1 /* Process declarations and variables for C compiler. 2 Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 3 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 4 Free Software Foundation, Inc. 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 /* Process declarations and symbol lookup for C front end. 23 Also constructs types; the standard scalar types at initialization, 24 and structure, union, array and enum types when they are declared. */ 25 26 /* ??? not all decl nodes are given the most useful possible 27 line numbers. For example, the CONST_DECLs for enum values. */ 28 29 #include "config.h" 30 #include "system.h" 31 #include "coretypes.h" 32 #include "input.h" 33 #include "tm.h" 34 #include "intl.h" 35 #include "tree.h" 36 #include "tree-inline.h" 37 #include "flags.h" 38 #include "function.h" 39 #include "output.h" 40 #include "c-tree.h" 41 #include "toplev.h" 42 #include "tm_p.h" 43 #include "cpplib.h" 44 #include "target.h" 45 #include "debug.h" 46 #include "opts.h" 47 #include "timevar.h" 48 #include "c-family/c-common.h" 49 #include "c-family/c-objc.h" 50 #include "c-family/c-pragma.h" 51 #include "c-lang.h" 52 #include "langhooks.h" 53 #include "tree-iterator.h" 54 #include "diagnostic-core.h" 55 #include "tree-dump.h" 56 #include "cgraph.h" 57 #include "hashtab.h" 58 #include "langhooks-def.h" 59 #include "pointer-set.h" 60 #include "plugin.h" 61 #include "c-family/c-ada-spec.h" 62 63 /* In grokdeclarator, distinguish syntactic contexts of declarators. */ 64 enum decl_context 65 { NORMAL, /* Ordinary declaration */ 66 FUNCDEF, /* Function definition */ 67 PARM, /* Declaration of parm before function body */ 68 FIELD, /* Declaration inside struct or union */ 69 TYPENAME}; /* Typename (inside cast or sizeof) */ 70 71 /* States indicating how grokdeclarator() should handle declspecs marked 72 with __attribute__((deprecated)). An object declared as 73 __attribute__((deprecated)) suppresses warnings of uses of other 74 deprecated items. */ 75 76 enum deprecated_states { 77 DEPRECATED_NORMAL, 78 DEPRECATED_SUPPRESS 79 }; 80 81 82 /* Nonzero if we have seen an invalid cross reference 83 to a struct, union, or enum, but not yet printed the message. */ 84 tree pending_invalid_xref; 85 86 /* File and line to appear in the eventual error message. */ 87 location_t pending_invalid_xref_location; 88 89 /* The file and line that the prototype came from if this is an 90 old-style definition; used for diagnostics in 91 store_parm_decls_oldstyle. */ 92 93 static location_t current_function_prototype_locus; 94 95 /* Whether this prototype was built-in. */ 96 97 static bool current_function_prototype_built_in; 98 99 /* The argument type information of this prototype. */ 100 101 static tree current_function_prototype_arg_types; 102 103 /* The argument information structure for the function currently being 104 defined. */ 105 106 static struct c_arg_info *current_function_arg_info; 107 108 /* The obstack on which parser and related data structures, which are 109 not live beyond their top-level declaration or definition, are 110 allocated. */ 111 struct obstack parser_obstack; 112 113 /* The current statement tree. */ 114 115 static GTY(()) struct stmt_tree_s c_stmt_tree; 116 117 /* State saving variables. */ 118 tree c_break_label; 119 tree c_cont_label; 120 121 /* A list of decls to be made automatically visible in each file scope. */ 122 static GTY(()) tree visible_builtins; 123 124 /* Set to 0 at beginning of a function definition, set to 1 if 125 a return statement that specifies a return value is seen. */ 126 127 int current_function_returns_value; 128 129 /* Set to 0 at beginning of a function definition, set to 1 if 130 a return statement with no argument is seen. */ 131 132 int current_function_returns_null; 133 134 /* Set to 0 at beginning of a function definition, set to 1 if 135 a call to a noreturn function is seen. */ 136 137 int current_function_returns_abnormally; 138 139 /* Set to nonzero by `grokdeclarator' for a function 140 whose return type is defaulted, if warnings for this are desired. */ 141 142 static int warn_about_return_type; 143 144 /* Nonzero when the current toplevel function contains a declaration 145 of a nested function which is never defined. */ 146 147 static bool undef_nested_function; 148 149 150 /* Each c_binding structure describes one binding of an identifier to 151 a decl. All the decls in a scope - irrespective of namespace - are 152 chained together by the ->prev field, which (as the name implies) 153 runs in reverse order. All the decls in a given namespace bound to 154 a given identifier are chained by the ->shadowed field, which runs 155 from inner to outer scopes. 156 157 The ->decl field usually points to a DECL node, but there are two 158 exceptions. In the namespace of type tags, the bound entity is a 159 RECORD_TYPE, UNION_TYPE, or ENUMERAL_TYPE node. If an undeclared 160 identifier is encountered, it is bound to error_mark_node to 161 suppress further errors about that identifier in the current 162 function. 163 164 The ->u.type field stores the type of the declaration in this scope; 165 if NULL, the type is the type of the ->decl field. This is only of 166 relevance for objects with external or internal linkage which may 167 be redeclared in inner scopes, forming composite types that only 168 persist for the duration of those scopes. In the external scope, 169 this stores the composite of all the types declared for this 170 object, visible or not. The ->inner_comp field (used only at file 171 scope) stores whether an incomplete array type at file scope was 172 completed at an inner scope to an array size other than 1. 173 174 The ->u.label field is used for labels. It points to a structure 175 which stores additional information used for warnings. 176 177 The depth field is copied from the scope structure that holds this 178 decl. It is used to preserve the proper ordering of the ->shadowed 179 field (see bind()) and also for a handful of special-case checks. 180 Finally, the invisible bit is true for a decl which should be 181 ignored for purposes of normal name lookup, and the nested bit is 182 true for a decl that's been bound a second time in an inner scope; 183 in all such cases, the binding in the outer scope will have its 184 invisible bit true. */ 185 186 struct GTY((chain_next ("%h.prev"))) c_binding { 187 union GTY(()) { /* first so GTY desc can use decl */ 188 tree GTY((tag ("0"))) type; /* the type in this scope */ 189 struct c_label_vars * GTY((tag ("1"))) label; /* for warnings */ 190 } GTY((desc ("TREE_CODE (%0.decl) == LABEL_DECL"))) u; 191 tree decl; /* the decl bound */ 192 tree id; /* the identifier it's bound to */ 193 struct c_binding *prev; /* the previous decl in this scope */ 194 struct c_binding *shadowed; /* the innermost decl shadowed by this one */ 195 unsigned int depth : 28; /* depth of this scope */ 196 BOOL_BITFIELD invisible : 1; /* normal lookup should ignore this binding */ 197 BOOL_BITFIELD nested : 1; /* do not set DECL_CONTEXT when popping */ 198 BOOL_BITFIELD inner_comp : 1; /* incomplete array completed in inner scope */ 199 BOOL_BITFIELD in_struct : 1; /* currently defined as struct field */ 200 location_t locus; /* location for nested bindings */ 201 }; 202 #define B_IN_SCOPE(b1, b2) ((b1)->depth == (b2)->depth) 203 #define B_IN_CURRENT_SCOPE(b) ((b)->depth == current_scope->depth) 204 #define B_IN_FILE_SCOPE(b) ((b)->depth == 1 /*file_scope->depth*/) 205 #define B_IN_EXTERNAL_SCOPE(b) ((b)->depth == 0 /*external_scope->depth*/) 206 207 #define I_SYMBOL_BINDING(node) \ 208 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->symbol_binding) 209 #define I_SYMBOL_DECL(node) \ 210 (I_SYMBOL_BINDING(node) ? I_SYMBOL_BINDING(node)->decl : 0) 211 212 #define I_TAG_BINDING(node) \ 213 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->tag_binding) 214 #define I_TAG_DECL(node) \ 215 (I_TAG_BINDING(node) ? I_TAG_BINDING(node)->decl : 0) 216 217 #define I_LABEL_BINDING(node) \ 218 (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->label_binding) 219 #define I_LABEL_DECL(node) \ 220 (I_LABEL_BINDING(node) ? I_LABEL_BINDING(node)->decl : 0) 221 222 /* Each C symbol points to three linked lists of c_binding structures. 223 These describe the values of the identifier in the three different 224 namespaces defined by the language. */ 225 226 struct GTY(()) lang_identifier { 227 struct c_common_identifier common_id; 228 struct c_binding *symbol_binding; /* vars, funcs, constants, typedefs */ 229 struct c_binding *tag_binding; /* struct/union/enum tags */ 230 struct c_binding *label_binding; /* labels */ 231 }; 232 233 /* Validate c-lang.c's assumptions. */ 234 extern char C_SIZEOF_STRUCT_LANG_IDENTIFIER_isnt_accurate 235 [(sizeof(struct lang_identifier) == C_SIZEOF_STRUCT_LANG_IDENTIFIER) ? 1 : -1]; 236 237 /* The resulting tree type. */ 238 239 union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"), 240 chain_next ("(union lang_tree_node *) c_tree_chain_next (&%h.generic)"))) lang_tree_node 241 { 242 union tree_node GTY ((tag ("0"), 243 desc ("tree_node_structure (&%h)"))) 244 generic; 245 struct lang_identifier GTY ((tag ("1"))) identifier; 246 }; 247 248 /* Track bindings and other things that matter for goto warnings. For 249 efficiency, we do not gather all the decls at the point of 250 definition. Instead, we point into the bindings structure. As 251 scopes are popped, we update these structures and gather the decls 252 that matter at that time. */ 253 254 struct GTY(()) c_spot_bindings { 255 /* The currently open scope which holds bindings defined when the 256 label was defined or the goto statement was found. */ 257 struct c_scope *scope; 258 /* The bindings in the scope field which were defined at the point 259 of the label or goto. This lets us look at older or newer 260 bindings in the scope, as appropriate. */ 261 struct c_binding *bindings_in_scope; 262 /* The number of statement expressions that have started since this 263 label or goto statement was defined. This is zero if we are at 264 the same statement expression level. It is positive if we are in 265 a statement expression started since this spot. It is negative 266 if this spot was in a statement expression and we have left 267 it. */ 268 int stmt_exprs; 269 /* Whether we started in a statement expression but are no longer in 270 it. This is set to true if stmt_exprs ever goes negative. */ 271 bool left_stmt_expr; 272 }; 273 274 /* This structure is used to keep track of bindings seen when a goto 275 statement is defined. This is only used if we see the goto 276 statement before we see the label. */ 277 278 struct GTY(()) c_goto_bindings { 279 /* The location of the goto statement. */ 280 location_t loc; 281 /* The bindings of the goto statement. */ 282 struct c_spot_bindings goto_bindings; 283 }; 284 285 typedef struct c_goto_bindings *c_goto_bindings_p; 286 DEF_VEC_P(c_goto_bindings_p); 287 DEF_VEC_ALLOC_P(c_goto_bindings_p,gc); 288 289 /* The additional information we keep track of for a label binding. 290 These fields are updated as scopes are popped. */ 291 292 struct GTY(()) c_label_vars { 293 /* The shadowed c_label_vars, when one label shadows another (which 294 can only happen using a __label__ declaration). */ 295 struct c_label_vars *shadowed; 296 /* The bindings when the label was defined. */ 297 struct c_spot_bindings label_bindings; 298 /* A list of decls that we care about: decls about which we should 299 warn if a goto branches to this label from later in the function. 300 Decls are added to this list as scopes are popped. We only add 301 the decls that matter. */ 302 VEC(tree,gc) *decls_in_scope; 303 /* A list of goto statements to this label. This is only used for 304 goto statements seen before the label was defined, so that we can 305 issue appropriate warnings for them. */ 306 VEC(c_goto_bindings_p,gc) *gotos; 307 }; 308 309 /* Each c_scope structure describes the complete contents of one 310 scope. Four scopes are distinguished specially: the innermost or 311 current scope, the innermost function scope, the file scope (always 312 the second to outermost) and the outermost or external scope. 313 314 Most declarations are recorded in the current scope. 315 316 All normal label declarations are recorded in the innermost 317 function scope, as are bindings of undeclared identifiers to 318 error_mark_node. (GCC permits nested functions as an extension, 319 hence the 'innermost' qualifier.) Explicitly declared labels 320 (using the __label__ extension) appear in the current scope. 321 322 Being in the file scope (current_scope == file_scope) causes 323 special behavior in several places below. Also, under some 324 conditions the Objective-C front end records declarations in the 325 file scope even though that isn't the current scope. 326 327 All declarations with external linkage are recorded in the external 328 scope, even if they aren't visible there; this models the fact that 329 such declarations are visible to the entire program, and (with a 330 bit of cleverness, see pushdecl) allows diagnosis of some violations 331 of C99 6.2.2p7 and 6.2.7p2: 332 333 If, within the same translation unit, the same identifier appears 334 with both internal and external linkage, the behavior is 335 undefined. 336 337 All declarations that refer to the same object or function shall 338 have compatible type; otherwise, the behavior is undefined. 339 340 Initially only the built-in declarations, which describe compiler 341 intrinsic functions plus a subset of the standard library, are in 342 this scope. 343 344 The order of the blocks list matters, and it is frequently appended 345 to. To avoid having to walk all the way to the end of the list on 346 each insertion, or reverse the list later, we maintain a pointer to 347 the last list entry. (FIXME: It should be feasible to use a reversed 348 list here.) 349 350 The bindings list is strictly in reverse order of declarations; 351 pop_scope relies on this. */ 352 353 354 struct GTY((chain_next ("%h.outer"))) c_scope { 355 /* The scope containing this one. */ 356 struct c_scope *outer; 357 358 /* The next outermost function scope. */ 359 struct c_scope *outer_function; 360 361 /* All bindings in this scope. */ 362 struct c_binding *bindings; 363 364 /* For each scope (except the global one), a chain of BLOCK nodes 365 for all the scopes that were entered and exited one level down. */ 366 tree blocks; 367 tree blocks_last; 368 369 /* The depth of this scope. Used to keep the ->shadowed chain of 370 bindings sorted innermost to outermost. */ 371 unsigned int depth : 28; 372 373 /* True if we are currently filling this scope with parameter 374 declarations. */ 375 BOOL_BITFIELD parm_flag : 1; 376 377 /* True if we saw [*] in this scope. Used to give an error messages 378 if these appears in a function definition. */ 379 BOOL_BITFIELD had_vla_unspec : 1; 380 381 /* True if we already complained about forward parameter decls 382 in this scope. This prevents double warnings on 383 foo (int a; int b; ...) */ 384 BOOL_BITFIELD warned_forward_parm_decls : 1; 385 386 /* True if this is the outermost block scope of a function body. 387 This scope contains the parameters, the local variables declared 388 in the outermost block, and all the labels (except those in 389 nested functions, or declared at block scope with __label__). */ 390 BOOL_BITFIELD function_body : 1; 391 392 /* True means make a BLOCK for this scope no matter what. */ 393 BOOL_BITFIELD keep : 1; 394 395 /* True means that an unsuffixed float constant is _Decimal64. */ 396 BOOL_BITFIELD float_const_decimal64 : 1; 397 398 /* True if this scope has any label bindings. This is used to speed 399 up searching for labels when popping scopes, particularly since 400 labels are normally only found at function scope. */ 401 BOOL_BITFIELD has_label_bindings : 1; 402 403 /* True if we should issue a warning if a goto statement crosses any 404 of the bindings. We still need to check the list of bindings to 405 find the specific ones we need to warn about. This is true if 406 decl_jump_unsafe would return true for any of the bindings. This 407 is used to avoid looping over all the bindings unnecessarily. */ 408 BOOL_BITFIELD has_jump_unsafe_decl : 1; 409 }; 410 411 /* The scope currently in effect. */ 412 413 static GTY(()) struct c_scope *current_scope; 414 415 /* The innermost function scope. Ordinary (not explicitly declared) 416 labels, bindings to error_mark_node, and the lazily-created 417 bindings of __func__ and its friends get this scope. */ 418 419 static GTY(()) struct c_scope *current_function_scope; 420 421 /* The C file scope. This is reset for each input translation unit. */ 422 423 static GTY(()) struct c_scope *file_scope; 424 425 /* The outermost scope. This is used for all declarations with 426 external linkage, and only these, hence the name. */ 427 428 static GTY(()) struct c_scope *external_scope; 429 430 /* A chain of c_scope structures awaiting reuse. */ 431 432 static GTY((deletable)) struct c_scope *scope_freelist; 433 434 /* A chain of c_binding structures awaiting reuse. */ 435 436 static GTY((deletable)) struct c_binding *binding_freelist; 437 438 /* Append VAR to LIST in scope SCOPE. */ 439 #define SCOPE_LIST_APPEND(scope, list, decl) do { \ 440 struct c_scope *s_ = (scope); \ 441 tree d_ = (decl); \ 442 if (s_->list##_last) \ 443 BLOCK_CHAIN (s_->list##_last) = d_; \ 444 else \ 445 s_->list = d_; \ 446 s_->list##_last = d_; \ 447 } while (0) 448 449 /* Concatenate FROM in scope FSCOPE onto TO in scope TSCOPE. */ 450 #define SCOPE_LIST_CONCAT(tscope, to, fscope, from) do { \ 451 struct c_scope *t_ = (tscope); \ 452 struct c_scope *f_ = (fscope); \ 453 if (t_->to##_last) \ 454 BLOCK_CHAIN (t_->to##_last) = f_->from; \ 455 else \ 456 t_->to = f_->from; \ 457 t_->to##_last = f_->from##_last; \ 458 } while (0) 459 460 /* A c_inline_static structure stores details of a static identifier 461 referenced in a definition of a function that may be an inline 462 definition if no subsequent declaration of that function uses 463 "extern" or does not use "inline". */ 464 465 struct GTY((chain_next ("%h.next"))) c_inline_static { 466 /* The location for a diagnostic. */ 467 location_t location; 468 469 /* The function that may be an inline definition. */ 470 tree function; 471 472 /* The object or function referenced. */ 473 tree static_decl; 474 475 /* What sort of reference this is. */ 476 enum c_inline_static_type type; 477 478 /* The next such structure or NULL. */ 479 struct c_inline_static *next; 480 }; 481 482 /* List of static identifiers used or referenced in functions that may 483 be inline definitions. */ 484 static GTY(()) struct c_inline_static *c_inline_statics; 485 486 /* True means unconditionally make a BLOCK for the next scope pushed. */ 487 488 static bool keep_next_level_flag; 489 490 /* True means the next call to push_scope will be the outermost scope 491 of a function body, so do not push a new scope, merely cease 492 expecting parameter decls. */ 493 494 static bool next_is_function_body; 495 496 /* A VEC of pointers to c_binding structures. */ 497 498 typedef struct c_binding *c_binding_ptr; 499 DEF_VEC_P(c_binding_ptr); 500 DEF_VEC_ALLOC_P(c_binding_ptr,heap); 501 502 /* Information that we keep for a struct or union while it is being 503 parsed. */ 504 505 struct c_struct_parse_info 506 { 507 /* If warn_cxx_compat, a list of types defined within this 508 struct. */ 509 VEC(tree,heap) *struct_types; 510 /* If warn_cxx_compat, a list of field names which have bindings, 511 and which are defined in this struct, but which are not defined 512 in any enclosing struct. This is used to clear the in_struct 513 field of the c_bindings structure. */ 514 VEC(c_binding_ptr,heap) *fields; 515 /* If warn_cxx_compat, a list of typedef names used when defining 516 fields in this struct. */ 517 VEC(tree,heap) *typedefs_seen; 518 }; 519 520 /* Information for the struct or union currently being parsed, or 521 NULL if not parsing a struct or union. */ 522 static struct c_struct_parse_info *struct_parse_info; 523 524 /* Forward declarations. */ 525 static tree lookup_name_in_scope (tree, struct c_scope *); 526 static tree c_make_fname_decl (location_t, tree, int); 527 static tree grokdeclarator (const struct c_declarator *, 528 struct c_declspecs *, 529 enum decl_context, bool, tree *, tree *, tree *, 530 bool *, enum deprecated_states); 531 static tree grokparms (struct c_arg_info *, bool); 532 static void layout_array_type (tree); 533 534 /* T is a statement. Add it to the statement-tree. This is the 535 C/ObjC version--C++ has a slightly different version of this 536 function. */ 537 538 tree 539 add_stmt (tree t) 540 { 541 enum tree_code code = TREE_CODE (t); 542 543 if (CAN_HAVE_LOCATION_P (t) && code != LABEL_EXPR) 544 { 545 if (!EXPR_HAS_LOCATION (t)) 546 SET_EXPR_LOCATION (t, input_location); 547 } 548 549 if (code == LABEL_EXPR || code == CASE_LABEL_EXPR) 550 STATEMENT_LIST_HAS_LABEL (cur_stmt_list) = 1; 551 552 /* Add T to the statement-tree. Non-side-effect statements need to be 553 recorded during statement expressions. */ 554 if (!building_stmt_list_p ()) 555 push_stmt_list (); 556 append_to_statement_list_force (t, &cur_stmt_list); 557 558 return t; 559 } 560 561 /* Return true if we will want to say something if a goto statement 562 crosses DECL. */ 563 564 static bool 565 decl_jump_unsafe (tree decl) 566 { 567 if (error_operand_p (decl)) 568 return false; 569 570 /* Always warn about crossing variably modified types. */ 571 if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == TYPE_DECL) 572 && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 573 return true; 574 575 /* Otherwise, only warn if -Wgoto-misses-init and this is an 576 initialized automatic decl. */ 577 if (warn_jump_misses_init 578 && TREE_CODE (decl) == VAR_DECL 579 && !TREE_STATIC (decl) 580 && DECL_INITIAL (decl) != NULL_TREE) 581 return true; 582 583 return false; 584 } 585 586 587 void 588 c_print_identifier (FILE *file, tree node, int indent) 589 { 590 print_node (file, "symbol", I_SYMBOL_DECL (node), indent + 4); 591 print_node (file, "tag", I_TAG_DECL (node), indent + 4); 592 print_node (file, "label", I_LABEL_DECL (node), indent + 4); 593 if (C_IS_RESERVED_WORD (node) && C_RID_CODE (node) != RID_CXX_COMPAT_WARN) 594 { 595 tree rid = ridpointers[C_RID_CODE (node)]; 596 indent_to (file, indent + 4); 597 fprintf (file, "rid " HOST_PTR_PRINTF " \"%s\"", 598 (void *) rid, IDENTIFIER_POINTER (rid)); 599 } 600 } 601 602 /* Establish a binding between NAME, an IDENTIFIER_NODE, and DECL, 603 which may be any of several kinds of DECL or TYPE or error_mark_node, 604 in the scope SCOPE. */ 605 static void 606 bind (tree name, tree decl, struct c_scope *scope, bool invisible, 607 bool nested, location_t locus) 608 { 609 struct c_binding *b, **here; 610 611 if (binding_freelist) 612 { 613 b = binding_freelist; 614 binding_freelist = b->prev; 615 } 616 else 617 b = ggc_alloc_c_binding (); 618 619 b->shadowed = 0; 620 b->decl = decl; 621 b->id = name; 622 b->depth = scope->depth; 623 b->invisible = invisible; 624 b->nested = nested; 625 b->inner_comp = 0; 626 b->in_struct = 0; 627 b->locus = locus; 628 629 b->u.type = NULL; 630 631 b->prev = scope->bindings; 632 scope->bindings = b; 633 634 if (decl_jump_unsafe (decl)) 635 scope->has_jump_unsafe_decl = 1; 636 637 if (!name) 638 return; 639 640 switch (TREE_CODE (decl)) 641 { 642 case LABEL_DECL: here = &I_LABEL_BINDING (name); break; 643 case ENUMERAL_TYPE: 644 case UNION_TYPE: 645 case RECORD_TYPE: here = &I_TAG_BINDING (name); break; 646 case VAR_DECL: 647 case FUNCTION_DECL: 648 case TYPE_DECL: 649 case CONST_DECL: 650 case PARM_DECL: 651 case ERROR_MARK: here = &I_SYMBOL_BINDING (name); break; 652 653 default: 654 gcc_unreachable (); 655 } 656 657 /* Locate the appropriate place in the chain of shadowed decls 658 to insert this binding. Normally, scope == current_scope and 659 this does nothing. */ 660 while (*here && (*here)->depth > scope->depth) 661 here = &(*here)->shadowed; 662 663 b->shadowed = *here; 664 *here = b; 665 } 666 667 /* Clear the binding structure B, stick it on the binding_freelist, 668 and return the former value of b->prev. This is used by pop_scope 669 and get_parm_info to iterate destructively over all the bindings 670 from a given scope. */ 671 static struct c_binding * 672 free_binding_and_advance (struct c_binding *b) 673 { 674 struct c_binding *prev = b->prev; 675 676 memset (b, 0, sizeof (struct c_binding)); 677 b->prev = binding_freelist; 678 binding_freelist = b; 679 680 return prev; 681 } 682 683 /* Bind a label. Like bind, but skip fields which aren't used for 684 labels, and add the LABEL_VARS value. */ 685 static void 686 bind_label (tree name, tree label, struct c_scope *scope, 687 struct c_label_vars *label_vars) 688 { 689 struct c_binding *b; 690 691 bind (name, label, scope, /*invisible=*/false, /*nested=*/false, 692 UNKNOWN_LOCATION); 693 694 scope->has_label_bindings = true; 695 696 b = scope->bindings; 697 gcc_assert (b->decl == label); 698 label_vars->shadowed = b->u.label; 699 b->u.label = label_vars; 700 } 701 702 /* Hook called at end of compilation to assume 1 elt 703 for a file-scope tentative array defn that wasn't complete before. */ 704 705 void 706 c_finish_incomplete_decl (tree decl) 707 { 708 if (TREE_CODE (decl) == VAR_DECL) 709 { 710 tree type = TREE_TYPE (decl); 711 if (type != error_mark_node 712 && TREE_CODE (type) == ARRAY_TYPE 713 && !DECL_EXTERNAL (decl) 714 && TYPE_DOMAIN (type) == 0) 715 { 716 warning_at (DECL_SOURCE_LOCATION (decl), 717 0, "array %q+D assumed to have one element", decl); 718 719 complete_array_type (&TREE_TYPE (decl), NULL_TREE, true); 720 721 relayout_decl (decl); 722 } 723 } 724 } 725 726 /* Record that inline function FUNC contains a reference (location 727 LOC) to static DECL (file-scope or function-local according to 728 TYPE). */ 729 730 void 731 record_inline_static (location_t loc, tree func, tree decl, 732 enum c_inline_static_type type) 733 { 734 struct c_inline_static *csi = ggc_alloc_c_inline_static (); 735 csi->location = loc; 736 csi->function = func; 737 csi->static_decl = decl; 738 csi->type = type; 739 csi->next = c_inline_statics; 740 c_inline_statics = csi; 741 } 742 743 /* Check for references to static declarations in inline functions at 744 the end of the translation unit and diagnose them if the functions 745 are still inline definitions. */ 746 747 static void 748 check_inline_statics (void) 749 { 750 struct c_inline_static *csi; 751 for (csi = c_inline_statics; csi; csi = csi->next) 752 { 753 if (DECL_EXTERNAL (csi->function)) 754 switch (csi->type) 755 { 756 case csi_internal: 757 pedwarn (csi->location, 0, 758 "%qD is static but used in inline function %qD " 759 "which is not static", csi->static_decl, csi->function); 760 break; 761 case csi_modifiable: 762 pedwarn (csi->location, 0, 763 "%q+D is static but declared in inline function %qD " 764 "which is not static", csi->static_decl, csi->function); 765 break; 766 default: 767 gcc_unreachable (); 768 } 769 } 770 c_inline_statics = NULL; 771 } 772 773 /* Fill in a c_spot_bindings structure. If DEFINING is true, set it 774 for the current state, otherwise set it to uninitialized. */ 775 776 static void 777 set_spot_bindings (struct c_spot_bindings *p, bool defining) 778 { 779 if (defining) 780 { 781 p->scope = current_scope; 782 p->bindings_in_scope = current_scope->bindings; 783 } 784 else 785 { 786 p->scope = NULL; 787 p->bindings_in_scope = NULL; 788 } 789 p->stmt_exprs = 0; 790 p->left_stmt_expr = false; 791 } 792 793 /* Update spot bindings P as we pop out of SCOPE. Return true if we 794 should push decls for a label. */ 795 796 static bool 797 update_spot_bindings (struct c_scope *scope, struct c_spot_bindings *p) 798 { 799 if (p->scope != scope) 800 { 801 /* This label or goto is defined in some other scope, or it is a 802 label which is not yet defined. There is nothing to 803 update. */ 804 return false; 805 } 806 807 /* Adjust the spot bindings to refer to the bindings already defined 808 in the enclosing scope. */ 809 p->scope = scope->outer; 810 p->bindings_in_scope = p->scope->bindings; 811 812 return true; 813 } 814 815 /* The Objective-C front-end often needs to determine the current scope. */ 816 817 void * 818 objc_get_current_scope (void) 819 { 820 return current_scope; 821 } 822 823 /* The following function is used only by Objective-C. It needs to live here 824 because it accesses the innards of c_scope. */ 825 826 void 827 objc_mark_locals_volatile (void *enclosing_blk) 828 { 829 struct c_scope *scope; 830 struct c_binding *b; 831 832 for (scope = current_scope; 833 scope && scope != enclosing_blk; 834 scope = scope->outer) 835 { 836 for (b = scope->bindings; b; b = b->prev) 837 objc_volatilize_decl (b->decl); 838 839 /* Do not climb up past the current function. */ 840 if (scope->function_body) 841 break; 842 } 843 } 844 845 /* Return true if we are in the global binding level. */ 846 847 bool 848 global_bindings_p (void) 849 { 850 return current_scope == file_scope; 851 } 852 853 void 854 keep_next_level (void) 855 { 856 keep_next_level_flag = true; 857 } 858 859 /* Set the flag for the FLOAT_CONST_DECIMAL64 pragma being ON. */ 860 861 void 862 set_float_const_decimal64 (void) 863 { 864 current_scope->float_const_decimal64 = true; 865 } 866 867 /* Clear the flag for the FLOAT_CONST_DECIMAL64 pragma. */ 868 869 void 870 clear_float_const_decimal64 (void) 871 { 872 current_scope->float_const_decimal64 = false; 873 } 874 875 /* Return nonzero if an unsuffixed float constant is _Decimal64. */ 876 877 bool 878 float_const_decimal64_p (void) 879 { 880 return current_scope->float_const_decimal64; 881 } 882 883 /* Identify this scope as currently being filled with parameters. */ 884 885 void 886 declare_parm_level (void) 887 { 888 current_scope->parm_flag = true; 889 } 890 891 void 892 push_scope (void) 893 { 894 if (next_is_function_body) 895 { 896 /* This is the transition from the parameters to the top level 897 of the function body. These are the same scope 898 (C99 6.2.1p4,6) so we do not push another scope structure. 899 next_is_function_body is set only by store_parm_decls, which 900 in turn is called when and only when we are about to 901 encounter the opening curly brace for the function body. 902 903 The outermost block of a function always gets a BLOCK node, 904 because the debugging output routines expect that each 905 function has at least one BLOCK. */ 906 current_scope->parm_flag = false; 907 current_scope->function_body = true; 908 current_scope->keep = true; 909 current_scope->outer_function = current_function_scope; 910 current_function_scope = current_scope; 911 912 keep_next_level_flag = false; 913 next_is_function_body = false; 914 915 /* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes. */ 916 if (current_scope->outer) 917 current_scope->float_const_decimal64 918 = current_scope->outer->float_const_decimal64; 919 else 920 current_scope->float_const_decimal64 = false; 921 } 922 else 923 { 924 struct c_scope *scope; 925 if (scope_freelist) 926 { 927 scope = scope_freelist; 928 scope_freelist = scope->outer; 929 } 930 else 931 scope = ggc_alloc_cleared_c_scope (); 932 933 /* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes. */ 934 if (current_scope) 935 scope->float_const_decimal64 = current_scope->float_const_decimal64; 936 else 937 scope->float_const_decimal64 = false; 938 939 scope->keep = keep_next_level_flag; 940 scope->outer = current_scope; 941 scope->depth = current_scope ? (current_scope->depth + 1) : 0; 942 943 /* Check for scope depth overflow. Unlikely (2^28 == 268,435,456) but 944 possible. */ 945 if (current_scope && scope->depth == 0) 946 { 947 scope->depth--; 948 sorry ("GCC supports only %u nested scopes", scope->depth); 949 } 950 951 current_scope = scope; 952 keep_next_level_flag = false; 953 } 954 } 955 956 /* This is called when we are leaving SCOPE. For each label defined 957 in SCOPE, add any appropriate decls to its decls_in_scope fields. 958 These are the decls whose initialization will be skipped by a goto 959 later in the function. */ 960 961 static void 962 update_label_decls (struct c_scope *scope) 963 { 964 struct c_scope *s; 965 966 s = scope; 967 while (s != NULL) 968 { 969 if (s->has_label_bindings) 970 { 971 struct c_binding *b; 972 973 for (b = s->bindings; b != NULL; b = b->prev) 974 { 975 struct c_label_vars *label_vars; 976 struct c_binding *b1; 977 bool hjud; 978 unsigned int ix; 979 struct c_goto_bindings *g; 980 981 if (TREE_CODE (b->decl) != LABEL_DECL) 982 continue; 983 label_vars = b->u.label; 984 985 b1 = label_vars->label_bindings.bindings_in_scope; 986 if (label_vars->label_bindings.scope == NULL) 987 hjud = false; 988 else 989 hjud = label_vars->label_bindings.scope->has_jump_unsafe_decl; 990 if (update_spot_bindings (scope, &label_vars->label_bindings)) 991 { 992 /* This label is defined in this scope. */ 993 if (hjud) 994 { 995 for (; b1 != NULL; b1 = b1->prev) 996 { 997 /* A goto from later in the function to this 998 label will never see the initialization 999 of B1, if any. Save it to issue a 1000 warning if needed. */ 1001 if (decl_jump_unsafe (b1->decl)) 1002 VEC_safe_push (tree, gc, 1003 label_vars->decls_in_scope, 1004 b1->decl); 1005 } 1006 } 1007 } 1008 1009 /* Update the bindings of any goto statements associated 1010 with this label. */ 1011 FOR_EACH_VEC_ELT (c_goto_bindings_p, label_vars->gotos, ix, g) 1012 update_spot_bindings (scope, &g->goto_bindings); 1013 } 1014 } 1015 1016 /* Don't search beyond the current function. */ 1017 if (s == current_function_scope) 1018 break; 1019 1020 s = s->outer; 1021 } 1022 } 1023 1024 /* Set the TYPE_CONTEXT of all of TYPE's variants to CONTEXT. */ 1025 1026 static void 1027 set_type_context (tree type, tree context) 1028 { 1029 for (type = TYPE_MAIN_VARIANT (type); type; 1030 type = TYPE_NEXT_VARIANT (type)) 1031 TYPE_CONTEXT (type) = context; 1032 } 1033 1034 /* Exit a scope. Restore the state of the identifier-decl mappings 1035 that were in effect when this scope was entered. Return a BLOCK 1036 node containing all the DECLs in this scope that are of interest 1037 to debug info generation. */ 1038 1039 tree 1040 pop_scope (void) 1041 { 1042 struct c_scope *scope = current_scope; 1043 tree block, context, p; 1044 struct c_binding *b; 1045 1046 bool functionbody = scope->function_body; 1047 bool keep = functionbody || scope->keep || scope->bindings; 1048 1049 update_label_decls (scope); 1050 1051 /* If appropriate, create a BLOCK to record the decls for the life 1052 of this function. */ 1053 block = 0; 1054 if (keep) 1055 { 1056 block = make_node (BLOCK); 1057 BLOCK_SUBBLOCKS (block) = scope->blocks; 1058 TREE_USED (block) = 1; 1059 1060 /* In each subblock, record that this is its superior. */ 1061 for (p = scope->blocks; p; p = BLOCK_CHAIN (p)) 1062 BLOCK_SUPERCONTEXT (p) = block; 1063 1064 BLOCK_VARS (block) = 0; 1065 } 1066 1067 /* The TYPE_CONTEXTs for all of the tagged types belonging to this 1068 scope must be set so that they point to the appropriate 1069 construct, i.e. either to the current FUNCTION_DECL node, or 1070 else to the BLOCK node we just constructed. 1071 1072 Note that for tagged types whose scope is just the formal 1073 parameter list for some function type specification, we can't 1074 properly set their TYPE_CONTEXTs here, because we don't have a 1075 pointer to the appropriate FUNCTION_TYPE node readily available 1076 to us. For those cases, the TYPE_CONTEXTs of the relevant tagged 1077 type nodes get set in `grokdeclarator' as soon as we have created 1078 the FUNCTION_TYPE node which will represent the "scope" for these 1079 "parameter list local" tagged types. */ 1080 if (scope->function_body) 1081 context = current_function_decl; 1082 else if (scope == file_scope) 1083 { 1084 tree file_decl = build_translation_unit_decl (NULL_TREE); 1085 context = file_decl; 1086 } 1087 else 1088 context = block; 1089 1090 /* Clear all bindings in this scope. */ 1091 for (b = scope->bindings; b; b = free_binding_and_advance (b)) 1092 { 1093 p = b->decl; 1094 switch (TREE_CODE (p)) 1095 { 1096 case LABEL_DECL: 1097 /* Warnings for unused labels, errors for undefined labels. */ 1098 if (TREE_USED (p) && !DECL_INITIAL (p)) 1099 { 1100 error ("label %q+D used but not defined", p); 1101 DECL_INITIAL (p) = error_mark_node; 1102 } 1103 else 1104 warn_for_unused_label (p); 1105 1106 /* Labels go in BLOCK_VARS. */ 1107 DECL_CHAIN (p) = BLOCK_VARS (block); 1108 BLOCK_VARS (block) = p; 1109 gcc_assert (I_LABEL_BINDING (b->id) == b); 1110 I_LABEL_BINDING (b->id) = b->shadowed; 1111 1112 /* Also pop back to the shadowed label_vars. */ 1113 release_tree_vector (b->u.label->decls_in_scope); 1114 b->u.label = b->u.label->shadowed; 1115 break; 1116 1117 case ENUMERAL_TYPE: 1118 case UNION_TYPE: 1119 case RECORD_TYPE: 1120 set_type_context (p, context); 1121 1122 /* Types may not have tag-names, in which case the type 1123 appears in the bindings list with b->id NULL. */ 1124 if (b->id) 1125 { 1126 gcc_assert (I_TAG_BINDING (b->id) == b); 1127 I_TAG_BINDING (b->id) = b->shadowed; 1128 } 1129 break; 1130 1131 case FUNCTION_DECL: 1132 /* Propagate TREE_ADDRESSABLE from nested functions to their 1133 containing functions. */ 1134 if (!TREE_ASM_WRITTEN (p) 1135 && DECL_INITIAL (p) != 0 1136 && TREE_ADDRESSABLE (p) 1137 && DECL_ABSTRACT_ORIGIN (p) != 0 1138 && DECL_ABSTRACT_ORIGIN (p) != p) 1139 TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (p)) = 1; 1140 if (!DECL_EXTERNAL (p) 1141 && !DECL_INITIAL (p) 1142 && scope != file_scope 1143 && scope != external_scope) 1144 { 1145 error ("nested function %q+D declared but never defined", p); 1146 undef_nested_function = true; 1147 } 1148 else if (DECL_DECLARED_INLINE_P (p) 1149 && TREE_PUBLIC (p) 1150 && !DECL_INITIAL (p)) 1151 { 1152 /* C99 6.7.4p6: "a function with external linkage... declared 1153 with an inline function specifier ... shall also be defined 1154 in the same translation unit." */ 1155 if (!flag_gnu89_inline) 1156 pedwarn (input_location, 0, 1157 "inline function %q+D declared but never defined", p); 1158 DECL_EXTERNAL (p) = 1; 1159 } 1160 1161 goto common_symbol; 1162 1163 case VAR_DECL: 1164 /* Warnings for unused variables. */ 1165 if ((!TREE_USED (p) || !DECL_READ_P (p)) 1166 && !TREE_NO_WARNING (p) 1167 && !DECL_IN_SYSTEM_HEADER (p) 1168 && DECL_NAME (p) 1169 && !DECL_ARTIFICIAL (p) 1170 && scope != file_scope 1171 && scope != external_scope) 1172 { 1173 if (!TREE_USED (p)) 1174 warning (OPT_Wunused_variable, "unused variable %q+D", p); 1175 else if (DECL_CONTEXT (p) == current_function_decl) 1176 warning_at (DECL_SOURCE_LOCATION (p), 1177 OPT_Wunused_but_set_variable, 1178 "variable %qD set but not used", p); 1179 } 1180 1181 if (b->inner_comp) 1182 { 1183 error ("type of array %q+D completed incompatibly with" 1184 " implicit initialization", p); 1185 } 1186 1187 /* Fall through. */ 1188 case TYPE_DECL: 1189 case CONST_DECL: 1190 common_symbol: 1191 /* All of these go in BLOCK_VARS, but only if this is the 1192 binding in the home scope. */ 1193 if (!b->nested) 1194 { 1195 DECL_CHAIN (p) = BLOCK_VARS (block); 1196 BLOCK_VARS (block) = p; 1197 } 1198 else if (VAR_OR_FUNCTION_DECL_P (p) && scope != file_scope) 1199 { 1200 /* For block local externs add a special 1201 DECL_EXTERNAL decl for debug info generation. */ 1202 tree extp = copy_node (p); 1203 1204 DECL_EXTERNAL (extp) = 1; 1205 TREE_STATIC (extp) = 0; 1206 TREE_PUBLIC (extp) = 1; 1207 DECL_INITIAL (extp) = NULL_TREE; 1208 DECL_LANG_SPECIFIC (extp) = NULL; 1209 DECL_CONTEXT (extp) = current_function_decl; 1210 if (TREE_CODE (p) == FUNCTION_DECL) 1211 { 1212 DECL_RESULT (extp) = NULL_TREE; 1213 DECL_SAVED_TREE (extp) = NULL_TREE; 1214 DECL_STRUCT_FUNCTION (extp) = NULL; 1215 } 1216 if (b->locus != UNKNOWN_LOCATION) 1217 DECL_SOURCE_LOCATION (extp) = b->locus; 1218 DECL_CHAIN (extp) = BLOCK_VARS (block); 1219 BLOCK_VARS (block) = extp; 1220 } 1221 /* If this is the file scope set DECL_CONTEXT of each decl to 1222 the TRANSLATION_UNIT_DECL. This makes same_translation_unit_p 1223 work. */ 1224 if (scope == file_scope) 1225 { 1226 DECL_CONTEXT (p) = context; 1227 if (TREE_CODE (p) == TYPE_DECL 1228 && TREE_TYPE (p) != error_mark_node) 1229 set_type_context (TREE_TYPE (p), context); 1230 } 1231 1232 /* Fall through. */ 1233 /* Parameters go in DECL_ARGUMENTS, not BLOCK_VARS, and have 1234 already been put there by store_parm_decls. Unused- 1235 parameter warnings are handled by function.c. 1236 error_mark_node obviously does not go in BLOCK_VARS and 1237 does not get unused-variable warnings. */ 1238 case PARM_DECL: 1239 case ERROR_MARK: 1240 /* It is possible for a decl not to have a name. We get 1241 here with b->id NULL in this case. */ 1242 if (b->id) 1243 { 1244 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 1245 I_SYMBOL_BINDING (b->id) = b->shadowed; 1246 if (b->shadowed && b->shadowed->u.type) 1247 TREE_TYPE (b->shadowed->decl) = b->shadowed->u.type; 1248 } 1249 break; 1250 1251 default: 1252 gcc_unreachable (); 1253 } 1254 } 1255 1256 1257 /* Dispose of the block that we just made inside some higher level. */ 1258 if ((scope->function_body || scope == file_scope) && context) 1259 { 1260 DECL_INITIAL (context) = block; 1261 BLOCK_SUPERCONTEXT (block) = context; 1262 } 1263 else if (scope->outer) 1264 { 1265 if (block) 1266 SCOPE_LIST_APPEND (scope->outer, blocks, block); 1267 /* If we did not make a block for the scope just exited, any 1268 blocks made for inner scopes must be carried forward so they 1269 will later become subblocks of something else. */ 1270 else if (scope->blocks) 1271 SCOPE_LIST_CONCAT (scope->outer, blocks, scope, blocks); 1272 } 1273 1274 /* Pop the current scope, and free the structure for reuse. */ 1275 current_scope = scope->outer; 1276 if (scope->function_body) 1277 current_function_scope = scope->outer_function; 1278 1279 memset (scope, 0, sizeof (struct c_scope)); 1280 scope->outer = scope_freelist; 1281 scope_freelist = scope; 1282 1283 return block; 1284 } 1285 1286 void 1287 push_file_scope (void) 1288 { 1289 tree decl; 1290 1291 if (file_scope) 1292 return; 1293 1294 push_scope (); 1295 file_scope = current_scope; 1296 1297 start_fname_decls (); 1298 1299 for (decl = visible_builtins; decl; decl = DECL_CHAIN (decl)) 1300 bind (DECL_NAME (decl), decl, file_scope, 1301 /*invisible=*/false, /*nested=*/true, DECL_SOURCE_LOCATION (decl)); 1302 } 1303 1304 void 1305 pop_file_scope (void) 1306 { 1307 /* In case there were missing closebraces, get us back to the global 1308 binding level. */ 1309 while (current_scope != file_scope) 1310 pop_scope (); 1311 1312 /* __FUNCTION__ is defined at file scope (""). This 1313 call may not be necessary as my tests indicate it 1314 still works without it. */ 1315 finish_fname_decls (); 1316 1317 check_inline_statics (); 1318 1319 /* This is the point to write out a PCH if we're doing that. 1320 In that case we do not want to do anything else. */ 1321 if (pch_file) 1322 { 1323 c_common_write_pch (); 1324 return; 1325 } 1326 1327 /* Pop off the file scope and close this translation unit. */ 1328 pop_scope (); 1329 file_scope = 0; 1330 1331 maybe_apply_pending_pragma_weaks (); 1332 } 1333 1334 /* Adjust the bindings for the start of a statement expression. */ 1335 1336 void 1337 c_bindings_start_stmt_expr (struct c_spot_bindings* switch_bindings) 1338 { 1339 struct c_scope *scope; 1340 1341 for (scope = current_scope; scope != NULL; scope = scope->outer) 1342 { 1343 struct c_binding *b; 1344 1345 if (!scope->has_label_bindings) 1346 continue; 1347 1348 for (b = scope->bindings; b != NULL; b = b->prev) 1349 { 1350 struct c_label_vars *label_vars; 1351 unsigned int ix; 1352 struct c_goto_bindings *g; 1353 1354 if (TREE_CODE (b->decl) != LABEL_DECL) 1355 continue; 1356 label_vars = b->u.label; 1357 ++label_vars->label_bindings.stmt_exprs; 1358 FOR_EACH_VEC_ELT (c_goto_bindings_p, label_vars->gotos, ix, g) 1359 ++g->goto_bindings.stmt_exprs; 1360 } 1361 } 1362 1363 if (switch_bindings != NULL) 1364 ++switch_bindings->stmt_exprs; 1365 } 1366 1367 /* Adjust the bindings for the end of a statement expression. */ 1368 1369 void 1370 c_bindings_end_stmt_expr (struct c_spot_bindings *switch_bindings) 1371 { 1372 struct c_scope *scope; 1373 1374 for (scope = current_scope; scope != NULL; scope = scope->outer) 1375 { 1376 struct c_binding *b; 1377 1378 if (!scope->has_label_bindings) 1379 continue; 1380 1381 for (b = scope->bindings; b != NULL; b = b->prev) 1382 { 1383 struct c_label_vars *label_vars; 1384 unsigned int ix; 1385 struct c_goto_bindings *g; 1386 1387 if (TREE_CODE (b->decl) != LABEL_DECL) 1388 continue; 1389 label_vars = b->u.label; 1390 --label_vars->label_bindings.stmt_exprs; 1391 if (label_vars->label_bindings.stmt_exprs < 0) 1392 { 1393 label_vars->label_bindings.left_stmt_expr = true; 1394 label_vars->label_bindings.stmt_exprs = 0; 1395 } 1396 FOR_EACH_VEC_ELT (c_goto_bindings_p, label_vars->gotos, ix, g) 1397 { 1398 --g->goto_bindings.stmt_exprs; 1399 if (g->goto_bindings.stmt_exprs < 0) 1400 { 1401 g->goto_bindings.left_stmt_expr = true; 1402 g->goto_bindings.stmt_exprs = 0; 1403 } 1404 } 1405 } 1406 } 1407 1408 if (switch_bindings != NULL) 1409 { 1410 --switch_bindings->stmt_exprs; 1411 gcc_assert (switch_bindings->stmt_exprs >= 0); 1412 } 1413 } 1414 1415 /* Push a definition or a declaration of struct, union or enum tag "name". 1416 "type" should be the type node. 1417 We assume that the tag "name" is not already defined, and has a location 1418 of LOC. 1419 1420 Note that the definition may really be just a forward reference. 1421 In that case, the TYPE_SIZE will be zero. */ 1422 1423 static void 1424 pushtag (location_t loc, tree name, tree type) 1425 { 1426 /* Record the identifier as the type's name if it has none. */ 1427 if (name && !TYPE_NAME (type)) 1428 TYPE_NAME (type) = name; 1429 bind (name, type, current_scope, /*invisible=*/false, /*nested=*/false, loc); 1430 1431 /* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the 1432 tagged type we just added to the current scope. This fake 1433 NULL-named TYPE_DECL node helps dwarfout.c to know when it needs 1434 to output a representation of a tagged type, and it also gives 1435 us a convenient place to record the "scope start" address for the 1436 tagged type. */ 1437 1438 TYPE_STUB_DECL (type) = pushdecl (build_decl (loc, 1439 TYPE_DECL, NULL_TREE, type)); 1440 1441 /* An approximation for now, so we can tell this is a function-scope tag. 1442 This will be updated in pop_scope. */ 1443 TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type)); 1444 1445 if (warn_cxx_compat && name != NULL_TREE) 1446 { 1447 struct c_binding *b = I_SYMBOL_BINDING (name); 1448 1449 if (b != NULL 1450 && b->decl != NULL_TREE 1451 && TREE_CODE (b->decl) == TYPE_DECL 1452 && (B_IN_CURRENT_SCOPE (b) 1453 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 1454 && (TYPE_MAIN_VARIANT (TREE_TYPE (b->decl)) 1455 != TYPE_MAIN_VARIANT (type))) 1456 { 1457 warning_at (loc, OPT_Wc___compat, 1458 ("using %qD as both a typedef and a tag is " 1459 "invalid in C++"), 1460 b->decl); 1461 if (b->locus != UNKNOWN_LOCATION) 1462 inform (b->locus, "originally defined here"); 1463 } 1464 } 1465 } 1466 1467 /* Subroutine of compare_decls. Allow harmless mismatches in return 1468 and argument types provided that the type modes match. This function 1469 return a unified type given a suitable match, and 0 otherwise. */ 1470 1471 static tree 1472 match_builtin_function_types (tree newtype, tree oldtype) 1473 { 1474 tree newrettype, oldrettype; 1475 tree newargs, oldargs; 1476 tree trytype, tryargs; 1477 1478 /* Accept the return type of the new declaration if same modes. */ 1479 oldrettype = TREE_TYPE (oldtype); 1480 newrettype = TREE_TYPE (newtype); 1481 1482 if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype)) 1483 return 0; 1484 1485 oldargs = TYPE_ARG_TYPES (oldtype); 1486 newargs = TYPE_ARG_TYPES (newtype); 1487 tryargs = newargs; 1488 1489 while (oldargs || newargs) 1490 { 1491 if (!oldargs 1492 || !newargs 1493 || !TREE_VALUE (oldargs) 1494 || !TREE_VALUE (newargs) 1495 || TYPE_MODE (TREE_VALUE (oldargs)) 1496 != TYPE_MODE (TREE_VALUE (newargs))) 1497 return 0; 1498 1499 oldargs = TREE_CHAIN (oldargs); 1500 newargs = TREE_CHAIN (newargs); 1501 } 1502 1503 trytype = build_function_type (newrettype, tryargs); 1504 return build_type_attribute_variant (trytype, TYPE_ATTRIBUTES (oldtype)); 1505 } 1506 1507 /* Subroutine of diagnose_mismatched_decls. Check for function type 1508 mismatch involving an empty arglist vs a nonempty one and give clearer 1509 diagnostics. */ 1510 static void 1511 diagnose_arglist_conflict (tree newdecl, tree olddecl, 1512 tree newtype, tree oldtype) 1513 { 1514 tree t; 1515 1516 if (TREE_CODE (olddecl) != FUNCTION_DECL 1517 || !comptypes (TREE_TYPE (oldtype), TREE_TYPE (newtype)) 1518 || !((!prototype_p (oldtype) && DECL_INITIAL (olddecl) == 0) 1519 || (!prototype_p (newtype) && DECL_INITIAL (newdecl) == 0))) 1520 return; 1521 1522 t = TYPE_ARG_TYPES (oldtype); 1523 if (t == 0) 1524 t = TYPE_ARG_TYPES (newtype); 1525 for (; t; t = TREE_CHAIN (t)) 1526 { 1527 tree type = TREE_VALUE (t); 1528 1529 if (TREE_CHAIN (t) == 0 1530 && TYPE_MAIN_VARIANT (type) != void_type_node) 1531 { 1532 inform (input_location, "a parameter list with an ellipsis can%'t match " 1533 "an empty parameter name list declaration"); 1534 break; 1535 } 1536 1537 if (c_type_promotes_to (type) != type) 1538 { 1539 inform (input_location, "an argument type that has a default promotion can%'t match " 1540 "an empty parameter name list declaration"); 1541 break; 1542 } 1543 } 1544 } 1545 1546 /* Another subroutine of diagnose_mismatched_decls. OLDDECL is an 1547 old-style function definition, NEWDECL is a prototype declaration. 1548 Diagnose inconsistencies in the argument list. Returns TRUE if 1549 the prototype is compatible, FALSE if not. */ 1550 static bool 1551 validate_proto_after_old_defn (tree newdecl, tree newtype, tree oldtype) 1552 { 1553 tree newargs, oldargs; 1554 int i; 1555 1556 #define END_OF_ARGLIST(t) ((t) == void_type_node) 1557 1558 oldargs = TYPE_ACTUAL_ARG_TYPES (oldtype); 1559 newargs = TYPE_ARG_TYPES (newtype); 1560 i = 1; 1561 1562 for (;;) 1563 { 1564 tree oldargtype = TREE_VALUE (oldargs); 1565 tree newargtype = TREE_VALUE (newargs); 1566 1567 if (oldargtype == error_mark_node || newargtype == error_mark_node) 1568 return false; 1569 1570 oldargtype = TYPE_MAIN_VARIANT (oldargtype); 1571 newargtype = TYPE_MAIN_VARIANT (newargtype); 1572 1573 if (END_OF_ARGLIST (oldargtype) && END_OF_ARGLIST (newargtype)) 1574 break; 1575 1576 /* Reaching the end of just one list means the two decls don't 1577 agree on the number of arguments. */ 1578 if (END_OF_ARGLIST (oldargtype)) 1579 { 1580 error ("prototype for %q+D declares more arguments " 1581 "than previous old-style definition", newdecl); 1582 return false; 1583 } 1584 else if (END_OF_ARGLIST (newargtype)) 1585 { 1586 error ("prototype for %q+D declares fewer arguments " 1587 "than previous old-style definition", newdecl); 1588 return false; 1589 } 1590 1591 /* Type for passing arg must be consistent with that declared 1592 for the arg. */ 1593 else if (!comptypes (oldargtype, newargtype)) 1594 { 1595 error ("prototype for %q+D declares argument %d" 1596 " with incompatible type", 1597 newdecl, i); 1598 return false; 1599 } 1600 1601 oldargs = TREE_CHAIN (oldargs); 1602 newargs = TREE_CHAIN (newargs); 1603 i++; 1604 } 1605 1606 /* If we get here, no errors were found, but do issue a warning 1607 for this poor-style construct. */ 1608 warning (0, "prototype for %q+D follows non-prototype definition", 1609 newdecl); 1610 return true; 1611 #undef END_OF_ARGLIST 1612 } 1613 1614 /* Subroutine of diagnose_mismatched_decls. Report the location of DECL, 1615 first in a pair of mismatched declarations, using the diagnostic 1616 function DIAG. */ 1617 static void 1618 locate_old_decl (tree decl) 1619 { 1620 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) 1621 ; 1622 else if (DECL_INITIAL (decl)) 1623 inform (input_location, "previous definition of %q+D was here", decl); 1624 else if (C_DECL_IMPLICIT (decl)) 1625 inform (input_location, "previous implicit declaration of %q+D was here", decl); 1626 else 1627 inform (input_location, "previous declaration of %q+D was here", decl); 1628 } 1629 1630 /* Subroutine of duplicate_decls. Compare NEWDECL to OLDDECL. 1631 Returns true if the caller should proceed to merge the two, false 1632 if OLDDECL should simply be discarded. As a side effect, issues 1633 all necessary diagnostics for invalid or poor-style combinations. 1634 If it returns true, writes the types of NEWDECL and OLDDECL to 1635 *NEWTYPEP and *OLDTYPEP - these may have been adjusted from 1636 TREE_TYPE (NEWDECL, OLDDECL) respectively. */ 1637 1638 static bool 1639 diagnose_mismatched_decls (tree newdecl, tree olddecl, 1640 tree *newtypep, tree *oldtypep) 1641 { 1642 tree newtype, oldtype; 1643 bool pedwarned = false; 1644 bool warned = false; 1645 bool retval = true; 1646 1647 #define DECL_EXTERN_INLINE(DECL) (DECL_DECLARED_INLINE_P (DECL) \ 1648 && DECL_EXTERNAL (DECL)) 1649 1650 /* If we have error_mark_node for either decl or type, just discard 1651 the previous decl - we're in an error cascade already. */ 1652 if (olddecl == error_mark_node || newdecl == error_mark_node) 1653 return false; 1654 *oldtypep = oldtype = TREE_TYPE (olddecl); 1655 *newtypep = newtype = TREE_TYPE (newdecl); 1656 if (oldtype == error_mark_node || newtype == error_mark_node) 1657 return false; 1658 1659 /* Two different categories of symbol altogether. This is an error 1660 unless OLDDECL is a builtin. OLDDECL will be discarded in any case. */ 1661 if (TREE_CODE (olddecl) != TREE_CODE (newdecl)) 1662 { 1663 if (!(TREE_CODE (olddecl) == FUNCTION_DECL 1664 && DECL_BUILT_IN (olddecl) 1665 && !C_DECL_DECLARED_BUILTIN (olddecl))) 1666 { 1667 error ("%q+D redeclared as different kind of symbol", newdecl); 1668 locate_old_decl (olddecl); 1669 } 1670 else if (TREE_PUBLIC (newdecl)) 1671 warning (0, "built-in function %q+D declared as non-function", 1672 newdecl); 1673 else 1674 warning (OPT_Wshadow, "declaration of %q+D shadows " 1675 "a built-in function", newdecl); 1676 return false; 1677 } 1678 1679 /* Enumerators have no linkage, so may only be declared once in a 1680 given scope. */ 1681 if (TREE_CODE (olddecl) == CONST_DECL) 1682 { 1683 error ("redeclaration of enumerator %q+D", newdecl); 1684 locate_old_decl (olddecl); 1685 return false; 1686 } 1687 1688 if (!comptypes (oldtype, newtype)) 1689 { 1690 if (TREE_CODE (olddecl) == FUNCTION_DECL 1691 && DECL_BUILT_IN (olddecl) && !C_DECL_DECLARED_BUILTIN (olddecl)) 1692 { 1693 /* Accept harmless mismatch in function types. 1694 This is for the ffs and fprintf builtins. */ 1695 tree trytype = match_builtin_function_types (newtype, oldtype); 1696 1697 if (trytype && comptypes (newtype, trytype)) 1698 *oldtypep = oldtype = trytype; 1699 else 1700 { 1701 /* If types don't match for a built-in, throw away the 1702 built-in. No point in calling locate_old_decl here, it 1703 won't print anything. */ 1704 warning (0, "conflicting types for built-in function %q+D", 1705 newdecl); 1706 return false; 1707 } 1708 } 1709 else if (TREE_CODE (olddecl) == FUNCTION_DECL 1710 && DECL_IS_BUILTIN (olddecl)) 1711 { 1712 /* A conflicting function declaration for a predeclared 1713 function that isn't actually built in. Objective C uses 1714 these. The new declaration silently overrides everything 1715 but the volatility (i.e. noreturn) indication. See also 1716 below. FIXME: Make Objective C use normal builtins. */ 1717 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 1718 return false; 1719 } 1720 /* Permit void foo (...) to match int foo (...) if the latter is 1721 the definition and implicit int was used. See 1722 c-torture/compile/920625-2.c. */ 1723 else if (TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl) 1724 && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == void_type_node 1725 && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == integer_type_node 1726 && C_FUNCTION_IMPLICIT_INT (newdecl) && !DECL_INITIAL (olddecl)) 1727 { 1728 pedwarned = pedwarn (input_location, 0, 1729 "conflicting types for %q+D", newdecl); 1730 /* Make sure we keep void as the return type. */ 1731 TREE_TYPE (newdecl) = *newtypep = newtype = oldtype; 1732 C_FUNCTION_IMPLICIT_INT (newdecl) = 0; 1733 } 1734 /* Permit void foo (...) to match an earlier call to foo (...) with 1735 no declared type (thus, implicitly int). */ 1736 else if (TREE_CODE (newdecl) == FUNCTION_DECL 1737 && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == void_type_node 1738 && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == integer_type_node 1739 && C_DECL_IMPLICIT (olddecl) && !DECL_INITIAL (olddecl)) 1740 { 1741 pedwarned = pedwarn (input_location, 0, 1742 "conflicting types for %q+D", newdecl); 1743 /* Make sure we keep void as the return type. */ 1744 TREE_TYPE (olddecl) = *oldtypep = oldtype = newtype; 1745 } 1746 else 1747 { 1748 int new_quals = TYPE_QUALS (newtype); 1749 int old_quals = TYPE_QUALS (oldtype); 1750 1751 if (new_quals != old_quals) 1752 { 1753 addr_space_t new_addr = DECODE_QUAL_ADDR_SPACE (new_quals); 1754 addr_space_t old_addr = DECODE_QUAL_ADDR_SPACE (old_quals); 1755 if (new_addr != old_addr) 1756 { 1757 if (ADDR_SPACE_GENERIC_P (new_addr)) 1758 error ("conflicting named address spaces (generic vs %s) " 1759 "for %q+D", 1760 c_addr_space_name (old_addr), newdecl); 1761 else if (ADDR_SPACE_GENERIC_P (old_addr)) 1762 error ("conflicting named address spaces (%s vs generic) " 1763 "for %q+D", 1764 c_addr_space_name (new_addr), newdecl); 1765 else 1766 error ("conflicting named address spaces (%s vs %s) " 1767 "for %q+D", 1768 c_addr_space_name (new_addr), 1769 c_addr_space_name (old_addr), 1770 newdecl); 1771 } 1772 1773 if (CLEAR_QUAL_ADDR_SPACE (new_quals) 1774 != CLEAR_QUAL_ADDR_SPACE (old_quals)) 1775 error ("conflicting type qualifiers for %q+D", newdecl); 1776 } 1777 else 1778 error ("conflicting types for %q+D", newdecl); 1779 diagnose_arglist_conflict (newdecl, olddecl, newtype, oldtype); 1780 locate_old_decl (olddecl); 1781 return false; 1782 } 1783 } 1784 1785 /* Redeclaration of a type is a constraint violation (6.7.2.3p1), 1786 but silently ignore the redeclaration if either is in a system 1787 header. (Conflicting redeclarations were handled above.) This 1788 is allowed for C11 if the types are the same, not just 1789 compatible. */ 1790 if (TREE_CODE (newdecl) == TYPE_DECL) 1791 { 1792 bool types_different = false; 1793 int comptypes_result; 1794 1795 comptypes_result 1796 = comptypes_check_different_types (oldtype, newtype, &types_different); 1797 1798 if (comptypes_result != 1 || types_different) 1799 { 1800 error ("redefinition of typedef %q+D with different type", newdecl); 1801 locate_old_decl (olddecl); 1802 return false; 1803 } 1804 1805 if (DECL_IN_SYSTEM_HEADER (newdecl) 1806 || DECL_IN_SYSTEM_HEADER (olddecl) 1807 || TREE_NO_WARNING (newdecl) 1808 || TREE_NO_WARNING (olddecl)) 1809 return true; /* Allow OLDDECL to continue in use. */ 1810 1811 if (variably_modified_type_p (newtype, NULL)) 1812 { 1813 error ("redefinition of typedef %q+D with variably modified type", 1814 newdecl); 1815 locate_old_decl (olddecl); 1816 } 1817 else if (pedantic && !flag_isoc11) 1818 { 1819 pedwarn (input_location, OPT_pedantic, 1820 "redefinition of typedef %q+D", newdecl); 1821 locate_old_decl (olddecl); 1822 } 1823 1824 return true; 1825 } 1826 1827 /* Function declarations can either be 'static' or 'extern' (no 1828 qualifier is equivalent to 'extern' - C99 6.2.2p5) and therefore 1829 can never conflict with each other on account of linkage 1830 (6.2.2p4). Multiple definitions are not allowed (6.9p3,5) but 1831 gnu89 mode permits two definitions if one is 'extern inline' and 1832 one is not. The non- extern-inline definition supersedes the 1833 extern-inline definition. */ 1834 1835 else if (TREE_CODE (newdecl) == FUNCTION_DECL) 1836 { 1837 /* If you declare a built-in function name as static, or 1838 define the built-in with an old-style definition (so we 1839 can't validate the argument list) the built-in definition is 1840 overridden, but optionally warn this was a bad choice of name. */ 1841 if (DECL_BUILT_IN (olddecl) 1842 && !C_DECL_DECLARED_BUILTIN (olddecl) 1843 && (!TREE_PUBLIC (newdecl) 1844 || (DECL_INITIAL (newdecl) 1845 && !prototype_p (TREE_TYPE (newdecl))))) 1846 { 1847 warning (OPT_Wshadow, "declaration of %q+D shadows " 1848 "a built-in function", newdecl); 1849 /* Discard the old built-in function. */ 1850 return false; 1851 } 1852 1853 if (DECL_INITIAL (newdecl)) 1854 { 1855 if (DECL_INITIAL (olddecl)) 1856 { 1857 /* If both decls are in the same TU and the new declaration 1858 isn't overriding an extern inline reject the new decl. 1859 In c99, no overriding is allowed in the same translation 1860 unit. */ 1861 if ((!DECL_EXTERN_INLINE (olddecl) 1862 || DECL_EXTERN_INLINE (newdecl) 1863 || (!flag_gnu89_inline 1864 && (!DECL_DECLARED_INLINE_P (olddecl) 1865 || !lookup_attribute ("gnu_inline", 1866 DECL_ATTRIBUTES (olddecl))) 1867 && (!DECL_DECLARED_INLINE_P (newdecl) 1868 || !lookup_attribute ("gnu_inline", 1869 DECL_ATTRIBUTES (newdecl)))) 1870 ) 1871 && same_translation_unit_p (newdecl, olddecl)) 1872 { 1873 error ("redefinition of %q+D", newdecl); 1874 locate_old_decl (olddecl); 1875 return false; 1876 } 1877 } 1878 } 1879 /* If we have a prototype after an old-style function definition, 1880 the argument types must be checked specially. */ 1881 else if (DECL_INITIAL (olddecl) 1882 && !prototype_p (oldtype) && prototype_p (newtype) 1883 && TYPE_ACTUAL_ARG_TYPES (oldtype) 1884 && !validate_proto_after_old_defn (newdecl, newtype, oldtype)) 1885 { 1886 locate_old_decl (olddecl); 1887 return false; 1888 } 1889 /* A non-static declaration (even an "extern") followed by a 1890 static declaration is undefined behavior per C99 6.2.2p3-5,7. 1891 The same is true for a static forward declaration at block 1892 scope followed by a non-static declaration/definition at file 1893 scope. Static followed by non-static at the same scope is 1894 not undefined behavior, and is the most convenient way to get 1895 some effects (see e.g. what unwind-dw2-fde-glibc.c does to 1896 the definition of _Unwind_Find_FDE in unwind-dw2-fde.c), but 1897 we do diagnose it if -Wtraditional. */ 1898 if (TREE_PUBLIC (olddecl) && !TREE_PUBLIC (newdecl)) 1899 { 1900 /* Two exceptions to the rule. If olddecl is an extern 1901 inline, or a predeclared function that isn't actually 1902 built in, newdecl silently overrides olddecl. The latter 1903 occur only in Objective C; see also above. (FIXME: Make 1904 Objective C use normal builtins.) */ 1905 if (!DECL_IS_BUILTIN (olddecl) 1906 && !DECL_EXTERN_INLINE (olddecl)) 1907 { 1908 error ("static declaration of %q+D follows " 1909 "non-static declaration", newdecl); 1910 locate_old_decl (olddecl); 1911 } 1912 return false; 1913 } 1914 else if (TREE_PUBLIC (newdecl) && !TREE_PUBLIC (olddecl)) 1915 { 1916 if (DECL_CONTEXT (olddecl)) 1917 { 1918 error ("non-static declaration of %q+D follows " 1919 "static declaration", newdecl); 1920 locate_old_decl (olddecl); 1921 return false; 1922 } 1923 else if (warn_traditional) 1924 { 1925 warned |= warning (OPT_Wtraditional, 1926 "non-static declaration of %q+D " 1927 "follows static declaration", newdecl); 1928 } 1929 } 1930 1931 /* Make sure gnu_inline attribute is either not present, or 1932 present on all inline decls. */ 1933 if (DECL_DECLARED_INLINE_P (olddecl) 1934 && DECL_DECLARED_INLINE_P (newdecl)) 1935 { 1936 bool newa = lookup_attribute ("gnu_inline", 1937 DECL_ATTRIBUTES (newdecl)) != NULL; 1938 bool olda = lookup_attribute ("gnu_inline", 1939 DECL_ATTRIBUTES (olddecl)) != NULL; 1940 if (newa != olda) 1941 { 1942 error_at (input_location, "%<gnu_inline%> attribute present on %q+D", 1943 newa ? newdecl : olddecl); 1944 error_at (DECL_SOURCE_LOCATION (newa ? olddecl : newdecl), 1945 "but not here"); 1946 } 1947 } 1948 } 1949 else if (TREE_CODE (newdecl) == VAR_DECL) 1950 { 1951 /* Only variables can be thread-local, and all declarations must 1952 agree on this property. */ 1953 if (C_DECL_THREADPRIVATE_P (olddecl) && !DECL_THREAD_LOCAL_P (newdecl)) 1954 { 1955 /* Nothing to check. Since OLDDECL is marked threadprivate 1956 and NEWDECL does not have a thread-local attribute, we 1957 will merge the threadprivate attribute into NEWDECL. */ 1958 ; 1959 } 1960 else if (DECL_THREAD_LOCAL_P (newdecl) != DECL_THREAD_LOCAL_P (olddecl)) 1961 { 1962 if (DECL_THREAD_LOCAL_P (newdecl)) 1963 error ("thread-local declaration of %q+D follows " 1964 "non-thread-local declaration", newdecl); 1965 else 1966 error ("non-thread-local declaration of %q+D follows " 1967 "thread-local declaration", newdecl); 1968 1969 locate_old_decl (olddecl); 1970 return false; 1971 } 1972 1973 /* Multiple initialized definitions are not allowed (6.9p3,5). */ 1974 if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl)) 1975 { 1976 error ("redefinition of %q+D", newdecl); 1977 locate_old_decl (olddecl); 1978 return false; 1979 } 1980 1981 /* Objects declared at file scope: if the first declaration had 1982 external linkage (even if it was an external reference) the 1983 second must have external linkage as well, or the behavior is 1984 undefined. If the first declaration had internal linkage, then 1985 the second must too, or else be an external reference (in which 1986 case the composite declaration still has internal linkage). 1987 As for function declarations, we warn about the static-then- 1988 extern case only for -Wtraditional. See generally 6.2.2p3-5,7. */ 1989 if (DECL_FILE_SCOPE_P (newdecl) 1990 && TREE_PUBLIC (newdecl) != TREE_PUBLIC (olddecl)) 1991 { 1992 if (DECL_EXTERNAL (newdecl)) 1993 { 1994 if (!DECL_FILE_SCOPE_P (olddecl)) 1995 { 1996 error ("extern declaration of %q+D follows " 1997 "declaration with no linkage", newdecl); 1998 locate_old_decl (olddecl); 1999 return false; 2000 } 2001 else if (warn_traditional) 2002 { 2003 warned |= warning (OPT_Wtraditional, 2004 "non-static declaration of %q+D " 2005 "follows static declaration", newdecl); 2006 } 2007 } 2008 else 2009 { 2010 if (TREE_PUBLIC (newdecl)) 2011 error ("non-static declaration of %q+D follows " 2012 "static declaration", newdecl); 2013 else 2014 error ("static declaration of %q+D follows " 2015 "non-static declaration", newdecl); 2016 2017 locate_old_decl (olddecl); 2018 return false; 2019 } 2020 } 2021 /* Two objects with the same name declared at the same block 2022 scope must both be external references (6.7p3). */ 2023 else if (!DECL_FILE_SCOPE_P (newdecl)) 2024 { 2025 if (DECL_EXTERNAL (newdecl)) 2026 { 2027 /* Extern with initializer at block scope, which will 2028 already have received an error. */ 2029 } 2030 else if (DECL_EXTERNAL (olddecl)) 2031 { 2032 error ("declaration of %q+D with no linkage follows " 2033 "extern declaration", newdecl); 2034 locate_old_decl (olddecl); 2035 } 2036 else 2037 { 2038 error ("redeclaration of %q+D with no linkage", newdecl); 2039 locate_old_decl (olddecl); 2040 } 2041 2042 return false; 2043 } 2044 2045 /* C++ does not permit a decl to appear multiple times at file 2046 scope. */ 2047 if (warn_cxx_compat 2048 && DECL_FILE_SCOPE_P (newdecl) 2049 && !DECL_EXTERNAL (newdecl) 2050 && !DECL_EXTERNAL (olddecl)) 2051 warned |= warning_at (DECL_SOURCE_LOCATION (newdecl), 2052 OPT_Wc___compat, 2053 ("duplicate declaration of %qD is " 2054 "invalid in C++"), 2055 newdecl); 2056 } 2057 2058 /* warnings */ 2059 /* All decls must agree on a visibility. */ 2060 if (CODE_CONTAINS_STRUCT (TREE_CODE (newdecl), TS_DECL_WITH_VIS) 2061 && DECL_VISIBILITY_SPECIFIED (newdecl) && DECL_VISIBILITY_SPECIFIED (olddecl) 2062 && DECL_VISIBILITY (newdecl) != DECL_VISIBILITY (olddecl)) 2063 { 2064 warned |= warning (0, "redeclaration of %q+D with different visibility " 2065 "(old visibility preserved)", newdecl); 2066 } 2067 2068 if (TREE_CODE (newdecl) == FUNCTION_DECL) 2069 { 2070 /* Diagnose inline __attribute__ ((noinline)) which is silly. */ 2071 if (DECL_DECLARED_INLINE_P (newdecl) 2072 && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl))) 2073 { 2074 warned |= warning (OPT_Wattributes, 2075 "inline declaration of %qD follows " 2076 "declaration with attribute noinline", newdecl); 2077 } 2078 else if (DECL_DECLARED_INLINE_P (olddecl) 2079 && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl))) 2080 { 2081 warned |= warning (OPT_Wattributes, 2082 "declaration of %q+D with attribute " 2083 "noinline follows inline declaration ", newdecl); 2084 } 2085 } 2086 else /* PARM_DECL, VAR_DECL */ 2087 { 2088 /* Redeclaration of a parameter is a constraint violation (this is 2089 not explicitly stated, but follows from C99 6.7p3 [no more than 2090 one declaration of the same identifier with no linkage in the 2091 same scope, except type tags] and 6.2.2p6 [parameters have no 2092 linkage]). We must check for a forward parameter declaration, 2093 indicated by TREE_ASM_WRITTEN on the old declaration - this is 2094 an extension, the mandatory diagnostic for which is handled by 2095 mark_forward_parm_decls. */ 2096 2097 if (TREE_CODE (newdecl) == PARM_DECL 2098 && (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl))) 2099 { 2100 error ("redefinition of parameter %q+D", newdecl); 2101 locate_old_decl (olddecl); 2102 return false; 2103 } 2104 } 2105 2106 /* Optional warning for completely redundant decls. */ 2107 if (!warned && !pedwarned 2108 && warn_redundant_decls 2109 /* Don't warn about a function declaration followed by a 2110 definition. */ 2111 && !(TREE_CODE (newdecl) == FUNCTION_DECL 2112 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl)) 2113 /* Don't warn about redundant redeclarations of builtins. */ 2114 && !(TREE_CODE (newdecl) == FUNCTION_DECL 2115 && !DECL_BUILT_IN (newdecl) 2116 && DECL_BUILT_IN (olddecl) 2117 && !C_DECL_DECLARED_BUILTIN (olddecl)) 2118 /* Don't warn about an extern followed by a definition. */ 2119 && !(DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl)) 2120 /* Don't warn about forward parameter decls. */ 2121 && !(TREE_CODE (newdecl) == PARM_DECL 2122 && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl)) 2123 /* Don't warn about a variable definition following a declaration. */ 2124 && !(TREE_CODE (newdecl) == VAR_DECL 2125 && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl))) 2126 { 2127 warned = warning (OPT_Wredundant_decls, "redundant redeclaration of %q+D", 2128 newdecl); 2129 } 2130 2131 /* Report location of previous decl/defn. */ 2132 if (warned || pedwarned) 2133 locate_old_decl (olddecl); 2134 2135 #undef DECL_EXTERN_INLINE 2136 2137 return retval; 2138 } 2139 2140 /* Subroutine of duplicate_decls. NEWDECL has been found to be 2141 consistent with OLDDECL, but carries new information. Merge the 2142 new information into OLDDECL. This function issues no 2143 diagnostics. */ 2144 2145 static void 2146 merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype) 2147 { 2148 bool new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL 2149 && DECL_INITIAL (newdecl) != 0); 2150 bool new_is_prototype = (TREE_CODE (newdecl) == FUNCTION_DECL 2151 && prototype_p (TREE_TYPE (newdecl))); 2152 bool old_is_prototype = (TREE_CODE (olddecl) == FUNCTION_DECL 2153 && prototype_p (TREE_TYPE (olddecl))); 2154 bool extern_changed = false; 2155 2156 /* For real parm decl following a forward decl, rechain the old decl 2157 in its new location and clear TREE_ASM_WRITTEN (it's not a 2158 forward decl anymore). */ 2159 if (TREE_CODE (newdecl) == PARM_DECL 2160 && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl)) 2161 { 2162 struct c_binding *b, **here; 2163 2164 for (here = ¤t_scope->bindings; *here; here = &(*here)->prev) 2165 if ((*here)->decl == olddecl) 2166 goto found; 2167 gcc_unreachable (); 2168 2169 found: 2170 b = *here; 2171 *here = b->prev; 2172 b->prev = current_scope->bindings; 2173 current_scope->bindings = b; 2174 2175 TREE_ASM_WRITTEN (olddecl) = 0; 2176 } 2177 2178 DECL_ATTRIBUTES (newdecl) 2179 = targetm.merge_decl_attributes (olddecl, newdecl); 2180 2181 /* Merge the data types specified in the two decls. */ 2182 TREE_TYPE (newdecl) 2183 = TREE_TYPE (olddecl) 2184 = composite_type (newtype, oldtype); 2185 2186 /* Lay the type out, unless already done. */ 2187 if (!comptypes (oldtype, TREE_TYPE (newdecl))) 2188 { 2189 if (TREE_TYPE (newdecl) != error_mark_node) 2190 layout_type (TREE_TYPE (newdecl)); 2191 if (TREE_CODE (newdecl) != FUNCTION_DECL 2192 && TREE_CODE (newdecl) != TYPE_DECL 2193 && TREE_CODE (newdecl) != CONST_DECL) 2194 layout_decl (newdecl, 0); 2195 } 2196 else 2197 { 2198 /* Since the type is OLDDECL's, make OLDDECL's size go with. */ 2199 DECL_SIZE (newdecl) = DECL_SIZE (olddecl); 2200 DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl); 2201 DECL_MODE (newdecl) = DECL_MODE (olddecl); 2202 if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl)) 2203 { 2204 DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl); 2205 DECL_USER_ALIGN (newdecl) |= DECL_USER_ALIGN (olddecl); 2206 } 2207 } 2208 2209 /* Keep the old rtl since we can safely use it. */ 2210 if (HAS_RTL_P (olddecl)) 2211 COPY_DECL_RTL (olddecl, newdecl); 2212 2213 /* Merge the type qualifiers. */ 2214 if (TREE_READONLY (newdecl)) 2215 TREE_READONLY (olddecl) = 1; 2216 2217 if (TREE_THIS_VOLATILE (newdecl)) 2218 TREE_THIS_VOLATILE (olddecl) = 1; 2219 2220 /* Merge deprecatedness. */ 2221 if (TREE_DEPRECATED (newdecl)) 2222 TREE_DEPRECATED (olddecl) = 1; 2223 2224 /* If a decl is in a system header and the other isn't, keep the one on the 2225 system header. Otherwise, keep source location of definition rather than 2226 declaration and of prototype rather than non-prototype unless that 2227 prototype is built-in. */ 2228 if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS) 2229 && DECL_IN_SYSTEM_HEADER (olddecl) 2230 && !DECL_IN_SYSTEM_HEADER (newdecl) ) 2231 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 2232 else if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS) 2233 && DECL_IN_SYSTEM_HEADER (newdecl) 2234 && !DECL_IN_SYSTEM_HEADER (olddecl)) 2235 DECL_SOURCE_LOCATION (olddecl) = DECL_SOURCE_LOCATION (newdecl); 2236 else if ((DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0) 2237 || (old_is_prototype && !new_is_prototype 2238 && !C_DECL_BUILTIN_PROTOTYPE (olddecl))) 2239 DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl); 2240 2241 /* Merge the initialization information. */ 2242 if (DECL_INITIAL (newdecl) == 0) 2243 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 2244 2245 /* Merge the threadprivate attribute. */ 2246 if (TREE_CODE (olddecl) == VAR_DECL && C_DECL_THREADPRIVATE_P (olddecl)) 2247 { 2248 DECL_TLS_MODEL (newdecl) = DECL_TLS_MODEL (olddecl); 2249 C_DECL_THREADPRIVATE_P (newdecl) = 1; 2250 } 2251 2252 if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)) 2253 { 2254 /* Merge the section attribute. 2255 We want to issue an error if the sections conflict but that 2256 must be done later in decl_attributes since we are called 2257 before attributes are assigned. */ 2258 if (DECL_SECTION_NAME (newdecl) == NULL_TREE) 2259 DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl); 2260 2261 /* Copy the assembler name. 2262 Currently, it can only be defined in the prototype. */ 2263 COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl); 2264 2265 /* Use visibility of whichever declaration had it specified */ 2266 if (DECL_VISIBILITY_SPECIFIED (olddecl)) 2267 { 2268 DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl); 2269 DECL_VISIBILITY_SPECIFIED (newdecl) = 1; 2270 } 2271 2272 if (TREE_CODE (newdecl) == FUNCTION_DECL) 2273 { 2274 DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl); 2275 DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl); 2276 DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl); 2277 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl) 2278 |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl); 2279 TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl); 2280 DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl); 2281 DECL_IS_OPERATOR_NEW (newdecl) |= DECL_IS_OPERATOR_NEW (olddecl); 2282 TREE_READONLY (newdecl) |= TREE_READONLY (olddecl); 2283 DECL_PURE_P (newdecl) |= DECL_PURE_P (olddecl); 2284 DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl); 2285 } 2286 2287 /* Merge the storage class information. */ 2288 merge_weak (newdecl, olddecl); 2289 2290 /* For functions, static overrides non-static. */ 2291 if (TREE_CODE (newdecl) == FUNCTION_DECL) 2292 { 2293 TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl); 2294 /* This is since we don't automatically 2295 copy the attributes of NEWDECL into OLDDECL. */ 2296 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 2297 /* If this clears `static', clear it in the identifier too. */ 2298 if (!TREE_PUBLIC (olddecl)) 2299 TREE_PUBLIC (DECL_NAME (olddecl)) = 0; 2300 } 2301 } 2302 2303 /* In c99, 'extern' declaration before (or after) 'inline' means this 2304 function is not DECL_EXTERNAL, unless 'gnu_inline' attribute 2305 is present. */ 2306 if (TREE_CODE (newdecl) == FUNCTION_DECL 2307 && !flag_gnu89_inline 2308 && (DECL_DECLARED_INLINE_P (newdecl) 2309 || DECL_DECLARED_INLINE_P (olddecl)) 2310 && (!DECL_DECLARED_INLINE_P (newdecl) 2311 || !DECL_DECLARED_INLINE_P (olddecl) 2312 || !DECL_EXTERNAL (olddecl)) 2313 && DECL_EXTERNAL (newdecl) 2314 && !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl)) 2315 && !current_function_decl) 2316 DECL_EXTERNAL (newdecl) = 0; 2317 2318 if (DECL_EXTERNAL (newdecl)) 2319 { 2320 TREE_STATIC (newdecl) = TREE_STATIC (olddecl); 2321 DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl); 2322 2323 /* An extern decl does not override previous storage class. */ 2324 TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl); 2325 if (!DECL_EXTERNAL (newdecl)) 2326 { 2327 DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl); 2328 DECL_COMMON (newdecl) = DECL_COMMON (olddecl); 2329 } 2330 } 2331 else 2332 { 2333 TREE_STATIC (olddecl) = TREE_STATIC (newdecl); 2334 TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl); 2335 } 2336 2337 if (TREE_CODE (newdecl) == FUNCTION_DECL) 2338 { 2339 /* If we're redefining a function previously defined as extern 2340 inline, make sure we emit debug info for the inline before we 2341 throw it away, in case it was inlined into a function that 2342 hasn't been written out yet. */ 2343 if (new_is_definition && DECL_INITIAL (olddecl)) 2344 /* The new defn must not be inline. */ 2345 DECL_UNINLINABLE (newdecl) = 1; 2346 else 2347 { 2348 /* If either decl says `inline', this fn is inline, unless 2349 its definition was passed already. */ 2350 if (DECL_DECLARED_INLINE_P (newdecl) 2351 || DECL_DECLARED_INLINE_P (olddecl)) 2352 DECL_DECLARED_INLINE_P (newdecl) = 1; 2353 2354 DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl) 2355 = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)); 2356 2357 DECL_DISREGARD_INLINE_LIMITS (newdecl) 2358 = DECL_DISREGARD_INLINE_LIMITS (olddecl) 2359 = (DECL_DISREGARD_INLINE_LIMITS (newdecl) 2360 || DECL_DISREGARD_INLINE_LIMITS (olddecl)); 2361 } 2362 2363 if (DECL_BUILT_IN (olddecl)) 2364 { 2365 /* If redeclaring a builtin function, it stays built in. 2366 But it gets tagged as having been declared. */ 2367 DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl); 2368 DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl); 2369 C_DECL_DECLARED_BUILTIN (newdecl) = 1; 2370 if (new_is_prototype) 2371 { 2372 C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0; 2373 if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL) 2374 { 2375 enum built_in_function fncode = DECL_FUNCTION_CODE (newdecl); 2376 switch (fncode) 2377 { 2378 /* If a compatible prototype of these builtin functions 2379 is seen, assume the runtime implements it with the 2380 expected semantics. */ 2381 case BUILT_IN_STPCPY: 2382 if (builtin_decl_explicit_p (fncode)) 2383 set_builtin_decl_implicit_p (fncode, true); 2384 break; 2385 default: 2386 break; 2387 } 2388 } 2389 } 2390 else 2391 C_DECL_BUILTIN_PROTOTYPE (newdecl) 2392 = C_DECL_BUILTIN_PROTOTYPE (olddecl); 2393 } 2394 2395 /* Preserve function specific target and optimization options */ 2396 if (DECL_FUNCTION_SPECIFIC_TARGET (olddecl) 2397 && !DECL_FUNCTION_SPECIFIC_TARGET (newdecl)) 2398 DECL_FUNCTION_SPECIFIC_TARGET (newdecl) 2399 = DECL_FUNCTION_SPECIFIC_TARGET (olddecl); 2400 2401 if (DECL_FUNCTION_SPECIFIC_OPTIMIZATION (olddecl) 2402 && !DECL_FUNCTION_SPECIFIC_OPTIMIZATION (newdecl)) 2403 DECL_FUNCTION_SPECIFIC_OPTIMIZATION (newdecl) 2404 = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (olddecl); 2405 2406 /* Also preserve various other info from the definition. */ 2407 if (!new_is_definition) 2408 { 2409 tree t; 2410 DECL_RESULT (newdecl) = DECL_RESULT (olddecl); 2411 DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl); 2412 DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl); 2413 DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl); 2414 DECL_ARGUMENTS (newdecl) = copy_list (DECL_ARGUMENTS (olddecl)); 2415 for (t = DECL_ARGUMENTS (newdecl); t ; t = DECL_CHAIN (t)) 2416 DECL_CONTEXT (t) = newdecl; 2417 2418 /* See if we've got a function to instantiate from. */ 2419 if (DECL_SAVED_TREE (olddecl)) 2420 DECL_ABSTRACT_ORIGIN (newdecl) 2421 = DECL_ABSTRACT_ORIGIN (olddecl); 2422 } 2423 } 2424 2425 extern_changed = DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl); 2426 2427 /* Merge the USED information. */ 2428 if (TREE_USED (olddecl)) 2429 TREE_USED (newdecl) = 1; 2430 else if (TREE_USED (newdecl)) 2431 TREE_USED (olddecl) = 1; 2432 if (TREE_CODE (olddecl) == VAR_DECL || TREE_CODE (olddecl) == PARM_DECL) 2433 DECL_READ_P (newdecl) |= DECL_READ_P (olddecl); 2434 if (DECL_PRESERVE_P (olddecl)) 2435 DECL_PRESERVE_P (newdecl) = 1; 2436 else if (DECL_PRESERVE_P (newdecl)) 2437 DECL_PRESERVE_P (olddecl) = 1; 2438 2439 /* Copy most of the decl-specific fields of NEWDECL into OLDDECL. 2440 But preserve OLDDECL's DECL_UID, DECL_CONTEXT and 2441 DECL_ARGUMENTS (if appropriate). */ 2442 { 2443 unsigned olddecl_uid = DECL_UID (olddecl); 2444 tree olddecl_context = DECL_CONTEXT (olddecl); 2445 tree olddecl_arguments = NULL; 2446 if (TREE_CODE (olddecl) == FUNCTION_DECL) 2447 olddecl_arguments = DECL_ARGUMENTS (olddecl); 2448 2449 memcpy ((char *) olddecl + sizeof (struct tree_common), 2450 (char *) newdecl + sizeof (struct tree_common), 2451 sizeof (struct tree_decl_common) - sizeof (struct tree_common)); 2452 DECL_USER_ALIGN (olddecl) = DECL_USER_ALIGN (newdecl); 2453 switch (TREE_CODE (olddecl)) 2454 { 2455 case FUNCTION_DECL: 2456 case FIELD_DECL: 2457 case VAR_DECL: 2458 case PARM_DECL: 2459 case LABEL_DECL: 2460 case RESULT_DECL: 2461 case CONST_DECL: 2462 case TYPE_DECL: 2463 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 2464 (char *) newdecl + sizeof (struct tree_decl_common), 2465 tree_code_size (TREE_CODE (olddecl)) - sizeof (struct tree_decl_common)); 2466 break; 2467 2468 default: 2469 2470 memcpy ((char *) olddecl + sizeof (struct tree_decl_common), 2471 (char *) newdecl + sizeof (struct tree_decl_common), 2472 sizeof (struct tree_decl_non_common) - sizeof (struct tree_decl_common)); 2473 } 2474 DECL_UID (olddecl) = olddecl_uid; 2475 DECL_CONTEXT (olddecl) = olddecl_context; 2476 if (TREE_CODE (olddecl) == FUNCTION_DECL) 2477 DECL_ARGUMENTS (olddecl) = olddecl_arguments; 2478 } 2479 2480 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl 2481 so that encode_section_info has a chance to look at the new decl 2482 flags and attributes. */ 2483 if (DECL_RTL_SET_P (olddecl) 2484 && (TREE_CODE (olddecl) == FUNCTION_DECL 2485 || (TREE_CODE (olddecl) == VAR_DECL 2486 && TREE_STATIC (olddecl)))) 2487 make_decl_rtl (olddecl); 2488 2489 /* If we changed a function from DECL_EXTERNAL to !DECL_EXTERNAL, 2490 and the definition is coming from the old version, cgraph needs 2491 to be called again. */ 2492 if (extern_changed && !new_is_definition 2493 && TREE_CODE (olddecl) == FUNCTION_DECL && DECL_INITIAL (olddecl)) 2494 cgraph_mark_if_needed (olddecl); 2495 } 2496 2497 /* Handle when a new declaration NEWDECL has the same name as an old 2498 one OLDDECL in the same binding contour. Prints an error message 2499 if appropriate. 2500 2501 If safely possible, alter OLDDECL to look like NEWDECL, and return 2502 true. Otherwise, return false. */ 2503 2504 static bool 2505 duplicate_decls (tree newdecl, tree olddecl) 2506 { 2507 tree newtype = NULL, oldtype = NULL; 2508 2509 if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype)) 2510 { 2511 /* Avoid `unused variable' and other warnings for OLDDECL. */ 2512 TREE_NO_WARNING (olddecl) = 1; 2513 return false; 2514 } 2515 2516 merge_decls (newdecl, olddecl, newtype, oldtype); 2517 return true; 2518 } 2519 2520 2521 /* Check whether decl-node NEW_DECL shadows an existing declaration. */ 2522 static void 2523 warn_if_shadowing (tree new_decl) 2524 { 2525 struct c_binding *b; 2526 2527 /* Shadow warnings wanted? */ 2528 if (!warn_shadow 2529 /* No shadow warnings for internally generated vars. */ 2530 || DECL_IS_BUILTIN (new_decl) 2531 /* No shadow warnings for vars made for inlining. */ 2532 || DECL_FROM_INLINE (new_decl)) 2533 return; 2534 2535 /* Is anything being shadowed? Invisible decls do not count. */ 2536 for (b = I_SYMBOL_BINDING (DECL_NAME (new_decl)); b; b = b->shadowed) 2537 if (b->decl && b->decl != new_decl && !b->invisible 2538 && (b->decl == error_mark_node 2539 || diagnostic_report_warnings_p (global_dc, 2540 DECL_SOURCE_LOCATION (b->decl)))) 2541 { 2542 tree old_decl = b->decl; 2543 2544 if (old_decl == error_mark_node) 2545 { 2546 warning (OPT_Wshadow, "declaration of %q+D shadows previous " 2547 "non-variable", new_decl); 2548 break; 2549 } 2550 else if (TREE_CODE (old_decl) == PARM_DECL) 2551 warning (OPT_Wshadow, "declaration of %q+D shadows a parameter", 2552 new_decl); 2553 else if (DECL_FILE_SCOPE_P (old_decl)) 2554 warning (OPT_Wshadow, "declaration of %q+D shadows a global " 2555 "declaration", new_decl); 2556 else if (TREE_CODE (old_decl) == FUNCTION_DECL 2557 && DECL_BUILT_IN (old_decl)) 2558 { 2559 warning (OPT_Wshadow, "declaration of %q+D shadows " 2560 "a built-in function", new_decl); 2561 break; 2562 } 2563 else 2564 warning (OPT_Wshadow, "declaration of %q+D shadows a previous local", 2565 new_decl); 2566 2567 warning_at (DECL_SOURCE_LOCATION (old_decl), OPT_Wshadow, 2568 "shadowed declaration is here"); 2569 2570 break; 2571 } 2572 } 2573 2574 /* Record a decl-node X as belonging to the current lexical scope. 2575 Check for errors (such as an incompatible declaration for the same 2576 name already seen in the same scope). 2577 2578 Returns either X or an old decl for the same name. 2579 If an old decl is returned, it may have been smashed 2580 to agree with what X says. */ 2581 2582 tree 2583 pushdecl (tree x) 2584 { 2585 tree name = DECL_NAME (x); 2586 struct c_scope *scope = current_scope; 2587 struct c_binding *b; 2588 bool nested = false; 2589 location_t locus = DECL_SOURCE_LOCATION (x); 2590 2591 /* Must set DECL_CONTEXT for everything not at file scope or 2592 DECL_FILE_SCOPE_P won't work. Local externs don't count 2593 unless they have initializers (which generate code). */ 2594 if (current_function_decl 2595 && ((TREE_CODE (x) != FUNCTION_DECL && TREE_CODE (x) != VAR_DECL) 2596 || DECL_INITIAL (x) || !DECL_EXTERNAL (x))) 2597 DECL_CONTEXT (x) = current_function_decl; 2598 2599 /* Anonymous decls are just inserted in the scope. */ 2600 if (!name) 2601 { 2602 bind (name, x, scope, /*invisible=*/false, /*nested=*/false, 2603 locus); 2604 return x; 2605 } 2606 2607 /* First, see if there is another declaration with the same name in 2608 the current scope. If there is, duplicate_decls may do all the 2609 work for us. If duplicate_decls returns false, that indicates 2610 two incompatible decls in the same scope; we are to silently 2611 replace the old one (duplicate_decls has issued all appropriate 2612 diagnostics). In particular, we should not consider possible 2613 duplicates in the external scope, or shadowing. */ 2614 b = I_SYMBOL_BINDING (name); 2615 if (b && B_IN_SCOPE (b, scope)) 2616 { 2617 struct c_binding *b_ext, *b_use; 2618 tree type = TREE_TYPE (x); 2619 tree visdecl = b->decl; 2620 tree vistype = TREE_TYPE (visdecl); 2621 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 2622 && COMPLETE_TYPE_P (TREE_TYPE (x))) 2623 b->inner_comp = false; 2624 b_use = b; 2625 b_ext = b; 2626 /* If this is an external linkage declaration, we should check 2627 for compatibility with the type in the external scope before 2628 setting the type at this scope based on the visible 2629 information only. */ 2630 if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl)) 2631 { 2632 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 2633 b_ext = b_ext->shadowed; 2634 if (b_ext) 2635 { 2636 b_use = b_ext; 2637 if (b_use->u.type) 2638 TREE_TYPE (b_use->decl) = b_use->u.type; 2639 } 2640 } 2641 if (duplicate_decls (x, b_use->decl)) 2642 { 2643 if (b_use != b) 2644 { 2645 /* Save the updated type in the external scope and 2646 restore the proper type for this scope. */ 2647 tree thistype; 2648 if (comptypes (vistype, type)) 2649 thistype = composite_type (vistype, type); 2650 else 2651 thistype = TREE_TYPE (b_use->decl); 2652 b_use->u.type = TREE_TYPE (b_use->decl); 2653 if (TREE_CODE (b_use->decl) == FUNCTION_DECL 2654 && DECL_BUILT_IN (b_use->decl)) 2655 thistype 2656 = build_type_attribute_variant (thistype, 2657 TYPE_ATTRIBUTES 2658 (b_use->u.type)); 2659 TREE_TYPE (b_use->decl) = thistype; 2660 } 2661 return b_use->decl; 2662 } 2663 else 2664 goto skip_external_and_shadow_checks; 2665 } 2666 2667 /* All declarations with external linkage, and all external 2668 references, go in the external scope, no matter what scope is 2669 current. However, the binding in that scope is ignored for 2670 purposes of normal name lookup. A separate binding structure is 2671 created in the requested scope; this governs the normal 2672 visibility of the symbol. 2673 2674 The binding in the externals scope is used exclusively for 2675 detecting duplicate declarations of the same object, no matter 2676 what scope they are in; this is what we do here. (C99 6.2.7p2: 2677 All declarations that refer to the same object or function shall 2678 have compatible type; otherwise, the behavior is undefined.) */ 2679 if (DECL_EXTERNAL (x) || scope == file_scope) 2680 { 2681 tree type = TREE_TYPE (x); 2682 tree vistype = 0; 2683 tree visdecl = 0; 2684 bool type_saved = false; 2685 if (b && !B_IN_EXTERNAL_SCOPE (b) 2686 && (TREE_CODE (b->decl) == FUNCTION_DECL 2687 || TREE_CODE (b->decl) == VAR_DECL) 2688 && DECL_FILE_SCOPE_P (b->decl)) 2689 { 2690 visdecl = b->decl; 2691 vistype = TREE_TYPE (visdecl); 2692 } 2693 if (scope != file_scope 2694 && !DECL_IN_SYSTEM_HEADER (x)) 2695 warning (OPT_Wnested_externs, "nested extern declaration of %qD", x); 2696 2697 while (b && !B_IN_EXTERNAL_SCOPE (b)) 2698 { 2699 /* If this decl might be modified, save its type. This is 2700 done here rather than when the decl is first bound 2701 because the type may change after first binding, through 2702 being completed or through attributes being added. If we 2703 encounter multiple such decls, only the first should have 2704 its type saved; the others will already have had their 2705 proper types saved and the types will not have changed as 2706 their scopes will not have been re-entered. */ 2707 if (DECL_P (b->decl) && DECL_FILE_SCOPE_P (b->decl) && !type_saved) 2708 { 2709 b->u.type = TREE_TYPE (b->decl); 2710 type_saved = true; 2711 } 2712 if (B_IN_FILE_SCOPE (b) 2713 && TREE_CODE (b->decl) == VAR_DECL 2714 && TREE_STATIC (b->decl) 2715 && TREE_CODE (TREE_TYPE (b->decl)) == ARRAY_TYPE 2716 && !TYPE_DOMAIN (TREE_TYPE (b->decl)) 2717 && TREE_CODE (type) == ARRAY_TYPE 2718 && TYPE_DOMAIN (type) 2719 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) 2720 && !integer_zerop (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))) 2721 { 2722 /* Array type completed in inner scope, which should be 2723 diagnosed if the completion does not have size 1 and 2724 it does not get completed in the file scope. */ 2725 b->inner_comp = true; 2726 } 2727 b = b->shadowed; 2728 } 2729 2730 /* If a matching external declaration has been found, set its 2731 type to the composite of all the types of that declaration. 2732 After the consistency checks, it will be reset to the 2733 composite of the visible types only. */ 2734 if (b && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2735 && b->u.type) 2736 TREE_TYPE (b->decl) = b->u.type; 2737 2738 /* The point of the same_translation_unit_p check here is, 2739 we want to detect a duplicate decl for a construct like 2740 foo() { extern bar(); } ... static bar(); but not if 2741 they are in different translation units. In any case, 2742 the static does not go in the externals scope. */ 2743 if (b 2744 && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl)) 2745 && duplicate_decls (x, b->decl)) 2746 { 2747 tree thistype; 2748 if (vistype) 2749 { 2750 if (comptypes (vistype, type)) 2751 thistype = composite_type (vistype, type); 2752 else 2753 thistype = TREE_TYPE (b->decl); 2754 } 2755 else 2756 thistype = type; 2757 b->u.type = TREE_TYPE (b->decl); 2758 if (TREE_CODE (b->decl) == FUNCTION_DECL && DECL_BUILT_IN (b->decl)) 2759 thistype 2760 = build_type_attribute_variant (thistype, 2761 TYPE_ATTRIBUTES (b->u.type)); 2762 TREE_TYPE (b->decl) = thistype; 2763 bind (name, b->decl, scope, /*invisible=*/false, /*nested=*/true, 2764 locus); 2765 return b->decl; 2766 } 2767 else if (TREE_PUBLIC (x)) 2768 { 2769 if (visdecl && !b && duplicate_decls (x, visdecl)) 2770 { 2771 /* An external declaration at block scope referring to a 2772 visible entity with internal linkage. The composite 2773 type will already be correct for this scope, so we 2774 just need to fall through to make the declaration in 2775 this scope. */ 2776 nested = true; 2777 x = visdecl; 2778 } 2779 else 2780 { 2781 bind (name, x, external_scope, /*invisible=*/true, 2782 /*nested=*/false, locus); 2783 nested = true; 2784 } 2785 } 2786 } 2787 2788 if (TREE_CODE (x) != PARM_DECL) 2789 warn_if_shadowing (x); 2790 2791 skip_external_and_shadow_checks: 2792 if (TREE_CODE (x) == TYPE_DECL) 2793 { 2794 /* So this is a typedef, set its underlying type. */ 2795 set_underlying_type (x); 2796 2797 /* If X is a typedef defined in the current function, record it 2798 for the purpose of implementing the -Wunused-local-typedefs 2799 warning. */ 2800 record_locally_defined_typedef (x); 2801 } 2802 2803 bind (name, x, scope, /*invisible=*/false, nested, locus); 2804 2805 /* If x's type is incomplete because it's based on a 2806 structure or union which has not yet been fully declared, 2807 attach it to that structure or union type, so we can go 2808 back and complete the variable declaration later, if the 2809 structure or union gets fully declared. 2810 2811 If the input is erroneous, we can have error_mark in the type 2812 slot (e.g. "f(void a, ...)") - that doesn't count as an 2813 incomplete type. */ 2814 if (TREE_TYPE (x) != error_mark_node 2815 && !COMPLETE_TYPE_P (TREE_TYPE (x))) 2816 { 2817 tree element = TREE_TYPE (x); 2818 2819 while (TREE_CODE (element) == ARRAY_TYPE) 2820 element = TREE_TYPE (element); 2821 element = TYPE_MAIN_VARIANT (element); 2822 2823 if ((TREE_CODE (element) == RECORD_TYPE 2824 || TREE_CODE (element) == UNION_TYPE) 2825 && (TREE_CODE (x) != TYPE_DECL 2826 || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE) 2827 && !COMPLETE_TYPE_P (element)) 2828 C_TYPE_INCOMPLETE_VARS (element) 2829 = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element)); 2830 } 2831 return x; 2832 } 2833 2834 /* Record X as belonging to file scope. 2835 This is used only internally by the Objective-C front end, 2836 and is limited to its needs. duplicate_decls is not called; 2837 if there is any preexisting decl for this identifier, it is an ICE. */ 2838 2839 tree 2840 pushdecl_top_level (tree x) 2841 { 2842 tree name; 2843 bool nested = false; 2844 gcc_assert (TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == CONST_DECL); 2845 2846 name = DECL_NAME (x); 2847 2848 gcc_assert (TREE_CODE (x) == CONST_DECL || !I_SYMBOL_BINDING (name)); 2849 2850 if (TREE_PUBLIC (x)) 2851 { 2852 bind (name, x, external_scope, /*invisible=*/true, /*nested=*/false, 2853 UNKNOWN_LOCATION); 2854 nested = true; 2855 } 2856 if (file_scope) 2857 bind (name, x, file_scope, /*invisible=*/false, nested, UNKNOWN_LOCATION); 2858 2859 return x; 2860 } 2861 2862 static void 2863 implicit_decl_warning (tree id, tree olddecl) 2864 { 2865 if (warn_implicit_function_declaration) 2866 { 2867 bool warned; 2868 2869 if (flag_isoc99) 2870 warned = pedwarn (input_location, OPT_Wimplicit_function_declaration, 2871 "implicit declaration of function %qE", id); 2872 else 2873 warned = warning (OPT_Wimplicit_function_declaration, 2874 G_("implicit declaration of function %qE"), id); 2875 if (olddecl && warned) 2876 locate_old_decl (olddecl); 2877 } 2878 } 2879 2880 /* Generate an implicit declaration for identifier FUNCTIONID at LOC as a 2881 function of type int (). */ 2882 2883 tree 2884 implicitly_declare (location_t loc, tree functionid) 2885 { 2886 struct c_binding *b; 2887 tree decl = 0; 2888 tree asmspec_tree; 2889 2890 for (b = I_SYMBOL_BINDING (functionid); b; b = b->shadowed) 2891 { 2892 if (B_IN_SCOPE (b, external_scope)) 2893 { 2894 decl = b->decl; 2895 break; 2896 } 2897 } 2898 2899 if (decl) 2900 { 2901 if (decl == error_mark_node) 2902 return decl; 2903 2904 /* FIXME: Objective-C has weird not-really-builtin functions 2905 which are supposed to be visible automatically. They wind up 2906 in the external scope because they're pushed before the file 2907 scope gets created. Catch this here and rebind them into the 2908 file scope. */ 2909 if (!DECL_BUILT_IN (decl) && DECL_IS_BUILTIN (decl)) 2910 { 2911 bind (functionid, decl, file_scope, 2912 /*invisible=*/false, /*nested=*/true, 2913 DECL_SOURCE_LOCATION (decl)); 2914 return decl; 2915 } 2916 else 2917 { 2918 tree newtype = default_function_type; 2919 if (b->u.type) 2920 TREE_TYPE (decl) = b->u.type; 2921 /* Implicit declaration of a function already declared 2922 (somehow) in a different scope, or as a built-in. 2923 If this is the first time this has happened, warn; 2924 then recycle the old declaration but with the new type. */ 2925 if (!C_DECL_IMPLICIT (decl)) 2926 { 2927 implicit_decl_warning (functionid, decl); 2928 C_DECL_IMPLICIT (decl) = 1; 2929 } 2930 if (DECL_BUILT_IN (decl)) 2931 { 2932 newtype = build_type_attribute_variant (newtype, 2933 TYPE_ATTRIBUTES 2934 (TREE_TYPE (decl))); 2935 if (!comptypes (newtype, TREE_TYPE (decl))) 2936 { 2937 warning_at (loc, 0, "incompatible implicit declaration of " 2938 "built-in function %qD", decl); 2939 newtype = TREE_TYPE (decl); 2940 } 2941 } 2942 else 2943 { 2944 if (!comptypes (newtype, TREE_TYPE (decl))) 2945 { 2946 error_at (loc, "incompatible implicit declaration of function %qD", decl); 2947 locate_old_decl (decl); 2948 } 2949 } 2950 b->u.type = TREE_TYPE (decl); 2951 TREE_TYPE (decl) = newtype; 2952 bind (functionid, decl, current_scope, 2953 /*invisible=*/false, /*nested=*/true, 2954 DECL_SOURCE_LOCATION (decl)); 2955 return decl; 2956 } 2957 } 2958 2959 /* Not seen before. */ 2960 decl = build_decl (loc, FUNCTION_DECL, functionid, default_function_type); 2961 DECL_EXTERNAL (decl) = 1; 2962 TREE_PUBLIC (decl) = 1; 2963 C_DECL_IMPLICIT (decl) = 1; 2964 implicit_decl_warning (functionid, 0); 2965 asmspec_tree = maybe_apply_renaming_pragma (decl, /*asmname=*/NULL); 2966 if (asmspec_tree) 2967 set_user_assembler_name (decl, TREE_STRING_POINTER (asmspec_tree)); 2968 2969 /* C89 says implicit declarations are in the innermost block. 2970 So we record the decl in the standard fashion. */ 2971 decl = pushdecl (decl); 2972 2973 /* No need to call objc_check_decl here - it's a function type. */ 2974 rest_of_decl_compilation (decl, 0, 0); 2975 2976 /* Write a record describing this implicit function declaration 2977 to the prototypes file (if requested). */ 2978 gen_aux_info_record (decl, 0, 1, 0); 2979 2980 /* Possibly apply some default attributes to this implicit declaration. */ 2981 decl_attributes (&decl, NULL_TREE, 0); 2982 2983 return decl; 2984 } 2985 2986 /* Issue an error message for a reference to an undeclared variable 2987 ID, including a reference to a builtin outside of function-call 2988 context. Establish a binding of the identifier to error_mark_node 2989 in an appropriate scope, which will suppress further errors for the 2990 same identifier. The error message should be given location LOC. */ 2991 void 2992 undeclared_variable (location_t loc, tree id) 2993 { 2994 static bool already = false; 2995 struct c_scope *scope; 2996 2997 if (current_function_decl == 0) 2998 { 2999 error_at (loc, "%qE undeclared here (not in a function)", id); 3000 scope = current_scope; 3001 } 3002 else 3003 { 3004 if (!objc_diagnose_private_ivar (id)) 3005 error_at (loc, "%qE undeclared (first use in this function)", id); 3006 if (!already) 3007 { 3008 inform (loc, "each undeclared identifier is reported only" 3009 " once for each function it appears in"); 3010 already = true; 3011 } 3012 3013 /* If we are parsing old-style parameter decls, current_function_decl 3014 will be nonnull but current_function_scope will be null. */ 3015 scope = current_function_scope ? current_function_scope : current_scope; 3016 } 3017 bind (id, error_mark_node, scope, /*invisible=*/false, /*nested=*/false, 3018 UNKNOWN_LOCATION); 3019 } 3020 3021 /* Subroutine of lookup_label, declare_label, define_label: construct a 3022 LABEL_DECL with all the proper frills. Also create a struct 3023 c_label_vars initialized for the current scope. */ 3024 3025 static tree 3026 make_label (location_t location, tree name, bool defining, 3027 struct c_label_vars **p_label_vars) 3028 { 3029 tree label = build_decl (location, LABEL_DECL, name, void_type_node); 3030 struct c_label_vars *label_vars; 3031 3032 DECL_CONTEXT (label) = current_function_decl; 3033 DECL_MODE (label) = VOIDmode; 3034 3035 label_vars = ggc_alloc_c_label_vars (); 3036 label_vars->shadowed = NULL; 3037 set_spot_bindings (&label_vars->label_bindings, defining); 3038 label_vars->decls_in_scope = make_tree_vector (); 3039 label_vars->gotos = VEC_alloc (c_goto_bindings_p, gc, 0); 3040 *p_label_vars = label_vars; 3041 3042 return label; 3043 } 3044 3045 /* Get the LABEL_DECL corresponding to identifier NAME as a label. 3046 Create one if none exists so far for the current function. 3047 This is called when a label is used in a goto expression or 3048 has its address taken. */ 3049 3050 tree 3051 lookup_label (tree name) 3052 { 3053 tree label; 3054 struct c_label_vars *label_vars; 3055 3056 if (current_function_scope == 0) 3057 { 3058 error ("label %qE referenced outside of any function", name); 3059 return 0; 3060 } 3061 3062 /* Use a label already defined or ref'd with this name, but not if 3063 it is inherited from a containing function and wasn't declared 3064 using __label__. */ 3065 label = I_LABEL_DECL (name); 3066 if (label && (DECL_CONTEXT (label) == current_function_decl 3067 || C_DECLARED_LABEL_FLAG (label))) 3068 { 3069 /* If the label has only been declared, update its apparent 3070 location to point here, for better diagnostics if it 3071 turns out not to have been defined. */ 3072 if (DECL_INITIAL (label) == NULL_TREE) 3073 DECL_SOURCE_LOCATION (label) = input_location; 3074 return label; 3075 } 3076 3077 /* No label binding for that identifier; make one. */ 3078 label = make_label (input_location, name, false, &label_vars); 3079 3080 /* Ordinary labels go in the current function scope. */ 3081 bind_label (name, label, current_function_scope, label_vars); 3082 3083 return label; 3084 } 3085 3086 /* Issue a warning about DECL for a goto statement at GOTO_LOC going 3087 to LABEL. */ 3088 3089 static void 3090 warn_about_goto (location_t goto_loc, tree label, tree decl) 3091 { 3092 if (variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 3093 error_at (goto_loc, 3094 "jump into scope of identifier with variably modified type"); 3095 else 3096 warning_at (goto_loc, OPT_Wjump_misses_init, 3097 "jump skips variable initialization"); 3098 inform (DECL_SOURCE_LOCATION (label), "label %qD defined here", label); 3099 inform (DECL_SOURCE_LOCATION (decl), "%qD declared here", decl); 3100 } 3101 3102 /* Look up a label because of a goto statement. This is like 3103 lookup_label, but also issues any appropriate warnings. */ 3104 3105 tree 3106 lookup_label_for_goto (location_t loc, tree name) 3107 { 3108 tree label; 3109 struct c_label_vars *label_vars; 3110 unsigned int ix; 3111 tree decl; 3112 3113 label = lookup_label (name); 3114 if (label == NULL_TREE) 3115 return NULL_TREE; 3116 3117 /* If we are jumping to a different function, we can't issue any 3118 useful warnings. */ 3119 if (DECL_CONTEXT (label) != current_function_decl) 3120 { 3121 gcc_assert (C_DECLARED_LABEL_FLAG (label)); 3122 return label; 3123 } 3124 3125 label_vars = I_LABEL_BINDING (name)->u.label; 3126 3127 /* If the label has not yet been defined, then push this goto on a 3128 list for possible later warnings. */ 3129 if (label_vars->label_bindings.scope == NULL) 3130 { 3131 struct c_goto_bindings *g; 3132 3133 g = ggc_alloc_c_goto_bindings (); 3134 g->loc = loc; 3135 set_spot_bindings (&g->goto_bindings, true); 3136 VEC_safe_push (c_goto_bindings_p, gc, label_vars->gotos, g); 3137 return label; 3138 } 3139 3140 /* If there are any decls in label_vars->decls_in_scope, then this 3141 goto has missed the declaration of the decl. This happens for a 3142 case like 3143 int i = 1; 3144 lab: 3145 ... 3146 goto lab; 3147 Issue a warning or error. */ 3148 FOR_EACH_VEC_ELT (tree, label_vars->decls_in_scope, ix, decl) 3149 warn_about_goto (loc, label, decl); 3150 3151 if (label_vars->label_bindings.left_stmt_expr) 3152 { 3153 error_at (loc, "jump into statement expression"); 3154 inform (DECL_SOURCE_LOCATION (label), "label %qD defined here", label); 3155 } 3156 3157 return label; 3158 } 3159 3160 /* Make a label named NAME in the current function, shadowing silently 3161 any that may be inherited from containing functions or containing 3162 scopes. This is called for __label__ declarations. */ 3163 3164 tree 3165 declare_label (tree name) 3166 { 3167 struct c_binding *b = I_LABEL_BINDING (name); 3168 tree label; 3169 struct c_label_vars *label_vars; 3170 3171 /* Check to make sure that the label hasn't already been declared 3172 at this scope */ 3173 if (b && B_IN_CURRENT_SCOPE (b)) 3174 { 3175 error ("duplicate label declaration %qE", name); 3176 locate_old_decl (b->decl); 3177 3178 /* Just use the previous declaration. */ 3179 return b->decl; 3180 } 3181 3182 label = make_label (input_location, name, false, &label_vars); 3183 C_DECLARED_LABEL_FLAG (label) = 1; 3184 3185 /* Declared labels go in the current scope. */ 3186 bind_label (name, label, current_scope, label_vars); 3187 3188 return label; 3189 } 3190 3191 /* When we define a label, issue any appropriate warnings if there are 3192 any gotos earlier in the function which jump to this label. */ 3193 3194 static void 3195 check_earlier_gotos (tree label, struct c_label_vars* label_vars) 3196 { 3197 unsigned int ix; 3198 struct c_goto_bindings *g; 3199 3200 FOR_EACH_VEC_ELT (c_goto_bindings_p, label_vars->gotos, ix, g) 3201 { 3202 struct c_binding *b; 3203 struct c_scope *scope; 3204 3205 /* We have a goto to this label. The goto is going forward. In 3206 g->scope, the goto is going to skip any binding which was 3207 defined after g->bindings_in_scope. */ 3208 if (g->goto_bindings.scope->has_jump_unsafe_decl) 3209 { 3210 for (b = g->goto_bindings.scope->bindings; 3211 b != g->goto_bindings.bindings_in_scope; 3212 b = b->prev) 3213 { 3214 if (decl_jump_unsafe (b->decl)) 3215 warn_about_goto (g->loc, label, b->decl); 3216 } 3217 } 3218 3219 /* We also need to warn about decls defined in any scopes 3220 between the scope of the label and the scope of the goto. */ 3221 for (scope = label_vars->label_bindings.scope; 3222 scope != g->goto_bindings.scope; 3223 scope = scope->outer) 3224 { 3225 gcc_assert (scope != NULL); 3226 if (scope->has_jump_unsafe_decl) 3227 { 3228 if (scope == label_vars->label_bindings.scope) 3229 b = label_vars->label_bindings.bindings_in_scope; 3230 else 3231 b = scope->bindings; 3232 for (; b != NULL; b = b->prev) 3233 { 3234 if (decl_jump_unsafe (b->decl)) 3235 warn_about_goto (g->loc, label, b->decl); 3236 } 3237 } 3238 } 3239 3240 if (g->goto_bindings.stmt_exprs > 0) 3241 { 3242 error_at (g->loc, "jump into statement expression"); 3243 inform (DECL_SOURCE_LOCATION (label), "label %qD defined here", 3244 label); 3245 } 3246 } 3247 3248 /* Now that the label is defined, we will issue warnings about 3249 subsequent gotos to this label when we see them. */ 3250 VEC_truncate (c_goto_bindings_p, label_vars->gotos, 0); 3251 label_vars->gotos = NULL; 3252 } 3253 3254 /* Define a label, specifying the location in the source file. 3255 Return the LABEL_DECL node for the label, if the definition is valid. 3256 Otherwise return 0. */ 3257 3258 tree 3259 define_label (location_t location, tree name) 3260 { 3261 /* Find any preexisting label with this name. It is an error 3262 if that label has already been defined in this function, or 3263 if there is a containing function with a declared label with 3264 the same name. */ 3265 tree label = I_LABEL_DECL (name); 3266 3267 if (label 3268 && ((DECL_CONTEXT (label) == current_function_decl 3269 && DECL_INITIAL (label) != 0) 3270 || (DECL_CONTEXT (label) != current_function_decl 3271 && C_DECLARED_LABEL_FLAG (label)))) 3272 { 3273 error_at (location, "duplicate label %qD", label); 3274 locate_old_decl (label); 3275 return 0; 3276 } 3277 else if (label && DECL_CONTEXT (label) == current_function_decl) 3278 { 3279 struct c_label_vars *label_vars = I_LABEL_BINDING (name)->u.label; 3280 3281 /* The label has been used or declared already in this function, 3282 but not defined. Update its location to point to this 3283 definition. */ 3284 DECL_SOURCE_LOCATION (label) = location; 3285 set_spot_bindings (&label_vars->label_bindings, true); 3286 3287 /* Issue warnings as required about any goto statements from 3288 earlier in the function. */ 3289 check_earlier_gotos (label, label_vars); 3290 } 3291 else 3292 { 3293 struct c_label_vars *label_vars; 3294 3295 /* No label binding for that identifier; make one. */ 3296 label = make_label (location, name, true, &label_vars); 3297 3298 /* Ordinary labels go in the current function scope. */ 3299 bind_label (name, label, current_function_scope, label_vars); 3300 } 3301 3302 if (!in_system_header && lookup_name (name)) 3303 warning_at (location, OPT_Wtraditional, 3304 "traditional C lacks a separate namespace " 3305 "for labels, identifier %qE conflicts", name); 3306 3307 /* Mark label as having been defined. */ 3308 DECL_INITIAL (label) = error_mark_node; 3309 return label; 3310 } 3311 3312 /* Get the bindings for a new switch statement. This is used to issue 3313 warnings as appropriate for jumps from the switch to case or 3314 default labels. */ 3315 3316 struct c_spot_bindings * 3317 c_get_switch_bindings (void) 3318 { 3319 struct c_spot_bindings *switch_bindings; 3320 3321 switch_bindings = XNEW (struct c_spot_bindings); 3322 set_spot_bindings (switch_bindings, true); 3323 return switch_bindings; 3324 } 3325 3326 void 3327 c_release_switch_bindings (struct c_spot_bindings *bindings) 3328 { 3329 gcc_assert (bindings->stmt_exprs == 0 && !bindings->left_stmt_expr); 3330 XDELETE (bindings); 3331 } 3332 3333 /* This is called at the point of a case or default label to issue 3334 warnings about decls as needed. It returns true if it found an 3335 error, not just a warning. */ 3336 3337 bool 3338 c_check_switch_jump_warnings (struct c_spot_bindings *switch_bindings, 3339 location_t switch_loc, location_t case_loc) 3340 { 3341 bool saw_error; 3342 struct c_scope *scope; 3343 3344 saw_error = false; 3345 for (scope = current_scope; 3346 scope != switch_bindings->scope; 3347 scope = scope->outer) 3348 { 3349 struct c_binding *b; 3350 3351 gcc_assert (scope != NULL); 3352 3353 if (!scope->has_jump_unsafe_decl) 3354 continue; 3355 3356 for (b = scope->bindings; b != NULL; b = b->prev) 3357 { 3358 if (decl_jump_unsafe (b->decl)) 3359 { 3360 if (variably_modified_type_p (TREE_TYPE (b->decl), NULL_TREE)) 3361 { 3362 saw_error = true; 3363 error_at (case_loc, 3364 ("switch jumps into scope of identifier with " 3365 "variably modified type")); 3366 } 3367 else 3368 warning_at (case_loc, OPT_Wjump_misses_init, 3369 "switch jumps over variable initialization"); 3370 inform (switch_loc, "switch starts here"); 3371 inform (DECL_SOURCE_LOCATION (b->decl), "%qD declared here", 3372 b->decl); 3373 } 3374 } 3375 } 3376 3377 if (switch_bindings->stmt_exprs > 0) 3378 { 3379 saw_error = true; 3380 error_at (case_loc, "switch jumps into statement expression"); 3381 inform (switch_loc, "switch starts here"); 3382 } 3383 3384 return saw_error; 3385 } 3386 3387 /* Given NAME, an IDENTIFIER_NODE, 3388 return the structure (or union or enum) definition for that name. 3389 If THISLEVEL_ONLY is nonzero, searches only the current_scope. 3390 CODE says which kind of type the caller wants; 3391 it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE. 3392 If PLOC is not NULL and this returns non-null, it sets *PLOC to the 3393 location where the tag was defined. 3394 If the wrong kind of type is found, an error is reported. */ 3395 3396 static tree 3397 lookup_tag (enum tree_code code, tree name, int thislevel_only, 3398 location_t *ploc) 3399 { 3400 struct c_binding *b = I_TAG_BINDING (name); 3401 int thislevel = 0; 3402 3403 if (!b || !b->decl) 3404 return 0; 3405 3406 /* We only care about whether it's in this level if 3407 thislevel_only was set or it might be a type clash. */ 3408 if (thislevel_only || TREE_CODE (b->decl) != code) 3409 { 3410 /* For our purposes, a tag in the external scope is the same as 3411 a tag in the file scope. (Primarily relevant to Objective-C 3412 and its builtin structure tags, which get pushed before the 3413 file scope is created.) */ 3414 if (B_IN_CURRENT_SCOPE (b) 3415 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 3416 thislevel = 1; 3417 } 3418 3419 if (thislevel_only && !thislevel) 3420 return 0; 3421 3422 if (TREE_CODE (b->decl) != code) 3423 { 3424 /* Definition isn't the kind we were looking for. */ 3425 pending_invalid_xref = name; 3426 pending_invalid_xref_location = input_location; 3427 3428 /* If in the same binding level as a declaration as a tag 3429 of a different type, this must not be allowed to 3430 shadow that tag, so give the error immediately. 3431 (For example, "struct foo; union foo;" is invalid.) */ 3432 if (thislevel) 3433 pending_xref_error (); 3434 } 3435 3436 if (ploc != NULL) 3437 *ploc = b->locus; 3438 3439 return b->decl; 3440 } 3441 3442 /* Print an error message now 3443 for a recent invalid struct, union or enum cross reference. 3444 We don't print them immediately because they are not invalid 3445 when used in the `struct foo;' construct for shadowing. */ 3446 3447 void 3448 pending_xref_error (void) 3449 { 3450 if (pending_invalid_xref != 0) 3451 error_at (pending_invalid_xref_location, "%qE defined as wrong kind of tag", 3452 pending_invalid_xref); 3453 pending_invalid_xref = 0; 3454 } 3455 3456 3457 /* Look up NAME in the current scope and its superiors 3458 in the namespace of variables, functions and typedefs. 3459 Return a ..._DECL node of some kind representing its definition, 3460 or return 0 if it is undefined. */ 3461 3462 tree 3463 lookup_name (tree name) 3464 { 3465 struct c_binding *b = I_SYMBOL_BINDING (name); 3466 if (b && !b->invisible) 3467 { 3468 maybe_record_typedef_use (b->decl); 3469 return b->decl; 3470 } 3471 return 0; 3472 } 3473 3474 /* Similar to `lookup_name' but look only at the indicated scope. */ 3475 3476 static tree 3477 lookup_name_in_scope (tree name, struct c_scope *scope) 3478 { 3479 struct c_binding *b; 3480 3481 for (b = I_SYMBOL_BINDING (name); b; b = b->shadowed) 3482 if (B_IN_SCOPE (b, scope)) 3483 return b->decl; 3484 return 0; 3485 } 3486 3487 /* Create the predefined scalar types of C, 3488 and some nodes representing standard constants (0, 1, (void *) 0). 3489 Initialize the global scope. 3490 Make definitions for built-in primitive functions. */ 3491 3492 void 3493 c_init_decl_processing (void) 3494 { 3495 location_t save_loc = input_location; 3496 3497 /* Initialize reserved words for parser. */ 3498 c_parse_init (); 3499 3500 current_function_decl = 0; 3501 3502 gcc_obstack_init (&parser_obstack); 3503 3504 /* Make the externals scope. */ 3505 push_scope (); 3506 external_scope = current_scope; 3507 3508 /* Declarations from c_common_nodes_and_builtins must not be associated 3509 with this input file, lest we get differences between using and not 3510 using preprocessed headers. */ 3511 input_location = BUILTINS_LOCATION; 3512 3513 c_common_nodes_and_builtins (); 3514 3515 /* In C, comparisons and TRUTH_* expressions have type int. */ 3516 truthvalue_type_node = integer_type_node; 3517 truthvalue_true_node = integer_one_node; 3518 truthvalue_false_node = integer_zero_node; 3519 3520 /* Even in C99, which has a real boolean type. */ 3521 pushdecl (build_decl (UNKNOWN_LOCATION, TYPE_DECL, get_identifier ("_Bool"), 3522 boolean_type_node)); 3523 3524 input_location = save_loc; 3525 3526 pedantic_lvalues = true; 3527 3528 make_fname_decl = c_make_fname_decl; 3529 start_fname_decls (); 3530 } 3531 3532 /* Create the VAR_DECL at LOC for __FUNCTION__ etc. ID is the name to 3533 give the decl, NAME is the initialization string and TYPE_DEP 3534 indicates whether NAME depended on the type of the function. As we 3535 don't yet implement delayed emission of static data, we mark the 3536 decl as emitted so it is not placed in the output. Anything using 3537 it must therefore pull out the STRING_CST initializer directly. 3538 FIXME. */ 3539 3540 static tree 3541 c_make_fname_decl (location_t loc, tree id, int type_dep) 3542 { 3543 const char *name = fname_as_string (type_dep); 3544 tree decl, type, init; 3545 size_t length = strlen (name); 3546 3547 type = build_array_type (char_type_node, 3548 build_index_type (size_int (length))); 3549 type = c_build_qualified_type (type, TYPE_QUAL_CONST); 3550 3551 decl = build_decl (loc, VAR_DECL, id, type); 3552 3553 TREE_STATIC (decl) = 1; 3554 TREE_READONLY (decl) = 1; 3555 DECL_ARTIFICIAL (decl) = 1; 3556 3557 init = build_string (length + 1, name); 3558 free (CONST_CAST (char *, name)); 3559 TREE_TYPE (init) = type; 3560 DECL_INITIAL (decl) = init; 3561 3562 TREE_USED (decl) = 1; 3563 3564 if (current_function_decl 3565 /* For invalid programs like this: 3566 3567 void foo() 3568 const char* p = __FUNCTION__; 3569 3570 the __FUNCTION__ is believed to appear in K&R style function 3571 parameter declarator. In that case we still don't have 3572 function_scope. */ 3573 && (!seen_error () || current_function_scope)) 3574 { 3575 DECL_CONTEXT (decl) = current_function_decl; 3576 bind (id, decl, current_function_scope, 3577 /*invisible=*/false, /*nested=*/false, UNKNOWN_LOCATION); 3578 } 3579 3580 finish_decl (decl, loc, init, NULL_TREE, NULL_TREE); 3581 3582 return decl; 3583 } 3584 3585 tree 3586 c_builtin_function (tree decl) 3587 { 3588 tree type = TREE_TYPE (decl); 3589 tree id = DECL_NAME (decl); 3590 3591 const char *name = IDENTIFIER_POINTER (id); 3592 C_DECL_BUILTIN_PROTOTYPE (decl) = prototype_p (type); 3593 3594 /* Should never be called on a symbol with a preexisting meaning. */ 3595 gcc_assert (!I_SYMBOL_BINDING (id)); 3596 3597 bind (id, decl, external_scope, /*invisible=*/true, /*nested=*/false, 3598 UNKNOWN_LOCATION); 3599 3600 /* Builtins in the implementation namespace are made visible without 3601 needing to be explicitly declared. See push_file_scope. */ 3602 if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1]))) 3603 { 3604 DECL_CHAIN (decl) = visible_builtins; 3605 visible_builtins = decl; 3606 } 3607 3608 return decl; 3609 } 3610 3611 tree 3612 c_builtin_function_ext_scope (tree decl) 3613 { 3614 tree type = TREE_TYPE (decl); 3615 tree id = DECL_NAME (decl); 3616 3617 const char *name = IDENTIFIER_POINTER (id); 3618 C_DECL_BUILTIN_PROTOTYPE (decl) = prototype_p (type); 3619 3620 /* Should never be called on a symbol with a preexisting meaning. */ 3621 gcc_assert (!I_SYMBOL_BINDING (id)); 3622 3623 bind (id, decl, external_scope, /*invisible=*/false, /*nested=*/false, 3624 UNKNOWN_LOCATION); 3625 3626 /* Builtins in the implementation namespace are made visible without 3627 needing to be explicitly declared. See push_file_scope. */ 3628 if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1]))) 3629 { 3630 DECL_CHAIN (decl) = visible_builtins; 3631 visible_builtins = decl; 3632 } 3633 3634 return decl; 3635 } 3636 3637 /* Called when a declaration is seen that contains no names to declare. 3638 If its type is a reference to a structure, union or enum inherited 3639 from a containing scope, shadow that tag name for the current scope 3640 with a forward reference. 3641 If its type defines a new named structure or union 3642 or defines an enum, it is valid but we need not do anything here. 3643 Otherwise, it is an error. */ 3644 3645 void 3646 shadow_tag (const struct c_declspecs *declspecs) 3647 { 3648 shadow_tag_warned (declspecs, 0); 3649 } 3650 3651 /* WARNED is 1 if we have done a pedwarn, 2 if we have done a warning, 3652 but no pedwarn. */ 3653 void 3654 shadow_tag_warned (const struct c_declspecs *declspecs, int warned) 3655 { 3656 bool found_tag = false; 3657 3658 if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p) 3659 { 3660 tree value = declspecs->type; 3661 enum tree_code code = TREE_CODE (value); 3662 3663 if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) 3664 /* Used to test also that TYPE_SIZE (value) != 0. 3665 That caused warning for `struct foo;' at top level in the file. */ 3666 { 3667 tree name = TYPE_NAME (value); 3668 tree t; 3669 3670 found_tag = true; 3671 3672 if (declspecs->restrict_p) 3673 { 3674 error ("invalid use of %<restrict%>"); 3675 warned = 1; 3676 } 3677 3678 if (name == 0) 3679 { 3680 if (warned != 1 && code != ENUMERAL_TYPE) 3681 /* Empty unnamed enum OK */ 3682 { 3683 pedwarn (input_location, 0, 3684 "unnamed struct/union that defines no instances"); 3685 warned = 1; 3686 } 3687 } 3688 else if (declspecs->typespec_kind != ctsk_tagdef 3689 && declspecs->typespec_kind != ctsk_tagfirstref 3690 && declspecs->storage_class != csc_none) 3691 { 3692 if (warned != 1) 3693 pedwarn (input_location, 0, 3694 "empty declaration with storage class specifier " 3695 "does not redeclare tag"); 3696 warned = 1; 3697 pending_xref_error (); 3698 } 3699 else if (declspecs->typespec_kind != ctsk_tagdef 3700 && declspecs->typespec_kind != ctsk_tagfirstref 3701 && (declspecs->const_p 3702 || declspecs->volatile_p 3703 || declspecs->restrict_p 3704 || declspecs->address_space)) 3705 { 3706 if (warned != 1) 3707 pedwarn (input_location, 0, 3708 "empty declaration with type qualifier " 3709 "does not redeclare tag"); 3710 warned = 1; 3711 pending_xref_error (); 3712 } 3713 else if (declspecs->typespec_kind != ctsk_tagdef 3714 && declspecs->typespec_kind != ctsk_tagfirstref 3715 && declspecs->alignas_p) 3716 { 3717 if (warned != 1) 3718 pedwarn (input_location, 0, 3719 "empty declaration with %<_Alignas%> " 3720 "does not redeclare tag"); 3721 warned = 1; 3722 pending_xref_error (); 3723 } 3724 else 3725 { 3726 pending_invalid_xref = 0; 3727 t = lookup_tag (code, name, 1, NULL); 3728 3729 if (t == 0) 3730 { 3731 t = make_node (code); 3732 pushtag (input_location, name, t); 3733 } 3734 } 3735 } 3736 else 3737 { 3738 if (warned != 1 && !in_system_header) 3739 { 3740 pedwarn (input_location, 0, 3741 "useless type name in empty declaration"); 3742 warned = 1; 3743 } 3744 } 3745 } 3746 else if (warned != 1 && !in_system_header && declspecs->typedef_p) 3747 { 3748 pedwarn (input_location, 0, "useless type name in empty declaration"); 3749 warned = 1; 3750 } 3751 3752 pending_invalid_xref = 0; 3753 3754 if (declspecs->inline_p) 3755 { 3756 error ("%<inline%> in empty declaration"); 3757 warned = 1; 3758 } 3759 3760 if (declspecs->noreturn_p) 3761 { 3762 error ("%<_Noreturn%> in empty declaration"); 3763 warned = 1; 3764 } 3765 3766 if (current_scope == file_scope && declspecs->storage_class == csc_auto) 3767 { 3768 error ("%<auto%> in file-scope empty declaration"); 3769 warned = 1; 3770 } 3771 3772 if (current_scope == file_scope && declspecs->storage_class == csc_register) 3773 { 3774 error ("%<register%> in file-scope empty declaration"); 3775 warned = 1; 3776 } 3777 3778 if (!warned && !in_system_header && declspecs->storage_class != csc_none) 3779 { 3780 warning (0, "useless storage class specifier in empty declaration"); 3781 warned = 2; 3782 } 3783 3784 if (!warned && !in_system_header && declspecs->thread_p) 3785 { 3786 warning (0, "useless %<__thread%> in empty declaration"); 3787 warned = 2; 3788 } 3789 3790 if (!warned && !in_system_header && (declspecs->const_p 3791 || declspecs->volatile_p 3792 || declspecs->restrict_p 3793 || declspecs->address_space)) 3794 { 3795 warning (0, "useless type qualifier in empty declaration"); 3796 warned = 2; 3797 } 3798 3799 if (!warned && !in_system_header && declspecs->alignas_p) 3800 { 3801 warning (0, "useless %<_Alignas%> in empty declaration"); 3802 warned = 2; 3803 } 3804 3805 if (warned != 1) 3806 { 3807 if (!found_tag) 3808 pedwarn (input_location, 0, "empty declaration"); 3809 } 3810 } 3811 3812 3813 /* Return the qualifiers from SPECS as a bitwise OR of TYPE_QUAL_* 3814 bits. SPECS represents declaration specifiers that the grammar 3815 only permits to contain type qualifiers and attributes. */ 3816 3817 int 3818 quals_from_declspecs (const struct c_declspecs *specs) 3819 { 3820 int quals = ((specs->const_p ? TYPE_QUAL_CONST : 0) 3821 | (specs->volatile_p ? TYPE_QUAL_VOLATILE : 0) 3822 | (specs->restrict_p ? TYPE_QUAL_RESTRICT : 0) 3823 | (ENCODE_QUAL_ADDR_SPACE (specs->address_space))); 3824 gcc_assert (!specs->type 3825 && !specs->decl_attr 3826 && specs->typespec_word == cts_none 3827 && specs->storage_class == csc_none 3828 && !specs->typedef_p 3829 && !specs->explicit_signed_p 3830 && !specs->deprecated_p 3831 && !specs->long_p 3832 && !specs->long_long_p 3833 && !specs->short_p 3834 && !specs->signed_p 3835 && !specs->unsigned_p 3836 && !specs->complex_p 3837 && !specs->inline_p 3838 && !specs->noreturn_p 3839 && !specs->thread_p); 3840 return quals; 3841 } 3842 3843 /* Construct an array declarator. LOC is the location of the 3844 beginning of the array (usually the opening brace). EXPR is the 3845 expression inside [], or NULL_TREE. QUALS are the type qualifiers 3846 inside the [] (to be applied to the pointer to which a parameter 3847 array is converted). STATIC_P is true if "static" is inside the 3848 [], false otherwise. VLA_UNSPEC_P is true if the array is [*], a 3849 VLA of unspecified length which is nevertheless a complete type, 3850 false otherwise. The field for the contained declarator is left to 3851 be filled in by set_array_declarator_inner. */ 3852 3853 struct c_declarator * 3854 build_array_declarator (location_t loc, 3855 tree expr, struct c_declspecs *quals, bool static_p, 3856 bool vla_unspec_p) 3857 { 3858 struct c_declarator *declarator = XOBNEW (&parser_obstack, 3859 struct c_declarator); 3860 declarator->id_loc = loc; 3861 declarator->kind = cdk_array; 3862 declarator->declarator = 0; 3863 declarator->u.array.dimen = expr; 3864 if (quals) 3865 { 3866 declarator->u.array.attrs = quals->attrs; 3867 declarator->u.array.quals = quals_from_declspecs (quals); 3868 } 3869 else 3870 { 3871 declarator->u.array.attrs = NULL_TREE; 3872 declarator->u.array.quals = 0; 3873 } 3874 declarator->u.array.static_p = static_p; 3875 declarator->u.array.vla_unspec_p = vla_unspec_p; 3876 if (!flag_isoc99) 3877 { 3878 if (static_p || quals != NULL) 3879 pedwarn (loc, OPT_pedantic, 3880 "ISO C90 does not support %<static%> or type " 3881 "qualifiers in parameter array declarators"); 3882 if (vla_unspec_p) 3883 pedwarn (loc, OPT_pedantic, 3884 "ISO C90 does not support %<[*]%> array declarators"); 3885 } 3886 if (vla_unspec_p) 3887 { 3888 if (!current_scope->parm_flag) 3889 { 3890 /* C99 6.7.5.2p4 */ 3891 error_at (loc, "%<[*]%> not allowed in other than " 3892 "function prototype scope"); 3893 declarator->u.array.vla_unspec_p = false; 3894 return NULL; 3895 } 3896 current_scope->had_vla_unspec = true; 3897 } 3898 return declarator; 3899 } 3900 3901 /* Set the contained declarator of an array declarator. DECL is the 3902 declarator, as constructed by build_array_declarator; INNER is what 3903 appears on the left of the []. */ 3904 3905 struct c_declarator * 3906 set_array_declarator_inner (struct c_declarator *decl, 3907 struct c_declarator *inner) 3908 { 3909 decl->declarator = inner; 3910 return decl; 3911 } 3912 3913 /* INIT is a constructor that forms DECL's initializer. If the final 3914 element initializes a flexible array field, add the size of that 3915 initializer to DECL's size. */ 3916 3917 static void 3918 add_flexible_array_elts_to_size (tree decl, tree init) 3919 { 3920 tree elt, type; 3921 3922 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init))) 3923 return; 3924 3925 elt = VEC_last (constructor_elt, CONSTRUCTOR_ELTS (init))->value; 3926 type = TREE_TYPE (elt); 3927 if (TREE_CODE (type) == ARRAY_TYPE 3928 && TYPE_SIZE (type) == NULL_TREE 3929 && TYPE_DOMAIN (type) != NULL_TREE 3930 && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL_TREE) 3931 { 3932 complete_array_type (&type, elt, false); 3933 DECL_SIZE (decl) 3934 = size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type)); 3935 DECL_SIZE_UNIT (decl) 3936 = size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type)); 3937 } 3938 } 3939 3940 /* Decode a "typename", such as "int **", returning a ..._TYPE node. 3941 Set *EXPR, if EXPR not NULL, to any expression to be evaluated 3942 before the type name, and set *EXPR_CONST_OPERANDS, if 3943 EXPR_CONST_OPERANDS not NULL, to indicate whether the type name may 3944 appear in a constant expression. */ 3945 3946 tree 3947 groktypename (struct c_type_name *type_name, tree *expr, 3948 bool *expr_const_operands) 3949 { 3950 tree type; 3951 tree attrs = type_name->specs->attrs; 3952 3953 type_name->specs->attrs = NULL_TREE; 3954 3955 type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME, 3956 false, NULL, &attrs, expr, expr_const_operands, 3957 DEPRECATED_NORMAL); 3958 3959 /* Apply attributes. */ 3960 decl_attributes (&type, attrs, 0); 3961 3962 return type; 3963 } 3964 3965 /* Decode a declarator in an ordinary declaration or data definition. 3966 This is called as soon as the type information and variable name 3967 have been parsed, before parsing the initializer if any. 3968 Here we create the ..._DECL node, fill in its type, 3969 and put it on the list of decls for the current context. 3970 The ..._DECL node is returned as the value. 3971 3972 Exception: for arrays where the length is not specified, 3973 the type is left null, to be filled in by `finish_decl'. 3974 3975 Function definitions do not come here; they go to start_function 3976 instead. However, external and forward declarations of functions 3977 do go through here. Structure field declarations are done by 3978 grokfield and not through here. */ 3979 3980 tree 3981 start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, 3982 bool initialized, tree attributes) 3983 { 3984 tree decl; 3985 tree tem; 3986 tree expr = NULL_TREE; 3987 enum deprecated_states deprecated_state = DEPRECATED_NORMAL; 3988 3989 /* An object declared as __attribute__((deprecated)) suppresses 3990 warnings of uses of other deprecated items. */ 3991 if (lookup_attribute ("deprecated", attributes)) 3992 deprecated_state = DEPRECATED_SUPPRESS; 3993 3994 decl = grokdeclarator (declarator, declspecs, 3995 NORMAL, initialized, NULL, &attributes, &expr, NULL, 3996 deprecated_state); 3997 if (!decl) 3998 return 0; 3999 4000 if (expr) 4001 add_stmt (fold_convert (void_type_node, expr)); 4002 4003 if (TREE_CODE (decl) != FUNCTION_DECL && MAIN_NAME_P (DECL_NAME (decl))) 4004 warning (OPT_Wmain, "%q+D is usually a function", decl); 4005 4006 if (initialized) 4007 /* Is it valid for this decl to have an initializer at all? 4008 If not, set INITIALIZED to zero, which will indirectly 4009 tell 'finish_decl' to ignore the initializer once it is parsed. */ 4010 switch (TREE_CODE (decl)) 4011 { 4012 case TYPE_DECL: 4013 error ("typedef %qD is initialized (use __typeof__ instead)", decl); 4014 initialized = 0; 4015 break; 4016 4017 case FUNCTION_DECL: 4018 error ("function %qD is initialized like a variable", decl); 4019 initialized = 0; 4020 break; 4021 4022 case PARM_DECL: 4023 /* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE. */ 4024 error ("parameter %qD is initialized", decl); 4025 initialized = 0; 4026 break; 4027 4028 default: 4029 /* Don't allow initializations for incomplete types except for 4030 arrays which might be completed by the initialization. */ 4031 4032 /* This can happen if the array size is an undefined macro. 4033 We already gave a warning, so we don't need another one. */ 4034 if (TREE_TYPE (decl) == error_mark_node) 4035 initialized = 0; 4036 else if (COMPLETE_TYPE_P (TREE_TYPE (decl))) 4037 { 4038 /* A complete type is ok if size is fixed. */ 4039 4040 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST 4041 || C_DECL_VARIABLE_SIZE (decl)) 4042 { 4043 error ("variable-sized object may not be initialized"); 4044 initialized = 0; 4045 } 4046 } 4047 else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE) 4048 { 4049 error ("variable %qD has initializer but incomplete type", decl); 4050 initialized = 0; 4051 } 4052 else if (C_DECL_VARIABLE_SIZE (decl)) 4053 { 4054 /* Although C99 is unclear about whether incomplete arrays 4055 of VLAs themselves count as VLAs, it does not make 4056 sense to permit them to be initialized given that 4057 ordinary VLAs may not be initialized. */ 4058 error ("variable-sized object may not be initialized"); 4059 initialized = 0; 4060 } 4061 } 4062 4063 if (initialized) 4064 { 4065 if (current_scope == file_scope) 4066 TREE_STATIC (decl) = 1; 4067 4068 /* Tell 'pushdecl' this is an initialized decl 4069 even though we don't yet have the initializer expression. 4070 Also tell 'finish_decl' it may store the real initializer. */ 4071 DECL_INITIAL (decl) = error_mark_node; 4072 } 4073 4074 /* If this is a function declaration, write a record describing it to the 4075 prototypes file (if requested). */ 4076 4077 if (TREE_CODE (decl) == FUNCTION_DECL) 4078 gen_aux_info_record (decl, 0, 0, prototype_p (TREE_TYPE (decl))); 4079 4080 /* ANSI specifies that a tentative definition which is not merged with 4081 a non-tentative definition behaves exactly like a definition with an 4082 initializer equal to zero. (Section 3.7.2) 4083 4084 -fno-common gives strict ANSI behavior, though this tends to break 4085 a large body of code that grew up without this rule. 4086 4087 Thread-local variables are never common, since there's no entrenched 4088 body of code to break, and it allows more efficient variable references 4089 in the presence of dynamic linking. */ 4090 4091 if (TREE_CODE (decl) == VAR_DECL 4092 && !initialized 4093 && TREE_PUBLIC (decl) 4094 && !DECL_THREAD_LOCAL_P (decl) 4095 && !flag_no_common) 4096 DECL_COMMON (decl) = 1; 4097 4098 /* Set attributes here so if duplicate decl, will have proper attributes. */ 4099 decl_attributes (&decl, attributes, 0); 4100 4101 /* Handle gnu_inline attribute. */ 4102 if (declspecs->inline_p 4103 && !flag_gnu89_inline 4104 && TREE_CODE (decl) == FUNCTION_DECL 4105 && (lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl)) 4106 || current_function_decl)) 4107 { 4108 if (declspecs->storage_class == csc_auto && current_scope != file_scope) 4109 ; 4110 else if (declspecs->storage_class != csc_static) 4111 DECL_EXTERNAL (decl) = !DECL_EXTERNAL (decl); 4112 } 4113 4114 if (TREE_CODE (decl) == FUNCTION_DECL 4115 && targetm.calls.promote_prototypes (TREE_TYPE (decl))) 4116 { 4117 struct c_declarator *ce = declarator; 4118 4119 if (ce->kind == cdk_pointer) 4120 ce = declarator->declarator; 4121 if (ce->kind == cdk_function) 4122 { 4123 tree args = ce->u.arg_info->parms; 4124 for (; args; args = DECL_CHAIN (args)) 4125 { 4126 tree type = TREE_TYPE (args); 4127 if (type && INTEGRAL_TYPE_P (type) 4128 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 4129 DECL_ARG_TYPE (args) = integer_type_node; 4130 } 4131 } 4132 } 4133 4134 if (TREE_CODE (decl) == FUNCTION_DECL 4135 && DECL_DECLARED_INLINE_P (decl) 4136 && DECL_UNINLINABLE (decl) 4137 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl))) 4138 warning (OPT_Wattributes, "inline function %q+D given attribute noinline", 4139 decl); 4140 4141 /* C99 6.7.4p3: An inline definition of a function with external 4142 linkage shall not contain a definition of a modifiable object 4143 with static storage duration... */ 4144 if (TREE_CODE (decl) == VAR_DECL 4145 && current_scope != file_scope 4146 && TREE_STATIC (decl) 4147 && !TREE_READONLY (decl) 4148 && DECL_DECLARED_INLINE_P (current_function_decl) 4149 && DECL_EXTERNAL (current_function_decl)) 4150 record_inline_static (input_location, current_function_decl, 4151 decl, csi_modifiable); 4152 4153 if (c_dialect_objc () 4154 && (TREE_CODE (decl) == VAR_DECL 4155 || TREE_CODE (decl) == FUNCTION_DECL)) 4156 objc_check_global_decl (decl); 4157 4158 /* Add this decl to the current scope. 4159 TEM may equal DECL or it may be a previous decl of the same name. */ 4160 tem = pushdecl (decl); 4161 4162 if (initialized && DECL_EXTERNAL (tem)) 4163 { 4164 DECL_EXTERNAL (tem) = 0; 4165 TREE_STATIC (tem) = 1; 4166 } 4167 4168 return tem; 4169 } 4170 4171 /* Subroutine of finish_decl. TYPE is the type of an uninitialized object 4172 DECL or the non-array element type if DECL is an uninitialized array. 4173 If that type has a const member, diagnose this. */ 4174 4175 static void 4176 diagnose_uninitialized_cst_member (tree decl, tree type) 4177 { 4178 tree field; 4179 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 4180 { 4181 tree field_type; 4182 if (TREE_CODE (field) != FIELD_DECL) 4183 continue; 4184 field_type = strip_array_types (TREE_TYPE (field)); 4185 4186 if (TYPE_QUALS (field_type) & TYPE_QUAL_CONST) 4187 { 4188 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wc___compat, 4189 "uninitialized const member in %qT is invalid in C++", 4190 strip_array_types (TREE_TYPE (decl))); 4191 inform (DECL_SOURCE_LOCATION (field), "%qD should be initialized", field); 4192 } 4193 4194 if (TREE_CODE (field_type) == RECORD_TYPE 4195 || TREE_CODE (field_type) == UNION_TYPE) 4196 diagnose_uninitialized_cst_member (decl, field_type); 4197 } 4198 } 4199 4200 /* Finish processing of a declaration; 4201 install its initial value. 4202 If ORIGTYPE is not NULL_TREE, it is the original type of INIT. 4203 If the length of an array type is not known before, 4204 it must be determined now, from the initial value, or it is an error. 4205 4206 INIT_LOC is the location of the initial value. */ 4207 4208 void 4209 finish_decl (tree decl, location_t init_loc, tree init, 4210 tree origtype, tree asmspec_tree) 4211 { 4212 tree type; 4213 bool was_incomplete = (DECL_SIZE (decl) == 0); 4214 const char *asmspec = 0; 4215 4216 /* If a name was specified, get the string. */ 4217 if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL) 4218 && DECL_FILE_SCOPE_P (decl)) 4219 asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree); 4220 if (asmspec_tree) 4221 asmspec = TREE_STRING_POINTER (asmspec_tree); 4222 4223 if (TREE_CODE (decl) == VAR_DECL 4224 && TREE_STATIC (decl) 4225 && global_bindings_p ()) 4226 /* So decl is a global variable. Record the types it uses 4227 so that we can decide later to emit debug info for them. */ 4228 record_types_used_by_current_var_decl (decl); 4229 4230 /* If `start_decl' didn't like having an initialization, ignore it now. */ 4231 if (init != 0 && DECL_INITIAL (decl) == 0) 4232 init = 0; 4233 4234 /* Don't crash if parm is initialized. */ 4235 if (TREE_CODE (decl) == PARM_DECL) 4236 init = 0; 4237 4238 if (init) 4239 store_init_value (init_loc, decl, init, origtype); 4240 4241 if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL 4242 || TREE_CODE (decl) == FUNCTION_DECL 4243 || TREE_CODE (decl) == FIELD_DECL)) 4244 objc_check_decl (decl); 4245 4246 type = TREE_TYPE (decl); 4247 4248 /* Deduce size of array from initialization, if not already known. */ 4249 if (TREE_CODE (type) == ARRAY_TYPE 4250 && TYPE_DOMAIN (type) == 0 4251 && TREE_CODE (decl) != TYPE_DECL) 4252 { 4253 bool do_default 4254 = (TREE_STATIC (decl) 4255 /* Even if pedantic, an external linkage array 4256 may have incomplete type at first. */ 4257 ? pedantic && !TREE_PUBLIC (decl) 4258 : !DECL_EXTERNAL (decl)); 4259 int failure 4260 = complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl), 4261 do_default); 4262 4263 /* Get the completed type made by complete_array_type. */ 4264 type = TREE_TYPE (decl); 4265 4266 switch (failure) 4267 { 4268 case 1: 4269 error ("initializer fails to determine size of %q+D", decl); 4270 break; 4271 4272 case 2: 4273 if (do_default) 4274 error ("array size missing in %q+D", decl); 4275 /* If a `static' var's size isn't known, 4276 make it extern as well as static, so it does not get 4277 allocated. 4278 If it is not `static', then do not mark extern; 4279 finish_incomplete_decl will give it a default size 4280 and it will get allocated. */ 4281 else if (!pedantic && TREE_STATIC (decl) && !TREE_PUBLIC (decl)) 4282 DECL_EXTERNAL (decl) = 1; 4283 break; 4284 4285 case 3: 4286 error ("zero or negative size array %q+D", decl); 4287 break; 4288 4289 case 0: 4290 /* For global variables, update the copy of the type that 4291 exists in the binding. */ 4292 if (TREE_PUBLIC (decl)) 4293 { 4294 struct c_binding *b_ext = I_SYMBOL_BINDING (DECL_NAME (decl)); 4295 while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext)) 4296 b_ext = b_ext->shadowed; 4297 if (b_ext) 4298 { 4299 if (b_ext->u.type && comptypes (b_ext->u.type, type)) 4300 b_ext->u.type = composite_type (b_ext->u.type, type); 4301 else 4302 b_ext->u.type = type; 4303 } 4304 } 4305 break; 4306 4307 default: 4308 gcc_unreachable (); 4309 } 4310 4311 if (DECL_INITIAL (decl)) 4312 TREE_TYPE (DECL_INITIAL (decl)) = type; 4313 4314 relayout_decl (decl); 4315 } 4316 4317 if (TREE_CODE (decl) == VAR_DECL) 4318 { 4319 if (init && TREE_CODE (init) == CONSTRUCTOR) 4320 add_flexible_array_elts_to_size (decl, init); 4321 4322 if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node 4323 && COMPLETE_TYPE_P (TREE_TYPE (decl))) 4324 layout_decl (decl, 0); 4325 4326 if (DECL_SIZE (decl) == 0 4327 /* Don't give an error if we already gave one earlier. */ 4328 && TREE_TYPE (decl) != error_mark_node 4329 && (TREE_STATIC (decl) 4330 /* A static variable with an incomplete type 4331 is an error if it is initialized. 4332 Also if it is not file scope. 4333 Otherwise, let it through, but if it is not `extern' 4334 then it may cause an error message later. */ 4335 ? (DECL_INITIAL (decl) != 0 4336 || !DECL_FILE_SCOPE_P (decl)) 4337 /* An automatic variable with an incomplete type 4338 is an error. */ 4339 : !DECL_EXTERNAL (decl))) 4340 { 4341 error ("storage size of %q+D isn%'t known", decl); 4342 TREE_TYPE (decl) = error_mark_node; 4343 } 4344 4345 if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl)) 4346 && DECL_SIZE (decl) != 0) 4347 { 4348 if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST) 4349 constant_expression_warning (DECL_SIZE (decl)); 4350 else 4351 { 4352 error ("storage size of %q+D isn%'t constant", decl); 4353 TREE_TYPE (decl) = error_mark_node; 4354 } 4355 } 4356 4357 if (TREE_USED (type)) 4358 { 4359 TREE_USED (decl) = 1; 4360 DECL_READ_P (decl) = 1; 4361 } 4362 } 4363 4364 /* If this is a function and an assembler name is specified, reset DECL_RTL 4365 so we can give it its new name. Also, update builtin_decl if it 4366 was a normal built-in. */ 4367 if (TREE_CODE (decl) == FUNCTION_DECL && asmspec) 4368 { 4369 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) 4370 set_builtin_user_assembler_name (decl, asmspec); 4371 set_user_assembler_name (decl, asmspec); 4372 } 4373 4374 /* If #pragma weak was used, mark the decl weak now. */ 4375 maybe_apply_pragma_weak (decl); 4376 4377 /* Output the assembler code and/or RTL code for variables and functions, 4378 unless the type is an undefined structure or union. 4379 If not, it will get done when the type is completed. */ 4380 4381 if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL) 4382 { 4383 /* Determine the ELF visibility. */ 4384 if (TREE_PUBLIC (decl)) 4385 c_determine_visibility (decl); 4386 4387 /* This is a no-op in c-lang.c or something real in objc-act.c. */ 4388 if (c_dialect_objc ()) 4389 objc_check_decl (decl); 4390 4391 if (asmspec) 4392 { 4393 /* If this is not a static variable, issue a warning. 4394 It doesn't make any sense to give an ASMSPEC for an 4395 ordinary, non-register local variable. Historically, 4396 GCC has accepted -- but ignored -- the ASMSPEC in 4397 this case. */ 4398 if (!DECL_FILE_SCOPE_P (decl) 4399 && TREE_CODE (decl) == VAR_DECL 4400 && !C_DECL_REGISTER (decl) 4401 && !TREE_STATIC (decl)) 4402 warning (0, "ignoring asm-specifier for non-static local " 4403 "variable %q+D", decl); 4404 else 4405 set_user_assembler_name (decl, asmspec); 4406 } 4407 4408 if (DECL_FILE_SCOPE_P (decl)) 4409 { 4410 if (DECL_INITIAL (decl) == NULL_TREE 4411 || DECL_INITIAL (decl) == error_mark_node) 4412 /* Don't output anything 4413 when a tentative file-scope definition is seen. 4414 But at end of compilation, do output code for them. */ 4415 DECL_DEFER_OUTPUT (decl) = 1; 4416 if (asmspec && C_DECL_REGISTER (decl)) 4417 DECL_HARD_REGISTER (decl) = 1; 4418 rest_of_decl_compilation (decl, true, 0); 4419 } 4420 else 4421 { 4422 /* In conjunction with an ASMSPEC, the `register' 4423 keyword indicates that we should place the variable 4424 in a particular register. */ 4425 if (asmspec && C_DECL_REGISTER (decl)) 4426 { 4427 DECL_HARD_REGISTER (decl) = 1; 4428 /* This cannot be done for a structure with volatile 4429 fields, on which DECL_REGISTER will have been 4430 reset. */ 4431 if (!DECL_REGISTER (decl)) 4432 error ("cannot put object with volatile field into register"); 4433 } 4434 4435 if (TREE_CODE (decl) != FUNCTION_DECL) 4436 { 4437 /* If we're building a variable sized type, and we might be 4438 reachable other than via the top of the current binding 4439 level, then create a new BIND_EXPR so that we deallocate 4440 the object at the right time. */ 4441 /* Note that DECL_SIZE can be null due to errors. */ 4442 if (DECL_SIZE (decl) 4443 && !TREE_CONSTANT (DECL_SIZE (decl)) 4444 && STATEMENT_LIST_HAS_LABEL (cur_stmt_list)) 4445 { 4446 tree bind; 4447 bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL); 4448 TREE_SIDE_EFFECTS (bind) = 1; 4449 add_stmt (bind); 4450 BIND_EXPR_BODY (bind) = push_stmt_list (); 4451 } 4452 add_stmt (build_stmt (DECL_SOURCE_LOCATION (decl), 4453 DECL_EXPR, decl)); 4454 } 4455 } 4456 4457 4458 if (!DECL_FILE_SCOPE_P (decl)) 4459 { 4460 /* Recompute the RTL of a local array now 4461 if it used to be an incomplete type. */ 4462 if (was_incomplete 4463 && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) 4464 { 4465 /* If we used it already as memory, it must stay in memory. */ 4466 TREE_ADDRESSABLE (decl) = TREE_USED (decl); 4467 /* If it's still incomplete now, no init will save it. */ 4468 if (DECL_SIZE (decl) == 0) 4469 DECL_INITIAL (decl) = 0; 4470 } 4471 } 4472 } 4473 4474 if (TREE_CODE (decl) == TYPE_DECL) 4475 { 4476 if (!DECL_FILE_SCOPE_P (decl) 4477 && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)) 4478 add_stmt (build_stmt (DECL_SOURCE_LOCATION (decl), DECL_EXPR, decl)); 4479 4480 rest_of_decl_compilation (decl, DECL_FILE_SCOPE_P (decl), 0); 4481 } 4482 4483 /* Install a cleanup (aka destructor) if one was given. */ 4484 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 4485 { 4486 tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl)); 4487 if (attr) 4488 { 4489 tree cleanup_id = TREE_VALUE (TREE_VALUE (attr)); 4490 tree cleanup_decl = lookup_name (cleanup_id); 4491 tree cleanup; 4492 VEC(tree,gc) *vec; 4493 4494 /* Build "cleanup(&decl)" for the destructor. */ 4495 cleanup = build_unary_op (input_location, ADDR_EXPR, decl, 0); 4496 vec = VEC_alloc (tree, gc, 1); 4497 VEC_quick_push (tree, vec, cleanup); 4498 cleanup = build_function_call_vec (DECL_SOURCE_LOCATION (decl), 4499 cleanup_decl, vec, NULL); 4500 VEC_free (tree, gc, vec); 4501 4502 /* Don't warn about decl unused; the cleanup uses it. */ 4503 TREE_USED (decl) = 1; 4504 TREE_USED (cleanup_decl) = 1; 4505 DECL_READ_P (decl) = 1; 4506 4507 push_cleanup (decl, cleanup, false); 4508 } 4509 } 4510 4511 if (warn_cxx_compat 4512 && TREE_CODE (decl) == VAR_DECL 4513 && !DECL_EXTERNAL (decl) 4514 && DECL_INITIAL (decl) == NULL_TREE) 4515 { 4516 type = strip_array_types (type); 4517 if (TREE_READONLY (decl)) 4518 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wc___compat, 4519 "uninitialized const %qD is invalid in C++", decl); 4520 else if ((TREE_CODE (type) == RECORD_TYPE 4521 || TREE_CODE (type) == UNION_TYPE) 4522 && C_TYPE_FIELDS_READONLY (type)) 4523 diagnose_uninitialized_cst_member (decl, type); 4524 } 4525 4526 invoke_plugin_callbacks (PLUGIN_FINISH_DECL, decl); 4527 } 4528 4529 /* Given a parsed parameter declaration, decode it into a PARM_DECL. 4530 EXPR is NULL or a pointer to an expression that needs to be 4531 evaluated for the side effects of array size expressions in the 4532 parameters. */ 4533 4534 tree 4535 grokparm (const struct c_parm *parm, tree *expr) 4536 { 4537 tree attrs = parm->attrs; 4538 tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, 4539 NULL, &attrs, expr, NULL, DEPRECATED_NORMAL); 4540 4541 decl_attributes (&decl, attrs, 0); 4542 4543 return decl; 4544 } 4545 4546 /* Given a parsed parameter declaration, decode it into a PARM_DECL 4547 and push that on the current scope. EXPR is a pointer to an 4548 expression that needs to be evaluated for the side effects of array 4549 size expressions in the parameters. */ 4550 4551 void 4552 push_parm_decl (const struct c_parm *parm, tree *expr) 4553 { 4554 tree attrs = parm->attrs; 4555 tree decl; 4556 4557 decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL, 4558 &attrs, expr, NULL, DEPRECATED_NORMAL); 4559 decl_attributes (&decl, attrs, 0); 4560 4561 decl = pushdecl (decl); 4562 4563 finish_decl (decl, input_location, NULL_TREE, NULL_TREE, NULL_TREE); 4564 } 4565 4566 /* Mark all the parameter declarations to date as forward decls. 4567 Also diagnose use of this extension. */ 4568 4569 void 4570 mark_forward_parm_decls (void) 4571 { 4572 struct c_binding *b; 4573 4574 if (pedantic && !current_scope->warned_forward_parm_decls) 4575 { 4576 pedwarn (input_location, OPT_pedantic, 4577 "ISO C forbids forward parameter declarations"); 4578 current_scope->warned_forward_parm_decls = true; 4579 } 4580 4581 for (b = current_scope->bindings; b; b = b->prev) 4582 if (TREE_CODE (b->decl) == PARM_DECL) 4583 TREE_ASM_WRITTEN (b->decl) = 1; 4584 } 4585 4586 /* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound 4587 literal, which may be an incomplete array type completed by the 4588 initializer; INIT is a CONSTRUCTOR at LOC that initializes the compound 4589 literal. NON_CONST is true if the initializers contain something 4590 that cannot occur in a constant expression. */ 4591 4592 tree 4593 build_compound_literal (location_t loc, tree type, tree init, bool non_const) 4594 { 4595 /* We do not use start_decl here because we have a type, not a declarator; 4596 and do not use finish_decl because the decl should be stored inside 4597 the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_EXPR. */ 4598 tree decl; 4599 tree complit; 4600 tree stmt; 4601 4602 if (type == error_mark_node 4603 || init == error_mark_node) 4604 return error_mark_node; 4605 4606 decl = build_decl (loc, VAR_DECL, NULL_TREE, type); 4607 DECL_EXTERNAL (decl) = 0; 4608 TREE_PUBLIC (decl) = 0; 4609 TREE_STATIC (decl) = (current_scope == file_scope); 4610 DECL_CONTEXT (decl) = current_function_decl; 4611 TREE_USED (decl) = 1; 4612 DECL_READ_P (decl) = 1; 4613 TREE_TYPE (decl) = type; 4614 TREE_READONLY (decl) = TYPE_READONLY (type); 4615 store_init_value (loc, decl, init, NULL_TREE); 4616 4617 if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type)) 4618 { 4619 int failure = complete_array_type (&TREE_TYPE (decl), 4620 DECL_INITIAL (decl), true); 4621 gcc_assert (!failure); 4622 4623 type = TREE_TYPE (decl); 4624 TREE_TYPE (DECL_INITIAL (decl)) = type; 4625 } 4626 4627 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 4628 return error_mark_node; 4629 4630 stmt = build_stmt (DECL_SOURCE_LOCATION (decl), DECL_EXPR, decl); 4631 complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt); 4632 TREE_SIDE_EFFECTS (complit) = 1; 4633 4634 layout_decl (decl, 0); 4635 4636 if (TREE_STATIC (decl)) 4637 { 4638 /* This decl needs a name for the assembler output. */ 4639 set_compound_literal_name (decl); 4640 DECL_DEFER_OUTPUT (decl) = 1; 4641 DECL_COMDAT (decl) = 1; 4642 DECL_ARTIFICIAL (decl) = 1; 4643 DECL_IGNORED_P (decl) = 1; 4644 pushdecl (decl); 4645 rest_of_decl_compilation (decl, 1, 0); 4646 } 4647 4648 if (non_const) 4649 { 4650 complit = build2 (C_MAYBE_CONST_EXPR, type, NULL, complit); 4651 C_MAYBE_CONST_EXPR_NON_CONST (complit) = 1; 4652 } 4653 4654 return complit; 4655 } 4656 4657 /* Check the type of a compound literal. Here we just check that it 4658 is valid for C++. */ 4659 4660 void 4661 check_compound_literal_type (location_t loc, struct c_type_name *type_name) 4662 { 4663 if (warn_cxx_compat 4664 && (type_name->specs->typespec_kind == ctsk_tagdef 4665 || type_name->specs->typespec_kind == ctsk_tagfirstref)) 4666 warning_at (loc, OPT_Wc___compat, 4667 "defining a type in a compound literal is invalid in C++"); 4668 } 4669 4670 /* Determine whether TYPE is a structure with a flexible array member, 4671 or a union containing such a structure (possibly recursively). */ 4672 4673 static bool 4674 flexible_array_type_p (tree type) 4675 { 4676 tree x; 4677 switch (TREE_CODE (type)) 4678 { 4679 case RECORD_TYPE: 4680 x = TYPE_FIELDS (type); 4681 if (x == NULL_TREE) 4682 return false; 4683 while (DECL_CHAIN (x) != NULL_TREE) 4684 x = DECL_CHAIN (x); 4685 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 4686 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 4687 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 4688 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 4689 return true; 4690 return false; 4691 case UNION_TYPE: 4692 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x)) 4693 { 4694 if (flexible_array_type_p (TREE_TYPE (x))) 4695 return true; 4696 } 4697 return false; 4698 default: 4699 return false; 4700 } 4701 } 4702 4703 /* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 4704 replacing with appropriate values if they are invalid. */ 4705 static void 4706 check_bitfield_type_and_width (tree *type, tree *width, tree orig_name) 4707 { 4708 tree type_mv; 4709 unsigned int max_width; 4710 unsigned HOST_WIDE_INT w; 4711 const char *name = (orig_name 4712 ? identifier_to_locale (IDENTIFIER_POINTER (orig_name)) 4713 : _("<anonymous>")); 4714 4715 /* Detect and ignore out of range field width and process valid 4716 field widths. */ 4717 if (!INTEGRAL_TYPE_P (TREE_TYPE (*width))) 4718 { 4719 error ("bit-field %qs width not an integer constant", name); 4720 *width = integer_one_node; 4721 } 4722 else 4723 { 4724 if (TREE_CODE (*width) != INTEGER_CST) 4725 { 4726 *width = c_fully_fold (*width, false, NULL); 4727 if (TREE_CODE (*width) == INTEGER_CST) 4728 pedwarn (input_location, OPT_pedantic, 4729 "bit-field %qs width not an integer constant expression", 4730 name); 4731 } 4732 if (TREE_CODE (*width) != INTEGER_CST) 4733 { 4734 error ("bit-field %qs width not an integer constant", name); 4735 *width = integer_one_node; 4736 } 4737 constant_expression_warning (*width); 4738 if (tree_int_cst_sgn (*width) < 0) 4739 { 4740 error ("negative width in bit-field %qs", name); 4741 *width = integer_one_node; 4742 } 4743 else if (integer_zerop (*width) && orig_name) 4744 { 4745 error ("zero width for bit-field %qs", name); 4746 *width = integer_one_node; 4747 } 4748 } 4749 4750 /* Detect invalid bit-field type. */ 4751 if (TREE_CODE (*type) != INTEGER_TYPE 4752 && TREE_CODE (*type) != BOOLEAN_TYPE 4753 && TREE_CODE (*type) != ENUMERAL_TYPE) 4754 { 4755 error ("bit-field %qs has invalid type", name); 4756 *type = unsigned_type_node; 4757 } 4758 4759 type_mv = TYPE_MAIN_VARIANT (*type); 4760 if (!in_system_header 4761 && type_mv != integer_type_node 4762 && type_mv != unsigned_type_node 4763 && type_mv != boolean_type_node) 4764 pedwarn (input_location, OPT_pedantic, 4765 "type of bit-field %qs is a GCC extension", name); 4766 4767 max_width = TYPE_PRECISION (*type); 4768 4769 if (0 < compare_tree_int (*width, max_width)) 4770 { 4771 error ("width of %qs exceeds its type", name); 4772 w = max_width; 4773 *width = build_int_cst (integer_type_node, w); 4774 } 4775 else 4776 w = tree_low_cst (*width, 1); 4777 4778 if (TREE_CODE (*type) == ENUMERAL_TYPE) 4779 { 4780 struct lang_type *lt = TYPE_LANG_SPECIFIC (*type); 4781 if (!lt 4782 || w < tree_int_cst_min_precision (lt->enum_min, TYPE_UNSIGNED (*type)) 4783 || w < tree_int_cst_min_precision (lt->enum_max, TYPE_UNSIGNED (*type))) 4784 warning (0, "%qs is narrower than values of its type", name); 4785 } 4786 } 4787 4788 4789 4790 /* Print warning about variable length array if necessary. */ 4791 4792 static void 4793 warn_variable_length_array (tree name, tree size) 4794 { 4795 int const_size = TREE_CONSTANT (size); 4796 4797 if (!flag_isoc99 && pedantic && warn_vla != 0) 4798 { 4799 if (const_size) 4800 { 4801 if (name) 4802 pedwarn (input_location, OPT_Wvla, 4803 "ISO C90 forbids array %qE whose size " 4804 "can%'t be evaluated", 4805 name); 4806 else 4807 pedwarn (input_location, OPT_Wvla, "ISO C90 forbids array whose size " 4808 "can%'t be evaluated"); 4809 } 4810 else 4811 { 4812 if (name) 4813 pedwarn (input_location, OPT_Wvla, 4814 "ISO C90 forbids variable length array %qE", 4815 name); 4816 else 4817 pedwarn (input_location, OPT_Wvla, "ISO C90 forbids variable length array"); 4818 } 4819 } 4820 else if (warn_vla > 0) 4821 { 4822 if (const_size) 4823 { 4824 if (name) 4825 warning (OPT_Wvla, 4826 "the size of array %qE can" 4827 "%'t be evaluated", name); 4828 else 4829 warning (OPT_Wvla, 4830 "the size of array can %'t be evaluated"); 4831 } 4832 else 4833 { 4834 if (name) 4835 warning (OPT_Wvla, 4836 "variable length array %qE is used", 4837 name); 4838 else 4839 warning (OPT_Wvla, 4840 "variable length array is used"); 4841 } 4842 } 4843 } 4844 4845 /* Given declspecs and a declarator, 4846 determine the name and type of the object declared 4847 and construct a ..._DECL node for it. 4848 (In one case we can return a ..._TYPE node instead. 4849 For invalid input we sometimes return 0.) 4850 4851 DECLSPECS is a c_declspecs structure for the declaration specifiers. 4852 4853 DECL_CONTEXT says which syntactic context this declaration is in: 4854 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 4855 FUNCDEF for a function definition. Like NORMAL but a few different 4856 error messages in each case. Return value may be zero meaning 4857 this definition is too screwy to try to parse. 4858 PARM for a parameter declaration (either within a function prototype 4859 or before a function body). Make a PARM_DECL, or return void_type_node. 4860 TYPENAME if for a typename (in a cast or sizeof). 4861 Don't make a DECL node; just return the ..._TYPE node. 4862 FIELD for a struct or union field; make a FIELD_DECL. 4863 INITIALIZED is true if the decl has an initializer. 4864 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 4865 representing the width of the bit-field. 4866 DECL_ATTRS points to the list of attributes that should be added to this 4867 decl. Any nested attributes that belong on the decl itself will be 4868 added to this list. 4869 If EXPR is not NULL, any expressions that need to be evaluated as 4870 part of evaluating variably modified types will be stored in *EXPR. 4871 If EXPR_CONST_OPERANDS is not NULL, *EXPR_CONST_OPERANDS will be 4872 set to indicate whether operands in *EXPR can be used in constant 4873 expressions. 4874 DEPRECATED_STATE is a deprecated_states value indicating whether 4875 deprecation warnings should be suppressed. 4876 4877 In the TYPENAME case, DECLARATOR is really an absolute declarator. 4878 It may also be so in the PARM case, for a prototype where the 4879 argument type is specified but not the name. 4880 4881 This function is where the complicated C meanings of `static' 4882 and `extern' are interpreted. */ 4883 4884 static tree 4885 grokdeclarator (const struct c_declarator *declarator, 4886 struct c_declspecs *declspecs, 4887 enum decl_context decl_context, bool initialized, tree *width, 4888 tree *decl_attrs, tree *expr, bool *expr_const_operands, 4889 enum deprecated_states deprecated_state) 4890 { 4891 tree type = declspecs->type; 4892 bool threadp = declspecs->thread_p; 4893 enum c_storage_class storage_class = declspecs->storage_class; 4894 int constp; 4895 int restrictp; 4896 int volatilep; 4897 int type_quals = TYPE_UNQUALIFIED; 4898 tree name = NULL_TREE; 4899 bool funcdef_flag = false; 4900 bool funcdef_syntax = false; 4901 bool size_varies = false; 4902 tree decl_attr = declspecs->decl_attr; 4903 int array_ptr_quals = TYPE_UNQUALIFIED; 4904 tree array_ptr_attrs = NULL_TREE; 4905 int array_parm_static = 0; 4906 bool array_parm_vla_unspec_p = false; 4907 tree returned_attrs = NULL_TREE; 4908 bool bitfield = width != NULL; 4909 tree element_type; 4910 struct c_arg_info *arg_info = 0; 4911 addr_space_t as1, as2, address_space; 4912 location_t loc = UNKNOWN_LOCATION; 4913 const char *errmsg; 4914 tree expr_dummy; 4915 bool expr_const_operands_dummy; 4916 enum c_declarator_kind first_non_attr_kind; 4917 unsigned int alignas_align = 0; 4918 4919 if (TREE_CODE (type) == ERROR_MARK) 4920 return error_mark_node; 4921 if (expr == NULL) 4922 expr = &expr_dummy; 4923 if (expr_const_operands == NULL) 4924 expr_const_operands = &expr_const_operands_dummy; 4925 4926 *expr = declspecs->expr; 4927 *expr_const_operands = declspecs->expr_const_operands; 4928 4929 if (decl_context == FUNCDEF) 4930 funcdef_flag = true, decl_context = NORMAL; 4931 4932 /* Look inside a declarator for the name being declared 4933 and get it as an IDENTIFIER_NODE, for an error message. */ 4934 { 4935 const struct c_declarator *decl = declarator; 4936 4937 first_non_attr_kind = cdk_attrs; 4938 while (decl) 4939 switch (decl->kind) 4940 { 4941 case cdk_array: 4942 loc = decl->id_loc; 4943 /* FALL THRU. */ 4944 4945 case cdk_function: 4946 case cdk_pointer: 4947 funcdef_syntax = (decl->kind == cdk_function); 4948 decl = decl->declarator; 4949 if (first_non_attr_kind == cdk_attrs) 4950 first_non_attr_kind = decl->kind; 4951 break; 4952 4953 case cdk_attrs: 4954 decl = decl->declarator; 4955 break; 4956 4957 case cdk_id: 4958 loc = decl->id_loc; 4959 if (decl->u.id) 4960 name = decl->u.id; 4961 if (first_non_attr_kind == cdk_attrs) 4962 first_non_attr_kind = decl->kind; 4963 decl = 0; 4964 break; 4965 4966 default: 4967 gcc_unreachable (); 4968 } 4969 if (name == 0) 4970 { 4971 gcc_assert (decl_context == PARM 4972 || decl_context == TYPENAME 4973 || (decl_context == FIELD 4974 && declarator->kind == cdk_id)); 4975 gcc_assert (!initialized); 4976 } 4977 } 4978 4979 /* A function definition's declarator must have the form of 4980 a function declarator. */ 4981 4982 if (funcdef_flag && !funcdef_syntax) 4983 return 0; 4984 4985 /* If this looks like a function definition, make it one, 4986 even if it occurs where parms are expected. 4987 Then store_parm_decls will reject it and not use it as a parm. */ 4988 if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag) 4989 decl_context = PARM; 4990 4991 if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS) 4992 warn_deprecated_use (declspecs->type, declspecs->decl_attr); 4993 4994 if ((decl_context == NORMAL || decl_context == FIELD) 4995 && current_scope == file_scope 4996 && variably_modified_type_p (type, NULL_TREE)) 4997 { 4998 if (name) 4999 error_at (loc, "variably modified %qE at file scope", name); 5000 else 5001 error_at (loc, "variably modified field at file scope"); 5002 type = integer_type_node; 5003 } 5004 5005 size_varies = C_TYPE_VARIABLE_SIZE (type) != 0; 5006 5007 /* Diagnose defaulting to "int". */ 5008 5009 if (declspecs->default_int_p && !in_system_header) 5010 { 5011 /* Issue a warning if this is an ISO C 99 program or if 5012 -Wreturn-type and this is a function, or if -Wimplicit; 5013 prefer the former warning since it is more explicit. */ 5014 if ((warn_implicit_int || warn_return_type || flag_isoc99) 5015 && funcdef_flag) 5016 warn_about_return_type = 1; 5017 else 5018 { 5019 if (name) 5020 pedwarn_c99 (loc, flag_isoc99 ? 0 : OPT_Wimplicit_int, 5021 "type defaults to %<int%> in declaration of %qE", 5022 name); 5023 else 5024 pedwarn_c99 (input_location, flag_isoc99 ? 0 : OPT_Wimplicit_int, 5025 "type defaults to %<int%> in type name"); 5026 } 5027 } 5028 5029 /* Adjust the type if a bit-field is being declared, 5030 -funsigned-bitfields applied and the type is not explicitly 5031 "signed". */ 5032 if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p 5033 && TREE_CODE (type) == INTEGER_TYPE) 5034 type = unsigned_type_for (type); 5035 5036 /* Figure out the type qualifiers for the declaration. There are 5037 two ways a declaration can become qualified. One is something 5038 like `const int i' where the `const' is explicit. Another is 5039 something like `typedef const int CI; CI i' where the type of the 5040 declaration contains the `const'. A third possibility is that 5041 there is a type qualifier on the element type of a typedefed 5042 array type, in which case we should extract that qualifier so 5043 that c_apply_type_quals_to_decl receives the full list of 5044 qualifiers to work with (C90 is not entirely clear about whether 5045 duplicate qualifiers should be diagnosed in this case, but it 5046 seems most appropriate to do so). */ 5047 element_type = strip_array_types (type); 5048 constp = declspecs->const_p + TYPE_READONLY (element_type); 5049 restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type); 5050 volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type); 5051 as1 = declspecs->address_space; 5052 as2 = TYPE_ADDR_SPACE (element_type); 5053 address_space = ADDR_SPACE_GENERIC_P (as1)? as2 : as1; 5054 5055 if (pedantic && !flag_isoc99) 5056 { 5057 if (constp > 1) 5058 pedwarn (loc, OPT_pedantic, "duplicate %<const%>"); 5059 if (restrictp > 1) 5060 pedwarn (loc, OPT_pedantic, "duplicate %<restrict%>"); 5061 if (volatilep > 1) 5062 pedwarn (loc, OPT_pedantic, "duplicate %<volatile%>"); 5063 } 5064 5065 if (!ADDR_SPACE_GENERIC_P (as1) && !ADDR_SPACE_GENERIC_P (as2) && as1 != as2) 5066 error_at (loc, "conflicting named address spaces (%s vs %s)", 5067 c_addr_space_name (as1), c_addr_space_name (as2)); 5068 5069 if ((TREE_CODE (type) == ARRAY_TYPE 5070 || first_non_attr_kind == cdk_array) 5071 && TYPE_QUALS (element_type)) 5072 type = TYPE_MAIN_VARIANT (type); 5073 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 5074 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 5075 | (volatilep ? TYPE_QUAL_VOLATILE : 0) 5076 | ENCODE_QUAL_ADDR_SPACE (address_space)); 5077 5078 /* Warn about storage classes that are invalid for certain 5079 kinds of declarations (parameters, typenames, etc.). */ 5080 5081 if (funcdef_flag 5082 && (threadp 5083 || storage_class == csc_auto 5084 || storage_class == csc_register 5085 || storage_class == csc_typedef)) 5086 { 5087 if (storage_class == csc_auto) 5088 pedwarn (loc, 5089 (current_scope == file_scope) ? 0 : OPT_pedantic, 5090 "function definition declared %<auto%>"); 5091 if (storage_class == csc_register) 5092 error_at (loc, "function definition declared %<register%>"); 5093 if (storage_class == csc_typedef) 5094 error_at (loc, "function definition declared %<typedef%>"); 5095 if (threadp) 5096 error_at (loc, "function definition declared %<__thread%>"); 5097 threadp = false; 5098 if (storage_class == csc_auto 5099 || storage_class == csc_register 5100 || storage_class == csc_typedef) 5101 storage_class = csc_none; 5102 } 5103 else if (decl_context != NORMAL && (storage_class != csc_none || threadp)) 5104 { 5105 if (decl_context == PARM && storage_class == csc_register) 5106 ; 5107 else 5108 { 5109 switch (decl_context) 5110 { 5111 case FIELD: 5112 if (name) 5113 error_at (loc, "storage class specified for structure " 5114 "field %qE", name); 5115 else 5116 error_at (loc, "storage class specified for structure field"); 5117 break; 5118 case PARM: 5119 if (name) 5120 error_at (loc, "storage class specified for parameter %qE", 5121 name); 5122 else 5123 error_at (loc, "storage class specified for unnamed parameter"); 5124 break; 5125 default: 5126 error_at (loc, "storage class specified for typename"); 5127 break; 5128 } 5129 storage_class = csc_none; 5130 threadp = false; 5131 } 5132 } 5133 else if (storage_class == csc_extern 5134 && initialized 5135 && !funcdef_flag) 5136 { 5137 /* 'extern' with initialization is invalid if not at file scope. */ 5138 if (current_scope == file_scope) 5139 { 5140 /* It is fine to have 'extern const' when compiling at C 5141 and C++ intersection. */ 5142 if (!(warn_cxx_compat && constp)) 5143 warning_at (loc, 0, "%qE initialized and declared %<extern%>", 5144 name); 5145 } 5146 else 5147 error_at (loc, "%qE has both %<extern%> and initializer", name); 5148 } 5149 else if (current_scope == file_scope) 5150 { 5151 if (storage_class == csc_auto) 5152 error_at (loc, "file-scope declaration of %qE specifies %<auto%>", 5153 name); 5154 if (pedantic && storage_class == csc_register) 5155 pedwarn (input_location, OPT_pedantic, 5156 "file-scope declaration of %qE specifies %<register%>", name); 5157 } 5158 else 5159 { 5160 if (storage_class == csc_extern && funcdef_flag) 5161 error_at (loc, "nested function %qE declared %<extern%>", name); 5162 else if (threadp && storage_class == csc_none) 5163 { 5164 error_at (loc, "function-scope %qE implicitly auto and declared " 5165 "%<__thread%>", 5166 name); 5167 threadp = false; 5168 } 5169 } 5170 5171 /* Now figure out the structure of the declarator proper. 5172 Descend through it, creating more complex types, until we reach 5173 the declared identifier (or NULL_TREE, in an absolute declarator). 5174 At each stage we maintain an unqualified version of the type 5175 together with any qualifiers that should be applied to it with 5176 c_build_qualified_type; this way, array types including 5177 multidimensional array types are first built up in unqualified 5178 form and then the qualified form is created with 5179 TYPE_MAIN_VARIANT pointing to the unqualified form. */ 5180 5181 while (declarator && declarator->kind != cdk_id) 5182 { 5183 if (type == error_mark_node) 5184 { 5185 declarator = declarator->declarator; 5186 continue; 5187 } 5188 5189 /* Each level of DECLARATOR is either a cdk_array (for ...[..]), 5190 a cdk_pointer (for *...), 5191 a cdk_function (for ...(...)), 5192 a cdk_attrs (for nested attributes), 5193 or a cdk_id (for the name being declared 5194 or the place in an absolute declarator 5195 where the name was omitted). 5196 For the last case, we have just exited the loop. 5197 5198 At this point, TYPE is the type of elements of an array, 5199 or for a function to return, or for a pointer to point to. 5200 After this sequence of ifs, TYPE is the type of the 5201 array or function or pointer, and DECLARATOR has had its 5202 outermost layer removed. */ 5203 5204 if (array_ptr_quals != TYPE_UNQUALIFIED 5205 || array_ptr_attrs != NULL_TREE 5206 || array_parm_static) 5207 { 5208 /* Only the innermost declarator (making a parameter be of 5209 array type which is converted to pointer type) 5210 may have static or type qualifiers. */ 5211 error_at (loc, "static or type qualifiers in non-parameter array declarator"); 5212 array_ptr_quals = TYPE_UNQUALIFIED; 5213 array_ptr_attrs = NULL_TREE; 5214 array_parm_static = 0; 5215 } 5216 5217 switch (declarator->kind) 5218 { 5219 case cdk_attrs: 5220 { 5221 /* A declarator with embedded attributes. */ 5222 tree attrs = declarator->u.attrs; 5223 const struct c_declarator *inner_decl; 5224 int attr_flags = 0; 5225 declarator = declarator->declarator; 5226 inner_decl = declarator; 5227 while (inner_decl->kind == cdk_attrs) 5228 inner_decl = inner_decl->declarator; 5229 if (inner_decl->kind == cdk_id) 5230 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 5231 else if (inner_decl->kind == cdk_function) 5232 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 5233 else if (inner_decl->kind == cdk_array) 5234 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 5235 returned_attrs = decl_attributes (&type, 5236 chainon (returned_attrs, attrs), 5237 attr_flags); 5238 break; 5239 } 5240 case cdk_array: 5241 { 5242 tree itype = NULL_TREE; 5243 tree size = declarator->u.array.dimen; 5244 /* The index is a signed object `sizetype' bits wide. */ 5245 tree index_type = c_common_signed_type (sizetype); 5246 5247 array_ptr_quals = declarator->u.array.quals; 5248 array_ptr_attrs = declarator->u.array.attrs; 5249 array_parm_static = declarator->u.array.static_p; 5250 array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p; 5251 5252 declarator = declarator->declarator; 5253 5254 /* Check for some types that there cannot be arrays of. */ 5255 5256 if (VOID_TYPE_P (type)) 5257 { 5258 if (name) 5259 error_at (loc, "declaration of %qE as array of voids", name); 5260 else 5261 error_at (loc, "declaration of type name as array of voids"); 5262 type = error_mark_node; 5263 } 5264 5265 if (TREE_CODE (type) == FUNCTION_TYPE) 5266 { 5267 if (name) 5268 error_at (loc, "declaration of %qE as array of functions", 5269 name); 5270 else 5271 error_at (loc, "declaration of type name as array of " 5272 "functions"); 5273 type = error_mark_node; 5274 } 5275 5276 if (pedantic && !in_system_header && flexible_array_type_p (type)) 5277 pedwarn (loc, OPT_pedantic, 5278 "invalid use of structure with flexible array member"); 5279 5280 if (size == error_mark_node) 5281 type = error_mark_node; 5282 5283 if (type == error_mark_node) 5284 continue; 5285 5286 /* If size was specified, set ITYPE to a range-type for 5287 that size. Otherwise, ITYPE remains null. finish_decl 5288 may figure it out from an initial value. */ 5289 5290 if (size) 5291 { 5292 bool size_maybe_const = true; 5293 bool size_int_const = (TREE_CODE (size) == INTEGER_CST 5294 && !TREE_OVERFLOW (size)); 5295 bool this_size_varies = false; 5296 5297 /* Strip NON_LVALUE_EXPRs since we aren't using as an 5298 lvalue. */ 5299 STRIP_TYPE_NOPS (size); 5300 5301 if (!INTEGRAL_TYPE_P (TREE_TYPE (size))) 5302 { 5303 if (name) 5304 error_at (loc, "size of array %qE has non-integer type", 5305 name); 5306 else 5307 error_at (loc, 5308 "size of unnamed array has non-integer type"); 5309 size = integer_one_node; 5310 } 5311 5312 size = c_fully_fold (size, false, &size_maybe_const); 5313 5314 if (pedantic && size_maybe_const && integer_zerop (size)) 5315 { 5316 if (name) 5317 pedwarn (loc, OPT_pedantic, 5318 "ISO C forbids zero-size array %qE", name); 5319 else 5320 pedwarn (loc, OPT_pedantic, 5321 "ISO C forbids zero-size array"); 5322 } 5323 5324 if (TREE_CODE (size) == INTEGER_CST && size_maybe_const) 5325 { 5326 constant_expression_warning (size); 5327 if (tree_int_cst_sgn (size) < 0) 5328 { 5329 if (name) 5330 error_at (loc, "size of array %qE is negative", name); 5331 else 5332 error_at (loc, "size of unnamed array is negative"); 5333 size = integer_one_node; 5334 } 5335 /* Handle a size folded to an integer constant but 5336 not an integer constant expression. */ 5337 if (!size_int_const) 5338 { 5339 /* If this is a file scope declaration of an 5340 ordinary identifier, this is invalid code; 5341 diagnosing it here and not subsequently 5342 treating the type as variable-length avoids 5343 more confusing diagnostics later. */ 5344 if ((decl_context == NORMAL || decl_context == FIELD) 5345 && current_scope == file_scope) 5346 pedwarn (input_location, 0, 5347 "variably modified %qE at file scope", 5348 name); 5349 else 5350 this_size_varies = size_varies = true; 5351 warn_variable_length_array (name, size); 5352 } 5353 } 5354 else if ((decl_context == NORMAL || decl_context == FIELD) 5355 && current_scope == file_scope) 5356 { 5357 error_at (loc, "variably modified %qE at file scope", name); 5358 size = integer_one_node; 5359 } 5360 else 5361 { 5362 /* Make sure the array size remains visibly 5363 nonconstant even if it is (eg) a const variable 5364 with known value. */ 5365 this_size_varies = size_varies = true; 5366 warn_variable_length_array (name, size); 5367 } 5368 5369 if (integer_zerop (size) && !this_size_varies) 5370 { 5371 /* A zero-length array cannot be represented with 5372 an unsigned index type, which is what we'll 5373 get with build_index_type. Create an 5374 open-ended range instead. */ 5375 itype = build_range_type (sizetype, size, NULL_TREE); 5376 } 5377 else 5378 { 5379 /* Arrange for the SAVE_EXPR on the inside of the 5380 MINUS_EXPR, which allows the -1 to get folded 5381 with the +1 that happens when building TYPE_SIZE. */ 5382 if (size_varies) 5383 size = save_expr (size); 5384 if (this_size_varies && TREE_CODE (size) == INTEGER_CST) 5385 size = build2 (COMPOUND_EXPR, TREE_TYPE (size), 5386 integer_zero_node, size); 5387 5388 /* Compute the maximum valid index, that is, size 5389 - 1. Do the calculation in index_type, so that 5390 if it is a variable the computations will be 5391 done in the proper mode. */ 5392 itype = fold_build2_loc (loc, MINUS_EXPR, index_type, 5393 convert (index_type, size), 5394 convert (index_type, 5395 size_one_node)); 5396 5397 /* The above overflows when size does not fit 5398 in index_type. 5399 ??? While a size of INT_MAX+1 technically shouldn't 5400 cause an overflow (because we subtract 1), handling 5401 this case seems like an unnecessary complication. */ 5402 if (TREE_CODE (size) == INTEGER_CST 5403 && !int_fits_type_p (size, index_type)) 5404 { 5405 if (name) 5406 error_at (loc, "size of array %qE is too large", 5407 name); 5408 else 5409 error_at (loc, "size of unnamed array is too large"); 5410 type = error_mark_node; 5411 continue; 5412 } 5413 5414 itype = build_index_type (itype); 5415 } 5416 if (this_size_varies) 5417 { 5418 if (*expr) 5419 *expr = build2 (COMPOUND_EXPR, TREE_TYPE (size), 5420 *expr, size); 5421 else 5422 *expr = size; 5423 *expr_const_operands &= size_maybe_const; 5424 } 5425 } 5426 else if (decl_context == FIELD) 5427 { 5428 bool flexible_array_member = false; 5429 if (array_parm_vla_unspec_p) 5430 /* Field names can in fact have function prototype 5431 scope so [*] is disallowed here through making 5432 the field variably modified, not through being 5433 something other than a declaration with function 5434 prototype scope. */ 5435 size_varies = true; 5436 else 5437 { 5438 const struct c_declarator *t = declarator; 5439 while (t->kind == cdk_attrs) 5440 t = t->declarator; 5441 flexible_array_member = (t->kind == cdk_id); 5442 } 5443 if (flexible_array_member 5444 && pedantic && !flag_isoc99 && !in_system_header) 5445 pedwarn (loc, OPT_pedantic, 5446 "ISO C90 does not support flexible array members"); 5447 5448 /* ISO C99 Flexible array members are effectively 5449 identical to GCC's zero-length array extension. */ 5450 if (flexible_array_member || array_parm_vla_unspec_p) 5451 itype = build_range_type (sizetype, size_zero_node, 5452 NULL_TREE); 5453 } 5454 else if (decl_context == PARM) 5455 { 5456 if (array_parm_vla_unspec_p) 5457 { 5458 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 5459 size_varies = true; 5460 } 5461 } 5462 else if (decl_context == TYPENAME) 5463 { 5464 if (array_parm_vla_unspec_p) 5465 { 5466 /* C99 6.7.5.2p4 */ 5467 warning (0, "%<[*]%> not in a declaration"); 5468 /* We use this to avoid messing up with incomplete 5469 array types of the same type, that would 5470 otherwise be modified below. */ 5471 itype = build_range_type (sizetype, size_zero_node, 5472 NULL_TREE); 5473 size_varies = true; 5474 } 5475 } 5476 5477 /* Complain about arrays of incomplete types. */ 5478 if (!COMPLETE_TYPE_P (type)) 5479 { 5480 error_at (loc, "array type has incomplete element type"); 5481 type = error_mark_node; 5482 } 5483 else 5484 /* When itype is NULL, a shared incomplete array type is 5485 returned for all array of a given type. Elsewhere we 5486 make sure we don't complete that type before copying 5487 it, but here we want to make sure we don't ever 5488 modify the shared type, so we gcc_assert (itype) 5489 below. */ 5490 { 5491 addr_space_t as = DECODE_QUAL_ADDR_SPACE (type_quals); 5492 if (!ADDR_SPACE_GENERIC_P (as) && as != TYPE_ADDR_SPACE (type)) 5493 type = build_qualified_type (type, 5494 ENCODE_QUAL_ADDR_SPACE (as)); 5495 5496 type = build_array_type (type, itype); 5497 } 5498 5499 if (type != error_mark_node) 5500 { 5501 if (size_varies) 5502 { 5503 /* It is ok to modify type here even if itype is 5504 NULL: if size_varies, we're in a 5505 multi-dimensional array and the inner type has 5506 variable size, so the enclosing shared array type 5507 must too. */ 5508 if (size && TREE_CODE (size) == INTEGER_CST) 5509 type 5510 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5511 C_TYPE_VARIABLE_SIZE (type) = 1; 5512 } 5513 5514 /* The GCC extension for zero-length arrays differs from 5515 ISO flexible array members in that sizeof yields 5516 zero. */ 5517 if (size && integer_zerop (size)) 5518 { 5519 gcc_assert (itype); 5520 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5521 TYPE_SIZE (type) = bitsize_zero_node; 5522 TYPE_SIZE_UNIT (type) = size_zero_node; 5523 SET_TYPE_STRUCTURAL_EQUALITY (type); 5524 } 5525 if (array_parm_vla_unspec_p) 5526 { 5527 gcc_assert (itype); 5528 /* The type is complete. C99 6.7.5.2p4 */ 5529 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5530 TYPE_SIZE (type) = bitsize_zero_node; 5531 TYPE_SIZE_UNIT (type) = size_zero_node; 5532 SET_TYPE_STRUCTURAL_EQUALITY (type); 5533 } 5534 } 5535 5536 if (decl_context != PARM 5537 && (array_ptr_quals != TYPE_UNQUALIFIED 5538 || array_ptr_attrs != NULL_TREE 5539 || array_parm_static)) 5540 { 5541 error_at (loc, "static or type qualifiers in non-parameter array declarator"); 5542 array_ptr_quals = TYPE_UNQUALIFIED; 5543 array_ptr_attrs = NULL_TREE; 5544 array_parm_static = 0; 5545 } 5546 break; 5547 } 5548 case cdk_function: 5549 { 5550 /* Say it's a definition only for the declarator closest 5551 to the identifier, apart possibly from some 5552 attributes. */ 5553 bool really_funcdef = false; 5554 tree arg_types; 5555 if (funcdef_flag) 5556 { 5557 const struct c_declarator *t = declarator->declarator; 5558 while (t->kind == cdk_attrs) 5559 t = t->declarator; 5560 really_funcdef = (t->kind == cdk_id); 5561 } 5562 5563 /* Declaring a function type. Make sure we have a valid 5564 type for the function to return. */ 5565 if (type == error_mark_node) 5566 continue; 5567 5568 size_varies = false; 5569 5570 /* Warn about some types functions can't return. */ 5571 if (TREE_CODE (type) == FUNCTION_TYPE) 5572 { 5573 if (name) 5574 error_at (loc, "%qE declared as function returning a " 5575 "function", name); 5576 else 5577 error_at (loc, "type name declared as function " 5578 "returning a function"); 5579 type = integer_type_node; 5580 } 5581 if (TREE_CODE (type) == ARRAY_TYPE) 5582 { 5583 if (name) 5584 error_at (loc, "%qE declared as function returning an array", 5585 name); 5586 else 5587 error_at (loc, "type name declared as function returning " 5588 "an array"); 5589 type = integer_type_node; 5590 } 5591 errmsg = targetm.invalid_return_type (type); 5592 if (errmsg) 5593 { 5594 error (errmsg); 5595 type = integer_type_node; 5596 } 5597 5598 /* Construct the function type and go to the next 5599 inner layer of declarator. */ 5600 arg_info = declarator->u.arg_info; 5601 arg_types = grokparms (arg_info, really_funcdef); 5602 5603 /* Type qualifiers before the return type of the function 5604 qualify the return type, not the function type. */ 5605 if (type_quals) 5606 { 5607 /* Type qualifiers on a function return type are 5608 normally permitted by the standard but have no 5609 effect, so give a warning at -Wreturn-type. 5610 Qualifiers on a void return type are banned on 5611 function definitions in ISO C; GCC used to used 5612 them for noreturn functions. */ 5613 if (VOID_TYPE_P (type) && really_funcdef) 5614 pedwarn (loc, 0, 5615 "function definition has qualified void return type"); 5616 else 5617 warning_at (loc, OPT_Wignored_qualifiers, 5618 "type qualifiers ignored on function return type"); 5619 5620 type = c_build_qualified_type (type, type_quals); 5621 } 5622 type_quals = TYPE_UNQUALIFIED; 5623 5624 type = build_function_type (type, arg_types); 5625 declarator = declarator->declarator; 5626 5627 /* Set the TYPE_CONTEXTs for each tagged type which is local to 5628 the formal parameter list of this FUNCTION_TYPE to point to 5629 the FUNCTION_TYPE node itself. */ 5630 { 5631 c_arg_tag *tag; 5632 unsigned ix; 5633 5634 FOR_EACH_VEC_ELT_REVERSE (c_arg_tag, arg_info->tags, ix, tag) 5635 TYPE_CONTEXT (tag->type) = type; 5636 } 5637 break; 5638 } 5639 case cdk_pointer: 5640 { 5641 /* Merge any constancy or volatility into the target type 5642 for the pointer. */ 5643 5644 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5645 && type_quals) 5646 pedwarn (loc, OPT_pedantic, 5647 "ISO C forbids qualified function types"); 5648 if (type_quals) 5649 type = c_build_qualified_type (type, type_quals); 5650 size_varies = false; 5651 5652 /* When the pointed-to type involves components of variable size, 5653 care must be taken to ensure that the size evaluation code is 5654 emitted early enough to dominate all the possible later uses 5655 and late enough for the variables on which it depends to have 5656 been assigned. 5657 5658 This is expected to happen automatically when the pointed-to 5659 type has a name/declaration of it's own, but special attention 5660 is required if the type is anonymous. 5661 5662 We handle the NORMAL and FIELD contexts here by attaching an 5663 artificial TYPE_DECL to such pointed-to type. This forces the 5664 sizes evaluation at a safe point and ensures it is not deferred 5665 until e.g. within a deeper conditional context. 5666 5667 We expect nothing to be needed here for PARM or TYPENAME. 5668 Pushing a TYPE_DECL at this point for TYPENAME would actually 5669 be incorrect, as we might be in the middle of an expression 5670 with side effects on the pointed-to type size "arguments" prior 5671 to the pointer declaration point and the fake TYPE_DECL in the 5672 enclosing context would force the size evaluation prior to the 5673 side effects. */ 5674 5675 if (!TYPE_NAME (type) 5676 && (decl_context == NORMAL || decl_context == FIELD) 5677 && variably_modified_type_p (type, NULL_TREE)) 5678 { 5679 tree decl = build_decl (loc, TYPE_DECL, NULL_TREE, type); 5680 DECL_ARTIFICIAL (decl) = 1; 5681 pushdecl (decl); 5682 finish_decl (decl, loc, NULL_TREE, NULL_TREE, NULL_TREE); 5683 TYPE_NAME (type) = decl; 5684 } 5685 5686 type = build_pointer_type (type); 5687 5688 /* Process type qualifiers (such as const or volatile) 5689 that were given inside the `*'. */ 5690 type_quals = declarator->u.pointer_quals; 5691 5692 declarator = declarator->declarator; 5693 break; 5694 } 5695 default: 5696 gcc_unreachable (); 5697 } 5698 } 5699 *decl_attrs = chainon (returned_attrs, *decl_attrs); 5700 5701 /* Now TYPE has the actual type, apart from any qualifiers in 5702 TYPE_QUALS. */ 5703 5704 /* Warn about address space used for things other than static memory or 5705 pointers. */ 5706 address_space = DECODE_QUAL_ADDR_SPACE (type_quals); 5707 if (!ADDR_SPACE_GENERIC_P (address_space)) 5708 { 5709 if (decl_context == NORMAL) 5710 { 5711 switch (storage_class) 5712 { 5713 case csc_auto: 5714 error ("%qs combined with %<auto%> qualifier for %qE", 5715 c_addr_space_name (address_space), name); 5716 break; 5717 case csc_register: 5718 error ("%qs combined with %<register%> qualifier for %qE", 5719 c_addr_space_name (address_space), name); 5720 break; 5721 case csc_none: 5722 if (current_function_scope) 5723 { 5724 error ("%qs specified for auto variable %qE", 5725 c_addr_space_name (address_space), name); 5726 break; 5727 } 5728 break; 5729 case csc_static: 5730 case csc_extern: 5731 case csc_typedef: 5732 break; 5733 default: 5734 gcc_unreachable (); 5735 } 5736 } 5737 else if (decl_context == PARM && TREE_CODE (type) != ARRAY_TYPE) 5738 { 5739 if (name) 5740 error ("%qs specified for parameter %qE", 5741 c_addr_space_name (address_space), name); 5742 else 5743 error ("%qs specified for unnamed parameter", 5744 c_addr_space_name (address_space)); 5745 } 5746 else if (decl_context == FIELD) 5747 { 5748 if (name) 5749 error ("%qs specified for structure field %qE", 5750 c_addr_space_name (address_space), name); 5751 else 5752 error ("%qs specified for structure field", 5753 c_addr_space_name (address_space)); 5754 } 5755 } 5756 5757 /* Check the type and width of a bit-field. */ 5758 if (bitfield) 5759 check_bitfield_type_and_width (&type, width, name); 5760 5761 /* Reject invalid uses of _Alignas. */ 5762 if (declspecs->alignas_p) 5763 { 5764 if (storage_class == csc_typedef) 5765 error_at (loc, "alignment specified for typedef %qE", name); 5766 else if (storage_class == csc_register) 5767 error_at (loc, "alignment specified for %<register%> object %qE", 5768 name); 5769 else if (decl_context == PARM) 5770 { 5771 if (name) 5772 error_at (loc, "alignment specified for parameter %qE", name); 5773 else 5774 error_at (loc, "alignment specified for unnamed parameter"); 5775 } 5776 else if (bitfield) 5777 { 5778 if (name) 5779 error_at (loc, "alignment specified for bit-field %qE", name); 5780 else 5781 error_at (loc, "alignment specified for unnamed bit-field"); 5782 } 5783 else if (TREE_CODE (type) == FUNCTION_TYPE) 5784 error_at (loc, "alignment specified for function %qE", name); 5785 else if (declspecs->align_log != -1) 5786 { 5787 alignas_align = 1U << declspecs->align_log; 5788 if (alignas_align < TYPE_ALIGN_UNIT (type)) 5789 { 5790 if (name) 5791 error_at (loc, "%<_Alignas%> specifiers cannot reduce " 5792 "alignment of %qE", name); 5793 else 5794 error_at (loc, "%<_Alignas%> specifiers cannot reduce " 5795 "alignment of unnamed field"); 5796 alignas_align = 0; 5797 } 5798 } 5799 } 5800 5801 /* Did array size calculations overflow? */ 5802 5803 if (TREE_CODE (type) == ARRAY_TYPE 5804 && COMPLETE_TYPE_P (type) 5805 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 5806 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 5807 { 5808 if (name) 5809 error_at (loc, "size of array %qE is too large", name); 5810 else 5811 error_at (loc, "size of unnamed array is too large"); 5812 /* If we proceed with the array type as it is, we'll eventually 5813 crash in tree_low_cst(). */ 5814 type = error_mark_node; 5815 } 5816 5817 /* If this is declaring a typedef name, return a TYPE_DECL. */ 5818 5819 if (storage_class == csc_typedef) 5820 { 5821 tree decl; 5822 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5823 && type_quals) 5824 pedwarn (loc, OPT_pedantic, 5825 "ISO C forbids qualified function types"); 5826 if (type_quals) 5827 type = c_build_qualified_type (type, type_quals); 5828 decl = build_decl (declarator->id_loc, 5829 TYPE_DECL, declarator->u.id, type); 5830 if (declspecs->explicit_signed_p) 5831 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 5832 if (declspecs->inline_p) 5833 pedwarn (loc, 0,"typedef %q+D declared %<inline%>", decl); 5834 if (declspecs->noreturn_p) 5835 pedwarn (loc, 0,"typedef %q+D declared %<_Noreturn%>", decl); 5836 5837 if (warn_cxx_compat && declarator->u.id != NULL_TREE) 5838 { 5839 struct c_binding *b = I_TAG_BINDING (declarator->u.id); 5840 5841 if (b != NULL 5842 && b->decl != NULL_TREE 5843 && (B_IN_CURRENT_SCOPE (b) 5844 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 5845 && TYPE_MAIN_VARIANT (b->decl) != TYPE_MAIN_VARIANT (type)) 5846 { 5847 warning_at (declarator->id_loc, OPT_Wc___compat, 5848 ("using %qD as both a typedef and a tag is " 5849 "invalid in C++"), 5850 decl); 5851 if (b->locus != UNKNOWN_LOCATION) 5852 inform (b->locus, "originally defined here"); 5853 } 5854 } 5855 5856 return decl; 5857 } 5858 5859 /* If this is a type name (such as, in a cast or sizeof), 5860 compute the type and return it now. */ 5861 5862 if (decl_context == TYPENAME) 5863 { 5864 /* Note that the grammar rejects storage classes in typenames 5865 and fields. */ 5866 gcc_assert (storage_class == csc_none && !threadp 5867 && !declspecs->inline_p && !declspecs->noreturn_p); 5868 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5869 && type_quals) 5870 pedwarn (loc, OPT_pedantic, 5871 "ISO C forbids const or volatile function types"); 5872 if (type_quals) 5873 type = c_build_qualified_type (type, type_quals); 5874 return type; 5875 } 5876 5877 if (pedantic && decl_context == FIELD 5878 && variably_modified_type_p (type, NULL_TREE)) 5879 { 5880 /* C99 6.7.2.1p8 */ 5881 pedwarn (loc, OPT_pedantic, "a member of a structure or union cannot " 5882 "have a variably modified type"); 5883 } 5884 5885 /* Aside from typedefs and type names (handle above), 5886 `void' at top level (not within pointer) 5887 is allowed only in public variables. 5888 We don't complain about parms either, but that is because 5889 a better error message can be made later. */ 5890 5891 if (VOID_TYPE_P (type) && decl_context != PARM 5892 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 5893 && (storage_class == csc_extern 5894 || (current_scope == file_scope 5895 && !(storage_class == csc_static 5896 || storage_class == csc_register))))) 5897 { 5898 error_at (loc, "variable or field %qE declared void", name); 5899 type = integer_type_node; 5900 } 5901 5902 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 5903 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 5904 5905 { 5906 tree decl; 5907 5908 if (decl_context == PARM) 5909 { 5910 tree promoted_type; 5911 5912 /* A parameter declared as an array of T is really a pointer to T. 5913 One declared as a function is really a pointer to a function. */ 5914 5915 if (TREE_CODE (type) == ARRAY_TYPE) 5916 { 5917 /* Transfer const-ness of array into that of type pointed to. */ 5918 type = TREE_TYPE (type); 5919 if (type_quals) 5920 type = c_build_qualified_type (type, type_quals); 5921 type = build_pointer_type (type); 5922 type_quals = array_ptr_quals; 5923 if (type_quals) 5924 type = c_build_qualified_type (type, type_quals); 5925 5926 /* We don't yet implement attributes in this context. */ 5927 if (array_ptr_attrs != NULL_TREE) 5928 warning_at (loc, OPT_Wattributes, 5929 "attributes in parameter array declarator ignored"); 5930 5931 size_varies = false; 5932 } 5933 else if (TREE_CODE (type) == FUNCTION_TYPE) 5934 { 5935 if (type_quals) 5936 pedwarn (loc, OPT_pedantic, 5937 "ISO C forbids qualified function types"); 5938 if (type_quals) 5939 type = c_build_qualified_type (type, type_quals); 5940 type = build_pointer_type (type); 5941 type_quals = TYPE_UNQUALIFIED; 5942 } 5943 else if (type_quals) 5944 type = c_build_qualified_type (type, type_quals); 5945 5946 decl = build_decl (declarator->id_loc, 5947 PARM_DECL, declarator->u.id, type); 5948 if (size_varies) 5949 C_DECL_VARIABLE_SIZE (decl) = 1; 5950 5951 /* Compute the type actually passed in the parmlist, 5952 for the case where there is no prototype. 5953 (For example, shorts and chars are passed as ints.) 5954 When there is a prototype, this is overridden later. */ 5955 5956 if (type == error_mark_node) 5957 promoted_type = type; 5958 else 5959 promoted_type = c_type_promotes_to (type); 5960 5961 DECL_ARG_TYPE (decl) = promoted_type; 5962 if (declspecs->inline_p) 5963 pedwarn (loc, 0, "parameter %q+D declared %<inline%>", decl); 5964 if (declspecs->noreturn_p) 5965 pedwarn (loc, 0, "parameter %q+D declared %<_Noreturn%>", decl); 5966 } 5967 else if (decl_context == FIELD) 5968 { 5969 /* Note that the grammar rejects storage classes in typenames 5970 and fields. */ 5971 gcc_assert (storage_class == csc_none && !threadp 5972 && !declspecs->inline_p && !declspecs->noreturn_p); 5973 5974 /* Structure field. It may not be a function. */ 5975 5976 if (TREE_CODE (type) == FUNCTION_TYPE) 5977 { 5978 error_at (loc, "field %qE declared as a function", name); 5979 type = build_pointer_type (type); 5980 } 5981 else if (TREE_CODE (type) != ERROR_MARK 5982 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 5983 { 5984 if (name) 5985 error_at (loc, "field %qE has incomplete type", name); 5986 else 5987 error_at (loc, "unnamed field has incomplete type"); 5988 type = error_mark_node; 5989 } 5990 type = c_build_qualified_type (type, type_quals); 5991 decl = build_decl (declarator->id_loc, 5992 FIELD_DECL, declarator->u.id, type); 5993 DECL_NONADDRESSABLE_P (decl) = bitfield; 5994 if (bitfield && !declarator->u.id) 5995 TREE_NO_WARNING (decl) = 1; 5996 5997 if (size_varies) 5998 C_DECL_VARIABLE_SIZE (decl) = 1; 5999 } 6000 else if (TREE_CODE (type) == FUNCTION_TYPE) 6001 { 6002 if (storage_class == csc_register || threadp) 6003 { 6004 error_at (loc, "invalid storage class for function %qE", name); 6005 } 6006 else if (current_scope != file_scope) 6007 { 6008 /* Function declaration not at file scope. Storage 6009 classes other than `extern' are not allowed, C99 6010 6.7.1p5, and `extern' makes no difference. However, 6011 GCC allows 'auto', perhaps with 'inline', to support 6012 nested functions. */ 6013 if (storage_class == csc_auto) 6014 pedwarn (loc, OPT_pedantic, 6015 "invalid storage class for function %qE", name); 6016 else if (storage_class == csc_static) 6017 { 6018 error_at (loc, "invalid storage class for function %qE", name); 6019 if (funcdef_flag) 6020 storage_class = declspecs->storage_class = csc_none; 6021 else 6022 return 0; 6023 } 6024 } 6025 6026 decl = build_decl (declarator->id_loc, 6027 FUNCTION_DECL, declarator->u.id, type); 6028 decl = build_decl_attribute_variant (decl, decl_attr); 6029 6030 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 6031 pedwarn (loc, OPT_pedantic, 6032 "ISO C forbids qualified function types"); 6033 6034 /* Every function declaration is an external reference 6035 (DECL_EXTERNAL) except for those which are not at file 6036 scope and are explicitly declared "auto". This is 6037 forbidden by standard C (C99 6.7.1p5) and is interpreted by 6038 GCC to signify a forward declaration of a nested function. */ 6039 if (storage_class == csc_auto && current_scope != file_scope) 6040 DECL_EXTERNAL (decl) = 0; 6041 /* In C99, a function which is declared 'inline' with 'extern' 6042 is not an external reference (which is confusing). It 6043 means that the later definition of the function must be output 6044 in this file, C99 6.7.4p6. In GNU C89, a function declared 6045 'extern inline' is an external reference. */ 6046 else if (declspecs->inline_p && storage_class != csc_static) 6047 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 6048 == flag_gnu89_inline); 6049 else 6050 DECL_EXTERNAL (decl) = !initialized; 6051 6052 /* Record absence of global scope for `static' or `auto'. */ 6053 TREE_PUBLIC (decl) 6054 = !(storage_class == csc_static || storage_class == csc_auto); 6055 6056 /* For a function definition, record the argument information 6057 block where store_parm_decls will look for it. */ 6058 if (funcdef_flag) 6059 current_function_arg_info = arg_info; 6060 6061 if (declspecs->default_int_p) 6062 C_FUNCTION_IMPLICIT_INT (decl) = 1; 6063 6064 /* Record presence of `inline' and `_Noreturn', if it is 6065 reasonable. */ 6066 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 6067 { 6068 if (declspecs->inline_p) 6069 pedwarn (loc, 0, "cannot inline function %<main%>"); 6070 if (declspecs->noreturn_p) 6071 pedwarn (loc, 0, "%<main%> declared %<_Noreturn%>"); 6072 } 6073 else 6074 { 6075 if (declspecs->inline_p) 6076 /* Record that the function is declared `inline'. */ 6077 DECL_DECLARED_INLINE_P (decl) = 1; 6078 if (declspecs->noreturn_p) 6079 { 6080 if (!flag_isoc11) 6081 { 6082 if (flag_isoc99) 6083 pedwarn (loc, OPT_pedantic, 6084 "ISO C99 does not support %<_Noreturn%>"); 6085 else 6086 pedwarn (loc, OPT_pedantic, 6087 "ISO C90 does not support %<_Noreturn%>"); 6088 } 6089 TREE_THIS_VOLATILE (decl) = 1; 6090 } 6091 } 6092 } 6093 else 6094 { 6095 /* It's a variable. */ 6096 /* An uninitialized decl with `extern' is a reference. */ 6097 int extern_ref = !initialized && storage_class == csc_extern; 6098 6099 type = c_build_qualified_type (type, type_quals); 6100 6101 /* C99 6.2.2p7: It is invalid (compile-time undefined 6102 behavior) to create an 'extern' declaration for a 6103 variable if there is a global declaration that is 6104 'static' and the global declaration is not visible. 6105 (If the static declaration _is_ currently visible, 6106 the 'extern' declaration is taken to refer to that decl.) */ 6107 if (extern_ref && current_scope != file_scope) 6108 { 6109 tree global_decl = identifier_global_value (declarator->u.id); 6110 tree visible_decl = lookup_name (declarator->u.id); 6111 6112 if (global_decl 6113 && global_decl != visible_decl 6114 && TREE_CODE (global_decl) == VAR_DECL 6115 && !TREE_PUBLIC (global_decl)) 6116 error_at (loc, "variable previously declared %<static%> " 6117 "redeclared %<extern%>"); 6118 } 6119 6120 decl = build_decl (declarator->id_loc, 6121 VAR_DECL, declarator->u.id, type); 6122 if (size_varies) 6123 C_DECL_VARIABLE_SIZE (decl) = 1; 6124 6125 if (declspecs->inline_p) 6126 pedwarn (loc, 0, "variable %q+D declared %<inline%>", decl); 6127 if (declspecs->noreturn_p) 6128 pedwarn (loc, 0, "variable %q+D declared %<_Noreturn%>", decl); 6129 6130 /* At file scope, an initialized extern declaration may follow 6131 a static declaration. In that case, DECL_EXTERNAL will be 6132 reset later in start_decl. */ 6133 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 6134 6135 /* At file scope, the presence of a `static' or `register' storage 6136 class specifier, or the absence of all storage class specifiers 6137 makes this declaration a definition (perhaps tentative). Also, 6138 the absence of `static' makes it public. */ 6139 if (current_scope == file_scope) 6140 { 6141 TREE_PUBLIC (decl) = storage_class != csc_static; 6142 TREE_STATIC (decl) = !extern_ref; 6143 } 6144 /* Not at file scope, only `static' makes a static definition. */ 6145 else 6146 { 6147 TREE_STATIC (decl) = (storage_class == csc_static); 6148 TREE_PUBLIC (decl) = extern_ref; 6149 } 6150 6151 if (threadp) 6152 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 6153 } 6154 6155 if ((storage_class == csc_extern 6156 || (storage_class == csc_none 6157 && TREE_CODE (type) == FUNCTION_TYPE 6158 && !funcdef_flag)) 6159 && variably_modified_type_p (type, NULL_TREE)) 6160 { 6161 /* C99 6.7.5.2p2 */ 6162 if (TREE_CODE (type) == FUNCTION_TYPE) 6163 error_at (loc, "non-nested function with variably modified type"); 6164 else 6165 error_at (loc, "object with variably modified type must have " 6166 "no linkage"); 6167 } 6168 6169 /* Record `register' declaration for warnings on & 6170 and in case doing stupid register allocation. */ 6171 6172 if (storage_class == csc_register) 6173 { 6174 C_DECL_REGISTER (decl) = 1; 6175 DECL_REGISTER (decl) = 1; 6176 } 6177 6178 /* Record constancy and volatility. */ 6179 c_apply_type_quals_to_decl (type_quals, decl); 6180 6181 /* Apply _Alignas specifiers. */ 6182 if (alignas_align) 6183 { 6184 DECL_ALIGN (decl) = alignas_align * BITS_PER_UNIT; 6185 DECL_USER_ALIGN (decl) = 1; 6186 } 6187 6188 /* If a type has volatile components, it should be stored in memory. 6189 Otherwise, the fact that those components are volatile 6190 will be ignored, and would even crash the compiler. 6191 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 6192 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 6193 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 6194 || TREE_CODE (decl) == RESULT_DECL)) 6195 { 6196 /* It is not an error for a structure with volatile fields to 6197 be declared register, but reset DECL_REGISTER since it 6198 cannot actually go in a register. */ 6199 int was_reg = C_DECL_REGISTER (decl); 6200 C_DECL_REGISTER (decl) = 0; 6201 DECL_REGISTER (decl) = 0; 6202 c_mark_addressable (decl); 6203 C_DECL_REGISTER (decl) = was_reg; 6204 } 6205 6206 /* This is the earliest point at which we might know the assembler 6207 name of a variable. Thus, if it's known before this, die horribly. */ 6208 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 6209 6210 if (warn_cxx_compat 6211 && TREE_CODE (decl) == VAR_DECL 6212 && TREE_PUBLIC (decl) 6213 && TREE_STATIC (decl) 6214 && (TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 6215 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 6216 || TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE) 6217 && TYPE_NAME (TREE_TYPE (decl)) == NULL_TREE) 6218 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wc___compat, 6219 ("non-local variable %qD with anonymous type is " 6220 "questionable in C++"), 6221 decl); 6222 6223 return decl; 6224 } 6225 } 6226 6227 /* Decode the parameter-list info for a function type or function definition. 6228 The argument is the value returned by `get_parm_info' (or made in c-parse.c 6229 if there is an identifier list instead of a parameter decl list). 6230 These two functions are separate because when a function returns 6231 or receives functions then each is called multiple times but the order 6232 of calls is different. The last call to `grokparms' is always the one 6233 that contains the formal parameter names of a function definition. 6234 6235 Return a list of arg types to use in the FUNCTION_TYPE for this function. 6236 6237 FUNCDEF_FLAG is true for a function definition, false for 6238 a mere declaration. A nonempty identifier-list gets an error message 6239 when FUNCDEF_FLAG is false. */ 6240 6241 static tree 6242 grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 6243 { 6244 tree arg_types = arg_info->types; 6245 6246 if (funcdef_flag && arg_info->had_vla_unspec) 6247 { 6248 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 6249 /* C99 6.7.5.2p4 */ 6250 error ("%<[*]%> not allowed in other than function prototype scope"); 6251 } 6252 6253 if (arg_types == 0 && !funcdef_flag && !in_system_header) 6254 warning (OPT_Wstrict_prototypes, 6255 "function declaration isn%'t a prototype"); 6256 6257 if (arg_types == error_mark_node) 6258 return 0; /* don't set TYPE_ARG_TYPES in this case */ 6259 6260 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 6261 { 6262 if (!funcdef_flag) 6263 { 6264 pedwarn (input_location, 0, "parameter names (without types) in function declaration"); 6265 arg_info->parms = NULL_TREE; 6266 } 6267 else 6268 arg_info->parms = arg_info->types; 6269 6270 arg_info->types = 0; 6271 return 0; 6272 } 6273 else 6274 { 6275 tree parm, type, typelt; 6276 unsigned int parmno; 6277 const char *errmsg; 6278 6279 /* If there is a parameter of incomplete type in a definition, 6280 this is an error. In a declaration this is valid, and a 6281 struct or union type may be completed later, before any calls 6282 or definition of the function. In the case where the tag was 6283 first declared within the parameter list, a warning has 6284 already been given. If a parameter has void type, then 6285 however the function cannot be defined or called, so 6286 warn. */ 6287 6288 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 6289 parm; 6290 parm = DECL_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 6291 { 6292 type = TREE_VALUE (typelt); 6293 if (type == error_mark_node) 6294 continue; 6295 6296 if (!COMPLETE_TYPE_P (type)) 6297 { 6298 if (funcdef_flag) 6299 { 6300 if (DECL_NAME (parm)) 6301 error_at (input_location, 6302 "parameter %u (%q+D) has incomplete type", 6303 parmno, parm); 6304 else 6305 error_at (DECL_SOURCE_LOCATION (parm), 6306 "parameter %u has incomplete type", 6307 parmno); 6308 6309 TREE_VALUE (typelt) = error_mark_node; 6310 TREE_TYPE (parm) = error_mark_node; 6311 arg_types = NULL_TREE; 6312 } 6313 else if (VOID_TYPE_P (type)) 6314 { 6315 if (DECL_NAME (parm)) 6316 warning_at (input_location, 0, 6317 "parameter %u (%q+D) has void type", 6318 parmno, parm); 6319 else 6320 warning_at (DECL_SOURCE_LOCATION (parm), 0, 6321 "parameter %u has void type", 6322 parmno); 6323 } 6324 } 6325 6326 errmsg = targetm.invalid_parameter_type (type); 6327 if (errmsg) 6328 { 6329 error (errmsg); 6330 TREE_VALUE (typelt) = error_mark_node; 6331 TREE_TYPE (parm) = error_mark_node; 6332 arg_types = NULL_TREE; 6333 } 6334 6335 if (DECL_NAME (parm) && TREE_USED (parm)) 6336 warn_if_shadowing (parm); 6337 } 6338 return arg_types; 6339 } 6340 } 6341 6342 /* Allocate and initialize a c_arg_info structure from the parser's 6343 obstack. */ 6344 6345 struct c_arg_info * 6346 build_arg_info (void) 6347 { 6348 struct c_arg_info *ret = XOBNEW (&parser_obstack, struct c_arg_info); 6349 ret->parms = NULL_TREE; 6350 ret->tags = NULL; 6351 ret->types = NULL_TREE; 6352 ret->others = NULL_TREE; 6353 ret->pending_sizes = NULL; 6354 ret->had_vla_unspec = 0; 6355 return ret; 6356 } 6357 6358 /* Take apart the current scope and return a c_arg_info structure with 6359 info on a parameter list just parsed. 6360 6361 This structure is later fed to 'grokparms' and 'store_parm_decls'. 6362 6363 ELLIPSIS being true means the argument list ended in '...' so don't 6364 append a sentinel (void_list_node) to the end of the type-list. 6365 6366 EXPR is NULL or an expression that needs to be evaluated for the 6367 side effects of array size expressions in the parameters. */ 6368 6369 struct c_arg_info * 6370 get_parm_info (bool ellipsis, tree expr) 6371 { 6372 struct c_binding *b = current_scope->bindings; 6373 struct c_arg_info *arg_info = build_arg_info (); 6374 6375 tree parms = 0; 6376 VEC(c_arg_tag,gc) *tags = NULL; 6377 tree types = 0; 6378 tree others = 0; 6379 6380 static bool explained_incomplete_types = false; 6381 bool gave_void_only_once_err = false; 6382 6383 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 6384 6385 /* The bindings in this scope must not get put into a block. 6386 We will take care of deleting the binding nodes. */ 6387 current_scope->bindings = 0; 6388 6389 /* This function is only called if there was *something* on the 6390 parameter list. */ 6391 gcc_assert (b); 6392 6393 /* A parameter list consisting solely of 'void' indicates that the 6394 function takes no arguments. But if the 'void' is qualified 6395 (by 'const' or 'volatile'), or has a storage class specifier 6396 ('register'), then the behavior is undefined; issue an error. 6397 Typedefs for 'void' are OK (see DR#157). */ 6398 if (b->prev == 0 /* one binding */ 6399 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 6400 && !DECL_NAME (b->decl) /* anonymous */ 6401 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 6402 { 6403 if (TREE_THIS_VOLATILE (b->decl) 6404 || TREE_READONLY (b->decl) 6405 || C_DECL_REGISTER (b->decl)) 6406 error ("%<void%> as only parameter may not be qualified"); 6407 6408 /* There cannot be an ellipsis. */ 6409 if (ellipsis) 6410 error ("%<void%> must be the only parameter"); 6411 6412 arg_info->types = void_list_node; 6413 return arg_info; 6414 } 6415 6416 if (!ellipsis) 6417 types = void_list_node; 6418 6419 /* Break up the bindings list into parms, tags, types, and others; 6420 apply sanity checks; purge the name-to-decl bindings. */ 6421 while (b) 6422 { 6423 tree decl = b->decl; 6424 tree type = TREE_TYPE (decl); 6425 c_arg_tag *tag; 6426 const char *keyword; 6427 6428 switch (TREE_CODE (decl)) 6429 { 6430 case PARM_DECL: 6431 if (b->id) 6432 { 6433 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 6434 I_SYMBOL_BINDING (b->id) = b->shadowed; 6435 } 6436 6437 /* Check for forward decls that never got their actual decl. */ 6438 if (TREE_ASM_WRITTEN (decl)) 6439 error ("parameter %q+D has just a forward declaration", decl); 6440 /* Check for (..., void, ...) and issue an error. */ 6441 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 6442 { 6443 if (!gave_void_only_once_err) 6444 { 6445 error ("%<void%> must be the only parameter"); 6446 gave_void_only_once_err = true; 6447 } 6448 } 6449 else 6450 { 6451 /* Valid parameter, add it to the list. */ 6452 DECL_CHAIN (decl) = parms; 6453 parms = decl; 6454 6455 /* Since there is a prototype, args are passed in their 6456 declared types. The back end may override this later. */ 6457 DECL_ARG_TYPE (decl) = type; 6458 types = tree_cons (0, type, types); 6459 } 6460 break; 6461 6462 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 6463 case UNION_TYPE: keyword = "union"; goto tag; 6464 case RECORD_TYPE: keyword = "struct"; goto tag; 6465 tag: 6466 /* Types may not have tag-names, in which case the type 6467 appears in the bindings list with b->id NULL. */ 6468 if (b->id) 6469 { 6470 gcc_assert (I_TAG_BINDING (b->id) == b); 6471 I_TAG_BINDING (b->id) = b->shadowed; 6472 } 6473 6474 /* Warn about any struct, union or enum tags defined in a 6475 parameter list. The scope of such types is limited to 6476 the parameter list, which is rarely if ever desirable 6477 (it's impossible to call such a function with type- 6478 correct arguments). An anonymous union parm type is 6479 meaningful as a GNU extension, so don't warn for that. */ 6480 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 6481 { 6482 if (b->id) 6483 /* The %s will be one of 'struct', 'union', or 'enum'. */ 6484 warning (0, "%<%s %E%> declared inside parameter list", 6485 keyword, b->id); 6486 else 6487 /* The %s will be one of 'struct', 'union', or 'enum'. */ 6488 warning (0, "anonymous %s declared inside parameter list", 6489 keyword); 6490 6491 if (!explained_incomplete_types) 6492 { 6493 warning (0, "its scope is only this definition or declaration," 6494 " which is probably not what you want"); 6495 explained_incomplete_types = true; 6496 } 6497 } 6498 6499 tag = VEC_safe_push (c_arg_tag, gc, tags, NULL); 6500 tag->id = b->id; 6501 tag->type = decl; 6502 break; 6503 6504 case CONST_DECL: 6505 case TYPE_DECL: 6506 case FUNCTION_DECL: 6507 /* CONST_DECLs appear here when we have an embedded enum, 6508 and TYPE_DECLs appear here when we have an embedded struct 6509 or union. No warnings for this - we already warned about the 6510 type itself. FUNCTION_DECLs appear when there is an implicit 6511 function declaration in the parameter list. */ 6512 6513 /* When we reinsert this decl in the function body, we need 6514 to reconstruct whether it was marked as nested. */ 6515 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 6516 ? b->nested 6517 : !b->nested); 6518 DECL_CHAIN (decl) = others; 6519 others = decl; 6520 /* fall through */ 6521 6522 case ERROR_MARK: 6523 /* error_mark_node appears here when we have an undeclared 6524 variable. Just throw it away. */ 6525 if (b->id) 6526 { 6527 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 6528 I_SYMBOL_BINDING (b->id) = b->shadowed; 6529 } 6530 break; 6531 6532 /* Other things that might be encountered. */ 6533 case LABEL_DECL: 6534 case VAR_DECL: 6535 default: 6536 gcc_unreachable (); 6537 } 6538 6539 b = free_binding_and_advance (b); 6540 } 6541 6542 arg_info->parms = parms; 6543 arg_info->tags = tags; 6544 arg_info->types = types; 6545 arg_info->others = others; 6546 arg_info->pending_sizes = expr; 6547 return arg_info; 6548 } 6549 6550 /* Get the struct, enum or union (CODE says which) with tag NAME. 6551 Define the tag as a forward-reference with location LOC if it is 6552 not defined. Return a c_typespec structure for the type 6553 specifier. */ 6554 6555 struct c_typespec 6556 parser_xref_tag (location_t loc, enum tree_code code, tree name) 6557 { 6558 struct c_typespec ret; 6559 tree ref; 6560 location_t refloc; 6561 6562 ret.expr = NULL_TREE; 6563 ret.expr_const_operands = true; 6564 6565 /* If a cross reference is requested, look up the type 6566 already defined for this tag and return it. */ 6567 6568 ref = lookup_tag (code, name, 0, &refloc); 6569 /* If this is the right type of tag, return what we found. 6570 (This reference will be shadowed by shadow_tag later if appropriate.) 6571 If this is the wrong type of tag, do not return it. If it was the 6572 wrong type in the same scope, we will have had an error 6573 message already; if in a different scope and declaring 6574 a name, pending_xref_error will give an error message; but if in a 6575 different scope and not declaring a name, this tag should 6576 shadow the previous declaration of a different type of tag, and 6577 this would not work properly if we return the reference found. 6578 (For example, with "struct foo" in an outer scope, "union foo;" 6579 must shadow that tag with a new one of union type.) */ 6580 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 6581 if (ref && TREE_CODE (ref) == code) 6582 { 6583 if (C_TYPE_DEFINED_IN_STRUCT (ref) 6584 && loc != UNKNOWN_LOCATION 6585 && warn_cxx_compat) 6586 { 6587 switch (code) 6588 { 6589 case ENUMERAL_TYPE: 6590 warning_at (loc, OPT_Wc___compat, 6591 ("enum type defined in struct or union " 6592 "is not visible in C++")); 6593 inform (refloc, "enum type defined here"); 6594 break; 6595 case RECORD_TYPE: 6596 warning_at (loc, OPT_Wc___compat, 6597 ("struct defined in struct or union " 6598 "is not visible in C++")); 6599 inform (refloc, "struct defined here"); 6600 break; 6601 case UNION_TYPE: 6602 warning_at (loc, OPT_Wc___compat, 6603 ("union defined in struct or union " 6604 "is not visible in C++")); 6605 inform (refloc, "union defined here"); 6606 break; 6607 default: 6608 gcc_unreachable(); 6609 } 6610 } 6611 6612 ret.spec = ref; 6613 return ret; 6614 } 6615 6616 /* If no such tag is yet defined, create a forward-reference node 6617 and record it as the "definition". 6618 When a real declaration of this type is found, 6619 the forward-reference will be altered into a real type. */ 6620 6621 ref = make_node (code); 6622 if (code == ENUMERAL_TYPE) 6623 { 6624 /* Give the type a default layout like unsigned int 6625 to avoid crashing if it does not get defined. */ 6626 SET_TYPE_MODE (ref, TYPE_MODE (unsigned_type_node)); 6627 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 6628 TYPE_USER_ALIGN (ref) = 0; 6629 TYPE_UNSIGNED (ref) = 1; 6630 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 6631 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 6632 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 6633 } 6634 6635 pushtag (loc, name, ref); 6636 6637 ret.spec = ref; 6638 return ret; 6639 } 6640 6641 /* Get the struct, enum or union (CODE says which) with tag NAME. 6642 Define the tag as a forward-reference if it is not defined. 6643 Return a tree for the type. */ 6644 6645 tree 6646 xref_tag (enum tree_code code, tree name) 6647 { 6648 return parser_xref_tag (input_location, code, name).spec; 6649 } 6650 6651 /* Make sure that the tag NAME is defined *in the current scope* 6652 at least as a forward reference. 6653 LOC is the location of the struct's definition. 6654 CODE says which kind of tag NAME ought to be. 6655 6656 This stores the current value of the file static STRUCT_PARSE_INFO 6657 in *ENCLOSING_STRUCT_PARSE_INFO, and points STRUCT_PARSE_INFO at a 6658 new c_struct_parse_info structure. The old value of 6659 STRUCT_PARSE_INFO is restored in finish_struct. */ 6660 6661 tree 6662 start_struct (location_t loc, enum tree_code code, tree name, 6663 struct c_struct_parse_info **enclosing_struct_parse_info) 6664 { 6665 /* If there is already a tag defined at this scope 6666 (as a forward reference), just return it. */ 6667 6668 tree ref = NULL_TREE; 6669 location_t refloc = UNKNOWN_LOCATION; 6670 6671 if (name != NULL_TREE) 6672 ref = lookup_tag (code, name, 1, &refloc); 6673 if (ref && TREE_CODE (ref) == code) 6674 { 6675 if (TYPE_SIZE (ref)) 6676 { 6677 if (code == UNION_TYPE) 6678 error_at (loc, "redefinition of %<union %E%>", name); 6679 else 6680 error_at (loc, "redefinition of %<struct %E%>", name); 6681 if (refloc != UNKNOWN_LOCATION) 6682 inform (refloc, "originally defined here"); 6683 /* Don't create structures using a name already in use. */ 6684 ref = NULL_TREE; 6685 } 6686 else if (C_TYPE_BEING_DEFINED (ref)) 6687 { 6688 if (code == UNION_TYPE) 6689 error_at (loc, "nested redefinition of %<union %E%>", name); 6690 else 6691 error_at (loc, "nested redefinition of %<struct %E%>", name); 6692 /* Don't bother to report "originally defined here" for a 6693 nested redefinition; the original definition should be 6694 obvious. */ 6695 /* Don't create structures that contain themselves. */ 6696 ref = NULL_TREE; 6697 } 6698 } 6699 6700 /* Otherwise create a forward-reference just so the tag is in scope. */ 6701 6702 if (ref == NULL_TREE || TREE_CODE (ref) != code) 6703 { 6704 ref = make_node (code); 6705 pushtag (loc, name, ref); 6706 } 6707 6708 C_TYPE_BEING_DEFINED (ref) = 1; 6709 TYPE_PACKED (ref) = flag_pack_struct; 6710 6711 *enclosing_struct_parse_info = struct_parse_info; 6712 struct_parse_info = XNEW (struct c_struct_parse_info); 6713 struct_parse_info->struct_types = VEC_alloc (tree, heap, 0); 6714 struct_parse_info->fields = VEC_alloc (c_binding_ptr, heap, 0); 6715 struct_parse_info->typedefs_seen = VEC_alloc (tree, heap, 0); 6716 6717 /* FIXME: This will issue a warning for a use of a type defined 6718 within a statement expr used within sizeof, et. al. This is not 6719 terribly serious as C++ doesn't permit statement exprs within 6720 sizeof anyhow. */ 6721 if (warn_cxx_compat && (in_sizeof || in_typeof || in_alignof)) 6722 warning_at (loc, OPT_Wc___compat, 6723 "defining type in %qs expression is invalid in C++", 6724 (in_sizeof 6725 ? "sizeof" 6726 : (in_typeof ? "typeof" : "alignof"))); 6727 6728 return ref; 6729 } 6730 6731 /* Process the specs, declarator and width (NULL if omitted) 6732 of a structure component, returning a FIELD_DECL node. 6733 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 6734 DECL_ATTRS is as for grokdeclarator. 6735 6736 LOC is the location of the structure component. 6737 6738 This is done during the parsing of the struct declaration. 6739 The FIELD_DECL nodes are chained together and the lot of them 6740 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 6741 6742 tree 6743 grokfield (location_t loc, 6744 struct c_declarator *declarator, struct c_declspecs *declspecs, 6745 tree width, tree *decl_attrs) 6746 { 6747 tree value; 6748 6749 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 6750 && width == NULL_TREE) 6751 { 6752 /* This is an unnamed decl. 6753 6754 If we have something of the form "union { list } ;" then this 6755 is the anonymous union extension. Similarly for struct. 6756 6757 If this is something of the form "struct foo;", then 6758 If MS or Plan 9 extensions are enabled, this is handled as 6759 an anonymous struct. 6760 Otherwise this is a forward declaration of a structure tag. 6761 6762 If this is something of the form "foo;" and foo is a TYPE_DECL, then 6763 If foo names a structure or union without a tag, then this 6764 is an anonymous struct (this is permitted by C11). 6765 If MS or Plan 9 extensions are enabled and foo names a 6766 structure, then again this is an anonymous struct. 6767 Otherwise this is an error. 6768 6769 Oh what a horrid tangled web we weave. I wonder if MS consciously 6770 took this from Plan 9 or if it was an accident of implementation 6771 that took root before someone noticed the bug... */ 6772 6773 tree type = declspecs->type; 6774 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 6775 || TREE_CODE (type) == UNION_TYPE); 6776 bool ok = false; 6777 6778 if (type_ok 6779 && (flag_ms_extensions 6780 || flag_plan9_extensions 6781 || !declspecs->typedef_p)) 6782 { 6783 if (flag_ms_extensions || flag_plan9_extensions) 6784 ok = true; 6785 else if (TYPE_NAME (type) == NULL) 6786 ok = true; 6787 else 6788 ok = false; 6789 } 6790 if (!ok) 6791 { 6792 pedwarn (loc, 0, "declaration does not declare anything"); 6793 return NULL_TREE; 6794 } 6795 if (!flag_isoc11) 6796 { 6797 if (flag_isoc99) 6798 pedwarn (loc, OPT_pedantic, 6799 "ISO C99 doesn%'t support unnamed structs/unions"); 6800 else 6801 pedwarn (loc, OPT_pedantic, 6802 "ISO C90 doesn%'t support unnamed structs/unions"); 6803 } 6804 } 6805 6806 value = grokdeclarator (declarator, declspecs, FIELD, false, 6807 width ? &width : NULL, decl_attrs, NULL, NULL, 6808 DEPRECATED_NORMAL); 6809 6810 finish_decl (value, loc, NULL_TREE, NULL_TREE, NULL_TREE); 6811 DECL_INITIAL (value) = width; 6812 6813 if (warn_cxx_compat && DECL_NAME (value) != NULL_TREE) 6814 { 6815 /* If we currently have a binding for this field, set the 6816 in_struct field in the binding, so that we warn about lookups 6817 which find it. */ 6818 struct c_binding *b = I_SYMBOL_BINDING (DECL_NAME (value)); 6819 if (b != NULL) 6820 { 6821 /* If the in_struct field is not yet set, push it on a list 6822 to be cleared when this struct is finished. */ 6823 if (!b->in_struct) 6824 { 6825 VEC_safe_push (c_binding_ptr, heap, 6826 struct_parse_info->fields, b); 6827 b->in_struct = 1; 6828 } 6829 } 6830 } 6831 6832 return value; 6833 } 6834 6835 /* Subroutine of detect_field_duplicates: return whether X and Y, 6836 which are both fields in the same struct, have duplicate field 6837 names. */ 6838 6839 static bool 6840 is_duplicate_field (tree x, tree y) 6841 { 6842 if (DECL_NAME (x) != NULL_TREE && DECL_NAME (x) == DECL_NAME (y)) 6843 return true; 6844 6845 /* When using -fplan9-extensions, an anonymous field whose name is a 6846 typedef can duplicate a field name. */ 6847 if (flag_plan9_extensions 6848 && (DECL_NAME (x) == NULL_TREE || DECL_NAME (y) == NULL_TREE)) 6849 { 6850 tree xt, xn, yt, yn; 6851 6852 xt = TREE_TYPE (x); 6853 if (DECL_NAME (x) != NULL_TREE) 6854 xn = DECL_NAME (x); 6855 else if ((TREE_CODE (xt) == RECORD_TYPE || TREE_CODE (xt) == UNION_TYPE) 6856 && TYPE_NAME (xt) != NULL_TREE 6857 && TREE_CODE (TYPE_NAME (xt)) == TYPE_DECL) 6858 xn = DECL_NAME (TYPE_NAME (xt)); 6859 else 6860 xn = NULL_TREE; 6861 6862 yt = TREE_TYPE (y); 6863 if (DECL_NAME (y) != NULL_TREE) 6864 yn = DECL_NAME (y); 6865 else if ((TREE_CODE (yt) == RECORD_TYPE || TREE_CODE (yt) == UNION_TYPE) 6866 && TYPE_NAME (yt) != NULL_TREE 6867 && TREE_CODE (TYPE_NAME (yt)) == TYPE_DECL) 6868 yn = DECL_NAME (TYPE_NAME (yt)); 6869 else 6870 yn = NULL_TREE; 6871 6872 if (xn != NULL_TREE && xn == yn) 6873 return true; 6874 } 6875 6876 return false; 6877 } 6878 6879 /* Subroutine of detect_field_duplicates: add the fields of FIELDLIST 6880 to HTAB, giving errors for any duplicates. */ 6881 6882 static void 6883 detect_field_duplicates_hash (tree fieldlist, htab_t htab) 6884 { 6885 tree x, y; 6886 void **slot; 6887 6888 for (x = fieldlist; x ; x = DECL_CHAIN (x)) 6889 if ((y = DECL_NAME (x)) != 0) 6890 { 6891 slot = htab_find_slot (htab, y, INSERT); 6892 if (*slot) 6893 { 6894 error ("duplicate member %q+D", x); 6895 DECL_NAME (x) = NULL_TREE; 6896 } 6897 *slot = y; 6898 } 6899 else if (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6900 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 6901 { 6902 detect_field_duplicates_hash (TYPE_FIELDS (TREE_TYPE (x)), htab); 6903 6904 /* When using -fplan9-extensions, an anonymous field whose 6905 name is a typedef can duplicate a field name. */ 6906 if (flag_plan9_extensions 6907 && TYPE_NAME (TREE_TYPE (x)) != NULL_TREE 6908 && TREE_CODE (TYPE_NAME (TREE_TYPE (x))) == TYPE_DECL) 6909 { 6910 tree xn = DECL_NAME (TYPE_NAME (TREE_TYPE (x))); 6911 slot = htab_find_slot (htab, xn, INSERT); 6912 if (*slot) 6913 error ("duplicate member %q+D", TYPE_NAME (TREE_TYPE (x))); 6914 *slot = xn; 6915 } 6916 } 6917 } 6918 6919 /* Generate an error for any duplicate field names in FIELDLIST. Munge 6920 the list such that this does not present a problem later. */ 6921 6922 static void 6923 detect_field_duplicates (tree fieldlist) 6924 { 6925 tree x, y; 6926 int timeout = 10; 6927 6928 /* If the struct is the list of instance variables of an Objective-C 6929 class, then we need to check all the instance variables of 6930 superclasses when checking for duplicates (since you can't have 6931 an instance variable in a subclass with the same name as an 6932 instance variable in a superclass). We pass on this job to the 6933 Objective-C compiler. objc_detect_field_duplicates() will return 6934 false if we are not checking the list of instance variables and 6935 the C frontend should proceed with the standard field duplicate 6936 checks. If we are checking the list of instance variables, the 6937 ObjC frontend will do the check, emit the errors if needed, and 6938 then return true. */ 6939 if (c_dialect_objc ()) 6940 if (objc_detect_field_duplicates (false)) 6941 return; 6942 6943 /* First, see if there are more than "a few" fields. 6944 This is trivially true if there are zero or one fields. */ 6945 if (!fieldlist || !DECL_CHAIN (fieldlist)) 6946 return; 6947 x = fieldlist; 6948 do { 6949 timeout--; 6950 if (DECL_NAME (x) == NULL_TREE 6951 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6952 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE)) 6953 timeout = 0; 6954 x = DECL_CHAIN (x); 6955 } while (timeout > 0 && x); 6956 6957 /* If there were "few" fields and no anonymous structures or unions, 6958 avoid the overhead of allocating a hash table. Instead just do 6959 the nested traversal thing. */ 6960 if (timeout > 0) 6961 { 6962 for (x = DECL_CHAIN (fieldlist); x; x = DECL_CHAIN (x)) 6963 /* When using -fplan9-extensions, we can have duplicates 6964 between typedef names and fields. */ 6965 if (DECL_NAME (x) 6966 || (flag_plan9_extensions 6967 && DECL_NAME (x) == NULL_TREE 6968 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6969 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 6970 && TYPE_NAME (TREE_TYPE (x)) != NULL_TREE 6971 && TREE_CODE (TYPE_NAME (TREE_TYPE (x))) == TYPE_DECL)) 6972 { 6973 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 6974 if (is_duplicate_field (y, x)) 6975 { 6976 error ("duplicate member %q+D", x); 6977 DECL_NAME (x) = NULL_TREE; 6978 } 6979 } 6980 } 6981 else 6982 { 6983 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 6984 6985 detect_field_duplicates_hash (fieldlist, htab); 6986 htab_delete (htab); 6987 } 6988 } 6989 6990 /* Finish up struct info used by -Wc++-compat. */ 6991 6992 static void 6993 warn_cxx_compat_finish_struct (tree fieldlist) 6994 { 6995 unsigned int ix; 6996 tree x; 6997 struct c_binding *b; 6998 6999 /* Set the C_TYPE_DEFINED_IN_STRUCT flag for each type defined in 7000 the current struct. We do this now at the end of the struct 7001 because the flag is used to issue visibility warnings, and we 7002 only want to issue those warnings if the type is referenced 7003 outside of the struct declaration. */ 7004 FOR_EACH_VEC_ELT (tree, struct_parse_info->struct_types, ix, x) 7005 C_TYPE_DEFINED_IN_STRUCT (x) = 1; 7006 7007 /* The TYPEDEFS_SEEN field of STRUCT_PARSE_INFO is a list of 7008 typedefs used when declaring fields in this struct. If the name 7009 of any of the fields is also a typedef name then the struct would 7010 not parse in C++, because the C++ lookup rules say that the 7011 typedef name would be looked up in the context of the struct, and 7012 would thus be the field rather than the typedef. */ 7013 if (!VEC_empty (tree, struct_parse_info->typedefs_seen) 7014 && fieldlist != NULL_TREE) 7015 { 7016 /* Use a pointer_set using the name of the typedef. We can use 7017 a pointer_set because identifiers are interned. */ 7018 struct pointer_set_t *tset = pointer_set_create (); 7019 7020 FOR_EACH_VEC_ELT (tree, struct_parse_info->typedefs_seen, ix, x) 7021 pointer_set_insert (tset, DECL_NAME (x)); 7022 7023 for (x = fieldlist; x != NULL_TREE; x = DECL_CHAIN (x)) 7024 { 7025 if (DECL_NAME (x) != NULL_TREE 7026 && pointer_set_contains (tset, DECL_NAME (x))) 7027 { 7028 warning_at (DECL_SOURCE_LOCATION (x), OPT_Wc___compat, 7029 ("using %qD as both field and typedef name is " 7030 "invalid in C++"), 7031 x); 7032 /* FIXME: It would be nice to report the location where 7033 the typedef name is used. */ 7034 } 7035 } 7036 7037 pointer_set_destroy (tset); 7038 } 7039 7040 /* For each field which has a binding and which was not defined in 7041 an enclosing struct, clear the in_struct field. */ 7042 FOR_EACH_VEC_ELT (c_binding_ptr, struct_parse_info->fields, ix, b) 7043 b->in_struct = 0; 7044 } 7045 7046 /* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 7047 LOC is the location of the RECORD_TYPE or UNION_TYPE's definition. 7048 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 7049 ATTRIBUTES are attributes to be applied to the structure. 7050 7051 ENCLOSING_STRUCT_PARSE_INFO is the value of STRUCT_PARSE_INFO when 7052 the struct was started. */ 7053 7054 tree 7055 finish_struct (location_t loc, tree t, tree fieldlist, tree attributes, 7056 struct c_struct_parse_info *enclosing_struct_parse_info) 7057 { 7058 tree x; 7059 bool toplevel = file_scope == current_scope; 7060 int saw_named_field; 7061 7062 /* If this type was previously laid out as a forward reference, 7063 make sure we lay it out again. */ 7064 7065 TYPE_SIZE (t) = 0; 7066 7067 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7068 7069 if (pedantic) 7070 { 7071 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7072 { 7073 if (DECL_NAME (x) != 0) 7074 break; 7075 if (flag_isoc11 7076 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 7077 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE)) 7078 break; 7079 } 7080 7081 if (x == 0) 7082 { 7083 if (TREE_CODE (t) == UNION_TYPE) 7084 { 7085 if (fieldlist) 7086 pedwarn (loc, OPT_pedantic, "union has no named members"); 7087 else 7088 pedwarn (loc, OPT_pedantic, "union has no members"); 7089 } 7090 else 7091 { 7092 if (fieldlist) 7093 pedwarn (loc, OPT_pedantic, "struct has no named members"); 7094 else 7095 pedwarn (loc, OPT_pedantic, "struct has no members"); 7096 } 7097 } 7098 } 7099 7100 /* Install struct as DECL_CONTEXT of each field decl. 7101 Also process specified field sizes, found in the DECL_INITIAL, 7102 storing 0 there after the type has been changed to precision equal 7103 to its width, rather than the precision of the specified standard 7104 type. (Correct layout requires the original type to have been preserved 7105 until now.) */ 7106 7107 saw_named_field = 0; 7108 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7109 { 7110 if (TREE_TYPE (x) == error_mark_node) 7111 continue; 7112 7113 DECL_CONTEXT (x) = t; 7114 7115 /* If any field is const, the structure type is pseudo-const. */ 7116 if (TREE_READONLY (x)) 7117 C_TYPE_FIELDS_READONLY (t) = 1; 7118 else 7119 { 7120 /* A field that is pseudo-const makes the structure likewise. */ 7121 tree t1 = strip_array_types (TREE_TYPE (x)); 7122 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 7123 && C_TYPE_FIELDS_READONLY (t1)) 7124 C_TYPE_FIELDS_READONLY (t) = 1; 7125 } 7126 7127 /* Any field that is volatile means variables of this type must be 7128 treated in some ways as volatile. */ 7129 if (TREE_THIS_VOLATILE (x)) 7130 C_TYPE_FIELDS_VOLATILE (t) = 1; 7131 7132 /* Any field of nominal variable size implies structure is too. */ 7133 if (C_DECL_VARIABLE_SIZE (x)) 7134 C_TYPE_VARIABLE_SIZE (t) = 1; 7135 7136 if (DECL_INITIAL (x)) 7137 { 7138 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 7139 DECL_SIZE (x) = bitsize_int (width); 7140 DECL_BIT_FIELD (x) = 1; 7141 SET_DECL_C_BIT_FIELD (x); 7142 } 7143 7144 if (TYPE_PACKED (t) 7145 && (DECL_BIT_FIELD (x) 7146 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)) 7147 DECL_PACKED (x) = 1; 7148 7149 /* Detect flexible array member in an invalid context. */ 7150 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 7151 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 7152 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 7153 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 7154 { 7155 if (TREE_CODE (t) == UNION_TYPE) 7156 { 7157 error_at (DECL_SOURCE_LOCATION (x), 7158 "flexible array member in union"); 7159 TREE_TYPE (x) = error_mark_node; 7160 } 7161 else if (DECL_CHAIN (x) != NULL_TREE) 7162 { 7163 error_at (DECL_SOURCE_LOCATION (x), 7164 "flexible array member not at end of struct"); 7165 TREE_TYPE (x) = error_mark_node; 7166 } 7167 else if (!saw_named_field) 7168 { 7169 error_at (DECL_SOURCE_LOCATION (x), 7170 "flexible array member in otherwise empty struct"); 7171 TREE_TYPE (x) = error_mark_node; 7172 } 7173 } 7174 7175 if (pedantic && TREE_CODE (t) == RECORD_TYPE 7176 && flexible_array_type_p (TREE_TYPE (x))) 7177 pedwarn (DECL_SOURCE_LOCATION (x), OPT_pedantic, 7178 "invalid use of structure with flexible array member"); 7179 7180 if (DECL_NAME (x) 7181 || TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 7182 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 7183 saw_named_field = 1; 7184 } 7185 7186 detect_field_duplicates (fieldlist); 7187 7188 /* Now we have the nearly final fieldlist. Record it, 7189 then lay out the structure or union (including the fields). */ 7190 7191 TYPE_FIELDS (t) = fieldlist; 7192 7193 layout_type (t); 7194 7195 /* Give bit-fields their proper types. */ 7196 { 7197 tree *fieldlistp = &fieldlist; 7198 while (*fieldlistp) 7199 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 7200 && TREE_TYPE (*fieldlistp) != error_mark_node) 7201 { 7202 unsigned HOST_WIDE_INT width 7203 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 7204 tree type = TREE_TYPE (*fieldlistp); 7205 if (width != TYPE_PRECISION (type)) 7206 { 7207 TREE_TYPE (*fieldlistp) 7208 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 7209 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 7210 } 7211 DECL_INITIAL (*fieldlistp) = 0; 7212 } 7213 else 7214 fieldlistp = &DECL_CHAIN (*fieldlistp); 7215 } 7216 7217 /* Now we have the truly final field list. 7218 Store it in this type and in the variants. */ 7219 7220 TYPE_FIELDS (t) = fieldlist; 7221 7222 /* If there are lots of fields, sort so we can look through them fast. 7223 We arbitrarily consider 16 or more elts to be "a lot". */ 7224 7225 { 7226 int len = 0; 7227 7228 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7229 { 7230 if (len > 15 || DECL_NAME (x) == NULL) 7231 break; 7232 len += 1; 7233 } 7234 7235 if (len > 15) 7236 { 7237 tree *field_array; 7238 struct lang_type *space; 7239 struct sorted_fields_type *space2; 7240 7241 len += list_length (x); 7242 7243 /* Use the same allocation policy here that make_node uses, to 7244 ensure that this lives as long as the rest of the struct decl. 7245 All decls in an inline function need to be saved. */ 7246 7247 space = ggc_alloc_cleared_lang_type (sizeof (struct lang_type)); 7248 space2 = ggc_alloc_sorted_fields_type 7249 (sizeof (struct sorted_fields_type) + len * sizeof (tree)); 7250 7251 len = 0; 7252 space->s = space2; 7253 field_array = &space2->elts[0]; 7254 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7255 { 7256 field_array[len++] = x; 7257 7258 /* If there is anonymous struct or union, break out of the loop. */ 7259 if (DECL_NAME (x) == NULL) 7260 break; 7261 } 7262 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 7263 if (x == NULL) 7264 { 7265 TYPE_LANG_SPECIFIC (t) = space; 7266 TYPE_LANG_SPECIFIC (t)->s->len = len; 7267 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 7268 qsort (field_array, len, sizeof (tree), field_decl_cmp); 7269 } 7270 } 7271 } 7272 7273 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 7274 { 7275 TYPE_FIELDS (x) = TYPE_FIELDS (t); 7276 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 7277 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 7278 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 7279 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 7280 } 7281 7282 /* If this was supposed to be a transparent union, but we can't 7283 make it one, warn and turn off the flag. */ 7284 if (TREE_CODE (t) == UNION_TYPE 7285 && TYPE_TRANSPARENT_AGGR (t) 7286 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 7287 { 7288 TYPE_TRANSPARENT_AGGR (t) = 0; 7289 warning_at (loc, 0, "union cannot be made transparent"); 7290 } 7291 7292 /* If this structure or union completes the type of any previous 7293 variable declaration, lay it out and output its rtl. */ 7294 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 7295 x; 7296 x = TREE_CHAIN (x)) 7297 { 7298 tree decl = TREE_VALUE (x); 7299 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 7300 layout_array_type (TREE_TYPE (decl)); 7301 if (TREE_CODE (decl) != TYPE_DECL) 7302 { 7303 layout_decl (decl, 0); 7304 if (c_dialect_objc ()) 7305 objc_check_decl (decl); 7306 rest_of_decl_compilation (decl, toplevel, 0); 7307 if (!toplevel) 7308 expand_decl (decl); 7309 } 7310 } 7311 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 7312 7313 /* Update type location to the one of the definition, instead of e.g. 7314 a forward declaration. */ 7315 if (TYPE_STUB_DECL (t)) 7316 DECL_SOURCE_LOCATION (TYPE_STUB_DECL (t)) = loc; 7317 7318 /* Finish debugging output for this type. */ 7319 rest_of_type_compilation (t, toplevel); 7320 7321 /* If we're inside a function proper, i.e. not file-scope and not still 7322 parsing parameters, then arrange for the size of a variable sized type 7323 to be bound now. */ 7324 if (building_stmt_list_p () && variably_modified_type_p (t, NULL_TREE)) 7325 add_stmt (build_stmt (loc, 7326 DECL_EXPR, build_decl (loc, TYPE_DECL, NULL, t))); 7327 7328 if (warn_cxx_compat) 7329 warn_cxx_compat_finish_struct (fieldlist); 7330 7331 VEC_free (tree, heap, struct_parse_info->struct_types); 7332 VEC_free (c_binding_ptr, heap, struct_parse_info->fields); 7333 VEC_free (tree, heap, struct_parse_info->typedefs_seen); 7334 XDELETE (struct_parse_info); 7335 7336 struct_parse_info = enclosing_struct_parse_info; 7337 7338 /* If this struct is defined inside a struct, add it to 7339 struct_types. */ 7340 if (warn_cxx_compat 7341 && struct_parse_info != NULL 7342 && !in_sizeof && !in_typeof && !in_alignof) 7343 VEC_safe_push (tree, heap, struct_parse_info->struct_types, t); 7344 7345 return t; 7346 } 7347 7348 /* Lay out the type T, and its element type, and so on. */ 7349 7350 static void 7351 layout_array_type (tree t) 7352 { 7353 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 7354 layout_array_type (TREE_TYPE (t)); 7355 layout_type (t); 7356 } 7357 7358 /* Begin compiling the definition of an enumeration type. 7359 NAME is its name (or null if anonymous). 7360 LOC is the enum's location. 7361 Returns the type object, as yet incomplete. 7362 Also records info about it so that build_enumerator 7363 may be used to declare the individual values as they are read. */ 7364 7365 tree 7366 start_enum (location_t loc, struct c_enum_contents *the_enum, tree name) 7367 { 7368 tree enumtype = NULL_TREE; 7369 location_t enumloc = UNKNOWN_LOCATION; 7370 7371 /* If this is the real definition for a previous forward reference, 7372 fill in the contents in the same object that used to be the 7373 forward reference. */ 7374 7375 if (name != NULL_TREE) 7376 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1, &enumloc); 7377 7378 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 7379 { 7380 enumtype = make_node (ENUMERAL_TYPE); 7381 pushtag (loc, name, enumtype); 7382 } 7383 7384 if (C_TYPE_BEING_DEFINED (enumtype)) 7385 error_at (loc, "nested redefinition of %<enum %E%>", name); 7386 7387 C_TYPE_BEING_DEFINED (enumtype) = 1; 7388 7389 if (TYPE_VALUES (enumtype) != 0) 7390 { 7391 /* This enum is a named one that has been declared already. */ 7392 error_at (loc, "redeclaration of %<enum %E%>", name); 7393 if (enumloc != UNKNOWN_LOCATION) 7394 inform (enumloc, "originally defined here"); 7395 7396 /* Completely replace its old definition. 7397 The old enumerators remain defined, however. */ 7398 TYPE_VALUES (enumtype) = 0; 7399 } 7400 7401 the_enum->enum_next_value = integer_zero_node; 7402 the_enum->enum_overflow = 0; 7403 7404 if (flag_short_enums) 7405 TYPE_PACKED (enumtype) = 1; 7406 7407 /* FIXME: This will issue a warning for a use of a type defined 7408 within sizeof in a statement expr. This is not terribly serious 7409 as C++ doesn't permit statement exprs within sizeof anyhow. */ 7410 if (warn_cxx_compat && (in_sizeof || in_typeof || in_alignof)) 7411 warning_at (loc, OPT_Wc___compat, 7412 "defining type in %qs expression is invalid in C++", 7413 (in_sizeof 7414 ? "sizeof" 7415 : (in_typeof ? "typeof" : "alignof"))); 7416 7417 return enumtype; 7418 } 7419 7420 /* After processing and defining all the values of an enumeration type, 7421 install their decls in the enumeration type and finish it off. 7422 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 7423 and ATTRIBUTES are the specified attributes. 7424 Returns ENUMTYPE. */ 7425 7426 tree 7427 finish_enum (tree enumtype, tree values, tree attributes) 7428 { 7429 tree pair, tem; 7430 tree minnode = 0, maxnode = 0; 7431 int precision, unsign; 7432 bool toplevel = (file_scope == current_scope); 7433 struct lang_type *lt; 7434 7435 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7436 7437 /* Calculate the maximum value of any enumerator in this type. */ 7438 7439 if (values == error_mark_node) 7440 minnode = maxnode = integer_zero_node; 7441 else 7442 { 7443 minnode = maxnode = TREE_VALUE (values); 7444 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 7445 { 7446 tree value = TREE_VALUE (pair); 7447 if (tree_int_cst_lt (maxnode, value)) 7448 maxnode = value; 7449 if (tree_int_cst_lt (value, minnode)) 7450 minnode = value; 7451 } 7452 } 7453 7454 /* Construct the final type of this enumeration. It is the same 7455 as one of the integral types - the narrowest one that fits, except 7456 that normally we only go as narrow as int - and signed iff any of 7457 the values are negative. */ 7458 unsign = (tree_int_cst_sgn (minnode) >= 0); 7459 precision = MAX (tree_int_cst_min_precision (minnode, unsign), 7460 tree_int_cst_min_precision (maxnode, unsign)); 7461 7462 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 7463 { 7464 tem = c_common_type_for_size (precision, unsign); 7465 if (tem == NULL) 7466 { 7467 warning (0, "enumeration values exceed range of largest integer"); 7468 tem = long_long_integer_type_node; 7469 } 7470 } 7471 else 7472 tem = unsign ? unsigned_type_node : integer_type_node; 7473 7474 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 7475 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 7476 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 7477 TYPE_SIZE (enumtype) = 0; 7478 7479 /* If the precision of the type was specific with an attribute and it 7480 was too small, give an error. Otherwise, use it. */ 7481 if (TYPE_PRECISION (enumtype)) 7482 { 7483 if (precision > TYPE_PRECISION (enumtype)) 7484 error ("specified mode too small for enumeral values"); 7485 } 7486 else 7487 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 7488 7489 layout_type (enumtype); 7490 7491 if (values != error_mark_node) 7492 { 7493 /* Change the type of the enumerators to be the enum type. We 7494 need to do this irrespective of the size of the enum, for 7495 proper type checking. Replace the DECL_INITIALs of the 7496 enumerators, and the value slots of the list, with copies 7497 that have the enum type; they cannot be modified in place 7498 because they may be shared (e.g. integer_zero_node) Finally, 7499 change the purpose slots to point to the names of the decls. */ 7500 for (pair = values; pair; pair = TREE_CHAIN (pair)) 7501 { 7502 tree enu = TREE_PURPOSE (pair); 7503 tree ini = DECL_INITIAL (enu); 7504 7505 TREE_TYPE (enu) = enumtype; 7506 7507 /* The ISO C Standard mandates enumerators to have type int, 7508 even though the underlying type of an enum type is 7509 unspecified. However, GCC allows enumerators of any 7510 integer type as an extensions. build_enumerator() 7511 converts any enumerators that fit in an int to type int, 7512 to avoid promotions to unsigned types when comparing 7513 integers with enumerators that fit in the int range. 7514 When -pedantic is given, build_enumerator() would have 7515 already warned about those that don't fit. Here we 7516 convert the rest to the enumerator type. */ 7517 if (TREE_TYPE (ini) != integer_type_node) 7518 ini = convert (enumtype, ini); 7519 7520 DECL_INITIAL (enu) = ini; 7521 TREE_PURPOSE (pair) = DECL_NAME (enu); 7522 TREE_VALUE (pair) = ini; 7523 } 7524 7525 TYPE_VALUES (enumtype) = values; 7526 } 7527 7528 /* Record the min/max values so that we can warn about bit-field 7529 enumerations that are too small for the values. */ 7530 lt = ggc_alloc_cleared_lang_type (sizeof (struct lang_type)); 7531 lt->enum_min = minnode; 7532 lt->enum_max = maxnode; 7533 TYPE_LANG_SPECIFIC (enumtype) = lt; 7534 7535 /* Fix up all variant types of this enum type. */ 7536 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 7537 { 7538 if (tem == enumtype) 7539 continue; 7540 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 7541 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 7542 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 7543 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 7544 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 7545 SET_TYPE_MODE (tem, TYPE_MODE (enumtype)); 7546 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 7547 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 7548 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 7549 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 7550 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 7551 } 7552 7553 /* Finish debugging output for this type. */ 7554 rest_of_type_compilation (enumtype, toplevel); 7555 7556 /* If this enum is defined inside a struct, add it to 7557 struct_types. */ 7558 if (warn_cxx_compat 7559 && struct_parse_info != NULL 7560 && !in_sizeof && !in_typeof && !in_alignof) 7561 VEC_safe_push (tree, heap, struct_parse_info->struct_types, enumtype); 7562 7563 return enumtype; 7564 } 7565 7566 /* Build and install a CONST_DECL for one value of the 7567 current enumeration type (one that was begun with start_enum). 7568 DECL_LOC is the location of the enumerator. 7569 LOC is the location of the '=' operator if any, DECL_LOC otherwise. 7570 Return a tree-list containing the CONST_DECL and its value. 7571 Assignment of sequential values by default is handled here. */ 7572 7573 tree 7574 build_enumerator (location_t decl_loc, location_t loc, 7575 struct c_enum_contents *the_enum, tree name, tree value) 7576 { 7577 tree decl, type; 7578 7579 /* Validate and default VALUE. */ 7580 7581 if (value != 0) 7582 { 7583 /* Don't issue more errors for error_mark_node (i.e. an 7584 undeclared identifier) - just ignore the value expression. */ 7585 if (value == error_mark_node) 7586 value = 0; 7587 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value))) 7588 { 7589 error_at (loc, "enumerator value for %qE is not an integer constant", 7590 name); 7591 value = 0; 7592 } 7593 else 7594 { 7595 if (TREE_CODE (value) != INTEGER_CST) 7596 { 7597 value = c_fully_fold (value, false, NULL); 7598 if (TREE_CODE (value) == INTEGER_CST) 7599 pedwarn (loc, OPT_pedantic, 7600 "enumerator value for %qE is not an integer " 7601 "constant expression", name); 7602 } 7603 if (TREE_CODE (value) != INTEGER_CST) 7604 { 7605 error ("enumerator value for %qE is not an integer constant", 7606 name); 7607 value = 0; 7608 } 7609 else 7610 { 7611 value = default_conversion (value); 7612 constant_expression_warning (value); 7613 } 7614 } 7615 } 7616 7617 /* Default based on previous value. */ 7618 /* It should no longer be possible to have NON_LVALUE_EXPR 7619 in the default. */ 7620 if (value == 0) 7621 { 7622 value = the_enum->enum_next_value; 7623 if (the_enum->enum_overflow) 7624 error_at (loc, "overflow in enumeration values"); 7625 } 7626 /* Even though the underlying type of an enum is unspecified, the 7627 type of enumeration constants is explicitly defined as int 7628 (6.4.4.3/2 in the C99 Standard). GCC allows any integer type as 7629 an extension. */ 7630 else if (!int_fits_type_p (value, integer_type_node)) 7631 pedwarn (loc, OPT_pedantic, 7632 "ISO C restricts enumerator values to range of %<int%>"); 7633 7634 /* The ISO C Standard mandates enumerators to have type int, even 7635 though the underlying type of an enum type is unspecified. 7636 However, GCC allows enumerators of any integer type as an 7637 extensions. Here we convert any enumerators that fit in an int 7638 to type int, to avoid promotions to unsigned types when comparing 7639 integers with enumerators that fit in the int range. When 7640 -pedantic is given, we would have already warned about those that 7641 don't fit. We have to do this here rather than in finish_enum 7642 because this value may be used to define more enumerators. */ 7643 if (int_fits_type_p (value, integer_type_node)) 7644 value = convert (integer_type_node, value); 7645 7646 /* Set basis for default for next value. */ 7647 the_enum->enum_next_value 7648 = build_binary_op (EXPR_LOC_OR_HERE (value), 7649 PLUS_EXPR, value, integer_one_node, 0); 7650 the_enum->enum_overflow = tree_int_cst_lt (the_enum->enum_next_value, value); 7651 7652 /* Now create a declaration for the enum value name. */ 7653 7654 type = TREE_TYPE (value); 7655 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 7656 TYPE_PRECISION (integer_type_node)), 7657 (TYPE_PRECISION (type) 7658 >= TYPE_PRECISION (integer_type_node) 7659 && TYPE_UNSIGNED (type))); 7660 7661 decl = build_decl (decl_loc, CONST_DECL, name, type); 7662 DECL_INITIAL (decl) = convert (type, value); 7663 pushdecl (decl); 7664 7665 return tree_cons (decl, value, NULL_TREE); 7666 } 7667 7668 7669 /* Create the FUNCTION_DECL for a function definition. 7670 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 7671 the declaration; they describe the function's name and the type it returns, 7672 but twisted together in a fashion that parallels the syntax of C. 7673 7674 This function creates a binding context for the function body 7675 as well as setting up the FUNCTION_DECL in current_function_decl. 7676 7677 Returns 1 on success. If the DECLARATOR is not suitable for a function 7678 (it defines a datum instead), we return 0, which tells 7679 yyparse to report a parse error. */ 7680 7681 int 7682 start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 7683 tree attributes) 7684 { 7685 tree decl1, old_decl; 7686 tree restype, resdecl; 7687 location_t loc; 7688 7689 current_function_returns_value = 0; /* Assume, until we see it does. */ 7690 current_function_returns_null = 0; 7691 current_function_returns_abnormally = 0; 7692 warn_about_return_type = 0; 7693 c_switch_stack = NULL; 7694 7695 /* Indicate no valid break/continue context by setting these variables 7696 to some non-null, non-label value. We'll notice and emit the proper 7697 error message in c_finish_bc_stmt. */ 7698 c_break_label = c_cont_label = size_zero_node; 7699 7700 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL, 7701 &attributes, NULL, NULL, DEPRECATED_NORMAL); 7702 7703 /* If the declarator is not suitable for a function definition, 7704 cause a syntax error. */ 7705 if (decl1 == 0 7706 || TREE_CODE (decl1) != FUNCTION_DECL) 7707 return 0; 7708 7709 loc = DECL_SOURCE_LOCATION (decl1); 7710 7711 decl_attributes (&decl1, attributes, 0); 7712 7713 if (DECL_DECLARED_INLINE_P (decl1) 7714 && DECL_UNINLINABLE (decl1) 7715 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 7716 warning_at (loc, OPT_Wattributes, 7717 "inline function %qD given attribute noinline", 7718 decl1); 7719 7720 /* Handle gnu_inline attribute. */ 7721 if (declspecs->inline_p 7722 && !flag_gnu89_inline 7723 && TREE_CODE (decl1) == FUNCTION_DECL 7724 && (lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1)) 7725 || current_function_decl)) 7726 { 7727 if (declspecs->storage_class != csc_static) 7728 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 7729 } 7730 7731 announce_function (decl1); 7732 7733 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 7734 { 7735 error_at (loc, "return type is an incomplete type"); 7736 /* Make it return void instead. */ 7737 TREE_TYPE (decl1) 7738 = build_function_type (void_type_node, 7739 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 7740 } 7741 7742 if (warn_about_return_type) 7743 pedwarn_c99 (loc, flag_isoc99 ? 0 7744 : (warn_return_type ? OPT_Wreturn_type : OPT_Wimplicit_int), 7745 "return type defaults to %<int%>"); 7746 7747 /* Make the init_value nonzero so pushdecl knows this is not tentative. 7748 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 7749 DECL_INITIAL (decl1) = error_mark_node; 7750 7751 /* A nested function is not global. */ 7752 if (current_function_decl != 0) 7753 TREE_PUBLIC (decl1) = 0; 7754 7755 /* If this definition isn't a prototype and we had a prototype declaration 7756 before, copy the arg type info from that prototype. */ 7757 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 7758 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 7759 old_decl = 0; 7760 current_function_prototype_locus = UNKNOWN_LOCATION; 7761 current_function_prototype_built_in = false; 7762 current_function_prototype_arg_types = NULL_TREE; 7763 if (!prototype_p (TREE_TYPE (decl1))) 7764 { 7765 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 7766 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 7767 TREE_TYPE (TREE_TYPE (old_decl)))) 7768 { 7769 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 7770 TREE_TYPE (decl1)); 7771 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 7772 current_function_prototype_built_in 7773 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 7774 current_function_prototype_arg_types 7775 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 7776 } 7777 if (TREE_PUBLIC (decl1)) 7778 { 7779 /* If there is an external prototype declaration of this 7780 function, record its location but do not copy information 7781 to this decl. This may be an invisible declaration 7782 (built-in or in a scope which has finished) or simply 7783 have more refined argument types than any declaration 7784 found above. */ 7785 struct c_binding *b; 7786 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 7787 if (B_IN_SCOPE (b, external_scope)) 7788 break; 7789 if (b) 7790 { 7791 tree ext_decl, ext_type; 7792 ext_decl = b->decl; 7793 ext_type = b->u.type ? b->u.type : TREE_TYPE (ext_decl); 7794 if (TREE_CODE (ext_type) == FUNCTION_TYPE 7795 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 7796 TREE_TYPE (ext_type))) 7797 { 7798 current_function_prototype_locus 7799 = DECL_SOURCE_LOCATION (ext_decl); 7800 current_function_prototype_built_in 7801 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 7802 current_function_prototype_arg_types 7803 = TYPE_ARG_TYPES (ext_type); 7804 } 7805 } 7806 } 7807 } 7808 7809 /* Optionally warn of old-fashioned def with no previous prototype. */ 7810 if (warn_strict_prototypes 7811 && old_decl != error_mark_node 7812 && !prototype_p (TREE_TYPE (decl1)) 7813 && C_DECL_ISNT_PROTOTYPE (old_decl)) 7814 warning_at (loc, OPT_Wstrict_prototypes, 7815 "function declaration isn%'t a prototype"); 7816 /* Optionally warn of any global def with no previous prototype. */ 7817 else if (warn_missing_prototypes 7818 && old_decl != error_mark_node 7819 && TREE_PUBLIC (decl1) 7820 && !MAIN_NAME_P (DECL_NAME (decl1)) 7821 && C_DECL_ISNT_PROTOTYPE (old_decl)) 7822 warning_at (loc, OPT_Wmissing_prototypes, 7823 "no previous prototype for %qD", decl1); 7824 /* Optionally warn of any def with no previous prototype 7825 if the function has already been used. */ 7826 else if (warn_missing_prototypes 7827 && old_decl != 0 7828 && old_decl != error_mark_node 7829 && TREE_USED (old_decl) 7830 && !prototype_p (TREE_TYPE (old_decl))) 7831 warning_at (loc, OPT_Wmissing_prototypes, 7832 "%qD was used with no prototype before its definition", decl1); 7833 /* Optionally warn of any global def with no previous declaration. */ 7834 else if (warn_missing_declarations 7835 && TREE_PUBLIC (decl1) 7836 && old_decl == 0 7837 && !MAIN_NAME_P (DECL_NAME (decl1))) 7838 warning_at (loc, OPT_Wmissing_declarations, 7839 "no previous declaration for %qD", 7840 decl1); 7841 /* Optionally warn of any def with no previous declaration 7842 if the function has already been used. */ 7843 else if (warn_missing_declarations 7844 && old_decl != 0 7845 && old_decl != error_mark_node 7846 && TREE_USED (old_decl) 7847 && C_DECL_IMPLICIT (old_decl)) 7848 warning_at (loc, OPT_Wmissing_declarations, 7849 "%qD was used with no declaration before its definition", decl1); 7850 7851 /* This function exists in static storage. 7852 (This does not mean `static' in the C sense!) */ 7853 TREE_STATIC (decl1) = 1; 7854 7855 /* This is the earliest point at which we might know the assembler 7856 name of the function. Thus, if it's set before this, die horribly. */ 7857 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 7858 7859 /* If #pragma weak was used, mark the decl weak now. */ 7860 if (current_scope == file_scope) 7861 maybe_apply_pragma_weak (decl1); 7862 7863 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 7864 if (warn_main && MAIN_NAME_P (DECL_NAME (decl1))) 7865 { 7866 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 7867 != integer_type_node) 7868 pedwarn (loc, OPT_Wmain, "return type of %qD is not %<int%>", decl1); 7869 7870 check_main_parameter_types (decl1); 7871 7872 if (!TREE_PUBLIC (decl1)) 7873 pedwarn (loc, OPT_Wmain, 7874 "%qD is normally a non-static function", decl1); 7875 } 7876 7877 /* Record the decl so that the function name is defined. 7878 If we already have a decl for this name, and it is a FUNCTION_DECL, 7879 use the old decl. */ 7880 7881 current_function_decl = pushdecl (decl1); 7882 7883 push_scope (); 7884 declare_parm_level (); 7885 7886 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 7887 resdecl = build_decl (loc, RESULT_DECL, NULL_TREE, restype); 7888 DECL_ARTIFICIAL (resdecl) = 1; 7889 DECL_IGNORED_P (resdecl) = 1; 7890 DECL_RESULT (current_function_decl) = resdecl; 7891 7892 start_fname_decls (); 7893 7894 return 1; 7895 } 7896 7897 /* Subroutine of store_parm_decls which handles new-style function 7898 definitions (prototype format). The parms already have decls, so we 7899 need only record them as in effect and complain if any redundant 7900 old-style parm decls were written. */ 7901 static void 7902 store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 7903 { 7904 tree decl; 7905 c_arg_tag *tag; 7906 unsigned ix; 7907 7908 if (current_scope->bindings) 7909 { 7910 error_at (DECL_SOURCE_LOCATION (fndecl), 7911 "old-style parameter declarations in prototyped " 7912 "function definition"); 7913 7914 /* Get rid of the old-style declarations. */ 7915 pop_scope (); 7916 push_scope (); 7917 } 7918 /* Don't issue this warning for nested functions, and don't issue this 7919 warning if we got here because ARG_INFO_TYPES was error_mark_node 7920 (this happens when a function definition has just an ellipsis in 7921 its parameter list). */ 7922 else if (!in_system_header && !current_function_scope 7923 && arg_info->types != error_mark_node) 7924 warning_at (DECL_SOURCE_LOCATION (fndecl), OPT_Wtraditional, 7925 "traditional C rejects ISO C style function definitions"); 7926 7927 /* Now make all the parameter declarations visible in the function body. 7928 We can bypass most of the grunt work of pushdecl. */ 7929 for (decl = arg_info->parms; decl; decl = DECL_CHAIN (decl)) 7930 { 7931 DECL_CONTEXT (decl) = current_function_decl; 7932 if (DECL_NAME (decl)) 7933 { 7934 bind (DECL_NAME (decl), decl, current_scope, 7935 /*invisible=*/false, /*nested=*/false, 7936 UNKNOWN_LOCATION); 7937 if (!TREE_USED (decl)) 7938 warn_if_shadowing (decl); 7939 } 7940 else 7941 error_at (DECL_SOURCE_LOCATION (decl), "parameter name omitted"); 7942 } 7943 7944 /* Record the parameter list in the function declaration. */ 7945 DECL_ARGUMENTS (fndecl) = arg_info->parms; 7946 7947 /* Now make all the ancillary declarations visible, likewise. */ 7948 for (decl = arg_info->others; decl; decl = DECL_CHAIN (decl)) 7949 { 7950 DECL_CONTEXT (decl) = current_function_decl; 7951 if (DECL_NAME (decl)) 7952 bind (DECL_NAME (decl), decl, current_scope, 7953 /*invisible=*/false, 7954 /*nested=*/(TREE_CODE (decl) == FUNCTION_DECL), 7955 UNKNOWN_LOCATION); 7956 } 7957 7958 /* And all the tag declarations. */ 7959 FOR_EACH_VEC_ELT_REVERSE (c_arg_tag, arg_info->tags, ix, tag) 7960 if (tag->id) 7961 bind (tag->id, tag->type, current_scope, 7962 /*invisible=*/false, /*nested=*/false, UNKNOWN_LOCATION); 7963 } 7964 7965 /* Subroutine of store_parm_decls which handles old-style function 7966 definitions (separate parameter list and declarations). */ 7967 7968 static void 7969 store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 7970 { 7971 struct c_binding *b; 7972 tree parm, decl, last; 7973 tree parmids = arg_info->parms; 7974 struct pointer_set_t *seen_args = pointer_set_create (); 7975 7976 if (!in_system_header) 7977 warning_at (DECL_SOURCE_LOCATION (fndecl), 7978 OPT_Wold_style_definition, "old-style function definition"); 7979 7980 /* Match each formal parameter name with its declaration. Save each 7981 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 7982 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 7983 { 7984 if (TREE_VALUE (parm) == 0) 7985 { 7986 error_at (DECL_SOURCE_LOCATION (fndecl), 7987 "parameter name missing from parameter list"); 7988 TREE_PURPOSE (parm) = 0; 7989 continue; 7990 } 7991 7992 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 7993 if (b && B_IN_CURRENT_SCOPE (b)) 7994 { 7995 decl = b->decl; 7996 /* Skip erroneous parameters. */ 7997 if (decl == error_mark_node) 7998 continue; 7999 /* If we got something other than a PARM_DECL it is an error. */ 8000 if (TREE_CODE (decl) != PARM_DECL) 8001 error_at (DECL_SOURCE_LOCATION (decl), 8002 "%qD declared as a non-parameter", decl); 8003 /* If the declaration is already marked, we have a duplicate 8004 name. Complain and ignore the duplicate. */ 8005 else if (pointer_set_contains (seen_args, decl)) 8006 { 8007 error_at (DECL_SOURCE_LOCATION (decl), 8008 "multiple parameters named %qD", decl); 8009 TREE_PURPOSE (parm) = 0; 8010 continue; 8011 } 8012 /* If the declaration says "void", complain and turn it into 8013 an int. */ 8014 else if (VOID_TYPE_P (TREE_TYPE (decl))) 8015 { 8016 error_at (DECL_SOURCE_LOCATION (decl), 8017 "parameter %qD declared with void type", decl); 8018 TREE_TYPE (decl) = integer_type_node; 8019 DECL_ARG_TYPE (decl) = integer_type_node; 8020 layout_decl (decl, 0); 8021 } 8022 warn_if_shadowing (decl); 8023 } 8024 /* If no declaration found, default to int. */ 8025 else 8026 { 8027 /* FIXME diagnostics: This should be the location of the argument, 8028 not the FNDECL. E.g., for an old-style declaration 8029 8030 int f10(v) { blah; } 8031 8032 We should use the location of the V, not the F10. 8033 Unfortunately, the V is an IDENTIFIER_NODE which has no 8034 location. In the future we need locations for c_arg_info 8035 entries. 8036 8037 See gcc.dg/Wshadow-3.c for an example of this problem. */ 8038 decl = build_decl (DECL_SOURCE_LOCATION (fndecl), 8039 PARM_DECL, TREE_VALUE (parm), integer_type_node); 8040 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 8041 pushdecl (decl); 8042 warn_if_shadowing (decl); 8043 8044 if (flag_isoc99) 8045 pedwarn (DECL_SOURCE_LOCATION (decl), 8046 0, "type of %qD defaults to %<int%>", decl); 8047 else 8048 warning_at (DECL_SOURCE_LOCATION (decl), 8049 OPT_Wmissing_parameter_type, 8050 "type of %qD defaults to %<int%>", decl); 8051 } 8052 8053 TREE_PURPOSE (parm) = decl; 8054 pointer_set_insert (seen_args, decl); 8055 } 8056 8057 /* Now examine the parms chain for incomplete declarations 8058 and declarations with no corresponding names. */ 8059 8060 for (b = current_scope->bindings; b; b = b->prev) 8061 { 8062 parm = b->decl; 8063 if (TREE_CODE (parm) != PARM_DECL) 8064 continue; 8065 8066 if (TREE_TYPE (parm) != error_mark_node 8067 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 8068 { 8069 error_at (DECL_SOURCE_LOCATION (parm), 8070 "parameter %qD has incomplete type", parm); 8071 TREE_TYPE (parm) = error_mark_node; 8072 } 8073 8074 if (!pointer_set_contains (seen_args, parm)) 8075 { 8076 error_at (DECL_SOURCE_LOCATION (parm), 8077 "declaration for parameter %qD but no such parameter", 8078 parm); 8079 8080 /* Pretend the parameter was not missing. 8081 This gets us to a standard state and minimizes 8082 further error messages. */ 8083 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 8084 } 8085 } 8086 8087 /* Chain the declarations together in the order of the list of 8088 names. Store that chain in the function decl, replacing the 8089 list of names. Update the current scope to match. */ 8090 DECL_ARGUMENTS (fndecl) = 0; 8091 8092 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 8093 if (TREE_PURPOSE (parm)) 8094 break; 8095 if (parm && TREE_PURPOSE (parm)) 8096 { 8097 last = TREE_PURPOSE (parm); 8098 DECL_ARGUMENTS (fndecl) = last; 8099 8100 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 8101 if (TREE_PURPOSE (parm)) 8102 { 8103 DECL_CHAIN (last) = TREE_PURPOSE (parm); 8104 last = TREE_PURPOSE (parm); 8105 } 8106 DECL_CHAIN (last) = 0; 8107 } 8108 8109 pointer_set_destroy (seen_args); 8110 8111 /* If there was a previous prototype, 8112 set the DECL_ARG_TYPE of each argument according to 8113 the type previously specified, and report any mismatches. */ 8114 8115 if (current_function_prototype_arg_types) 8116 { 8117 tree type; 8118 for (parm = DECL_ARGUMENTS (fndecl), 8119 type = current_function_prototype_arg_types; 8120 parm || (type && TREE_VALUE (type) != error_mark_node 8121 && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) != void_type_node)); 8122 parm = DECL_CHAIN (parm), type = TREE_CHAIN (type)) 8123 { 8124 if (parm == 0 || type == 0 8125 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 8126 { 8127 if (current_function_prototype_built_in) 8128 warning_at (DECL_SOURCE_LOCATION (fndecl), 8129 0, "number of arguments doesn%'t match " 8130 "built-in prototype"); 8131 else 8132 { 8133 /* FIXME diagnostics: This should be the location of 8134 FNDECL, but there is bug when a prototype is 8135 declared inside function context, but defined 8136 outside of it (e.g., gcc.dg/pr15698-2.c). In 8137 which case FNDECL gets the location of the 8138 prototype, not the definition. */ 8139 error_at (input_location, 8140 "number of arguments doesn%'t match prototype"); 8141 8142 error_at (current_function_prototype_locus, 8143 "prototype declaration"); 8144 } 8145 break; 8146 } 8147 /* Type for passing arg must be consistent with that 8148 declared for the arg. ISO C says we take the unqualified 8149 type for parameters declared with qualified type. */ 8150 if (TREE_TYPE (parm) != error_mark_node 8151 && TREE_TYPE (type) != error_mark_node 8152 && !comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 8153 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 8154 { 8155 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 8156 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 8157 { 8158 /* Adjust argument to match prototype. E.g. a previous 8159 `int foo(float);' prototype causes 8160 `int foo(x) float x; {...}' to be treated like 8161 `int foo(float x) {...}'. This is particularly 8162 useful for argument types like uid_t. */ 8163 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 8164 8165 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 8166 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 8167 && TYPE_PRECISION (TREE_TYPE (parm)) 8168 < TYPE_PRECISION (integer_type_node)) 8169 DECL_ARG_TYPE (parm) = integer_type_node; 8170 8171 /* ??? Is it possible to get here with a 8172 built-in prototype or will it always have 8173 been diagnosed as conflicting with an 8174 old-style definition and discarded? */ 8175 if (current_function_prototype_built_in) 8176 warning_at (DECL_SOURCE_LOCATION (parm), 8177 OPT_pedantic, "promoted argument %qD " 8178 "doesn%'t match built-in prototype", parm); 8179 else 8180 { 8181 pedwarn (DECL_SOURCE_LOCATION (parm), 8182 OPT_pedantic, "promoted argument %qD " 8183 "doesn%'t match prototype", parm); 8184 pedwarn (current_function_prototype_locus, OPT_pedantic, 8185 "prototype declaration"); 8186 } 8187 } 8188 else 8189 { 8190 if (current_function_prototype_built_in) 8191 warning_at (DECL_SOURCE_LOCATION (parm), 8192 0, "argument %qD doesn%'t match " 8193 "built-in prototype", parm); 8194 else 8195 { 8196 error_at (DECL_SOURCE_LOCATION (parm), 8197 "argument %qD doesn%'t match prototype", parm); 8198 error_at (current_function_prototype_locus, 8199 "prototype declaration"); 8200 } 8201 } 8202 } 8203 } 8204 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 8205 } 8206 8207 /* Otherwise, create a prototype that would match. */ 8208 8209 else 8210 { 8211 tree actual = 0, last = 0, type; 8212 8213 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = DECL_CHAIN (parm)) 8214 { 8215 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 8216 if (last) 8217 TREE_CHAIN (last) = type; 8218 else 8219 actual = type; 8220 last = type; 8221 } 8222 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 8223 if (last) 8224 TREE_CHAIN (last) = type; 8225 else 8226 actual = type; 8227 8228 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 8229 of the type of this function, but we need to avoid having this 8230 affect the types of other similarly-typed functions, so we must 8231 first force the generation of an identical (but separate) type 8232 node for the relevant function type. The new node we create 8233 will be a variant of the main variant of the original function 8234 type. */ 8235 8236 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 8237 8238 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 8239 } 8240 } 8241 8242 /* Store parameter declarations passed in ARG_INFO into the current 8243 function declaration. */ 8244 8245 void 8246 store_parm_decls_from (struct c_arg_info *arg_info) 8247 { 8248 current_function_arg_info = arg_info; 8249 store_parm_decls (); 8250 } 8251 8252 /* Store the parameter declarations into the current function declaration. 8253 This is called after parsing the parameter declarations, before 8254 digesting the body of the function. 8255 8256 For an old-style definition, construct a prototype out of the old-style 8257 parameter declarations and inject it into the function's type. */ 8258 8259 void 8260 store_parm_decls (void) 8261 { 8262 tree fndecl = current_function_decl; 8263 bool proto; 8264 8265 /* The argument information block for FNDECL. */ 8266 struct c_arg_info *arg_info = current_function_arg_info; 8267 current_function_arg_info = 0; 8268 8269 /* True if this definition is written with a prototype. Note: 8270 despite C99 6.7.5.3p14, we can *not* treat an empty argument 8271 list in a function definition as equivalent to (void) -- an 8272 empty argument list specifies the function has no parameters, 8273 but only (void) sets up a prototype for future calls. */ 8274 proto = arg_info->types != 0; 8275 8276 if (proto) 8277 store_parm_decls_newstyle (fndecl, arg_info); 8278 else 8279 store_parm_decls_oldstyle (fndecl, arg_info); 8280 8281 /* The next call to push_scope will be a function body. */ 8282 8283 next_is_function_body = true; 8284 8285 /* Write a record describing this function definition to the prototypes 8286 file (if requested). */ 8287 8288 gen_aux_info_record (fndecl, 1, 0, proto); 8289 8290 /* Initialize the RTL code for the function. */ 8291 allocate_struct_function (fndecl, false); 8292 8293 if (warn_unused_local_typedefs) 8294 cfun->language = ggc_alloc_cleared_language_function (); 8295 8296 /* Begin the statement tree for this function. */ 8297 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 8298 8299 /* ??? Insert the contents of the pending sizes list into the function 8300 to be evaluated. The only reason left to have this is 8301 void foo(int n, int array[n++]) 8302 because we throw away the array type in favor of a pointer type, and 8303 thus won't naturally see the SAVE_EXPR containing the increment. All 8304 other pending sizes would be handled by gimplify_parameters. */ 8305 if (arg_info->pending_sizes) 8306 add_stmt (arg_info->pending_sizes); 8307 } 8308 8309 8310 /* Finish up a function declaration and compile that function 8311 all the way to assembler language output. Then free the storage 8312 for the function definition. 8313 8314 This is called after parsing the body of the function definition. */ 8315 8316 void 8317 finish_function (void) 8318 { 8319 tree fndecl = current_function_decl; 8320 8321 if (c_dialect_objc ()) 8322 objc_finish_function (); 8323 8324 if (TREE_CODE (fndecl) == FUNCTION_DECL 8325 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 8326 { 8327 tree args = DECL_ARGUMENTS (fndecl); 8328 for (; args; args = DECL_CHAIN (args)) 8329 { 8330 tree type = TREE_TYPE (args); 8331 if (INTEGRAL_TYPE_P (type) 8332 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 8333 DECL_ARG_TYPE (args) = integer_type_node; 8334 } 8335 } 8336 8337 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 8338 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 8339 8340 /* Must mark the RESULT_DECL as being in this function. */ 8341 8342 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 8343 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 8344 8345 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted 8346 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 8347 == integer_type_node && flag_isoc99) 8348 { 8349 /* Hack. We don't want the middle-end to warn that this return 8350 is unreachable, so we mark its location as special. Using 8351 UNKNOWN_LOCATION has the problem that it gets clobbered in 8352 annotate_one_with_locus. A cleaner solution might be to 8353 ensure ! should_carry_locus_p (stmt), but that needs a flag. 8354 */ 8355 c_finish_return (BUILTINS_LOCATION, integer_zero_node, NULL_TREE); 8356 } 8357 8358 /* Tie off the statement tree for this function. */ 8359 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 8360 8361 finish_fname_decls (); 8362 8363 /* Complain if there's just no return statement. */ 8364 if (warn_return_type 8365 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 8366 && !current_function_returns_value && !current_function_returns_null 8367 /* Don't complain if we are no-return. */ 8368 && !current_function_returns_abnormally 8369 /* Don't complain if we are declared noreturn. */ 8370 && !TREE_THIS_VOLATILE (fndecl) 8371 /* Don't warn for main(). */ 8372 && !MAIN_NAME_P (DECL_NAME (fndecl)) 8373 /* Or if they didn't actually specify a return type. */ 8374 && !C_FUNCTION_IMPLICIT_INT (fndecl) 8375 /* Normally, with -Wreturn-type, flow will complain, but we might 8376 optimize out static functions. */ 8377 && !TREE_PUBLIC (fndecl)) 8378 { 8379 warning (OPT_Wreturn_type, 8380 "no return statement in function returning non-void"); 8381 TREE_NO_WARNING (fndecl) = 1; 8382 } 8383 8384 /* Complain about parameters that are only set, but never otherwise used. */ 8385 if (warn_unused_but_set_parameter) 8386 { 8387 tree decl; 8388 8389 for (decl = DECL_ARGUMENTS (fndecl); 8390 decl; 8391 decl = DECL_CHAIN (decl)) 8392 if (TREE_USED (decl) 8393 && TREE_CODE (decl) == PARM_DECL 8394 && !DECL_READ_P (decl) 8395 && DECL_NAME (decl) 8396 && !DECL_ARTIFICIAL (decl) 8397 && !TREE_NO_WARNING (decl)) 8398 warning_at (DECL_SOURCE_LOCATION (decl), 8399 OPT_Wunused_but_set_parameter, 8400 "parameter %qD set but not used", decl); 8401 } 8402 8403 /* Complain about locally defined typedefs that are not used in this 8404 function. */ 8405 maybe_warn_unused_local_typedefs (); 8406 8407 /* Store the end of the function, so that we get good line number 8408 info for the epilogue. */ 8409 cfun->function_end_locus = input_location; 8410 8411 /* Finalize the ELF visibility for the function. */ 8412 c_determine_visibility (fndecl); 8413 8414 /* For GNU C extern inline functions disregard inline limits. */ 8415 if (DECL_EXTERNAL (fndecl) 8416 && DECL_DECLARED_INLINE_P (fndecl)) 8417 DECL_DISREGARD_INLINE_LIMITS (fndecl) = 1; 8418 8419 /* Genericize before inlining. Delay genericizing nested functions 8420 until their parent function is genericized. Since finalizing 8421 requires GENERIC, delay that as well. */ 8422 8423 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 8424 && !undef_nested_function) 8425 { 8426 if (!decl_function_context (fndecl)) 8427 { 8428 invoke_plugin_callbacks (PLUGIN_PRE_GENERICIZE, fndecl); 8429 c_genericize (fndecl); 8430 8431 /* ??? Objc emits functions after finalizing the compilation unit. 8432 This should be cleaned up later and this conditional removed. */ 8433 if (cgraph_global_info_ready) 8434 { 8435 cgraph_add_new_function (fndecl, false); 8436 return; 8437 } 8438 cgraph_finalize_function (fndecl, false); 8439 } 8440 else 8441 { 8442 /* Register this function with cgraph just far enough to get it 8443 added to our parent's nested function list. Handy, since the 8444 C front end doesn't have such a list. */ 8445 (void) cgraph_get_create_node (fndecl); 8446 } 8447 } 8448 8449 if (!decl_function_context (fndecl)) 8450 undef_nested_function = false; 8451 8452 if (cfun->language != NULL) 8453 { 8454 ggc_free (cfun->language); 8455 cfun->language = NULL; 8456 } 8457 8458 /* We're leaving the context of this function, so zap cfun. 8459 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 8460 tree_rest_of_compilation. */ 8461 set_cfun (NULL); 8462 current_function_decl = NULL; 8463 } 8464 8465 /* Check the declarations given in a for-loop for satisfying the C99 8466 constraints. If exactly one such decl is found, return it. LOC is 8467 the location of the opening parenthesis of the for loop. The last 8468 parameter allows you to control the "for loop initial declarations 8469 are only allowed in C99 mode". Normally, you should pass 8470 flag_isoc99 as that parameter. But in some cases (Objective-C 8471 foreach loop, for example) we want to run the checks in this 8472 function even if not in C99 mode, so we allow the caller to turn 8473 off the error about not being in C99 mode. 8474 */ 8475 8476 tree 8477 check_for_loop_decls (location_t loc, bool turn_off_iso_c99_error) 8478 { 8479 struct c_binding *b; 8480 tree one_decl = NULL_TREE; 8481 int n_decls = 0; 8482 8483 if (!turn_off_iso_c99_error) 8484 { 8485 static bool hint = true; 8486 /* If we get here, declarations have been used in a for loop without 8487 the C99 for loop scope. This doesn't make much sense, so don't 8488 allow it. */ 8489 error_at (loc, "%<for%> loop initial declarations " 8490 "are only allowed in C99 mode"); 8491 if (hint) 8492 { 8493 inform (loc, 8494 "use option -std=c99 or -std=gnu99 to compile your code"); 8495 hint = false; 8496 } 8497 return NULL_TREE; 8498 } 8499 /* C99 subclause 6.8.5 paragraph 3: 8500 8501 [#3] The declaration part of a for statement shall only 8502 declare identifiers for objects having storage class auto or 8503 register. 8504 8505 It isn't clear whether, in this sentence, "identifiers" binds to 8506 "shall only declare" or to "objects" - that is, whether all identifiers 8507 declared must be identifiers for objects, or whether the restriction 8508 only applies to those that are. (A question on this in comp.std.c 8509 in November 2000 received no answer.) We implement the strictest 8510 interpretation, to avoid creating an extension which later causes 8511 problems. */ 8512 8513 for (b = current_scope->bindings; b; b = b->prev) 8514 { 8515 tree id = b->id; 8516 tree decl = b->decl; 8517 8518 if (!id) 8519 continue; 8520 8521 switch (TREE_CODE (decl)) 8522 { 8523 case VAR_DECL: 8524 { 8525 location_t decl_loc = DECL_SOURCE_LOCATION (decl); 8526 if (TREE_STATIC (decl)) 8527 error_at (decl_loc, 8528 "declaration of static variable %qD in %<for%> loop " 8529 "initial declaration", decl); 8530 else if (DECL_EXTERNAL (decl)) 8531 error_at (decl_loc, 8532 "declaration of %<extern%> variable %qD in %<for%> loop " 8533 "initial declaration", decl); 8534 } 8535 break; 8536 8537 case RECORD_TYPE: 8538 error_at (loc, 8539 "%<struct %E%> declared in %<for%> loop initial " 8540 "declaration", id); 8541 break; 8542 case UNION_TYPE: 8543 error_at (loc, 8544 "%<union %E%> declared in %<for%> loop initial declaration", 8545 id); 8546 break; 8547 case ENUMERAL_TYPE: 8548 error_at (loc, "%<enum %E%> declared in %<for%> loop " 8549 "initial declaration", id); 8550 break; 8551 default: 8552 error_at (loc, "declaration of non-variable " 8553 "%qD in %<for%> loop initial declaration", decl); 8554 } 8555 8556 n_decls++; 8557 one_decl = decl; 8558 } 8559 8560 return n_decls == 1 ? one_decl : NULL_TREE; 8561 } 8562 8563 /* Save and reinitialize the variables 8564 used during compilation of a C function. */ 8565 8566 void 8567 c_push_function_context (void) 8568 { 8569 struct language_function *p = cfun->language; 8570 /* cfun->language might have been already allocated by the use of 8571 -Wunused-local-typedefs. In that case, just re-use it. */ 8572 if (p == NULL) 8573 cfun->language = p = ggc_alloc_cleared_language_function (); 8574 8575 p->base.x_stmt_tree = c_stmt_tree; 8576 c_stmt_tree.x_cur_stmt_list 8577 = VEC_copy (tree, gc, c_stmt_tree.x_cur_stmt_list); 8578 p->x_break_label = c_break_label; 8579 p->x_cont_label = c_cont_label; 8580 p->x_switch_stack = c_switch_stack; 8581 p->arg_info = current_function_arg_info; 8582 p->returns_value = current_function_returns_value; 8583 p->returns_null = current_function_returns_null; 8584 p->returns_abnormally = current_function_returns_abnormally; 8585 p->warn_about_return_type = warn_about_return_type; 8586 8587 push_function_context (); 8588 } 8589 8590 /* Restore the variables used during compilation of a C function. */ 8591 8592 void 8593 c_pop_function_context (void) 8594 { 8595 struct language_function *p; 8596 8597 pop_function_context (); 8598 p = cfun->language; 8599 /* When -Wunused-local-typedefs is in effect, cfun->languages is 8600 used to store data throughout the life time of the current cfun, 8601 So don't deallocate it. */ 8602 if (!warn_unused_local_typedefs) 8603 cfun->language = NULL; 8604 8605 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 8606 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 8607 { 8608 /* Stop pointing to the local nodes about to be freed. */ 8609 /* But DECL_INITIAL must remain nonzero so we know this 8610 was an actual function definition. */ 8611 DECL_INITIAL (current_function_decl) = error_mark_node; 8612 DECL_ARGUMENTS (current_function_decl) = 0; 8613 } 8614 8615 c_stmt_tree = p->base.x_stmt_tree; 8616 c_break_label = p->x_break_label; 8617 c_cont_label = p->x_cont_label; 8618 c_switch_stack = p->x_switch_stack; 8619 current_function_arg_info = p->arg_info; 8620 current_function_returns_value = p->returns_value; 8621 current_function_returns_null = p->returns_null; 8622 current_function_returns_abnormally = p->returns_abnormally; 8623 warn_about_return_type = p->warn_about_return_type; 8624 } 8625 8626 /* The functions below are required for functionality of doing 8627 function at once processing in the C front end. Currently these 8628 functions are not called from anywhere in the C front end, but as 8629 these changes continue, that will change. */ 8630 8631 /* Returns the stmt_tree (if any) to which statements are currently 8632 being added. If there is no active statement-tree, NULL is 8633 returned. */ 8634 8635 stmt_tree 8636 current_stmt_tree (void) 8637 { 8638 return &c_stmt_tree; 8639 } 8640 8641 /* Return the global value of T as a symbol. */ 8642 8643 tree 8644 identifier_global_value (tree t) 8645 { 8646 struct c_binding *b; 8647 8648 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 8649 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 8650 return b->decl; 8651 8652 return 0; 8653 } 8654 8655 /* In C, the only C-linkage public declaration is at file scope. */ 8656 8657 tree 8658 c_linkage_bindings (tree name) 8659 { 8660 return identifier_global_value (name); 8661 } 8662 8663 /* Record a builtin type for C. If NAME is non-NULL, it is the name used; 8664 otherwise the name is found in ridpointers from RID_INDEX. */ 8665 8666 void 8667 record_builtin_type (enum rid rid_index, const char *name, tree type) 8668 { 8669 tree id, decl; 8670 if (name == 0) 8671 id = ridpointers[(int) rid_index]; 8672 else 8673 id = get_identifier (name); 8674 decl = build_decl (UNKNOWN_LOCATION, TYPE_DECL, id, type); 8675 pushdecl (decl); 8676 if (debug_hooks->type_decl) 8677 debug_hooks->type_decl (decl, false); 8678 } 8679 8680 /* Build the void_list_node (void_type_node having been created). */ 8681 tree 8682 build_void_list_node (void) 8683 { 8684 tree t = build_tree_list (NULL_TREE, void_type_node); 8685 return t; 8686 } 8687 8688 /* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 8689 8690 struct c_parm * 8691 build_c_parm (struct c_declspecs *specs, tree attrs, 8692 struct c_declarator *declarator) 8693 { 8694 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 8695 ret->specs = specs; 8696 ret->attrs = attrs; 8697 ret->declarator = declarator; 8698 return ret; 8699 } 8700 8701 /* Return a declarator with nested attributes. TARGET is the inner 8702 declarator to which these attributes apply. ATTRS are the 8703 attributes. */ 8704 8705 struct c_declarator * 8706 build_attrs_declarator (tree attrs, struct c_declarator *target) 8707 { 8708 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8709 ret->kind = cdk_attrs; 8710 ret->declarator = target; 8711 ret->u.attrs = attrs; 8712 return ret; 8713 } 8714 8715 /* Return a declarator for a function with arguments specified by ARGS 8716 and return type specified by TARGET. */ 8717 8718 struct c_declarator * 8719 build_function_declarator (struct c_arg_info *args, 8720 struct c_declarator *target) 8721 { 8722 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8723 ret->kind = cdk_function; 8724 ret->declarator = target; 8725 ret->u.arg_info = args; 8726 return ret; 8727 } 8728 8729 /* Return a declarator for the identifier IDENT (which may be 8730 NULL_TREE for an abstract declarator). */ 8731 8732 struct c_declarator * 8733 build_id_declarator (tree ident) 8734 { 8735 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8736 ret->kind = cdk_id; 8737 ret->declarator = 0; 8738 ret->u.id = ident; 8739 /* Default value - may get reset to a more precise location. */ 8740 ret->id_loc = input_location; 8741 return ret; 8742 } 8743 8744 /* Return something to represent absolute declarators containing a *. 8745 TARGET is the absolute declarator that the * contains. 8746 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 8747 to apply to the pointer type. */ 8748 8749 struct c_declarator * 8750 make_pointer_declarator (struct c_declspecs *type_quals_attrs, 8751 struct c_declarator *target) 8752 { 8753 tree attrs; 8754 int quals = 0; 8755 struct c_declarator *itarget = target; 8756 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8757 if (type_quals_attrs) 8758 { 8759 attrs = type_quals_attrs->attrs; 8760 quals = quals_from_declspecs (type_quals_attrs); 8761 if (attrs != NULL_TREE) 8762 itarget = build_attrs_declarator (attrs, target); 8763 } 8764 ret->kind = cdk_pointer; 8765 ret->declarator = itarget; 8766 ret->u.pointer_quals = quals; 8767 return ret; 8768 } 8769 8770 /* Return a pointer to a structure for an empty list of declaration 8771 specifiers. */ 8772 8773 struct c_declspecs * 8774 build_null_declspecs (void) 8775 { 8776 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 8777 ret->type = 0; 8778 ret->expr = 0; 8779 ret->decl_attr = 0; 8780 ret->attrs = 0; 8781 ret->align_log = -1; 8782 ret->typespec_word = cts_none; 8783 ret->storage_class = csc_none; 8784 ret->expr_const_operands = true; 8785 ret->declspecs_seen_p = false; 8786 ret->typespec_kind = ctsk_none; 8787 ret->non_sc_seen_p = false; 8788 ret->typedef_p = false; 8789 ret->explicit_signed_p = false; 8790 ret->deprecated_p = false; 8791 ret->default_int_p = false; 8792 ret->long_p = false; 8793 ret->long_long_p = false; 8794 ret->short_p = false; 8795 ret->signed_p = false; 8796 ret->unsigned_p = false; 8797 ret->complex_p = false; 8798 ret->inline_p = false; 8799 ret->noreturn_p = false; 8800 ret->thread_p = false; 8801 ret->const_p = false; 8802 ret->volatile_p = false; 8803 ret->restrict_p = false; 8804 ret->saturating_p = false; 8805 ret->alignas_p = false; 8806 ret->address_space = ADDR_SPACE_GENERIC; 8807 return ret; 8808 } 8809 8810 /* Add the address space ADDRSPACE to the declaration specifiers 8811 SPECS, returning SPECS. */ 8812 8813 struct c_declspecs * 8814 declspecs_add_addrspace (struct c_declspecs *specs, addr_space_t as) 8815 { 8816 specs->non_sc_seen_p = true; 8817 specs->declspecs_seen_p = true; 8818 8819 if (!ADDR_SPACE_GENERIC_P (specs->address_space) 8820 && specs->address_space != as) 8821 error ("incompatible address space qualifiers %qs and %qs", 8822 c_addr_space_name (as), 8823 c_addr_space_name (specs->address_space)); 8824 else 8825 specs->address_space = as; 8826 return specs; 8827 } 8828 8829 /* Add the type qualifier QUAL to the declaration specifiers SPECS, 8830 returning SPECS. */ 8831 8832 struct c_declspecs * 8833 declspecs_add_qual (struct c_declspecs *specs, tree qual) 8834 { 8835 enum rid i; 8836 bool dupe = false; 8837 specs->non_sc_seen_p = true; 8838 specs->declspecs_seen_p = true; 8839 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 8840 && C_IS_RESERVED_WORD (qual)); 8841 i = C_RID_CODE (qual); 8842 switch (i) 8843 { 8844 case RID_CONST: 8845 dupe = specs->const_p; 8846 specs->const_p = true; 8847 break; 8848 case RID_VOLATILE: 8849 dupe = specs->volatile_p; 8850 specs->volatile_p = true; 8851 break; 8852 case RID_RESTRICT: 8853 dupe = specs->restrict_p; 8854 specs->restrict_p = true; 8855 break; 8856 default: 8857 gcc_unreachable (); 8858 } 8859 if (dupe && !flag_isoc99) 8860 pedwarn (input_location, OPT_pedantic, "duplicate %qE", qual); 8861 return specs; 8862 } 8863 8864 /* Add the type specifier TYPE to the declaration specifiers SPECS, 8865 returning SPECS. */ 8866 8867 struct c_declspecs * 8868 declspecs_add_type (location_t loc, struct c_declspecs *specs, 8869 struct c_typespec spec) 8870 { 8871 tree type = spec.spec; 8872 specs->non_sc_seen_p = true; 8873 specs->declspecs_seen_p = true; 8874 specs->typespec_kind = spec.kind; 8875 if (TREE_DEPRECATED (type)) 8876 specs->deprecated_p = true; 8877 8878 /* Handle type specifier keywords. */ 8879 if (TREE_CODE (type) == IDENTIFIER_NODE 8880 && C_IS_RESERVED_WORD (type) 8881 && C_RID_CODE (type) != RID_CXX_COMPAT_WARN) 8882 { 8883 enum rid i = C_RID_CODE (type); 8884 if (specs->type) 8885 { 8886 error_at (loc, "two or more data types in declaration specifiers"); 8887 return specs; 8888 } 8889 if ((int) i <= (int) RID_LAST_MODIFIER) 8890 { 8891 /* "long", "short", "signed", "unsigned", "_Complex" or "_Sat". */ 8892 bool dupe = false; 8893 switch (i) 8894 { 8895 case RID_LONG: 8896 if (specs->long_long_p) 8897 { 8898 error_at (loc, "%<long long long%> is too long for GCC"); 8899 break; 8900 } 8901 if (specs->long_p) 8902 { 8903 if (specs->typespec_word == cts_double) 8904 { 8905 error_at (loc, 8906 ("both %<long long%> and %<double%> in " 8907 "declaration specifiers")); 8908 break; 8909 } 8910 pedwarn_c90 (loc, OPT_Wlong_long, 8911 "ISO C90 does not support %<long long%>"); 8912 specs->long_long_p = 1; 8913 break; 8914 } 8915 if (specs->short_p) 8916 error_at (loc, 8917 ("both %<long%> and %<short%> in " 8918 "declaration specifiers")); 8919 else if (specs->typespec_word == cts_void) 8920 error_at (loc, 8921 ("both %<long%> and %<void%> in " 8922 "declaration specifiers")); 8923 else if (specs->typespec_word == cts_int128) 8924 error_at (loc, 8925 ("both %<long%> and %<__int128%> in " 8926 "declaration specifiers")); 8927 else if (specs->typespec_word == cts_bool) 8928 error_at (loc, 8929 ("both %<long%> and %<_Bool%> in " 8930 "declaration specifiers")); 8931 else if (specs->typespec_word == cts_char) 8932 error_at (loc, 8933 ("both %<long%> and %<char%> in " 8934 "declaration specifiers")); 8935 else if (specs->typespec_word == cts_float) 8936 error_at (loc, 8937 ("both %<long%> and %<float%> in " 8938 "declaration specifiers")); 8939 else if (specs->typespec_word == cts_dfloat32) 8940 error_at (loc, 8941 ("both %<long%> and %<_Decimal32%> in " 8942 "declaration specifiers")); 8943 else if (specs->typespec_word == cts_dfloat64) 8944 error_at (loc, 8945 ("both %<long%> and %<_Decimal64%> in " 8946 "declaration specifiers")); 8947 else if (specs->typespec_word == cts_dfloat128) 8948 error_at (loc, 8949 ("both %<long%> and %<_Decimal128%> in " 8950 "declaration specifiers")); 8951 else 8952 specs->long_p = true; 8953 break; 8954 case RID_SHORT: 8955 dupe = specs->short_p; 8956 if (specs->long_p) 8957 error_at (loc, 8958 ("both %<long%> and %<short%> in " 8959 "declaration specifiers")); 8960 else if (specs->typespec_word == cts_void) 8961 error_at (loc, 8962 ("both %<short%> and %<void%> in " 8963 "declaration specifiers")); 8964 else if (specs->typespec_word == cts_int128) 8965 error_at (loc, 8966 ("both %<short%> and %<__int128%> in " 8967 "declaration specifiers")); 8968 else if (specs->typespec_word == cts_bool) 8969 error_at (loc, 8970 ("both %<short%> and %<_Bool%> in " 8971 "declaration specifiers")); 8972 else if (specs->typespec_word == cts_char) 8973 error_at (loc, 8974 ("both %<short%> and %<char%> in " 8975 "declaration specifiers")); 8976 else if (specs->typespec_word == cts_float) 8977 error_at (loc, 8978 ("both %<short%> and %<float%> in " 8979 "declaration specifiers")); 8980 else if (specs->typespec_word == cts_double) 8981 error_at (loc, 8982 ("both %<short%> and %<double%> in " 8983 "declaration specifiers")); 8984 else if (specs->typespec_word == cts_dfloat32) 8985 error_at (loc, 8986 ("both %<short%> and %<_Decimal32%> in " 8987 "declaration specifiers")); 8988 else if (specs->typespec_word == cts_dfloat64) 8989 error_at (loc, 8990 ("both %<short%> and %<_Decimal64%> in " 8991 "declaration specifiers")); 8992 else if (specs->typespec_word == cts_dfloat128) 8993 error_at (loc, 8994 ("both %<short%> and %<_Decimal128%> in " 8995 "declaration specifiers")); 8996 else 8997 specs->short_p = true; 8998 break; 8999 case RID_SIGNED: 9000 dupe = specs->signed_p; 9001 if (specs->unsigned_p) 9002 error_at (loc, 9003 ("both %<signed%> and %<unsigned%> in " 9004 "declaration specifiers")); 9005 else if (specs->typespec_word == cts_void) 9006 error_at (loc, 9007 ("both %<signed%> and %<void%> in " 9008 "declaration specifiers")); 9009 else if (specs->typespec_word == cts_bool) 9010 error_at (loc, 9011 ("both %<signed%> and %<_Bool%> in " 9012 "declaration specifiers")); 9013 else if (specs->typespec_word == cts_float) 9014 error_at (loc, 9015 ("both %<signed%> and %<float%> in " 9016 "declaration specifiers")); 9017 else if (specs->typespec_word == cts_double) 9018 error_at (loc, 9019 ("both %<signed%> and %<double%> in " 9020 "declaration specifiers")); 9021 else if (specs->typespec_word == cts_dfloat32) 9022 error_at (loc, 9023 ("both %<signed%> and %<_Decimal32%> in " 9024 "declaration specifiers")); 9025 else if (specs->typespec_word == cts_dfloat64) 9026 error_at (loc, 9027 ("both %<signed%> and %<_Decimal64%> in " 9028 "declaration specifiers")); 9029 else if (specs->typespec_word == cts_dfloat128) 9030 error_at (loc, 9031 ("both %<signed%> and %<_Decimal128%> in " 9032 "declaration specifiers")); 9033 else 9034 specs->signed_p = true; 9035 break; 9036 case RID_UNSIGNED: 9037 dupe = specs->unsigned_p; 9038 if (specs->signed_p) 9039 error_at (loc, 9040 ("both %<signed%> and %<unsigned%> in " 9041 "declaration specifiers")); 9042 else if (specs->typespec_word == cts_void) 9043 error_at (loc, 9044 ("both %<unsigned%> and %<void%> in " 9045 "declaration specifiers")); 9046 else if (specs->typespec_word == cts_bool) 9047 error_at (loc, 9048 ("both %<unsigned%> and %<_Bool%> in " 9049 "declaration specifiers")); 9050 else if (specs->typespec_word == cts_float) 9051 error_at (loc, 9052 ("both %<unsigned%> and %<float%> in " 9053 "declaration specifiers")); 9054 else if (specs->typespec_word == cts_double) 9055 error_at (loc, 9056 ("both %<unsigned%> and %<double%> in " 9057 "declaration specifiers")); 9058 else if (specs->typespec_word == cts_dfloat32) 9059 error_at (loc, 9060 ("both %<unsigned%> and %<_Decimal32%> in " 9061 "declaration specifiers")); 9062 else if (specs->typespec_word == cts_dfloat64) 9063 error_at (loc, 9064 ("both %<unsigned%> and %<_Decimal64%> in " 9065 "declaration specifiers")); 9066 else if (specs->typespec_word == cts_dfloat128) 9067 error_at (loc, 9068 ("both %<unsigned%> and %<_Decimal128%> in " 9069 "declaration specifiers")); 9070 else 9071 specs->unsigned_p = true; 9072 break; 9073 case RID_COMPLEX: 9074 dupe = specs->complex_p; 9075 if (!flag_isoc99 && !in_system_header) 9076 pedwarn (loc, OPT_pedantic, 9077 "ISO C90 does not support complex types"); 9078 if (specs->typespec_word == cts_void) 9079 error_at (loc, 9080 ("both %<complex%> and %<void%> in " 9081 "declaration specifiers")); 9082 else if (specs->typespec_word == cts_bool) 9083 error_at (loc, 9084 ("both %<complex%> and %<_Bool%> in " 9085 "declaration specifiers")); 9086 else if (specs->typespec_word == cts_dfloat32) 9087 error_at (loc, 9088 ("both %<complex%> and %<_Decimal32%> in " 9089 "declaration specifiers")); 9090 else if (specs->typespec_word == cts_dfloat64) 9091 error_at (loc, 9092 ("both %<complex%> and %<_Decimal64%> in " 9093 "declaration specifiers")); 9094 else if (specs->typespec_word == cts_dfloat128) 9095 error_at (loc, 9096 ("both %<complex%> and %<_Decimal128%> in " 9097 "declaration specifiers")); 9098 else if (specs->typespec_word == cts_fract) 9099 error_at (loc, 9100 ("both %<complex%> and %<_Fract%> in " 9101 "declaration specifiers")); 9102 else if (specs->typespec_word == cts_accum) 9103 error_at (loc, 9104 ("both %<complex%> and %<_Accum%> in " 9105 "declaration specifiers")); 9106 else if (specs->saturating_p) 9107 error_at (loc, 9108 ("both %<complex%> and %<_Sat%> in " 9109 "declaration specifiers")); 9110 else 9111 specs->complex_p = true; 9112 break; 9113 case RID_SAT: 9114 dupe = specs->saturating_p; 9115 pedwarn (loc, OPT_pedantic, 9116 "ISO C does not support saturating types"); 9117 if (specs->typespec_word == cts_int128) 9118 { 9119 error_at (loc, 9120 ("both %<_Sat%> and %<__int128%> in " 9121 "declaration specifiers")); 9122 } 9123 else if (specs->typespec_word == cts_void) 9124 error_at (loc, 9125 ("both %<_Sat%> and %<void%> in " 9126 "declaration specifiers")); 9127 else if (specs->typespec_word == cts_bool) 9128 error_at (loc, 9129 ("both %<_Sat%> and %<_Bool%> in " 9130 "declaration specifiers")); 9131 else if (specs->typespec_word == cts_char) 9132 error_at (loc, 9133 ("both %<_Sat%> and %<char%> in " 9134 "declaration specifiers")); 9135 else if (specs->typespec_word == cts_int) 9136 error_at (loc, 9137 ("both %<_Sat%> and %<int%> in " 9138 "declaration specifiers")); 9139 else if (specs->typespec_word == cts_float) 9140 error_at (loc, 9141 ("both %<_Sat%> and %<float%> in " 9142 "declaration specifiers")); 9143 else if (specs->typespec_word == cts_double) 9144 error_at (loc, 9145 ("both %<_Sat%> and %<double%> in " 9146 "declaration specifiers")); 9147 else if (specs->typespec_word == cts_dfloat32) 9148 error_at (loc, 9149 ("both %<_Sat%> and %<_Decimal32%> in " 9150 "declaration specifiers")); 9151 else if (specs->typespec_word == cts_dfloat64) 9152 error_at (loc, 9153 ("both %<_Sat%> and %<_Decimal64%> in " 9154 "declaration specifiers")); 9155 else if (specs->typespec_word == cts_dfloat128) 9156 error_at (loc, 9157 ("both %<_Sat%> and %<_Decimal128%> in " 9158 "declaration specifiers")); 9159 else if (specs->complex_p) 9160 error_at (loc, 9161 ("both %<_Sat%> and %<complex%> in " 9162 "declaration specifiers")); 9163 else 9164 specs->saturating_p = true; 9165 break; 9166 default: 9167 gcc_unreachable (); 9168 } 9169 9170 if (dupe) 9171 error_at (loc, "duplicate %qE", type); 9172 9173 return specs; 9174 } 9175 else 9176 { 9177 /* "void", "_Bool", "char", "int", "float", "double", "_Decimal32", 9178 "__int128", "_Decimal64", "_Decimal128", "_Fract" or "_Accum". */ 9179 if (specs->typespec_word != cts_none) 9180 { 9181 error_at (loc, 9182 "two or more data types in declaration specifiers"); 9183 return specs; 9184 } 9185 switch (i) 9186 { 9187 case RID_INT128: 9188 if (int128_integer_type_node == NULL_TREE) 9189 { 9190 error_at (loc, "%<__int128%> is not supported for this target"); 9191 return specs; 9192 } 9193 if (!in_system_header) 9194 pedwarn (loc, OPT_pedantic, 9195 "ISO C does not support %<__int128%> type"); 9196 9197 if (specs->long_p) 9198 error_at (loc, 9199 ("both %<__int128%> and %<long%> in " 9200 "declaration specifiers")); 9201 else if (specs->saturating_p) 9202 error_at (loc, 9203 ("both %<_Sat%> and %<__int128%> in " 9204 "declaration specifiers")); 9205 else if (specs->short_p) 9206 error_at (loc, 9207 ("both %<__int128%> and %<short%> in " 9208 "declaration specifiers")); 9209 else 9210 specs->typespec_word = cts_int128; 9211 return specs; 9212 case RID_VOID: 9213 if (specs->long_p) 9214 error_at (loc, 9215 ("both %<long%> and %<void%> in " 9216 "declaration specifiers")); 9217 else if (specs->short_p) 9218 error_at (loc, 9219 ("both %<short%> and %<void%> in " 9220 "declaration specifiers")); 9221 else if (specs->signed_p) 9222 error_at (loc, 9223 ("both %<signed%> and %<void%> in " 9224 "declaration specifiers")); 9225 else if (specs->unsigned_p) 9226 error_at (loc, 9227 ("both %<unsigned%> and %<void%> in " 9228 "declaration specifiers")); 9229 else if (specs->complex_p) 9230 error_at (loc, 9231 ("both %<complex%> and %<void%> in " 9232 "declaration specifiers")); 9233 else if (specs->saturating_p) 9234 error_at (loc, 9235 ("both %<_Sat%> and %<void%> in " 9236 "declaration specifiers")); 9237 else 9238 specs->typespec_word = cts_void; 9239 return specs; 9240 case RID_BOOL: 9241 if (specs->long_p) 9242 error_at (loc, 9243 ("both %<long%> and %<_Bool%> in " 9244 "declaration specifiers")); 9245 else if (specs->short_p) 9246 error_at (loc, 9247 ("both %<short%> and %<_Bool%> in " 9248 "declaration specifiers")); 9249 else if (specs->signed_p) 9250 error_at (loc, 9251 ("both %<signed%> and %<_Bool%> in " 9252 "declaration specifiers")); 9253 else if (specs->unsigned_p) 9254 error_at (loc, 9255 ("both %<unsigned%> and %<_Bool%> in " 9256 "declaration specifiers")); 9257 else if (specs->complex_p) 9258 error_at (loc, 9259 ("both %<complex%> and %<_Bool%> in " 9260 "declaration specifiers")); 9261 else if (specs->saturating_p) 9262 error_at (loc, 9263 ("both %<_Sat%> and %<_Bool%> in " 9264 "declaration specifiers")); 9265 else 9266 specs->typespec_word = cts_bool; 9267 return specs; 9268 case RID_CHAR: 9269 if (specs->long_p) 9270 error_at (loc, 9271 ("both %<long%> and %<char%> in " 9272 "declaration specifiers")); 9273 else if (specs->short_p) 9274 error_at (loc, 9275 ("both %<short%> and %<char%> in " 9276 "declaration specifiers")); 9277 else if (specs->saturating_p) 9278 error_at (loc, 9279 ("both %<_Sat%> and %<char%> in " 9280 "declaration specifiers")); 9281 else 9282 specs->typespec_word = cts_char; 9283 return specs; 9284 case RID_INT: 9285 if (specs->saturating_p) 9286 error_at (loc, 9287 ("both %<_Sat%> and %<int%> in " 9288 "declaration specifiers")); 9289 else 9290 specs->typespec_word = cts_int; 9291 return specs; 9292 case RID_FLOAT: 9293 if (specs->long_p) 9294 error_at (loc, 9295 ("both %<long%> and %<float%> in " 9296 "declaration specifiers")); 9297 else if (specs->short_p) 9298 error_at (loc, 9299 ("both %<short%> and %<float%> in " 9300 "declaration specifiers")); 9301 else if (specs->signed_p) 9302 error_at (loc, 9303 ("both %<signed%> and %<float%> in " 9304 "declaration specifiers")); 9305 else if (specs->unsigned_p) 9306 error_at (loc, 9307 ("both %<unsigned%> and %<float%> in " 9308 "declaration specifiers")); 9309 else if (specs->saturating_p) 9310 error_at (loc, 9311 ("both %<_Sat%> and %<float%> in " 9312 "declaration specifiers")); 9313 else 9314 specs->typespec_word = cts_float; 9315 return specs; 9316 case RID_DOUBLE: 9317 if (specs->long_long_p) 9318 error_at (loc, 9319 ("both %<long long%> and %<double%> in " 9320 "declaration specifiers")); 9321 else if (specs->short_p) 9322 error_at (loc, 9323 ("both %<short%> and %<double%> in " 9324 "declaration specifiers")); 9325 else if (specs->signed_p) 9326 error_at (loc, 9327 ("both %<signed%> and %<double%> in " 9328 "declaration specifiers")); 9329 else if (specs->unsigned_p) 9330 error_at (loc, 9331 ("both %<unsigned%> and %<double%> in " 9332 "declaration specifiers")); 9333 else if (specs->saturating_p) 9334 error_at (loc, 9335 ("both %<_Sat%> and %<double%> in " 9336 "declaration specifiers")); 9337 else 9338 specs->typespec_word = cts_double; 9339 return specs; 9340 case RID_DFLOAT32: 9341 case RID_DFLOAT64: 9342 case RID_DFLOAT128: 9343 { 9344 const char *str; 9345 if (i == RID_DFLOAT32) 9346 str = "_Decimal32"; 9347 else if (i == RID_DFLOAT64) 9348 str = "_Decimal64"; 9349 else 9350 str = "_Decimal128"; 9351 if (specs->long_long_p) 9352 error_at (loc, 9353 ("both %<long long%> and %<%s%> in " 9354 "declaration specifiers"), 9355 str); 9356 if (specs->long_p) 9357 error_at (loc, 9358 ("both %<long%> and %<%s%> in " 9359 "declaration specifiers"), 9360 str); 9361 else if (specs->short_p) 9362 error_at (loc, 9363 ("both %<short%> and %<%s%> in " 9364 "declaration specifiers"), 9365 str); 9366 else if (specs->signed_p) 9367 error_at (loc, 9368 ("both %<signed%> and %<%s%> in " 9369 "declaration specifiers"), 9370 str); 9371 else if (specs->unsigned_p) 9372 error_at (loc, 9373 ("both %<unsigned%> and %<%s%> in " 9374 "declaration specifiers"), 9375 str); 9376 else if (specs->complex_p) 9377 error_at (loc, 9378 ("both %<complex%> and %<%s%> in " 9379 "declaration specifiers"), 9380 str); 9381 else if (specs->saturating_p) 9382 error_at (loc, 9383 ("both %<_Sat%> and %<%s%> in " 9384 "declaration specifiers"), 9385 str); 9386 else if (i == RID_DFLOAT32) 9387 specs->typespec_word = cts_dfloat32; 9388 else if (i == RID_DFLOAT64) 9389 specs->typespec_word = cts_dfloat64; 9390 else 9391 specs->typespec_word = cts_dfloat128; 9392 } 9393 if (!targetm.decimal_float_supported_p ()) 9394 error_at (loc, 9395 ("decimal floating point not supported " 9396 "for this target")); 9397 pedwarn (loc, OPT_pedantic, 9398 "ISO C does not support decimal floating point"); 9399 return specs; 9400 case RID_FRACT: 9401 case RID_ACCUM: 9402 { 9403 const char *str; 9404 if (i == RID_FRACT) 9405 str = "_Fract"; 9406 else 9407 str = "_Accum"; 9408 if (specs->complex_p) 9409 error_at (loc, 9410 ("both %<complex%> and %<%s%> in " 9411 "declaration specifiers"), 9412 str); 9413 else if (i == RID_FRACT) 9414 specs->typespec_word = cts_fract; 9415 else 9416 specs->typespec_word = cts_accum; 9417 } 9418 if (!targetm.fixed_point_supported_p ()) 9419 error_at (loc, 9420 "fixed-point types not supported for this target"); 9421 pedwarn (loc, OPT_pedantic, 9422 "ISO C does not support fixed-point types"); 9423 return specs; 9424 default: 9425 /* ObjC reserved word "id", handled below. */ 9426 break; 9427 } 9428 } 9429 } 9430 9431 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 9432 form of ObjC type, cases such as "int" and "long" being handled 9433 above), a TYPE (struct, union, enum and typeof specifiers) or an 9434 ERROR_MARK. In none of these cases may there have previously 9435 been any type specifiers. */ 9436 if (specs->type || specs->typespec_word != cts_none 9437 || specs->long_p || specs->short_p || specs->signed_p 9438 || specs->unsigned_p || specs->complex_p) 9439 error_at (loc, "two or more data types in declaration specifiers"); 9440 else if (TREE_CODE (type) == TYPE_DECL) 9441 { 9442 if (TREE_TYPE (type) == error_mark_node) 9443 ; /* Allow the type to default to int to avoid cascading errors. */ 9444 else 9445 { 9446 specs->type = TREE_TYPE (type); 9447 specs->decl_attr = DECL_ATTRIBUTES (type); 9448 specs->typedef_p = true; 9449 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 9450 9451 /* If this typedef name is defined in a struct, then a C++ 9452 lookup would return a different value. */ 9453 if (warn_cxx_compat 9454 && I_SYMBOL_BINDING (DECL_NAME (type))->in_struct) 9455 warning_at (loc, OPT_Wc___compat, 9456 "C++ lookup of %qD would return a field, not a type", 9457 type); 9458 9459 /* If we are parsing a struct, record that a struct field 9460 used a typedef. */ 9461 if (warn_cxx_compat && struct_parse_info != NULL) 9462 VEC_safe_push (tree, heap, struct_parse_info->typedefs_seen, type); 9463 } 9464 } 9465 else if (TREE_CODE (type) == IDENTIFIER_NODE) 9466 { 9467 tree t = lookup_name (type); 9468 if (!t || TREE_CODE (t) != TYPE_DECL) 9469 error_at (loc, "%qE fails to be a typedef or built in type", type); 9470 else if (TREE_TYPE (t) == error_mark_node) 9471 ; 9472 else 9473 specs->type = TREE_TYPE (t); 9474 } 9475 else 9476 { 9477 if (TREE_CODE (type) != ERROR_MARK && spec.kind == ctsk_typeof) 9478 { 9479 specs->typedef_p = true; 9480 if (spec.expr) 9481 { 9482 if (specs->expr) 9483 specs->expr = build2 (COMPOUND_EXPR, TREE_TYPE (spec.expr), 9484 specs->expr, spec.expr); 9485 else 9486 specs->expr = spec.expr; 9487 specs->expr_const_operands &= spec.expr_const_operands; 9488 } 9489 } 9490 specs->type = type; 9491 } 9492 9493 return specs; 9494 } 9495 9496 /* Add the storage class specifier or function specifier SCSPEC to the 9497 declaration specifiers SPECS, returning SPECS. */ 9498 9499 struct c_declspecs * 9500 declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 9501 { 9502 enum rid i; 9503 enum c_storage_class n = csc_none; 9504 bool dupe = false; 9505 specs->declspecs_seen_p = true; 9506 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 9507 && C_IS_RESERVED_WORD (scspec)); 9508 i = C_RID_CODE (scspec); 9509 if (specs->non_sc_seen_p) 9510 warning (OPT_Wold_style_declaration, 9511 "%qE is not at beginning of declaration", scspec); 9512 switch (i) 9513 { 9514 case RID_INLINE: 9515 /* C99 permits duplicate inline. Although of doubtful utility, 9516 it seems simplest to permit it in gnu89 mode as well, as 9517 there is also little utility in maintaining this as a 9518 difference between gnu89 and C99 inline. */ 9519 dupe = false; 9520 specs->inline_p = true; 9521 break; 9522 case RID_NORETURN: 9523 /* Duplicate _Noreturn is permitted. */ 9524 dupe = false; 9525 specs->noreturn_p = true; 9526 break; 9527 case RID_THREAD: 9528 dupe = specs->thread_p; 9529 if (specs->storage_class == csc_auto) 9530 error ("%<__thread%> used with %<auto%>"); 9531 else if (specs->storage_class == csc_register) 9532 error ("%<__thread%> used with %<register%>"); 9533 else if (specs->storage_class == csc_typedef) 9534 error ("%<__thread%> used with %<typedef%>"); 9535 else 9536 specs->thread_p = true; 9537 break; 9538 case RID_AUTO: 9539 n = csc_auto; 9540 break; 9541 case RID_EXTERN: 9542 n = csc_extern; 9543 /* Diagnose "__thread extern". */ 9544 if (specs->thread_p) 9545 error ("%<__thread%> before %<extern%>"); 9546 break; 9547 case RID_REGISTER: 9548 n = csc_register; 9549 break; 9550 case RID_STATIC: 9551 n = csc_static; 9552 /* Diagnose "__thread static". */ 9553 if (specs->thread_p) 9554 error ("%<__thread%> before %<static%>"); 9555 break; 9556 case RID_TYPEDEF: 9557 n = csc_typedef; 9558 break; 9559 default: 9560 gcc_unreachable (); 9561 } 9562 if (n != csc_none && n == specs->storage_class) 9563 dupe = true; 9564 if (dupe) 9565 error ("duplicate %qE", scspec); 9566 if (n != csc_none) 9567 { 9568 if (specs->storage_class != csc_none && n != specs->storage_class) 9569 { 9570 error ("multiple storage classes in declaration specifiers"); 9571 } 9572 else 9573 { 9574 specs->storage_class = n; 9575 if (n != csc_extern && n != csc_static && specs->thread_p) 9576 { 9577 error ("%<__thread%> used with %qE", scspec); 9578 specs->thread_p = false; 9579 } 9580 } 9581 } 9582 return specs; 9583 } 9584 9585 /* Add the attributes ATTRS to the declaration specifiers SPECS, 9586 returning SPECS. */ 9587 9588 struct c_declspecs * 9589 declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 9590 { 9591 specs->attrs = chainon (attrs, specs->attrs); 9592 specs->declspecs_seen_p = true; 9593 return specs; 9594 } 9595 9596 /* Add an _Alignas specifier (expression ALIGN, or type whose 9597 alignment is ALIGN) to the declaration specifiers SPECS, returning 9598 SPECS. */ 9599 struct c_declspecs * 9600 declspecs_add_alignas (struct c_declspecs *specs, tree align) 9601 { 9602 int align_log; 9603 specs->alignas_p = true; 9604 if (align == error_mark_node) 9605 return specs; 9606 align_log = check_user_alignment (align, true); 9607 if (align_log > specs->align_log) 9608 specs->align_log = align_log; 9609 return specs; 9610 } 9611 9612 /* Combine "long", "short", "signed", "unsigned" and "_Complex" type 9613 specifiers with any other type specifier to determine the resulting 9614 type. This is where ISO C checks on complex types are made, since 9615 "_Complex long" is a prefix of the valid ISO C type "_Complex long 9616 double". */ 9617 9618 struct c_declspecs * 9619 finish_declspecs (struct c_declspecs *specs) 9620 { 9621 /* If a type was specified as a whole, we have no modifiers and are 9622 done. */ 9623 if (specs->type != NULL_TREE) 9624 { 9625 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 9626 && !specs->signed_p && !specs->unsigned_p 9627 && !specs->complex_p); 9628 9629 /* Set a dummy type. */ 9630 if (TREE_CODE (specs->type) == ERROR_MARK) 9631 specs->type = integer_type_node; 9632 return specs; 9633 } 9634 9635 /* If none of "void", "_Bool", "char", "int", "float" or "double" 9636 has been specified, treat it as "int" unless "_Complex" is 9637 present and there are no other specifiers. If we just have 9638 "_Complex", it is equivalent to "_Complex double", but e.g. 9639 "_Complex short" is equivalent to "_Complex short int". */ 9640 if (specs->typespec_word == cts_none) 9641 { 9642 if (specs->saturating_p) 9643 { 9644 error ("%<_Sat%> is used without %<_Fract%> or %<_Accum%>"); 9645 if (!targetm.fixed_point_supported_p ()) 9646 error ("fixed-point types not supported for this target"); 9647 specs->typespec_word = cts_fract; 9648 } 9649 else if (specs->long_p || specs->short_p 9650 || specs->signed_p || specs->unsigned_p) 9651 { 9652 specs->typespec_word = cts_int; 9653 } 9654 else if (specs->complex_p) 9655 { 9656 specs->typespec_word = cts_double; 9657 pedwarn (input_location, OPT_pedantic, 9658 "ISO C does not support plain %<complex%> meaning " 9659 "%<double complex%>"); 9660 } 9661 else 9662 { 9663 specs->typespec_word = cts_int; 9664 specs->default_int_p = true; 9665 /* We don't diagnose this here because grokdeclarator will 9666 give more specific diagnostics according to whether it is 9667 a function definition. */ 9668 } 9669 } 9670 9671 /* If "signed" was specified, record this to distinguish "int" and 9672 "signed int" in the case of a bit-field with 9673 -funsigned-bitfields. */ 9674 specs->explicit_signed_p = specs->signed_p; 9675 9676 /* Now compute the actual type. */ 9677 switch (specs->typespec_word) 9678 { 9679 case cts_void: 9680 gcc_assert (!specs->long_p && !specs->short_p 9681 && !specs->signed_p && !specs->unsigned_p 9682 && !specs->complex_p); 9683 specs->type = void_type_node; 9684 break; 9685 case cts_bool: 9686 gcc_assert (!specs->long_p && !specs->short_p 9687 && !specs->signed_p && !specs->unsigned_p 9688 && !specs->complex_p); 9689 specs->type = boolean_type_node; 9690 break; 9691 case cts_char: 9692 gcc_assert (!specs->long_p && !specs->short_p); 9693 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9694 if (specs->signed_p) 9695 specs->type = signed_char_type_node; 9696 else if (specs->unsigned_p) 9697 specs->type = unsigned_char_type_node; 9698 else 9699 specs->type = char_type_node; 9700 if (specs->complex_p) 9701 { 9702 pedwarn (input_location, OPT_pedantic, 9703 "ISO C does not support complex integer types"); 9704 specs->type = build_complex_type (specs->type); 9705 } 9706 break; 9707 case cts_int128: 9708 gcc_assert (!specs->long_p && !specs->short_p && !specs->long_long_p); 9709 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9710 specs->type = (specs->unsigned_p 9711 ? int128_unsigned_type_node 9712 : int128_integer_type_node); 9713 if (specs->complex_p) 9714 { 9715 pedwarn (input_location, OPT_pedantic, 9716 "ISO C does not support complex integer types"); 9717 specs->type = build_complex_type (specs->type); 9718 } 9719 break; 9720 case cts_int: 9721 gcc_assert (!(specs->long_p && specs->short_p)); 9722 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9723 if (specs->long_long_p) 9724 specs->type = (specs->unsigned_p 9725 ? long_long_unsigned_type_node 9726 : long_long_integer_type_node); 9727 else if (specs->long_p) 9728 specs->type = (specs->unsigned_p 9729 ? long_unsigned_type_node 9730 : long_integer_type_node); 9731 else if (specs->short_p) 9732 specs->type = (specs->unsigned_p 9733 ? short_unsigned_type_node 9734 : short_integer_type_node); 9735 else 9736 specs->type = (specs->unsigned_p 9737 ? unsigned_type_node 9738 : integer_type_node); 9739 if (specs->complex_p) 9740 { 9741 pedwarn (input_location, OPT_pedantic, 9742 "ISO C does not support complex integer types"); 9743 specs->type = build_complex_type (specs->type); 9744 } 9745 break; 9746 case cts_float: 9747 gcc_assert (!specs->long_p && !specs->short_p 9748 && !specs->signed_p && !specs->unsigned_p); 9749 specs->type = (specs->complex_p 9750 ? complex_float_type_node 9751 : float_type_node); 9752 break; 9753 case cts_double: 9754 gcc_assert (!specs->long_long_p && !specs->short_p 9755 && !specs->signed_p && !specs->unsigned_p); 9756 if (specs->long_p) 9757 { 9758 specs->type = (specs->complex_p 9759 ? complex_long_double_type_node 9760 : long_double_type_node); 9761 } 9762 else 9763 { 9764 specs->type = (specs->complex_p 9765 ? complex_double_type_node 9766 : double_type_node); 9767 } 9768 break; 9769 case cts_dfloat32: 9770 case cts_dfloat64: 9771 case cts_dfloat128: 9772 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 9773 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 9774 if (specs->typespec_word == cts_dfloat32) 9775 specs->type = dfloat32_type_node; 9776 else if (specs->typespec_word == cts_dfloat64) 9777 specs->type = dfloat64_type_node; 9778 else 9779 specs->type = dfloat128_type_node; 9780 break; 9781 case cts_fract: 9782 gcc_assert (!specs->complex_p); 9783 if (!targetm.fixed_point_supported_p ()) 9784 specs->type = integer_type_node; 9785 else if (specs->saturating_p) 9786 { 9787 if (specs->long_long_p) 9788 specs->type = specs->unsigned_p 9789 ? sat_unsigned_long_long_fract_type_node 9790 : sat_long_long_fract_type_node; 9791 else if (specs->long_p) 9792 specs->type = specs->unsigned_p 9793 ? sat_unsigned_long_fract_type_node 9794 : sat_long_fract_type_node; 9795 else if (specs->short_p) 9796 specs->type = specs->unsigned_p 9797 ? sat_unsigned_short_fract_type_node 9798 : sat_short_fract_type_node; 9799 else 9800 specs->type = specs->unsigned_p 9801 ? sat_unsigned_fract_type_node 9802 : sat_fract_type_node; 9803 } 9804 else 9805 { 9806 if (specs->long_long_p) 9807 specs->type = specs->unsigned_p 9808 ? unsigned_long_long_fract_type_node 9809 : long_long_fract_type_node; 9810 else if (specs->long_p) 9811 specs->type = specs->unsigned_p 9812 ? unsigned_long_fract_type_node 9813 : long_fract_type_node; 9814 else if (specs->short_p) 9815 specs->type = specs->unsigned_p 9816 ? unsigned_short_fract_type_node 9817 : short_fract_type_node; 9818 else 9819 specs->type = specs->unsigned_p 9820 ? unsigned_fract_type_node 9821 : fract_type_node; 9822 } 9823 break; 9824 case cts_accum: 9825 gcc_assert (!specs->complex_p); 9826 if (!targetm.fixed_point_supported_p ()) 9827 specs->type = integer_type_node; 9828 else if (specs->saturating_p) 9829 { 9830 if (specs->long_long_p) 9831 specs->type = specs->unsigned_p 9832 ? sat_unsigned_long_long_accum_type_node 9833 : sat_long_long_accum_type_node; 9834 else if (specs->long_p) 9835 specs->type = specs->unsigned_p 9836 ? sat_unsigned_long_accum_type_node 9837 : sat_long_accum_type_node; 9838 else if (specs->short_p) 9839 specs->type = specs->unsigned_p 9840 ? sat_unsigned_short_accum_type_node 9841 : sat_short_accum_type_node; 9842 else 9843 specs->type = specs->unsigned_p 9844 ? sat_unsigned_accum_type_node 9845 : sat_accum_type_node; 9846 } 9847 else 9848 { 9849 if (specs->long_long_p) 9850 specs->type = specs->unsigned_p 9851 ? unsigned_long_long_accum_type_node 9852 : long_long_accum_type_node; 9853 else if (specs->long_p) 9854 specs->type = specs->unsigned_p 9855 ? unsigned_long_accum_type_node 9856 : long_accum_type_node; 9857 else if (specs->short_p) 9858 specs->type = specs->unsigned_p 9859 ? unsigned_short_accum_type_node 9860 : short_accum_type_node; 9861 else 9862 specs->type = specs->unsigned_p 9863 ? unsigned_accum_type_node 9864 : accum_type_node; 9865 } 9866 break; 9867 default: 9868 gcc_unreachable (); 9869 } 9870 9871 return specs; 9872 } 9873 9874 /* A subroutine of c_write_global_declarations. Perform final processing 9875 on one file scope's declarations (or the external scope's declarations), 9876 GLOBALS. */ 9877 9878 static void 9879 c_write_global_declarations_1 (tree globals) 9880 { 9881 tree decl; 9882 bool reconsider; 9883 9884 /* Process the decls in the order they were written. */ 9885 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9886 { 9887 /* Check for used but undefined static functions using the C 9888 standard's definition of "used", and set TREE_NO_WARNING so 9889 that check_global_declarations doesn't repeat the check. */ 9890 if (TREE_CODE (decl) == FUNCTION_DECL 9891 && DECL_INITIAL (decl) == 0 9892 && DECL_EXTERNAL (decl) 9893 && !TREE_PUBLIC (decl) 9894 && C_DECL_USED (decl)) 9895 { 9896 pedwarn (input_location, 0, "%q+F used but never defined", decl); 9897 TREE_NO_WARNING (decl) = 1; 9898 } 9899 9900 wrapup_global_declaration_1 (decl); 9901 } 9902 9903 do 9904 { 9905 reconsider = false; 9906 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9907 reconsider |= wrapup_global_declaration_2 (decl); 9908 } 9909 while (reconsider); 9910 9911 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9912 check_global_declaration_1 (decl); 9913 } 9914 9915 /* A subroutine of c_write_global_declarations Emit debug information for each 9916 of the declarations in GLOBALS. */ 9917 9918 static void 9919 c_write_global_declarations_2 (tree globals) 9920 { 9921 tree decl; 9922 9923 for (decl = globals; decl ; decl = DECL_CHAIN (decl)) 9924 debug_hooks->global_decl (decl); 9925 } 9926 9927 /* Callback to collect a source_ref from a DECL. */ 9928 9929 static void 9930 collect_source_ref_cb (tree decl) 9931 { 9932 if (!DECL_IS_BUILTIN (decl)) 9933 collect_source_ref (LOCATION_FILE (decl_sloc (decl, false))); 9934 } 9935 9936 /* Preserve the external declarations scope across a garbage collect. */ 9937 static GTY(()) tree ext_block; 9938 9939 /* Collect all references relevant to SOURCE_FILE. */ 9940 9941 static void 9942 collect_all_refs (const char *source_file) 9943 { 9944 tree t; 9945 unsigned i; 9946 9947 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 9948 collect_ada_nodes (BLOCK_VARS (DECL_INITIAL (t)), source_file); 9949 9950 collect_ada_nodes (BLOCK_VARS (ext_block), source_file); 9951 } 9952 9953 /* Iterate over all global declarations and call CALLBACK. */ 9954 9955 static void 9956 for_each_global_decl (void (*callback) (tree decl)) 9957 { 9958 tree t; 9959 tree decls; 9960 tree decl; 9961 unsigned i; 9962 9963 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 9964 { 9965 decls = DECL_INITIAL (t); 9966 for (decl = BLOCK_VARS (decls); decl; decl = TREE_CHAIN (decl)) 9967 callback (decl); 9968 } 9969 9970 for (decl = BLOCK_VARS (ext_block); decl; decl = TREE_CHAIN (decl)) 9971 callback (decl); 9972 } 9973 9974 void 9975 c_write_global_declarations (void) 9976 { 9977 tree t; 9978 unsigned i; 9979 9980 /* We don't want to do this if generating a PCH. */ 9981 if (pch_file) 9982 return; 9983 9984 timevar_start (TV_PHASE_DEFERRED); 9985 9986 /* Do the Objective-C stuff. This is where all the Objective-C 9987 module stuff gets generated (symtab, class/protocol/selector 9988 lists etc). */ 9989 if (c_dialect_objc ()) 9990 objc_write_global_declarations (); 9991 9992 /* Close the external scope. */ 9993 ext_block = pop_scope (); 9994 external_scope = 0; 9995 gcc_assert (!current_scope); 9996 9997 /* Handle -fdump-ada-spec[-slim]. */ 9998 if (dump_enabled_p (TDI_ada)) 9999 { 10000 /* Build a table of files to generate specs for */ 10001 if (get_dump_file_info (TDI_ada)->flags & TDF_SLIM) 10002 collect_source_ref (main_input_filename); 10003 else 10004 for_each_global_decl (collect_source_ref_cb); 10005 10006 dump_ada_specs (collect_all_refs, NULL); 10007 } 10008 10009 if (ext_block) 10010 { 10011 tree tmp = BLOCK_VARS (ext_block); 10012 int flags; 10013 FILE * stream = dump_begin (TDI_tu, &flags); 10014 if (stream && tmp) 10015 { 10016 dump_node (tmp, flags & ~TDF_SLIM, stream); 10017 dump_end (TDI_tu, stream); 10018 } 10019 } 10020 10021 /* Process all file scopes in this compilation, and the external_scope, 10022 through wrapup_global_declarations and check_global_declarations. */ 10023 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 10024 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 10025 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 10026 10027 timevar_stop (TV_PHASE_DEFERRED); 10028 timevar_start (TV_PHASE_CGRAPH); 10029 10030 /* We're done parsing; proceed to optimize and emit assembly. 10031 FIXME: shouldn't be the front end's responsibility to call this. */ 10032 cgraph_finalize_compilation_unit (); 10033 10034 timevar_stop (TV_PHASE_CGRAPH); 10035 timevar_start (TV_PHASE_DBGINFO); 10036 10037 /* After cgraph has had a chance to emit everything that's going to 10038 be emitted, output debug information for globals. */ 10039 if (!seen_error ()) 10040 { 10041 timevar_push (TV_SYMOUT); 10042 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 10043 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 10044 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 10045 timevar_pop (TV_SYMOUT); 10046 } 10047 10048 ext_block = NULL; 10049 timevar_stop (TV_PHASE_DBGINFO); 10050 } 10051 10052 /* Register reserved keyword WORD as qualifier for address space AS. */ 10053 10054 void 10055 c_register_addr_space (const char *word, addr_space_t as) 10056 { 10057 int rid = RID_FIRST_ADDR_SPACE + as; 10058 tree id; 10059 10060 /* Address space qualifiers are only supported 10061 in C with GNU extensions enabled. */ 10062 if (c_dialect_objc () || flag_no_asm) 10063 return; 10064 10065 id = get_identifier (word); 10066 C_SET_RID_CODE (id, rid); 10067 C_IS_RESERVED_WORD (id) = 1; 10068 ridpointers [rid] = id; 10069 } 10070 10071 #include "gt-c-decl.h" 10072