c-decl.c revision 149846
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 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, 59 Temple Place - Suite 330, Boston, MA 2002111-1307, USA. */ 21 22/* $FreeBSD: head/contrib/gcc/c-decl.c 149846 2005-09-07 09:23:39Z obrien $ */ 23 24/* Process declarations and symbol lookup for C front end. 25 Also constructs types; the standard scalar types at initialization, 26 and structure, union, array and enum types when they are declared. */ 27 28/* ??? not all decl nodes are given the most useful possible 29 line numbers. For example, the CONST_DECLs for enum values. */ 30 31#include "config.h" 32#include "system.h" 33#include "coretypes.h" 34#include "tm.h" 35#include "intl.h" 36#include "tree.h" 37#include "tree-inline.h" 38#include "rtl.h" 39#include "flags.h" 40#include "function.h" 41#include "output.h" 42#include "expr.h" 43#include "c-tree.h" 44#include "toplev.h" 45#include "ggc.h" 46#include "tm_p.h" 47#include "cpplib.h" 48#include "target.h" 49#include "debug.h" 50#include "opts.h" 51#include "timevar.h" 52#include "c-common.h" 53#include "c-pragma.h" 54#include "cgraph.h" 55#include "hashtab.h" 56#include "libfuncs.h" 57#include "except.h" 58#include "langhooks-def.h" 59 60/* In grokdeclarator, distinguish syntactic contexts of declarators. */ 61enum decl_context 62{ NORMAL, /* Ordinary declaration */ 63 FUNCDEF, /* Function definition */ 64 PARM, /* Declaration of parm before function body */ 65 FIELD, /* Declaration inside struct or union */ 66 TYPENAME}; /* Typename (inside cast or sizeof) */ 67 68 69/* Nonzero if we have seen an invalid cross reference 70 to a struct, union, or enum, but not yet printed the message. */ 71 72tree pending_invalid_xref; 73/* File and line to appear in the eventual error message. */ 74location_t pending_invalid_xref_location; 75 76/* While defining an enum type, this is 1 plus the last enumerator 77 constant value. Note that will do not have to save this or `enum_overflow' 78 around nested function definition since such a definition could only 79 occur in an enum value expression and we don't use these variables in 80 that case. */ 81 82static tree enum_next_value; 83 84/* Nonzero means that there was overflow computing enum_next_value. */ 85 86static int enum_overflow; 87 88/* Parsing a function declarator leaves a list of parameter names 89 or a chain of parameter decls here. */ 90 91static tree last_function_parms; 92 93/* ... and a chain of structure and enum types declared in the 94 parmlist here. */ 95 96static tree last_function_parm_tags; 97 98/* ... and a chain of all non-parameter declarations (such as 99 CONST_DECLs from enumerations) here. */ 100 101static tree last_function_parm_others; 102 103/* After parsing the declarator that starts a function definition, 104 `start_function' puts the list of parameter names or chain of decls here 105 for `store_parm_decls' to find. */ 106 107static tree current_function_parms; 108 109/* Similar, for last_function_parm_tags. */ 110 111static tree current_function_parm_tags; 112 113/* And for last_function_parm_others. */ 114 115static tree current_function_parm_others; 116 117/* Similar, for the file and line that the prototype came from if this is 118 an old-style definition. */ 119 120static location_t current_function_prototype_locus; 121 122/* The current statement tree. */ 123 124static GTY(()) struct stmt_tree_s c_stmt_tree; 125 126/* The current scope statement stack. */ 127 128static GTY(()) tree c_scope_stmt_stack; 129 130/* State saving variables. */ 131int c_in_iteration_stmt; 132int c_in_case_stmt; 133 134/* A list of external DECLs that appeared at block scope when there was 135 some other global meaning for that identifier. */ 136static GTY(()) tree truly_local_externals; 137 138/* All the builtins; this is a subset of the entries of global_scope. */ 139 140static GTY(()) tree first_builtin_decl; 141static GTY(()) tree last_builtin_decl; 142 143/* A DECL for the current file-scope context. */ 144 145static GTY(()) tree current_file_decl; 146 147/* Set to 0 at beginning of a function definition, set to 1 if 148 a return statement that specifies a return value is seen. */ 149 150int current_function_returns_value; 151 152/* Set to 0 at beginning of a function definition, set to 1 if 153 a return statement with no argument is seen. */ 154 155int current_function_returns_null; 156 157/* Set to 0 at beginning of a function definition, set to 1 if 158 a call to a noreturn function is seen. */ 159 160int current_function_returns_abnormally; 161 162/* Set to nonzero by `grokdeclarator' for a function 163 whose return type is defaulted, if warnings for this are desired. */ 164 165static int warn_about_return_type; 166 167/* Nonzero when starting a function declared `extern inline'. */ 168 169static int current_extern_inline; 170 171/* Each c_scope structure describes the complete contents of one scope. 172 Three scopes are distinguished specially: the innermost or current 173 scope, the innermost function scope, and the outermost or file scope. 174 175 Most declarations are recorded in the current scope. 176 177 All normal label declarations are recorded in the innermost 178 function scope, as are bindings of undeclared identifiers to 179 error_mark_node. (GCC permits nested functions as an extension, 180 hence the 'innermost' qualifier.) Explicitly declared labels 181 (using the __label__ extension) appear in the current scope. 182 183 Being in the global scope (current_scope == global_scope) causes 184 special behavior in several places below. Also, under some 185 conditions the Objective-C front end records declarations in the 186 global scope even though that isn't the current scope. 187 188 The order of the names, parms, and blocks lists matters, and they 189 are frequently appended to. To avoid having to walk all the way to 190 the end of the list on each insertion, or reverse the lists later, 191 we maintain a pointer to the last list entry for each of the lists. 192 193 The order of the tags, shadowed, and shadowed_tags 194 lists does not matter, so we just prepend to these lists. */ 195 196struct c_scope GTY(()) 197{ 198 /* The scope containing this one. */ 199 struct c_scope *outer; 200 201 /* The next outermost function scope. */ 202 struct c_scope *outer_function; 203 204 /* All variables, constants, functions, labels, and typedef names. */ 205 tree names; 206 tree names_last; 207 208 /* All parameter declarations. Used only in the outermost scope of 209 a function. */ 210 tree parms; 211 tree parms_last; 212 213 /* All structure, union, and enum type tags. */ 214 tree tags; 215 216 /* For each scope, a list of shadowed outer-scope definitions 217 to be restored when this scope is popped. 218 Each link is a TREE_LIST whose TREE_PURPOSE is an identifier and 219 whose TREE_VALUE is its old definition (a kind of ..._DECL node). */ 220 tree shadowed; 221 222 /* For each scope, a list of shadowed outer-scope tag definitions 223 to be restored when this scope is popped. 224 Each link is a TREE_LIST whose TREE_PURPOSE is an identifier and 225 whose TREE_VALUE is its old definition (a kind of ..._TYPE node). */ 226 tree shadowed_tags; 227 228 /* For each scope (except the global one), a chain of BLOCK nodes 229 for all the scopes that were entered and exited one level down. */ 230 tree blocks; 231 tree blocks_last; 232 233 /* True if we are currently filling this scope with parameter 234 declarations. */ 235 BOOL_BITFIELD parm_flag : 1; 236 237 /* True if we already complained about forward parameter decls 238 in this scope. This prevents double warnings on 239 foo (int a; int b; ...) */ 240 BOOL_BITFIELD warned_forward_parm_decls : 1; 241 242 /* True if this is the outermost block scope of a function body. 243 This scope contains the parameters, the local variables declared 244 in the outermost block, and all the labels (except those in 245 nested functions, or declared at block scope with __label__). */ 246 BOOL_BITFIELD function_body : 1; 247 248 /* True means make a BLOCK for this scope no matter what. */ 249 BOOL_BITFIELD keep : 1; 250}; 251 252/* The scope currently in effect. */ 253 254static GTY(()) struct c_scope *current_scope; 255 256/* A chain of c_scope structures awaiting reuse. */ 257 258static GTY((deletable (""))) struct c_scope *scope_freelist; 259 260/* The innermost function scope. Ordinary (not explicitly declared) 261 labels, bindings to error_mark_node, and the lazily-created 262 bindings of __func__ and its friends get this scope. */ 263 264static GTY(()) struct c_scope *current_function_scope; 265 266/* The outermost scope, corresponding to the C "file scope". This is 267 created when the compiler is started and exists through the entire run. */ 268 269static GTY(()) struct c_scope *global_scope; 270 271/* Append VAR to LIST in scope SCOPE. */ 272#define SCOPE_LIST_APPEND(scope, list, decl) do { \ 273 struct c_scope *s_ = (scope); \ 274 tree d_ = (decl); \ 275 if (s_->list##_last) \ 276 TREE_CHAIN (s_->list##_last) = d_; \ 277 else \ 278 s_->list = d_; \ 279 s_->list##_last = d_; \ 280} while (0) 281 282/* Concatenate FROM in scope FSCOPE onto TO in scope TSCOPE. */ 283#define SCOPE_LIST_CONCAT(tscope, to, fscope, from) do { \ 284 struct c_scope *t_ = (tscope); \ 285 struct c_scope *f_ = (fscope); \ 286 if (t_->to##_last) \ 287 TREE_CHAIN (t_->to##_last) = f_->from; \ 288 else \ 289 t_->to = f_->from; \ 290 t_->to##_last = f_->from##_last; \ 291} while (0) 292 293/* True means unconditionally make a BLOCK for the next scope pushed. */ 294 295static bool keep_next_level_flag; 296 297/* True means the next call to pushlevel will be the outermost scope 298 of a function body, so do not push a new scope, merely cease 299 expecting parameter decls. */ 300 301static bool next_is_function_body; 302 303/* Functions called automatically at the beginning and end of execution. */ 304 305tree static_ctors, static_dtors; 306 307/* Forward declarations. */ 308 309static struct c_scope *make_scope (void); 310static void pop_scope (void); 311static tree make_label (tree, location_t); 312static void bind_label (tree, tree, struct c_scope *); 313static void implicit_decl_warning (tree); 314static tree lookup_tag (enum tree_code, tree, int); 315static tree lookup_name_current_level (tree); 316static tree grokdeclarator (tree, tree, enum decl_context, int, tree *); 317static tree grokparms (tree, int); 318static void layout_array_type (tree); 319static void store_parm_decls_newstyle (void); 320static void store_parm_decls_oldstyle (void); 321static tree c_make_fname_decl (tree, int); 322static void c_expand_body_1 (tree, int); 323static tree any_external_decl (tree); 324static void record_external_decl (tree); 325static void warn_if_shadowing (tree, tree); 326static void check_bitfield_type_and_width (tree *, tree *, const char *); 327static void clone_underlying_type (tree); 328static bool flexible_array_type_p (tree); 329static hashval_t link_hash_hash (const void *); 330static int link_hash_eq (const void *, const void *); 331 332/* States indicating how grokdeclarator() should handle declspecs marked 333 with __attribute__((deprecated)). An object declared as 334 __attribute__((deprecated)) suppresses warnings of uses of other 335 deprecated items. */ 336 337enum deprecated_states { 338 DEPRECATED_NORMAL, 339 DEPRECATED_SUPPRESS 340}; 341 342static enum deprecated_states deprecated_state = DEPRECATED_NORMAL; 343 344void 345c_print_identifier (FILE *file, tree node, int indent) 346{ 347 print_node (file, "symbol", IDENTIFIER_SYMBOL_VALUE (node), indent + 4); 348 print_node (file, "tag", IDENTIFIER_TAG_VALUE (node), indent + 4); 349 print_node (file, "label", IDENTIFIER_LABEL_VALUE (node), indent + 4); 350 if (C_IS_RESERVED_WORD (node)) 351 { 352 tree rid = ridpointers[C_RID_CODE (node)]; 353 indent_to (file, indent + 4); 354 fprintf (file, "rid " HOST_PTR_PRINTF " \"%s\"", 355 (void *) rid, IDENTIFIER_POINTER (rid)); 356 } 357} 358 359/* Hook called at end of compilation to assume 1 elt 360 for a file-scope tentative array defn that wasn't complete before. */ 361 362void 363c_finish_incomplete_decl (tree decl) 364{ 365 if (TREE_CODE (decl) == VAR_DECL) 366 { 367 tree type = TREE_TYPE (decl); 368 if (type != error_mark_node 369 && TREE_CODE (type) == ARRAY_TYPE 370 && ! DECL_EXTERNAL (decl) 371 && TYPE_DOMAIN (type) == 0) 372 { 373 warning ("%Jarray '%D' assumed to have one element", decl, decl); 374 375 complete_array_type (type, NULL_TREE, 1); 376 377 layout_decl (decl, 0); 378 } 379 } 380} 381 382/* Reuse or create a struct for this scope. */ 383 384static struct c_scope * 385make_scope (void) 386{ 387 struct c_scope *result; 388 if (scope_freelist) 389 { 390 result = scope_freelist; 391 scope_freelist = result->outer; 392 } 393 else 394 result = ggc_alloc_cleared (sizeof (struct c_scope)); 395 396 return result; 397} 398 399/* Remove the topmost scope from the stack and add it to the 400 free list, updating current_function_scope if necessary. */ 401 402static void 403pop_scope (void) 404{ 405 struct c_scope *scope = current_scope; 406 407 current_scope = scope->outer; 408 if (scope->function_body) 409 current_function_scope = scope->outer_function; 410 411 memset (scope, 0, sizeof (struct c_scope)); 412 scope->outer = scope_freelist; 413 scope_freelist = scope; 414} 415 416/* The Objective-C front-end often needs to determine the current scope. */ 417 418void * 419get_current_scope (void) 420{ 421 return current_scope; 422} 423 424/* The following function is used only by Objective-C. It needs to live here 425 because it accesses the innards of c_scope. */ 426 427void 428objc_mark_locals_volatile (void *enclosing_blk) 429{ 430 struct c_scope *scope; 431 432 for (scope = current_scope; 433 scope && scope != enclosing_blk; 434 scope = scope->outer) 435 { 436 tree decl; 437 438 for (decl = scope->names; decl; decl = TREE_CHAIN (decl)) 439 { 440 DECL_REGISTER (decl) = 0; 441 TREE_THIS_VOLATILE (decl) = 1; 442 } 443 /* Do not climb up past the current function. */ 444 if (scope->function_body) 445 break; 446 } 447} 448 449/* Nonzero if we are currently in the global scope. */ 450 451int 452global_bindings_p (void) 453{ 454 return current_scope == global_scope; 455} 456 457void 458keep_next_level (void) 459{ 460 keep_next_level_flag = true; 461} 462 463/* Identify this scope as currently being filled with parameters. */ 464 465void 466declare_parm_level (void) 467{ 468 current_scope->parm_flag = true; 469} 470 471/* Nonzero if currently making parm declarations. */ 472 473int 474in_parm_level_p (void) 475{ 476 return current_scope->parm_flag; 477} 478 479/* Enter a new scope. The dummy parameter is for signature 480 compatibility with lang_hooks.decls.pushlevel. */ 481 482void 483pushlevel (int dummy ATTRIBUTE_UNUSED) 484{ 485 if (next_is_function_body) 486 { 487 /* This is the transition from the parameters to the top level 488 of the function body. These are the same scope 489 (C99 6.2.1p4,6) so we do not push another scope structure. 490 next_is_function_body is set only by store_parm_decls, which 491 in turn is called when and only when we are about to 492 encounter the opening curly brace for the function body. 493 494 The outermost block of a function always gets a BLOCK node, 495 because the debugging output routines expect that each 496 function has at least one BLOCK. */ 497 current_scope->parm_flag = false; 498 current_scope->function_body = true; 499 current_scope->keep = true; 500 current_scope->outer_function = current_function_scope; 501 current_function_scope = current_scope; 502 503 keep_next_level_flag = false; 504 next_is_function_body = false; 505 } 506 else 507 { 508 struct c_scope *scope = make_scope (); 509 510 scope->keep = keep_next_level_flag; 511 scope->outer = current_scope; 512 current_scope = scope; 513 keep_next_level_flag = false; 514 } 515} 516 517/* Exit a scope. Restore the state of the identifier-decl mappings 518 that were in effect when this scope was entered. 519 520 If KEEP is KEEP_YES (1), this scope had explicit declarations, so 521 create a BLOCK node to record its declarations and subblocks for 522 debugging output. If KEEP is KEEP_MAYBE, do so only if the names 523 or tags lists are nonempty. 524 525 The second parameter is ignored; it is present only for 526 signature compatibility with lang_hooks.decls.poplevel. 527 528 If FUNCTIONBODY is nonzero, this level is the body of a function, 529 even if current_scope->function_body is not set. This is used 530 by language-independent code that generates synthetic functions, 531 and cannot set current_scope->function_body. 532 533 FIXME: Eliminate the need for all arguments. */ 534 535tree 536poplevel (int keep, int dummy ATTRIBUTE_UNUSED, int functionbody) 537{ 538 struct c_scope *scope = current_scope; 539 tree block; 540 tree decl; 541 tree p; 542 543 /* The following line does not use |= due to a bug in HP's C compiler. */ 544 scope->function_body = scope->function_body | functionbody; 545 546 if (keep == KEEP_MAYBE) 547 keep = (scope->names || scope->tags); 548 549 keep |= scope->keep; 550 keep |= scope->function_body; 551 552 /* If appropriate, create a BLOCK to record the decls for the life 553 of this function. */ 554 block = 0; 555 if (keep) 556 { 557 block = make_node (BLOCK); 558 BLOCK_VARS (block) = scope->names; 559 BLOCK_SUBBLOCKS (block) = scope->blocks; 560 TREE_USED (block) = 1; 561 } 562 563 /* In each subblock, record that this is its superior. */ 564 for (p = scope->blocks; p; p = TREE_CHAIN (p)) 565 BLOCK_SUPERCONTEXT (p) = block; 566 567 /* Clear out the variable bindings in this scope. 568 569 Propagate TREE_ADDRESSABLE from nested functions to their 570 containing functions. 571 572 Issue warnings for unused variables and labels, and errors for 573 undefined labels, if there are any. */ 574 575 for (p = scope->names; p; p = TREE_CHAIN (p)) 576 { 577 switch (TREE_CODE (p)) 578 { 579 case LABEL_DECL: 580 if (TREE_USED (p) && !DECL_INITIAL (p)) 581 { 582 error ("%Jlabel `%D' used but not defined", p, p); 583 DECL_INITIAL (p) = error_mark_node; 584 } 585 else if (!TREE_USED (p) && warn_unused_label) 586 { 587 if (DECL_INITIAL (p)) 588 warning ("%Jlabel `%D' defined but not used", p, p); 589 else 590 warning ("%Jlabel `%D' declared but not defined", p, p); 591 } 592 593 IDENTIFIER_LABEL_VALUE (DECL_NAME (p)) = 0; 594 break; 595 596 case FUNCTION_DECL: 597 if (! TREE_ASM_WRITTEN (p) 598 && DECL_INITIAL (p) != 0 599 && TREE_ADDRESSABLE (p) 600 && DECL_ABSTRACT_ORIGIN (p) != 0 601 && DECL_ABSTRACT_ORIGIN (p) != p) 602 TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (p)) = 1; 603 goto normal; 604 605 case VAR_DECL: 606 /* Keep this in sync with stmt.c:warn_about_unused_variables. 607 No warnings when the global scope is popped because the 608 global scope isn't popped for the last translation unit, 609 so the warnings are done in c_write_global_declaration. */ 610 if (warn_unused_variable && scope != global_scope 611 && !TREE_USED (p) 612 && !DECL_IN_SYSTEM_HEADER (p) 613 && DECL_NAME (p) 614 && !DECL_ARTIFICIAL (p)) 615 warning ("%Junused variable `%D'", p, p); 616 /* fall through */ 617 618 default: 619 normal: 620 if (DECL_NAME (p)) 621 { 622 if (DECL_EXTERNAL (p) && scope != global_scope) 623 /* External decls stay in the symbol-value slot but are 624 inaccessible. */ 625 C_DECL_INVISIBLE (p) = 1; 626 else 627 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (p)) = 0; 628 } 629 break; 630 } 631 } 632 633 /* Clear out the parameter bindings in this scope, if any. 634 Unused-parameter warnings are handled by function.c. */ 635 for (p = scope->parms; p; p = TREE_CHAIN (p)) 636 if (DECL_NAME (p)) 637 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (p)) = 0; 638 639 /* Clear out the tag-meanings declared in this scope. 640 641 Set the TYPE_CONTEXTs for all of the tagged types belonging to 642 this scope so that they point to the appropriate construct, i.e. 643 either to the current FUNCTION_DECL node, or else to the BLOCK 644 node we just constructed. 645 646 Note that for tagged types whose scope is just the formal 647 parameter list for some function type specification, we can't 648 properly set their TYPE_CONTEXTs here, because we don't have a 649 pointer to the appropriate FUNCTION_TYPE node readily available 650 to us. For those cases, the TYPE_CONTEXTs of the relevant tagged 651 type nodes get set in `grokdeclarator' as soon as we have created 652 the FUNCTION_TYPE node which will represent the "scope" for these 653 "parameter list local" tagged types. */ 654 655 decl = scope->function_body ? current_function_decl : block; 656 for (p = scope->tags; p; p = TREE_CHAIN (p)) 657 { 658 if (TREE_PURPOSE (p)) 659 IDENTIFIER_TAG_VALUE (TREE_PURPOSE (p)) = 0; 660 if (decl) 661 TYPE_CONTEXT (TREE_VALUE (p)) = decl; 662 } 663 664 /* Restore all name- and label-meanings from outer scopes that were 665 shadowed by this scope. */ 666 for (p = scope->shadowed; p; p = TREE_CHAIN (p)) 667 if (TREE_VALUE (p) && TREE_CODE (TREE_VALUE (p)) == LABEL_DECL) 668 IDENTIFIER_LABEL_VALUE (TREE_PURPOSE (p)) = TREE_VALUE (p); 669 else 670 IDENTIFIER_SYMBOL_VALUE (TREE_PURPOSE (p)) = TREE_VALUE (p); 671 672 /* Restore all tag-meanings from outer scopes that were shadowed by 673 this scope. */ 674 for (p = scope->shadowed_tags; p; p = TREE_CHAIN (p)) 675 IDENTIFIER_TAG_VALUE (TREE_PURPOSE (p)) = TREE_VALUE (p); 676 677 /* Dispose of the block that we just made inside some higher level. */ 678 if (scope->function_body && current_function_decl) 679 DECL_INITIAL (current_function_decl) = block; 680 else if (scope->outer) 681 { 682 if (block) 683 SCOPE_LIST_APPEND (scope->outer, blocks, block); 684 /* If we did not make a block for the scope just exited, any 685 blocks made for inner scopes must be carried forward so they 686 will later become subblocks of something else. */ 687 else if (scope->blocks) 688 SCOPE_LIST_CONCAT (scope->outer, blocks, scope, blocks); 689 } 690 691 /* Pop the current scope, and free the structure for reuse. */ 692 pop_scope (); 693 694 return block; 695} 696 697/* Insert BLOCK at the end of the list of subblocks of the current 698 scope. This is used when a BIND_EXPR is expanded, to handle the 699 BLOCK node inside the BIND_EXPR. */ 700 701void 702insert_block (tree block) 703{ 704 TREE_USED (block) = 1; 705 SCOPE_LIST_APPEND (current_scope, blocks, block); 706} 707 708/* Set the BLOCK node for the innermost scope (the one we are 709 currently in). The RTL expansion machinery requires us to provide 710 this hook, but it is not useful in function-at-a-time mode. */ 711 712void 713set_block (tree block ATTRIBUTE_UNUSED) 714{ 715} 716 717/* Push a definition or a declaration of struct, union or enum tag "name". 718 "type" should be the type node. 719 We assume that the tag "name" is not already defined. 720 721 Note that the definition may really be just a forward reference. 722 In that case, the TYPE_SIZE will be zero. */ 723 724void 725pushtag (tree name, tree type) 726{ 727 struct c_scope *b = current_scope; 728 729 /* Record the identifier as the type's name if it has none. */ 730 if (name) 731 { 732 if (TYPE_NAME (type) == 0) 733 TYPE_NAME (type) = name; 734 735 if (IDENTIFIER_TAG_VALUE (name)) 736 b->shadowed_tags = tree_cons (name, IDENTIFIER_TAG_VALUE (name), 737 b->shadowed_tags); 738 IDENTIFIER_TAG_VALUE (name) = type; 739 } 740 741 b->tags = tree_cons (name, type, b->tags); 742 743 /* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the 744 tagged type we just added to the current scope. This fake 745 NULL-named TYPE_DECL node helps dwarfout.c to know when it needs 746 to output a representation of a tagged type, and it also gives 747 us a convenient place to record the "scope start" address for the 748 tagged type. */ 749 750 TYPE_STUB_DECL (type) = pushdecl (build_decl (TYPE_DECL, NULL_TREE, type)); 751 752 /* An approximation for now, so we can tell this is a function-scope tag. 753 This will be updated in poplevel. */ 754 TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type)); 755} 756 757/* Subroutine of compare_decls. Allow harmless mismatches in return 758 and argument types provided that the type modes match. This function 759 return a unified type given a suitable match, and 0 otherwise. */ 760 761static tree 762match_builtin_function_types (tree newtype, tree oldtype) 763{ 764 tree newrettype, oldrettype; 765 tree newargs, oldargs; 766 tree trytype, tryargs; 767 768 /* Accept the return type of the new declaration if same modes. */ 769 oldrettype = TREE_TYPE (oldtype); 770 newrettype = TREE_TYPE (newtype); 771 772 if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype)) 773 return 0; 774 775 oldargs = TYPE_ARG_TYPES (oldtype); 776 newargs = TYPE_ARG_TYPES (newtype); 777 tryargs = newargs; 778 779 while (oldargs || newargs) 780 { 781 if (! oldargs 782 || ! newargs 783 || ! TREE_VALUE (oldargs) 784 || ! TREE_VALUE (newargs) 785 || TYPE_MODE (TREE_VALUE (oldargs)) 786 != TYPE_MODE (TREE_VALUE (newargs))) 787 return 0; 788 789 oldargs = TREE_CHAIN (oldargs); 790 newargs = TREE_CHAIN (newargs); 791 } 792 793 trytype = build_function_type (newrettype, tryargs); 794 return build_type_attribute_variant (trytype, TYPE_ATTRIBUTES (oldtype)); 795} 796 797/* Subroutine of diagnose_mismathed_decls. Check for function type 798 mismatch involving an empty arglist vs a nonempty one and give clearer 799 diagnostics. */ 800static void 801diagnose_arglist_conflict (tree newdecl, tree olddecl, 802 tree newtype, tree oldtype) 803{ 804 tree t; 805 806 if (TREE_CODE (olddecl) != FUNCTION_DECL 807 || !comptypes (TREE_TYPE (oldtype), TREE_TYPE (newtype), COMPARE_STRICT) 808 || !((TYPE_ARG_TYPES (oldtype) == 0 && DECL_INITIAL (olddecl) == 0) 809 || 810 (TYPE_ARG_TYPES (newtype) == 0 && DECL_INITIAL (newdecl) == 0))) 811 return; 812 813 t = TYPE_ARG_TYPES (oldtype); 814 if (t == 0) 815 t = TYPE_ARG_TYPES (newtype); 816 for (; t; t = TREE_CHAIN (t)) 817 { 818 tree type = TREE_VALUE (t); 819 820 if (TREE_CHAIN (t) == 0 821 && TYPE_MAIN_VARIANT (type) != void_type_node) 822 { 823 inform ("a parameter list with an ellipsis can't match " 824 "an empty parameter name list declaration"); 825 break; 826 } 827 828 if (c_type_promotes_to (type) != type) 829 { 830 inform ("an argument type that has a default promotion can't match " 831 "an empty parameter name list declaration"); 832 break; 833 } 834 } 835} 836 837/* Another subroutine of diagnose_mismatched_decls. OLDDECL is an 838 old-style function definition, NEWDECL is a prototype declaration. 839 Diagnose inconsistencies in the argument list. Returns TRUE if 840 the prototype is compatible, FALSE if not. */ 841static bool 842validate_proto_after_old_defn (tree newdecl, tree newtype, tree oldtype) 843{ 844 tree newargs, oldargs; 845 int i; 846 847 /* ??? Elsewhere TYPE_MAIN_VARIANT is not used in this context. */ 848#define END_OF_ARGLIST(t) (TYPE_MAIN_VARIANT (t) == void_type_node) 849 850 oldargs = TYPE_ACTUAL_ARG_TYPES (oldtype); 851 newargs = TYPE_ARG_TYPES (newtype); 852 i = 1; 853 854 for (;;) 855 { 856 tree oldargtype = TREE_VALUE (oldargs); 857 tree newargtype = TREE_VALUE (newargs); 858 859 if (END_OF_ARGLIST (oldargtype) && END_OF_ARGLIST (newargtype)) 860 break; 861 862 /* Reaching the end of just one list means the two decls don't 863 agree on the number of arguments. */ 864 if (END_OF_ARGLIST (oldargtype)) 865 { 866 error ("%Jprototype for '%D' declares more arguments " 867 "than previous old-style definition", newdecl, newdecl); 868 return false; 869 } 870 else if (END_OF_ARGLIST (newargtype)) 871 { 872 error ("%Jprototype for '%D' declares fewer arguments " 873 "than previous old-style definition", newdecl, newdecl); 874 return false; 875 } 876 877 /* Type for passing arg must be consistent with that declared 878 for the arg. */ 879 else if (! comptypes (oldargtype, newargtype, COMPARE_STRICT)) 880 { 881 error ("%Jprototype for '%D' declares arg %d with incompatible type", 882 newdecl, newdecl, i); 883 return false; 884 } 885 886 oldargs = TREE_CHAIN (oldargs); 887 newargs = TREE_CHAIN (newargs); 888 i++; 889 } 890 891 /* If we get here, no errors were found, but do issue a warning 892 for this poor-style construct. */ 893 warning ("%Jprototype for '%D' follows non-prototype definition", 894 newdecl, newdecl); 895 return true; 896#undef END_OF_ARGLIST 897} 898 899/* Subroutine of diagnose_mismatched_decls. Report the location of DECL, 900 first in a pair of mismatched declarations, using the diagnostic 901 function DIAG. */ 902static void 903locate_old_decl (tree decl, void (*diag)(const char *, ...)) 904{ 905 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) 906 ; 907 else if (DECL_INITIAL (decl)) 908 diag (N_("%Jprevious definition of '%D' was here"), decl, decl); 909 else if (C_DECL_IMPLICIT (decl)) 910 diag (N_("%Jprevious implicit declaration of '%D' was here"), decl, decl); 911 else 912 diag (N_("%Jprevious declaration of '%D' was here"), decl, decl); 913} 914 915/* Subroutine of duplicate_decls. Compare NEWDECL to OLDDECL. 916 Returns true if the caller should proceed to merge the two, false 917 if OLDDECL should simply be discarded. As a side effect, issues 918 all necessary diagnostics for invalid or poor-style combinations. 919 If it returns true, writes the types of NEWDECL and OLDDECL to 920 *NEWTYPEP and *OLDTYPEP - these may have been adjusted from 921 TREE_TYPE (NEWDECL, OLDDECL) respectively. */ 922 923static bool 924diagnose_mismatched_decls (tree newdecl, tree olddecl, 925 tree *newtypep, tree *oldtypep) 926{ 927 tree newtype, oldtype; 928 bool pedwarned = false; 929 bool warned = false; 930 931 /* If we have error_mark_node for either decl or type, just discard 932 the previous decl - we're in an error cascade already. */ 933 if (olddecl == error_mark_node || newdecl == error_mark_node) 934 return false; 935 *oldtypep = oldtype = TREE_TYPE (olddecl); 936 *newtypep = newtype = TREE_TYPE (newdecl); 937 if (oldtype == error_mark_node || newtype == error_mark_node) 938 return false; 939 940 /* Two different categories of symbol altogether. This is an error 941 unless OLDDECL is a builtin. OLDDECL will be discarded in any case. */ 942 if (TREE_CODE (olddecl) != TREE_CODE (newdecl)) 943 { 944 if (TREE_CODE (olddecl) != FUNCTION_DECL 945 || !DECL_BUILT_IN (olddecl) || !C_DECL_INVISIBLE (olddecl)) 946 { 947 error ("%J'%D' redeclared as different kind of symbol", 948 newdecl, newdecl); 949 locate_old_decl (olddecl, error); 950 } 951 else if (TREE_PUBLIC (newdecl)) 952 warning ("%Jbuilt-in function '%D' declared as non-function", 953 newdecl, newdecl); 954 else if (warn_shadow) 955 warning ("%Jshadowing built-in function '%D'", 956 newdecl, newdecl); 957 return false; 958 } 959 960 if (!comptypes (oldtype, newtype, COMPARE_STRICT)) 961 { 962 if (TREE_CODE (olddecl) == FUNCTION_DECL 963 && DECL_BUILT_IN (olddecl) && C_DECL_INVISIBLE (olddecl)) 964 { 965 /* Accept harmless mismatch in function types. 966 This is for the ffs and fprintf builtins. */ 967 tree trytype = match_builtin_function_types (newtype, oldtype); 968 969 if (trytype && comptypes (newtype, trytype, COMPARE_STRICT)) 970 *oldtypep = oldtype = trytype; 971 else 972 { 973 /* If types don't match for a built-in, throw away the 974 built-in. No point in calling locate_old_decl here, it 975 won't print anything. */ 976 warning ("%Jconflicting types for built-in function '%D'", 977 newdecl, newdecl); 978 return false; 979 } 980 } 981 else if (TREE_CODE (olddecl) == FUNCTION_DECL 982 && DECL_SOURCE_LINE (olddecl) == 0) 983 { 984 /* A conflicting function declaration for a predeclared 985 function that isn't actually built in. Objective C uses 986 these. The new declaration silently overrides everything 987 but the volatility (i.e. noreturn) indication. See also 988 below. FIXME: Make Objective C use normal builtins. */ 989 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 990 return false; 991 } 992 /* Permit void foo (...) to match int foo (...) if the latter is 993 the definition and implicit int was used. See 994 c-torture/compile/920625-2.c. */ 995 else if (TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl) 996 && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == void_type_node 997 && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == integer_type_node 998 && C_FUNCTION_IMPLICIT_INT (newdecl)) 999 { 1000 pedwarn ("%Jconflicting types for '%D'", newdecl, newdecl); 1001 /* Make sure we keep void as the return type. */ 1002 TREE_TYPE (newdecl) = *newtypep = newtype = oldtype; 1003 C_FUNCTION_IMPLICIT_INT (newdecl) = 0; 1004 pedwarned = true; 1005 } 1006 else 1007 { 1008 error ("%Jconflicting types for '%D'", newdecl, newdecl); 1009 diagnose_arglist_conflict (newdecl, olddecl, newtype, oldtype); 1010 locate_old_decl (olddecl, error); 1011 return false; 1012 } 1013 } 1014 1015 /* Redeclaration of a type is a constraint violation (6.7.2.3p1), 1016 but silently ignore the redeclaration if either is in a system 1017 header. (Conflicting redeclarations were handled above.) */ 1018 if (TREE_CODE (newdecl) == TYPE_DECL) 1019 { 1020 if (DECL_IN_SYSTEM_HEADER (newdecl) || DECL_IN_SYSTEM_HEADER (olddecl)) 1021 return true; /* allow OLDDECL to continue in use */ 1022 1023 error ("%Jredefinition of typedef '%D'", newdecl, newdecl); 1024 locate_old_decl (olddecl, error); 1025 return false; 1026 } 1027 1028 /* Function declarations can either be 'static' or 'extern' (no 1029 qualifier is equivalent to 'extern' - C99 6.2.2p5) and therefore 1030 can never conflict with each other on account of linkage (6.2.2p4). 1031 Multiple definitions are not allowed (6.9p3,5) but GCC permits 1032 two definitions if one is 'extern inline' and one is not. The non- 1033 extern-inline definition supersedes the extern-inline definition. */ 1034 else if (TREE_CODE (newdecl) == FUNCTION_DECL) 1035 { 1036 /* If you declare a built-in function name as static, or 1037 define the built-in with an old-style definition (so we 1038 can't validate the argument list) the built-in definition is 1039 overridden, but optionally warn this was a bad choice of name. */ 1040 if (DECL_BUILT_IN (olddecl) 1041 && C_DECL_INVISIBLE (olddecl) 1042 && (!TREE_PUBLIC (newdecl) 1043 || (DECL_INITIAL (newdecl) 1044 && !TYPE_ARG_TYPES (TREE_TYPE (newdecl))))) 1045 { 1046 if (warn_shadow) 1047 warning ("%Jshadowing built-in function '%D'", newdecl, newdecl); 1048 /* Discard the old built-in function. */ 1049 return false; 1050 } 1051 1052 if (DECL_INITIAL (newdecl)) 1053 { 1054 if (DECL_INITIAL (olddecl) 1055 && !(DECL_DECLARED_INLINE_P (olddecl) 1056 && DECL_EXTERNAL (olddecl) 1057 && !(DECL_DECLARED_INLINE_P (newdecl) 1058 && DECL_EXTERNAL (newdecl)))) 1059 { 1060 error ("%Jredefinition of '%D'", newdecl, newdecl); 1061 locate_old_decl (olddecl, error); 1062 return false; 1063 } 1064 } 1065 /* If we have a prototype after an old-style function definition, 1066 the argument types must be checked specially. */ 1067 else if (DECL_INITIAL (olddecl) 1068 && !TYPE_ARG_TYPES (oldtype) && TYPE_ARG_TYPES (newtype) 1069 && TYPE_ACTUAL_ARG_TYPES (oldtype) 1070 && !validate_proto_after_old_defn (newdecl, newtype, oldtype)) 1071 { 1072 locate_old_decl (olddecl, error); 1073 return false; 1074 } 1075 /* Mismatched non-static and static is considered poor style. 1076 We only diagnose static then non-static if -Wtraditional, 1077 because it is the most convenient way to get some effects 1078 (see e.g. what unwind-dw2-fde-glibc.c does to the definition 1079 of _Unwind_Find_FDE in unwind-dw2-fde.c). Revisit? */ 1080 if (TREE_PUBLIC (olddecl) && !TREE_PUBLIC (newdecl)) 1081 { 1082 /* A static function declaration for a predeclared function 1083 that isn't actually built in, silently overrides the 1084 default. Objective C uses these. See also above. 1085 FIXME: Make Objective C use normal builtins. */ 1086 if (TREE_CODE (olddecl) == FUNCTION_DECL 1087 && DECL_SOURCE_LINE (olddecl) == 0) 1088 return false; 1089 else 1090 { 1091 warning ("%Jstatic declaration of '%D' follows " 1092 "non-static declaration", newdecl, newdecl); 1093 warned = true; 1094 } 1095 } 1096 else if (TREE_PUBLIC (newdecl) && !TREE_PUBLIC (olddecl) 1097 && warn_traditional) 1098 { 1099 warning ("%Jnon-static declaration of '%D' follows " 1100 "static declaration", newdecl, newdecl); 1101 warned = true; 1102 } 1103 } 1104 else if (TREE_CODE (newdecl) == VAR_DECL) 1105 { 1106 /* Only variables can be thread-local, and all declarations must 1107 agree on this property. */ 1108 if (DECL_THREAD_LOCAL (newdecl) != DECL_THREAD_LOCAL (olddecl)) 1109 { 1110 if (DECL_THREAD_LOCAL (newdecl)) 1111 error ("%Jthread-local declaration of '%D' follows " 1112 "non-thread-local declaration", newdecl, newdecl); 1113 else 1114 error ("%Jnon-thread-local declaration of '%D' follows " 1115 "thread-local declaration", newdecl, newdecl); 1116 1117 locate_old_decl (olddecl, error); 1118 return false; 1119 } 1120 1121 /* Multiple initialized definitions are not allowed (6.9p3,5). */ 1122 if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl)) 1123 { 1124 error ("%Jredefinition of '%D'", newdecl, newdecl); 1125 locate_old_decl (olddecl, error); 1126 return false; 1127 } 1128 1129 /* Objects declared at file scope: if at least one is 'extern', 1130 it's fine (6.2.2p4); otherwise the linkage must agree (6.2.2p7). */ 1131 if (DECL_FILE_SCOPE_P (newdecl)) 1132 { 1133 if (!DECL_EXTERNAL (newdecl) 1134 && !DECL_EXTERNAL (olddecl) 1135 && TREE_PUBLIC (newdecl) != TREE_PUBLIC (olddecl)) 1136 { 1137 if (TREE_PUBLIC (newdecl)) 1138 error ("%Jnon-static declaration of '%D' follows " 1139 "static declaration", newdecl, newdecl); 1140 else 1141 error ("%Jstatic declaration of '%D' follows " 1142 "non-static declaration", newdecl, newdecl); 1143 1144 locate_old_decl (olddecl, error); 1145 return false; 1146 } 1147 } 1148 /* Two objects with the same name declared at the same block 1149 scope must both be external references (6.7p3). */ 1150 else if (DECL_CONTEXT (newdecl) == DECL_CONTEXT (olddecl) 1151 && (!DECL_EXTERNAL (newdecl) || !DECL_EXTERNAL (olddecl))) 1152 { 1153 if (DECL_EXTERNAL (newdecl)) 1154 error ("%Jextern declaration of '%D' follows " 1155 "declaration with no linkage", newdecl, newdecl); 1156 else if (DECL_EXTERNAL (olddecl)) 1157 error ("%Jdeclaration of '%D' with no linkage follows " 1158 "extern declaration", newdecl, newdecl); 1159 else 1160 error ("%Jredeclaration of '%D' with no linkage", 1161 newdecl, newdecl); 1162 1163 locate_old_decl (olddecl, error); 1164 return false; 1165 } 1166 } 1167 1168 /* warnings */ 1169 /* All decls must agree on a non-default visibility. */ 1170 if (DECL_VISIBILITY (newdecl) != VISIBILITY_DEFAULT 1171 && DECL_VISIBILITY (olddecl) != VISIBILITY_DEFAULT 1172 && DECL_VISIBILITY (newdecl) != DECL_VISIBILITY (olddecl)) 1173 { 1174 warning ("%Jredeclaration of '%D' with different visibility " 1175 "(old visibility preserved)", newdecl, newdecl); 1176 warned = true; 1177 } 1178 1179 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1180 { 1181 /* Diagnose inline __attribute__ ((noinline)) which is silly. */ 1182 if (DECL_DECLARED_INLINE_P (newdecl) 1183 && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl))) 1184 { 1185 warning ("%Jinline declaration of '%D' follows " 1186 "declaration with attribute noinline", newdecl, newdecl); 1187 warned = true; 1188 } 1189 else if (DECL_DECLARED_INLINE_P (olddecl) 1190 && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl))) 1191 { 1192 warning ("%Jdeclaration of '%D' with attribute noinline follows " 1193 "inline declaration ", newdecl, newdecl); 1194 warned = true; 1195 } 1196 1197 /* Inline declaration after use or definition. 1198 ??? Should we still warn about this now we have unit-at-a-time 1199 mode and can get it right? */ 1200 if (DECL_DECLARED_INLINE_P (newdecl) && !DECL_DECLARED_INLINE_P (olddecl)) 1201 { 1202 if (TREE_USED (olddecl)) 1203 { 1204 warning ("%J'%D' declared inline after being called", 1205 olddecl, olddecl); 1206 warned = true; 1207 } 1208 else if (DECL_INITIAL (olddecl)) 1209 { 1210 warning ("%J'%D' declared inline after its definition", 1211 olddecl, olddecl); 1212 warned = true; 1213 } 1214 } 1215 } 1216 else /* PARM_DECL, VAR_DECL */ 1217 { 1218 /* Redeclaration of a PARM_DECL is invalid unless this is the 1219 real position of a forward-declared parameter (GCC extension). */ 1220 if (TREE_CODE (newdecl) == PARM_DECL 1221 && (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl))) 1222 { 1223 error ("%Jredefinition of parameter '%D'", newdecl, newdecl); 1224 locate_old_decl (olddecl, error); 1225 return false; 1226 } 1227 1228 /* These bits are only type qualifiers when applied to objects. */ 1229 if (TREE_THIS_VOLATILE (newdecl) != TREE_THIS_VOLATILE (olddecl)) 1230 { 1231 if (TREE_THIS_VOLATILE (newdecl)) 1232 pedwarn ("%Jvolatile declaration of '%D' follows " 1233 "non-volatile declaration", newdecl, newdecl); 1234 else 1235 pedwarn ("%Jnon-volatile declaration of '%D' follows " 1236 "volatile declaration", newdecl, newdecl); 1237 pedwarned = true; 1238 } 1239 if (TREE_READONLY (newdecl) != TREE_READONLY (olddecl)) 1240 { 1241 if (TREE_READONLY (newdecl)) 1242 pedwarn ("%Jconst declaration of '%D' follows " 1243 "non-const declaration", newdecl, newdecl); 1244 else 1245 pedwarn ("%Jnon-const declaration of '%D' follows " 1246 "const declaration", newdecl, newdecl); 1247 pedwarned = true; 1248 } 1249 } 1250 1251 /* Optional warning for completely redundant decls. */ 1252 if (!warned && !pedwarned 1253 && warn_redundant_decls 1254 /* Don't warn about a function declaration followed by a 1255 definition. */ 1256 && !(TREE_CODE (newdecl) == FUNCTION_DECL 1257 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl)) 1258 /* Don't warn about redundant redeclarations of builtins. */ 1259 && !(TREE_CODE (newdecl) == FUNCTION_DECL 1260 && !DECL_BUILT_IN (newdecl) 1261 && DECL_BUILT_IN (olddecl) 1262 && C_DECL_INVISIBLE (olddecl)) 1263 /* Don't warn about an extern followed by a definition. */ 1264 && !(DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl)) 1265 /* Don't warn about forward parameter decls. */ 1266 && !(TREE_CODE (newdecl) == PARM_DECL 1267 && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl)) 1268 /* Don't warn about a variable definition following a declaration. */ 1269 && !(TREE_CODE (newdecl) == VAR_DECL 1270 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl))) 1271 { 1272 warning ("%Jredundant redeclaration of '%D'", newdecl, newdecl); 1273 warned = true; 1274 } 1275 1276 /* Report location of previous decl/defn in a consistent manner. */ 1277 if (warned || pedwarned) 1278 locate_old_decl (olddecl, pedwarned ? pedwarn : warning); 1279 1280 return true; 1281} 1282 1283/* Subroutine of duplicate_decls. NEWDECL has been found to be 1284 consistent with OLDDECL, but carries new information. Merge the 1285 new information into OLDDECL. This function issues no 1286 diagnostics. */ 1287 1288static void 1289merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype) 1290{ 1291 int new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL 1292 && DECL_INITIAL (newdecl) != 0); 1293 1294 /* For real parm decl following a forward decl, return 1 so old decl 1295 will be reused. Only allow this to happen once. */ 1296 if (TREE_CODE (newdecl) == PARM_DECL 1297 && TREE_ASM_WRITTEN (olddecl) && ! TREE_ASM_WRITTEN (newdecl)) 1298 { 1299 TREE_ASM_WRITTEN (olddecl) = 0; 1300 return; 1301 } 1302 1303 DECL_ATTRIBUTES (newdecl) 1304 = (*targetm.merge_decl_attributes) (olddecl, newdecl); 1305 1306 /* Merge the data types specified in the two decls. */ 1307 TREE_TYPE (newdecl) 1308 = TREE_TYPE (olddecl) 1309 = common_type (newtype, oldtype); 1310 1311 /* Lay the type out, unless already done. */ 1312 if (oldtype != TREE_TYPE (newdecl)) 1313 { 1314 if (TREE_TYPE (newdecl) != error_mark_node) 1315 layout_type (TREE_TYPE (newdecl)); 1316 if (TREE_CODE (newdecl) != FUNCTION_DECL 1317 && TREE_CODE (newdecl) != TYPE_DECL 1318 && TREE_CODE (newdecl) != CONST_DECL) 1319 layout_decl (newdecl, 0); 1320 } 1321 else 1322 { 1323 /* Since the type is OLDDECL's, make OLDDECL's size go with. */ 1324 DECL_SIZE (newdecl) = DECL_SIZE (olddecl); 1325 DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl); 1326 DECL_MODE (newdecl) = DECL_MODE (olddecl); 1327 if (TREE_CODE (olddecl) != FUNCTION_DECL) 1328 if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl)) 1329 { 1330 DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl); 1331 DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl); 1332 } 1333 } 1334 1335 /* Keep the old rtl since we can safely use it. */ 1336 COPY_DECL_RTL (olddecl, newdecl); 1337 1338 /* Merge the type qualifiers. */ 1339 if (TREE_READONLY (newdecl)) 1340 TREE_READONLY (olddecl) = 1; 1341 1342 if (TREE_THIS_VOLATILE (newdecl)) 1343 { 1344 TREE_THIS_VOLATILE (olddecl) = 1; 1345 if (TREE_CODE (newdecl) == VAR_DECL) 1346 make_var_volatile (newdecl); 1347 } 1348 1349 /* Keep source location of definition rather than declaration. */ 1350 if (DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0) 1351 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 1352 1353 /* Merge the unused-warning information. */ 1354 if (DECL_IN_SYSTEM_HEADER (olddecl)) 1355 DECL_IN_SYSTEM_HEADER (newdecl) = 1; 1356 else if (DECL_IN_SYSTEM_HEADER (newdecl)) 1357 DECL_IN_SYSTEM_HEADER (olddecl) = 1; 1358 1359 /* Merge the initialization information. */ 1360 if (DECL_INITIAL (newdecl) == 0) 1361 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1362 1363 /* Merge the section attribute. 1364 We want to issue an error if the sections conflict but that must be 1365 done later in decl_attributes since we are called before attributes 1366 are assigned. */ 1367 if (DECL_SECTION_NAME (newdecl) == NULL_TREE) 1368 DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl); 1369 1370 /* Copy the assembler name. 1371 Currently, it can only be defined in the prototype. */ 1372 COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl); 1373 1374 /* If either declaration has a nondefault visibility, use it. */ 1375 if (DECL_VISIBILITY (olddecl) != VISIBILITY_DEFAULT) 1376 DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl); 1377 1378 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1379 { 1380 DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl); 1381 DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl); 1382 DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl); 1383 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl) 1384 |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl); 1385 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1386 TREE_READONLY (newdecl) |= TREE_READONLY (olddecl); 1387 DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl); 1388 DECL_IS_PURE (newdecl) |= DECL_IS_PURE (olddecl); 1389 } 1390 1391 /* Merge the storage class information. */ 1392 merge_weak (newdecl, olddecl); 1393 1394 /* For functions, static overrides non-static. */ 1395 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1396 { 1397 TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl); 1398 /* This is since we don't automatically 1399 copy the attributes of NEWDECL into OLDDECL. */ 1400 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1401 /* If this clears `static', clear it in the identifier too. */ 1402 if (! TREE_PUBLIC (olddecl)) 1403 TREE_PUBLIC (DECL_NAME (olddecl)) = 0; 1404 } 1405 if (DECL_EXTERNAL (newdecl)) 1406 { 1407 TREE_STATIC (newdecl) = TREE_STATIC (olddecl); 1408 DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl); 1409 1410 /* An extern decl does not override previous storage class. */ 1411 TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl); 1412 if (! DECL_EXTERNAL (newdecl)) 1413 { 1414 DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl); 1415 DECL_COMMON (newdecl) = DECL_COMMON (olddecl); 1416 } 1417 } 1418 else 1419 { 1420 TREE_STATIC (olddecl) = TREE_STATIC (newdecl); 1421 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 1422 } 1423 1424 if (TREE_CODE (newdecl) == FUNCTION_DECL) 1425 { 1426 /* If we're redefining a function previously defined as extern 1427 inline, make sure we emit debug info for the inline before we 1428 throw it away, in case it was inlined into a function that hasn't 1429 been written out yet. */ 1430 if (new_is_definition && DECL_INITIAL (olddecl)) 1431 { 1432 if (TREE_USED (olddecl) 1433 /* In unit-at-a-time mode we never inline re-defined extern 1434 inline functions. */ 1435 && !flag_unit_at_a_time 1436 && cgraph_function_possibly_inlined_p (olddecl)) 1437 (*debug_hooks->outlining_inline_function) (olddecl); 1438 1439 /* The new defn must not be inline. */ 1440 DECL_INLINE (newdecl) = 0; 1441 DECL_UNINLINABLE (newdecl) = 1; 1442 } 1443 else 1444 { 1445 /* If either decl says `inline', this fn is inline, 1446 unless its definition was passed already. */ 1447 if (DECL_DECLARED_INLINE_P (newdecl) 1448 || DECL_DECLARED_INLINE_P (olddecl)) 1449 DECL_DECLARED_INLINE_P (newdecl) = 1; 1450 1451 DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl) 1452 = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)); 1453 } 1454 1455 if (DECL_BUILT_IN (olddecl)) 1456 { 1457 /* If redeclaring a builtin function, it stays built in. */ 1458 DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl); 1459 DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl); 1460 } 1461 1462 /* Also preserve various other info from the definition. */ 1463 if (! new_is_definition) 1464 { 1465 DECL_RESULT (newdecl) = DECL_RESULT (olddecl); 1466 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 1467 DECL_SAVED_INSNS (newdecl) = DECL_SAVED_INSNS (olddecl); 1468 DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl); 1469 DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl); 1470 1471 /* Set DECL_INLINE on the declaration if we've got a body 1472 from which to instantiate. */ 1473 if (DECL_INLINE (olddecl) && ! DECL_UNINLINABLE (newdecl)) 1474 { 1475 DECL_INLINE (newdecl) = 1; 1476 DECL_ABSTRACT_ORIGIN (newdecl) 1477 = DECL_ABSTRACT_ORIGIN (olddecl); 1478 } 1479 } 1480 else 1481 { 1482 /* If a previous declaration said inline, mark the 1483 definition as inlinable. */ 1484 if (DECL_DECLARED_INLINE_P (newdecl) 1485 && ! DECL_UNINLINABLE (newdecl)) 1486 DECL_INLINE (newdecl) = 1; 1487 } 1488 } 1489 1490 /* Copy most of the decl-specific fields of NEWDECL into OLDDECL. 1491 But preserve OLDDECL's DECL_UID and C_DECL_INVISIBLE. */ 1492 { 1493 unsigned olddecl_uid = DECL_UID (olddecl); 1494 unsigned olddecl_invisible = C_DECL_INVISIBLE (olddecl); 1495 1496 memcpy ((char *) olddecl + sizeof (struct tree_common), 1497 (char *) newdecl + sizeof (struct tree_common), 1498 sizeof (struct tree_decl) - sizeof (struct tree_common)); 1499 DECL_UID (olddecl) = olddecl_uid; 1500 C_DECL_INVISIBLE (olddecl) = olddecl_invisible; 1501 } 1502 1503 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl 1504 so that encode_section_info has a chance to look at the new decl 1505 flags and attributes. */ 1506 if (DECL_RTL_SET_P (olddecl) 1507 && (TREE_CODE (olddecl) == FUNCTION_DECL 1508 || (TREE_CODE (olddecl) == VAR_DECL 1509 && TREE_STATIC (olddecl)))) 1510 make_decl_rtl (olddecl, NULL); 1511} 1512 1513/* Handle when a new declaration NEWDECL has the same name as an old 1514 one OLDDECL in the same binding contour. Prints an error message 1515 if appropriate. 1516 1517 If safely possible, alter OLDDECL to look like NEWDECL, and return 1518 true. Otherwise, return false. */ 1519 1520static bool 1521duplicate_decls (tree newdecl, tree olddecl) 1522{ 1523 tree newtype, oldtype; 1524 1525 if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype)) 1526 return false; 1527 1528 merge_decls (newdecl, olddecl, newtype, oldtype); 1529 return true; 1530} 1531 1532 1533/* Return any external DECL associated with ID, whether or not it is 1534 currently in scope. */ 1535 1536static tree 1537any_external_decl (tree id) 1538{ 1539 tree decl = IDENTIFIER_SYMBOL_VALUE (id); 1540 tree t; 1541 1542 if (decl == 0 || TREE_CODE (decl) == ERROR_MARK) 1543 return 0; 1544 else if (TREE_CODE (decl) != TYPE_DECL && DECL_EXTERNAL (decl)) 1545 return decl; 1546 1547 t = purpose_member (id, truly_local_externals); 1548 if (t) 1549 return TREE_VALUE (t); 1550 1551 return 0; 1552} 1553 1554/* Record an external decl DECL. This only does something if a 1555 shadowing decl already exists. */ 1556static void 1557record_external_decl (tree decl) 1558{ 1559 tree name = DECL_NAME (decl); 1560 if (!IDENTIFIER_SYMBOL_VALUE (name)) 1561 return; 1562 1563 truly_local_externals = tree_cons (name, decl, truly_local_externals); 1564} 1565 1566/* Check whether decl-node X shadows an existing declaration. 1567 OLD is the old IDENTIFIER_SYMBOL_VALUE of the DECL_NAME of X, 1568 which might be a NULL_TREE. */ 1569static void 1570warn_if_shadowing (tree x, tree old) 1571{ 1572 /* Nothing to shadow? */ 1573 if (old == 0 1574 /* Shadow warnings not wanted? */ 1575 || !warn_shadow 1576 /* No shadow warnings for internally generated vars. */ 1577 || DECL_SOURCE_LINE (x) == 0 1578 /* No shadow warnings for vars made for inlining. */ 1579 || DECL_FROM_INLINE (x) 1580 /* Don't warn about the parm names in function declarator 1581 within a function declarator. 1582 It would be nice to avoid warning in any function 1583 declarator in a declaration, as opposed to a definition, 1584 but there is no way to tell it's not a definition. */ 1585 || (TREE_CODE (x) == PARM_DECL && current_scope->outer->parm_flag) 1586 /* Shadow warnings only apply to local variables and parameters. */ 1587 || (TREE_CODE (x) != PARM_DECL && DECL_FILE_SCOPE_P (x))) 1588 return; 1589 1590 if (TREE_CODE (old) == PARM_DECL) 1591 warning ("%Jdeclaration of '%D' shadows a parameter", x, x); 1592 else if (DECL_FILE_SCOPE_P (old)) 1593 warning ("%Jdeclaration of '%D' shadows a global declaration", x, x); 1594 else 1595 warning ("%Jdeclaration of '%D' shadows a previous local", x, x); 1596 1597 warning ("%Jshadowed declaration is here", old); 1598} 1599 1600 1601/* Subroutine of pushdecl. 1602 1603 X is a TYPE_DECL for a typedef statement. Create a brand new 1604 ..._TYPE node (which will be just a variant of the existing 1605 ..._TYPE node with identical properties) and then install X 1606 as the TYPE_NAME of this brand new (duplicate) ..._TYPE node. 1607 1608 The whole point here is to end up with a situation where each 1609 and every ..._TYPE node the compiler creates will be uniquely 1610 associated with AT MOST one node representing a typedef name. 1611 This way, even though the compiler substitutes corresponding 1612 ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very 1613 early on, later parts of the compiler can always do the reverse 1614 translation and get back the corresponding typedef name. For 1615 example, given: 1616 1617 typedef struct S MY_TYPE; 1618 MY_TYPE object; 1619 1620 Later parts of the compiler might only know that `object' was of 1621 type `struct S' if it were not for code just below. With this 1622 code however, later parts of the compiler see something like: 1623 1624 struct S' == struct S 1625 typedef struct S' MY_TYPE; 1626 struct S' object; 1627 1628 And they can then deduce (from the node for type struct S') that 1629 the original object declaration was: 1630 1631 MY_TYPE object; 1632 1633 Being able to do this is important for proper support of protoize, 1634 and also for generating precise symbolic debugging information 1635 which takes full account of the programmer's (typedef) vocabulary. 1636 1637 Obviously, we don't want to generate a duplicate ..._TYPE node if 1638 the TYPE_DECL node that we are now processing really represents a 1639 standard built-in type. 1640 1641 Since all standard types are effectively declared at line zero 1642 in the source file, we can easily check to see if we are working 1643 on a standard type by checking the current value of lineno. */ 1644 1645static void 1646clone_underlying_type (tree x) 1647{ 1648 if (DECL_SOURCE_LINE (x) == 0) 1649 { 1650 if (TYPE_NAME (TREE_TYPE (x)) == 0) 1651 TYPE_NAME (TREE_TYPE (x)) = x; 1652 } 1653 else if (TREE_TYPE (x) != error_mark_node 1654 && DECL_ORIGINAL_TYPE (x) == NULL_TREE) 1655 { 1656 tree tt = TREE_TYPE (x); 1657 DECL_ORIGINAL_TYPE (x) = tt; 1658 tt = build_type_copy (tt); 1659 TYPE_NAME (tt) = x; 1660 TREE_USED (tt) = TREE_USED (x); 1661 TREE_TYPE (x) = tt; 1662 } 1663} 1664 1665/* Record a decl-node X as belonging to the current lexical scope. 1666 Check for errors (such as an incompatible declaration for the same 1667 name already seen in the same scope). 1668 1669 Returns either X or an old decl for the same name. 1670 If an old decl is returned, it may have been smashed 1671 to agree with what X says. */ 1672 1673tree 1674pushdecl (tree x) 1675{ 1676 tree name = DECL_NAME (x); 1677 struct c_scope *scope = current_scope; 1678 1679#ifdef ENABLE_CHECKING 1680 if (error_mark_node == 0) 1681 /* Called too early. */ 1682 abort (); 1683#endif 1684 1685 /* Functions need the lang_decl data. */ 1686 if (TREE_CODE (x) == FUNCTION_DECL && ! DECL_LANG_SPECIFIC (x)) 1687 DECL_LANG_SPECIFIC (x) = ggc_alloc_cleared (sizeof (struct lang_decl)); 1688 1689 /* A local extern declaration for a function doesn't constitute nesting. 1690 A local auto declaration does, since it's a forward decl 1691 for a nested function coming later. */ 1692 if (current_function_decl == NULL 1693 || ((TREE_CODE (x) == FUNCTION_DECL || TREE_CODE (x) == VAR_DECL) 1694 && DECL_INITIAL (x) == 0 && DECL_EXTERNAL (x))) 1695 DECL_CONTEXT (x) = current_file_decl; 1696 else 1697 DECL_CONTEXT (x) = current_function_decl; 1698 1699 if (name) 1700 { 1701 tree old; 1702 1703 if (warn_nested_externs 1704 && scope != global_scope 1705 && DECL_EXTERNAL (x) 1706 && !DECL_IN_SYSTEM_HEADER (x)) 1707 warning ("nested extern declaration of `%s'", 1708 IDENTIFIER_POINTER (name)); 1709 1710 old = lookup_name_current_level (name); 1711 if (old && duplicate_decls (x, old)) 1712 { 1713 /* For PARM_DECLs, old may be a forward declaration. 1714 If so, we want to remove it from its old location 1715 (in the variables chain) and rechain it in the 1716 location given by the new declaration. */ 1717 if (TREE_CODE (x) == PARM_DECL) 1718 { 1719 tree *p; 1720 for (p = &scope->names; *p; p = &TREE_CHAIN (*p)) 1721 if (*p == old) 1722 { 1723 *p = TREE_CHAIN (old); 1724 SCOPE_LIST_APPEND (scope, parms, old); 1725 break; 1726 } 1727 } 1728 return old; 1729 } 1730 if (DECL_EXTERNAL (x) || scope == global_scope) 1731 { 1732 /* Find and check against a previous, not-in-scope, external 1733 decl for this identifier. (C99 6.2.7p2: All declarations 1734 that refer to the same object or function shall have 1735 compatible type; otherwise, the behavior is undefined.) */ 1736 tree ext = any_external_decl (name); 1737 if (ext) 1738 { 1739 if (duplicate_decls (x, ext)) 1740 x = copy_node (ext); 1741 } 1742 else 1743 record_external_decl (x); 1744 } 1745 1746 if (TREE_CODE (x) == TYPE_DECL) 1747 clone_underlying_type (x); 1748 1749 /* If storing a local value, there may already be one 1750 (inherited). If so, record it for restoration when this 1751 scope ends. Take care not to do this if we are replacing an 1752 older decl in the same scope (i.e. duplicate_decls returned 1753 false, above). */ 1754 if (scope != global_scope) 1755 { 1756 tree inherited_decl = lookup_name (name); 1757 if (inherited_decl && inherited_decl != old) 1758 { 1759 warn_if_shadowing (x, inherited_decl); 1760 scope->shadowed = tree_cons (name, inherited_decl, 1761 scope->shadowed); 1762 } 1763 } 1764 1765 /* Install the new declaration in the requested scope. */ 1766 IDENTIFIER_SYMBOL_VALUE (name) = x; 1767 C_DECL_INVISIBLE (x) = 0; 1768 1769 /* If x's type is incomplete because it's based on a 1770 structure or union which has not yet been fully declared, 1771 attach it to that structure or union type, so we can go 1772 back and complete the variable declaration later, if the 1773 structure or union gets fully declared. 1774 1775 If the input is erroneous, we can have error_mark in the type 1776 slot (e.g. "f(void a, ...)") - that doesn't count as an 1777 incomplete type. */ 1778 if (TREE_TYPE (x) != error_mark_node 1779 && !COMPLETE_TYPE_P (TREE_TYPE (x))) 1780 { 1781 tree element = TREE_TYPE (x); 1782 1783 while (TREE_CODE (element) == ARRAY_TYPE) 1784 element = TREE_TYPE (element); 1785 element = TYPE_MAIN_VARIANT (element); 1786 1787 if ((TREE_CODE (element) == RECORD_TYPE 1788 || TREE_CODE (element) == UNION_TYPE) 1789 && (TREE_CODE (x) != TYPE_DECL 1790 || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE) 1791 && !COMPLETE_TYPE_P (element)) 1792 C_TYPE_INCOMPLETE_VARS (element) 1793 = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element)); 1794 } 1795 } 1796 1797 if (TREE_CODE (x) == PARM_DECL) 1798 SCOPE_LIST_APPEND (scope, parms, x); 1799 else 1800 SCOPE_LIST_APPEND (scope, names, x); 1801 1802 return x; 1803} 1804 1805/* Record X as belonging to the global scope (C99 "file scope"). 1806 This is used only internally by the Objective-C front end, 1807 and is limited to its needs. duplicate_decls is not called; 1808 if there is any preexisting decl for this identifier, it is an ICE. */ 1809 1810tree 1811pushdecl_top_level (tree x) 1812{ 1813 tree name; 1814 1815 if (TREE_CODE (x) != VAR_DECL) 1816 abort (); 1817 1818 name = DECL_NAME (x); 1819 1820 if (IDENTIFIER_SYMBOL_VALUE (name)) 1821 abort (); 1822 1823 DECL_CONTEXT (x) = current_file_decl; 1824 IDENTIFIER_SYMBOL_VALUE (name) = x; 1825 1826 SCOPE_LIST_APPEND (global_scope, names, x); 1827 return x; 1828} 1829 1830/* Generate an implicit declaration for identifier FUNCTIONID as a 1831 function of type int (). */ 1832 1833tree 1834implicitly_declare (tree functionid) 1835{ 1836 tree decl = any_external_decl (functionid); 1837 1838 if (decl) 1839 { 1840 /* Implicit declaration of a function already declared 1841 (somehow) in a different scope, or as a built-in. 1842 If this is the first time this has happened, warn; 1843 then recycle the old declaration. */ 1844 if (!C_DECL_IMPLICIT (decl)) 1845 { 1846 implicit_decl_warning (DECL_NAME (decl)); 1847 if (! DECL_FILE_SCOPE_P (decl)) 1848 warning ("%Jprevious declaration of '%D'", decl, decl); 1849 C_DECL_IMPLICIT (decl) = 1; 1850 } 1851 /* If this function is global, then it must already be in the 1852 global scope, so there's no need to push it again. */ 1853 if (current_scope == global_scope) 1854 return decl; 1855 /* If this is a local declaration, make a copy; we can't have 1856 the same DECL listed in two different scopes. */ 1857 return pushdecl (copy_node (decl)); 1858 } 1859 1860 /* Not seen before. */ 1861 decl = build_decl (FUNCTION_DECL, functionid, default_function_type); 1862 DECL_EXTERNAL (decl) = 1; 1863 TREE_PUBLIC (decl) = 1; 1864 C_DECL_IMPLICIT (decl) = 1; 1865 implicit_decl_warning (functionid); 1866 1867 /* C89 says implicit declarations are in the innermost block. 1868 So we record the decl in the standard fashion. */ 1869 decl = pushdecl (decl); 1870 1871 /* No need to call objc_check_decl here - it's a function type. */ 1872 rest_of_decl_compilation (decl, NULL, 0, 0); 1873 1874 /* Write a record describing this implicit function declaration 1875 to the prototypes file (if requested). */ 1876 gen_aux_info_record (decl, 0, 1, 0); 1877 1878 /* Possibly apply some default attributes to this implicit declaration. */ 1879 decl_attributes (&decl, NULL_TREE, 0); 1880 1881 return decl; 1882} 1883 1884static void 1885implicit_decl_warning (tree id) 1886{ 1887 const char *name = IDENTIFIER_POINTER (id); 1888 if (mesg_implicit_function_declaration == 2) 1889 error ("implicit declaration of function `%s'", name); 1890 else if (mesg_implicit_function_declaration == 1) 1891 warning ("implicit declaration of function `%s'", name); 1892} 1893 1894/* Issue an error message for a reference to an undeclared variable 1895 ID, including a reference to a builtin outside of function-call 1896 context. Establish a binding of the identifier to error_mark_node 1897 in an appropriate scope, which will suppress further errors for the 1898 same identifier. */ 1899void 1900undeclared_variable (tree id) 1901{ 1902 static bool already = false; 1903 struct c_scope *scope; 1904 1905 if (current_function_decl == 0) 1906 { 1907 error ("`%s' undeclared here (not in a function)", 1908 IDENTIFIER_POINTER (id)); 1909 scope = current_scope; 1910 } 1911 else 1912 { 1913 error ("`%s' undeclared (first use in this function)", 1914 IDENTIFIER_POINTER (id)); 1915 1916 if (! already) 1917 { 1918 error ("(Each undeclared identifier is reported only once"); 1919 error ("for each function it appears in.)"); 1920 already = true; 1921 } 1922 1923 scope = current_function_scope; 1924 } 1925 1926 scope->shadowed = tree_cons (id, IDENTIFIER_SYMBOL_VALUE (id), 1927 scope->shadowed); 1928 IDENTIFIER_SYMBOL_VALUE (id) = error_mark_node; 1929} 1930 1931/* Subroutine of lookup_label, declare_label, define_label: construct a 1932 LABEL_DECL with all the proper frills. */ 1933 1934static tree 1935make_label (tree name, location_t location) 1936{ 1937 tree label = build_decl (LABEL_DECL, name, void_type_node); 1938 1939 DECL_CONTEXT (label) = current_function_decl; 1940 DECL_MODE (label) = VOIDmode; 1941 DECL_SOURCE_LOCATION (label) = location; 1942 1943 return label; 1944} 1945 1946/* Another subroutine of lookup_label, declare_label, define_label: 1947 set up the binding of name to LABEL_DECL in the given SCOPE. */ 1948 1949static void 1950bind_label (tree name, tree label, struct c_scope *scope) 1951{ 1952 if (IDENTIFIER_LABEL_VALUE (name)) 1953 scope->shadowed = tree_cons (name, IDENTIFIER_LABEL_VALUE (name), 1954 scope->shadowed); 1955 IDENTIFIER_LABEL_VALUE (name) = label; 1956 1957 SCOPE_LIST_APPEND (scope, names, label); 1958} 1959 1960/* Get the LABEL_DECL corresponding to identifier NAME as a label. 1961 Create one if none exists so far for the current function. 1962 This is called when a label is used in a goto expression or 1963 has its address taken. */ 1964 1965tree 1966lookup_label (tree name) 1967{ 1968 tree label; 1969 1970 if (current_function_decl == 0) 1971 { 1972 error ("label %s referenced outside of any function", 1973 IDENTIFIER_POINTER (name)); 1974 return 0; 1975 } 1976 1977 /* Use a label already defined or ref'd with this name, but not if 1978 it is inherited from a containing function and wasn't declared 1979 using __label__. */ 1980 label = IDENTIFIER_LABEL_VALUE (name); 1981 if (label && (DECL_CONTEXT (label) == current_function_decl 1982 || C_DECLARED_LABEL_FLAG (label))) 1983 { 1984 /* If the label has only been declared, update its apparent 1985 location to point here, for better diagnostics if it 1986 turns out not to have been defined. */ 1987 if (!TREE_USED (label)) 1988 DECL_SOURCE_LOCATION (label) = input_location; 1989 return label; 1990 } 1991 1992 /* No label binding for that identifier; make one. */ 1993 label = make_label (name, input_location); 1994 1995 /* Ordinary labels go in the current function scope. */ 1996 bind_label (name, label, current_function_scope); 1997 return label; 1998} 1999 2000/* Make a label named NAME in the current function, shadowing silently 2001 any that may be inherited from containing functions or containing 2002 scopes. This is called for __label__ declarations. */ 2003 2004/* Note that valid use, if the label being shadowed comes from another 2005 scope in the same function, requires calling declare_nonlocal_label 2006 right away. (Is this still true? -zw 2003-07-17) */ 2007 2008tree 2009declare_label (tree name) 2010{ 2011 tree label = IDENTIFIER_LABEL_VALUE (name); 2012 tree dup; 2013 2014 /* Check to make sure that the label hasn't already been declared 2015 at this scope */ 2016 for (dup = current_scope->names; dup; dup = TREE_CHAIN (dup)) 2017 if (dup == label) 2018 { 2019 error ("duplicate label declaration `%s'", IDENTIFIER_POINTER (name)); 2020 error ("%Jthis is a previous declaration", dup); 2021 2022 /* Just use the previous declaration. */ 2023 return dup; 2024 } 2025 2026 label = make_label (name, input_location); 2027 C_DECLARED_LABEL_FLAG (label) = 1; 2028 2029 /* Declared labels go in the current scope. */ 2030 bind_label (name, label, current_scope); 2031 return label; 2032} 2033 2034/* Define a label, specifying the location in the source file. 2035 Return the LABEL_DECL node for the label, if the definition is valid. 2036 Otherwise return 0. */ 2037 2038tree 2039define_label (location_t location, tree name) 2040{ 2041 tree label; 2042 2043 /* Find any preexisting label with this name. It is an error 2044 if that label has already been defined in this function, or 2045 if there is a containing function with a declared label with 2046 the same name. */ 2047 label = IDENTIFIER_LABEL_VALUE (name); 2048 2049 if (label 2050 && ((DECL_CONTEXT (label) == current_function_decl 2051 && DECL_INITIAL (label) != 0) 2052 || (DECL_CONTEXT (label) != current_function_decl 2053 && C_DECLARED_LABEL_FLAG (label)))) 2054 { 2055 error ("%Hduplicate label `%D'", &location, label); 2056 if (DECL_INITIAL (label)) 2057 error ("%J`%D' previously defined here", label, label); 2058 else 2059 error ("%J`%D' previously declared here", label, label); 2060 return 0; 2061 } 2062 else if (label && DECL_CONTEXT (label) == current_function_decl) 2063 { 2064 /* The label has been used or declared already in this function, 2065 but not defined. Update its location to point to this 2066 definition. */ 2067 DECL_SOURCE_LOCATION (label) = location; 2068 } 2069 else 2070 { 2071 /* No label binding for that identifier; make one. */ 2072 label = make_label (name, location); 2073 2074 /* Ordinary labels go in the current function scope. */ 2075 bind_label (name, label, current_function_scope); 2076 } 2077 2078 if (warn_traditional && !in_system_header && lookup_name (name)) 2079 warning ("%Htraditional C lacks a separate namespace for labels, " 2080 "identifier `%s' conflicts", &location, 2081 IDENTIFIER_POINTER (name)); 2082 2083 /* Mark label as having been defined. */ 2084 DECL_INITIAL (label) = error_mark_node; 2085 return label; 2086} 2087 2088/* Return the list of declarations of the current scope. */ 2089 2090tree 2091getdecls (void) 2092{ 2093 return current_scope->names; 2094} 2095 2096 2097/* Given NAME, an IDENTIFIER_NODE, 2098 return the structure (or union or enum) definition for that name. 2099 If THISLEVEL_ONLY is nonzero, searches only the current_scope. 2100 CODE says which kind of type the caller wants; 2101 it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE. 2102 If the wrong kind of type is found, an error is reported. */ 2103 2104static tree 2105lookup_tag (enum tree_code code, tree name, int thislevel_only) 2106{ 2107 tree tag = IDENTIFIER_TAG_VALUE (name); 2108 int thislevel = 0; 2109 2110 if (!tag) 2111 return 0; 2112 2113 /* We only care about whether it's in this level if 2114 thislevel_only was set or it might be a type clash. */ 2115 if (thislevel_only || TREE_CODE (tag) != code) 2116 { 2117 if (current_scope == global_scope 2118 || purpose_member (name, current_scope->tags)) 2119 thislevel = 1; 2120 } 2121 2122 if (thislevel_only && !thislevel) 2123 return 0; 2124 2125 if (TREE_CODE (tag) != code) 2126 { 2127 /* Definition isn't the kind we were looking for. */ 2128 pending_invalid_xref = name; 2129 pending_invalid_xref_location = input_location; 2130 2131 /* If in the same binding level as a declaration as a tag 2132 of a different type, this must not be allowed to 2133 shadow that tag, so give the error immediately. 2134 (For example, "struct foo; union foo;" is invalid.) */ 2135 if (thislevel) 2136 pending_xref_error (); 2137 } 2138 return tag; 2139} 2140 2141/* Print an error message now 2142 for a recent invalid struct, union or enum cross reference. 2143 We don't print them immediately because they are not invalid 2144 when used in the `struct foo;' construct for shadowing. */ 2145 2146void 2147pending_xref_error (void) 2148{ 2149 if (pending_invalid_xref != 0) 2150 error ("%H`%s' defined as wrong kind of tag", 2151 &pending_invalid_xref_location, 2152 IDENTIFIER_POINTER (pending_invalid_xref)); 2153 pending_invalid_xref = 0; 2154} 2155 2156 2157/* Look up NAME in the current scope and its superiors 2158 in the namespace of variables, functions and typedefs. 2159 Return a ..._DECL node of some kind representing its definition, 2160 or return 0 if it is undefined. */ 2161 2162tree 2163lookup_name (tree name) 2164{ 2165 tree decl = IDENTIFIER_SYMBOL_VALUE (name); 2166 if (decl == 0 || decl == error_mark_node) 2167 return decl; 2168 if (C_DECL_INVISIBLE (decl)) 2169 return 0; 2170 return decl; 2171} 2172 2173/* Similar to `lookup_name' but look only at the current scope. */ 2174 2175static tree 2176lookup_name_current_level (tree name) 2177{ 2178 tree decl = IDENTIFIER_SYMBOL_VALUE (name); 2179 2180 if (decl == 0 || decl == error_mark_node || C_DECL_INVISIBLE (decl)) 2181 return 0; 2182 2183 if (current_scope == global_scope) 2184 return decl; 2185 2186 /* Scan the current scope for a decl with name NAME. 2187 For PARM_DECLs, we have to look at both ->parms and ->names, since 2188 forward parameter declarations wind up on the ->names list. */ 2189 if (TREE_CODE (decl) == PARM_DECL 2190 && chain_member (decl, current_scope->parms)) 2191 return decl; 2192 if (chain_member (decl, current_scope->names)) 2193 return decl; 2194 2195 return 0; 2196} 2197 2198/* Create the predefined scalar types of C, 2199 and some nodes representing standard constants (0, 1, (void *) 0). 2200 Initialize the global scope. 2201 Make definitions for built-in primitive functions. */ 2202 2203void 2204c_init_decl_processing (void) 2205{ 2206 tree endlink; 2207 tree ptr_ftype_void, ptr_ftype_ptr; 2208 location_t save_loc = input_location; 2209 2210 /* Adds some ggc roots, and reserved words for c-parse.in. */ 2211 c_parse_init (); 2212 2213 current_function_decl = 0; 2214 2215 /* Make the c_scope structure for global names. */ 2216 pushlevel (0); 2217 global_scope = current_scope; 2218 2219 /* Declarations from c_common_nodes_and_builtins must not be associated 2220 with this input file, lest we get differences between using and not 2221 using preprocessed headers. */ 2222 input_location.file = "<internal>"; 2223 input_location.line = 0; 2224 2225 /* Make the DECL for the toplevel file scope. */ 2226 current_file_decl = build_decl (TRANSLATION_UNIT_DECL, NULL, NULL); 2227 2228 build_common_tree_nodes (flag_signed_char); 2229 2230 c_common_nodes_and_builtins (); 2231 2232 /* In C, comparisons and TRUTH_* expressions have type int. */ 2233 truthvalue_type_node = integer_type_node; 2234 truthvalue_true_node = integer_one_node; 2235 truthvalue_false_node = integer_zero_node; 2236 2237 /* Even in C99, which has a real boolean type. */ 2238 pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"), 2239 boolean_type_node)); 2240 2241 endlink = void_list_node; 2242 ptr_ftype_void = build_function_type (ptr_type_node, endlink); 2243 ptr_ftype_ptr 2244 = build_function_type (ptr_type_node, 2245 tree_cons (NULL_TREE, ptr_type_node, endlink)); 2246 2247 input_location = save_loc; 2248 2249 pedantic_lvalues = pedantic; 2250 2251 make_fname_decl = c_make_fname_decl; 2252 start_fname_decls (); 2253 2254 first_builtin_decl = global_scope->names; 2255 last_builtin_decl = global_scope->names_last; 2256} 2257 2258/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the 2259 decl, NAME is the initialization string and TYPE_DEP indicates whether 2260 NAME depended on the type of the function. As we don't yet implement 2261 delayed emission of static data, we mark the decl as emitted 2262 so it is not placed in the output. Anything using it must therefore pull 2263 out the STRING_CST initializer directly. FIXME. */ 2264 2265static tree 2266c_make_fname_decl (tree id, int type_dep) 2267{ 2268 const char *name = fname_as_string (type_dep); 2269 tree decl, type, init; 2270 size_t length = strlen (name); 2271 2272 type = build_array_type 2273 (build_qualified_type (char_type_node, TYPE_QUAL_CONST), 2274 build_index_type (size_int (length))); 2275 2276 decl = build_decl (VAR_DECL, id, type); 2277 2278 TREE_STATIC (decl) = 1; 2279 TREE_READONLY (decl) = 1; 2280 DECL_ARTIFICIAL (decl) = 1; 2281 2282 init = build_string (length + 1, name); 2283 TREE_TYPE (init) = type; 2284 DECL_INITIAL (decl) = init; 2285 2286 TREE_USED (decl) = 1; 2287 2288 if (current_function_decl) 2289 { 2290 DECL_CONTEXT (decl) = current_function_decl; 2291 IDENTIFIER_SYMBOL_VALUE (id) = decl; 2292 SCOPE_LIST_APPEND (current_function_scope, names, decl); 2293 } 2294 2295 finish_decl (decl, init, NULL_TREE); 2296 2297 return decl; 2298} 2299 2300/* Return a definition for a builtin function named NAME and whose data type 2301 is TYPE. TYPE should be a function type with argument types. 2302 FUNCTION_CODE tells later passes how to compile calls to this function. 2303 See tree.h for its possible values. 2304 2305 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, 2306 the name to be called if we can't opencode the function. If 2307 ATTRS is nonzero, use that for the function's attribute list. */ 2308 2309tree 2310builtin_function (const char *name, tree type, int function_code, 2311 enum built_in_class class, const char *library_name, 2312 tree attrs) 2313{ 2314 tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type); 2315 DECL_EXTERNAL (decl) = 1; 2316 TREE_PUBLIC (decl) = 1; 2317 if (library_name) 2318 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name)); 2319 make_decl_rtl (decl, NULL); 2320 pushdecl (decl); 2321 DECL_BUILT_IN_CLASS (decl) = class; 2322 DECL_FUNCTION_CODE (decl) = function_code; 2323 2324 /* Warn if a function in the namespace for users 2325 is used without an occasion to consider it declared. */ 2326 if (name[0] != '_' || name[1] != '_') 2327 C_DECL_INVISIBLE (decl) = 1; 2328 2329 /* Possibly apply some default attributes to this built-in function. */ 2330 if (attrs) 2331 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN); 2332 else 2333 decl_attributes (&decl, NULL_TREE, 0); 2334 2335 return decl; 2336} 2337 2338/* Called when a declaration is seen that contains no names to declare. 2339 If its type is a reference to a structure, union or enum inherited 2340 from a containing scope, shadow that tag name for the current scope 2341 with a forward reference. 2342 If its type defines a new named structure or union 2343 or defines an enum, it is valid but we need not do anything here. 2344 Otherwise, it is an error. */ 2345 2346void 2347shadow_tag (tree declspecs) 2348{ 2349 shadow_tag_warned (declspecs, 0); 2350} 2351 2352void 2353shadow_tag_warned (tree declspecs, int warned) 2354 2355 2356 /* 1 => we have done a pedwarn. 2 => we have done a warning, but 2357 no pedwarn. */ 2358{ 2359 int found_tag = 0; 2360 tree link; 2361 tree specs, attrs; 2362 2363 pending_invalid_xref = 0; 2364 2365 /* Remove the attributes from declspecs, since they will confuse the 2366 following code. */ 2367 split_specs_attrs (declspecs, &specs, &attrs); 2368 2369 for (link = specs; link; link = TREE_CHAIN (link)) 2370 { 2371 tree value = TREE_VALUE (link); 2372 enum tree_code code = TREE_CODE (value); 2373 2374 if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) 2375 /* Used to test also that TYPE_SIZE (value) != 0. 2376 That caused warning for `struct foo;' at top level in the file. */ 2377 { 2378 tree name = TYPE_NAME (value); 2379 tree t; 2380 2381 found_tag++; 2382 2383 if (name == 0) 2384 { 2385 if (warned != 1 && code != ENUMERAL_TYPE) 2386 /* Empty unnamed enum OK */ 2387 { 2388 pedwarn ("unnamed struct/union that defines no instances"); 2389 warned = 1; 2390 } 2391 } 2392 else 2393 { 2394 t = lookup_tag (code, name, 1); 2395 2396 if (t == 0) 2397 { 2398 t = make_node (code); 2399 pushtag (name, t); 2400 } 2401 } 2402 } 2403 else 2404 { 2405 if (!warned && ! in_system_header) 2406 { 2407 warning ("useless keyword or type name in empty declaration"); 2408 warned = 2; 2409 } 2410 } 2411 } 2412 2413 if (found_tag > 1) 2414 error ("two types specified in one empty declaration"); 2415 2416 if (warned != 1) 2417 { 2418 if (found_tag == 0) 2419 pedwarn ("empty declaration"); 2420 } 2421} 2422 2423/* Construct an array declarator. EXPR is the expression inside [], or 2424 NULL_TREE. QUALS are the type qualifiers inside the [] (to be applied 2425 to the pointer to which a parameter array is converted). STATIC_P is 2426 nonzero if "static" is inside the [], zero otherwise. VLA_UNSPEC_P 2427 is nonzero is the array is [*], a VLA of unspecified length which is 2428 nevertheless a complete type (not currently implemented by GCC), 2429 zero otherwise. The declarator is constructed as an ARRAY_REF 2430 (to be decoded by grokdeclarator), whose operand 0 is what's on the 2431 left of the [] (filled by in set_array_declarator_type) and operand 1 2432 is the expression inside; whose TREE_TYPE is the type qualifiers and 2433 which has TREE_STATIC set if "static" is used. */ 2434 2435tree 2436build_array_declarator (tree expr, tree quals, int static_p, int vla_unspec_p) 2437{ 2438 tree decl; 2439 decl = build_nt (ARRAY_REF, NULL_TREE, expr); 2440 TREE_TYPE (decl) = quals; 2441 TREE_STATIC (decl) = (static_p ? 1 : 0); 2442 if (pedantic && !flag_isoc99) 2443 { 2444 if (static_p || quals != NULL_TREE) 2445 pedwarn ("ISO C90 does not support `static' or type qualifiers in parameter array declarators"); 2446 if (vla_unspec_p) 2447 pedwarn ("ISO C90 does not support `[*]' array declarators"); 2448 } 2449 if (vla_unspec_p) 2450 warning ("GCC does not yet properly implement `[*]' array declarators"); 2451 return decl; 2452} 2453 2454/* Set the type of an array declarator. DECL is the declarator, as 2455 constructed by build_array_declarator; TYPE is what appears on the left 2456 of the [] and goes in operand 0. ABSTRACT_P is nonzero if it is an 2457 abstract declarator, zero otherwise; this is used to reject static and 2458 type qualifiers in abstract declarators, where they are not in the 2459 C99 grammar. */ 2460 2461tree 2462set_array_declarator_type (tree decl, tree type, int abstract_p) 2463{ 2464 TREE_OPERAND (decl, 0) = type; 2465 if (abstract_p && (TREE_TYPE (decl) != NULL_TREE || TREE_STATIC (decl))) 2466 error ("static or type qualifiers in abstract declarator"); 2467 return decl; 2468} 2469 2470/* Decode a "typename", such as "int **", returning a ..._TYPE node. */ 2471 2472tree 2473groktypename (tree typename) 2474{ 2475 tree specs, attrs; 2476 2477 if (TREE_CODE (typename) != TREE_LIST) 2478 return typename; 2479 2480 split_specs_attrs (TREE_PURPOSE (typename), &specs, &attrs); 2481 2482 typename = grokdeclarator (TREE_VALUE (typename), specs, TYPENAME, 0, 2483 NULL); 2484 2485 /* Apply attributes. */ 2486 decl_attributes (&typename, attrs, 0); 2487 2488 return typename; 2489} 2490 2491/* Return a PARM_DECL node for a given pair of specs and declarator. */ 2492 2493tree 2494groktypename_in_parm_context (tree typename) 2495{ 2496 if (TREE_CODE (typename) != TREE_LIST) 2497 return typename; 2498 return grokdeclarator (TREE_VALUE (typename), 2499 TREE_PURPOSE (typename), 2500 PARM, 0, NULL); 2501} 2502 2503/* Decode a declarator in an ordinary declaration or data definition. 2504 This is called as soon as the type information and variable name 2505 have been parsed, before parsing the initializer if any. 2506 Here we create the ..._DECL node, fill in its type, 2507 and put it on the list of decls for the current context. 2508 The ..._DECL node is returned as the value. 2509 2510 Exception: for arrays where the length is not specified, 2511 the type is left null, to be filled in by `finish_decl'. 2512 2513 Function definitions do not come here; they go to start_function 2514 instead. However, external and forward declarations of functions 2515 do go through here. Structure field declarations are done by 2516 grokfield and not through here. */ 2517 2518tree 2519start_decl (tree declarator, tree declspecs, int initialized, tree attributes) 2520{ 2521 tree decl; 2522 tree tem; 2523 2524 /* An object declared as __attribute__((deprecated)) suppresses 2525 warnings of uses of other deprecated items. */ 2526 if (lookup_attribute ("deprecated", attributes)) 2527 deprecated_state = DEPRECATED_SUPPRESS; 2528 2529 decl = grokdeclarator (declarator, declspecs, 2530 NORMAL, initialized, NULL); 2531 2532 deprecated_state = DEPRECATED_NORMAL; 2533 2534 if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL 2535 && MAIN_NAME_P (DECL_NAME (decl))) 2536 warning ("%J'%D' is usually a function", decl, decl); 2537 2538 if (initialized) 2539 /* Is it valid for this decl to have an initializer at all? 2540 If not, set INITIALIZED to zero, which will indirectly 2541 tell `finish_decl' to ignore the initializer once it is parsed. */ 2542 switch (TREE_CODE (decl)) 2543 { 2544 case TYPE_DECL: 2545 error ("typedef `%s' is initialized (use __typeof__ instead)", 2546 IDENTIFIER_POINTER (DECL_NAME (decl))); 2547 initialized = 0; 2548 break; 2549 2550 case FUNCTION_DECL: 2551 error ("function `%s' is initialized like a variable", 2552 IDENTIFIER_POINTER (DECL_NAME (decl))); 2553 initialized = 0; 2554 break; 2555 2556 case PARM_DECL: 2557 /* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE. */ 2558 error ("parameter `%s' is initialized", 2559 IDENTIFIER_POINTER (DECL_NAME (decl))); 2560 initialized = 0; 2561 break; 2562 2563 default: 2564 /* Don't allow initializations for incomplete types 2565 except for arrays which might be completed by the initialization. */ 2566 2567 /* This can happen if the array size is an undefined macro. We already 2568 gave a warning, so we don't need another one. */ 2569 if (TREE_TYPE (decl) == error_mark_node) 2570 initialized = 0; 2571 else if (COMPLETE_TYPE_P (TREE_TYPE (decl))) 2572 { 2573 /* A complete type is ok if size is fixed. */ 2574 2575 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST 2576 || C_DECL_VARIABLE_SIZE (decl)) 2577 { 2578 error ("variable-sized object may not be initialized"); 2579 initialized = 0; 2580 } 2581 } 2582 else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE) 2583 { 2584 error ("variable `%s' has initializer but incomplete type", 2585 IDENTIFIER_POINTER (DECL_NAME (decl))); 2586 initialized = 0; 2587 } 2588 else if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 2589 { 2590 error ("elements of array `%s' have incomplete type", 2591 IDENTIFIER_POINTER (DECL_NAME (decl))); 2592 initialized = 0; 2593 } 2594 } 2595 2596 if (initialized) 2597 { 2598 DECL_EXTERNAL (decl) = 0; 2599 if (current_scope == global_scope) 2600 TREE_STATIC (decl) = 1; 2601 2602 /* Tell `pushdecl' this is an initialized decl 2603 even though we don't yet have the initializer expression. 2604 Also tell `finish_decl' it may store the real initializer. */ 2605 DECL_INITIAL (decl) = error_mark_node; 2606 } 2607 2608 /* If this is a function declaration, write a record describing it to the 2609 prototypes file (if requested). */ 2610 2611 if (TREE_CODE (decl) == FUNCTION_DECL) 2612 gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0); 2613 2614 /* ANSI specifies that a tentative definition which is not merged with 2615 a non-tentative definition behaves exactly like a definition with an 2616 initializer equal to zero. (Section 3.7.2) 2617 2618 -fno-common gives strict ANSI behavior, though this tends to break 2619 a large body of code that grew up without this rule. 2620 2621 Thread-local variables are never common, since there's no entrenched 2622 body of code to break, and it allows more efficient variable references 2623 in the presence of dynamic linking. */ 2624 2625 if (TREE_CODE (decl) == VAR_DECL 2626 && !initialized 2627 && TREE_PUBLIC (decl) 2628 && !DECL_THREAD_LOCAL (decl) 2629 && !flag_no_common) 2630 DECL_COMMON (decl) = 1; 2631 2632 /* Set attributes here so if duplicate decl, will have proper attributes. */ 2633 decl_attributes (&decl, attributes, 0); 2634 2635 if (TREE_CODE (decl) == FUNCTION_DECL 2636 && targetm.calls.promote_prototypes (TREE_TYPE (decl))) 2637 { 2638 tree ce = declarator; 2639 2640 if (TREE_CODE (ce) == INDIRECT_REF) 2641 ce = TREE_OPERAND (declarator, 0); 2642 if (TREE_CODE (ce) == CALL_EXPR) 2643 { 2644 tree args = TREE_PURPOSE (TREE_OPERAND (ce, 1)); 2645 for (; args; args = TREE_CHAIN (args)) 2646 { 2647 tree type = TREE_TYPE (args); 2648 if (INTEGRAL_TYPE_P (type) 2649 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 2650 DECL_ARG_TYPE (args) = integer_type_node; 2651 } 2652 } 2653 } 2654 2655 if (TREE_CODE (decl) == FUNCTION_DECL 2656 && DECL_DECLARED_INLINE_P (decl) 2657 && DECL_UNINLINABLE (decl) 2658 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl))) 2659 warning ("%Jinline function '%D' given attribute noinline", decl, decl); 2660 2661 /* Add this decl to the current scope. 2662 TEM may equal DECL or it may be a previous decl of the same name. */ 2663 tem = pushdecl (decl); 2664 2665 /* For a local variable, define the RTL now. */ 2666 if (current_scope != global_scope 2667 /* But not if this is a duplicate decl 2668 and we preserved the rtl from the previous one 2669 (which may or may not happen). */ 2670 && !DECL_RTL_SET_P (tem) 2671 && DECL_FILE_SCOPE_P (tem)) 2672 { 2673 if (TREE_TYPE (tem) != error_mark_node 2674 && (COMPLETE_TYPE_P (TREE_TYPE (tem)) 2675 || (TREE_CODE (TREE_TYPE (tem)) == ARRAY_TYPE 2676 && DECL_INITIAL (tem) != 0))) 2677 expand_decl (tem); 2678 } 2679 2680 return tem; 2681} 2682 2683/* Finish processing of a declaration; 2684 install its initial value. 2685 If the length of an array type is not known before, 2686 it must be determined now, from the initial value, or it is an error. */ 2687 2688void 2689finish_decl (tree decl, tree init, tree asmspec_tree) 2690{ 2691 tree type = TREE_TYPE (decl); 2692 int was_incomplete = (DECL_SIZE (decl) == 0); 2693 const char *asmspec = 0; 2694 2695 /* If a name was specified, get the string. */ 2696 if (current_scope == global_scope) 2697 asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree); 2698 if (asmspec_tree) 2699 asmspec = TREE_STRING_POINTER (asmspec_tree); 2700 2701 /* If `start_decl' didn't like having an initialization, ignore it now. */ 2702 if (init != 0 && DECL_INITIAL (decl) == 0) 2703 init = 0; 2704 2705 /* Don't crash if parm is initialized. */ 2706 if (TREE_CODE (decl) == PARM_DECL) 2707 init = 0; 2708 2709 if (init) 2710 store_init_value (decl, init); 2711 2712 if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL 2713 || TREE_CODE (decl) == FUNCTION_DECL 2714 || TREE_CODE (decl) == FIELD_DECL)) 2715 objc_check_decl (decl); 2716 2717 /* Deduce size of array from initialization, if not already known. */ 2718 if (TREE_CODE (type) == ARRAY_TYPE 2719 && TYPE_DOMAIN (type) == 0 2720 && TREE_CODE (decl) != TYPE_DECL) 2721 { 2722 int do_default 2723 = (TREE_STATIC (decl) 2724 /* Even if pedantic, an external linkage array 2725 may have incomplete type at first. */ 2726 ? pedantic && !TREE_PUBLIC (decl) 2727 : !DECL_EXTERNAL (decl)); 2728 int failure 2729 = complete_array_type (type, DECL_INITIAL (decl), do_default); 2730 2731 /* Get the completed type made by complete_array_type. */ 2732 type = TREE_TYPE (decl); 2733 2734 if (failure == 1) 2735 error ("%Jinitializer fails to determine size of '%D'", decl, decl); 2736 2737 else if (failure == 2) 2738 { 2739 if (do_default) 2740 error ("%Jarray size missing in '%D'", decl, decl); 2741 /* If a `static' var's size isn't known, 2742 make it extern as well as static, so it does not get 2743 allocated. 2744 If it is not `static', then do not mark extern; 2745 finish_incomplete_decl will give it a default size 2746 and it will get allocated. */ 2747 else if (!pedantic && TREE_STATIC (decl) && ! TREE_PUBLIC (decl)) 2748 DECL_EXTERNAL (decl) = 1; 2749 } 2750 2751 /* TYPE_MAX_VALUE is always one less than the number of elements 2752 in the array, because we start counting at zero. Therefore, 2753 warn only if the value is less than zero. */ 2754 else if (pedantic && TYPE_DOMAIN (type) != 0 2755 && tree_int_cst_sgn (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) < 0) 2756 error ("%Jzero or negative size array '%D'", decl, decl); 2757 2758 layout_decl (decl, 0); 2759 } 2760 2761 if (TREE_CODE (decl) == VAR_DECL) 2762 { 2763 if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node 2764 && COMPLETE_TYPE_P (TREE_TYPE (decl))) 2765 layout_decl (decl, 0); 2766 2767 if (DECL_SIZE (decl) == 0 2768 /* Don't give an error if we already gave one earlier. */ 2769 && TREE_TYPE (decl) != error_mark_node 2770 && (TREE_STATIC (decl) 2771 ? 2772 /* A static variable with an incomplete type 2773 is an error if it is initialized. 2774 Also if it is not file scope. 2775 Otherwise, let it through, but if it is not `extern' 2776 then it may cause an error message later. */ 2777 (DECL_INITIAL (decl) != 0 2778 || !DECL_FILE_SCOPE_P (decl)) 2779 : 2780 /* An automatic variable with an incomplete type 2781 is an error. */ 2782 !DECL_EXTERNAL (decl))) 2783 { 2784 error ("%Jstorage size of '%D' isn't known", decl, decl); 2785 TREE_TYPE (decl) = error_mark_node; 2786 } 2787 2788 if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl)) 2789 && DECL_SIZE (decl) != 0) 2790 { 2791 if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) 2792 constant_expression_warning (DECL_SIZE (decl)); 2793 else 2794 error ("%Jstorage size of '%D' isn't constant", decl, decl); 2795 } 2796 2797 if (TREE_USED (type)) 2798 TREE_USED (decl) = 1; 2799 } 2800 2801 /* If this is a function and an assembler name is specified, reset DECL_RTL 2802 so we can give it its new name. Also, update built_in_decls if it 2803 was a normal built-in. */ 2804 if (TREE_CODE (decl) == FUNCTION_DECL && asmspec) 2805 { 2806 /* ASMSPEC is given, and not the name of a register. Mark the 2807 name with a star so assemble_name won't munge it. */ 2808 char *starred = alloca (strlen (asmspec) + 2); 2809 starred[0] = '*'; 2810 strcpy (starred + 1, asmspec); 2811 2812 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) 2813 { 2814 tree builtin = built_in_decls [DECL_FUNCTION_CODE (decl)]; 2815 SET_DECL_RTL (builtin, NULL_RTX); 2816 SET_DECL_ASSEMBLER_NAME (builtin, get_identifier (starred)); 2817#ifdef TARGET_MEM_FUNCTIONS 2818 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY) 2819 init_block_move_fn (starred); 2820 else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET) 2821 init_block_clear_fn (starred); 2822#else 2823 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_BCOPY) 2824 init_block_move_fn (starred); 2825 else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_BZERO) 2826 init_block_clear_fn (starred); 2827#endif 2828 } 2829 SET_DECL_RTL (decl, NULL_RTX); 2830 change_decl_assembler_name (decl, get_identifier (starred)); 2831 } 2832 2833 /* If #pragma weak was used, mark the decl weak now. */ 2834 if (current_scope == global_scope) 2835 maybe_apply_pragma_weak (decl); 2836 2837 /* Output the assembler code and/or RTL code for variables and functions, 2838 unless the type is an undefined structure or union. 2839 If not, it will get done when the type is completed. */ 2840 2841 if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL) 2842 { 2843 /* This is a no-op in c-lang.c or something real in objc-act.c. */ 2844 if (c_dialect_objc ()) 2845 objc_check_decl (decl); 2846 2847 if (DECL_FILE_SCOPE_P (decl)) 2848 { 2849 if (DECL_INITIAL (decl) == NULL_TREE 2850 || DECL_INITIAL (decl) == error_mark_node) 2851 /* Don't output anything 2852 when a tentative file-scope definition is seen. 2853 But at end of compilation, do output code for them. */ 2854 DECL_DEFER_OUTPUT (decl) = 1; 2855 rest_of_decl_compilation (decl, asmspec, true, 0); 2856 } 2857 else 2858 { 2859 /* This is a local variable. If there is an ASMSPEC, the 2860 user has requested that we handle it specially. */ 2861 if (asmspec) 2862 { 2863 /* In conjunction with an ASMSPEC, the `register' 2864 keyword indicates that we should place the variable 2865 in a particular register. */ 2866 if (DECL_REGISTER (decl)) 2867 DECL_C_HARD_REGISTER (decl) = 1; 2868 2869 /* If this is not a static variable, issue a warning. 2870 It doesn't make any sense to give an ASMSPEC for an 2871 ordinary, non-register local variable. Historically, 2872 GCC has accepted -- but ignored -- the ASMSPEC in 2873 this case. */ 2874 if (TREE_CODE (decl) == VAR_DECL 2875 && !DECL_REGISTER (decl) 2876 && !TREE_STATIC (decl)) 2877 warning ("%Jignoring asm-specifier for non-static local " 2878 "variable '%D'", decl, decl); 2879 else 2880 change_decl_assembler_name (decl, get_identifier (asmspec)); 2881 } 2882 2883 if (TREE_CODE (decl) != FUNCTION_DECL) 2884 add_decl_stmt (decl); 2885 } 2886 2887 if (!DECL_FILE_SCOPE_P (decl)) 2888 { 2889 /* Recompute the RTL of a local array now 2890 if it used to be an incomplete type. */ 2891 if (was_incomplete 2892 && ! TREE_STATIC (decl) && ! DECL_EXTERNAL (decl)) 2893 { 2894 /* If we used it already as memory, it must stay in memory. */ 2895 TREE_ADDRESSABLE (decl) = TREE_USED (decl); 2896 /* If it's still incomplete now, no init will save it. */ 2897 if (DECL_SIZE (decl) == 0) 2898 DECL_INITIAL (decl) = 0; 2899 } 2900 } 2901 } 2902 2903 /* If this was marked 'used', be sure it will be output. */ 2904 if (lookup_attribute ("used", DECL_ATTRIBUTES (decl))) 2905 mark_referenced (DECL_ASSEMBLER_NAME (decl)); 2906 2907 if (TREE_CODE (decl) == TYPE_DECL) 2908 rest_of_decl_compilation (decl, NULL, DECL_FILE_SCOPE_P (decl), 0); 2909 2910 /* At the end of a declaration, throw away any variable type sizes 2911 of types defined inside that declaration. There is no use 2912 computing them in the following function definition. */ 2913 if (current_scope == global_scope) 2914 get_pending_sizes (); 2915 2916 /* Install a cleanup (aka destructor) if one was given. */ 2917 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 2918 { 2919 tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl)); 2920 if (attr) 2921 { 2922 static bool eh_initialized_p; 2923 2924 tree cleanup_id = TREE_VALUE (TREE_VALUE (attr)); 2925 tree cleanup_decl = lookup_name (cleanup_id); 2926 tree cleanup; 2927 2928 /* Build "cleanup(&decl)" for the destructor. */ 2929 cleanup = build_unary_op (ADDR_EXPR, decl, 0); 2930 cleanup = build_tree_list (NULL_TREE, cleanup); 2931 cleanup = build_function_call (cleanup_decl, cleanup); 2932 2933 /* Don't warn about decl unused; the cleanup uses it. */ 2934 TREE_USED (decl) = 1; 2935 2936 /* Initialize EH, if we've been told to do so. */ 2937 if (flag_exceptions && !eh_initialized_p) 2938 { 2939 eh_initialized_p = true; 2940 eh_personality_libfunc 2941 = init_one_libfunc (USING_SJLJ_EXCEPTIONS 2942 ? "__gcc_personality_sj0" 2943 : "__gcc_personality_v0"); 2944 using_eh_for_cleanups (); 2945 } 2946 2947 add_stmt (build_stmt (CLEANUP_STMT, decl, cleanup)); 2948 } 2949 } 2950} 2951 2952/* Given a parsed parameter declaration, decode it into a PARM_DECL 2953 and push that on the current scope. */ 2954 2955void 2956push_parm_decl (tree parm) 2957{ 2958 tree decl; 2959 2960 /* Don't attempt to expand sizes while parsing this decl. 2961 (We can get here with i_s_e 1 somehow from Objective-C.) */ 2962 int save_immediate_size_expand = immediate_size_expand; 2963 immediate_size_expand = 0; 2964 2965 decl = grokdeclarator (TREE_VALUE (TREE_PURPOSE (parm)), 2966 TREE_PURPOSE (TREE_PURPOSE (parm)), 2967 PARM, 0, NULL); 2968 decl_attributes (&decl, TREE_VALUE (parm), 0); 2969 2970 decl = pushdecl (decl); 2971 2972 finish_decl (decl, NULL_TREE, NULL_TREE); 2973 2974 immediate_size_expand = save_immediate_size_expand; 2975} 2976 2977/* Mark all the parameter declarations to date as forward decls, 2978 shift them to the variables list, and reset the parameters list. 2979 Also diagnose use of this extension. */ 2980 2981void 2982mark_forward_parm_decls (void) 2983{ 2984 tree parm; 2985 2986 if (pedantic && !current_scope->warned_forward_parm_decls) 2987 { 2988 pedwarn ("ISO C forbids forward parameter declarations"); 2989 current_scope->warned_forward_parm_decls = true; 2990 } 2991 2992 for (parm = current_scope->parms; parm; parm = TREE_CHAIN (parm)) 2993 TREE_ASM_WRITTEN (parm) = 1; 2994 2995 SCOPE_LIST_CONCAT (current_scope, names, current_scope, parms); 2996 current_scope->parms = 0; 2997 current_scope->parms_last = 0; 2998} 2999 3000static GTY(()) int compound_literal_number; 3001 3002/* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound 3003 literal, which may be an incomplete array type completed by the 3004 initializer; INIT is a CONSTRUCTOR that initializes the compound 3005 literal. */ 3006 3007tree 3008build_compound_literal (tree type, tree init) 3009{ 3010 /* We do not use start_decl here because we have a type, not a declarator; 3011 and do not use finish_decl because the decl should be stored inside 3012 the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_STMT. */ 3013 tree decl = build_decl (VAR_DECL, NULL_TREE, type); 3014 tree complit; 3015 tree stmt; 3016 DECL_EXTERNAL (decl) = 0; 3017 TREE_PUBLIC (decl) = 0; 3018 TREE_STATIC (decl) = (current_scope == global_scope); 3019 DECL_CONTEXT (decl) = current_function_decl; 3020 TREE_USED (decl) = 1; 3021 TREE_TYPE (decl) = type; 3022 TREE_READONLY (decl) = TREE_READONLY (type); 3023 store_init_value (decl, init); 3024 3025 if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type)) 3026 { 3027 int failure = complete_array_type (type, DECL_INITIAL (decl), 1); 3028 if (failure) 3029 abort (); 3030 } 3031 3032 type = TREE_TYPE (decl); 3033 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 3034 return error_mark_node; 3035 3036 stmt = build_stmt (DECL_STMT, decl); 3037 complit = build1 (COMPOUND_LITERAL_EXPR, TREE_TYPE (decl), stmt); 3038 TREE_SIDE_EFFECTS (complit) = 1; 3039 3040 layout_decl (decl, 0); 3041 3042 if (TREE_STATIC (decl)) 3043 { 3044 /* This decl needs a name for the assembler output. We also need 3045 a unique suffix to be added to the name. */ 3046 char *name; 3047 3048 ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal", 3049 compound_literal_number); 3050 compound_literal_number++; 3051 DECL_NAME (decl) = get_identifier (name); 3052 DECL_DEFER_OUTPUT (decl) = 1; 3053 DECL_COMDAT (decl) = 1; 3054 DECL_ARTIFICIAL (decl) = 1; 3055 pushdecl (decl); 3056 rest_of_decl_compilation (decl, NULL, 1, 0); 3057 } 3058 3059 return complit; 3060} 3061 3062/* Make TYPE a complete type based on INITIAL_VALUE. 3063 Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered, 3064 2 if there was no information (in which case assume 1 if DO_DEFAULT). */ 3065 3066int 3067complete_array_type (tree type, tree initial_value, int do_default) 3068{ 3069 tree maxindex = NULL_TREE; 3070 int value = 0; 3071 3072 if (initial_value) 3073 { 3074 /* Note MAXINDEX is really the maximum index, 3075 one less than the size. */ 3076 if (TREE_CODE (initial_value) == STRING_CST) 3077 { 3078 int eltsize 3079 = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value))); 3080 maxindex = build_int_2 ((TREE_STRING_LENGTH (initial_value) 3081 / eltsize) - 1, 0); 3082 } 3083 else if (TREE_CODE (initial_value) == CONSTRUCTOR) 3084 { 3085 tree elts = CONSTRUCTOR_ELTS (initial_value); 3086 maxindex = build_int_2 (-1, -1); 3087 for (; elts; elts = TREE_CHAIN (elts)) 3088 { 3089 if (TREE_PURPOSE (elts)) 3090 maxindex = TREE_PURPOSE (elts); 3091 else 3092 maxindex = fold (build (PLUS_EXPR, integer_type_node, 3093 maxindex, integer_one_node)); 3094 } 3095 maxindex = copy_node (maxindex); 3096 } 3097 else 3098 { 3099 /* Make an error message unless that happened already. */ 3100 if (initial_value != error_mark_node) 3101 value = 1; 3102 3103 /* Prevent further error messages. */ 3104 maxindex = build_int_2 (0, 0); 3105 } 3106 } 3107 3108 if (!maxindex) 3109 { 3110 if (do_default) 3111 maxindex = build_int_2 (0, 0); 3112 value = 2; 3113 } 3114 3115 if (maxindex) 3116 { 3117 TYPE_DOMAIN (type) = build_index_type (maxindex); 3118 if (!TREE_TYPE (maxindex)) 3119 TREE_TYPE (maxindex) = TYPE_DOMAIN (type); 3120 } 3121 3122 /* Lay out the type now that we can get the real answer. */ 3123 3124 layout_type (type); 3125 3126 return value; 3127} 3128 3129/* Determine whether TYPE is a structure with a flexible array member, 3130 or a union containing such a structure (possibly recursively). */ 3131 3132static bool 3133flexible_array_type_p (tree type) 3134{ 3135 tree x; 3136 switch (TREE_CODE (type)) 3137 { 3138 case RECORD_TYPE: 3139 x = TYPE_FIELDS (type); 3140 if (x == NULL_TREE) 3141 return false; 3142 while (TREE_CHAIN (x) != NULL_TREE) 3143 x = TREE_CHAIN (x); 3144 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 3145 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 3146 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 3147 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 3148 return true; 3149 return false; 3150 case UNION_TYPE: 3151 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x)) 3152 { 3153 if (flexible_array_type_p (TREE_TYPE (x))) 3154 return true; 3155 } 3156 return false; 3157 default: 3158 return false; 3159 } 3160} 3161 3162/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 3163 replacing with appropriate values if they are invalid. */ 3164static void 3165check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name) 3166{ 3167 tree type_mv; 3168 unsigned int max_width; 3169 unsigned HOST_WIDE_INT w; 3170 const char *name = orig_name ? orig_name: _("<anonymous>"); 3171 3172 /* Necessary? */ 3173 STRIP_NOPS (*width); 3174 3175 /* Detect and ignore out of range field width and process valid 3176 field widths. */ 3177 if (TREE_CODE (*width) != INTEGER_CST) 3178 { 3179 error ("bit-field `%s' width not an integer constant", name); 3180 *width = integer_one_node; 3181 } 3182 else 3183 { 3184 constant_expression_warning (*width); 3185 if (tree_int_cst_sgn (*width) < 0) 3186 { 3187 error ("negative width in bit-field `%s'", name); 3188 *width = integer_one_node; 3189 } 3190 else if (integer_zerop (*width) && orig_name) 3191 { 3192 error ("zero width for bit-field `%s'", name); 3193 *width = integer_one_node; 3194 } 3195 } 3196 3197 /* Detect invalid bit-field type. */ 3198 if (TREE_CODE (*type) != INTEGER_TYPE 3199 && TREE_CODE (*type) != BOOLEAN_TYPE 3200 && TREE_CODE (*type) != ENUMERAL_TYPE) 3201 { 3202 error ("bit-field `%s' has invalid type", name); 3203 *type = unsigned_type_node; 3204 } 3205 3206 type_mv = TYPE_MAIN_VARIANT (*type); 3207 if (pedantic 3208 && type_mv != integer_type_node 3209 && type_mv != unsigned_type_node 3210 && type_mv != boolean_type_node) 3211 pedwarn ("type of bit-field `%s' is a GCC extension", name); 3212 3213 if (type_mv == boolean_type_node) 3214 max_width = CHAR_TYPE_SIZE; 3215 else 3216 max_width = TYPE_PRECISION (*type); 3217 3218 if (0 < compare_tree_int (*width, max_width)) 3219 { 3220 error ("width of `%s' exceeds its type", name); 3221 w = max_width; 3222 *width = build_int_2 (w, 0); 3223 } 3224 else 3225 w = tree_low_cst (*width, 1); 3226 3227 if (TREE_CODE (*type) == ENUMERAL_TYPE 3228 && (w < min_precision (TYPE_MIN_VALUE (*type), TREE_UNSIGNED (*type)) 3229 || w < min_precision (TYPE_MAX_VALUE (*type), TREE_UNSIGNED (*type)))) 3230 warning ("`%s' is narrower than values of its type", name); 3231} 3232 3233/* Given declspecs and a declarator, 3234 determine the name and type of the object declared 3235 and construct a ..._DECL node for it. 3236 (In one case we can return a ..._TYPE node instead. 3237 For invalid input we sometimes return 0.) 3238 3239 DECLSPECS is a chain of tree_list nodes whose value fields 3240 are the storage classes and type specifiers. 3241 3242 DECL_CONTEXT says which syntactic context this declaration is in: 3243 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 3244 FUNCDEF for a function definition. Like NORMAL but a few different 3245 error messages in each case. Return value may be zero meaning 3246 this definition is too screwy to try to parse. 3247 PARM for a parameter declaration (either within a function prototype 3248 or before a function body). Make a PARM_DECL, or return void_type_node. 3249 TYPENAME if for a typename (in a cast or sizeof). 3250 Don't make a DECL node; just return the ..._TYPE node. 3251 FIELD for a struct or union field; make a FIELD_DECL. 3252 INITIALIZED is 1 if the decl has an initializer. 3253 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 3254 representing the width of the bit-field. 3255 3256 In the TYPENAME case, DECLARATOR is really an absolute declarator. 3257 It may also be so in the PARM case, for a prototype where the 3258 argument type is specified but not the name. 3259 3260 This function is where the complicated C meanings of `static' 3261 and `extern' are interpreted. */ 3262 3263static tree 3264grokdeclarator (tree declarator, tree declspecs, 3265 enum decl_context decl_context, int initialized, tree *width) 3266{ 3267 int specbits = 0; 3268 tree spec; 3269 tree type = NULL_TREE; 3270 int longlong = 0; 3271 int constp; 3272 int restrictp; 3273 int volatilep; 3274 int type_quals = TYPE_UNQUALIFIED; 3275 int inlinep; 3276 int explicit_int = 0; 3277 int explicit_char = 0; 3278 int defaulted_int = 0; 3279 tree typedef_decl = 0; 3280 const char *name, *orig_name; 3281 tree typedef_type = 0; 3282 int funcdef_flag = 0; 3283 enum tree_code innermost_code = ERROR_MARK; 3284 int size_varies = 0; 3285 tree decl_attr = NULL_TREE; 3286 tree array_ptr_quals = NULL_TREE; 3287 int array_parm_static = 0; 3288 tree returned_attrs = NULL_TREE; 3289 bool bitfield = width != NULL; 3290 tree element_type; 3291 3292 if (decl_context == FUNCDEF) 3293 funcdef_flag = 1, decl_context = NORMAL; 3294 3295 /* Look inside a declarator for the name being declared 3296 and get it as a string, for an error message. */ 3297 { 3298 tree decl = declarator; 3299 name = 0; 3300 3301 while (decl) 3302 switch (TREE_CODE (decl)) 3303 { 3304 case ARRAY_REF: 3305 case INDIRECT_REF: 3306 case CALL_EXPR: 3307 innermost_code = TREE_CODE (decl); 3308 decl = TREE_OPERAND (decl, 0); 3309 break; 3310 3311 case TREE_LIST: 3312 decl = TREE_VALUE (decl); 3313 break; 3314 3315 case IDENTIFIER_NODE: 3316 name = IDENTIFIER_POINTER (decl); 3317 decl = 0; 3318 break; 3319 3320 default: 3321 abort (); 3322 } 3323 orig_name = name; 3324 if (name == 0) 3325 name = "type name"; 3326 } 3327 3328 /* A function definition's declarator must have the form of 3329 a function declarator. */ 3330 3331 if (funcdef_flag && innermost_code != CALL_EXPR) 3332 return 0; 3333 3334 /* If this looks like a function definition, make it one, 3335 even if it occurs where parms are expected. 3336 Then store_parm_decls will reject it and not use it as a parm. */ 3337 if (decl_context == NORMAL && !funcdef_flag 3338 && current_scope->parm_flag) 3339 decl_context = PARM; 3340 3341 /* Look through the decl specs and record which ones appear. 3342 Some typespecs are defined as built-in typenames. 3343 Others, the ones that are modifiers of other types, 3344 are represented by bits in SPECBITS: set the bits for 3345 the modifiers that appear. Storage class keywords are also in SPECBITS. 3346 3347 If there is a typedef name or a type, store the type in TYPE. 3348 This includes builtin typedefs such as `int'. 3349 3350 Set EXPLICIT_INT or EXPLICIT_CHAR if the type is `int' or `char' 3351 and did not come from a user typedef. 3352 3353 Set LONGLONG if `long' is mentioned twice. */ 3354 3355 for (spec = declspecs; spec; spec = TREE_CHAIN (spec)) 3356 { 3357 tree id = TREE_VALUE (spec); 3358 3359 /* If the entire declaration is itself tagged as deprecated then 3360 suppress reports of deprecated items. */ 3361 if (id && TREE_DEPRECATED (id)) 3362 { 3363 if (deprecated_state != DEPRECATED_SUPPRESS) 3364 warn_deprecated_use (id); 3365 } 3366 3367 if (id == ridpointers[(int) RID_INT]) 3368 explicit_int = 1; 3369 if (id == ridpointers[(int) RID_CHAR]) 3370 explicit_char = 1; 3371 3372 if (TREE_CODE (id) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (id)) 3373 { 3374 enum rid i = C_RID_CODE (id); 3375 if ((int) i <= (int) RID_LAST_MODIFIER) 3376 { 3377 if (i == RID_LONG && (specbits & (1 << (int) RID_LONG))) 3378 { 3379 if (longlong) 3380 error ("`long long long' is too long for GCC"); 3381 else 3382 { 3383 if (pedantic && !flag_isoc99 && ! in_system_header 3384 && warn_long_long) 3385 pedwarn ("ISO C90 does not support `long long'"); 3386 longlong = 1; 3387 } 3388 } 3389 else if (specbits & (1 << (int) i)) 3390 { 3391 if (i == RID_CONST || i == RID_VOLATILE || i == RID_RESTRICT) 3392 { 3393 if (pedantic && !flag_isoc99) 3394 pedwarn ("duplicate `%s'", IDENTIFIER_POINTER (id)); 3395 } 3396 else 3397 error ("duplicate `%s'", IDENTIFIER_POINTER (id)); 3398 } 3399 3400 /* Diagnose "__thread extern". Recall that this list 3401 is in the reverse order seen in the text. */ 3402 if (i == RID_THREAD 3403 && (specbits & (1 << (int) RID_EXTERN 3404 | 1 << (int) RID_STATIC))) 3405 { 3406 if (specbits & 1 << (int) RID_EXTERN) 3407 error ("`__thread' before `extern'"); 3408 else 3409 error ("`__thread' before `static'"); 3410 } 3411 3412 specbits |= 1 << (int) i; 3413 goto found; 3414 } 3415 } 3416 if (type) 3417 error ("two or more data types in declaration of `%s'", name); 3418 /* Actual typedefs come to us as TYPE_DECL nodes. */ 3419 else if (TREE_CODE (id) == TYPE_DECL) 3420 { 3421 if (TREE_TYPE (id) == error_mark_node) 3422 ; /* Allow the type to default to int to avoid cascading errors. */ 3423 else 3424 { 3425 type = TREE_TYPE (id); 3426 decl_attr = DECL_ATTRIBUTES (id); 3427 typedef_decl = id; 3428 } 3429 } 3430 /* Built-in types come as identifiers. */ 3431 else if (TREE_CODE (id) == IDENTIFIER_NODE) 3432 { 3433 tree t = lookup_name (id); 3434 if (TREE_TYPE (t) == error_mark_node) 3435 ; 3436 else if (!t || TREE_CODE (t) != TYPE_DECL) 3437 error ("`%s' fails to be a typedef or built in type", 3438 IDENTIFIER_POINTER (id)); 3439 else 3440 { 3441 type = TREE_TYPE (t); 3442 typedef_decl = t; 3443 } 3444 } 3445 else if (TREE_CODE (id) != ERROR_MARK) 3446 type = id; 3447 3448 found: 3449 ; 3450 } 3451 3452 typedef_type = type; 3453 if (type) 3454 size_varies = C_TYPE_VARIABLE_SIZE (type); 3455 3456 /* No type at all: default to `int', and set DEFAULTED_INT 3457 because it was not a user-defined typedef. */ 3458 3459 if (type == 0) 3460 { 3461 if ((! (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT) 3462 | (1 << (int) RID_SIGNED) 3463 | (1 << (int) RID_UNSIGNED) 3464 | (1 << (int) RID_COMPLEX)))) 3465 /* Don't warn about typedef foo = bar. */ 3466 && ! (specbits & (1 << (int) RID_TYPEDEF) && initialized) 3467 && ! in_system_header) 3468 { 3469 /* Issue a warning if this is an ISO C 99 program or if -Wreturn-type 3470 and this is a function, or if -Wimplicit; prefer the former 3471 warning since it is more explicit. */ 3472 if ((warn_implicit_int || warn_return_type || flag_isoc99) 3473 && funcdef_flag) 3474 warn_about_return_type = 1; 3475 else if (warn_implicit_int || flag_isoc99) 3476 pedwarn_c99 ("type defaults to `int' in declaration of `%s'", 3477 name); 3478 } 3479 3480 defaulted_int = 1; 3481 type = integer_type_node; 3482 } 3483 3484 /* Now process the modifiers that were specified 3485 and check for invalid combinations. */ 3486 3487 /* Long double is a special combination. */ 3488 3489 if ((specbits & 1 << (int) RID_LONG) && ! longlong 3490 && TYPE_MAIN_VARIANT (type) == double_type_node) 3491 { 3492 specbits &= ~(1 << (int) RID_LONG); 3493 type = long_double_type_node; 3494 } 3495 3496 /* Check all other uses of type modifiers. */ 3497 3498 if (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT) 3499 | (1 << (int) RID_UNSIGNED) | (1 << (int) RID_SIGNED))) 3500 { 3501 int ok = 0; 3502 3503 if ((specbits & 1 << (int) RID_LONG) 3504 && (specbits & 1 << (int) RID_SHORT)) 3505 error ("both long and short specified for `%s'", name); 3506 else if (((specbits & 1 << (int) RID_LONG) 3507 || (specbits & 1 << (int) RID_SHORT)) 3508 && explicit_char) 3509 error ("long or short specified with char for `%s'", name); 3510 else if (((specbits & 1 << (int) RID_LONG) 3511 || (specbits & 1 << (int) RID_SHORT)) 3512 && TREE_CODE (type) == REAL_TYPE) 3513 { 3514 static int already = 0; 3515 3516 error ("long or short specified with floating type for `%s'", name); 3517 if (! already && ! pedantic) 3518 { 3519 error ("the only valid combination is `long double'"); 3520 already = 1; 3521 } 3522 } 3523 else if ((specbits & 1 << (int) RID_SIGNED) 3524 && (specbits & 1 << (int) RID_UNSIGNED)) 3525 error ("both signed and unsigned specified for `%s'", name); 3526 else if (TREE_CODE (type) != INTEGER_TYPE) 3527 error ("long, short, signed or unsigned invalid for `%s'", name); 3528 else 3529 { 3530 ok = 1; 3531 if (!explicit_int && !defaulted_int && !explicit_char) 3532 { 3533 error ("long, short, signed or unsigned used invalidly for `%s'", 3534 name); 3535 ok = 0; 3536 } 3537 } 3538 3539 /* Discard the type modifiers if they are invalid. */ 3540 if (! ok) 3541 { 3542 specbits &= ~((1 << (int) RID_LONG) | (1 << (int) RID_SHORT) 3543 | (1 << (int) RID_UNSIGNED) | (1 << (int) RID_SIGNED)); 3544 longlong = 0; 3545 } 3546 } 3547 3548 if ((specbits & (1 << (int) RID_COMPLEX)) 3549 && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE) 3550 { 3551 error ("complex invalid for `%s'", name); 3552 specbits &= ~(1 << (int) RID_COMPLEX); 3553 } 3554 3555 /* Decide whether an integer type is signed or not. 3556 Optionally treat bit-fields as signed by default. */ 3557 if (specbits & 1 << (int) RID_UNSIGNED 3558 || (bitfield && ! flag_signed_bitfields 3559 && (explicit_int || defaulted_int || explicit_char 3560 /* A typedef for plain `int' without `signed' 3561 can be controlled just like plain `int'. */ 3562 || ! (typedef_decl != 0 3563 && C_TYPEDEF_EXPLICITLY_SIGNED (typedef_decl))) 3564 && TREE_CODE (type) != ENUMERAL_TYPE 3565 && !(specbits & 1 << (int) RID_SIGNED))) 3566 { 3567 if (longlong) 3568 type = long_long_unsigned_type_node; 3569 else if (specbits & 1 << (int) RID_LONG) 3570 type = long_unsigned_type_node; 3571 else if (specbits & 1 << (int) RID_SHORT) 3572 type = short_unsigned_type_node; 3573 else if (type == char_type_node) 3574 type = unsigned_char_type_node; 3575 else if (typedef_decl) 3576 type = c_common_unsigned_type (type); 3577 else 3578 type = unsigned_type_node; 3579 } 3580 else if ((specbits & 1 << (int) RID_SIGNED) 3581 && type == char_type_node) 3582 type = signed_char_type_node; 3583 else if (longlong) 3584 type = long_long_integer_type_node; 3585 else if (specbits & 1 << (int) RID_LONG) 3586 type = long_integer_type_node; 3587 else if (specbits & 1 << (int) RID_SHORT) 3588 type = short_integer_type_node; 3589 3590 if (specbits & 1 << (int) RID_COMPLEX) 3591 { 3592 if (pedantic && !flag_isoc99) 3593 pedwarn ("ISO C90 does not support complex types"); 3594 /* If we just have "complex", it is equivalent to 3595 "complex double", but if any modifiers at all are specified it is 3596 the complex form of TYPE. E.g, "complex short" is 3597 "complex short int". */ 3598 3599 if (defaulted_int && ! longlong 3600 && ! (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT) 3601 | (1 << (int) RID_SIGNED) 3602 | (1 << (int) RID_UNSIGNED)))) 3603 { 3604 if (pedantic) 3605 pedwarn ("ISO C does not support plain `complex' meaning `double complex'"); 3606 type = complex_double_type_node; 3607 } 3608 else if (type == integer_type_node) 3609 { 3610 if (pedantic) 3611 pedwarn ("ISO C does not support complex integer types"); 3612 type = complex_integer_type_node; 3613 } 3614 else if (type == float_type_node) 3615 type = complex_float_type_node; 3616 else if (type == double_type_node) 3617 type = complex_double_type_node; 3618 else if (type == long_double_type_node) 3619 type = complex_long_double_type_node; 3620 else 3621 { 3622 if (pedantic) 3623 pedwarn ("ISO C does not support complex integer types"); 3624 type = build_complex_type (type); 3625 } 3626 } 3627 3628 /* Figure out the type qualifiers for the declaration. There are 3629 two ways a declaration can become qualified. One is something 3630 like `const int i' where the `const' is explicit. Another is 3631 something like `typedef const int CI; CI i' where the type of the 3632 declaration contains the `const'. A third possibility is that 3633 there is a type qualifier on the element type of a typedefed 3634 array type, in which case we should extract that qualifier so 3635 that c_apply_type_quals_to_decls receives the full list of 3636 qualifiers to work with (C90 is not entirely clear about whether 3637 duplicate qualifiers should be diagnosed in this case, but it 3638 seems most appropriate to do so). */ 3639 element_type = strip_array_types (type); 3640 constp = !! (specbits & 1 << (int) RID_CONST) + TYPE_READONLY (element_type); 3641 restrictp 3642 = !! (specbits & 1 << (int) RID_RESTRICT) + TYPE_RESTRICT (element_type); 3643 volatilep 3644 = !! (specbits & 1 << (int) RID_VOLATILE) + TYPE_VOLATILE (element_type); 3645 inlinep = !! (specbits & (1 << (int) RID_INLINE)); 3646 if (pedantic && !flag_isoc99) 3647 { 3648 if (constp > 1) 3649 pedwarn ("duplicate `const'"); 3650 if (restrictp > 1) 3651 pedwarn ("duplicate `restrict'"); 3652 if (volatilep > 1) 3653 pedwarn ("duplicate `volatile'"); 3654 } 3655 if (! flag_gen_aux_info && (TYPE_QUALS (type))) 3656 type = TYPE_MAIN_VARIANT (type); 3657 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 3658 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 3659 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 3660 3661 /* Warn if two storage classes are given. Default to `auto'. */ 3662 3663 { 3664 int nclasses = 0; 3665 3666 if (specbits & 1 << (int) RID_AUTO) nclasses++; 3667 if (specbits & 1 << (int) RID_STATIC) nclasses++; 3668 if (specbits & 1 << (int) RID_EXTERN) nclasses++; 3669 if (specbits & 1 << (int) RID_REGISTER) nclasses++; 3670 if (specbits & 1 << (int) RID_TYPEDEF) nclasses++; 3671 3672 /* "static __thread" and "extern __thread" are allowed. */ 3673 if ((specbits & (1 << (int) RID_THREAD 3674 | 1 << (int) RID_STATIC 3675 | 1 << (int) RID_EXTERN)) == (1 << (int) RID_THREAD)) 3676 nclasses++; 3677 3678 /* Warn about storage classes that are invalid for certain 3679 kinds of declarations (parameters, typenames, etc.). */ 3680 3681 if (nclasses > 1) 3682 error ("multiple storage classes in declaration of `%s'", name); 3683 else if (funcdef_flag 3684 && (specbits 3685 & ((1 << (int) RID_REGISTER) 3686 | (1 << (int) RID_AUTO) 3687 | (1 << (int) RID_TYPEDEF) 3688 | (1 << (int) RID_THREAD)))) 3689 { 3690 if (specbits & 1 << (int) RID_AUTO 3691 && (pedantic || current_scope == global_scope)) 3692 pedwarn ("function definition declared `auto'"); 3693 if (specbits & 1 << (int) RID_REGISTER) 3694 error ("function definition declared `register'"); 3695 if (specbits & 1 << (int) RID_TYPEDEF) 3696 error ("function definition declared `typedef'"); 3697 if (specbits & 1 << (int) RID_THREAD) 3698 error ("function definition declared `__thread'"); 3699 specbits &= ~((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER) 3700 | (1 << (int) RID_AUTO) | (1 << (int) RID_THREAD)); 3701 } 3702 else if (decl_context != NORMAL && nclasses > 0) 3703 { 3704 if (decl_context == PARM && specbits & 1 << (int) RID_REGISTER) 3705 ; 3706 else 3707 { 3708 switch (decl_context) 3709 { 3710 case FIELD: 3711 error ("storage class specified for structure field `%s'", 3712 name); 3713 break; 3714 case PARM: 3715 error ("storage class specified for parameter `%s'", name); 3716 break; 3717 default: 3718 error ("storage class specified for typename"); 3719 break; 3720 } 3721 specbits &= ~((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER) 3722 | (1 << (int) RID_AUTO) | (1 << (int) RID_STATIC) 3723 | (1 << (int) RID_EXTERN) | (1 << (int) RID_THREAD)); 3724 } 3725 } 3726 else if (specbits & 1 << (int) RID_EXTERN && initialized && ! funcdef_flag) 3727 { 3728 /* `extern' with initialization is invalid if not at file scope. */ 3729 if (current_scope == global_scope) 3730 warning ("`%s' initialized and declared `extern'", name); 3731 else 3732 error ("`%s' has both `extern' and initializer", name); 3733 } 3734 else if (current_scope == global_scope) 3735 { 3736 if (specbits & 1 << (int) RID_AUTO) 3737 error ("file-scope declaration of `%s' specifies `auto'", name); 3738 } 3739 else 3740 { 3741 if (specbits & 1 << (int) RID_EXTERN && funcdef_flag) 3742 error ("nested function `%s' declared `extern'", name); 3743 else if ((specbits & (1 << (int) RID_THREAD 3744 | 1 << (int) RID_EXTERN 3745 | 1 << (int) RID_STATIC)) 3746 == (1 << (int) RID_THREAD)) 3747 { 3748 error ("function-scope `%s' implicitly auto and declared `__thread'", 3749 name); 3750 specbits &= ~(1 << (int) RID_THREAD); 3751 } 3752 } 3753 } 3754 3755 /* Now figure out the structure of the declarator proper. 3756 Descend through it, creating more complex types, until we reach 3757 the declared identifier (or NULL_TREE, in an absolute declarator). */ 3758 3759 while (declarator && TREE_CODE (declarator) != IDENTIFIER_NODE) 3760 { 3761 if (type == error_mark_node) 3762 { 3763 declarator = TREE_OPERAND (declarator, 0); 3764 continue; 3765 } 3766 3767 /* Each level of DECLARATOR is either an ARRAY_REF (for ...[..]), 3768 an INDIRECT_REF (for *...), 3769 a CALL_EXPR (for ...(...)), 3770 a TREE_LIST (for nested attributes), 3771 an identifier (for the name being declared) 3772 or a null pointer (for the place in an absolute declarator 3773 where the name was omitted). 3774 For the last two cases, we have just exited the loop. 3775 3776 At this point, TYPE is the type of elements of an array, 3777 or for a function to return, or for a pointer to point to. 3778 After this sequence of ifs, TYPE is the type of the 3779 array or function or pointer, and DECLARATOR has had its 3780 outermost layer removed. */ 3781 3782 if (array_ptr_quals != NULL_TREE || array_parm_static) 3783 { 3784 /* Only the innermost declarator (making a parameter be of 3785 array type which is converted to pointer type) 3786 may have static or type qualifiers. */ 3787 error ("static or type qualifiers in non-parameter array declarator"); 3788 array_ptr_quals = NULL_TREE; 3789 array_parm_static = 0; 3790 } 3791 3792 if (TREE_CODE (declarator) == TREE_LIST) 3793 { 3794 /* We encode a declarator with embedded attributes using 3795 a TREE_LIST. */ 3796 tree attrs = TREE_PURPOSE (declarator); 3797 tree inner_decl; 3798 int attr_flags = 0; 3799 declarator = TREE_VALUE (declarator); 3800 inner_decl = declarator; 3801 while (inner_decl != NULL_TREE 3802 && TREE_CODE (inner_decl) == TREE_LIST) 3803 inner_decl = TREE_VALUE (inner_decl); 3804 if (inner_decl == NULL_TREE 3805 || TREE_CODE (inner_decl) == IDENTIFIER_NODE) 3806 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 3807 else if (TREE_CODE (inner_decl) == CALL_EXPR) 3808 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 3809 else if (TREE_CODE (inner_decl) == ARRAY_REF) 3810 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 3811 returned_attrs = decl_attributes (&type, 3812 chainon (returned_attrs, attrs), 3813 attr_flags); 3814 } 3815 else if (TREE_CODE (declarator) == ARRAY_REF) 3816 { 3817 tree itype = NULL_TREE; 3818 tree size = TREE_OPERAND (declarator, 1); 3819 /* The index is a signed object `sizetype' bits wide. */ 3820 tree index_type = c_common_signed_type (sizetype); 3821 3822 array_ptr_quals = TREE_TYPE (declarator); 3823 array_parm_static = TREE_STATIC (declarator); 3824 3825 declarator = TREE_OPERAND (declarator, 0); 3826 3827 /* Check for some types that there cannot be arrays of. */ 3828 3829 if (VOID_TYPE_P (type)) 3830 { 3831 error ("declaration of `%s' as array of voids", name); 3832 type = error_mark_node; 3833 } 3834 3835 if (TREE_CODE (type) == FUNCTION_TYPE) 3836 { 3837 error ("declaration of `%s' as array of functions", name); 3838 type = error_mark_node; 3839 } 3840 3841 if (pedantic && !in_system_header && flexible_array_type_p (type)) 3842 pedwarn ("invalid use of structure with flexible array member"); 3843 3844 if (size == error_mark_node) 3845 type = error_mark_node; 3846 3847 if (type == error_mark_node) 3848 continue; 3849 3850 /* If size was specified, set ITYPE to a range-type for that size. 3851 Otherwise, ITYPE remains null. finish_decl may figure it out 3852 from an initial value. */ 3853 3854 if (size) 3855 { 3856 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 3857 STRIP_TYPE_NOPS (size); 3858 3859 if (! INTEGRAL_TYPE_P (TREE_TYPE (size))) 3860 { 3861 error ("size of array `%s' has non-integer type", name); 3862 size = integer_one_node; 3863 } 3864 3865 if (pedantic && integer_zerop (size)) 3866 pedwarn ("ISO C forbids zero-size array `%s'", name); 3867 3868 if (TREE_CODE (size) == INTEGER_CST) 3869 { 3870 constant_expression_warning (size); 3871 if (tree_int_cst_sgn (size) < 0) 3872 { 3873 error ("size of array `%s' is negative", name); 3874 size = integer_one_node; 3875 } 3876 } 3877 else 3878 { 3879 /* Make sure the array size remains visibly nonconstant 3880 even if it is (eg) a const variable with known value. */ 3881 size_varies = 1; 3882 3883 if (!flag_isoc99 && pedantic) 3884 { 3885 if (TREE_CONSTANT (size)) 3886 pedwarn ("ISO C90 forbids array `%s' whose size can't be evaluated", 3887 name); 3888 else 3889 pedwarn ("ISO C90 forbids variable-size array `%s'", 3890 name); 3891 } 3892 } 3893 3894 if (integer_zerop (size)) 3895 { 3896 /* A zero-length array cannot be represented with an 3897 unsigned index type, which is what we'll get with 3898 build_index_type. Create an open-ended range instead. */ 3899 itype = build_range_type (sizetype, size, NULL_TREE); 3900 } 3901 else 3902 { 3903 /* Compute the maximum valid index, that is, size - 1. 3904 Do the calculation in index_type, so that if it is 3905 a variable the computations will be done in the 3906 proper mode. */ 3907 itype = fold (build (MINUS_EXPR, index_type, 3908 convert (index_type, size), 3909 convert (index_type, size_one_node))); 3910 3911 /* If that overflowed, the array is too big. 3912 ??? While a size of INT_MAX+1 technically shouldn't 3913 cause an overflow (because we subtract 1), the overflow 3914 is recorded during the conversion to index_type, before 3915 the subtraction. Handling this case seems like an 3916 unnecessary complication. */ 3917 if (TREE_OVERFLOW (itype)) 3918 { 3919 error ("size of array `%s' is too large", name); 3920 type = error_mark_node; 3921 continue; 3922 } 3923 3924 if (size_varies) 3925 { 3926 /* We must be able to distinguish the 3927 SAVE_EXPR_CONTEXT for the variably-sized type 3928 so that we can set it correctly in 3929 set_save_expr_context. The convention is 3930 that all SAVE_EXPRs that need to be reset 3931 have NULL_TREE for their SAVE_EXPR_CONTEXT. */ 3932 tree cfd = current_function_decl; 3933 if (decl_context == PARM) 3934 current_function_decl = NULL_TREE; 3935 itype = variable_size (itype); 3936 if (decl_context == PARM) 3937 current_function_decl = cfd; 3938 } 3939 itype = build_index_type (itype); 3940 } 3941 } 3942 else if (decl_context == FIELD) 3943 { 3944 if (pedantic && !flag_isoc99 && !in_system_header) 3945 pedwarn ("ISO C90 does not support flexible array members"); 3946 3947 /* ISO C99 Flexible array members are effectively identical 3948 to GCC's zero-length array extension. */ 3949 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 3950 } 3951 3952 /* If pedantic, complain about arrays of incomplete types. */ 3953 3954 if (pedantic && !COMPLETE_TYPE_P (type)) 3955 pedwarn ("array type has incomplete element type"); 3956 3957 /* Build the array type itself, then merge any constancy or 3958 volatility into the target type. We must do it in this order 3959 to ensure that the TYPE_MAIN_VARIANT field of the array type 3960 is set correctly. */ 3961 3962 type = build_array_type (type, itype); 3963 if (type_quals) 3964 type = c_build_qualified_type (type, type_quals); 3965 3966 if (size_varies) 3967 C_TYPE_VARIABLE_SIZE (type) = 1; 3968 3969 /* The GCC extension for zero-length arrays differs from 3970 ISO flexible array members in that sizeof yields zero. */ 3971 if (size && integer_zerop (size)) 3972 { 3973 layout_type (type); 3974 TYPE_SIZE (type) = bitsize_zero_node; 3975 TYPE_SIZE_UNIT (type) = size_zero_node; 3976 } 3977 if (decl_context != PARM 3978 && (array_ptr_quals != NULL_TREE || array_parm_static)) 3979 { 3980 error ("static or type qualifiers in non-parameter array declarator"); 3981 array_ptr_quals = NULL_TREE; 3982 array_parm_static = 0; 3983 } 3984 } 3985 else if (TREE_CODE (declarator) == CALL_EXPR) 3986 { 3987 /* Say it's a definition only for the declarator closest to 3988 the identifier, apart possibly from some attributes. */ 3989 bool really_funcdef = false; 3990 tree arg_types; 3991 if (funcdef_flag) 3992 { 3993 tree t = TREE_OPERAND (declarator, 0); 3994 while (TREE_CODE (t) == TREE_LIST) 3995 t = TREE_VALUE (t); 3996 really_funcdef = (TREE_CODE (t) == IDENTIFIER_NODE); 3997 } 3998 3999 /* Declaring a function type. 4000 Make sure we have a valid type for the function to return. */ 4001 if (type == error_mark_node) 4002 continue; 4003 4004 size_varies = 0; 4005 4006 /* Warn about some types functions can't return. */ 4007 4008 if (TREE_CODE (type) == FUNCTION_TYPE) 4009 { 4010 error ("`%s' declared as function returning a function", name); 4011 type = integer_type_node; 4012 } 4013 if (TREE_CODE (type) == ARRAY_TYPE) 4014 { 4015 error ("`%s' declared as function returning an array", name); 4016 type = integer_type_node; 4017 } 4018 4019 /* Construct the function type and go to the next 4020 inner layer of declarator. */ 4021 4022 arg_types = grokparms (TREE_OPERAND (declarator, 1), 4023 really_funcdef); 4024 /* Type qualifiers before the return type of the function 4025 qualify the return type, not the function type. */ 4026 if (type_quals) 4027 { 4028 /* Type qualifiers on a function return type are normally 4029 permitted by the standard but have no effect, so give a 4030 warning at -Wextra. Qualifiers on a void return type have 4031 meaning as a GNU extension, and are banned on function 4032 definitions in ISO C. FIXME: strictly we shouldn't 4033 pedwarn for qualified void return types except on function 4034 definitions, but not doing so could lead to the undesirable 4035 state of a "volatile void" function return type not being 4036 warned about, and a use of the function being compiled 4037 with GNU semantics, with no diagnostics under -pedantic. */ 4038 if (VOID_TYPE_P (type) && pedantic && !in_system_header) 4039 pedwarn ("ISO C forbids qualified void function return type"); 4040 else if (extra_warnings 4041 && !(VOID_TYPE_P (type) 4042 && type_quals == TYPE_QUAL_VOLATILE)) 4043 warning ("type qualifiers ignored on function return type"); 4044 4045 type = c_build_qualified_type (type, type_quals); 4046 } 4047 type_quals = TYPE_UNQUALIFIED; 4048 4049 type = build_function_type (type, arg_types); 4050 declarator = TREE_OPERAND (declarator, 0); 4051 4052 /* Set the TYPE_CONTEXTs for each tagged type which is local to 4053 the formal parameter list of this FUNCTION_TYPE to point to 4054 the FUNCTION_TYPE node itself. */ 4055 4056 { 4057 tree link; 4058 4059 for (link = last_function_parm_tags; 4060 link; 4061 link = TREE_CHAIN (link)) 4062 TYPE_CONTEXT (TREE_VALUE (link)) = type; 4063 } 4064 } 4065 else if (TREE_CODE (declarator) == INDIRECT_REF) 4066 { 4067 /* Merge any constancy or volatility into the target type 4068 for the pointer. */ 4069 4070 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4071 && type_quals) 4072 pedwarn ("ISO C forbids qualified function types"); 4073 if (type_quals) 4074 type = c_build_qualified_type (type, type_quals); 4075 type_quals = TYPE_UNQUALIFIED; 4076 size_varies = 0; 4077 4078 type = build_pointer_type (type); 4079 4080 /* Process a list of type modifier keywords 4081 (such as const or volatile) that were given inside the `*'. */ 4082 4083 if (TREE_TYPE (declarator)) 4084 { 4085 tree typemodlist; 4086 int erred = 0; 4087 4088 constp = 0; 4089 volatilep = 0; 4090 restrictp = 0; 4091 for (typemodlist = TREE_TYPE (declarator); typemodlist; 4092 typemodlist = TREE_CHAIN (typemodlist)) 4093 { 4094 tree qualifier = TREE_VALUE (typemodlist); 4095 4096 if (C_IS_RESERVED_WORD (qualifier)) 4097 { 4098 if (C_RID_CODE (qualifier) == RID_CONST) 4099 constp++; 4100 else if (C_RID_CODE (qualifier) == RID_VOLATILE) 4101 volatilep++; 4102 else if (C_RID_CODE (qualifier) == RID_RESTRICT) 4103 restrictp++; 4104 else 4105 erred++; 4106 } 4107 else 4108 erred++; 4109 } 4110 4111 if (erred) 4112 error ("invalid type modifier within pointer declarator"); 4113 if (pedantic && !flag_isoc99) 4114 { 4115 if (constp > 1) 4116 pedwarn ("duplicate `const'"); 4117 if (volatilep > 1) 4118 pedwarn ("duplicate `volatile'"); 4119 if (restrictp > 1) 4120 pedwarn ("duplicate `restrict'"); 4121 } 4122 4123 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 4124 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 4125 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 4126 } 4127 4128 declarator = TREE_OPERAND (declarator, 0); 4129 } 4130 else 4131 abort (); 4132 4133 } 4134 4135 /* Now TYPE has the actual type. */ 4136 4137 /* Check the type and width of a bit-field. */ 4138 if (bitfield) 4139 check_bitfield_type_and_width (&type, width, orig_name); 4140 4141 /* Did array size calculations overflow? */ 4142 4143 if (TREE_CODE (type) == ARRAY_TYPE 4144 && COMPLETE_TYPE_P (type) 4145 && TREE_OVERFLOW (TYPE_SIZE (type))) 4146 { 4147 error ("size of array `%s' is too large", name); 4148 /* If we proceed with the array type as it is, we'll eventually 4149 crash in tree_low_cst(). */ 4150 type = error_mark_node; 4151 } 4152 4153 /* If this is declaring a typedef name, return a TYPE_DECL. */ 4154 4155 if (specbits & (1 << (int) RID_TYPEDEF)) 4156 { 4157 tree decl; 4158 /* Note that the grammar rejects storage classes 4159 in typenames, fields or parameters */ 4160 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4161 && type_quals) 4162 pedwarn ("ISO C forbids qualified function types"); 4163 if (type_quals) 4164 type = c_build_qualified_type (type, type_quals); 4165 decl = build_decl (TYPE_DECL, declarator, type); 4166 if ((specbits & (1 << (int) RID_SIGNED)) 4167 || (typedef_decl && C_TYPEDEF_EXPLICITLY_SIGNED (typedef_decl))) 4168 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 4169 decl_attributes (&decl, returned_attrs, 0); 4170 return decl; 4171 } 4172 4173 /* Detect the case of an array type of unspecified size 4174 which came, as such, direct from a typedef name. 4175 We must copy the type, so that each identifier gets 4176 a distinct type, so that each identifier's size can be 4177 controlled separately by its own initializer. */ 4178 4179 if (type != 0 && typedef_type != 0 4180 && TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == 0 4181 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (typedef_type)) 4182 { 4183 type = build_array_type (TREE_TYPE (type), 0); 4184 if (size_varies) 4185 C_TYPE_VARIABLE_SIZE (type) = 1; 4186 } 4187 4188 /* If this is a type name (such as, in a cast or sizeof), 4189 compute the type and return it now. */ 4190 4191 if (decl_context == TYPENAME) 4192 { 4193 /* Note that the grammar rejects storage classes 4194 in typenames, fields or parameters */ 4195 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 4196 && type_quals) 4197 pedwarn ("ISO C forbids const or volatile function types"); 4198 if (type_quals) 4199 type = c_build_qualified_type (type, type_quals); 4200 decl_attributes (&type, returned_attrs, 0); 4201 return type; 4202 } 4203 4204 /* Aside from typedefs and type names (handle above), 4205 `void' at top level (not within pointer) 4206 is allowed only in public variables. 4207 We don't complain about parms either, but that is because 4208 a better error message can be made later. */ 4209 4210 if (VOID_TYPE_P (type) && decl_context != PARM 4211 && ! ((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 4212 && ((specbits & (1 << (int) RID_EXTERN)) 4213 || (current_scope == global_scope 4214 && !(specbits 4215 & ((1 << (int) RID_STATIC) | (1 << (int) RID_REGISTER))))))) 4216 { 4217 error ("variable or field `%s' declared void", name); 4218 type = integer_type_node; 4219 } 4220 4221 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 4222 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 4223 4224 { 4225 tree decl; 4226 4227 if (decl_context == PARM) 4228 { 4229 tree type_as_written; 4230 tree promoted_type; 4231 4232 /* A parameter declared as an array of T is really a pointer to T. 4233 One declared as a function is really a pointer to a function. */ 4234 4235 if (TREE_CODE (type) == ARRAY_TYPE) 4236 { 4237 /* Transfer const-ness of array into that of type pointed to. */ 4238 type = TREE_TYPE (type); 4239 if (type_quals) 4240 type = c_build_qualified_type (type, type_quals); 4241 type = build_pointer_type (type); 4242 type_quals = TYPE_UNQUALIFIED; 4243 if (array_ptr_quals) 4244 { 4245 tree new_ptr_quals, new_ptr_attrs; 4246 int erred = 0; 4247 split_specs_attrs (array_ptr_quals, &new_ptr_quals, &new_ptr_attrs); 4248 /* We don't yet implement attributes in this context. */ 4249 if (new_ptr_attrs != NULL_TREE) 4250 warning ("attributes in parameter array declarator ignored"); 4251 4252 constp = 0; 4253 volatilep = 0; 4254 restrictp = 0; 4255 for (; new_ptr_quals; new_ptr_quals = TREE_CHAIN (new_ptr_quals)) 4256 { 4257 tree qualifier = TREE_VALUE (new_ptr_quals); 4258 4259 if (C_IS_RESERVED_WORD (qualifier)) 4260 { 4261 if (C_RID_CODE (qualifier) == RID_CONST) 4262 constp++; 4263 else if (C_RID_CODE (qualifier) == RID_VOLATILE) 4264 volatilep++; 4265 else if (C_RID_CODE (qualifier) == RID_RESTRICT) 4266 restrictp++; 4267 else 4268 erred++; 4269 } 4270 else 4271 erred++; 4272 } 4273 4274 if (erred) 4275 error ("invalid type modifier within array declarator"); 4276 4277 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 4278 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 4279 | (volatilep ? TYPE_QUAL_VOLATILE : 0)); 4280 } 4281 size_varies = 0; 4282 } 4283 else if (TREE_CODE (type) == FUNCTION_TYPE) 4284 { 4285 if (pedantic && type_quals) 4286 pedwarn ("ISO C forbids qualified function types"); 4287 if (type_quals) 4288 type = c_build_qualified_type (type, type_quals); 4289 type = build_pointer_type (type); 4290 type_quals = TYPE_UNQUALIFIED; 4291 } 4292 else if (type_quals) 4293 type = c_build_qualified_type (type, type_quals); 4294 4295 type_as_written = type; 4296 4297 decl = build_decl (PARM_DECL, declarator, type); 4298 if (size_varies) 4299 C_DECL_VARIABLE_SIZE (decl) = 1; 4300 4301 /* Compute the type actually passed in the parmlist, 4302 for the case where there is no prototype. 4303 (For example, shorts and chars are passed as ints.) 4304 When there is a prototype, this is overridden later. */ 4305 4306 if (type == error_mark_node) 4307 promoted_type = type; 4308 else 4309 promoted_type = c_type_promotes_to (type); 4310 4311 DECL_ARG_TYPE (decl) = promoted_type; 4312 DECL_ARG_TYPE_AS_WRITTEN (decl) = type_as_written; 4313 } 4314 else if (decl_context == FIELD) 4315 { 4316 /* Structure field. It may not be a function. */ 4317 4318 if (TREE_CODE (type) == FUNCTION_TYPE) 4319 { 4320 error ("field `%s' declared as a function", name); 4321 type = build_pointer_type (type); 4322 } 4323 else if (TREE_CODE (type) != ERROR_MARK 4324 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 4325 { 4326 error ("field `%s' has incomplete type", name); 4327 type = error_mark_node; 4328 } 4329 /* Move type qualifiers down to element of an array. */ 4330 if (TREE_CODE (type) == ARRAY_TYPE && type_quals) 4331 type = build_array_type (c_build_qualified_type (TREE_TYPE (type), 4332 type_quals), 4333 TYPE_DOMAIN (type)); 4334 decl = build_decl (FIELD_DECL, declarator, type); 4335 DECL_NONADDRESSABLE_P (decl) = bitfield; 4336 4337 if (size_varies) 4338 C_DECL_VARIABLE_SIZE (decl) = 1; 4339 } 4340 else if (TREE_CODE (type) == FUNCTION_TYPE) 4341 { 4342 /* Every function declaration is "external" 4343 except for those which are inside a function body 4344 in which `auto' is used. 4345 That is a case not specified by ANSI C, 4346 and we use it for forward declarations for nested functions. */ 4347 int extern_ref = (!(specbits & (1 << (int) RID_AUTO)) 4348 || current_scope == global_scope); 4349 4350 if (specbits & (1 << (int) RID_AUTO) 4351 && (pedantic || current_scope == global_scope)) 4352 pedwarn ("invalid storage class for function `%s'", name); 4353 if (specbits & (1 << (int) RID_REGISTER)) 4354 error ("invalid storage class for function `%s'", name); 4355 if (specbits & (1 << (int) RID_THREAD)) 4356 error ("invalid storage class for function `%s'", name); 4357 /* Function declaration not at file scope. 4358 Storage classes other than `extern' are not allowed 4359 and `extern' makes no difference. */ 4360 if (current_scope != global_scope 4361 && (specbits & ((1 << (int) RID_STATIC) | (1 << (int) RID_INLINE))) 4362 && pedantic) 4363 pedwarn ("invalid storage class for function `%s'", name); 4364 4365 decl = build_decl (FUNCTION_DECL, declarator, type); 4366 decl = build_decl_attribute_variant (decl, decl_attr); 4367 4368 DECL_LANG_SPECIFIC (decl) 4369 = ggc_alloc_cleared (sizeof (struct lang_decl)); 4370 4371 if (pedantic && type_quals && ! DECL_IN_SYSTEM_HEADER (decl)) 4372 pedwarn ("ISO C forbids qualified function types"); 4373 4374 /* GNU C interprets a `volatile void' return type to indicate 4375 that the function does not return. */ 4376 if ((type_quals & TYPE_QUAL_VOLATILE) 4377 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) 4378 warning ("`noreturn' function returns non-void value"); 4379 4380 if (extern_ref) 4381 DECL_EXTERNAL (decl) = 1; 4382 /* Record absence of global scope for `static' or `auto'. */ 4383 TREE_PUBLIC (decl) 4384 = !(specbits & ((1 << (int) RID_STATIC) | (1 << (int) RID_AUTO))); 4385 4386 if (defaulted_int) 4387 C_FUNCTION_IMPLICIT_INT (decl) = 1; 4388 4389 /* Record presence of `inline', if it is reasonable. */ 4390 if (MAIN_NAME_P (declarator)) 4391 { 4392 if (inlinep) 4393 warning ("cannot inline function `main'"); 4394 } 4395 else if (inlinep) 4396 { 4397 /* Record that the function is declared `inline'. */ 4398 DECL_DECLARED_INLINE_P (decl) = 1; 4399 4400 /* Do not mark bare declarations as DECL_INLINE. Doing so 4401 in the presence of multiple declarations can result in 4402 the abstract origin pointing between the declarations, 4403 which will confuse dwarf2out. */ 4404 if (initialized) 4405 { 4406 DECL_INLINE (decl) = 1; 4407 if (specbits & (1 << (int) RID_EXTERN)) 4408 current_extern_inline = 1; 4409 } 4410 } 4411 /* If -finline-functions, assume it can be inlined. This does 4412 two things: let the function be deferred until it is actually 4413 needed, and let dwarf2 know that the function is inlinable. */ 4414 else if (flag_inline_trees == 2 && initialized) 4415 DECL_INLINE (decl) = 1; 4416 } 4417 else 4418 { 4419 /* It's a variable. */ 4420 /* An uninitialized decl with `extern' is a reference. */ 4421 int extern_ref = !initialized && (specbits & (1 << (int) RID_EXTERN)); 4422 4423 /* Move type qualifiers down to element of an array. */ 4424 if (TREE_CODE (type) == ARRAY_TYPE && type_quals) 4425 { 4426 int saved_align = TYPE_ALIGN(type); 4427 type = build_array_type (c_build_qualified_type (TREE_TYPE (type), 4428 type_quals), 4429 TYPE_DOMAIN (type)); 4430 TYPE_ALIGN (type) = saved_align; 4431 } 4432 else if (type_quals) 4433 type = c_build_qualified_type (type, type_quals); 4434 4435 /* It is invalid to create an `extern' declaration for a 4436 variable if there is a global declaration that is 4437 `static' and the global declaration is not visible. */ 4438 if (extern_ref && current_scope != global_scope) 4439 { 4440 tree global_decl; 4441 4442 global_decl = identifier_global_value (declarator); 4443 if (global_decl 4444 && TREE_CODE (global_decl) == VAR_DECL 4445 && lookup_name (declarator) != global_decl 4446 && !TREE_PUBLIC (global_decl)) 4447 error ("variable previously declared `static' redeclared " 4448 "`extern'"); 4449 } 4450 4451 decl = build_decl (VAR_DECL, declarator, type); 4452 if (size_varies) 4453 C_DECL_VARIABLE_SIZE (decl) = 1; 4454 4455 if (inlinep) 4456 pedwarn ("%Jvariable '%D' declared `inline'", decl, decl); 4457 4458 DECL_EXTERNAL (decl) = extern_ref; 4459 4460 /* At file scope, the presence of a `static' or `register' storage 4461 class specifier, or the absence of all storage class specifiers 4462 makes this declaration a definition (perhaps tentative). Also, 4463 the absence of both `static' and `register' makes it public. */ 4464 if (current_scope == global_scope) 4465 { 4466 TREE_PUBLIC (decl) = !(specbits & ((1 << (int) RID_STATIC) 4467 | (1 << (int) RID_REGISTER))); 4468 TREE_STATIC (decl) = !extern_ref; 4469 } 4470 /* Not at file scope, only `static' makes a static definition. */ 4471 else 4472 { 4473 TREE_STATIC (decl) = (specbits & (1 << (int) RID_STATIC)) != 0; 4474 TREE_PUBLIC (decl) = extern_ref; 4475 } 4476 4477 if (specbits & 1 << (int) RID_THREAD) 4478 { 4479 if (targetm.have_tls) 4480 DECL_THREAD_LOCAL (decl) = 1; 4481 else 4482 /* A mere warning is sure to result in improper semantics 4483 at runtime. Don't bother to allow this to compile. */ 4484 error ("thread-local storage not supported for this target"); 4485 } 4486 } 4487 4488 /* Record `register' declaration for warnings on & 4489 and in case doing stupid register allocation. */ 4490 4491 if (specbits & (1 << (int) RID_REGISTER)) 4492 DECL_REGISTER (decl) = 1; 4493 4494 /* Record constancy and volatility. */ 4495 c_apply_type_quals_to_decl (type_quals, decl); 4496 4497 /* If a type has volatile components, it should be stored in memory. 4498 Otherwise, the fact that those components are volatile 4499 will be ignored, and would even crash the compiler. */ 4500 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl))) 4501 c_mark_addressable (decl); 4502 4503#ifdef ENABLE_CHECKING 4504 /* This is the earliest point at which we might know the assembler 4505 name of a variable. Thus, if it's known before this, die horribly. */ 4506 if (DECL_ASSEMBLER_NAME_SET_P (decl)) 4507 abort (); 4508#endif 4509 4510 decl_attributes (&decl, returned_attrs, 0); 4511 4512 return decl; 4513 } 4514} 4515 4516/* Decode the parameter-list info for a function type or function definition. 4517 The argument is the value returned by `get_parm_info' (or made in parse.y 4518 if there is an identifier list instead of a parameter decl list). 4519 These two functions are separate because when a function returns 4520 or receives functions then each is called multiple times but the order 4521 of calls is different. The last call to `grokparms' is always the one 4522 that contains the formal parameter names of a function definition. 4523 4524 Store in `last_function_parms' a chain of the decls of parms. 4525 Also store in `last_function_parm_tags' a chain of the struct, union, 4526 and enum tags declared among the parms. 4527 4528 Return a list of arg types to use in the FUNCTION_TYPE for this function. 4529 4530 FUNCDEF_FLAG is nonzero for a function definition, 0 for 4531 a mere declaration. A nonempty identifier-list gets an error message 4532 when FUNCDEF_FLAG is zero. */ 4533 4534static tree 4535grokparms (tree parms_info, int funcdef_flag) 4536{ 4537 tree first_parm = TREE_CHAIN (parms_info); 4538 4539 last_function_parms = TREE_PURPOSE (parms_info); 4540 last_function_parm_tags = TREE_VALUE (parms_info); 4541 last_function_parm_others = TREE_TYPE (parms_info); 4542 4543 if (warn_strict_prototypes && first_parm == 0 && !funcdef_flag 4544 && !in_system_header) 4545 warning ("function declaration isn't a prototype"); 4546 4547 if (first_parm != 0 4548 && TREE_CODE (TREE_VALUE (first_parm)) == IDENTIFIER_NODE) 4549 { 4550 if (! funcdef_flag) 4551 pedwarn ("parameter names (without types) in function declaration"); 4552 4553 last_function_parms = first_parm; 4554 return 0; 4555 } 4556 else 4557 { 4558 tree parm; 4559 tree typelt; 4560 /* If the arg types are incomplete in a declaration, 4561 they must include undefined tags. 4562 These tags can never be defined in the scope of the declaration, 4563 so the types can never be completed, 4564 and no call can be compiled successfully. */ 4565 4566 for (parm = last_function_parms, typelt = first_parm; 4567 parm; 4568 parm = TREE_CHAIN (parm)) 4569 /* Skip over any enumeration constants declared here. */ 4570 if (TREE_CODE (parm) == PARM_DECL) 4571 { 4572 /* Barf if the parameter itself has an incomplete type. */ 4573 tree type = TREE_VALUE (typelt); 4574 if (type == error_mark_node) 4575 continue; 4576 if (!COMPLETE_TYPE_P (type)) 4577 { 4578 if (funcdef_flag && DECL_NAME (parm) != 0) 4579 error ("parameter `%s' has incomplete type", 4580 IDENTIFIER_POINTER (DECL_NAME (parm))); 4581 else 4582 warning ("parameter has incomplete type"); 4583 if (funcdef_flag) 4584 { 4585 TREE_VALUE (typelt) = error_mark_node; 4586 TREE_TYPE (parm) = error_mark_node; 4587 } 4588 } 4589 typelt = TREE_CHAIN (typelt); 4590 } 4591 4592 return first_parm; 4593 } 4594} 4595 4596/* Return a tree_list node with info on a parameter list just parsed. 4597 The TREE_PURPOSE is a list of decls of those parms. 4598 The TREE_VALUE is a list of structure, union and enum tags defined. 4599 The TREE_CHAIN is a list of argument types to go in the FUNCTION_TYPE. 4600 The TREE_TYPE is a list of non-parameter decls which appeared with the 4601 parameters. 4602 This tree_list node is later fed to `grokparms'. 4603 4604 VOID_AT_END nonzero means append `void' to the end of the type-list. 4605 Zero means the parmlist ended with an ellipsis so don't append `void'. */ 4606 4607tree 4608get_parm_info (int void_at_end) 4609{ 4610 tree decl, type, list; 4611 tree types = 0; 4612 tree *last_type = &types; 4613 tree tags = current_scope->tags; 4614 tree parms = current_scope->parms; 4615 tree others = current_scope->names; 4616 static bool explained_incomplete_types = false; 4617 bool gave_void_only_once_err = false; 4618 4619 /* Just "void" (and no ellipsis) is special. There are really no parms. 4620 But if the "void" is qualified (by "const" or "volatile"), or has a 4621 storage class specifier ("register"), then the behavior is undefined; 4622 issue an error. Typedefs for "void" are OK (see DR#157). */ 4623 if (void_at_end && parms != 0 4624 && TREE_CHAIN (parms) == 0 4625 && VOID_TYPE_P (TREE_TYPE (parms)) 4626 && !DECL_NAME (parms)) 4627 { 4628 if (TREE_THIS_VOLATILE (parms) 4629 || TREE_READONLY (parms) 4630 || DECL_REGISTER (parms)) 4631 error ("\"void\" as only parameter may not be qualified"); 4632 4633 return tree_cons (0, 0, tree_cons (0, void_type_node, 0)); 4634 } 4635 4636 /* Sanity check all of the parameter declarations. */ 4637 for (decl = parms; decl; decl = TREE_CHAIN (decl)) 4638 { 4639 if (TREE_CODE (decl) != PARM_DECL) 4640 abort (); 4641 if (TREE_ASM_WRITTEN (decl)) 4642 abort (); 4643 4644 /* Since there is a prototype, args are passed in their 4645 declared types. The back end may override this. */ 4646 type = TREE_TYPE (decl); 4647 DECL_ARG_TYPE (decl) = type; 4648 4649 /* Check for (..., void, ...) and issue an error. */ 4650 if (VOID_TYPE_P (type) && !DECL_NAME (decl) && !gave_void_only_once_err) 4651 { 4652 error ("\"void\" must be the only parameter"); 4653 gave_void_only_once_err = true; 4654 } 4655 4656 type = build_tree_list (0, type); 4657 *last_type = type; 4658 last_type = &TREE_CHAIN (type); 4659 } 4660 4661 /* Check the list of non-parameter decls for any forward parm decls 4662 that never got real decls. */ 4663 for (decl = others; decl; decl = TREE_CHAIN (decl)) 4664 if (TREE_CODE (decl) == PARM_DECL) 4665 { 4666 if (!TREE_ASM_WRITTEN (decl)) 4667 abort (); 4668 4669 error ("%Jparameter \"%D\" has just a forward declaration", 4670 decl, decl); 4671 } 4672 4673 /* Warn about any struct, union or enum tags defined within this 4674 list. The scope of such types is limited to this declaration, 4675 which is rarely if ever desirable (it's impossible to call such 4676 a function with type-correct arguments). */ 4677 for (decl = tags; decl; decl = TREE_CHAIN (decl)) 4678 { 4679 enum tree_code code = TREE_CODE (TREE_VALUE (decl)); 4680 const char *keyword; 4681 /* An anonymous union parm type is meaningful as a GNU extension. 4682 So don't warn for that. */ 4683 if (code == UNION_TYPE && TREE_PURPOSE (decl) == 0 && !pedantic) 4684 continue; 4685 4686 /* The keyword should not be translated. */ 4687 switch (code) 4688 { 4689 case RECORD_TYPE: keyword = "struct"; break; 4690 case UNION_TYPE: keyword = "union"; break; 4691 case ENUMERAL_TYPE: keyword = "enum"; break; 4692 default: abort (); 4693 } 4694 4695 if (TREE_PURPOSE (decl)) 4696 /* The first %s will be one of 'struct', 'union', or 'enum'. */ 4697 warning ("\"%s %s\" declared inside parameter list", 4698 keyword, IDENTIFIER_POINTER (TREE_PURPOSE (decl))); 4699 else 4700 /* The %s will be one of 'struct', 'union', or 'enum'. */ 4701 warning ("anonymous %s declared inside parameter list", keyword); 4702 4703 if (! explained_incomplete_types) 4704 { 4705 warning ("its scope is only this definition or declaration," 4706 " which is probably not what you want"); 4707 explained_incomplete_types = true; 4708 } 4709 } 4710 4711 4712 if (void_at_end) 4713 { 4714 type = build_tree_list (0, void_type_node); 4715 *last_type = type; 4716 } 4717 4718 list = tree_cons (parms, tags, types); 4719 TREE_TYPE (list) = others; 4720 return list; 4721} 4722 4723/* Get the struct, enum or union (CODE says which) with tag NAME. 4724 Define the tag as a forward-reference if it is not defined. */ 4725 4726tree 4727xref_tag (enum tree_code code, tree name) 4728{ 4729 /* If a cross reference is requested, look up the type 4730 already defined for this tag and return it. */ 4731 4732 tree ref = lookup_tag (code, name, 0); 4733 /* If this is the right type of tag, return what we found. 4734 (This reference will be shadowed by shadow_tag later if appropriate.) 4735 If this is the wrong type of tag, do not return it. If it was the 4736 wrong type in the same scope, we will have had an error 4737 message already; if in a different scope and declaring 4738 a name, pending_xref_error will give an error message; but if in a 4739 different scope and not declaring a name, this tag should 4740 shadow the previous declaration of a different type of tag, and 4741 this would not work properly if we return the reference found. 4742 (For example, with "struct foo" in an outer scope, "union foo;" 4743 must shadow that tag with a new one of union type.) */ 4744 if (ref && TREE_CODE (ref) == code) 4745 return ref; 4746 4747 /* If no such tag is yet defined, create a forward-reference node 4748 and record it as the "definition". 4749 When a real declaration of this type is found, 4750 the forward-reference will be altered into a real type. */ 4751 4752 ref = make_node (code); 4753 if (code == ENUMERAL_TYPE) 4754 { 4755 /* Give the type a default layout like unsigned int 4756 to avoid crashing if it does not get defined. */ 4757 TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node); 4758 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 4759 TYPE_USER_ALIGN (ref) = 0; 4760 TREE_UNSIGNED (ref) = 1; 4761 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 4762 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 4763 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 4764 } 4765 4766 pushtag (name, ref); 4767 4768 return ref; 4769} 4770 4771/* Make sure that the tag NAME is defined *in the current scope* 4772 at least as a forward reference. 4773 CODE says which kind of tag NAME ought to be. */ 4774 4775tree 4776start_struct (enum tree_code code, tree name) 4777{ 4778 /* If there is already a tag defined at this scope 4779 (as a forward reference), just return it. */ 4780 4781 tree ref = 0; 4782 4783 if (name != 0) 4784 ref = lookup_tag (code, name, 1); 4785 if (ref && TREE_CODE (ref) == code) 4786 { 4787 if (TYPE_FIELDS (ref)) 4788 { 4789 if (code == UNION_TYPE) 4790 error ("redefinition of `union %s'", IDENTIFIER_POINTER (name)); 4791 else 4792 error ("redefinition of `struct %s'", IDENTIFIER_POINTER (name)); 4793 } 4794 } 4795 else 4796 { 4797 /* Otherwise create a forward-reference just so the tag is in scope. */ 4798 4799 ref = make_node (code); 4800 pushtag (name, ref); 4801 } 4802 4803 C_TYPE_BEING_DEFINED (ref) = 1; 4804 TYPE_PACKED (ref) = flag_pack_struct; 4805 return ref; 4806} 4807 4808/* Process the specs, declarator (NULL if omitted) and width (NULL if omitted) 4809 of a structure component, returning a FIELD_DECL node. 4810 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 4811 4812 This is done during the parsing of the struct declaration. 4813 The FIELD_DECL nodes are chained together and the lot of them 4814 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 4815 4816tree 4817grokfield (tree declarator, tree declspecs, tree width) 4818{ 4819 tree value; 4820 4821 if (declarator == NULL_TREE && width == NULL_TREE) 4822 { 4823 /* This is an unnamed decl. 4824 4825 If we have something of the form "union { list } ;" then this 4826 is the anonymous union extension. Similarly for struct. 4827 4828 If this is something of the form "struct foo;", then 4829 If MS extensions are enabled, this is handled as an 4830 anonymous struct. 4831 Otherwise this is a forward declaration of a structure tag. 4832 4833 If this is something of the form "foo;" and foo is a TYPE_DECL, then 4834 If MS extensions are enabled and foo names a structure, then 4835 again this is an anonymous struct. 4836 Otherwise this is an error. 4837 4838 Oh what a horrid tangled web we weave. I wonder if MS consciously 4839 took this from Plan 9 or if it was an accident of implementation 4840 that took root before someone noticed the bug... */ 4841 4842 tree type = TREE_VALUE (declspecs); 4843 4844 if (flag_ms_extensions && TREE_CODE (type) == TYPE_DECL) 4845 type = TREE_TYPE (type); 4846 if (TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE) 4847 { 4848 if (flag_ms_extensions) 4849 ; /* ok */ 4850 else if (flag_iso) 4851 goto warn_unnamed_field; 4852 else if (TYPE_NAME (type) == NULL) 4853 ; /* ok */ 4854 else 4855 goto warn_unnamed_field; 4856 } 4857 else 4858 { 4859 warn_unnamed_field: 4860 warning ("declaration does not declare anything"); 4861 return NULL_TREE; 4862 } 4863 } 4864 4865 value = grokdeclarator (declarator, declspecs, FIELD, 0, 4866 width ? &width : NULL); 4867 4868 finish_decl (value, NULL_TREE, NULL_TREE); 4869 DECL_INITIAL (value) = width; 4870 4871 return value; 4872} 4873 4874/* Generate an error for any duplicate field names in FIELDLIST. Munge 4875 the list such that this does not present a problem later. */ 4876 4877static void 4878detect_field_duplicates (tree fieldlist) 4879{ 4880 tree x, y; 4881 int timeout = 10; 4882 4883 /* First, see if there are more than "a few" fields. 4884 This is trivially true if there are zero or one fields. */ 4885 if (!fieldlist) 4886 return; 4887 x = TREE_CHAIN (fieldlist); 4888 if (!x) 4889 return; 4890 do { 4891 timeout--; 4892 x = TREE_CHAIN (x); 4893 } while (timeout > 0 && x); 4894 4895 /* If there were "few" fields, avoid the overhead of allocating 4896 a hash table. Instead just do the nested traversal thing. */ 4897 if (timeout > 0) 4898 { 4899 for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x)) 4900 if (DECL_NAME (x)) 4901 { 4902 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 4903 if (DECL_NAME (y) == DECL_NAME (x)) 4904 { 4905 error ("%Jduplicate member '%D'", x, x); 4906 DECL_NAME (x) = NULL_TREE; 4907 } 4908 } 4909 } 4910 else 4911 { 4912 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 4913 void **slot; 4914 4915 for (x = fieldlist; x ; x = TREE_CHAIN (x)) 4916 if ((y = DECL_NAME (x)) != 0) 4917 { 4918 slot = htab_find_slot (htab, y, INSERT); 4919 if (*slot) 4920 { 4921 error ("%Jduplicate member '%D'", x, x); 4922 DECL_NAME (x) = NULL_TREE; 4923 } 4924 *slot = y; 4925 } 4926 4927 htab_delete (htab); 4928 } 4929} 4930 4931/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 4932 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 4933 ATTRIBUTES are attributes to be applied to the structure. */ 4934 4935tree 4936finish_struct (tree t, tree fieldlist, tree attributes) 4937{ 4938 tree x; 4939 int toplevel = global_scope == current_scope; 4940 int saw_named_field; 4941 4942 /* If this type was previously laid out as a forward reference, 4943 make sure we lay it out again. */ 4944 4945 TYPE_SIZE (t) = 0; 4946 4947 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 4948 4949 /* Nameless union parm types are useful as GCC extension. */ 4950 if (! (TREE_CODE (t) == UNION_TYPE && TYPE_NAME (t) == 0) && !pedantic) 4951 /* Otherwise, warn about any struct or union def. in parmlist. */ 4952 if (in_parm_level_p ()) 4953 { 4954 if (pedantic) 4955 pedwarn ("%s defined inside parms", 4956 TREE_CODE (t) == UNION_TYPE ? _("union") : _("structure")); 4957 else 4958 warning ("%s defined inside parms", 4959 TREE_CODE (t) == UNION_TYPE ? _("union") : _("structure")); 4960 } 4961 4962 if (pedantic) 4963 { 4964 for (x = fieldlist; x; x = TREE_CHAIN (x)) 4965 if (DECL_NAME (x) != 0) 4966 break; 4967 4968 if (x == 0) 4969 pedwarn ("%s has no %s", 4970 TREE_CODE (t) == UNION_TYPE ? _("union") : _("struct"), 4971 fieldlist ? _("named members") : _("members")); 4972 } 4973 4974 /* Install struct as DECL_CONTEXT of each field decl. 4975 Also process specified field sizes,m which is found in the DECL_INITIAL. 4976 Store 0 there, except for ": 0" fields (so we can find them 4977 and delete them, below). */ 4978 4979 saw_named_field = 0; 4980 for (x = fieldlist; x; x = TREE_CHAIN (x)) 4981 { 4982 DECL_CONTEXT (x) = t; 4983 DECL_PACKED (x) |= TYPE_PACKED (t); 4984 4985 /* If any field is const, the structure type is pseudo-const. */ 4986 if (TREE_READONLY (x)) 4987 C_TYPE_FIELDS_READONLY (t) = 1; 4988 else 4989 { 4990 /* A field that is pseudo-const makes the structure likewise. */ 4991 tree t1 = TREE_TYPE (x); 4992 while (TREE_CODE (t1) == ARRAY_TYPE) 4993 t1 = TREE_TYPE (t1); 4994 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 4995 && C_TYPE_FIELDS_READONLY (t1)) 4996 C_TYPE_FIELDS_READONLY (t) = 1; 4997 } 4998 4999 /* Any field that is volatile means variables of this type must be 5000 treated in some ways as volatile. */ 5001 if (TREE_THIS_VOLATILE (x)) 5002 C_TYPE_FIELDS_VOLATILE (t) = 1; 5003 5004 /* Any field of nominal variable size implies structure is too. */ 5005 if (C_DECL_VARIABLE_SIZE (x)) 5006 C_TYPE_VARIABLE_SIZE (t) = 1; 5007 5008 /* Detect invalid nested redefinition. */ 5009 if (TREE_TYPE (x) == t) 5010 error ("nested redefinition of `%s'", 5011 IDENTIFIER_POINTER (TYPE_NAME (t))); 5012 5013 if (DECL_INITIAL (x)) 5014 { 5015 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 5016 DECL_SIZE (x) = bitsize_int (width); 5017 DECL_BIT_FIELD (x) = 1; 5018 SET_DECL_C_BIT_FIELD (x); 5019 } 5020 5021 DECL_INITIAL (x) = 0; 5022 5023 /* Detect flexible array member in an invalid context. */ 5024 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 5025 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 5026 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 5027 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 5028 { 5029 if (TREE_CODE (t) == UNION_TYPE) 5030 { 5031 error ("%Jflexible array member in union", x); 5032 TREE_TYPE (x) = error_mark_node; 5033 } 5034 else if (TREE_CHAIN (x) != NULL_TREE) 5035 { 5036 error ("%Jflexible array member not at end of struct", x); 5037 TREE_TYPE (x) = error_mark_node; 5038 } 5039 else if (! saw_named_field) 5040 { 5041 error ("%Jflexible array member in otherwise empty struct", x); 5042 TREE_TYPE (x) = error_mark_node; 5043 } 5044 } 5045 5046 if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE 5047 && flexible_array_type_p (TREE_TYPE (x))) 5048 pedwarn ("%Jinvalid use of structure with flexible array member", x); 5049 5050 if (DECL_NAME (x)) 5051 saw_named_field = 1; 5052 } 5053 5054 detect_field_duplicates (fieldlist); 5055 5056 /* Now we have the nearly final fieldlist. Record it, 5057 then lay out the structure or union (including the fields). */ 5058 5059 TYPE_FIELDS (t) = fieldlist; 5060 5061 layout_type (t); 5062 5063 /* Delete all zero-width bit-fields from the fieldlist. */ 5064 { 5065 tree *fieldlistp = &fieldlist; 5066 while (*fieldlistp) 5067 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp)) 5068 *fieldlistp = TREE_CHAIN (*fieldlistp); 5069 else 5070 fieldlistp = &TREE_CHAIN (*fieldlistp); 5071 } 5072 5073 /* Now we have the truly final field list. 5074 Store it in this type and in the variants. */ 5075 5076 TYPE_FIELDS (t) = fieldlist; 5077 5078 /* If there are lots of fields, sort so we can look through them fast. 5079 We arbitrarily consider 16 or more elts to be "a lot". */ 5080 5081 { 5082 int len = 0; 5083 5084 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5085 { 5086 if (len > 15 || DECL_NAME (x) == NULL) 5087 break; 5088 len += 1; 5089 } 5090 5091 if (len > 15) 5092 { 5093 tree *field_array; 5094 struct lang_type *space; 5095 struct sorted_fields_type *space2; 5096 5097 len += list_length (x); 5098 5099 /* Use the same allocation policy here that make_node uses, to 5100 ensure that this lives as long as the rest of the struct decl. 5101 All decls in an inline function need to be saved. */ 5102 5103 space = ggc_alloc (sizeof (struct lang_type)); 5104 space2 = ggc_alloc (sizeof (struct sorted_fields_type) + len * sizeof (tree)); 5105 5106 len = 0; 5107 space->s = space2; 5108 field_array = &space2->elts[0]; 5109 for (x = fieldlist; x; x = TREE_CHAIN (x)) 5110 { 5111 field_array[len++] = x; 5112 5113 /* If there is anonymous struct or union, break out of the loop. */ 5114 if (DECL_NAME (x) == NULL) 5115 break; 5116 } 5117 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 5118 if (x == NULL) 5119 { 5120 TYPE_LANG_SPECIFIC (t) = space; 5121 TYPE_LANG_SPECIFIC (t)->s->len = len; 5122 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 5123 qsort (field_array, len, sizeof (tree), field_decl_cmp); 5124 } 5125 } 5126 } 5127 5128 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 5129 { 5130 TYPE_FIELDS (x) = TYPE_FIELDS (t); 5131 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 5132 TYPE_ALIGN (x) = TYPE_ALIGN (t); 5133 TYPE_USER_ALIGN (x) = TYPE_USER_ALIGN (t); 5134 } 5135 5136 /* If this was supposed to be a transparent union, but we can't 5137 make it one, warn and turn off the flag. */ 5138 if (TREE_CODE (t) == UNION_TYPE 5139 && TYPE_TRANSPARENT_UNION (t) 5140 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 5141 { 5142 TYPE_TRANSPARENT_UNION (t) = 0; 5143 warning ("union cannot be made transparent"); 5144 } 5145 5146 /* If this structure or union completes the type of any previous 5147 variable declaration, lay it out and output its rtl. */ 5148 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 5149 x; 5150 x = TREE_CHAIN (x)) 5151 { 5152 tree decl = TREE_VALUE (x); 5153 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 5154 layout_array_type (TREE_TYPE (decl)); 5155 if (TREE_CODE (decl) != TYPE_DECL) 5156 { 5157 layout_decl (decl, 0); 5158 if (c_dialect_objc ()) 5159 objc_check_decl (decl); 5160 rest_of_decl_compilation (decl, NULL, toplevel, 0); 5161 if (! toplevel) 5162 expand_decl (decl); 5163 } 5164 } 5165 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 5166 5167 /* Finish debugging output for this type. */ 5168 rest_of_type_compilation (t, toplevel); 5169 5170 return t; 5171} 5172 5173/* Lay out the type T, and its element type, and so on. */ 5174 5175static void 5176layout_array_type (tree t) 5177{ 5178 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 5179 layout_array_type (TREE_TYPE (t)); 5180 layout_type (t); 5181} 5182 5183/* Begin compiling the definition of an enumeration type. 5184 NAME is its name (or null if anonymous). 5185 Returns the type object, as yet incomplete. 5186 Also records info about it so that build_enumerator 5187 may be used to declare the individual values as they are read. */ 5188 5189tree 5190start_enum (tree name) 5191{ 5192 tree enumtype = 0; 5193 5194 /* If this is the real definition for a previous forward reference, 5195 fill in the contents in the same object that used to be the 5196 forward reference. */ 5197 5198 if (name != 0) 5199 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1); 5200 5201 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 5202 { 5203 enumtype = make_node (ENUMERAL_TYPE); 5204 pushtag (name, enumtype); 5205 } 5206 5207 C_TYPE_BEING_DEFINED (enumtype) = 1; 5208 5209 if (TYPE_VALUES (enumtype) != 0) 5210 { 5211 /* This enum is a named one that has been declared already. */ 5212 error ("redeclaration of `enum %s'", IDENTIFIER_POINTER (name)); 5213 5214 /* Completely replace its old definition. 5215 The old enumerators remain defined, however. */ 5216 TYPE_VALUES (enumtype) = 0; 5217 } 5218 5219 enum_next_value = integer_zero_node; 5220 enum_overflow = 0; 5221 5222 if (flag_short_enums) 5223 TYPE_PACKED (enumtype) = 1; 5224 5225 return enumtype; 5226} 5227 5228/* After processing and defining all the values of an enumeration type, 5229 install their decls in the enumeration type and finish it off. 5230 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 5231 and ATTRIBUTES are the specified attributes. 5232 Returns ENUMTYPE. */ 5233 5234tree 5235finish_enum (tree enumtype, tree values, tree attributes) 5236{ 5237 tree pair, tem; 5238 tree minnode = 0, maxnode = 0, enum_value_type; 5239 int precision, unsign; 5240 int toplevel = (global_scope == current_scope); 5241 5242 if (in_parm_level_p ()) 5243 warning ("enum defined inside parms"); 5244 5245 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5246 5247 /* Calculate the maximum value of any enumerator in this type. */ 5248 5249 if (values == error_mark_node) 5250 minnode = maxnode = integer_zero_node; 5251 else 5252 { 5253 minnode = maxnode = TREE_VALUE (values); 5254 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 5255 { 5256 tree value = TREE_VALUE (pair); 5257 if (tree_int_cst_lt (maxnode, value)) 5258 maxnode = value; 5259 if (tree_int_cst_lt (value, minnode)) 5260 minnode = value; 5261 } 5262 } 5263 5264 /* Construct the final type of this enumeration. It is the same 5265 as one of the integral types - the narrowest one that fits, except 5266 that normally we only go as narrow as int - and signed iff any of 5267 the values are negative. */ 5268 unsign = (tree_int_cst_sgn (minnode) >= 0); 5269 precision = MAX (min_precision (minnode, unsign), 5270 min_precision (maxnode, unsign)); 5271 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 5272 { 5273 tree narrowest = c_common_type_for_size (precision, unsign); 5274 if (narrowest == 0) 5275 { 5276 warning ("enumeration values exceed range of largest integer"); 5277 narrowest = long_long_integer_type_node; 5278 } 5279 5280 precision = TYPE_PRECISION (narrowest); 5281 } 5282 else 5283 precision = TYPE_PRECISION (integer_type_node); 5284 5285 if (precision == TYPE_PRECISION (integer_type_node)) 5286 enum_value_type = c_common_type_for_size (precision, 0); 5287 else 5288 enum_value_type = enumtype; 5289 5290 TYPE_MIN_VALUE (enumtype) = minnode; 5291 TYPE_MAX_VALUE (enumtype) = maxnode; 5292 TREE_UNSIGNED (enumtype) = unsign; 5293 TYPE_SIZE (enumtype) = 0; 5294 5295 /* If the precision of the type was specific with an attribute and it 5296 was too small, give an error. Otherwise, use it. */ 5297 if (TYPE_PRECISION (enumtype)) 5298 { 5299 if (precision > TYPE_PRECISION (enumtype)) 5300 error ("specified mode too small for enumeral values"); 5301 } 5302 else 5303 TYPE_PRECISION (enumtype) = precision; 5304 5305 layout_type (enumtype); 5306 5307 if (values != error_mark_node) 5308 { 5309 /* Change the type of the enumerators to be the enum type. We 5310 need to do this irrespective of the size of the enum, for 5311 proper type checking. Replace the DECL_INITIALs of the 5312 enumerators, and the value slots of the list, with copies 5313 that have the enum type; they cannot be modified in place 5314 because they may be shared (e.g. integer_zero_node) Finally, 5315 change the purpose slots to point to the names of the decls. */ 5316 for (pair = values; pair; pair = TREE_CHAIN (pair)) 5317 { 5318 tree enu = TREE_PURPOSE (pair); 5319 5320 TREE_TYPE (enu) = enumtype; 5321 5322 /* The ISO C Standard mandates enumerators to have type int, 5323 even though the underlying type of an enum type is 5324 unspecified. Here we convert any enumerators that fit in 5325 an int to type int, to avoid promotions to unsigned types 5326 when comparing integers with enumerators that fit in the 5327 int range. When -pedantic is given, build_enumerator() 5328 would have already taken care of those that don't fit. */ 5329 if (int_fits_type_p (DECL_INITIAL (enu), enum_value_type)) 5330 DECL_INITIAL (enu) = convert (enum_value_type, DECL_INITIAL (enu)); 5331 else 5332 DECL_INITIAL (enu) = convert (enumtype, DECL_INITIAL (enu)); 5333 5334 TREE_PURPOSE (pair) = DECL_NAME (enu); 5335 TREE_VALUE (pair) = DECL_INITIAL (enu); 5336 } 5337 5338 TYPE_VALUES (enumtype) = values; 5339 } 5340 5341 /* Fix up all variant types of this enum type. */ 5342 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 5343 { 5344 if (tem == enumtype) 5345 continue; 5346 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 5347 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 5348 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 5349 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 5350 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 5351 TYPE_MODE (tem) = TYPE_MODE (enumtype); 5352 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 5353 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 5354 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 5355 TREE_UNSIGNED (tem) = TREE_UNSIGNED (enumtype); 5356 } 5357 5358 /* Finish debugging output for this type. */ 5359 rest_of_type_compilation (enumtype, toplevel); 5360 5361 return enumtype; 5362} 5363 5364/* Build and install a CONST_DECL for one value of the 5365 current enumeration type (one that was begun with start_enum). 5366 Return a tree-list containing the CONST_DECL and its value. 5367 Assignment of sequential values by default is handled here. */ 5368 5369tree 5370build_enumerator (tree name, tree value) 5371{ 5372 tree decl, type; 5373 5374 /* Validate and default VALUE. */ 5375 5376 /* Remove no-op casts from the value. */ 5377 if (value) 5378 STRIP_TYPE_NOPS (value); 5379 5380 if (value != 0) 5381 { 5382 if (TREE_CODE (value) == INTEGER_CST) 5383 { 5384 value = default_conversion (value); 5385 constant_expression_warning (value); 5386 } 5387 else 5388 { 5389 error ("enumerator value for `%s' not integer constant", 5390 IDENTIFIER_POINTER (name)); 5391 value = 0; 5392 } 5393 } 5394 5395 /* Default based on previous value. */ 5396 /* It should no longer be possible to have NON_LVALUE_EXPR 5397 in the default. */ 5398 if (value == 0) 5399 { 5400 value = enum_next_value; 5401 if (enum_overflow) 5402 error ("overflow in enumeration values"); 5403 } 5404 5405 if (pedantic && ! int_fits_type_p (value, integer_type_node)) 5406 { 5407 pedwarn ("ISO C restricts enumerator values to range of `int'"); 5408 value = convert (integer_type_node, value); 5409 } 5410 5411 /* Set basis for default for next value. */ 5412 enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0); 5413 enum_overflow = tree_int_cst_lt (enum_next_value, value); 5414 5415 /* Now create a declaration for the enum value name. */ 5416 5417 type = TREE_TYPE (value); 5418 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 5419 TYPE_PRECISION (integer_type_node)), 5420 (TYPE_PRECISION (type) 5421 >= TYPE_PRECISION (integer_type_node) 5422 && TREE_UNSIGNED (type))); 5423 5424 decl = build_decl (CONST_DECL, name, type); 5425 DECL_INITIAL (decl) = convert (type, value); 5426 pushdecl (decl); 5427 5428 return tree_cons (decl, value, NULL_TREE); 5429} 5430 5431 5432/* Create the FUNCTION_DECL for a function definition. 5433 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 5434 the declaration; they describe the function's name and the type it returns, 5435 but twisted together in a fashion that parallels the syntax of C. 5436 5437 This function creates a binding context for the function body 5438 as well as setting up the FUNCTION_DECL in current_function_decl. 5439 5440 Returns 1 on success. If the DECLARATOR is not suitable for a function 5441 (it defines a datum instead), we return 0, which tells 5442 yyparse to report a parse error. */ 5443 5444int 5445start_function (tree declspecs, tree declarator, tree attributes) 5446{ 5447 tree decl1, old_decl; 5448 tree restype; 5449 int old_immediate_size_expand = immediate_size_expand; 5450 5451 current_function_returns_value = 0; /* Assume, until we see it does. */ 5452 current_function_returns_null = 0; 5453 current_function_returns_abnormally = 0; 5454 warn_about_return_type = 0; 5455 current_extern_inline = 0; 5456 c_in_iteration_stmt = 0; 5457 c_in_case_stmt = 0; 5458 5459 /* Don't expand any sizes in the return type of the function. */ 5460 immediate_size_expand = 0; 5461 5462 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1, NULL); 5463 5464 /* If the declarator is not suitable for a function definition, 5465 cause a syntax error. */ 5466 if (decl1 == 0) 5467 { 5468 immediate_size_expand = old_immediate_size_expand; 5469 return 0; 5470 } 5471 5472 decl_attributes (&decl1, attributes, 0); 5473 5474 if (DECL_DECLARED_INLINE_P (decl1) 5475 && DECL_UNINLINABLE (decl1) 5476 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 5477 warning ("%Jinline function '%D' given attribute noinline", decl1, decl1); 5478 5479 announce_function (decl1); 5480 5481 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 5482 { 5483 error ("return type is an incomplete type"); 5484 /* Make it return void instead. */ 5485 TREE_TYPE (decl1) 5486 = build_function_type (void_type_node, 5487 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 5488 } 5489 5490 if (warn_about_return_type) 5491 pedwarn_c99 ("return type defaults to `int'"); 5492 5493 /* Save the parm names or decls from this function's declarator 5494 where store_parm_decls will find them. */ 5495 current_function_parms = last_function_parms; 5496 current_function_parm_tags = last_function_parm_tags; 5497 current_function_parm_others = last_function_parm_others; 5498 5499 /* Make the init_value nonzero so pushdecl knows this is not tentative. 5500 error_mark_node is replaced below (in poplevel) with the BLOCK. */ 5501 DECL_INITIAL (decl1) = error_mark_node; 5502 5503 /* If this definition isn't a prototype and we had a prototype declaration 5504 before, copy the arg type info from that prototype. 5505 But not if what we had before was a builtin function. */ 5506 old_decl = lookup_name_current_level (DECL_NAME (decl1)); 5507 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 5508 && !DECL_BUILT_IN (old_decl) 5509 && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 5510 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (old_decl)))) 5511 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0) 5512 { 5513 TREE_TYPE (decl1) = TREE_TYPE (old_decl); 5514 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 5515 } 5516 5517 /* Optionally warn of old-fashioned def with no previous prototype. */ 5518 if (warn_strict_prototypes 5519 && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0 5520 && C_DECL_ISNT_PROTOTYPE (old_decl)) 5521 warning ("function declaration isn't a prototype"); 5522 /* Optionally warn of any global def with no previous prototype. */ 5523 else if (warn_missing_prototypes 5524 && TREE_PUBLIC (decl1) 5525 && ! MAIN_NAME_P (DECL_NAME (decl1)) 5526 && C_DECL_ISNT_PROTOTYPE (old_decl)) 5527 warning ("%Jno previous prototype for '%D'", decl1, decl1); 5528 /* Optionally warn of any def with no previous prototype 5529 if the function has already been used. */ 5530 else if (warn_missing_prototypes 5531 && old_decl != 0 && TREE_USED (old_decl) 5532 && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0) 5533 warning ("%J'%D' was used with no prototype before its definition", 5534 decl1, decl1); 5535 /* Optionally warn of any global def with no previous declaration. */ 5536 else if (warn_missing_declarations 5537 && TREE_PUBLIC (decl1) 5538 && old_decl == 0 5539 && ! MAIN_NAME_P (DECL_NAME (decl1))) 5540 warning ("%Jno previous declaration for '%D'", decl1, decl1); 5541 /* Optionally warn of any def with no previous declaration 5542 if the function has already been used. */ 5543 else if (warn_missing_declarations 5544 && old_decl != 0 && TREE_USED (old_decl) 5545 && C_DECL_IMPLICIT (old_decl)) 5546 warning ("%J`%D' was used with no declaration before its definition", 5547 decl1, decl1); 5548 5549 /* This is a definition, not a reference. 5550 So normally clear DECL_EXTERNAL. 5551 However, `extern inline' acts like a declaration 5552 except for defining how to inline. So set DECL_EXTERNAL in that case. */ 5553 DECL_EXTERNAL (decl1) = current_extern_inline; 5554 5555 /* This function exists in static storage. 5556 (This does not mean `static' in the C sense!) */ 5557 TREE_STATIC (decl1) = 1; 5558 5559 /* A nested function is not global. */ 5560 if (current_function_decl != 0) 5561 TREE_PUBLIC (decl1) = 0; 5562 5563#ifdef ENABLE_CHECKING 5564 /* This is the earliest point at which we might know the assembler 5565 name of the function. Thus, if it's set before this, die horribly. */ 5566 if (DECL_ASSEMBLER_NAME_SET_P (decl1)) 5567 abort (); 5568#endif 5569 5570 /* If #pragma weak was used, mark the decl weak now. */ 5571 if (current_scope == global_scope) 5572 maybe_apply_pragma_weak (decl1); 5573 5574 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 5575 if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1))) 5576 { 5577 tree args; 5578 int argct = 0; 5579 5580 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 5581 != integer_type_node) 5582 pedwarn ("%Jreturn type of '%D' is not `int'", decl1, decl1); 5583 5584 for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args; 5585 args = TREE_CHAIN (args)) 5586 { 5587 tree type = args ? TREE_VALUE (args) : 0; 5588 5589 if (type == void_type_node) 5590 break; 5591 5592 ++argct; 5593 switch (argct) 5594 { 5595 case 1: 5596 if (TYPE_MAIN_VARIANT (type) != integer_type_node) 5597 pedwarn ("%Jfirst argument of '%D' should be `int'", 5598 decl1, decl1); 5599 break; 5600 5601 case 2: 5602 if (TREE_CODE (type) != POINTER_TYPE 5603 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 5604 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 5605 != char_type_node)) 5606 pedwarn ("%Jsecond argument of '%D' should be 'char **'", 5607 decl1, decl1); 5608 break; 5609 5610 case 3: 5611 if (TREE_CODE (type) != POINTER_TYPE 5612 || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE 5613 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) 5614 != char_type_node)) 5615 pedwarn ("%Jthird argument of '%D' should probably be " 5616 "'char **'", decl1, decl1); 5617 break; 5618 } 5619 } 5620 5621 /* It is intentional that this message does not mention the third 5622 argument because it's only mentioned in an appendix of the 5623 standard. */ 5624 if (argct > 0 && (argct < 2 || argct > 3)) 5625 pedwarn ("%J'%D' takes only zero or two arguments", decl1, decl1); 5626 5627 if (! TREE_PUBLIC (decl1)) 5628 pedwarn ("%J'%D' is normally a non-static function", decl1, decl1); 5629 } 5630 5631 /* Record the decl so that the function name is defined. 5632 If we already have a decl for this name, and it is a FUNCTION_DECL, 5633 use the old decl. */ 5634 5635 current_function_decl = pushdecl (decl1); 5636 5637 pushlevel (0); 5638 declare_parm_level (); 5639 5640 make_decl_rtl (current_function_decl, NULL); 5641 5642 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 5643 /* Promote the value to int before returning it. */ 5644 if (c_promoting_integer_type_p (restype)) 5645 { 5646 /* It retains unsignedness if not really getting wider. */ 5647 if (TREE_UNSIGNED (restype) 5648 && (TYPE_PRECISION (restype) 5649 == TYPE_PRECISION (integer_type_node))) 5650 restype = unsigned_type_node; 5651 else 5652 restype = integer_type_node; 5653 } 5654 DECL_RESULT (current_function_decl) 5655 = build_decl (RESULT_DECL, NULL_TREE, restype); 5656 5657 /* If this fcn was already referenced via a block-scope `extern' decl 5658 (or an implicit decl), propagate certain information about the usage. */ 5659 if (TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (current_function_decl))) 5660 TREE_ADDRESSABLE (current_function_decl) = 1; 5661 5662 immediate_size_expand = old_immediate_size_expand; 5663 5664 start_fname_decls (); 5665 5666 return 1; 5667} 5668 5669/* Subroutine of store_parm_decls which handles new-style function 5670 definitions (prototype format). The parms already have decls, so we 5671 need only record them as in effect and complain if any redundant 5672 old-style parm decls were written. */ 5673static void 5674store_parm_decls_newstyle (void) 5675{ 5676 tree decl, last; 5677 tree fndecl = current_function_decl; 5678 tree parms = current_function_parms; 5679 tree tags = current_function_parm_tags; 5680 tree others = current_function_parm_others; 5681 5682 if (current_scope->parms || current_scope->names || current_scope->tags) 5683 { 5684 error ("%Jold-style parameter declarations in prototyped " 5685 "function definition", fndecl); 5686 5687 /* Get rid of the old-style declarations. */ 5688 poplevel (0, 0, 0); 5689 pushlevel (0); 5690 } 5691 5692 /* Now make all the parameter declarations visible in the function body. 5693 We can bypass most of the grunt work of pushdecl. */ 5694 for (last = 0, decl = parms; decl; last = decl, decl = TREE_CHAIN (decl)) 5695 { 5696 DECL_CONTEXT (decl) = current_function_decl; 5697 if (DECL_NAME (decl) == 0) 5698 error ("%Jparameter name omitted", decl); 5699 else 5700 { 5701 if (IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl))) 5702 current_scope->shadowed 5703 = tree_cons (DECL_NAME (decl), 5704 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl)), 5705 current_scope->shadowed); 5706 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl)) = decl; 5707 } 5708 } 5709 current_scope->parms = parms; 5710 current_scope->parms_last = last; 5711 5712 /* Record the parameter list in the function declaration. */ 5713 DECL_ARGUMENTS (fndecl) = parms; 5714 5715 /* Now make all the ancillary declarations visible, likewise. */ 5716 for (last = 0, decl = others; decl; last = decl, decl = TREE_CHAIN (decl)) 5717 { 5718 DECL_CONTEXT (decl) = current_function_decl; 5719 if (DECL_NAME (decl) 5720 && TYPE_MAIN_VARIANT (TREE_TYPE (decl)) != void_type_node) 5721 { 5722 if (IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl))) 5723 current_scope->shadowed 5724 = tree_cons (DECL_NAME (decl), 5725 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl)), 5726 current_scope->shadowed); 5727 IDENTIFIER_SYMBOL_VALUE (DECL_NAME (decl)) = decl; 5728 } 5729 } 5730 current_scope->names = others; 5731 current_scope->names_last = last; 5732 5733 /* And all the tag declarations. */ 5734 for (decl = tags; decl; decl = TREE_CHAIN (decl)) 5735 if (TREE_PURPOSE (decl)) 5736 { 5737 if (IDENTIFIER_TAG_VALUE (TREE_PURPOSE (decl))) 5738 current_scope->shadowed_tags 5739 = tree_cons (TREE_PURPOSE (decl), 5740 IDENTIFIER_SYMBOL_VALUE (TREE_PURPOSE (decl)), 5741 current_scope->shadowed_tags); 5742 IDENTIFIER_TAG_VALUE (TREE_PURPOSE (decl)) = TREE_VALUE (decl); 5743 } 5744 current_scope->tags = tags; 5745} 5746 5747/* Subroutine of store_parm_decls which handles old-style function 5748 definitions (separate parameter list and declarations). */ 5749 5750static void 5751store_parm_decls_oldstyle (void) 5752{ 5753 tree parm, decl, last; 5754 tree fndecl = current_function_decl; 5755 5756 /* This is the identifier list from the function declarator. */ 5757 tree parmids = current_function_parms; 5758 5759 /* We use DECL_WEAK as a flag to show which parameters have been 5760 seen already, since it is not used on PARM_DECL. */ 5761#ifdef ENABLE_CHECKING 5762 for (parm = current_scope->parms; parm; parm = TREE_CHAIN (parm)) 5763 if (DECL_WEAK (parm)) 5764 abort (); 5765#endif 5766 5767 /* Match each formal parameter name with its declaration. Save each 5768 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 5769 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 5770 { 5771 if (TREE_VALUE (parm) == 0) 5772 { 5773 error ("%Jparameter name missing from parameter list", fndecl); 5774 TREE_PURPOSE (parm) = 0; 5775 continue; 5776 } 5777 5778 decl = IDENTIFIER_SYMBOL_VALUE (TREE_VALUE (parm)); 5779 if (decl && DECL_CONTEXT (decl) == fndecl) 5780 { 5781 /* If we got something other than a PARM_DECL it is an error. */ 5782 if (TREE_CODE (decl) != PARM_DECL) 5783 error ("%J\"%D\" declared as a non-parameter", decl, decl); 5784 /* If the declaration is already marked, we have a duplicate 5785 name. Complain and ignore the duplicate. */ 5786 else if (DECL_WEAK (decl)) 5787 { 5788 error ("%Jmultiple parameters named \"%D\"", decl, decl); 5789 TREE_PURPOSE (parm) = 0; 5790 continue; 5791 } 5792 /* If the declaration says "void", complain and turn it into 5793 an int. */ 5794 else if (VOID_TYPE_P (TREE_TYPE (decl))) 5795 { 5796 error ("%Jparameter \"%D\" declared void", decl, decl); 5797 TREE_TYPE (decl) = integer_type_node; 5798 DECL_ARG_TYPE (decl) = integer_type_node; 5799 layout_decl (decl, 0); 5800 } 5801 } 5802 /* If no declaration found, default to int. */ 5803 else 5804 { 5805 decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node); 5806 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 5807 DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl); 5808 pushdecl (decl); 5809 5810 if (flag_isoc99) 5811 pedwarn ("%Jtype of \"%D\" defaults to \"int\"", decl, decl); 5812 else if (extra_warnings) 5813 warning ("%Jtype of \"%D\" defaults to \"int\"", decl, decl); 5814 } 5815 5816 TREE_PURPOSE (parm) = decl; 5817 DECL_WEAK (decl) = 1; 5818 } 5819 5820 /* Now examine the parms chain for incomplete declarations 5821 and declarations with no corresponding names. */ 5822 5823 for (parm = current_scope->parms; parm; parm = TREE_CHAIN (parm)) 5824 { 5825 if (!COMPLETE_TYPE_P (TREE_TYPE (parm))) 5826 { 5827 error ("%Jparameter \"%D\" has incomplete type", parm, parm); 5828 TREE_TYPE (parm) = error_mark_node; 5829 } 5830 5831 if (! DECL_WEAK (parm)) 5832 { 5833 error ("%Jdeclaration for parameter \"%D\" but no such parameter", 5834 parm, parm); 5835 5836 /* Pretend the parameter was not missing. 5837 This gets us to a standard state and minimizes 5838 further error messages. */ 5839 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 5840 } 5841 } 5842 5843 /* Chain the declarations together in the order of the list of 5844 names. Store that chain in the function decl, replacing the 5845 list of names. Update the current scope to match. */ 5846 DECL_ARGUMENTS (fndecl) = 0; 5847 5848 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 5849 if (TREE_PURPOSE (parm)) 5850 break; 5851 if (parm && TREE_PURPOSE (parm)) 5852 { 5853 last = TREE_PURPOSE (parm); 5854 DECL_ARGUMENTS (fndecl) = last; 5855 current_scope->parms = last; 5856 DECL_WEAK (last) = 0; 5857 5858 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 5859 if (TREE_PURPOSE (parm)) 5860 { 5861 TREE_CHAIN (last) = TREE_PURPOSE (parm); 5862 last = TREE_PURPOSE (parm); 5863 DECL_WEAK (last) = 0; 5864 } 5865 current_scope->parms_last = last; 5866 TREE_CHAIN (last) = 0; 5867 } 5868 5869 /* If there was a previous prototype, 5870 set the DECL_ARG_TYPE of each argument according to 5871 the type previously specified, and report any mismatches. */ 5872 5873 if (TYPE_ARG_TYPES (TREE_TYPE (fndecl))) 5874 { 5875 tree type; 5876 for (parm = DECL_ARGUMENTS (fndecl), 5877 type = TYPE_ARG_TYPES (TREE_TYPE (fndecl)); 5878 parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) 5879 != void_type_node)); 5880 parm = TREE_CHAIN (parm), type = TREE_CHAIN (type)) 5881 { 5882 if (parm == 0 || type == 0 5883 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 5884 { 5885 error ("number of arguments doesn't match prototype"); 5886 error ("%Hprototype declaration", 5887 ¤t_function_prototype_locus); 5888 break; 5889 } 5890 /* Type for passing arg must be consistent with that 5891 declared for the arg. ISO C says we take the unqualified 5892 type for parameters declared with qualified type. */ 5893 if (! comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 5894 TYPE_MAIN_VARIANT (TREE_VALUE (type)), 5895 COMPARE_STRICT)) 5896 { 5897 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 5898 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 5899 { 5900 /* Adjust argument to match prototype. E.g. a previous 5901 `int foo(float);' prototype causes 5902 `int foo(x) float x; {...}' to be treated like 5903 `int foo(float x) {...}'. This is particularly 5904 useful for argument types like uid_t. */ 5905 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 5906 5907 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 5908 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 5909 && TYPE_PRECISION (TREE_TYPE (parm)) 5910 < TYPE_PRECISION (integer_type_node)) 5911 DECL_ARG_TYPE (parm) = integer_type_node; 5912 5913 if (pedantic) 5914 { 5915 pedwarn ("promoted argument \"%D\" " 5916 "doesn't match prototype", parm); 5917 pedwarn ("%Hprototype declaration", 5918 ¤t_function_prototype_locus); 5919 } 5920 } 5921 else 5922 { 5923 error ("argument \"%D\" doesn't match prototype", parm); 5924 error ("%Hprototype declaration", 5925 ¤t_function_prototype_locus); 5926 } 5927 } 5928 } 5929 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 5930 } 5931 5932 /* Otherwise, create a prototype that would match. */ 5933 5934 else 5935 { 5936 tree actual = 0, last = 0, type; 5937 5938 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm)) 5939 { 5940 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 5941 if (last) 5942 TREE_CHAIN (last) = type; 5943 else 5944 actual = type; 5945 last = type; 5946 } 5947 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 5948 if (last) 5949 TREE_CHAIN (last) = type; 5950 else 5951 actual = type; 5952 5953 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 5954 of the type of this function, but we need to avoid having this 5955 affect the types of other similarly-typed functions, so we must 5956 first force the generation of an identical (but separate) type 5957 node for the relevant function type. The new node we create 5958 will be a variant of the main variant of the original function 5959 type. */ 5960 5961 TREE_TYPE (fndecl) = build_type_copy (TREE_TYPE (fndecl)); 5962 5963 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 5964 } 5965} 5966 5967/* Store the parameter declarations into the current function declaration. 5968 This is called after parsing the parameter declarations, before 5969 digesting the body of the function. 5970 5971 For an old-style definition, construct a prototype out of the old-style 5972 parameter declarations and inject it into the function's type. */ 5973 5974void 5975store_parm_decls (void) 5976{ 5977 tree fndecl = current_function_decl; 5978 5979 /* The function containing FNDECL, if any. */ 5980 tree context = decl_function_context (fndecl); 5981 5982 /* True if this definition is written with a prototype. */ 5983 bool prototype = (current_function_parms 5984 && TREE_CODE (current_function_parms) != TREE_LIST); 5985 5986 if (prototype) 5987 store_parm_decls_newstyle (); 5988 else 5989 store_parm_decls_oldstyle (); 5990 5991 /* The next call to pushlevel will be a function body. */ 5992 5993 next_is_function_body = true; 5994 5995 /* Write a record describing this function definition to the prototypes 5996 file (if requested). */ 5997 5998 gen_aux_info_record (fndecl, 1, 0, prototype); 5999 6000 /* Initialize the RTL code for the function. */ 6001 allocate_struct_function (fndecl); 6002 6003 /* Begin the statement tree for this function. */ 6004 begin_stmt_tree (&DECL_SAVED_TREE (fndecl)); 6005 6006 /* If this is a nested function, save away the sizes of any 6007 variable-size types so that we can expand them when generating 6008 RTL. */ 6009 if (context) 6010 { 6011 tree t; 6012 6013 DECL_LANG_SPECIFIC (fndecl)->pending_sizes 6014 = nreverse (get_pending_sizes ()); 6015 for (t = DECL_LANG_SPECIFIC (fndecl)->pending_sizes; 6016 t; 6017 t = TREE_CHAIN (t)) 6018 SAVE_EXPR_CONTEXT (TREE_VALUE (t)) = context; 6019 } 6020 6021 /* This function is being processed in whole-function mode. */ 6022 cfun->x_whole_function_mode_p = 1; 6023 6024 /* Even though we're inside a function body, we still don't want to 6025 call expand_expr to calculate the size of a variable-sized array. 6026 We haven't necessarily assigned RTL to all variables yet, so it's 6027 not safe to try to expand expressions involving them. */ 6028 immediate_size_expand = 0; 6029 cfun->x_dont_save_pending_sizes_p = 1; 6030} 6031 6032/* Finish up a function declaration and compile that function 6033 all the way to assembler language output. The free the storage 6034 for the function definition. 6035 6036 This is called after parsing the body of the function definition. */ 6037 6038void 6039finish_function (void) 6040{ 6041 tree fndecl = current_function_decl; 6042 6043 /* When a function declaration is totally empty, e.g. 6044 void foo(void) { } 6045 (the argument list is irrelevant) the compstmt rule will not 6046 bother calling pushlevel/poplevel, which means we get here with 6047 the scope stack out of sync. Detect this situation by noticing 6048 that current_scope is still as store_parm_decls left it, and do 6049 a dummy push/pop to get back to consistency. 6050 Note that the call to pushlevel does not actually push another 6051 scope - see there for details. */ 6052 6053 if (current_scope->parm_flag && next_is_function_body) 6054 { 6055 pushlevel (0); 6056 poplevel (0, 0, 0); 6057 } 6058 6059 if (TREE_CODE (fndecl) == FUNCTION_DECL 6060 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 6061 { 6062 tree args = DECL_ARGUMENTS (fndecl); 6063 for (; args; args = TREE_CHAIN (args)) 6064 { 6065 tree type = TREE_TYPE (args); 6066 if (INTEGRAL_TYPE_P (type) 6067 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 6068 DECL_ARG_TYPE (args) = integer_type_node; 6069 } 6070 } 6071 6072 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6073 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 6074 6075 /* Must mark the RESULT_DECL as being in this function. */ 6076 6077 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 6078 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 6079 6080 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted) 6081 { 6082 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 6083 != integer_type_node) 6084 { 6085 /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned. 6086 If warn_main is -1 (-Wno-main) we don't want to be warned. */ 6087 if (!warn_main) 6088 pedwarn ("%Jreturn type of '%D' is not `int'", fndecl, fndecl); 6089 } 6090 else 6091 { 6092#ifdef DEFAULT_MAIN_RETURN 6093 /* Make it so that `main' always returns success by default. */ 6094 DEFAULT_MAIN_RETURN; 6095#else 6096 if (flag_isoc99) 6097 c_expand_return (integer_zero_node); 6098#endif 6099 } 6100 } 6101 6102 finish_fname_decls (); 6103 6104 /* Tie off the statement tree for this function. */ 6105 finish_stmt_tree (&DECL_SAVED_TREE (fndecl)); 6106 6107 /* Complain if there's just no return statement. */ 6108 if (warn_return_type 6109 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 6110 && !current_function_returns_value && !current_function_returns_null 6111 /* Don't complain if we abort. */ 6112 && !current_function_returns_abnormally 6113 /* Don't warn for main(). */ 6114 && !MAIN_NAME_P (DECL_NAME (fndecl)) 6115 /* Or if they didn't actually specify a return type. */ 6116 && !C_FUNCTION_IMPLICIT_INT (fndecl) 6117 /* Normally, with -Wreturn-type, flow will complain. Unless we're an 6118 inline function, as we might never be compiled separately. */ 6119 && DECL_INLINE (fndecl)) 6120 warning ("no return statement in function returning non-void"); 6121 6122 /* With just -Wextra, complain only if function returns both with 6123 and without a value. */ 6124 if (extra_warnings 6125 && current_function_returns_value 6126 && current_function_returns_null) 6127 warning ("this function may return with or without a value"); 6128 6129 /* We're leaving the context of this function, so zap cfun. It's still in 6130 DECL_SAVED_INSNS, and we'll restore it in tree_rest_of_compilation. */ 6131 cfun = NULL; 6132 6133 /* ??? Objc emits functions after finalizing the compilation unit. 6134 This should be cleaned up later and this conditional removed. */ 6135 if (!cgraph_global_info_ready) 6136 cgraph_finalize_function (fndecl, false); 6137 else 6138 c_expand_body (fndecl); 6139 current_function_decl = NULL; 6140} 6141 6142/* Generate the RTL for a deferred function FNDECL. */ 6143 6144void 6145c_expand_deferred_function (tree fndecl) 6146{ 6147 /* DECL_INLINE or DECL_RESULT might got cleared after the inline 6148 function was deferred, e.g. in duplicate_decls. */ 6149 if (DECL_INLINE (fndecl) && DECL_RESULT (fndecl)) 6150 { 6151 if (flag_inline_trees) 6152 { 6153 timevar_push (TV_INTEGRATION); 6154 optimize_inline_calls (fndecl); 6155 timevar_pop (TV_INTEGRATION); 6156 } 6157 c_expand_body (fndecl); 6158 current_function_decl = NULL; 6159 } 6160} 6161 6162/* Generate the RTL for the body of FNDECL. If NESTED_P is nonzero, 6163 then we are already in the process of generating RTL for another 6164 function. */ 6165 6166static void 6167c_expand_body_1 (tree fndecl, int nested_p) 6168{ 6169 if (nested_p) 6170 { 6171 /* Make sure that we will evaluate variable-sized types involved 6172 in our function's type. */ 6173 expand_pending_sizes (DECL_LANG_SPECIFIC (fndecl)->pending_sizes); 6174 6175 /* Squirrel away our current state. */ 6176 push_function_context (); 6177 } 6178 6179 tree_rest_of_compilation (fndecl, nested_p); 6180 6181 if (nested_p) 6182 /* Return to the enclosing function. */ 6183 pop_function_context (); 6184 6185 if (DECL_STATIC_CONSTRUCTOR (fndecl)) 6186 { 6187 if (targetm.have_ctors_dtors) 6188 (* targetm.asm_out.constructor) (XEXP (DECL_RTL (fndecl), 0), 6189 DEFAULT_INIT_PRIORITY); 6190 else 6191 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors); 6192 } 6193 6194 if (DECL_STATIC_DESTRUCTOR (fndecl)) 6195 { 6196 if (targetm.have_ctors_dtors) 6197 (* targetm.asm_out.destructor) (XEXP (DECL_RTL (fndecl), 0), 6198 DEFAULT_INIT_PRIORITY); 6199 else 6200 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors); 6201 } 6202} 6203 6204/* Like c_expand_body_1 but only for unnested functions. */ 6205 6206void 6207c_expand_body (tree fndecl) 6208{ 6209 6210 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 6211 c_expand_body_1 (fndecl, 0); 6212} 6213 6214/* Check the declarations given in a for-loop for satisfying the C99 6215 constraints. */ 6216void 6217check_for_loop_decls (void) 6218{ 6219 tree t; 6220 6221 if (!flag_isoc99) 6222 { 6223 /* If we get here, declarations have been used in a for loop without 6224 the C99 for loop scope. This doesn't make much sense, so don't 6225 allow it. */ 6226 error ("'for' loop initial declaration used outside C99 mode"); 6227 return; 6228 } 6229 /* C99 subclause 6.8.5 paragraph 3: 6230 6231 [#3] The declaration part of a for statement shall only 6232 declare identifiers for objects having storage class auto or 6233 register. 6234 6235 It isn't clear whether, in this sentence, "identifiers" binds to 6236 "shall only declare" or to "objects" - that is, whether all identifiers 6237 declared must be identifiers for objects, or whether the restriction 6238 only applies to those that are. (A question on this in comp.std.c 6239 in November 2000 received no answer.) We implement the strictest 6240 interpretation, to avoid creating an extension which later causes 6241 problems. */ 6242 6243 for (t = current_scope->tags; t; t = TREE_CHAIN (t)) 6244 { 6245 if (TREE_PURPOSE (t) != 0) 6246 { 6247 enum tree_code code = TREE_CODE (TREE_VALUE (t)); 6248 6249 if (code == RECORD_TYPE) 6250 error ("'struct %s' declared in 'for' loop initial declaration", 6251 IDENTIFIER_POINTER (TREE_PURPOSE (t))); 6252 else if (code == UNION_TYPE) 6253 error ("'union %s' declared in 'for' loop initial declaration", 6254 IDENTIFIER_POINTER (TREE_PURPOSE (t))); 6255 else 6256 error ("'enum %s' declared in 'for' loop initial declaration", 6257 IDENTIFIER_POINTER (TREE_PURPOSE (t))); 6258 } 6259 } 6260 6261 for (t = getdecls (); t; t = TREE_CHAIN (t)) 6262 { 6263 if (TREE_CODE (t) != VAR_DECL && DECL_NAME (t)) 6264 error ("%Jdeclaration of non-variable '%D' in 'for' loop " 6265 "initial declaration", t, t); 6266 else if (TREE_STATIC (t)) 6267 error ("%Jdeclaration of static variable '%D' in 'for' loop " 6268 "initial declaration", t, t); 6269 else if (DECL_EXTERNAL (t)) 6270 error ("%Jdeclaration of 'extern' variable '%D' in 'for' loop " 6271 "initial declaration", t, t); 6272 } 6273} 6274 6275/* Save and reinitialize the variables 6276 used during compilation of a C function. */ 6277 6278void 6279c_push_function_context (struct function *f) 6280{ 6281 struct language_function *p; 6282 p = ggc_alloc (sizeof (struct language_function)); 6283 f->language = p; 6284 6285 p->base.x_stmt_tree = c_stmt_tree; 6286 p->base.x_scope_stmt_stack = c_scope_stmt_stack; 6287 p->x_in_iteration_stmt = c_in_iteration_stmt; 6288 p->x_in_case_stmt = c_in_case_stmt; 6289 p->returns_value = current_function_returns_value; 6290 p->returns_null = current_function_returns_null; 6291 p->returns_abnormally = current_function_returns_abnormally; 6292 p->warn_about_return_type = warn_about_return_type; 6293 p->extern_inline = current_extern_inline; 6294} 6295 6296/* Restore the variables used during compilation of a C function. */ 6297 6298void 6299c_pop_function_context (struct function *f) 6300{ 6301 struct language_function *p = f->language; 6302 6303 if (DECL_SAVED_INSNS (current_function_decl) == 0 6304 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 6305 { 6306 /* Stop pointing to the local nodes about to be freed. */ 6307 /* But DECL_INITIAL must remain nonzero so we know this 6308 was an actual function definition. */ 6309 DECL_INITIAL (current_function_decl) = error_mark_node; 6310 DECL_ARGUMENTS (current_function_decl) = 0; 6311 } 6312 6313 c_stmt_tree = p->base.x_stmt_tree; 6314 c_scope_stmt_stack = p->base.x_scope_stmt_stack; 6315 c_in_iteration_stmt = p->x_in_iteration_stmt; 6316 c_in_case_stmt = p->x_in_case_stmt; 6317 current_function_returns_value = p->returns_value; 6318 current_function_returns_null = p->returns_null; 6319 current_function_returns_abnormally = p->returns_abnormally; 6320 warn_about_return_type = p->warn_about_return_type; 6321 current_extern_inline = p->extern_inline; 6322 6323 f->language = NULL; 6324} 6325 6326/* Copy the DECL_LANG_SPECIFIC data associated with DECL. */ 6327 6328void 6329c_dup_lang_specific_decl (tree decl) 6330{ 6331 struct lang_decl *ld; 6332 6333 if (!DECL_LANG_SPECIFIC (decl)) 6334 return; 6335 6336 ld = ggc_alloc (sizeof (struct lang_decl)); 6337 memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl)); 6338 DECL_LANG_SPECIFIC (decl) = ld; 6339} 6340 6341/* The functions below are required for functionality of doing 6342 function at once processing in the C front end. Currently these 6343 functions are not called from anywhere in the C front end, but as 6344 these changes continue, that will change. */ 6345 6346/* Returns nonzero if the current statement is a full expression, 6347 i.e. temporaries created during that statement should be destroyed 6348 at the end of the statement. */ 6349 6350int 6351stmts_are_full_exprs_p (void) 6352{ 6353 return 0; 6354} 6355 6356/* Returns the stmt_tree (if any) to which statements are currently 6357 being added. If there is no active statement-tree, NULL is 6358 returned. */ 6359 6360stmt_tree 6361current_stmt_tree (void) 6362{ 6363 return &c_stmt_tree; 6364} 6365 6366/* Returns the stack of SCOPE_STMTs for the current function. */ 6367 6368tree * 6369current_scope_stmt_stack (void) 6370{ 6371 return &c_scope_stmt_stack; 6372} 6373 6374/* Nonzero if TYPE is an anonymous union or struct type. Always 0 in 6375 C. */ 6376 6377int 6378anon_aggr_type_p (tree node ATTRIBUTE_UNUSED) 6379{ 6380 return 0; 6381} 6382 6383/* Dummy function in place of callback used by C++. */ 6384 6385void 6386extract_interface_info (void) 6387{ 6388} 6389 6390/* Return a new COMPOUND_STMT, after adding it to the current 6391 statement tree. */ 6392 6393tree 6394c_begin_compound_stmt (void) 6395{ 6396 tree stmt; 6397 6398 /* Create the COMPOUND_STMT. */ 6399 stmt = add_stmt (build_stmt (COMPOUND_STMT, NULL_TREE)); 6400 6401 return stmt; 6402} 6403 6404/* Expand T (a DECL_STMT) if it declares an entity not handled by the 6405 common code. */ 6406 6407void 6408c_expand_decl_stmt (tree t) 6409{ 6410 tree decl = DECL_STMT_DECL (t); 6411 6412 /* Expand nested functions. */ 6413 if (TREE_CODE (decl) == FUNCTION_DECL 6414 && DECL_CONTEXT (decl) == current_function_decl 6415 && DECL_SAVED_TREE (decl)) 6416 c_expand_body_1 (decl, 1); 6417} 6418 6419/* Return the global value of T as a symbol. */ 6420 6421tree 6422identifier_global_value (tree t) 6423{ 6424 tree decl = IDENTIFIER_SYMBOL_VALUE (t); 6425 if (decl == 0 || DECL_FILE_SCOPE_P (decl)) 6426 return decl; 6427 6428 /* Shadowed by something else; find the true global value. */ 6429 for (decl = global_scope->names; decl; decl = TREE_CHAIN (decl)) 6430 if (DECL_NAME (decl) == t) 6431 return decl; 6432 6433 /* Only local values for this decl. */ 6434 return 0; 6435} 6436 6437/* Record a builtin type for C. If NAME is non-NULL, it is the name used; 6438 otherwise the name is found in ridpointers from RID_INDEX. */ 6439 6440void 6441record_builtin_type (enum rid rid_index, const char *name, tree type) 6442{ 6443 tree id; 6444 if (name == 0) 6445 id = ridpointers[(int) rid_index]; 6446 else 6447 id = get_identifier (name); 6448 pushdecl (build_decl (TYPE_DECL, id, type)); 6449} 6450 6451/* Build the void_list_node (void_type_node having been created). */ 6452tree 6453build_void_list_node (void) 6454{ 6455 tree t = build_tree_list (NULL_TREE, void_type_node); 6456 return t; 6457} 6458 6459/* Return something to represent absolute declarators containing a *. 6460 TARGET is the absolute declarator that the * contains. 6461 TYPE_QUALS_ATTRS is a list of modifiers such as const or volatile 6462 to apply to the pointer type, represented as identifiers, possible mixed 6463 with attributes. 6464 6465 We return an INDIRECT_REF whose "contents" are TARGET (inside a TREE_LIST, 6466 if attributes are present) and whose type is the modifier list. */ 6467 6468tree 6469make_pointer_declarator (tree type_quals_attrs, tree target) 6470{ 6471 tree quals, attrs; 6472 tree itarget = target; 6473 split_specs_attrs (type_quals_attrs, &quals, &attrs); 6474 if (attrs != NULL_TREE) 6475 itarget = tree_cons (attrs, target, NULL_TREE); 6476 return build1 (INDIRECT_REF, quals, itarget); 6477} 6478 6479/* A wrapper around lhd_set_decl_assembler_name that gives static 6480 variables their C names if they are at file scope and only one 6481 translation unit is being compiled, for backwards compatibility 6482 with certain bizarre assembler hacks (like crtstuff.c). */ 6483 6484void 6485c_static_assembler_name (tree decl) 6486{ 6487 if (num_in_fnames == 1 6488 && !TREE_PUBLIC (decl) && DECL_CONTEXT (decl) 6489 && TREE_CODE (DECL_CONTEXT (decl)) == TRANSLATION_UNIT_DECL) 6490 SET_DECL_ASSEMBLER_NAME (decl, DECL_NAME (decl)); 6491 else 6492 lhd_set_decl_assembler_name (decl); 6493} 6494 6495/* Hash and equality functions for link_hash_table: key off 6496 DECL_ASSEMBLER_NAME. */ 6497 6498static hashval_t 6499link_hash_hash (const void *x_p) 6500{ 6501 tree x = (tree)x_p; 6502 return (hashval_t) (long)DECL_ASSEMBLER_NAME (x); 6503} 6504 6505static int 6506link_hash_eq (const void *x1_p, const void *x2_p) 6507{ 6508 tree x1 = (tree)x1_p; 6509 tree x2 = (tree)x2_p; 6510 return DECL_ASSEMBLER_NAME (x1) == DECL_ASSEMBLER_NAME (x2); 6511} 6512 6513/* Propagate information between definitions and uses between multiple 6514 translation units in TU_LIST based on linkage rules. */ 6515 6516void 6517merge_translation_unit_decls (void) 6518{ 6519 const tree tu_list = current_file_decl; 6520 tree tu; 6521 tree decl; 6522 htab_t link_hash_table; 6523 tree block; 6524 6525 /* Create the BLOCK that poplevel would have created, but don't 6526 actually call poplevel since that's expensive. */ 6527 block = make_node (BLOCK); 6528 BLOCK_VARS (block) = current_scope->names; 6529 TREE_USED (block) = 1; 6530 DECL_INITIAL (current_file_decl) = block; 6531 6532 /* If only one translation unit seen, no copying necessary. */ 6533 if (TREE_CHAIN (tu_list) == NULL_TREE) 6534 return; 6535 6536 link_hash_table = htab_create (1021, link_hash_hash, link_hash_eq, NULL); 6537 6538 /* Enter any actual definitions into the hash table. */ 6539 for (tu = tu_list; tu; tu = TREE_CHAIN (tu)) 6540 for (decl = BLOCK_VARS (DECL_INITIAL (tu)); decl; decl = TREE_CHAIN (decl)) 6541 if (TREE_PUBLIC (decl) && ! DECL_EXTERNAL (decl)) 6542 { 6543 PTR *slot; 6544 slot = htab_find_slot (link_hash_table, decl, INSERT); 6545 6546 /* If we've already got a definition, work out which one is 6547 the real one, put it into the hash table, and make the 6548 other one DECL_EXTERNAL. This is important to avoid 6549 putting out two definitions of the same symbol in the 6550 assembly output. */ 6551 if (*slot != NULL) 6552 { 6553 tree old_decl = (tree) *slot; 6554 6555 /* If this is weak or common or whatever, suppress it 6556 in favor of the other definition. */ 6557 if (DECL_WEAK (decl)) 6558 DECL_EXTERNAL (decl) = 1; 6559 else if (DECL_WEAK (old_decl) && ! DECL_WEAK (decl)) 6560 DECL_EXTERNAL (old_decl) = 1; 6561 else if (DECL_COMMON (decl) || DECL_ONE_ONLY (decl)) 6562 DECL_EXTERNAL (decl) = 1; 6563 else if (DECL_COMMON (old_decl) || DECL_ONE_ONLY (old_decl)) 6564 DECL_EXTERNAL (old_decl) = 1; 6565 6566 if (DECL_EXTERNAL (decl)) 6567 { 6568 DECL_INITIAL (decl) = NULL_TREE; 6569 DECL_COMMON (decl) = 0; 6570 DECL_ONE_ONLY (decl) = 0; 6571 DECL_WEAK (decl) = 0; 6572 } 6573 else if (DECL_EXTERNAL (old_decl)) 6574 { 6575 DECL_INITIAL (old_decl) = NULL_TREE; 6576 DECL_COMMON (old_decl) = 0; 6577 DECL_ONE_ONLY (old_decl) = 0; 6578 DECL_WEAK (old_decl) = 0; 6579 *slot = decl; 6580 } 6581 else 6582 { 6583 error ("%Jredefinition of global '%D'", decl, decl); 6584 error ("%J'%D' previously defined here", old_decl, old_decl); 6585 } 6586 } 6587 else 6588 *slot = decl; 6589 } 6590 6591 /* Now insert the desired information from all the definitions 6592 into any plain declarations. */ 6593 for (tu = tu_list; tu; tu = TREE_CHAIN (tu)) 6594 for (decl = BLOCK_VARS (DECL_INITIAL (tu)); decl; decl = TREE_CHAIN (decl)) 6595 if (TREE_PUBLIC (decl) && DECL_EXTERNAL (decl)) 6596 { 6597 tree global_decl; 6598 global_decl = htab_find (link_hash_table, decl); 6599 6600 if (! global_decl) 6601 continue; 6602 6603 /* Print any appropriate error messages, and partially merge 6604 the decls. */ 6605 (void) duplicate_decls (decl, global_decl); 6606 } 6607 6608 htab_delete (link_hash_table); 6609} 6610 6611/* Perform final processing on file-scope data. */ 6612 6613void 6614c_write_global_declarations(void) 6615{ 6616 tree link; 6617 6618 for (link = current_file_decl; link; link = TREE_CHAIN (link)) 6619 { 6620 tree globals = BLOCK_VARS (DECL_INITIAL (link)); 6621 int len = list_length (globals); 6622 tree *vec = xmalloc (sizeof (tree) * len); 6623 int i; 6624 tree decl; 6625 6626 /* Process the decls in the order they were written. */ 6627 6628 for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl)) 6629 vec[i] = decl; 6630 6631 wrapup_global_declarations (vec, len); 6632 6633 check_global_declarations (vec, len); 6634 6635 /* Clean up. */ 6636 free (vec); 6637 } 6638} 6639 6640/* Reset the parser's state in preparation for a new file. */ 6641 6642void 6643c_reset_state (void) 6644{ 6645 tree link; 6646 tree file_scope_decl; 6647 6648 /* Pop the global scope. */ 6649 if (current_scope != global_scope) 6650 current_scope = global_scope; 6651 file_scope_decl = current_file_decl; 6652 DECL_INITIAL (file_scope_decl) = poplevel (1, 0, 0); 6653 BLOCK_SUPERCONTEXT (DECL_INITIAL (file_scope_decl)) = file_scope_decl; 6654 truly_local_externals = NULL_TREE; 6655 6656 /* Start a new global binding level. */ 6657 pushlevel (0); 6658 global_scope = current_scope; 6659 current_file_decl = build_decl (TRANSLATION_UNIT_DECL, NULL, NULL); 6660 TREE_CHAIN (current_file_decl) = file_scope_decl; 6661 6662 /* Reintroduce the builtin declarations. */ 6663 for (link = first_builtin_decl; 6664 link != TREE_CHAIN (last_builtin_decl); 6665 link = TREE_CHAIN (link)) 6666 pushdecl (copy_node (link)); 6667} 6668 6669#include "gt-c-decl.h" 6670