c-typeck.c revision 260075
111820Sjulian/* Build expressions with type checking for C compiler. 211820Sjulian Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 311820Sjulian 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 411820Sjulian Free Software Foundation, Inc. 511820Sjulian 611820SjulianThis file is part of GCC. 711820Sjulian 811820SjulianGCC is free software; you can redistribute it and/or modify it under 911820Sjulianthe terms of the GNU General Public License as published by the Free 1011820SjulianSoftware Foundation; either version 2, or (at your option) any later 1111820Sjulianversion. 1211820Sjulian 1311820SjulianGCC is distributed in the hope that it will be useful, but WITHOUT ANY 1411820SjulianWARRANTY; without even the implied warranty of MERCHANTABILITY or 1511820SjulianFITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1611820Sjulianfor more details. 1711820Sjulian 1811820SjulianYou should have received a copy of the GNU General Public License 1911820Sjulianalong with GCC; see the file COPYING. If not, write to the Free 2011820SjulianSoftware Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2111820Sjulian02110-1301, USA. */ 2211820Sjulian 2311820Sjulian 2411820Sjulian/* This file is part of the C front end. 2511820Sjulian It contains routines to build C expressions given their operands, 2611820Sjulian including computing the types of the result, C-specific error checks, 2711820Sjulian and some optimization. */ 2811820Sjulian 2911820Sjulian#include "config.h" 3011820Sjulian#include "system.h" 3111820Sjulian#include "coretypes.h" 3211820Sjulian#include "tm.h" 3311820Sjulian#include "rtl.h" 3411820Sjulian#include "tree.h" 3511820Sjulian#include "langhooks.h" 3611820Sjulian#include "c-tree.h" 3711820Sjulian#include "tm_p.h" 3811820Sjulian#include "flags.h" 3911820Sjulian#include "output.h" 4011820Sjulian#include "expr.h" 4111820Sjulian#include "toplev.h" 4211820Sjulian#include "intl.h" 4311820Sjulian#include "ggc.h" 4411820Sjulian#include "target.h" 4511820Sjulian#include "tree-iterator.h" 4611820Sjulian#include "tree-gimple.h" 4711820Sjulian#include "tree-flow.h" 4811820Sjulian 4911820Sjulian/* Possible cases of implicit bad conversions. Used to select 5011820Sjulian diagnostic messages in convert_for_assignment. */ 5111820Sjulianenum impl_conv { 5211820Sjulian ic_argpass, 5311820Sjulian ic_argpass_nonproto, 5411820Sjulian ic_assign, 5511820Sjulian ic_init, 5611820Sjulian ic_return 5711820Sjulian}; 5811820Sjulian 5911820Sjulian/* The level of nesting inside "__alignof__". */ 6011820Sjulianint in_alignof; 6111820Sjulian 6211820Sjulian/* The level of nesting inside "sizeof". */ 6311820Sjulianint in_sizeof; 6411820Sjulian 6511820Sjulian/* The level of nesting inside "typeof". */ 6611820Sjulianint in_typeof; 6711820Sjulian 6811820Sjulianstruct c_label_context_se *label_context_stack_se; 6911820Sjulianstruct c_label_context_vm *label_context_stack_vm; 7011820Sjulian 7111820Sjulian/* Nonzero if we've already printed a "missing braces around initializer" 7211820Sjulian message within this initializer. */ 7311820Sjulianstatic int missing_braces_mentioned; 7411820Sjulian 7511820Sjulianstatic int require_constant_value; 7611820Sjulianstatic int require_constant_elements; 7711820Sjulian 7811820Sjulianstatic bool null_pointer_constant_p (tree); 7911820Sjulianstatic tree qualify_type (tree, tree); 8011820Sjulianstatic int tagged_types_tu_compatible_p (tree, tree); 8111820Sjulianstatic int comp_target_types (tree, tree); 8211820Sjulianstatic int function_types_compatible_p (tree, tree); 8311820Sjulianstatic int type_lists_compatible_p (tree, tree); 8411820Sjulianstatic tree decl_constant_value_for_broken_optimization (tree); 8511820Sjulianstatic tree lookup_field (tree, tree); 8611820Sjulianstatic tree convert_arguments (tree, tree, tree, tree); 8711820Sjulianstatic tree pointer_diff (tree, tree); 8811820Sjulianstatic tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree, 8911820Sjulian int); 9011820Sjulianstatic tree valid_compound_expr_initializer (tree, tree); 9111820Sjulianstatic void push_string (const char *); 9211820Sjulianstatic void push_member_name (tree); 9311820Sjulianstatic int spelling_length (void); 9411820Sjulianstatic char *print_spelling (char *); 9511820Sjulianstatic void warning_init (const char *); 9611820Sjulianstatic tree digest_init (tree, tree, bool, int); 9711820Sjulianstatic void output_init_element (tree, bool, tree, tree, int); 9811820Sjulianstatic void output_pending_init_elements (int); 9911820Sjulianstatic int set_designator (int); 10011820Sjulianstatic void push_range_stack (tree); 10111820Sjulianstatic void add_pending_init (tree, tree); 10211820Sjulianstatic void set_nonincremental_init (void); 10311820Sjulianstatic void set_nonincremental_init_from_string (tree); 10411820Sjulianstatic tree find_init_member (tree); 10511820Sjulianstatic void readonly_error (tree, enum lvalue_use); 10611820Sjulianstatic int lvalue_or_else (tree, enum lvalue_use); 10711820Sjulianstatic int lvalue_p (tree); 10811820Sjulianstatic void record_maybe_used_decl (tree); 10911820Sjulianstatic int comptypes_internal (tree, tree); 11011820Sjulian 11111820Sjulian/* Return true if EXP is a null pointer constant, false otherwise. */ 11211820Sjulian 11311820Sjulianstatic bool 11411820Sjuliannull_pointer_constant_p (tree expr) 11511820Sjulian{ 11611820Sjulian /* This should really operate on c_expr structures, but they aren't 11711820Sjulian yet available everywhere required. */ 11811820Sjulian tree type = TREE_TYPE (expr); 11911820Sjulian return (TREE_CODE (expr) == INTEGER_CST 12011820Sjulian && !TREE_CONSTANT_OVERFLOW (expr) 12111820Sjulian && integer_zerop (expr) 12211820Sjulian && (INTEGRAL_TYPE_P (type) 12311820Sjulian || (TREE_CODE (type) == POINTER_TYPE 12411820Sjulian && VOID_TYPE_P (TREE_TYPE (type)) 12511820Sjulian && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED))); 12611820Sjulian} 12711820Sjulian/* This is a cache to hold if two types are compatible or not. */ 12811820Sjulian 12911820Sjulianstruct tagged_tu_seen_cache { 13011820Sjulian const struct tagged_tu_seen_cache * next; 13111820Sjulian tree t1; 13211820Sjulian tree t2; 13311820Sjulian /* The return value of tagged_types_tu_compatible_p if we had seen 13411820Sjulian these two types already. */ 13511820Sjulian int val; 13611820Sjulian}; 13711820Sjulian 13811820Sjulianstatic const struct tagged_tu_seen_cache * tagged_tu_seen_base; 13911820Sjulianstatic void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *); 14011820Sjulian 14111820Sjulian/* Do `exp = require_complete_type (exp);' to make sure exp 14211820Sjulian does not have an incomplete type. (That includes void types.) */ 14311820Sjulian 14411820Sjuliantree 14511820Sjulianrequire_complete_type (tree value) 14611820Sjulian{ 14711820Sjulian tree type = TREE_TYPE (value); 14811820Sjulian 14911820Sjulian if (value == error_mark_node || type == error_mark_node) 15011820Sjulian return error_mark_node; 15111820Sjulian 15211820Sjulian /* First, detect a valid value with a complete type. */ 15311820Sjulian if (COMPLETE_TYPE_P (type)) 15411820Sjulian return value; 15511820Sjulian 15611820Sjulian c_incomplete_type_error (value, type); 15711820Sjulian return error_mark_node; 15811820Sjulian} 15911820Sjulian 16011820Sjulian/* Print an error message for invalid use of an incomplete type. 16111820Sjulian VALUE is the expression that was used (or 0 if that isn't known) 16211820Sjulian and TYPE is the type that was invalid. */ 16311820Sjulian 16411820Sjulianvoid 16511820Sjulianc_incomplete_type_error (tree value, tree type) 16611820Sjulian{ 16711820Sjulian const char *type_code_string; 16811820Sjulian 16911820Sjulian /* Avoid duplicate error message. */ 17011820Sjulian if (TREE_CODE (type) == ERROR_MARK) 17111820Sjulian return; 17211820Sjulian 17311820Sjulian if (value != 0 && (TREE_CODE (value) == VAR_DECL 17411820Sjulian || TREE_CODE (value) == PARM_DECL)) 17511820Sjulian error ("%qD has an incomplete type", value); 17611820Sjulian else 17711820Sjulian { 17811820Sjulian retry: 17911820Sjulian /* We must print an error message. Be clever about what it says. */ 18011820Sjulian 18111820Sjulian switch (TREE_CODE (type)) 18211820Sjulian { 18311820Sjulian case RECORD_TYPE: 18411820Sjulian type_code_string = "struct"; 18511820Sjulian break; 18611820Sjulian 18711820Sjulian case UNION_TYPE: 18811820Sjulian type_code_string = "union"; 18911820Sjulian break; 19011820Sjulian 19111820Sjulian case ENUMERAL_TYPE: 19211820Sjulian type_code_string = "enum"; 19311820Sjulian break; 19411820Sjulian 19511820Sjulian case VOID_TYPE: 19611820Sjulian error ("invalid use of void expression"); 19711820Sjulian return; 19811820Sjulian 19911820Sjulian case ARRAY_TYPE: 20011820Sjulian if (TYPE_DOMAIN (type)) 20111820Sjulian { 20211820Sjulian if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL) 20311820Sjulian { 20411820Sjulian error ("invalid use of flexible array member"); 20511820Sjulian return; 20611820Sjulian } 20711820Sjulian type = TREE_TYPE (type); 20811820Sjulian goto retry; 20911820Sjulian } 21011820Sjulian error ("invalid use of array with unspecified bounds"); 21111820Sjulian return; 21211820Sjulian 21311820Sjulian default: 21411820Sjulian gcc_unreachable (); 21511820Sjulian } 21611820Sjulian 21711820Sjulian if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 21811820Sjulian error ("invalid use of undefined type %<%s %E%>", 21911820Sjulian type_code_string, TYPE_NAME (type)); 22011820Sjulian else 22111820Sjulian /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */ 22211820Sjulian error ("invalid use of incomplete typedef %qD", TYPE_NAME (type)); 22311820Sjulian } 22411820Sjulian} 22511820Sjulian 22611820Sjulian/* Given a type, apply default promotions wrt unnamed function 22711820Sjulian arguments and return the new type. */ 22811820Sjulian 22911820Sjuliantree 23011820Sjulianc_type_promotes_to (tree type) 23111820Sjulian{ 23211820Sjulian if (TYPE_MAIN_VARIANT (type) == float_type_node) 23311820Sjulian return double_type_node; 23411820Sjulian 23511820Sjulian if (c_promoting_integer_type_p (type)) 23611820Sjulian { 23711820Sjulian /* Preserve unsignedness if not really getting any wider. */ 23811820Sjulian if (TYPE_UNSIGNED (type) 23911820Sjulian && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))) 24011820Sjulian return unsigned_type_node; 24111820Sjulian return integer_type_node; 24211820Sjulian } 24311820Sjulian 24411820Sjulian return type; 24511820Sjulian} 24611820Sjulian 24711820Sjulian/* Return a variant of TYPE which has all the type qualifiers of LIKE 24811820Sjulian as well as those of TYPE. */ 24911820Sjulian 25011820Sjulianstatic tree 25111820Sjulianqualify_type (tree type, tree like) 25211820Sjulian{ 25311820Sjulian return c_build_qualified_type (type, 25411820Sjulian TYPE_QUALS (type) | TYPE_QUALS (like)); 25511820Sjulian} 25611820Sjulian 25711820Sjulian/* Return true iff the given tree T is a variable length array. */ 25811820Sjulian 25911820Sjulianbool 26011820Sjulianc_vla_type_p (tree t) 26111820Sjulian{ 26211820Sjulian if (TREE_CODE (t) == ARRAY_TYPE 26311820Sjulian && C_TYPE_VARIABLE_SIZE (t)) 26411820Sjulian return true; 26511820Sjulian return false; 26611820Sjulian} 26711820Sjulian 26811820Sjulian/* Return the composite type of two compatible types. 26911820Sjulian 27011820Sjulian We assume that comptypes has already been done and returned 27111820Sjulian nonzero; if that isn't so, this may crash. In particular, we 27211820Sjulian assume that qualifiers match. */ 27311820Sjulian 27411820Sjuliantree 27511820Sjuliancomposite_type (tree t1, tree t2) 27611820Sjulian{ 27711820Sjulian enum tree_code code1; 27811820Sjulian enum tree_code code2; 27911820Sjulian tree attributes; 28011820Sjulian 28111820Sjulian /* Save time if the two types are the same. */ 28211820Sjulian 283 if (t1 == t2) return t1; 284 285 /* If one type is nonsense, use the other. */ 286 if (t1 == error_mark_node) 287 return t2; 288 if (t2 == error_mark_node) 289 return t1; 290 291 code1 = TREE_CODE (t1); 292 code2 = TREE_CODE (t2); 293 294 /* Merge the attributes. */ 295 attributes = targetm.merge_type_attributes (t1, t2); 296 297 /* If one is an enumerated type and the other is the compatible 298 integer type, the composite type might be either of the two 299 (DR#013 question 3). For consistency, use the enumerated type as 300 the composite type. */ 301 302 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE) 303 return t1; 304 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE) 305 return t2; 306 307 gcc_assert (code1 == code2); 308 309 switch (code1) 310 { 311 case POINTER_TYPE: 312 /* For two pointers, do this recursively on the target type. */ 313 { 314 tree pointed_to_1 = TREE_TYPE (t1); 315 tree pointed_to_2 = TREE_TYPE (t2); 316 tree target = composite_type (pointed_to_1, pointed_to_2); 317 t1 = build_pointer_type (target); 318 t1 = build_type_attribute_variant (t1, attributes); 319 return qualify_type (t1, t2); 320 } 321 322 case ARRAY_TYPE: 323 { 324 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2)); 325 int quals; 326 tree unqual_elt; 327 tree d1 = TYPE_DOMAIN (t1); 328 tree d2 = TYPE_DOMAIN (t2); 329 bool d1_variable, d2_variable; 330 bool d1_zero, d2_zero; 331 332 /* We should not have any type quals on arrays at all. */ 333 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2)); 334 335 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1); 336 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2); 337 338 d1_variable = (!d1_zero 339 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST 340 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST)); 341 d2_variable = (!d2_zero 342 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST 343 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)); 344 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1)); 345 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2)); 346 347 /* Save space: see if the result is identical to one of the args. */ 348 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1) 349 && (d2_variable || d2_zero || !d1_variable)) 350 return build_type_attribute_variant (t1, attributes); 351 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2) 352 && (d1_variable || d1_zero || !d2_variable)) 353 return build_type_attribute_variant (t2, attributes); 354 355 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1)) 356 return build_type_attribute_variant (t1, attributes); 357 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1)) 358 return build_type_attribute_variant (t2, attributes); 359 360 /* Merge the element types, and have a size if either arg has 361 one. We may have qualifiers on the element types. To set 362 up TYPE_MAIN_VARIANT correctly, we need to form the 363 composite of the unqualified types and add the qualifiers 364 back at the end. */ 365 quals = TYPE_QUALS (strip_array_types (elt)); 366 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED); 367 t1 = build_array_type (unqual_elt, 368 TYPE_DOMAIN ((TYPE_DOMAIN (t1) 369 && (d2_variable 370 || d2_zero 371 || !d1_variable)) 372 ? t1 373 : t2)); 374 t1 = c_build_qualified_type (t1, quals); 375 return build_type_attribute_variant (t1, attributes); 376 } 377 378 case ENUMERAL_TYPE: 379 case RECORD_TYPE: 380 case UNION_TYPE: 381 if (attributes != NULL) 382 { 383 /* Try harder not to create a new aggregate type. */ 384 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes)) 385 return t1; 386 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes)) 387 return t2; 388 } 389 return build_type_attribute_variant (t1, attributes); 390 391 case FUNCTION_TYPE: 392 /* Function types: prefer the one that specified arg types. 393 If both do, merge the arg types. Also merge the return types. */ 394 { 395 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2)); 396 tree p1 = TYPE_ARG_TYPES (t1); 397 tree p2 = TYPE_ARG_TYPES (t2); 398 int len; 399 tree newargs, n; 400 int i; 401 402 /* Save space: see if the result is identical to one of the args. */ 403 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2)) 404 return build_type_attribute_variant (t1, attributes); 405 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1)) 406 return build_type_attribute_variant (t2, attributes); 407 408 /* Simple way if one arg fails to specify argument types. */ 409 if (TYPE_ARG_TYPES (t1) == 0) 410 { 411 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2)); 412 t1 = build_type_attribute_variant (t1, attributes); 413 return qualify_type (t1, t2); 414 } 415 if (TYPE_ARG_TYPES (t2) == 0) 416 { 417 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1)); 418 t1 = build_type_attribute_variant (t1, attributes); 419 return qualify_type (t1, t2); 420 } 421 422 /* If both args specify argument types, we must merge the two 423 lists, argument by argument. */ 424 /* Tell global_bindings_p to return false so that variable_size 425 doesn't die on VLAs in parameter types. */ 426 c_override_global_bindings_to_false = true; 427 428 len = list_length (p1); 429 newargs = 0; 430 431 for (i = 0; i < len; i++) 432 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs); 433 434 n = newargs; 435 436 for (; p1; 437 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n)) 438 { 439 /* A null type means arg type is not specified. 440 Take whatever the other function type has. */ 441 if (TREE_VALUE (p1) == 0) 442 { 443 TREE_VALUE (n) = TREE_VALUE (p2); 444 goto parm_done; 445 } 446 if (TREE_VALUE (p2) == 0) 447 { 448 TREE_VALUE (n) = TREE_VALUE (p1); 449 goto parm_done; 450 } 451 452 /* Given wait (union {union wait *u; int *i} *) 453 and wait (union wait *), 454 prefer union wait * as type of parm. */ 455 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE 456 && TREE_VALUE (p1) != TREE_VALUE (p2)) 457 { 458 tree memb; 459 tree mv2 = TREE_VALUE (p2); 460 if (mv2 && mv2 != error_mark_node 461 && TREE_CODE (mv2) != ARRAY_TYPE) 462 mv2 = TYPE_MAIN_VARIANT (mv2); 463 for (memb = TYPE_FIELDS (TREE_VALUE (p1)); 464 memb; memb = TREE_CHAIN (memb)) 465 { 466 tree mv3 = TREE_TYPE (memb); 467 if (mv3 && mv3 != error_mark_node 468 && TREE_CODE (mv3) != ARRAY_TYPE) 469 mv3 = TYPE_MAIN_VARIANT (mv3); 470 if (comptypes (mv3, mv2)) 471 { 472 TREE_VALUE (n) = composite_type (TREE_TYPE (memb), 473 TREE_VALUE (p2)); 474 if (pedantic) 475 pedwarn ("function types not truly compatible in ISO C"); 476 goto parm_done; 477 } 478 } 479 } 480 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE 481 && TREE_VALUE (p2) != TREE_VALUE (p1)) 482 { 483 tree memb; 484 tree mv1 = TREE_VALUE (p1); 485 if (mv1 && mv1 != error_mark_node 486 && TREE_CODE (mv1) != ARRAY_TYPE) 487 mv1 = TYPE_MAIN_VARIANT (mv1); 488 for (memb = TYPE_FIELDS (TREE_VALUE (p2)); 489 memb; memb = TREE_CHAIN (memb)) 490 { 491 tree mv3 = TREE_TYPE (memb); 492 if (mv3 && mv3 != error_mark_node 493 && TREE_CODE (mv3) != ARRAY_TYPE) 494 mv3 = TYPE_MAIN_VARIANT (mv3); 495 if (comptypes (mv3, mv1)) 496 { 497 TREE_VALUE (n) = composite_type (TREE_TYPE (memb), 498 TREE_VALUE (p1)); 499 if (pedantic) 500 pedwarn ("function types not truly compatible in ISO C"); 501 goto parm_done; 502 } 503 } 504 } 505 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2)); 506 parm_done: ; 507 } 508 509 c_override_global_bindings_to_false = false; 510 t1 = build_function_type (valtype, newargs); 511 t1 = qualify_type (t1, t2); 512 /* ... falls through ... */ 513 } 514 515 default: 516 return build_type_attribute_variant (t1, attributes); 517 } 518 519} 520 521/* Return the type of a conditional expression between pointers to 522 possibly differently qualified versions of compatible types. 523 524 We assume that comp_target_types has already been done and returned 525 nonzero; if that isn't so, this may crash. */ 526 527static tree 528common_pointer_type (tree t1, tree t2) 529{ 530 tree attributes; 531 tree pointed_to_1, mv1; 532 tree pointed_to_2, mv2; 533 tree target; 534 535 /* Save time if the two types are the same. */ 536 537 if (t1 == t2) return t1; 538 539 /* If one type is nonsense, use the other. */ 540 if (t1 == error_mark_node) 541 return t2; 542 if (t2 == error_mark_node) 543 return t1; 544 545 gcc_assert (TREE_CODE (t1) == POINTER_TYPE 546 && TREE_CODE (t2) == POINTER_TYPE); 547 548 /* Merge the attributes. */ 549 attributes = targetm.merge_type_attributes (t1, t2); 550 551 /* Find the composite type of the target types, and combine the 552 qualifiers of the two types' targets. Do not lose qualifiers on 553 array element types by taking the TYPE_MAIN_VARIANT. */ 554 mv1 = pointed_to_1 = TREE_TYPE (t1); 555 mv2 = pointed_to_2 = TREE_TYPE (t2); 556 if (TREE_CODE (mv1) != ARRAY_TYPE) 557 mv1 = TYPE_MAIN_VARIANT (pointed_to_1); 558 if (TREE_CODE (mv2) != ARRAY_TYPE) 559 mv2 = TYPE_MAIN_VARIANT (pointed_to_2); 560 target = composite_type (mv1, mv2); 561 t1 = build_pointer_type (c_build_qualified_type 562 (target, 563 TYPE_QUALS (pointed_to_1) | 564 TYPE_QUALS (pointed_to_2))); 565 return build_type_attribute_variant (t1, attributes); 566} 567 568/* Return the common type for two arithmetic types under the usual 569 arithmetic conversions. The default conversions have already been 570 applied, and enumerated types converted to their compatible integer 571 types. The resulting type is unqualified and has no attributes. 572 573 This is the type for the result of most arithmetic operations 574 if the operands have the given two types. */ 575 576static tree 577c_common_type (tree t1, tree t2) 578{ 579 enum tree_code code1; 580 enum tree_code code2; 581 582 /* If one type is nonsense, use the other. */ 583 if (t1 == error_mark_node) 584 return t2; 585 if (t2 == error_mark_node) 586 return t1; 587 588 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED) 589 t1 = TYPE_MAIN_VARIANT (t1); 590 591 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED) 592 t2 = TYPE_MAIN_VARIANT (t2); 593 594 if (TYPE_ATTRIBUTES (t1) != NULL_TREE) 595 t1 = build_type_attribute_variant (t1, NULL_TREE); 596 597 if (TYPE_ATTRIBUTES (t2) != NULL_TREE) 598 t2 = build_type_attribute_variant (t2, NULL_TREE); 599 600 /* Save time if the two types are the same. */ 601 602 if (t1 == t2) return t1; 603 604 code1 = TREE_CODE (t1); 605 code2 = TREE_CODE (t2); 606 607 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE 608 || code1 == REAL_TYPE || code1 == INTEGER_TYPE); 609 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE 610 || code2 == REAL_TYPE || code2 == INTEGER_TYPE); 611 612 /* When one operand is a decimal float type, the other operand cannot be 613 a generic float type or a complex type. We also disallow vector types 614 here. */ 615 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2)) 616 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2))) 617 { 618 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE) 619 { 620 error ("can%'t mix operands of decimal float and vector types"); 621 return error_mark_node; 622 } 623 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) 624 { 625 error ("can%'t mix operands of decimal float and complex types"); 626 return error_mark_node; 627 } 628 if (code1 == REAL_TYPE && code2 == REAL_TYPE) 629 { 630 error ("can%'t mix operands of decimal float and other float types"); 631 return error_mark_node; 632 } 633 } 634 635 /* If one type is a vector type, return that type. (How the usual 636 arithmetic conversions apply to the vector types extension is not 637 precisely specified.) */ 638 if (code1 == VECTOR_TYPE) 639 return t1; 640 641 if (code2 == VECTOR_TYPE) 642 return t2; 643 644 /* If one type is complex, form the common type of the non-complex 645 components, then make that complex. Use T1 or T2 if it is the 646 required type. */ 647 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) 648 { 649 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1; 650 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2; 651 tree subtype = c_common_type (subtype1, subtype2); 652 653 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype) 654 return t1; 655 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype) 656 return t2; 657 else 658 return build_complex_type (subtype); 659 } 660 661 /* If only one is real, use it as the result. */ 662 663 if (code1 == REAL_TYPE && code2 != REAL_TYPE) 664 return t1; 665 666 if (code2 == REAL_TYPE && code1 != REAL_TYPE) 667 return t2; 668 669 /* If both are real and either are decimal floating point types, use 670 the decimal floating point type with the greater precision. */ 671 672 if (code1 == REAL_TYPE && code2 == REAL_TYPE) 673 { 674 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node 675 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node) 676 return dfloat128_type_node; 677 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node 678 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node) 679 return dfloat64_type_node; 680 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node 681 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node) 682 return dfloat32_type_node; 683 } 684 685 /* Both real or both integers; use the one with greater precision. */ 686 687 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2)) 688 return t1; 689 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1)) 690 return t2; 691 692 /* Same precision. Prefer long longs to longs to ints when the 693 same precision, following the C99 rules on integer type rank 694 (which are equivalent to the C90 rules for C90 types). */ 695 696 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node 697 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node) 698 return long_long_unsigned_type_node; 699 700 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node 701 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node) 702 { 703 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) 704 return long_long_unsigned_type_node; 705 else 706 return long_long_integer_type_node; 707 } 708 709 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node 710 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node) 711 return long_unsigned_type_node; 712 713 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node 714 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node) 715 { 716 /* But preserve unsignedness from the other type, 717 since long cannot hold all the values of an unsigned int. */ 718 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) 719 return long_unsigned_type_node; 720 else 721 return long_integer_type_node; 722 } 723 724 /* Likewise, prefer long double to double even if same size. */ 725 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node 726 || TYPE_MAIN_VARIANT (t2) == long_double_type_node) 727 return long_double_type_node; 728 729 /* Otherwise prefer the unsigned one. */ 730 731 if (TYPE_UNSIGNED (t1)) 732 return t1; 733 else 734 return t2; 735} 736 737/* Wrapper around c_common_type that is used by c-common.c and other 738 front end optimizations that remove promotions. ENUMERAL_TYPEs 739 are allowed here and are converted to their compatible integer types. 740 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or 741 preferably a non-Boolean type as the common type. */ 742tree 743common_type (tree t1, tree t2) 744{ 745 if (TREE_CODE (t1) == ENUMERAL_TYPE) 746 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1); 747 if (TREE_CODE (t2) == ENUMERAL_TYPE) 748 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1); 749 750 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */ 751 if (TREE_CODE (t1) == BOOLEAN_TYPE 752 && TREE_CODE (t2) == BOOLEAN_TYPE) 753 return boolean_type_node; 754 755 /* If either type is BOOLEAN_TYPE, then return the other. */ 756 if (TREE_CODE (t1) == BOOLEAN_TYPE) 757 return t2; 758 if (TREE_CODE (t2) == BOOLEAN_TYPE) 759 return t1; 760 761 return c_common_type (t1, t2); 762} 763 764/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment 765 or various other operations. Return 2 if they are compatible 766 but a warning may be needed if you use them together. */ 767 768int 769comptypes (tree type1, tree type2) 770{ 771 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base; 772 int val; 773 774 val = comptypes_internal (type1, type2); 775 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1); 776 777 return val; 778} 779 780/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment 781 or various other operations. Return 2 if they are compatible 782 but a warning may be needed if you use them together. This 783 differs from comptypes, in that we don't free the seen types. */ 784 785static int 786comptypes_internal (tree type1, tree type2) 787{ 788 tree t1 = type1; 789 tree t2 = type2; 790 int attrval, val; 791 792 /* Suppress errors caused by previously reported errors. */ 793 794 if (t1 == t2 || !t1 || !t2 795 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK) 796 return 1; 797 798 /* If either type is the internal version of sizetype, return the 799 language version. */ 800 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1) 801 && TYPE_ORIG_SIZE_TYPE (t1)) 802 t1 = TYPE_ORIG_SIZE_TYPE (t1); 803 804 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2) 805 && TYPE_ORIG_SIZE_TYPE (t2)) 806 t2 = TYPE_ORIG_SIZE_TYPE (t2); 807 808 809 /* Enumerated types are compatible with integer types, but this is 810 not transitive: two enumerated types in the same translation unit 811 are compatible with each other only if they are the same type. */ 812 813 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE) 814 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1)); 815 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE) 816 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2)); 817 818 if (t1 == t2) 819 return 1; 820 821 /* Different classes of types can't be compatible. */ 822 823 if (TREE_CODE (t1) != TREE_CODE (t2)) 824 return 0; 825 826 /* Qualifiers must match. C99 6.7.3p9 */ 827 828 if (TYPE_QUALS (t1) != TYPE_QUALS (t2)) 829 return 0; 830 831 /* Allow for two different type nodes which have essentially the same 832 definition. Note that we already checked for equality of the type 833 qualifiers (just above). */ 834 835 if (TREE_CODE (t1) != ARRAY_TYPE 836 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) 837 return 1; 838 839 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 840 if (!(attrval = targetm.comp_type_attributes (t1, t2))) 841 return 0; 842 843 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 844 val = 0; 845 846 switch (TREE_CODE (t1)) 847 { 848 case POINTER_TYPE: 849 /* Do not remove mode or aliasing information. */ 850 if (TYPE_MODE (t1) != TYPE_MODE (t2) 851 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)) 852 break; 853 val = (TREE_TYPE (t1) == TREE_TYPE (t2) 854 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))); 855 break; 856 857 case FUNCTION_TYPE: 858 val = function_types_compatible_p (t1, t2); 859 break; 860 861 case ARRAY_TYPE: 862 { 863 tree d1 = TYPE_DOMAIN (t1); 864 tree d2 = TYPE_DOMAIN (t2); 865 bool d1_variable, d2_variable; 866 bool d1_zero, d2_zero; 867 val = 1; 868 869 /* Target types must match incl. qualifiers. */ 870 if (TREE_TYPE (t1) != TREE_TYPE (t2) 871 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)))) 872 return 0; 873 874 /* Sizes must match unless one is missing or variable. */ 875 if (d1 == 0 || d2 == 0 || d1 == d2) 876 break; 877 878 d1_zero = !TYPE_MAX_VALUE (d1); 879 d2_zero = !TYPE_MAX_VALUE (d2); 880 881 d1_variable = (!d1_zero 882 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST 883 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST)); 884 d2_variable = (!d2_zero 885 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST 886 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)); 887 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1)); 888 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2)); 889 890 if (d1_variable || d2_variable) 891 break; 892 if (d1_zero && d2_zero) 893 break; 894 if (d1_zero || d2_zero 895 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)) 896 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2))) 897 val = 0; 898 899 break; 900 } 901 902 case ENUMERAL_TYPE: 903 case RECORD_TYPE: 904 case UNION_TYPE: 905 if (val != 1 && !same_translation_unit_p (t1, t2)) 906 { 907 tree a1 = TYPE_ATTRIBUTES (t1); 908 tree a2 = TYPE_ATTRIBUTES (t2); 909 910 if (! attribute_list_contained (a1, a2) 911 && ! attribute_list_contained (a2, a1)) 912 break; 913 914 if (attrval != 2) 915 return tagged_types_tu_compatible_p (t1, t2); 916 val = tagged_types_tu_compatible_p (t1, t2); 917 } 918 break; 919 920 case VECTOR_TYPE: 921 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2) 922 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)); 923 break; 924 925 default: 926 break; 927 } 928 return attrval == 2 && val == 1 ? 2 : val; 929} 930 931/* Return 1 if TTL and TTR are pointers to types that are equivalent, 932 ignoring their qualifiers. */ 933 934static int 935comp_target_types (tree ttl, tree ttr) 936{ 937 int val; 938 tree mvl, mvr; 939 940 /* Do not lose qualifiers on element types of array types that are 941 pointer targets by taking their TYPE_MAIN_VARIANT. */ 942 mvl = TREE_TYPE (ttl); 943 mvr = TREE_TYPE (ttr); 944 if (TREE_CODE (mvl) != ARRAY_TYPE) 945 mvl = TYPE_MAIN_VARIANT (mvl); 946 if (TREE_CODE (mvr) != ARRAY_TYPE) 947 mvr = TYPE_MAIN_VARIANT (mvr); 948 val = comptypes (mvl, mvr); 949 950 if (val == 2 && pedantic) 951 pedwarn ("types are not quite compatible"); 952 return val; 953} 954 955/* Subroutines of `comptypes'. */ 956 957/* Determine whether two trees derive from the same translation unit. 958 If the CONTEXT chain ends in a null, that tree's context is still 959 being parsed, so if two trees have context chains ending in null, 960 they're in the same translation unit. */ 961int 962same_translation_unit_p (tree t1, tree t2) 963{ 964 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL) 965 switch (TREE_CODE_CLASS (TREE_CODE (t1))) 966 { 967 case tcc_declaration: 968 t1 = DECL_CONTEXT (t1); break; 969 case tcc_type: 970 t1 = TYPE_CONTEXT (t1); break; 971 case tcc_exceptional: 972 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */ 973 default: gcc_unreachable (); 974 } 975 976 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL) 977 switch (TREE_CODE_CLASS (TREE_CODE (t2))) 978 { 979 case tcc_declaration: 980 t2 = DECL_CONTEXT (t2); break; 981 case tcc_type: 982 t2 = TYPE_CONTEXT (t2); break; 983 case tcc_exceptional: 984 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */ 985 default: gcc_unreachable (); 986 } 987 988 return t1 == t2; 989} 990 991/* Allocate the seen two types, assuming that they are compatible. */ 992 993static struct tagged_tu_seen_cache * 994alloc_tagged_tu_seen_cache (tree t1, tree t2) 995{ 996 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache); 997 tu->next = tagged_tu_seen_base; 998 tu->t1 = t1; 999 tu->t2 = t2; 1000 1001 tagged_tu_seen_base = tu; 1002 1003 /* The C standard says that two structures in different translation 1004 units are compatible with each other only if the types of their 1005 fields are compatible (among other things). We assume that they 1006 are compatible until proven otherwise when building the cache. 1007 An example where this can occur is: 1008 struct a 1009 { 1010 struct a *next; 1011 }; 1012 If we are comparing this against a similar struct in another TU, 1013 and did not assume they were compatible, we end up with an infinite 1014 loop. */ 1015 tu->val = 1; 1016 return tu; 1017} 1018 1019/* Free the seen types until we get to TU_TIL. */ 1020 1021static void 1022free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til) 1023{ 1024 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base; 1025 while (tu != tu_til) 1026 { 1027 struct tagged_tu_seen_cache *tu1 = (struct tagged_tu_seen_cache*)tu; 1028 tu = tu1->next; 1029 free (tu1); 1030 } 1031 tagged_tu_seen_base = tu_til; 1032} 1033 1034/* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are 1035 compatible. If the two types are not the same (which has been 1036 checked earlier), this can only happen when multiple translation 1037 units are being compiled. See C99 6.2.7 paragraph 1 for the exact 1038 rules. */ 1039 1040static int 1041tagged_types_tu_compatible_p (tree t1, tree t2) 1042{ 1043 tree s1, s2; 1044 bool needs_warning = false; 1045 1046 /* We have to verify that the tags of the types are the same. This 1047 is harder than it looks because this may be a typedef, so we have 1048 to go look at the original type. It may even be a typedef of a 1049 typedef... 1050 In the case of compiler-created builtin structs the TYPE_DECL 1051 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */ 1052 while (TYPE_NAME (t1) 1053 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL 1054 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1))) 1055 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1)); 1056 1057 while (TYPE_NAME (t2) 1058 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL 1059 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2))) 1060 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2)); 1061 1062 /* C90 didn't have the requirement that the two tags be the same. */ 1063 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2)) 1064 return 0; 1065 1066 /* C90 didn't say what happened if one or both of the types were 1067 incomplete; we choose to follow C99 rules here, which is that they 1068 are compatible. */ 1069 if (TYPE_SIZE (t1) == NULL 1070 || TYPE_SIZE (t2) == NULL) 1071 return 1; 1072 1073 { 1074 const struct tagged_tu_seen_cache * tts_i; 1075 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next) 1076 if (tts_i->t1 == t1 && tts_i->t2 == t2) 1077 return tts_i->val; 1078 } 1079 1080 switch (TREE_CODE (t1)) 1081 { 1082 case ENUMERAL_TYPE: 1083 { 1084 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2); 1085 /* Speed up the case where the type values are in the same order. */ 1086 tree tv1 = TYPE_VALUES (t1); 1087 tree tv2 = TYPE_VALUES (t2); 1088 1089 if (tv1 == tv2) 1090 { 1091 return 1; 1092 } 1093 1094 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2)) 1095 { 1096 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2)) 1097 break; 1098 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1) 1099 { 1100 tu->val = 0; 1101 return 0; 1102 } 1103 } 1104 1105 if (tv1 == NULL_TREE && tv2 == NULL_TREE) 1106 { 1107 return 1; 1108 } 1109 if (tv1 == NULL_TREE || tv2 == NULL_TREE) 1110 { 1111 tu->val = 0; 1112 return 0; 1113 } 1114 1115 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2))) 1116 { 1117 tu->val = 0; 1118 return 0; 1119 } 1120 1121 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1)) 1122 { 1123 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2)); 1124 if (s2 == NULL 1125 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1) 1126 { 1127 tu->val = 0; 1128 return 0; 1129 } 1130 } 1131 return 1; 1132 } 1133 1134 case UNION_TYPE: 1135 { 1136 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2); 1137 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2))) 1138 { 1139 tu->val = 0; 1140 return 0; 1141 } 1142 1143 /* Speed up the common case where the fields are in the same order. */ 1144 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2; 1145 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2)) 1146 { 1147 int result; 1148 1149 1150 if (DECL_NAME (s1) == NULL 1151 || DECL_NAME (s1) != DECL_NAME (s2)) 1152 break; 1153 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2)); 1154 if (result == 0) 1155 { 1156 tu->val = 0; 1157 return 0; 1158 } 1159 if (result == 2) 1160 needs_warning = true; 1161 1162 if (TREE_CODE (s1) == FIELD_DECL 1163 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), 1164 DECL_FIELD_BIT_OFFSET (s2)) != 1) 1165 { 1166 tu->val = 0; 1167 return 0; 1168 } 1169 } 1170 if (!s1 && !s2) 1171 { 1172 tu->val = needs_warning ? 2 : 1; 1173 return tu->val; 1174 } 1175 1176 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1)) 1177 { 1178 bool ok = false; 1179 1180 if (DECL_NAME (s1) != NULL) 1181 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2)) 1182 if (DECL_NAME (s1) == DECL_NAME (s2)) 1183 { 1184 int result; 1185 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2)); 1186 if (result == 0) 1187 { 1188 tu->val = 0; 1189 return 0; 1190 } 1191 if (result == 2) 1192 needs_warning = true; 1193 1194 if (TREE_CODE (s1) == FIELD_DECL 1195 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), 1196 DECL_FIELD_BIT_OFFSET (s2)) != 1) 1197 break; 1198 1199 ok = true; 1200 break; 1201 } 1202 if (!ok) 1203 { 1204 tu->val = 0; 1205 return 0; 1206 } 1207 } 1208 tu->val = needs_warning ? 2 : 10; 1209 return tu->val; 1210 } 1211 1212 case RECORD_TYPE: 1213 { 1214 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2); 1215 1216 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); 1217 s1 && s2; 1218 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2)) 1219 { 1220 int result; 1221 if (TREE_CODE (s1) != TREE_CODE (s2) 1222 || DECL_NAME (s1) != DECL_NAME (s2)) 1223 break; 1224 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2)); 1225 if (result == 0) 1226 break; 1227 if (result == 2) 1228 needs_warning = true; 1229 1230 if (TREE_CODE (s1) == FIELD_DECL 1231 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), 1232 DECL_FIELD_BIT_OFFSET (s2)) != 1) 1233 break; 1234 } 1235 if (s1 && s2) 1236 tu->val = 0; 1237 else 1238 tu->val = needs_warning ? 2 : 1; 1239 return tu->val; 1240 } 1241 1242 default: 1243 gcc_unreachable (); 1244 } 1245} 1246 1247/* Return 1 if two function types F1 and F2 are compatible. 1248 If either type specifies no argument types, 1249 the other must specify a fixed number of self-promoting arg types. 1250 Otherwise, if one type specifies only the number of arguments, 1251 the other must specify that number of self-promoting arg types. 1252 Otherwise, the argument types must match. */ 1253 1254static int 1255function_types_compatible_p (tree f1, tree f2) 1256{ 1257 tree args1, args2; 1258 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 1259 int val = 1; 1260 int val1; 1261 tree ret1, ret2; 1262 1263 ret1 = TREE_TYPE (f1); 1264 ret2 = TREE_TYPE (f2); 1265 1266 /* 'volatile' qualifiers on a function's return type used to mean 1267 the function is noreturn. */ 1268 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2)) 1269 pedwarn ("function return types not compatible due to %<volatile%>"); 1270 if (TYPE_VOLATILE (ret1)) 1271 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1), 1272 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE); 1273 if (TYPE_VOLATILE (ret2)) 1274 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2), 1275 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE); 1276 val = comptypes_internal (ret1, ret2); 1277 if (val == 0) 1278 return 0; 1279 1280 args1 = TYPE_ARG_TYPES (f1); 1281 args2 = TYPE_ARG_TYPES (f2); 1282 1283 /* An unspecified parmlist matches any specified parmlist 1284 whose argument types don't need default promotions. */ 1285 1286 if (args1 == 0) 1287 { 1288 if (!self_promoting_args_p (args2)) 1289 return 0; 1290 /* If one of these types comes from a non-prototype fn definition, 1291 compare that with the other type's arglist. 1292 If they don't match, ask for a warning (but no error). */ 1293 if (TYPE_ACTUAL_ARG_TYPES (f1) 1294 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1))) 1295 val = 2; 1296 return val; 1297 } 1298 if (args2 == 0) 1299 { 1300 if (!self_promoting_args_p (args1)) 1301 return 0; 1302 if (TYPE_ACTUAL_ARG_TYPES (f2) 1303 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2))) 1304 val = 2; 1305 return val; 1306 } 1307 1308 /* Both types have argument lists: compare them and propagate results. */ 1309 val1 = type_lists_compatible_p (args1, args2); 1310 return val1 != 1 ? val1 : val; 1311} 1312 1313/* Check two lists of types for compatibility, 1314 returning 0 for incompatible, 1 for compatible, 1315 or 2 for compatible with warning. */ 1316 1317static int 1318type_lists_compatible_p (tree args1, tree args2) 1319{ 1320 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 1321 int val = 1; 1322 int newval = 0; 1323 1324 while (1) 1325 { 1326 tree a1, mv1, a2, mv2; 1327 if (args1 == 0 && args2 == 0) 1328 return val; 1329 /* If one list is shorter than the other, 1330 they fail to match. */ 1331 if (args1 == 0 || args2 == 0) 1332 return 0; 1333 mv1 = a1 = TREE_VALUE (args1); 1334 mv2 = a2 = TREE_VALUE (args2); 1335 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE) 1336 mv1 = TYPE_MAIN_VARIANT (mv1); 1337 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE) 1338 mv2 = TYPE_MAIN_VARIANT (mv2); 1339 /* A null pointer instead of a type 1340 means there is supposed to be an argument 1341 but nothing is specified about what type it has. 1342 So match anything that self-promotes. */ 1343 if (a1 == 0) 1344 { 1345 if (c_type_promotes_to (a2) != a2) 1346 return 0; 1347 } 1348 else if (a2 == 0) 1349 { 1350 if (c_type_promotes_to (a1) != a1) 1351 return 0; 1352 } 1353 /* If one of the lists has an error marker, ignore this arg. */ 1354 else if (TREE_CODE (a1) == ERROR_MARK 1355 || TREE_CODE (a2) == ERROR_MARK) 1356 ; 1357 else if (!(newval = comptypes_internal (mv1, mv2))) 1358 { 1359 /* Allow wait (union {union wait *u; int *i} *) 1360 and wait (union wait *) to be compatible. */ 1361 if (TREE_CODE (a1) == UNION_TYPE 1362 && (TYPE_NAME (a1) == 0 1363 || TYPE_TRANSPARENT_UNION (a1)) 1364 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST 1365 && tree_int_cst_equal (TYPE_SIZE (a1), 1366 TYPE_SIZE (a2))) 1367 { 1368 tree memb; 1369 for (memb = TYPE_FIELDS (a1); 1370 memb; memb = TREE_CHAIN (memb)) 1371 { 1372 tree mv3 = TREE_TYPE (memb); 1373 if (mv3 && mv3 != error_mark_node 1374 && TREE_CODE (mv3) != ARRAY_TYPE) 1375 mv3 = TYPE_MAIN_VARIANT (mv3); 1376 if (comptypes_internal (mv3, mv2)) 1377 break; 1378 } 1379 if (memb == 0) 1380 return 0; 1381 } 1382 else if (TREE_CODE (a2) == UNION_TYPE 1383 && (TYPE_NAME (a2) == 0 1384 || TYPE_TRANSPARENT_UNION (a2)) 1385 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST 1386 && tree_int_cst_equal (TYPE_SIZE (a2), 1387 TYPE_SIZE (a1))) 1388 { 1389 tree memb; 1390 for (memb = TYPE_FIELDS (a2); 1391 memb; memb = TREE_CHAIN (memb)) 1392 { 1393 tree mv3 = TREE_TYPE (memb); 1394 if (mv3 && mv3 != error_mark_node 1395 && TREE_CODE (mv3) != ARRAY_TYPE) 1396 mv3 = TYPE_MAIN_VARIANT (mv3); 1397 if (comptypes_internal (mv3, mv1)) 1398 break; 1399 } 1400 if (memb == 0) 1401 return 0; 1402 } 1403 else 1404 return 0; 1405 } 1406 1407 /* comptypes said ok, but record if it said to warn. */ 1408 if (newval > val) 1409 val = newval; 1410 1411 args1 = TREE_CHAIN (args1); 1412 args2 = TREE_CHAIN (args2); 1413 } 1414} 1415 1416/* Compute the size to increment a pointer by. */ 1417 1418static tree 1419c_size_in_bytes (tree type) 1420{ 1421 enum tree_code code = TREE_CODE (type); 1422 1423 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK) 1424 return size_one_node; 1425 1426 if (!COMPLETE_OR_VOID_TYPE_P (type)) 1427 { 1428 error ("arithmetic on pointer to an incomplete type"); 1429 return size_one_node; 1430 } 1431 1432 /* Convert in case a char is more than one unit. */ 1433 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), 1434 size_int (TYPE_PRECISION (char_type_node) 1435 / BITS_PER_UNIT)); 1436} 1437 1438/* Return either DECL or its known constant value (if it has one). */ 1439 1440tree 1441decl_constant_value (tree decl) 1442{ 1443 if (/* Don't change a variable array bound or initial value to a constant 1444 in a place where a variable is invalid. Note that DECL_INITIAL 1445 isn't valid for a PARM_DECL. */ 1446 current_function_decl != 0 1447 && TREE_CODE (decl) != PARM_DECL 1448 && !TREE_THIS_VOLATILE (decl) 1449 && TREE_READONLY (decl) 1450 && DECL_INITIAL (decl) != 0 1451 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK 1452 /* This is invalid if initial value is not constant. 1453 If it has either a function call, a memory reference, 1454 or a variable, then re-evaluating it could give different results. */ 1455 && TREE_CONSTANT (DECL_INITIAL (decl)) 1456 /* Check for cases where this is sub-optimal, even though valid. */ 1457 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR) 1458 return DECL_INITIAL (decl); 1459 return decl; 1460} 1461 1462/* Return either DECL or its known constant value (if it has one), but 1463 return DECL if pedantic or DECL has mode BLKmode. This is for 1464 bug-compatibility with the old behavior of decl_constant_value 1465 (before GCC 3.0); every use of this function is a bug and it should 1466 be removed before GCC 3.1. It is not appropriate to use pedantic 1467 in a way that affects optimization, and BLKmode is probably not the 1468 right test for avoiding misoptimizations either. */ 1469 1470static tree 1471decl_constant_value_for_broken_optimization (tree decl) 1472{ 1473 tree ret; 1474 1475 if (pedantic || DECL_MODE (decl) == BLKmode) 1476 return decl; 1477 1478 ret = decl_constant_value (decl); 1479 /* Avoid unwanted tree sharing between the initializer and current 1480 function's body where the tree can be modified e.g. by the 1481 gimplifier. */ 1482 if (ret != decl && TREE_STATIC (decl)) 1483 ret = unshare_expr (ret); 1484 return ret; 1485} 1486 1487/* Convert the array expression EXP to a pointer. */ 1488static tree 1489array_to_pointer_conversion (tree exp) 1490{ 1491 tree orig_exp = exp; 1492 tree type = TREE_TYPE (exp); 1493 tree adr; 1494 tree restype = TREE_TYPE (type); 1495 tree ptrtype; 1496 1497 gcc_assert (TREE_CODE (type) == ARRAY_TYPE); 1498 1499 STRIP_TYPE_NOPS (exp); 1500 1501 if (TREE_NO_WARNING (orig_exp)) 1502 TREE_NO_WARNING (exp) = 1; 1503 1504 ptrtype = build_pointer_type (restype); 1505 1506 if (TREE_CODE (exp) == INDIRECT_REF) 1507 return convert (ptrtype, TREE_OPERAND (exp, 0)); 1508 1509 if (TREE_CODE (exp) == VAR_DECL) 1510 { 1511 /* We are making an ADDR_EXPR of ptrtype. This is a valid 1512 ADDR_EXPR because it's the best way of representing what 1513 happens in C when we take the address of an array and place 1514 it in a pointer to the element type. */ 1515 adr = build1 (ADDR_EXPR, ptrtype, exp); 1516 if (!c_mark_addressable (exp)) 1517 return error_mark_node; 1518 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */ 1519 return adr; 1520 } 1521 1522 /* This way is better for a COMPONENT_REF since it can 1523 simplify the offset for a component. */ 1524 adr = build_unary_op (ADDR_EXPR, exp, 1); 1525 return convert (ptrtype, adr); 1526} 1527 1528/* Convert the function expression EXP to a pointer. */ 1529static tree 1530function_to_pointer_conversion (tree exp) 1531{ 1532 tree orig_exp = exp; 1533 1534 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE); 1535 1536 STRIP_TYPE_NOPS (exp); 1537 1538 if (TREE_NO_WARNING (orig_exp)) 1539 TREE_NO_WARNING (exp) = 1; 1540 1541 return build_unary_op (ADDR_EXPR, exp, 0); 1542} 1543 1544/* Perform the default conversion of arrays and functions to pointers. 1545 Return the result of converting EXP. For any other expression, just 1546 return EXP after removing NOPs. */ 1547 1548struct c_expr 1549default_function_array_conversion (struct c_expr exp) 1550{ 1551 tree orig_exp = exp.value; 1552 tree type = TREE_TYPE (exp.value); 1553 enum tree_code code = TREE_CODE (type); 1554 1555 switch (code) 1556 { 1557 case ARRAY_TYPE: 1558 { 1559 bool not_lvalue = false; 1560 bool lvalue_array_p; 1561 1562 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR 1563 || TREE_CODE (exp.value) == NOP_EXPR 1564 || TREE_CODE (exp.value) == CONVERT_EXPR) 1565 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type) 1566 { 1567 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR) 1568 not_lvalue = true; 1569 exp.value = TREE_OPERAND (exp.value, 0); 1570 } 1571 1572 if (TREE_NO_WARNING (orig_exp)) 1573 TREE_NO_WARNING (exp.value) = 1; 1574 1575 lvalue_array_p = !not_lvalue && lvalue_p (exp.value); 1576 if (!flag_isoc99 && !lvalue_array_p) 1577 { 1578 /* Before C99, non-lvalue arrays do not decay to pointers. 1579 Normally, using such an array would be invalid; but it can 1580 be used correctly inside sizeof or as a statement expression. 1581 Thus, do not give an error here; an error will result later. */ 1582 return exp; 1583 } 1584 1585 exp.value = array_to_pointer_conversion (exp.value); 1586 } 1587 break; 1588 case FUNCTION_TYPE: 1589 exp.value = function_to_pointer_conversion (exp.value); 1590 break; 1591 default: 1592 STRIP_TYPE_NOPS (exp.value); 1593 if (TREE_NO_WARNING (orig_exp)) 1594 TREE_NO_WARNING (exp.value) = 1; 1595 break; 1596 } 1597 1598 return exp; 1599} 1600 1601 1602/* EXP is an expression of integer type. Apply the integer promotions 1603 to it and return the promoted value. */ 1604 1605tree 1606perform_integral_promotions (tree exp) 1607{ 1608 tree type = TREE_TYPE (exp); 1609 enum tree_code code = TREE_CODE (type); 1610 1611 gcc_assert (INTEGRAL_TYPE_P (type)); 1612 1613 /* Normally convert enums to int, 1614 but convert wide enums to something wider. */ 1615 if (code == ENUMERAL_TYPE) 1616 { 1617 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 1618 TYPE_PRECISION (integer_type_node)), 1619 ((TYPE_PRECISION (type) 1620 >= TYPE_PRECISION (integer_type_node)) 1621 && TYPE_UNSIGNED (type))); 1622 1623 return convert (type, exp); 1624 } 1625 1626 /* ??? This should no longer be needed now bit-fields have their 1627 proper types. */ 1628 if (TREE_CODE (exp) == COMPONENT_REF 1629 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1)) 1630 /* If it's thinner than an int, promote it like a 1631 c_promoting_integer_type_p, otherwise leave it alone. */ 1632 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)), 1633 TYPE_PRECISION (integer_type_node))) 1634 return convert (integer_type_node, exp); 1635 1636 if (c_promoting_integer_type_p (type)) 1637 { 1638 /* Preserve unsignedness if not really getting any wider. */ 1639 if (TYPE_UNSIGNED (type) 1640 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) 1641 return convert (unsigned_type_node, exp); 1642 1643 return convert (integer_type_node, exp); 1644 } 1645 1646 return exp; 1647} 1648 1649 1650/* Perform default promotions for C data used in expressions. 1651 Enumeral types or short or char are converted to int. 1652 In addition, manifest constants symbols are replaced by their values. */ 1653 1654tree 1655default_conversion (tree exp) 1656{ 1657 tree orig_exp; 1658 tree type = TREE_TYPE (exp); 1659 enum tree_code code = TREE_CODE (type); 1660 1661 /* Functions and arrays have been converted during parsing. */ 1662 gcc_assert (code != FUNCTION_TYPE); 1663 if (code == ARRAY_TYPE) 1664 return exp; 1665 1666 /* Constants can be used directly unless they're not loadable. */ 1667 if (TREE_CODE (exp) == CONST_DECL) 1668 exp = DECL_INITIAL (exp); 1669 1670 /* Replace a nonvolatile const static variable with its value unless 1671 it is an array, in which case we must be sure that taking the 1672 address of the array produces consistent results. */ 1673 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE) 1674 { 1675 exp = decl_constant_value_for_broken_optimization (exp); 1676 type = TREE_TYPE (exp); 1677 } 1678 1679 /* Strip no-op conversions. */ 1680 orig_exp = exp; 1681 STRIP_TYPE_NOPS (exp); 1682 1683 if (TREE_NO_WARNING (orig_exp)) 1684 TREE_NO_WARNING (exp) = 1; 1685 1686 if (INTEGRAL_TYPE_P (type)) 1687 return perform_integral_promotions (exp); 1688 1689 if (code == VOID_TYPE) 1690 { 1691 error ("void value not ignored as it ought to be"); 1692 return error_mark_node; 1693 } 1694 return exp; 1695} 1696 1697/* Look up COMPONENT in a structure or union DECL. 1698 1699 If the component name is not found, returns NULL_TREE. Otherwise, 1700 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL 1701 stepping down the chain to the component, which is in the last 1702 TREE_VALUE of the list. Normally the list is of length one, but if 1703 the component is embedded within (nested) anonymous structures or 1704 unions, the list steps down the chain to the component. */ 1705 1706static tree 1707lookup_field (tree decl, tree component) 1708{ 1709 tree type = TREE_TYPE (decl); 1710 tree field; 1711 1712 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers 1713 to the field elements. Use a binary search on this array to quickly 1714 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC 1715 will always be set for structures which have many elements. */ 1716 1717 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s) 1718 { 1719 int bot, top, half; 1720 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0]; 1721 1722 field = TYPE_FIELDS (type); 1723 bot = 0; 1724 top = TYPE_LANG_SPECIFIC (type)->s->len; 1725 while (top - bot > 1) 1726 { 1727 half = (top - bot + 1) >> 1; 1728 field = field_array[bot+half]; 1729 1730 if (DECL_NAME (field) == NULL_TREE) 1731 { 1732 /* Step through all anon unions in linear fashion. */ 1733 while (DECL_NAME (field_array[bot]) == NULL_TREE) 1734 { 1735 field = field_array[bot++]; 1736 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE 1737 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE) 1738 { 1739 tree anon = lookup_field (field, component); 1740 1741 if (anon) 1742 return tree_cons (NULL_TREE, field, anon); 1743 } 1744 } 1745 1746 /* Entire record is only anon unions. */ 1747 if (bot > top) 1748 return NULL_TREE; 1749 1750 /* Restart the binary search, with new lower bound. */ 1751 continue; 1752 } 1753 1754 if (DECL_NAME (field) == component) 1755 break; 1756 if (DECL_NAME (field) < component) 1757 bot += half; 1758 else 1759 top = bot + half; 1760 } 1761 1762 if (DECL_NAME (field_array[bot]) == component) 1763 field = field_array[bot]; 1764 else if (DECL_NAME (field) != component) 1765 return NULL_TREE; 1766 } 1767 else 1768 { 1769 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 1770 { 1771 if (DECL_NAME (field) == NULL_TREE 1772 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE 1773 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)) 1774 { 1775 tree anon = lookup_field (field, component); 1776 1777 if (anon) 1778 return tree_cons (NULL_TREE, field, anon); 1779 } 1780 1781 if (DECL_NAME (field) == component) 1782 break; 1783 } 1784 1785 if (field == NULL_TREE) 1786 return NULL_TREE; 1787 } 1788 1789 return tree_cons (NULL_TREE, field, NULL_TREE); 1790} 1791 1792/* Make an expression to refer to the COMPONENT field of 1793 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */ 1794 1795tree 1796build_component_ref (tree datum, tree component) 1797{ 1798 tree type = TREE_TYPE (datum); 1799 enum tree_code code = TREE_CODE (type); 1800 tree field = NULL; 1801 tree ref; 1802 1803 if (!objc_is_public (datum, component)) 1804 return error_mark_node; 1805 1806 /* See if there is a field or component with name COMPONENT. */ 1807 1808 if (code == RECORD_TYPE || code == UNION_TYPE) 1809 { 1810 if (!COMPLETE_TYPE_P (type)) 1811 { 1812 c_incomplete_type_error (NULL_TREE, type); 1813 return error_mark_node; 1814 } 1815 1816 field = lookup_field (datum, component); 1817 1818 if (!field) 1819 { 1820 error ("%qT has no member named %qE", type, component); 1821 return error_mark_node; 1822 } 1823 1824 /* Chain the COMPONENT_REFs if necessary down to the FIELD. 1825 This might be better solved in future the way the C++ front 1826 end does it - by giving the anonymous entities each a 1827 separate name and type, and then have build_component_ref 1828 recursively call itself. We can't do that here. */ 1829 do 1830 { 1831 tree subdatum = TREE_VALUE (field); 1832 int quals; 1833 tree subtype; 1834 1835 if (TREE_TYPE (subdatum) == error_mark_node) 1836 return error_mark_node; 1837 1838 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum))); 1839 quals |= TYPE_QUALS (TREE_TYPE (datum)); 1840 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals); 1841 1842 ref = build3 (COMPONENT_REF, subtype, datum, subdatum, 1843 NULL_TREE); 1844 if (TREE_READONLY (datum) || TREE_READONLY (subdatum)) 1845 TREE_READONLY (ref) = 1; 1846 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum)) 1847 TREE_THIS_VOLATILE (ref) = 1; 1848 1849 if (TREE_DEPRECATED (subdatum)) 1850 warn_deprecated_use (subdatum); 1851 1852 datum = ref; 1853 1854 field = TREE_CHAIN (field); 1855 } 1856 while (field); 1857 1858 return ref; 1859 } 1860 else if (code != ERROR_MARK) 1861 error ("request for member %qE in something not a structure or union", 1862 component); 1863 1864 return error_mark_node; 1865} 1866 1867/* Given an expression PTR for a pointer, return an expression 1868 for the value pointed to. 1869 ERRORSTRING is the name of the operator to appear in error messages. */ 1870 1871tree 1872build_indirect_ref (tree ptr, const char *errorstring) 1873{ 1874 tree pointer = default_conversion (ptr); 1875 tree type = TREE_TYPE (pointer); 1876 1877 if (TREE_CODE (type) == POINTER_TYPE) 1878 { 1879 if (TREE_CODE (pointer) == CONVERT_EXPR 1880 || TREE_CODE (pointer) == NOP_EXPR 1881 || TREE_CODE (pointer) == VIEW_CONVERT_EXPR) 1882 { 1883 /* If a warning is issued, mark it to avoid duplicates from 1884 the backend. This only needs to be done at 1885 warn_strict_aliasing > 2. */ 1886 if (warn_strict_aliasing > 2) 1887 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (pointer, 0)), 1888 type, TREE_OPERAND (pointer, 0))) 1889 TREE_NO_WARNING (pointer) = 1; 1890 } 1891 1892 if (TREE_CODE (pointer) == ADDR_EXPR 1893 && (TREE_TYPE (TREE_OPERAND (pointer, 0)) 1894 == TREE_TYPE (type))) 1895 return TREE_OPERAND (pointer, 0); 1896 else 1897 { 1898 tree t = TREE_TYPE (type); 1899 tree ref; 1900 1901 ref = build1 (INDIRECT_REF, t, pointer); 1902 1903 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) 1904 { 1905 error ("dereferencing pointer to incomplete type"); 1906 return error_mark_node; 1907 } 1908 if (VOID_TYPE_P (t) && skip_evaluation == 0) 1909 warning (0, "dereferencing %<void *%> pointer"); 1910 1911 /* We *must* set TREE_READONLY when dereferencing a pointer to const, 1912 so that we get the proper error message if the result is used 1913 to assign to. Also, &* is supposed to be a no-op. 1914 And ANSI C seems to specify that the type of the result 1915 should be the const type. */ 1916 /* A de-reference of a pointer to const is not a const. It is valid 1917 to change it via some other pointer. */ 1918 TREE_READONLY (ref) = TYPE_READONLY (t); 1919 TREE_SIDE_EFFECTS (ref) 1920 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer); 1921 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t); 1922 return ref; 1923 } 1924 } 1925 else if (TREE_CODE (pointer) != ERROR_MARK) 1926 error ("invalid type argument of %qs (have %qT)", errorstring, type); 1927 return error_mark_node; 1928} 1929 1930/* This handles expressions of the form "a[i]", which denotes 1931 an array reference. 1932 1933 This is logically equivalent in C to *(a+i), but we may do it differently. 1934 If A is a variable or a member, we generate a primitive ARRAY_REF. 1935 This avoids forcing the array out of registers, and can work on 1936 arrays that are not lvalues (for example, members of structures returned 1937 by functions). */ 1938 1939tree 1940build_array_ref (tree array, tree index) 1941{ 1942 bool swapped = false; 1943 if (TREE_TYPE (array) == error_mark_node 1944 || TREE_TYPE (index) == error_mark_node) 1945 return error_mark_node; 1946 1947 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE 1948 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE) 1949 { 1950 tree temp; 1951 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE 1952 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE) 1953 { 1954 error ("subscripted value is neither array nor pointer"); 1955 return error_mark_node; 1956 } 1957 temp = array; 1958 array = index; 1959 index = temp; 1960 swapped = true; 1961 } 1962 1963 if (!INTEGRAL_TYPE_P (TREE_TYPE (index))) 1964 { 1965 error ("array subscript is not an integer"); 1966 return error_mark_node; 1967 } 1968 1969 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE) 1970 { 1971 error ("subscripted value is pointer to function"); 1972 return error_mark_node; 1973 } 1974 1975 /* ??? Existing practice has been to warn only when the char 1976 index is syntactically the index, not for char[array]. */ 1977 if (!swapped) 1978 warn_array_subscript_with_type_char (index); 1979 1980 /* Apply default promotions *after* noticing character types. */ 1981 index = default_conversion (index); 1982 1983 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE); 1984 1985 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE) 1986 { 1987 tree rval, type; 1988 1989 /* An array that is indexed by a non-constant 1990 cannot be stored in a register; we must be able to do 1991 address arithmetic on its address. 1992 Likewise an array of elements of variable size. */ 1993 if (TREE_CODE (index) != INTEGER_CST 1994 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) 1995 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST)) 1996 { 1997 if (!c_mark_addressable (array)) 1998 return error_mark_node; 1999 } 2000 /* An array that is indexed by a constant value which is not within 2001 the array bounds cannot be stored in a register either; because we 2002 would get a crash in store_bit_field/extract_bit_field when trying 2003 to access a non-existent part of the register. */ 2004 if (TREE_CODE (index) == INTEGER_CST 2005 && TYPE_DOMAIN (TREE_TYPE (array)) 2006 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array)))) 2007 { 2008 if (!c_mark_addressable (array)) 2009 return error_mark_node; 2010 } 2011 2012 if (pedantic) 2013 { 2014 tree foo = array; 2015 while (TREE_CODE (foo) == COMPONENT_REF) 2016 foo = TREE_OPERAND (foo, 0); 2017 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo)) 2018 pedwarn ("ISO C forbids subscripting %<register%> array"); 2019 else if (!flag_isoc99 && !lvalue_p (foo)) 2020 pedwarn ("ISO C90 forbids subscripting non-lvalue array"); 2021 } 2022 2023 type = TREE_TYPE (TREE_TYPE (array)); 2024 if (TREE_CODE (type) != ARRAY_TYPE) 2025 type = TYPE_MAIN_VARIANT (type); 2026 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE); 2027 /* Array ref is const/volatile if the array elements are 2028 or if the array is. */ 2029 TREE_READONLY (rval) 2030 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array))) 2031 | TREE_READONLY (array)); 2032 TREE_SIDE_EFFECTS (rval) 2033 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 2034 | TREE_SIDE_EFFECTS (array)); 2035 TREE_THIS_VOLATILE (rval) 2036 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 2037 /* This was added by rms on 16 Nov 91. 2038 It fixes vol struct foo *a; a->elts[1] 2039 in an inline function. 2040 Hope it doesn't break something else. */ 2041 | TREE_THIS_VOLATILE (array)); 2042 return require_complete_type (fold (rval)); 2043 } 2044 else 2045 { 2046 tree ar = default_conversion (array); 2047 2048 if (ar == error_mark_node) 2049 return ar; 2050 2051 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE); 2052 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE); 2053 2054 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0), 2055 "array indexing"); 2056 } 2057} 2058 2059/* Build an external reference to identifier ID. FUN indicates 2060 whether this will be used for a function call. LOC is the source 2061 location of the identifier. */ 2062tree 2063build_external_ref (tree id, int fun, location_t loc) 2064{ 2065 tree ref; 2066 tree decl = lookup_name (id); 2067 2068 /* In Objective-C, an instance variable (ivar) may be preferred to 2069 whatever lookup_name() found. */ 2070 decl = objc_lookup_ivar (decl, id); 2071 2072 if (decl && decl != error_mark_node) 2073 ref = decl; 2074 else if (fun) 2075 /* Implicit function declaration. */ 2076 ref = implicitly_declare (id); 2077 else if (decl == error_mark_node) 2078 /* Don't complain about something that's already been 2079 complained about. */ 2080 return error_mark_node; 2081 else 2082 { 2083 undeclared_variable (id, loc); 2084 return error_mark_node; 2085 } 2086 2087 if (TREE_TYPE (ref) == error_mark_node) 2088 return error_mark_node; 2089 2090 if (TREE_DEPRECATED (ref)) 2091 warn_deprecated_use (ref); 2092 2093 if (!skip_evaluation) 2094 assemble_external (ref); 2095 TREE_USED (ref) = 1; 2096 2097 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof) 2098 { 2099 if (!in_sizeof && !in_typeof) 2100 C_DECL_USED (ref) = 1; 2101 else if (DECL_INITIAL (ref) == 0 2102 && DECL_EXTERNAL (ref) 2103 && !TREE_PUBLIC (ref)) 2104 record_maybe_used_decl (ref); 2105 } 2106 2107 if (TREE_CODE (ref) == CONST_DECL) 2108 { 2109 used_types_insert (TREE_TYPE (ref)); 2110 ref = DECL_INITIAL (ref); 2111 TREE_CONSTANT (ref) = 1; 2112 TREE_INVARIANT (ref) = 1; 2113 } 2114 else if (current_function_decl != 0 2115 && !DECL_FILE_SCOPE_P (current_function_decl) 2116 && (TREE_CODE (ref) == VAR_DECL 2117 || TREE_CODE (ref) == PARM_DECL 2118 || TREE_CODE (ref) == FUNCTION_DECL)) 2119 { 2120 tree context = decl_function_context (ref); 2121 2122 if (context != 0 && context != current_function_decl) 2123 DECL_NONLOCAL (ref) = 1; 2124 } 2125 /* C99 6.7.4p3: An inline definition of a function with external 2126 linkage ... shall not contain a reference to an identifier with 2127 internal linkage. */ 2128 else if (current_function_decl != 0 2129 && DECL_DECLARED_INLINE_P (current_function_decl) 2130 && DECL_EXTERNAL (current_function_decl) 2131 && VAR_OR_FUNCTION_DECL_P (ref) 2132 && DECL_FILE_SCOPE_P (ref) 2133 && pedantic 2134 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref)) 2135 && ! TREE_PUBLIC (ref)) 2136 pedwarn ("%H%qD is static but used in inline function %qD " 2137 "which is not static", &loc, ref, current_function_decl); 2138 2139 return ref; 2140} 2141 2142/* Record details of decls possibly used inside sizeof or typeof. */ 2143struct maybe_used_decl 2144{ 2145 /* The decl. */ 2146 tree decl; 2147 /* The level seen at (in_sizeof + in_typeof). */ 2148 int level; 2149 /* The next one at this level or above, or NULL. */ 2150 struct maybe_used_decl *next; 2151}; 2152 2153static struct maybe_used_decl *maybe_used_decls; 2154 2155/* Record that DECL, an undefined static function reference seen 2156 inside sizeof or typeof, might be used if the operand of sizeof is 2157 a VLA type or the operand of typeof is a variably modified 2158 type. */ 2159 2160static void 2161record_maybe_used_decl (tree decl) 2162{ 2163 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl); 2164 t->decl = decl; 2165 t->level = in_sizeof + in_typeof; 2166 t->next = maybe_used_decls; 2167 maybe_used_decls = t; 2168} 2169 2170/* Pop the stack of decls possibly used inside sizeof or typeof. If 2171 USED is false, just discard them. If it is true, mark them used 2172 (if no longer inside sizeof or typeof) or move them to the next 2173 level up (if still inside sizeof or typeof). */ 2174 2175void 2176pop_maybe_used (bool used) 2177{ 2178 struct maybe_used_decl *p = maybe_used_decls; 2179 int cur_level = in_sizeof + in_typeof; 2180 while (p && p->level > cur_level) 2181 { 2182 if (used) 2183 { 2184 if (cur_level == 0) 2185 C_DECL_USED (p->decl) = 1; 2186 else 2187 p->level = cur_level; 2188 } 2189 p = p->next; 2190 } 2191 if (!used || cur_level == 0) 2192 maybe_used_decls = p; 2193} 2194 2195/* Return the result of sizeof applied to EXPR. */ 2196 2197struct c_expr 2198c_expr_sizeof_expr (struct c_expr expr) 2199{ 2200 struct c_expr ret; 2201 if (expr.value == error_mark_node) 2202 { 2203 ret.value = error_mark_node; 2204 ret.original_code = ERROR_MARK; 2205 pop_maybe_used (false); 2206 } 2207 else 2208 { 2209 ret.value = c_sizeof (TREE_TYPE (expr.value)); 2210 ret.original_code = ERROR_MARK; 2211 if (c_vla_type_p (TREE_TYPE (expr.value))) 2212 { 2213 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */ 2214 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value); 2215 } 2216 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value))); 2217 } 2218 return ret; 2219} 2220 2221/* Return the result of sizeof applied to T, a structure for the type 2222 name passed to sizeof (rather than the type itself). */ 2223 2224struct c_expr 2225c_expr_sizeof_type (struct c_type_name *t) 2226{ 2227 tree type; 2228 struct c_expr ret; 2229 type = groktypename (t); 2230 ret.value = c_sizeof (type); 2231 ret.original_code = ERROR_MARK; 2232 pop_maybe_used (type != error_mark_node 2233 ? C_TYPE_VARIABLE_SIZE (type) : false); 2234 return ret; 2235} 2236 2237/* Build a function call to function FUNCTION with parameters PARAMS. 2238 PARAMS is a list--a chain of TREE_LIST nodes--in which the 2239 TREE_VALUE of each node is a parameter-expression. 2240 FUNCTION's data type may be a function type or a pointer-to-function. */ 2241 2242tree 2243build_function_call (tree function, tree params) 2244{ 2245 tree fntype, fundecl = 0; 2246 tree coerced_params; 2247 tree name = NULL_TREE, result; 2248 tree tem; 2249 2250 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 2251 STRIP_TYPE_NOPS (function); 2252 2253 /* Convert anything with function type to a pointer-to-function. */ 2254 if (TREE_CODE (function) == FUNCTION_DECL) 2255 { 2256 /* Implement type-directed function overloading for builtins. 2257 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin 2258 handle all the type checking. The result is a complete expression 2259 that implements this function call. */ 2260 tem = resolve_overloaded_builtin (function, params); 2261 if (tem) 2262 return tem; 2263 2264 name = DECL_NAME (function); 2265 fundecl = function; 2266 } 2267 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE) 2268 function = function_to_pointer_conversion (function); 2269 2270 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF 2271 expressions, like those used for ObjC messenger dispatches. */ 2272 function = objc_rewrite_function_call (function, params); 2273 2274 fntype = TREE_TYPE (function); 2275 2276 if (TREE_CODE (fntype) == ERROR_MARK) 2277 return error_mark_node; 2278 2279 if (!(TREE_CODE (fntype) == POINTER_TYPE 2280 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) 2281 { 2282 error ("called object %qE is not a function", function); 2283 return error_mark_node; 2284 } 2285 2286 if (fundecl && TREE_THIS_VOLATILE (fundecl)) 2287 current_function_returns_abnormally = 1; 2288 2289 /* fntype now gets the type of function pointed to. */ 2290 fntype = TREE_TYPE (fntype); 2291 2292 /* Check that the function is called through a compatible prototype. 2293 If it is not, replace the call by a trap, wrapped up in a compound 2294 expression if necessary. This has the nice side-effect to prevent 2295 the tree-inliner from generating invalid assignment trees which may 2296 blow up in the RTL expander later. */ 2297 if ((TREE_CODE (function) == NOP_EXPR 2298 || TREE_CODE (function) == CONVERT_EXPR) 2299 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR 2300 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL 2301 && !comptypes (fntype, TREE_TYPE (tem))) 2302 { 2303 tree return_type = TREE_TYPE (fntype); 2304 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], 2305 NULL_TREE); 2306 2307 /* This situation leads to run-time undefined behavior. We can't, 2308 therefore, simply error unless we can prove that all possible 2309 executions of the program must execute the code. */ 2310 warning (0, "function called through a non-compatible type"); 2311 2312 /* We can, however, treat "undefined" any way we please. 2313 Call abort to encourage the user to fix the program. */ 2314 inform ("if this code is reached, the program will abort"); 2315 2316 if (VOID_TYPE_P (return_type)) 2317 return trap; 2318 else 2319 { 2320 tree rhs; 2321 2322 if (AGGREGATE_TYPE_P (return_type)) 2323 rhs = build_compound_literal (return_type, 2324 build_constructor (return_type, 0)); 2325 else 2326 rhs = fold_convert (return_type, integer_zero_node); 2327 2328 return build2 (COMPOUND_EXPR, return_type, trap, rhs); 2329 } 2330 } 2331 2332 /* Convert the parameters to the types declared in the 2333 function prototype, or apply default promotions. */ 2334 2335 coerced_params 2336 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl); 2337 2338 if (coerced_params == error_mark_node) 2339 return error_mark_node; 2340 2341 /* Check that the arguments to the function are valid. */ 2342 2343 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params, 2344 TYPE_ARG_TYPES (fntype)); 2345 2346 if (require_constant_value) 2347 { 2348 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype), 2349 function, coerced_params, NULL_TREE); 2350 2351 if (TREE_CONSTANT (result) 2352 && (name == NULL_TREE 2353 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) 2354 pedwarn_init ("initializer element is not constant"); 2355 } 2356 else 2357 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype), 2358 function, coerced_params, NULL_TREE); 2359 2360 if (VOID_TYPE_P (TREE_TYPE (result))) 2361 return result; 2362 return require_complete_type (result); 2363} 2364 2365/* Convert the argument expressions in the list VALUES 2366 to the types in the list TYPELIST. The result is a list of converted 2367 argument expressions, unless there are too few arguments in which 2368 case it is error_mark_node. 2369 2370 If TYPELIST is exhausted, or when an element has NULL as its type, 2371 perform the default conversions. 2372 2373 PARMLIST is the chain of parm decls for the function being called. 2374 It may be 0, if that info is not available. 2375 It is used only for generating error messages. 2376 2377 FUNCTION is a tree for the called function. It is used only for 2378 error messages, where it is formatted with %qE. 2379 2380 This is also where warnings about wrong number of args are generated. 2381 2382 Both VALUES and the returned value are chains of TREE_LIST nodes 2383 with the elements of the list in the TREE_VALUE slots of those nodes. */ 2384 2385static tree 2386convert_arguments (tree typelist, tree values, tree function, tree fundecl) 2387{ 2388 tree typetail, valtail; 2389 tree result = NULL; 2390 int parmnum; 2391 tree selector; 2392 2393 /* Change pointer to function to the function itself for 2394 diagnostics. */ 2395 if (TREE_CODE (function) == ADDR_EXPR 2396 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 2397 function = TREE_OPERAND (function, 0); 2398 2399 /* Handle an ObjC selector specially for diagnostics. */ 2400 selector = objc_message_selector (); 2401 2402 /* Scan the given expressions and types, producing individual 2403 converted arguments and pushing them on RESULT in reverse order. */ 2404 2405 for (valtail = values, typetail = typelist, parmnum = 0; 2406 valtail; 2407 valtail = TREE_CHAIN (valtail), parmnum++) 2408 { 2409 tree type = typetail ? TREE_VALUE (typetail) : 0; 2410 tree val = TREE_VALUE (valtail); 2411 tree rname = function; 2412 int argnum = parmnum + 1; 2413 const char *invalid_func_diag; 2414 2415 if (type == void_type_node) 2416 { 2417 error ("too many arguments to function %qE", function); 2418 break; 2419 } 2420 2421 if (selector && argnum > 2) 2422 { 2423 rname = selector; 2424 argnum -= 2; 2425 } 2426 2427 STRIP_TYPE_NOPS (val); 2428 2429 val = require_complete_type (val); 2430 2431 if (type != 0) 2432 { 2433 /* Formal parm type is specified by a function prototype. */ 2434 tree parmval; 2435 2436 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 2437 { 2438 error ("type of formal parameter %d is incomplete", parmnum + 1); 2439 parmval = val; 2440 } 2441 else 2442 { 2443 /* Optionally warn about conversions that 2444 differ from the default conversions. */ 2445 if (warn_conversion || warn_traditional) 2446 { 2447 unsigned int formal_prec = TYPE_PRECISION (type); 2448 2449 if (INTEGRAL_TYPE_P (type) 2450 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2451 warning (0, "passing argument %d of %qE as integer " 2452 "rather than floating due to prototype", 2453 argnum, rname); 2454 if (INTEGRAL_TYPE_P (type) 2455 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2456 warning (0, "passing argument %d of %qE as integer " 2457 "rather than complex due to prototype", 2458 argnum, rname); 2459 else if (TREE_CODE (type) == COMPLEX_TYPE 2460 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2461 warning (0, "passing argument %d of %qE as complex " 2462 "rather than floating due to prototype", 2463 argnum, rname); 2464 else if (TREE_CODE (type) == REAL_TYPE 2465 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2466 warning (0, "passing argument %d of %qE as floating " 2467 "rather than integer due to prototype", 2468 argnum, rname); 2469 else if (TREE_CODE (type) == COMPLEX_TYPE 2470 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2471 warning (0, "passing argument %d of %qE as complex " 2472 "rather than integer due to prototype", 2473 argnum, rname); 2474 else if (TREE_CODE (type) == REAL_TYPE 2475 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2476 warning (0, "passing argument %d of %qE as floating " 2477 "rather than complex due to prototype", 2478 argnum, rname); 2479 /* ??? At some point, messages should be written about 2480 conversions between complex types, but that's too messy 2481 to do now. */ 2482 else if (TREE_CODE (type) == REAL_TYPE 2483 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2484 { 2485 /* Warn if any argument is passed as `float', 2486 since without a prototype it would be `double'. */ 2487 if (formal_prec == TYPE_PRECISION (float_type_node) 2488 && type != dfloat32_type_node) 2489 warning (0, "passing argument %d of %qE as %<float%> " 2490 "rather than %<double%> due to prototype", 2491 argnum, rname); 2492 2493 /* Warn if mismatch between argument and prototype 2494 for decimal float types. Warn of conversions with 2495 binary float types and of precision narrowing due to 2496 prototype. */ 2497 else if (type != TREE_TYPE (val) 2498 && (type == dfloat32_type_node 2499 || type == dfloat64_type_node 2500 || type == dfloat128_type_node 2501 || TREE_TYPE (val) == dfloat32_type_node 2502 || TREE_TYPE (val) == dfloat64_type_node 2503 || TREE_TYPE (val) == dfloat128_type_node) 2504 && (formal_prec 2505 <= TYPE_PRECISION (TREE_TYPE (val)) 2506 || (type == dfloat128_type_node 2507 && (TREE_TYPE (val) 2508 != dfloat64_type_node 2509 && (TREE_TYPE (val) 2510 != dfloat32_type_node))) 2511 || (type == dfloat64_type_node 2512 && (TREE_TYPE (val) 2513 != dfloat32_type_node)))) 2514 warning (0, "passing argument %d of %qE as %qT " 2515 "rather than %qT due to prototype", 2516 argnum, rname, type, TREE_TYPE (val)); 2517 2518 } 2519 /* Detect integer changing in width or signedness. 2520 These warnings are only activated with 2521 -Wconversion, not with -Wtraditional. */ 2522 else if (warn_conversion && INTEGRAL_TYPE_P (type) 2523 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2524 { 2525 tree would_have_been = default_conversion (val); 2526 tree type1 = TREE_TYPE (would_have_been); 2527 2528 if (TREE_CODE (type) == ENUMERAL_TYPE 2529 && (TYPE_MAIN_VARIANT (type) 2530 == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) 2531 /* No warning if function asks for enum 2532 and the actual arg is that enum type. */ 2533 ; 2534 else if (formal_prec != TYPE_PRECISION (type1)) 2535 warning (OPT_Wconversion, "passing argument %d of %qE " 2536 "with different width due to prototype", 2537 argnum, rname); 2538 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1)) 2539 ; 2540 /* Don't complain if the formal parameter type 2541 is an enum, because we can't tell now whether 2542 the value was an enum--even the same enum. */ 2543 else if (TREE_CODE (type) == ENUMERAL_TYPE) 2544 ; 2545 else if (TREE_CODE (val) == INTEGER_CST 2546 && int_fits_type_p (val, type)) 2547 /* Change in signedness doesn't matter 2548 if a constant value is unaffected. */ 2549 ; 2550 /* If the value is extended from a narrower 2551 unsigned type, it doesn't matter whether we 2552 pass it as signed or unsigned; the value 2553 certainly is the same either way. */ 2554 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) 2555 && TYPE_UNSIGNED (TREE_TYPE (val))) 2556 ; 2557 else if (TYPE_UNSIGNED (type)) 2558 warning (OPT_Wconversion, "passing argument %d of %qE " 2559 "as unsigned due to prototype", 2560 argnum, rname); 2561 else 2562 warning (OPT_Wconversion, "passing argument %d of %qE " 2563 "as signed due to prototype", argnum, rname); 2564 } 2565 } 2566 2567 parmval = convert_for_assignment (type, val, ic_argpass, 2568 fundecl, function, 2569 parmnum + 1); 2570 2571 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) 2572 && INTEGRAL_TYPE_P (type) 2573 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 2574 parmval = default_conversion (parmval); 2575 } 2576 result = tree_cons (NULL_TREE, parmval, result); 2577 } 2578 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE 2579 && (TYPE_PRECISION (TREE_TYPE (val)) 2580 < TYPE_PRECISION (double_type_node)) 2581 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val)))) 2582 /* Convert `float' to `double'. */ 2583 result = tree_cons (NULL_TREE, convert (double_type_node, val), result); 2584 else if ((invalid_func_diag = 2585 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val))) 2586 { 2587 error (invalid_func_diag, ""); 2588 return error_mark_node; 2589 } 2590 else 2591 /* Convert `short' and `char' to full-size `int'. */ 2592 result = tree_cons (NULL_TREE, default_conversion (val), result); 2593 2594 if (typetail) 2595 typetail = TREE_CHAIN (typetail); 2596 } 2597 2598 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) 2599 { 2600 error ("too few arguments to function %qE", function); 2601 return error_mark_node; 2602 } 2603 2604 return nreverse (result); 2605} 2606 2607/* This is the entry point used by the parser to build unary operators 2608 in the input. CODE, a tree_code, specifies the unary operator, and 2609 ARG is the operand. For unary plus, the C parser currently uses 2610 CONVERT_EXPR for code. */ 2611 2612struct c_expr 2613parser_build_unary_op (enum tree_code code, struct c_expr arg) 2614{ 2615 struct c_expr result; 2616 2617 result.original_code = ERROR_MARK; 2618 result.value = build_unary_op (code, arg.value, 0); 2619 2620 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value)) 2621 overflow_warning (result.value); 2622 2623 return result; 2624} 2625 2626/* This is the entry point used by the parser to build binary operators 2627 in the input. CODE, a tree_code, specifies the binary operator, and 2628 ARG1 and ARG2 are the operands. In addition to constructing the 2629 expression, we check for operands that were written with other binary 2630 operators in a way that is likely to confuse the user. */ 2631 2632struct c_expr 2633parser_build_binary_op (enum tree_code code, struct c_expr arg1, 2634 struct c_expr arg2) 2635{ 2636 struct c_expr result; 2637 2638 enum tree_code code1 = arg1.original_code; 2639 enum tree_code code2 = arg2.original_code; 2640 2641 result.value = build_binary_op (code, arg1.value, arg2.value, 1); 2642 result.original_code = code; 2643 2644 if (TREE_CODE (result.value) == ERROR_MARK) 2645 return result; 2646 2647 /* Check for cases such as x+y<<z which users are likely 2648 to misinterpret. */ 2649 if (warn_parentheses) 2650 warn_about_parentheses (code, code1, code2); 2651 2652 /* Warn about comparisons against string literals, with the exception 2653 of testing for equality or inequality of a string literal with NULL. */ 2654 if (code == EQ_EXPR || code == NE_EXPR) 2655 { 2656 if ((code1 == STRING_CST && !integer_zerop (arg2.value)) 2657 || (code2 == STRING_CST && !integer_zerop (arg1.value))) 2658 warning (OPT_Waddress, 2659 "comparison with string literal results in unspecified behaviour"); 2660 } 2661 else if (TREE_CODE_CLASS (code) == tcc_comparison 2662 && (code1 == STRING_CST || code2 == STRING_CST)) 2663 warning (OPT_Waddress, 2664 "comparison with string literal results in unspecified behaviour"); 2665 2666 if (TREE_OVERFLOW_P (result.value) 2667 && !TREE_OVERFLOW_P (arg1.value) 2668 && !TREE_OVERFLOW_P (arg2.value)) 2669 overflow_warning (result.value); 2670 2671 return result; 2672} 2673 2674/* Return a tree for the difference of pointers OP0 and OP1. 2675 The resulting tree has type int. */ 2676 2677static tree 2678pointer_diff (tree op0, tree op1) 2679{ 2680 tree restype = ptrdiff_type_node; 2681 2682 tree target_type = TREE_TYPE (TREE_TYPE (op0)); 2683 tree con0, con1, lit0, lit1; 2684 tree orig_op1 = op1; 2685 2686 if (pedantic || warn_pointer_arith) 2687 { 2688 if (TREE_CODE (target_type) == VOID_TYPE) 2689 pedwarn ("pointer of type %<void *%> used in subtraction"); 2690 if (TREE_CODE (target_type) == FUNCTION_TYPE) 2691 pedwarn ("pointer to a function used in subtraction"); 2692 } 2693 2694 /* If the conversion to ptrdiff_type does anything like widening or 2695 converting a partial to an integral mode, we get a convert_expression 2696 that is in the way to do any simplifications. 2697 (fold-const.c doesn't know that the extra bits won't be needed. 2698 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a 2699 different mode in place.) 2700 So first try to find a common term here 'by hand'; we want to cover 2701 at least the cases that occur in legal static initializers. */ 2702 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR) 2703 && (TYPE_PRECISION (TREE_TYPE (op0)) 2704 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0))))) 2705 con0 = TREE_OPERAND (op0, 0); 2706 else 2707 con0 = op0; 2708 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR) 2709 && (TYPE_PRECISION (TREE_TYPE (op1)) 2710 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0))))) 2711 con1 = TREE_OPERAND (op1, 0); 2712 else 2713 con1 = op1; 2714 2715 if (TREE_CODE (con0) == PLUS_EXPR) 2716 { 2717 lit0 = TREE_OPERAND (con0, 1); 2718 con0 = TREE_OPERAND (con0, 0); 2719 } 2720 else 2721 lit0 = integer_zero_node; 2722 2723 if (TREE_CODE (con1) == PLUS_EXPR) 2724 { 2725 lit1 = TREE_OPERAND (con1, 1); 2726 con1 = TREE_OPERAND (con1, 0); 2727 } 2728 else 2729 lit1 = integer_zero_node; 2730 2731 if (operand_equal_p (con0, con1, 0)) 2732 { 2733 op0 = lit0; 2734 op1 = lit1; 2735 } 2736 2737 2738 /* First do the subtraction as integers; 2739 then drop through to build the divide operator. 2740 Do not do default conversions on the minus operator 2741 in case restype is a short type. */ 2742 2743 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), 2744 convert (restype, op1), 0); 2745 /* This generates an error if op1 is pointer to incomplete type. */ 2746 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) 2747 error ("arithmetic on pointer to an incomplete type"); 2748 2749 /* This generates an error if op0 is pointer to incomplete type. */ 2750 op1 = c_size_in_bytes (target_type); 2751 2752 /* Divide by the size, in easiest possible way. */ 2753 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1)); 2754} 2755 2756/* Construct and perhaps optimize a tree representation 2757 for a unary operation. CODE, a tree_code, specifies the operation 2758 and XARG is the operand. 2759 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses 2760 the default promotions (such as from short to int). 2761 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero 2762 allows non-lvalues; this is only used to handle conversion of non-lvalue 2763 arrays to pointers in C99. */ 2764 2765tree 2766build_unary_op (enum tree_code code, tree xarg, int flag) 2767{ 2768 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 2769 tree arg = xarg; 2770 tree argtype = 0; 2771 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); 2772 tree val; 2773 int noconvert = flag; 2774 const char *invalid_op_diag; 2775 2776 if (typecode == ERROR_MARK) 2777 return error_mark_node; 2778 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) 2779 typecode = INTEGER_TYPE; 2780 2781 if ((invalid_op_diag 2782 = targetm.invalid_unary_op (code, TREE_TYPE (xarg)))) 2783 { 2784 error (invalid_op_diag, ""); 2785 return error_mark_node; 2786 } 2787 2788 switch (code) 2789 { 2790 case CONVERT_EXPR: 2791 /* This is used for unary plus, because a CONVERT_EXPR 2792 is enough to prevent anybody from looking inside for 2793 associativity, but won't generate any code. */ 2794 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2795 || typecode == COMPLEX_TYPE 2796 || typecode == VECTOR_TYPE)) 2797 { 2798 error ("wrong type argument to unary plus"); 2799 return error_mark_node; 2800 } 2801 else if (!noconvert) 2802 arg = default_conversion (arg); 2803 arg = non_lvalue (arg); 2804 break; 2805 2806 case NEGATE_EXPR: 2807 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2808 || typecode == COMPLEX_TYPE 2809 || typecode == VECTOR_TYPE)) 2810 { 2811 error ("wrong type argument to unary minus"); 2812 return error_mark_node; 2813 } 2814 else if (!noconvert) 2815 arg = default_conversion (arg); 2816 break; 2817 2818 case BIT_NOT_EXPR: 2819 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) 2820 { 2821 if (!noconvert) 2822 arg = default_conversion (arg); 2823 } 2824 else if (typecode == COMPLEX_TYPE) 2825 { 2826 code = CONJ_EXPR; 2827 if (pedantic) 2828 pedwarn ("ISO C does not support %<~%> for complex conjugation"); 2829 if (!noconvert) 2830 arg = default_conversion (arg); 2831 } 2832 else 2833 { 2834 error ("wrong type argument to bit-complement"); 2835 return error_mark_node; 2836 } 2837 break; 2838 2839 case ABS_EXPR: 2840 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) 2841 { 2842 error ("wrong type argument to abs"); 2843 return error_mark_node; 2844 } 2845 else if (!noconvert) 2846 arg = default_conversion (arg); 2847 break; 2848 2849 case CONJ_EXPR: 2850 /* Conjugating a real value is a no-op, but allow it anyway. */ 2851 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2852 || typecode == COMPLEX_TYPE)) 2853 { 2854 error ("wrong type argument to conjugation"); 2855 return error_mark_node; 2856 } 2857 else if (!noconvert) 2858 arg = default_conversion (arg); 2859 break; 2860 2861 case TRUTH_NOT_EXPR: 2862 if (typecode != INTEGER_TYPE 2863 && typecode != REAL_TYPE && typecode != POINTER_TYPE 2864 && typecode != COMPLEX_TYPE) 2865 { 2866 error ("wrong type argument to unary exclamation mark"); 2867 return error_mark_node; 2868 } 2869 arg = c_objc_common_truthvalue_conversion (arg); 2870 return invert_truthvalue (arg); 2871 2872 case REALPART_EXPR: 2873 if (TREE_CODE (arg) == COMPLEX_CST) 2874 return TREE_REALPART (arg); 2875 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2876 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2877 else 2878 return arg; 2879 2880 case IMAGPART_EXPR: 2881 if (TREE_CODE (arg) == COMPLEX_CST) 2882 return TREE_IMAGPART (arg); 2883 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2884 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2885 else 2886 return convert (TREE_TYPE (arg), integer_zero_node); 2887 2888 case PREINCREMENT_EXPR: 2889 case POSTINCREMENT_EXPR: 2890 case PREDECREMENT_EXPR: 2891 case POSTDECREMENT_EXPR: 2892 2893 /* Increment or decrement the real part of the value, 2894 and don't change the imaginary part. */ 2895 if (typecode == COMPLEX_TYPE) 2896 { 2897 tree real, imag; 2898 2899 if (pedantic) 2900 pedwarn ("ISO C does not support %<++%> and %<--%>" 2901 " on complex types"); 2902 2903 arg = stabilize_reference (arg); 2904 real = build_unary_op (REALPART_EXPR, arg, 1); 2905 imag = build_unary_op (IMAGPART_EXPR, arg, 1); 2906 return build2 (COMPLEX_EXPR, TREE_TYPE (arg), 2907 build_unary_op (code, real, 1), imag); 2908 } 2909 2910 /* Report invalid types. */ 2911 2912 if (typecode != POINTER_TYPE 2913 && typecode != INTEGER_TYPE && typecode != REAL_TYPE) 2914 { 2915 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2916 error ("wrong type argument to increment"); 2917 else 2918 error ("wrong type argument to decrement"); 2919 2920 return error_mark_node; 2921 } 2922 2923 { 2924 tree inc; 2925 tree result_type = TREE_TYPE (arg); 2926 2927 arg = get_unwidened (arg, 0); 2928 argtype = TREE_TYPE (arg); 2929 2930 /* Compute the increment. */ 2931 2932 if (typecode == POINTER_TYPE) 2933 { 2934 /* If pointer target is an undefined struct, 2935 we just cannot know how to do the arithmetic. */ 2936 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) 2937 { 2938 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2939 error ("increment of pointer to unknown structure"); 2940 else 2941 error ("decrement of pointer to unknown structure"); 2942 } 2943 else if ((pedantic || warn_pointer_arith) 2944 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE 2945 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) 2946 { 2947 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2948 pedwarn ("wrong type argument to increment"); 2949 else 2950 pedwarn ("wrong type argument to decrement"); 2951 } 2952 2953 inc = c_size_in_bytes (TREE_TYPE (result_type)); 2954 } 2955 else 2956 inc = integer_one_node; 2957 2958 inc = convert (argtype, inc); 2959 2960 /* Complain about anything else that is not a true lvalue. */ 2961 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 2962 || code == POSTINCREMENT_EXPR) 2963 ? lv_increment 2964 : lv_decrement))) 2965 return error_mark_node; 2966 2967 /* Report a read-only lvalue. */ 2968 if (TREE_READONLY (arg)) 2969 { 2970 readonly_error (arg, 2971 ((code == PREINCREMENT_EXPR 2972 || code == POSTINCREMENT_EXPR) 2973 ? lv_increment : lv_decrement)); 2974 return error_mark_node; 2975 } 2976 2977 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 2978 val = boolean_increment (code, arg); 2979 else 2980 val = build2 (code, TREE_TYPE (arg), arg, inc); 2981 TREE_SIDE_EFFECTS (val) = 1; 2982 val = convert (result_type, val); 2983 if (TREE_CODE (val) != code) 2984 TREE_NO_WARNING (val) = 1; 2985 return val; 2986 } 2987 2988 case ADDR_EXPR: 2989 /* Note that this operation never does default_conversion. */ 2990 2991 /* Let &* cancel out to simplify resulting code. */ 2992 if (TREE_CODE (arg) == INDIRECT_REF) 2993 { 2994 /* Don't let this be an lvalue. */ 2995 if (lvalue_p (TREE_OPERAND (arg, 0))) 2996 return non_lvalue (TREE_OPERAND (arg, 0)); 2997 return TREE_OPERAND (arg, 0); 2998 } 2999 3000 /* For &x[y], return x+y */ 3001 if (TREE_CODE (arg) == ARRAY_REF) 3002 { 3003 tree op0 = TREE_OPERAND (arg, 0); 3004 if (!c_mark_addressable (op0)) 3005 return error_mark_node; 3006 return build_binary_op (PLUS_EXPR, 3007 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE 3008 ? array_to_pointer_conversion (op0) 3009 : op0), 3010 TREE_OPERAND (arg, 1), 1); 3011 } 3012 3013 /* Anything not already handled and not a true memory reference 3014 or a non-lvalue array is an error. */ 3015 else if (typecode != FUNCTION_TYPE && !flag 3016 && !lvalue_or_else (arg, lv_addressof)) 3017 return error_mark_node; 3018 3019 /* Ordinary case; arg is a COMPONENT_REF or a decl. */ 3020 argtype = TREE_TYPE (arg); 3021 3022 /* If the lvalue is const or volatile, merge that into the type 3023 to which the address will point. Note that you can't get a 3024 restricted pointer by taking the address of something, so we 3025 only have to deal with `const' and `volatile' here. */ 3026 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg)) 3027 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) 3028 argtype = c_build_type_variant (argtype, 3029 TREE_READONLY (arg), 3030 TREE_THIS_VOLATILE (arg)); 3031 3032 if (!c_mark_addressable (arg)) 3033 return error_mark_node; 3034 3035 gcc_assert (TREE_CODE (arg) != COMPONENT_REF 3036 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))); 3037 3038 argtype = build_pointer_type (argtype); 3039 3040 /* ??? Cope with user tricks that amount to offsetof. Delete this 3041 when we have proper support for integer constant expressions. */ 3042 val = get_base_address (arg); 3043 if (val && TREE_CODE (val) == INDIRECT_REF 3044 && TREE_CONSTANT (TREE_OPERAND (val, 0))) 3045 { 3046 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1; 3047 3048 op1 = fold_convert (argtype, TREE_OPERAND (val, 0)); 3049 return fold_build2 (PLUS_EXPR, argtype, op0, op1); 3050 } 3051 3052 val = build1 (ADDR_EXPR, argtype, arg); 3053 3054 return val; 3055 3056 default: 3057 gcc_unreachable (); 3058 } 3059 3060 if (argtype == 0) 3061 argtype = TREE_TYPE (arg); 3062 return require_constant_value ? fold_build1_initializer (code, argtype, arg) 3063 : fold_build1 (code, argtype, arg); 3064} 3065 3066/* Return nonzero if REF is an lvalue valid for this language. 3067 Lvalues can be assigned, unless their type has TYPE_READONLY. 3068 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */ 3069 3070static int 3071lvalue_p (tree ref) 3072{ 3073 enum tree_code code = TREE_CODE (ref); 3074 3075 switch (code) 3076 { 3077 case REALPART_EXPR: 3078 case IMAGPART_EXPR: 3079 case COMPONENT_REF: 3080 return lvalue_p (TREE_OPERAND (ref, 0)); 3081 3082 case COMPOUND_LITERAL_EXPR: 3083 case STRING_CST: 3084 return 1; 3085 3086 case INDIRECT_REF: 3087 case ARRAY_REF: 3088 case VAR_DECL: 3089 case PARM_DECL: 3090 case RESULT_DECL: 3091 case ERROR_MARK: 3092 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE 3093 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); 3094 3095 case BIND_EXPR: 3096 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; 3097 3098 default: 3099 return 0; 3100 } 3101} 3102 3103/* Give an error for storing in something that is 'const'. */ 3104 3105static void 3106readonly_error (tree arg, enum lvalue_use use) 3107{ 3108 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement 3109 || use == lv_asm); 3110 /* Using this macro rather than (for example) arrays of messages 3111 ensures that all the format strings are checked at compile 3112 time. */ 3113#define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \ 3114 : (use == lv_increment ? (I) \ 3115 : (use == lv_decrement ? (D) : (AS)))) 3116 if (TREE_CODE (arg) == COMPONENT_REF) 3117 { 3118 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) 3119 readonly_error (TREE_OPERAND (arg, 0), use); 3120 else 3121 error (READONLY_MSG (G_("assignment of read-only member %qD"), 3122 G_("increment of read-only member %qD"), 3123 G_("decrement of read-only member %qD"), 3124 G_("read-only member %qD used as %<asm%> output")), 3125 TREE_OPERAND (arg, 1)); 3126 } 3127 else if (TREE_CODE (arg) == VAR_DECL) 3128 error (READONLY_MSG (G_("assignment of read-only variable %qD"), 3129 G_("increment of read-only variable %qD"), 3130 G_("decrement of read-only variable %qD"), 3131 G_("read-only variable %qD used as %<asm%> output")), 3132 arg); 3133 else 3134 error (READONLY_MSG (G_("assignment of read-only location"), 3135 G_("increment of read-only location"), 3136 G_("decrement of read-only location"), 3137 G_("read-only location used as %<asm%> output"))); 3138} 3139 3140 3141/* Return nonzero if REF is an lvalue valid for this language; 3142 otherwise, print an error message and return zero. USE says 3143 how the lvalue is being used and so selects the error message. */ 3144 3145static int 3146lvalue_or_else (tree ref, enum lvalue_use use) 3147{ 3148 int win = lvalue_p (ref); 3149 3150 if (!win) 3151 lvalue_error (use); 3152 3153 return win; 3154} 3155 3156/* Mark EXP saying that we need to be able to take the 3157 address of it; it should not be allocated in a register. 3158 Returns true if successful. */ 3159 3160bool 3161c_mark_addressable (tree exp) 3162{ 3163 tree x = exp; 3164 3165 while (1) 3166 switch (TREE_CODE (x)) 3167 { 3168 case COMPONENT_REF: 3169 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) 3170 { 3171 error 3172 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1)); 3173 return false; 3174 } 3175 3176 /* ... fall through ... */ 3177 3178 case ADDR_EXPR: 3179 case ARRAY_REF: 3180 case REALPART_EXPR: 3181 case IMAGPART_EXPR: 3182 x = TREE_OPERAND (x, 0); 3183 break; 3184 3185 case COMPOUND_LITERAL_EXPR: 3186 case CONSTRUCTOR: 3187 TREE_ADDRESSABLE (x) = 1; 3188 return true; 3189 3190 case VAR_DECL: 3191 case CONST_DECL: 3192 case PARM_DECL: 3193 case RESULT_DECL: 3194 if (C_DECL_REGISTER (x) 3195 && DECL_NONLOCAL (x)) 3196 { 3197 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3198 { 3199 error 3200 ("global register variable %qD used in nested function", x); 3201 return false; 3202 } 3203 pedwarn ("register variable %qD used in nested function", x); 3204 } 3205 else if (C_DECL_REGISTER (x)) 3206 { 3207 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3208 error ("address of global register variable %qD requested", x); 3209 else 3210 error ("address of register variable %qD requested", x); 3211 return false; 3212 } 3213 3214 /* drops in */ 3215 case FUNCTION_DECL: 3216 TREE_ADDRESSABLE (x) = 1; 3217 /* drops out */ 3218 default: 3219 return true; 3220 } 3221} 3222 3223/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 3224 3225tree 3226build_conditional_expr (tree ifexp, tree op1, tree op2) 3227{ 3228 tree type1; 3229 tree type2; 3230 enum tree_code code1; 3231 enum tree_code code2; 3232 tree result_type = NULL; 3233 tree orig_op1 = op1, orig_op2 = op2; 3234 3235 /* Promote both alternatives. */ 3236 3237 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) 3238 op1 = default_conversion (op1); 3239 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) 3240 op2 = default_conversion (op2); 3241 3242 if (TREE_CODE (ifexp) == ERROR_MARK 3243 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK 3244 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) 3245 return error_mark_node; 3246 3247 type1 = TREE_TYPE (op1); 3248 code1 = TREE_CODE (type1); 3249 type2 = TREE_TYPE (op2); 3250 code2 = TREE_CODE (type2); 3251 3252 /* C90 does not permit non-lvalue arrays in conditional expressions. 3253 In C99 they will be pointers by now. */ 3254 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE) 3255 { 3256 error ("non-lvalue array in conditional expression"); 3257 return error_mark_node; 3258 } 3259 3260 /* Quickly detect the usual case where op1 and op2 have the same type 3261 after promotion. */ 3262 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) 3263 { 3264 if (type1 == type2) 3265 result_type = type1; 3266 else 3267 result_type = TYPE_MAIN_VARIANT (type1); 3268 } 3269 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE 3270 || code1 == COMPLEX_TYPE) 3271 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE 3272 || code2 == COMPLEX_TYPE)) 3273 { 3274 result_type = c_common_type (type1, type2); 3275 3276 /* If -Wsign-compare, warn here if type1 and type2 have 3277 different signedness. We'll promote the signed to unsigned 3278 and later code won't know it used to be different. 3279 Do this check on the original types, so that explicit casts 3280 will be considered, but default promotions won't. */ 3281 if (warn_sign_compare && !skip_evaluation) 3282 { 3283 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 3284 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2)); 3285 3286 if (unsigned_op1 ^ unsigned_op2) 3287 { 3288 bool ovf; 3289 3290 /* Do not warn if the result type is signed, since the 3291 signed type will only be chosen if it can represent 3292 all the values of the unsigned type. */ 3293 if (!TYPE_UNSIGNED (result_type)) 3294 /* OK */; 3295 /* Do not warn if the signed quantity is an unsuffixed 3296 integer literal (or some static constant expression 3297 involving such literals) and it is non-negative. */ 3298 else if ((unsigned_op2 3299 && tree_expr_nonnegative_warnv_p (op1, &ovf)) 3300 || (unsigned_op1 3301 && tree_expr_nonnegative_warnv_p (op2, &ovf))) 3302 /* OK */; 3303 else 3304 warning (0, "signed and unsigned type in conditional expression"); 3305 } 3306 } 3307 } 3308 else if (code1 == VOID_TYPE || code2 == VOID_TYPE) 3309 { 3310 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) 3311 pedwarn ("ISO C forbids conditional expr with only one void side"); 3312 result_type = void_type_node; 3313 } 3314 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) 3315 { 3316 if (comp_target_types (type1, type2)) 3317 result_type = common_pointer_type (type1, type2); 3318 else if (null_pointer_constant_p (orig_op1)) 3319 result_type = qualify_type (type2, type1); 3320 else if (null_pointer_constant_p (orig_op2)) 3321 result_type = qualify_type (type1, type2); 3322 else if (VOID_TYPE_P (TREE_TYPE (type1))) 3323 { 3324 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) 3325 pedwarn ("ISO C forbids conditional expr between " 3326 "%<void *%> and function pointer"); 3327 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), 3328 TREE_TYPE (type2))); 3329 } 3330 else if (VOID_TYPE_P (TREE_TYPE (type2))) 3331 { 3332 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) 3333 pedwarn ("ISO C forbids conditional expr between " 3334 "%<void *%> and function pointer"); 3335 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), 3336 TREE_TYPE (type1))); 3337 } 3338 else 3339 { 3340 pedwarn ("pointer type mismatch in conditional expression"); 3341 result_type = build_pointer_type (void_type_node); 3342 } 3343 } 3344 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) 3345 { 3346 if (!null_pointer_constant_p (orig_op2)) 3347 pedwarn ("pointer/integer type mismatch in conditional expression"); 3348 else 3349 { 3350 op2 = null_pointer_node; 3351 } 3352 result_type = type1; 3353 } 3354 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) 3355 { 3356 if (!null_pointer_constant_p (orig_op1)) 3357 pedwarn ("pointer/integer type mismatch in conditional expression"); 3358 else 3359 { 3360 op1 = null_pointer_node; 3361 } 3362 result_type = type2; 3363 } 3364 3365 if (!result_type) 3366 { 3367 if (flag_cond_mismatch) 3368 result_type = void_type_node; 3369 else 3370 { 3371 error ("type mismatch in conditional expression"); 3372 return error_mark_node; 3373 } 3374 } 3375 3376 /* Merge const and volatile flags of the incoming types. */ 3377 result_type 3378 = build_type_variant (result_type, 3379 TREE_READONLY (op1) || TREE_READONLY (op2), 3380 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); 3381 3382 if (result_type != TREE_TYPE (op1)) 3383 op1 = convert_and_check (result_type, op1); 3384 if (result_type != TREE_TYPE (op2)) 3385 op2 = convert_and_check (result_type, op2); 3386 3387 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2); 3388} 3389 3390/* Return a compound expression that performs two expressions and 3391 returns the value of the second of them. */ 3392 3393tree 3394build_compound_expr (tree expr1, tree expr2) 3395{ 3396 if (!TREE_SIDE_EFFECTS (expr1)) 3397 { 3398 /* The left-hand operand of a comma expression is like an expression 3399 statement: with -Wextra or -Wunused, we should warn if it doesn't have 3400 any side-effects, unless it was explicitly cast to (void). */ 3401 if (warn_unused_value) 3402 { 3403 if (VOID_TYPE_P (TREE_TYPE (expr1)) 3404 && (TREE_CODE (expr1) == NOP_EXPR 3405 || TREE_CODE (expr1) == CONVERT_EXPR)) 3406 ; /* (void) a, b */ 3407 else if (VOID_TYPE_P (TREE_TYPE (expr1)) 3408 && TREE_CODE (expr1) == COMPOUND_EXPR 3409 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR 3410 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR)) 3411 ; /* (void) a, (void) b, c */ 3412 else 3413 warning (0, "left-hand operand of comma expression has no effect"); 3414 } 3415 } 3416 3417 /* With -Wunused, we should also warn if the left-hand operand does have 3418 side-effects, but computes a value which is not used. For example, in 3419 `foo() + bar(), baz()' the result of the `+' operator is not used, 3420 so we should issue a warning. */ 3421 else if (warn_unused_value) 3422 warn_if_unused_value (expr1, input_location); 3423 3424 if (expr2 == error_mark_node) 3425 return error_mark_node; 3426 3427 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2); 3428} 3429 3430/* Build an expression representing a cast to type TYPE of expression EXPR. */ 3431 3432tree 3433build_c_cast (tree type, tree expr) 3434{ 3435 tree value = expr; 3436 3437 if (type == error_mark_node || expr == error_mark_node) 3438 return error_mark_node; 3439 3440 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing 3441 only in <protocol> qualifications. But when constructing cast expressions, 3442 the protocols do matter and must be kept around. */ 3443 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr))) 3444 return build1 (NOP_EXPR, type, expr); 3445 3446 type = TYPE_MAIN_VARIANT (type); 3447 3448 if (TREE_CODE (type) == ARRAY_TYPE) 3449 { 3450 error ("cast specifies array type"); 3451 return error_mark_node; 3452 } 3453 3454 if (TREE_CODE (type) == FUNCTION_TYPE) 3455 { 3456 error ("cast specifies function type"); 3457 return error_mark_node; 3458 } 3459 3460 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) 3461 { 3462 if (pedantic) 3463 { 3464 if (TREE_CODE (type) == RECORD_TYPE 3465 || TREE_CODE (type) == UNION_TYPE) 3466 pedwarn ("ISO C forbids casting nonscalar to the same type"); 3467 } 3468 } 3469 else if (TREE_CODE (type) == UNION_TYPE) 3470 { 3471 tree field; 3472 3473 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3474 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), 3475 TYPE_MAIN_VARIANT (TREE_TYPE (value)))) 3476 break; 3477 3478 if (field) 3479 { 3480 tree t; 3481 3482 if (pedantic) 3483 pedwarn ("ISO C forbids casts to union type"); 3484 t = digest_init (type, 3485 build_constructor_single (type, field, value), 3486 true, 0); 3487 TREE_CONSTANT (t) = TREE_CONSTANT (value); 3488 TREE_INVARIANT (t) = TREE_INVARIANT (value); 3489 return t; 3490 } 3491 error ("cast to union type from type not present in union"); 3492 return error_mark_node; 3493 } 3494 else 3495 { 3496 tree otype, ovalue; 3497 3498 if (type == void_type_node) 3499 return build1 (CONVERT_EXPR, type, value); 3500 3501 otype = TREE_TYPE (value); 3502 3503 /* Optionally warn about potentially worrisome casts. */ 3504 3505 if (warn_cast_qual 3506 && TREE_CODE (type) == POINTER_TYPE 3507 && TREE_CODE (otype) == POINTER_TYPE) 3508 { 3509 tree in_type = type; 3510 tree in_otype = otype; 3511 int added = 0; 3512 int discarded = 0; 3513 3514 /* Check that the qualifiers on IN_TYPE are a superset of 3515 the qualifiers of IN_OTYPE. The outermost level of 3516 POINTER_TYPE nodes is uninteresting and we stop as soon 3517 as we hit a non-POINTER_TYPE node on either type. */ 3518 do 3519 { 3520 in_otype = TREE_TYPE (in_otype); 3521 in_type = TREE_TYPE (in_type); 3522 3523 /* GNU C allows cv-qualified function types. 'const' 3524 means the function is very pure, 'volatile' means it 3525 can't return. We need to warn when such qualifiers 3526 are added, not when they're taken away. */ 3527 if (TREE_CODE (in_otype) == FUNCTION_TYPE 3528 && TREE_CODE (in_type) == FUNCTION_TYPE) 3529 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); 3530 else 3531 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); 3532 } 3533 while (TREE_CODE (in_type) == POINTER_TYPE 3534 && TREE_CODE (in_otype) == POINTER_TYPE); 3535 3536 if (added) 3537 warning (0, "cast adds new qualifiers to function type"); 3538 3539 if (discarded) 3540 /* There are qualifiers present in IN_OTYPE that are not 3541 present in IN_TYPE. */ 3542 warning (0, "cast discards qualifiers from pointer target type"); 3543 } 3544 3545 /* Warn about possible alignment problems. */ 3546 if (STRICT_ALIGNMENT 3547 && TREE_CODE (type) == POINTER_TYPE 3548 && TREE_CODE (otype) == POINTER_TYPE 3549 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE 3550 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3551 /* Don't warn about opaque types, where the actual alignment 3552 restriction is unknown. */ 3553 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE 3554 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) 3555 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) 3556 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) 3557 warning (OPT_Wcast_align, 3558 "cast increases required alignment of target type"); 3559 3560 if (TREE_CODE (type) == INTEGER_TYPE 3561 && TREE_CODE (otype) == POINTER_TYPE 3562 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)) 3563 /* Unlike conversion of integers to pointers, where the 3564 warning is disabled for converting constants because 3565 of cases such as SIG_*, warn about converting constant 3566 pointers to integers. In some cases it may cause unwanted 3567 sign extension, and a warning is appropriate. */ 3568 warning (OPT_Wpointer_to_int_cast, 3569 "cast from pointer to integer of different size"); 3570 3571 if (TREE_CODE (value) == CALL_EXPR 3572 && TREE_CODE (type) != TREE_CODE (otype)) 3573 warning (OPT_Wbad_function_cast, "cast from function call of type %qT " 3574 "to non-matching type %qT", otype, type); 3575 3576 if (TREE_CODE (type) == POINTER_TYPE 3577 && TREE_CODE (otype) == INTEGER_TYPE 3578 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3579 /* Don't warn about converting any constant. */ 3580 && !TREE_CONSTANT (value)) 3581 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer " 3582 "of different size"); 3583 3584 if (warn_strict_aliasing <= 2) 3585 strict_aliasing_warning (otype, type, expr); 3586 3587 /* If pedantic, warn for conversions between function and object 3588 pointer types, except for converting a null pointer constant 3589 to function pointer type. */ 3590 if (pedantic 3591 && TREE_CODE (type) == POINTER_TYPE 3592 && TREE_CODE (otype) == POINTER_TYPE 3593 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE 3594 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) 3595 pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); 3596 3597 if (pedantic 3598 && TREE_CODE (type) == POINTER_TYPE 3599 && TREE_CODE (otype) == POINTER_TYPE 3600 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 3601 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3602 && !null_pointer_constant_p (value)) 3603 pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); 3604 3605 ovalue = value; 3606 value = convert (type, value); 3607 3608 /* Ignore any integer overflow caused by the cast. */ 3609 if (TREE_CODE (value) == INTEGER_CST) 3610 { 3611 if (CONSTANT_CLASS_P (ovalue) 3612 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue))) 3613 { 3614 /* Avoid clobbering a shared constant. */ 3615 value = copy_node (value); 3616 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); 3617 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); 3618 } 3619 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value)) 3620 /* Reset VALUE's overflow flags, ensuring constant sharing. */ 3621 value = build_int_cst_wide (TREE_TYPE (value), 3622 TREE_INT_CST_LOW (value), 3623 TREE_INT_CST_HIGH (value)); 3624 } 3625 } 3626 3627 /* Don't let a cast be an lvalue. */ 3628 if (value == expr) 3629 value = non_lvalue (value); 3630 3631 return value; 3632} 3633 3634/* Interpret a cast of expression EXPR to type TYPE. */ 3635tree 3636c_cast_expr (struct c_type_name *type_name, tree expr) 3637{ 3638 tree type; 3639 int saved_wsp = warn_strict_prototypes; 3640 3641 /* This avoids warnings about unprototyped casts on 3642 integers. E.g. "#define SIG_DFL (void(*)())0". */ 3643 if (TREE_CODE (expr) == INTEGER_CST) 3644 warn_strict_prototypes = 0; 3645 type = groktypename (type_name); 3646 warn_strict_prototypes = saved_wsp; 3647 3648 return build_c_cast (type, expr); 3649} 3650 3651/* Build an assignment expression of lvalue LHS from value RHS. 3652 MODIFYCODE is the code for a binary operator that we use 3653 to combine the old value of LHS with RHS to get the new value. 3654 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ 3655 3656tree 3657build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) 3658{ 3659 tree result; 3660 tree newrhs; 3661 tree lhstype = TREE_TYPE (lhs); 3662 tree olhstype = lhstype; 3663 3664 /* Types that aren't fully specified cannot be used in assignments. */ 3665 lhs = require_complete_type (lhs); 3666 3667 /* Avoid duplicate error messages from operands that had errors. */ 3668 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) 3669 return error_mark_node; 3670 3671 if (!lvalue_or_else (lhs, lv_assign)) 3672 return error_mark_node; 3673 3674 STRIP_TYPE_NOPS (rhs); 3675 3676 newrhs = rhs; 3677 3678 /* If a binary op has been requested, combine the old LHS value with the RHS 3679 producing the value we should actually store into the LHS. */ 3680 3681 if (modifycode != NOP_EXPR) 3682 { 3683 lhs = stabilize_reference (lhs); 3684 newrhs = build_binary_op (modifycode, lhs, rhs, 1); 3685 } 3686 3687 /* Give an error for storing in something that is 'const'. */ 3688 3689 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) 3690 || ((TREE_CODE (lhstype) == RECORD_TYPE 3691 || TREE_CODE (lhstype) == UNION_TYPE) 3692 && C_TYPE_FIELDS_READONLY (lhstype))) 3693 { 3694 readonly_error (lhs, lv_assign); 3695 return error_mark_node; 3696 } 3697 3698 /* If storing into a structure or union member, 3699 it has probably been given type `int'. 3700 Compute the type that would go with 3701 the actual amount of storage the member occupies. */ 3702 3703 if (TREE_CODE (lhs) == COMPONENT_REF 3704 && (TREE_CODE (lhstype) == INTEGER_TYPE 3705 || TREE_CODE (lhstype) == BOOLEAN_TYPE 3706 || TREE_CODE (lhstype) == REAL_TYPE 3707 || TREE_CODE (lhstype) == ENUMERAL_TYPE)) 3708 lhstype = TREE_TYPE (get_unwidened (lhs, 0)); 3709 3710 /* If storing in a field that is in actuality a short or narrower than one, 3711 we must store in the field in its actual type. */ 3712 3713 if (lhstype != TREE_TYPE (lhs)) 3714 { 3715 lhs = copy_node (lhs); 3716 TREE_TYPE (lhs) = lhstype; 3717 } 3718 3719 /* Convert new value to destination type. */ 3720 3721 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign, 3722 NULL_TREE, NULL_TREE, 0); 3723 if (TREE_CODE (newrhs) == ERROR_MARK) 3724 return error_mark_node; 3725 3726 /* Emit ObjC write barrier, if necessary. */ 3727 if (c_dialect_objc () && flag_objc_gc) 3728 { 3729 result = objc_generate_write_barrier (lhs, modifycode, newrhs); 3730 if (result) 3731 return result; 3732 } 3733 3734 /* Scan operands. */ 3735 3736 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs); 3737 TREE_SIDE_EFFECTS (result) = 1; 3738 3739 /* If we got the LHS in a different type for storing in, 3740 convert the result back to the nominal type of LHS 3741 so that the value we return always has the same type 3742 as the LHS argument. */ 3743 3744 if (olhstype == TREE_TYPE (result)) 3745 return result; 3746 return convert_for_assignment (olhstype, result, ic_assign, 3747 NULL_TREE, NULL_TREE, 0); 3748} 3749 3750/* Convert value RHS to type TYPE as preparation for an assignment 3751 to an lvalue of type TYPE. 3752 The real work of conversion is done by `convert'. 3753 The purpose of this function is to generate error messages 3754 for assignments that are not allowed in C. 3755 ERRTYPE says whether it is argument passing, assignment, 3756 initialization or return. 3757 3758 FUNCTION is a tree for the function being called. 3759 PARMNUM is the number of the argument, for printing in error messages. */ 3760 3761static tree 3762convert_for_assignment (tree type, tree rhs, enum impl_conv errtype, 3763 tree fundecl, tree function, int parmnum) 3764{ 3765 enum tree_code codel = TREE_CODE (type); 3766 tree rhstype; 3767 enum tree_code coder; 3768 tree rname = NULL_TREE; 3769 bool objc_ok = false; 3770 3771 if (errtype == ic_argpass || errtype == ic_argpass_nonproto) 3772 { 3773 tree selector; 3774 /* Change pointer to function to the function itself for 3775 diagnostics. */ 3776 if (TREE_CODE (function) == ADDR_EXPR 3777 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 3778 function = TREE_OPERAND (function, 0); 3779 3780 /* Handle an ObjC selector specially for diagnostics. */ 3781 selector = objc_message_selector (); 3782 rname = function; 3783 if (selector && parmnum > 2) 3784 { 3785 rname = selector; 3786 parmnum -= 2; 3787 } 3788 } 3789 3790 /* This macro is used to emit diagnostics to ensure that all format 3791 strings are complete sentences, visible to gettext and checked at 3792 compile time. */ 3793#define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \ 3794 do { \ 3795 switch (errtype) \ 3796 { \ 3797 case ic_argpass: \ 3798 pedwarn (AR, parmnum, rname); \ 3799 break; \ 3800 case ic_argpass_nonproto: \ 3801 warning (0, AR, parmnum, rname); \ 3802 break; \ 3803 case ic_assign: \ 3804 pedwarn (AS); \ 3805 break; \ 3806 case ic_init: \ 3807 pedwarn (IN); \ 3808 break; \ 3809 case ic_return: \ 3810 pedwarn (RE); \ 3811 break; \ 3812 default: \ 3813 gcc_unreachable (); \ 3814 } \ 3815 } while (0) 3816 3817 STRIP_TYPE_NOPS (rhs); 3818 3819 if (optimize && TREE_CODE (rhs) == VAR_DECL 3820 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE) 3821 rhs = decl_constant_value_for_broken_optimization (rhs); 3822 3823 rhstype = TREE_TYPE (rhs); 3824 coder = TREE_CODE (rhstype); 3825 3826 if (coder == ERROR_MARK) 3827 return error_mark_node; 3828 3829 if (c_dialect_objc ()) 3830 { 3831 int parmno; 3832 3833 switch (errtype) 3834 { 3835 case ic_return: 3836 parmno = 0; 3837 break; 3838 3839 case ic_assign: 3840 parmno = -1; 3841 break; 3842 3843 case ic_init: 3844 parmno = -2; 3845 break; 3846 3847 default: 3848 parmno = parmnum; 3849 break; 3850 } 3851 3852 objc_ok = objc_compare_types (type, rhstype, parmno, rname); 3853 } 3854 3855 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) 3856 return rhs; 3857 3858 if (coder == VOID_TYPE) 3859 { 3860 /* Except for passing an argument to an unprototyped function, 3861 this is a constraint violation. When passing an argument to 3862 an unprototyped function, it is compile-time undefined; 3863 making it a constraint in that case was rejected in 3864 DR#252. */ 3865 error ("void value not ignored as it ought to be"); 3866 return error_mark_node; 3867 } 3868 /* A type converts to a reference to it. 3869 This code doesn't fully support references, it's just for the 3870 special case of va_start and va_copy. */ 3871 if (codel == REFERENCE_TYPE 3872 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1) 3873 { 3874 if (!lvalue_p (rhs)) 3875 { 3876 error ("cannot pass rvalue to reference parameter"); 3877 return error_mark_node; 3878 } 3879 if (!c_mark_addressable (rhs)) 3880 return error_mark_node; 3881 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); 3882 3883 /* We already know that these two types are compatible, but they 3884 may not be exactly identical. In fact, `TREE_TYPE (type)' is 3885 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is 3886 likely to be va_list, a typedef to __builtin_va_list, which 3887 is different enough that it will cause problems later. */ 3888 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) 3889 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); 3890 3891 rhs = build1 (NOP_EXPR, type, rhs); 3892 return rhs; 3893 } 3894 /* Some types can interconvert without explicit casts. */ 3895 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE 3896 && vector_types_convertible_p (type, TREE_TYPE (rhs), true)) 3897 return convert (type, rhs); 3898 /* Arithmetic types all interconvert, and enum is treated like int. */ 3899 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 3900 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE 3901 || codel == BOOLEAN_TYPE) 3902 && (coder == INTEGER_TYPE || coder == REAL_TYPE 3903 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE 3904 || coder == BOOLEAN_TYPE)) 3905 return convert_and_check (type, rhs); 3906 3907 /* Aggregates in different TUs might need conversion. */ 3908 if ((codel == RECORD_TYPE || codel == UNION_TYPE) 3909 && codel == coder 3910 && comptypes (type, rhstype)) 3911 return convert_and_check (type, rhs); 3912 3913 /* Conversion to a transparent union from its member types. 3914 This applies only to function arguments. */ 3915 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) 3916 && (errtype == ic_argpass || errtype == ic_argpass_nonproto)) 3917 { 3918 tree memb, marginal_memb = NULL_TREE; 3919 3920 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb)) 3921 { 3922 tree memb_type = TREE_TYPE (memb); 3923 3924 if (comptypes (TYPE_MAIN_VARIANT (memb_type), 3925 TYPE_MAIN_VARIANT (rhstype))) 3926 break; 3927 3928 if (TREE_CODE (memb_type) != POINTER_TYPE) 3929 continue; 3930 3931 if (coder == POINTER_TYPE) 3932 { 3933 tree ttl = TREE_TYPE (memb_type); 3934 tree ttr = TREE_TYPE (rhstype); 3935 3936 /* Any non-function converts to a [const][volatile] void * 3937 and vice versa; otherwise, targets must be the same. 3938 Meanwhile, the lhs target must have all the qualifiers of 3939 the rhs. */ 3940 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3941 || comp_target_types (memb_type, rhstype)) 3942 { 3943 /* If this type won't generate any warnings, use it. */ 3944 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) 3945 || ((TREE_CODE (ttr) == FUNCTION_TYPE 3946 && TREE_CODE (ttl) == FUNCTION_TYPE) 3947 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3948 == TYPE_QUALS (ttr)) 3949 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3950 == TYPE_QUALS (ttl)))) 3951 break; 3952 3953 /* Keep looking for a better type, but remember this one. */ 3954 if (!marginal_memb) 3955 marginal_memb = memb; 3956 } 3957 } 3958 3959 /* Can convert integer zero to any pointer type. */ 3960 if (null_pointer_constant_p (rhs)) 3961 { 3962 rhs = null_pointer_node; 3963 break; 3964 } 3965 } 3966 3967 if (memb || marginal_memb) 3968 { 3969 if (!memb) 3970 { 3971 /* We have only a marginally acceptable member type; 3972 it needs a warning. */ 3973 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb)); 3974 tree ttr = TREE_TYPE (rhstype); 3975 3976 /* Const and volatile mean something different for function 3977 types, so the usual warnings are not appropriate. */ 3978 if (TREE_CODE (ttr) == FUNCTION_TYPE 3979 && TREE_CODE (ttl) == FUNCTION_TYPE) 3980 { 3981 /* Because const and volatile on functions are 3982 restrictions that say the function will not do 3983 certain things, it is okay to use a const or volatile 3984 function where an ordinary one is wanted, but not 3985 vice-versa. */ 3986 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 3987 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE " 3988 "makes qualified function " 3989 "pointer from unqualified"), 3990 G_("assignment makes qualified " 3991 "function pointer from " 3992 "unqualified"), 3993 G_("initialization makes qualified " 3994 "function pointer from " 3995 "unqualified"), 3996 G_("return makes qualified function " 3997 "pointer from unqualified")); 3998 } 3999 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4000 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4001 "qualifiers from pointer target type"), 4002 G_("assignment discards qualifiers " 4003 "from pointer target type"), 4004 G_("initialization discards qualifiers " 4005 "from pointer target type"), 4006 G_("return discards qualifiers from " 4007 "pointer target type")); 4008 4009 memb = marginal_memb; 4010 } 4011 4012 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))) 4013 pedwarn ("ISO C prohibits argument conversion to union type"); 4014 4015 return build_constructor_single (type, memb, rhs); 4016 } 4017 } 4018 4019 /* Conversions among pointers */ 4020 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 4021 && (coder == codel)) 4022 { 4023 tree ttl = TREE_TYPE (type); 4024 tree ttr = TREE_TYPE (rhstype); 4025 tree mvl = ttl; 4026 tree mvr = ttr; 4027 bool is_opaque_pointer; 4028 int target_cmp = 0; /* Cache comp_target_types () result. */ 4029 4030 if (TREE_CODE (mvl) != ARRAY_TYPE) 4031 mvl = TYPE_MAIN_VARIANT (mvl); 4032 if (TREE_CODE (mvr) != ARRAY_TYPE) 4033 mvr = TYPE_MAIN_VARIANT (mvr); 4034 /* Opaque pointers are treated like void pointers. */ 4035 is_opaque_pointer = (targetm.vector_opaque_p (type) 4036 || targetm.vector_opaque_p (rhstype)) 4037 && TREE_CODE (ttl) == VECTOR_TYPE 4038 && TREE_CODE (ttr) == VECTOR_TYPE; 4039 4040 /* C++ does not allow the implicit conversion void* -> T*. However, 4041 for the purpose of reducing the number of false positives, we 4042 tolerate the special case of 4043 4044 int *p = NULL; 4045 4046 where NULL is typically defined in C to be '(void *) 0'. */ 4047 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl)) 4048 warning (OPT_Wc___compat, "request for implicit conversion from " 4049 "%qT to %qT not permitted in C++", rhstype, type); 4050 4051 /* Check if the right-hand side has a format attribute but the 4052 left-hand side doesn't. */ 4053 if (warn_missing_format_attribute 4054 && check_missing_format_attribute (type, rhstype)) 4055 { 4056 switch (errtype) 4057 { 4058 case ic_argpass: 4059 case ic_argpass_nonproto: 4060 warning (OPT_Wmissing_format_attribute, 4061 "argument %d of %qE might be " 4062 "a candidate for a format attribute", 4063 parmnum, rname); 4064 break; 4065 case ic_assign: 4066 warning (OPT_Wmissing_format_attribute, 4067 "assignment left-hand side might be " 4068 "a candidate for a format attribute"); 4069 break; 4070 case ic_init: 4071 warning (OPT_Wmissing_format_attribute, 4072 "initialization left-hand side might be " 4073 "a candidate for a format attribute"); 4074 break; 4075 case ic_return: 4076 warning (OPT_Wmissing_format_attribute, 4077 "return type might be " 4078 "a candidate for a format attribute"); 4079 break; 4080 default: 4081 gcc_unreachable (); 4082 } 4083 } 4084 4085 /* Any non-function converts to a [const][volatile] void * 4086 and vice versa; otherwise, targets must be the same. 4087 Meanwhile, the lhs target must have all the qualifiers of the rhs. */ 4088 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4089 || (target_cmp = comp_target_types (type, rhstype)) 4090 || is_opaque_pointer 4091 || (c_common_unsigned_type (mvl) 4092 == c_common_unsigned_type (mvr))) 4093 { 4094 if (pedantic 4095 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) 4096 || 4097 (VOID_TYPE_P (ttr) 4098 && !null_pointer_constant_p (rhs) 4099 && TREE_CODE (ttl) == FUNCTION_TYPE))) 4100 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of " 4101 "%qE between function pointer " 4102 "and %<void *%>"), 4103 G_("ISO C forbids assignment between " 4104 "function pointer and %<void *%>"), 4105 G_("ISO C forbids initialization between " 4106 "function pointer and %<void *%>"), 4107 G_("ISO C forbids return between function " 4108 "pointer and %<void *%>")); 4109 /* Const and volatile mean something different for function types, 4110 so the usual warnings are not appropriate. */ 4111 else if (TREE_CODE (ttr) != FUNCTION_TYPE 4112 && TREE_CODE (ttl) != FUNCTION_TYPE) 4113 { 4114 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4115 { 4116 /* Types differing only by the presence of the 'volatile' 4117 qualifier are acceptable if the 'volatile' has been added 4118 in by the Objective-C EH machinery. */ 4119 if (!objc_type_quals_match (ttl, ttr)) 4120 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4121 "qualifiers from pointer target type"), 4122 G_("assignment discards qualifiers " 4123 "from pointer target type"), 4124 G_("initialization discards qualifiers " 4125 "from pointer target type"), 4126 G_("return discards qualifiers from " 4127 "pointer target type")); 4128 } 4129 /* If this is not a case of ignoring a mismatch in signedness, 4130 no warning. */ 4131 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4132 || target_cmp) 4133 ; 4134 /* If there is a mismatch, do warn. */ 4135 else if (warn_pointer_sign) 4136 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument " 4137 "%d of %qE differ in signedness"), 4138 G_("pointer targets in assignment " 4139 "differ in signedness"), 4140 G_("pointer targets in initialization " 4141 "differ in signedness"), 4142 G_("pointer targets in return differ " 4143 "in signedness")); 4144 } 4145 else if (TREE_CODE (ttl) == FUNCTION_TYPE 4146 && TREE_CODE (ttr) == FUNCTION_TYPE) 4147 { 4148 /* Because const and volatile on functions are restrictions 4149 that say the function will not do certain things, 4150 it is okay to use a const or volatile function 4151 where an ordinary one is wanted, but not vice-versa. */ 4152 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 4153 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4154 "qualified function pointer " 4155 "from unqualified"), 4156 G_("assignment makes qualified function " 4157 "pointer from unqualified"), 4158 G_("initialization makes qualified " 4159 "function pointer from unqualified"), 4160 G_("return makes qualified function " 4161 "pointer from unqualified")); 4162 } 4163 } 4164 else 4165 /* Avoid warning about the volatile ObjC EH puts on decls. */ 4166 if (!objc_ok) 4167 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from " 4168 "incompatible pointer type"), 4169 G_("assignment from incompatible pointer type"), 4170 G_("initialization from incompatible " 4171 "pointer type"), 4172 G_("return from incompatible pointer type")); 4173 4174 return convert (type, rhs); 4175 } 4176 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) 4177 { 4178 /* ??? This should not be an error when inlining calls to 4179 unprototyped functions. */ 4180 error ("invalid use of non-lvalue array"); 4181 return error_mark_node; 4182 } 4183 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) 4184 { 4185 /* An explicit constant 0 can convert to a pointer, 4186 or one that results from arithmetic, even including 4187 a cast to integer type. */ 4188 if (!null_pointer_constant_p (rhs)) 4189 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4190 "pointer from integer without a cast"), 4191 G_("assignment makes pointer from integer " 4192 "without a cast"), 4193 G_("initialization makes pointer from " 4194 "integer without a cast"), 4195 G_("return makes pointer from integer " 4196 "without a cast")); 4197 4198 return convert (type, rhs); 4199 } 4200 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) 4201 { 4202 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer " 4203 "from pointer without a cast"), 4204 G_("assignment makes integer from pointer " 4205 "without a cast"), 4206 G_("initialization makes integer from pointer " 4207 "without a cast"), 4208 G_("return makes integer from pointer " 4209 "without a cast")); 4210 return convert (type, rhs); 4211 } 4212 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) 4213 return convert (type, rhs); 4214 4215 switch (errtype) 4216 { 4217 case ic_argpass: 4218 case ic_argpass_nonproto: 4219 /* ??? This should not be an error when inlining calls to 4220 unprototyped functions. */ 4221 error ("incompatible type for argument %d of %qE", parmnum, rname); 4222 break; 4223 case ic_assign: 4224 error ("incompatible types in assignment"); 4225 break; 4226 case ic_init: 4227 error ("incompatible types in initialization"); 4228 break; 4229 case ic_return: 4230 error ("incompatible types in return"); 4231 break; 4232 default: 4233 gcc_unreachable (); 4234 } 4235 4236 return error_mark_node; 4237} 4238 4239/* Convert VALUE for assignment into inlined parameter PARM. ARGNUM 4240 is used for error and warning reporting and indicates which argument 4241 is being processed. */ 4242 4243tree 4244c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) 4245{ 4246 tree ret, type; 4247 4248 /* If FN was prototyped at the call site, the value has been converted 4249 already in convert_arguments. 4250 However, we might see a prototype now that was not in place when 4251 the function call was seen, so check that the VALUE actually matches 4252 PARM before taking an early exit. */ 4253 if (!value 4254 || (TYPE_ARG_TYPES (TREE_TYPE (fn)) 4255 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 4256 == TYPE_MAIN_VARIANT (TREE_TYPE (value))))) 4257 return value; 4258 4259 type = TREE_TYPE (parm); 4260 ret = convert_for_assignment (type, value, 4261 ic_argpass_nonproto, fn, 4262 fn, argnum); 4263 if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) 4264 && INTEGRAL_TYPE_P (type) 4265 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 4266 ret = default_conversion (ret); 4267 return ret; 4268} 4269 4270/* If VALUE is a compound expr all of whose expressions are constant, then 4271 return its value. Otherwise, return error_mark_node. 4272 4273 This is for handling COMPOUND_EXPRs as initializer elements 4274 which is allowed with a warning when -pedantic is specified. */ 4275 4276static tree 4277valid_compound_expr_initializer (tree value, tree endtype) 4278{ 4279 if (TREE_CODE (value) == COMPOUND_EXPR) 4280 { 4281 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) 4282 == error_mark_node) 4283 return error_mark_node; 4284 return valid_compound_expr_initializer (TREE_OPERAND (value, 1), 4285 endtype); 4286 } 4287 else if (!initializer_constant_valid_p (value, endtype)) 4288 return error_mark_node; 4289 else 4290 return value; 4291} 4292 4293/* Perform appropriate conversions on the initial value of a variable, 4294 store it in the declaration DECL, 4295 and print any error messages that are appropriate. 4296 If the init is invalid, store an ERROR_MARK. */ 4297 4298void 4299store_init_value (tree decl, tree init) 4300{ 4301 tree value, type; 4302 4303 /* If variable's type was invalidly declared, just ignore it. */ 4304 4305 type = TREE_TYPE (decl); 4306 if (TREE_CODE (type) == ERROR_MARK) 4307 return; 4308 4309 /* Digest the specified initializer into an expression. */ 4310 4311 value = digest_init (type, init, true, TREE_STATIC (decl)); 4312 4313 /* Store the expression if valid; else report error. */ 4314 4315 if (!in_system_header 4316 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl)) 4317 warning (OPT_Wtraditional, "traditional C rejects automatic " 4318 "aggregate initialization"); 4319 4320 DECL_INITIAL (decl) = value; 4321 4322 /* ANSI wants warnings about out-of-range constant initializers. */ 4323 STRIP_TYPE_NOPS (value); 4324 constant_expression_warning (value); 4325 4326 /* Check if we need to set array size from compound literal size. */ 4327 if (TREE_CODE (type) == ARRAY_TYPE 4328 && TYPE_DOMAIN (type) == 0 4329 && value != error_mark_node) 4330 { 4331 tree inside_init = init; 4332 4333 STRIP_TYPE_NOPS (inside_init); 4334 inside_init = fold (inside_init); 4335 4336 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4337 { 4338 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4339 4340 if (TYPE_DOMAIN (TREE_TYPE (cldecl))) 4341 { 4342 /* For int foo[] = (int [3]){1}; we need to set array size 4343 now since later on array initializer will be just the 4344 brace enclosed list of the compound literal. */ 4345 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4346 TREE_TYPE (decl) = type; 4347 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl)); 4348 layout_type (type); 4349 layout_decl (cldecl, 0); 4350 } 4351 } 4352 } 4353} 4354 4355/* Methods for storing and printing names for error messages. */ 4356 4357/* Implement a spelling stack that allows components of a name to be pushed 4358 and popped. Each element on the stack is this structure. */ 4359 4360struct spelling 4361{ 4362 int kind; 4363 union 4364 { 4365 unsigned HOST_WIDE_INT i; 4366 const char *s; 4367 } u; 4368}; 4369 4370#define SPELLING_STRING 1 4371#define SPELLING_MEMBER 2 4372#define SPELLING_BOUNDS 3 4373 4374static struct spelling *spelling; /* Next stack element (unused). */ 4375static struct spelling *spelling_base; /* Spelling stack base. */ 4376static int spelling_size; /* Size of the spelling stack. */ 4377 4378/* Macros to save and restore the spelling stack around push_... functions. 4379 Alternative to SAVE_SPELLING_STACK. */ 4380 4381#define SPELLING_DEPTH() (spelling - spelling_base) 4382#define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) 4383 4384/* Push an element on the spelling stack with type KIND and assign VALUE 4385 to MEMBER. */ 4386 4387#define PUSH_SPELLING(KIND, VALUE, MEMBER) \ 4388{ \ 4389 int depth = SPELLING_DEPTH (); \ 4390 \ 4391 if (depth >= spelling_size) \ 4392 { \ 4393 spelling_size += 10; \ 4394 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \ 4395 spelling_size); \ 4396 RESTORE_SPELLING_DEPTH (depth); \ 4397 } \ 4398 \ 4399 spelling->kind = (KIND); \ 4400 spelling->MEMBER = (VALUE); \ 4401 spelling++; \ 4402} 4403 4404/* Push STRING on the stack. Printed literally. */ 4405 4406static void 4407push_string (const char *string) 4408{ 4409 PUSH_SPELLING (SPELLING_STRING, string, u.s); 4410} 4411 4412/* Push a member name on the stack. Printed as '.' STRING. */ 4413 4414static void 4415push_member_name (tree decl) 4416{ 4417 const char *const string 4418 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>"; 4419 PUSH_SPELLING (SPELLING_MEMBER, string, u.s); 4420} 4421 4422/* Push an array bounds on the stack. Printed as [BOUNDS]. */ 4423 4424static void 4425push_array_bounds (unsigned HOST_WIDE_INT bounds) 4426{ 4427 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); 4428} 4429 4430/* Compute the maximum size in bytes of the printed spelling. */ 4431 4432static int 4433spelling_length (void) 4434{ 4435 int size = 0; 4436 struct spelling *p; 4437 4438 for (p = spelling_base; p < spelling; p++) 4439 { 4440 if (p->kind == SPELLING_BOUNDS) 4441 size += 25; 4442 else 4443 size += strlen (p->u.s) + 1; 4444 } 4445 4446 return size; 4447} 4448 4449/* Print the spelling to BUFFER and return it. */ 4450 4451static char * 4452print_spelling (char *buffer) 4453{ 4454 char *d = buffer; 4455 struct spelling *p; 4456 4457 for (p = spelling_base; p < spelling; p++) 4458 if (p->kind == SPELLING_BOUNDS) 4459 { 4460 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i); 4461 d += strlen (d); 4462 } 4463 else 4464 { 4465 const char *s; 4466 if (p->kind == SPELLING_MEMBER) 4467 *d++ = '.'; 4468 for (s = p->u.s; (*d = *s++); d++) 4469 ; 4470 } 4471 *d++ = '\0'; 4472 return buffer; 4473} 4474 4475/* Issue an error message for a bad initializer component. 4476 MSGID identifies the message. 4477 The component name is taken from the spelling stack. */ 4478 4479void 4480error_init (const char *msgid) 4481{ 4482 char *ofwhat; 4483 4484 error ("%s", _(msgid)); 4485 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4486 if (*ofwhat) 4487 error ("(near initialization for %qs)", ofwhat); 4488} 4489 4490/* Issue a pedantic warning for a bad initializer component. 4491 MSGID identifies the message. 4492 The component name is taken from the spelling stack. */ 4493 4494void 4495pedwarn_init (const char *msgid) 4496{ 4497 char *ofwhat; 4498 4499 pedwarn ("%s", _(msgid)); 4500 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4501 if (*ofwhat) 4502 pedwarn ("(near initialization for %qs)", ofwhat); 4503} 4504 4505/* Issue a warning for a bad initializer component. 4506 MSGID identifies the message. 4507 The component name is taken from the spelling stack. */ 4508 4509static void 4510warning_init (const char *msgid) 4511{ 4512 char *ofwhat; 4513 4514 warning (0, "%s", _(msgid)); 4515 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4516 if (*ofwhat) 4517 warning (0, "(near initialization for %qs)", ofwhat); 4518} 4519 4520/* If TYPE is an array type and EXPR is a parenthesized string 4521 constant, warn if pedantic that EXPR is being used to initialize an 4522 object of type TYPE. */ 4523 4524void 4525maybe_warn_string_init (tree type, struct c_expr expr) 4526{ 4527 if (pedantic 4528 && TREE_CODE (type) == ARRAY_TYPE 4529 && TREE_CODE (expr.value) == STRING_CST 4530 && expr.original_code != STRING_CST) 4531 pedwarn_init ("array initialized from parenthesized string constant"); 4532} 4533 4534/* Digest the parser output INIT as an initializer for type TYPE. 4535 Return a C expression of type TYPE to represent the initial value. 4536 4537 If INIT is a string constant, STRICT_STRING is true if it is 4538 unparenthesized or we should not warn here for it being parenthesized. 4539 For other types of INIT, STRICT_STRING is not used. 4540 4541 REQUIRE_CONSTANT requests an error if non-constant initializers or 4542 elements are seen. */ 4543 4544static tree 4545digest_init (tree type, tree init, bool strict_string, int require_constant) 4546{ 4547 enum tree_code code = TREE_CODE (type); 4548 tree inside_init = init; 4549 4550 if (type == error_mark_node 4551 || !init 4552 || init == error_mark_node 4553 || TREE_TYPE (init) == error_mark_node) 4554 return error_mark_node; 4555 4556 STRIP_TYPE_NOPS (inside_init); 4557 4558 inside_init = fold (inside_init); 4559 4560 /* Initialization of an array of chars from a string constant 4561 optionally enclosed in braces. */ 4562 4563 if (code == ARRAY_TYPE && inside_init 4564 && TREE_CODE (inside_init) == STRING_CST) 4565 { 4566 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); 4567 /* Note that an array could be both an array of character type 4568 and an array of wchar_t if wchar_t is signed char or unsigned 4569 char. */ 4570 bool char_array = (typ1 == char_type_node 4571 || typ1 == signed_char_type_node 4572 || typ1 == unsigned_char_type_node); 4573 bool wchar_array = !!comptypes (typ1, wchar_type_node); 4574 if (char_array || wchar_array) 4575 { 4576 struct c_expr expr; 4577 bool char_string; 4578 expr.value = inside_init; 4579 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK); 4580 maybe_warn_string_init (type, expr); 4581 4582 char_string 4583 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4584 == char_type_node); 4585 4586 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4587 TYPE_MAIN_VARIANT (type))) 4588 return inside_init; 4589 4590 if (!wchar_array && !char_string) 4591 { 4592 error_init ("char-array initialized from wide string"); 4593 return error_mark_node; 4594 } 4595 if (char_string && !char_array) 4596 { 4597 error_init ("wchar_t-array initialized from non-wide string"); 4598 return error_mark_node; 4599 } 4600 4601 TREE_TYPE (inside_init) = type; 4602 if (TYPE_DOMAIN (type) != 0 4603 && TYPE_SIZE (type) != 0 4604 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST 4605 /* Subtract 1 (or sizeof (wchar_t)) 4606 because it's ok to ignore the terminating null char 4607 that is counted in the length of the constant. */ 4608 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), 4609 TREE_STRING_LENGTH (inside_init) 4610 - ((TYPE_PRECISION (typ1) 4611 != TYPE_PRECISION (char_type_node)) 4612 ? (TYPE_PRECISION (wchar_type_node) 4613 / BITS_PER_UNIT) 4614 : 1))) 4615 pedwarn_init ("initializer-string for array of chars is too long"); 4616 4617 return inside_init; 4618 } 4619 else if (INTEGRAL_TYPE_P (typ1)) 4620 { 4621 error_init ("array of inappropriate type initialized " 4622 "from string constant"); 4623 return error_mark_node; 4624 } 4625 } 4626 4627 /* Build a VECTOR_CST from a *constant* vector constructor. If the 4628 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt 4629 below and handle as a constructor. */ 4630 if (code == VECTOR_TYPE 4631 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE 4632 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true) 4633 && TREE_CONSTANT (inside_init)) 4634 { 4635 if (TREE_CODE (inside_init) == VECTOR_CST 4636 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4637 TYPE_MAIN_VARIANT (type))) 4638 return inside_init; 4639 4640 if (TREE_CODE (inside_init) == CONSTRUCTOR) 4641 { 4642 unsigned HOST_WIDE_INT ix; 4643 tree value; 4644 bool constant_p = true; 4645 4646 /* Iterate through elements and check if all constructor 4647 elements are *_CSTs. */ 4648 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value) 4649 if (!CONSTANT_CLASS_P (value)) 4650 { 4651 constant_p = false; 4652 break; 4653 } 4654 4655 if (constant_p) 4656 return build_vector_from_ctor (type, 4657 CONSTRUCTOR_ELTS (inside_init)); 4658 } 4659 } 4660 4661 /* Any type can be initialized 4662 from an expression of the same type, optionally with braces. */ 4663 4664 if (inside_init && TREE_TYPE (inside_init) != 0 4665 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4666 TYPE_MAIN_VARIANT (type)) 4667 || (code == ARRAY_TYPE 4668 && comptypes (TREE_TYPE (inside_init), type)) 4669 || (code == VECTOR_TYPE 4670 && comptypes (TREE_TYPE (inside_init), type)) 4671 || (code == POINTER_TYPE 4672 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4673 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4674 TREE_TYPE (type))))) 4675 { 4676 if (code == POINTER_TYPE) 4677 { 4678 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4679 { 4680 if (TREE_CODE (inside_init) == STRING_CST 4681 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4682 inside_init = array_to_pointer_conversion (inside_init); 4683 else 4684 { 4685 error_init ("invalid use of non-lvalue array"); 4686 return error_mark_node; 4687 } 4688 } 4689 } 4690 4691 if (code == VECTOR_TYPE) 4692 /* Although the types are compatible, we may require a 4693 conversion. */ 4694 inside_init = convert (type, inside_init); 4695 4696 if (require_constant 4697 && (code == VECTOR_TYPE || !flag_isoc99) 4698 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4699 { 4700 /* As an extension, allow initializing objects with static storage 4701 duration with compound literals (which are then treated just as 4702 the brace enclosed list they contain). Also allow this for 4703 vectors, as we can only assign them with compound literals. */ 4704 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4705 inside_init = DECL_INITIAL (decl); 4706 } 4707 4708 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4709 && TREE_CODE (inside_init) != CONSTRUCTOR) 4710 { 4711 error_init ("array initialized from non-constant array expression"); 4712 return error_mark_node; 4713 } 4714 4715 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4716 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4717 4718 /* Compound expressions can only occur here if -pedantic or 4719 -pedantic-errors is specified. In the later case, we always want 4720 an error. In the former case, we simply want a warning. */ 4721 if (require_constant && pedantic 4722 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4723 { 4724 inside_init 4725 = valid_compound_expr_initializer (inside_init, 4726 TREE_TYPE (inside_init)); 4727 if (inside_init == error_mark_node) 4728 error_init ("initializer element is not constant"); 4729 else 4730 pedwarn_init ("initializer element is not constant"); 4731 if (flag_pedantic_errors) 4732 inside_init = error_mark_node; 4733 } 4734 else if (require_constant 4735 && !initializer_constant_valid_p (inside_init, 4736 TREE_TYPE (inside_init))) 4737 { 4738 error_init ("initializer element is not constant"); 4739 inside_init = error_mark_node; 4740 } 4741 4742 /* Added to enable additional -Wmissing-format-attribute warnings. */ 4743 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE) 4744 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE, 4745 NULL_TREE, 0); 4746 return inside_init; 4747 } 4748 4749 /* Handle scalar types, including conversions. */ 4750 4751 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4752 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE 4753 || code == VECTOR_TYPE) 4754 { 4755 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE 4756 && (TREE_CODE (init) == STRING_CST 4757 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR)) 4758 init = array_to_pointer_conversion (init); 4759 inside_init 4760 = convert_for_assignment (type, init, ic_init, 4761 NULL_TREE, NULL_TREE, 0); 4762 4763 /* Check to see if we have already given an error message. */ 4764 if (inside_init == error_mark_node) 4765 ; 4766 else if (require_constant && !TREE_CONSTANT (inside_init)) 4767 { 4768 error_init ("initializer element is not constant"); 4769 inside_init = error_mark_node; 4770 } 4771 else if (require_constant 4772 && !initializer_constant_valid_p (inside_init, 4773 TREE_TYPE (inside_init))) 4774 { 4775 error_init ("initializer element is not computable at load time"); 4776 inside_init = error_mark_node; 4777 } 4778 4779 return inside_init; 4780 } 4781 4782 /* Come here only for records and arrays. */ 4783 4784 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4785 { 4786 error_init ("variable-sized object may not be initialized"); 4787 return error_mark_node; 4788 } 4789 4790 error_init ("invalid initializer"); 4791 return error_mark_node; 4792} 4793 4794/* Handle initializers that use braces. */ 4795 4796/* Type of object we are accumulating a constructor for. 4797 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4798static tree constructor_type; 4799 4800/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4801 left to fill. */ 4802static tree constructor_fields; 4803 4804/* For an ARRAY_TYPE, this is the specified index 4805 at which to store the next element we get. */ 4806static tree constructor_index; 4807 4808/* For an ARRAY_TYPE, this is the maximum index. */ 4809static tree constructor_max_index; 4810 4811/* For a RECORD_TYPE, this is the first field not yet written out. */ 4812static tree constructor_unfilled_fields; 4813 4814/* For an ARRAY_TYPE, this is the index of the first element 4815 not yet written out. */ 4816static tree constructor_unfilled_index; 4817 4818/* In a RECORD_TYPE, the byte index of the next consecutive field. 4819 This is so we can generate gaps between fields, when appropriate. */ 4820static tree constructor_bit_index; 4821 4822/* If we are saving up the elements rather than allocating them, 4823 this is the list of elements so far (in reverse order, 4824 most recent first). */ 4825static VEC(constructor_elt,gc) *constructor_elements; 4826 4827/* 1 if constructor should be incrementally stored into a constructor chain, 4828 0 if all the elements should be kept in AVL tree. */ 4829static int constructor_incremental; 4830 4831/* 1 if so far this constructor's elements are all compile-time constants. */ 4832static int constructor_constant; 4833 4834/* 1 if so far this constructor's elements are all valid address constants. */ 4835static int constructor_simple; 4836 4837/* 1 if this constructor is erroneous so far. */ 4838static int constructor_erroneous; 4839 4840/* Structure for managing pending initializer elements, organized as an 4841 AVL tree. */ 4842 4843struct init_node 4844{ 4845 struct init_node *left, *right; 4846 struct init_node *parent; 4847 int balance; 4848 tree purpose; 4849 tree value; 4850}; 4851 4852/* Tree of pending elements at this constructor level. 4853 These are elements encountered out of order 4854 which belong at places we haven't reached yet in actually 4855 writing the output. 4856 Will never hold tree nodes across GC runs. */ 4857static struct init_node *constructor_pending_elts; 4858 4859/* The SPELLING_DEPTH of this constructor. */ 4860static int constructor_depth; 4861 4862/* DECL node for which an initializer is being read. 4863 0 means we are reading a constructor expression 4864 such as (struct foo) {...}. */ 4865static tree constructor_decl; 4866 4867/* Nonzero if this is an initializer for a top-level decl. */ 4868static int constructor_top_level; 4869 4870/* Nonzero if there were any member designators in this initializer. */ 4871static int constructor_designated; 4872 4873/* Nesting depth of designator list. */ 4874static int designator_depth; 4875 4876/* Nonzero if there were diagnosed errors in this designator list. */ 4877static int designator_erroneous; 4878 4879 4880/* This stack has a level for each implicit or explicit level of 4881 structuring in the initializer, including the outermost one. It 4882 saves the values of most of the variables above. */ 4883 4884struct constructor_range_stack; 4885 4886struct constructor_stack 4887{ 4888 struct constructor_stack *next; 4889 tree type; 4890 tree fields; 4891 tree index; 4892 tree max_index; 4893 tree unfilled_index; 4894 tree unfilled_fields; 4895 tree bit_index; 4896 VEC(constructor_elt,gc) *elements; 4897 struct init_node *pending_elts; 4898 int offset; 4899 int depth; 4900 /* If value nonzero, this value should replace the entire 4901 constructor at this level. */ 4902 struct c_expr replacement_value; 4903 struct constructor_range_stack *range_stack; 4904 char constant; 4905 char simple; 4906 char implicit; 4907 char erroneous; 4908 char outer; 4909 char incremental; 4910 char designated; 4911}; 4912 4913static struct constructor_stack *constructor_stack; 4914 4915/* This stack represents designators from some range designator up to 4916 the last designator in the list. */ 4917 4918struct constructor_range_stack 4919{ 4920 struct constructor_range_stack *next, *prev; 4921 struct constructor_stack *stack; 4922 tree range_start; 4923 tree index; 4924 tree range_end; 4925 tree fields; 4926}; 4927 4928static struct constructor_range_stack *constructor_range_stack; 4929 4930/* This stack records separate initializers that are nested. 4931 Nested initializers can't happen in ANSI C, but GNU C allows them 4932 in cases like { ... (struct foo) { ... } ... }. */ 4933 4934struct initializer_stack 4935{ 4936 struct initializer_stack *next; 4937 tree decl; 4938 struct constructor_stack *constructor_stack; 4939 struct constructor_range_stack *constructor_range_stack; 4940 VEC(constructor_elt,gc) *elements; 4941 struct spelling *spelling; 4942 struct spelling *spelling_base; 4943 int spelling_size; 4944 char top_level; 4945 char require_constant_value; 4946 char require_constant_elements; 4947}; 4948 4949static struct initializer_stack *initializer_stack; 4950 4951/* Prepare to parse and output the initializer for variable DECL. */ 4952 4953void 4954start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level) 4955{ 4956 const char *locus; 4957 struct initializer_stack *p = XNEW (struct initializer_stack); 4958 4959 p->decl = constructor_decl; 4960 p->require_constant_value = require_constant_value; 4961 p->require_constant_elements = require_constant_elements; 4962 p->constructor_stack = constructor_stack; 4963 p->constructor_range_stack = constructor_range_stack; 4964 p->elements = constructor_elements; 4965 p->spelling = spelling; 4966 p->spelling_base = spelling_base; 4967 p->spelling_size = spelling_size; 4968 p->top_level = constructor_top_level; 4969 p->next = initializer_stack; 4970 initializer_stack = p; 4971 4972 constructor_decl = decl; 4973 constructor_designated = 0; 4974 constructor_top_level = top_level; 4975 4976 if (decl != 0 && decl != error_mark_node) 4977 { 4978 require_constant_value = TREE_STATIC (decl); 4979 require_constant_elements 4980 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 4981 /* For a scalar, you can always use any value to initialize, 4982 even within braces. */ 4983 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 4984 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 4985 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 4986 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 4987 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 4988 } 4989 else 4990 { 4991 require_constant_value = 0; 4992 require_constant_elements = 0; 4993 locus = "(anonymous)"; 4994 } 4995 4996 constructor_stack = 0; 4997 constructor_range_stack = 0; 4998 4999 missing_braces_mentioned = 0; 5000 5001 spelling_base = 0; 5002 spelling_size = 0; 5003 RESTORE_SPELLING_DEPTH (0); 5004 5005 if (locus) 5006 push_string (locus); 5007} 5008 5009void 5010finish_init (void) 5011{ 5012 struct initializer_stack *p = initializer_stack; 5013 5014 /* Free the whole constructor stack of this initializer. */ 5015 while (constructor_stack) 5016 { 5017 struct constructor_stack *q = constructor_stack; 5018 constructor_stack = q->next; 5019 free (q); 5020 } 5021 5022 gcc_assert (!constructor_range_stack); 5023 5024 /* Pop back to the data of the outer initializer (if any). */ 5025 free (spelling_base); 5026 5027 constructor_decl = p->decl; 5028 require_constant_value = p->require_constant_value; 5029 require_constant_elements = p->require_constant_elements; 5030 constructor_stack = p->constructor_stack; 5031 constructor_range_stack = p->constructor_range_stack; 5032 constructor_elements = p->elements; 5033 spelling = p->spelling; 5034 spelling_base = p->spelling_base; 5035 spelling_size = p->spelling_size; 5036 constructor_top_level = p->top_level; 5037 initializer_stack = p->next; 5038 free (p); 5039} 5040 5041/* Call here when we see the initializer is surrounded by braces. 5042 This is instead of a call to push_init_level; 5043 it is matched by a call to pop_init_level. 5044 5045 TYPE is the type to initialize, for a constructor expression. 5046 For an initializer for a decl, TYPE is zero. */ 5047 5048void 5049really_start_incremental_init (tree type) 5050{ 5051 struct constructor_stack *p = XNEW (struct constructor_stack); 5052 5053 if (type == 0) 5054 type = TREE_TYPE (constructor_decl); 5055 5056 if (targetm.vector_opaque_p (type)) 5057 error ("opaque vector types cannot be initialized"); 5058 5059 p->type = constructor_type; 5060 p->fields = constructor_fields; 5061 p->index = constructor_index; 5062 p->max_index = constructor_max_index; 5063 p->unfilled_index = constructor_unfilled_index; 5064 p->unfilled_fields = constructor_unfilled_fields; 5065 p->bit_index = constructor_bit_index; 5066 p->elements = constructor_elements; 5067 p->constant = constructor_constant; 5068 p->simple = constructor_simple; 5069 p->erroneous = constructor_erroneous; 5070 p->pending_elts = constructor_pending_elts; 5071 p->depth = constructor_depth; 5072 p->replacement_value.value = 0; 5073 p->replacement_value.original_code = ERROR_MARK; 5074 p->implicit = 0; 5075 p->range_stack = 0; 5076 p->outer = 0; 5077 p->incremental = constructor_incremental; 5078 p->designated = constructor_designated; 5079 p->next = 0; 5080 constructor_stack = p; 5081 5082 constructor_constant = 1; 5083 constructor_simple = 1; 5084 constructor_depth = SPELLING_DEPTH (); 5085 constructor_elements = 0; 5086 constructor_pending_elts = 0; 5087 constructor_type = type; 5088 constructor_incremental = 1; 5089 constructor_designated = 0; 5090 designator_depth = 0; 5091 designator_erroneous = 0; 5092 5093 if (TREE_CODE (constructor_type) == RECORD_TYPE 5094 || TREE_CODE (constructor_type) == UNION_TYPE) 5095 { 5096 constructor_fields = TYPE_FIELDS (constructor_type); 5097 /* Skip any nameless bit fields at the beginning. */ 5098 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5099 && DECL_NAME (constructor_fields) == 0) 5100 constructor_fields = TREE_CHAIN (constructor_fields); 5101 5102 constructor_unfilled_fields = constructor_fields; 5103 constructor_bit_index = bitsize_zero_node; 5104 } 5105 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5106 { 5107 if (TYPE_DOMAIN (constructor_type)) 5108 { 5109 constructor_max_index 5110 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5111 5112 /* Detect non-empty initializations of zero-length arrays. */ 5113 if (constructor_max_index == NULL_TREE 5114 && TYPE_SIZE (constructor_type)) 5115 constructor_max_index = build_int_cst (NULL_TREE, -1); 5116 5117 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5118 to initialize VLAs will cause a proper error; avoid tree 5119 checking errors as well by setting a safe value. */ 5120 if (constructor_max_index 5121 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5122 constructor_max_index = build_int_cst (NULL_TREE, -1); 5123 5124 constructor_index 5125 = convert (bitsizetype, 5126 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5127 } 5128 else 5129 { 5130 constructor_index = bitsize_zero_node; 5131 constructor_max_index = NULL_TREE; 5132 } 5133 5134 constructor_unfilled_index = constructor_index; 5135 } 5136 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5137 { 5138 /* Vectors are like simple fixed-size arrays. */ 5139 constructor_max_index = 5140 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5141 constructor_index = bitsize_zero_node; 5142 constructor_unfilled_index = constructor_index; 5143 } 5144 else 5145 { 5146 /* Handle the case of int x = {5}; */ 5147 constructor_fields = constructor_type; 5148 constructor_unfilled_fields = constructor_type; 5149 } 5150} 5151 5152/* Push down into a subobject, for initialization. 5153 If this is for an explicit set of braces, IMPLICIT is 0. 5154 If it is because the next element belongs at a lower level, 5155 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 5156 5157void 5158push_init_level (int implicit) 5159{ 5160 struct constructor_stack *p; 5161 tree value = NULL_TREE; 5162 5163 /* If we've exhausted any levels that didn't have braces, 5164 pop them now. If implicit == 1, this will have been done in 5165 process_init_element; do not repeat it here because in the case 5166 of excess initializers for an empty aggregate this leads to an 5167 infinite cycle of popping a level and immediately recreating 5168 it. */ 5169 if (implicit != 1) 5170 { 5171 while (constructor_stack->implicit) 5172 { 5173 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5174 || TREE_CODE (constructor_type) == UNION_TYPE) 5175 && constructor_fields == 0) 5176 process_init_element (pop_init_level (1)); 5177 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5178 && constructor_max_index 5179 && tree_int_cst_lt (constructor_max_index, 5180 constructor_index)) 5181 process_init_element (pop_init_level (1)); 5182 else 5183 break; 5184 } 5185 } 5186 5187 /* Unless this is an explicit brace, we need to preserve previous 5188 content if any. */ 5189 if (implicit) 5190 { 5191 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5192 || TREE_CODE (constructor_type) == UNION_TYPE) 5193 && constructor_fields) 5194 value = find_init_member (constructor_fields); 5195 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5196 value = find_init_member (constructor_index); 5197 } 5198 5199 p = XNEW (struct constructor_stack); 5200 p->type = constructor_type; 5201 p->fields = constructor_fields; 5202 p->index = constructor_index; 5203 p->max_index = constructor_max_index; 5204 p->unfilled_index = constructor_unfilled_index; 5205 p->unfilled_fields = constructor_unfilled_fields; 5206 p->bit_index = constructor_bit_index; 5207 p->elements = constructor_elements; 5208 p->constant = constructor_constant; 5209 p->simple = constructor_simple; 5210 p->erroneous = constructor_erroneous; 5211 p->pending_elts = constructor_pending_elts; 5212 p->depth = constructor_depth; 5213 p->replacement_value.value = 0; 5214 p->replacement_value.original_code = ERROR_MARK; 5215 p->implicit = implicit; 5216 p->outer = 0; 5217 p->incremental = constructor_incremental; 5218 p->designated = constructor_designated; 5219 p->next = constructor_stack; 5220 p->range_stack = 0; 5221 constructor_stack = p; 5222 5223 constructor_constant = 1; 5224 constructor_simple = 1; 5225 constructor_depth = SPELLING_DEPTH (); 5226 constructor_elements = 0; 5227 constructor_incremental = 1; 5228 constructor_designated = 0; 5229 constructor_pending_elts = 0; 5230 if (!implicit) 5231 { 5232 p->range_stack = constructor_range_stack; 5233 constructor_range_stack = 0; 5234 designator_depth = 0; 5235 designator_erroneous = 0; 5236 } 5237 5238 /* Don't die if an entire brace-pair level is superfluous 5239 in the containing level. */ 5240 if (constructor_type == 0) 5241 ; 5242 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5243 || TREE_CODE (constructor_type) == UNION_TYPE) 5244 { 5245 /* Don't die if there are extra init elts at the end. */ 5246 if (constructor_fields == 0) 5247 constructor_type = 0; 5248 else 5249 { 5250 constructor_type = TREE_TYPE (constructor_fields); 5251 push_member_name (constructor_fields); 5252 constructor_depth++; 5253 } 5254 } 5255 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5256 { 5257 constructor_type = TREE_TYPE (constructor_type); 5258 push_array_bounds (tree_low_cst (constructor_index, 1)); 5259 constructor_depth++; 5260 } 5261 5262 if (constructor_type == 0) 5263 { 5264 error_init ("extra brace group at end of initializer"); 5265 constructor_fields = 0; 5266 constructor_unfilled_fields = 0; 5267 return; 5268 } 5269 5270 if (value && TREE_CODE (value) == CONSTRUCTOR) 5271 { 5272 constructor_constant = TREE_CONSTANT (value); 5273 constructor_simple = TREE_STATIC (value); 5274 constructor_elements = CONSTRUCTOR_ELTS (value); 5275 if (!VEC_empty (constructor_elt, constructor_elements) 5276 && (TREE_CODE (constructor_type) == RECORD_TYPE 5277 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 5278 set_nonincremental_init (); 5279 } 5280 5281 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 5282 { 5283 missing_braces_mentioned = 1; 5284 warning_init ("missing braces around initializer"); 5285 } 5286 5287 if (TREE_CODE (constructor_type) == RECORD_TYPE 5288 || TREE_CODE (constructor_type) == UNION_TYPE) 5289 { 5290 constructor_fields = TYPE_FIELDS (constructor_type); 5291 /* Skip any nameless bit fields at the beginning. */ 5292 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5293 && DECL_NAME (constructor_fields) == 0) 5294 constructor_fields = TREE_CHAIN (constructor_fields); 5295 5296 constructor_unfilled_fields = constructor_fields; 5297 constructor_bit_index = bitsize_zero_node; 5298 } 5299 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5300 { 5301 /* Vectors are like simple fixed-size arrays. */ 5302 constructor_max_index = 5303 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5304 constructor_index = convert (bitsizetype, integer_zero_node); 5305 constructor_unfilled_index = constructor_index; 5306 } 5307 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5308 { 5309 if (TYPE_DOMAIN (constructor_type)) 5310 { 5311 constructor_max_index 5312 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5313 5314 /* Detect non-empty initializations of zero-length arrays. */ 5315 if (constructor_max_index == NULL_TREE 5316 && TYPE_SIZE (constructor_type)) 5317 constructor_max_index = build_int_cst (NULL_TREE, -1); 5318 5319 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5320 to initialize VLAs will cause a proper error; avoid tree 5321 checking errors as well by setting a safe value. */ 5322 if (constructor_max_index 5323 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5324 constructor_max_index = build_int_cst (NULL_TREE, -1); 5325 5326 constructor_index 5327 = convert (bitsizetype, 5328 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5329 } 5330 else 5331 constructor_index = bitsize_zero_node; 5332 5333 constructor_unfilled_index = constructor_index; 5334 if (value && TREE_CODE (value) == STRING_CST) 5335 { 5336 /* We need to split the char/wchar array into individual 5337 characters, so that we don't have to special case it 5338 everywhere. */ 5339 set_nonincremental_init_from_string (value); 5340 } 5341 } 5342 else 5343 { 5344 if (constructor_type != error_mark_node) 5345 warning_init ("braces around scalar initializer"); 5346 constructor_fields = constructor_type; 5347 constructor_unfilled_fields = constructor_type; 5348 } 5349} 5350 5351/* At the end of an implicit or explicit brace level, 5352 finish up that level of constructor. If a single expression 5353 with redundant braces initialized that level, return the 5354 c_expr structure for that expression. Otherwise, the original_code 5355 element is set to ERROR_MARK. 5356 If we were outputting the elements as they are read, return 0 as the value 5357 from inner levels (process_init_element ignores that), 5358 but return error_mark_node as the value from the outermost level 5359 (that's what we want to put in DECL_INITIAL). 5360 Otherwise, return a CONSTRUCTOR expression as the value. */ 5361 5362struct c_expr 5363pop_init_level (int implicit) 5364{ 5365 struct constructor_stack *p; 5366 struct c_expr ret; 5367 ret.value = 0; 5368 ret.original_code = ERROR_MARK; 5369 5370 if (implicit == 0) 5371 { 5372 /* When we come to an explicit close brace, 5373 pop any inner levels that didn't have explicit braces. */ 5374 while (constructor_stack->implicit) 5375 process_init_element (pop_init_level (1)); 5376 5377 gcc_assert (!constructor_range_stack); 5378 } 5379 5380 /* Now output all pending elements. */ 5381 constructor_incremental = 1; 5382 output_pending_init_elements (1); 5383 5384 p = constructor_stack; 5385 5386 /* Error for initializing a flexible array member, or a zero-length 5387 array member in an inappropriate context. */ 5388 if (constructor_type && constructor_fields 5389 && TREE_CODE (constructor_type) == ARRAY_TYPE 5390 && TYPE_DOMAIN (constructor_type) 5391 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 5392 { 5393 /* Silently discard empty initializations. The parser will 5394 already have pedwarned for empty brackets. */ 5395 if (integer_zerop (constructor_unfilled_index)) 5396 constructor_type = NULL_TREE; 5397 else 5398 { 5399 gcc_assert (!TYPE_SIZE (constructor_type)); 5400 5401 if (constructor_depth > 2) 5402 error_init ("initialization of flexible array member in a nested context"); 5403 else if (pedantic) 5404 pedwarn_init ("initialization of a flexible array member"); 5405 5406 /* We have already issued an error message for the existence 5407 of a flexible array member not at the end of the structure. 5408 Discard the initializer so that we do not die later. */ 5409 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 5410 constructor_type = NULL_TREE; 5411 } 5412 } 5413 5414 /* Warn when some struct elements are implicitly initialized to zero. */ 5415 if (warn_missing_field_initializers 5416 && constructor_type 5417 && TREE_CODE (constructor_type) == RECORD_TYPE 5418 && constructor_unfilled_fields) 5419 { 5420 /* Do not warn for flexible array members or zero-length arrays. */ 5421 while (constructor_unfilled_fields 5422 && (!DECL_SIZE (constructor_unfilled_fields) 5423 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 5424 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5425 5426 /* Do not warn if this level of the initializer uses member 5427 designators; it is likely to be deliberate. */ 5428 if (constructor_unfilled_fields && !constructor_designated) 5429 { 5430 push_member_name (constructor_unfilled_fields); 5431 warning_init ("missing initializer"); 5432 RESTORE_SPELLING_DEPTH (constructor_depth); 5433 } 5434 } 5435 5436 /* Pad out the end of the structure. */ 5437 if (p->replacement_value.value) 5438 /* If this closes a superfluous brace pair, 5439 just pass out the element between them. */ 5440 ret = p->replacement_value; 5441 else if (constructor_type == 0) 5442 ; 5443 else if (TREE_CODE (constructor_type) != RECORD_TYPE 5444 && TREE_CODE (constructor_type) != UNION_TYPE 5445 && TREE_CODE (constructor_type) != ARRAY_TYPE 5446 && TREE_CODE (constructor_type) != VECTOR_TYPE) 5447 { 5448 /* A nonincremental scalar initializer--just return 5449 the element, after verifying there is just one. */ 5450 if (VEC_empty (constructor_elt,constructor_elements)) 5451 { 5452 if (!constructor_erroneous) 5453 error_init ("empty scalar initializer"); 5454 ret.value = error_mark_node; 5455 } 5456 else if (VEC_length (constructor_elt,constructor_elements) != 1) 5457 { 5458 error_init ("extra elements in scalar initializer"); 5459 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5460 } 5461 else 5462 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5463 } 5464 else 5465 { 5466 if (constructor_erroneous) 5467 ret.value = error_mark_node; 5468 else 5469 { 5470 ret.value = build_constructor (constructor_type, 5471 constructor_elements); 5472 if (constructor_constant) 5473 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1; 5474 if (constructor_constant && constructor_simple) 5475 TREE_STATIC (ret.value) = 1; 5476 } 5477 } 5478 5479 constructor_type = p->type; 5480 constructor_fields = p->fields; 5481 constructor_index = p->index; 5482 constructor_max_index = p->max_index; 5483 constructor_unfilled_index = p->unfilled_index; 5484 constructor_unfilled_fields = p->unfilled_fields; 5485 constructor_bit_index = p->bit_index; 5486 constructor_elements = p->elements; 5487 constructor_constant = p->constant; 5488 constructor_simple = p->simple; 5489 constructor_erroneous = p->erroneous; 5490 constructor_incremental = p->incremental; 5491 constructor_designated = p->designated; 5492 constructor_pending_elts = p->pending_elts; 5493 constructor_depth = p->depth; 5494 if (!p->implicit) 5495 constructor_range_stack = p->range_stack; 5496 RESTORE_SPELLING_DEPTH (constructor_depth); 5497 5498 constructor_stack = p->next; 5499 free (p); 5500 5501 if (ret.value == 0 && constructor_stack == 0) 5502 ret.value = error_mark_node; 5503 return ret; 5504} 5505 5506/* Common handling for both array range and field name designators. 5507 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 5508 5509static int 5510set_designator (int array) 5511{ 5512 tree subtype; 5513 enum tree_code subcode; 5514 5515 /* Don't die if an entire brace-pair level is superfluous 5516 in the containing level. */ 5517 if (constructor_type == 0) 5518 return 1; 5519 5520 /* If there were errors in this designator list already, bail out 5521 silently. */ 5522 if (designator_erroneous) 5523 return 1; 5524 5525 if (!designator_depth) 5526 { 5527 gcc_assert (!constructor_range_stack); 5528 5529 /* Designator list starts at the level of closest explicit 5530 braces. */ 5531 while (constructor_stack->implicit) 5532 process_init_element (pop_init_level (1)); 5533 constructor_designated = 1; 5534 return 0; 5535 } 5536 5537 switch (TREE_CODE (constructor_type)) 5538 { 5539 case RECORD_TYPE: 5540 case UNION_TYPE: 5541 subtype = TREE_TYPE (constructor_fields); 5542 if (subtype != error_mark_node) 5543 subtype = TYPE_MAIN_VARIANT (subtype); 5544 break; 5545 case ARRAY_TYPE: 5546 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5547 break; 5548 default: 5549 gcc_unreachable (); 5550 } 5551 5552 subcode = TREE_CODE (subtype); 5553 if (array && subcode != ARRAY_TYPE) 5554 { 5555 error_init ("array index in non-array initializer"); 5556 return 1; 5557 } 5558 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5559 { 5560 error_init ("field name not in record or union initializer"); 5561 return 1; 5562 } 5563 5564 constructor_designated = 1; 5565 push_init_level (2); 5566 return 0; 5567} 5568 5569/* If there are range designators in designator list, push a new designator 5570 to constructor_range_stack. RANGE_END is end of such stack range or 5571 NULL_TREE if there is no range designator at this level. */ 5572 5573static void 5574push_range_stack (tree range_end) 5575{ 5576 struct constructor_range_stack *p; 5577 5578 p = GGC_NEW (struct constructor_range_stack); 5579 p->prev = constructor_range_stack; 5580 p->next = 0; 5581 p->fields = constructor_fields; 5582 p->range_start = constructor_index; 5583 p->index = constructor_index; 5584 p->stack = constructor_stack; 5585 p->range_end = range_end; 5586 if (constructor_range_stack) 5587 constructor_range_stack->next = p; 5588 constructor_range_stack = p; 5589} 5590 5591/* Within an array initializer, specify the next index to be initialized. 5592 FIRST is that index. If LAST is nonzero, then initialize a range 5593 of indices, running from FIRST through LAST. */ 5594 5595void 5596set_init_index (tree first, tree last) 5597{ 5598 if (set_designator (1)) 5599 return; 5600 5601 designator_erroneous = 1; 5602 5603 if (!INTEGRAL_TYPE_P (TREE_TYPE (first)) 5604 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last)))) 5605 { 5606 error_init ("array index in initializer not of integer type"); 5607 return; 5608 } 5609 5610 if (TREE_CODE (first) != INTEGER_CST) 5611 error_init ("nonconstant array index in initializer"); 5612 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5613 error_init ("nonconstant array index in initializer"); 5614 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5615 error_init ("array index in non-array initializer"); 5616 else if (tree_int_cst_sgn (first) == -1) 5617 error_init ("array index in initializer exceeds array bounds"); 5618 else if (constructor_max_index 5619 && tree_int_cst_lt (constructor_max_index, first)) 5620 error_init ("array index in initializer exceeds array bounds"); 5621 else 5622 { 5623 constructor_index = convert (bitsizetype, first); 5624 5625 if (last) 5626 { 5627 if (tree_int_cst_equal (first, last)) 5628 last = 0; 5629 else if (tree_int_cst_lt (last, first)) 5630 { 5631 error_init ("empty index range in initializer"); 5632 last = 0; 5633 } 5634 else 5635 { 5636 last = convert (bitsizetype, last); 5637 if (constructor_max_index != 0 5638 && tree_int_cst_lt (constructor_max_index, last)) 5639 { 5640 error_init ("array index range in initializer exceeds array bounds"); 5641 last = 0; 5642 } 5643 } 5644 } 5645 5646 designator_depth++; 5647 designator_erroneous = 0; 5648 if (constructor_range_stack || last) 5649 push_range_stack (last); 5650 } 5651} 5652 5653/* Within a struct initializer, specify the next field to be initialized. */ 5654 5655void 5656set_init_label (tree fieldname) 5657{ 5658 tree tail; 5659 5660 if (set_designator (0)) 5661 return; 5662 5663 designator_erroneous = 1; 5664 5665 if (TREE_CODE (constructor_type) != RECORD_TYPE 5666 && TREE_CODE (constructor_type) != UNION_TYPE) 5667 { 5668 error_init ("field name not in record or union initializer"); 5669 return; 5670 } 5671 5672 for (tail = TYPE_FIELDS (constructor_type); tail; 5673 tail = TREE_CHAIN (tail)) 5674 { 5675 if (DECL_NAME (tail) == fieldname) 5676 break; 5677 } 5678 5679 if (tail == 0) 5680 error ("unknown field %qE specified in initializer", fieldname); 5681 else 5682 { 5683 constructor_fields = tail; 5684 designator_depth++; 5685 designator_erroneous = 0; 5686 if (constructor_range_stack) 5687 push_range_stack (NULL_TREE); 5688 } 5689} 5690 5691/* Add a new initializer to the tree of pending initializers. PURPOSE 5692 identifies the initializer, either array index or field in a structure. 5693 VALUE is the value of that index or field. */ 5694 5695static void 5696add_pending_init (tree purpose, tree value) 5697{ 5698 struct init_node *p, **q, *r; 5699 5700 q = &constructor_pending_elts; 5701 p = 0; 5702 5703 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5704 { 5705 while (*q != 0) 5706 { 5707 p = *q; 5708 if (tree_int_cst_lt (purpose, p->purpose)) 5709 q = &p->left; 5710 else if (tree_int_cst_lt (p->purpose, purpose)) 5711 q = &p->right; 5712 else 5713 { 5714 if (TREE_SIDE_EFFECTS (p->value)) 5715 warning_init ("initialized field with side-effects overwritten"); 5716 else if (warn_override_init) 5717 warning_init ("initialized field overwritten"); 5718 p->value = value; 5719 return; 5720 } 5721 } 5722 } 5723 else 5724 { 5725 tree bitpos; 5726 5727 bitpos = bit_position (purpose); 5728 while (*q != NULL) 5729 { 5730 p = *q; 5731 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5732 q = &p->left; 5733 else if (p->purpose != purpose) 5734 q = &p->right; 5735 else 5736 { 5737 if (TREE_SIDE_EFFECTS (p->value)) 5738 warning_init ("initialized field with side-effects overwritten"); 5739 else if (warn_override_init) 5740 warning_init ("initialized field overwritten"); 5741 p->value = value; 5742 return; 5743 } 5744 } 5745 } 5746 5747 r = GGC_NEW (struct init_node); 5748 r->purpose = purpose; 5749 r->value = value; 5750 5751 *q = r; 5752 r->parent = p; 5753 r->left = 0; 5754 r->right = 0; 5755 r->balance = 0; 5756 5757 while (p) 5758 { 5759 struct init_node *s; 5760 5761 if (r == p->left) 5762 { 5763 if (p->balance == 0) 5764 p->balance = -1; 5765 else if (p->balance < 0) 5766 { 5767 if (r->balance < 0) 5768 { 5769 /* L rotation. */ 5770 p->left = r->right; 5771 if (p->left) 5772 p->left->parent = p; 5773 r->right = p; 5774 5775 p->balance = 0; 5776 r->balance = 0; 5777 5778 s = p->parent; 5779 p->parent = r; 5780 r->parent = s; 5781 if (s) 5782 { 5783 if (s->left == p) 5784 s->left = r; 5785 else 5786 s->right = r; 5787 } 5788 else 5789 constructor_pending_elts = r; 5790 } 5791 else 5792 { 5793 /* LR rotation. */ 5794 struct init_node *t = r->right; 5795 5796 r->right = t->left; 5797 if (r->right) 5798 r->right->parent = r; 5799 t->left = r; 5800 5801 p->left = t->right; 5802 if (p->left) 5803 p->left->parent = p; 5804 t->right = p; 5805 5806 p->balance = t->balance < 0; 5807 r->balance = -(t->balance > 0); 5808 t->balance = 0; 5809 5810 s = p->parent; 5811 p->parent = t; 5812 r->parent = t; 5813 t->parent = s; 5814 if (s) 5815 { 5816 if (s->left == p) 5817 s->left = t; 5818 else 5819 s->right = t; 5820 } 5821 else 5822 constructor_pending_elts = t; 5823 } 5824 break; 5825 } 5826 else 5827 { 5828 /* p->balance == +1; growth of left side balances the node. */ 5829 p->balance = 0; 5830 break; 5831 } 5832 } 5833 else /* r == p->right */ 5834 { 5835 if (p->balance == 0) 5836 /* Growth propagation from right side. */ 5837 p->balance++; 5838 else if (p->balance > 0) 5839 { 5840 if (r->balance > 0) 5841 { 5842 /* R rotation. */ 5843 p->right = r->left; 5844 if (p->right) 5845 p->right->parent = p; 5846 r->left = p; 5847 5848 p->balance = 0; 5849 r->balance = 0; 5850 5851 s = p->parent; 5852 p->parent = r; 5853 r->parent = s; 5854 if (s) 5855 { 5856 if (s->left == p) 5857 s->left = r; 5858 else 5859 s->right = r; 5860 } 5861 else 5862 constructor_pending_elts = r; 5863 } 5864 else /* r->balance == -1 */ 5865 { 5866 /* RL rotation */ 5867 struct init_node *t = r->left; 5868 5869 r->left = t->right; 5870 if (r->left) 5871 r->left->parent = r; 5872 t->right = r; 5873 5874 p->right = t->left; 5875 if (p->right) 5876 p->right->parent = p; 5877 t->left = p; 5878 5879 r->balance = (t->balance < 0); 5880 p->balance = -(t->balance > 0); 5881 t->balance = 0; 5882 5883 s = p->parent; 5884 p->parent = t; 5885 r->parent = t; 5886 t->parent = s; 5887 if (s) 5888 { 5889 if (s->left == p) 5890 s->left = t; 5891 else 5892 s->right = t; 5893 } 5894 else 5895 constructor_pending_elts = t; 5896 } 5897 break; 5898 } 5899 else 5900 { 5901 /* p->balance == -1; growth of right side balances the node. */ 5902 p->balance = 0; 5903 break; 5904 } 5905 } 5906 5907 r = p; 5908 p = p->parent; 5909 } 5910} 5911 5912/* Build AVL tree from a sorted chain. */ 5913 5914static void 5915set_nonincremental_init (void) 5916{ 5917 unsigned HOST_WIDE_INT ix; 5918 tree index, value; 5919 5920 if (TREE_CODE (constructor_type) != RECORD_TYPE 5921 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5922 return; 5923 5924 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value) 5925 add_pending_init (index, value); 5926 constructor_elements = 0; 5927 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5928 { 5929 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5930 /* Skip any nameless bit fields at the beginning. */ 5931 while (constructor_unfilled_fields != 0 5932 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5933 && DECL_NAME (constructor_unfilled_fields) == 0) 5934 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5935 5936 } 5937 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5938 { 5939 if (TYPE_DOMAIN (constructor_type)) 5940 constructor_unfilled_index 5941 = convert (bitsizetype, 5942 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5943 else 5944 constructor_unfilled_index = bitsize_zero_node; 5945 } 5946 constructor_incremental = 0; 5947} 5948 5949/* Build AVL tree from a string constant. */ 5950 5951static void 5952set_nonincremental_init_from_string (tree str) 5953{ 5954 tree value, purpose, type; 5955 HOST_WIDE_INT val[2]; 5956 const char *p, *end; 5957 int byte, wchar_bytes, charwidth, bitpos; 5958 5959 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE); 5960 5961 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5962 == TYPE_PRECISION (char_type_node)) 5963 wchar_bytes = 1; 5964 else 5965 { 5966 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5967 == TYPE_PRECISION (wchar_type_node)); 5968 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 5969 } 5970 charwidth = TYPE_PRECISION (char_type_node); 5971 type = TREE_TYPE (constructor_type); 5972 p = TREE_STRING_POINTER (str); 5973 end = p + TREE_STRING_LENGTH (str); 5974 5975 for (purpose = bitsize_zero_node; 5976 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 5977 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 5978 { 5979 if (wchar_bytes == 1) 5980 { 5981 val[1] = (unsigned char) *p++; 5982 val[0] = 0; 5983 } 5984 else 5985 { 5986 val[0] = 0; 5987 val[1] = 0; 5988 for (byte = 0; byte < wchar_bytes; byte++) 5989 { 5990 if (BYTES_BIG_ENDIAN) 5991 bitpos = (wchar_bytes - byte - 1) * charwidth; 5992 else 5993 bitpos = byte * charwidth; 5994 val[bitpos < HOST_BITS_PER_WIDE_INT] 5995 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 5996 << (bitpos % HOST_BITS_PER_WIDE_INT); 5997 } 5998 } 5999 6000 if (!TYPE_UNSIGNED (type)) 6001 { 6002 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 6003 if (bitpos < HOST_BITS_PER_WIDE_INT) 6004 { 6005 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 6006 { 6007 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 6008 val[0] = -1; 6009 } 6010 } 6011 else if (bitpos == HOST_BITS_PER_WIDE_INT) 6012 { 6013 if (val[1] < 0) 6014 val[0] = -1; 6015 } 6016 else if (val[0] & (((HOST_WIDE_INT) 1) 6017 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 6018 val[0] |= ((HOST_WIDE_INT) -1) 6019 << (bitpos - HOST_BITS_PER_WIDE_INT); 6020 } 6021 6022 value = build_int_cst_wide (type, val[1], val[0]); 6023 add_pending_init (purpose, value); 6024 } 6025 6026 constructor_incremental = 0; 6027} 6028 6029/* Return value of FIELD in pending initializer or zero if the field was 6030 not initialized yet. */ 6031 6032static tree 6033find_init_member (tree field) 6034{ 6035 struct init_node *p; 6036 6037 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6038 { 6039 if (constructor_incremental 6040 && tree_int_cst_lt (field, constructor_unfilled_index)) 6041 set_nonincremental_init (); 6042 6043 p = constructor_pending_elts; 6044 while (p) 6045 { 6046 if (tree_int_cst_lt (field, p->purpose)) 6047 p = p->left; 6048 else if (tree_int_cst_lt (p->purpose, field)) 6049 p = p->right; 6050 else 6051 return p->value; 6052 } 6053 } 6054 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6055 { 6056 tree bitpos = bit_position (field); 6057 6058 if (constructor_incremental 6059 && (!constructor_unfilled_fields 6060 || tree_int_cst_lt (bitpos, 6061 bit_position (constructor_unfilled_fields)))) 6062 set_nonincremental_init (); 6063 6064 p = constructor_pending_elts; 6065 while (p) 6066 { 6067 if (field == p->purpose) 6068 return p->value; 6069 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 6070 p = p->left; 6071 else 6072 p = p->right; 6073 } 6074 } 6075 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6076 { 6077 if (!VEC_empty (constructor_elt, constructor_elements) 6078 && (VEC_last (constructor_elt, constructor_elements)->index 6079 == field)) 6080 return VEC_last (constructor_elt, constructor_elements)->value; 6081 } 6082 return 0; 6083} 6084 6085/* "Output" the next constructor element. 6086 At top level, really output it to assembler code now. 6087 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 6088 TYPE is the data type that the containing data type wants here. 6089 FIELD is the field (a FIELD_DECL) or the index that this element fills. 6090 If VALUE is a string constant, STRICT_STRING is true if it is 6091 unparenthesized or we should not warn here for it being parenthesized. 6092 For other types of VALUE, STRICT_STRING is not used. 6093 6094 PENDING if non-nil means output pending elements that belong 6095 right after this element. (PENDING is normally 1; 6096 it is 0 while outputting pending elements, to avoid recursion.) */ 6097 6098static void 6099output_init_element (tree value, bool strict_string, tree type, tree field, 6100 int pending) 6101{ 6102 constructor_elt *celt; 6103 6104 if (type == error_mark_node || value == error_mark_node) 6105 { 6106 constructor_erroneous = 1; 6107 return; 6108 } 6109 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 6110 && (TREE_CODE (value) == STRING_CST 6111 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR) 6112 && !(TREE_CODE (value) == STRING_CST 6113 && TREE_CODE (type) == ARRAY_TYPE 6114 && INTEGRAL_TYPE_P (TREE_TYPE (type))) 6115 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 6116 TYPE_MAIN_VARIANT (type))) 6117 value = array_to_pointer_conversion (value); 6118 6119 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 6120 && require_constant_value && !flag_isoc99 && pending) 6121 { 6122 /* As an extension, allow initializing objects with static storage 6123 duration with compound literals (which are then treated just as 6124 the brace enclosed list they contain). */ 6125 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 6126 value = DECL_INITIAL (decl); 6127 } 6128 6129 if (value == error_mark_node) 6130 constructor_erroneous = 1; 6131 else if (!TREE_CONSTANT (value)) 6132 constructor_constant = 0; 6133 else if (!initializer_constant_valid_p (value, TREE_TYPE (value)) 6134 || ((TREE_CODE (constructor_type) == RECORD_TYPE 6135 || TREE_CODE (constructor_type) == UNION_TYPE) 6136 && DECL_C_BIT_FIELD (field) 6137 && TREE_CODE (value) != INTEGER_CST)) 6138 constructor_simple = 0; 6139 6140 if (!initializer_constant_valid_p (value, TREE_TYPE (value))) 6141 { 6142 if (require_constant_value) 6143 { 6144 error_init ("initializer element is not constant"); 6145 value = error_mark_node; 6146 } 6147 else if (require_constant_elements) 6148 pedwarn ("initializer element is not computable at load time"); 6149 } 6150 6151 /* If this field is empty (and not at the end of structure), 6152 don't do anything other than checking the initializer. */ 6153 if (field 6154 && (TREE_TYPE (field) == error_mark_node 6155 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 6156 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 6157 && (TREE_CODE (constructor_type) == ARRAY_TYPE 6158 || TREE_CHAIN (field))))) 6159 return; 6160 6161 value = digest_init (type, value, strict_string, require_constant_value); 6162 if (value == error_mark_node) 6163 { 6164 constructor_erroneous = 1; 6165 return; 6166 } 6167 6168 /* If this element doesn't come next in sequence, 6169 put it on constructor_pending_elts. */ 6170 if (TREE_CODE (constructor_type) == ARRAY_TYPE 6171 && (!constructor_incremental 6172 || !tree_int_cst_equal (field, constructor_unfilled_index))) 6173 { 6174 if (constructor_incremental 6175 && tree_int_cst_lt (field, constructor_unfilled_index)) 6176 set_nonincremental_init (); 6177 6178 add_pending_init (field, value); 6179 return; 6180 } 6181 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6182 && (!constructor_incremental 6183 || field != constructor_unfilled_fields)) 6184 { 6185 /* We do this for records but not for unions. In a union, 6186 no matter which field is specified, it can be initialized 6187 right away since it starts at the beginning of the union. */ 6188 if (constructor_incremental) 6189 { 6190 if (!constructor_unfilled_fields) 6191 set_nonincremental_init (); 6192 else 6193 { 6194 tree bitpos, unfillpos; 6195 6196 bitpos = bit_position (field); 6197 unfillpos = bit_position (constructor_unfilled_fields); 6198 6199 if (tree_int_cst_lt (bitpos, unfillpos)) 6200 set_nonincremental_init (); 6201 } 6202 } 6203 6204 add_pending_init (field, value); 6205 return; 6206 } 6207 else if (TREE_CODE (constructor_type) == UNION_TYPE 6208 && !VEC_empty (constructor_elt, constructor_elements)) 6209 { 6210 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt, 6211 constructor_elements)->value)) 6212 warning_init ("initialized field with side-effects overwritten"); 6213 else if (warn_override_init) 6214 warning_init ("initialized field overwritten"); 6215 6216 /* We can have just one union field set. */ 6217 constructor_elements = 0; 6218 } 6219 6220 /* Otherwise, output this element either to 6221 constructor_elements or to the assembler file. */ 6222 6223 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL); 6224 celt->index = field; 6225 celt->value = value; 6226 6227 /* Advance the variable that indicates sequential elements output. */ 6228 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6229 constructor_unfilled_index 6230 = size_binop (PLUS_EXPR, constructor_unfilled_index, 6231 bitsize_one_node); 6232 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6233 { 6234 constructor_unfilled_fields 6235 = TREE_CHAIN (constructor_unfilled_fields); 6236 6237 /* Skip any nameless bit fields. */ 6238 while (constructor_unfilled_fields != 0 6239 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6240 && DECL_NAME (constructor_unfilled_fields) == 0) 6241 constructor_unfilled_fields = 6242 TREE_CHAIN (constructor_unfilled_fields); 6243 } 6244 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6245 constructor_unfilled_fields = 0; 6246 6247 /* Now output any pending elements which have become next. */ 6248 if (pending) 6249 output_pending_init_elements (0); 6250} 6251 6252/* Output any pending elements which have become next. 6253 As we output elements, constructor_unfilled_{fields,index} 6254 advances, which may cause other elements to become next; 6255 if so, they too are output. 6256 6257 If ALL is 0, we return when there are 6258 no more pending elements to output now. 6259 6260 If ALL is 1, we output space as necessary so that 6261 we can output all the pending elements. */ 6262 6263static void 6264output_pending_init_elements (int all) 6265{ 6266 struct init_node *elt = constructor_pending_elts; 6267 tree next; 6268 6269 retry: 6270 6271 /* Look through the whole pending tree. 6272 If we find an element that should be output now, 6273 output it. Otherwise, set NEXT to the element 6274 that comes first among those still pending. */ 6275 6276 next = 0; 6277 while (elt) 6278 { 6279 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6280 { 6281 if (tree_int_cst_equal (elt->purpose, 6282 constructor_unfilled_index)) 6283 output_init_element (elt->value, true, 6284 TREE_TYPE (constructor_type), 6285 constructor_unfilled_index, 0); 6286 else if (tree_int_cst_lt (constructor_unfilled_index, 6287 elt->purpose)) 6288 { 6289 /* Advance to the next smaller node. */ 6290 if (elt->left) 6291 elt = elt->left; 6292 else 6293 { 6294 /* We have reached the smallest node bigger than the 6295 current unfilled index. Fill the space first. */ 6296 next = elt->purpose; 6297 break; 6298 } 6299 } 6300 else 6301 { 6302 /* Advance to the next bigger node. */ 6303 if (elt->right) 6304 elt = elt->right; 6305 else 6306 { 6307 /* We have reached the biggest node in a subtree. Find 6308 the parent of it, which is the next bigger node. */ 6309 while (elt->parent && elt->parent->right == elt) 6310 elt = elt->parent; 6311 elt = elt->parent; 6312 if (elt && tree_int_cst_lt (constructor_unfilled_index, 6313 elt->purpose)) 6314 { 6315 next = elt->purpose; 6316 break; 6317 } 6318 } 6319 } 6320 } 6321 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6322 || TREE_CODE (constructor_type) == UNION_TYPE) 6323 { 6324 tree ctor_unfilled_bitpos, elt_bitpos; 6325 6326 /* If the current record is complete we are done. */ 6327 if (constructor_unfilled_fields == 0) 6328 break; 6329 6330 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 6331 elt_bitpos = bit_position (elt->purpose); 6332 /* We can't compare fields here because there might be empty 6333 fields in between. */ 6334 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 6335 { 6336 constructor_unfilled_fields = elt->purpose; 6337 output_init_element (elt->value, true, TREE_TYPE (elt->purpose), 6338 elt->purpose, 0); 6339 } 6340 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 6341 { 6342 /* Advance to the next smaller node. */ 6343 if (elt->left) 6344 elt = elt->left; 6345 else 6346 { 6347 /* We have reached the smallest node bigger than the 6348 current unfilled field. Fill the space first. */ 6349 next = elt->purpose; 6350 break; 6351 } 6352 } 6353 else 6354 { 6355 /* Advance to the next bigger node. */ 6356 if (elt->right) 6357 elt = elt->right; 6358 else 6359 { 6360 /* We have reached the biggest node in a subtree. Find 6361 the parent of it, which is the next bigger node. */ 6362 while (elt->parent && elt->parent->right == elt) 6363 elt = elt->parent; 6364 elt = elt->parent; 6365 if (elt 6366 && (tree_int_cst_lt (ctor_unfilled_bitpos, 6367 bit_position (elt->purpose)))) 6368 { 6369 next = elt->purpose; 6370 break; 6371 } 6372 } 6373 } 6374 } 6375 } 6376 6377 /* Ordinarily return, but not if we want to output all 6378 and there are elements left. */ 6379 if (!(all && next != 0)) 6380 return; 6381 6382 /* If it's not incremental, just skip over the gap, so that after 6383 jumping to retry we will output the next successive element. */ 6384 if (TREE_CODE (constructor_type) == RECORD_TYPE 6385 || TREE_CODE (constructor_type) == UNION_TYPE) 6386 constructor_unfilled_fields = next; 6387 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6388 constructor_unfilled_index = next; 6389 6390 /* ELT now points to the node in the pending tree with the next 6391 initializer to output. */ 6392 goto retry; 6393} 6394 6395/* Add one non-braced element to the current constructor level. 6396 This adjusts the current position within the constructor's type. 6397 This may also start or terminate implicit levels 6398 to handle a partly-braced initializer. 6399 6400 Once this has found the correct level for the new element, 6401 it calls output_init_element. */ 6402 6403void 6404process_init_element (struct c_expr value) 6405{ 6406 tree orig_value = value.value; 6407 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST; 6408 bool strict_string = value.original_code == STRING_CST; 6409 6410 designator_depth = 0; 6411 designator_erroneous = 0; 6412 6413 /* Handle superfluous braces around string cst as in 6414 char x[] = {"foo"}; */ 6415 if (string_flag 6416 && constructor_type 6417 && TREE_CODE (constructor_type) == ARRAY_TYPE 6418 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type)) 6419 && integer_zerop (constructor_unfilled_index)) 6420 { 6421 if (constructor_stack->replacement_value.value) 6422 error_init ("excess elements in char array initializer"); 6423 constructor_stack->replacement_value = value; 6424 return; 6425 } 6426 6427 if (constructor_stack->replacement_value.value != 0) 6428 { 6429 error_init ("excess elements in struct initializer"); 6430 return; 6431 } 6432 6433 /* Ignore elements of a brace group if it is entirely superfluous 6434 and has already been diagnosed. */ 6435 if (constructor_type == 0) 6436 return; 6437 6438 /* If we've exhausted any levels that didn't have braces, 6439 pop them now. */ 6440 while (constructor_stack->implicit) 6441 { 6442 if ((TREE_CODE (constructor_type) == RECORD_TYPE 6443 || TREE_CODE (constructor_type) == UNION_TYPE) 6444 && constructor_fields == 0) 6445 process_init_element (pop_init_level (1)); 6446 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 6447 && (constructor_max_index == 0 6448 || tree_int_cst_lt (constructor_max_index, 6449 constructor_index))) 6450 process_init_element (pop_init_level (1)); 6451 else 6452 break; 6453 } 6454 6455 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 6456 if (constructor_range_stack) 6457 { 6458 /* If value is a compound literal and we'll be just using its 6459 content, don't put it into a SAVE_EXPR. */ 6460 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR 6461 || !require_constant_value 6462 || flag_isoc99) 6463 value.value = save_expr (value.value); 6464 } 6465 6466 while (1) 6467 { 6468 if (TREE_CODE (constructor_type) == RECORD_TYPE) 6469 { 6470 tree fieldtype; 6471 enum tree_code fieldcode; 6472 6473 if (constructor_fields == 0) 6474 { 6475 pedwarn_init ("excess elements in struct initializer"); 6476 break; 6477 } 6478 6479 fieldtype = TREE_TYPE (constructor_fields); 6480 if (fieldtype != error_mark_node) 6481 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6482 fieldcode = TREE_CODE (fieldtype); 6483 6484 /* Error for non-static initialization of a flexible array member. */ 6485 if (fieldcode == ARRAY_TYPE 6486 && !require_constant_value 6487 && TYPE_SIZE (fieldtype) == NULL_TREE 6488 && TREE_CHAIN (constructor_fields) == NULL_TREE) 6489 { 6490 error_init ("non-static initialization of a flexible array member"); 6491 break; 6492 } 6493 6494 /* Accept a string constant to initialize a subarray. */ 6495 if (value.value != 0 6496 && fieldcode == ARRAY_TYPE 6497 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6498 && string_flag) 6499 value.value = orig_value; 6500 /* Otherwise, if we have come to a subaggregate, 6501 and we don't have an element of its type, push into it. */ 6502 else if (value.value != 0 6503 && value.value != error_mark_node 6504 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6505 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6506 || fieldcode == UNION_TYPE)) 6507 { 6508 push_init_level (1); 6509 continue; 6510 } 6511 6512 if (value.value) 6513 { 6514 push_member_name (constructor_fields); 6515 output_init_element (value.value, strict_string, 6516 fieldtype, constructor_fields, 1); 6517 RESTORE_SPELLING_DEPTH (constructor_depth); 6518 } 6519 else 6520 /* Do the bookkeeping for an element that was 6521 directly output as a constructor. */ 6522 { 6523 /* For a record, keep track of end position of last field. */ 6524 if (DECL_SIZE (constructor_fields)) 6525 constructor_bit_index 6526 = size_binop (PLUS_EXPR, 6527 bit_position (constructor_fields), 6528 DECL_SIZE (constructor_fields)); 6529 6530 /* If the current field was the first one not yet written out, 6531 it isn't now, so update. */ 6532 if (constructor_unfilled_fields == constructor_fields) 6533 { 6534 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6535 /* Skip any nameless bit fields. */ 6536 while (constructor_unfilled_fields != 0 6537 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6538 && DECL_NAME (constructor_unfilled_fields) == 0) 6539 constructor_unfilled_fields = 6540 TREE_CHAIN (constructor_unfilled_fields); 6541 } 6542 } 6543 6544 constructor_fields = TREE_CHAIN (constructor_fields); 6545 /* Skip any nameless bit fields at the beginning. */ 6546 while (constructor_fields != 0 6547 && DECL_C_BIT_FIELD (constructor_fields) 6548 && DECL_NAME (constructor_fields) == 0) 6549 constructor_fields = TREE_CHAIN (constructor_fields); 6550 } 6551 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6552 { 6553 tree fieldtype; 6554 enum tree_code fieldcode; 6555 6556 if (constructor_fields == 0) 6557 { 6558 pedwarn_init ("excess elements in union initializer"); 6559 break; 6560 } 6561 6562 fieldtype = TREE_TYPE (constructor_fields); 6563 if (fieldtype != error_mark_node) 6564 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6565 fieldcode = TREE_CODE (fieldtype); 6566 6567 /* Warn that traditional C rejects initialization of unions. 6568 We skip the warning if the value is zero. This is done 6569 under the assumption that the zero initializer in user 6570 code appears conditioned on e.g. __STDC__ to avoid 6571 "missing initializer" warnings and relies on default 6572 initialization to zero in the traditional C case. 6573 We also skip the warning if the initializer is designated, 6574 again on the assumption that this must be conditional on 6575 __STDC__ anyway (and we've already complained about the 6576 member-designator already). */ 6577 if (!in_system_header && !constructor_designated 6578 && !(value.value && (integer_zerop (value.value) 6579 || real_zerop (value.value)))) 6580 warning (OPT_Wtraditional, "traditional C rejects initialization " 6581 "of unions"); 6582 6583 /* Accept a string constant to initialize a subarray. */ 6584 if (value.value != 0 6585 && fieldcode == ARRAY_TYPE 6586 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6587 && string_flag) 6588 value.value = orig_value; 6589 /* Otherwise, if we have come to a subaggregate, 6590 and we don't have an element of its type, push into it. */ 6591 else if (value.value != 0 6592 && value.value != error_mark_node 6593 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6594 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6595 || fieldcode == UNION_TYPE)) 6596 { 6597 push_init_level (1); 6598 continue; 6599 } 6600 6601 if (value.value) 6602 { 6603 push_member_name (constructor_fields); 6604 output_init_element (value.value, strict_string, 6605 fieldtype, constructor_fields, 1); 6606 RESTORE_SPELLING_DEPTH (constructor_depth); 6607 } 6608 else 6609 /* Do the bookkeeping for an element that was 6610 directly output as a constructor. */ 6611 { 6612 constructor_bit_index = DECL_SIZE (constructor_fields); 6613 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6614 } 6615 6616 constructor_fields = 0; 6617 } 6618 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6619 { 6620 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6621 enum tree_code eltcode = TREE_CODE (elttype); 6622 6623 /* Accept a string constant to initialize a subarray. */ 6624 if (value.value != 0 6625 && eltcode == ARRAY_TYPE 6626 && INTEGRAL_TYPE_P (TREE_TYPE (elttype)) 6627 && string_flag) 6628 value.value = orig_value; 6629 /* Otherwise, if we have come to a subaggregate, 6630 and we don't have an element of its type, push into it. */ 6631 else if (value.value != 0 6632 && value.value != error_mark_node 6633 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype 6634 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6635 || eltcode == UNION_TYPE)) 6636 { 6637 push_init_level (1); 6638 continue; 6639 } 6640 6641 if (constructor_max_index != 0 6642 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6643 || integer_all_onesp (constructor_max_index))) 6644 { 6645 pedwarn_init ("excess elements in array initializer"); 6646 break; 6647 } 6648 6649 /* Now output the actual element. */ 6650 if (value.value) 6651 { 6652 push_array_bounds (tree_low_cst (constructor_index, 1)); 6653 output_init_element (value.value, strict_string, 6654 elttype, constructor_index, 1); 6655 RESTORE_SPELLING_DEPTH (constructor_depth); 6656 } 6657 6658 constructor_index 6659 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6660 6661 if (!value.value) 6662 /* If we are doing the bookkeeping for an element that was 6663 directly output as a constructor, we must update 6664 constructor_unfilled_index. */ 6665 constructor_unfilled_index = constructor_index; 6666 } 6667 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6668 { 6669 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6670 6671 /* Do a basic check of initializer size. Note that vectors 6672 always have a fixed size derived from their type. */ 6673 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6674 { 6675 pedwarn_init ("excess elements in vector initializer"); 6676 break; 6677 } 6678 6679 /* Now output the actual element. */ 6680 if (value.value) 6681 output_init_element (value.value, strict_string, 6682 elttype, constructor_index, 1); 6683 6684 constructor_index 6685 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6686 6687 if (!value.value) 6688 /* If we are doing the bookkeeping for an element that was 6689 directly output as a constructor, we must update 6690 constructor_unfilled_index. */ 6691 constructor_unfilled_index = constructor_index; 6692 } 6693 6694 /* Handle the sole element allowed in a braced initializer 6695 for a scalar variable. */ 6696 else if (constructor_type != error_mark_node 6697 && constructor_fields == 0) 6698 { 6699 pedwarn_init ("excess elements in scalar initializer"); 6700 break; 6701 } 6702 else 6703 { 6704 if (value.value) 6705 output_init_element (value.value, strict_string, 6706 constructor_type, NULL_TREE, 1); 6707 constructor_fields = 0; 6708 } 6709 6710 /* Handle range initializers either at this level or anywhere higher 6711 in the designator stack. */ 6712 if (constructor_range_stack) 6713 { 6714 struct constructor_range_stack *p, *range_stack; 6715 int finish = 0; 6716 6717 range_stack = constructor_range_stack; 6718 constructor_range_stack = 0; 6719 while (constructor_stack != range_stack->stack) 6720 { 6721 gcc_assert (constructor_stack->implicit); 6722 process_init_element (pop_init_level (1)); 6723 } 6724 for (p = range_stack; 6725 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6726 p = p->prev) 6727 { 6728 gcc_assert (constructor_stack->implicit); 6729 process_init_element (pop_init_level (1)); 6730 } 6731 6732 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6733 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6734 finish = 1; 6735 6736 while (1) 6737 { 6738 constructor_index = p->index; 6739 constructor_fields = p->fields; 6740 if (finish && p->range_end && p->index == p->range_start) 6741 { 6742 finish = 0; 6743 p->prev = 0; 6744 } 6745 p = p->next; 6746 if (!p) 6747 break; 6748 push_init_level (2); 6749 p->stack = constructor_stack; 6750 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6751 p->index = p->range_start; 6752 } 6753 6754 if (!finish) 6755 constructor_range_stack = range_stack; 6756 continue; 6757 } 6758 6759 break; 6760 } 6761 6762 constructor_range_stack = 0; 6763} 6764 6765/* Build a complete asm-statement, whose components are a CV_QUALIFIER 6766 (guaranteed to be 'volatile' or null) and ARGS (represented using 6767 an ASM_EXPR node). */ 6768tree 6769build_asm_stmt (tree cv_qualifier, tree args) 6770{ 6771 if (!ASM_VOLATILE_P (args) && cv_qualifier) 6772 ASM_VOLATILE_P (args) = 1; 6773 return add_stmt (args); 6774} 6775 6776/* Build an asm-expr, whose components are a STRING, some OUTPUTS, 6777 some INPUTS, and some CLOBBERS. The latter three may be NULL. 6778 SIMPLE indicates whether there was anything at all after the 6779 string in the asm expression -- asm("blah") and asm("blah" : ) 6780 are subtly different. We use a ASM_EXPR node to represent this. */ 6781tree 6782build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers, 6783 bool simple) 6784{ 6785 tree tail; 6786 tree args; 6787 int i; 6788 const char *constraint; 6789 const char **oconstraints; 6790 bool allows_mem, allows_reg, is_inout; 6791 int ninputs, noutputs; 6792 6793 ninputs = list_length (inputs); 6794 noutputs = list_length (outputs); 6795 oconstraints = (const char **) alloca (noutputs * sizeof (const char *)); 6796 6797 string = resolve_asm_operand_names (string, outputs, inputs); 6798 6799 /* Remove output conversions that change the type but not the mode. */ 6800 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail)) 6801 { 6802 tree output = TREE_VALUE (tail); 6803 6804 /* ??? Really, this should not be here. Users should be using a 6805 proper lvalue, dammit. But there's a long history of using casts 6806 in the output operands. In cases like longlong.h, this becomes a 6807 primitive form of typechecking -- if the cast can be removed, then 6808 the output operand had a type of the proper width; otherwise we'll 6809 get an error. Gross, but ... */ 6810 STRIP_NOPS (output); 6811 6812 if (!lvalue_or_else (output, lv_asm)) 6813 output = error_mark_node; 6814 6815 if (output != error_mark_node 6816 && (TREE_READONLY (output) 6817 || TYPE_READONLY (TREE_TYPE (output)) 6818 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE 6819 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE) 6820 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output))))) 6821 readonly_error (output, lv_asm); 6822 6823 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6824 oconstraints[i] = constraint; 6825 6826 if (parse_output_constraint (&constraint, i, ninputs, noutputs, 6827 &allows_mem, &allows_reg, &is_inout)) 6828 { 6829 /* If the operand is going to end up in memory, 6830 mark it addressable. */ 6831 if (!allows_reg && !c_mark_addressable (output)) 6832 output = error_mark_node; 6833 } 6834 else 6835 output = error_mark_node; 6836 6837 TREE_VALUE (tail) = output; 6838 } 6839 6840 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail)) 6841 { 6842 tree input; 6843 6844 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6845 input = TREE_VALUE (tail); 6846 6847 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0, 6848 oconstraints, &allows_mem, &allows_reg)) 6849 { 6850 /* If the operand is going to end up in memory, 6851 mark it addressable. */ 6852 if (!allows_reg && allows_mem) 6853 { 6854 /* Strip the nops as we allow this case. FIXME, this really 6855 should be rejected or made deprecated. */ 6856 STRIP_NOPS (input); 6857 if (!c_mark_addressable (input)) 6858 input = error_mark_node; 6859 } 6860 } 6861 else 6862 input = error_mark_node; 6863 6864 TREE_VALUE (tail) = input; 6865 } 6866 6867 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers); 6868 6869 /* asm statements without outputs, including simple ones, are treated 6870 as volatile. */ 6871 ASM_INPUT_P (args) = simple; 6872 ASM_VOLATILE_P (args) = (noutputs == 0); 6873 6874 return args; 6875} 6876 6877/* Generate a goto statement to LABEL. */ 6878 6879tree 6880c_finish_goto_label (tree label) 6881{ 6882 tree decl = lookup_label (label); 6883 if (!decl) 6884 return NULL_TREE; 6885 6886 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl)) 6887 { 6888 error ("jump into statement expression"); 6889 return NULL_TREE; 6890 } 6891 6892 if (C_DECL_UNJUMPABLE_VM (decl)) 6893 { 6894 error ("jump into scope of identifier with variably modified type"); 6895 return NULL_TREE; 6896 } 6897 6898 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl)) 6899 { 6900 /* No jump from outside this statement expression context, so 6901 record that there is a jump from within this context. */ 6902 struct c_label_list *nlist; 6903 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6904 nlist->next = label_context_stack_se->labels_used; 6905 nlist->label = decl; 6906 label_context_stack_se->labels_used = nlist; 6907 } 6908 6909 if (!C_DECL_UNDEFINABLE_VM (decl)) 6910 { 6911 /* No jump from outside this context context of identifiers with 6912 variably modified type, so record that there is a jump from 6913 within this context. */ 6914 struct c_label_list *nlist; 6915 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6916 nlist->next = label_context_stack_vm->labels_used; 6917 nlist->label = decl; 6918 label_context_stack_vm->labels_used = nlist; 6919 } 6920 6921 TREE_USED (decl) = 1; 6922 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl)); 6923} 6924 6925/* Generate a computed goto statement to EXPR. */ 6926 6927tree 6928c_finish_goto_ptr (tree expr) 6929{ 6930 if (pedantic) 6931 pedwarn ("ISO C forbids %<goto *expr;%>"); 6932 expr = convert (ptr_type_node, expr); 6933 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr)); 6934} 6935 6936/* Generate a C `return' statement. RETVAL is the expression for what 6937 to return, or a null pointer for `return;' with no value. */ 6938 6939tree 6940c_finish_return (tree retval) 6941{ 6942 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt; 6943 bool no_warning = false; 6944 6945 if (TREE_THIS_VOLATILE (current_function_decl)) 6946 warning (0, "function declared %<noreturn%> has a %<return%> statement"); 6947 6948 if (!retval) 6949 { 6950 current_function_returns_null = 1; 6951 if ((warn_return_type || flag_isoc99) 6952 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 6953 { 6954 pedwarn_c99 ("%<return%> with no value, in " 6955 "function returning non-void"); 6956 no_warning = true; 6957 } 6958 } 6959 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 6960 { 6961 current_function_returns_null = 1; 6962 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 6963 pedwarn ("%<return%> with a value, in function returning void"); 6964 } 6965 else 6966 { 6967 tree t = convert_for_assignment (valtype, retval, ic_return, 6968 NULL_TREE, NULL_TREE, 0); 6969 tree res = DECL_RESULT (current_function_decl); 6970 tree inner; 6971 6972 current_function_returns_value = 1; 6973 if (t == error_mark_node) 6974 return NULL_TREE; 6975 6976 inner = t = convert (TREE_TYPE (res), t); 6977 6978 /* Strip any conversions, additions, and subtractions, and see if 6979 we are returning the address of a local variable. Warn if so. */ 6980 while (1) 6981 { 6982 switch (TREE_CODE (inner)) 6983 { 6984 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 6985 case PLUS_EXPR: 6986 inner = TREE_OPERAND (inner, 0); 6987 continue; 6988 6989 case MINUS_EXPR: 6990 /* If the second operand of the MINUS_EXPR has a pointer 6991 type (or is converted from it), this may be valid, so 6992 don't give a warning. */ 6993 { 6994 tree op1 = TREE_OPERAND (inner, 1); 6995 6996 while (!POINTER_TYPE_P (TREE_TYPE (op1)) 6997 && (TREE_CODE (op1) == NOP_EXPR 6998 || TREE_CODE (op1) == NON_LVALUE_EXPR 6999 || TREE_CODE (op1) == CONVERT_EXPR)) 7000 op1 = TREE_OPERAND (op1, 0); 7001 7002 if (POINTER_TYPE_P (TREE_TYPE (op1))) 7003 break; 7004 7005 inner = TREE_OPERAND (inner, 0); 7006 continue; 7007 } 7008 7009 case ADDR_EXPR: 7010 inner = TREE_OPERAND (inner, 0); 7011 7012 while (REFERENCE_CLASS_P (inner) 7013 && TREE_CODE (inner) != INDIRECT_REF) 7014 inner = TREE_OPERAND (inner, 0); 7015 7016 if (DECL_P (inner) 7017 && !DECL_EXTERNAL (inner) 7018 && !TREE_STATIC (inner) 7019 && DECL_CONTEXT (inner) == current_function_decl) 7020 warning (0, "function returns address of local variable"); 7021 break; 7022 7023 default: 7024 break; 7025 } 7026 7027 break; 7028 } 7029 7030 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t); 7031 } 7032 7033 ret_stmt = build_stmt (RETURN_EXPR, retval); 7034 TREE_NO_WARNING (ret_stmt) |= no_warning; 7035 return add_stmt (ret_stmt); 7036} 7037 7038struct c_switch { 7039 /* The SWITCH_EXPR being built. */ 7040 tree switch_expr; 7041 7042 /* The original type of the testing expression, i.e. before the 7043 default conversion is applied. */ 7044 tree orig_type; 7045 7046 /* A splay-tree mapping the low element of a case range to the high 7047 element, or NULL_TREE if there is no high element. Used to 7048 determine whether or not a new case label duplicates an old case 7049 label. We need a tree, rather than simply a hash table, because 7050 of the GNU case range extension. */ 7051 splay_tree cases; 7052 7053 /* Number of nested statement expressions within this switch 7054 statement; if nonzero, case and default labels may not 7055 appear. */ 7056 unsigned int blocked_stmt_expr; 7057 7058 /* Scope of outermost declarations of identifiers with variably 7059 modified type within this switch statement; if nonzero, case and 7060 default labels may not appear. */ 7061 unsigned int blocked_vm; 7062 7063 /* The next node on the stack. */ 7064 struct c_switch *next; 7065}; 7066 7067/* A stack of the currently active switch statements. The innermost 7068 switch statement is on the top of the stack. There is no need to 7069 mark the stack for garbage collection because it is only active 7070 during the processing of the body of a function, and we never 7071 collect at that point. */ 7072 7073struct c_switch *c_switch_stack; 7074 7075/* Start a C switch statement, testing expression EXP. Return the new 7076 SWITCH_EXPR. */ 7077 7078tree 7079c_start_case (tree exp) 7080{ 7081 tree orig_type = error_mark_node; 7082 struct c_switch *cs; 7083 7084 if (exp != error_mark_node) 7085 { 7086 orig_type = TREE_TYPE (exp); 7087 7088 if (!INTEGRAL_TYPE_P (orig_type)) 7089 { 7090 if (orig_type != error_mark_node) 7091 { 7092 error ("switch quantity not an integer"); 7093 orig_type = error_mark_node; 7094 } 7095 exp = integer_zero_node; 7096 } 7097 else 7098 { 7099 tree type = TYPE_MAIN_VARIANT (orig_type); 7100 7101 if (!in_system_header 7102 && (type == long_integer_type_node 7103 || type == long_unsigned_type_node)) 7104 warning (OPT_Wtraditional, "%<long%> switch expression not " 7105 "converted to %<int%> in ISO C"); 7106 7107 exp = default_conversion (exp); 7108 } 7109 } 7110 7111 /* Add this new SWITCH_EXPR to the stack. */ 7112 cs = XNEW (struct c_switch); 7113 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE); 7114 cs->orig_type = orig_type; 7115 cs->cases = splay_tree_new (case_compare, NULL, NULL); 7116 cs->blocked_stmt_expr = 0; 7117 cs->blocked_vm = 0; 7118 cs->next = c_switch_stack; 7119 c_switch_stack = cs; 7120 7121 return add_stmt (cs->switch_expr); 7122} 7123 7124/* Process a case label. */ 7125 7126tree 7127do_case (tree low_value, tree high_value) 7128{ 7129 tree label = NULL_TREE; 7130 7131 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr 7132 && !c_switch_stack->blocked_vm) 7133 { 7134 label = c_add_case_label (c_switch_stack->cases, 7135 SWITCH_COND (c_switch_stack->switch_expr), 7136 c_switch_stack->orig_type, 7137 low_value, high_value); 7138 if (label == error_mark_node) 7139 label = NULL_TREE; 7140 } 7141 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr) 7142 { 7143 if (low_value) 7144 error ("case label in statement expression not containing " 7145 "enclosing switch statement"); 7146 else 7147 error ("%<default%> label in statement expression not containing " 7148 "enclosing switch statement"); 7149 } 7150 else if (c_switch_stack && c_switch_stack->blocked_vm) 7151 { 7152 if (low_value) 7153 error ("case label in scope of identifier with variably modified " 7154 "type not containing enclosing switch statement"); 7155 else 7156 error ("%<default%> label in scope of identifier with variably " 7157 "modified type not containing enclosing switch statement"); 7158 } 7159 else if (low_value) 7160 error ("case label not within a switch statement"); 7161 else 7162 error ("%<default%> label not within a switch statement"); 7163 7164 return label; 7165} 7166 7167/* Finish the switch statement. */ 7168 7169void 7170c_finish_case (tree body) 7171{ 7172 struct c_switch *cs = c_switch_stack; 7173 location_t switch_location; 7174 7175 SWITCH_BODY (cs->switch_expr) = body; 7176 7177 /* We must not be within a statement expression nested in the switch 7178 at this point; we might, however, be within the scope of an 7179 identifier with variably modified type nested in the switch. */ 7180 gcc_assert (!cs->blocked_stmt_expr); 7181 7182 /* Emit warnings as needed. */ 7183 if (EXPR_HAS_LOCATION (cs->switch_expr)) 7184 switch_location = EXPR_LOCATION (cs->switch_expr); 7185 else 7186 switch_location = input_location; 7187 c_do_switch_warnings (cs->cases, switch_location, 7188 TREE_TYPE (cs->switch_expr), 7189 SWITCH_COND (cs->switch_expr)); 7190 7191 /* Pop the stack. */ 7192 c_switch_stack = cs->next; 7193 splay_tree_delete (cs->cases); 7194 XDELETE (cs); 7195} 7196 7197/* Emit an if statement. IF_LOCUS is the location of the 'if'. COND, 7198 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK 7199 may be null. NESTED_IF is true if THEN_BLOCK contains another IF 7200 statement, and was not surrounded with parenthesis. */ 7201 7202void 7203c_finish_if_stmt (location_t if_locus, tree cond, tree then_block, 7204 tree else_block, bool nested_if) 7205{ 7206 tree stmt; 7207 7208 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */ 7209 if (warn_parentheses && nested_if && else_block == NULL) 7210 { 7211 tree inner_if = then_block; 7212 7213 /* We know from the grammar productions that there is an IF nested 7214 within THEN_BLOCK. Due to labels and c99 conditional declarations, 7215 it might not be exactly THEN_BLOCK, but should be the last 7216 non-container statement within. */ 7217 while (1) 7218 switch (TREE_CODE (inner_if)) 7219 { 7220 case COND_EXPR: 7221 goto found; 7222 case BIND_EXPR: 7223 inner_if = BIND_EXPR_BODY (inner_if); 7224 break; 7225 case STATEMENT_LIST: 7226 inner_if = expr_last (then_block); 7227 break; 7228 case TRY_FINALLY_EXPR: 7229 case TRY_CATCH_EXPR: 7230 inner_if = TREE_OPERAND (inner_if, 0); 7231 break; 7232 default: 7233 gcc_unreachable (); 7234 } 7235 found: 7236 7237 if (COND_EXPR_ELSE (inner_if)) 7238 warning (OPT_Wparentheses, 7239 "%Hsuggest explicit braces to avoid ambiguous %<else%>", 7240 &if_locus); 7241 } 7242 7243 empty_body_warning (then_block, else_block); 7244 7245 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block); 7246 SET_EXPR_LOCATION (stmt, if_locus); 7247 add_stmt (stmt); 7248} 7249 7250/* Emit a general-purpose loop construct. START_LOCUS is the location of 7251 the beginning of the loop. COND is the loop condition. COND_IS_FIRST 7252 is false for DO loops. INCR is the FOR increment expression. BODY is 7253 the statement controlled by the loop. BLAB is the break label. CLAB is 7254 the continue label. Everything is allowed to be NULL. */ 7255 7256void 7257c_finish_loop (location_t start_locus, tree cond, tree incr, tree body, 7258 tree blab, tree clab, bool cond_is_first) 7259{ 7260 tree entry = NULL, exit = NULL, t; 7261 7262 /* If the condition is zero don't generate a loop construct. */ 7263 if (cond && integer_zerop (cond)) 7264 { 7265 if (cond_is_first) 7266 { 7267 t = build_and_jump (&blab); 7268 SET_EXPR_LOCATION (t, start_locus); 7269 add_stmt (t); 7270 } 7271 } 7272 else 7273 { 7274 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7275 7276 /* If we have an exit condition, then we build an IF with gotos either 7277 out of the loop, or to the top of it. If there's no exit condition, 7278 then we just build a jump back to the top. */ 7279 exit = build_and_jump (&LABEL_EXPR_LABEL (top)); 7280 7281 if (cond && !integer_nonzerop (cond)) 7282 { 7283 /* Canonicalize the loop condition to the end. This means 7284 generating a branch to the loop condition. Reuse the 7285 continue label, if possible. */ 7286 if (cond_is_first) 7287 { 7288 if (incr || !clab) 7289 { 7290 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7291 t = build_and_jump (&LABEL_EXPR_LABEL (entry)); 7292 } 7293 else 7294 t = build1 (GOTO_EXPR, void_type_node, clab); 7295 SET_EXPR_LOCATION (t, start_locus); 7296 add_stmt (t); 7297 } 7298 7299 t = build_and_jump (&blab); 7300 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t); 7301 if (cond_is_first) 7302 SET_EXPR_LOCATION (exit, start_locus); 7303 else 7304 SET_EXPR_LOCATION (exit, input_location); 7305 } 7306 7307 add_stmt (top); 7308 } 7309 7310 if (body) 7311 add_stmt (body); 7312 if (clab) 7313 add_stmt (build1 (LABEL_EXPR, void_type_node, clab)); 7314 if (incr) 7315 add_stmt (incr); 7316 if (entry) 7317 add_stmt (entry); 7318 if (exit) 7319 add_stmt (exit); 7320 if (blab) 7321 add_stmt (build1 (LABEL_EXPR, void_type_node, blab)); 7322} 7323 7324tree 7325c_finish_bc_stmt (tree *label_p, bool is_break) 7326{ 7327 bool skip; 7328 tree label = *label_p; 7329 7330 /* In switch statements break is sometimes stylistically used after 7331 a return statement. This can lead to spurious warnings about 7332 control reaching the end of a non-void function when it is 7333 inlined. Note that we are calling block_may_fallthru with 7334 language specific tree nodes; this works because 7335 block_may_fallthru returns true when given something it does not 7336 understand. */ 7337 skip = !block_may_fallthru (cur_stmt_list); 7338 7339 if (!label) 7340 { 7341 if (!skip) 7342 *label_p = label = create_artificial_label (); 7343 } 7344 else if (TREE_CODE (label) == LABEL_DECL) 7345 ; 7346 else switch (TREE_INT_CST_LOW (label)) 7347 { 7348 case 0: 7349 if (is_break) 7350 error ("break statement not within loop or switch"); 7351 else 7352 error ("continue statement not within a loop"); 7353 return NULL_TREE; 7354 7355 case 1: 7356 gcc_assert (is_break); 7357 error ("break statement used with OpenMP for loop"); 7358 return NULL_TREE; 7359 7360 default: 7361 gcc_unreachable (); 7362 } 7363 7364 if (skip) 7365 return NULL_TREE; 7366 7367 return add_stmt (build1 (GOTO_EXPR, void_type_node, label)); 7368} 7369 7370/* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */ 7371 7372static void 7373emit_side_effect_warnings (tree expr) 7374{ 7375 if (expr == error_mark_node) 7376 ; 7377 else if (!TREE_SIDE_EFFECTS (expr)) 7378 { 7379 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr)) 7380 warning (0, "%Hstatement with no effect", 7381 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location); 7382 } 7383 else if (warn_unused_value) 7384 warn_if_unused_value (expr, input_location); 7385} 7386 7387/* Process an expression as if it were a complete statement. Emit 7388 diagnostics, but do not call ADD_STMT. */ 7389 7390tree 7391c_process_expr_stmt (tree expr) 7392{ 7393 if (!expr) 7394 return NULL_TREE; 7395 7396 if (warn_sequence_point) 7397 verify_sequence_points (expr); 7398 7399 if (TREE_TYPE (expr) != error_mark_node 7400 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr)) 7401 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE) 7402 error ("expression statement has incomplete type"); 7403 7404 /* If we're not processing a statement expression, warn about unused values. 7405 Warnings for statement expressions will be emitted later, once we figure 7406 out which is the result. */ 7407 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7408 && (extra_warnings || warn_unused_value)) 7409 emit_side_effect_warnings (expr); 7410 7411 /* If the expression is not of a type to which we cannot assign a line 7412 number, wrap the thing in a no-op NOP_EXPR. */ 7413 if (DECL_P (expr) || CONSTANT_CLASS_P (expr)) 7414 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr); 7415 7416 if (EXPR_P (expr)) 7417 SET_EXPR_LOCATION (expr, input_location); 7418 7419 return expr; 7420} 7421 7422/* Emit an expression as a statement. */ 7423 7424tree 7425c_finish_expr_stmt (tree expr) 7426{ 7427 if (expr) 7428 return add_stmt (c_process_expr_stmt (expr)); 7429 else 7430 return NULL; 7431} 7432 7433/* Do the opposite and emit a statement as an expression. To begin, 7434 create a new binding level and return it. */ 7435 7436tree 7437c_begin_stmt_expr (void) 7438{ 7439 tree ret; 7440 struct c_label_context_se *nstack; 7441 struct c_label_list *glist; 7442 7443 /* We must force a BLOCK for this level so that, if it is not expanded 7444 later, there is a way to turn off the entire subtree of blocks that 7445 are contained in it. */ 7446 keep_next_level (); 7447 ret = c_begin_compound_stmt (true); 7448 if (c_switch_stack) 7449 { 7450 c_switch_stack->blocked_stmt_expr++; 7451 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7452 } 7453 for (glist = label_context_stack_se->labels_used; 7454 glist != NULL; 7455 glist = glist->next) 7456 { 7457 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1; 7458 } 7459 nstack = XOBNEW (&parser_obstack, struct c_label_context_se); 7460 nstack->labels_def = NULL; 7461 nstack->labels_used = NULL; 7462 nstack->next = label_context_stack_se; 7463 label_context_stack_se = nstack; 7464 7465 /* Mark the current statement list as belonging to a statement list. */ 7466 STATEMENT_LIST_STMT_EXPR (ret) = 1; 7467 7468 return ret; 7469} 7470 7471tree 7472c_finish_stmt_expr (tree body) 7473{ 7474 tree last, type, tmp, val; 7475 tree *last_p; 7476 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7477 7478 body = c_end_compound_stmt (body, true); 7479 if (c_switch_stack) 7480 { 7481 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7482 c_switch_stack->blocked_stmt_expr--; 7483 } 7484 /* It is no longer possible to jump to labels defined within this 7485 statement expression. */ 7486 for (dlist = label_context_stack_se->labels_def; 7487 dlist != NULL; 7488 dlist = dlist->next) 7489 { 7490 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1; 7491 } 7492 /* It is again possible to define labels with a goto just outside 7493 this statement expression. */ 7494 for (glist = label_context_stack_se->next->labels_used; 7495 glist != NULL; 7496 glist = glist->next) 7497 { 7498 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0; 7499 glist_prev = glist; 7500 } 7501 if (glist_prev != NULL) 7502 glist_prev->next = label_context_stack_se->labels_used; 7503 else 7504 label_context_stack_se->next->labels_used 7505 = label_context_stack_se->labels_used; 7506 label_context_stack_se = label_context_stack_se->next; 7507 7508 /* Locate the last statement in BODY. See c_end_compound_stmt 7509 about always returning a BIND_EXPR. */ 7510 last_p = &BIND_EXPR_BODY (body); 7511 last = BIND_EXPR_BODY (body); 7512 7513 continue_searching: 7514 if (TREE_CODE (last) == STATEMENT_LIST) 7515 { 7516 tree_stmt_iterator i; 7517 7518 /* This can happen with degenerate cases like ({ }). No value. */ 7519 if (!TREE_SIDE_EFFECTS (last)) 7520 return body; 7521 7522 /* If we're supposed to generate side effects warnings, process 7523 all of the statements except the last. */ 7524 if (extra_warnings || warn_unused_value) 7525 { 7526 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i)) 7527 emit_side_effect_warnings (tsi_stmt (i)); 7528 } 7529 else 7530 i = tsi_last (last); 7531 last_p = tsi_stmt_ptr (i); 7532 last = *last_p; 7533 } 7534 7535 /* If the end of the list is exception related, then the list was split 7536 by a call to push_cleanup. Continue searching. */ 7537 if (TREE_CODE (last) == TRY_FINALLY_EXPR 7538 || TREE_CODE (last) == TRY_CATCH_EXPR) 7539 { 7540 last_p = &TREE_OPERAND (last, 0); 7541 last = *last_p; 7542 goto continue_searching; 7543 } 7544 7545 /* In the case that the BIND_EXPR is not necessary, return the 7546 expression out from inside it. */ 7547 if (last == error_mark_node 7548 || (last == BIND_EXPR_BODY (body) 7549 && BIND_EXPR_VARS (body) == NULL)) 7550 { 7551 /* Do not warn if the return value of a statement expression is 7552 unused. */ 7553 if (EXPR_P (last)) 7554 TREE_NO_WARNING (last) = 1; 7555 return last; 7556 } 7557 7558 /* Extract the type of said expression. */ 7559 type = TREE_TYPE (last); 7560 7561 /* If we're not returning a value at all, then the BIND_EXPR that 7562 we already have is a fine expression to return. */ 7563 if (!type || VOID_TYPE_P (type)) 7564 return body; 7565 7566 /* Now that we've located the expression containing the value, it seems 7567 silly to make voidify_wrapper_expr repeat the process. Create a 7568 temporary of the appropriate type and stick it in a TARGET_EXPR. */ 7569 tmp = create_tmp_var_raw (type, NULL); 7570 7571 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids 7572 tree_expr_nonnegative_p giving up immediately. */ 7573 val = last; 7574 if (TREE_CODE (val) == NOP_EXPR 7575 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))) 7576 val = TREE_OPERAND (val, 0); 7577 7578 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val); 7579 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last)); 7580 7581 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE); 7582} 7583 7584/* Begin the scope of an identifier of variably modified type, scope 7585 number SCOPE. Jumping from outside this scope to inside it is not 7586 permitted. */ 7587 7588void 7589c_begin_vm_scope (unsigned int scope) 7590{ 7591 struct c_label_context_vm *nstack; 7592 struct c_label_list *glist; 7593 7594 gcc_assert (scope > 0); 7595 7596 /* At file_scope, we don't have to do any processing. */ 7597 if (label_context_stack_vm == NULL) 7598 return; 7599 7600 if (c_switch_stack && !c_switch_stack->blocked_vm) 7601 c_switch_stack->blocked_vm = scope; 7602 for (glist = label_context_stack_vm->labels_used; 7603 glist != NULL; 7604 glist = glist->next) 7605 { 7606 C_DECL_UNDEFINABLE_VM (glist->label) = 1; 7607 } 7608 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm); 7609 nstack->labels_def = NULL; 7610 nstack->labels_used = NULL; 7611 nstack->scope = scope; 7612 nstack->next = label_context_stack_vm; 7613 label_context_stack_vm = nstack; 7614} 7615 7616/* End a scope which may contain identifiers of variably modified 7617 type, scope number SCOPE. */ 7618 7619void 7620c_end_vm_scope (unsigned int scope) 7621{ 7622 if (label_context_stack_vm == NULL) 7623 return; 7624 if (c_switch_stack && c_switch_stack->blocked_vm == scope) 7625 c_switch_stack->blocked_vm = 0; 7626 /* We may have a number of nested scopes of identifiers with 7627 variably modified type, all at this depth. Pop each in turn. */ 7628 while (label_context_stack_vm->scope == scope) 7629 { 7630 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7631 7632 /* It is no longer possible to jump to labels defined within this 7633 scope. */ 7634 for (dlist = label_context_stack_vm->labels_def; 7635 dlist != NULL; 7636 dlist = dlist->next) 7637 { 7638 C_DECL_UNJUMPABLE_VM (dlist->label) = 1; 7639 } 7640 /* It is again possible to define labels with a goto just outside 7641 this scope. */ 7642 for (glist = label_context_stack_vm->next->labels_used; 7643 glist != NULL; 7644 glist = glist->next) 7645 { 7646 C_DECL_UNDEFINABLE_VM (glist->label) = 0; 7647 glist_prev = glist; 7648 } 7649 if (glist_prev != NULL) 7650 glist_prev->next = label_context_stack_vm->labels_used; 7651 else 7652 label_context_stack_vm->next->labels_used 7653 = label_context_stack_vm->labels_used; 7654 label_context_stack_vm = label_context_stack_vm->next; 7655 } 7656} 7657 7658/* Begin and end compound statements. This is as simple as pushing 7659 and popping new statement lists from the tree. */ 7660 7661tree 7662c_begin_compound_stmt (bool do_scope) 7663{ 7664 tree stmt = push_stmt_list (); 7665 if (do_scope) 7666 push_scope (); 7667 return stmt; 7668} 7669 7670tree 7671c_end_compound_stmt (tree stmt, bool do_scope) 7672{ 7673 tree block = NULL; 7674 7675 if (do_scope) 7676 { 7677 if (c_dialect_objc ()) 7678 objc_clear_super_receiver (); 7679 block = pop_scope (); 7680 } 7681 7682 stmt = pop_stmt_list (stmt); 7683 stmt = c_build_bind_expr (block, stmt); 7684 7685 /* If this compound statement is nested immediately inside a statement 7686 expression, then force a BIND_EXPR to be created. Otherwise we'll 7687 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular, 7688 STATEMENT_LISTs merge, and thus we can lose track of what statement 7689 was really last. */ 7690 if (cur_stmt_list 7691 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7692 && TREE_CODE (stmt) != BIND_EXPR) 7693 { 7694 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL); 7695 TREE_SIDE_EFFECTS (stmt) = 1; 7696 } 7697 7698 return stmt; 7699} 7700 7701/* Queue a cleanup. CLEANUP is an expression/statement to be executed 7702 when the current scope is exited. EH_ONLY is true when this is not 7703 meant to apply to normal control flow transfer. */ 7704 7705void 7706push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only) 7707{ 7708 enum tree_code code; 7709 tree stmt, list; 7710 bool stmt_expr; 7711 7712 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR; 7713 stmt = build_stmt (code, NULL, cleanup); 7714 add_stmt (stmt); 7715 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list); 7716 list = push_stmt_list (); 7717 TREE_OPERAND (stmt, 0) = list; 7718 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr; 7719} 7720 7721/* Build a binary-operation expression without default conversions. 7722 CODE is the kind of expression to build. 7723 This function differs from `build' in several ways: 7724 the data type of the result is computed and recorded in it, 7725 warnings are generated if arg data types are invalid, 7726 special handling for addition and subtraction of pointers is known, 7727 and some optimization is done (operations on narrow ints 7728 are done in the narrower type when that gives the same result). 7729 Constant folding is also done before the result is returned. 7730 7731 Note that the operands will never have enumeral types, or function 7732 or array types, because either they will have the default conversions 7733 performed or they have both just been converted to some other type in which 7734 the arithmetic is to be done. */ 7735 7736tree 7737build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 7738 int convert_p) 7739{ 7740 tree type0, type1; 7741 enum tree_code code0, code1; 7742 tree op0, op1; 7743 const char *invalid_op_diag; 7744 7745 /* Expression code to give to the expression when it is built. 7746 Normally this is CODE, which is what the caller asked for, 7747 but in some special cases we change it. */ 7748 enum tree_code resultcode = code; 7749 7750 /* Data type in which the computation is to be performed. 7751 In the simplest cases this is the common type of the arguments. */ 7752 tree result_type = NULL; 7753 7754 /* Nonzero means operands have already been type-converted 7755 in whatever way is necessary. 7756 Zero means they need to be converted to RESULT_TYPE. */ 7757 int converted = 0; 7758 7759 /* Nonzero means create the expression with this type, rather than 7760 RESULT_TYPE. */ 7761 tree build_type = 0; 7762 7763 /* Nonzero means after finally constructing the expression 7764 convert it to this type. */ 7765 tree final_type = 0; 7766 7767 /* Nonzero if this is an operation like MIN or MAX which can 7768 safely be computed in short if both args are promoted shorts. 7769 Also implies COMMON. 7770 -1 indicates a bitwise operation; this makes a difference 7771 in the exact conditions for when it is safe to do the operation 7772 in a narrower mode. */ 7773 int shorten = 0; 7774 7775 /* Nonzero if this is a comparison operation; 7776 if both args are promoted shorts, compare the original shorts. 7777 Also implies COMMON. */ 7778 int short_compare = 0; 7779 7780 /* Nonzero if this is a right-shift operation, which can be computed on the 7781 original short and then promoted if the operand is a promoted short. */ 7782 int short_shift = 0; 7783 7784 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 7785 int common = 0; 7786 7787 /* True means types are compatible as far as ObjC is concerned. */ 7788 bool objc_ok; 7789 7790 if (convert_p) 7791 { 7792 op0 = default_conversion (orig_op0); 7793 op1 = default_conversion (orig_op1); 7794 } 7795 else 7796 { 7797 op0 = orig_op0; 7798 op1 = orig_op1; 7799 } 7800 7801 type0 = TREE_TYPE (op0); 7802 type1 = TREE_TYPE (op1); 7803 7804 /* The expression codes of the data types of the arguments tell us 7805 whether the arguments are integers, floating, pointers, etc. */ 7806 code0 = TREE_CODE (type0); 7807 code1 = TREE_CODE (type1); 7808 7809 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 7810 STRIP_TYPE_NOPS (op0); 7811 STRIP_TYPE_NOPS (op1); 7812 7813 /* If an error was already reported for one of the arguments, 7814 avoid reporting another error. */ 7815 7816 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 7817 return error_mark_node; 7818 7819 if ((invalid_op_diag 7820 = targetm.invalid_binary_op (code, type0, type1))) 7821 { 7822 error (invalid_op_diag, ""); 7823 return error_mark_node; 7824 } 7825 7826 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE); 7827 7828 switch (code) 7829 { 7830 case PLUS_EXPR: 7831 /* Handle the pointer + int case. */ 7832 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7833 return pointer_int_sum (PLUS_EXPR, op0, op1); 7834 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 7835 return pointer_int_sum (PLUS_EXPR, op1, op0); 7836 else 7837 common = 1; 7838 break; 7839 7840 case MINUS_EXPR: 7841 /* Subtraction of two similar pointers. 7842 We must subtract them as integers, then divide by object size. */ 7843 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 7844 && comp_target_types (type0, type1)) 7845 return pointer_diff (op0, op1); 7846 /* Handle pointer minus int. Just like pointer plus int. */ 7847 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7848 return pointer_int_sum (MINUS_EXPR, op0, op1); 7849 else 7850 common = 1; 7851 break; 7852 7853 case MULT_EXPR: 7854 common = 1; 7855 break; 7856 7857 case TRUNC_DIV_EXPR: 7858 case CEIL_DIV_EXPR: 7859 case FLOOR_DIV_EXPR: 7860 case ROUND_DIV_EXPR: 7861 case EXACT_DIV_EXPR: 7862 /* Floating point division by zero is a legitimate way to obtain 7863 infinities and NaNs. */ 7864 if (skip_evaluation == 0 && integer_zerop (op1)) 7865 warning (OPT_Wdiv_by_zero, "division by zero"); 7866 7867 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 7868 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7869 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 7870 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 7871 { 7872 enum tree_code tcode0 = code0, tcode1 = code1; 7873 7874 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7875 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); 7876 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE) 7877 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); 7878 7879 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)) 7880 resultcode = RDIV_EXPR; 7881 else 7882 /* Although it would be tempting to shorten always here, that 7883 loses on some targets, since the modulo instruction is 7884 undefined if the quotient can't be represented in the 7885 computation mode. We shorten only if unsigned or if 7886 dividing by something we know != -1. */ 7887 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7888 || (TREE_CODE (op1) == INTEGER_CST 7889 && !integer_all_onesp (op1))); 7890 common = 1; 7891 } 7892 break; 7893 7894 case BIT_AND_EXPR: 7895 case BIT_IOR_EXPR: 7896 case BIT_XOR_EXPR: 7897 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7898 shorten = -1; 7899 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 7900 common = 1; 7901 break; 7902 7903 case TRUNC_MOD_EXPR: 7904 case FLOOR_MOD_EXPR: 7905 if (skip_evaluation == 0 && integer_zerop (op1)) 7906 warning (OPT_Wdiv_by_zero, "division by zero"); 7907 7908 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7909 { 7910 /* Although it would be tempting to shorten always here, that loses 7911 on some targets, since the modulo instruction is undefined if the 7912 quotient can't be represented in the computation mode. We shorten 7913 only if unsigned or if dividing by something we know != -1. */ 7914 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7915 || (TREE_CODE (op1) == INTEGER_CST 7916 && !integer_all_onesp (op1))); 7917 common = 1; 7918 } 7919 break; 7920 7921 case TRUTH_ANDIF_EXPR: 7922 case TRUTH_ORIF_EXPR: 7923 case TRUTH_AND_EXPR: 7924 case TRUTH_OR_EXPR: 7925 case TRUTH_XOR_EXPR: 7926 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 7927 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 7928 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 7929 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 7930 { 7931 /* Result of these operations is always an int, 7932 but that does not mean the operands should be 7933 converted to ints! */ 7934 result_type = integer_type_node; 7935 op0 = c_common_truthvalue_conversion (op0); 7936 op1 = c_common_truthvalue_conversion (op1); 7937 converted = 1; 7938 } 7939 break; 7940 7941 /* Shift operations: result has same type as first operand; 7942 always convert second operand to int. 7943 Also set SHORT_SHIFT if shifting rightward. */ 7944 7945 case RSHIFT_EXPR: 7946 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7947 { 7948 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 7949 { 7950 if (tree_int_cst_sgn (op1) < 0) 7951 warning (0, "right shift count is negative"); 7952 else 7953 { 7954 if (!integer_zerop (op1)) 7955 short_shift = 1; 7956 7957 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 7958 warning (0, "right shift count >= width of type"); 7959 } 7960 } 7961 7962 /* Use the type of the value to be shifted. */ 7963 result_type = type0; 7964 /* Convert the shift-count to an integer, regardless of size 7965 of value being shifted. */ 7966 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 7967 op1 = convert (integer_type_node, op1); 7968 /* Avoid converting op1 to result_type later. */ 7969 converted = 1; 7970 } 7971 break; 7972 7973 case LSHIFT_EXPR: 7974 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7975 { 7976 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 7977 { 7978 if (tree_int_cst_sgn (op1) < 0) 7979 warning (0, "left shift count is negative"); 7980 7981 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 7982 warning (0, "left shift count >= width of type"); 7983 } 7984 7985 /* Use the type of the value to be shifted. */ 7986 result_type = type0; 7987 /* Convert the shift-count to an integer, regardless of size 7988 of value being shifted. */ 7989 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 7990 op1 = convert (integer_type_node, op1); 7991 /* Avoid converting op1 to result_type later. */ 7992 converted = 1; 7993 } 7994 break; 7995 7996 case EQ_EXPR: 7997 case NE_EXPR: 7998 if (code0 == REAL_TYPE || code1 == REAL_TYPE) 7999 warning (OPT_Wfloat_equal, 8000 "comparing floating point with == or != is unsafe"); 8001 /* Result of comparison is always int, 8002 but don't convert the args to int! */ 8003 build_type = integer_type_node; 8004 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 8005 || code0 == COMPLEX_TYPE) 8006 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 8007 || code1 == COMPLEX_TYPE)) 8008 short_compare = 1; 8009 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8010 { 8011 tree tt0 = TREE_TYPE (type0); 8012 tree tt1 = TREE_TYPE (type1); 8013 /* Anything compares with void *. void * compares with anything. 8014 Otherwise, the targets must be compatible 8015 and both must be object or both incomplete. */ 8016 if (comp_target_types (type0, type1)) 8017 result_type = common_pointer_type (type0, type1); 8018 else if (VOID_TYPE_P (tt0)) 8019 { 8020 /* op0 != orig_op0 detects the case of something 8021 whose value is 0 but which isn't a valid null ptr const. */ 8022 if (pedantic && !null_pointer_constant_p (orig_op0) 8023 && TREE_CODE (tt1) == FUNCTION_TYPE) 8024 pedwarn ("ISO C forbids comparison of %<void *%>" 8025 " with function pointer"); 8026 } 8027 else if (VOID_TYPE_P (tt1)) 8028 { 8029 if (pedantic && !null_pointer_constant_p (orig_op1) 8030 && TREE_CODE (tt0) == FUNCTION_TYPE) 8031 pedwarn ("ISO C forbids comparison of %<void *%>" 8032 " with function pointer"); 8033 } 8034 else 8035 /* Avoid warning about the volatile ObjC EH puts on decls. */ 8036 if (!objc_ok) 8037 pedwarn ("comparison of distinct pointer types lacks a cast"); 8038 8039 if (result_type == NULL_TREE) 8040 result_type = ptr_type_node; 8041 } 8042 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8043 { 8044 if (TREE_CODE (op0) == ADDR_EXPR 8045 && DECL_P (TREE_OPERAND (op0, 0)) 8046 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL 8047 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL 8048 || !DECL_WEAK (TREE_OPERAND (op0, 0)))) 8049 warning (OPT_Waddress, "the address of %qD will never be NULL", 8050 TREE_OPERAND (op0, 0)); 8051 result_type = type0; 8052 } 8053 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8054 { 8055 if (TREE_CODE (op1) == ADDR_EXPR 8056 && DECL_P (TREE_OPERAND (op1, 0)) 8057 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL 8058 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL 8059 || !DECL_WEAK (TREE_OPERAND (op1, 0)))) 8060 warning (OPT_Waddress, "the address of %qD will never be NULL", 8061 TREE_OPERAND (op1, 0)); 8062 result_type = type1; 8063 } 8064 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8065 { 8066 result_type = type0; 8067 pedwarn ("comparison between pointer and integer"); 8068 } 8069 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8070 { 8071 result_type = type1; 8072 pedwarn ("comparison between pointer and integer"); 8073 } 8074 break; 8075 8076 case LE_EXPR: 8077 case GE_EXPR: 8078 case LT_EXPR: 8079 case GT_EXPR: 8080 build_type = integer_type_node; 8081 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 8082 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 8083 short_compare = 1; 8084 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8085 { 8086 if (comp_target_types (type0, type1)) 8087 { 8088 result_type = common_pointer_type (type0, type1); 8089 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 8090 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 8091 pedwarn ("comparison of complete and incomplete pointers"); 8092 else if (pedantic 8093 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 8094 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 8095 } 8096 else 8097 { 8098 result_type = ptr_type_node; 8099 pedwarn ("comparison of distinct pointer types lacks a cast"); 8100 } 8101 } 8102 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8103 { 8104 result_type = type0; 8105 if (pedantic || extra_warnings) 8106 pedwarn ("ordered comparison of pointer with integer zero"); 8107 } 8108 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8109 { 8110 result_type = type1; 8111 if (pedantic) 8112 pedwarn ("ordered comparison of pointer with integer zero"); 8113 } 8114 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8115 { 8116 result_type = type0; 8117 pedwarn ("comparison between pointer and integer"); 8118 } 8119 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8120 { 8121 result_type = type1; 8122 pedwarn ("comparison between pointer and integer"); 8123 } 8124 break; 8125 8126 default: 8127 gcc_unreachable (); 8128 } 8129 8130 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 8131 return error_mark_node; 8132 8133 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE 8134 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)) 8135 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0), 8136 TREE_TYPE (type1)))) 8137 { 8138 binary_op_error (code, type0, type1); 8139 return error_mark_node; 8140 } 8141 8142 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 8143 || code0 == VECTOR_TYPE) 8144 && 8145 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 8146 || code1 == VECTOR_TYPE)) 8147 { 8148 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 8149 8150 if (shorten || common || short_compare) 8151 result_type = c_common_type (type0, type1); 8152 8153 /* For certain operations (which identify themselves by shorten != 0) 8154 if both args were extended from the same smaller type, 8155 do the arithmetic in that type and then extend. 8156 8157 shorten !=0 and !=1 indicates a bitwise operation. 8158 For them, this optimization is safe only if 8159 both args are zero-extended or both are sign-extended. 8160 Otherwise, we might change the result. 8161 Eg, (short)-1 | (unsigned short)-1 is (int)-1 8162 but calculated in (unsigned short) it would be (unsigned short)-1. */ 8163 8164 if (shorten && none_complex) 8165 { 8166 int unsigned0, unsigned1; 8167 tree arg0, arg1; 8168 int uns; 8169 tree type; 8170 8171 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents 8172 excessive narrowing when we call get_narrower below. For 8173 example, suppose that OP0 is of unsigned int extended 8174 from signed char and that RESULT_TYPE is long long int. 8175 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look 8176 like 8177 8178 (long long int) (unsigned int) signed_char 8179 8180 which get_narrower would narrow down to 8181 8182 (unsigned int) signed char 8183 8184 If we do not cast OP0 first, get_narrower would return 8185 signed_char, which is inconsistent with the case of the 8186 explicit cast. */ 8187 op0 = convert (result_type, op0); 8188 op1 = convert (result_type, op1); 8189 8190 arg0 = get_narrower (op0, &unsigned0); 8191 arg1 = get_narrower (op1, &unsigned1); 8192 8193 /* UNS is 1 if the operation to be done is an unsigned one. */ 8194 uns = TYPE_UNSIGNED (result_type); 8195 8196 final_type = result_type; 8197 8198 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 8199 but it *requires* conversion to FINAL_TYPE. */ 8200 8201 if ((TYPE_PRECISION (TREE_TYPE (op0)) 8202 == TYPE_PRECISION (TREE_TYPE (arg0))) 8203 && TREE_TYPE (op0) != final_type) 8204 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 8205 if ((TYPE_PRECISION (TREE_TYPE (op1)) 8206 == TYPE_PRECISION (TREE_TYPE (arg1))) 8207 && TREE_TYPE (op1) != final_type) 8208 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 8209 8210 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 8211 8212 /* For bitwise operations, signedness of nominal type 8213 does not matter. Consider only how operands were extended. */ 8214 if (shorten == -1) 8215 uns = unsigned0; 8216 8217 /* Note that in all three cases below we refrain from optimizing 8218 an unsigned operation on sign-extended args. 8219 That would not be valid. */ 8220 8221 /* Both args variable: if both extended in same way 8222 from same width, do it in that width. 8223 Do it unsigned if args were zero-extended. */ 8224 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 8225 < TYPE_PRECISION (result_type)) 8226 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8227 == TYPE_PRECISION (TREE_TYPE (arg0))) 8228 && unsigned0 == unsigned1 8229 && (unsigned0 || !uns)) 8230 result_type 8231 = c_common_signed_or_unsigned_type 8232 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 8233 else if (TREE_CODE (arg0) == INTEGER_CST 8234 && (unsigned1 || !uns) 8235 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8236 < TYPE_PRECISION (result_type)) 8237 && (type 8238 = c_common_signed_or_unsigned_type (unsigned1, 8239 TREE_TYPE (arg1)), 8240 int_fits_type_p (arg0, type))) 8241 result_type = type; 8242 else if (TREE_CODE (arg1) == INTEGER_CST 8243 && (unsigned0 || !uns) 8244 && (TYPE_PRECISION (TREE_TYPE (arg0)) 8245 < TYPE_PRECISION (result_type)) 8246 && (type 8247 = c_common_signed_or_unsigned_type (unsigned0, 8248 TREE_TYPE (arg0)), 8249 int_fits_type_p (arg1, type))) 8250 result_type = type; 8251 } 8252 8253 /* Shifts can be shortened if shifting right. */ 8254 8255 if (short_shift) 8256 { 8257 int unsigned_arg; 8258 tree arg0 = get_narrower (op0, &unsigned_arg); 8259 8260 final_type = result_type; 8261 8262 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 8263 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0)); 8264 8265 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 8266 /* We can shorten only if the shift count is less than the 8267 number of bits in the smaller type size. */ 8268 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 8269 /* We cannot drop an unsigned shift after sign-extension. */ 8270 && (!TYPE_UNSIGNED (final_type) || unsigned_arg)) 8271 { 8272 /* Do an unsigned shift if the operand was zero-extended. */ 8273 result_type 8274 = c_common_signed_or_unsigned_type (unsigned_arg, 8275 TREE_TYPE (arg0)); 8276 /* Convert value-to-be-shifted to that type. */ 8277 if (TREE_TYPE (op0) != result_type) 8278 op0 = convert (result_type, op0); 8279 converted = 1; 8280 } 8281 } 8282 8283 /* Comparison operations are shortened too but differently. 8284 They identify themselves by setting short_compare = 1. */ 8285 8286 if (short_compare) 8287 { 8288 /* Don't write &op0, etc., because that would prevent op0 8289 from being kept in a register. 8290 Instead, make copies of the our local variables and 8291 pass the copies by reference, then copy them back afterward. */ 8292 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 8293 enum tree_code xresultcode = resultcode; 8294 tree val 8295 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 8296 8297 if (val != 0) 8298 return val; 8299 8300 op0 = xop0, op1 = xop1; 8301 converted = 1; 8302 resultcode = xresultcode; 8303 8304 if (warn_sign_compare && skip_evaluation == 0) 8305 { 8306 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0)); 8307 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 8308 int unsignedp0, unsignedp1; 8309 tree primop0 = get_narrower (op0, &unsignedp0); 8310 tree primop1 = get_narrower (op1, &unsignedp1); 8311 8312 xop0 = orig_op0; 8313 xop1 = orig_op1; 8314 STRIP_TYPE_NOPS (xop0); 8315 STRIP_TYPE_NOPS (xop1); 8316 8317 /* Give warnings for comparisons between signed and unsigned 8318 quantities that may fail. 8319 8320 Do the checking based on the original operand trees, so that 8321 casts will be considered, but default promotions won't be. 8322 8323 Do not warn if the comparison is being done in a signed type, 8324 since the signed type will only be chosen if it can represent 8325 all the values of the unsigned type. */ 8326 if (!TYPE_UNSIGNED (result_type)) 8327 /* OK */; 8328 /* Do not warn if both operands are the same signedness. */ 8329 else if (op0_signed == op1_signed) 8330 /* OK */; 8331 else 8332 { 8333 tree sop, uop; 8334 bool ovf; 8335 8336 if (op0_signed) 8337 sop = xop0, uop = xop1; 8338 else 8339 sop = xop1, uop = xop0; 8340 8341 /* Do not warn if the signed quantity is an 8342 unsuffixed integer literal (or some static 8343 constant expression involving such literals or a 8344 conditional expression involving such literals) 8345 and it is non-negative. */ 8346 if (tree_expr_nonnegative_warnv_p (sop, &ovf)) 8347 /* OK */; 8348 /* Do not warn if the comparison is an equality operation, 8349 the unsigned quantity is an integral constant, and it 8350 would fit in the result if the result were signed. */ 8351 else if (TREE_CODE (uop) == INTEGER_CST 8352 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 8353 && int_fits_type_p 8354 (uop, c_common_signed_type (result_type))) 8355 /* OK */; 8356 /* Do not warn if the unsigned quantity is an enumeration 8357 constant and its maximum value would fit in the result 8358 if the result were signed. */ 8359 else if (TREE_CODE (uop) == INTEGER_CST 8360 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 8361 && int_fits_type_p 8362 (TYPE_MAX_VALUE (TREE_TYPE (uop)), 8363 c_common_signed_type (result_type))) 8364 /* OK */; 8365 else 8366 warning (0, "comparison between signed and unsigned"); 8367 } 8368 8369 /* Warn if two unsigned values are being compared in a size 8370 larger than their original size, and one (and only one) is the 8371 result of a `~' operator. This comparison will always fail. 8372 8373 Also warn if one operand is a constant, and the constant 8374 does not have all bits set that are set in the ~ operand 8375 when it is extended. */ 8376 8377 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 8378 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 8379 { 8380 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 8381 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 8382 &unsignedp0); 8383 else 8384 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 8385 &unsignedp1); 8386 8387 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 8388 { 8389 tree primop; 8390 HOST_WIDE_INT constant, mask; 8391 int unsignedp, bits; 8392 8393 if (host_integerp (primop0, 0)) 8394 { 8395 primop = primop1; 8396 unsignedp = unsignedp1; 8397 constant = tree_low_cst (primop0, 0); 8398 } 8399 else 8400 { 8401 primop = primop0; 8402 unsignedp = unsignedp0; 8403 constant = tree_low_cst (primop1, 0); 8404 } 8405 8406 bits = TYPE_PRECISION (TREE_TYPE (primop)); 8407 if (bits < TYPE_PRECISION (result_type) 8408 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 8409 { 8410 mask = (~(HOST_WIDE_INT) 0) << bits; 8411 if ((mask & constant) != mask) 8412 warning (0, "comparison of promoted ~unsigned with constant"); 8413 } 8414 } 8415 else if (unsignedp0 && unsignedp1 8416 && (TYPE_PRECISION (TREE_TYPE (primop0)) 8417 < TYPE_PRECISION (result_type)) 8418 && (TYPE_PRECISION (TREE_TYPE (primop1)) 8419 < TYPE_PRECISION (result_type))) 8420 warning (0, "comparison of promoted ~unsigned with unsigned"); 8421 } 8422 } 8423 } 8424 } 8425 8426 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 8427 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 8428 Then the expression will be built. 8429 It will be given type FINAL_TYPE if that is nonzero; 8430 otherwise, it will be given type RESULT_TYPE. */ 8431 8432 if (!result_type) 8433 { 8434 binary_op_error (code, TREE_TYPE (op0), TREE_TYPE (op1)); 8435 return error_mark_node; 8436 } 8437 8438 if (!converted) 8439 { 8440 if (TREE_TYPE (op0) != result_type) 8441 op0 = convert_and_check (result_type, op0); 8442 if (TREE_TYPE (op1) != result_type) 8443 op1 = convert_and_check (result_type, op1); 8444 8445 /* This can happen if one operand has a vector type, and the other 8446 has a different type. */ 8447 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) 8448 return error_mark_node; 8449 } 8450 8451 if (build_type == NULL_TREE) 8452 build_type = result_type; 8453 8454 { 8455 /* Treat expressions in initializers specially as they can't trap. */ 8456 tree result = require_constant_value ? fold_build2_initializer (resultcode, 8457 build_type, 8458 op0, op1) 8459 : fold_build2 (resultcode, build_type, 8460 op0, op1); 8461 8462 if (final_type != 0) 8463 result = convert (final_type, result); 8464 return result; 8465 } 8466} 8467 8468 8469/* Convert EXPR to be a truth-value, validating its type for this 8470 purpose. */ 8471 8472tree 8473c_objc_common_truthvalue_conversion (tree expr) 8474{ 8475 switch (TREE_CODE (TREE_TYPE (expr))) 8476 { 8477 case ARRAY_TYPE: 8478 error ("used array that cannot be converted to pointer where scalar is required"); 8479 return error_mark_node; 8480 8481 case RECORD_TYPE: 8482 error ("used struct type value where scalar is required"); 8483 return error_mark_node; 8484 8485 case UNION_TYPE: 8486 error ("used union type value where scalar is required"); 8487 return error_mark_node; 8488 8489 case FUNCTION_TYPE: 8490 gcc_unreachable (); 8491 8492 default: 8493 break; 8494 } 8495 8496 /* ??? Should we also give an error for void and vectors rather than 8497 leaving those to give errors later? */ 8498 return c_common_truthvalue_conversion (expr); 8499} 8500 8501 8502/* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as 8503 required. */ 8504 8505tree 8506c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, 8507 bool *ti ATTRIBUTE_UNUSED, bool *se) 8508{ 8509 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR) 8510 { 8511 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr); 8512 /* Executing a compound literal inside a function reinitializes 8513 it. */ 8514 if (!TREE_STATIC (decl)) 8515 *se = true; 8516 return decl; 8517 } 8518 else 8519 return expr; 8520} 8521 8522/* Like c_begin_compound_stmt, except force the retention of the BLOCK. */ 8523 8524tree 8525c_begin_omp_parallel (void) 8526{ 8527 tree block; 8528 8529 keep_next_level (); 8530 block = c_begin_compound_stmt (true); 8531 8532 return block; 8533} 8534 8535tree 8536c_finish_omp_parallel (tree clauses, tree block) 8537{ 8538 tree stmt; 8539 8540 block = c_end_compound_stmt (block, true); 8541 8542 stmt = make_node (OMP_PARALLEL); 8543 TREE_TYPE (stmt) = void_type_node; 8544 OMP_PARALLEL_CLAUSES (stmt) = clauses; 8545 OMP_PARALLEL_BODY (stmt) = block; 8546 8547 return add_stmt (stmt); 8548} 8549 8550/* For all elements of CLAUSES, validate them vs OpenMP constraints. 8551 Remove any elements from the list that are invalid. */ 8552 8553tree 8554c_finish_omp_clauses (tree clauses) 8555{ 8556 bitmap_head generic_head, firstprivate_head, lastprivate_head; 8557 tree c, t, *pc = &clauses; 8558 const char *name; 8559 8560 bitmap_obstack_initialize (NULL); 8561 bitmap_initialize (&generic_head, &bitmap_default_obstack); 8562 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack); 8563 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack); 8564 8565 for (pc = &clauses, c = clauses; c ; c = *pc) 8566 { 8567 bool remove = false; 8568 bool need_complete = false; 8569 bool need_implicitly_determined = false; 8570 8571 switch (OMP_CLAUSE_CODE (c)) 8572 { 8573 case OMP_CLAUSE_SHARED: 8574 name = "shared"; 8575 need_implicitly_determined = true; 8576 goto check_dup_generic; 8577 8578 case OMP_CLAUSE_PRIVATE: 8579 name = "private"; 8580 need_complete = true; 8581 need_implicitly_determined = true; 8582 goto check_dup_generic; 8583 8584 case OMP_CLAUSE_REDUCTION: 8585 name = "reduction"; 8586 need_implicitly_determined = true; 8587 t = OMP_CLAUSE_DECL (c); 8588 if (AGGREGATE_TYPE_P (TREE_TYPE (t)) 8589 || POINTER_TYPE_P (TREE_TYPE (t))) 8590 { 8591 error ("%qE has invalid type for %<reduction%>", t); 8592 remove = true; 8593 } 8594 else if (FLOAT_TYPE_P (TREE_TYPE (t))) 8595 { 8596 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c); 8597 const char *r_name = NULL; 8598 8599 switch (r_code) 8600 { 8601 case PLUS_EXPR: 8602 case MULT_EXPR: 8603 case MINUS_EXPR: 8604 break; 8605 case BIT_AND_EXPR: 8606 r_name = "&"; 8607 break; 8608 case BIT_XOR_EXPR: 8609 r_name = "^"; 8610 break; 8611 case BIT_IOR_EXPR: 8612 r_name = "|"; 8613 break; 8614 case TRUTH_ANDIF_EXPR: 8615 r_name = "&&"; 8616 break; 8617 case TRUTH_ORIF_EXPR: 8618 r_name = "||"; 8619 break; 8620 default: 8621 gcc_unreachable (); 8622 } 8623 if (r_name) 8624 { 8625 error ("%qE has invalid type for %<reduction(%s)%>", 8626 t, r_name); 8627 remove = true; 8628 } 8629 } 8630 goto check_dup_generic; 8631 8632 case OMP_CLAUSE_COPYPRIVATE: 8633 name = "copyprivate"; 8634 goto check_dup_generic; 8635 8636 case OMP_CLAUSE_COPYIN: 8637 name = "copyin"; 8638 t = OMP_CLAUSE_DECL (c); 8639 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t)) 8640 { 8641 error ("%qE must be %<threadprivate%> for %<copyin%>", t); 8642 remove = true; 8643 } 8644 goto check_dup_generic; 8645 8646 check_dup_generic: 8647 t = OMP_CLAUSE_DECL (c); 8648 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8649 { 8650 error ("%qE is not a variable in clause %qs", t, name); 8651 remove = true; 8652 } 8653 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8654 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)) 8655 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8656 { 8657 error ("%qE appears more than once in data clauses", t); 8658 remove = true; 8659 } 8660 else 8661 bitmap_set_bit (&generic_head, DECL_UID (t)); 8662 break; 8663 8664 case OMP_CLAUSE_FIRSTPRIVATE: 8665 name = "firstprivate"; 8666 t = OMP_CLAUSE_DECL (c); 8667 need_complete = true; 8668 need_implicitly_determined = true; 8669 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8670 { 8671 error ("%qE is not a variable in clause %<firstprivate%>", t); 8672 remove = true; 8673 } 8674 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8675 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))) 8676 { 8677 error ("%qE appears more than once in data clauses", t); 8678 remove = true; 8679 } 8680 else 8681 bitmap_set_bit (&firstprivate_head, DECL_UID (t)); 8682 break; 8683 8684 case OMP_CLAUSE_LASTPRIVATE: 8685 name = "lastprivate"; 8686 t = OMP_CLAUSE_DECL (c); 8687 need_complete = true; 8688 need_implicitly_determined = true; 8689 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8690 { 8691 error ("%qE is not a variable in clause %<lastprivate%>", t); 8692 remove = true; 8693 } 8694 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8695 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8696 { 8697 error ("%qE appears more than once in data clauses", t); 8698 remove = true; 8699 } 8700 else 8701 bitmap_set_bit (&lastprivate_head, DECL_UID (t)); 8702 break; 8703 8704 case OMP_CLAUSE_IF: 8705 case OMP_CLAUSE_NUM_THREADS: 8706 case OMP_CLAUSE_SCHEDULE: 8707 case OMP_CLAUSE_NOWAIT: 8708 case OMP_CLAUSE_ORDERED: 8709 case OMP_CLAUSE_DEFAULT: 8710 pc = &OMP_CLAUSE_CHAIN (c); 8711 continue; 8712 8713 default: 8714 gcc_unreachable (); 8715 } 8716 8717 if (!remove) 8718 { 8719 t = OMP_CLAUSE_DECL (c); 8720 8721 if (need_complete) 8722 { 8723 t = require_complete_type (t); 8724 if (t == error_mark_node) 8725 remove = true; 8726 } 8727 8728 if (need_implicitly_determined) 8729 { 8730 const char *share_name = NULL; 8731 8732 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t)) 8733 share_name = "threadprivate"; 8734 else switch (c_omp_predetermined_sharing (t)) 8735 { 8736 case OMP_CLAUSE_DEFAULT_UNSPECIFIED: 8737 break; 8738 case OMP_CLAUSE_DEFAULT_SHARED: 8739 share_name = "shared"; 8740 break; 8741 case OMP_CLAUSE_DEFAULT_PRIVATE: 8742 share_name = "private"; 8743 break; 8744 default: 8745 gcc_unreachable (); 8746 } 8747 if (share_name) 8748 { 8749 error ("%qE is predetermined %qs for %qs", 8750 t, share_name, name); 8751 remove = true; 8752 } 8753 } 8754 } 8755 8756 if (remove) 8757 *pc = OMP_CLAUSE_CHAIN (c); 8758 else 8759 pc = &OMP_CLAUSE_CHAIN (c); 8760 } 8761 8762 bitmap_obstack_release (NULL); 8763 return clauses; 8764} 8765