920 4921 /* Do not mark bare declarations as DECL_INLINE. Doing so 4922 in the presence of multiple declarations can result in 4923 the abstract origin pointing between the declarations, 4924 which will confuse dwarf2out. */ 4925 if (initialized) 4926 DECL_INLINE (decl) = 1; 4927 } 4928 /* If -finline-functions, assume it can be inlined. This does 4929 two things: let the function be deferred until it is actually 4930 needed, and let dwarf2 know that the function is inlinable. */ 4931 else if (flag_inline_trees == 2 && initialized) 4932 DECL_INLINE (decl) = 1; 4933 } 4934 else 4935 { 4936 /* It's a variable. */ 4937 /* An uninitialized decl with `extern' is a reference. */ 4938 int extern_ref = !initialized && storage_class == csc_extern; 4939 4940 type = c_build_qualified_type (type, type_quals); 4941 4942 /* C99 6.2.2p7: It is invalid (compile-time undefined 4943 behavior) to create an 'extern' declaration for a 4944 variable if there is a global declaration that is 4945 'static' and the global declaration is not visible. 4946 (If the static declaration _is_ currently visible, 4947 the 'extern' declaration is taken to refer to that decl.) */ 4948 if (extern_ref && current_scope != file_scope) 4949 { 4950 tree global_decl = identifier_global_value (declarator->u.id); 4951 tree visible_decl = lookup_name (declarator->u.id); 4952 4953 if (global_decl 4954 && global_decl != visible_decl 4955 && TREE_CODE (global_decl) == VAR_DECL 4956 && !TREE_PUBLIC (global_decl)) 4957 error ("variable previously declared %<static%> redeclared " 4958 "%<extern%>"); 4959 } 4960 4961 decl = build_decl (VAR_DECL, declarator->u.id, type); 4962 DECL_SOURCE_LOCATION (decl) = declarator->id_loc; 4963 if (size_varies) 4964 C_DECL_VARIABLE_SIZE (decl) = 1; 4965 4966 if (declspecs->inline_p) 4967 pedwarn ("variable %q+D declared %<inline%>", decl); 4968 4969 /* At file scope, an initialized extern declaration may follow 4970 a static declaration. In that case, DECL_EXTERNAL will be 4971 reset later in start_decl. */ 4972 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 4973 4974 /* At file scope, the presence of a `static' or `register' storage 4975 class specifier, or the absence of all storage class specifiers 4976 makes this declaration a definition (perhaps tentative). Also, 4977 the absence of `static' makes it public. */ 4978 if (current_scope == file_scope) 4979 { 4980 TREE_PUBLIC (decl) = storage_class != csc_static; 4981 TREE_STATIC (decl) = !extern_ref; 4982 } 4983 /* Not at file scope, only `static' makes a static definition. */ 4984 else 4985 { 4986 TREE_STATIC (decl) = (storage_class == csc_static); 4987 TREE_PUBLIC (decl) = extern_ref; 4988 } 4989 4990 if (threadp) 4991 { 4992 if (targetm.have_tls) 4993 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 4994 else 4995 /* A mere warning is sure to result in improper semantics 4996 at runtime. Don't bother to allow this to compile. */ 4997 error ("thread-local storage not supported for this target"); 4998 } 4999 } 5000 5001 if (storage_class == csc_extern 5002 && variably_modified_type_p (type, NULL_TREE)) 5003 { 5004 /* C99 6.7.5.2p2 */ 5005 error ("object with variably modified type must have no linkage"); 5006 } 5007 5008 /* Record `register' declaration for warnings on & 5009 and in case doing stupid register allocation. */ 5010 5011 if (storage_class == csc_register) 5012 { 5013 C_DECL_REGISTER (decl) = 1; 5014 DECL_REGISTER (decl) = 1; 5015 } 5016 5017 /* Record constancy and volatility. */ 5018 c_apply_type_quals_to_decl (type_quals, decl); 5019 5020 /* If a type has volatile components, it should be stored in memory. 5021 Otherwise, the fact that those components are volatile 5022 will be ignored, and would even crash the compiler. 5023 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 5024 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 5025 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 5026 || TREE_CODE (decl) == RESULT_DECL)) 5027 { 5028 /* It is not an error for a structure with volatile fields to 5029 be declared register, but reset DECL_REGISTER since it 5030 cannot actually go in a register. */ 5031 int was_reg = C_DECL_REGISTER (decl); 5032 C_DECL_REGISTER (decl) = 0; 5033 DECL_REGISTER (decl) = 0; 5034 c_mark_addressable (decl); 5035 C_DECL_REGISTER (decl) = was_reg; 5036 } 5037 5038 /* This is the earliest point at which we might know the assembler 5039 name of a variable. Thus, if it's known before this, die horribly. */ 5040 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 5041 5042 decl_attributes (&decl, returned_attrs, 0); 5043 5044 return decl; 5045 } 5046} 5047 5048/* Decode the parameter-list info for a function type or function definition. 5049 The argument is the value returned by `get_parm_info' (or made in c-parse.c 5050 if there is an identifier list instead of a parameter decl list). 5051 These two functions are separate because when a function returns 5052 or receives functions then each is called multiple times but the order 5053 of calls is different. The last call to `grokparms' is always the one 5054 that contains the formal parameter names of a function definition. 5055 5056 Return a list of arg types to use in the FUNCTION_TYPE for this function. 5057 5058 FUNCDEF_FLAG is true for a function definition, false for 5059 a mere declaration. A nonempty identifier-list gets an error message 5060 when FUNCDEF_FLAG is false. */ 5061 5062static tree 5063grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 5064{ 5065 tree arg_types = arg_info->types; 5066 5067 if (funcdef_flag && arg_info->had_vla_unspec) 5068 { 5069 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 5070 /* C99 6.7.5.2p4 */ 5071 error ("%<[*]%> not allowed in other than function prototype scope"); 5072 } 5073 5074 if (arg_types == 0 && !funcdef_flag && !in_system_header) 5075 warning (OPT_Wstrict_prototypes, 5076 "function declaration isn%'t a prototype"); 5077 5078 if (arg_types == error_mark_node) 5079 return 0; /* don't set TYPE_ARG_TYPES in this case */ 5080 5081 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 5082 { 5083 if (!funcdef_flag) 5084 pedwarn ("parameter names (without types) in function declaration"); 5085 5086 arg_info->parms = arg_info->types; 5087 arg_info->types = 0; 5088 return 0; 5089 } 5090 else 5091 { 5092 tree parm, type, typelt; 5093 unsigned int parmno; 5094 5095 /* If there is a parameter of incomplete type in a definition, 5096 this is an error. In a declaration this is valid, and a 5097 struct or union type may be completed later, before any calls 5098 or definition of the function. In the case where the tag was 5099 first declared within the parameter list, a warning has 5100 already been given. If a parameter has void type, then 5101 however the function cannot be defined or called, so 5102 warn. */ 5103 5104 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 5105 parm; 5106 parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 5107 { 5108 type = TREE_VALUE (typelt); 5109 if (type == error_mark_node) 5110 continue; 5111 5112 if (!COMPLETE_TYPE_P (type)) 5113 { 5114 if (funcdef_flag) 5115 { 5116 if (DECL_NAME (parm)) 5117 error ("parameter %u (%q+D) has incomplete type", 5118 parmno, parm); 5119 else 5120 error ("%Jparameter %u has incomplete type", 5121 parm, parmno); 5122 5123 TREE_VALUE (typelt) = error_mark_node; 5124 TREE_TYPE (parm) = error_mark_node; 5125 } 5126 else if (VOID_TYPE_P (type)) 5127 { 5128 if (DECL_NAME (parm)) 5129 warning (0, "parameter %u (%q+D) has void type", 5130 parmno, parm); 5131 else 5132 warning (0, "%Jparameter %u has void type", 5133 parm, parmno); 5134 } 5135 } 5136 5137 if (DECL_NAME (parm) && TREE_USED (parm)) 5138 warn_if_shadowing (parm); 5139 } 5140 return arg_types; 5141 } 5142} 5143 5144/* Take apart the current scope and return a c_arg_info structure with 5145 info on a parameter list just parsed. 5146 5147 This structure is later fed to 'grokparms' and 'store_parm_decls'. 5148 5149 ELLIPSIS being true means the argument list ended in '...' so don't 5150 append a sentinel (void_list_node) to the end of the type-list. */ 5151 5152struct c_arg_info * 5153get_parm_info (bool ellipsis) 5154{ 5155 struct c_binding *b = current_scope->bindings; 5156 struct c_arg_info *arg_info = XOBNEW (&parser_obstack, 5157 struct c_arg_info); 5158 tree parms = 0; 5159 tree tags = 0; 5160 tree types = 0; 5161 tree others = 0; 5162 5163 static bool explained_incomplete_types = false; 5164 bool gave_void_only_once_err = false; 5165 5166 arg_info->parms = 0; 5167 arg_info->tags = 0; 5168 arg_info->types = 0; 5169 arg_info->others = 0; 5170 arg_info->pending_sizes = 0; 5171 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 5172 5173 /* The bindings in this scope must not get put into a block. 5174 We will take care of deleting the binding nodes. */ 5175 current_scope->bindings = 0; 5176 5177 /* This function is only called if there was *something* on the 5178 parameter list. */ 5179 gcc_assert (b); 5180 5181 /* A parameter list consisting solely of 'void' indicates that the 5182 function takes no arguments. But if the 'void' is qualified 5183 (by 'const' or 'volatile'), or has a storage class specifier 5184 ('register'), then the behavior is undefined; issue an error. 5185 Typedefs for 'void' are OK (see DR#157). */ 5186 if (b->prev == 0 /* one binding */ 5187 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 5188 && !DECL_NAME (b->decl) /* anonymous */ 5189 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 5190 { 5191 if (TREE_THIS_VOLATILE (b->decl) 5192 || TREE_READONLY (b->decl) 5193 || C_DECL_REGISTER (b->decl)) 5194 error ("%<void%> as only parameter may not be qualified"); 5195 5196 /* There cannot be an ellipsis. */ 5197 if (ellipsis) 5198 error ("%<void%> must be the only parameter"); 5199 5200 arg_info->types = void_list_node; 5201 return arg_info; 5202 } 5203 5204 if (!ellipsis) 5205 types = void_list_node; 5206 5207 /* Break up the bindings list into parms, tags, types, and others; 5208 apply sanity checks; purge the name-to-decl bindings. */ 5209 while (b) 5210 { 5211 tree decl = b->decl; 5212 tree type = TREE_TYPE (decl); 5213 const char *keyword; 5214 5215 switch (TREE_CODE (decl)) 5216 { 5217 case PARM_DECL: 5218 if (b->id) 5219 { 5220 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5221 I_SYMBOL_BINDING (b->id) = b->shadowed; 5222 } 5223 5224 /* Check for forward decls that never got their actual decl. */ 5225 if (TREE_ASM_WRITTEN (decl)) 5226 error ("parameter %q+D has just a forward declaration", decl); 5227 /* Check for (..., void, ...) and issue an error. */ 5228 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 5229 { 5230 if (!gave_void_only_once_err) 5231 { 5232 error ("%<void%> must be the only parameter"); 5233 gave_void_only_once_err = true; 5234 } 5235 } 5236 else 5237 { 5238 /* Valid parameter, add it to the list. */ 5239 TREE_CHAIN (decl) = parms; 5240 parms = decl; 5241 5242 /* Since there is a prototype, args are passed in their 5243 declared types. The back end may override this later. */ 5244 DECL_ARG_TYPE (decl) = type; 5245 types = tree_cons (0, type, types); 5246 } 5247 break; 5248 5249 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 5250 case UNION_TYPE: keyword = "union"; goto tag; 5251 case RECORD_TYPE: keyword = "struct"; goto tag; 5252 tag: 5253 /* Types may not have tag-names, in which case the type 5254 appears in the bindings list with b->id NULL. */ 5255 if (b->id) 5256 { 5257 gcc_assert (I_TAG_BINDING (b->id) == b); 5258 I_TAG_BINDING (b->id) = b->shadowed; 5259 } 5260 5261 /* Warn about any struct, union or enum tags defined in a 5262 parameter list. The scope of such types is limited to 5263 the parameter list, which is rarely if ever desirable 5264 (it's impossible to call such a function with type- 5265 correct arguments). An anonymous union parm type is 5266 meaningful as a GNU extension, so don't warn for that. */ 5267 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 5268 { 5269 if (b->id) 5270 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5271 warning (0, "%<%s %E%> declared inside parameter list", 5272 keyword, b->id); 5273 else 5274 /* The %s will be one of 'struct', 'union', or 'enum'. */ 5275 warning (0, "anonymous %s declared inside parameter list", 5276 keyword); 5277 5278 if (!explained_incomplete_types) 5279 { 5280 warning (0, "its scope is only this definition or declaration," 5281 " which is probably not what you want"); 5282 explained_incomplete_types = true; 5283 } 5284 } 5285 5286 tags = tree_cons (b->id, decl, tags); 5287 break; 5288 5289 case CONST_DECL: 5290 case TYPE_DECL: 5291 case FUNCTION_DECL: 5292 /* CONST_DECLs appear here when we have an embedded enum, 5293 and TYPE_DECLs appear here when we have an embedded struct 5294 or union. No warnings for this - we already warned about the 5295 type itself. FUNCTION_DECLs appear when there is an implicit 5296 function declaration in the parameter list. */ 5297 5298 TREE_CHAIN (decl) = others; 5299 others = decl; 5300 /* fall through */ 5301 5302 case ERROR_MARK: 5303 /* error_mark_node appears here when we have an undeclared 5304 variable. Just throw it away. */ 5305 if (b->id) 5306 { 5307 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 5308 I_SYMBOL_BINDING (b->id) = b->shadowed; 5309 } 5310 break; 5311 5312 /* Other things that might be encountered. */ 5313 case LABEL_DECL: 5314 case VAR_DECL: 5315 default: 5316 gcc_unreachable (); 5317 } 5318 5319 b = free_binding_and_advance (b); 5320 } 5321 5322 arg_info->parms = parms; 5323 arg_info->tags = tags; 5324 arg_info->types = types; 5325 arg_info->others = others; 5326 arg_info->pending_sizes = get_pending_sizes (); 5327 return arg_info; 5328} 5329 5330/* Get the struct, enum or union (CODE says which) with tag NAME. 5331 Define the tag as a forward-reference if it is not defined. 5332 Return a c_typespec structure for the type specifier. */ 5333 5334struct c_typespec 5335parser_xref_tag (enum tree_code code, tree name) 5336{ 5337 struct c_typespec ret; 5338 /* If a cross reference is requested, look up the type 5339 already defined for this tag and return it. */ 5340 5341 tree ref = lookup_tag (code, name, 0); 5342 /* If this is the right type of tag, return what we found. 5343 (This reference will be shadowed by shadow_tag later if appropriate.) 5344 If this is the wrong type of tag, do not return it. If it was the 5345 wrong type in the same scope, we will have had an error 5346 message already; if in a different scope and declaring 5347 a name, pending_xref_error will give an error message; but if in a 5348 different scope and not declaring a name, this tag should 5349 shadow the previous declaration of a different type of tag, and 5350 this would not work properly if we return the reference found. 5351 (For example, with "struct foo" in an outer scope, "union foo;" 5352 must shadow that tag with a new one of union type.) */ 5353 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 5354 if (ref && TREE_CODE (ref) == code) 5355 { 5356 ret.spec = ref; 5357 return ret; 5358 } 5359 5360 /* If no such tag is yet defined, create a forward-reference node 5361 and record it as the "definition". 5362 When a real declaration of this type is found, 5363 the forward-reference will be altered into a real type. */ 5364 5365 ref = make_node (code); 5366 if (code == ENUMERAL_TYPE) 5367 { 5368 /* Give the type a default layout like unsigned int 5369 to avoid crashing if it does not get defined. */ 5370 TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node); 5371 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 5372 TYPE_USER_ALIGN (ref) = 0; 5373 TYPE_UNSIGNED (ref) = 1; 5374 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 5375 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 5376 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 5377 } 5378 5379 pushtag (name, ref); 5380 5381 ret.spec = ref; 5382 return ret; 5383} 5384 5385/* Get the struct, enum or union (CODE says which) with tag NAME. 5386 Define the tag as a forward-reference if it is not defined. 5387 Return a tree for the type. */ 5388 5389tree 5390xref_tag (enum tree_code code, tree name) 5391{ 5392 return parser_xref_tag (code, name).spec; 5393} 5394 5395/* Make sure that the tag NAME is defined *in the current scope* 5396 at least as a forward reference. 5397 CODE says which kind of tag NAME ought to be. */ 5398 5399tree 5400start_struct (enum tree_code code, tree name) 5401{ 5402 /* If there is already a tag defined at this scope 5403 (as a forward reference), just return it. */ 5404 5405 tree ref = 0; 5406 5407 if (name != 0) 5408 ref = lookup_tag (code, name, 1); 5409 if (ref && TREE_CODE (ref) == code) 5410 { 5411 if (TYPE_SIZE (ref)) 5412 { 5413 if (code == UNION_TYPE) 5414 error ("redefinition of %<union %E%>", name); 5415 else 5416 error ("redefinition of %<struct %E%>", name); 5417 } 5418 else if (C_TYPE_BEING_DEFINED (ref)) 5419 { 5420 if (code == UNION_TYPE) 5421 error ("nested redefinition of %<union %E%>", name); 5422 else 5423 error ("nested redefinition of %<struct %E%>", name); 5424 /* Don't create structures that contain themselves. */ 5425 ref = NULL_TREE; 5426 } 5427 } 5428 5429 /* Otherwise create a forward-reference just so the tag is in scope. */ 5430 5431 if (ref == NULL_TREE || TREE_CODE (ref) != code) 5432 { 5433 ref = make_node (code); 5434 pushtag (name, ref); 5435 } 5436 5437 C_TYPE_BEING_DEFINED (ref) = 1; 5438 TYPE_PACKED (ref) = flag_pack_struct; 5439 return ref; 5440} 5441 5442/* Process the specs, declarator and width (NULL if omitted) 5443 of a structure component, returning a FIELD_DECL node. 5444 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 5445 5446 This is done during the parsing of the struct declaration. 5447 The FIELD_DECL nodes are chained together and the lot of them 5448 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 5449 5450tree 5451grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs, 5452 tree width) 5453{ 5454 tree value; 5455 5456 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 5457 && width == NULL_TREE) 5458 { 5459 /* This is an unnamed decl. 5460 5461 If we have something of the form "union { list } ;" then this 5462 is the anonymous union extension. Similarly for struct. 5463 5464 If this is something of the form "struct foo;", then 5465 If MS extensions are enabled, this is handled as an 5466 anonymous struct. 5467 Otherwise this is a forward declaration of a structure tag. 5468 5469 If this is something of the form "foo;" and foo is a TYPE_DECL, then 5470 If MS extensions are enabled and foo names a structure, then 5471 again this is an anonymous struct. 5472 Otherwise this is an error. 5473 5474 Oh what a horrid tangled web we weave. I wonder if MS consciously 5475 took this from Plan 9 or if it was an accident of implementation 5476 that took root before someone noticed the bug... */ 5477 5478 tree type = declspecs->type; 5479 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 5480 || TREE_CODE (type) == UNION_TYPE); 5481 bool ok = false; 5482 5483 if (type_ok 5484 && (flag_ms_extensions || !declspecs->typedef_p)) 5485 { 5486 if (flag_ms_extensions) 5487 ok = true; 5488 else if (flag_iso) 5489 ok = false; 5490 else if (TYPE_NAME (type) == NULL) 5491 ok = true; 5492 else 5493 ok = false; 5494 } 5495 if (!ok) 5496 { 5497 pedwarn ("declaration does not declare anything"); 5498 return NULL_TREE; 5499 } 5500 if (pedantic) 5501 pedwarn ("ISO C doesn%'t support unnamed structs/unions"); 5502 } 5503 5504 value = grokdeclarator (declarator, declspecs, FIELD, false, 5505 width ? &width : NULL); 5506 5507 finish_decl (value, NULL_TREE, NULL_TREE); 5508 DECL_INITIAL (value) = width; 5509 5510 return value; 5511} 5512 5513/* Generate an error for any duplicate field names in FIELDLIST. Munge 5514 the list such that this does not present a problem later. */ 5515 5516static void 5517detect_field_duplicates (tree fieldlist) 5518{ 5519 tree x, y; 5520 int timeout = 10; 5521 5522 /* First, see if there are more than "a few" fields. 5523 This is trivially true if there are zero or one fields. */ 5524 if (!fieldlist) 5525 return; 5526 x = TREE_CHAIN (fieldlist); 5527 if (!x) 5528 return; 5529 do { 5530 timeout--; 5531 x = TREE_CHAIN (x); 5532 } while (timeout > 0 && x); 5533 5534 /* If there were "few" fields, avoid the overhead of allocating 5535 a hash table. Instead just do the nested traversal thing. */ 5536 if (timeout > 0) 5537 { 5538 for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x)) 5539 if (DECL_NAME (x)) 5540 { 5541 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 5542 if (DECL_NAME (y) == DECL_NAME (x)) 5543 { 5544 error ("duplicate member %q+D", x); 5545 DECL_NAME (x) = NULL_TREE; 5546 } 5547 } 5548 } 5549 else 5550 { 5551 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 5552 void **slot; 5553 5554 for (x = fieldlist; x ; x = TREE_CHAIN (x)) 5555 if ((y = DECL_NAME (x)) != 0) 5556 { 5557 slot = htab_find_slot (htab, y, INSERT); 5558 if (*slot) 5559 { 5560 error ("duplicate member %q+D", x); 5561 DECL_NAME (x) = NULL_TREE; 5562 } 5563 *slot = y; 5564 } 5565 5566 htab_delete (htab); 5567 } 5568} 5569 5570/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 5571 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 5572 ATTRIBUTES are attributes to be applied to the structure. */ 5573 5574tree 5575finish_struct (tree t, tree fieldlist, tree attributes) 5576{ 5577 tree x; 5578 bool toplevel = file_scope == current_scope; 5579 int saw_named_field; 5580 5581 /* If this type was previously laid out as a forward reference, 5582 make sure we lay it out again. */ 5583 5584 TYPE_SIZE (t) = 0; 5585 5586 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5587 5588 if (pedantic) 5589 { 5590 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5591 if (DECL_NAME (x) != 0) 5592 break; 5593 5594 if (x == 0) 5595 { 5596 if (TREE_CODE (t) == UNION_TYPE) 5597 { 5598 if (fieldlist) 5599 pedwarn ("union has no named members"); 5600 else 5601 pedwarn ("union has no members"); 5602 } 5603 else 5604 { 5605 if (fieldlist) 5606 pedwarn ("struct has no named members"); 5607 else 5608 pedwarn ("struct has no members"); 5609 } 5610 } 5611 } 5612 5613 /* Install struct as DECL_CONTEXT of each field decl. 5614 Also process specified field sizes, found in the DECL_INITIAL, 5615 storing 0 there after the type has been changed to precision equal 5616 to its width, rather than the precision of the specified standard 5617 type. (Correct layout requires the original type to have been preserved 5618 until now.) */ 5619 5620 saw_named_field = 0; 5621 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5622 { 5623 if (TREE_TYPE (x) == error_mark_node) 5624 continue; 5625 5626 DECL_CONTEXT (x) = t; 5627 5628 if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 5629 DECL_PACKED (x) = 1; 5630 5631 /* If any field is const, the structure type is pseudo-const. */ 5632 if (TREE_READONLY (x)) 5633 C_TYPE_FIELDS_READONLY (t) = 1; 5634 else 5635 { 5636 /* A field that is pseudo-const makes the structure likewise. */ 5637 tree t1 = TREE_TYPE (x); 5638 while (TREE_CODE (t1) == ARRAY_TYPE) 5639 t1 = TREE_TYPE (t1); 5640 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 5641 && C_TYPE_FIELDS_READONLY (t1)) 5642 C_TYPE_FIELDS_READONLY (t) = 1; 5643 } 5644 5645 /* Any field that is volatile means variables of this type must be 5646 treated in some ways as volatile. */ 5647 if (TREE_THIS_VOLATILE (x)) 5648 C_TYPE_FIELDS_VOLATILE (t) = 1; 5649 5650 /* Any field of nominal variable size implies structure is too. */ 5651 if (C_DECL_VARIABLE_SIZE (x)) 5652 C_TYPE_VARIABLE_SIZE (t) = 1; 5653 5654 if (DECL_INITIAL (x)) 5655 { 5656 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 5657 DECL_SIZE (x) = bitsize_int (width); 5658 DECL_BIT_FIELD (x) = 1; 5659 SET_DECL_C_BIT_FIELD (x); 5660 } 5661 5662 /* Detect flexible array member in an invalid context. */ 5663 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 5664 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 5665 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 5666 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 5667 { 5668 if (TREE_CODE (t) == UNION_TYPE) 5669 { 5670 error ("%Jflexible array member in union", x); 5671 TREE_TYPE (x) = error_mark_node; 5672 } 5673 else if (TREE_CHAIN (x) != NULL_TREE) 5674 { 5675 error ("%Jflexible array member not at end of struct", x); 5676 TREE_TYPE (x) = error_mark_node; 5677 } 5678 else if (!saw_named_field) 5679 { 5680 error ("%Jflexible array member in otherwise empty struct", x); 5681 TREE_TYPE (x) = error_mark_node; 5682 } 5683 } 5684 5685 if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE 5686 && flexible_array_type_p (TREE_TYPE (x))) 5687 pedwarn ("%Jinvalid use of structure with flexible array member", x); 5688 5689 if (DECL_NAME (x)) 5690 saw_named_field = 1; 5691 } 5692 5693 detect_field_duplicates (fieldlist); 5694 5695 /* Now we have the nearly final fieldlist. Record it, 5696 then lay out the structure or union (including the fields). */ 5697 5698 TYPE_FIELDS (t) = fieldlist; 5699 5700 layout_type (t); 5701 5702 /* Give bit-fields their proper types. */ 5703 { 5704 tree *fieldlistp = &fieldlist; 5705 while (*fieldlistp) 5706 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 5707 && TREE_TYPE (*fieldlistp) != error_mark_node) 5708 { 5709 unsigned HOST_WIDE_INT width 5710 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 5711 tree type = TREE_TYPE (*fieldlistp); 5712 if (width != TYPE_PRECISION (type)) 5713 { 5714 TREE_TYPE (*fieldlistp) 5715 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 5716 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 5717 } 5718 DECL_INITIAL (*fieldlistp) = 0; 5719 } 5720 else 5721 fieldlistp = &TREE_CHAIN (*fieldlistp); 5722 } 5723 5724 /* Now we have the truly final field list. 5725 Store it in this type and in the variants. */ 5726 5727 TYPE_FIELDS (t) = fieldlist; 5728 5729 /* If there are lots of fields, sort so we can look through them fast. 5730 We arbitrarily consider 16 or more elts to be "a lot". */ 5731 5732 { 5733 int len = 0; 5734 5735 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5736 { 5737 if (len > 15 || DECL_NAME (x) == NULL) 5738 break; 5739 len += 1; 5740 } 5741 5742 if (len > 15) 5743 { 5744 tree *field_array; 5745 struct lang_type *space; 5746 struct sorted_fields_type *space2; 5747 5748 len += list_length (x); 5749 5750 /* Use the same allocation policy here that make_node uses, to 5751 ensure that this lives as long as the rest of the struct decl. 5752 All decls in an inline function need to be saved. */ 5753 5754 space = GGC_CNEW (struct lang_type); 5755 space2 = GGC_NEWVAR (struct sorted_fields_type, 5756 sizeof (struct sorted_fields_type) + len * sizeof (tree)); 5757 5758 len = 0; 5759 space->s = space2; 5760 field_array = &space2->elts[0]; 5761 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5762 { 5763 field_array[len++] = x; 5764 5765 /* If there is anonymous struct or union, break out of the loop. */ 5766 if (DECL_NAME (x) == NULL) 5767 break; 5768 } 5769 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 5770 if (x == NULL) 5771 { 5772 TYPE_LANG_SPECIFIC (t) = space; 5773 TYPE_LANG_SPECIFIC (t)->s->len = len; 5774 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 5775 qsort (field_array, len, sizeof (tree), field_decl_cmp); 5776 } 5777 } 5778 } 5779 5780 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 5781 { 5782 TYPE_FIELDS (x) = TYPE_FIELDS (t); 5783 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 5784 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 5785 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 5786 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 5787 } 5788 5789 /* If this was supposed to be a transparent union, but we can't 5790 make it one, warn and turn off the flag. */ 5791 if (TREE_CODE (t) == UNION_TYPE 5792 && TYPE_TRANSPARENT_UNION (t) 5793 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 5794 { 5795 TYPE_TRANSPARENT_UNION (t) = 0; 5796 warning (0, "union cannot be made transparent"); 5797 } 5798 5799 /* If this structure or union completes the type of any previous 5800 variable declaration, lay it out and output its rtl. */ 5801 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 5802 x; 5803 x = TREE_CHAIN (x)) 5804 { 5805 tree decl = TREE_VALUE (x); 5806 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 5807 layout_array_type (TREE_TYPE (decl)); 5808 if (TREE_CODE (decl) != TYPE_DECL) 5809 { 5810 layout_decl (decl, 0); 5811 if (c_dialect_objc ()) 5812 objc_check_decl (decl); 5813 rest_of_decl_compilation (decl, toplevel, 0); 5814 if (!toplevel) 5815 expand_decl (decl); 5816 } 5817 } 5818 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 5819 5820 /* Finish debugging output for this type. */ 5821 rest_of_type_compilation (t, toplevel); 5822 5823 /* If we're inside a function proper, i.e. not file-scope and not still 5824 parsing parameters, then arrange for the size of a variable sized type 5825 to be bound now. */ 5826 if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE)) 5827 add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t))); 5828 5829 return t; 5830} 5831 5832/* Lay out the type T, and its element type, and so on. */ 5833 5834static void 5835layout_array_type (tree t) 5836{ 5837 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 5838 layout_array_type (TREE_TYPE (t)); 5839 layout_type (t); 5840} 5841 5842/* Begin compiling the definition of an enumeration type. 5843 NAME is its name (or null if anonymous). 5844 Returns the type object, as yet incomplete. 5845 Also records info about it so that build_enumerator 5846 may be used to declare the individual values as they are read. */ 5847 5848tree 5849start_enum (tree name) 5850{ 5851 tree enumtype = 0; 5852 5853 /* If this is the real definition for a previous forward reference, 5854 fill in the contents in the same object that used to be the 5855 forward reference. */ 5856 5857 if (name != 0) 5858 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1); 5859 5860 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 5861 { 5862 enumtype = make_node (ENUMERAL_TYPE); 5863 pushtag (name, enumtype); 5864 } 5865 5866 if (C_TYPE_BEING_DEFINED (enumtype)) 5867 error ("nested redefinition of %<enum %E%>", name); 5868 5869 C_TYPE_BEING_DEFINED (enumtype) = 1; 5870 5871 if (TYPE_VALUES (enumtype) != 0) 5872 { 5873 /* This enum is a named one that has been declared already. */ 5874 error ("redeclaration of %<enum %E%>", name); 5875 5876 /* Completely replace its old definition. 5877 The old enumerators remain defined, however. */ 5878 TYPE_VALUES (enumtype) = 0; 5879 } 5880 5881 enum_next_value = integer_zero_node; 5882 enum_overflow = 0; 5883 5884 if (flag_short_enums) 5885 TYPE_PACKED (enumtype) = 1; 5886 5887 return enumtype; 5888} 5889 5890/* After processing and defining all the values of an enumeration type, 5891 install their decls in the enumeration type and finish it off. 5892 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 5893 and ATTRIBUTES are the specified attributes. 5894 Returns ENUMTYPE. */ 5895 5896tree 5897finish_enum (tree enumtype, tree values, tree attributes) 5898{ 5899 tree pair, tem; 5900 tree minnode = 0, maxnode = 0; 5901 int precision, unsign; 5902 bool toplevel = (file_scope == current_scope); 5903 struct lang_type *lt; 5904 5905 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5906 5907 /* Calculate the maximum value of any enumerator in this type. */ 5908 5909 if (values == error_mark_node) 5910 minnode = maxnode = integer_zero_node; 5911 else 5912 { 5913 minnode = maxnode = TREE_VALUE (values); 5914 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 5915 { 5916 tree value = TREE_VALUE (pair); 5917 if (tree_int_cst_lt (maxnode, value)) 5918 maxnode = value; 5919 if (tree_int_cst_lt (value, minnode)) 5920 minnode = value; 5921 } 5922 } 5923 5924 /* Construct the final type of this enumeration. It is the same 5925 as one of the integral types - the narrowest one that fits, except 5926 that normally we only go as narrow as int - and signed iff any of 5927 the values are negative. */ 5928 unsign = (tree_int_cst_sgn (minnode) >= 0); 5929 precision = MAX (min_precision (minnode, unsign), 5930 min_precision (maxnode, unsign)); 5931 5932 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 5933 { 5934 tem = c_common_type_for_size (precision, unsign); 5935 if (tem == NULL) 5936 { 5937 warning (0, "enumeration values exceed range of largest integer"); 5938 tem = long_long_integer_type_node; 5939 } 5940 } 5941 else 5942 tem = unsign ? unsigned_type_node : integer_type_node; 5943 5944 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 5945 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 5946 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 5947 TYPE_SIZE (enumtype) = 0; 5948 5949 /* If the precision of the type was specific with an attribute and it 5950 was too small, give an error. Otherwise, use it. */ 5951 if (TYPE_PRECISION (enumtype)) 5952 { 5953 if (precision > TYPE_PRECISION (enumtype)) 5954 error ("specified mode too small for enumeral values"); 5955 } 5956 else 5957 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 5958 5959 layout_type (enumtype); 5960 5961 if (values != error_mark_node) 5962 { 5963 /* Change the type of the enumerators to be the enum type. We 5964 need to do this irrespective of the size of the enum, for 5965 proper type checking. Replace the DECL_INITIALs of the 5966 enumerators, and the value slots of the list, with copies 5967 that have the enum type; they cannot be modified in place 5968 because they may be shared (e.g. integer_zero_node) Finally, 5969 change the purpose slots to point to the names of the decls. */ 5970 for (pair = values; pair; pair = TREE_CHAIN (pair)) 5971 { 5972 tree enu = TREE_PURPOSE (pair); 5973 tree ini = DECL_INITIAL (enu); 5974 5975 TREE_TYPE (enu) = enumtype; 5976 5977 /* The ISO C Standard mandates enumerators to have type int, 5978 even though the underlying type of an enum type is 5979 unspecified. Here we convert any enumerators that fit in 5980 an int to type int, to avoid promotions to unsigned types 5981 when comparing integers with enumerators that fit in the 5982 int range. When -pedantic is given, build_enumerator() 5983 would have already taken care of those that don't fit. */ 5984 if (int_fits_type_p (ini, integer_type_node)) 5985 tem = integer_type_node; 5986 else 5987 tem = enumtype; 5988 ini = convert (tem, ini); 5989 5990 DECL_INITIAL (enu) = ini; 5991 TREE_PURPOSE (pair) = DECL_NAME (enu); 5992 TREE_VALUE (pair) = ini; 5993 } 5994 5995 TYPE_VALUES (enumtype) = values; 5996 } 5997 5998 /* Record the min/max values so that we can warn about bit-field 5999 enumerations that are too small for the values. */ 6000 lt = GGC_CNEW (struct lang_type); 6001 lt->enum_min = minnode; 6002 lt->enum_max = maxnode; 6003 TYPE_LANG_SPECIFIC (enumtype) = lt; 6004 6005 /* Fix up all variant types of this enum type. */ 6006 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 6007 { 6008 if (tem == enumtype) 6009 continue; 6010 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 6011 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 6012 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 6013 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 6014 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 6015 TYPE_MODE (tem) = TYPE_MODE (enumtype); 6016 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 6017 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 6018 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 6019 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 6020 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 6021 } 6022 6023 /* Finish debugging output for this type. */ 6024 rest_of_type_compilation (enumtype, toplevel); 6025 6026 return enumtype; 6027} 6028 6029/* Build and install a CONST_DECL for one value of the 6030 current enumeration type (one that was begun with start_enum). 6031 Return a tree-list containing the CONST_DECL and its value. 6032 Assignment of sequential values by default is handled here. */ 6033 6034tree 6035build_enumerator (tree name, tree value) 6036{ 6037 tree decl, type; 6038 6039 /* Validate and default VALUE. */ 6040 6041 if (value != 0) 6042 { 6043 /* Don't issue more errors for error_mark_node (i.e. an 6044 undeclared identifier) - just ignore the value expression. */ 6045 if (value == error_mark_node) 6046 value = 0; 6047 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value)) 6048 || TREE_CODE (value) != INTEGER_CST) 6049 { 6050 error ("enumerator value for %qE is not an integer constant", name); 6051 value = 0; 6052 } 6053 else 6054 { 6055 value = default_conversion (value); 6056 constant_expression_warning (value); 6057 } 6058 } 6059 6060 /* Default based on previous value. */ 6061 /* It should no longer be possible to have NON_LVALUE_EXPR 6062 in the default. */ 6063 if (value == 0) 6064 { 6065 value = enum_next_value; 6066 if (enum_overflow) 6067 error ("overflow in enumeration values"); 6068 } 6069 6070 if (pedantic && !int_fits_type_p (value, integer_type_node)) 6071 { 6072 pedwarn ("ISO C restricts enumerator values to range of %<int%>"); 6073 /* XXX This causes -pedantic to change the meaning of the program. 6074 Remove? -zw 2004-03-15 */ 6075 value = convert (integer_type_node, value); 6076 } 6077 6078 /* Set basis for default for next value. */ 6079 enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0); 6080 enum_overflow = tree_int_cst_lt (enum_next_value, value); 6081 6082 /* Now create a declaration for the enum value name. */ 6083 6084 type = TREE_TYPE (value); 6085 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 6086 TYPE_PRECISION (integer_type_node)), 6087 (TYPE_PRECISION (type) 6088 >= TYPE_PRECISION (integer_type_node) 6089 && TYPE_UNSIGNED (type))); 6090 6091 decl = build_decl (CONST_DECL, name, type); 6092 DECL_INITIAL (decl) = convert (type, value); 6093 pushdecl (decl); 6094 6095 return tree_cons (decl, value, NULL_TREE); 6096} 6097 6098 6099/* Create the FUNCTION_DECL for a function definition. 6100 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 6101 the declaration; they describe the function's name and the type it returns, 6102 but twisted together in a fashion that parallels the syntax of C. 6103 6104 This function creates a binding context for the function body 6105 as well as setting up the FUNCTION_DECL in current_function_decl. 6106 6107 Returns 1 on success. If the DECLARATOR is not suitable for a function 6108 (it defines a datum instead), we return 0, which tells 6109 yyparse to report a parse error. */ 6110 6111int 6112start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 6113 tree attributes) 6114{ 6115 tree decl1, old_decl; 6116 tree restype, resdecl; 6117 struct c_label_context_se *nstack_se; 6118 struct c_label_context_vm *nstack_vm; 6119 6120 current_function_returns_value = 0; /* Assume, until we see it does. */ 6121 current_function_returns_null = 0; 6122 current_function_returns_abnormally = 0; 6123 warn_about_return_type = 0; 6124 c_switch_stack = NULL; 6125 6126 nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se); 6127 nstack_se->labels_def = NULL; 6128 nstack_se->labels_used = NULL; 6129 nstack_se->next = label_context_stack_se; 6130 label_context_stack_se = nstack_se; 6131 6132 nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm); 6133 nstack_vm->labels_def = NULL; 6134 nstack_vm->labels_used = NULL; 6135 nstack_vm->scope = 0; 6136 nstack_vm->next = label_context_stack_vm; 6137 label_context_stack_vm = nstack_vm; 6138 6139 /* Indicate no valid break/continue context by setting these variables 6140 to some non-null, non-label value. We'll notice and emit the proper 6141 error message in c_finish_bc_stmt. */ 6142 c_break_label = c_cont_label = size_zero_node; 6143 6144 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL); 6145 6146 /* If the declarator is not suitable for a function definition, 6147 cause a syntax error. */ 6148 if (decl1 == 0) 6149 { 6150 label_context_stack_se = label_context_stack_se->next; 6151 label_context_stack_vm = label_context_stack_vm->next; 6152 return 0; 6153 } 6154 6155 decl_attributes (&decl1, attributes, 0); 6156 6157 if (DECL_DECLARED_INLINE_P (decl1) 6158 && DECL_UNINLINABLE (decl1) 6159 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 6160 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 6161 decl1); 6162 6163 /* Handle gnu_inline attribute. */ 6164 if (declspecs->inline_p 6165 && !flag_gnu89_inline 6166 && TREE_CODE (decl1) == FUNCTION_DECL 6167 && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1))) 6168 { 6169 if (declspecs->storage_class != csc_static) 6170 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 6171 } 6172 6173 announce_function (decl1); 6174 6175 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 6176 { 6177 error ("return type is an incomplete type"); 6178 /* Make it return void instead. */ 6179 TREE_TYPE (decl1) 6180 = build_function_type (void_type_node, 6181 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 6182 } 6183 6184 if (warn_about_return_type) 6185 pedwarn_c99 ("return type defaults to %<int%>"); 6186 6187 /* Make the init_value nonzero so pushdecl knows this is not tentative. 6188 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 6189 DECL_INITIAL (decl1) = error_mark_node; 6190 6191 /* If this definition isn't a prototype and we had a prototype declaration 6192 before, copy the arg type info from that prototype. */ 6193 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 6194 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 6195 old_decl = 0; 6196 current_function_prototype_locus = UNKNOWN_LOCATION; 6197 current_function_prototype_built_in = false; 6198 current_function_prototype_arg_types = NULL_TREE; 6199 if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0) 6200 { 6201 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 6202 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6203 TREE_TYPE (TREE_TYPE (old_decl)))) 6204 { 6205 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 6206 TREE_TYPE (decl1)); 6207 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 6208 current_function_prototype_built_in 6209 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 6210 current_function_prototype_arg_types 6211 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 6212 } 6213 if (TREE_PUBLIC (decl1)) 6214 { 6215 /* If there is an external prototype declaration of this 6216 function, record its location but do not copy information 6217 to this decl. This may be an invisible declaration 6218 (built-in or in a scope which has finished) or simply 6219 have more refined argument types than any declaration 6220 found above. */ 6221 struct c_binding *b; 6222 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 6223 if (B_IN_SCOPE (b, external_scope)) 6224 break; 6225 if (b) 6226 { 6227 tree ext_decl, ext_type; 6228 ext_decl = b->decl; 6229 ext_type = b->type ? b->type : TREE_TYPE (ext_decl); 6230 if (TREE_CODE (ext_type) == FUNCTION_TYPE 6231 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 6232 TREE_TYPE (ext_type))) 6233 { 6234 current_function_prototype_locus 6235 = DECL_SOURCE_LOCATION (ext_decl); 6236 current_function_prototype_built_in 6237 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 6238 current_function_prototype_arg_types 6239 = TYPE_ARG_TYPES (ext_type); 6240 } 6241 } 6242 } 6243 } 6244 6245 /* Optionally warn of old-fashioned def with no previous prototype. */ 6246 if (warn_strict_prototypes 6247 && old_decl != error_mark_node 6248 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0 6249 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6250 warning (OPT_Wstrict_prototypes, 6251 "function declaration isn%'t a prototype"); 6252 /* Optionally warn of any global def with no previous prototype. */ 6253 else if (warn_missing_prototypes 6254 && old_decl != error_mark_node 6255 && TREE_PUBLIC (decl1) 6256 && !MAIN_NAME_P (DECL_NAME (decl1)) 6257 && C_DECL_ISNT_PROTOTYPE (old_decl)) 6258 warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1); 6259 /* Optionally warn of any def with no previous prototype 6260 if the function has already been used. */ 6261 else if (warn_missing_prototypes 6262 && old_decl != 0 6263 && old_decl != error_mark_node 6264 && TREE_USED (old_decl) 6265 && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0) 6266 warning (OPT_Wmissing_prototypes, 6267 "%q+D was used with no prototype before its definition", decl1); 6268 /* Optionally warn of any global def with no previous declaration. */ 6269 else if (warn_missing_declarations 6270 && TREE_PUBLIC (decl1) 6271 && old_decl == 0 6272 && !MAIN_NAME_P (DECL_NAME (decl1))) 6273 warning (OPT_Wmissing_declarations, "no previous declaration for %q+D", 6274 decl1); 6275 /* Optionally warn of any def with no previous declaration 6276 if the function has already been used. */ 6277 else if (warn_missing_declarations 6278 && old_decl != 0 6279 && old_decl != error_mark_node 6280 && TREE_USED (old_decl) 6281 && C_DECL_IMPLICIT (old_decl)) 6282 warning (OPT_Wmissing_declarations, 6283 "%q+D was used with no declaration before its definition", decl1); 6284 6285 /* This function exists in static storage. 6286 (This does not mean `static' in the C sense!) */ 6287 TREE_STATIC (decl1) = 1; 6288 6289 /* A nested function is not global. */ 6290 if (current_function_decl != 0) 6291 TREE_PUBLIC (decl1) = 0; 6292 6293 /* This is the earliest point at which we might know the assembler 6294 name of the function. Thus, if it's set before this, die horribly. */ 6295 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 6296 6297 /* If #pragma weak was used, mark the decl weak now. */ 6298 if (current_scope == file_scope) 6299 maybe_apply_pragma_weak (decl1); 6300 6301 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 6302 if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1))) 6303 { 6304 tree args; 6305 int argct = 0; 6306 6307 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 6308 != integer_type_node) 6309 pedwarn ("return type of %q+D is not %<int%>", decl1); 6310 6311 for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args; 6312 args = TREE_CHAIN (args)) 6313 { 6314 tree type = args ? TREE_VALUE (args) : 0; 6315 6316 if (type == void_type_node) 6317 break; 6318 6319 ++argct; 6320 switch (argct) 6321 { 6322 case 1: 6323 if (TYPE_MAIN_VARIANT (type) != integer_type_node) 6324 pedwarn ("first argument of %q+D should be %<int%>", decl1); 6325 break; 6326 6327 case 2: 6328 if (TREE_CODE (type) != POINTER_TYPE 6329 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6330 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6331 != char_type_node)) 6332 pedwarn ("second argument of %q+D should be %<char **%>", 6333 decl1); 6334 break; 6335 6336 case 3: 6337 if (TREE_CODE (type) != POINTER_TYPE 6338 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 6339 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 6340 != char_type_node)) 6341 pedwarn ("third argument of %q+D should probably be " 6342 "%<char **%>", decl1); 6343 break; 6344 } 6345 } 6346 6347 /* It is intentional that this message does not mention the third 6348 argument because it's only mentioned in an appendix of the 6349 standard. */ 6350 if (argct > 0 && (argct < 2 || argct > 3)) 6351 pedwarn ("%q+D takes only zero or two arguments", decl1); 6352 6353 if (!TREE_PUBLIC (decl1)) 6354 pedwarn ("%q+D is normally a non-static function", decl1); 6355 } 6356 6357 /* Record the decl so that the function name is defined. 6358 If we already have a decl for this name, and it is a FUNCTION_DECL, 6359 use the old decl. */ 6360 6361 current_function_decl = pushdecl (decl1); 6362 6363 push_scope (); 6364 declare_parm_level (); 6365 6366 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6367 /* Promote the value to int before returning it. */ 6368 if (c_promoting_integer_type_p (restype)) 6369 { 6370 /* It retains unsignedness if not really getting wider. */ 6371 if (TYPE_UNSIGNED (restype) 6372 && (TYPE_PRECISION (restype) 6373 == TYPE_PRECISION (integer_type_node))) 6374 restype = unsigned_type_node; 6375 else 6376 restype = integer_type_node; 6377 } 6378 6379 resdecl = build_decl (RESULT_DECL, NULL_TREE, restype); 6380 DECL_ARTIFICIAL (resdecl) = 1; 6381 DECL_IGNORED_P (resdecl) = 1; 6382 DECL_RESULT (current_function_decl) = resdecl; 6383 6384 start_fname_decls (); 6385 6386 return 1; 6387} 6388 6389/* Subroutine of store_parm_decls which handles new-style function 6390 definitions (prototype format). The parms already have decls, so we 6391 need only record them as in effect and complain if any redundant 6392 old-style parm decls were written. */ 6393static void 6394store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 6395{ 6396 tree decl; 6397 6398 if (current_scope->bindings) 6399 { 6400 error ("%Jold-style parameter declarations in prototyped " 6401 "function definition", fndecl); 6402 6403 /* Get rid of the old-style declarations. */ 6404 pop_scope (); 6405 push_scope (); 6406 } 6407 /* Don't issue this warning for nested functions, and don't issue this 6408 warning if we got here because ARG_INFO_TYPES was error_mark_node 6409 (this happens when a function definition has just an ellipsis in 6410 its parameter list). */ 6411 else if (!in_system_header && !current_function_scope 6412 && arg_info->types != error_mark_node) 6413 warning (OPT_Wtraditional, 6414 "%Jtraditional C rejects ISO C style function definitions", 6415 fndecl); 6416 6417 /* Now make all the parameter declarations visible in the function body. 6418 We can bypass most of the grunt work of pushdecl. */ 6419 for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl)) 6420 { 6421 DECL_CONTEXT (decl) = current_function_decl; 6422 if (DECL_NAME (decl)) 6423 { 6424 bind (DECL_NAME (decl), decl, current_scope, 6425 /*invisible=*/false, /*nested=*/false); 6426 if (!TREE_USED (decl)) 6427 warn_if_shadowing (decl); 6428 } 6429 else 6430 error ("%Jparameter name omitted", decl); 6431 } 6432 6433 /* Record the parameter list in the function declaration. */ 6434 DECL_ARGUMENTS (fndecl) = arg_info->parms; 6435 6436 /* Now make all the ancillary declarations visible, likewise. */ 6437 for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl)) 6438 { 6439 DECL_CONTEXT (decl) = current_function_decl; 6440 if (DECL_NAME (decl)) 6441 bind (DECL_NAME (decl), decl, current_scope, 6442 /*invisible=*/false, /*nested=*/false); 6443 } 6444 6445 /* And all the tag declarations. */ 6446 for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl)) 6447 if (TREE_PURPOSE (decl)) 6448 bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope, 6449 /*invisible=*/false, /*nested=*/false); 6450} 6451 6452/* Subroutine of store_parm_decls which handles old-style function 6453 definitions (separate parameter list and declarations). */ 6454 6455static void 6456store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 6457{ 6458 struct c_binding *b; 6459 tree parm, decl, last; 6460 tree parmids = arg_info->parms; 6461 struct pointer_set_t *seen_args = pointer_set_create (); 6462 6463 if (!in_system_header) 6464 warning (OPT_Wold_style_definition, "%Jold-style function definition", 6465 fndecl); 6466 6467 /* Match each formal parameter name with its declaration. Save each 6468 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 6469 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6470 { 6471 if (TREE_VALUE (parm) == 0) 6472 { 6473 error ("%Jparameter name missing from parameter list", fndecl); 6474 TREE_PURPOSE (parm) = 0; 6475 continue; 6476 } 6477 6478 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 6479 if (b && B_IN_CURRENT_SCOPE (b)) 6480 { 6481 decl = b->decl; 6482 /* If we got something other than a PARM_DECL it is an error. */ 6483 if (TREE_CODE (decl) != PARM_DECL) 6484 error ("%q+D declared as a non-parameter", decl); 6485 /* If the declaration is already marked, we have a duplicate 6486 name. Complain and ignore the duplicate. */ 6487 else if (pointer_set_contains (seen_args, decl)) 6488 { 6489 error ("multiple parameters named %q+D", decl); 6490 TREE_PURPOSE (parm) = 0; 6491 continue; 6492 } 6493 /* If the declaration says "void", complain and turn it into 6494 an int. */ 6495 else if (VOID_TYPE_P (TREE_TYPE (decl))) 6496 { 6497 error ("parameter %q+D declared with void type", decl); 6498 TREE_TYPE (decl) = integer_type_node; 6499 DECL_ARG_TYPE (decl) = integer_type_node; 6500 layout_decl (decl, 0); 6501 } 6502 warn_if_shadowing (decl); 6503 } 6504 /* If no declaration found, default to int. */ 6505 else 6506 { 6507 decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node); 6508 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 6509 DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl); 6510 pushdecl (decl); 6511 warn_if_shadowing (decl); 6512 6513 if (flag_isoc99) 6514 pedwarn ("type of %q+D defaults to %<int%>", decl); 6515 else if (extra_warnings) 6516 warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl); 6517 } 6518 6519 TREE_PURPOSE (parm) = decl; 6520 pointer_set_insert (seen_args, decl); 6521 } 6522 6523 /* Now examine the parms chain for incomplete declarations 6524 and declarations with no corresponding names. */ 6525 6526 for (b = current_scope->bindings; b; b = b->prev) 6527 { 6528 parm = b->decl; 6529 if (TREE_CODE (parm) != PARM_DECL) 6530 continue; 6531 6532 if (TREE_TYPE (parm) != error_mark_node 6533 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 6534 { 6535 error ("parameter %q+D has incomplete type", parm); 6536 TREE_TYPE (parm) = error_mark_node; 6537 } 6538 6539 if (!pointer_set_contains (seen_args, parm)) 6540 { 6541 error ("declaration for parameter %q+D but no such parameter", parm); 6542 6543 /* Pretend the parameter was not missing. 6544 This gets us to a standard state and minimizes 6545 further error messages. */ 6546 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 6547 } 6548 } 6549 6550 /* Chain the declarations together in the order of the list of 6551 names. Store that chain in the function decl, replacing the 6552 list of names. Update the current scope to match. */ 6553 DECL_ARGUMENTS (fndecl) = 0; 6554 6555 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 6556 if (TREE_PURPOSE (parm)) 6557 break; 6558 if (parm && TREE_PURPOSE (parm)) 6559 { 6560 last = TREE_PURPOSE (parm); 6561 DECL_ARGUMENTS (fndecl) = last; 6562 6563 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 6564 if (TREE_PURPOSE (parm)) 6565 { 6566 TREE_CHAIN (last) = TREE_PURPOSE (parm); 6567 last = TREE_PURPOSE (parm); 6568 } 6569 TREE_CHAIN (last) = 0; 6570 } 6571 6572 pointer_set_destroy (seen_args); 6573 6574 /* If there was a previous prototype, 6575 set the DECL_ARG_TYPE of each argument according to 6576 the type previously specified, and report any mismatches. */ 6577 6578 if (current_function_prototype_arg_types) 6579 { 6580 tree type; 6581 for (parm = DECL_ARGUMENTS (fndecl), 6582 type = current_function_prototype_arg_types; 6583 parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) 6584 != void_type_node)); 6585 parm = TREE_CHAIN (parm), type = TREE_CHAIN (type)) 6586 { 6587 if (parm == 0 || type == 0 6588 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 6589 { 6590 if (current_function_prototype_built_in) 6591 warning (0, "number of arguments doesn%'t match " 6592 "built-in prototype"); 6593 else 6594 { 6595 error ("number of arguments doesn%'t match prototype"); 6596 error ("%Hprototype declaration", 6597 ¤t_function_prototype_locus); 6598 } 6599 break; 6600 } 6601 /* Type for passing arg must be consistent with that 6602 declared for the arg. ISO C says we take the unqualified 6603 type for parameters declared with qualified type. */ 6604 if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 6605 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 6606 { 6607 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 6608 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 6609 { 6610 /* Adjust argument to match prototype. E.g. a previous 6611 `int foo(float);' prototype causes 6612 `int foo(x) float x; {...}' to be treated like 6613 `int foo(float x) {...}'. This is particularly 6614 useful for argument types like uid_t. */ 6615 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 6616 6617 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 6618 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 6619 && TYPE_PRECISION (TREE_TYPE (parm)) 6620 < TYPE_PRECISION (integer_type_node)) 6621 DECL_ARG_TYPE (parm) = integer_type_node; 6622 6623 if (pedantic) 6624 { 6625 /* ??? Is it possible to get here with a 6626 built-in prototype or will it always have 6627 been diagnosed as conflicting with an 6628 old-style definition and discarded? */ 6629 if (current_function_prototype_built_in) 6630 warning (0, "promoted argument %qD " 6631 "doesn%'t match built-in prototype", parm); 6632 else 6633 { 6634 pedwarn ("promoted argument %qD " 6635 "doesn%'t match prototype", parm); 6636 pedwarn ("%Hprototype declaration", 6637 ¤t_function_prototype_locus); 6638 } 6639 } 6640 } 6641 else 6642 { 6643 if (current_function_prototype_built_in) 6644 warning (0, "argument %qD doesn%'t match " 6645 "built-in prototype", parm); 6646 else 6647 { 6648 error ("argument %qD doesn%'t match prototype", parm); 6649 error ("%Hprototype declaration", 6650 ¤t_function_prototype_locus); 6651 } 6652 } 6653 } 6654 } 6655 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 6656 } 6657 6658 /* Otherwise, create a prototype that would match. */ 6659 6660 else 6661 { 6662 tree actual = 0, last = 0, type; 6663 6664 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm)) 6665 { 6666 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 6667 if (last) 6668 TREE_CHAIN (last) = type; 6669 else 6670 actual = type; 6671 last = type; 6672 } 6673 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 6674 if (last) 6675 TREE_CHAIN (last) = type; 6676 else 6677 actual = type; 6678 6679 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 6680 of the type of this function, but we need to avoid having this 6681 affect the types of other similarly-typed functions, so we must 6682 first force the generation of an identical (but separate) type 6683 node for the relevant function type. The new node we create 6684 will be a variant of the main variant of the original function 6685 type. */ 6686 6687 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 6688 6689 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 6690 } 6691} 6692 6693/* Store parameter declarations passed in ARG_INFO into the current 6694 function declaration. */ 6695 6696void 6697store_parm_decls_from (struct c_arg_info *arg_info) 6698{ 6699 current_function_arg_info = arg_info; 6700 store_parm_decls (); 6701} 6702 6703/* Store the parameter declarations into the current function declaration. 6704 This is called after parsing the parameter declarations, before 6705 digesting the body of the function. 6706 6707 For an old-style definition, construct a prototype out of the old-style 6708 parameter declarations and inject it into the function's type. */ 6709 6710void 6711store_parm_decls (void) 6712{ 6713 tree fndecl = current_function_decl; 6714 bool proto; 6715 6716 /* The argument information block for FNDECL. */ 6717 struct c_arg_info *arg_info = current_function_arg_info; 6718 current_function_arg_info = 0; 6719 6720 /* True if this definition is written with a prototype. Note: 6721 despite C99 6.7.5.3p14, we can *not* treat an empty argument 6722 list in a function definition as equivalent to (void) -- an 6723 empty argument list specifies the function has no parameters, 6724 but only (void) sets up a prototype for future calls. */ 6725 proto = arg_info->types != 0; 6726 6727 if (proto) 6728 store_parm_decls_newstyle (fndecl, arg_info); 6729 else 6730 store_parm_decls_oldstyle (fndecl, arg_info); 6731 6732 /* The next call to push_scope will be a function body. */ 6733 6734 next_is_function_body = true; 6735 6736 /* Write a record describing this function definition to the prototypes 6737 file (if requested). */ 6738 6739 gen_aux_info_record (fndecl, 1, 0, proto); 6740 6741 /* Initialize the RTL code for the function. */ 6742 allocate_struct_function (fndecl); 6743 6744 /* Begin the statement tree for this function. */ 6745 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 6746 6747 /* ??? Insert the contents of the pending sizes list into the function 6748 to be evaluated. The only reason left to have this is 6749 void foo(int n, int array[n++]) 6750 because we throw away the array type in favor of a pointer type, and 6751 thus won't naturally see the SAVE_EXPR containing the increment. All 6752 other pending sizes would be handled by gimplify_parameters. */ 6753 { 6754 tree t; 6755 for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t)) 6756 add_stmt (TREE_VALUE (t)); 6757 } 6758 6759 /* Even though we're inside a function body, we still don't want to 6760 call expand_expr to calculate the size of a variable-sized array. 6761 We haven't necessarily assigned RTL to all variables yet, so it's 6762 not safe to try to expand expressions involving them. */ 6763 cfun->x_dont_save_pending_sizes_p = 1; 6764} 6765 6766/* Emit diagnostics that require gimple input for detection. Operate on 6767 FNDECL and all its nested functions. */ 6768 6769static void 6770c_gimple_diagnostics_recursively (tree fndecl) 6771{ 6772 struct cgraph_node *cgn; 6773 6774 /* Handle attribute((warn_unused_result)). Relies on gimple input. */ 6775 c_warn_unused_result (&DECL_SAVED_TREE (fndecl)); 6776 6777 /* Notice when OpenMP structured block constraints are violated. */ 6778 if (flag_openmp) 6779 diagnose_omp_structured_block_errors (fndecl); 6780 6781 /* Finalize all nested functions now. */ 6782 cgn = cgraph_node (fndecl); 6783 for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) 6784 c_gimple_diagnostics_recursively (cgn->decl); 6785} 6786 6787/* Finish up a function declaration and compile that function 6788 all the way to assembler language output. The free the storage 6789 for the function definition. 6790 6791 This is called after parsing the body of the function definition. */ 6792 6793void 6794finish_function (void) 6795{ 6796 tree fndecl = current_function_decl; 6797 6798 label_context_stack_se = label_context_stack_se->next; 6799 label_context_stack_vm = label_context_stack_vm->next; 6800 6801 if (TREE_CODE (fndecl) == FUNCTION_DECL 6802 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 6803 { 6804 tree args = DECL_ARGUMENTS (fndecl); 6805 for (; args; args = TREE_CHAIN (args)) 6806 { 6807 tree type = TREE_TYPE (args); 6808 if (INTEGRAL_TYPE_P (type) 6809 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 6810 DECL_ARG_TYPE (args) = integer_type_node; 6811 } 6812 } 6813 6814 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6815 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 6816 6817 /* Must mark the RESULT_DECL as being in this function. */ 6818 6819 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 6820 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 6821 6822 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted) 6823 { 6824 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 6825 != integer_type_node) 6826 { 6827 /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned. 6828 If warn_main is -1 (-Wno-main) we don't want to be warned. */ 6829 if (!warn_main) 6830 pedwarn ("return type of %q+D is not %<int%>", fndecl); 6831 } 6832 else 6833 { 6834 if (flag_isoc99) 6835 { 6836 tree stmt = c_finish_return (integer_zero_node); 6837#ifdef USE_MAPPED_LOCATION 6838 /* Hack. We don't want the middle-end to warn that this return 6839 is unreachable, so we mark its location as special. Using 6840 UNKNOWN_LOCATION has the problem that it gets clobbered in 6841 annotate_one_with_locus. A cleaner solution might be to 6842 ensure ! should_carry_locus_p (stmt), but that needs a flag. 6843 */ 6844 SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION); 6845#else 6846 /* Hack. We don't want the middle-end to warn that this 6847 return is unreachable, so put the statement on the 6848 special line 0. */ 6849 annotate_with_file_line (stmt, input_filename, 0); 6850#endif 6851 } 6852 } 6853 } 6854 6855 /* Tie off the statement tree for this function. */ 6856 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 6857 6858 finish_fname_decls (); 6859 6860 /* Complain if there's just no return statement. */ 6861 if (warn_return_type 6862 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 6863 && !current_function_returns_value && !current_function_returns_null 6864 /* Don't complain if we are no-return. */ 6865 && !current_function_returns_abnormally 6866 /* Don't warn for main(). */ 6867 && !MAIN_NAME_P (DECL_NAME (fndecl)) 6868 /* Or if they didn't actually specify a return type. */ 6869 && !C_FUNCTION_IMPLICIT_INT (fndecl) 6870 /* Normally, with -Wreturn-type, flow will complain. Unless we're an 6871 inline function, as we might never be compiled separately. */ 6872 && DECL_INLINE (fndecl)) 6873 { 6874 warning (OPT_Wreturn_type, 6875 "no return statement in function returning non-void"); 6876 TREE_NO_WARNING (fndecl) = 1; 6877 } 6878 6879 /* With just -Wextra, complain only if function returns both with 6880 and without a value. */ 6881 if (extra_warnings 6882 && current_function_returns_value 6883 && current_function_returns_null) 6884 warning (OPT_Wextra, "this function may return with or without a value"); 6885 6886 /* Store the end of the function, so that we get good line number 6887 info for the epilogue. */ 6888 cfun->function_end_locus = input_location; 6889 6890 /* If we don't have ctors/dtors sections, and this is a static 6891 constructor or destructor, it must be recorded now. */ 6892 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6893 && !targetm.have_ctors_dtors) 6894 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors); 6895 if (DECL_STATIC_DESTRUCTOR (fndecl) 6896 && !targetm.have_ctors_dtors) 6897 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors); 6898 6899 /* Finalize the ELF visibility for the function. */ 6900 c_determine_visibility (fndecl); 6901 6902 /* Genericize before inlining. Delay genericizing nested functions 6903 until their parent function is genericized. Since finalizing 6904 requires GENERIC, delay that as well. */ 6905 6906 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 6907 && !undef_nested_function) 6908 { 6909 if (!decl_function_context (fndecl)) 6910 { 6911 c_genericize (fndecl); 6912 c_gimple_diagnostics_recursively (fndecl); 6913 6914 /* ??? Objc emits functions after finalizing the compilation unit. 6915 This should be cleaned up later and this conditional removed. */ 6916 if (cgraph_global_info_ready) 6917 { 6918 c_expand_body (fndecl); 6919 return; 6920 } 6921 6922 cgraph_finalize_function (fndecl, false); 6923 } 6924 else 6925 { 6926 /* Register this function with cgraph just far enough to get it 6927 added to our parent's nested function list. Handy, since the 6928 C front end doesn't have such a list. */ 6929 (void) cgraph_node (fndecl); 6930 } 6931 } 6932 6933 if (!decl_function_context (fndecl)) 6934 undef_nested_function = false; 6935 6936 /* We're leaving the context of this function, so zap cfun. 6937 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 6938 tree_rest_of_compilation. */ 6939 cfun = NULL; 6940 current_function_decl = NULL; 6941} 6942 6943/* Generate the RTL for the body of FNDECL. */ 6944 6945void 6946c_expand_body (tree fndecl) 6947{ 6948 6949 if (!DECL_INITIAL (fndecl) 6950 || DECL_INITIAL (fndecl) == error_mark_node) 6951 return; 6952 6953 tree_rest_of_compilation (fndecl); 6954 6955 if (DECL_STATIC_CONSTRUCTOR (fndecl) 6956 && targetm.have_ctors_dtors) 6957 targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0), 6958 DEFAULT_INIT_PRIORITY); 6959 if (DECL_STATIC_DESTRUCTOR (fndecl) 6960 && targetm.have_ctors_dtors) 6961 targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0), 6962 DEFAULT_INIT_PRIORITY); 6963} 6964 6965/* Check the declarations given in a for-loop for satisfying the C99 6966 constraints. If exactly one such decl is found, return it. */ 6967 6968tree 6969check_for_loop_decls (void) 6970{ 6971 struct c_binding *b; 6972 tree one_decl = NULL_TREE; 6973 int n_decls = 0; 6974 6975 6976 if (!flag_isoc99) 6977 { 6978 /* If we get here, declarations have been used in a for loop without 6979 the C99 for loop scope. This doesn't make much sense, so don't 6980 allow it. */ 6981 error ("%<for%> loop initial declaration used outside C99 mode"); 6982 return NULL_TREE; 6983 } 6984 /* C99 subclause 6.8.5 paragraph 3: 6985 6986 [#3] The declaration part of a for statement shall only 6987 declare identifiers for objects having storage class auto or 6988 register. 6989 6990 It isn't clear whether, in this sentence, "identifiers" binds to 6991 "shall only declare" or to "objects" - that is, whether all identifiers 6992 declared must be identifiers for objects, or whether the restriction 6993 only applies to those that are. (A question on this in comp.std.c 6994 in November 2000 received no answer.) We implement the strictest 6995 interpretation, to avoid creating an extension which later causes 6996 problems. */ 6997 6998 for (b = current_scope->bindings; b; b = b->prev) 6999 { 7000 tree id = b->id; 7001 tree decl = b->decl; 7002 7003 if (!id) 7004 continue; 7005 7006 switch (TREE_CODE (decl)) 7007 { 7008 case VAR_DECL: 7009 if (TREE_STATIC (decl)) 7010 error ("declaration of static variable %q+D in %<for%> loop " 7011 "initial declaration", decl); 7012 else if (DECL_EXTERNAL (decl)) 7013 error ("declaration of %<extern%> variable %q+D in %<for%> loop " 7014 "initial declaration", decl); 7015 break; 7016 7017 case RECORD_TYPE: 7018 error ("%<struct %E%> declared in %<for%> loop initial declaration", 7019 id); 7020 break; 7021 case UNION_TYPE: 7022 error ("%<union %E%> declared in %<for%> loop initial declaration", 7023 id); 7024 break; 7025 case ENUMERAL_TYPE: 7026 error ("%<enum %E%> declared in %<for%> loop initial declaration", 7027 id); 7028 break; 7029 default: 7030 error ("declaration of non-variable %q+D in %<for%> loop " 7031 "initial declaration", decl); 7032 } 7033 7034 n_decls++; 7035 one_decl = decl; 7036 } 7037 7038 return n_decls == 1 ? one_decl : NULL_TREE; 7039} 7040 7041/* Save and reinitialize the variables 7042 used during compilation of a C function. */ 7043 7044void 7045c_push_function_context (struct function *f) 7046{ 7047 struct language_function *p; 7048 p = GGC_NEW (struct language_function); 7049 f->language = p; 7050 7051 p->base.x_stmt_tree = c_stmt_tree; 7052 p->x_break_label = c_break_label; 7053 p->x_cont_label = c_cont_label; 7054 p->x_switch_stack = c_switch_stack; 7055 p->arg_info = current_function_arg_info; 7056 p->returns_value = current_function_returns_value; 7057 p->returns_null = current_function_returns_null; 7058 p->returns_abnormally = current_function_returns_abnormally; 7059 p->warn_about_return_type = warn_about_return_type; 7060} 7061 7062/* Restore the variables used during compilation of a C function. */ 7063 7064void 7065c_pop_function_context (struct function *f) 7066{ 7067 struct language_function *p = f->language; 7068 7069 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 7070 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 7071 { 7072 /* Stop pointing to the local nodes about to be freed. */ 7073 /* But DECL_INITIAL must remain nonzero so we know this 7074 was an actual function definition. */ 7075 DECL_INITIAL (current_function_decl) = error_mark_node; 7076 DECL_ARGUMENTS (current_function_decl) = 0; 7077 } 7078 7079 c_stmt_tree = p->base.x_stmt_tree; 7080 c_break_label = p->x_break_label; 7081 c_cont_label = p->x_cont_label; 7082 c_switch_stack = p->x_switch_stack; 7083 current_function_arg_info = p->arg_info; 7084 current_function_returns_value = p->returns_value; 7085 current_function_returns_null = p->returns_null; 7086 current_function_returns_abnormally = p->returns_abnormally; 7087 warn_about_return_type = p->warn_about_return_type; 7088 7089 f->language = NULL; 7090} 7091 7092/* Copy the DECL_LANG_SPECIFIC data associated with DECL. */ 7093 7094void 7095c_dup_lang_specific_decl (tree decl) 7096{ 7097 struct lang_decl *ld; 7098 7099 if (!DECL_LANG_SPECIFIC (decl)) 7100 return; 7101 7102 ld = GGC_NEW (struct lang_decl); 7103 memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl)); 7104 DECL_LANG_SPECIFIC (decl) = ld; 7105} 7106 7107/* The functions below are required for functionality of doing 7108 function at once processing in the C front end. Currently these 7109 functions are not called from anywhere in the C front end, but as 7110 these changes continue, that will change. */ 7111 7112/* Returns the stmt_tree (if any) to which statements are currently 7113 being added. If there is no active statement-tree, NULL is 7114 returned. */ 7115 7116stmt_tree 7117current_stmt_tree (void) 7118{ 7119 return &c_stmt_tree; 7120} 7121 7122/* Nonzero if TYPE is an anonymous union or struct type. Always 0 in 7123 C. */ 7124 7125int 7126anon_aggr_type_p (tree ARG_UNUSED (node)) 7127{ 7128 return 0; 7129} 7130 7131/* Return the global value of T as a symbol. */ 7132 7133tree 7134identifier_global_value (tree t) 7135{ 7136 struct c_binding *b; 7137 7138 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 7139 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 7140 return b->decl; 7141 7142 return 0; 7143} 7144 7145/* Record a builtin type for C. If NAME is non-NULL, it is the name used; 7146 otherwise the name is found in ridpointers from RID_INDEX. */ 7147 7148void 7149record_builtin_type (enum rid rid_index, const char *name, tree type) 7150{ 7151 tree id, decl; 7152 if (name == 0) 7153 id = ridpointers[(int) rid_index]; 7154 else 7155 id = get_identifier (name); 7156 decl = build_decl (TYPE_DECL, id, type); 7157 pushdecl (decl); 7158 if (debug_hooks->type_decl) 7159 debug_hooks->type_decl (decl, false); 7160} 7161 7162/* Build the void_list_node (void_type_node having been created). */ 7163tree 7164build_void_list_node (void) 7165{ 7166 tree t = build_tree_list (NULL_TREE, void_type_node); 7167 return t; 7168} 7169 7170/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 7171 7172struct c_parm * 7173build_c_parm (struct c_declspecs *specs, tree attrs, 7174 struct c_declarator *declarator) 7175{ 7176 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 7177 ret->specs = specs; 7178 ret->attrs = attrs; 7179 ret->declarator = declarator; 7180 return ret; 7181} 7182 7183/* Return a declarator with nested attributes. TARGET is the inner 7184 declarator to which these attributes apply. ATTRS are the 7185 attributes. */ 7186 7187struct c_declarator * 7188build_attrs_declarator (tree attrs, struct c_declarator *target) 7189{ 7190 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7191 ret->kind = cdk_attrs; 7192 ret->declarator = target; 7193 ret->u.attrs = attrs; 7194 return ret; 7195} 7196 7197/* Return a declarator for a function with arguments specified by ARGS 7198 and return type specified by TARGET. */ 7199 7200struct c_declarator * 7201build_function_declarator (struct c_arg_info *args, 7202 struct c_declarator *target) 7203{ 7204 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7205 ret->kind = cdk_function; 7206 ret->declarator = target; 7207 ret->u.arg_info = args; 7208 return ret; 7209} 7210 7211/* Return a declarator for the identifier IDENT (which may be 7212 NULL_TREE for an abstract declarator). */ 7213 7214struct c_declarator * 7215build_id_declarator (tree ident) 7216{ 7217 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7218 ret->kind = cdk_id; 7219 ret->declarator = 0; 7220 ret->u.id = ident; 7221 /* Default value - may get reset to a more precise location. */ 7222 ret->id_loc = input_location; 7223 return ret; 7224} 7225 7226/* Return something to represent absolute declarators containing a *. 7227 TARGET is the absolute declarator that the * contains. 7228 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 7229 to apply to the pointer type. */ 7230 7231struct c_declarator * 7232make_pointer_declarator (struct c_declspecs *type_quals_attrs, 7233 struct c_declarator *target) 7234{ 7235 tree attrs; 7236 int quals = 0; 7237 struct c_declarator *itarget = target; 7238 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 7239 if (type_quals_attrs) 7240 { 7241 attrs = type_quals_attrs->attrs; 7242 quals = quals_from_declspecs (type_quals_attrs); 7243 if (attrs != NULL_TREE) 7244 itarget = build_attrs_declarator (attrs, target); 7245 } 7246 ret->kind = cdk_pointer; 7247 ret->declarator = itarget; 7248 ret->u.pointer_quals = quals; 7249 return ret; 7250} 7251 7252/* Return a pointer to a structure for an empty list of declaration 7253 specifiers. */ 7254 7255struct c_declspecs * 7256build_null_declspecs (void) 7257{ 7258 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 7259 ret->type = 0; 7260 ret->decl_attr = 0; 7261 ret->attrs = 0; 7262 ret->typespec_word = cts_none; 7263 ret->storage_class = csc_none; 7264 ret->declspecs_seen_p = false; 7265 ret->type_seen_p = false; 7266 ret->non_sc_seen_p = false; 7267 ret->typedef_p = false; 7268 ret->tag_defined_p = false; 7269 ret->explicit_signed_p = false; 7270 ret->deprecated_p = false; 7271 ret->default_int_p = false; 7272 ret->long_p = false; 7273 ret->long_long_p = false; 7274 ret->short_p = false; 7275 ret->signed_p = false; 7276 ret->unsigned_p = false; 7277 ret->complex_p = false; 7278 ret->inline_p = false; 7279 ret->thread_p = false; 7280 ret->const_p = false; 7281 ret->volatile_p = false; 7282 ret->restrict_p = false; 7283 return ret; 7284} 7285 7286/* Add the type qualifier QUAL to the declaration specifiers SPECS, 7287 returning SPECS. */ 7288 7289struct c_declspecs * 7290declspecs_add_qual (struct c_declspecs *specs, tree qual) 7291{ 7292 enum rid i; 7293 bool dupe = false; 7294 specs->non_sc_seen_p = true; 7295 specs->declspecs_seen_p = true; 7296 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 7297 && C_IS_RESERVED_WORD (qual)); 7298 i = C_RID_CODE (qual); 7299 switch (i) 7300 { 7301 case RID_CONST: 7302 dupe = specs->const_p; 7303 specs->const_p = true; 7304 break; 7305 case RID_VOLATILE: 7306 dupe = specs->volatile_p; 7307 specs->volatile_p = true; 7308 break; 7309 case RID_RESTRICT: 7310 dupe = specs->restrict_p; 7311 specs->restrict_p = true; 7312 break; 7313 default: 7314 gcc_unreachable (); 7315 } 7316 if (dupe && pedantic && !flag_isoc99) 7317 pedwarn ("duplicate %qE", qual); 7318 return specs; 7319} 7320 7321/* Add the type specifier TYPE to the declaration specifiers SPECS, 7322 returning SPECS. */ 7323 7324struct c_declspecs * 7325declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec) 7326{ 7327 tree type = spec.spec; 7328 specs->non_sc_seen_p = true; 7329 specs->declspecs_seen_p = true; 7330 specs->type_seen_p = true; 7331 if (TREE_DEPRECATED (type)) 7332 specs->deprecated_p = true; 7333 7334 /* Handle type specifier keywords. */ 7335 if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type)) 7336 { 7337 enum rid i = C_RID_CODE (type); 7338 if (specs->type) 7339 { 7340 error ("two or more data types in declaration specifiers"); 7341 return specs; 7342 } 7343 if ((int) i <= (int) RID_LAST_MODIFIER) 7344 { 7345 /* "long", "short", "signed", "unsigned" or "_Complex". */ 7346 bool dupe = false; 7347 switch (i) 7348 { 7349 case RID_LONG: 7350 if (specs->long_long_p) 7351 { 7352 error ("%<long long long%> is too long for GCC"); 7353 break; 7354 } 7355 if (specs->long_p) 7356 { 7357 if (specs->typespec_word == cts_double) 7358 { 7359 error ("both %<long long%> and %<double%> in " 7360 "declaration specifiers"); 7361 break; 7362 } 7363 if (pedantic && !flag_isoc99 && !in_system_header 7364 && warn_long_long) 7365 pedwarn ("ISO C90 does not support %<long long%>"); 7366 specs->long_long_p = 1; 7367 break; 7368 } 7369 if (specs->short_p) 7370 error ("both %<long%> and %<short%> in " 7371 "declaration specifiers"); 7372 else if (specs->typespec_word == cts_void) 7373 error ("both %<long%> and %<void%> in " 7374 "declaration specifiers"); 7375 else if (specs->typespec_word == cts_bool) 7376 error ("both %<long%> and %<_Bool%> in " 7377 "declaration specifiers"); 7378 else if (specs->typespec_word == cts_char) 7379 error ("both %<long%> and %<char%> in " 7380 "declaration specifiers"); 7381 else if (specs->typespec_word == cts_float) 7382 error ("both %<long%> and %<float%> in " 7383 "declaration specifiers"); 7384 else if (specs->typespec_word == cts_dfloat32) 7385 error ("both %<long%> and %<_Decimal32%> in " 7386 "declaration specifiers"); 7387 else if (specs->typespec_word == cts_dfloat64) 7388 error ("both %<long%> and %<_Decimal64%> in " 7389 "declaration specifiers"); 7390 else if (specs->typespec_word == cts_dfloat128) 7391 error ("both %<long%> and %<_Decimal128%> in " 7392 "declaration specifiers"); 7393 else 7394 specs->long_p = true; 7395 break; 7396 case RID_SHORT: 7397 dupe = specs->short_p; 7398 if (specs->long_p) 7399 error ("both %<long%> and %<short%> in " 7400 "declaration specifiers"); 7401 else if (specs->typespec_word == cts_void) 7402 error ("both %<short%> and %<void%> in " 7403 "declaration specifiers"); 7404 else if (specs->typespec_word == cts_bool) 7405 error ("both %<short%> and %<_Bool%> in " 7406 "declaration specifiers"); 7407 else if (specs->typespec_word == cts_char) 7408 error ("both %<short%> and %<char%> in " 7409 "declaration specifiers"); 7410 else if (specs->typespec_word == cts_float) 7411 error ("both %<short%> and %<float%> in " 7412 "declaration specifiers"); 7413 else if (specs->typespec_word == cts_double) 7414 error ("both %<short%> and %<double%> in " 7415 "declaration specifiers"); 7416 else if (specs->typespec_word == cts_dfloat32) 7417 error ("both %<short%> and %<_Decimal32%> in " 7418 "declaration specifiers"); 7419 else if (specs->typespec_word == cts_dfloat64) 7420 error ("both %<short%> and %<_Decimal64%> in " 7421 "declaration specifiers"); 7422 else if (specs->typespec_word == cts_dfloat128) 7423 error ("both %<short%> and %<_Decimal128%> in " 7424 "declaration specifiers"); 7425 else 7426 specs->short_p = true; 7427 break; 7428 case RID_SIGNED: 7429 dupe = specs->signed_p; 7430 if (specs->unsigned_p) 7431 error ("both %<signed%> and %<unsigned%> in " 7432 "declaration specifiers"); 7433 else if (specs->typespec_word == cts_void) 7434 error ("both %<signed%> and %<void%> in " 7435 "declaration specifiers"); 7436 else if (specs->typespec_word == cts_bool) 7437 error ("both %<signed%> and %<_Bool%> in " 7438 "declaration specifiers"); 7439 else if (specs->typespec_word == cts_float) 7440 error ("both %<signed%> and %<float%> in " 7441 "declaration specifiers"); 7442 else if (specs->typespec_word == cts_double) 7443 error ("both %<signed%> and %<double%> in " 7444 "declaration specifiers"); 7445 else if (specs->typespec_word == cts_dfloat32) 7446 error ("both %<signed%> and %<_Decimal32%> in " 7447 "declaration specifiers"); 7448 else if (specs->typespec_word == cts_dfloat64) 7449 error ("both %<signed%> and %<_Decimal64%> in " 7450 "declaration specifiers"); 7451 else if (specs->typespec_word == cts_dfloat128) 7452 error ("both %<signed%> and %<_Decimal128%> in " 7453 "declaration specifiers"); 7454 else 7455 specs->signed_p = true; 7456 break; 7457 case RID_UNSIGNED: 7458 dupe = specs->unsigned_p; 7459 if (specs->signed_p) 7460 error ("both %<signed%> and %<unsigned%> in " 7461 "declaration specifiers"); 7462 else if (specs->typespec_word == cts_void) 7463 error ("both %<unsigned%> and %<void%> in " 7464 "declaration specifiers"); 7465 else if (specs->typespec_word == cts_bool) 7466 error ("both %<unsigned%> and %<_Bool%> in " 7467 "declaration specifiers"); 7468 else if (specs->typespec_word == cts_float) 7469 error ("both %<unsigned%> and %<float%> in " 7470 "declaration specifiers"); 7471 else if (specs->typespec_word == cts_double) 7472 error ("both %<unsigned%> and %<double%> in " 7473 "declaration specifiers"); 7474 else if (specs->typespec_word == cts_dfloat32) 7475 error ("both %<unsigned%> and %<_Decimal32%> in " 7476 "declaration specifiers"); 7477 else if (specs->typespec_word == cts_dfloat64) 7478 error ("both %<unsigned%> and %<_Decimal64%> in " 7479 "declaration specifiers"); 7480 else if (specs->typespec_word == cts_dfloat128) 7481 error ("both %<unsigned%> and %<_Decimal128%> in " 7482 "declaration specifiers"); 7483 else 7484 specs->unsigned_p = true; 7485 break; 7486 case RID_COMPLEX: 7487 dupe = specs->complex_p; 7488 if (pedantic && !flag_isoc99 && !in_system_header) 7489 pedwarn ("ISO C90 does not support complex types"); 7490 if (specs->typespec_word == cts_void) 7491 error ("both %<complex%> and %<void%> in " 7492 "declaration specifiers"); 7493 else if (specs->typespec_word == cts_bool) 7494 error ("both %<complex%> and %<_Bool%> in " 7495 "declaration specifiers"); 7496 else if (specs->typespec_word == cts_dfloat32) 7497 error ("both %<complex%> and %<_Decimal32%> in " 7498 "declaration specifiers"); 7499 else if (specs->typespec_word == cts_dfloat64) 7500 error ("both %<complex%> and %<_Decimal64%> in " 7501 "declaration specifiers"); 7502 else if (specs->typespec_word == cts_dfloat128) 7503 error ("both %<complex%> and %<_Decimal128%> in " 7504 "declaration specifiers"); 7505 else 7506 specs->complex_p = true; 7507 break; 7508 default: 7509 gcc_unreachable (); 7510 } 7511 7512 if (dupe) 7513 error ("duplicate %qE", type); 7514 7515 return specs; 7516 } 7517 else 7518 { 7519 /* "void", "_Bool", "char", "int", "float" or "double". */ 7520 if (specs->typespec_word != cts_none) 7521 { 7522 error ("two or more data types in declaration specifiers"); 7523 return specs; 7524 } 7525 switch (i) 7526 { 7527 case RID_VOID: 7528 if (specs->long_p) 7529 error ("both %<long%> and %<void%> in " 7530 "declaration specifiers"); 7531 else if (specs->short_p) 7532 error ("both %<short%> and %<void%> in " 7533 "declaration specifiers"); 7534 else if (specs->signed_p) 7535 error ("both %<signed%> and %<void%> in " 7536 "declaration specifiers"); 7537 else if (specs->unsigned_p) 7538 error ("both %<unsigned%> and %<void%> in " 7539 "declaration specifiers"); 7540 else if (specs->complex_p) 7541 error ("both %<complex%> and %<void%> in " 7542 "declaration specifiers"); 7543 else 7544 specs->typespec_word = cts_void; 7545 return specs; 7546 case RID_BOOL: 7547 if (specs->long_p) 7548 error ("both %<long%> and %<_Bool%> in " 7549 "declaration specifiers"); 7550 else if (specs->short_p) 7551 error ("both %<short%> and %<_Bool%> in " 7552 "declaration specifiers"); 7553 else if (specs->signed_p) 7554 error ("both %<signed%> and %<_Bool%> in " 7555 "declaration specifiers"); 7556 else if (specs->unsigned_p) 7557 error ("both %<unsigned%> and %<_Bool%> in " 7558 "declaration specifiers"); 7559 else if (specs->complex_p) 7560 error ("both %<complex%> and %<_Bool%> in " 7561 "declaration specifiers"); 7562 else 7563 specs->typespec_word = cts_bool; 7564 return specs; 7565 case RID_CHAR: 7566 if (specs->long_p) 7567 error ("both %<long%> and %<char%> in " 7568 "declaration specifiers"); 7569 else if (specs->short_p) 7570 error ("both %<short%> and %<char%> in " 7571 "declaration specifiers"); 7572 else 7573 specs->typespec_word = cts_char; 7574 return specs; 7575 case RID_INT: 7576 specs->typespec_word = cts_int; 7577 return specs; 7578 case RID_FLOAT: 7579 if (specs->long_p) 7580 error ("both %<long%> and %<float%> in " 7581 "declaration specifiers"); 7582 else if (specs->short_p) 7583 error ("both %<short%> and %<float%> in " 7584 "declaration specifiers"); 7585 else if (specs->signed_p) 7586 error ("both %<signed%> and %<float%> in " 7587 "declaration specifiers"); 7588 else if (specs->unsigned_p) 7589 error ("both %<unsigned%> and %<float%> in " 7590 "declaration specifiers"); 7591 else 7592 specs->typespec_word = cts_float; 7593 return specs; 7594 case RID_DOUBLE: 7595 if (specs->long_long_p) 7596 error ("both %<long long%> and %<double%> in " 7597 "declaration specifiers"); 7598 else if (specs->short_p) 7599 error ("both %<short%> and %<double%> in " 7600 "declaration specifiers"); 7601 else if (specs->signed_p) 7602 error ("both %<signed%> and %<double%> in " 7603 "declaration specifiers"); 7604 else if (specs->unsigned_p) 7605 error ("both %<unsigned%> and %<double%> in " 7606 "declaration specifiers"); 7607 else 7608 specs->typespec_word = cts_double; 7609 return specs; 7610 case RID_DFLOAT32: 7611 case RID_DFLOAT64: 7612 case RID_DFLOAT128: 7613 { 7614 const char *str; 7615 if (i == RID_DFLOAT32) 7616 str = "_Decimal32"; 7617 else if (i == RID_DFLOAT64) 7618 str = "_Decimal64"; 7619 else 7620 str = "_Decimal128"; 7621 if (specs->long_long_p) 7622 error ("both %<long long%> and %<%s%> in " 7623 "declaration specifiers", str); 7624 if (specs->long_p) 7625 error ("both %<long%> and %<%s%> in " 7626 "declaration specifiers", str); 7627 else if (specs->short_p) 7628 error ("both %<short%> and %<%s%> in " 7629 "declaration specifiers", str); 7630 else if (specs->signed_p) 7631 error ("both %<signed%> and %<%s%> in " 7632 "declaration specifiers", str); 7633 else if (specs->unsigned_p) 7634 error ("both %<unsigned%> and %<%s%> in " 7635 "declaration specifiers", str); 7636 else if (specs->complex_p) 7637 error ("both %<complex%> and %<%s%> in " 7638 "declaration specifiers", str); 7639 else if (i == RID_DFLOAT32) 7640 specs->typespec_word = cts_dfloat32; 7641 else if (i == RID_DFLOAT64) 7642 specs->typespec_word = cts_dfloat64; 7643 else 7644 specs->typespec_word = cts_dfloat128; 7645 } 7646 if (!targetm.decimal_float_supported_p ()) 7647 error ("decimal floating point not supported for this target"); 7648 if (pedantic) 7649 pedwarn ("ISO C does not support decimal floating point"); 7650 return specs; 7651 default: 7652 /* ObjC reserved word "id", handled below. */ 7653 break; 7654 } 7655 } 7656 } 7657 7658 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 7659 form of ObjC type, cases such as "int" and "long" being handled 7660 above), a TYPE (struct, union, enum and typeof specifiers) or an 7661 ERROR_MARK. In none of these cases may there have previously 7662 been any type specifiers. */ 7663 if (specs->type || specs->typespec_word != cts_none 7664 || specs->long_p || specs->short_p || specs->signed_p 7665 || specs->unsigned_p || specs->complex_p) 7666 error ("two or more data types in declaration specifiers"); 7667 else if (TREE_CODE (type) == TYPE_DECL) 7668 { 7669 if (TREE_TYPE (type) == error_mark_node) 7670 ; /* Allow the type to default to int to avoid cascading errors. */ 7671 else 7672 { 7673 specs->type = TREE_TYPE (type); 7674 specs->decl_attr = DECL_ATTRIBUTES (type); 7675 specs->typedef_p = true; 7676 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 7677 } 7678 } 7679 else if (TREE_CODE (type) == IDENTIFIER_NODE) 7680 { 7681 tree t = lookup_name (type); 7682 if (!t || TREE_CODE (t) != TYPE_DECL) 7683 error ("%qE fails to be a typedef or built in type", type); 7684 else if (TREE_TYPE (t) == error_mark_node) 7685 ; 7686 else 7687 specs->type = TREE_TYPE (t); 7688 } 7689 else if (TREE_CODE (type) != ERROR_MARK) 7690 { 7691 if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref) 7692 specs->tag_defined_p = true; 7693 if (spec.kind == ctsk_typeof) 7694 specs->typedef_p = true; 7695 specs->type = type; 7696 } 7697 7698 return specs; 7699} 7700 7701/* Add the storage class specifier or function specifier SCSPEC to the 7702 declaration specifiers SPECS, returning SPECS. */ 7703 7704struct c_declspecs * 7705declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 7706{ 7707 enum rid i; 7708 enum c_storage_class n = csc_none; 7709 bool dupe = false; 7710 specs->declspecs_seen_p = true; 7711 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 7712 && C_IS_RESERVED_WORD (scspec)); 7713 i = C_RID_CODE (scspec); 7714 if (extra_warnings && specs->non_sc_seen_p) 7715 warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec); 7716 switch (i) 7717 { 7718 case RID_INLINE: 7719 /* C99 permits duplicate inline. Although of doubtful utility, 7720 it seems simplest to permit it in gnu89 mode as well, as 7721 there is also little utility in maintaining this as a 7722 difference between gnu89 and C99 inline. */ 7723 dupe = false; 7724 specs->inline_p = true; 7725 break; 7726 case RID_THREAD: 7727 dupe = specs->thread_p; 7728 if (specs->storage_class == csc_auto) 7729 error ("%<__thread%> used with %<auto%>"); 7730 else if (specs->storage_class == csc_register) 7731 error ("%<__thread%> used with %<register%>"); 7732 else if (specs->storage_class == csc_typedef) 7733 error ("%<__thread%> used with %<typedef%>"); 7734 else 7735 specs->thread_p = true; 7736 break; 7737 case RID_AUTO: 7738 n = csc_auto; 7739 break; 7740 case RID_EXTERN: 7741 n = csc_extern; 7742 /* Diagnose "__thread extern". */ 7743 if (specs->thread_p) 7744 error ("%<__thread%> before %<extern%>"); 7745 break; 7746 case RID_REGISTER: 7747 n = csc_register; 7748 break; 7749 case RID_STATIC: 7750 n = csc_static; 7751 /* Diagnose "__thread static". */ 7752 if (specs->thread_p) 7753 error ("%<__thread%> before %<static%>"); 7754 break; 7755 case RID_TYPEDEF: 7756 n = csc_typedef; 7757 break; 7758 default: 7759 gcc_unreachable (); 7760 } 7761 if (n != csc_none && n == specs->storage_class) 7762 dupe = true; 7763 if (dupe) 7764 error ("duplicate %qE", scspec); 7765 if (n != csc_none) 7766 { 7767 if (specs->storage_class != csc_none && n != specs->storage_class) 7768 { 7769 error ("multiple storage classes in declaration specifiers"); 7770 } 7771 else 7772 { 7773 specs->storage_class = n; 7774 if (n != csc_extern && n != csc_static && specs->thread_p) 7775 { 7776 error ("%<__thread%> used with %qE", scspec); 7777 specs->thread_p = false; 7778 } 7779 } 7780 } 7781 return specs; 7782} 7783 7784/* Add the attributes ATTRS to the declaration specifiers SPECS, 7785 returning SPECS. */ 7786 7787struct c_declspecs * 7788declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 7789{ 7790 specs->attrs = chainon (attrs, specs->attrs); 7791 specs->declspecs_seen_p = true; 7792 return specs; 7793} 7794 7795/* Combine "long", "short", "signed", "unsigned" and "_Complex" type 7796 specifiers with any other type specifier to determine the resulting 7797 type. This is where ISO C checks on complex types are made, since 7798 "_Complex long" is a prefix of the valid ISO C type "_Complex long 7799 double". */ 7800 7801struct c_declspecs * 7802finish_declspecs (struct c_declspecs *specs) 7803{ 7804 /* If a type was specified as a whole, we have no modifiers and are 7805 done. */ 7806 if (specs->type != NULL_TREE) 7807 { 7808 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7809 && !specs->signed_p && !specs->unsigned_p 7810 && !specs->complex_p); 7811 return specs; 7812 } 7813 7814 /* If none of "void", "_Bool", "char", "int", "float" or "double" 7815 has been specified, treat it as "int" unless "_Complex" is 7816 present and there are no other specifiers. If we just have 7817 "_Complex", it is equivalent to "_Complex double", but e.g. 7818 "_Complex short" is equivalent to "_Complex short int". */ 7819 if (specs->typespec_word == cts_none) 7820 { 7821 if (specs->long_p || specs->short_p 7822 || specs->signed_p || specs->unsigned_p) 7823 { 7824 specs->typespec_word = cts_int; 7825 } 7826 else if (specs->complex_p) 7827 { 7828 specs->typespec_word = cts_double; 7829 if (pedantic) 7830 pedwarn ("ISO C does not support plain %<complex%> meaning " 7831 "%<double complex%>"); 7832 } 7833 else 7834 { 7835 specs->typespec_word = cts_int; 7836 specs->default_int_p = true; 7837 /* We don't diagnose this here because grokdeclarator will 7838 give more specific diagnostics according to whether it is 7839 a function definition. */ 7840 } 7841 } 7842 7843 /* If "signed" was specified, record this to distinguish "int" and 7844 "signed int" in the case of a bit-field with 7845 -funsigned-bitfields. */ 7846 specs->explicit_signed_p = specs->signed_p; 7847 7848 /* Now compute the actual type. */ 7849 switch (specs->typespec_word) 7850 { 7851 case cts_void: 7852 gcc_assert (!specs->long_p && !specs->short_p 7853 && !specs->signed_p && !specs->unsigned_p 7854 && !specs->complex_p); 7855 specs->type = void_type_node; 7856 break; 7857 case cts_bool: 7858 gcc_assert (!specs->long_p && !specs->short_p 7859 && !specs->signed_p && !specs->unsigned_p 7860 && !specs->complex_p); 7861 specs->type = boolean_type_node; 7862 break; 7863 case cts_char: 7864 gcc_assert (!specs->long_p && !specs->short_p); 7865 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7866 if (specs->signed_p) 7867 specs->type = signed_char_type_node; 7868 else if (specs->unsigned_p) 7869 specs->type = unsigned_char_type_node; 7870 else 7871 specs->type = char_type_node; 7872 if (specs->complex_p) 7873 { 7874 if (pedantic) 7875 pedwarn ("ISO C does not support complex integer types"); 7876 specs->type = build_complex_type (specs->type); 7877 } 7878 break; 7879 case cts_int: 7880 gcc_assert (!(specs->long_p && specs->short_p)); 7881 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 7882 if (specs->long_long_p) 7883 specs->type = (specs->unsigned_p 7884 ? long_long_unsigned_type_node 7885 : long_long_integer_type_node); 7886 else if (specs->long_p) 7887 specs->type = (specs->unsigned_p 7888 ? long_unsigned_type_node 7889 : long_integer_type_node); 7890 else if (specs->short_p) 7891 specs->type = (specs->unsigned_p 7892 ? short_unsigned_type_node 7893 : short_integer_type_node); 7894 else 7895 specs->type = (specs->unsigned_p 7896 ? unsigned_type_node 7897 : integer_type_node); 7898 if (specs->complex_p) 7899 { 7900 if (pedantic) 7901 pedwarn ("ISO C does not support complex integer types"); 7902 specs->type = build_complex_type (specs->type); 7903 } 7904 break; 7905 case cts_float: 7906 gcc_assert (!specs->long_p && !specs->short_p 7907 && !specs->signed_p && !specs->unsigned_p); 7908 specs->type = (specs->complex_p 7909 ? complex_float_type_node 7910 : float_type_node); 7911 break; 7912 case cts_double: 7913 gcc_assert (!specs->long_long_p && !specs->short_p 7914 && !specs->signed_p && !specs->unsigned_p); 7915 if (specs->long_p) 7916 { 7917 specs->type = (specs->complex_p 7918 ? complex_long_double_type_node 7919 : long_double_type_node); 7920 } 7921 else 7922 { 7923 specs->type = (specs->complex_p 7924 ? complex_double_type_node 7925 : double_type_node); 7926 } 7927 break; 7928 case cts_dfloat32: 7929 case cts_dfloat64: 7930 case cts_dfloat128: 7931 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 7932 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 7933 if (specs->typespec_word == cts_dfloat32) 7934 specs->type = dfloat32_type_node; 7935 else if (specs->typespec_word == cts_dfloat64) 7936 specs->type = dfloat64_type_node; 7937 else 7938 specs->type = dfloat128_type_node; 7939 break; 7940 default: 7941 gcc_unreachable (); 7942 } 7943 7944 return specs; 7945} 7946 7947/* Synthesize a function which calls all the global ctors or global 7948 dtors in this file. This is only used for targets which do not 7949 support .ctors/.dtors sections. FIXME: Migrate into cgraph. */ 7950static void 7951build_cdtor (int method_type, tree cdtors) 7952{ 7953 tree body = 0; 7954 7955 if (!cdtors) 7956 return; 7957 7958 for (; cdtors; cdtors = TREE_CHAIN (cdtors)) 7959 append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0), 7960 &body); 7961 7962 cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY); 7963} 7964 7965/* A subroutine of c_write_global_declarations. Perform final processing 7966 on one file scope's declarations (or the external scope's declarations), 7967 GLOBALS. */ 7968 7969static void 7970c_write_global_declarations_1 (tree globals) 7971{ 7972 tree decl; 7973 bool reconsider; 7974 7975 /* Process the decls in the order they were written. */ 7976 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7977 { 7978 /* Check for used but undefined static functions using the C 7979 standard's definition of "used", and set TREE_NO_WARNING so 7980 that check_global_declarations doesn't repeat the check. */ 7981 if (TREE_CODE (decl) == FUNCTION_DECL 7982 && DECL_INITIAL (decl) == 0 7983 && DECL_EXTERNAL (decl) 7984 && !TREE_PUBLIC (decl) 7985 && C_DECL_USED (decl)) 7986 { 7987 pedwarn ("%q+F used but never defined", decl); 7988 TREE_NO_WARNING (decl) = 1; 7989 } 7990 7991 wrapup_global_declaration_1 (decl); 7992 } 7993 7994 do 7995 { 7996 reconsider = false; 7997 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 7998 reconsider |= wrapup_global_declaration_2 (decl); 7999 } 8000 while (reconsider); 8001 8002 for (decl = globals; decl; decl = TREE_CHAIN (decl)) 8003 check_global_declaration_1 (decl); 8004} 8005 8006/* A subroutine of c_write_global_declarations Emit debug information for each 8007 of the declarations in GLOBALS. */ 8008 8009static void 8010c_write_global_declarations_2 (tree globals) 8011{ 8012 tree decl; 8013 8014 for (decl = globals; decl ; decl = TREE_CHAIN (decl)) 8015 debug_hooks->global_decl (decl); 8016} 8017 8018/* Preserve the external declarations scope across a garbage collect. */ 8019static GTY(()) tree ext_block; 8020 8021void 8022c_write_global_declarations (void) 8023{ 8024 tree t; 8025 8026 /* We don't want to do this if generating a PCH. */ 8027 if (pch_file) 8028 return; 8029 8030 /* Don't waste time on further processing if -fsyntax-only or we've 8031 encountered errors. */ 8032 if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in)) 8033 return; 8034 8035 /* Close the external scope. */ 8036 ext_block = pop_scope (); 8037 external_scope = 0; 8038 gcc_assert (!current_scope); 8039 8040 if (ext_block) 8041 { 8042 tree tmp = BLOCK_VARS (ext_block); 8043 int flags; 8044 FILE * stream = dump_begin (TDI_tu, &flags); 8045 if (stream && tmp) 8046 { 8047 dump_node (tmp, flags & ~TDF_SLIM, stream); 8048 dump_end (TDI_tu, stream); 8049 } 8050 } 8051 8052 /* Process all file scopes in this compilation, and the external_scope, 8053 through wrapup_global_declarations and check_global_declarations. */ 8054 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8055 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 8056 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 8057 8058 /* Generate functions to call static constructors and destructors 8059 for targets that do not support .ctors/.dtors sections. These 8060 functions have magic names which are detected by collect2. */ 8061 build_cdtor ('I', static_ctors); static_ctors = 0; 8062 build_cdtor ('D', static_dtors); static_dtors = 0; 8063 8064 /* We're done parsing; proceed to optimize and emit assembly. 8065 FIXME: shouldn't be the front end's responsibility to call this. */ 8066 cgraph_optimize (); 8067 8068 /* After cgraph has had a chance to emit everything that's going to 8069 be emitted, output debug information for globals. */ 8070 if (errorcount == 0 && sorrycount == 0) 8071 { 8072 timevar_push (TV_SYMOUT); 8073 for (t = all_translation_units; t; t = TREE_CHAIN (t)) 8074 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 8075 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 8076 timevar_pop (TV_SYMOUT); 8077 } 8078 8079 ext_block = NULL; 8080} 8081 8082#include "gt-c-decl.h" 8083