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 /* If complete_array_type returns 3, it means that the 4622 initial value of the compound literal is empty. Allow it. */ 4623 gcc_assert (failure == 0 || failure == 3); 4624 4625 type = TREE_TYPE (decl); 4626 TREE_TYPE (DECL_INITIAL (decl)) = type; 4627 } 4628 4629 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 4630 return error_mark_node; 4631 4632 stmt = build_stmt (DECL_SOURCE_LOCATION (decl), DECL_EXPR, decl); 4633 complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt); 4634 TREE_SIDE_EFFECTS (complit) = 1; 4635 4636 layout_decl (decl, 0); 4637 4638 if (TREE_STATIC (decl)) 4639 { 4640 /* This decl needs a name for the assembler output. */ 4641 set_compound_literal_name (decl); 4642 DECL_DEFER_OUTPUT (decl) = 1; 4643 DECL_COMDAT (decl) = 1; 4644 DECL_ARTIFICIAL (decl) = 1; 4645 DECL_IGNORED_P (decl) = 1; 4646 pushdecl (decl); 4647 rest_of_decl_compilation (decl, 1, 0); 4648 } 4649 4650 if (non_const) 4651 { 4652 complit = build2 (C_MAYBE_CONST_EXPR, type, NULL, complit); 4653 C_MAYBE_CONST_EXPR_NON_CONST (complit) = 1; 4654 } 4655 4656 return complit; 4657 } 4658 4659 /* Check the type of a compound literal. Here we just check that it 4660 is valid for C++. */ 4661 4662 void 4663 check_compound_literal_type (location_t loc, struct c_type_name *type_name) 4664 { 4665 if (warn_cxx_compat 4666 && (type_name->specs->typespec_kind == ctsk_tagdef 4667 || type_name->specs->typespec_kind == ctsk_tagfirstref)) 4668 warning_at (loc, OPT_Wc___compat, 4669 "defining a type in a compound literal is invalid in C++"); 4670 } 4671 4672 /* Determine whether TYPE is a structure with a flexible array member, 4673 or a union containing such a structure (possibly recursively). */ 4674 4675 static bool 4676 flexible_array_type_p (tree type) 4677 { 4678 tree x; 4679 switch (TREE_CODE (type)) 4680 { 4681 case RECORD_TYPE: 4682 x = TYPE_FIELDS (type); 4683 if (x == NULL_TREE) 4684 return false; 4685 while (DECL_CHAIN (x) != NULL_TREE) 4686 x = DECL_CHAIN (x); 4687 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 4688 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 4689 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 4690 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 4691 return true; 4692 return false; 4693 case UNION_TYPE: 4694 for (x = TYPE_FIELDS (type); x != NULL_TREE; x = DECL_CHAIN (x)) 4695 { 4696 if (flexible_array_type_p (TREE_TYPE (x))) 4697 return true; 4698 } 4699 return false; 4700 default: 4701 return false; 4702 } 4703 } 4704 4705 /* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME, 4706 replacing with appropriate values if they are invalid. */ 4707 static void 4708 check_bitfield_type_and_width (tree *type, tree *width, tree orig_name) 4709 { 4710 tree type_mv; 4711 unsigned int max_width; 4712 unsigned HOST_WIDE_INT w; 4713 const char *name = (orig_name 4714 ? identifier_to_locale (IDENTIFIER_POINTER (orig_name)) 4715 : _("<anonymous>")); 4716 4717 /* Detect and ignore out of range field width and process valid 4718 field widths. */ 4719 if (!INTEGRAL_TYPE_P (TREE_TYPE (*width))) 4720 { 4721 error ("bit-field %qs width not an integer constant", name); 4722 *width = integer_one_node; 4723 } 4724 else 4725 { 4726 if (TREE_CODE (*width) != INTEGER_CST) 4727 { 4728 *width = c_fully_fold (*width, false, NULL); 4729 if (TREE_CODE (*width) == INTEGER_CST) 4730 pedwarn (input_location, OPT_pedantic, 4731 "bit-field %qs width not an integer constant expression", 4732 name); 4733 } 4734 if (TREE_CODE (*width) != INTEGER_CST) 4735 { 4736 error ("bit-field %qs width not an integer constant", name); 4737 *width = integer_one_node; 4738 } 4739 constant_expression_warning (*width); 4740 if (tree_int_cst_sgn (*width) < 0) 4741 { 4742 error ("negative width in bit-field %qs", name); 4743 *width = integer_one_node; 4744 } 4745 else if (integer_zerop (*width) && orig_name) 4746 { 4747 error ("zero width for bit-field %qs", name); 4748 *width = integer_one_node; 4749 } 4750 } 4751 4752 /* Detect invalid bit-field type. */ 4753 if (TREE_CODE (*type) != INTEGER_TYPE 4754 && TREE_CODE (*type) != BOOLEAN_TYPE 4755 && TREE_CODE (*type) != ENUMERAL_TYPE) 4756 { 4757 error ("bit-field %qs has invalid type", name); 4758 *type = unsigned_type_node; 4759 } 4760 4761 type_mv = TYPE_MAIN_VARIANT (*type); 4762 if (!in_system_header 4763 && type_mv != integer_type_node 4764 && type_mv != unsigned_type_node 4765 && type_mv != boolean_type_node) 4766 pedwarn (input_location, OPT_pedantic, 4767 "type of bit-field %qs is a GCC extension", name); 4768 4769 max_width = TYPE_PRECISION (*type); 4770 4771 if (0 < compare_tree_int (*width, max_width)) 4772 { 4773 error ("width of %qs exceeds its type", name); 4774 w = max_width; 4775 *width = build_int_cst (integer_type_node, w); 4776 } 4777 else 4778 w = tree_low_cst (*width, 1); 4779 4780 if (TREE_CODE (*type) == ENUMERAL_TYPE) 4781 { 4782 struct lang_type *lt = TYPE_LANG_SPECIFIC (*type); 4783 if (!lt 4784 || w < tree_int_cst_min_precision (lt->enum_min, TYPE_UNSIGNED (*type)) 4785 || w < tree_int_cst_min_precision (lt->enum_max, TYPE_UNSIGNED (*type))) 4786 warning (0, "%qs is narrower than values of its type", name); 4787 } 4788 } 4789 4790 4791 4792 /* Print warning about variable length array if necessary. */ 4793 4794 static void 4795 warn_variable_length_array (tree name, tree size) 4796 { 4797 int const_size = TREE_CONSTANT (size); 4798 4799 if (!flag_isoc99 && pedantic && warn_vla != 0) 4800 { 4801 if (const_size) 4802 { 4803 if (name) 4804 pedwarn (input_location, OPT_Wvla, 4805 "ISO C90 forbids array %qE whose size " 4806 "can%'t be evaluated", 4807 name); 4808 else 4809 pedwarn (input_location, OPT_Wvla, "ISO C90 forbids array whose size " 4810 "can%'t be evaluated"); 4811 } 4812 else 4813 { 4814 if (name) 4815 pedwarn (input_location, OPT_Wvla, 4816 "ISO C90 forbids variable length array %qE", 4817 name); 4818 else 4819 pedwarn (input_location, OPT_Wvla, "ISO C90 forbids variable length array"); 4820 } 4821 } 4822 else if (warn_vla > 0) 4823 { 4824 if (const_size) 4825 { 4826 if (name) 4827 warning (OPT_Wvla, 4828 "the size of array %qE can" 4829 "%'t be evaluated", name); 4830 else 4831 warning (OPT_Wvla, 4832 "the size of array can %'t be evaluated"); 4833 } 4834 else 4835 { 4836 if (name) 4837 warning (OPT_Wvla, 4838 "variable length array %qE is used", 4839 name); 4840 else 4841 warning (OPT_Wvla, 4842 "variable length array is used"); 4843 } 4844 } 4845 } 4846 4847 /* Given declspecs and a declarator, 4848 determine the name and type of the object declared 4849 and construct a ..._DECL node for it. 4850 (In one case we can return a ..._TYPE node instead. 4851 For invalid input we sometimes return 0.) 4852 4853 DECLSPECS is a c_declspecs structure for the declaration specifiers. 4854 4855 DECL_CONTEXT says which syntactic context this declaration is in: 4856 NORMAL for most contexts. Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL. 4857 FUNCDEF for a function definition. Like NORMAL but a few different 4858 error messages in each case. Return value may be zero meaning 4859 this definition is too screwy to try to parse. 4860 PARM for a parameter declaration (either within a function prototype 4861 or before a function body). Make a PARM_DECL, or return void_type_node. 4862 TYPENAME if for a typename (in a cast or sizeof). 4863 Don't make a DECL node; just return the ..._TYPE node. 4864 FIELD for a struct or union field; make a FIELD_DECL. 4865 INITIALIZED is true if the decl has an initializer. 4866 WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node 4867 representing the width of the bit-field. 4868 DECL_ATTRS points to the list of attributes that should be added to this 4869 decl. Any nested attributes that belong on the decl itself will be 4870 added to this list. 4871 If EXPR is not NULL, any expressions that need to be evaluated as 4872 part of evaluating variably modified types will be stored in *EXPR. 4873 If EXPR_CONST_OPERANDS is not NULL, *EXPR_CONST_OPERANDS will be 4874 set to indicate whether operands in *EXPR can be used in constant 4875 expressions. 4876 DEPRECATED_STATE is a deprecated_states value indicating whether 4877 deprecation warnings should be suppressed. 4878 4879 In the TYPENAME case, DECLARATOR is really an absolute declarator. 4880 It may also be so in the PARM case, for a prototype where the 4881 argument type is specified but not the name. 4882 4883 This function is where the complicated C meanings of `static' 4884 and `extern' are interpreted. */ 4885 4886 static tree 4887 grokdeclarator (const struct c_declarator *declarator, 4888 struct c_declspecs *declspecs, 4889 enum decl_context decl_context, bool initialized, tree *width, 4890 tree *decl_attrs, tree *expr, bool *expr_const_operands, 4891 enum deprecated_states deprecated_state) 4892 { 4893 tree type = declspecs->type; 4894 bool threadp = declspecs->thread_p; 4895 enum c_storage_class storage_class = declspecs->storage_class; 4896 int constp; 4897 int restrictp; 4898 int volatilep; 4899 int type_quals = TYPE_UNQUALIFIED; 4900 tree name = NULL_TREE; 4901 bool funcdef_flag = false; 4902 bool funcdef_syntax = false; 4903 bool size_varies = false; 4904 tree decl_attr = declspecs->decl_attr; 4905 int array_ptr_quals = TYPE_UNQUALIFIED; 4906 tree array_ptr_attrs = NULL_TREE; 4907 int array_parm_static = 0; 4908 bool array_parm_vla_unspec_p = false; 4909 tree returned_attrs = NULL_TREE; 4910 bool bitfield = width != NULL; 4911 tree element_type; 4912 struct c_arg_info *arg_info = 0; 4913 addr_space_t as1, as2, address_space; 4914 location_t loc = UNKNOWN_LOCATION; 4915 const char *errmsg; 4916 tree expr_dummy; 4917 bool expr_const_operands_dummy; 4918 enum c_declarator_kind first_non_attr_kind; 4919 unsigned int alignas_align = 0; 4920 4921 if (TREE_CODE (type) == ERROR_MARK) 4922 return error_mark_node; 4923 if (expr == NULL) 4924 expr = &expr_dummy; 4925 if (expr_const_operands == NULL) 4926 expr_const_operands = &expr_const_operands_dummy; 4927 4928 *expr = declspecs->expr; 4929 *expr_const_operands = declspecs->expr_const_operands; 4930 4931 if (decl_context == FUNCDEF) 4932 funcdef_flag = true, decl_context = NORMAL; 4933 4934 /* Look inside a declarator for the name being declared 4935 and get it as an IDENTIFIER_NODE, for an error message. */ 4936 { 4937 const struct c_declarator *decl = declarator; 4938 4939 first_non_attr_kind = cdk_attrs; 4940 while (decl) 4941 switch (decl->kind) 4942 { 4943 case cdk_array: 4944 loc = decl->id_loc; 4945 /* FALL THRU. */ 4946 4947 case cdk_function: 4948 case cdk_pointer: 4949 funcdef_syntax = (decl->kind == cdk_function); 4950 decl = decl->declarator; 4951 if (first_non_attr_kind == cdk_attrs) 4952 first_non_attr_kind = decl->kind; 4953 break; 4954 4955 case cdk_attrs: 4956 decl = decl->declarator; 4957 break; 4958 4959 case cdk_id: 4960 loc = decl->id_loc; 4961 if (decl->u.id) 4962 name = decl->u.id; 4963 if (first_non_attr_kind == cdk_attrs) 4964 first_non_attr_kind = decl->kind; 4965 decl = 0; 4966 break; 4967 4968 default: 4969 gcc_unreachable (); 4970 } 4971 if (name == 0) 4972 { 4973 gcc_assert (decl_context == PARM 4974 || decl_context == TYPENAME 4975 || (decl_context == FIELD 4976 && declarator->kind == cdk_id)); 4977 gcc_assert (!initialized); 4978 } 4979 } 4980 4981 /* A function definition's declarator must have the form of 4982 a function declarator. */ 4983 4984 if (funcdef_flag && !funcdef_syntax) 4985 return 0; 4986 4987 /* If this looks like a function definition, make it one, 4988 even if it occurs where parms are expected. 4989 Then store_parm_decls will reject it and not use it as a parm. */ 4990 if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag) 4991 decl_context = PARM; 4992 4993 if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS) 4994 warn_deprecated_use (declspecs->type, declspecs->decl_attr); 4995 4996 if ((decl_context == NORMAL || decl_context == FIELD) 4997 && current_scope == file_scope 4998 && variably_modified_type_p (type, NULL_TREE)) 4999 { 5000 if (name) 5001 error_at (loc, "variably modified %qE at file scope", name); 5002 else 5003 error_at (loc, "variably modified field at file scope"); 5004 type = integer_type_node; 5005 } 5006 5007 size_varies = C_TYPE_VARIABLE_SIZE (type) != 0; 5008 5009 /* Diagnose defaulting to "int". */ 5010 5011 if (declspecs->default_int_p && !in_system_header) 5012 { 5013 /* Issue a warning if this is an ISO C 99 program or if 5014 -Wreturn-type and this is a function, or if -Wimplicit; 5015 prefer the former warning since it is more explicit. */ 5016 if ((warn_implicit_int || warn_return_type || flag_isoc99) 5017 && funcdef_flag) 5018 warn_about_return_type = 1; 5019 else 5020 { 5021 if (name) 5022 pedwarn_c99 (loc, flag_isoc99 ? 0 : OPT_Wimplicit_int, 5023 "type defaults to %<int%> in declaration of %qE", 5024 name); 5025 else 5026 pedwarn_c99 (input_location, flag_isoc99 ? 0 : OPT_Wimplicit_int, 5027 "type defaults to %<int%> in type name"); 5028 } 5029 } 5030 5031 /* Adjust the type if a bit-field is being declared, 5032 -funsigned-bitfields applied and the type is not explicitly 5033 "signed". */ 5034 if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p 5035 && TREE_CODE (type) == INTEGER_TYPE) 5036 type = unsigned_type_for (type); 5037 5038 /* Figure out the type qualifiers for the declaration. There are 5039 two ways a declaration can become qualified. One is something 5040 like `const int i' where the `const' is explicit. Another is 5041 something like `typedef const int CI; CI i' where the type of the 5042 declaration contains the `const'. A third possibility is that 5043 there is a type qualifier on the element type of a typedefed 5044 array type, in which case we should extract that qualifier so 5045 that c_apply_type_quals_to_decl receives the full list of 5046 qualifiers to work with (C90 is not entirely clear about whether 5047 duplicate qualifiers should be diagnosed in this case, but it 5048 seems most appropriate to do so). */ 5049 element_type = strip_array_types (type); 5050 constp = declspecs->const_p + TYPE_READONLY (element_type); 5051 restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type); 5052 volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type); 5053 as1 = declspecs->address_space; 5054 as2 = TYPE_ADDR_SPACE (element_type); 5055 address_space = ADDR_SPACE_GENERIC_P (as1)? as2 : as1; 5056 5057 if (pedantic && !flag_isoc99) 5058 { 5059 if (constp > 1) 5060 pedwarn (loc, OPT_pedantic, "duplicate %<const%>"); 5061 if (restrictp > 1) 5062 pedwarn (loc, OPT_pedantic, "duplicate %<restrict%>"); 5063 if (volatilep > 1) 5064 pedwarn (loc, OPT_pedantic, "duplicate %<volatile%>"); 5065 } 5066 5067 if (!ADDR_SPACE_GENERIC_P (as1) && !ADDR_SPACE_GENERIC_P (as2) && as1 != as2) 5068 error_at (loc, "conflicting named address spaces (%s vs %s)", 5069 c_addr_space_name (as1), c_addr_space_name (as2)); 5070 5071 if ((TREE_CODE (type) == ARRAY_TYPE 5072 || first_non_attr_kind == cdk_array) 5073 && TYPE_QUALS (element_type)) 5074 type = TYPE_MAIN_VARIANT (type); 5075 type_quals = ((constp ? TYPE_QUAL_CONST : 0) 5076 | (restrictp ? TYPE_QUAL_RESTRICT : 0) 5077 | (volatilep ? TYPE_QUAL_VOLATILE : 0) 5078 | ENCODE_QUAL_ADDR_SPACE (address_space)); 5079 5080 /* Warn about storage classes that are invalid for certain 5081 kinds of declarations (parameters, typenames, etc.). */ 5082 5083 if (funcdef_flag 5084 && (threadp 5085 || storage_class == csc_auto 5086 || storage_class == csc_register 5087 || storage_class == csc_typedef)) 5088 { 5089 if (storage_class == csc_auto) 5090 pedwarn (loc, 5091 (current_scope == file_scope) ? 0 : OPT_pedantic, 5092 "function definition declared %<auto%>"); 5093 if (storage_class == csc_register) 5094 error_at (loc, "function definition declared %<register%>"); 5095 if (storage_class == csc_typedef) 5096 error_at (loc, "function definition declared %<typedef%>"); 5097 if (threadp) 5098 error_at (loc, "function definition declared %<__thread%>"); 5099 threadp = false; 5100 if (storage_class == csc_auto 5101 || storage_class == csc_register 5102 || storage_class == csc_typedef) 5103 storage_class = csc_none; 5104 } 5105 else if (decl_context != NORMAL && (storage_class != csc_none || threadp)) 5106 { 5107 if (decl_context == PARM && storage_class == csc_register) 5108 ; 5109 else 5110 { 5111 switch (decl_context) 5112 { 5113 case FIELD: 5114 if (name) 5115 error_at (loc, "storage class specified for structure " 5116 "field %qE", name); 5117 else 5118 error_at (loc, "storage class specified for structure field"); 5119 break; 5120 case PARM: 5121 if (name) 5122 error_at (loc, "storage class specified for parameter %qE", 5123 name); 5124 else 5125 error_at (loc, "storage class specified for unnamed parameter"); 5126 break; 5127 default: 5128 error_at (loc, "storage class specified for typename"); 5129 break; 5130 } 5131 storage_class = csc_none; 5132 threadp = false; 5133 } 5134 } 5135 else if (storage_class == csc_extern 5136 && initialized 5137 && !funcdef_flag) 5138 { 5139 /* 'extern' with initialization is invalid if not at file scope. */ 5140 if (current_scope == file_scope) 5141 { 5142 /* It is fine to have 'extern const' when compiling at C 5143 and C++ intersection. */ 5144 if (!(warn_cxx_compat && constp)) 5145 warning_at (loc, 0, "%qE initialized and declared %<extern%>", 5146 name); 5147 } 5148 else 5149 error_at (loc, "%qE has both %<extern%> and initializer", name); 5150 } 5151 else if (current_scope == file_scope) 5152 { 5153 if (storage_class == csc_auto) 5154 error_at (loc, "file-scope declaration of %qE specifies %<auto%>", 5155 name); 5156 if (pedantic && storage_class == csc_register) 5157 pedwarn (input_location, OPT_pedantic, 5158 "file-scope declaration of %qE specifies %<register%>", name); 5159 } 5160 else 5161 { 5162 if (storage_class == csc_extern && funcdef_flag) 5163 error_at (loc, "nested function %qE declared %<extern%>", name); 5164 else if (threadp && storage_class == csc_none) 5165 { 5166 error_at (loc, "function-scope %qE implicitly auto and declared " 5167 "%<__thread%>", 5168 name); 5169 threadp = false; 5170 } 5171 } 5172 5173 /* Now figure out the structure of the declarator proper. 5174 Descend through it, creating more complex types, until we reach 5175 the declared identifier (or NULL_TREE, in an absolute declarator). 5176 At each stage we maintain an unqualified version of the type 5177 together with any qualifiers that should be applied to it with 5178 c_build_qualified_type; this way, array types including 5179 multidimensional array types are first built up in unqualified 5180 form and then the qualified form is created with 5181 TYPE_MAIN_VARIANT pointing to the unqualified form. */ 5182 5183 while (declarator && declarator->kind != cdk_id) 5184 { 5185 if (type == error_mark_node) 5186 { 5187 declarator = declarator->declarator; 5188 continue; 5189 } 5190 5191 /* Each level of DECLARATOR is either a cdk_array (for ...[..]), 5192 a cdk_pointer (for *...), 5193 a cdk_function (for ...(...)), 5194 a cdk_attrs (for nested attributes), 5195 or a cdk_id (for the name being declared 5196 or the place in an absolute declarator 5197 where the name was omitted). 5198 For the last case, we have just exited the loop. 5199 5200 At this point, TYPE is the type of elements of an array, 5201 or for a function to return, or for a pointer to point to. 5202 After this sequence of ifs, TYPE is the type of the 5203 array or function or pointer, and DECLARATOR has had its 5204 outermost layer removed. */ 5205 5206 if (array_ptr_quals != TYPE_UNQUALIFIED 5207 || array_ptr_attrs != NULL_TREE 5208 || array_parm_static) 5209 { 5210 /* Only the innermost declarator (making a parameter be of 5211 array type which is converted to pointer type) 5212 may have static or type qualifiers. */ 5213 error_at (loc, "static or type qualifiers in non-parameter array declarator"); 5214 array_ptr_quals = TYPE_UNQUALIFIED; 5215 array_ptr_attrs = NULL_TREE; 5216 array_parm_static = 0; 5217 } 5218 5219 switch (declarator->kind) 5220 { 5221 case cdk_attrs: 5222 { 5223 /* A declarator with embedded attributes. */ 5224 tree attrs = declarator->u.attrs; 5225 const struct c_declarator *inner_decl; 5226 int attr_flags = 0; 5227 declarator = declarator->declarator; 5228 inner_decl = declarator; 5229 while (inner_decl->kind == cdk_attrs) 5230 inner_decl = inner_decl->declarator; 5231 if (inner_decl->kind == cdk_id) 5232 attr_flags |= (int) ATTR_FLAG_DECL_NEXT; 5233 else if (inner_decl->kind == cdk_function) 5234 attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT; 5235 else if (inner_decl->kind == cdk_array) 5236 attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT; 5237 returned_attrs = decl_attributes (&type, 5238 chainon (returned_attrs, attrs), 5239 attr_flags); 5240 break; 5241 } 5242 case cdk_array: 5243 { 5244 tree itype = NULL_TREE; 5245 tree size = declarator->u.array.dimen; 5246 /* The index is a signed object `sizetype' bits wide. */ 5247 tree index_type = c_common_signed_type (sizetype); 5248 5249 array_ptr_quals = declarator->u.array.quals; 5250 array_ptr_attrs = declarator->u.array.attrs; 5251 array_parm_static = declarator->u.array.static_p; 5252 array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p; 5253 5254 declarator = declarator->declarator; 5255 5256 /* Check for some types that there cannot be arrays of. */ 5257 5258 if (VOID_TYPE_P (type)) 5259 { 5260 if (name) 5261 error_at (loc, "declaration of %qE as array of voids", name); 5262 else 5263 error_at (loc, "declaration of type name as array of voids"); 5264 type = error_mark_node; 5265 } 5266 5267 if (TREE_CODE (type) == FUNCTION_TYPE) 5268 { 5269 if (name) 5270 error_at (loc, "declaration of %qE as array of functions", 5271 name); 5272 else 5273 error_at (loc, "declaration of type name as array of " 5274 "functions"); 5275 type = error_mark_node; 5276 } 5277 5278 if (pedantic && !in_system_header && flexible_array_type_p (type)) 5279 pedwarn (loc, OPT_pedantic, 5280 "invalid use of structure with flexible array member"); 5281 5282 if (size == error_mark_node) 5283 type = error_mark_node; 5284 5285 if (type == error_mark_node) 5286 continue; 5287 5288 /* If size was specified, set ITYPE to a range-type for 5289 that size. Otherwise, ITYPE remains null. finish_decl 5290 may figure it out from an initial value. */ 5291 5292 if (size) 5293 { 5294 bool size_maybe_const = true; 5295 bool size_int_const = (TREE_CODE (size) == INTEGER_CST 5296 && !TREE_OVERFLOW (size)); 5297 bool this_size_varies = false; 5298 5299 /* Strip NON_LVALUE_EXPRs since we aren't using as an 5300 lvalue. */ 5301 STRIP_TYPE_NOPS (size); 5302 5303 if (!INTEGRAL_TYPE_P (TREE_TYPE (size))) 5304 { 5305 if (name) 5306 error_at (loc, "size of array %qE has non-integer type", 5307 name); 5308 else 5309 error_at (loc, 5310 "size of unnamed array has non-integer type"); 5311 size = integer_one_node; 5312 } 5313 5314 size = c_fully_fold (size, false, &size_maybe_const); 5315 5316 if (pedantic && size_maybe_const && integer_zerop (size)) 5317 { 5318 if (name) 5319 pedwarn (loc, OPT_pedantic, 5320 "ISO C forbids zero-size array %qE", name); 5321 else 5322 pedwarn (loc, OPT_pedantic, 5323 "ISO C forbids zero-size array"); 5324 } 5325 5326 if (TREE_CODE (size) == INTEGER_CST && size_maybe_const) 5327 { 5328 constant_expression_warning (size); 5329 if (tree_int_cst_sgn (size) < 0) 5330 { 5331 if (name) 5332 error_at (loc, "size of array %qE is negative", name); 5333 else 5334 error_at (loc, "size of unnamed array is negative"); 5335 size = integer_one_node; 5336 } 5337 /* Handle a size folded to an integer constant but 5338 not an integer constant expression. */ 5339 if (!size_int_const) 5340 { 5341 /* If this is a file scope declaration of an 5342 ordinary identifier, this is invalid code; 5343 diagnosing it here and not subsequently 5344 treating the type as variable-length avoids 5345 more confusing diagnostics later. */ 5346 if ((decl_context == NORMAL || decl_context == FIELD) 5347 && current_scope == file_scope) 5348 pedwarn (input_location, 0, 5349 "variably modified %qE at file scope", 5350 name); 5351 else 5352 this_size_varies = size_varies = true; 5353 warn_variable_length_array (name, size); 5354 } 5355 } 5356 else if ((decl_context == NORMAL || decl_context == FIELD) 5357 && current_scope == file_scope) 5358 { 5359 error_at (loc, "variably modified %qE at file scope", name); 5360 size = integer_one_node; 5361 } 5362 else 5363 { 5364 /* Make sure the array size remains visibly 5365 nonconstant even if it is (eg) a const variable 5366 with known value. */ 5367 this_size_varies = size_varies = true; 5368 warn_variable_length_array (name, size); 5369 } 5370 5371 if (integer_zerop (size) && !this_size_varies) 5372 { 5373 /* A zero-length array cannot be represented with 5374 an unsigned index type, which is what we'll 5375 get with build_index_type. Create an 5376 open-ended range instead. */ 5377 itype = build_range_type (sizetype, size, NULL_TREE); 5378 } 5379 else 5380 { 5381 /* Arrange for the SAVE_EXPR on the inside of the 5382 MINUS_EXPR, which allows the -1 to get folded 5383 with the +1 that happens when building TYPE_SIZE. */ 5384 if (size_varies) 5385 size = save_expr (size); 5386 if (this_size_varies && TREE_CODE (size) == INTEGER_CST) 5387 size = build2 (COMPOUND_EXPR, TREE_TYPE (size), 5388 integer_zero_node, size); 5389 5390 /* Compute the maximum valid index, that is, size 5391 - 1. Do the calculation in index_type, so that 5392 if it is a variable the computations will be 5393 done in the proper mode. */ 5394 itype = fold_build2_loc (loc, MINUS_EXPR, index_type, 5395 convert (index_type, size), 5396 convert (index_type, 5397 size_one_node)); 5398 5399 /* The above overflows when size does not fit 5400 in index_type. 5401 ??? While a size of INT_MAX+1 technically shouldn't 5402 cause an overflow (because we subtract 1), handling 5403 this case seems like an unnecessary complication. */ 5404 if (TREE_CODE (size) == INTEGER_CST 5405 && !int_fits_type_p (size, index_type)) 5406 { 5407 if (name) 5408 error_at (loc, "size of array %qE is too large", 5409 name); 5410 else 5411 error_at (loc, "size of unnamed array is too large"); 5412 type = error_mark_node; 5413 continue; 5414 } 5415 5416 itype = build_index_type (itype); 5417 } 5418 if (this_size_varies) 5419 { 5420 if (*expr) 5421 *expr = build2 (COMPOUND_EXPR, TREE_TYPE (size), 5422 *expr, size); 5423 else 5424 *expr = size; 5425 *expr_const_operands &= size_maybe_const; 5426 } 5427 } 5428 else if (decl_context == FIELD) 5429 { 5430 bool flexible_array_member = false; 5431 if (array_parm_vla_unspec_p) 5432 /* Field names can in fact have function prototype 5433 scope so [*] is disallowed here through making 5434 the field variably modified, not through being 5435 something other than a declaration with function 5436 prototype scope. */ 5437 size_varies = true; 5438 else 5439 { 5440 const struct c_declarator *t = declarator; 5441 while (t->kind == cdk_attrs) 5442 t = t->declarator; 5443 flexible_array_member = (t->kind == cdk_id); 5444 } 5445 if (flexible_array_member 5446 && pedantic && !flag_isoc99 && !in_system_header) 5447 pedwarn (loc, OPT_pedantic, 5448 "ISO C90 does not support flexible array members"); 5449 5450 /* ISO C99 Flexible array members are effectively 5451 identical to GCC's zero-length array extension. */ 5452 if (flexible_array_member || array_parm_vla_unspec_p) 5453 itype = build_range_type (sizetype, size_zero_node, 5454 NULL_TREE); 5455 } 5456 else if (decl_context == PARM) 5457 { 5458 if (array_parm_vla_unspec_p) 5459 { 5460 itype = build_range_type (sizetype, size_zero_node, NULL_TREE); 5461 size_varies = true; 5462 } 5463 } 5464 else if (decl_context == TYPENAME) 5465 { 5466 if (array_parm_vla_unspec_p) 5467 { 5468 /* C99 6.7.5.2p4 */ 5469 warning (0, "%<[*]%> not in a declaration"); 5470 /* We use this to avoid messing up with incomplete 5471 array types of the same type, that would 5472 otherwise be modified below. */ 5473 itype = build_range_type (sizetype, size_zero_node, 5474 NULL_TREE); 5475 size_varies = true; 5476 } 5477 } 5478 5479 /* Complain about arrays of incomplete types. */ 5480 if (!COMPLETE_TYPE_P (type)) 5481 { 5482 error_at (loc, "array type has incomplete element type"); 5483 type = error_mark_node; 5484 } 5485 else 5486 /* When itype is NULL, a shared incomplete array type is 5487 returned for all array of a given type. Elsewhere we 5488 make sure we don't complete that type before copying 5489 it, but here we want to make sure we don't ever 5490 modify the shared type, so we gcc_assert (itype) 5491 below. */ 5492 { 5493 addr_space_t as = DECODE_QUAL_ADDR_SPACE (type_quals); 5494 if (!ADDR_SPACE_GENERIC_P (as) && as != TYPE_ADDR_SPACE (type)) 5495 type = build_qualified_type (type, 5496 ENCODE_QUAL_ADDR_SPACE (as)); 5497 5498 type = build_array_type (type, itype); 5499 } 5500 5501 if (type != error_mark_node) 5502 { 5503 if (size_varies) 5504 { 5505 /* It is ok to modify type here even if itype is 5506 NULL: if size_varies, we're in a 5507 multi-dimensional array and the inner type has 5508 variable size, so the enclosing shared array type 5509 must too. */ 5510 if (size && TREE_CODE (size) == INTEGER_CST) 5511 type 5512 = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5513 C_TYPE_VARIABLE_SIZE (type) = 1; 5514 } 5515 5516 /* The GCC extension for zero-length arrays differs from 5517 ISO flexible array members in that sizeof yields 5518 zero. */ 5519 if (size && integer_zerop (size)) 5520 { 5521 gcc_assert (itype); 5522 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5523 TYPE_SIZE (type) = bitsize_zero_node; 5524 TYPE_SIZE_UNIT (type) = size_zero_node; 5525 SET_TYPE_STRUCTURAL_EQUALITY (type); 5526 } 5527 if (array_parm_vla_unspec_p) 5528 { 5529 gcc_assert (itype); 5530 /* The type is complete. C99 6.7.5.2p4 */ 5531 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 5532 TYPE_SIZE (type) = bitsize_zero_node; 5533 TYPE_SIZE_UNIT (type) = size_zero_node; 5534 SET_TYPE_STRUCTURAL_EQUALITY (type); 5535 } 5536 } 5537 5538 if (decl_context != PARM 5539 && (array_ptr_quals != TYPE_UNQUALIFIED 5540 || array_ptr_attrs != NULL_TREE 5541 || array_parm_static)) 5542 { 5543 error_at (loc, "static or type qualifiers in non-parameter array declarator"); 5544 array_ptr_quals = TYPE_UNQUALIFIED; 5545 array_ptr_attrs = NULL_TREE; 5546 array_parm_static = 0; 5547 } 5548 break; 5549 } 5550 case cdk_function: 5551 { 5552 /* Say it's a definition only for the declarator closest 5553 to the identifier, apart possibly from some 5554 attributes. */ 5555 bool really_funcdef = false; 5556 tree arg_types; 5557 if (funcdef_flag) 5558 { 5559 const struct c_declarator *t = declarator->declarator; 5560 while (t->kind == cdk_attrs) 5561 t = t->declarator; 5562 really_funcdef = (t->kind == cdk_id); 5563 } 5564 5565 /* Declaring a function type. Make sure we have a valid 5566 type for the function to return. */ 5567 if (type == error_mark_node) 5568 continue; 5569 5570 size_varies = false; 5571 5572 /* Warn about some types functions can't return. */ 5573 if (TREE_CODE (type) == FUNCTION_TYPE) 5574 { 5575 if (name) 5576 error_at (loc, "%qE declared as function returning a " 5577 "function", name); 5578 else 5579 error_at (loc, "type name declared as function " 5580 "returning a function"); 5581 type = integer_type_node; 5582 } 5583 if (TREE_CODE (type) == ARRAY_TYPE) 5584 { 5585 if (name) 5586 error_at (loc, "%qE declared as function returning an array", 5587 name); 5588 else 5589 error_at (loc, "type name declared as function returning " 5590 "an array"); 5591 type = integer_type_node; 5592 } 5593 errmsg = targetm.invalid_return_type (type); 5594 if (errmsg) 5595 { 5596 error (errmsg); 5597 type = integer_type_node; 5598 } 5599 5600 /* Construct the function type and go to the next 5601 inner layer of declarator. */ 5602 arg_info = declarator->u.arg_info; 5603 arg_types = grokparms (arg_info, really_funcdef); 5604 5605 /* Type qualifiers before the return type of the function 5606 qualify the return type, not the function type. */ 5607 if (type_quals) 5608 { 5609 /* Type qualifiers on a function return type are 5610 normally permitted by the standard but have no 5611 effect, so give a warning at -Wreturn-type. 5612 Qualifiers on a void return type are banned on 5613 function definitions in ISO C; GCC used to used 5614 them for noreturn functions. */ 5615 if (VOID_TYPE_P (type) && really_funcdef) 5616 pedwarn (loc, 0, 5617 "function definition has qualified void return type"); 5618 else 5619 warning_at (loc, OPT_Wignored_qualifiers, 5620 "type qualifiers ignored on function return type"); 5621 5622 type = c_build_qualified_type (type, type_quals); 5623 } 5624 type_quals = TYPE_UNQUALIFIED; 5625 5626 type = build_function_type (type, arg_types); 5627 declarator = declarator->declarator; 5628 5629 /* Set the TYPE_CONTEXTs for each tagged type which is local to 5630 the formal parameter list of this FUNCTION_TYPE to point to 5631 the FUNCTION_TYPE node itself. */ 5632 { 5633 c_arg_tag *tag; 5634 unsigned ix; 5635 5636 FOR_EACH_VEC_ELT_REVERSE (c_arg_tag, arg_info->tags, ix, tag) 5637 TYPE_CONTEXT (tag->type) = type; 5638 } 5639 break; 5640 } 5641 case cdk_pointer: 5642 { 5643 /* Merge any constancy or volatility into the target type 5644 for the pointer. */ 5645 5646 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5647 && type_quals) 5648 pedwarn (loc, OPT_pedantic, 5649 "ISO C forbids qualified function types"); 5650 if (type_quals) 5651 type = c_build_qualified_type (type, type_quals); 5652 size_varies = false; 5653 5654 /* When the pointed-to type involves components of variable size, 5655 care must be taken to ensure that the size evaluation code is 5656 emitted early enough to dominate all the possible later uses 5657 and late enough for the variables on which it depends to have 5658 been assigned. 5659 5660 This is expected to happen automatically when the pointed-to 5661 type has a name/declaration of it's own, but special attention 5662 is required if the type is anonymous. 5663 5664 We handle the NORMAL and FIELD contexts here by attaching an 5665 artificial TYPE_DECL to such pointed-to type. This forces the 5666 sizes evaluation at a safe point and ensures it is not deferred 5667 until e.g. within a deeper conditional context. 5668 5669 We expect nothing to be needed here for PARM or TYPENAME. 5670 Pushing a TYPE_DECL at this point for TYPENAME would actually 5671 be incorrect, as we might be in the middle of an expression 5672 with side effects on the pointed-to type size "arguments" prior 5673 to the pointer declaration point and the fake TYPE_DECL in the 5674 enclosing context would force the size evaluation prior to the 5675 side effects. */ 5676 5677 if (!TYPE_NAME (type) 5678 && (decl_context == NORMAL || decl_context == FIELD) 5679 && variably_modified_type_p (type, NULL_TREE)) 5680 { 5681 tree decl = build_decl (loc, TYPE_DECL, NULL_TREE, type); 5682 DECL_ARTIFICIAL (decl) = 1; 5683 pushdecl (decl); 5684 finish_decl (decl, loc, NULL_TREE, NULL_TREE, NULL_TREE); 5685 TYPE_NAME (type) = decl; 5686 } 5687 5688 type = build_pointer_type (type); 5689 5690 /* Process type qualifiers (such as const or volatile) 5691 that were given inside the `*'. */ 5692 type_quals = declarator->u.pointer_quals; 5693 5694 declarator = declarator->declarator; 5695 break; 5696 } 5697 default: 5698 gcc_unreachable (); 5699 } 5700 } 5701 *decl_attrs = chainon (returned_attrs, *decl_attrs); 5702 5703 /* Now TYPE has the actual type, apart from any qualifiers in 5704 TYPE_QUALS. */ 5705 5706 /* Warn about address space used for things other than static memory or 5707 pointers. */ 5708 address_space = DECODE_QUAL_ADDR_SPACE (type_quals); 5709 if (!ADDR_SPACE_GENERIC_P (address_space)) 5710 { 5711 if (decl_context == NORMAL) 5712 { 5713 switch (storage_class) 5714 { 5715 case csc_auto: 5716 error ("%qs combined with %<auto%> qualifier for %qE", 5717 c_addr_space_name (address_space), name); 5718 break; 5719 case csc_register: 5720 error ("%qs combined with %<register%> qualifier for %qE", 5721 c_addr_space_name (address_space), name); 5722 break; 5723 case csc_none: 5724 if (current_function_scope) 5725 { 5726 error ("%qs specified for auto variable %qE", 5727 c_addr_space_name (address_space), name); 5728 break; 5729 } 5730 break; 5731 case csc_static: 5732 case csc_extern: 5733 case csc_typedef: 5734 break; 5735 default: 5736 gcc_unreachable (); 5737 } 5738 } 5739 else if (decl_context == PARM && TREE_CODE (type) != ARRAY_TYPE) 5740 { 5741 if (name) 5742 error ("%qs specified for parameter %qE", 5743 c_addr_space_name (address_space), name); 5744 else 5745 error ("%qs specified for unnamed parameter", 5746 c_addr_space_name (address_space)); 5747 } 5748 else if (decl_context == FIELD) 5749 { 5750 if (name) 5751 error ("%qs specified for structure field %qE", 5752 c_addr_space_name (address_space), name); 5753 else 5754 error ("%qs specified for structure field", 5755 c_addr_space_name (address_space)); 5756 } 5757 } 5758 5759 /* Check the type and width of a bit-field. */ 5760 if (bitfield) 5761 check_bitfield_type_and_width (&type, width, name); 5762 5763 /* Reject invalid uses of _Alignas. */ 5764 if (declspecs->alignas_p) 5765 { 5766 if (storage_class == csc_typedef) 5767 error_at (loc, "alignment specified for typedef %qE", name); 5768 else if (storage_class == csc_register) 5769 error_at (loc, "alignment specified for %<register%> object %qE", 5770 name); 5771 else if (decl_context == PARM) 5772 { 5773 if (name) 5774 error_at (loc, "alignment specified for parameter %qE", name); 5775 else 5776 error_at (loc, "alignment specified for unnamed parameter"); 5777 } 5778 else if (bitfield) 5779 { 5780 if (name) 5781 error_at (loc, "alignment specified for bit-field %qE", name); 5782 else 5783 error_at (loc, "alignment specified for unnamed bit-field"); 5784 } 5785 else if (TREE_CODE (type) == FUNCTION_TYPE) 5786 error_at (loc, "alignment specified for function %qE", name); 5787 else if (declspecs->align_log != -1) 5788 { 5789 alignas_align = 1U << declspecs->align_log; 5790 if (alignas_align < TYPE_ALIGN_UNIT (type)) 5791 { 5792 if (name) 5793 error_at (loc, "%<_Alignas%> specifiers cannot reduce " 5794 "alignment of %qE", name); 5795 else 5796 error_at (loc, "%<_Alignas%> specifiers cannot reduce " 5797 "alignment of unnamed field"); 5798 alignas_align = 0; 5799 } 5800 } 5801 } 5802 5803 /* Did array size calculations overflow? */ 5804 5805 if (TREE_CODE (type) == ARRAY_TYPE 5806 && COMPLETE_TYPE_P (type) 5807 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST 5808 && TREE_OVERFLOW (TYPE_SIZE_UNIT (type))) 5809 { 5810 if (name) 5811 error_at (loc, "size of array %qE is too large", name); 5812 else 5813 error_at (loc, "size of unnamed array is too large"); 5814 /* If we proceed with the array type as it is, we'll eventually 5815 crash in tree_low_cst(). */ 5816 type = error_mark_node; 5817 } 5818 5819 /* If this is declaring a typedef name, return a TYPE_DECL. */ 5820 5821 if (storage_class == csc_typedef) 5822 { 5823 tree decl; 5824 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5825 && type_quals) 5826 pedwarn (loc, OPT_pedantic, 5827 "ISO C forbids qualified function types"); 5828 if (type_quals) 5829 type = c_build_qualified_type (type, type_quals); 5830 decl = build_decl (declarator->id_loc, 5831 TYPE_DECL, declarator->u.id, type); 5832 if (declspecs->explicit_signed_p) 5833 C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1; 5834 if (declspecs->inline_p) 5835 pedwarn (loc, 0,"typedef %q+D declared %<inline%>", decl); 5836 if (declspecs->noreturn_p) 5837 pedwarn (loc, 0,"typedef %q+D declared %<_Noreturn%>", decl); 5838 5839 if (warn_cxx_compat && declarator->u.id != NULL_TREE) 5840 { 5841 struct c_binding *b = I_TAG_BINDING (declarator->u.id); 5842 5843 if (b != NULL 5844 && b->decl != NULL_TREE 5845 && (B_IN_CURRENT_SCOPE (b) 5846 || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b))) 5847 && TYPE_MAIN_VARIANT (b->decl) != TYPE_MAIN_VARIANT (type)) 5848 { 5849 warning_at (declarator->id_loc, OPT_Wc___compat, 5850 ("using %qD as both a typedef and a tag is " 5851 "invalid in C++"), 5852 decl); 5853 if (b->locus != UNKNOWN_LOCATION) 5854 inform (b->locus, "originally defined here"); 5855 } 5856 } 5857 5858 return decl; 5859 } 5860 5861 /* If this is a type name (such as, in a cast or sizeof), 5862 compute the type and return it now. */ 5863 5864 if (decl_context == TYPENAME) 5865 { 5866 /* Note that the grammar rejects storage classes in typenames 5867 and fields. */ 5868 gcc_assert (storage_class == csc_none && !threadp 5869 && !declspecs->inline_p && !declspecs->noreturn_p); 5870 if (pedantic && TREE_CODE (type) == FUNCTION_TYPE 5871 && type_quals) 5872 pedwarn (loc, OPT_pedantic, 5873 "ISO C forbids const or volatile function types"); 5874 if (type_quals) 5875 type = c_build_qualified_type (type, type_quals); 5876 return type; 5877 } 5878 5879 if (pedantic && decl_context == FIELD 5880 && variably_modified_type_p (type, NULL_TREE)) 5881 { 5882 /* C99 6.7.2.1p8 */ 5883 pedwarn (loc, OPT_pedantic, "a member of a structure or union cannot " 5884 "have a variably modified type"); 5885 } 5886 5887 /* Aside from typedefs and type names (handle above), 5888 `void' at top level (not within pointer) 5889 is allowed only in public variables. 5890 We don't complain about parms either, but that is because 5891 a better error message can be made later. */ 5892 5893 if (VOID_TYPE_P (type) && decl_context != PARM 5894 && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE) 5895 && (storage_class == csc_extern 5896 || (current_scope == file_scope 5897 && !(storage_class == csc_static 5898 || storage_class == csc_register))))) 5899 { 5900 error_at (loc, "variable or field %qE declared void", name); 5901 type = integer_type_node; 5902 } 5903 5904 /* Now create the decl, which may be a VAR_DECL, a PARM_DECL 5905 or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE. */ 5906 5907 { 5908 tree decl; 5909 5910 if (decl_context == PARM) 5911 { 5912 tree promoted_type; 5913 5914 /* A parameter declared as an array of T is really a pointer to T. 5915 One declared as a function is really a pointer to a function. */ 5916 5917 if (TREE_CODE (type) == ARRAY_TYPE) 5918 { 5919 /* Transfer const-ness of array into that of type pointed to. */ 5920 type = TREE_TYPE (type); 5921 if (type_quals) 5922 type = c_build_qualified_type (type, type_quals); 5923 type = build_pointer_type (type); 5924 type_quals = array_ptr_quals; 5925 if (type_quals) 5926 type = c_build_qualified_type (type, type_quals); 5927 5928 /* We don't yet implement attributes in this context. */ 5929 if (array_ptr_attrs != NULL_TREE) 5930 warning_at (loc, OPT_Wattributes, 5931 "attributes in parameter array declarator ignored"); 5932 5933 size_varies = false; 5934 } 5935 else if (TREE_CODE (type) == FUNCTION_TYPE) 5936 { 5937 if (type_quals) 5938 pedwarn (loc, OPT_pedantic, 5939 "ISO C forbids qualified function types"); 5940 if (type_quals) 5941 type = c_build_qualified_type (type, type_quals); 5942 type = build_pointer_type (type); 5943 type_quals = TYPE_UNQUALIFIED; 5944 } 5945 else if (type_quals) 5946 type = c_build_qualified_type (type, type_quals); 5947 5948 decl = build_decl (declarator->id_loc, 5949 PARM_DECL, declarator->u.id, type); 5950 if (size_varies) 5951 C_DECL_VARIABLE_SIZE (decl) = 1; 5952 5953 /* Compute the type actually passed in the parmlist, 5954 for the case where there is no prototype. 5955 (For example, shorts and chars are passed as ints.) 5956 When there is a prototype, this is overridden later. */ 5957 5958 if (type == error_mark_node) 5959 promoted_type = type; 5960 else 5961 promoted_type = c_type_promotes_to (type); 5962 5963 DECL_ARG_TYPE (decl) = promoted_type; 5964 if (declspecs->inline_p) 5965 pedwarn (loc, 0, "parameter %q+D declared %<inline%>", decl); 5966 if (declspecs->noreturn_p) 5967 pedwarn (loc, 0, "parameter %q+D declared %<_Noreturn%>", decl); 5968 } 5969 else if (decl_context == FIELD) 5970 { 5971 /* Note that the grammar rejects storage classes in typenames 5972 and fields. */ 5973 gcc_assert (storage_class == csc_none && !threadp 5974 && !declspecs->inline_p && !declspecs->noreturn_p); 5975 5976 /* Structure field. It may not be a function. */ 5977 5978 if (TREE_CODE (type) == FUNCTION_TYPE) 5979 { 5980 error_at (loc, "field %qE declared as a function", name); 5981 type = build_pointer_type (type); 5982 } 5983 else if (TREE_CODE (type) != ERROR_MARK 5984 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type)) 5985 { 5986 if (name) 5987 error_at (loc, "field %qE has incomplete type", name); 5988 else 5989 error_at (loc, "unnamed field has incomplete type"); 5990 type = error_mark_node; 5991 } 5992 type = c_build_qualified_type (type, type_quals); 5993 decl = build_decl (declarator->id_loc, 5994 FIELD_DECL, declarator->u.id, type); 5995 DECL_NONADDRESSABLE_P (decl) = bitfield; 5996 if (bitfield && !declarator->u.id) 5997 TREE_NO_WARNING (decl) = 1; 5998 5999 if (size_varies) 6000 C_DECL_VARIABLE_SIZE (decl) = 1; 6001 } 6002 else if (TREE_CODE (type) == FUNCTION_TYPE) 6003 { 6004 if (storage_class == csc_register || threadp) 6005 { 6006 error_at (loc, "invalid storage class for function %qE", name); 6007 } 6008 else if (current_scope != file_scope) 6009 { 6010 /* Function declaration not at file scope. Storage 6011 classes other than `extern' are not allowed, C99 6012 6.7.1p5, and `extern' makes no difference. However, 6013 GCC allows 'auto', perhaps with 'inline', to support 6014 nested functions. */ 6015 if (storage_class == csc_auto) 6016 pedwarn (loc, OPT_pedantic, 6017 "invalid storage class for function %qE", name); 6018 else if (storage_class == csc_static) 6019 { 6020 error_at (loc, "invalid storage class for function %qE", name); 6021 if (funcdef_flag) 6022 storage_class = declspecs->storage_class = csc_none; 6023 else 6024 return 0; 6025 } 6026 } 6027 6028 decl = build_decl (declarator->id_loc, 6029 FUNCTION_DECL, declarator->u.id, type); 6030 decl = build_decl_attribute_variant (decl, decl_attr); 6031 6032 if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl)) 6033 pedwarn (loc, OPT_pedantic, 6034 "ISO C forbids qualified function types"); 6035 6036 /* Every function declaration is an external reference 6037 (DECL_EXTERNAL) except for those which are not at file 6038 scope and are explicitly declared "auto". This is 6039 forbidden by standard C (C99 6.7.1p5) and is interpreted by 6040 GCC to signify a forward declaration of a nested function. */ 6041 if (storage_class == csc_auto && current_scope != file_scope) 6042 DECL_EXTERNAL (decl) = 0; 6043 /* In C99, a function which is declared 'inline' with 'extern' 6044 is not an external reference (which is confusing). It 6045 means that the later definition of the function must be output 6046 in this file, C99 6.7.4p6. In GNU C89, a function declared 6047 'extern inline' is an external reference. */ 6048 else if (declspecs->inline_p && storage_class != csc_static) 6049 DECL_EXTERNAL (decl) = ((storage_class == csc_extern) 6050 == flag_gnu89_inline); 6051 else 6052 DECL_EXTERNAL (decl) = !initialized; 6053 6054 /* Record absence of global scope for `static' or `auto'. */ 6055 TREE_PUBLIC (decl) 6056 = !(storage_class == csc_static || storage_class == csc_auto); 6057 6058 /* For a function definition, record the argument information 6059 block where store_parm_decls will look for it. */ 6060 if (funcdef_flag) 6061 current_function_arg_info = arg_info; 6062 6063 if (declspecs->default_int_p) 6064 C_FUNCTION_IMPLICIT_INT (decl) = 1; 6065 6066 /* Record presence of `inline' and `_Noreturn', if it is 6067 reasonable. */ 6068 if (flag_hosted && MAIN_NAME_P (declarator->u.id)) 6069 { 6070 if (declspecs->inline_p) 6071 pedwarn (loc, 0, "cannot inline function %<main%>"); 6072 if (declspecs->noreturn_p) 6073 pedwarn (loc, 0, "%<main%> declared %<_Noreturn%>"); 6074 } 6075 else 6076 { 6077 if (declspecs->inline_p) 6078 /* Record that the function is declared `inline'. */ 6079 DECL_DECLARED_INLINE_P (decl) = 1; 6080 if (declspecs->noreturn_p) 6081 { 6082 if (!flag_isoc11) 6083 { 6084 if (flag_isoc99) 6085 pedwarn (loc, OPT_pedantic, 6086 "ISO C99 does not support %<_Noreturn%>"); 6087 else 6088 pedwarn (loc, OPT_pedantic, 6089 "ISO C90 does not support %<_Noreturn%>"); 6090 } 6091 TREE_THIS_VOLATILE (decl) = 1; 6092 } 6093 } 6094 } 6095 else 6096 { 6097 /* It's a variable. */ 6098 /* An uninitialized decl with `extern' is a reference. */ 6099 int extern_ref = !initialized && storage_class == csc_extern; 6100 6101 type = c_build_qualified_type (type, type_quals); 6102 6103 /* C99 6.2.2p7: It is invalid (compile-time undefined 6104 behavior) to create an 'extern' declaration for a 6105 variable if there is a global declaration that is 6106 'static' and the global declaration is not visible. 6107 (If the static declaration _is_ currently visible, 6108 the 'extern' declaration is taken to refer to that decl.) */ 6109 if (extern_ref && current_scope != file_scope) 6110 { 6111 tree global_decl = identifier_global_value (declarator->u.id); 6112 tree visible_decl = lookup_name (declarator->u.id); 6113 6114 if (global_decl 6115 && global_decl != visible_decl 6116 && TREE_CODE (global_decl) == VAR_DECL 6117 && !TREE_PUBLIC (global_decl)) 6118 error_at (loc, "variable previously declared %<static%> " 6119 "redeclared %<extern%>"); 6120 } 6121 6122 decl = build_decl (declarator->id_loc, 6123 VAR_DECL, declarator->u.id, type); 6124 if (size_varies) 6125 C_DECL_VARIABLE_SIZE (decl) = 1; 6126 6127 if (declspecs->inline_p) 6128 pedwarn (loc, 0, "variable %q+D declared %<inline%>", decl); 6129 if (declspecs->noreturn_p) 6130 pedwarn (loc, 0, "variable %q+D declared %<_Noreturn%>", decl); 6131 6132 /* At file scope, an initialized extern declaration may follow 6133 a static declaration. In that case, DECL_EXTERNAL will be 6134 reset later in start_decl. */ 6135 DECL_EXTERNAL (decl) = (storage_class == csc_extern); 6136 6137 /* At file scope, the presence of a `static' or `register' storage 6138 class specifier, or the absence of all storage class specifiers 6139 makes this declaration a definition (perhaps tentative). Also, 6140 the absence of `static' makes it public. */ 6141 if (current_scope == file_scope) 6142 { 6143 TREE_PUBLIC (decl) = storage_class != csc_static; 6144 TREE_STATIC (decl) = !extern_ref; 6145 } 6146 /* Not at file scope, only `static' makes a static definition. */ 6147 else 6148 { 6149 TREE_STATIC (decl) = (storage_class == csc_static); 6150 TREE_PUBLIC (decl) = extern_ref; 6151 } 6152 6153 if (threadp) 6154 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl); 6155 } 6156 6157 if ((storage_class == csc_extern 6158 || (storage_class == csc_none 6159 && TREE_CODE (type) == FUNCTION_TYPE 6160 && !funcdef_flag)) 6161 && variably_modified_type_p (type, NULL_TREE)) 6162 { 6163 /* C99 6.7.5.2p2 */ 6164 if (TREE_CODE (type) == FUNCTION_TYPE) 6165 error_at (loc, "non-nested function with variably modified type"); 6166 else 6167 error_at (loc, "object with variably modified type must have " 6168 "no linkage"); 6169 } 6170 6171 /* Record `register' declaration for warnings on & 6172 and in case doing stupid register allocation. */ 6173 6174 if (storage_class == csc_register) 6175 { 6176 C_DECL_REGISTER (decl) = 1; 6177 DECL_REGISTER (decl) = 1; 6178 } 6179 6180 /* Record constancy and volatility. */ 6181 c_apply_type_quals_to_decl (type_quals, decl); 6182 6183 /* Apply _Alignas specifiers. */ 6184 if (alignas_align) 6185 { 6186 DECL_ALIGN (decl) = alignas_align * BITS_PER_UNIT; 6187 DECL_USER_ALIGN (decl) = 1; 6188 } 6189 6190 /* If a type has volatile components, it should be stored in memory. 6191 Otherwise, the fact that those components are volatile 6192 will be ignored, and would even crash the compiler. 6193 Of course, this only makes sense on VAR,PARM, and RESULT decl's. */ 6194 if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)) 6195 && (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL 6196 || TREE_CODE (decl) == RESULT_DECL)) 6197 { 6198 /* It is not an error for a structure with volatile fields to 6199 be declared register, but reset DECL_REGISTER since it 6200 cannot actually go in a register. */ 6201 int was_reg = C_DECL_REGISTER (decl); 6202 C_DECL_REGISTER (decl) = 0; 6203 DECL_REGISTER (decl) = 0; 6204 c_mark_addressable (decl); 6205 C_DECL_REGISTER (decl) = was_reg; 6206 } 6207 6208 /* This is the earliest point at which we might know the assembler 6209 name of a variable. Thus, if it's known before this, die horribly. */ 6210 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)); 6211 6212 if (warn_cxx_compat 6213 && TREE_CODE (decl) == VAR_DECL 6214 && TREE_PUBLIC (decl) 6215 && TREE_STATIC (decl) 6216 && (TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 6217 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 6218 || TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE) 6219 && TYPE_NAME (TREE_TYPE (decl)) == NULL_TREE) 6220 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wc___compat, 6221 ("non-local variable %qD with anonymous type is " 6222 "questionable in C++"), 6223 decl); 6224 6225 return decl; 6226 } 6227 } 6228 6229 /* Decode the parameter-list info for a function type or function definition. 6230 The argument is the value returned by `get_parm_info' (or made in c-parse.c 6231 if there is an identifier list instead of a parameter decl list). 6232 These two functions are separate because when a function returns 6233 or receives functions then each is called multiple times but the order 6234 of calls is different. The last call to `grokparms' is always the one 6235 that contains the formal parameter names of a function definition. 6236 6237 Return a list of arg types to use in the FUNCTION_TYPE for this function. 6238 6239 FUNCDEF_FLAG is true for a function definition, false for 6240 a mere declaration. A nonempty identifier-list gets an error message 6241 when FUNCDEF_FLAG is false. */ 6242 6243 static tree 6244 grokparms (struct c_arg_info *arg_info, bool funcdef_flag) 6245 { 6246 tree arg_types = arg_info->types; 6247 6248 if (funcdef_flag && arg_info->had_vla_unspec) 6249 { 6250 /* A function definition isn't function prototype scope C99 6.2.1p4. */ 6251 /* C99 6.7.5.2p4 */ 6252 error ("%<[*]%> not allowed in other than function prototype scope"); 6253 } 6254 6255 if (arg_types == 0 && !funcdef_flag && !in_system_header) 6256 warning (OPT_Wstrict_prototypes, 6257 "function declaration isn%'t a prototype"); 6258 6259 if (arg_types == error_mark_node) 6260 return 0; /* don't set TYPE_ARG_TYPES in this case */ 6261 6262 else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE) 6263 { 6264 if (!funcdef_flag) 6265 { 6266 pedwarn (input_location, 0, "parameter names (without types) in function declaration"); 6267 arg_info->parms = NULL_TREE; 6268 } 6269 else 6270 arg_info->parms = arg_info->types; 6271 6272 arg_info->types = 0; 6273 return 0; 6274 } 6275 else 6276 { 6277 tree parm, type, typelt; 6278 unsigned int parmno; 6279 const char *errmsg; 6280 6281 /* If there is a parameter of incomplete type in a definition, 6282 this is an error. In a declaration this is valid, and a 6283 struct or union type may be completed later, before any calls 6284 or definition of the function. In the case where the tag was 6285 first declared within the parameter list, a warning has 6286 already been given. If a parameter has void type, then 6287 however the function cannot be defined or called, so 6288 warn. */ 6289 6290 for (parm = arg_info->parms, typelt = arg_types, parmno = 1; 6291 parm; 6292 parm = DECL_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++) 6293 { 6294 type = TREE_VALUE (typelt); 6295 if (type == error_mark_node) 6296 continue; 6297 6298 if (!COMPLETE_TYPE_P (type)) 6299 { 6300 if (funcdef_flag) 6301 { 6302 if (DECL_NAME (parm)) 6303 error_at (input_location, 6304 "parameter %u (%q+D) has incomplete type", 6305 parmno, parm); 6306 else 6307 error_at (DECL_SOURCE_LOCATION (parm), 6308 "parameter %u has incomplete type", 6309 parmno); 6310 6311 TREE_VALUE (typelt) = error_mark_node; 6312 TREE_TYPE (parm) = error_mark_node; 6313 arg_types = NULL_TREE; 6314 } 6315 else if (VOID_TYPE_P (type)) 6316 { 6317 if (DECL_NAME (parm)) 6318 warning_at (input_location, 0, 6319 "parameter %u (%q+D) has void type", 6320 parmno, parm); 6321 else 6322 warning_at (DECL_SOURCE_LOCATION (parm), 0, 6323 "parameter %u has void type", 6324 parmno); 6325 } 6326 } 6327 6328 errmsg = targetm.invalid_parameter_type (type); 6329 if (errmsg) 6330 { 6331 error (errmsg); 6332 TREE_VALUE (typelt) = error_mark_node; 6333 TREE_TYPE (parm) = error_mark_node; 6334 arg_types = NULL_TREE; 6335 } 6336 6337 if (DECL_NAME (parm) && TREE_USED (parm)) 6338 warn_if_shadowing (parm); 6339 } 6340 return arg_types; 6341 } 6342 } 6343 6344 /* Allocate and initialize a c_arg_info structure from the parser's 6345 obstack. */ 6346 6347 struct c_arg_info * 6348 build_arg_info (void) 6349 { 6350 struct c_arg_info *ret = XOBNEW (&parser_obstack, struct c_arg_info); 6351 ret->parms = NULL_TREE; 6352 ret->tags = NULL; 6353 ret->types = NULL_TREE; 6354 ret->others = NULL_TREE; 6355 ret->pending_sizes = NULL; 6356 ret->had_vla_unspec = 0; 6357 return ret; 6358 } 6359 6360 /* Take apart the current scope and return a c_arg_info structure with 6361 info on a parameter list just parsed. 6362 6363 This structure is later fed to 'grokparms' and 'store_parm_decls'. 6364 6365 ELLIPSIS being true means the argument list ended in '...' so don't 6366 append a sentinel (void_list_node) to the end of the type-list. 6367 6368 EXPR is NULL or an expression that needs to be evaluated for the 6369 side effects of array size expressions in the parameters. */ 6370 6371 struct c_arg_info * 6372 get_parm_info (bool ellipsis, tree expr) 6373 { 6374 struct c_binding *b = current_scope->bindings; 6375 struct c_arg_info *arg_info = build_arg_info (); 6376 6377 tree parms = 0; 6378 VEC(c_arg_tag,gc) *tags = NULL; 6379 tree types = 0; 6380 tree others = 0; 6381 6382 static bool explained_incomplete_types = false; 6383 bool gave_void_only_once_err = false; 6384 6385 arg_info->had_vla_unspec = current_scope->had_vla_unspec; 6386 6387 /* The bindings in this scope must not get put into a block. 6388 We will take care of deleting the binding nodes. */ 6389 current_scope->bindings = 0; 6390 6391 /* This function is only called if there was *something* on the 6392 parameter list. */ 6393 gcc_assert (b); 6394 6395 /* A parameter list consisting solely of 'void' indicates that the 6396 function takes no arguments. But if the 'void' is qualified 6397 (by 'const' or 'volatile'), or has a storage class specifier 6398 ('register'), then the behavior is undefined; issue an error. 6399 Typedefs for 'void' are OK (see DR#157). */ 6400 if (b->prev == 0 /* one binding */ 6401 && TREE_CODE (b->decl) == PARM_DECL /* which is a parameter */ 6402 && !DECL_NAME (b->decl) /* anonymous */ 6403 && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */ 6404 { 6405 if (TREE_THIS_VOLATILE (b->decl) 6406 || TREE_READONLY (b->decl) 6407 || C_DECL_REGISTER (b->decl)) 6408 error ("%<void%> as only parameter may not be qualified"); 6409 6410 /* There cannot be an ellipsis. */ 6411 if (ellipsis) 6412 error ("%<void%> must be the only parameter"); 6413 6414 arg_info->types = void_list_node; 6415 return arg_info; 6416 } 6417 6418 if (!ellipsis) 6419 types = void_list_node; 6420 6421 /* Break up the bindings list into parms, tags, types, and others; 6422 apply sanity checks; purge the name-to-decl bindings. */ 6423 while (b) 6424 { 6425 tree decl = b->decl; 6426 tree type = TREE_TYPE (decl); 6427 c_arg_tag *tag; 6428 const char *keyword; 6429 6430 switch (TREE_CODE (decl)) 6431 { 6432 case PARM_DECL: 6433 if (b->id) 6434 { 6435 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 6436 I_SYMBOL_BINDING (b->id) = b->shadowed; 6437 } 6438 6439 /* Check for forward decls that never got their actual decl. */ 6440 if (TREE_ASM_WRITTEN (decl)) 6441 error ("parameter %q+D has just a forward declaration", decl); 6442 /* Check for (..., void, ...) and issue an error. */ 6443 else if (VOID_TYPE_P (type) && !DECL_NAME (decl)) 6444 { 6445 if (!gave_void_only_once_err) 6446 { 6447 error ("%<void%> must be the only parameter"); 6448 gave_void_only_once_err = true; 6449 } 6450 } 6451 else 6452 { 6453 /* Valid parameter, add it to the list. */ 6454 DECL_CHAIN (decl) = parms; 6455 parms = decl; 6456 6457 /* Since there is a prototype, args are passed in their 6458 declared types. The back end may override this later. */ 6459 DECL_ARG_TYPE (decl) = type; 6460 types = tree_cons (0, type, types); 6461 } 6462 break; 6463 6464 case ENUMERAL_TYPE: keyword = "enum"; goto tag; 6465 case UNION_TYPE: keyword = "union"; goto tag; 6466 case RECORD_TYPE: keyword = "struct"; goto tag; 6467 tag: 6468 /* Types may not have tag-names, in which case the type 6469 appears in the bindings list with b->id NULL. */ 6470 if (b->id) 6471 { 6472 gcc_assert (I_TAG_BINDING (b->id) == b); 6473 I_TAG_BINDING (b->id) = b->shadowed; 6474 } 6475 6476 /* Warn about any struct, union or enum tags defined in a 6477 parameter list. The scope of such types is limited to 6478 the parameter list, which is rarely if ever desirable 6479 (it's impossible to call such a function with type- 6480 correct arguments). An anonymous union parm type is 6481 meaningful as a GNU extension, so don't warn for that. */ 6482 if (TREE_CODE (decl) != UNION_TYPE || b->id != 0) 6483 { 6484 if (b->id) 6485 /* The %s will be one of 'struct', 'union', or 'enum'. */ 6486 warning (0, "%<%s %E%> declared inside parameter list", 6487 keyword, b->id); 6488 else 6489 /* The %s will be one of 'struct', 'union', or 'enum'. */ 6490 warning (0, "anonymous %s declared inside parameter list", 6491 keyword); 6492 6493 if (!explained_incomplete_types) 6494 { 6495 warning (0, "its scope is only this definition or declaration," 6496 " which is probably not what you want"); 6497 explained_incomplete_types = true; 6498 } 6499 } 6500 6501 tag = VEC_safe_push (c_arg_tag, gc, tags, NULL); 6502 tag->id = b->id; 6503 tag->type = decl; 6504 break; 6505 6506 case CONST_DECL: 6507 case TYPE_DECL: 6508 case FUNCTION_DECL: 6509 /* CONST_DECLs appear here when we have an embedded enum, 6510 and TYPE_DECLs appear here when we have an embedded struct 6511 or union. No warnings for this - we already warned about the 6512 type itself. FUNCTION_DECLs appear when there is an implicit 6513 function declaration in the parameter list. */ 6514 6515 /* When we reinsert this decl in the function body, we need 6516 to reconstruct whether it was marked as nested. */ 6517 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 6518 ? b->nested 6519 : !b->nested); 6520 DECL_CHAIN (decl) = others; 6521 others = decl; 6522 /* fall through */ 6523 6524 case ERROR_MARK: 6525 /* error_mark_node appears here when we have an undeclared 6526 variable. Just throw it away. */ 6527 if (b->id) 6528 { 6529 gcc_assert (I_SYMBOL_BINDING (b->id) == b); 6530 I_SYMBOL_BINDING (b->id) = b->shadowed; 6531 } 6532 break; 6533 6534 /* Other things that might be encountered. */ 6535 case LABEL_DECL: 6536 case VAR_DECL: 6537 default: 6538 gcc_unreachable (); 6539 } 6540 6541 b = free_binding_and_advance (b); 6542 } 6543 6544 arg_info->parms = parms; 6545 arg_info->tags = tags; 6546 arg_info->types = types; 6547 arg_info->others = others; 6548 arg_info->pending_sizes = expr; 6549 return arg_info; 6550 } 6551 6552 /* Get the struct, enum or union (CODE says which) with tag NAME. 6553 Define the tag as a forward-reference with location LOC if it is 6554 not defined. Return a c_typespec structure for the type 6555 specifier. */ 6556 6557 struct c_typespec 6558 parser_xref_tag (location_t loc, enum tree_code code, tree name) 6559 { 6560 struct c_typespec ret; 6561 tree ref; 6562 location_t refloc; 6563 6564 ret.expr = NULL_TREE; 6565 ret.expr_const_operands = true; 6566 6567 /* If a cross reference is requested, look up the type 6568 already defined for this tag and return it. */ 6569 6570 ref = lookup_tag (code, name, 0, &refloc); 6571 /* If this is the right type of tag, return what we found. 6572 (This reference will be shadowed by shadow_tag later if appropriate.) 6573 If this is the wrong type of tag, do not return it. If it was the 6574 wrong type in the same scope, we will have had an error 6575 message already; if in a different scope and declaring 6576 a name, pending_xref_error will give an error message; but if in a 6577 different scope and not declaring a name, this tag should 6578 shadow the previous declaration of a different type of tag, and 6579 this would not work properly if we return the reference found. 6580 (For example, with "struct foo" in an outer scope, "union foo;" 6581 must shadow that tag with a new one of union type.) */ 6582 ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref); 6583 if (ref && TREE_CODE (ref) == code) 6584 { 6585 if (C_TYPE_DEFINED_IN_STRUCT (ref) 6586 && loc != UNKNOWN_LOCATION 6587 && warn_cxx_compat) 6588 { 6589 switch (code) 6590 { 6591 case ENUMERAL_TYPE: 6592 warning_at (loc, OPT_Wc___compat, 6593 ("enum type defined in struct or union " 6594 "is not visible in C++")); 6595 inform (refloc, "enum type defined here"); 6596 break; 6597 case RECORD_TYPE: 6598 warning_at (loc, OPT_Wc___compat, 6599 ("struct defined in struct or union " 6600 "is not visible in C++")); 6601 inform (refloc, "struct defined here"); 6602 break; 6603 case UNION_TYPE: 6604 warning_at (loc, OPT_Wc___compat, 6605 ("union defined in struct or union " 6606 "is not visible in C++")); 6607 inform (refloc, "union defined here"); 6608 break; 6609 default: 6610 gcc_unreachable(); 6611 } 6612 } 6613 6614 ret.spec = ref; 6615 return ret; 6616 } 6617 6618 /* If no such tag is yet defined, create a forward-reference node 6619 and record it as the "definition". 6620 When a real declaration of this type is found, 6621 the forward-reference will be altered into a real type. */ 6622 6623 ref = make_node (code); 6624 if (code == ENUMERAL_TYPE) 6625 { 6626 /* Give the type a default layout like unsigned int 6627 to avoid crashing if it does not get defined. */ 6628 SET_TYPE_MODE (ref, TYPE_MODE (unsigned_type_node)); 6629 TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node); 6630 TYPE_USER_ALIGN (ref) = 0; 6631 TYPE_UNSIGNED (ref) = 1; 6632 TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node); 6633 TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node); 6634 TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node); 6635 } 6636 6637 pushtag (loc, name, ref); 6638 6639 ret.spec = ref; 6640 return ret; 6641 } 6642 6643 /* Get the struct, enum or union (CODE says which) with tag NAME. 6644 Define the tag as a forward-reference if it is not defined. 6645 Return a tree for the type. */ 6646 6647 tree 6648 xref_tag (enum tree_code code, tree name) 6649 { 6650 return parser_xref_tag (input_location, code, name).spec; 6651 } 6652 6653 /* Make sure that the tag NAME is defined *in the current scope* 6654 at least as a forward reference. 6655 LOC is the location of the struct's definition. 6656 CODE says which kind of tag NAME ought to be. 6657 6658 This stores the current value of the file static STRUCT_PARSE_INFO 6659 in *ENCLOSING_STRUCT_PARSE_INFO, and points STRUCT_PARSE_INFO at a 6660 new c_struct_parse_info structure. The old value of 6661 STRUCT_PARSE_INFO is restored in finish_struct. */ 6662 6663 tree 6664 start_struct (location_t loc, enum tree_code code, tree name, 6665 struct c_struct_parse_info **enclosing_struct_parse_info) 6666 { 6667 /* If there is already a tag defined at this scope 6668 (as a forward reference), just return it. */ 6669 6670 tree ref = NULL_TREE; 6671 location_t refloc = UNKNOWN_LOCATION; 6672 6673 if (name != NULL_TREE) 6674 ref = lookup_tag (code, name, 1, &refloc); 6675 if (ref && TREE_CODE (ref) == code) 6676 { 6677 if (TYPE_SIZE (ref)) 6678 { 6679 if (code == UNION_TYPE) 6680 error_at (loc, "redefinition of %<union %E%>", name); 6681 else 6682 error_at (loc, "redefinition of %<struct %E%>", name); 6683 if (refloc != UNKNOWN_LOCATION) 6684 inform (refloc, "originally defined here"); 6685 /* Don't create structures using a name already in use. */ 6686 ref = NULL_TREE; 6687 } 6688 else if (C_TYPE_BEING_DEFINED (ref)) 6689 { 6690 if (code == UNION_TYPE) 6691 error_at (loc, "nested redefinition of %<union %E%>", name); 6692 else 6693 error_at (loc, "nested redefinition of %<struct %E%>", name); 6694 /* Don't bother to report "originally defined here" for a 6695 nested redefinition; the original definition should be 6696 obvious. */ 6697 /* Don't create structures that contain themselves. */ 6698 ref = NULL_TREE; 6699 } 6700 } 6701 6702 /* Otherwise create a forward-reference just so the tag is in scope. */ 6703 6704 if (ref == NULL_TREE || TREE_CODE (ref) != code) 6705 { 6706 ref = make_node (code); 6707 pushtag (loc, name, ref); 6708 } 6709 6710 C_TYPE_BEING_DEFINED (ref) = 1; 6711 TYPE_PACKED (ref) = flag_pack_struct; 6712 6713 *enclosing_struct_parse_info = struct_parse_info; 6714 struct_parse_info = XNEW (struct c_struct_parse_info); 6715 struct_parse_info->struct_types = VEC_alloc (tree, heap, 0); 6716 struct_parse_info->fields = VEC_alloc (c_binding_ptr, heap, 0); 6717 struct_parse_info->typedefs_seen = VEC_alloc (tree, heap, 0); 6718 6719 /* FIXME: This will issue a warning for a use of a type defined 6720 within a statement expr used within sizeof, et. al. This is not 6721 terribly serious as C++ doesn't permit statement exprs within 6722 sizeof anyhow. */ 6723 if (warn_cxx_compat && (in_sizeof || in_typeof || in_alignof)) 6724 warning_at (loc, OPT_Wc___compat, 6725 "defining type in %qs expression is invalid in C++", 6726 (in_sizeof 6727 ? "sizeof" 6728 : (in_typeof ? "typeof" : "alignof"))); 6729 6730 return ref; 6731 } 6732 6733 /* Process the specs, declarator and width (NULL if omitted) 6734 of a structure component, returning a FIELD_DECL node. 6735 WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node. 6736 DECL_ATTRS is as for grokdeclarator. 6737 6738 LOC is the location of the structure component. 6739 6740 This is done during the parsing of the struct declaration. 6741 The FIELD_DECL nodes are chained together and the lot of them 6742 are ultimately passed to `build_struct' to make the RECORD_TYPE node. */ 6743 6744 tree 6745 grokfield (location_t loc, 6746 struct c_declarator *declarator, struct c_declspecs *declspecs, 6747 tree width, tree *decl_attrs) 6748 { 6749 tree value; 6750 6751 if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE 6752 && width == NULL_TREE) 6753 { 6754 /* This is an unnamed decl. 6755 6756 If we have something of the form "union { list } ;" then this 6757 is the anonymous union extension. Similarly for struct. 6758 6759 If this is something of the form "struct foo;", then 6760 If MS or Plan 9 extensions are enabled, this is handled as 6761 an anonymous struct. 6762 Otherwise this is a forward declaration of a structure tag. 6763 6764 If this is something of the form "foo;" and foo is a TYPE_DECL, then 6765 If foo names a structure or union without a tag, then this 6766 is an anonymous struct (this is permitted by C11). 6767 If MS or Plan 9 extensions are enabled and foo names a 6768 structure, then again this is an anonymous struct. 6769 Otherwise this is an error. 6770 6771 Oh what a horrid tangled web we weave. I wonder if MS consciously 6772 took this from Plan 9 or if it was an accident of implementation 6773 that took root before someone noticed the bug... */ 6774 6775 tree type = declspecs->type; 6776 bool type_ok = (TREE_CODE (type) == RECORD_TYPE 6777 || TREE_CODE (type) == UNION_TYPE); 6778 bool ok = false; 6779 6780 if (type_ok 6781 && (flag_ms_extensions 6782 || flag_plan9_extensions 6783 || !declspecs->typedef_p)) 6784 { 6785 if (flag_ms_extensions || flag_plan9_extensions) 6786 ok = true; 6787 else if (TYPE_NAME (type) == NULL) 6788 ok = true; 6789 else 6790 ok = false; 6791 } 6792 if (!ok) 6793 { 6794 pedwarn (loc, 0, "declaration does not declare anything"); 6795 return NULL_TREE; 6796 } 6797 if (!flag_isoc11) 6798 { 6799 if (flag_isoc99) 6800 pedwarn (loc, OPT_pedantic, 6801 "ISO C99 doesn%'t support unnamed structs/unions"); 6802 else 6803 pedwarn (loc, OPT_pedantic, 6804 "ISO C90 doesn%'t support unnamed structs/unions"); 6805 } 6806 } 6807 6808 value = grokdeclarator (declarator, declspecs, FIELD, false, 6809 width ? &width : NULL, decl_attrs, NULL, NULL, 6810 DEPRECATED_NORMAL); 6811 6812 finish_decl (value, loc, NULL_TREE, NULL_TREE, NULL_TREE); 6813 DECL_INITIAL (value) = width; 6814 6815 if (warn_cxx_compat && DECL_NAME (value) != NULL_TREE) 6816 { 6817 /* If we currently have a binding for this field, set the 6818 in_struct field in the binding, so that we warn about lookups 6819 which find it. */ 6820 struct c_binding *b = I_SYMBOL_BINDING (DECL_NAME (value)); 6821 if (b != NULL) 6822 { 6823 /* If the in_struct field is not yet set, push it on a list 6824 to be cleared when this struct is finished. */ 6825 if (!b->in_struct) 6826 { 6827 VEC_safe_push (c_binding_ptr, heap, 6828 struct_parse_info->fields, b); 6829 b->in_struct = 1; 6830 } 6831 } 6832 } 6833 6834 return value; 6835 } 6836 6837 /* Subroutine of detect_field_duplicates: return whether X and Y, 6838 which are both fields in the same struct, have duplicate field 6839 names. */ 6840 6841 static bool 6842 is_duplicate_field (tree x, tree y) 6843 { 6844 if (DECL_NAME (x) != NULL_TREE && DECL_NAME (x) == DECL_NAME (y)) 6845 return true; 6846 6847 /* When using -fplan9-extensions, an anonymous field whose name is a 6848 typedef can duplicate a field name. */ 6849 if (flag_plan9_extensions 6850 && (DECL_NAME (x) == NULL_TREE || DECL_NAME (y) == NULL_TREE)) 6851 { 6852 tree xt, xn, yt, yn; 6853 6854 xt = TREE_TYPE (x); 6855 if (DECL_NAME (x) != NULL_TREE) 6856 xn = DECL_NAME (x); 6857 else if ((TREE_CODE (xt) == RECORD_TYPE || TREE_CODE (xt) == UNION_TYPE) 6858 && TYPE_NAME (xt) != NULL_TREE 6859 && TREE_CODE (TYPE_NAME (xt)) == TYPE_DECL) 6860 xn = DECL_NAME (TYPE_NAME (xt)); 6861 else 6862 xn = NULL_TREE; 6863 6864 yt = TREE_TYPE (y); 6865 if (DECL_NAME (y) != NULL_TREE) 6866 yn = DECL_NAME (y); 6867 else if ((TREE_CODE (yt) == RECORD_TYPE || TREE_CODE (yt) == UNION_TYPE) 6868 && TYPE_NAME (yt) != NULL_TREE 6869 && TREE_CODE (TYPE_NAME (yt)) == TYPE_DECL) 6870 yn = DECL_NAME (TYPE_NAME (yt)); 6871 else 6872 yn = NULL_TREE; 6873 6874 if (xn != NULL_TREE && xn == yn) 6875 return true; 6876 } 6877 6878 return false; 6879 } 6880 6881 /* Subroutine of detect_field_duplicates: add the fields of FIELDLIST 6882 to HTAB, giving errors for any duplicates. */ 6883 6884 static void 6885 detect_field_duplicates_hash (tree fieldlist, htab_t htab) 6886 { 6887 tree x, y; 6888 void **slot; 6889 6890 for (x = fieldlist; x ; x = DECL_CHAIN (x)) 6891 if ((y = DECL_NAME (x)) != 0) 6892 { 6893 slot = htab_find_slot (htab, y, INSERT); 6894 if (*slot) 6895 { 6896 error ("duplicate member %q+D", x); 6897 DECL_NAME (x) = NULL_TREE; 6898 } 6899 *slot = y; 6900 } 6901 else if (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6902 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 6903 { 6904 detect_field_duplicates_hash (TYPE_FIELDS (TREE_TYPE (x)), htab); 6905 6906 /* When using -fplan9-extensions, an anonymous field whose 6907 name is a typedef can duplicate a field name. */ 6908 if (flag_plan9_extensions 6909 && TYPE_NAME (TREE_TYPE (x)) != NULL_TREE 6910 && TREE_CODE (TYPE_NAME (TREE_TYPE (x))) == TYPE_DECL) 6911 { 6912 tree xn = DECL_NAME (TYPE_NAME (TREE_TYPE (x))); 6913 slot = htab_find_slot (htab, xn, INSERT); 6914 if (*slot) 6915 error ("duplicate member %q+D", TYPE_NAME (TREE_TYPE (x))); 6916 *slot = xn; 6917 } 6918 } 6919 } 6920 6921 /* Generate an error for any duplicate field names in FIELDLIST. Munge 6922 the list such that this does not present a problem later. */ 6923 6924 static void 6925 detect_field_duplicates (tree fieldlist) 6926 { 6927 tree x, y; 6928 int timeout = 10; 6929 6930 /* If the struct is the list of instance variables of an Objective-C 6931 class, then we need to check all the instance variables of 6932 superclasses when checking for duplicates (since you can't have 6933 an instance variable in a subclass with the same name as an 6934 instance variable in a superclass). We pass on this job to the 6935 Objective-C compiler. objc_detect_field_duplicates() will return 6936 false if we are not checking the list of instance variables and 6937 the C frontend should proceed with the standard field duplicate 6938 checks. If we are checking the list of instance variables, the 6939 ObjC frontend will do the check, emit the errors if needed, and 6940 then return true. */ 6941 if (c_dialect_objc ()) 6942 if (objc_detect_field_duplicates (false)) 6943 return; 6944 6945 /* First, see if there are more than "a few" fields. 6946 This is trivially true if there are zero or one fields. */ 6947 if (!fieldlist || !DECL_CHAIN (fieldlist)) 6948 return; 6949 x = fieldlist; 6950 do { 6951 timeout--; 6952 if (DECL_NAME (x) == NULL_TREE 6953 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6954 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE)) 6955 timeout = 0; 6956 x = DECL_CHAIN (x); 6957 } while (timeout > 0 && x); 6958 6959 /* If there were "few" fields and no anonymous structures or unions, 6960 avoid the overhead of allocating a hash table. Instead just do 6961 the nested traversal thing. */ 6962 if (timeout > 0) 6963 { 6964 for (x = DECL_CHAIN (fieldlist); x; x = DECL_CHAIN (x)) 6965 /* When using -fplan9-extensions, we can have duplicates 6966 between typedef names and fields. */ 6967 if (DECL_NAME (x) 6968 || (flag_plan9_extensions 6969 && DECL_NAME (x) == NULL_TREE 6970 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 6971 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 6972 && TYPE_NAME (TREE_TYPE (x)) != NULL_TREE 6973 && TREE_CODE (TYPE_NAME (TREE_TYPE (x))) == TYPE_DECL)) 6974 { 6975 for (y = fieldlist; y != x; y = TREE_CHAIN (y)) 6976 if (is_duplicate_field (y, x)) 6977 { 6978 error ("duplicate member %q+D", x); 6979 DECL_NAME (x) = NULL_TREE; 6980 } 6981 } 6982 } 6983 else 6984 { 6985 htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); 6986 6987 detect_field_duplicates_hash (fieldlist, htab); 6988 htab_delete (htab); 6989 } 6990 } 6991 6992 /* Finish up struct info used by -Wc++-compat. */ 6993 6994 static void 6995 warn_cxx_compat_finish_struct (tree fieldlist) 6996 { 6997 unsigned int ix; 6998 tree x; 6999 struct c_binding *b; 7000 7001 /* Set the C_TYPE_DEFINED_IN_STRUCT flag for each type defined in 7002 the current struct. We do this now at the end of the struct 7003 because the flag is used to issue visibility warnings, and we 7004 only want to issue those warnings if the type is referenced 7005 outside of the struct declaration. */ 7006 FOR_EACH_VEC_ELT (tree, struct_parse_info->struct_types, ix, x) 7007 C_TYPE_DEFINED_IN_STRUCT (x) = 1; 7008 7009 /* The TYPEDEFS_SEEN field of STRUCT_PARSE_INFO is a list of 7010 typedefs used when declaring fields in this struct. If the name 7011 of any of the fields is also a typedef name then the struct would 7012 not parse in C++, because the C++ lookup rules say that the 7013 typedef name would be looked up in the context of the struct, and 7014 would thus be the field rather than the typedef. */ 7015 if (!VEC_empty (tree, struct_parse_info->typedefs_seen) 7016 && fieldlist != NULL_TREE) 7017 { 7018 /* Use a pointer_set using the name of the typedef. We can use 7019 a pointer_set because identifiers are interned. */ 7020 struct pointer_set_t *tset = pointer_set_create (); 7021 7022 FOR_EACH_VEC_ELT (tree, struct_parse_info->typedefs_seen, ix, x) 7023 pointer_set_insert (tset, DECL_NAME (x)); 7024 7025 for (x = fieldlist; x != NULL_TREE; x = DECL_CHAIN (x)) 7026 { 7027 if (DECL_NAME (x) != NULL_TREE 7028 && pointer_set_contains (tset, DECL_NAME (x))) 7029 { 7030 warning_at (DECL_SOURCE_LOCATION (x), OPT_Wc___compat, 7031 ("using %qD as both field and typedef name is " 7032 "invalid in C++"), 7033 x); 7034 /* FIXME: It would be nice to report the location where 7035 the typedef name is used. */ 7036 } 7037 } 7038 7039 pointer_set_destroy (tset); 7040 } 7041 7042 /* For each field which has a binding and which was not defined in 7043 an enclosing struct, clear the in_struct field. */ 7044 FOR_EACH_VEC_ELT (c_binding_ptr, struct_parse_info->fields, ix, b) 7045 b->in_struct = 0; 7046 } 7047 7048 /* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T. 7049 LOC is the location of the RECORD_TYPE or UNION_TYPE's definition. 7050 FIELDLIST is a chain of FIELD_DECL nodes for the fields. 7051 ATTRIBUTES are attributes to be applied to the structure. 7052 7053 ENCLOSING_STRUCT_PARSE_INFO is the value of STRUCT_PARSE_INFO when 7054 the struct was started. */ 7055 7056 tree 7057 finish_struct (location_t loc, tree t, tree fieldlist, tree attributes, 7058 struct c_struct_parse_info *enclosing_struct_parse_info) 7059 { 7060 tree x; 7061 bool toplevel = file_scope == current_scope; 7062 int saw_named_field; 7063 7064 /* If this type was previously laid out as a forward reference, 7065 make sure we lay it out again. */ 7066 7067 TYPE_SIZE (t) = 0; 7068 7069 decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7070 7071 if (pedantic) 7072 { 7073 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7074 { 7075 if (DECL_NAME (x) != 0) 7076 break; 7077 if (flag_isoc11 7078 && (TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 7079 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE)) 7080 break; 7081 } 7082 7083 if (x == 0) 7084 { 7085 if (TREE_CODE (t) == UNION_TYPE) 7086 { 7087 if (fieldlist) 7088 pedwarn (loc, OPT_pedantic, "union has no named members"); 7089 else 7090 pedwarn (loc, OPT_pedantic, "union has no members"); 7091 } 7092 else 7093 { 7094 if (fieldlist) 7095 pedwarn (loc, OPT_pedantic, "struct has no named members"); 7096 else 7097 pedwarn (loc, OPT_pedantic, "struct has no members"); 7098 } 7099 } 7100 } 7101 7102 /* Install struct as DECL_CONTEXT of each field decl. 7103 Also process specified field sizes, found in the DECL_INITIAL, 7104 storing 0 there after the type has been changed to precision equal 7105 to its width, rather than the precision of the specified standard 7106 type. (Correct layout requires the original type to have been preserved 7107 until now.) */ 7108 7109 saw_named_field = 0; 7110 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7111 { 7112 if (TREE_TYPE (x) == error_mark_node) 7113 continue; 7114 7115 DECL_CONTEXT (x) = t; 7116 7117 /* If any field is const, the structure type is pseudo-const. */ 7118 if (TREE_READONLY (x)) 7119 C_TYPE_FIELDS_READONLY (t) = 1; 7120 else 7121 { 7122 /* A field that is pseudo-const makes the structure likewise. */ 7123 tree t1 = strip_array_types (TREE_TYPE (x)); 7124 if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE) 7125 && C_TYPE_FIELDS_READONLY (t1)) 7126 C_TYPE_FIELDS_READONLY (t) = 1; 7127 } 7128 7129 /* Any field that is volatile means variables of this type must be 7130 treated in some ways as volatile. */ 7131 if (TREE_THIS_VOLATILE (x)) 7132 C_TYPE_FIELDS_VOLATILE (t) = 1; 7133 7134 /* Any field of nominal variable size implies structure is too. */ 7135 if (C_DECL_VARIABLE_SIZE (x)) 7136 C_TYPE_VARIABLE_SIZE (t) = 1; 7137 7138 if (DECL_INITIAL (x)) 7139 { 7140 unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1); 7141 DECL_SIZE (x) = bitsize_int (width); 7142 DECL_BIT_FIELD (x) = 1; 7143 SET_DECL_C_BIT_FIELD (x); 7144 } 7145 7146 if (TYPE_PACKED (t) 7147 && (DECL_BIT_FIELD (x) 7148 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)) 7149 DECL_PACKED (x) = 1; 7150 7151 /* Detect flexible array member in an invalid context. */ 7152 if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE 7153 && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE 7154 && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE 7155 && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE) 7156 { 7157 if (TREE_CODE (t) == UNION_TYPE) 7158 { 7159 error_at (DECL_SOURCE_LOCATION (x), 7160 "flexible array member in union"); 7161 TREE_TYPE (x) = error_mark_node; 7162 } 7163 else if (DECL_CHAIN (x) != NULL_TREE) 7164 { 7165 error_at (DECL_SOURCE_LOCATION (x), 7166 "flexible array member not at end of struct"); 7167 TREE_TYPE (x) = error_mark_node; 7168 } 7169 else if (!saw_named_field) 7170 { 7171 error_at (DECL_SOURCE_LOCATION (x), 7172 "flexible array member in otherwise empty struct"); 7173 TREE_TYPE (x) = error_mark_node; 7174 } 7175 } 7176 7177 if (pedantic && TREE_CODE (t) == RECORD_TYPE 7178 && flexible_array_type_p (TREE_TYPE (x))) 7179 pedwarn (DECL_SOURCE_LOCATION (x), OPT_pedantic, 7180 "invalid use of structure with flexible array member"); 7181 7182 if (DECL_NAME (x) 7183 || TREE_CODE (TREE_TYPE (x)) == RECORD_TYPE 7184 || TREE_CODE (TREE_TYPE (x)) == UNION_TYPE) 7185 saw_named_field = 1; 7186 } 7187 7188 detect_field_duplicates (fieldlist); 7189 7190 /* Now we have the nearly final fieldlist. Record it, 7191 then lay out the structure or union (including the fields). */ 7192 7193 TYPE_FIELDS (t) = fieldlist; 7194 7195 layout_type (t); 7196 7197 /* Give bit-fields their proper types. */ 7198 { 7199 tree *fieldlistp = &fieldlist; 7200 while (*fieldlistp) 7201 if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp) 7202 && TREE_TYPE (*fieldlistp) != error_mark_node) 7203 { 7204 unsigned HOST_WIDE_INT width 7205 = tree_low_cst (DECL_INITIAL (*fieldlistp), 1); 7206 tree type = TREE_TYPE (*fieldlistp); 7207 if (width != TYPE_PRECISION (type)) 7208 { 7209 TREE_TYPE (*fieldlistp) 7210 = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type)); 7211 DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp)); 7212 } 7213 DECL_INITIAL (*fieldlistp) = 0; 7214 } 7215 else 7216 fieldlistp = &DECL_CHAIN (*fieldlistp); 7217 } 7218 7219 /* Now we have the truly final field list. 7220 Store it in this type and in the variants. */ 7221 7222 TYPE_FIELDS (t) = fieldlist; 7223 7224 /* If there are lots of fields, sort so we can look through them fast. 7225 We arbitrarily consider 16 or more elts to be "a lot". */ 7226 7227 { 7228 int len = 0; 7229 7230 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7231 { 7232 if (len > 15 || DECL_NAME (x) == NULL) 7233 break; 7234 len += 1; 7235 } 7236 7237 if (len > 15) 7238 { 7239 tree *field_array; 7240 struct lang_type *space; 7241 struct sorted_fields_type *space2; 7242 7243 len += list_length (x); 7244 7245 /* Use the same allocation policy here that make_node uses, to 7246 ensure that this lives as long as the rest of the struct decl. 7247 All decls in an inline function need to be saved. */ 7248 7249 space = ggc_alloc_cleared_lang_type (sizeof (struct lang_type)); 7250 space2 = ggc_alloc_sorted_fields_type 7251 (sizeof (struct sorted_fields_type) + len * sizeof (tree)); 7252 7253 len = 0; 7254 space->s = space2; 7255 field_array = &space2->elts[0]; 7256 for (x = fieldlist; x; x = DECL_CHAIN (x)) 7257 { 7258 field_array[len++] = x; 7259 7260 /* If there is anonymous struct or union, break out of the loop. */ 7261 if (DECL_NAME (x) == NULL) 7262 break; 7263 } 7264 /* Found no anonymous struct/union. Add the TYPE_LANG_SPECIFIC. */ 7265 if (x == NULL) 7266 { 7267 TYPE_LANG_SPECIFIC (t) = space; 7268 TYPE_LANG_SPECIFIC (t)->s->len = len; 7269 field_array = TYPE_LANG_SPECIFIC (t)->s->elts; 7270 qsort (field_array, len, sizeof (tree), field_decl_cmp); 7271 } 7272 } 7273 } 7274 7275 for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x)) 7276 { 7277 TYPE_FIELDS (x) = TYPE_FIELDS (t); 7278 TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t); 7279 C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t); 7280 C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t); 7281 C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t); 7282 } 7283 7284 /* If this was supposed to be a transparent union, but we can't 7285 make it one, warn and turn off the flag. */ 7286 if (TREE_CODE (t) == UNION_TYPE 7287 && TYPE_TRANSPARENT_AGGR (t) 7288 && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))) 7289 { 7290 TYPE_TRANSPARENT_AGGR (t) = 0; 7291 warning_at (loc, 0, "union cannot be made transparent"); 7292 } 7293 7294 /* If this structure or union completes the type of any previous 7295 variable declaration, lay it out and output its rtl. */ 7296 for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)); 7297 x; 7298 x = TREE_CHAIN (x)) 7299 { 7300 tree decl = TREE_VALUE (x); 7301 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) 7302 layout_array_type (TREE_TYPE (decl)); 7303 if (TREE_CODE (decl) != TYPE_DECL) 7304 { 7305 layout_decl (decl, 0); 7306 if (c_dialect_objc ()) 7307 objc_check_decl (decl); 7308 rest_of_decl_compilation (decl, toplevel, 0); 7309 if (!toplevel) 7310 expand_decl (decl); 7311 } 7312 } 7313 C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0; 7314 7315 /* Update type location to the one of the definition, instead of e.g. 7316 a forward declaration. */ 7317 if (TYPE_STUB_DECL (t)) 7318 DECL_SOURCE_LOCATION (TYPE_STUB_DECL (t)) = loc; 7319 7320 /* Finish debugging output for this type. */ 7321 rest_of_type_compilation (t, toplevel); 7322 7323 /* If we're inside a function proper, i.e. not file-scope and not still 7324 parsing parameters, then arrange for the size of a variable sized type 7325 to be bound now. */ 7326 if (building_stmt_list_p () && variably_modified_type_p (t, NULL_TREE)) 7327 add_stmt (build_stmt (loc, 7328 DECL_EXPR, build_decl (loc, TYPE_DECL, NULL, t))); 7329 7330 if (warn_cxx_compat) 7331 warn_cxx_compat_finish_struct (fieldlist); 7332 7333 VEC_free (tree, heap, struct_parse_info->struct_types); 7334 VEC_free (c_binding_ptr, heap, struct_parse_info->fields); 7335 VEC_free (tree, heap, struct_parse_info->typedefs_seen); 7336 XDELETE (struct_parse_info); 7337 7338 struct_parse_info = enclosing_struct_parse_info; 7339 7340 /* If this struct is defined inside a struct, add it to 7341 struct_types. */ 7342 if (warn_cxx_compat 7343 && struct_parse_info != NULL 7344 && !in_sizeof && !in_typeof && !in_alignof) 7345 VEC_safe_push (tree, heap, struct_parse_info->struct_types, t); 7346 7347 return t; 7348 } 7349 7350 /* Lay out the type T, and its element type, and so on. */ 7351 7352 static void 7353 layout_array_type (tree t) 7354 { 7355 if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) 7356 layout_array_type (TREE_TYPE (t)); 7357 layout_type (t); 7358 } 7359 7360 /* Begin compiling the definition of an enumeration type. 7361 NAME is its name (or null if anonymous). 7362 LOC is the enum's location. 7363 Returns the type object, as yet incomplete. 7364 Also records info about it so that build_enumerator 7365 may be used to declare the individual values as they are read. */ 7366 7367 tree 7368 start_enum (location_t loc, struct c_enum_contents *the_enum, tree name) 7369 { 7370 tree enumtype = NULL_TREE; 7371 location_t enumloc = UNKNOWN_LOCATION; 7372 7373 /* If this is the real definition for a previous forward reference, 7374 fill in the contents in the same object that used to be the 7375 forward reference. */ 7376 7377 if (name != NULL_TREE) 7378 enumtype = lookup_tag (ENUMERAL_TYPE, name, 1, &enumloc); 7379 7380 if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE) 7381 { 7382 enumtype = make_node (ENUMERAL_TYPE); 7383 pushtag (loc, name, enumtype); 7384 } 7385 7386 if (C_TYPE_BEING_DEFINED (enumtype)) 7387 error_at (loc, "nested redefinition of %<enum %E%>", name); 7388 7389 C_TYPE_BEING_DEFINED (enumtype) = 1; 7390 7391 if (TYPE_VALUES (enumtype) != 0) 7392 { 7393 /* This enum is a named one that has been declared already. */ 7394 error_at (loc, "redeclaration of %<enum %E%>", name); 7395 if (enumloc != UNKNOWN_LOCATION) 7396 inform (enumloc, "originally defined here"); 7397 7398 /* Completely replace its old definition. 7399 The old enumerators remain defined, however. */ 7400 TYPE_VALUES (enumtype) = 0; 7401 } 7402 7403 the_enum->enum_next_value = integer_zero_node; 7404 the_enum->enum_overflow = 0; 7405 7406 if (flag_short_enums) 7407 TYPE_PACKED (enumtype) = 1; 7408 7409 /* FIXME: This will issue a warning for a use of a type defined 7410 within sizeof in a statement expr. This is not terribly serious 7411 as C++ doesn't permit statement exprs within sizeof anyhow. */ 7412 if (warn_cxx_compat && (in_sizeof || in_typeof || in_alignof)) 7413 warning_at (loc, OPT_Wc___compat, 7414 "defining type in %qs expression is invalid in C++", 7415 (in_sizeof 7416 ? "sizeof" 7417 : (in_typeof ? "typeof" : "alignof"))); 7418 7419 return enumtype; 7420 } 7421 7422 /* After processing and defining all the values of an enumeration type, 7423 install their decls in the enumeration type and finish it off. 7424 ENUMTYPE is the type object, VALUES a list of decl-value pairs, 7425 and ATTRIBUTES are the specified attributes. 7426 Returns ENUMTYPE. */ 7427 7428 tree 7429 finish_enum (tree enumtype, tree values, tree attributes) 7430 { 7431 tree pair, tem; 7432 tree minnode = 0, maxnode = 0; 7433 int precision, unsign; 7434 bool toplevel = (file_scope == current_scope); 7435 struct lang_type *lt; 7436 7437 decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 7438 7439 /* Calculate the maximum value of any enumerator in this type. */ 7440 7441 if (values == error_mark_node) 7442 minnode = maxnode = integer_zero_node; 7443 else 7444 { 7445 minnode = maxnode = TREE_VALUE (values); 7446 for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair)) 7447 { 7448 tree value = TREE_VALUE (pair); 7449 if (tree_int_cst_lt (maxnode, value)) 7450 maxnode = value; 7451 if (tree_int_cst_lt (value, minnode)) 7452 minnode = value; 7453 } 7454 } 7455 7456 /* Construct the final type of this enumeration. It is the same 7457 as one of the integral types - the narrowest one that fits, except 7458 that normally we only go as narrow as int - and signed iff any of 7459 the values are negative. */ 7460 unsign = (tree_int_cst_sgn (minnode) >= 0); 7461 precision = MAX (tree_int_cst_min_precision (minnode, unsign), 7462 tree_int_cst_min_precision (maxnode, unsign)); 7463 7464 if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node)) 7465 { 7466 tem = c_common_type_for_size (precision, unsign); 7467 if (tem == NULL) 7468 { 7469 warning (0, "enumeration values exceed range of largest integer"); 7470 tem = long_long_integer_type_node; 7471 } 7472 } 7473 else 7474 tem = unsign ? unsigned_type_node : integer_type_node; 7475 7476 TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem); 7477 TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem); 7478 TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem); 7479 TYPE_SIZE (enumtype) = 0; 7480 7481 /* If the precision of the type was specific with an attribute and it 7482 was too small, give an error. Otherwise, use it. */ 7483 if (TYPE_PRECISION (enumtype)) 7484 { 7485 if (precision > TYPE_PRECISION (enumtype)) 7486 error ("specified mode too small for enumeral values"); 7487 } 7488 else 7489 TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem); 7490 7491 layout_type (enumtype); 7492 7493 if (values != error_mark_node) 7494 { 7495 /* Change the type of the enumerators to be the enum type. We 7496 need to do this irrespective of the size of the enum, for 7497 proper type checking. Replace the DECL_INITIALs of the 7498 enumerators, and the value slots of the list, with copies 7499 that have the enum type; they cannot be modified in place 7500 because they may be shared (e.g. integer_zero_node) Finally, 7501 change the purpose slots to point to the names of the decls. */ 7502 for (pair = values; pair; pair = TREE_CHAIN (pair)) 7503 { 7504 tree enu = TREE_PURPOSE (pair); 7505 tree ini = DECL_INITIAL (enu); 7506 7507 TREE_TYPE (enu) = enumtype; 7508 7509 /* The ISO C Standard mandates enumerators to have type int, 7510 even though the underlying type of an enum type is 7511 unspecified. However, GCC allows enumerators of any 7512 integer type as an extensions. build_enumerator() 7513 converts any enumerators that fit in an int to type int, 7514 to avoid promotions to unsigned types when comparing 7515 integers with enumerators that fit in the int range. 7516 When -pedantic is given, build_enumerator() would have 7517 already warned about those that don't fit. Here we 7518 convert the rest to the enumerator type. */ 7519 if (TREE_TYPE (ini) != integer_type_node) 7520 ini = convert (enumtype, ini); 7521 7522 DECL_INITIAL (enu) = ini; 7523 TREE_PURPOSE (pair) = DECL_NAME (enu); 7524 TREE_VALUE (pair) = ini; 7525 } 7526 7527 TYPE_VALUES (enumtype) = values; 7528 } 7529 7530 /* Record the min/max values so that we can warn about bit-field 7531 enumerations that are too small for the values. */ 7532 lt = ggc_alloc_cleared_lang_type (sizeof (struct lang_type)); 7533 lt->enum_min = minnode; 7534 lt->enum_max = maxnode; 7535 TYPE_LANG_SPECIFIC (enumtype) = lt; 7536 7537 /* Fix up all variant types of this enum type. */ 7538 for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem)) 7539 { 7540 if (tem == enumtype) 7541 continue; 7542 TYPE_VALUES (tem) = TYPE_VALUES (enumtype); 7543 TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype); 7544 TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype); 7545 TYPE_SIZE (tem) = TYPE_SIZE (enumtype); 7546 TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype); 7547 SET_TYPE_MODE (tem, TYPE_MODE (enumtype)); 7548 TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype); 7549 TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype); 7550 TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype); 7551 TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype); 7552 TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype); 7553 } 7554 7555 /* Finish debugging output for this type. */ 7556 rest_of_type_compilation (enumtype, toplevel); 7557 7558 /* If this enum is defined inside a struct, add it to 7559 struct_types. */ 7560 if (warn_cxx_compat 7561 && struct_parse_info != NULL 7562 && !in_sizeof && !in_typeof && !in_alignof) 7563 VEC_safe_push (tree, heap, struct_parse_info->struct_types, enumtype); 7564 7565 return enumtype; 7566 } 7567 7568 /* Build and install a CONST_DECL for one value of the 7569 current enumeration type (one that was begun with start_enum). 7570 DECL_LOC is the location of the enumerator. 7571 LOC is the location of the '=' operator if any, DECL_LOC otherwise. 7572 Return a tree-list containing the CONST_DECL and its value. 7573 Assignment of sequential values by default is handled here. */ 7574 7575 tree 7576 build_enumerator (location_t decl_loc, location_t loc, 7577 struct c_enum_contents *the_enum, tree name, tree value) 7578 { 7579 tree decl, type; 7580 7581 /* Validate and default VALUE. */ 7582 7583 if (value != 0) 7584 { 7585 /* Don't issue more errors for error_mark_node (i.e. an 7586 undeclared identifier) - just ignore the value expression. */ 7587 if (value == error_mark_node) 7588 value = 0; 7589 else if (!INTEGRAL_TYPE_P (TREE_TYPE (value))) 7590 { 7591 error_at (loc, "enumerator value for %qE is not an integer constant", 7592 name); 7593 value = 0; 7594 } 7595 else 7596 { 7597 if (TREE_CODE (value) != INTEGER_CST) 7598 { 7599 value = c_fully_fold (value, false, NULL); 7600 if (TREE_CODE (value) == INTEGER_CST) 7601 pedwarn (loc, OPT_pedantic, 7602 "enumerator value for %qE is not an integer " 7603 "constant expression", name); 7604 } 7605 if (TREE_CODE (value) != INTEGER_CST) 7606 { 7607 error ("enumerator value for %qE is not an integer constant", 7608 name); 7609 value = 0; 7610 } 7611 else 7612 { 7613 value = default_conversion (value); 7614 constant_expression_warning (value); 7615 } 7616 } 7617 } 7618 7619 /* Default based on previous value. */ 7620 /* It should no longer be possible to have NON_LVALUE_EXPR 7621 in the default. */ 7622 if (value == 0) 7623 { 7624 value = the_enum->enum_next_value; 7625 if (the_enum->enum_overflow) 7626 error_at (loc, "overflow in enumeration values"); 7627 } 7628 /* Even though the underlying type of an enum is unspecified, the 7629 type of enumeration constants is explicitly defined as int 7630 (6.4.4.3/2 in the C99 Standard). GCC allows any integer type as 7631 an extension. */ 7632 else if (!int_fits_type_p (value, integer_type_node)) 7633 pedwarn (loc, OPT_pedantic, 7634 "ISO C restricts enumerator values to range of %<int%>"); 7635 7636 /* The ISO C Standard mandates enumerators to have type int, even 7637 though the underlying type of an enum type is unspecified. 7638 However, GCC allows enumerators of any integer type as an 7639 extensions. Here we convert any enumerators that fit in an int 7640 to type int, to avoid promotions to unsigned types when comparing 7641 integers with enumerators that fit in the int range. When 7642 -pedantic is given, we would have already warned about those that 7643 don't fit. We have to do this here rather than in finish_enum 7644 because this value may be used to define more enumerators. */ 7645 if (int_fits_type_p (value, integer_type_node)) 7646 value = convert (integer_type_node, value); 7647 7648 /* Set basis for default for next value. */ 7649 the_enum->enum_next_value 7650 = build_binary_op (EXPR_LOC_OR_HERE (value), 7651 PLUS_EXPR, value, integer_one_node, 0); 7652 the_enum->enum_overflow = tree_int_cst_lt (the_enum->enum_next_value, value); 7653 7654 /* Now create a declaration for the enum value name. */ 7655 7656 type = TREE_TYPE (value); 7657 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 7658 TYPE_PRECISION (integer_type_node)), 7659 (TYPE_PRECISION (type) 7660 >= TYPE_PRECISION (integer_type_node) 7661 && TYPE_UNSIGNED (type))); 7662 7663 decl = build_decl (decl_loc, CONST_DECL, name, type); 7664 DECL_INITIAL (decl) = convert (type, value); 7665 pushdecl (decl); 7666 7667 return tree_cons (decl, value, NULL_TREE); 7668 } 7669 7670 7671 /* Create the FUNCTION_DECL for a function definition. 7672 DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of 7673 the declaration; they describe the function's name and the type it returns, 7674 but twisted together in a fashion that parallels the syntax of C. 7675 7676 This function creates a binding context for the function body 7677 as well as setting up the FUNCTION_DECL in current_function_decl. 7678 7679 Returns 1 on success. If the DECLARATOR is not suitable for a function 7680 (it defines a datum instead), we return 0, which tells 7681 yyparse to report a parse error. */ 7682 7683 int 7684 start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, 7685 tree attributes) 7686 { 7687 tree decl1, old_decl; 7688 tree restype, resdecl; 7689 location_t loc; 7690 7691 current_function_returns_value = 0; /* Assume, until we see it does. */ 7692 current_function_returns_null = 0; 7693 current_function_returns_abnormally = 0; 7694 warn_about_return_type = 0; 7695 c_switch_stack = NULL; 7696 7697 /* Indicate no valid break/continue context by setting these variables 7698 to some non-null, non-label value. We'll notice and emit the proper 7699 error message in c_finish_bc_stmt. */ 7700 c_break_label = c_cont_label = size_zero_node; 7701 7702 decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL, 7703 &attributes, NULL, NULL, DEPRECATED_NORMAL); 7704 7705 /* If the declarator is not suitable for a function definition, 7706 cause a syntax error. */ 7707 if (decl1 == 0 7708 || TREE_CODE (decl1) != FUNCTION_DECL) 7709 return 0; 7710 7711 loc = DECL_SOURCE_LOCATION (decl1); 7712 7713 decl_attributes (&decl1, attributes, 0); 7714 7715 if (DECL_DECLARED_INLINE_P (decl1) 7716 && DECL_UNINLINABLE (decl1) 7717 && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1))) 7718 warning_at (loc, OPT_Wattributes, 7719 "inline function %qD given attribute noinline", 7720 decl1); 7721 7722 /* Handle gnu_inline attribute. */ 7723 if (declspecs->inline_p 7724 && !flag_gnu89_inline 7725 && TREE_CODE (decl1) == FUNCTION_DECL 7726 && (lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1)) 7727 || current_function_decl)) 7728 { 7729 if (declspecs->storage_class != csc_static) 7730 DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1); 7731 } 7732 7733 announce_function (decl1); 7734 7735 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1)))) 7736 { 7737 error_at (loc, "return type is an incomplete type"); 7738 /* Make it return void instead. */ 7739 TREE_TYPE (decl1) 7740 = build_function_type (void_type_node, 7741 TYPE_ARG_TYPES (TREE_TYPE (decl1))); 7742 } 7743 7744 if (warn_about_return_type) 7745 pedwarn_c99 (loc, flag_isoc99 ? 0 7746 : (warn_return_type ? OPT_Wreturn_type : OPT_Wimplicit_int), 7747 "return type defaults to %<int%>"); 7748 7749 /* Make the init_value nonzero so pushdecl knows this is not tentative. 7750 error_mark_node is replaced below (in pop_scope) with the BLOCK. */ 7751 DECL_INITIAL (decl1) = error_mark_node; 7752 7753 /* A nested function is not global. */ 7754 if (current_function_decl != 0) 7755 TREE_PUBLIC (decl1) = 0; 7756 7757 /* If this definition isn't a prototype and we had a prototype declaration 7758 before, copy the arg type info from that prototype. */ 7759 old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope); 7760 if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL) 7761 old_decl = 0; 7762 current_function_prototype_locus = UNKNOWN_LOCATION; 7763 current_function_prototype_built_in = false; 7764 current_function_prototype_arg_types = NULL_TREE; 7765 if (!prototype_p (TREE_TYPE (decl1))) 7766 { 7767 if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE 7768 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 7769 TREE_TYPE (TREE_TYPE (old_decl)))) 7770 { 7771 TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl), 7772 TREE_TYPE (decl1)); 7773 current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl); 7774 current_function_prototype_built_in 7775 = C_DECL_BUILTIN_PROTOTYPE (old_decl); 7776 current_function_prototype_arg_types 7777 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); 7778 } 7779 if (TREE_PUBLIC (decl1)) 7780 { 7781 /* If there is an external prototype declaration of this 7782 function, record its location but do not copy information 7783 to this decl. This may be an invisible declaration 7784 (built-in or in a scope which has finished) or simply 7785 have more refined argument types than any declaration 7786 found above. */ 7787 struct c_binding *b; 7788 for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed) 7789 if (B_IN_SCOPE (b, external_scope)) 7790 break; 7791 if (b) 7792 { 7793 tree ext_decl, ext_type; 7794 ext_decl = b->decl; 7795 ext_type = b->u.type ? b->u.type : TREE_TYPE (ext_decl); 7796 if (TREE_CODE (ext_type) == FUNCTION_TYPE 7797 && comptypes (TREE_TYPE (TREE_TYPE (decl1)), 7798 TREE_TYPE (ext_type))) 7799 { 7800 current_function_prototype_locus 7801 = DECL_SOURCE_LOCATION (ext_decl); 7802 current_function_prototype_built_in 7803 = C_DECL_BUILTIN_PROTOTYPE (ext_decl); 7804 current_function_prototype_arg_types 7805 = TYPE_ARG_TYPES (ext_type); 7806 } 7807 } 7808 } 7809 } 7810 7811 /* Optionally warn of old-fashioned def with no previous prototype. */ 7812 if (warn_strict_prototypes 7813 && old_decl != error_mark_node 7814 && !prototype_p (TREE_TYPE (decl1)) 7815 && C_DECL_ISNT_PROTOTYPE (old_decl)) 7816 warning_at (loc, OPT_Wstrict_prototypes, 7817 "function declaration isn%'t a prototype"); 7818 /* Optionally warn of any global def with no previous prototype. */ 7819 else if (warn_missing_prototypes 7820 && old_decl != error_mark_node 7821 && TREE_PUBLIC (decl1) 7822 && !MAIN_NAME_P (DECL_NAME (decl1)) 7823 && C_DECL_ISNT_PROTOTYPE (old_decl)) 7824 warning_at (loc, OPT_Wmissing_prototypes, 7825 "no previous prototype for %qD", decl1); 7826 /* Optionally warn of any def with no previous prototype 7827 if the function has already been used. */ 7828 else if (warn_missing_prototypes 7829 && old_decl != 0 7830 && old_decl != error_mark_node 7831 && TREE_USED (old_decl) 7832 && !prototype_p (TREE_TYPE (old_decl))) 7833 warning_at (loc, OPT_Wmissing_prototypes, 7834 "%qD was used with no prototype before its definition", decl1); 7835 /* Optionally warn of any global def with no previous declaration. */ 7836 else if (warn_missing_declarations 7837 && TREE_PUBLIC (decl1) 7838 && old_decl == 0 7839 && !MAIN_NAME_P (DECL_NAME (decl1))) 7840 warning_at (loc, OPT_Wmissing_declarations, 7841 "no previous declaration for %qD", 7842 decl1); 7843 /* Optionally warn of any def with no previous declaration 7844 if the function has already been used. */ 7845 else if (warn_missing_declarations 7846 && old_decl != 0 7847 && old_decl != error_mark_node 7848 && TREE_USED (old_decl) 7849 && C_DECL_IMPLICIT (old_decl)) 7850 warning_at (loc, OPT_Wmissing_declarations, 7851 "%qD was used with no declaration before its definition", decl1); 7852 7853 /* This function exists in static storage. 7854 (This does not mean `static' in the C sense!) */ 7855 TREE_STATIC (decl1) = 1; 7856 7857 /* This is the earliest point at which we might know the assembler 7858 name of the function. Thus, if it's set before this, die horribly. */ 7859 gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1)); 7860 7861 /* If #pragma weak was used, mark the decl weak now. */ 7862 if (current_scope == file_scope) 7863 maybe_apply_pragma_weak (decl1); 7864 7865 /* Warn for unlikely, improbable, or stupid declarations of `main'. */ 7866 if (warn_main && MAIN_NAME_P (DECL_NAME (decl1))) 7867 { 7868 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1))) 7869 != integer_type_node) 7870 pedwarn (loc, OPT_Wmain, "return type of %qD is not %<int%>", decl1); 7871 7872 check_main_parameter_types (decl1); 7873 7874 if (!TREE_PUBLIC (decl1)) 7875 pedwarn (loc, OPT_Wmain, 7876 "%qD is normally a non-static function", decl1); 7877 } 7878 7879 /* Record the decl so that the function name is defined. 7880 If we already have a decl for this name, and it is a FUNCTION_DECL, 7881 use the old decl. */ 7882 7883 current_function_decl = pushdecl (decl1); 7884 7885 push_scope (); 7886 declare_parm_level (); 7887 7888 restype = TREE_TYPE (TREE_TYPE (current_function_decl)); 7889 resdecl = build_decl (loc, RESULT_DECL, NULL_TREE, restype); 7890 DECL_ARTIFICIAL (resdecl) = 1; 7891 DECL_IGNORED_P (resdecl) = 1; 7892 DECL_RESULT (current_function_decl) = resdecl; 7893 7894 start_fname_decls (); 7895 7896 return 1; 7897 } 7898 7899 /* Subroutine of store_parm_decls which handles new-style function 7900 definitions (prototype format). The parms already have decls, so we 7901 need only record them as in effect and complain if any redundant 7902 old-style parm decls were written. */ 7903 static void 7904 store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info) 7905 { 7906 tree decl; 7907 c_arg_tag *tag; 7908 unsigned ix; 7909 7910 if (current_scope->bindings) 7911 { 7912 error_at (DECL_SOURCE_LOCATION (fndecl), 7913 "old-style parameter declarations in prototyped " 7914 "function definition"); 7915 7916 /* Get rid of the old-style declarations. */ 7917 pop_scope (); 7918 push_scope (); 7919 } 7920 /* Don't issue this warning for nested functions, and don't issue this 7921 warning if we got here because ARG_INFO_TYPES was error_mark_node 7922 (this happens when a function definition has just an ellipsis in 7923 its parameter list). */ 7924 else if (!in_system_header && !current_function_scope 7925 && arg_info->types != error_mark_node) 7926 warning_at (DECL_SOURCE_LOCATION (fndecl), OPT_Wtraditional, 7927 "traditional C rejects ISO C style function definitions"); 7928 7929 /* Now make all the parameter declarations visible in the function body. 7930 We can bypass most of the grunt work of pushdecl. */ 7931 for (decl = arg_info->parms; decl; decl = DECL_CHAIN (decl)) 7932 { 7933 DECL_CONTEXT (decl) = current_function_decl; 7934 if (DECL_NAME (decl)) 7935 { 7936 bind (DECL_NAME (decl), decl, current_scope, 7937 /*invisible=*/false, /*nested=*/false, 7938 UNKNOWN_LOCATION); 7939 if (!TREE_USED (decl)) 7940 warn_if_shadowing (decl); 7941 } 7942 else 7943 error_at (DECL_SOURCE_LOCATION (decl), "parameter name omitted"); 7944 } 7945 7946 /* Record the parameter list in the function declaration. */ 7947 DECL_ARGUMENTS (fndecl) = arg_info->parms; 7948 7949 /* Now make all the ancillary declarations visible, likewise. */ 7950 for (decl = arg_info->others; decl; decl = DECL_CHAIN (decl)) 7951 { 7952 DECL_CONTEXT (decl) = current_function_decl; 7953 if (DECL_NAME (decl)) 7954 bind (DECL_NAME (decl), decl, current_scope, 7955 /*invisible=*/false, 7956 /*nested=*/(TREE_CODE (decl) == FUNCTION_DECL), 7957 UNKNOWN_LOCATION); 7958 } 7959 7960 /* And all the tag declarations. */ 7961 FOR_EACH_VEC_ELT_REVERSE (c_arg_tag, arg_info->tags, ix, tag) 7962 if (tag->id) 7963 bind (tag->id, tag->type, current_scope, 7964 /*invisible=*/false, /*nested=*/false, UNKNOWN_LOCATION); 7965 } 7966 7967 /* Subroutine of store_parm_decls which handles old-style function 7968 definitions (separate parameter list and declarations). */ 7969 7970 static void 7971 store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info) 7972 { 7973 struct c_binding *b; 7974 tree parm, decl, last; 7975 tree parmids = arg_info->parms; 7976 struct pointer_set_t *seen_args = pointer_set_create (); 7977 7978 if (!in_system_header) 7979 warning_at (DECL_SOURCE_LOCATION (fndecl), 7980 OPT_Wold_style_definition, "old-style function definition"); 7981 7982 /* Match each formal parameter name with its declaration. Save each 7983 decl in the appropriate TREE_PURPOSE slot of the parmids chain. */ 7984 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 7985 { 7986 if (TREE_VALUE (parm) == 0) 7987 { 7988 error_at (DECL_SOURCE_LOCATION (fndecl), 7989 "parameter name missing from parameter list"); 7990 TREE_PURPOSE (parm) = 0; 7991 continue; 7992 } 7993 7994 b = I_SYMBOL_BINDING (TREE_VALUE (parm)); 7995 if (b && B_IN_CURRENT_SCOPE (b)) 7996 { 7997 decl = b->decl; 7998 /* Skip erroneous parameters. */ 7999 if (decl == error_mark_node) 8000 continue; 8001 /* If we got something other than a PARM_DECL it is an error. */ 8002 if (TREE_CODE (decl) != PARM_DECL) 8003 error_at (DECL_SOURCE_LOCATION (decl), 8004 "%qD declared as a non-parameter", decl); 8005 /* If the declaration is already marked, we have a duplicate 8006 name. Complain and ignore the duplicate. */ 8007 else if (pointer_set_contains (seen_args, decl)) 8008 { 8009 error_at (DECL_SOURCE_LOCATION (decl), 8010 "multiple parameters named %qD", decl); 8011 TREE_PURPOSE (parm) = 0; 8012 continue; 8013 } 8014 /* If the declaration says "void", complain and turn it into 8015 an int. */ 8016 else if (VOID_TYPE_P (TREE_TYPE (decl))) 8017 { 8018 error_at (DECL_SOURCE_LOCATION (decl), 8019 "parameter %qD declared with void type", decl); 8020 TREE_TYPE (decl) = integer_type_node; 8021 DECL_ARG_TYPE (decl) = integer_type_node; 8022 layout_decl (decl, 0); 8023 } 8024 warn_if_shadowing (decl); 8025 } 8026 /* If no declaration found, default to int. */ 8027 else 8028 { 8029 /* FIXME diagnostics: This should be the location of the argument, 8030 not the FNDECL. E.g., for an old-style declaration 8031 8032 int f10(v) { blah; } 8033 8034 We should use the location of the V, not the F10. 8035 Unfortunately, the V is an IDENTIFIER_NODE which has no 8036 location. In the future we need locations for c_arg_info 8037 entries. 8038 8039 See gcc.dg/Wshadow-3.c for an example of this problem. */ 8040 decl = build_decl (DECL_SOURCE_LOCATION (fndecl), 8041 PARM_DECL, TREE_VALUE (parm), integer_type_node); 8042 DECL_ARG_TYPE (decl) = TREE_TYPE (decl); 8043 pushdecl (decl); 8044 warn_if_shadowing (decl); 8045 8046 if (flag_isoc99) 8047 pedwarn (DECL_SOURCE_LOCATION (decl), 8048 0, "type of %qD defaults to %<int%>", decl); 8049 else 8050 warning_at (DECL_SOURCE_LOCATION (decl), 8051 OPT_Wmissing_parameter_type, 8052 "type of %qD defaults to %<int%>", decl); 8053 } 8054 8055 TREE_PURPOSE (parm) = decl; 8056 pointer_set_insert (seen_args, decl); 8057 } 8058 8059 /* Now examine the parms chain for incomplete declarations 8060 and declarations with no corresponding names. */ 8061 8062 for (b = current_scope->bindings; b; b = b->prev) 8063 { 8064 parm = b->decl; 8065 if (TREE_CODE (parm) != PARM_DECL) 8066 continue; 8067 8068 if (TREE_TYPE (parm) != error_mark_node 8069 && !COMPLETE_TYPE_P (TREE_TYPE (parm))) 8070 { 8071 error_at (DECL_SOURCE_LOCATION (parm), 8072 "parameter %qD has incomplete type", parm); 8073 TREE_TYPE (parm) = error_mark_node; 8074 } 8075 8076 if (!pointer_set_contains (seen_args, parm)) 8077 { 8078 error_at (DECL_SOURCE_LOCATION (parm), 8079 "declaration for parameter %qD but no such parameter", 8080 parm); 8081 8082 /* Pretend the parameter was not missing. 8083 This gets us to a standard state and minimizes 8084 further error messages. */ 8085 parmids = chainon (parmids, tree_cons (parm, 0, 0)); 8086 } 8087 } 8088 8089 /* Chain the declarations together in the order of the list of 8090 names. Store that chain in the function decl, replacing the 8091 list of names. Update the current scope to match. */ 8092 DECL_ARGUMENTS (fndecl) = 0; 8093 8094 for (parm = parmids; parm; parm = TREE_CHAIN (parm)) 8095 if (TREE_PURPOSE (parm)) 8096 break; 8097 if (parm && TREE_PURPOSE (parm)) 8098 { 8099 last = TREE_PURPOSE (parm); 8100 DECL_ARGUMENTS (fndecl) = last; 8101 8102 for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm)) 8103 if (TREE_PURPOSE (parm)) 8104 { 8105 DECL_CHAIN (last) = TREE_PURPOSE (parm); 8106 last = TREE_PURPOSE (parm); 8107 } 8108 DECL_CHAIN (last) = 0; 8109 } 8110 8111 pointer_set_destroy (seen_args); 8112 8113 /* If there was a previous prototype, 8114 set the DECL_ARG_TYPE of each argument according to 8115 the type previously specified, and report any mismatches. */ 8116 8117 if (current_function_prototype_arg_types) 8118 { 8119 tree type; 8120 for (parm = DECL_ARGUMENTS (fndecl), 8121 type = current_function_prototype_arg_types; 8122 parm || (type && TREE_VALUE (type) != error_mark_node 8123 && (TYPE_MAIN_VARIANT (TREE_VALUE (type)) != void_type_node)); 8124 parm = DECL_CHAIN (parm), type = TREE_CHAIN (type)) 8125 { 8126 if (parm == 0 || type == 0 8127 || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node) 8128 { 8129 if (current_function_prototype_built_in) 8130 warning_at (DECL_SOURCE_LOCATION (fndecl), 8131 0, "number of arguments doesn%'t match " 8132 "built-in prototype"); 8133 else 8134 { 8135 /* FIXME diagnostics: This should be the location of 8136 FNDECL, but there is bug when a prototype is 8137 declared inside function context, but defined 8138 outside of it (e.g., gcc.dg/pr15698-2.c). In 8139 which case FNDECL gets the location of the 8140 prototype, not the definition. */ 8141 error_at (input_location, 8142 "number of arguments doesn%'t match prototype"); 8143 8144 error_at (current_function_prototype_locus, 8145 "prototype declaration"); 8146 } 8147 break; 8148 } 8149 /* Type for passing arg must be consistent with that 8150 declared for the arg. ISO C says we take the unqualified 8151 type for parameters declared with qualified type. */ 8152 if (TREE_TYPE (parm) != error_mark_node 8153 && TREE_TYPE (type) != error_mark_node 8154 && !comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)), 8155 TYPE_MAIN_VARIANT (TREE_VALUE (type)))) 8156 { 8157 if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 8158 == TYPE_MAIN_VARIANT (TREE_VALUE (type))) 8159 { 8160 /* Adjust argument to match prototype. E.g. a previous 8161 `int foo(float);' prototype causes 8162 `int foo(x) float x; {...}' to be treated like 8163 `int foo(float x) {...}'. This is particularly 8164 useful for argument types like uid_t. */ 8165 DECL_ARG_TYPE (parm) = TREE_TYPE (parm); 8166 8167 if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl)) 8168 && INTEGRAL_TYPE_P (TREE_TYPE (parm)) 8169 && TYPE_PRECISION (TREE_TYPE (parm)) 8170 < TYPE_PRECISION (integer_type_node)) 8171 DECL_ARG_TYPE (parm) = integer_type_node; 8172 8173 /* ??? Is it possible to get here with a 8174 built-in prototype or will it always have 8175 been diagnosed as conflicting with an 8176 old-style definition and discarded? */ 8177 if (current_function_prototype_built_in) 8178 warning_at (DECL_SOURCE_LOCATION (parm), 8179 OPT_pedantic, "promoted argument %qD " 8180 "doesn%'t match built-in prototype", parm); 8181 else 8182 { 8183 pedwarn (DECL_SOURCE_LOCATION (parm), 8184 OPT_pedantic, "promoted argument %qD " 8185 "doesn%'t match prototype", parm); 8186 pedwarn (current_function_prototype_locus, OPT_pedantic, 8187 "prototype declaration"); 8188 } 8189 } 8190 else 8191 { 8192 if (current_function_prototype_built_in) 8193 warning_at (DECL_SOURCE_LOCATION (parm), 8194 0, "argument %qD doesn%'t match " 8195 "built-in prototype", parm); 8196 else 8197 { 8198 error_at (DECL_SOURCE_LOCATION (parm), 8199 "argument %qD doesn%'t match prototype", parm); 8200 error_at (current_function_prototype_locus, 8201 "prototype declaration"); 8202 } 8203 } 8204 } 8205 } 8206 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0; 8207 } 8208 8209 /* Otherwise, create a prototype that would match. */ 8210 8211 else 8212 { 8213 tree actual = 0, last = 0, type; 8214 8215 for (parm = DECL_ARGUMENTS (fndecl); parm; parm = DECL_CHAIN (parm)) 8216 { 8217 type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE); 8218 if (last) 8219 TREE_CHAIN (last) = type; 8220 else 8221 actual = type; 8222 last = type; 8223 } 8224 type = tree_cons (NULL_TREE, void_type_node, NULL_TREE); 8225 if (last) 8226 TREE_CHAIN (last) = type; 8227 else 8228 actual = type; 8229 8230 /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES 8231 of the type of this function, but we need to avoid having this 8232 affect the types of other similarly-typed functions, so we must 8233 first force the generation of an identical (but separate) type 8234 node for the relevant function type. The new node we create 8235 will be a variant of the main variant of the original function 8236 type. */ 8237 8238 TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl)); 8239 8240 TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual; 8241 } 8242 } 8243 8244 /* Store parameter declarations passed in ARG_INFO into the current 8245 function declaration. */ 8246 8247 void 8248 store_parm_decls_from (struct c_arg_info *arg_info) 8249 { 8250 current_function_arg_info = arg_info; 8251 store_parm_decls (); 8252 } 8253 8254 /* Store the parameter declarations into the current function declaration. 8255 This is called after parsing the parameter declarations, before 8256 digesting the body of the function. 8257 8258 For an old-style definition, construct a prototype out of the old-style 8259 parameter declarations and inject it into the function's type. */ 8260 8261 void 8262 store_parm_decls (void) 8263 { 8264 tree fndecl = current_function_decl; 8265 bool proto; 8266 8267 /* The argument information block for FNDECL. */ 8268 struct c_arg_info *arg_info = current_function_arg_info; 8269 current_function_arg_info = 0; 8270 8271 /* True if this definition is written with a prototype. Note: 8272 despite C99 6.7.5.3p14, we can *not* treat an empty argument 8273 list in a function definition as equivalent to (void) -- an 8274 empty argument list specifies the function has no parameters, 8275 but only (void) sets up a prototype for future calls. */ 8276 proto = arg_info->types != 0; 8277 8278 if (proto) 8279 store_parm_decls_newstyle (fndecl, arg_info); 8280 else 8281 store_parm_decls_oldstyle (fndecl, arg_info); 8282 8283 /* The next call to push_scope will be a function body. */ 8284 8285 next_is_function_body = true; 8286 8287 /* Write a record describing this function definition to the prototypes 8288 file (if requested). */ 8289 8290 gen_aux_info_record (fndecl, 1, 0, proto); 8291 8292 /* Initialize the RTL code for the function. */ 8293 allocate_struct_function (fndecl, false); 8294 8295 if (warn_unused_local_typedefs) 8296 cfun->language = ggc_alloc_cleared_language_function (); 8297 8298 /* Begin the statement tree for this function. */ 8299 DECL_SAVED_TREE (fndecl) = push_stmt_list (); 8300 8301 /* ??? Insert the contents of the pending sizes list into the function 8302 to be evaluated. The only reason left to have this is 8303 void foo(int n, int array[n++]) 8304 because we throw away the array type in favor of a pointer type, and 8305 thus won't naturally see the SAVE_EXPR containing the increment. All 8306 other pending sizes would be handled by gimplify_parameters. */ 8307 if (arg_info->pending_sizes) 8308 add_stmt (arg_info->pending_sizes); 8309 } 8310 8311 8312 /* Finish up a function declaration and compile that function 8313 all the way to assembler language output. Then free the storage 8314 for the function definition. 8315 8316 This is called after parsing the body of the function definition. */ 8317 8318 void 8319 finish_function (void) 8320 { 8321 tree fndecl = current_function_decl; 8322 8323 if (c_dialect_objc ()) 8324 objc_finish_function (); 8325 8326 if (TREE_CODE (fndecl) == FUNCTION_DECL 8327 && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))) 8328 { 8329 tree args = DECL_ARGUMENTS (fndecl); 8330 for (; args; args = DECL_CHAIN (args)) 8331 { 8332 tree type = TREE_TYPE (args); 8333 if (INTEGRAL_TYPE_P (type) 8334 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) 8335 DECL_ARG_TYPE (args) = integer_type_node; 8336 } 8337 } 8338 8339 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node) 8340 BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl; 8341 8342 /* Must mark the RESULT_DECL as being in this function. */ 8343 8344 if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node) 8345 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; 8346 8347 if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted 8348 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))) 8349 == integer_type_node && flag_isoc99) 8350 { 8351 /* Hack. We don't want the middle-end to warn that this return 8352 is unreachable, so we mark its location as special. Using 8353 UNKNOWN_LOCATION has the problem that it gets clobbered in 8354 annotate_one_with_locus. A cleaner solution might be to 8355 ensure ! should_carry_locus_p (stmt), but that needs a flag. 8356 */ 8357 c_finish_return (BUILTINS_LOCATION, integer_zero_node, NULL_TREE); 8358 } 8359 8360 /* Tie off the statement tree for this function. */ 8361 DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl)); 8362 8363 finish_fname_decls (); 8364 8365 /* Complain if there's just no return statement. */ 8366 if (warn_return_type 8367 && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE 8368 && !current_function_returns_value && !current_function_returns_null 8369 /* Don't complain if we are no-return. */ 8370 && !current_function_returns_abnormally 8371 /* Don't complain if we are declared noreturn. */ 8372 && !TREE_THIS_VOLATILE (fndecl) 8373 /* Don't warn for main(). */ 8374 && !MAIN_NAME_P (DECL_NAME (fndecl)) 8375 /* Or if they didn't actually specify a return type. */ 8376 && !C_FUNCTION_IMPLICIT_INT (fndecl) 8377 /* Normally, with -Wreturn-type, flow will complain, but we might 8378 optimize out static functions. */ 8379 && !TREE_PUBLIC (fndecl)) 8380 { 8381 warning (OPT_Wreturn_type, 8382 "no return statement in function returning non-void"); 8383 TREE_NO_WARNING (fndecl) = 1; 8384 } 8385 8386 /* Complain about parameters that are only set, but never otherwise used. */ 8387 if (warn_unused_but_set_parameter) 8388 { 8389 tree decl; 8390 8391 for (decl = DECL_ARGUMENTS (fndecl); 8392 decl; 8393 decl = DECL_CHAIN (decl)) 8394 if (TREE_USED (decl) 8395 && TREE_CODE (decl) == PARM_DECL 8396 && !DECL_READ_P (decl) 8397 && DECL_NAME (decl) 8398 && !DECL_ARTIFICIAL (decl) 8399 && !TREE_NO_WARNING (decl)) 8400 warning_at (DECL_SOURCE_LOCATION (decl), 8401 OPT_Wunused_but_set_parameter, 8402 "parameter %qD set but not used", decl); 8403 } 8404 8405 /* Complain about locally defined typedefs that are not used in this 8406 function. */ 8407 maybe_warn_unused_local_typedefs (); 8408 8409 /* Store the end of the function, so that we get good line number 8410 info for the epilogue. */ 8411 cfun->function_end_locus = input_location; 8412 8413 /* Finalize the ELF visibility for the function. */ 8414 c_determine_visibility (fndecl); 8415 8416 /* For GNU C extern inline functions disregard inline limits. */ 8417 if (DECL_EXTERNAL (fndecl) 8418 && DECL_DECLARED_INLINE_P (fndecl)) 8419 DECL_DISREGARD_INLINE_LIMITS (fndecl) = 1; 8420 8421 /* Genericize before inlining. Delay genericizing nested functions 8422 until their parent function is genericized. Since finalizing 8423 requires GENERIC, delay that as well. */ 8424 8425 if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node 8426 && !undef_nested_function) 8427 { 8428 if (!decl_function_context (fndecl)) 8429 { 8430 invoke_plugin_callbacks (PLUGIN_PRE_GENERICIZE, fndecl); 8431 c_genericize (fndecl); 8432 8433 /* ??? Objc emits functions after finalizing the compilation unit. 8434 This should be cleaned up later and this conditional removed. */ 8435 if (cgraph_global_info_ready) 8436 { 8437 cgraph_add_new_function (fndecl, false); 8438 return; 8439 } 8440 cgraph_finalize_function (fndecl, false); 8441 } 8442 else 8443 { 8444 /* Register this function with cgraph just far enough to get it 8445 added to our parent's nested function list. Handy, since the 8446 C front end doesn't have such a list. */ 8447 (void) cgraph_get_create_node (fndecl); 8448 } 8449 } 8450 8451 if (!decl_function_context (fndecl)) 8452 undef_nested_function = false; 8453 8454 if (cfun->language != NULL) 8455 { 8456 ggc_free (cfun->language); 8457 cfun->language = NULL; 8458 } 8459 8460 /* We're leaving the context of this function, so zap cfun. 8461 It's still in DECL_STRUCT_FUNCTION, and we'll restore it in 8462 tree_rest_of_compilation. */ 8463 set_cfun (NULL); 8464 current_function_decl = NULL; 8465 } 8466 8467 /* Check the declarations given in a for-loop for satisfying the C99 8468 constraints. If exactly one such decl is found, return it. LOC is 8469 the location of the opening parenthesis of the for loop. The last 8470 parameter allows you to control the "for loop initial declarations 8471 are only allowed in C99 mode". Normally, you should pass 8472 flag_isoc99 as that parameter. But in some cases (Objective-C 8473 foreach loop, for example) we want to run the checks in this 8474 function even if not in C99 mode, so we allow the caller to turn 8475 off the error about not being in C99 mode. 8476 */ 8477 8478 tree 8479 check_for_loop_decls (location_t loc, bool turn_off_iso_c99_error) 8480 { 8481 struct c_binding *b; 8482 tree one_decl = NULL_TREE; 8483 int n_decls = 0; 8484 8485 if (!turn_off_iso_c99_error) 8486 { 8487 static bool hint = true; 8488 /* If we get here, declarations have been used in a for loop without 8489 the C99 for loop scope. This doesn't make much sense, so don't 8490 allow it. */ 8491 error_at (loc, "%<for%> loop initial declarations " 8492 "are only allowed in C99 mode"); 8493 if (hint) 8494 { 8495 inform (loc, 8496 "use option -std=c99 or -std=gnu99 to compile your code"); 8497 hint = false; 8498 } 8499 return NULL_TREE; 8500 } 8501 /* C99 subclause 6.8.5 paragraph 3: 8502 8503 [#3] The declaration part of a for statement shall only 8504 declare identifiers for objects having storage class auto or 8505 register. 8506 8507 It isn't clear whether, in this sentence, "identifiers" binds to 8508 "shall only declare" or to "objects" - that is, whether all identifiers 8509 declared must be identifiers for objects, or whether the restriction 8510 only applies to those that are. (A question on this in comp.std.c 8511 in November 2000 received no answer.) We implement the strictest 8512 interpretation, to avoid creating an extension which later causes 8513 problems. */ 8514 8515 for (b = current_scope->bindings; b; b = b->prev) 8516 { 8517 tree id = b->id; 8518 tree decl = b->decl; 8519 8520 if (!id) 8521 continue; 8522 8523 switch (TREE_CODE (decl)) 8524 { 8525 case VAR_DECL: 8526 { 8527 location_t decl_loc = DECL_SOURCE_LOCATION (decl); 8528 if (TREE_STATIC (decl)) 8529 error_at (decl_loc, 8530 "declaration of static variable %qD in %<for%> loop " 8531 "initial declaration", decl); 8532 else if (DECL_EXTERNAL (decl)) 8533 error_at (decl_loc, 8534 "declaration of %<extern%> variable %qD in %<for%> loop " 8535 "initial declaration", decl); 8536 } 8537 break; 8538 8539 case RECORD_TYPE: 8540 error_at (loc, 8541 "%<struct %E%> declared in %<for%> loop initial " 8542 "declaration", id); 8543 break; 8544 case UNION_TYPE: 8545 error_at (loc, 8546 "%<union %E%> declared in %<for%> loop initial declaration", 8547 id); 8548 break; 8549 case ENUMERAL_TYPE: 8550 error_at (loc, "%<enum %E%> declared in %<for%> loop " 8551 "initial declaration", id); 8552 break; 8553 default: 8554 error_at (loc, "declaration of non-variable " 8555 "%qD in %<for%> loop initial declaration", decl); 8556 } 8557 8558 n_decls++; 8559 one_decl = decl; 8560 } 8561 8562 return n_decls == 1 ? one_decl : NULL_TREE; 8563 } 8564 8565 /* Save and reinitialize the variables 8566 used during compilation of a C function. */ 8567 8568 void 8569 c_push_function_context (void) 8570 { 8571 struct language_function *p = cfun->language; 8572 /* cfun->language might have been already allocated by the use of 8573 -Wunused-local-typedefs. In that case, just re-use it. */ 8574 if (p == NULL) 8575 cfun->language = p = ggc_alloc_cleared_language_function (); 8576 8577 p->base.x_stmt_tree = c_stmt_tree; 8578 c_stmt_tree.x_cur_stmt_list 8579 = VEC_copy (tree, gc, c_stmt_tree.x_cur_stmt_list); 8580 p->x_break_label = c_break_label; 8581 p->x_cont_label = c_cont_label; 8582 p->x_switch_stack = c_switch_stack; 8583 p->arg_info = current_function_arg_info; 8584 p->returns_value = current_function_returns_value; 8585 p->returns_null = current_function_returns_null; 8586 p->returns_abnormally = current_function_returns_abnormally; 8587 p->warn_about_return_type = warn_about_return_type; 8588 8589 push_function_context (); 8590 } 8591 8592 /* Restore the variables used during compilation of a C function. */ 8593 8594 void 8595 c_pop_function_context (void) 8596 { 8597 struct language_function *p; 8598 8599 pop_function_context (); 8600 p = cfun->language; 8601 /* When -Wunused-local-typedefs is in effect, cfun->languages is 8602 used to store data throughout the life time of the current cfun, 8603 So don't deallocate it. */ 8604 if (!warn_unused_local_typedefs) 8605 cfun->language = NULL; 8606 8607 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0 8608 && DECL_SAVED_TREE (current_function_decl) == NULL_TREE) 8609 { 8610 /* Stop pointing to the local nodes about to be freed. */ 8611 /* But DECL_INITIAL must remain nonzero so we know this 8612 was an actual function definition. */ 8613 DECL_INITIAL (current_function_decl) = error_mark_node; 8614 DECL_ARGUMENTS (current_function_decl) = 0; 8615 } 8616 8617 c_stmt_tree = p->base.x_stmt_tree; 8618 c_break_label = p->x_break_label; 8619 c_cont_label = p->x_cont_label; 8620 c_switch_stack = p->x_switch_stack; 8621 current_function_arg_info = p->arg_info; 8622 current_function_returns_value = p->returns_value; 8623 current_function_returns_null = p->returns_null; 8624 current_function_returns_abnormally = p->returns_abnormally; 8625 warn_about_return_type = p->warn_about_return_type; 8626 } 8627 8628 /* The functions below are required for functionality of doing 8629 function at once processing in the C front end. Currently these 8630 functions are not called from anywhere in the C front end, but as 8631 these changes continue, that will change. */ 8632 8633 /* Returns the stmt_tree (if any) to which statements are currently 8634 being added. If there is no active statement-tree, NULL is 8635 returned. */ 8636 8637 stmt_tree 8638 current_stmt_tree (void) 8639 { 8640 return &c_stmt_tree; 8641 } 8642 8643 /* Return the global value of T as a symbol. */ 8644 8645 tree 8646 identifier_global_value (tree t) 8647 { 8648 struct c_binding *b; 8649 8650 for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed) 8651 if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b)) 8652 return b->decl; 8653 8654 return 0; 8655 } 8656 8657 /* In C, the only C-linkage public declaration is at file scope. */ 8658 8659 tree 8660 c_linkage_bindings (tree name) 8661 { 8662 return identifier_global_value (name); 8663 } 8664 8665 /* Record a builtin type for C. If NAME is non-NULL, it is the name used; 8666 otherwise the name is found in ridpointers from RID_INDEX. */ 8667 8668 void 8669 record_builtin_type (enum rid rid_index, const char *name, tree type) 8670 { 8671 tree id, decl; 8672 if (name == 0) 8673 id = ridpointers[(int) rid_index]; 8674 else 8675 id = get_identifier (name); 8676 decl = build_decl (UNKNOWN_LOCATION, TYPE_DECL, id, type); 8677 pushdecl (decl); 8678 if (debug_hooks->type_decl) 8679 debug_hooks->type_decl (decl, false); 8680 } 8681 8682 /* Build the void_list_node (void_type_node having been created). */ 8683 tree 8684 build_void_list_node (void) 8685 { 8686 tree t = build_tree_list (NULL_TREE, void_type_node); 8687 return t; 8688 } 8689 8690 /* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR. */ 8691 8692 struct c_parm * 8693 build_c_parm (struct c_declspecs *specs, tree attrs, 8694 struct c_declarator *declarator) 8695 { 8696 struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm); 8697 ret->specs = specs; 8698 ret->attrs = attrs; 8699 ret->declarator = declarator; 8700 return ret; 8701 } 8702 8703 /* Return a declarator with nested attributes. TARGET is the inner 8704 declarator to which these attributes apply. ATTRS are the 8705 attributes. */ 8706 8707 struct c_declarator * 8708 build_attrs_declarator (tree attrs, struct c_declarator *target) 8709 { 8710 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8711 ret->kind = cdk_attrs; 8712 ret->declarator = target; 8713 ret->u.attrs = attrs; 8714 return ret; 8715 } 8716 8717 /* Return a declarator for a function with arguments specified by ARGS 8718 and return type specified by TARGET. */ 8719 8720 struct c_declarator * 8721 build_function_declarator (struct c_arg_info *args, 8722 struct c_declarator *target) 8723 { 8724 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8725 ret->kind = cdk_function; 8726 ret->declarator = target; 8727 ret->u.arg_info = args; 8728 return ret; 8729 } 8730 8731 /* Return a declarator for the identifier IDENT (which may be 8732 NULL_TREE for an abstract declarator). */ 8733 8734 struct c_declarator * 8735 build_id_declarator (tree ident) 8736 { 8737 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8738 ret->kind = cdk_id; 8739 ret->declarator = 0; 8740 ret->u.id = ident; 8741 /* Default value - may get reset to a more precise location. */ 8742 ret->id_loc = input_location; 8743 return ret; 8744 } 8745 8746 /* Return something to represent absolute declarators containing a *. 8747 TARGET is the absolute declarator that the * contains. 8748 TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes 8749 to apply to the pointer type. */ 8750 8751 struct c_declarator * 8752 make_pointer_declarator (struct c_declspecs *type_quals_attrs, 8753 struct c_declarator *target) 8754 { 8755 tree attrs; 8756 int quals = 0; 8757 struct c_declarator *itarget = target; 8758 struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator); 8759 if (type_quals_attrs) 8760 { 8761 attrs = type_quals_attrs->attrs; 8762 quals = quals_from_declspecs (type_quals_attrs); 8763 if (attrs != NULL_TREE) 8764 itarget = build_attrs_declarator (attrs, target); 8765 } 8766 ret->kind = cdk_pointer; 8767 ret->declarator = itarget; 8768 ret->u.pointer_quals = quals; 8769 return ret; 8770 } 8771 8772 /* Return a pointer to a structure for an empty list of declaration 8773 specifiers. */ 8774 8775 struct c_declspecs * 8776 build_null_declspecs (void) 8777 { 8778 struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); 8779 ret->type = 0; 8780 ret->expr = 0; 8781 ret->decl_attr = 0; 8782 ret->attrs = 0; 8783 ret->align_log = -1; 8784 ret->typespec_word = cts_none; 8785 ret->storage_class = csc_none; 8786 ret->expr_const_operands = true; 8787 ret->declspecs_seen_p = false; 8788 ret->typespec_kind = ctsk_none; 8789 ret->non_sc_seen_p = false; 8790 ret->typedef_p = false; 8791 ret->explicit_signed_p = false; 8792 ret->deprecated_p = false; 8793 ret->default_int_p = false; 8794 ret->long_p = false; 8795 ret->long_long_p = false; 8796 ret->short_p = false; 8797 ret->signed_p = false; 8798 ret->unsigned_p = false; 8799 ret->complex_p = false; 8800 ret->inline_p = false; 8801 ret->noreturn_p = false; 8802 ret->thread_p = false; 8803 ret->const_p = false; 8804 ret->volatile_p = false; 8805 ret->restrict_p = false; 8806 ret->saturating_p = false; 8807 ret->alignas_p = false; 8808 ret->address_space = ADDR_SPACE_GENERIC; 8809 return ret; 8810 } 8811 8812 /* Add the address space ADDRSPACE to the declaration specifiers 8813 SPECS, returning SPECS. */ 8814 8815 struct c_declspecs * 8816 declspecs_add_addrspace (struct c_declspecs *specs, addr_space_t as) 8817 { 8818 specs->non_sc_seen_p = true; 8819 specs->declspecs_seen_p = true; 8820 8821 if (!ADDR_SPACE_GENERIC_P (specs->address_space) 8822 && specs->address_space != as) 8823 error ("incompatible address space qualifiers %qs and %qs", 8824 c_addr_space_name (as), 8825 c_addr_space_name (specs->address_space)); 8826 else 8827 specs->address_space = as; 8828 return specs; 8829 } 8830 8831 /* Add the type qualifier QUAL to the declaration specifiers SPECS, 8832 returning SPECS. */ 8833 8834 struct c_declspecs * 8835 declspecs_add_qual (struct c_declspecs *specs, tree qual) 8836 { 8837 enum rid i; 8838 bool dupe = false; 8839 specs->non_sc_seen_p = true; 8840 specs->declspecs_seen_p = true; 8841 gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE 8842 && C_IS_RESERVED_WORD (qual)); 8843 i = C_RID_CODE (qual); 8844 switch (i) 8845 { 8846 case RID_CONST: 8847 dupe = specs->const_p; 8848 specs->const_p = true; 8849 break; 8850 case RID_VOLATILE: 8851 dupe = specs->volatile_p; 8852 specs->volatile_p = true; 8853 break; 8854 case RID_RESTRICT: 8855 dupe = specs->restrict_p; 8856 specs->restrict_p = true; 8857 break; 8858 default: 8859 gcc_unreachable (); 8860 } 8861 if (dupe && !flag_isoc99) 8862 pedwarn (input_location, OPT_pedantic, "duplicate %qE", qual); 8863 return specs; 8864 } 8865 8866 /* Add the type specifier TYPE to the declaration specifiers SPECS, 8867 returning SPECS. */ 8868 8869 struct c_declspecs * 8870 declspecs_add_type (location_t loc, struct c_declspecs *specs, 8871 struct c_typespec spec) 8872 { 8873 tree type = spec.spec; 8874 specs->non_sc_seen_p = true; 8875 specs->declspecs_seen_p = true; 8876 specs->typespec_kind = spec.kind; 8877 if (TREE_DEPRECATED (type)) 8878 specs->deprecated_p = true; 8879 8880 /* Handle type specifier keywords. */ 8881 if (TREE_CODE (type) == IDENTIFIER_NODE 8882 && C_IS_RESERVED_WORD (type) 8883 && C_RID_CODE (type) != RID_CXX_COMPAT_WARN) 8884 { 8885 enum rid i = C_RID_CODE (type); 8886 if (specs->type) 8887 { 8888 error_at (loc, "two or more data types in declaration specifiers"); 8889 return specs; 8890 } 8891 if ((int) i <= (int) RID_LAST_MODIFIER) 8892 { 8893 /* "long", "short", "signed", "unsigned", "_Complex" or "_Sat". */ 8894 bool dupe = false; 8895 switch (i) 8896 { 8897 case RID_LONG: 8898 if (specs->long_long_p) 8899 { 8900 error_at (loc, "%<long long long%> is too long for GCC"); 8901 break; 8902 } 8903 if (specs->long_p) 8904 { 8905 if (specs->typespec_word == cts_double) 8906 { 8907 error_at (loc, 8908 ("both %<long long%> and %<double%> in " 8909 "declaration specifiers")); 8910 break; 8911 } 8912 pedwarn_c90 (loc, OPT_Wlong_long, 8913 "ISO C90 does not support %<long long%>"); 8914 specs->long_long_p = 1; 8915 break; 8916 } 8917 if (specs->short_p) 8918 error_at (loc, 8919 ("both %<long%> and %<short%> in " 8920 "declaration specifiers")); 8921 else if (specs->typespec_word == cts_void) 8922 error_at (loc, 8923 ("both %<long%> and %<void%> in " 8924 "declaration specifiers")); 8925 else if (specs->typespec_word == cts_int128) 8926 error_at (loc, 8927 ("both %<long%> and %<__int128%> in " 8928 "declaration specifiers")); 8929 else if (specs->typespec_word == cts_bool) 8930 error_at (loc, 8931 ("both %<long%> and %<_Bool%> in " 8932 "declaration specifiers")); 8933 else if (specs->typespec_word == cts_char) 8934 error_at (loc, 8935 ("both %<long%> and %<char%> in " 8936 "declaration specifiers")); 8937 else if (specs->typespec_word == cts_float) 8938 error_at (loc, 8939 ("both %<long%> and %<float%> in " 8940 "declaration specifiers")); 8941 else if (specs->typespec_word == cts_dfloat32) 8942 error_at (loc, 8943 ("both %<long%> and %<_Decimal32%> in " 8944 "declaration specifiers")); 8945 else if (specs->typespec_word == cts_dfloat64) 8946 error_at (loc, 8947 ("both %<long%> and %<_Decimal64%> in " 8948 "declaration specifiers")); 8949 else if (specs->typespec_word == cts_dfloat128) 8950 error_at (loc, 8951 ("both %<long%> and %<_Decimal128%> in " 8952 "declaration specifiers")); 8953 else 8954 specs->long_p = true; 8955 break; 8956 case RID_SHORT: 8957 dupe = specs->short_p; 8958 if (specs->long_p) 8959 error_at (loc, 8960 ("both %<long%> and %<short%> in " 8961 "declaration specifiers")); 8962 else if (specs->typespec_word == cts_void) 8963 error_at (loc, 8964 ("both %<short%> and %<void%> in " 8965 "declaration specifiers")); 8966 else if (specs->typespec_word == cts_int128) 8967 error_at (loc, 8968 ("both %<short%> and %<__int128%> in " 8969 "declaration specifiers")); 8970 else if (specs->typespec_word == cts_bool) 8971 error_at (loc, 8972 ("both %<short%> and %<_Bool%> in " 8973 "declaration specifiers")); 8974 else if (specs->typespec_word == cts_char) 8975 error_at (loc, 8976 ("both %<short%> and %<char%> in " 8977 "declaration specifiers")); 8978 else if (specs->typespec_word == cts_float) 8979 error_at (loc, 8980 ("both %<short%> and %<float%> in " 8981 "declaration specifiers")); 8982 else if (specs->typespec_word == cts_double) 8983 error_at (loc, 8984 ("both %<short%> and %<double%> in " 8985 "declaration specifiers")); 8986 else if (specs->typespec_word == cts_dfloat32) 8987 error_at (loc, 8988 ("both %<short%> and %<_Decimal32%> in " 8989 "declaration specifiers")); 8990 else if (specs->typespec_word == cts_dfloat64) 8991 error_at (loc, 8992 ("both %<short%> and %<_Decimal64%> in " 8993 "declaration specifiers")); 8994 else if (specs->typespec_word == cts_dfloat128) 8995 error_at (loc, 8996 ("both %<short%> and %<_Decimal128%> in " 8997 "declaration specifiers")); 8998 else 8999 specs->short_p = true; 9000 break; 9001 case RID_SIGNED: 9002 dupe = specs->signed_p; 9003 if (specs->unsigned_p) 9004 error_at (loc, 9005 ("both %<signed%> and %<unsigned%> in " 9006 "declaration specifiers")); 9007 else if (specs->typespec_word == cts_void) 9008 error_at (loc, 9009 ("both %<signed%> and %<void%> in " 9010 "declaration specifiers")); 9011 else if (specs->typespec_word == cts_bool) 9012 error_at (loc, 9013 ("both %<signed%> and %<_Bool%> in " 9014 "declaration specifiers")); 9015 else if (specs->typespec_word == cts_float) 9016 error_at (loc, 9017 ("both %<signed%> and %<float%> in " 9018 "declaration specifiers")); 9019 else if (specs->typespec_word == cts_double) 9020 error_at (loc, 9021 ("both %<signed%> and %<double%> in " 9022 "declaration specifiers")); 9023 else if (specs->typespec_word == cts_dfloat32) 9024 error_at (loc, 9025 ("both %<signed%> and %<_Decimal32%> in " 9026 "declaration specifiers")); 9027 else if (specs->typespec_word == cts_dfloat64) 9028 error_at (loc, 9029 ("both %<signed%> and %<_Decimal64%> in " 9030 "declaration specifiers")); 9031 else if (specs->typespec_word == cts_dfloat128) 9032 error_at (loc, 9033 ("both %<signed%> and %<_Decimal128%> in " 9034 "declaration specifiers")); 9035 else 9036 specs->signed_p = true; 9037 break; 9038 case RID_UNSIGNED: 9039 dupe = specs->unsigned_p; 9040 if (specs->signed_p) 9041 error_at (loc, 9042 ("both %<signed%> and %<unsigned%> in " 9043 "declaration specifiers")); 9044 else if (specs->typespec_word == cts_void) 9045 error_at (loc, 9046 ("both %<unsigned%> and %<void%> in " 9047 "declaration specifiers")); 9048 else if (specs->typespec_word == cts_bool) 9049 error_at (loc, 9050 ("both %<unsigned%> and %<_Bool%> in " 9051 "declaration specifiers")); 9052 else if (specs->typespec_word == cts_float) 9053 error_at (loc, 9054 ("both %<unsigned%> and %<float%> in " 9055 "declaration specifiers")); 9056 else if (specs->typespec_word == cts_double) 9057 error_at (loc, 9058 ("both %<unsigned%> and %<double%> in " 9059 "declaration specifiers")); 9060 else if (specs->typespec_word == cts_dfloat32) 9061 error_at (loc, 9062 ("both %<unsigned%> and %<_Decimal32%> in " 9063 "declaration specifiers")); 9064 else if (specs->typespec_word == cts_dfloat64) 9065 error_at (loc, 9066 ("both %<unsigned%> and %<_Decimal64%> in " 9067 "declaration specifiers")); 9068 else if (specs->typespec_word == cts_dfloat128) 9069 error_at (loc, 9070 ("both %<unsigned%> and %<_Decimal128%> in " 9071 "declaration specifiers")); 9072 else 9073 specs->unsigned_p = true; 9074 break; 9075 case RID_COMPLEX: 9076 dupe = specs->complex_p; 9077 if (!flag_isoc99 && !in_system_header) 9078 pedwarn (loc, OPT_pedantic, 9079 "ISO C90 does not support complex types"); 9080 if (specs->typespec_word == cts_void) 9081 error_at (loc, 9082 ("both %<complex%> and %<void%> in " 9083 "declaration specifiers")); 9084 else if (specs->typespec_word == cts_bool) 9085 error_at (loc, 9086 ("both %<complex%> and %<_Bool%> in " 9087 "declaration specifiers")); 9088 else if (specs->typespec_word == cts_dfloat32) 9089 error_at (loc, 9090 ("both %<complex%> and %<_Decimal32%> in " 9091 "declaration specifiers")); 9092 else if (specs->typespec_word == cts_dfloat64) 9093 error_at (loc, 9094 ("both %<complex%> and %<_Decimal64%> in " 9095 "declaration specifiers")); 9096 else if (specs->typespec_word == cts_dfloat128) 9097 error_at (loc, 9098 ("both %<complex%> and %<_Decimal128%> in " 9099 "declaration specifiers")); 9100 else if (specs->typespec_word == cts_fract) 9101 error_at (loc, 9102 ("both %<complex%> and %<_Fract%> in " 9103 "declaration specifiers")); 9104 else if (specs->typespec_word == cts_accum) 9105 error_at (loc, 9106 ("both %<complex%> and %<_Accum%> in " 9107 "declaration specifiers")); 9108 else if (specs->saturating_p) 9109 error_at (loc, 9110 ("both %<complex%> and %<_Sat%> in " 9111 "declaration specifiers")); 9112 else 9113 specs->complex_p = true; 9114 break; 9115 case RID_SAT: 9116 dupe = specs->saturating_p; 9117 pedwarn (loc, OPT_pedantic, 9118 "ISO C does not support saturating types"); 9119 if (specs->typespec_word == cts_int128) 9120 { 9121 error_at (loc, 9122 ("both %<_Sat%> and %<__int128%> in " 9123 "declaration specifiers")); 9124 } 9125 else if (specs->typespec_word == cts_void) 9126 error_at (loc, 9127 ("both %<_Sat%> and %<void%> in " 9128 "declaration specifiers")); 9129 else if (specs->typespec_word == cts_bool) 9130 error_at (loc, 9131 ("both %<_Sat%> and %<_Bool%> in " 9132 "declaration specifiers")); 9133 else if (specs->typespec_word == cts_char) 9134 error_at (loc, 9135 ("both %<_Sat%> and %<char%> in " 9136 "declaration specifiers")); 9137 else if (specs->typespec_word == cts_int) 9138 error_at (loc, 9139 ("both %<_Sat%> and %<int%> in " 9140 "declaration specifiers")); 9141 else if (specs->typespec_word == cts_float) 9142 error_at (loc, 9143 ("both %<_Sat%> and %<float%> in " 9144 "declaration specifiers")); 9145 else if (specs->typespec_word == cts_double) 9146 error_at (loc, 9147 ("both %<_Sat%> and %<double%> in " 9148 "declaration specifiers")); 9149 else if (specs->typespec_word == cts_dfloat32) 9150 error_at (loc, 9151 ("both %<_Sat%> and %<_Decimal32%> in " 9152 "declaration specifiers")); 9153 else if (specs->typespec_word == cts_dfloat64) 9154 error_at (loc, 9155 ("both %<_Sat%> and %<_Decimal64%> in " 9156 "declaration specifiers")); 9157 else if (specs->typespec_word == cts_dfloat128) 9158 error_at (loc, 9159 ("both %<_Sat%> and %<_Decimal128%> in " 9160 "declaration specifiers")); 9161 else if (specs->complex_p) 9162 error_at (loc, 9163 ("both %<_Sat%> and %<complex%> in " 9164 "declaration specifiers")); 9165 else 9166 specs->saturating_p = true; 9167 break; 9168 default: 9169 gcc_unreachable (); 9170 } 9171 9172 if (dupe) 9173 error_at (loc, "duplicate %qE", type); 9174 9175 return specs; 9176 } 9177 else 9178 { 9179 /* "void", "_Bool", "char", "int", "float", "double", "_Decimal32", 9180 "__int128", "_Decimal64", "_Decimal128", "_Fract" or "_Accum". */ 9181 if (specs->typespec_word != cts_none) 9182 { 9183 error_at (loc, 9184 "two or more data types in declaration specifiers"); 9185 return specs; 9186 } 9187 switch (i) 9188 { 9189 case RID_INT128: 9190 if (int128_integer_type_node == NULL_TREE) 9191 { 9192 error_at (loc, "%<__int128%> is not supported for this target"); 9193 return specs; 9194 } 9195 if (!in_system_header) 9196 pedwarn (loc, OPT_pedantic, 9197 "ISO C does not support %<__int128%> type"); 9198 9199 if (specs->long_p) 9200 error_at (loc, 9201 ("both %<__int128%> and %<long%> in " 9202 "declaration specifiers")); 9203 else if (specs->saturating_p) 9204 error_at (loc, 9205 ("both %<_Sat%> and %<__int128%> in " 9206 "declaration specifiers")); 9207 else if (specs->short_p) 9208 error_at (loc, 9209 ("both %<__int128%> and %<short%> in " 9210 "declaration specifiers")); 9211 else 9212 specs->typespec_word = cts_int128; 9213 return specs; 9214 case RID_VOID: 9215 if (specs->long_p) 9216 error_at (loc, 9217 ("both %<long%> and %<void%> in " 9218 "declaration specifiers")); 9219 else if (specs->short_p) 9220 error_at (loc, 9221 ("both %<short%> and %<void%> in " 9222 "declaration specifiers")); 9223 else if (specs->signed_p) 9224 error_at (loc, 9225 ("both %<signed%> and %<void%> in " 9226 "declaration specifiers")); 9227 else if (specs->unsigned_p) 9228 error_at (loc, 9229 ("both %<unsigned%> and %<void%> in " 9230 "declaration specifiers")); 9231 else if (specs->complex_p) 9232 error_at (loc, 9233 ("both %<complex%> and %<void%> in " 9234 "declaration specifiers")); 9235 else if (specs->saturating_p) 9236 error_at (loc, 9237 ("both %<_Sat%> and %<void%> in " 9238 "declaration specifiers")); 9239 else 9240 specs->typespec_word = cts_void; 9241 return specs; 9242 case RID_BOOL: 9243 if (specs->long_p) 9244 error_at (loc, 9245 ("both %<long%> and %<_Bool%> in " 9246 "declaration specifiers")); 9247 else if (specs->short_p) 9248 error_at (loc, 9249 ("both %<short%> and %<_Bool%> in " 9250 "declaration specifiers")); 9251 else if (specs->signed_p) 9252 error_at (loc, 9253 ("both %<signed%> and %<_Bool%> in " 9254 "declaration specifiers")); 9255 else if (specs->unsigned_p) 9256 error_at (loc, 9257 ("both %<unsigned%> and %<_Bool%> in " 9258 "declaration specifiers")); 9259 else if (specs->complex_p) 9260 error_at (loc, 9261 ("both %<complex%> and %<_Bool%> in " 9262 "declaration specifiers")); 9263 else if (specs->saturating_p) 9264 error_at (loc, 9265 ("both %<_Sat%> and %<_Bool%> in " 9266 "declaration specifiers")); 9267 else 9268 specs->typespec_word = cts_bool; 9269 return specs; 9270 case RID_CHAR: 9271 if (specs->long_p) 9272 error_at (loc, 9273 ("both %<long%> and %<char%> in " 9274 "declaration specifiers")); 9275 else if (specs->short_p) 9276 error_at (loc, 9277 ("both %<short%> and %<char%> in " 9278 "declaration specifiers")); 9279 else if (specs->saturating_p) 9280 error_at (loc, 9281 ("both %<_Sat%> and %<char%> in " 9282 "declaration specifiers")); 9283 else 9284 specs->typespec_word = cts_char; 9285 return specs; 9286 case RID_INT: 9287 if (specs->saturating_p) 9288 error_at (loc, 9289 ("both %<_Sat%> and %<int%> in " 9290 "declaration specifiers")); 9291 else 9292 specs->typespec_word = cts_int; 9293 return specs; 9294 case RID_FLOAT: 9295 if (specs->long_p) 9296 error_at (loc, 9297 ("both %<long%> and %<float%> in " 9298 "declaration specifiers")); 9299 else if (specs->short_p) 9300 error_at (loc, 9301 ("both %<short%> and %<float%> in " 9302 "declaration specifiers")); 9303 else if (specs->signed_p) 9304 error_at (loc, 9305 ("both %<signed%> and %<float%> in " 9306 "declaration specifiers")); 9307 else if (specs->unsigned_p) 9308 error_at (loc, 9309 ("both %<unsigned%> and %<float%> in " 9310 "declaration specifiers")); 9311 else if (specs->saturating_p) 9312 error_at (loc, 9313 ("both %<_Sat%> and %<float%> in " 9314 "declaration specifiers")); 9315 else 9316 specs->typespec_word = cts_float; 9317 return specs; 9318 case RID_DOUBLE: 9319 if (specs->long_long_p) 9320 error_at (loc, 9321 ("both %<long long%> and %<double%> in " 9322 "declaration specifiers")); 9323 else if (specs->short_p) 9324 error_at (loc, 9325 ("both %<short%> and %<double%> in " 9326 "declaration specifiers")); 9327 else if (specs->signed_p) 9328 error_at (loc, 9329 ("both %<signed%> and %<double%> in " 9330 "declaration specifiers")); 9331 else if (specs->unsigned_p) 9332 error_at (loc, 9333 ("both %<unsigned%> and %<double%> in " 9334 "declaration specifiers")); 9335 else if (specs->saturating_p) 9336 error_at (loc, 9337 ("both %<_Sat%> and %<double%> in " 9338 "declaration specifiers")); 9339 else 9340 specs->typespec_word = cts_double; 9341 return specs; 9342 case RID_DFLOAT32: 9343 case RID_DFLOAT64: 9344 case RID_DFLOAT128: 9345 { 9346 const char *str; 9347 if (i == RID_DFLOAT32) 9348 str = "_Decimal32"; 9349 else if (i == RID_DFLOAT64) 9350 str = "_Decimal64"; 9351 else 9352 str = "_Decimal128"; 9353 if (specs->long_long_p) 9354 error_at (loc, 9355 ("both %<long long%> and %<%s%> in " 9356 "declaration specifiers"), 9357 str); 9358 if (specs->long_p) 9359 error_at (loc, 9360 ("both %<long%> and %<%s%> in " 9361 "declaration specifiers"), 9362 str); 9363 else if (specs->short_p) 9364 error_at (loc, 9365 ("both %<short%> and %<%s%> in " 9366 "declaration specifiers"), 9367 str); 9368 else if (specs->signed_p) 9369 error_at (loc, 9370 ("both %<signed%> and %<%s%> in " 9371 "declaration specifiers"), 9372 str); 9373 else if (specs->unsigned_p) 9374 error_at (loc, 9375 ("both %<unsigned%> and %<%s%> in " 9376 "declaration specifiers"), 9377 str); 9378 else if (specs->complex_p) 9379 error_at (loc, 9380 ("both %<complex%> and %<%s%> in " 9381 "declaration specifiers"), 9382 str); 9383 else if (specs->saturating_p) 9384 error_at (loc, 9385 ("both %<_Sat%> and %<%s%> in " 9386 "declaration specifiers"), 9387 str); 9388 else if (i == RID_DFLOAT32) 9389 specs->typespec_word = cts_dfloat32; 9390 else if (i == RID_DFLOAT64) 9391 specs->typespec_word = cts_dfloat64; 9392 else 9393 specs->typespec_word = cts_dfloat128; 9394 } 9395 if (!targetm.decimal_float_supported_p ()) 9396 error_at (loc, 9397 ("decimal floating point not supported " 9398 "for this target")); 9399 pedwarn (loc, OPT_pedantic, 9400 "ISO C does not support decimal floating point"); 9401 return specs; 9402 case RID_FRACT: 9403 case RID_ACCUM: 9404 { 9405 const char *str; 9406 if (i == RID_FRACT) 9407 str = "_Fract"; 9408 else 9409 str = "_Accum"; 9410 if (specs->complex_p) 9411 error_at (loc, 9412 ("both %<complex%> and %<%s%> in " 9413 "declaration specifiers"), 9414 str); 9415 else if (i == RID_FRACT) 9416 specs->typespec_word = cts_fract; 9417 else 9418 specs->typespec_word = cts_accum; 9419 } 9420 if (!targetm.fixed_point_supported_p ()) 9421 error_at (loc, 9422 "fixed-point types not supported for this target"); 9423 pedwarn (loc, OPT_pedantic, 9424 "ISO C does not support fixed-point types"); 9425 return specs; 9426 default: 9427 /* ObjC reserved word "id", handled below. */ 9428 break; 9429 } 9430 } 9431 } 9432 9433 /* Now we have a typedef (a TYPE_DECL node), an identifier (some 9434 form of ObjC type, cases such as "int" and "long" being handled 9435 above), a TYPE (struct, union, enum and typeof specifiers) or an 9436 ERROR_MARK. In none of these cases may there have previously 9437 been any type specifiers. */ 9438 if (specs->type || specs->typespec_word != cts_none 9439 || specs->long_p || specs->short_p || specs->signed_p 9440 || specs->unsigned_p || specs->complex_p) 9441 error_at (loc, "two or more data types in declaration specifiers"); 9442 else if (TREE_CODE (type) == TYPE_DECL) 9443 { 9444 if (TREE_TYPE (type) == error_mark_node) 9445 ; /* Allow the type to default to int to avoid cascading errors. */ 9446 else 9447 { 9448 specs->type = TREE_TYPE (type); 9449 specs->decl_attr = DECL_ATTRIBUTES (type); 9450 specs->typedef_p = true; 9451 specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type); 9452 9453 /* If this typedef name is defined in a struct, then a C++ 9454 lookup would return a different value. */ 9455 if (warn_cxx_compat 9456 && I_SYMBOL_BINDING (DECL_NAME (type))->in_struct) 9457 warning_at (loc, OPT_Wc___compat, 9458 "C++ lookup of %qD would return a field, not a type", 9459 type); 9460 9461 /* If we are parsing a struct, record that a struct field 9462 used a typedef. */ 9463 if (warn_cxx_compat && struct_parse_info != NULL) 9464 VEC_safe_push (tree, heap, struct_parse_info->typedefs_seen, type); 9465 } 9466 } 9467 else if (TREE_CODE (type) == IDENTIFIER_NODE) 9468 { 9469 tree t = lookup_name (type); 9470 if (!t || TREE_CODE (t) != TYPE_DECL) 9471 error_at (loc, "%qE fails to be a typedef or built in type", type); 9472 else if (TREE_TYPE (t) == error_mark_node) 9473 ; 9474 else 9475 specs->type = TREE_TYPE (t); 9476 } 9477 else 9478 { 9479 if (TREE_CODE (type) != ERROR_MARK && spec.kind == ctsk_typeof) 9480 { 9481 specs->typedef_p = true; 9482 if (spec.expr) 9483 { 9484 if (specs->expr) 9485 specs->expr = build2 (COMPOUND_EXPR, TREE_TYPE (spec.expr), 9486 specs->expr, spec.expr); 9487 else 9488 specs->expr = spec.expr; 9489 specs->expr_const_operands &= spec.expr_const_operands; 9490 } 9491 } 9492 specs->type = type; 9493 } 9494 9495 return specs; 9496 } 9497 9498 /* Add the storage class specifier or function specifier SCSPEC to the 9499 declaration specifiers SPECS, returning SPECS. */ 9500 9501 struct c_declspecs * 9502 declspecs_add_scspec (struct c_declspecs *specs, tree scspec) 9503 { 9504 enum rid i; 9505 enum c_storage_class n = csc_none; 9506 bool dupe = false; 9507 specs->declspecs_seen_p = true; 9508 gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE 9509 && C_IS_RESERVED_WORD (scspec)); 9510 i = C_RID_CODE (scspec); 9511 if (specs->non_sc_seen_p) 9512 warning (OPT_Wold_style_declaration, 9513 "%qE is not at beginning of declaration", scspec); 9514 switch (i) 9515 { 9516 case RID_INLINE: 9517 /* C99 permits duplicate inline. Although of doubtful utility, 9518 it seems simplest to permit it in gnu89 mode as well, as 9519 there is also little utility in maintaining this as a 9520 difference between gnu89 and C99 inline. */ 9521 dupe = false; 9522 specs->inline_p = true; 9523 break; 9524 case RID_NORETURN: 9525 /* Duplicate _Noreturn is permitted. */ 9526 dupe = false; 9527 specs->noreturn_p = true; 9528 break; 9529 case RID_THREAD: 9530 dupe = specs->thread_p; 9531 if (specs->storage_class == csc_auto) 9532 error ("%<__thread%> used with %<auto%>"); 9533 else if (specs->storage_class == csc_register) 9534 error ("%<__thread%> used with %<register%>"); 9535 else if (specs->storage_class == csc_typedef) 9536 error ("%<__thread%> used with %<typedef%>"); 9537 else 9538 specs->thread_p = true; 9539 break; 9540 case RID_AUTO: 9541 n = csc_auto; 9542 break; 9543 case RID_EXTERN: 9544 n = csc_extern; 9545 /* Diagnose "__thread extern". */ 9546 if (specs->thread_p) 9547 error ("%<__thread%> before %<extern%>"); 9548 break; 9549 case RID_REGISTER: 9550 n = csc_register; 9551 break; 9552 case RID_STATIC: 9553 n = csc_static; 9554 /* Diagnose "__thread static". */ 9555 if (specs->thread_p) 9556 error ("%<__thread%> before %<static%>"); 9557 break; 9558 case RID_TYPEDEF: 9559 n = csc_typedef; 9560 break; 9561 default: 9562 gcc_unreachable (); 9563 } 9564 if (n != csc_none && n == specs->storage_class) 9565 dupe = true; 9566 if (dupe) 9567 error ("duplicate %qE", scspec); 9568 if (n != csc_none) 9569 { 9570 if (specs->storage_class != csc_none && n != specs->storage_class) 9571 { 9572 error ("multiple storage classes in declaration specifiers"); 9573 } 9574 else 9575 { 9576 specs->storage_class = n; 9577 if (n != csc_extern && n != csc_static && specs->thread_p) 9578 { 9579 error ("%<__thread%> used with %qE", scspec); 9580 specs->thread_p = false; 9581 } 9582 } 9583 } 9584 return specs; 9585 } 9586 9587 /* Add the attributes ATTRS to the declaration specifiers SPECS, 9588 returning SPECS. */ 9589 9590 struct c_declspecs * 9591 declspecs_add_attrs (struct c_declspecs *specs, tree attrs) 9592 { 9593 specs->attrs = chainon (attrs, specs->attrs); 9594 specs->declspecs_seen_p = true; 9595 return specs; 9596 } 9597 9598 /* Add an _Alignas specifier (expression ALIGN, or type whose 9599 alignment is ALIGN) to the declaration specifiers SPECS, returning 9600 SPECS. */ 9601 struct c_declspecs * 9602 declspecs_add_alignas (struct c_declspecs *specs, tree align) 9603 { 9604 int align_log; 9605 specs->alignas_p = true; 9606 if (align == error_mark_node) 9607 return specs; 9608 align_log = check_user_alignment (align, true); 9609 if (align_log > specs->align_log) 9610 specs->align_log = align_log; 9611 return specs; 9612 } 9613 9614 /* Combine "long", "short", "signed", "unsigned" and "_Complex" type 9615 specifiers with any other type specifier to determine the resulting 9616 type. This is where ISO C checks on complex types are made, since 9617 "_Complex long" is a prefix of the valid ISO C type "_Complex long 9618 double". */ 9619 9620 struct c_declspecs * 9621 finish_declspecs (struct c_declspecs *specs) 9622 { 9623 /* If a type was specified as a whole, we have no modifiers and are 9624 done. */ 9625 if (specs->type != NULL_TREE) 9626 { 9627 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 9628 && !specs->signed_p && !specs->unsigned_p 9629 && !specs->complex_p); 9630 9631 /* Set a dummy type. */ 9632 if (TREE_CODE (specs->type) == ERROR_MARK) 9633 specs->type = integer_type_node; 9634 return specs; 9635 } 9636 9637 /* If none of "void", "_Bool", "char", "int", "float" or "double" 9638 has been specified, treat it as "int" unless "_Complex" is 9639 present and there are no other specifiers. If we just have 9640 "_Complex", it is equivalent to "_Complex double", but e.g. 9641 "_Complex short" is equivalent to "_Complex short int". */ 9642 if (specs->typespec_word == cts_none) 9643 { 9644 if (specs->saturating_p) 9645 { 9646 error ("%<_Sat%> is used without %<_Fract%> or %<_Accum%>"); 9647 if (!targetm.fixed_point_supported_p ()) 9648 error ("fixed-point types not supported for this target"); 9649 specs->typespec_word = cts_fract; 9650 } 9651 else if (specs->long_p || specs->short_p 9652 || specs->signed_p || specs->unsigned_p) 9653 { 9654 specs->typespec_word = cts_int; 9655 } 9656 else if (specs->complex_p) 9657 { 9658 specs->typespec_word = cts_double; 9659 pedwarn (input_location, OPT_pedantic, 9660 "ISO C does not support plain %<complex%> meaning " 9661 "%<double complex%>"); 9662 } 9663 else 9664 { 9665 specs->typespec_word = cts_int; 9666 specs->default_int_p = true; 9667 /* We don't diagnose this here because grokdeclarator will 9668 give more specific diagnostics according to whether it is 9669 a function definition. */ 9670 } 9671 } 9672 9673 /* If "signed" was specified, record this to distinguish "int" and 9674 "signed int" in the case of a bit-field with 9675 -funsigned-bitfields. */ 9676 specs->explicit_signed_p = specs->signed_p; 9677 9678 /* Now compute the actual type. */ 9679 switch (specs->typespec_word) 9680 { 9681 case cts_void: 9682 gcc_assert (!specs->long_p && !specs->short_p 9683 && !specs->signed_p && !specs->unsigned_p 9684 && !specs->complex_p); 9685 specs->type = void_type_node; 9686 break; 9687 case cts_bool: 9688 gcc_assert (!specs->long_p && !specs->short_p 9689 && !specs->signed_p && !specs->unsigned_p 9690 && !specs->complex_p); 9691 specs->type = boolean_type_node; 9692 break; 9693 case cts_char: 9694 gcc_assert (!specs->long_p && !specs->short_p); 9695 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9696 if (specs->signed_p) 9697 specs->type = signed_char_type_node; 9698 else if (specs->unsigned_p) 9699 specs->type = unsigned_char_type_node; 9700 else 9701 specs->type = char_type_node; 9702 if (specs->complex_p) 9703 { 9704 pedwarn (input_location, OPT_pedantic, 9705 "ISO C does not support complex integer types"); 9706 specs->type = build_complex_type (specs->type); 9707 } 9708 break; 9709 case cts_int128: 9710 gcc_assert (!specs->long_p && !specs->short_p && !specs->long_long_p); 9711 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9712 specs->type = (specs->unsigned_p 9713 ? int128_unsigned_type_node 9714 : int128_integer_type_node); 9715 if (specs->complex_p) 9716 { 9717 pedwarn (input_location, OPT_pedantic, 9718 "ISO C does not support complex integer types"); 9719 specs->type = build_complex_type (specs->type); 9720 } 9721 break; 9722 case cts_int: 9723 gcc_assert (!(specs->long_p && specs->short_p)); 9724 gcc_assert (!(specs->signed_p && specs->unsigned_p)); 9725 if (specs->long_long_p) 9726 specs->type = (specs->unsigned_p 9727 ? long_long_unsigned_type_node 9728 : long_long_integer_type_node); 9729 else if (specs->long_p) 9730 specs->type = (specs->unsigned_p 9731 ? long_unsigned_type_node 9732 : long_integer_type_node); 9733 else if (specs->short_p) 9734 specs->type = (specs->unsigned_p 9735 ? short_unsigned_type_node 9736 : short_integer_type_node); 9737 else 9738 specs->type = (specs->unsigned_p 9739 ? unsigned_type_node 9740 : integer_type_node); 9741 if (specs->complex_p) 9742 { 9743 pedwarn (input_location, OPT_pedantic, 9744 "ISO C does not support complex integer types"); 9745 specs->type = build_complex_type (specs->type); 9746 } 9747 break; 9748 case cts_float: 9749 gcc_assert (!specs->long_p && !specs->short_p 9750 && !specs->signed_p && !specs->unsigned_p); 9751 specs->type = (specs->complex_p 9752 ? complex_float_type_node 9753 : float_type_node); 9754 break; 9755 case cts_double: 9756 gcc_assert (!specs->long_long_p && !specs->short_p 9757 && !specs->signed_p && !specs->unsigned_p); 9758 if (specs->long_p) 9759 { 9760 specs->type = (specs->complex_p 9761 ? complex_long_double_type_node 9762 : long_double_type_node); 9763 } 9764 else 9765 { 9766 specs->type = (specs->complex_p 9767 ? complex_double_type_node 9768 : double_type_node); 9769 } 9770 break; 9771 case cts_dfloat32: 9772 case cts_dfloat64: 9773 case cts_dfloat128: 9774 gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p 9775 && !specs->signed_p && !specs->unsigned_p && !specs->complex_p); 9776 if (specs->typespec_word == cts_dfloat32) 9777 specs->type = dfloat32_type_node; 9778 else if (specs->typespec_word == cts_dfloat64) 9779 specs->type = dfloat64_type_node; 9780 else 9781 specs->type = dfloat128_type_node; 9782 break; 9783 case cts_fract: 9784 gcc_assert (!specs->complex_p); 9785 if (!targetm.fixed_point_supported_p ()) 9786 specs->type = integer_type_node; 9787 else if (specs->saturating_p) 9788 { 9789 if (specs->long_long_p) 9790 specs->type = specs->unsigned_p 9791 ? sat_unsigned_long_long_fract_type_node 9792 : sat_long_long_fract_type_node; 9793 else if (specs->long_p) 9794 specs->type = specs->unsigned_p 9795 ? sat_unsigned_long_fract_type_node 9796 : sat_long_fract_type_node; 9797 else if (specs->short_p) 9798 specs->type = specs->unsigned_p 9799 ? sat_unsigned_short_fract_type_node 9800 : sat_short_fract_type_node; 9801 else 9802 specs->type = specs->unsigned_p 9803 ? sat_unsigned_fract_type_node 9804 : sat_fract_type_node; 9805 } 9806 else 9807 { 9808 if (specs->long_long_p) 9809 specs->type = specs->unsigned_p 9810 ? unsigned_long_long_fract_type_node 9811 : long_long_fract_type_node; 9812 else if (specs->long_p) 9813 specs->type = specs->unsigned_p 9814 ? unsigned_long_fract_type_node 9815 : long_fract_type_node; 9816 else if (specs->short_p) 9817 specs->type = specs->unsigned_p 9818 ? unsigned_short_fract_type_node 9819 : short_fract_type_node; 9820 else 9821 specs->type = specs->unsigned_p 9822 ? unsigned_fract_type_node 9823 : fract_type_node; 9824 } 9825 break; 9826 case cts_accum: 9827 gcc_assert (!specs->complex_p); 9828 if (!targetm.fixed_point_supported_p ()) 9829 specs->type = integer_type_node; 9830 else if (specs->saturating_p) 9831 { 9832 if (specs->long_long_p) 9833 specs->type = specs->unsigned_p 9834 ? sat_unsigned_long_long_accum_type_node 9835 : sat_long_long_accum_type_node; 9836 else if (specs->long_p) 9837 specs->type = specs->unsigned_p 9838 ? sat_unsigned_long_accum_type_node 9839 : sat_long_accum_type_node; 9840 else if (specs->short_p) 9841 specs->type = specs->unsigned_p 9842 ? sat_unsigned_short_accum_type_node 9843 : sat_short_accum_type_node; 9844 else 9845 specs->type = specs->unsigned_p 9846 ? sat_unsigned_accum_type_node 9847 : sat_accum_type_node; 9848 } 9849 else 9850 { 9851 if (specs->long_long_p) 9852 specs->type = specs->unsigned_p 9853 ? unsigned_long_long_accum_type_node 9854 : long_long_accum_type_node; 9855 else if (specs->long_p) 9856 specs->type = specs->unsigned_p 9857 ? unsigned_long_accum_type_node 9858 : long_accum_type_node; 9859 else if (specs->short_p) 9860 specs->type = specs->unsigned_p 9861 ? unsigned_short_accum_type_node 9862 : short_accum_type_node; 9863 else 9864 specs->type = specs->unsigned_p 9865 ? unsigned_accum_type_node 9866 : accum_type_node; 9867 } 9868 break; 9869 default: 9870 gcc_unreachable (); 9871 } 9872 9873 return specs; 9874 } 9875 9876 /* A subroutine of c_write_global_declarations. Perform final processing 9877 on one file scope's declarations (or the external scope's declarations), 9878 GLOBALS. */ 9879 9880 static void 9881 c_write_global_declarations_1 (tree globals) 9882 { 9883 tree decl; 9884 bool reconsider; 9885 9886 /* Process the decls in the order they were written. */ 9887 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9888 { 9889 /* Check for used but undefined static functions using the C 9890 standard's definition of "used", and set TREE_NO_WARNING so 9891 that check_global_declarations doesn't repeat the check. */ 9892 if (TREE_CODE (decl) == FUNCTION_DECL 9893 && DECL_INITIAL (decl) == 0 9894 && DECL_EXTERNAL (decl) 9895 && !TREE_PUBLIC (decl) 9896 && C_DECL_USED (decl)) 9897 { 9898 pedwarn (input_location, 0, "%q+F used but never defined", decl); 9899 TREE_NO_WARNING (decl) = 1; 9900 } 9901 9902 wrapup_global_declaration_1 (decl); 9903 } 9904 9905 do 9906 { 9907 reconsider = false; 9908 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9909 reconsider |= wrapup_global_declaration_2 (decl); 9910 } 9911 while (reconsider); 9912 9913 for (decl = globals; decl; decl = DECL_CHAIN (decl)) 9914 check_global_declaration_1 (decl); 9915 } 9916 9917 /* A subroutine of c_write_global_declarations Emit debug information for each 9918 of the declarations in GLOBALS. */ 9919 9920 static void 9921 c_write_global_declarations_2 (tree globals) 9922 { 9923 tree decl; 9924 9925 for (decl = globals; decl ; decl = DECL_CHAIN (decl)) 9926 debug_hooks->global_decl (decl); 9927 } 9928 9929 /* Callback to collect a source_ref from a DECL. */ 9930 9931 static void 9932 collect_source_ref_cb (tree decl) 9933 { 9934 if (!DECL_IS_BUILTIN (decl)) 9935 collect_source_ref (LOCATION_FILE (decl_sloc (decl, false))); 9936 } 9937 9938 /* Preserve the external declarations scope across a garbage collect. */ 9939 static GTY(()) tree ext_block; 9940 9941 /* Collect all references relevant to SOURCE_FILE. */ 9942 9943 static void 9944 collect_all_refs (const char *source_file) 9945 { 9946 tree t; 9947 unsigned i; 9948 9949 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 9950 collect_ada_nodes (BLOCK_VARS (DECL_INITIAL (t)), source_file); 9951 9952 collect_ada_nodes (BLOCK_VARS (ext_block), source_file); 9953 } 9954 9955 /* Iterate over all global declarations and call CALLBACK. */ 9956 9957 static void 9958 for_each_global_decl (void (*callback) (tree decl)) 9959 { 9960 tree t; 9961 tree decls; 9962 tree decl; 9963 unsigned i; 9964 9965 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 9966 { 9967 decls = DECL_INITIAL (t); 9968 for (decl = BLOCK_VARS (decls); decl; decl = TREE_CHAIN (decl)) 9969 callback (decl); 9970 } 9971 9972 for (decl = BLOCK_VARS (ext_block); decl; decl = TREE_CHAIN (decl)) 9973 callback (decl); 9974 } 9975 9976 void 9977 c_write_global_declarations (void) 9978 { 9979 tree t; 9980 unsigned i; 9981 9982 /* We don't want to do this if generating a PCH. */ 9983 if (pch_file) 9984 return; 9985 9986 timevar_start (TV_PHASE_DEFERRED); 9987 9988 /* Do the Objective-C stuff. This is where all the Objective-C 9989 module stuff gets generated (symtab, class/protocol/selector 9990 lists etc). */ 9991 if (c_dialect_objc ()) 9992 objc_write_global_declarations (); 9993 9994 /* Close the external scope. */ 9995 ext_block = pop_scope (); 9996 external_scope = 0; 9997 gcc_assert (!current_scope); 9998 9999 /* Handle -fdump-ada-spec[-slim]. */ 10000 if (dump_enabled_p (TDI_ada)) 10001 { 10002 /* Build a table of files to generate specs for */ 10003 if (get_dump_file_info (TDI_ada)->flags & TDF_SLIM) 10004 collect_source_ref (main_input_filename); 10005 else 10006 for_each_global_decl (collect_source_ref_cb); 10007 10008 dump_ada_specs (collect_all_refs, NULL); 10009 } 10010 10011 if (ext_block) 10012 { 10013 tree tmp = BLOCK_VARS (ext_block); 10014 int flags; 10015 FILE * stream = dump_begin (TDI_tu, &flags); 10016 if (stream && tmp) 10017 { 10018 dump_node (tmp, flags & ~TDF_SLIM, stream); 10019 dump_end (TDI_tu, stream); 10020 } 10021 } 10022 10023 /* Process all file scopes in this compilation, and the external_scope, 10024 through wrapup_global_declarations and check_global_declarations. */ 10025 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 10026 c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t))); 10027 c_write_global_declarations_1 (BLOCK_VARS (ext_block)); 10028 10029 timevar_stop (TV_PHASE_DEFERRED); 10030 timevar_start (TV_PHASE_CGRAPH); 10031 10032 /* We're done parsing; proceed to optimize and emit assembly. 10033 FIXME: shouldn't be the front end's responsibility to call this. */ 10034 cgraph_finalize_compilation_unit (); 10035 10036 timevar_stop (TV_PHASE_CGRAPH); 10037 timevar_start (TV_PHASE_DBGINFO); 10038 10039 /* After cgraph has had a chance to emit everything that's going to 10040 be emitted, output debug information for globals. */ 10041 if (!seen_error ()) 10042 { 10043 timevar_push (TV_SYMOUT); 10044 FOR_EACH_VEC_ELT (tree, all_translation_units, i, t) 10045 c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t))); 10046 c_write_global_declarations_2 (BLOCK_VARS (ext_block)); 10047 timevar_pop (TV_SYMOUT); 10048 } 10049 10050 ext_block = NULL; 10051 timevar_stop (TV_PHASE_DBGINFO); 10052 } 10053 10054 /* Register reserved keyword WORD as qualifier for address space AS. */ 10055 10056 void 10057 c_register_addr_space (const char *word, addr_space_t as) 10058 { 10059 int rid = RID_FIRST_ADDR_SPACE + as; 10060 tree id; 10061 10062 /* Address space qualifiers are only supported 10063 in C with GNU extensions enabled. */ 10064 if (c_dialect_objc () || flag_no_asm) 10065 return; 10066 10067 id = get_identifier (word); 10068 C_SET_RID_CODE (id, rid); 10069 C_IS_RESERVED_WORD (id) = 1; 10070 ridpointers [rid] = id; 10071 } 10072 10073 #include "gt-c-decl.h" 10074