c-typeck.c revision 189824
1/* Build expressions with type checking for C compiler. 2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 4 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2102110-1301, USA. */ 22 23 24/* This file is part of the C front end. 25 It contains routines to build C expressions given their operands, 26 including computing the types of the result, C-specific error checks, 27 and some optimization. */ 28 29#include "config.h" 30#include "system.h" 31#include "coretypes.h" 32#include "tm.h" 33#include "rtl.h" 34#include "tree.h" 35#include "langhooks.h" 36#include "c-tree.h" 37#include "tm_p.h" 38#include "flags.h" 39#include "output.h" 40#include "expr.h" 41#include "toplev.h" 42#include "intl.h" 43#include "ggc.h" 44#include "target.h" 45#include "tree-iterator.h" 46#include "tree-gimple.h" 47#include "tree-flow.h" 48 49/* Possible cases of implicit bad conversions. Used to select 50 diagnostic messages in convert_for_assignment. */ 51enum impl_conv { 52 ic_argpass, 53 ic_argpass_nonproto, 54 ic_assign, 55 ic_init, 56 ic_return 57}; 58 59/* The level of nesting inside "__alignof__". */ 60int in_alignof; 61 62/* The level of nesting inside "sizeof". */ 63int in_sizeof; 64 65/* The level of nesting inside "typeof". */ 66int in_typeof; 67 68struct c_label_context_se *label_context_stack_se; 69struct c_label_context_vm *label_context_stack_vm; 70 71/* Nonzero if we've already printed a "missing braces around initializer" 72 message within this initializer. */ 73static int missing_braces_mentioned; 74 75static int require_constant_value; 76static int require_constant_elements; 77 78static bool null_pointer_constant_p (tree); 79static tree qualify_type (tree, tree); 80static int tagged_types_tu_compatible_p (tree, tree); 81static int comp_target_types (tree, tree); 82static int function_types_compatible_p (tree, tree); 83static int type_lists_compatible_p (tree, tree); 84static tree decl_constant_value_for_broken_optimization (tree); 85static tree lookup_field (tree, tree); 86static tree convert_arguments (tree, tree, tree, tree); 87static tree pointer_diff (tree, tree); 88static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree, 89 int); 90static tree valid_compound_expr_initializer (tree, tree); 91static void push_string (const char *); 92static void push_member_name (tree); 93static int spelling_length (void); 94static char *print_spelling (char *); 95static void warning_init (const char *); 96static tree digest_init (tree, tree, bool, int); 97static void output_init_element (tree, bool, tree, tree, int); 98static void output_pending_init_elements (int); 99static int set_designator (int); 100static void push_range_stack (tree); 101static void add_pending_init (tree, tree); 102static void set_nonincremental_init (void); 103static void set_nonincremental_init_from_string (tree); 104static tree find_init_member (tree); 105static void readonly_error (tree, enum lvalue_use); 106static int lvalue_or_else (tree, enum lvalue_use); 107static int lvalue_p (tree); 108static void record_maybe_used_decl (tree); 109static int comptypes_internal (tree, tree); 110 111/* Return true if EXP is a null pointer constant, false otherwise. */ 112 113static bool 114null_pointer_constant_p (tree expr) 115{ 116 /* This should really operate on c_expr structures, but they aren't 117 yet available everywhere required. */ 118 tree type = TREE_TYPE (expr); 119 return (TREE_CODE (expr) == INTEGER_CST 120 && !TREE_CONSTANT_OVERFLOW (expr) 121 && integer_zerop (expr) 122 && (INTEGRAL_TYPE_P (type) 123 || (TREE_CODE (type) == POINTER_TYPE 124 && VOID_TYPE_P (TREE_TYPE (type)) 125 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED))); 126} 127/* This is a cache to hold if two types are compatible or not. */ 128 129struct tagged_tu_seen_cache { 130 const struct tagged_tu_seen_cache * next; 131 tree t1; 132 tree t2; 133 /* The return value of tagged_types_tu_compatible_p if we had seen 134 these two types already. */ 135 int val; 136}; 137 138static const struct tagged_tu_seen_cache * tagged_tu_seen_base; 139static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *); 140 141/* Do `exp = require_complete_type (exp);' to make sure exp 142 does not have an incomplete type. (That includes void types.) */ 143 144tree 145require_complete_type (tree value) 146{ 147 tree type = TREE_TYPE (value); 148 149 if (value == error_mark_node || type == error_mark_node) 150 return error_mark_node; 151 152 /* First, detect a valid value with a complete type. */ 153 if (COMPLETE_TYPE_P (type)) 154 return value; 155 156 c_incomplete_type_error (value, type); 157 return error_mark_node; 158} 159 160/* Print an error message for invalid use of an incomplete type. 161 VALUE is the expression that was used (or 0 if that isn't known) 162 and TYPE is the type that was invalid. */ 163 164void 165c_incomplete_type_error (tree value, tree type) 166{ 167 const char *type_code_string; 168 169 /* Avoid duplicate error message. */ 170 if (TREE_CODE (type) == ERROR_MARK) 171 return; 172 173 if (value != 0 && (TREE_CODE (value) == VAR_DECL 174 || TREE_CODE (value) == PARM_DECL)) 175 error ("%qD has an incomplete type", value); 176 else 177 { 178 retry: 179 /* We must print an error message. Be clever about what it says. */ 180 181 switch (TREE_CODE (type)) 182 { 183 case RECORD_TYPE: 184 type_code_string = "struct"; 185 break; 186 187 case UNION_TYPE: 188 type_code_string = "union"; 189 break; 190 191 case ENUMERAL_TYPE: 192 type_code_string = "enum"; 193 break; 194 195 case VOID_TYPE: 196 error ("invalid use of void expression"); 197 return; 198 199 case ARRAY_TYPE: 200 if (TYPE_DOMAIN (type)) 201 { 202 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL) 203 { 204 error ("invalid use of flexible array member"); 205 return; 206 } 207 type = TREE_TYPE (type); 208 goto retry; 209 } 210 error ("invalid use of array with unspecified bounds"); 211 return; 212 213 default: 214 gcc_unreachable (); 215 } 216 217 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 218 error ("invalid use of undefined type %<%s %E%>", 219 type_code_string, TYPE_NAME (type)); 220 else 221 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */ 222 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type)); 223 } 224} 225 226/* Given a type, apply default promotions wrt unnamed function 227 arguments and return the new type. */ 228 229tree 230c_type_promotes_to (tree type) 231{ 232 if (TYPE_MAIN_VARIANT (type) == float_type_node) 233 return double_type_node; 234 235 if (c_promoting_integer_type_p (type)) 236 { 237 /* Preserve unsignedness if not really getting any wider. */ 238 if (TYPE_UNSIGNED (type) 239 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))) 240 return unsigned_type_node; 241 return integer_type_node; 242 } 243 244 return type; 245} 246 247/* Return a variant of TYPE which has all the type qualifiers of LIKE 248 as well as those of TYPE. */ 249 250static tree 251qualify_type (tree type, tree like) 252{ 253 return c_build_qualified_type (type, 254 TYPE_QUALS (type) | TYPE_QUALS (like)); 255} 256 257/* Return true iff the given tree T is a variable length array. */ 258 259bool 260c_vla_type_p (tree t) 261{ 262 if (TREE_CODE (t) == ARRAY_TYPE 263 && C_TYPE_VARIABLE_SIZE (t)) 264 return true; 265 return false; 266} 267 268/* Return the composite type of two compatible types. 269 270 We assume that comptypes has already been done and returned 271 nonzero; if that isn't so, this may crash. In particular, we 272 assume that qualifiers match. */ 273 274tree 275composite_type (tree t1, tree t2) 276{ 277 enum tree_code code1; 278 enum tree_code code2; 279 tree attributes; 280 281 /* Save time if the two types are the same. */ 282 283 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) == ADDR_EXPR 1880 && (TREE_TYPE (TREE_OPERAND (pointer, 0)) 1881 == TREE_TYPE (type))) 1882 return TREE_OPERAND (pointer, 0); 1883 else 1884 { 1885 tree t = TREE_TYPE (type); 1886 tree ref; 1887 1888 ref = build1 (INDIRECT_REF, t, pointer); 1889 1890 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) 1891 { 1892 error ("dereferencing pointer to incomplete type"); 1893 return error_mark_node; 1894 } 1895 if (VOID_TYPE_P (t) && skip_evaluation == 0) 1896 warning (0, "dereferencing %<void *%> pointer"); 1897 1898 /* We *must* set TREE_READONLY when dereferencing a pointer to const, 1899 so that we get the proper error message if the result is used 1900 to assign to. Also, &* is supposed to be a no-op. 1901 And ANSI C seems to specify that the type of the result 1902 should be the const type. */ 1903 /* A de-reference of a pointer to const is not a const. It is valid 1904 to change it via some other pointer. */ 1905 TREE_READONLY (ref) = TYPE_READONLY (t); 1906 TREE_SIDE_EFFECTS (ref) 1907 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer); 1908 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t); 1909 return ref; 1910 } 1911 } 1912 else if (TREE_CODE (pointer) != ERROR_MARK) 1913 error ("invalid type argument of %qs", errorstring); 1914 return error_mark_node; 1915} 1916 1917/* This handles expressions of the form "a[i]", which denotes 1918 an array reference. 1919 1920 This is logically equivalent in C to *(a+i), but we may do it differently. 1921 If A is a variable or a member, we generate a primitive ARRAY_REF. 1922 This avoids forcing the array out of registers, and can work on 1923 arrays that are not lvalues (for example, members of structures returned 1924 by functions). */ 1925 1926tree 1927build_array_ref (tree array, tree index) 1928{ 1929 bool swapped = false; 1930 if (TREE_TYPE (array) == error_mark_node 1931 || TREE_TYPE (index) == error_mark_node) 1932 return error_mark_node; 1933 1934 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE 1935 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE) 1936 { 1937 tree temp; 1938 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE 1939 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE) 1940 { 1941 error ("subscripted value is neither array nor pointer"); 1942 return error_mark_node; 1943 } 1944 temp = array; 1945 array = index; 1946 index = temp; 1947 swapped = true; 1948 } 1949 1950 if (!INTEGRAL_TYPE_P (TREE_TYPE (index))) 1951 { 1952 error ("array subscript is not an integer"); 1953 return error_mark_node; 1954 } 1955 1956 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE) 1957 { 1958 error ("subscripted value is pointer to function"); 1959 return error_mark_node; 1960 } 1961 1962 /* ??? Existing practice has been to warn only when the char 1963 index is syntactically the index, not for char[array]. */ 1964 if (!swapped) 1965 warn_array_subscript_with_type_char (index); 1966 1967 /* Apply default promotions *after* noticing character types. */ 1968 index = default_conversion (index); 1969 1970 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE); 1971 1972 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE) 1973 { 1974 tree rval, type; 1975 1976 /* An array that is indexed by a non-constant 1977 cannot be stored in a register; we must be able to do 1978 address arithmetic on its address. 1979 Likewise an array of elements of variable size. */ 1980 if (TREE_CODE (index) != INTEGER_CST 1981 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) 1982 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST)) 1983 { 1984 if (!c_mark_addressable (array)) 1985 return error_mark_node; 1986 } 1987 /* An array that is indexed by a constant value which is not within 1988 the array bounds cannot be stored in a register either; because we 1989 would get a crash in store_bit_field/extract_bit_field when trying 1990 to access a non-existent part of the register. */ 1991 if (TREE_CODE (index) == INTEGER_CST 1992 && TYPE_DOMAIN (TREE_TYPE (array)) 1993 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array)))) 1994 { 1995 if (!c_mark_addressable (array)) 1996 return error_mark_node; 1997 } 1998 1999 if (pedantic) 2000 { 2001 tree foo = array; 2002 while (TREE_CODE (foo) == COMPONENT_REF) 2003 foo = TREE_OPERAND (foo, 0); 2004 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo)) 2005 pedwarn ("ISO C forbids subscripting %<register%> array"); 2006 else if (!flag_isoc99 && !lvalue_p (foo)) 2007 pedwarn ("ISO C90 forbids subscripting non-lvalue array"); 2008 } 2009 2010 type = TREE_TYPE (TREE_TYPE (array)); 2011 if (TREE_CODE (type) != ARRAY_TYPE) 2012 type = TYPE_MAIN_VARIANT (type); 2013 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE); 2014 /* Array ref is const/volatile if the array elements are 2015 or if the array is. */ 2016 TREE_READONLY (rval) 2017 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array))) 2018 | TREE_READONLY (array)); 2019 TREE_SIDE_EFFECTS (rval) 2020 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 2021 | TREE_SIDE_EFFECTS (array)); 2022 TREE_THIS_VOLATILE (rval) 2023 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 2024 /* This was added by rms on 16 Nov 91. 2025 It fixes vol struct foo *a; a->elts[1] 2026 in an inline function. 2027 Hope it doesn't break something else. */ 2028 | TREE_THIS_VOLATILE (array)); 2029 return require_complete_type (fold (rval)); 2030 } 2031 else 2032 { 2033 tree ar = default_conversion (array); 2034 2035 if (ar == error_mark_node) 2036 return ar; 2037 2038 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE); 2039 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE); 2040 2041 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0), 2042 "array indexing"); 2043 } 2044} 2045 2046/* Build an external reference to identifier ID. FUN indicates 2047 whether this will be used for a function call. LOC is the source 2048 location of the identifier. */ 2049tree 2050build_external_ref (tree id, int fun, location_t loc) 2051{ 2052 tree ref; 2053 tree decl = lookup_name (id); 2054 2055 /* In Objective-C, an instance variable (ivar) may be preferred to 2056 whatever lookup_name() found. */ 2057 decl = objc_lookup_ivar (decl, id); 2058 2059 if (decl && decl != error_mark_node) 2060 ref = decl; 2061 else if (fun) 2062 /* Implicit function declaration. */ 2063 ref = implicitly_declare (id); 2064 else if (decl == error_mark_node) 2065 /* Don't complain about something that's already been 2066 complained about. */ 2067 return error_mark_node; 2068 else 2069 { 2070 undeclared_variable (id, loc); 2071 return error_mark_node; 2072 } 2073 2074 if (TREE_TYPE (ref) == error_mark_node) 2075 return error_mark_node; 2076 2077 if (TREE_DEPRECATED (ref)) 2078 warn_deprecated_use (ref); 2079 2080 if (!skip_evaluation) 2081 assemble_external (ref); 2082 TREE_USED (ref) = 1; 2083 2084 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof) 2085 { 2086 if (!in_sizeof && !in_typeof) 2087 C_DECL_USED (ref) = 1; 2088 else if (DECL_INITIAL (ref) == 0 2089 && DECL_EXTERNAL (ref) 2090 && !TREE_PUBLIC (ref)) 2091 record_maybe_used_decl (ref); 2092 } 2093 2094 if (TREE_CODE (ref) == CONST_DECL) 2095 { 2096 used_types_insert (TREE_TYPE (ref)); 2097 ref = DECL_INITIAL (ref); 2098 TREE_CONSTANT (ref) = 1; 2099 TREE_INVARIANT (ref) = 1; 2100 } 2101 else if (current_function_decl != 0 2102 && !DECL_FILE_SCOPE_P (current_function_decl) 2103 && (TREE_CODE (ref) == VAR_DECL 2104 || TREE_CODE (ref) == PARM_DECL 2105 || TREE_CODE (ref) == FUNCTION_DECL)) 2106 { 2107 tree context = decl_function_context (ref); 2108 2109 if (context != 0 && context != current_function_decl) 2110 DECL_NONLOCAL (ref) = 1; 2111 } 2112 /* C99 6.7.4p3: An inline definition of a function with external 2113 linkage ... shall not contain a reference to an identifier with 2114 internal linkage. */ 2115 else if (current_function_decl != 0 2116 && DECL_DECLARED_INLINE_P (current_function_decl) 2117 && DECL_EXTERNAL (current_function_decl) 2118 && VAR_OR_FUNCTION_DECL_P (ref) 2119 && DECL_FILE_SCOPE_P (ref) 2120 && pedantic 2121 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref)) 2122 && ! TREE_PUBLIC (ref)) 2123 pedwarn ("%H%qD is static but used in inline function %qD " 2124 "which is not static", &loc, ref, current_function_decl); 2125 2126 return ref; 2127} 2128 2129/* Record details of decls possibly used inside sizeof or typeof. */ 2130struct maybe_used_decl 2131{ 2132 /* The decl. */ 2133 tree decl; 2134 /* The level seen at (in_sizeof + in_typeof). */ 2135 int level; 2136 /* The next one at this level or above, or NULL. */ 2137 struct maybe_used_decl *next; 2138}; 2139 2140static struct maybe_used_decl *maybe_used_decls; 2141 2142/* Record that DECL, an undefined static function reference seen 2143 inside sizeof or typeof, might be used if the operand of sizeof is 2144 a VLA type or the operand of typeof is a variably modified 2145 type. */ 2146 2147static void 2148record_maybe_used_decl (tree decl) 2149{ 2150 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl); 2151 t->decl = decl; 2152 t->level = in_sizeof + in_typeof; 2153 t->next = maybe_used_decls; 2154 maybe_used_decls = t; 2155} 2156 2157/* Pop the stack of decls possibly used inside sizeof or typeof. If 2158 USED is false, just discard them. If it is true, mark them used 2159 (if no longer inside sizeof or typeof) or move them to the next 2160 level up (if still inside sizeof or typeof). */ 2161 2162void 2163pop_maybe_used (bool used) 2164{ 2165 struct maybe_used_decl *p = maybe_used_decls; 2166 int cur_level = in_sizeof + in_typeof; 2167 while (p && p->level > cur_level) 2168 { 2169 if (used) 2170 { 2171 if (cur_level == 0) 2172 C_DECL_USED (p->decl) = 1; 2173 else 2174 p->level = cur_level; 2175 } 2176 p = p->next; 2177 } 2178 if (!used || cur_level == 0) 2179 maybe_used_decls = p; 2180} 2181 2182/* Return the result of sizeof applied to EXPR. */ 2183 2184struct c_expr 2185c_expr_sizeof_expr (struct c_expr expr) 2186{ 2187 struct c_expr ret; 2188 if (expr.value == error_mark_node) 2189 { 2190 ret.value = error_mark_node; 2191 ret.original_code = ERROR_MARK; 2192 pop_maybe_used (false); 2193 } 2194 else 2195 { 2196 ret.value = c_sizeof (TREE_TYPE (expr.value)); 2197 ret.original_code = ERROR_MARK; 2198 if (c_vla_type_p (TREE_TYPE (expr.value))) 2199 { 2200 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */ 2201 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value); 2202 } 2203 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value))); 2204 } 2205 return ret; 2206} 2207 2208/* Return the result of sizeof applied to T, a structure for the type 2209 name passed to sizeof (rather than the type itself). */ 2210 2211struct c_expr 2212c_expr_sizeof_type (struct c_type_name *t) 2213{ 2214 tree type; 2215 struct c_expr ret; 2216 type = groktypename (t); 2217 ret.value = c_sizeof (type); 2218 ret.original_code = ERROR_MARK; 2219 pop_maybe_used (type != error_mark_node 2220 ? C_TYPE_VARIABLE_SIZE (type) : false); 2221 return ret; 2222} 2223 2224/* Build a function call to function FUNCTION with parameters PARAMS. 2225 PARAMS is a list--a chain of TREE_LIST nodes--in which the 2226 TREE_VALUE of each node is a parameter-expression. 2227 FUNCTION's data type may be a function type or a pointer-to-function. */ 2228 2229tree 2230build_function_call (tree function, tree params) 2231{ 2232 tree fntype, fundecl = 0; 2233 tree coerced_params; 2234 tree name = NULL_TREE, result; 2235 tree tem; 2236 2237 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 2238 STRIP_TYPE_NOPS (function); 2239 2240 /* Convert anything with function type to a pointer-to-function. */ 2241 if (TREE_CODE (function) == FUNCTION_DECL) 2242 { 2243 /* Implement type-directed function overloading for builtins. 2244 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin 2245 handle all the type checking. The result is a complete expression 2246 that implements this function call. */ 2247 tem = resolve_overloaded_builtin (function, params); 2248 if (tem) 2249 return tem; 2250 2251 name = DECL_NAME (function); 2252 fundecl = function; 2253 } 2254 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE) 2255 function = function_to_pointer_conversion (function); 2256 2257 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF 2258 expressions, like those used for ObjC messenger dispatches. */ 2259 function = objc_rewrite_function_call (function, params); 2260 2261 fntype = TREE_TYPE (function); 2262 2263 if (TREE_CODE (fntype) == ERROR_MARK) 2264 return error_mark_node; 2265 2266 if (!(TREE_CODE (fntype) == POINTER_TYPE 2267 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) 2268 { 2269 error ("called object %qE is not a function", function); 2270 return error_mark_node; 2271 } 2272 2273 if (fundecl && TREE_THIS_VOLATILE (fundecl)) 2274 current_function_returns_abnormally = 1; 2275 2276 /* fntype now gets the type of function pointed to. */ 2277 fntype = TREE_TYPE (fntype); 2278 2279 /* Check that the function is called through a compatible prototype. 2280 If it is not, replace the call by a trap, wrapped up in a compound 2281 expression if necessary. This has the nice side-effect to prevent 2282 the tree-inliner from generating invalid assignment trees which may 2283 blow up in the RTL expander later. */ 2284 if ((TREE_CODE (function) == NOP_EXPR 2285 || TREE_CODE (function) == CONVERT_EXPR) 2286 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR 2287 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL 2288 && !comptypes (fntype, TREE_TYPE (tem))) 2289 { 2290 tree return_type = TREE_TYPE (fntype); 2291 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], 2292 NULL_TREE); 2293 2294 /* This situation leads to run-time undefined behavior. We can't, 2295 therefore, simply error unless we can prove that all possible 2296 executions of the program must execute the code. */ 2297 warning (0, "function called through a non-compatible type"); 2298 2299 /* We can, however, treat "undefined" any way we please. 2300 Call abort to encourage the user to fix the program. */ 2301 inform ("if this code is reached, the program will abort"); 2302 2303 if (VOID_TYPE_P (return_type)) 2304 return trap; 2305 else 2306 { 2307 tree rhs; 2308 2309 if (AGGREGATE_TYPE_P (return_type)) 2310 rhs = build_compound_literal (return_type, 2311 build_constructor (return_type, 0)); 2312 else 2313 rhs = fold_convert (return_type, integer_zero_node); 2314 2315 return build2 (COMPOUND_EXPR, return_type, trap, rhs); 2316 } 2317 } 2318 2319 /* Convert the parameters to the types declared in the 2320 function prototype, or apply default promotions. */ 2321 2322 coerced_params 2323 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl); 2324 2325 if (coerced_params == error_mark_node) 2326 return error_mark_node; 2327 2328 /* Check that the arguments to the function are valid. */ 2329 2330 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params, 2331 TYPE_ARG_TYPES (fntype)); 2332 2333 if (require_constant_value) 2334 { 2335 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype), 2336 function, coerced_params, NULL_TREE); 2337 2338 if (TREE_CONSTANT (result) 2339 && (name == NULL_TREE 2340 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) 2341 pedwarn_init ("initializer element is not constant"); 2342 } 2343 else 2344 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype), 2345 function, coerced_params, NULL_TREE); 2346 2347 if (VOID_TYPE_P (TREE_TYPE (result))) 2348 return result; 2349 return require_complete_type (result); 2350} 2351 2352/* Convert the argument expressions in the list VALUES 2353 to the types in the list TYPELIST. The result is a list of converted 2354 argument expressions, unless there are too few arguments in which 2355 case it is error_mark_node. 2356 2357 If TYPELIST is exhausted, or when an element has NULL as its type, 2358 perform the default conversions. 2359 2360 PARMLIST is the chain of parm decls for the function being called. 2361 It may be 0, if that info is not available. 2362 It is used only for generating error messages. 2363 2364 FUNCTION is a tree for the called function. It is used only for 2365 error messages, where it is formatted with %qE. 2366 2367 This is also where warnings about wrong number of args are generated. 2368 2369 Both VALUES and the returned value are chains of TREE_LIST nodes 2370 with the elements of the list in the TREE_VALUE slots of those nodes. */ 2371 2372static tree 2373convert_arguments (tree typelist, tree values, tree function, tree fundecl) 2374{ 2375 tree typetail, valtail; 2376 tree result = NULL; 2377 int parmnum; 2378 tree selector; 2379 2380 /* Change pointer to function to the function itself for 2381 diagnostics. */ 2382 if (TREE_CODE (function) == ADDR_EXPR 2383 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 2384 function = TREE_OPERAND (function, 0); 2385 2386 /* Handle an ObjC selector specially for diagnostics. */ 2387 selector = objc_message_selector (); 2388 2389 /* Scan the given expressions and types, producing individual 2390 converted arguments and pushing them on RESULT in reverse order. */ 2391 2392 for (valtail = values, typetail = typelist, parmnum = 0; 2393 valtail; 2394 valtail = TREE_CHAIN (valtail), parmnum++) 2395 { 2396 tree type = typetail ? TREE_VALUE (typetail) : 0; 2397 tree val = TREE_VALUE (valtail); 2398 tree rname = function; 2399 int argnum = parmnum + 1; 2400 const char *invalid_func_diag; 2401 2402 if (type == void_type_node) 2403 { 2404 error ("too many arguments to function %qE", function); 2405 break; 2406 } 2407 2408 if (selector && argnum > 2) 2409 { 2410 rname = selector; 2411 argnum -= 2; 2412 } 2413 2414 STRIP_TYPE_NOPS (val); 2415 2416 val = require_complete_type (val); 2417 2418 if (type != 0) 2419 { 2420 /* Formal parm type is specified by a function prototype. */ 2421 tree parmval; 2422 2423 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 2424 { 2425 error ("type of formal parameter %d is incomplete", parmnum + 1); 2426 parmval = val; 2427 } 2428 else 2429 { 2430 /* Optionally warn about conversions that 2431 differ from the default conversions. */ 2432 if (warn_conversion || warn_traditional) 2433 { 2434 unsigned int formal_prec = TYPE_PRECISION (type); 2435 2436 if (INTEGRAL_TYPE_P (type) 2437 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2438 warning (0, "passing argument %d of %qE as integer " 2439 "rather than floating due to prototype", 2440 argnum, rname); 2441 if (INTEGRAL_TYPE_P (type) 2442 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2443 warning (0, "passing argument %d of %qE as integer " 2444 "rather than complex due to prototype", 2445 argnum, rname); 2446 else if (TREE_CODE (type) == COMPLEX_TYPE 2447 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2448 warning (0, "passing argument %d of %qE as complex " 2449 "rather than floating due to prototype", 2450 argnum, rname); 2451 else if (TREE_CODE (type) == REAL_TYPE 2452 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2453 warning (0, "passing argument %d of %qE as floating " 2454 "rather than integer due to prototype", 2455 argnum, rname); 2456 else if (TREE_CODE (type) == COMPLEX_TYPE 2457 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2458 warning (0, "passing argument %d of %qE as complex " 2459 "rather than integer due to prototype", 2460 argnum, rname); 2461 else if (TREE_CODE (type) == REAL_TYPE 2462 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2463 warning (0, "passing argument %d of %qE as floating " 2464 "rather than complex due to prototype", 2465 argnum, rname); 2466 /* ??? At some point, messages should be written about 2467 conversions between complex types, but that's too messy 2468 to do now. */ 2469 else if (TREE_CODE (type) == REAL_TYPE 2470 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2471 { 2472 /* Warn if any argument is passed as `float', 2473 since without a prototype it would be `double'. */ 2474 if (formal_prec == TYPE_PRECISION (float_type_node) 2475 && type != dfloat32_type_node) 2476 warning (0, "passing argument %d of %qE as %<float%> " 2477 "rather than %<double%> due to prototype", 2478 argnum, rname); 2479 2480 /* Warn if mismatch between argument and prototype 2481 for decimal float types. Warn of conversions with 2482 binary float types and of precision narrowing due to 2483 prototype. */ 2484 else if (type != TREE_TYPE (val) 2485 && (type == dfloat32_type_node 2486 || type == dfloat64_type_node 2487 || type == dfloat128_type_node 2488 || TREE_TYPE (val) == dfloat32_type_node 2489 || TREE_TYPE (val) == dfloat64_type_node 2490 || TREE_TYPE (val) == dfloat128_type_node) 2491 && (formal_prec 2492 <= TYPE_PRECISION (TREE_TYPE (val)) 2493 || (type == dfloat128_type_node 2494 && (TREE_TYPE (val) 2495 != dfloat64_type_node 2496 && (TREE_TYPE (val) 2497 != dfloat32_type_node))) 2498 || (type == dfloat64_type_node 2499 && (TREE_TYPE (val) 2500 != dfloat32_type_node)))) 2501 warning (0, "passing argument %d of %qE as %qT " 2502 "rather than %qT due to prototype", 2503 argnum, rname, type, TREE_TYPE (val)); 2504 2505 } 2506 /* Detect integer changing in width or signedness. 2507 These warnings are only activated with 2508 -Wconversion, not with -Wtraditional. */ 2509 else if (warn_conversion && INTEGRAL_TYPE_P (type) 2510 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2511 { 2512 tree would_have_been = default_conversion (val); 2513 tree type1 = TREE_TYPE (would_have_been); 2514 2515 if (TREE_CODE (type) == ENUMERAL_TYPE 2516 && (TYPE_MAIN_VARIANT (type) 2517 == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) 2518 /* No warning if function asks for enum 2519 and the actual arg is that enum type. */ 2520 ; 2521 else if (formal_prec != TYPE_PRECISION (type1)) 2522 warning (OPT_Wconversion, "passing argument %d of %qE " 2523 "with different width due to prototype", 2524 argnum, rname); 2525 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1)) 2526 ; 2527 /* Don't complain if the formal parameter type 2528 is an enum, because we can't tell now whether 2529 the value was an enum--even the same enum. */ 2530 else if (TREE_CODE (type) == ENUMERAL_TYPE) 2531 ; 2532 else if (TREE_CODE (val) == INTEGER_CST 2533 && int_fits_type_p (val, type)) 2534 /* Change in signedness doesn't matter 2535 if a constant value is unaffected. */ 2536 ; 2537 /* If the value is extended from a narrower 2538 unsigned type, it doesn't matter whether we 2539 pass it as signed or unsigned; the value 2540 certainly is the same either way. */ 2541 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) 2542 && TYPE_UNSIGNED (TREE_TYPE (val))) 2543 ; 2544 else if (TYPE_UNSIGNED (type)) 2545 warning (OPT_Wconversion, "passing argument %d of %qE " 2546 "as unsigned due to prototype", 2547 argnum, rname); 2548 else 2549 warning (OPT_Wconversion, "passing argument %d of %qE " 2550 "as signed due to prototype", argnum, rname); 2551 } 2552 } 2553 2554 parmval = convert_for_assignment (type, val, ic_argpass, 2555 fundecl, function, 2556 parmnum + 1); 2557 2558 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) 2559 && INTEGRAL_TYPE_P (type) 2560 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 2561 parmval = default_conversion (parmval); 2562 } 2563 result = tree_cons (NULL_TREE, parmval, result); 2564 } 2565 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE 2566 && (TYPE_PRECISION (TREE_TYPE (val)) 2567 < TYPE_PRECISION (double_type_node)) 2568 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val)))) 2569 /* Convert `float' to `double'. */ 2570 result = tree_cons (NULL_TREE, convert (double_type_node, val), result); 2571 else if ((invalid_func_diag = 2572 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val))) 2573 { 2574 error (invalid_func_diag); 2575 return error_mark_node; 2576 } 2577 else 2578 /* Convert `short' and `char' to full-size `int'. */ 2579 result = tree_cons (NULL_TREE, default_conversion (val), result); 2580 2581 if (typetail) 2582 typetail = TREE_CHAIN (typetail); 2583 } 2584 2585 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) 2586 { 2587 error ("too few arguments to function %qE", function); 2588 return error_mark_node; 2589 } 2590 2591 return nreverse (result); 2592} 2593 2594/* This is the entry point used by the parser to build unary operators 2595 in the input. CODE, a tree_code, specifies the unary operator, and 2596 ARG is the operand. For unary plus, the C parser currently uses 2597 CONVERT_EXPR for code. */ 2598 2599struct c_expr 2600parser_build_unary_op (enum tree_code code, struct c_expr arg) 2601{ 2602 struct c_expr result; 2603 2604 result.original_code = ERROR_MARK; 2605 result.value = build_unary_op (code, arg.value, 0); 2606 overflow_warning (result.value); 2607 return result; 2608} 2609 2610/* This is the entry point used by the parser to build binary operators 2611 in the input. CODE, a tree_code, specifies the binary operator, and 2612 ARG1 and ARG2 are the operands. In addition to constructing the 2613 expression, we check for operands that were written with other binary 2614 operators in a way that is likely to confuse the user. */ 2615 2616struct c_expr 2617parser_build_binary_op (enum tree_code code, struct c_expr arg1, 2618 struct c_expr arg2) 2619{ 2620 struct c_expr result; 2621 2622 enum tree_code code1 = arg1.original_code; 2623 enum tree_code code2 = arg2.original_code; 2624 2625 result.value = build_binary_op (code, arg1.value, arg2.value, 1); 2626 result.original_code = code; 2627 2628 if (TREE_CODE (result.value) == ERROR_MARK) 2629 return result; 2630 2631 /* Check for cases such as x+y<<z which users are likely 2632 to misinterpret. */ 2633 if (warn_parentheses) 2634 { 2635 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 2636 { 2637 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2638 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2639 warning (OPT_Wparentheses, 2640 "suggest parentheses around + or - inside shift"); 2641 } 2642 2643 if (code == TRUTH_ORIF_EXPR) 2644 { 2645 if (code1 == TRUTH_ANDIF_EXPR 2646 || code2 == TRUTH_ANDIF_EXPR) 2647 warning (OPT_Wparentheses, 2648 "suggest parentheses around && within ||"); 2649 } 2650 2651 if (code == BIT_IOR_EXPR) 2652 { 2653 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR 2654 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2655 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR 2656 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2657 warning (OPT_Wparentheses, 2658 "suggest parentheses around arithmetic in operand of |"); 2659 /* Check cases like x|y==z */ 2660 if (TREE_CODE_CLASS (code1) == tcc_comparison 2661 || TREE_CODE_CLASS (code2) == tcc_comparison) 2662 warning (OPT_Wparentheses, 2663 "suggest parentheses around comparison in operand of |"); 2664 } 2665 2666 if (code == BIT_XOR_EXPR) 2667 { 2668 if (code1 == BIT_AND_EXPR 2669 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2670 || code2 == BIT_AND_EXPR 2671 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2672 warning (OPT_Wparentheses, 2673 "suggest parentheses around arithmetic in operand of ^"); 2674 /* Check cases like x^y==z */ 2675 if (TREE_CODE_CLASS (code1) == tcc_comparison 2676 || TREE_CODE_CLASS (code2) == tcc_comparison) 2677 warning (OPT_Wparentheses, 2678 "suggest parentheses around comparison in operand of ^"); 2679 } 2680 2681 if (code == BIT_AND_EXPR) 2682 { 2683 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2684 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2685 warning (OPT_Wparentheses, 2686 "suggest parentheses around + or - in operand of &"); 2687 /* Check cases like x&y==z */ 2688 if (TREE_CODE_CLASS (code1) == tcc_comparison 2689 || TREE_CODE_CLASS (code2) == tcc_comparison) 2690 warning (OPT_Wparentheses, 2691 "suggest parentheses around comparison in operand of &"); 2692 } 2693 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 2694 if (TREE_CODE_CLASS (code) == tcc_comparison 2695 && (TREE_CODE_CLASS (code1) == tcc_comparison 2696 || TREE_CODE_CLASS (code2) == tcc_comparison)) 2697 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not " 2698 "have their mathematical meaning"); 2699 2700 } 2701 2702 /* Warn about comparisons against string literals, with the exception 2703 of testing for equality or inequality of a string literal with NULL. */ 2704 if (code == EQ_EXPR || code == NE_EXPR) 2705 { 2706 if ((code1 == STRING_CST && !integer_zerop (arg2.value)) 2707 || (code2 == STRING_CST && !integer_zerop (arg1.value))) 2708 warning (OPT_Waddress, 2709 "comparison with string literal results in unspecified behaviour"); 2710 } 2711 else if (TREE_CODE_CLASS (code) == tcc_comparison 2712 && (code1 == STRING_CST || code2 == STRING_CST)) 2713 warning (OPT_Waddress, 2714 "comparison with string literal results in unspecified behaviour"); 2715 2716 overflow_warning (result.value); 2717 2718 return result; 2719} 2720 2721/* Return a tree for the difference of pointers OP0 and OP1. 2722 The resulting tree has type int. */ 2723 2724static tree 2725pointer_diff (tree op0, tree op1) 2726{ 2727 tree restype = ptrdiff_type_node; 2728 2729 tree target_type = TREE_TYPE (TREE_TYPE (op0)); 2730 tree con0, con1, lit0, lit1; 2731 tree orig_op1 = op1; 2732 2733 if (pedantic || warn_pointer_arith) 2734 { 2735 if (TREE_CODE (target_type) == VOID_TYPE) 2736 pedwarn ("pointer of type %<void *%> used in subtraction"); 2737 if (TREE_CODE (target_type) == FUNCTION_TYPE) 2738 pedwarn ("pointer to a function used in subtraction"); 2739 } 2740 2741 /* If the conversion to ptrdiff_type does anything like widening or 2742 converting a partial to an integral mode, we get a convert_expression 2743 that is in the way to do any simplifications. 2744 (fold-const.c doesn't know that the extra bits won't be needed. 2745 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a 2746 different mode in place.) 2747 So first try to find a common term here 'by hand'; we want to cover 2748 at least the cases that occur in legal static initializers. */ 2749 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR) 2750 && (TYPE_PRECISION (TREE_TYPE (op0)) 2751 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0))))) 2752 con0 = TREE_OPERAND (op0, 0); 2753 else 2754 con0 = op0; 2755 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR) 2756 && (TYPE_PRECISION (TREE_TYPE (op1)) 2757 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0))))) 2758 con1 = TREE_OPERAND (op1, 0); 2759 else 2760 con1 = op1; 2761 2762 if (TREE_CODE (con0) == PLUS_EXPR) 2763 { 2764 lit0 = TREE_OPERAND (con0, 1); 2765 con0 = TREE_OPERAND (con0, 0); 2766 } 2767 else 2768 lit0 = integer_zero_node; 2769 2770 if (TREE_CODE (con1) == PLUS_EXPR) 2771 { 2772 lit1 = TREE_OPERAND (con1, 1); 2773 con1 = TREE_OPERAND (con1, 0); 2774 } 2775 else 2776 lit1 = integer_zero_node; 2777 2778 if (operand_equal_p (con0, con1, 0)) 2779 { 2780 op0 = lit0; 2781 op1 = lit1; 2782 } 2783 2784 2785 /* First do the subtraction as integers; 2786 then drop through to build the divide operator. 2787 Do not do default conversions on the minus operator 2788 in case restype is a short type. */ 2789 2790 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), 2791 convert (restype, op1), 0); 2792 /* This generates an error if op1 is pointer to incomplete type. */ 2793 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) 2794 error ("arithmetic on pointer to an incomplete type"); 2795 2796 /* This generates an error if op0 is pointer to incomplete type. */ 2797 op1 = c_size_in_bytes (target_type); 2798 2799 /* Divide by the size, in easiest possible way. */ 2800 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1)); 2801} 2802 2803/* Construct and perhaps optimize a tree representation 2804 for a unary operation. CODE, a tree_code, specifies the operation 2805 and XARG is the operand. 2806 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses 2807 the default promotions (such as from short to int). 2808 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero 2809 allows non-lvalues; this is only used to handle conversion of non-lvalue 2810 arrays to pointers in C99. */ 2811 2812tree 2813build_unary_op (enum tree_code code, tree xarg, int flag) 2814{ 2815 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 2816 tree arg = xarg; 2817 tree argtype = 0; 2818 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); 2819 tree val; 2820 int noconvert = flag; 2821 const char *invalid_op_diag; 2822 2823 if (typecode == ERROR_MARK) 2824 return error_mark_node; 2825 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) 2826 typecode = INTEGER_TYPE; 2827 2828 if ((invalid_op_diag 2829 = targetm.invalid_unary_op (code, TREE_TYPE (xarg)))) 2830 { 2831 error (invalid_op_diag); 2832 return error_mark_node; 2833 } 2834 2835 switch (code) 2836 { 2837 case CONVERT_EXPR: 2838 /* This is used for unary plus, because a CONVERT_EXPR 2839 is enough to prevent anybody from looking inside for 2840 associativity, but won't generate any code. */ 2841 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2842 || typecode == COMPLEX_TYPE 2843 || typecode == VECTOR_TYPE)) 2844 { 2845 error ("wrong type argument to unary plus"); 2846 return error_mark_node; 2847 } 2848 else if (!noconvert) 2849 arg = default_conversion (arg); 2850 arg = non_lvalue (arg); 2851 break; 2852 2853 case NEGATE_EXPR: 2854 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2855 || typecode == COMPLEX_TYPE 2856 || typecode == VECTOR_TYPE)) 2857 { 2858 error ("wrong type argument to unary minus"); 2859 return error_mark_node; 2860 } 2861 else if (!noconvert) 2862 arg = default_conversion (arg); 2863 break; 2864 2865 case BIT_NOT_EXPR: 2866 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) 2867 { 2868 if (!noconvert) 2869 arg = default_conversion (arg); 2870 } 2871 else if (typecode == COMPLEX_TYPE) 2872 { 2873 code = CONJ_EXPR; 2874 if (pedantic) 2875 pedwarn ("ISO C does not support %<~%> for complex conjugation"); 2876 if (!noconvert) 2877 arg = default_conversion (arg); 2878 } 2879 else 2880 { 2881 error ("wrong type argument to bit-complement"); 2882 return error_mark_node; 2883 } 2884 break; 2885 2886 case ABS_EXPR: 2887 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) 2888 { 2889 error ("wrong type argument to abs"); 2890 return error_mark_node; 2891 } 2892 else if (!noconvert) 2893 arg = default_conversion (arg); 2894 break; 2895 2896 case CONJ_EXPR: 2897 /* Conjugating a real value is a no-op, but allow it anyway. */ 2898 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2899 || typecode == COMPLEX_TYPE)) 2900 { 2901 error ("wrong type argument to conjugation"); 2902 return error_mark_node; 2903 } 2904 else if (!noconvert) 2905 arg = default_conversion (arg); 2906 break; 2907 2908 case TRUTH_NOT_EXPR: 2909 if (typecode != INTEGER_TYPE 2910 && typecode != REAL_TYPE && typecode != POINTER_TYPE 2911 && typecode != COMPLEX_TYPE) 2912 { 2913 error ("wrong type argument to unary exclamation mark"); 2914 return error_mark_node; 2915 } 2916 arg = c_objc_common_truthvalue_conversion (arg); 2917 return invert_truthvalue (arg); 2918 2919 case REALPART_EXPR: 2920 if (TREE_CODE (arg) == COMPLEX_CST) 2921 return TREE_REALPART (arg); 2922 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2923 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2924 else 2925 return arg; 2926 2927 case IMAGPART_EXPR: 2928 if (TREE_CODE (arg) == COMPLEX_CST) 2929 return TREE_IMAGPART (arg); 2930 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2931 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2932 else 2933 return convert (TREE_TYPE (arg), integer_zero_node); 2934 2935 case PREINCREMENT_EXPR: 2936 case POSTINCREMENT_EXPR: 2937 case PREDECREMENT_EXPR: 2938 case POSTDECREMENT_EXPR: 2939 2940 /* Increment or decrement the real part of the value, 2941 and don't change the imaginary part. */ 2942 if (typecode == COMPLEX_TYPE) 2943 { 2944 tree real, imag; 2945 2946 if (pedantic) 2947 pedwarn ("ISO C does not support %<++%> and %<--%>" 2948 " on complex types"); 2949 2950 arg = stabilize_reference (arg); 2951 real = build_unary_op (REALPART_EXPR, arg, 1); 2952 imag = build_unary_op (IMAGPART_EXPR, arg, 1); 2953 return build2 (COMPLEX_EXPR, TREE_TYPE (arg), 2954 build_unary_op (code, real, 1), imag); 2955 } 2956 2957 /* Report invalid types. */ 2958 2959 if (typecode != POINTER_TYPE 2960 && typecode != INTEGER_TYPE && typecode != REAL_TYPE) 2961 { 2962 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2963 error ("wrong type argument to increment"); 2964 else 2965 error ("wrong type argument to decrement"); 2966 2967 return error_mark_node; 2968 } 2969 2970 { 2971 tree inc; 2972 tree result_type = TREE_TYPE (arg); 2973 2974 arg = get_unwidened (arg, 0); 2975 argtype = TREE_TYPE (arg); 2976 2977 /* Compute the increment. */ 2978 2979 if (typecode == POINTER_TYPE) 2980 { 2981 /* If pointer target is an undefined struct, 2982 we just cannot know how to do the arithmetic. */ 2983 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) 2984 { 2985 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2986 error ("increment of pointer to unknown structure"); 2987 else 2988 error ("decrement of pointer to unknown structure"); 2989 } 2990 else if ((pedantic || warn_pointer_arith) 2991 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE 2992 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) 2993 { 2994 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2995 pedwarn ("wrong type argument to increment"); 2996 else 2997 pedwarn ("wrong type argument to decrement"); 2998 } 2999 3000 inc = c_size_in_bytes (TREE_TYPE (result_type)); 3001 } 3002 else 3003 inc = integer_one_node; 3004 3005 inc = convert (argtype, inc); 3006 3007 /* Complain about anything else that is not a true lvalue. */ 3008 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 3009 || code == POSTINCREMENT_EXPR) 3010 ? lv_increment 3011 : lv_decrement))) 3012 return error_mark_node; 3013 3014 /* Report a read-only lvalue. */ 3015 if (TREE_READONLY (arg)) 3016 { 3017 readonly_error (arg, 3018 ((code == PREINCREMENT_EXPR 3019 || code == POSTINCREMENT_EXPR) 3020 ? lv_increment : lv_decrement)); 3021 return error_mark_node; 3022 } 3023 3024 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 3025 val = boolean_increment (code, arg); 3026 else 3027 val = build2 (code, TREE_TYPE (arg), arg, inc); 3028 TREE_SIDE_EFFECTS (val) = 1; 3029 val = convert (result_type, val); 3030 if (TREE_CODE (val) != code) 3031 TREE_NO_WARNING (val) = 1; 3032 return val; 3033 } 3034 3035 case ADDR_EXPR: 3036 /* Note that this operation never does default_conversion. */ 3037 3038 /* Let &* cancel out to simplify resulting code. */ 3039 if (TREE_CODE (arg) == INDIRECT_REF) 3040 { 3041 /* Don't let this be an lvalue. */ 3042 if (lvalue_p (TREE_OPERAND (arg, 0))) 3043 return non_lvalue (TREE_OPERAND (arg, 0)); 3044 return TREE_OPERAND (arg, 0); 3045 } 3046 3047 /* For &x[y], return x+y */ 3048 if (TREE_CODE (arg) == ARRAY_REF) 3049 { 3050 tree op0 = TREE_OPERAND (arg, 0); 3051 if (!c_mark_addressable (op0)) 3052 return error_mark_node; 3053 return build_binary_op (PLUS_EXPR, 3054 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE 3055 ? array_to_pointer_conversion (op0) 3056 : op0), 3057 TREE_OPERAND (arg, 1), 1); 3058 } 3059 3060 /* Anything not already handled and not a true memory reference 3061 or a non-lvalue array is an error. */ 3062 else if (typecode != FUNCTION_TYPE && !flag 3063 && !lvalue_or_else (arg, lv_addressof)) 3064 return error_mark_node; 3065 3066 /* Ordinary case; arg is a COMPONENT_REF or a decl. */ 3067 argtype = TREE_TYPE (arg); 3068 3069 /* If the lvalue is const or volatile, merge that into the type 3070 to which the address will point. Note that you can't get a 3071 restricted pointer by taking the address of something, so we 3072 only have to deal with `const' and `volatile' here. */ 3073 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg)) 3074 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) 3075 argtype = c_build_type_variant (argtype, 3076 TREE_READONLY (arg), 3077 TREE_THIS_VOLATILE (arg)); 3078 3079 if (!c_mark_addressable (arg)) 3080 return error_mark_node; 3081 3082 gcc_assert (TREE_CODE (arg) != COMPONENT_REF 3083 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))); 3084 3085 argtype = build_pointer_type (argtype); 3086 3087 /* ??? Cope with user tricks that amount to offsetof. Delete this 3088 when we have proper support for integer constant expressions. */ 3089 val = get_base_address (arg); 3090 if (val && TREE_CODE (val) == INDIRECT_REF 3091 && TREE_CONSTANT (TREE_OPERAND (val, 0))) 3092 { 3093 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1; 3094 3095 op1 = fold_convert (argtype, TREE_OPERAND (val, 0)); 3096 return fold_build2 (PLUS_EXPR, argtype, op0, op1); 3097 } 3098 3099 val = build1 (ADDR_EXPR, argtype, arg); 3100 3101 return val; 3102 3103 default: 3104 gcc_unreachable (); 3105 } 3106 3107 if (argtype == 0) 3108 argtype = TREE_TYPE (arg); 3109 return require_constant_value ? fold_build1_initializer (code, argtype, arg) 3110 : fold_build1 (code, argtype, arg); 3111} 3112 3113/* Return nonzero if REF is an lvalue valid for this language. 3114 Lvalues can be assigned, unless their type has TYPE_READONLY. 3115 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */ 3116 3117static int 3118lvalue_p (tree ref) 3119{ 3120 enum tree_code code = TREE_CODE (ref); 3121 3122 switch (code) 3123 { 3124 case REALPART_EXPR: 3125 case IMAGPART_EXPR: 3126 case COMPONENT_REF: 3127 return lvalue_p (TREE_OPERAND (ref, 0)); 3128 3129 case COMPOUND_LITERAL_EXPR: 3130 case STRING_CST: 3131 return 1; 3132 3133 case INDIRECT_REF: 3134 case ARRAY_REF: 3135 case VAR_DECL: 3136 case PARM_DECL: 3137 case RESULT_DECL: 3138 case ERROR_MARK: 3139 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE 3140 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); 3141 3142 case BIND_EXPR: 3143 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; 3144 3145 default: 3146 return 0; 3147 } 3148} 3149 3150/* Give an error for storing in something that is 'const'. */ 3151 3152static void 3153readonly_error (tree arg, enum lvalue_use use) 3154{ 3155 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement 3156 || use == lv_asm); 3157 /* Using this macro rather than (for example) arrays of messages 3158 ensures that all the format strings are checked at compile 3159 time. */ 3160#define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \ 3161 : (use == lv_increment ? (I) \ 3162 : (use == lv_decrement ? (D) : (AS)))) 3163 if (TREE_CODE (arg) == COMPONENT_REF) 3164 { 3165 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) 3166 readonly_error (TREE_OPERAND (arg, 0), use); 3167 else 3168 error (READONLY_MSG (G_("assignment of read-only member %qD"), 3169 G_("increment of read-only member %qD"), 3170 G_("decrement of read-only member %qD"), 3171 G_("read-only member %qD used as %<asm%> output")), 3172 TREE_OPERAND (arg, 1)); 3173 } 3174 else if (TREE_CODE (arg) == VAR_DECL) 3175 error (READONLY_MSG (G_("assignment of read-only variable %qD"), 3176 G_("increment of read-only variable %qD"), 3177 G_("decrement of read-only variable %qD"), 3178 G_("read-only variable %qD used as %<asm%> output")), 3179 arg); 3180 else 3181 error (READONLY_MSG (G_("assignment of read-only location"), 3182 G_("increment of read-only location"), 3183 G_("decrement of read-only location"), 3184 G_("read-only location used as %<asm%> output"))); 3185} 3186 3187 3188/* Return nonzero if REF is an lvalue valid for this language; 3189 otherwise, print an error message and return zero. USE says 3190 how the lvalue is being used and so selects the error message. */ 3191 3192static int 3193lvalue_or_else (tree ref, enum lvalue_use use) 3194{ 3195 int win = lvalue_p (ref); 3196 3197 if (!win) 3198 lvalue_error (use); 3199 3200 return win; 3201} 3202 3203/* Mark EXP saying that we need to be able to take the 3204 address of it; it should not be allocated in a register. 3205 Returns true if successful. */ 3206 3207bool 3208c_mark_addressable (tree exp) 3209{ 3210 tree x = exp; 3211 3212 while (1) 3213 switch (TREE_CODE (x)) 3214 { 3215 case COMPONENT_REF: 3216 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) 3217 { 3218 error 3219 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1)); 3220 return false; 3221 } 3222 3223 /* ... fall through ... */ 3224 3225 case ADDR_EXPR: 3226 case ARRAY_REF: 3227 case REALPART_EXPR: 3228 case IMAGPART_EXPR: 3229 x = TREE_OPERAND (x, 0); 3230 break; 3231 3232 case COMPOUND_LITERAL_EXPR: 3233 case CONSTRUCTOR: 3234 TREE_ADDRESSABLE (x) = 1; 3235 return true; 3236 3237 case VAR_DECL: 3238 case CONST_DECL: 3239 case PARM_DECL: 3240 case RESULT_DECL: 3241 if (C_DECL_REGISTER (x) 3242 && DECL_NONLOCAL (x)) 3243 { 3244 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3245 { 3246 error 3247 ("global register variable %qD used in nested function", x); 3248 return false; 3249 } 3250 pedwarn ("register variable %qD used in nested function", x); 3251 } 3252 else if (C_DECL_REGISTER (x)) 3253 { 3254 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3255 error ("address of global register variable %qD requested", x); 3256 else 3257 error ("address of register variable %qD requested", x); 3258 return false; 3259 } 3260 3261 /* drops in */ 3262 case FUNCTION_DECL: 3263 TREE_ADDRESSABLE (x) = 1; 3264 /* drops out */ 3265 default: 3266 return true; 3267 } 3268} 3269 3270/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 3271 3272tree 3273build_conditional_expr (tree ifexp, tree op1, tree op2) 3274{ 3275 tree type1; 3276 tree type2; 3277 enum tree_code code1; 3278 enum tree_code code2; 3279 tree result_type = NULL; 3280 tree orig_op1 = op1, orig_op2 = op2; 3281 3282 /* Promote both alternatives. */ 3283 3284 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) 3285 op1 = default_conversion (op1); 3286 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) 3287 op2 = default_conversion (op2); 3288 3289 if (TREE_CODE (ifexp) == ERROR_MARK 3290 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK 3291 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) 3292 return error_mark_node; 3293 3294 type1 = TREE_TYPE (op1); 3295 code1 = TREE_CODE (type1); 3296 type2 = TREE_TYPE (op2); 3297 code2 = TREE_CODE (type2); 3298 3299 /* C90 does not permit non-lvalue arrays in conditional expressions. 3300 In C99 they will be pointers by now. */ 3301 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE) 3302 { 3303 error ("non-lvalue array in conditional expression"); 3304 return error_mark_node; 3305 } 3306 3307 /* Quickly detect the usual case where op1 and op2 have the same type 3308 after promotion. */ 3309 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) 3310 { 3311 if (type1 == type2) 3312 result_type = type1; 3313 else 3314 result_type = TYPE_MAIN_VARIANT (type1); 3315 } 3316 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE 3317 || code1 == COMPLEX_TYPE) 3318 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE 3319 || code2 == COMPLEX_TYPE)) 3320 { 3321 result_type = c_common_type (type1, type2); 3322 3323 /* If -Wsign-compare, warn here if type1 and type2 have 3324 different signedness. We'll promote the signed to unsigned 3325 and later code won't know it used to be different. 3326 Do this check on the original types, so that explicit casts 3327 will be considered, but default promotions won't. */ 3328 if (warn_sign_compare && !skip_evaluation) 3329 { 3330 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 3331 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2)); 3332 3333 if (unsigned_op1 ^ unsigned_op2) 3334 { 3335 bool ovf; 3336 3337 /* Do not warn if the result type is signed, since the 3338 signed type will only be chosen if it can represent 3339 all the values of the unsigned type. */ 3340 if (!TYPE_UNSIGNED (result_type)) 3341 /* OK */; 3342 /* Do not warn if the signed quantity is an unsuffixed 3343 integer literal (or some static constant expression 3344 involving such literals) and it is non-negative. */ 3345 else if ((unsigned_op2 3346 && tree_expr_nonnegative_warnv_p (op1, &ovf)) 3347 || (unsigned_op1 3348 && tree_expr_nonnegative_warnv_p (op2, &ovf))) 3349 /* OK */; 3350 else 3351 warning (0, "signed and unsigned type in conditional expression"); 3352 } 3353 } 3354 } 3355 else if (code1 == VOID_TYPE || code2 == VOID_TYPE) 3356 { 3357 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) 3358 pedwarn ("ISO C forbids conditional expr with only one void side"); 3359 result_type = void_type_node; 3360 } 3361 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) 3362 { 3363 if (comp_target_types (type1, type2)) 3364 result_type = common_pointer_type (type1, type2); 3365 else if (null_pointer_constant_p (orig_op1)) 3366 result_type = qualify_type (type2, type1); 3367 else if (null_pointer_constant_p (orig_op2)) 3368 result_type = qualify_type (type1, type2); 3369 else if (VOID_TYPE_P (TREE_TYPE (type1))) 3370 { 3371 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) 3372 pedwarn ("ISO C forbids conditional expr between " 3373 "%<void *%> and function pointer"); 3374 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), 3375 TREE_TYPE (type2))); 3376 } 3377 else if (VOID_TYPE_P (TREE_TYPE (type2))) 3378 { 3379 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) 3380 pedwarn ("ISO C forbids conditional expr between " 3381 "%<void *%> and function pointer"); 3382 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), 3383 TREE_TYPE (type1))); 3384 } 3385 else 3386 { 3387 pedwarn ("pointer type mismatch in conditional expression"); 3388 result_type = build_pointer_type (void_type_node); 3389 } 3390 } 3391 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) 3392 { 3393 if (!null_pointer_constant_p (orig_op2)) 3394 pedwarn ("pointer/integer type mismatch in conditional expression"); 3395 else 3396 { 3397 op2 = null_pointer_node; 3398 } 3399 result_type = type1; 3400 } 3401 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) 3402 { 3403 if (!null_pointer_constant_p (orig_op1)) 3404 pedwarn ("pointer/integer type mismatch in conditional expression"); 3405 else 3406 { 3407 op1 = null_pointer_node; 3408 } 3409 result_type = type2; 3410 } 3411 3412 if (!result_type) 3413 { 3414 if (flag_cond_mismatch) 3415 result_type = void_type_node; 3416 else 3417 { 3418 error ("type mismatch in conditional expression"); 3419 return error_mark_node; 3420 } 3421 } 3422 3423 /* Merge const and volatile flags of the incoming types. */ 3424 result_type 3425 = build_type_variant (result_type, 3426 TREE_READONLY (op1) || TREE_READONLY (op2), 3427 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); 3428 3429 if (result_type != TREE_TYPE (op1)) 3430 op1 = convert_and_check (result_type, op1); 3431 if (result_type != TREE_TYPE (op2)) 3432 op2 = convert_and_check (result_type, op2); 3433 3434 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2); 3435} 3436 3437/* Return a compound expression that performs two expressions and 3438 returns the value of the second of them. */ 3439 3440tree 3441build_compound_expr (tree expr1, tree expr2) 3442{ 3443 if (!TREE_SIDE_EFFECTS (expr1)) 3444 { 3445 /* The left-hand operand of a comma expression is like an expression 3446 statement: with -Wextra or -Wunused, we should warn if it doesn't have 3447 any side-effects, unless it was explicitly cast to (void). */ 3448 if (warn_unused_value) 3449 { 3450 if (VOID_TYPE_P (TREE_TYPE (expr1)) 3451 && (TREE_CODE (expr1) == NOP_EXPR 3452 || TREE_CODE (expr1) == CONVERT_EXPR)) 3453 ; /* (void) a, b */ 3454 else if (VOID_TYPE_P (TREE_TYPE (expr1)) 3455 && TREE_CODE (expr1) == COMPOUND_EXPR 3456 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR 3457 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR)) 3458 ; /* (void) a, (void) b, c */ 3459 else 3460 warning (0, "left-hand operand of comma expression has no effect"); 3461 } 3462 } 3463 3464 /* With -Wunused, we should also warn if the left-hand operand does have 3465 side-effects, but computes a value which is not used. For example, in 3466 `foo() + bar(), baz()' the result of the `+' operator is not used, 3467 so we should issue a warning. */ 3468 else if (warn_unused_value) 3469 warn_if_unused_value (expr1, input_location); 3470 3471 if (expr2 == error_mark_node) 3472 return error_mark_node; 3473 3474 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2); 3475} 3476 3477/* Build an expression representing a cast to type TYPE of expression EXPR. */ 3478 3479tree 3480build_c_cast (tree type, tree expr) 3481{ 3482 tree value = expr; 3483 3484 if (type == error_mark_node || expr == error_mark_node) 3485 return error_mark_node; 3486 3487 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing 3488 only in <protocol> qualifications. But when constructing cast expressions, 3489 the protocols do matter and must be kept around. */ 3490 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr))) 3491 return build1 (NOP_EXPR, type, expr); 3492 3493 type = TYPE_MAIN_VARIANT (type); 3494 3495 if (TREE_CODE (type) == ARRAY_TYPE) 3496 { 3497 error ("cast specifies array type"); 3498 return error_mark_node; 3499 } 3500 3501 if (TREE_CODE (type) == FUNCTION_TYPE) 3502 { 3503 error ("cast specifies function type"); 3504 return error_mark_node; 3505 } 3506 3507 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) 3508 { 3509 if (pedantic) 3510 { 3511 if (TREE_CODE (type) == RECORD_TYPE 3512 || TREE_CODE (type) == UNION_TYPE) 3513 pedwarn ("ISO C forbids casting nonscalar to the same type"); 3514 } 3515 } 3516 else if (TREE_CODE (type) == UNION_TYPE) 3517 { 3518 tree field; 3519 3520 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3521 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), 3522 TYPE_MAIN_VARIANT (TREE_TYPE (value)))) 3523 break; 3524 3525 if (field) 3526 { 3527 tree t; 3528 3529 if (pedantic) 3530 pedwarn ("ISO C forbids casts to union type"); 3531 t = digest_init (type, 3532 build_constructor_single (type, field, value), 3533 true, 0); 3534 TREE_CONSTANT (t) = TREE_CONSTANT (value); 3535 TREE_INVARIANT (t) = TREE_INVARIANT (value); 3536 return t; 3537 } 3538 error ("cast to union type from type not present in union"); 3539 return error_mark_node; 3540 } 3541 else 3542 { 3543 tree otype, ovalue; 3544 3545 if (type == void_type_node) 3546 return build1 (CONVERT_EXPR, type, value); 3547 3548 otype = TREE_TYPE (value); 3549 3550 /* Optionally warn about potentially worrisome casts. */ 3551 3552 if (warn_cast_qual 3553 && TREE_CODE (type) == POINTER_TYPE 3554 && TREE_CODE (otype) == POINTER_TYPE) 3555 { 3556 tree in_type = type; 3557 tree in_otype = otype; 3558 int added = 0; 3559 int discarded = 0; 3560 3561 /* Check that the qualifiers on IN_TYPE are a superset of 3562 the qualifiers of IN_OTYPE. The outermost level of 3563 POINTER_TYPE nodes is uninteresting and we stop as soon 3564 as we hit a non-POINTER_TYPE node on either type. */ 3565 do 3566 { 3567 in_otype = TREE_TYPE (in_otype); 3568 in_type = TREE_TYPE (in_type); 3569 3570 /* GNU C allows cv-qualified function types. 'const' 3571 means the function is very pure, 'volatile' means it 3572 can't return. We need to warn when such qualifiers 3573 are added, not when they're taken away. */ 3574 if (TREE_CODE (in_otype) == FUNCTION_TYPE 3575 && TREE_CODE (in_type) == FUNCTION_TYPE) 3576 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); 3577 else 3578 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); 3579 } 3580 while (TREE_CODE (in_type) == POINTER_TYPE 3581 && TREE_CODE (in_otype) == POINTER_TYPE); 3582 3583 if (added) 3584 warning (0, "cast adds new qualifiers to function type"); 3585 3586 if (discarded) 3587 /* There are qualifiers present in IN_OTYPE that are not 3588 present in IN_TYPE. */ 3589 warning (0, "cast discards qualifiers from pointer target type"); 3590 } 3591 3592 /* Warn about possible alignment problems. */ 3593 if (STRICT_ALIGNMENT 3594 && TREE_CODE (type) == POINTER_TYPE 3595 && TREE_CODE (otype) == POINTER_TYPE 3596 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE 3597 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3598 /* Don't warn about opaque types, where the actual alignment 3599 restriction is unknown. */ 3600 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE 3601 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) 3602 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) 3603 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) 3604 warning (OPT_Wcast_align, 3605 "cast increases required alignment of target type"); 3606 3607 if (TREE_CODE (type) == INTEGER_TYPE 3608 && TREE_CODE (otype) == POINTER_TYPE 3609 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)) 3610 /* Unlike conversion of integers to pointers, where the 3611 warning is disabled for converting constants because 3612 of cases such as SIG_*, warn about converting constant 3613 pointers to integers. In some cases it may cause unwanted 3614 sign extension, and a warning is appropriate. */ 3615 warning (OPT_Wpointer_to_int_cast, 3616 "cast from pointer to integer of different size"); 3617 3618 if (TREE_CODE (value) == CALL_EXPR 3619 && TREE_CODE (type) != TREE_CODE (otype)) 3620 warning (OPT_Wbad_function_cast, "cast from function call of type %qT " 3621 "to non-matching type %qT", otype, type); 3622 3623 if (TREE_CODE (type) == POINTER_TYPE 3624 && TREE_CODE (otype) == INTEGER_TYPE 3625 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3626 /* Don't warn about converting any constant. */ 3627 && !TREE_CONSTANT (value)) 3628 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer " 3629 "of different size"); 3630 3631 strict_aliasing_warning (otype, type, expr); 3632 3633 /* If pedantic, warn for conversions between function and object 3634 pointer types, except for converting a null pointer constant 3635 to function pointer type. */ 3636 if (pedantic 3637 && TREE_CODE (type) == POINTER_TYPE 3638 && TREE_CODE (otype) == POINTER_TYPE 3639 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE 3640 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) 3641 pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); 3642 3643 if (pedantic 3644 && TREE_CODE (type) == POINTER_TYPE 3645 && TREE_CODE (otype) == POINTER_TYPE 3646 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 3647 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3648 && !null_pointer_constant_p (value)) 3649 pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); 3650 3651 ovalue = value; 3652 value = convert (type, value); 3653 3654 /* Ignore any integer overflow caused by the cast. */ 3655 if (TREE_CODE (value) == INTEGER_CST) 3656 { 3657 if (CONSTANT_CLASS_P (ovalue) 3658 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue))) 3659 { 3660 /* Avoid clobbering a shared constant. */ 3661 value = copy_node (value); 3662 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); 3663 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); 3664 } 3665 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value)) 3666 /* Reset VALUE's overflow flags, ensuring constant sharing. */ 3667 value = build_int_cst_wide (TREE_TYPE (value), 3668 TREE_INT_CST_LOW (value), 3669 TREE_INT_CST_HIGH (value)); 3670 } 3671 } 3672 3673 /* Don't let a cast be an lvalue. */ 3674 if (value == expr) 3675 value = non_lvalue (value); 3676 3677 return value; 3678} 3679 3680/* Interpret a cast of expression EXPR to type TYPE. */ 3681tree 3682c_cast_expr (struct c_type_name *type_name, tree expr) 3683{ 3684 tree type; 3685 int saved_wsp = warn_strict_prototypes; 3686 3687 /* This avoids warnings about unprototyped casts on 3688 integers. E.g. "#define SIG_DFL (void(*)())0". */ 3689 if (TREE_CODE (expr) == INTEGER_CST) 3690 warn_strict_prototypes = 0; 3691 type = groktypename (type_name); 3692 warn_strict_prototypes = saved_wsp; 3693 3694 return build_c_cast (type, expr); 3695} 3696 3697/* Build an assignment expression of lvalue LHS from value RHS. 3698 MODIFYCODE is the code for a binary operator that we use 3699 to combine the old value of LHS with RHS to get the new value. 3700 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ 3701 3702tree 3703build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) 3704{ 3705 tree result; 3706 tree newrhs; 3707 tree lhstype = TREE_TYPE (lhs); 3708 tree olhstype = lhstype; 3709 3710 /* Types that aren't fully specified cannot be used in assignments. */ 3711 lhs = require_complete_type (lhs); 3712 3713 /* Avoid duplicate error messages from operands that had errors. */ 3714 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) 3715 return error_mark_node; 3716 3717 if (!lvalue_or_else (lhs, lv_assign)) 3718 return error_mark_node; 3719 3720 STRIP_TYPE_NOPS (rhs); 3721 3722 newrhs = rhs; 3723 3724 /* If a binary op has been requested, combine the old LHS value with the RHS 3725 producing the value we should actually store into the LHS. */ 3726 3727 if (modifycode != NOP_EXPR) 3728 { 3729 lhs = stabilize_reference (lhs); 3730 newrhs = build_binary_op (modifycode, lhs, rhs, 1); 3731 } 3732 3733 /* Give an error for storing in something that is 'const'. */ 3734 3735 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) 3736 || ((TREE_CODE (lhstype) == RECORD_TYPE 3737 || TREE_CODE (lhstype) == UNION_TYPE) 3738 && C_TYPE_FIELDS_READONLY (lhstype))) 3739 { 3740 readonly_error (lhs, lv_assign); 3741 return error_mark_node; 3742 } 3743 3744 /* If storing into a structure or union member, 3745 it has probably been given type `int'. 3746 Compute the type that would go with 3747 the actual amount of storage the member occupies. */ 3748 3749 if (TREE_CODE (lhs) == COMPONENT_REF 3750 && (TREE_CODE (lhstype) == INTEGER_TYPE 3751 || TREE_CODE (lhstype) == BOOLEAN_TYPE 3752 || TREE_CODE (lhstype) == REAL_TYPE 3753 || TREE_CODE (lhstype) == ENUMERAL_TYPE)) 3754 lhstype = TREE_TYPE (get_unwidened (lhs, 0)); 3755 3756 /* If storing in a field that is in actuality a short or narrower than one, 3757 we must store in the field in its actual type. */ 3758 3759 if (lhstype != TREE_TYPE (lhs)) 3760 { 3761 lhs = copy_node (lhs); 3762 TREE_TYPE (lhs) = lhstype; 3763 } 3764 3765 /* Convert new value to destination type. */ 3766 3767 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign, 3768 NULL_TREE, NULL_TREE, 0); 3769 if (TREE_CODE (newrhs) == ERROR_MARK) 3770 return error_mark_node; 3771 3772 /* Emit ObjC write barrier, if necessary. */ 3773 if (c_dialect_objc () && flag_objc_gc) 3774 { 3775 result = objc_generate_write_barrier (lhs, modifycode, newrhs); 3776 if (result) 3777 return result; 3778 } 3779 3780 /* Scan operands. */ 3781 3782 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs); 3783 TREE_SIDE_EFFECTS (result) = 1; 3784 3785 /* If we got the LHS in a different type for storing in, 3786 convert the result back to the nominal type of LHS 3787 so that the value we return always has the same type 3788 as the LHS argument. */ 3789 3790 if (olhstype == TREE_TYPE (result)) 3791 return result; 3792 return convert_for_assignment (olhstype, result, ic_assign, 3793 NULL_TREE, NULL_TREE, 0); 3794} 3795 3796/* Convert value RHS to type TYPE as preparation for an assignment 3797 to an lvalue of type TYPE. 3798 The real work of conversion is done by `convert'. 3799 The purpose of this function is to generate error messages 3800 for assignments that are not allowed in C. 3801 ERRTYPE says whether it is argument passing, assignment, 3802 initialization or return. 3803 3804 FUNCTION is a tree for the function being called. 3805 PARMNUM is the number of the argument, for printing in error messages. */ 3806 3807static tree 3808convert_for_assignment (tree type, tree rhs, enum impl_conv errtype, 3809 tree fundecl, tree function, int parmnum) 3810{ 3811 enum tree_code codel = TREE_CODE (type); 3812 tree rhstype; 3813 enum tree_code coder; 3814 tree rname = NULL_TREE; 3815 bool objc_ok = false; 3816 3817 if (errtype == ic_argpass || errtype == ic_argpass_nonproto) 3818 { 3819 tree selector; 3820 /* Change pointer to function to the function itself for 3821 diagnostics. */ 3822 if (TREE_CODE (function) == ADDR_EXPR 3823 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 3824 function = TREE_OPERAND (function, 0); 3825 3826 /* Handle an ObjC selector specially for diagnostics. */ 3827 selector = objc_message_selector (); 3828 rname = function; 3829 if (selector && parmnum > 2) 3830 { 3831 rname = selector; 3832 parmnum -= 2; 3833 } 3834 } 3835 3836 /* This macro is used to emit diagnostics to ensure that all format 3837 strings are complete sentences, visible to gettext and checked at 3838 compile time. */ 3839#define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \ 3840 do { \ 3841 switch (errtype) \ 3842 { \ 3843 case ic_argpass: \ 3844 pedwarn (AR, parmnum, rname); \ 3845 break; \ 3846 case ic_argpass_nonproto: \ 3847 warning (0, AR, parmnum, rname); \ 3848 break; \ 3849 case ic_assign: \ 3850 pedwarn (AS); \ 3851 break; \ 3852 case ic_init: \ 3853 pedwarn (IN); \ 3854 break; \ 3855 case ic_return: \ 3856 pedwarn (RE); \ 3857 break; \ 3858 default: \ 3859 gcc_unreachable (); \ 3860 } \ 3861 } while (0) 3862 3863 STRIP_TYPE_NOPS (rhs); 3864 3865 if (optimize && TREE_CODE (rhs) == VAR_DECL 3866 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE) 3867 rhs = decl_constant_value_for_broken_optimization (rhs); 3868 3869 rhstype = TREE_TYPE (rhs); 3870 coder = TREE_CODE (rhstype); 3871 3872 if (coder == ERROR_MARK) 3873 return error_mark_node; 3874 3875 if (c_dialect_objc ()) 3876 { 3877 int parmno; 3878 3879 switch (errtype) 3880 { 3881 case ic_return: 3882 parmno = 0; 3883 break; 3884 3885 case ic_assign: 3886 parmno = -1; 3887 break; 3888 3889 case ic_init: 3890 parmno = -2; 3891 break; 3892 3893 default: 3894 parmno = parmnum; 3895 break; 3896 } 3897 3898 objc_ok = objc_compare_types (type, rhstype, parmno, rname); 3899 } 3900 3901 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) 3902 { 3903 overflow_warning (rhs); 3904 return rhs; 3905 } 3906 3907 if (coder == VOID_TYPE) 3908 { 3909 /* Except for passing an argument to an unprototyped function, 3910 this is a constraint violation. When passing an argument to 3911 an unprototyped function, it is compile-time undefined; 3912 making it a constraint in that case was rejected in 3913 DR#252. */ 3914 error ("void value not ignored as it ought to be"); 3915 return error_mark_node; 3916 } 3917 /* A type converts to a reference to it. 3918 This code doesn't fully support references, it's just for the 3919 special case of va_start and va_copy. */ 3920 if (codel == REFERENCE_TYPE 3921 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1) 3922 { 3923 if (!lvalue_p (rhs)) 3924 { 3925 error ("cannot pass rvalue to reference parameter"); 3926 return error_mark_node; 3927 } 3928 if (!c_mark_addressable (rhs)) 3929 return error_mark_node; 3930 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); 3931 3932 /* We already know that these two types are compatible, but they 3933 may not be exactly identical. In fact, `TREE_TYPE (type)' is 3934 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is 3935 likely to be va_list, a typedef to __builtin_va_list, which 3936 is different enough that it will cause problems later. */ 3937 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) 3938 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); 3939 3940 rhs = build1 (NOP_EXPR, type, rhs); 3941 return rhs; 3942 } 3943 /* Some types can interconvert without explicit casts. */ 3944 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE 3945 && vector_types_convertible_p (type, TREE_TYPE (rhs))) 3946 return convert (type, rhs); 3947 /* Arithmetic types all interconvert, and enum is treated like int. */ 3948 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 3949 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE 3950 || codel == BOOLEAN_TYPE) 3951 && (coder == INTEGER_TYPE || coder == REAL_TYPE 3952 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE 3953 || coder == BOOLEAN_TYPE)) 3954 return convert_and_check (type, rhs); 3955 3956 /* Aggregates in different TUs might need conversion. */ 3957 if ((codel == RECORD_TYPE || codel == UNION_TYPE) 3958 && codel == coder 3959 && comptypes (type, rhstype)) 3960 return convert_and_check (type, rhs); 3961 3962 /* Conversion to a transparent union from its member types. 3963 This applies only to function arguments. */ 3964 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) 3965 && (errtype == ic_argpass || errtype == ic_argpass_nonproto)) 3966 { 3967 tree memb, marginal_memb = NULL_TREE; 3968 3969 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb)) 3970 { 3971 tree memb_type = TREE_TYPE (memb); 3972 3973 if (comptypes (TYPE_MAIN_VARIANT (memb_type), 3974 TYPE_MAIN_VARIANT (rhstype))) 3975 break; 3976 3977 if (TREE_CODE (memb_type) != POINTER_TYPE) 3978 continue; 3979 3980 if (coder == POINTER_TYPE) 3981 { 3982 tree ttl = TREE_TYPE (memb_type); 3983 tree ttr = TREE_TYPE (rhstype); 3984 3985 /* Any non-function converts to a [const][volatile] void * 3986 and vice versa; otherwise, targets must be the same. 3987 Meanwhile, the lhs target must have all the qualifiers of 3988 the rhs. */ 3989 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3990 || comp_target_types (memb_type, rhstype)) 3991 { 3992 /* If this type won't generate any warnings, use it. */ 3993 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) 3994 || ((TREE_CODE (ttr) == FUNCTION_TYPE 3995 && TREE_CODE (ttl) == FUNCTION_TYPE) 3996 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3997 == TYPE_QUALS (ttr)) 3998 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3999 == TYPE_QUALS (ttl)))) 4000 break; 4001 4002 /* Keep looking for a better type, but remember this one. */ 4003 if (!marginal_memb) 4004 marginal_memb = memb; 4005 } 4006 } 4007 4008 /* Can convert integer zero to any pointer type. */ 4009 if (null_pointer_constant_p (rhs)) 4010 { 4011 rhs = null_pointer_node; 4012 break; 4013 } 4014 } 4015 4016 if (memb || marginal_memb) 4017 { 4018 if (!memb) 4019 { 4020 /* We have only a marginally acceptable member type; 4021 it needs a warning. */ 4022 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb)); 4023 tree ttr = TREE_TYPE (rhstype); 4024 4025 /* Const and volatile mean something different for function 4026 types, so the usual warnings are not appropriate. */ 4027 if (TREE_CODE (ttr) == FUNCTION_TYPE 4028 && TREE_CODE (ttl) == FUNCTION_TYPE) 4029 { 4030 /* Because const and volatile on functions are 4031 restrictions that say the function will not do 4032 certain things, it is okay to use a const or volatile 4033 function where an ordinary one is wanted, but not 4034 vice-versa. */ 4035 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 4036 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE " 4037 "makes qualified function " 4038 "pointer from unqualified"), 4039 G_("assignment makes qualified " 4040 "function pointer from " 4041 "unqualified"), 4042 G_("initialization makes qualified " 4043 "function pointer from " 4044 "unqualified"), 4045 G_("return makes qualified function " 4046 "pointer from unqualified")); 4047 } 4048 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4049 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4050 "qualifiers from pointer target type"), 4051 G_("assignment discards qualifiers " 4052 "from pointer target type"), 4053 G_("initialization discards qualifiers " 4054 "from pointer target type"), 4055 G_("return discards qualifiers from " 4056 "pointer target type")); 4057 4058 memb = marginal_memb; 4059 } 4060 4061 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))) 4062 pedwarn ("ISO C prohibits argument conversion to union type"); 4063 4064 return build_constructor_single (type, memb, rhs); 4065 } 4066 } 4067 4068 /* Conversions among pointers */ 4069 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 4070 && (coder == codel)) 4071 { 4072 tree ttl = TREE_TYPE (type); 4073 tree ttr = TREE_TYPE (rhstype); 4074 tree mvl = ttl; 4075 tree mvr = ttr; 4076 bool is_opaque_pointer; 4077 int target_cmp = 0; /* Cache comp_target_types () result. */ 4078 4079 if (TREE_CODE (mvl) != ARRAY_TYPE) 4080 mvl = TYPE_MAIN_VARIANT (mvl); 4081 if (TREE_CODE (mvr) != ARRAY_TYPE) 4082 mvr = TYPE_MAIN_VARIANT (mvr); 4083 /* Opaque pointers are treated like void pointers. */ 4084 is_opaque_pointer = (targetm.vector_opaque_p (type) 4085 || targetm.vector_opaque_p (rhstype)) 4086 && TREE_CODE (ttl) == VECTOR_TYPE 4087 && TREE_CODE (ttr) == VECTOR_TYPE; 4088 4089 /* C++ does not allow the implicit conversion void* -> T*. However, 4090 for the purpose of reducing the number of false positives, we 4091 tolerate the special case of 4092 4093 int *p = NULL; 4094 4095 where NULL is typically defined in C to be '(void *) 0'. */ 4096 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl)) 4097 warning (OPT_Wc___compat, "request for implicit conversion from " 4098 "%qT to %qT not permitted in C++", rhstype, type); 4099 4100 /* Check if the right-hand side has a format attribute but the 4101 left-hand side doesn't. */ 4102 if (warn_missing_format_attribute 4103 && check_missing_format_attribute (type, rhstype)) 4104 { 4105 switch (errtype) 4106 { 4107 case ic_argpass: 4108 case ic_argpass_nonproto: 4109 warning (OPT_Wmissing_format_attribute, 4110 "argument %d of %qE might be " 4111 "a candidate for a format attribute", 4112 parmnum, rname); 4113 break; 4114 case ic_assign: 4115 warning (OPT_Wmissing_format_attribute, 4116 "assignment left-hand side might be " 4117 "a candidate for a format attribute"); 4118 break; 4119 case ic_init: 4120 warning (OPT_Wmissing_format_attribute, 4121 "initialization left-hand side might be " 4122 "a candidate for a format attribute"); 4123 break; 4124 case ic_return: 4125 warning (OPT_Wmissing_format_attribute, 4126 "return type might be " 4127 "a candidate for a format attribute"); 4128 break; 4129 default: 4130 gcc_unreachable (); 4131 } 4132 } 4133 4134 /* Any non-function converts to a [const][volatile] void * 4135 and vice versa; otherwise, targets must be the same. 4136 Meanwhile, the lhs target must have all the qualifiers of the rhs. */ 4137 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4138 || (target_cmp = comp_target_types (type, rhstype)) 4139 || is_opaque_pointer 4140 || (c_common_unsigned_type (mvl) 4141 == c_common_unsigned_type (mvr))) 4142 { 4143 if (pedantic 4144 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) 4145 || 4146 (VOID_TYPE_P (ttr) 4147 && !null_pointer_constant_p (rhs) 4148 && TREE_CODE (ttl) == FUNCTION_TYPE))) 4149 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of " 4150 "%qE between function pointer " 4151 "and %<void *%>"), 4152 G_("ISO C forbids assignment between " 4153 "function pointer and %<void *%>"), 4154 G_("ISO C forbids initialization between " 4155 "function pointer and %<void *%>"), 4156 G_("ISO C forbids return between function " 4157 "pointer and %<void *%>")); 4158 /* Const and volatile mean something different for function types, 4159 so the usual warnings are not appropriate. */ 4160 else if (TREE_CODE (ttr) != FUNCTION_TYPE 4161 && TREE_CODE (ttl) != FUNCTION_TYPE) 4162 { 4163 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4164 { 4165 /* Types differing only by the presence of the 'volatile' 4166 qualifier are acceptable if the 'volatile' has been added 4167 in by the Objective-C EH machinery. */ 4168 if (!objc_type_quals_match (ttl, ttr)) 4169 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4170 "qualifiers from pointer target type"), 4171 G_("assignment discards qualifiers " 4172 "from pointer target type"), 4173 G_("initialization discards qualifiers " 4174 "from pointer target type"), 4175 G_("return discards qualifiers from " 4176 "pointer target type")); 4177 } 4178 /* If this is not a case of ignoring a mismatch in signedness, 4179 no warning. */ 4180 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4181 || target_cmp) 4182 ; 4183 /* If there is a mismatch, do warn. */ 4184 else if (warn_pointer_sign) 4185 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument " 4186 "%d of %qE differ in signedness"), 4187 G_("pointer targets in assignment " 4188 "differ in signedness"), 4189 G_("pointer targets in initialization " 4190 "differ in signedness"), 4191 G_("pointer targets in return differ " 4192 "in signedness")); 4193 } 4194 else if (TREE_CODE (ttl) == FUNCTION_TYPE 4195 && TREE_CODE (ttr) == FUNCTION_TYPE) 4196 { 4197 /* Because const and volatile on functions are restrictions 4198 that say the function will not do certain things, 4199 it is okay to use a const or volatile function 4200 where an ordinary one is wanted, but not vice-versa. */ 4201 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 4202 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4203 "qualified function pointer " 4204 "from unqualified"), 4205 G_("assignment makes qualified function " 4206 "pointer from unqualified"), 4207 G_("initialization makes qualified " 4208 "function pointer from unqualified"), 4209 G_("return makes qualified function " 4210 "pointer from unqualified")); 4211 } 4212 } 4213 else 4214 /* Avoid warning about the volatile ObjC EH puts on decls. */ 4215 if (!objc_ok) 4216 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from " 4217 "incompatible pointer type"), 4218 G_("assignment from incompatible pointer type"), 4219 G_("initialization from incompatible " 4220 "pointer type"), 4221 G_("return from incompatible pointer type")); 4222 4223 return convert (type, rhs); 4224 } 4225 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) 4226 { 4227 /* ??? This should not be an error when inlining calls to 4228 unprototyped functions. */ 4229 error ("invalid use of non-lvalue array"); 4230 return error_mark_node; 4231 } 4232 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) 4233 { 4234 /* An explicit constant 0 can convert to a pointer, 4235 or one that results from arithmetic, even including 4236 a cast to integer type. */ 4237 if (!null_pointer_constant_p (rhs)) 4238 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4239 "pointer from integer without a cast"), 4240 G_("assignment makes pointer from integer " 4241 "without a cast"), 4242 G_("initialization makes pointer from " 4243 "integer without a cast"), 4244 G_("return makes pointer from integer " 4245 "without a cast")); 4246 4247 return convert (type, rhs); 4248 } 4249 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) 4250 { 4251 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer " 4252 "from pointer without a cast"), 4253 G_("assignment makes integer from pointer " 4254 "without a cast"), 4255 G_("initialization makes integer from pointer " 4256 "without a cast"), 4257 G_("return makes integer from pointer " 4258 "without a cast")); 4259 return convert (type, rhs); 4260 } 4261 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) 4262 return convert (type, rhs); 4263 4264 switch (errtype) 4265 { 4266 case ic_argpass: 4267 case ic_argpass_nonproto: 4268 /* ??? This should not be an error when inlining calls to 4269 unprototyped functions. */ 4270 error ("incompatible type for argument %d of %qE", parmnum, rname); 4271 break; 4272 case ic_assign: 4273 error ("incompatible types in assignment"); 4274 break; 4275 case ic_init: 4276 error ("incompatible types in initialization"); 4277 break; 4278 case ic_return: 4279 error ("incompatible types in return"); 4280 break; 4281 default: 4282 gcc_unreachable (); 4283 } 4284 4285 return error_mark_node; 4286} 4287 4288/* Convert VALUE for assignment into inlined parameter PARM. ARGNUM 4289 is used for error and warning reporting and indicates which argument 4290 is being processed. */ 4291 4292tree 4293c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) 4294{ 4295 tree ret, type; 4296 4297 /* If FN was prototyped at the call site, the value has been converted 4298 already in convert_arguments. 4299 However, we might see a prototype now that was not in place when 4300 the function call was seen, so check that the VALUE actually matches 4301 PARM before taking an early exit. */ 4302 if (!value 4303 || (TYPE_ARG_TYPES (TREE_TYPE (fn)) 4304 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 4305 == TYPE_MAIN_VARIANT (TREE_TYPE (value))))) 4306 return value; 4307 4308 type = TREE_TYPE (parm); 4309 ret = convert_for_assignment (type, value, 4310 ic_argpass_nonproto, fn, 4311 fn, argnum); 4312 if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) 4313 && INTEGRAL_TYPE_P (type) 4314 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 4315 ret = default_conversion (ret); 4316 return ret; 4317} 4318 4319/* If VALUE is a compound expr all of whose expressions are constant, then 4320 return its value. Otherwise, return error_mark_node. 4321 4322 This is for handling COMPOUND_EXPRs as initializer elements 4323 which is allowed with a warning when -pedantic is specified. */ 4324 4325static tree 4326valid_compound_expr_initializer (tree value, tree endtype) 4327{ 4328 if (TREE_CODE (value) == COMPOUND_EXPR) 4329 { 4330 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) 4331 == error_mark_node) 4332 return error_mark_node; 4333 return valid_compound_expr_initializer (TREE_OPERAND (value, 1), 4334 endtype); 4335 } 4336 else if (!initializer_constant_valid_p (value, endtype)) 4337 return error_mark_node; 4338 else 4339 return value; 4340} 4341 4342/* Perform appropriate conversions on the initial value of a variable, 4343 store it in the declaration DECL, 4344 and print any error messages that are appropriate. 4345 If the init is invalid, store an ERROR_MARK. */ 4346 4347void 4348store_init_value (tree decl, tree init) 4349{ 4350 tree value, type; 4351 4352 /* If variable's type was invalidly declared, just ignore it. */ 4353 4354 type = TREE_TYPE (decl); 4355 if (TREE_CODE (type) == ERROR_MARK) 4356 return; 4357 4358 /* Digest the specified initializer into an expression. */ 4359 4360 value = digest_init (type, init, true, TREE_STATIC (decl)); 4361 4362 /* Store the expression if valid; else report error. */ 4363 4364 if (!in_system_header 4365 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl)) 4366 warning (OPT_Wtraditional, "traditional C rejects automatic " 4367 "aggregate initialization"); 4368 4369 DECL_INITIAL (decl) = value; 4370 4371 /* ANSI wants warnings about out-of-range constant initializers. */ 4372 STRIP_TYPE_NOPS (value); 4373 constant_expression_warning (value); 4374 4375 /* Check if we need to set array size from compound literal size. */ 4376 if (TREE_CODE (type) == ARRAY_TYPE 4377 && TYPE_DOMAIN (type) == 0 4378 && value != error_mark_node) 4379 { 4380 tree inside_init = init; 4381 4382 STRIP_TYPE_NOPS (inside_init); 4383 inside_init = fold (inside_init); 4384 4385 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4386 { 4387 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4388 4389 if (TYPE_DOMAIN (TREE_TYPE (cldecl))) 4390 { 4391 /* For int foo[] = (int [3]){1}; we need to set array size 4392 now since later on array initializer will be just the 4393 brace enclosed list of the compound literal. */ 4394 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4395 TREE_TYPE (decl) = type; 4396 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl)); 4397 layout_type (type); 4398 layout_decl (cldecl, 0); 4399 } 4400 } 4401 } 4402} 4403 4404/* Methods for storing and printing names for error messages. */ 4405 4406/* Implement a spelling stack that allows components of a name to be pushed 4407 and popped. Each element on the stack is this structure. */ 4408 4409struct spelling 4410{ 4411 int kind; 4412 union 4413 { 4414 unsigned HOST_WIDE_INT i; 4415 const char *s; 4416 } u; 4417}; 4418 4419#define SPELLING_STRING 1 4420#define SPELLING_MEMBER 2 4421#define SPELLING_BOUNDS 3 4422 4423static struct spelling *spelling; /* Next stack element (unused). */ 4424static struct spelling *spelling_base; /* Spelling stack base. */ 4425static int spelling_size; /* Size of the spelling stack. */ 4426 4427/* Macros to save and restore the spelling stack around push_... functions. 4428 Alternative to SAVE_SPELLING_STACK. */ 4429 4430#define SPELLING_DEPTH() (spelling - spelling_base) 4431#define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) 4432 4433/* Push an element on the spelling stack with type KIND and assign VALUE 4434 to MEMBER. */ 4435 4436#define PUSH_SPELLING(KIND, VALUE, MEMBER) \ 4437{ \ 4438 int depth = SPELLING_DEPTH (); \ 4439 \ 4440 if (depth >= spelling_size) \ 4441 { \ 4442 spelling_size += 10; \ 4443 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \ 4444 spelling_size); \ 4445 RESTORE_SPELLING_DEPTH (depth); \ 4446 } \ 4447 \ 4448 spelling->kind = (KIND); \ 4449 spelling->MEMBER = (VALUE); \ 4450 spelling++; \ 4451} 4452 4453/* Push STRING on the stack. Printed literally. */ 4454 4455static void 4456push_string (const char *string) 4457{ 4458 PUSH_SPELLING (SPELLING_STRING, string, u.s); 4459} 4460 4461/* Push a member name on the stack. Printed as '.' STRING. */ 4462 4463static void 4464push_member_name (tree decl) 4465{ 4466 const char *const string 4467 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>"; 4468 PUSH_SPELLING (SPELLING_MEMBER, string, u.s); 4469} 4470 4471/* Push an array bounds on the stack. Printed as [BOUNDS]. */ 4472 4473static void 4474push_array_bounds (unsigned HOST_WIDE_INT bounds) 4475{ 4476 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); 4477} 4478 4479/* Compute the maximum size in bytes of the printed spelling. */ 4480 4481static int 4482spelling_length (void) 4483{ 4484 int size = 0; 4485 struct spelling *p; 4486 4487 for (p = spelling_base; p < spelling; p++) 4488 { 4489 if (p->kind == SPELLING_BOUNDS) 4490 size += 25; 4491 else 4492 size += strlen (p->u.s) + 1; 4493 } 4494 4495 return size; 4496} 4497 4498/* Print the spelling to BUFFER and return it. */ 4499 4500static char * 4501print_spelling (char *buffer) 4502{ 4503 char *d = buffer; 4504 struct spelling *p; 4505 4506 for (p = spelling_base; p < spelling; p++) 4507 if (p->kind == SPELLING_BOUNDS) 4508 { 4509 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i); 4510 d += strlen (d); 4511 } 4512 else 4513 { 4514 const char *s; 4515 if (p->kind == SPELLING_MEMBER) 4516 *d++ = '.'; 4517 for (s = p->u.s; (*d = *s++); d++) 4518 ; 4519 } 4520 *d++ = '\0'; 4521 return buffer; 4522} 4523 4524/* Issue an error message for a bad initializer component. 4525 MSGID identifies the message. 4526 The component name is taken from the spelling stack. */ 4527 4528void 4529error_init (const char *msgid) 4530{ 4531 char *ofwhat; 4532 4533 error ("%s", _(msgid)); 4534 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4535 if (*ofwhat) 4536 error ("(near initialization for %qs)", ofwhat); 4537} 4538 4539/* Issue a pedantic warning for a bad initializer component. 4540 MSGID identifies the message. 4541 The component name is taken from the spelling stack. */ 4542 4543void 4544pedwarn_init (const char *msgid) 4545{ 4546 char *ofwhat; 4547 4548 pedwarn ("%s", _(msgid)); 4549 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4550 if (*ofwhat) 4551 pedwarn ("(near initialization for %qs)", ofwhat); 4552} 4553 4554/* Issue a warning for a bad initializer component. 4555 MSGID identifies the message. 4556 The component name is taken from the spelling stack. */ 4557 4558static void 4559warning_init (const char *msgid) 4560{ 4561 char *ofwhat; 4562 4563 warning (0, "%s", _(msgid)); 4564 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4565 if (*ofwhat) 4566 warning (0, "(near initialization for %qs)", ofwhat); 4567} 4568 4569/* If TYPE is an array type and EXPR is a parenthesized string 4570 constant, warn if pedantic that EXPR is being used to initialize an 4571 object of type TYPE. */ 4572 4573void 4574maybe_warn_string_init (tree type, struct c_expr expr) 4575{ 4576 if (pedantic 4577 && TREE_CODE (type) == ARRAY_TYPE 4578 && TREE_CODE (expr.value) == STRING_CST 4579 && expr.original_code != STRING_CST) 4580 pedwarn_init ("array initialized from parenthesized string constant"); 4581} 4582 4583/* Digest the parser output INIT as an initializer for type TYPE. 4584 Return a C expression of type TYPE to represent the initial value. 4585 4586 If INIT is a string constant, STRICT_STRING is true if it is 4587 unparenthesized or we should not warn here for it being parenthesized. 4588 For other types of INIT, STRICT_STRING is not used. 4589 4590 REQUIRE_CONSTANT requests an error if non-constant initializers or 4591 elements are seen. */ 4592 4593static tree 4594digest_init (tree type, tree init, bool strict_string, int require_constant) 4595{ 4596 enum tree_code code = TREE_CODE (type); 4597 tree inside_init = init; 4598 4599 if (type == error_mark_node 4600 || !init 4601 || init == error_mark_node 4602 || TREE_TYPE (init) == error_mark_node) 4603 return error_mark_node; 4604 4605 STRIP_TYPE_NOPS (inside_init); 4606 4607 inside_init = fold (inside_init); 4608 4609 /* Initialization of an array of chars from a string constant 4610 optionally enclosed in braces. */ 4611 4612 if (code == ARRAY_TYPE && inside_init 4613 && TREE_CODE (inside_init) == STRING_CST) 4614 { 4615 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); 4616 /* Note that an array could be both an array of character type 4617 and an array of wchar_t if wchar_t is signed char or unsigned 4618 char. */ 4619 bool char_array = (typ1 == char_type_node 4620 || typ1 == signed_char_type_node 4621 || typ1 == unsigned_char_type_node); 4622 bool wchar_array = !!comptypes (typ1, wchar_type_node); 4623 if (char_array || wchar_array) 4624 { 4625 struct c_expr expr; 4626 bool char_string; 4627 expr.value = inside_init; 4628 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK); 4629 maybe_warn_string_init (type, expr); 4630 4631 char_string 4632 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4633 == char_type_node); 4634 4635 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4636 TYPE_MAIN_VARIANT (type))) 4637 return inside_init; 4638 4639 if (!wchar_array && !char_string) 4640 { 4641 error_init ("char-array initialized from wide string"); 4642 return error_mark_node; 4643 } 4644 if (char_string && !char_array) 4645 { 4646 error_init ("wchar_t-array initialized from non-wide string"); 4647 return error_mark_node; 4648 } 4649 4650 TREE_TYPE (inside_init) = type; 4651 if (TYPE_DOMAIN (type) != 0 4652 && TYPE_SIZE (type) != 0 4653 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST 4654 /* Subtract 1 (or sizeof (wchar_t)) 4655 because it's ok to ignore the terminating null char 4656 that is counted in the length of the constant. */ 4657 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), 4658 TREE_STRING_LENGTH (inside_init) 4659 - ((TYPE_PRECISION (typ1) 4660 != TYPE_PRECISION (char_type_node)) 4661 ? (TYPE_PRECISION (wchar_type_node) 4662 / BITS_PER_UNIT) 4663 : 1))) 4664 pedwarn_init ("initializer-string for array of chars is too long"); 4665 4666 return inside_init; 4667 } 4668 else if (INTEGRAL_TYPE_P (typ1)) 4669 { 4670 error_init ("array of inappropriate type initialized " 4671 "from string constant"); 4672 return error_mark_node; 4673 } 4674 } 4675 4676 /* Build a VECTOR_CST from a *constant* vector constructor. If the 4677 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt 4678 below and handle as a constructor. */ 4679 if (code == VECTOR_TYPE 4680 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE 4681 && vector_types_convertible_p (TREE_TYPE (inside_init), type) 4682 && TREE_CONSTANT (inside_init)) 4683 { 4684 if (TREE_CODE (inside_init) == VECTOR_CST 4685 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4686 TYPE_MAIN_VARIANT (type))) 4687 return inside_init; 4688 4689 if (TREE_CODE (inside_init) == CONSTRUCTOR) 4690 { 4691 unsigned HOST_WIDE_INT ix; 4692 tree value; 4693 bool constant_p = true; 4694 4695 /* Iterate through elements and check if all constructor 4696 elements are *_CSTs. */ 4697 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value) 4698 if (!CONSTANT_CLASS_P (value)) 4699 { 4700 constant_p = false; 4701 break; 4702 } 4703 4704 if (constant_p) 4705 return build_vector_from_ctor (type, 4706 CONSTRUCTOR_ELTS (inside_init)); 4707 } 4708 } 4709 4710 /* Any type can be initialized 4711 from an expression of the same type, optionally with braces. */ 4712 4713 if (inside_init && TREE_TYPE (inside_init) != 0 4714 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4715 TYPE_MAIN_VARIANT (type)) 4716 || (code == ARRAY_TYPE 4717 && comptypes (TREE_TYPE (inside_init), type)) 4718 || (code == VECTOR_TYPE 4719 && comptypes (TREE_TYPE (inside_init), type)) 4720 || (code == POINTER_TYPE 4721 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4722 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4723 TREE_TYPE (type))))) 4724 { 4725 if (code == POINTER_TYPE) 4726 { 4727 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4728 { 4729 if (TREE_CODE (inside_init) == STRING_CST 4730 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4731 inside_init = array_to_pointer_conversion (inside_init); 4732 else 4733 { 4734 error_init ("invalid use of non-lvalue array"); 4735 return error_mark_node; 4736 } 4737 } 4738 } 4739 4740 if (code == VECTOR_TYPE) 4741 /* Although the types are compatible, we may require a 4742 conversion. */ 4743 inside_init = convert (type, inside_init); 4744 4745 if (require_constant 4746 && (code == VECTOR_TYPE || !flag_isoc99) 4747 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4748 { 4749 /* As an extension, allow initializing objects with static storage 4750 duration with compound literals (which are then treated just as 4751 the brace enclosed list they contain). Also allow this for 4752 vectors, as we can only assign them with compound literals. */ 4753 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4754 inside_init = DECL_INITIAL (decl); 4755 } 4756 4757 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4758 && TREE_CODE (inside_init) != CONSTRUCTOR) 4759 { 4760 error_init ("array initialized from non-constant array expression"); 4761 return error_mark_node; 4762 } 4763 4764 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4765 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4766 4767 /* Compound expressions can only occur here if -pedantic or 4768 -pedantic-errors is specified. In the later case, we always want 4769 an error. In the former case, we simply want a warning. */ 4770 if (require_constant && pedantic 4771 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4772 { 4773 inside_init 4774 = valid_compound_expr_initializer (inside_init, 4775 TREE_TYPE (inside_init)); 4776 if (inside_init == error_mark_node) 4777 error_init ("initializer element is not constant"); 4778 else 4779 pedwarn_init ("initializer element is not constant"); 4780 if (flag_pedantic_errors) 4781 inside_init = error_mark_node; 4782 } 4783 else if (require_constant 4784 && !initializer_constant_valid_p (inside_init, 4785 TREE_TYPE (inside_init))) 4786 { 4787 error_init ("initializer element is not constant"); 4788 inside_init = error_mark_node; 4789 } 4790 4791 /* Added to enable additional -Wmissing-format-attribute warnings. */ 4792 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE) 4793 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE, 4794 NULL_TREE, 0); 4795 return inside_init; 4796 } 4797 4798 /* Handle scalar types, including conversions. */ 4799 4800 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4801 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE 4802 || code == VECTOR_TYPE) 4803 { 4804 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE 4805 && (TREE_CODE (init) == STRING_CST 4806 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR)) 4807 init = array_to_pointer_conversion (init); 4808 inside_init 4809 = convert_for_assignment (type, init, ic_init, 4810 NULL_TREE, NULL_TREE, 0); 4811 4812 /* Check to see if we have already given an error message. */ 4813 if (inside_init == error_mark_node) 4814 ; 4815 else if (require_constant && !TREE_CONSTANT (inside_init)) 4816 { 4817 error_init ("initializer element is not constant"); 4818 inside_init = error_mark_node; 4819 } 4820 else if (require_constant 4821 && !initializer_constant_valid_p (inside_init, 4822 TREE_TYPE (inside_init))) 4823 { 4824 error_init ("initializer element is not computable at load time"); 4825 inside_init = error_mark_node; 4826 } 4827 4828 return inside_init; 4829 } 4830 4831 /* Come here only for records and arrays. */ 4832 4833 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4834 { 4835 error_init ("variable-sized object may not be initialized"); 4836 return error_mark_node; 4837 } 4838 4839 error_init ("invalid initializer"); 4840 return error_mark_node; 4841} 4842 4843/* Handle initializers that use braces. */ 4844 4845/* Type of object we are accumulating a constructor for. 4846 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4847static tree constructor_type; 4848 4849/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4850 left to fill. */ 4851static tree constructor_fields; 4852 4853/* For an ARRAY_TYPE, this is the specified index 4854 at which to store the next element we get. */ 4855static tree constructor_index; 4856 4857/* For an ARRAY_TYPE, this is the maximum index. */ 4858static tree constructor_max_index; 4859 4860/* For a RECORD_TYPE, this is the first field not yet written out. */ 4861static tree constructor_unfilled_fields; 4862 4863/* For an ARRAY_TYPE, this is the index of the first element 4864 not yet written out. */ 4865static tree constructor_unfilled_index; 4866 4867/* In a RECORD_TYPE, the byte index of the next consecutive field. 4868 This is so we can generate gaps between fields, when appropriate. */ 4869static tree constructor_bit_index; 4870 4871/* If we are saving up the elements rather than allocating them, 4872 this is the list of elements so far (in reverse order, 4873 most recent first). */ 4874static VEC(constructor_elt,gc) *constructor_elements; 4875 4876/* 1 if constructor should be incrementally stored into a constructor chain, 4877 0 if all the elements should be kept in AVL tree. */ 4878static int constructor_incremental; 4879 4880/* 1 if so far this constructor's elements are all compile-time constants. */ 4881static int constructor_constant; 4882 4883/* 1 if so far this constructor's elements are all valid address constants. */ 4884static int constructor_simple; 4885 4886/* 1 if this constructor is erroneous so far. */ 4887static int constructor_erroneous; 4888 4889/* Structure for managing pending initializer elements, organized as an 4890 AVL tree. */ 4891 4892struct init_node 4893{ 4894 struct init_node *left, *right; 4895 struct init_node *parent; 4896 int balance; 4897 tree purpose; 4898 tree value; 4899}; 4900 4901/* Tree of pending elements at this constructor level. 4902 These are elements encountered out of order 4903 which belong at places we haven't reached yet in actually 4904 writing the output. 4905 Will never hold tree nodes across GC runs. */ 4906static struct init_node *constructor_pending_elts; 4907 4908/* The SPELLING_DEPTH of this constructor. */ 4909static int constructor_depth; 4910 4911/* DECL node for which an initializer is being read. 4912 0 means we are reading a constructor expression 4913 such as (struct foo) {...}. */ 4914static tree constructor_decl; 4915 4916/* Nonzero if this is an initializer for a top-level decl. */ 4917static int constructor_top_level; 4918 4919/* Nonzero if there were any member designators in this initializer. */ 4920static int constructor_designated; 4921 4922/* Nesting depth of designator list. */ 4923static int designator_depth; 4924 4925/* Nonzero if there were diagnosed errors in this designator list. */ 4926static int designator_erroneous; 4927 4928 4929/* This stack has a level for each implicit or explicit level of 4930 structuring in the initializer, including the outermost one. It 4931 saves the values of most of the variables above. */ 4932 4933struct constructor_range_stack; 4934 4935struct constructor_stack 4936{ 4937 struct constructor_stack *next; 4938 tree type; 4939 tree fields; 4940 tree index; 4941 tree max_index; 4942 tree unfilled_index; 4943 tree unfilled_fields; 4944 tree bit_index; 4945 VEC(constructor_elt,gc) *elements; 4946 struct init_node *pending_elts; 4947 int offset; 4948 int depth; 4949 /* If value nonzero, this value should replace the entire 4950 constructor at this level. */ 4951 struct c_expr replacement_value; 4952 struct constructor_range_stack *range_stack; 4953 char constant; 4954 char simple; 4955 char implicit; 4956 char erroneous; 4957 char outer; 4958 char incremental; 4959 char designated; 4960}; 4961 4962static struct constructor_stack *constructor_stack; 4963 4964/* This stack represents designators from some range designator up to 4965 the last designator in the list. */ 4966 4967struct constructor_range_stack 4968{ 4969 struct constructor_range_stack *next, *prev; 4970 struct constructor_stack *stack; 4971 tree range_start; 4972 tree index; 4973 tree range_end; 4974 tree fields; 4975}; 4976 4977static struct constructor_range_stack *constructor_range_stack; 4978 4979/* This stack records separate initializers that are nested. 4980 Nested initializers can't happen in ANSI C, but GNU C allows them 4981 in cases like { ... (struct foo) { ... } ... }. */ 4982 4983struct initializer_stack 4984{ 4985 struct initializer_stack *next; 4986 tree decl; 4987 struct constructor_stack *constructor_stack; 4988 struct constructor_range_stack *constructor_range_stack; 4989 VEC(constructor_elt,gc) *elements; 4990 struct spelling *spelling; 4991 struct spelling *spelling_base; 4992 int spelling_size; 4993 char top_level; 4994 char require_constant_value; 4995 char require_constant_elements; 4996}; 4997 4998static struct initializer_stack *initializer_stack; 4999 5000/* Prepare to parse and output the initializer for variable DECL. */ 5001 5002void 5003start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level) 5004{ 5005 const char *locus; 5006 struct initializer_stack *p = XNEW (struct initializer_stack); 5007 5008 p->decl = constructor_decl; 5009 p->require_constant_value = require_constant_value; 5010 p->require_constant_elements = require_constant_elements; 5011 p->constructor_stack = constructor_stack; 5012 p->constructor_range_stack = constructor_range_stack; 5013 p->elements = constructor_elements; 5014 p->spelling = spelling; 5015 p->spelling_base = spelling_base; 5016 p->spelling_size = spelling_size; 5017 p->top_level = constructor_top_level; 5018 p->next = initializer_stack; 5019 initializer_stack = p; 5020 5021 constructor_decl = decl; 5022 constructor_designated = 0; 5023 constructor_top_level = top_level; 5024 5025 if (decl != 0 && decl != error_mark_node) 5026 { 5027 require_constant_value = TREE_STATIC (decl); 5028 require_constant_elements 5029 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 5030 /* For a scalar, you can always use any value to initialize, 5031 even within braces. */ 5032 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 5033 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 5034 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 5035 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 5036 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 5037 } 5038 else 5039 { 5040 require_constant_value = 0; 5041 require_constant_elements = 0; 5042 locus = "(anonymous)"; 5043 } 5044 5045 constructor_stack = 0; 5046 constructor_range_stack = 0; 5047 5048 missing_braces_mentioned = 0; 5049 5050 spelling_base = 0; 5051 spelling_size = 0; 5052 RESTORE_SPELLING_DEPTH (0); 5053 5054 if (locus) 5055 push_string (locus); 5056} 5057 5058void 5059finish_init (void) 5060{ 5061 struct initializer_stack *p = initializer_stack; 5062 5063 /* Free the whole constructor stack of this initializer. */ 5064 while (constructor_stack) 5065 { 5066 struct constructor_stack *q = constructor_stack; 5067 constructor_stack = q->next; 5068 free (q); 5069 } 5070 5071 gcc_assert (!constructor_range_stack); 5072 5073 /* Pop back to the data of the outer initializer (if any). */ 5074 free (spelling_base); 5075 5076 constructor_decl = p->decl; 5077 require_constant_value = p->require_constant_value; 5078 require_constant_elements = p->require_constant_elements; 5079 constructor_stack = p->constructor_stack; 5080 constructor_range_stack = p->constructor_range_stack; 5081 constructor_elements = p->elements; 5082 spelling = p->spelling; 5083 spelling_base = p->spelling_base; 5084 spelling_size = p->spelling_size; 5085 constructor_top_level = p->top_level; 5086 initializer_stack = p->next; 5087 free (p); 5088} 5089 5090/* Call here when we see the initializer is surrounded by braces. 5091 This is instead of a call to push_init_level; 5092 it is matched by a call to pop_init_level. 5093 5094 TYPE is the type to initialize, for a constructor expression. 5095 For an initializer for a decl, TYPE is zero. */ 5096 5097void 5098really_start_incremental_init (tree type) 5099{ 5100 struct constructor_stack *p = XNEW (struct constructor_stack); 5101 5102 if (type == 0) 5103 type = TREE_TYPE (constructor_decl); 5104 5105 if (targetm.vector_opaque_p (type)) 5106 error ("opaque vector types cannot be initialized"); 5107 5108 p->type = constructor_type; 5109 p->fields = constructor_fields; 5110 p->index = constructor_index; 5111 p->max_index = constructor_max_index; 5112 p->unfilled_index = constructor_unfilled_index; 5113 p->unfilled_fields = constructor_unfilled_fields; 5114 p->bit_index = constructor_bit_index; 5115 p->elements = constructor_elements; 5116 p->constant = constructor_constant; 5117 p->simple = constructor_simple; 5118 p->erroneous = constructor_erroneous; 5119 p->pending_elts = constructor_pending_elts; 5120 p->depth = constructor_depth; 5121 p->replacement_value.value = 0; 5122 p->replacement_value.original_code = ERROR_MARK; 5123 p->implicit = 0; 5124 p->range_stack = 0; 5125 p->outer = 0; 5126 p->incremental = constructor_incremental; 5127 p->designated = constructor_designated; 5128 p->next = 0; 5129 constructor_stack = p; 5130 5131 constructor_constant = 1; 5132 constructor_simple = 1; 5133 constructor_depth = SPELLING_DEPTH (); 5134 constructor_elements = 0; 5135 constructor_pending_elts = 0; 5136 constructor_type = type; 5137 constructor_incremental = 1; 5138 constructor_designated = 0; 5139 designator_depth = 0; 5140 designator_erroneous = 0; 5141 5142 if (TREE_CODE (constructor_type) == RECORD_TYPE 5143 || TREE_CODE (constructor_type) == UNION_TYPE) 5144 { 5145 constructor_fields = TYPE_FIELDS (constructor_type); 5146 /* Skip any nameless bit fields at the beginning. */ 5147 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5148 && DECL_NAME (constructor_fields) == 0) 5149 constructor_fields = TREE_CHAIN (constructor_fields); 5150 5151 constructor_unfilled_fields = constructor_fields; 5152 constructor_bit_index = bitsize_zero_node; 5153 } 5154 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5155 { 5156 if (TYPE_DOMAIN (constructor_type)) 5157 { 5158 constructor_max_index 5159 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5160 5161 /* Detect non-empty initializations of zero-length arrays. */ 5162 if (constructor_max_index == NULL_TREE 5163 && TYPE_SIZE (constructor_type)) 5164 constructor_max_index = build_int_cst (NULL_TREE, -1); 5165 5166 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5167 to initialize VLAs will cause a proper error; avoid tree 5168 checking errors as well by setting a safe value. */ 5169 if (constructor_max_index 5170 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5171 constructor_max_index = build_int_cst (NULL_TREE, -1); 5172 5173 constructor_index 5174 = convert (bitsizetype, 5175 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5176 } 5177 else 5178 { 5179 constructor_index = bitsize_zero_node; 5180 constructor_max_index = NULL_TREE; 5181 } 5182 5183 constructor_unfilled_index = constructor_index; 5184 } 5185 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5186 { 5187 /* Vectors are like simple fixed-size arrays. */ 5188 constructor_max_index = 5189 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5190 constructor_index = bitsize_zero_node; 5191 constructor_unfilled_index = constructor_index; 5192 } 5193 else 5194 { 5195 /* Handle the case of int x = {5}; */ 5196 constructor_fields = constructor_type; 5197 constructor_unfilled_fields = constructor_type; 5198 } 5199} 5200 5201/* Push down into a subobject, for initialization. 5202 If this is for an explicit set of braces, IMPLICIT is 0. 5203 If it is because the next element belongs at a lower level, 5204 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 5205 5206void 5207push_init_level (int implicit) 5208{ 5209 struct constructor_stack *p; 5210 tree value = NULL_TREE; 5211 5212 /* If we've exhausted any levels that didn't have braces, 5213 pop them now. If implicit == 1, this will have been done in 5214 process_init_element; do not repeat it here because in the case 5215 of excess initializers for an empty aggregate this leads to an 5216 infinite cycle of popping a level and immediately recreating 5217 it. */ 5218 if (implicit != 1) 5219 { 5220 while (constructor_stack->implicit) 5221 { 5222 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5223 || TREE_CODE (constructor_type) == UNION_TYPE) 5224 && constructor_fields == 0) 5225 process_init_element (pop_init_level (1)); 5226 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5227 && constructor_max_index 5228 && tree_int_cst_lt (constructor_max_index, 5229 constructor_index)) 5230 process_init_element (pop_init_level (1)); 5231 else 5232 break; 5233 } 5234 } 5235 5236 /* Unless this is an explicit brace, we need to preserve previous 5237 content if any. */ 5238 if (implicit) 5239 { 5240 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5241 || TREE_CODE (constructor_type) == UNION_TYPE) 5242 && constructor_fields) 5243 value = find_init_member (constructor_fields); 5244 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5245 value = find_init_member (constructor_index); 5246 } 5247 5248 p = XNEW (struct constructor_stack); 5249 p->type = constructor_type; 5250 p->fields = constructor_fields; 5251 p->index = constructor_index; 5252 p->max_index = constructor_max_index; 5253 p->unfilled_index = constructor_unfilled_index; 5254 p->unfilled_fields = constructor_unfilled_fields; 5255 p->bit_index = constructor_bit_index; 5256 p->elements = constructor_elements; 5257 p->constant = constructor_constant; 5258 p->simple = constructor_simple; 5259 p->erroneous = constructor_erroneous; 5260 p->pending_elts = constructor_pending_elts; 5261 p->depth = constructor_depth; 5262 p->replacement_value.value = 0; 5263 p->replacement_value.original_code = ERROR_MARK; 5264 p->implicit = implicit; 5265 p->outer = 0; 5266 p->incremental = constructor_incremental; 5267 p->designated = constructor_designated; 5268 p->next = constructor_stack; 5269 p->range_stack = 0; 5270 constructor_stack = p; 5271 5272 constructor_constant = 1; 5273 constructor_simple = 1; 5274 constructor_depth = SPELLING_DEPTH (); 5275 constructor_elements = 0; 5276 constructor_incremental = 1; 5277 constructor_designated = 0; 5278 constructor_pending_elts = 0; 5279 if (!implicit) 5280 { 5281 p->range_stack = constructor_range_stack; 5282 constructor_range_stack = 0; 5283 designator_depth = 0; 5284 designator_erroneous = 0; 5285 } 5286 5287 /* Don't die if an entire brace-pair level is superfluous 5288 in the containing level. */ 5289 if (constructor_type == 0) 5290 ; 5291 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5292 || TREE_CODE (constructor_type) == UNION_TYPE) 5293 { 5294 /* Don't die if there are extra init elts at the end. */ 5295 if (constructor_fields == 0) 5296 constructor_type = 0; 5297 else 5298 { 5299 constructor_type = TREE_TYPE (constructor_fields); 5300 push_member_name (constructor_fields); 5301 constructor_depth++; 5302 } 5303 } 5304 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5305 { 5306 constructor_type = TREE_TYPE (constructor_type); 5307 push_array_bounds (tree_low_cst (constructor_index, 1)); 5308 constructor_depth++; 5309 } 5310 5311 if (constructor_type == 0) 5312 { 5313 error_init ("extra brace group at end of initializer"); 5314 constructor_fields = 0; 5315 constructor_unfilled_fields = 0; 5316 return; 5317 } 5318 5319 if (value && TREE_CODE (value) == CONSTRUCTOR) 5320 { 5321 constructor_constant = TREE_CONSTANT (value); 5322 constructor_simple = TREE_STATIC (value); 5323 constructor_elements = CONSTRUCTOR_ELTS (value); 5324 if (!VEC_empty (constructor_elt, constructor_elements) 5325 && (TREE_CODE (constructor_type) == RECORD_TYPE 5326 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 5327 set_nonincremental_init (); 5328 } 5329 5330 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 5331 { 5332 missing_braces_mentioned = 1; 5333 warning_init ("missing braces around initializer"); 5334 } 5335 5336 if (TREE_CODE (constructor_type) == RECORD_TYPE 5337 || TREE_CODE (constructor_type) == UNION_TYPE) 5338 { 5339 constructor_fields = TYPE_FIELDS (constructor_type); 5340 /* Skip any nameless bit fields at the beginning. */ 5341 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5342 && DECL_NAME (constructor_fields) == 0) 5343 constructor_fields = TREE_CHAIN (constructor_fields); 5344 5345 constructor_unfilled_fields = constructor_fields; 5346 constructor_bit_index = bitsize_zero_node; 5347 } 5348 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5349 { 5350 /* Vectors are like simple fixed-size arrays. */ 5351 constructor_max_index = 5352 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5353 constructor_index = convert (bitsizetype, integer_zero_node); 5354 constructor_unfilled_index = constructor_index; 5355 } 5356 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5357 { 5358 if (TYPE_DOMAIN (constructor_type)) 5359 { 5360 constructor_max_index 5361 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5362 5363 /* Detect non-empty initializations of zero-length arrays. */ 5364 if (constructor_max_index == NULL_TREE 5365 && TYPE_SIZE (constructor_type)) 5366 constructor_max_index = build_int_cst (NULL_TREE, -1); 5367 5368 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5369 to initialize VLAs will cause a proper error; avoid tree 5370 checking errors as well by setting a safe value. */ 5371 if (constructor_max_index 5372 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5373 constructor_max_index = build_int_cst (NULL_TREE, -1); 5374 5375 constructor_index 5376 = convert (bitsizetype, 5377 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5378 } 5379 else 5380 constructor_index = bitsize_zero_node; 5381 5382 constructor_unfilled_index = constructor_index; 5383 if (value && TREE_CODE (value) == STRING_CST) 5384 { 5385 /* We need to split the char/wchar array into individual 5386 characters, so that we don't have to special case it 5387 everywhere. */ 5388 set_nonincremental_init_from_string (value); 5389 } 5390 } 5391 else 5392 { 5393 if (constructor_type != error_mark_node) 5394 warning_init ("braces around scalar initializer"); 5395 constructor_fields = constructor_type; 5396 constructor_unfilled_fields = constructor_type; 5397 } 5398} 5399 5400/* At the end of an implicit or explicit brace level, 5401 finish up that level of constructor. If a single expression 5402 with redundant braces initialized that level, return the 5403 c_expr structure for that expression. Otherwise, the original_code 5404 element is set to ERROR_MARK. 5405 If we were outputting the elements as they are read, return 0 as the value 5406 from inner levels (process_init_element ignores that), 5407 but return error_mark_node as the value from the outermost level 5408 (that's what we want to put in DECL_INITIAL). 5409 Otherwise, return a CONSTRUCTOR expression as the value. */ 5410 5411struct c_expr 5412pop_init_level (int implicit) 5413{ 5414 struct constructor_stack *p; 5415 struct c_expr ret; 5416 ret.value = 0; 5417 ret.original_code = ERROR_MARK; 5418 5419 if (implicit == 0) 5420 { 5421 /* When we come to an explicit close brace, 5422 pop any inner levels that didn't have explicit braces. */ 5423 while (constructor_stack->implicit) 5424 process_init_element (pop_init_level (1)); 5425 5426 gcc_assert (!constructor_range_stack); 5427 } 5428 5429 /* Now output all pending elements. */ 5430 constructor_incremental = 1; 5431 output_pending_init_elements (1); 5432 5433 p = constructor_stack; 5434 5435 /* Error for initializing a flexible array member, or a zero-length 5436 array member in an inappropriate context. */ 5437 if (constructor_type && constructor_fields 5438 && TREE_CODE (constructor_type) == ARRAY_TYPE 5439 && TYPE_DOMAIN (constructor_type) 5440 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 5441 { 5442 /* Silently discard empty initializations. The parser will 5443 already have pedwarned for empty brackets. */ 5444 if (integer_zerop (constructor_unfilled_index)) 5445 constructor_type = NULL_TREE; 5446 else 5447 { 5448 gcc_assert (!TYPE_SIZE (constructor_type)); 5449 5450 if (constructor_depth > 2) 5451 error_init ("initialization of flexible array member in a nested context"); 5452 else if (pedantic) 5453 pedwarn_init ("initialization of a flexible array member"); 5454 5455 /* We have already issued an error message for the existence 5456 of a flexible array member not at the end of the structure. 5457 Discard the initializer so that we do not die later. */ 5458 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 5459 constructor_type = NULL_TREE; 5460 } 5461 } 5462 5463 /* Warn when some struct elements are implicitly initialized to zero. */ 5464 if (warn_missing_field_initializers 5465 && constructor_type 5466 && TREE_CODE (constructor_type) == RECORD_TYPE 5467 && constructor_unfilled_fields) 5468 { 5469 /* Do not warn for flexible array members or zero-length arrays. */ 5470 while (constructor_unfilled_fields 5471 && (!DECL_SIZE (constructor_unfilled_fields) 5472 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 5473 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5474 5475 /* Do not warn if this level of the initializer uses member 5476 designators; it is likely to be deliberate. */ 5477 if (constructor_unfilled_fields && !constructor_designated) 5478 { 5479 push_member_name (constructor_unfilled_fields); 5480 warning_init ("missing initializer"); 5481 RESTORE_SPELLING_DEPTH (constructor_depth); 5482 } 5483 } 5484 5485 /* Pad out the end of the structure. */ 5486 if (p->replacement_value.value) 5487 /* If this closes a superfluous brace pair, 5488 just pass out the element between them. */ 5489 ret = p->replacement_value; 5490 else if (constructor_type == 0) 5491 ; 5492 else if (TREE_CODE (constructor_type) != RECORD_TYPE 5493 && TREE_CODE (constructor_type) != UNION_TYPE 5494 && TREE_CODE (constructor_type) != ARRAY_TYPE 5495 && TREE_CODE (constructor_type) != VECTOR_TYPE) 5496 { 5497 /* A nonincremental scalar initializer--just return 5498 the element, after verifying there is just one. */ 5499 if (VEC_empty (constructor_elt,constructor_elements)) 5500 { 5501 if (!constructor_erroneous) 5502 error_init ("empty scalar initializer"); 5503 ret.value = error_mark_node; 5504 } 5505 else if (VEC_length (constructor_elt,constructor_elements) != 1) 5506 { 5507 error_init ("extra elements in scalar initializer"); 5508 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5509 } 5510 else 5511 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5512 } 5513 else 5514 { 5515 if (constructor_erroneous) 5516 ret.value = error_mark_node; 5517 else 5518 { 5519 ret.value = build_constructor (constructor_type, 5520 constructor_elements); 5521 if (constructor_constant) 5522 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1; 5523 if (constructor_constant && constructor_simple) 5524 TREE_STATIC (ret.value) = 1; 5525 } 5526 } 5527 5528 constructor_type = p->type; 5529 constructor_fields = p->fields; 5530 constructor_index = p->index; 5531 constructor_max_index = p->max_index; 5532 constructor_unfilled_index = p->unfilled_index; 5533 constructor_unfilled_fields = p->unfilled_fields; 5534 constructor_bit_index = p->bit_index; 5535 constructor_elements = p->elements; 5536 constructor_constant = p->constant; 5537 constructor_simple = p->simple; 5538 constructor_erroneous = p->erroneous; 5539 constructor_incremental = p->incremental; 5540 constructor_designated = p->designated; 5541 constructor_pending_elts = p->pending_elts; 5542 constructor_depth = p->depth; 5543 if (!p->implicit) 5544 constructor_range_stack = p->range_stack; 5545 RESTORE_SPELLING_DEPTH (constructor_depth); 5546 5547 constructor_stack = p->next; 5548 free (p); 5549 5550 if (ret.value == 0 && constructor_stack == 0) 5551 ret.value = error_mark_node; 5552 return ret; 5553} 5554 5555/* Common handling for both array range and field name designators. 5556 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 5557 5558static int 5559set_designator (int array) 5560{ 5561 tree subtype; 5562 enum tree_code subcode; 5563 5564 /* Don't die if an entire brace-pair level is superfluous 5565 in the containing level. */ 5566 if (constructor_type == 0) 5567 return 1; 5568 5569 /* If there were errors in this designator list already, bail out 5570 silently. */ 5571 if (designator_erroneous) 5572 return 1; 5573 5574 if (!designator_depth) 5575 { 5576 gcc_assert (!constructor_range_stack); 5577 5578 /* Designator list starts at the level of closest explicit 5579 braces. */ 5580 while (constructor_stack->implicit) 5581 process_init_element (pop_init_level (1)); 5582 constructor_designated = 1; 5583 return 0; 5584 } 5585 5586 switch (TREE_CODE (constructor_type)) 5587 { 5588 case RECORD_TYPE: 5589 case UNION_TYPE: 5590 subtype = TREE_TYPE (constructor_fields); 5591 if (subtype != error_mark_node) 5592 subtype = TYPE_MAIN_VARIANT (subtype); 5593 break; 5594 case ARRAY_TYPE: 5595 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5596 break; 5597 default: 5598 gcc_unreachable (); 5599 } 5600 5601 subcode = TREE_CODE (subtype); 5602 if (array && subcode != ARRAY_TYPE) 5603 { 5604 error_init ("array index in non-array initializer"); 5605 return 1; 5606 } 5607 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5608 { 5609 error_init ("field name not in record or union initializer"); 5610 return 1; 5611 } 5612 5613 constructor_designated = 1; 5614 push_init_level (2); 5615 return 0; 5616} 5617 5618/* If there are range designators in designator list, push a new designator 5619 to constructor_range_stack. RANGE_END is end of such stack range or 5620 NULL_TREE if there is no range designator at this level. */ 5621 5622static void 5623push_range_stack (tree range_end) 5624{ 5625 struct constructor_range_stack *p; 5626 5627 p = GGC_NEW (struct constructor_range_stack); 5628 p->prev = constructor_range_stack; 5629 p->next = 0; 5630 p->fields = constructor_fields; 5631 p->range_start = constructor_index; 5632 p->index = constructor_index; 5633 p->stack = constructor_stack; 5634 p->range_end = range_end; 5635 if (constructor_range_stack) 5636 constructor_range_stack->next = p; 5637 constructor_range_stack = p; 5638} 5639 5640/* Within an array initializer, specify the next index to be initialized. 5641 FIRST is that index. If LAST is nonzero, then initialize a range 5642 of indices, running from FIRST through LAST. */ 5643 5644void 5645set_init_index (tree first, tree last) 5646{ 5647 if (set_designator (1)) 5648 return; 5649 5650 designator_erroneous = 1; 5651 5652 if (!INTEGRAL_TYPE_P (TREE_TYPE (first)) 5653 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last)))) 5654 { 5655 error_init ("array index in initializer not of integer type"); 5656 return; 5657 } 5658 5659 if (TREE_CODE (first) != INTEGER_CST) 5660 error_init ("nonconstant array index in initializer"); 5661 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5662 error_init ("nonconstant array index in initializer"); 5663 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5664 error_init ("array index in non-array initializer"); 5665 else if (tree_int_cst_sgn (first) == -1) 5666 error_init ("array index in initializer exceeds array bounds"); 5667 else if (constructor_max_index 5668 && tree_int_cst_lt (constructor_max_index, first)) 5669 error_init ("array index in initializer exceeds array bounds"); 5670 else 5671 { 5672 constructor_index = convert (bitsizetype, first); 5673 5674 if (last) 5675 { 5676 if (tree_int_cst_equal (first, last)) 5677 last = 0; 5678 else if (tree_int_cst_lt (last, first)) 5679 { 5680 error_init ("empty index range in initializer"); 5681 last = 0; 5682 } 5683 else 5684 { 5685 last = convert (bitsizetype, last); 5686 if (constructor_max_index != 0 5687 && tree_int_cst_lt (constructor_max_index, last)) 5688 { 5689 error_init ("array index range in initializer exceeds array bounds"); 5690 last = 0; 5691 } 5692 } 5693 } 5694 5695 designator_depth++; 5696 designator_erroneous = 0; 5697 if (constructor_range_stack || last) 5698 push_range_stack (last); 5699 } 5700} 5701 5702/* Within a struct initializer, specify the next field to be initialized. */ 5703 5704void 5705set_init_label (tree fieldname) 5706{ 5707 tree tail; 5708 5709 if (set_designator (0)) 5710 return; 5711 5712 designator_erroneous = 1; 5713 5714 if (TREE_CODE (constructor_type) != RECORD_TYPE 5715 && TREE_CODE (constructor_type) != UNION_TYPE) 5716 { 5717 error_init ("field name not in record or union initializer"); 5718 return; 5719 } 5720 5721 for (tail = TYPE_FIELDS (constructor_type); tail; 5722 tail = TREE_CHAIN (tail)) 5723 { 5724 if (DECL_NAME (tail) == fieldname) 5725 break; 5726 } 5727 5728 if (tail == 0) 5729 error ("unknown field %qE specified in initializer", fieldname); 5730 else 5731 { 5732 constructor_fields = tail; 5733 designator_depth++; 5734 designator_erroneous = 0; 5735 if (constructor_range_stack) 5736 push_range_stack (NULL_TREE); 5737 } 5738} 5739 5740/* Add a new initializer to the tree of pending initializers. PURPOSE 5741 identifies the initializer, either array index or field in a structure. 5742 VALUE is the value of that index or field. */ 5743 5744static void 5745add_pending_init (tree purpose, tree value) 5746{ 5747 struct init_node *p, **q, *r; 5748 5749 q = &constructor_pending_elts; 5750 p = 0; 5751 5752 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5753 { 5754 while (*q != 0) 5755 { 5756 p = *q; 5757 if (tree_int_cst_lt (purpose, p->purpose)) 5758 q = &p->left; 5759 else if (tree_int_cst_lt (p->purpose, purpose)) 5760 q = &p->right; 5761 else 5762 { 5763 if (TREE_SIDE_EFFECTS (p->value)) 5764 warning_init ("initialized field with side-effects overwritten"); 5765 else if (warn_override_init) 5766 warning_init ("initialized field overwritten"); 5767 p->value = value; 5768 return; 5769 } 5770 } 5771 } 5772 else 5773 { 5774 tree bitpos; 5775 5776 bitpos = bit_position (purpose); 5777 while (*q != NULL) 5778 { 5779 p = *q; 5780 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5781 q = &p->left; 5782 else if (p->purpose != purpose) 5783 q = &p->right; 5784 else 5785 { 5786 if (TREE_SIDE_EFFECTS (p->value)) 5787 warning_init ("initialized field with side-effects overwritten"); 5788 else if (warn_override_init) 5789 warning_init ("initialized field overwritten"); 5790 p->value = value; 5791 return; 5792 } 5793 } 5794 } 5795 5796 r = GGC_NEW (struct init_node); 5797 r->purpose = purpose; 5798 r->value = value; 5799 5800 *q = r; 5801 r->parent = p; 5802 r->left = 0; 5803 r->right = 0; 5804 r->balance = 0; 5805 5806 while (p) 5807 { 5808 struct init_node *s; 5809 5810 if (r == p->left) 5811 { 5812 if (p->balance == 0) 5813 p->balance = -1; 5814 else if (p->balance < 0) 5815 { 5816 if (r->balance < 0) 5817 { 5818 /* L rotation. */ 5819 p->left = r->right; 5820 if (p->left) 5821 p->left->parent = p; 5822 r->right = p; 5823 5824 p->balance = 0; 5825 r->balance = 0; 5826 5827 s = p->parent; 5828 p->parent = r; 5829 r->parent = s; 5830 if (s) 5831 { 5832 if (s->left == p) 5833 s->left = r; 5834 else 5835 s->right = r; 5836 } 5837 else 5838 constructor_pending_elts = r; 5839 } 5840 else 5841 { 5842 /* LR rotation. */ 5843 struct init_node *t = r->right; 5844 5845 r->right = t->left; 5846 if (r->right) 5847 r->right->parent = r; 5848 t->left = r; 5849 5850 p->left = t->right; 5851 if (p->left) 5852 p->left->parent = p; 5853 t->right = p; 5854 5855 p->balance = t->balance < 0; 5856 r->balance = -(t->balance > 0); 5857 t->balance = 0; 5858 5859 s = p->parent; 5860 p->parent = t; 5861 r->parent = t; 5862 t->parent = s; 5863 if (s) 5864 { 5865 if (s->left == p) 5866 s->left = t; 5867 else 5868 s->right = t; 5869 } 5870 else 5871 constructor_pending_elts = t; 5872 } 5873 break; 5874 } 5875 else 5876 { 5877 /* p->balance == +1; growth of left side balances the node. */ 5878 p->balance = 0; 5879 break; 5880 } 5881 } 5882 else /* r == p->right */ 5883 { 5884 if (p->balance == 0) 5885 /* Growth propagation from right side. */ 5886 p->balance++; 5887 else if (p->balance > 0) 5888 { 5889 if (r->balance > 0) 5890 { 5891 /* R rotation. */ 5892 p->right = r->left; 5893 if (p->right) 5894 p->right->parent = p; 5895 r->left = p; 5896 5897 p->balance = 0; 5898 r->balance = 0; 5899 5900 s = p->parent; 5901 p->parent = r; 5902 r->parent = s; 5903 if (s) 5904 { 5905 if (s->left == p) 5906 s->left = r; 5907 else 5908 s->right = r; 5909 } 5910 else 5911 constructor_pending_elts = r; 5912 } 5913 else /* r->balance == -1 */ 5914 { 5915 /* RL rotation */ 5916 struct init_node *t = r->left; 5917 5918 r->left = t->right; 5919 if (r->left) 5920 r->left->parent = r; 5921 t->right = r; 5922 5923 p->right = t->left; 5924 if (p->right) 5925 p->right->parent = p; 5926 t->left = p; 5927 5928 r->balance = (t->balance < 0); 5929 p->balance = -(t->balance > 0); 5930 t->balance = 0; 5931 5932 s = p->parent; 5933 p->parent = t; 5934 r->parent = t; 5935 t->parent = s; 5936 if (s) 5937 { 5938 if (s->left == p) 5939 s->left = t; 5940 else 5941 s->right = t; 5942 } 5943 else 5944 constructor_pending_elts = t; 5945 } 5946 break; 5947 } 5948 else 5949 { 5950 /* p->balance == -1; growth of right side balances the node. */ 5951 p->balance = 0; 5952 break; 5953 } 5954 } 5955 5956 r = p; 5957 p = p->parent; 5958 } 5959} 5960 5961/* Build AVL tree from a sorted chain. */ 5962 5963static void 5964set_nonincremental_init (void) 5965{ 5966 unsigned HOST_WIDE_INT ix; 5967 tree index, value; 5968 5969 if (TREE_CODE (constructor_type) != RECORD_TYPE 5970 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5971 return; 5972 5973 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value) 5974 add_pending_init (index, value); 5975 constructor_elements = 0; 5976 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5977 { 5978 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5979 /* Skip any nameless bit fields at the beginning. */ 5980 while (constructor_unfilled_fields != 0 5981 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5982 && DECL_NAME (constructor_unfilled_fields) == 0) 5983 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5984 5985 } 5986 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5987 { 5988 if (TYPE_DOMAIN (constructor_type)) 5989 constructor_unfilled_index 5990 = convert (bitsizetype, 5991 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5992 else 5993 constructor_unfilled_index = bitsize_zero_node; 5994 } 5995 constructor_incremental = 0; 5996} 5997 5998/* Build AVL tree from a string constant. */ 5999 6000static void 6001set_nonincremental_init_from_string (tree str) 6002{ 6003 tree value, purpose, type; 6004 HOST_WIDE_INT val[2]; 6005 const char *p, *end; 6006 int byte, wchar_bytes, charwidth, bitpos; 6007 6008 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE); 6009 6010 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 6011 == TYPE_PRECISION (char_type_node)) 6012 wchar_bytes = 1; 6013 else 6014 { 6015 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 6016 == TYPE_PRECISION (wchar_type_node)); 6017 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 6018 } 6019 charwidth = TYPE_PRECISION (char_type_node); 6020 type = TREE_TYPE (constructor_type); 6021 p = TREE_STRING_POINTER (str); 6022 end = p + TREE_STRING_LENGTH (str); 6023 6024 for (purpose = bitsize_zero_node; 6025 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 6026 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 6027 { 6028 if (wchar_bytes == 1) 6029 { 6030 val[1] = (unsigned char) *p++; 6031 val[0] = 0; 6032 } 6033 else 6034 { 6035 val[0] = 0; 6036 val[1] = 0; 6037 for (byte = 0; byte < wchar_bytes; byte++) 6038 { 6039 if (BYTES_BIG_ENDIAN) 6040 bitpos = (wchar_bytes - byte - 1) * charwidth; 6041 else 6042 bitpos = byte * charwidth; 6043 val[bitpos < HOST_BITS_PER_WIDE_INT] 6044 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 6045 << (bitpos % HOST_BITS_PER_WIDE_INT); 6046 } 6047 } 6048 6049 if (!TYPE_UNSIGNED (type)) 6050 { 6051 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 6052 if (bitpos < HOST_BITS_PER_WIDE_INT) 6053 { 6054 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 6055 { 6056 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 6057 val[0] = -1; 6058 } 6059 } 6060 else if (bitpos == HOST_BITS_PER_WIDE_INT) 6061 { 6062 if (val[1] < 0) 6063 val[0] = -1; 6064 } 6065 else if (val[0] & (((HOST_WIDE_INT) 1) 6066 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 6067 val[0] |= ((HOST_WIDE_INT) -1) 6068 << (bitpos - HOST_BITS_PER_WIDE_INT); 6069 } 6070 6071 value = build_int_cst_wide (type, val[1], val[0]); 6072 add_pending_init (purpose, value); 6073 } 6074 6075 constructor_incremental = 0; 6076} 6077 6078/* Return value of FIELD in pending initializer or zero if the field was 6079 not initialized yet. */ 6080 6081static tree 6082find_init_member (tree field) 6083{ 6084 struct init_node *p; 6085 6086 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6087 { 6088 if (constructor_incremental 6089 && tree_int_cst_lt (field, constructor_unfilled_index)) 6090 set_nonincremental_init (); 6091 6092 p = constructor_pending_elts; 6093 while (p) 6094 { 6095 if (tree_int_cst_lt (field, p->purpose)) 6096 p = p->left; 6097 else if (tree_int_cst_lt (p->purpose, field)) 6098 p = p->right; 6099 else 6100 return p->value; 6101 } 6102 } 6103 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6104 { 6105 tree bitpos = bit_position (field); 6106 6107 if (constructor_incremental 6108 && (!constructor_unfilled_fields 6109 || tree_int_cst_lt (bitpos, 6110 bit_position (constructor_unfilled_fields)))) 6111 set_nonincremental_init (); 6112 6113 p = constructor_pending_elts; 6114 while (p) 6115 { 6116 if (field == p->purpose) 6117 return p->value; 6118 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 6119 p = p->left; 6120 else 6121 p = p->right; 6122 } 6123 } 6124 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6125 { 6126 if (!VEC_empty (constructor_elt, constructor_elements) 6127 && (VEC_last (constructor_elt, constructor_elements)->index 6128 == field)) 6129 return VEC_last (constructor_elt, constructor_elements)->value; 6130 } 6131 return 0; 6132} 6133 6134/* "Output" the next constructor element. 6135 At top level, really output it to assembler code now. 6136 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 6137 TYPE is the data type that the containing data type wants here. 6138 FIELD is the field (a FIELD_DECL) or the index that this element fills. 6139 If VALUE is a string constant, STRICT_STRING is true if it is 6140 unparenthesized or we should not warn here for it being parenthesized. 6141 For other types of VALUE, STRICT_STRING is not used. 6142 6143 PENDING if non-nil means output pending elements that belong 6144 right after this element. (PENDING is normally 1; 6145 it is 0 while outputting pending elements, to avoid recursion.) */ 6146 6147static void 6148output_init_element (tree value, bool strict_string, tree type, tree field, 6149 int pending) 6150{ 6151 constructor_elt *celt; 6152 6153 if (type == error_mark_node || value == error_mark_node) 6154 { 6155 constructor_erroneous = 1; 6156 return; 6157 } 6158 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 6159 && (TREE_CODE (value) == STRING_CST 6160 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR) 6161 && !(TREE_CODE (value) == STRING_CST 6162 && TREE_CODE (type) == ARRAY_TYPE 6163 && INTEGRAL_TYPE_P (TREE_TYPE (type))) 6164 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 6165 TYPE_MAIN_VARIANT (type))) 6166 value = array_to_pointer_conversion (value); 6167 6168 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 6169 && require_constant_value && !flag_isoc99 && pending) 6170 { 6171 /* As an extension, allow initializing objects with static storage 6172 duration with compound literals (which are then treated just as 6173 the brace enclosed list they contain). */ 6174 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 6175 value = DECL_INITIAL (decl); 6176 } 6177 6178 if (value == error_mark_node) 6179 constructor_erroneous = 1; 6180 else if (!TREE_CONSTANT (value)) 6181 constructor_constant = 0; 6182 else if (!initializer_constant_valid_p (value, TREE_TYPE (value)) 6183 || ((TREE_CODE (constructor_type) == RECORD_TYPE 6184 || TREE_CODE (constructor_type) == UNION_TYPE) 6185 && DECL_C_BIT_FIELD (field) 6186 && TREE_CODE (value) != INTEGER_CST)) 6187 constructor_simple = 0; 6188 6189 if (!initializer_constant_valid_p (value, TREE_TYPE (value))) 6190 { 6191 if (require_constant_value) 6192 { 6193 error_init ("initializer element is not constant"); 6194 value = error_mark_node; 6195 } 6196 else if (require_constant_elements) 6197 pedwarn ("initializer element is not computable at load time"); 6198 } 6199 6200 /* If this field is empty (and not at the end of structure), 6201 don't do anything other than checking the initializer. */ 6202 if (field 6203 && (TREE_TYPE (field) == error_mark_node 6204 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 6205 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 6206 && (TREE_CODE (constructor_type) == ARRAY_TYPE 6207 || TREE_CHAIN (field))))) 6208 return; 6209 6210 value = digest_init (type, value, strict_string, require_constant_value); 6211 if (value == error_mark_node) 6212 { 6213 constructor_erroneous = 1; 6214 return; 6215 } 6216 6217 /* If this element doesn't come next in sequence, 6218 put it on constructor_pending_elts. */ 6219 if (TREE_CODE (constructor_type) == ARRAY_TYPE 6220 && (!constructor_incremental 6221 || !tree_int_cst_equal (field, constructor_unfilled_index))) 6222 { 6223 if (constructor_incremental 6224 && tree_int_cst_lt (field, constructor_unfilled_index)) 6225 set_nonincremental_init (); 6226 6227 add_pending_init (field, value); 6228 return; 6229 } 6230 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6231 && (!constructor_incremental 6232 || field != constructor_unfilled_fields)) 6233 { 6234 /* We do this for records but not for unions. In a union, 6235 no matter which field is specified, it can be initialized 6236 right away since it starts at the beginning of the union. */ 6237 if (constructor_incremental) 6238 { 6239 if (!constructor_unfilled_fields) 6240 set_nonincremental_init (); 6241 else 6242 { 6243 tree bitpos, unfillpos; 6244 6245 bitpos = bit_position (field); 6246 unfillpos = bit_position (constructor_unfilled_fields); 6247 6248 if (tree_int_cst_lt (bitpos, unfillpos)) 6249 set_nonincremental_init (); 6250 } 6251 } 6252 6253 add_pending_init (field, value); 6254 return; 6255 } 6256 else if (TREE_CODE (constructor_type) == UNION_TYPE 6257 && !VEC_empty (constructor_elt, constructor_elements)) 6258 { 6259 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt, 6260 constructor_elements)->value)) 6261 warning_init ("initialized field with side-effects overwritten"); 6262 else if (warn_override_init) 6263 warning_init ("initialized field overwritten"); 6264 6265 /* We can have just one union field set. */ 6266 constructor_elements = 0; 6267 } 6268 6269 /* Otherwise, output this element either to 6270 constructor_elements or to the assembler file. */ 6271 6272 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL); 6273 celt->index = field; 6274 celt->value = value; 6275 6276 /* Advance the variable that indicates sequential elements output. */ 6277 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6278 constructor_unfilled_index 6279 = size_binop (PLUS_EXPR, constructor_unfilled_index, 6280 bitsize_one_node); 6281 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6282 { 6283 constructor_unfilled_fields 6284 = TREE_CHAIN (constructor_unfilled_fields); 6285 6286 /* Skip any nameless bit fields. */ 6287 while (constructor_unfilled_fields != 0 6288 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6289 && DECL_NAME (constructor_unfilled_fields) == 0) 6290 constructor_unfilled_fields = 6291 TREE_CHAIN (constructor_unfilled_fields); 6292 } 6293 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6294 constructor_unfilled_fields = 0; 6295 6296 /* Now output any pending elements which have become next. */ 6297 if (pending) 6298 output_pending_init_elements (0); 6299} 6300 6301/* Output any pending elements which have become next. 6302 As we output elements, constructor_unfilled_{fields,index} 6303 advances, which may cause other elements to become next; 6304 if so, they too are output. 6305 6306 If ALL is 0, we return when there are 6307 no more pending elements to output now. 6308 6309 If ALL is 1, we output space as necessary so that 6310 we can output all the pending elements. */ 6311 6312static void 6313output_pending_init_elements (int all) 6314{ 6315 struct init_node *elt = constructor_pending_elts; 6316 tree next; 6317 6318 retry: 6319 6320 /* Look through the whole pending tree. 6321 If we find an element that should be output now, 6322 output it. Otherwise, set NEXT to the element 6323 that comes first among those still pending. */ 6324 6325 next = 0; 6326 while (elt) 6327 { 6328 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6329 { 6330 if (tree_int_cst_equal (elt->purpose, 6331 constructor_unfilled_index)) 6332 output_init_element (elt->value, true, 6333 TREE_TYPE (constructor_type), 6334 constructor_unfilled_index, 0); 6335 else if (tree_int_cst_lt (constructor_unfilled_index, 6336 elt->purpose)) 6337 { 6338 /* Advance to the next smaller node. */ 6339 if (elt->left) 6340 elt = elt->left; 6341 else 6342 { 6343 /* We have reached the smallest node bigger than the 6344 current unfilled index. Fill the space first. */ 6345 next = elt->purpose; 6346 break; 6347 } 6348 } 6349 else 6350 { 6351 /* Advance to the next bigger node. */ 6352 if (elt->right) 6353 elt = elt->right; 6354 else 6355 { 6356 /* We have reached the biggest node in a subtree. Find 6357 the parent of it, which is the next bigger node. */ 6358 while (elt->parent && elt->parent->right == elt) 6359 elt = elt->parent; 6360 elt = elt->parent; 6361 if (elt && tree_int_cst_lt (constructor_unfilled_index, 6362 elt->purpose)) 6363 { 6364 next = elt->purpose; 6365 break; 6366 } 6367 } 6368 } 6369 } 6370 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6371 || TREE_CODE (constructor_type) == UNION_TYPE) 6372 { 6373 tree ctor_unfilled_bitpos, elt_bitpos; 6374 6375 /* If the current record is complete we are done. */ 6376 if (constructor_unfilled_fields == 0) 6377 break; 6378 6379 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 6380 elt_bitpos = bit_position (elt->purpose); 6381 /* We can't compare fields here because there might be empty 6382 fields in between. */ 6383 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 6384 { 6385 constructor_unfilled_fields = elt->purpose; 6386 output_init_element (elt->value, true, TREE_TYPE (elt->purpose), 6387 elt->purpose, 0); 6388 } 6389 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 6390 { 6391 /* Advance to the next smaller node. */ 6392 if (elt->left) 6393 elt = elt->left; 6394 else 6395 { 6396 /* We have reached the smallest node bigger than the 6397 current unfilled field. Fill the space first. */ 6398 next = elt->purpose; 6399 break; 6400 } 6401 } 6402 else 6403 { 6404 /* Advance to the next bigger node. */ 6405 if (elt->right) 6406 elt = elt->right; 6407 else 6408 { 6409 /* We have reached the biggest node in a subtree. Find 6410 the parent of it, which is the next bigger node. */ 6411 while (elt->parent && elt->parent->right == elt) 6412 elt = elt->parent; 6413 elt = elt->parent; 6414 if (elt 6415 && (tree_int_cst_lt (ctor_unfilled_bitpos, 6416 bit_position (elt->purpose)))) 6417 { 6418 next = elt->purpose; 6419 break; 6420 } 6421 } 6422 } 6423 } 6424 } 6425 6426 /* Ordinarily return, but not if we want to output all 6427 and there are elements left. */ 6428 if (!(all && next != 0)) 6429 return; 6430 6431 /* If it's not incremental, just skip over the gap, so that after 6432 jumping to retry we will output the next successive element. */ 6433 if (TREE_CODE (constructor_type) == RECORD_TYPE 6434 || TREE_CODE (constructor_type) == UNION_TYPE) 6435 constructor_unfilled_fields = next; 6436 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6437 constructor_unfilled_index = next; 6438 6439 /* ELT now points to the node in the pending tree with the next 6440 initializer to output. */ 6441 goto retry; 6442} 6443 6444/* Add one non-braced element to the current constructor level. 6445 This adjusts the current position within the constructor's type. 6446 This may also start or terminate implicit levels 6447 to handle a partly-braced initializer. 6448 6449 Once this has found the correct level for the new element, 6450 it calls output_init_element. */ 6451 6452void 6453process_init_element (struct c_expr value) 6454{ 6455 tree orig_value = value.value; 6456 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST; 6457 bool strict_string = value.original_code == STRING_CST; 6458 6459 designator_depth = 0; 6460 designator_erroneous = 0; 6461 6462 /* Handle superfluous braces around string cst as in 6463 char x[] = {"foo"}; */ 6464 if (string_flag 6465 && constructor_type 6466 && TREE_CODE (constructor_type) == ARRAY_TYPE 6467 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type)) 6468 && integer_zerop (constructor_unfilled_index)) 6469 { 6470 if (constructor_stack->replacement_value.value) 6471 error_init ("excess elements in char array initializer"); 6472 constructor_stack->replacement_value = value; 6473 return; 6474 } 6475 6476 if (constructor_stack->replacement_value.value != 0) 6477 { 6478 error_init ("excess elements in struct initializer"); 6479 return; 6480 } 6481 6482 /* Ignore elements of a brace group if it is entirely superfluous 6483 and has already been diagnosed. */ 6484 if (constructor_type == 0) 6485 return; 6486 6487 /* If we've exhausted any levels that didn't have braces, 6488 pop them now. */ 6489 while (constructor_stack->implicit) 6490 { 6491 if ((TREE_CODE (constructor_type) == RECORD_TYPE 6492 || TREE_CODE (constructor_type) == UNION_TYPE) 6493 && constructor_fields == 0) 6494 process_init_element (pop_init_level (1)); 6495 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 6496 && (constructor_max_index == 0 6497 || tree_int_cst_lt (constructor_max_index, 6498 constructor_index))) 6499 process_init_element (pop_init_level (1)); 6500 else 6501 break; 6502 } 6503 6504 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 6505 if (constructor_range_stack) 6506 { 6507 /* If value is a compound literal and we'll be just using its 6508 content, don't put it into a SAVE_EXPR. */ 6509 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR 6510 || !require_constant_value 6511 || flag_isoc99) 6512 value.value = save_expr (value.value); 6513 } 6514 6515 while (1) 6516 { 6517 if (TREE_CODE (constructor_type) == RECORD_TYPE) 6518 { 6519 tree fieldtype; 6520 enum tree_code fieldcode; 6521 6522 if (constructor_fields == 0) 6523 { 6524 pedwarn_init ("excess elements in struct initializer"); 6525 break; 6526 } 6527 6528 fieldtype = TREE_TYPE (constructor_fields); 6529 if (fieldtype != error_mark_node) 6530 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6531 fieldcode = TREE_CODE (fieldtype); 6532 6533 /* Error for non-static initialization of a flexible array member. */ 6534 if (fieldcode == ARRAY_TYPE 6535 && !require_constant_value 6536 && TYPE_SIZE (fieldtype) == NULL_TREE 6537 && TREE_CHAIN (constructor_fields) == NULL_TREE) 6538 { 6539 error_init ("non-static initialization of a flexible array member"); 6540 break; 6541 } 6542 6543 /* Accept a string constant to initialize a subarray. */ 6544 if (value.value != 0 6545 && fieldcode == ARRAY_TYPE 6546 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6547 && string_flag) 6548 value.value = orig_value; 6549 /* Otherwise, if we have come to a subaggregate, 6550 and we don't have an element of its type, push into it. */ 6551 else if (value.value != 0 6552 && value.value != error_mark_node 6553 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6554 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6555 || fieldcode == UNION_TYPE)) 6556 { 6557 push_init_level (1); 6558 continue; 6559 } 6560 6561 if (value.value) 6562 { 6563 push_member_name (constructor_fields); 6564 output_init_element (value.value, strict_string, 6565 fieldtype, constructor_fields, 1); 6566 RESTORE_SPELLING_DEPTH (constructor_depth); 6567 } 6568 else 6569 /* Do the bookkeeping for an element that was 6570 directly output as a constructor. */ 6571 { 6572 /* For a record, keep track of end position of last field. */ 6573 if (DECL_SIZE (constructor_fields)) 6574 constructor_bit_index 6575 = size_binop (PLUS_EXPR, 6576 bit_position (constructor_fields), 6577 DECL_SIZE (constructor_fields)); 6578 6579 /* If the current field was the first one not yet written out, 6580 it isn't now, so update. */ 6581 if (constructor_unfilled_fields == constructor_fields) 6582 { 6583 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6584 /* Skip any nameless bit fields. */ 6585 while (constructor_unfilled_fields != 0 6586 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6587 && DECL_NAME (constructor_unfilled_fields) == 0) 6588 constructor_unfilled_fields = 6589 TREE_CHAIN (constructor_unfilled_fields); 6590 } 6591 } 6592 6593 constructor_fields = TREE_CHAIN (constructor_fields); 6594 /* Skip any nameless bit fields at the beginning. */ 6595 while (constructor_fields != 0 6596 && DECL_C_BIT_FIELD (constructor_fields) 6597 && DECL_NAME (constructor_fields) == 0) 6598 constructor_fields = TREE_CHAIN (constructor_fields); 6599 } 6600 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6601 { 6602 tree fieldtype; 6603 enum tree_code fieldcode; 6604 6605 if (constructor_fields == 0) 6606 { 6607 pedwarn_init ("excess elements in union initializer"); 6608 break; 6609 } 6610 6611 fieldtype = TREE_TYPE (constructor_fields); 6612 if (fieldtype != error_mark_node) 6613 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6614 fieldcode = TREE_CODE (fieldtype); 6615 6616 /* Warn that traditional C rejects initialization of unions. 6617 We skip the warning if the value is zero. This is done 6618 under the assumption that the zero initializer in user 6619 code appears conditioned on e.g. __STDC__ to avoid 6620 "missing initializer" warnings and relies on default 6621 initialization to zero in the traditional C case. 6622 We also skip the warning if the initializer is designated, 6623 again on the assumption that this must be conditional on 6624 __STDC__ anyway (and we've already complained about the 6625 member-designator already). */ 6626 if (!in_system_header && !constructor_designated 6627 && !(value.value && (integer_zerop (value.value) 6628 || real_zerop (value.value)))) 6629 warning (OPT_Wtraditional, "traditional C rejects initialization " 6630 "of unions"); 6631 6632 /* Accept a string constant to initialize a subarray. */ 6633 if (value.value != 0 6634 && fieldcode == ARRAY_TYPE 6635 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6636 && string_flag) 6637 value.value = orig_value; 6638 /* Otherwise, if we have come to a subaggregate, 6639 and we don't have an element of its type, push into it. */ 6640 else if (value.value != 0 6641 && value.value != error_mark_node 6642 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6643 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6644 || fieldcode == UNION_TYPE)) 6645 { 6646 push_init_level (1); 6647 continue; 6648 } 6649 6650 if (value.value) 6651 { 6652 push_member_name (constructor_fields); 6653 output_init_element (value.value, strict_string, 6654 fieldtype, constructor_fields, 1); 6655 RESTORE_SPELLING_DEPTH (constructor_depth); 6656 } 6657 else 6658 /* Do the bookkeeping for an element that was 6659 directly output as a constructor. */ 6660 { 6661 constructor_bit_index = DECL_SIZE (constructor_fields); 6662 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6663 } 6664 6665 constructor_fields = 0; 6666 } 6667 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6668 { 6669 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6670 enum tree_code eltcode = TREE_CODE (elttype); 6671 6672 /* Accept a string constant to initialize a subarray. */ 6673 if (value.value != 0 6674 && eltcode == ARRAY_TYPE 6675 && INTEGRAL_TYPE_P (TREE_TYPE (elttype)) 6676 && string_flag) 6677 value.value = orig_value; 6678 /* Otherwise, if we have come to a subaggregate, 6679 and we don't have an element of its type, push into it. */ 6680 else if (value.value != 0 6681 && value.value != error_mark_node 6682 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype 6683 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6684 || eltcode == UNION_TYPE)) 6685 { 6686 push_init_level (1); 6687 continue; 6688 } 6689 6690 if (constructor_max_index != 0 6691 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6692 || integer_all_onesp (constructor_max_index))) 6693 { 6694 pedwarn_init ("excess elements in array initializer"); 6695 break; 6696 } 6697 6698 /* Now output the actual element. */ 6699 if (value.value) 6700 { 6701 push_array_bounds (tree_low_cst (constructor_index, 1)); 6702 output_init_element (value.value, strict_string, 6703 elttype, constructor_index, 1); 6704 RESTORE_SPELLING_DEPTH (constructor_depth); 6705 } 6706 6707 constructor_index 6708 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6709 6710 if (!value.value) 6711 /* If we are doing the bookkeeping for an element that was 6712 directly output as a constructor, we must update 6713 constructor_unfilled_index. */ 6714 constructor_unfilled_index = constructor_index; 6715 } 6716 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6717 { 6718 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6719 6720 /* Do a basic check of initializer size. Note that vectors 6721 always have a fixed size derived from their type. */ 6722 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6723 { 6724 pedwarn_init ("excess elements in vector initializer"); 6725 break; 6726 } 6727 6728 /* Now output the actual element. */ 6729 if (value.value) 6730 output_init_element (value.value, strict_string, 6731 elttype, constructor_index, 1); 6732 6733 constructor_index 6734 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6735 6736 if (!value.value) 6737 /* If we are doing the bookkeeping for an element that was 6738 directly output as a constructor, we must update 6739 constructor_unfilled_index. */ 6740 constructor_unfilled_index = constructor_index; 6741 } 6742 6743 /* Handle the sole element allowed in a braced initializer 6744 for a scalar variable. */ 6745 else if (constructor_type != error_mark_node 6746 && constructor_fields == 0) 6747 { 6748 pedwarn_init ("excess elements in scalar initializer"); 6749 break; 6750 } 6751 else 6752 { 6753 if (value.value) 6754 output_init_element (value.value, strict_string, 6755 constructor_type, NULL_TREE, 1); 6756 constructor_fields = 0; 6757 } 6758 6759 /* Handle range initializers either at this level or anywhere higher 6760 in the designator stack. */ 6761 if (constructor_range_stack) 6762 { 6763 struct constructor_range_stack *p, *range_stack; 6764 int finish = 0; 6765 6766 range_stack = constructor_range_stack; 6767 constructor_range_stack = 0; 6768 while (constructor_stack != range_stack->stack) 6769 { 6770 gcc_assert (constructor_stack->implicit); 6771 process_init_element (pop_init_level (1)); 6772 } 6773 for (p = range_stack; 6774 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6775 p = p->prev) 6776 { 6777 gcc_assert (constructor_stack->implicit); 6778 process_init_element (pop_init_level (1)); 6779 } 6780 6781 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6782 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6783 finish = 1; 6784 6785 while (1) 6786 { 6787 constructor_index = p->index; 6788 constructor_fields = p->fields; 6789 if (finish && p->range_end && p->index == p->range_start) 6790 { 6791 finish = 0; 6792 p->prev = 0; 6793 } 6794 p = p->next; 6795 if (!p) 6796 break; 6797 push_init_level (2); 6798 p->stack = constructor_stack; 6799 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6800 p->index = p->range_start; 6801 } 6802 6803 if (!finish) 6804 constructor_range_stack = range_stack; 6805 continue; 6806 } 6807 6808 break; 6809 } 6810 6811 constructor_range_stack = 0; 6812} 6813 6814/* Build a complete asm-statement, whose components are a CV_QUALIFIER 6815 (guaranteed to be 'volatile' or null) and ARGS (represented using 6816 an ASM_EXPR node). */ 6817tree 6818build_asm_stmt (tree cv_qualifier, tree args) 6819{ 6820 if (!ASM_VOLATILE_P (args) && cv_qualifier) 6821 ASM_VOLATILE_P (args) = 1; 6822 return add_stmt (args); 6823} 6824 6825/* Build an asm-expr, whose components are a STRING, some OUTPUTS, 6826 some INPUTS, and some CLOBBERS. The latter three may be NULL. 6827 SIMPLE indicates whether there was anything at all after the 6828 string in the asm expression -- asm("blah") and asm("blah" : ) 6829 are subtly different. We use a ASM_EXPR node to represent this. */ 6830tree 6831build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers, 6832 bool simple) 6833{ 6834 tree tail; 6835 tree args; 6836 int i; 6837 const char *constraint; 6838 const char **oconstraints; 6839 bool allows_mem, allows_reg, is_inout; 6840 int ninputs, noutputs; 6841 6842 ninputs = list_length (inputs); 6843 noutputs = list_length (outputs); 6844 oconstraints = (const char **) alloca (noutputs * sizeof (const char *)); 6845 6846 string = resolve_asm_operand_names (string, outputs, inputs); 6847 6848 /* Remove output conversions that change the type but not the mode. */ 6849 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail)) 6850 { 6851 tree output = TREE_VALUE (tail); 6852 6853 /* ??? Really, this should not be here. Users should be using a 6854 proper lvalue, dammit. But there's a long history of using casts 6855 in the output operands. In cases like longlong.h, this becomes a 6856 primitive form of typechecking -- if the cast can be removed, then 6857 the output operand had a type of the proper width; otherwise we'll 6858 get an error. Gross, but ... */ 6859 STRIP_NOPS (output); 6860 6861 if (!lvalue_or_else (output, lv_asm)) 6862 output = error_mark_node; 6863 6864 if (output != error_mark_node 6865 && (TREE_READONLY (output) 6866 || TYPE_READONLY (TREE_TYPE (output)) 6867 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE 6868 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE) 6869 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output))))) 6870 readonly_error (output, lv_asm); 6871 6872 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6873 oconstraints[i] = constraint; 6874 6875 if (parse_output_constraint (&constraint, i, ninputs, noutputs, 6876 &allows_mem, &allows_reg, &is_inout)) 6877 { 6878 /* If the operand is going to end up in memory, 6879 mark it addressable. */ 6880 if (!allows_reg && !c_mark_addressable (output)) 6881 output = error_mark_node; 6882 } 6883 else 6884 output = error_mark_node; 6885 6886 TREE_VALUE (tail) = output; 6887 } 6888 6889 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail)) 6890 { 6891 tree input; 6892 6893 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6894 input = TREE_VALUE (tail); 6895 6896 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0, 6897 oconstraints, &allows_mem, &allows_reg)) 6898 { 6899 /* If the operand is going to end up in memory, 6900 mark it addressable. */ 6901 if (!allows_reg && allows_mem) 6902 { 6903 /* Strip the nops as we allow this case. FIXME, this really 6904 should be rejected or made deprecated. */ 6905 STRIP_NOPS (input); 6906 if (!c_mark_addressable (input)) 6907 input = error_mark_node; 6908 } 6909 } 6910 else 6911 input = error_mark_node; 6912 6913 TREE_VALUE (tail) = input; 6914 } 6915 6916 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers); 6917 6918 /* asm statements without outputs, including simple ones, are treated 6919 as volatile. */ 6920 ASM_INPUT_P (args) = simple; 6921 ASM_VOLATILE_P (args) = (noutputs == 0); 6922 6923 return args; 6924} 6925 6926/* Generate a goto statement to LABEL. */ 6927 6928tree 6929c_finish_goto_label (tree label) 6930{ 6931 tree decl = lookup_label (label); 6932 if (!decl) 6933 return NULL_TREE; 6934 6935 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl)) 6936 { 6937 error ("jump into statement expression"); 6938 return NULL_TREE; 6939 } 6940 6941 if (C_DECL_UNJUMPABLE_VM (decl)) 6942 { 6943 error ("jump into scope of identifier with variably modified type"); 6944 return NULL_TREE; 6945 } 6946 6947 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl)) 6948 { 6949 /* No jump from outside this statement expression context, so 6950 record that there is a jump from within this context. */ 6951 struct c_label_list *nlist; 6952 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6953 nlist->next = label_context_stack_se->labels_used; 6954 nlist->label = decl; 6955 label_context_stack_se->labels_used = nlist; 6956 } 6957 6958 if (!C_DECL_UNDEFINABLE_VM (decl)) 6959 { 6960 /* No jump from outside this context context of identifiers with 6961 variably modified type, so record that there is a jump from 6962 within this context. */ 6963 struct c_label_list *nlist; 6964 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6965 nlist->next = label_context_stack_vm->labels_used; 6966 nlist->label = decl; 6967 label_context_stack_vm->labels_used = nlist; 6968 } 6969 6970 TREE_USED (decl) = 1; 6971 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl)); 6972} 6973 6974/* Generate a computed goto statement to EXPR. */ 6975 6976tree 6977c_finish_goto_ptr (tree expr) 6978{ 6979 if (pedantic) 6980 pedwarn ("ISO C forbids %<goto *expr;%>"); 6981 expr = convert (ptr_type_node, expr); 6982 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr)); 6983} 6984 6985/* Generate a C `return' statement. RETVAL is the expression for what 6986 to return, or a null pointer for `return;' with no value. */ 6987 6988tree 6989c_finish_return (tree retval) 6990{ 6991 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt; 6992 bool no_warning = false; 6993 6994 if (TREE_THIS_VOLATILE (current_function_decl)) 6995 warning (0, "function declared %<noreturn%> has a %<return%> statement"); 6996 6997 if (!retval) 6998 { 6999 current_function_returns_null = 1; 7000 if ((warn_return_type || flag_isoc99) 7001 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 7002 { 7003 pedwarn_c99 ("%<return%> with no value, in " 7004 "function returning non-void"); 7005 no_warning = true; 7006 } 7007 } 7008 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 7009 { 7010 current_function_returns_null = 1; 7011 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 7012 pedwarn ("%<return%> with a value, in function returning void"); 7013 } 7014 else 7015 { 7016 tree t = convert_for_assignment (valtype, retval, ic_return, 7017 NULL_TREE, NULL_TREE, 0); 7018 tree res = DECL_RESULT (current_function_decl); 7019 tree inner; 7020 7021 current_function_returns_value = 1; 7022 if (t == error_mark_node) 7023 return NULL_TREE; 7024 7025 inner = t = convert (TREE_TYPE (res), t); 7026 7027 /* Strip any conversions, additions, and subtractions, and see if 7028 we are returning the address of a local variable. Warn if so. */ 7029 while (1) 7030 { 7031 switch (TREE_CODE (inner)) 7032 { 7033 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 7034 case PLUS_EXPR: 7035 inner = TREE_OPERAND (inner, 0); 7036 continue; 7037 7038 case MINUS_EXPR: 7039 /* If the second operand of the MINUS_EXPR has a pointer 7040 type (or is converted from it), this may be valid, so 7041 don't give a warning. */ 7042 { 7043 tree op1 = TREE_OPERAND (inner, 1); 7044 7045 while (!POINTER_TYPE_P (TREE_TYPE (op1)) 7046 && (TREE_CODE (op1) == NOP_EXPR 7047 || TREE_CODE (op1) == NON_LVALUE_EXPR 7048 || TREE_CODE (op1) == CONVERT_EXPR)) 7049 op1 = TREE_OPERAND (op1, 0); 7050 7051 if (POINTER_TYPE_P (TREE_TYPE (op1))) 7052 break; 7053 7054 inner = TREE_OPERAND (inner, 0); 7055 continue; 7056 } 7057 7058 case ADDR_EXPR: 7059 inner = TREE_OPERAND (inner, 0); 7060 7061 while (REFERENCE_CLASS_P (inner) 7062 && TREE_CODE (inner) != INDIRECT_REF) 7063 inner = TREE_OPERAND (inner, 0); 7064 7065 if (DECL_P (inner) 7066 && !DECL_EXTERNAL (inner) 7067 && !TREE_STATIC (inner) 7068 && DECL_CONTEXT (inner) == current_function_decl) 7069 warning (0, "function returns address of local variable"); 7070 break; 7071 7072 default: 7073 break; 7074 } 7075 7076 break; 7077 } 7078 7079 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t); 7080 } 7081 7082 ret_stmt = build_stmt (RETURN_EXPR, retval); 7083 TREE_NO_WARNING (ret_stmt) |= no_warning; 7084 return add_stmt (ret_stmt); 7085} 7086 7087struct c_switch { 7088 /* The SWITCH_EXPR being built. */ 7089 tree switch_expr; 7090 7091 /* The original type of the testing expression, i.e. before the 7092 default conversion is applied. */ 7093 tree orig_type; 7094 7095 /* A splay-tree mapping the low element of a case range to the high 7096 element, or NULL_TREE if there is no high element. Used to 7097 determine whether or not a new case label duplicates an old case 7098 label. We need a tree, rather than simply a hash table, because 7099 of the GNU case range extension. */ 7100 splay_tree cases; 7101 7102 /* Number of nested statement expressions within this switch 7103 statement; if nonzero, case and default labels may not 7104 appear. */ 7105 unsigned int blocked_stmt_expr; 7106 7107 /* Scope of outermost declarations of identifiers with variably 7108 modified type within this switch statement; if nonzero, case and 7109 default labels may not appear. */ 7110 unsigned int blocked_vm; 7111 7112 /* The next node on the stack. */ 7113 struct c_switch *next; 7114}; 7115 7116/* A stack of the currently active switch statements. The innermost 7117 switch statement is on the top of the stack. There is no need to 7118 mark the stack for garbage collection because it is only active 7119 during the processing of the body of a function, and we never 7120 collect at that point. */ 7121 7122struct c_switch *c_switch_stack; 7123 7124/* Start a C switch statement, testing expression EXP. Return the new 7125 SWITCH_EXPR. */ 7126 7127tree 7128c_start_case (tree exp) 7129{ 7130 tree orig_type = error_mark_node; 7131 struct c_switch *cs; 7132 7133 if (exp != error_mark_node) 7134 { 7135 orig_type = TREE_TYPE (exp); 7136 7137 if (!INTEGRAL_TYPE_P (orig_type)) 7138 { 7139 if (orig_type != error_mark_node) 7140 { 7141 error ("switch quantity not an integer"); 7142 orig_type = error_mark_node; 7143 } 7144 exp = integer_zero_node; 7145 } 7146 else 7147 { 7148 tree type = TYPE_MAIN_VARIANT (orig_type); 7149 7150 if (!in_system_header 7151 && (type == long_integer_type_node 7152 || type == long_unsigned_type_node)) 7153 warning (OPT_Wtraditional, "%<long%> switch expression not " 7154 "converted to %<int%> in ISO C"); 7155 7156 exp = default_conversion (exp); 7157 } 7158 } 7159 7160 /* Add this new SWITCH_EXPR to the stack. */ 7161 cs = XNEW (struct c_switch); 7162 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE); 7163 cs->orig_type = orig_type; 7164 cs->cases = splay_tree_new (case_compare, NULL, NULL); 7165 cs->blocked_stmt_expr = 0; 7166 cs->blocked_vm = 0; 7167 cs->next = c_switch_stack; 7168 c_switch_stack = cs; 7169 7170 return add_stmt (cs->switch_expr); 7171} 7172 7173/* Process a case label. */ 7174 7175tree 7176do_case (tree low_value, tree high_value) 7177{ 7178 tree label = NULL_TREE; 7179 7180 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr 7181 && !c_switch_stack->blocked_vm) 7182 { 7183 label = c_add_case_label (c_switch_stack->cases, 7184 SWITCH_COND (c_switch_stack->switch_expr), 7185 c_switch_stack->orig_type, 7186 low_value, high_value); 7187 if (label == error_mark_node) 7188 label = NULL_TREE; 7189 } 7190 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr) 7191 { 7192 if (low_value) 7193 error ("case label in statement expression not containing " 7194 "enclosing switch statement"); 7195 else 7196 error ("%<default%> label in statement expression not containing " 7197 "enclosing switch statement"); 7198 } 7199 else if (c_switch_stack && c_switch_stack->blocked_vm) 7200 { 7201 if (low_value) 7202 error ("case label in scope of identifier with variably modified " 7203 "type not containing enclosing switch statement"); 7204 else 7205 error ("%<default%> label in scope of identifier with variably " 7206 "modified type not containing enclosing switch statement"); 7207 } 7208 else if (low_value) 7209 error ("case label not within a switch statement"); 7210 else 7211 error ("%<default%> label not within a switch statement"); 7212 7213 return label; 7214} 7215 7216/* Finish the switch statement. */ 7217 7218void 7219c_finish_case (tree body) 7220{ 7221 struct c_switch *cs = c_switch_stack; 7222 location_t switch_location; 7223 7224 SWITCH_BODY (cs->switch_expr) = body; 7225 7226 /* We must not be within a statement expression nested in the switch 7227 at this point; we might, however, be within the scope of an 7228 identifier with variably modified type nested in the switch. */ 7229 gcc_assert (!cs->blocked_stmt_expr); 7230 7231 /* Emit warnings as needed. */ 7232 if (EXPR_HAS_LOCATION (cs->switch_expr)) 7233 switch_location = EXPR_LOCATION (cs->switch_expr); 7234 else 7235 switch_location = input_location; 7236 c_do_switch_warnings (cs->cases, switch_location, 7237 TREE_TYPE (cs->switch_expr), 7238 SWITCH_COND (cs->switch_expr)); 7239 7240 /* Pop the stack. */ 7241 c_switch_stack = cs->next; 7242 splay_tree_delete (cs->cases); 7243 XDELETE (cs); 7244} 7245 7246/* Emit an if statement. IF_LOCUS is the location of the 'if'. COND, 7247 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK 7248 may be null. NESTED_IF is true if THEN_BLOCK contains another IF 7249 statement, and was not surrounded with parenthesis. */ 7250 7251void 7252c_finish_if_stmt (location_t if_locus, tree cond, tree then_block, 7253 tree else_block, bool nested_if) 7254{ 7255 tree stmt; 7256 7257 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */ 7258 if (warn_parentheses && nested_if && else_block == NULL) 7259 { 7260 tree inner_if = then_block; 7261 7262 /* We know from the grammar productions that there is an IF nested 7263 within THEN_BLOCK. Due to labels and c99 conditional declarations, 7264 it might not be exactly THEN_BLOCK, but should be the last 7265 non-container statement within. */ 7266 while (1) 7267 switch (TREE_CODE (inner_if)) 7268 { 7269 case COND_EXPR: 7270 goto found; 7271 case BIND_EXPR: 7272 inner_if = BIND_EXPR_BODY (inner_if); 7273 break; 7274 case STATEMENT_LIST: 7275 inner_if = expr_last (then_block); 7276 break; 7277 case TRY_FINALLY_EXPR: 7278 case TRY_CATCH_EXPR: 7279 inner_if = TREE_OPERAND (inner_if, 0); 7280 break; 7281 default: 7282 gcc_unreachable (); 7283 } 7284 found: 7285 7286 if (COND_EXPR_ELSE (inner_if)) 7287 warning (OPT_Wparentheses, 7288 "%Hsuggest explicit braces to avoid ambiguous %<else%>", 7289 &if_locus); 7290 } 7291 7292 empty_body_warning (then_block, else_block); 7293 7294 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block); 7295 SET_EXPR_LOCATION (stmt, if_locus); 7296 add_stmt (stmt); 7297} 7298 7299/* Emit a general-purpose loop construct. START_LOCUS is the location of 7300 the beginning of the loop. COND is the loop condition. COND_IS_FIRST 7301 is false for DO loops. INCR is the FOR increment expression. BODY is 7302 the statement controlled by the loop. BLAB is the break label. CLAB is 7303 the continue label. Everything is allowed to be NULL. */ 7304 7305void 7306c_finish_loop (location_t start_locus, tree cond, tree incr, tree body, 7307 tree blab, tree clab, bool cond_is_first) 7308{ 7309 tree entry = NULL, exit = NULL, t; 7310 7311 /* If the condition is zero don't generate a loop construct. */ 7312 if (cond && integer_zerop (cond)) 7313 { 7314 if (cond_is_first) 7315 { 7316 t = build_and_jump (&blab); 7317 SET_EXPR_LOCATION (t, start_locus); 7318 add_stmt (t); 7319 } 7320 } 7321 else 7322 { 7323 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7324 7325 /* If we have an exit condition, then we build an IF with gotos either 7326 out of the loop, or to the top of it. If there's no exit condition, 7327 then we just build a jump back to the top. */ 7328 exit = build_and_jump (&LABEL_EXPR_LABEL (top)); 7329 7330 if (cond && !integer_nonzerop (cond)) 7331 { 7332 /* Canonicalize the loop condition to the end. This means 7333 generating a branch to the loop condition. Reuse the 7334 continue label, if possible. */ 7335 if (cond_is_first) 7336 { 7337 if (incr || !clab) 7338 { 7339 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7340 t = build_and_jump (&LABEL_EXPR_LABEL (entry)); 7341 } 7342 else 7343 t = build1 (GOTO_EXPR, void_type_node, clab); 7344 SET_EXPR_LOCATION (t, start_locus); 7345 add_stmt (t); 7346 } 7347 7348 t = build_and_jump (&blab); 7349 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t); 7350 if (cond_is_first) 7351 SET_EXPR_LOCATION (exit, start_locus); 7352 else 7353 SET_EXPR_LOCATION (exit, input_location); 7354 } 7355 7356 add_stmt (top); 7357 } 7358 7359 if (body) 7360 add_stmt (body); 7361 if (clab) 7362 add_stmt (build1 (LABEL_EXPR, void_type_node, clab)); 7363 if (incr) 7364 add_stmt (incr); 7365 if (entry) 7366 add_stmt (entry); 7367 if (exit) 7368 add_stmt (exit); 7369 if (blab) 7370 add_stmt (build1 (LABEL_EXPR, void_type_node, blab)); 7371} 7372 7373tree 7374c_finish_bc_stmt (tree *label_p, bool is_break) 7375{ 7376 bool skip; 7377 tree label = *label_p; 7378 7379 /* In switch statements break is sometimes stylistically used after 7380 a return statement. This can lead to spurious warnings about 7381 control reaching the end of a non-void function when it is 7382 inlined. Note that we are calling block_may_fallthru with 7383 language specific tree nodes; this works because 7384 block_may_fallthru returns true when given something it does not 7385 understand. */ 7386 skip = !block_may_fallthru (cur_stmt_list); 7387 7388 if (!label) 7389 { 7390 if (!skip) 7391 *label_p = label = create_artificial_label (); 7392 } 7393 else if (TREE_CODE (label) == LABEL_DECL) 7394 ; 7395 else switch (TREE_INT_CST_LOW (label)) 7396 { 7397 case 0: 7398 if (is_break) 7399 error ("break statement not within loop or switch"); 7400 else 7401 error ("continue statement not within a loop"); 7402 return NULL_TREE; 7403 7404 case 1: 7405 gcc_assert (is_break); 7406 error ("break statement used with OpenMP for loop"); 7407 return NULL_TREE; 7408 7409 default: 7410 gcc_unreachable (); 7411 } 7412 7413 if (skip) 7414 return NULL_TREE; 7415 7416 return add_stmt (build1 (GOTO_EXPR, void_type_node, label)); 7417} 7418 7419/* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */ 7420 7421static void 7422emit_side_effect_warnings (tree expr) 7423{ 7424 if (expr == error_mark_node) 7425 ; 7426 else if (!TREE_SIDE_EFFECTS (expr)) 7427 { 7428 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr)) 7429 warning (0, "%Hstatement with no effect", 7430 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location); 7431 } 7432 else if (warn_unused_value) 7433 warn_if_unused_value (expr, input_location); 7434} 7435 7436/* Process an expression as if it were a complete statement. Emit 7437 diagnostics, but do not call ADD_STMT. */ 7438 7439tree 7440c_process_expr_stmt (tree expr) 7441{ 7442 if (!expr) 7443 return NULL_TREE; 7444 7445 if (warn_sequence_point) 7446 verify_sequence_points (expr); 7447 7448 if (TREE_TYPE (expr) != error_mark_node 7449 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr)) 7450 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE) 7451 error ("expression statement has incomplete type"); 7452 7453 /* If we're not processing a statement expression, warn about unused values. 7454 Warnings for statement expressions will be emitted later, once we figure 7455 out which is the result. */ 7456 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7457 && (extra_warnings || warn_unused_value)) 7458 emit_side_effect_warnings (expr); 7459 7460 /* If the expression is not of a type to which we cannot assign a line 7461 number, wrap the thing in a no-op NOP_EXPR. */ 7462 if (DECL_P (expr) || CONSTANT_CLASS_P (expr)) 7463 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr); 7464 7465 if (EXPR_P (expr)) 7466 SET_EXPR_LOCATION (expr, input_location); 7467 7468 return expr; 7469} 7470 7471/* Emit an expression as a statement. */ 7472 7473tree 7474c_finish_expr_stmt (tree expr) 7475{ 7476 if (expr) 7477 return add_stmt (c_process_expr_stmt (expr)); 7478 else 7479 return NULL; 7480} 7481 7482/* Do the opposite and emit a statement as an expression. To begin, 7483 create a new binding level and return it. */ 7484 7485tree 7486c_begin_stmt_expr (void) 7487{ 7488 tree ret; 7489 struct c_label_context_se *nstack; 7490 struct c_label_list *glist; 7491 7492 /* We must force a BLOCK for this level so that, if it is not expanded 7493 later, there is a way to turn off the entire subtree of blocks that 7494 are contained in it. */ 7495 keep_next_level (); 7496 ret = c_begin_compound_stmt (true); 7497 if (c_switch_stack) 7498 { 7499 c_switch_stack->blocked_stmt_expr++; 7500 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7501 } 7502 for (glist = label_context_stack_se->labels_used; 7503 glist != NULL; 7504 glist = glist->next) 7505 { 7506 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1; 7507 } 7508 nstack = XOBNEW (&parser_obstack, struct c_label_context_se); 7509 nstack->labels_def = NULL; 7510 nstack->labels_used = NULL; 7511 nstack->next = label_context_stack_se; 7512 label_context_stack_se = nstack; 7513 7514 /* Mark the current statement list as belonging to a statement list. */ 7515 STATEMENT_LIST_STMT_EXPR (ret) = 1; 7516 7517 return ret; 7518} 7519 7520tree 7521c_finish_stmt_expr (tree body) 7522{ 7523 tree last, type, tmp, val; 7524 tree *last_p; 7525 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7526 7527 body = c_end_compound_stmt (body, true); 7528 if (c_switch_stack) 7529 { 7530 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7531 c_switch_stack->blocked_stmt_expr--; 7532 } 7533 /* It is no longer possible to jump to labels defined within this 7534 statement expression. */ 7535 for (dlist = label_context_stack_se->labels_def; 7536 dlist != NULL; 7537 dlist = dlist->next) 7538 { 7539 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1; 7540 } 7541 /* It is again possible to define labels with a goto just outside 7542 this statement expression. */ 7543 for (glist = label_context_stack_se->next->labels_used; 7544 glist != NULL; 7545 glist = glist->next) 7546 { 7547 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0; 7548 glist_prev = glist; 7549 } 7550 if (glist_prev != NULL) 7551 glist_prev->next = label_context_stack_se->labels_used; 7552 else 7553 label_context_stack_se->next->labels_used 7554 = label_context_stack_se->labels_used; 7555 label_context_stack_se = label_context_stack_se->next; 7556 7557 /* Locate the last statement in BODY. See c_end_compound_stmt 7558 about always returning a BIND_EXPR. */ 7559 last_p = &BIND_EXPR_BODY (body); 7560 last = BIND_EXPR_BODY (body); 7561 7562 continue_searching: 7563 if (TREE_CODE (last) == STATEMENT_LIST) 7564 { 7565 tree_stmt_iterator i; 7566 7567 /* This can happen with degenerate cases like ({ }). No value. */ 7568 if (!TREE_SIDE_EFFECTS (last)) 7569 return body; 7570 7571 /* If we're supposed to generate side effects warnings, process 7572 all of the statements except the last. */ 7573 if (extra_warnings || warn_unused_value) 7574 { 7575 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i)) 7576 emit_side_effect_warnings (tsi_stmt (i)); 7577 } 7578 else 7579 i = tsi_last (last); 7580 last_p = tsi_stmt_ptr (i); 7581 last = *last_p; 7582 } 7583 7584 /* If the end of the list is exception related, then the list was split 7585 by a call to push_cleanup. Continue searching. */ 7586 if (TREE_CODE (last) == TRY_FINALLY_EXPR 7587 || TREE_CODE (last) == TRY_CATCH_EXPR) 7588 { 7589 last_p = &TREE_OPERAND (last, 0); 7590 last = *last_p; 7591 goto continue_searching; 7592 } 7593 7594 /* In the case that the BIND_EXPR is not necessary, return the 7595 expression out from inside it. */ 7596 if (last == error_mark_node 7597 || (last == BIND_EXPR_BODY (body) 7598 && BIND_EXPR_VARS (body) == NULL)) 7599 { 7600 /* Do not warn if the return value of a statement expression is 7601 unused. */ 7602 if (EXPR_P (last)) 7603 TREE_NO_WARNING (last) = 1; 7604 return last; 7605 } 7606 7607 /* Extract the type of said expression. */ 7608 type = TREE_TYPE (last); 7609 7610 /* If we're not returning a value at all, then the BIND_EXPR that 7611 we already have is a fine expression to return. */ 7612 if (!type || VOID_TYPE_P (type)) 7613 return body; 7614 7615 /* Now that we've located the expression containing the value, it seems 7616 silly to make voidify_wrapper_expr repeat the process. Create a 7617 temporary of the appropriate type and stick it in a TARGET_EXPR. */ 7618 tmp = create_tmp_var_raw (type, NULL); 7619 7620 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids 7621 tree_expr_nonnegative_p giving up immediately. */ 7622 val = last; 7623 if (TREE_CODE (val) == NOP_EXPR 7624 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))) 7625 val = TREE_OPERAND (val, 0); 7626 7627 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val); 7628 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last)); 7629 7630 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE); 7631} 7632 7633/* Begin the scope of an identifier of variably modified type, scope 7634 number SCOPE. Jumping from outside this scope to inside it is not 7635 permitted. */ 7636 7637void 7638c_begin_vm_scope (unsigned int scope) 7639{ 7640 struct c_label_context_vm *nstack; 7641 struct c_label_list *glist; 7642 7643 gcc_assert (scope > 0); 7644 7645 /* At file_scope, we don't have to do any processing. */ 7646 if (label_context_stack_vm == NULL) 7647 return; 7648 7649 if (c_switch_stack && !c_switch_stack->blocked_vm) 7650 c_switch_stack->blocked_vm = scope; 7651 for (glist = label_context_stack_vm->labels_used; 7652 glist != NULL; 7653 glist = glist->next) 7654 { 7655 C_DECL_UNDEFINABLE_VM (glist->label) = 1; 7656 } 7657 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm); 7658 nstack->labels_def = NULL; 7659 nstack->labels_used = NULL; 7660 nstack->scope = scope; 7661 nstack->next = label_context_stack_vm; 7662 label_context_stack_vm = nstack; 7663} 7664 7665/* End a scope which may contain identifiers of variably modified 7666 type, scope number SCOPE. */ 7667 7668void 7669c_end_vm_scope (unsigned int scope) 7670{ 7671 if (label_context_stack_vm == NULL) 7672 return; 7673 if (c_switch_stack && c_switch_stack->blocked_vm == scope) 7674 c_switch_stack->blocked_vm = 0; 7675 /* We may have a number of nested scopes of identifiers with 7676 variably modified type, all at this depth. Pop each in turn. */ 7677 while (label_context_stack_vm->scope == scope) 7678 { 7679 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7680 7681 /* It is no longer possible to jump to labels defined within this 7682 scope. */ 7683 for (dlist = label_context_stack_vm->labels_def; 7684 dlist != NULL; 7685 dlist = dlist->next) 7686 { 7687 C_DECL_UNJUMPABLE_VM (dlist->label) = 1; 7688 } 7689 /* It is again possible to define labels with a goto just outside 7690 this scope. */ 7691 for (glist = label_context_stack_vm->next->labels_used; 7692 glist != NULL; 7693 glist = glist->next) 7694 { 7695 C_DECL_UNDEFINABLE_VM (glist->label) = 0; 7696 glist_prev = glist; 7697 } 7698 if (glist_prev != NULL) 7699 glist_prev->next = label_context_stack_vm->labels_used; 7700 else 7701 label_context_stack_vm->next->labels_used 7702 = label_context_stack_vm->labels_used; 7703 label_context_stack_vm = label_context_stack_vm->next; 7704 } 7705} 7706 7707/* Begin and end compound statements. This is as simple as pushing 7708 and popping new statement lists from the tree. */ 7709 7710tree 7711c_begin_compound_stmt (bool do_scope) 7712{ 7713 tree stmt = push_stmt_list (); 7714 if (do_scope) 7715 push_scope (); 7716 return stmt; 7717} 7718 7719tree 7720c_end_compound_stmt (tree stmt, bool do_scope) 7721{ 7722 tree block = NULL; 7723 7724 if (do_scope) 7725 { 7726 if (c_dialect_objc ()) 7727 objc_clear_super_receiver (); 7728 block = pop_scope (); 7729 } 7730 7731 stmt = pop_stmt_list (stmt); 7732 stmt = c_build_bind_expr (block, stmt); 7733 7734 /* If this compound statement is nested immediately inside a statement 7735 expression, then force a BIND_EXPR to be created. Otherwise we'll 7736 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular, 7737 STATEMENT_LISTs merge, and thus we can lose track of what statement 7738 was really last. */ 7739 if (cur_stmt_list 7740 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7741 && TREE_CODE (stmt) != BIND_EXPR) 7742 { 7743 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL); 7744 TREE_SIDE_EFFECTS (stmt) = 1; 7745 } 7746 7747 return stmt; 7748} 7749 7750/* Queue a cleanup. CLEANUP is an expression/statement to be executed 7751 when the current scope is exited. EH_ONLY is true when this is not 7752 meant to apply to normal control flow transfer. */ 7753 7754void 7755push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only) 7756{ 7757 enum tree_code code; 7758 tree stmt, list; 7759 bool stmt_expr; 7760 7761 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR; 7762 stmt = build_stmt (code, NULL, cleanup); 7763 add_stmt (stmt); 7764 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list); 7765 list = push_stmt_list (); 7766 TREE_OPERAND (stmt, 0) = list; 7767 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr; 7768} 7769 7770/* Build a binary-operation expression without default conversions. 7771 CODE is the kind of expression to build. 7772 This function differs from `build' in several ways: 7773 the data type of the result is computed and recorded in it, 7774 warnings are generated if arg data types are invalid, 7775 special handling for addition and subtraction of pointers is known, 7776 and some optimization is done (operations on narrow ints 7777 are done in the narrower type when that gives the same result). 7778 Constant folding is also done before the result is returned. 7779 7780 Note that the operands will never have enumeral types, or function 7781 or array types, because either they will have the default conversions 7782 performed or they have both just been converted to some other type in which 7783 the arithmetic is to be done. */ 7784 7785tree 7786build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 7787 int convert_p) 7788{ 7789 tree type0, type1; 7790 enum tree_code code0, code1; 7791 tree op0, op1; 7792 const char *invalid_op_diag; 7793 7794 /* Expression code to give to the expression when it is built. 7795 Normally this is CODE, which is what the caller asked for, 7796 but in some special cases we change it. */ 7797 enum tree_code resultcode = code; 7798 7799 /* Data type in which the computation is to be performed. 7800 In the simplest cases this is the common type of the arguments. */ 7801 tree result_type = NULL; 7802 7803 /* Nonzero means operands have already been type-converted 7804 in whatever way is necessary. 7805 Zero means they need to be converted to RESULT_TYPE. */ 7806 int converted = 0; 7807 7808 /* Nonzero means create the expression with this type, rather than 7809 RESULT_TYPE. */ 7810 tree build_type = 0; 7811 7812 /* Nonzero means after finally constructing the expression 7813 convert it to this type. */ 7814 tree final_type = 0; 7815 7816 /* Nonzero if this is an operation like MIN or MAX which can 7817 safely be computed in short if both args are promoted shorts. 7818 Also implies COMMON. 7819 -1 indicates a bitwise operation; this makes a difference 7820 in the exact conditions for when it is safe to do the operation 7821 in a narrower mode. */ 7822 int shorten = 0; 7823 7824 /* Nonzero if this is a comparison operation; 7825 if both args are promoted shorts, compare the original shorts. 7826 Also implies COMMON. */ 7827 int short_compare = 0; 7828 7829 /* Nonzero if this is a right-shift operation, which can be computed on the 7830 original short and then promoted if the operand is a promoted short. */ 7831 int short_shift = 0; 7832 7833 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 7834 int common = 0; 7835 7836 /* True means types are compatible as far as ObjC is concerned. */ 7837 bool objc_ok; 7838 7839 if (convert_p) 7840 { 7841 op0 = default_conversion (orig_op0); 7842 op1 = default_conversion (orig_op1); 7843 } 7844 else 7845 { 7846 op0 = orig_op0; 7847 op1 = orig_op1; 7848 } 7849 7850 type0 = TREE_TYPE (op0); 7851 type1 = TREE_TYPE (op1); 7852 7853 /* The expression codes of the data types of the arguments tell us 7854 whether the arguments are integers, floating, pointers, etc. */ 7855 code0 = TREE_CODE (type0); 7856 code1 = TREE_CODE (type1); 7857 7858 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 7859 STRIP_TYPE_NOPS (op0); 7860 STRIP_TYPE_NOPS (op1); 7861 7862 /* If an error was already reported for one of the arguments, 7863 avoid reporting another error. */ 7864 7865 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 7866 return error_mark_node; 7867 7868 if ((invalid_op_diag 7869 = targetm.invalid_binary_op (code, type0, type1))) 7870 { 7871 error (invalid_op_diag); 7872 return error_mark_node; 7873 } 7874 7875 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE); 7876 7877 switch (code) 7878 { 7879 case PLUS_EXPR: 7880 /* Handle the pointer + int case. */ 7881 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7882 return pointer_int_sum (PLUS_EXPR, op0, op1); 7883 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 7884 return pointer_int_sum (PLUS_EXPR, op1, op0); 7885 else 7886 common = 1; 7887 break; 7888 7889 case MINUS_EXPR: 7890 /* Subtraction of two similar pointers. 7891 We must subtract them as integers, then divide by object size. */ 7892 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 7893 && comp_target_types (type0, type1)) 7894 return pointer_diff (op0, op1); 7895 /* Handle pointer minus int. Just like pointer plus int. */ 7896 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7897 return pointer_int_sum (MINUS_EXPR, op0, op1); 7898 else 7899 common = 1; 7900 break; 7901 7902 case MULT_EXPR: 7903 common = 1; 7904 break; 7905 7906 case TRUNC_DIV_EXPR: 7907 case CEIL_DIV_EXPR: 7908 case FLOOR_DIV_EXPR: 7909 case ROUND_DIV_EXPR: 7910 case EXACT_DIV_EXPR: 7911 /* Floating point division by zero is a legitimate way to obtain 7912 infinities and NaNs. */ 7913 if (skip_evaluation == 0 && integer_zerop (op1)) 7914 warning (OPT_Wdiv_by_zero, "division by zero"); 7915 7916 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 7917 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7918 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 7919 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 7920 { 7921 enum tree_code tcode0 = code0, tcode1 = code1; 7922 7923 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7924 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); 7925 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE) 7926 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); 7927 7928 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)) 7929 resultcode = RDIV_EXPR; 7930 else 7931 /* Although it would be tempting to shorten always here, that 7932 loses on some targets, since the modulo instruction is 7933 undefined if the quotient can't be represented in the 7934 computation mode. We shorten only if unsigned or if 7935 dividing by something we know != -1. */ 7936 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7937 || (TREE_CODE (op1) == INTEGER_CST 7938 && !integer_all_onesp (op1))); 7939 common = 1; 7940 } 7941 break; 7942 7943 case BIT_AND_EXPR: 7944 case BIT_IOR_EXPR: 7945 case BIT_XOR_EXPR: 7946 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7947 shorten = -1; 7948 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 7949 common = 1; 7950 break; 7951 7952 case TRUNC_MOD_EXPR: 7953 case FLOOR_MOD_EXPR: 7954 if (skip_evaluation == 0 && integer_zerop (op1)) 7955 warning (OPT_Wdiv_by_zero, "division by zero"); 7956 7957 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7958 { 7959 /* Although it would be tempting to shorten always here, that loses 7960 on some targets, since the modulo instruction is undefined if the 7961 quotient can't be represented in the computation mode. We shorten 7962 only if unsigned or if dividing by something we know != -1. */ 7963 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7964 || (TREE_CODE (op1) == INTEGER_CST 7965 && !integer_all_onesp (op1))); 7966 common = 1; 7967 } 7968 break; 7969 7970 case TRUTH_ANDIF_EXPR: 7971 case TRUTH_ORIF_EXPR: 7972 case TRUTH_AND_EXPR: 7973 case TRUTH_OR_EXPR: 7974 case TRUTH_XOR_EXPR: 7975 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 7976 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 7977 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 7978 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 7979 { 7980 /* Result of these operations is always an int, 7981 but that does not mean the operands should be 7982 converted to ints! */ 7983 result_type = integer_type_node; 7984 op0 = c_common_truthvalue_conversion (op0); 7985 op1 = c_common_truthvalue_conversion (op1); 7986 converted = 1; 7987 } 7988 break; 7989 7990 /* Shift operations: result has same type as first operand; 7991 always convert second operand to int. 7992 Also set SHORT_SHIFT if shifting rightward. */ 7993 7994 case RSHIFT_EXPR: 7995 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7996 { 7997 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 7998 { 7999 if (tree_int_cst_sgn (op1) < 0) 8000 warning (0, "right shift count is negative"); 8001 else 8002 { 8003 if (!integer_zerop (op1)) 8004 short_shift = 1; 8005 8006 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 8007 warning (0, "right shift count >= width of type"); 8008 } 8009 } 8010 8011 /* Use the type of the value to be shifted. */ 8012 result_type = type0; 8013 /* Convert the shift-count to an integer, regardless of size 8014 of value being shifted. */ 8015 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 8016 op1 = convert (integer_type_node, op1); 8017 /* Avoid converting op1 to result_type later. */ 8018 converted = 1; 8019 } 8020 break; 8021 8022 case LSHIFT_EXPR: 8023 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 8024 { 8025 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 8026 { 8027 if (tree_int_cst_sgn (op1) < 0) 8028 warning (0, "left shift count is negative"); 8029 8030 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 8031 warning (0, "left shift count >= width of type"); 8032 } 8033 8034 /* Use the type of the value to be shifted. */ 8035 result_type = type0; 8036 /* Convert the shift-count to an integer, regardless of size 8037 of value being shifted. */ 8038 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 8039 op1 = convert (integer_type_node, op1); 8040 /* Avoid converting op1 to result_type later. */ 8041 converted = 1; 8042 } 8043 break; 8044 8045 case EQ_EXPR: 8046 case NE_EXPR: 8047 if (code0 == REAL_TYPE || code1 == REAL_TYPE) 8048 warning (OPT_Wfloat_equal, 8049 "comparing floating point with == or != is unsafe"); 8050 /* Result of comparison is always int, 8051 but don't convert the args to int! */ 8052 build_type = integer_type_node; 8053 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 8054 || code0 == COMPLEX_TYPE) 8055 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 8056 || code1 == COMPLEX_TYPE)) 8057 short_compare = 1; 8058 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8059 { 8060 tree tt0 = TREE_TYPE (type0); 8061 tree tt1 = TREE_TYPE (type1); 8062 /* Anything compares with void *. void * compares with anything. 8063 Otherwise, the targets must be compatible 8064 and both must be object or both incomplete. */ 8065 if (comp_target_types (type0, type1)) 8066 result_type = common_pointer_type (type0, type1); 8067 else if (VOID_TYPE_P (tt0)) 8068 { 8069 /* op0 != orig_op0 detects the case of something 8070 whose value is 0 but which isn't a valid null ptr const. */ 8071 if (pedantic && !null_pointer_constant_p (orig_op0) 8072 && TREE_CODE (tt1) == FUNCTION_TYPE) 8073 pedwarn ("ISO C forbids comparison of %<void *%>" 8074 " with function pointer"); 8075 } 8076 else if (VOID_TYPE_P (tt1)) 8077 { 8078 if (pedantic && !null_pointer_constant_p (orig_op1) 8079 && TREE_CODE (tt0) == FUNCTION_TYPE) 8080 pedwarn ("ISO C forbids comparison of %<void *%>" 8081 " with function pointer"); 8082 } 8083 else 8084 /* Avoid warning about the volatile ObjC EH puts on decls. */ 8085 if (!objc_ok) 8086 pedwarn ("comparison of distinct pointer types lacks a cast"); 8087 8088 if (result_type == NULL_TREE) 8089 result_type = ptr_type_node; 8090 } 8091 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8092 { 8093 if (TREE_CODE (op0) == ADDR_EXPR 8094 && DECL_P (TREE_OPERAND (op0, 0)) 8095 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL 8096 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL 8097 || !DECL_WEAK (TREE_OPERAND (op0, 0)))) 8098 warning (OPT_Waddress, "the address of %qD will never be NULL", 8099 TREE_OPERAND (op0, 0)); 8100 result_type = type0; 8101 } 8102 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8103 { 8104 if (TREE_CODE (op1) == ADDR_EXPR 8105 && DECL_P (TREE_OPERAND (op1, 0)) 8106 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL 8107 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL 8108 || !DECL_WEAK (TREE_OPERAND (op1, 0)))) 8109 warning (OPT_Waddress, "the address of %qD will never be NULL", 8110 TREE_OPERAND (op1, 0)); 8111 result_type = type1; 8112 } 8113 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8114 { 8115 result_type = type0; 8116 pedwarn ("comparison between pointer and integer"); 8117 } 8118 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8119 { 8120 result_type = type1; 8121 pedwarn ("comparison between pointer and integer"); 8122 } 8123 break; 8124 8125 case LE_EXPR: 8126 case GE_EXPR: 8127 case LT_EXPR: 8128 case GT_EXPR: 8129 build_type = integer_type_node; 8130 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 8131 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 8132 short_compare = 1; 8133 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8134 { 8135 if (comp_target_types (type0, type1)) 8136 { 8137 result_type = common_pointer_type (type0, type1); 8138 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 8139 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 8140 pedwarn ("comparison of complete and incomplete pointers"); 8141 else if (pedantic 8142 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 8143 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 8144 } 8145 else 8146 { 8147 result_type = ptr_type_node; 8148 pedwarn ("comparison of distinct pointer types lacks a cast"); 8149 } 8150 } 8151 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8152 { 8153 result_type = type0; 8154 if (pedantic || extra_warnings) 8155 pedwarn ("ordered comparison of pointer with integer zero"); 8156 } 8157 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8158 { 8159 result_type = type1; 8160 if (pedantic) 8161 pedwarn ("ordered comparison of pointer with integer zero"); 8162 } 8163 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8164 { 8165 result_type = type0; 8166 pedwarn ("comparison between pointer and integer"); 8167 } 8168 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8169 { 8170 result_type = type1; 8171 pedwarn ("comparison between pointer and integer"); 8172 } 8173 break; 8174 8175 default: 8176 gcc_unreachable (); 8177 } 8178 8179 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 8180 return error_mark_node; 8181 8182 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE 8183 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)) 8184 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0), 8185 TREE_TYPE (type1)))) 8186 { 8187 binary_op_error (code); 8188 return error_mark_node; 8189 } 8190 8191 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 8192 || code0 == VECTOR_TYPE) 8193 && 8194 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 8195 || code1 == VECTOR_TYPE)) 8196 { 8197 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 8198 8199 if (shorten || common || short_compare) 8200 result_type = c_common_type (type0, type1); 8201 8202 /* For certain operations (which identify themselves by shorten != 0) 8203 if both args were extended from the same smaller type, 8204 do the arithmetic in that type and then extend. 8205 8206 shorten !=0 and !=1 indicates a bitwise operation. 8207 For them, this optimization is safe only if 8208 both args are zero-extended or both are sign-extended. 8209 Otherwise, we might change the result. 8210 Eg, (short)-1 | (unsigned short)-1 is (int)-1 8211 but calculated in (unsigned short) it would be (unsigned short)-1. */ 8212 8213 if (shorten && none_complex) 8214 { 8215 int unsigned0, unsigned1; 8216 tree arg0, arg1; 8217 int uns; 8218 tree type; 8219 8220 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents 8221 excessive narrowing when we call get_narrower below. For 8222 example, suppose that OP0 is of unsigned int extended 8223 from signed char and that RESULT_TYPE is long long int. 8224 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look 8225 like 8226 8227 (long long int) (unsigned int) signed_char 8228 8229 which get_narrower would narrow down to 8230 8231 (unsigned int) signed char 8232 8233 If we do not cast OP0 first, get_narrower would return 8234 signed_char, which is inconsistent with the case of the 8235 explicit cast. */ 8236 op0 = convert (result_type, op0); 8237 op1 = convert (result_type, op1); 8238 8239 arg0 = get_narrower (op0, &unsigned0); 8240 arg1 = get_narrower (op1, &unsigned1); 8241 8242 /* UNS is 1 if the operation to be done is an unsigned one. */ 8243 uns = TYPE_UNSIGNED (result_type); 8244 8245 final_type = result_type; 8246 8247 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 8248 but it *requires* conversion to FINAL_TYPE. */ 8249 8250 if ((TYPE_PRECISION (TREE_TYPE (op0)) 8251 == TYPE_PRECISION (TREE_TYPE (arg0))) 8252 && TREE_TYPE (op0) != final_type) 8253 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 8254 if ((TYPE_PRECISION (TREE_TYPE (op1)) 8255 == TYPE_PRECISION (TREE_TYPE (arg1))) 8256 && TREE_TYPE (op1) != final_type) 8257 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 8258 8259 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 8260 8261 /* For bitwise operations, signedness of nominal type 8262 does not matter. Consider only how operands were extended. */ 8263 if (shorten == -1) 8264 uns = unsigned0; 8265 8266 /* Note that in all three cases below we refrain from optimizing 8267 an unsigned operation on sign-extended args. 8268 That would not be valid. */ 8269 8270 /* Both args variable: if both extended in same way 8271 from same width, do it in that width. 8272 Do it unsigned if args were zero-extended. */ 8273 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 8274 < TYPE_PRECISION (result_type)) 8275 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8276 == TYPE_PRECISION (TREE_TYPE (arg0))) 8277 && unsigned0 == unsigned1 8278 && (unsigned0 || !uns)) 8279 result_type 8280 = c_common_signed_or_unsigned_type 8281 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 8282 else if (TREE_CODE (arg0) == INTEGER_CST 8283 && (unsigned1 || !uns) 8284 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8285 < TYPE_PRECISION (result_type)) 8286 && (type 8287 = c_common_signed_or_unsigned_type (unsigned1, 8288 TREE_TYPE (arg1)), 8289 int_fits_type_p (arg0, type))) 8290 result_type = type; 8291 else if (TREE_CODE (arg1) == INTEGER_CST 8292 && (unsigned0 || !uns) 8293 && (TYPE_PRECISION (TREE_TYPE (arg0)) 8294 < TYPE_PRECISION (result_type)) 8295 && (type 8296 = c_common_signed_or_unsigned_type (unsigned0, 8297 TREE_TYPE (arg0)), 8298 int_fits_type_p (arg1, type))) 8299 result_type = type; 8300 } 8301 8302 /* Shifts can be shortened if shifting right. */ 8303 8304 if (short_shift) 8305 { 8306 int unsigned_arg; 8307 tree arg0 = get_narrower (op0, &unsigned_arg); 8308 8309 final_type = result_type; 8310 8311 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 8312 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0)); 8313 8314 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 8315 /* We can shorten only if the shift count is less than the 8316 number of bits in the smaller type size. */ 8317 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 8318 /* We cannot drop an unsigned shift after sign-extension. */ 8319 && (!TYPE_UNSIGNED (final_type) || unsigned_arg)) 8320 { 8321 /* Do an unsigned shift if the operand was zero-extended. */ 8322 result_type 8323 = c_common_signed_or_unsigned_type (unsigned_arg, 8324 TREE_TYPE (arg0)); 8325 /* Convert value-to-be-shifted to that type. */ 8326 if (TREE_TYPE (op0) != result_type) 8327 op0 = convert (result_type, op0); 8328 converted = 1; 8329 } 8330 } 8331 8332 /* Comparison operations are shortened too but differently. 8333 They identify themselves by setting short_compare = 1. */ 8334 8335 if (short_compare) 8336 { 8337 /* Don't write &op0, etc., because that would prevent op0 8338 from being kept in a register. 8339 Instead, make copies of the our local variables and 8340 pass the copies by reference, then copy them back afterward. */ 8341 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 8342 enum tree_code xresultcode = resultcode; 8343 tree val 8344 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 8345 8346 if (val != 0) 8347 return val; 8348 8349 op0 = xop0, op1 = xop1; 8350 converted = 1; 8351 resultcode = xresultcode; 8352 8353 if (warn_sign_compare && skip_evaluation == 0) 8354 { 8355 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0)); 8356 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 8357 int unsignedp0, unsignedp1; 8358 tree primop0 = get_narrower (op0, &unsignedp0); 8359 tree primop1 = get_narrower (op1, &unsignedp1); 8360 8361 xop0 = orig_op0; 8362 xop1 = orig_op1; 8363 STRIP_TYPE_NOPS (xop0); 8364 STRIP_TYPE_NOPS (xop1); 8365 8366 /* Give warnings for comparisons between signed and unsigned 8367 quantities that may fail. 8368 8369 Do the checking based on the original operand trees, so that 8370 casts will be considered, but default promotions won't be. 8371 8372 Do not warn if the comparison is being done in a signed type, 8373 since the signed type will only be chosen if it can represent 8374 all the values of the unsigned type. */ 8375 if (!TYPE_UNSIGNED (result_type)) 8376 /* OK */; 8377 /* Do not warn if both operands are the same signedness. */ 8378 else if (op0_signed == op1_signed) 8379 /* OK */; 8380 else 8381 { 8382 tree sop, uop; 8383 bool ovf; 8384 8385 if (op0_signed) 8386 sop = xop0, uop = xop1; 8387 else 8388 sop = xop1, uop = xop0; 8389 8390 /* Do not warn if the signed quantity is an 8391 unsuffixed integer literal (or some static 8392 constant expression involving such literals or a 8393 conditional expression involving such literals) 8394 and it is non-negative. */ 8395 if (tree_expr_nonnegative_warnv_p (sop, &ovf)) 8396 /* OK */; 8397 /* Do not warn if the comparison is an equality operation, 8398 the unsigned quantity is an integral constant, and it 8399 would fit in the result if the result were signed. */ 8400 else if (TREE_CODE (uop) == INTEGER_CST 8401 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 8402 && int_fits_type_p 8403 (uop, c_common_signed_type (result_type))) 8404 /* OK */; 8405 /* Do not warn if the unsigned quantity is an enumeration 8406 constant and its maximum value would fit in the result 8407 if the result were signed. */ 8408 else if (TREE_CODE (uop) == INTEGER_CST 8409 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 8410 && int_fits_type_p 8411 (TYPE_MAX_VALUE (TREE_TYPE (uop)), 8412 c_common_signed_type (result_type))) 8413 /* OK */; 8414 else 8415 warning (0, "comparison between signed and unsigned"); 8416 } 8417 8418 /* Warn if two unsigned values are being compared in a size 8419 larger than their original size, and one (and only one) is the 8420 result of a `~' operator. This comparison will always fail. 8421 8422 Also warn if one operand is a constant, and the constant 8423 does not have all bits set that are set in the ~ operand 8424 when it is extended. */ 8425 8426 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 8427 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 8428 { 8429 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 8430 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 8431 &unsignedp0); 8432 else 8433 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 8434 &unsignedp1); 8435 8436 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 8437 { 8438 tree primop; 8439 HOST_WIDE_INT constant, mask; 8440 int unsignedp, bits; 8441 8442 if (host_integerp (primop0, 0)) 8443 { 8444 primop = primop1; 8445 unsignedp = unsignedp1; 8446 constant = tree_low_cst (primop0, 0); 8447 } 8448 else 8449 { 8450 primop = primop0; 8451 unsignedp = unsignedp0; 8452 constant = tree_low_cst (primop1, 0); 8453 } 8454 8455 bits = TYPE_PRECISION (TREE_TYPE (primop)); 8456 if (bits < TYPE_PRECISION (result_type) 8457 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 8458 { 8459 mask = (~(HOST_WIDE_INT) 0) << bits; 8460 if ((mask & constant) != mask) 8461 warning (0, "comparison of promoted ~unsigned with constant"); 8462 } 8463 } 8464 else if (unsignedp0 && unsignedp1 8465 && (TYPE_PRECISION (TREE_TYPE (primop0)) 8466 < TYPE_PRECISION (result_type)) 8467 && (TYPE_PRECISION (TREE_TYPE (primop1)) 8468 < TYPE_PRECISION (result_type))) 8469 warning (0, "comparison of promoted ~unsigned with unsigned"); 8470 } 8471 } 8472 } 8473 } 8474 8475 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 8476 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 8477 Then the expression will be built. 8478 It will be given type FINAL_TYPE if that is nonzero; 8479 otherwise, it will be given type RESULT_TYPE. */ 8480 8481 if (!result_type) 8482 { 8483 binary_op_error (code); 8484 return error_mark_node; 8485 } 8486 8487 if (!converted) 8488 { 8489 if (TREE_TYPE (op0) != result_type) 8490 op0 = convert_and_check (result_type, op0); 8491 if (TREE_TYPE (op1) != result_type) 8492 op1 = convert_and_check (result_type, op1); 8493 8494 /* This can happen if one operand has a vector type, and the other 8495 has a different type. */ 8496 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) 8497 return error_mark_node; 8498 } 8499 8500 if (build_type == NULL_TREE) 8501 build_type = result_type; 8502 8503 { 8504 /* Treat expressions in initializers specially as they can't trap. */ 8505 tree result = require_constant_value ? fold_build2_initializer (resultcode, 8506 build_type, 8507 op0, op1) 8508 : fold_build2 (resultcode, build_type, 8509 op0, op1); 8510 8511 if (final_type != 0) 8512 result = convert (final_type, result); 8513 return result; 8514 } 8515} 8516 8517 8518/* Convert EXPR to be a truth-value, validating its type for this 8519 purpose. */ 8520 8521tree 8522c_objc_common_truthvalue_conversion (tree expr) 8523{ 8524 switch (TREE_CODE (TREE_TYPE (expr))) 8525 { 8526 case ARRAY_TYPE: 8527 error ("used array that cannot be converted to pointer where scalar is required"); 8528 return error_mark_node; 8529 8530 case RECORD_TYPE: 8531 error ("used struct type value where scalar is required"); 8532 return error_mark_node; 8533 8534 case UNION_TYPE: 8535 error ("used union type value where scalar is required"); 8536 return error_mark_node; 8537 8538 case FUNCTION_TYPE: 8539 gcc_unreachable (); 8540 8541 default: 8542 break; 8543 } 8544 8545 /* ??? Should we also give an error for void and vectors rather than 8546 leaving those to give errors later? */ 8547 return c_common_truthvalue_conversion (expr); 8548} 8549 8550 8551/* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as 8552 required. */ 8553 8554tree 8555c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, 8556 bool *ti ATTRIBUTE_UNUSED, bool *se) 8557{ 8558 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR) 8559 { 8560 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr); 8561 /* Executing a compound literal inside a function reinitializes 8562 it. */ 8563 if (!TREE_STATIC (decl)) 8564 *se = true; 8565 return decl; 8566 } 8567 else 8568 return expr; 8569} 8570 8571/* Like c_begin_compound_stmt, except force the retention of the BLOCK. */ 8572 8573tree 8574c_begin_omp_parallel (void) 8575{ 8576 tree block; 8577 8578 keep_next_level (); 8579 block = c_begin_compound_stmt (true); 8580 8581 return block; 8582} 8583 8584tree 8585c_finish_omp_parallel (tree clauses, tree block) 8586{ 8587 tree stmt; 8588 8589 block = c_end_compound_stmt (block, true); 8590 8591 stmt = make_node (OMP_PARALLEL); 8592 TREE_TYPE (stmt) = void_type_node; 8593 OMP_PARALLEL_CLAUSES (stmt) = clauses; 8594 OMP_PARALLEL_BODY (stmt) = block; 8595 8596 return add_stmt (stmt); 8597} 8598 8599/* For all elements of CLAUSES, validate them vs OpenMP constraints. 8600 Remove any elements from the list that are invalid. */ 8601 8602tree 8603c_finish_omp_clauses (tree clauses) 8604{ 8605 bitmap_head generic_head, firstprivate_head, lastprivate_head; 8606 tree c, t, *pc = &clauses; 8607 const char *name; 8608 8609 bitmap_obstack_initialize (NULL); 8610 bitmap_initialize (&generic_head, &bitmap_default_obstack); 8611 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack); 8612 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack); 8613 8614 for (pc = &clauses, c = clauses; c ; c = *pc) 8615 { 8616 bool remove = false; 8617 bool need_complete = false; 8618 bool need_implicitly_determined = false; 8619 8620 switch (OMP_CLAUSE_CODE (c)) 8621 { 8622 case OMP_CLAUSE_SHARED: 8623 name = "shared"; 8624 need_implicitly_determined = true; 8625 goto check_dup_generic; 8626 8627 case OMP_CLAUSE_PRIVATE: 8628 name = "private"; 8629 need_complete = true; 8630 need_implicitly_determined = true; 8631 goto check_dup_generic; 8632 8633 case OMP_CLAUSE_REDUCTION: 8634 name = "reduction"; 8635 need_implicitly_determined = true; 8636 t = OMP_CLAUSE_DECL (c); 8637 if (AGGREGATE_TYPE_P (TREE_TYPE (t)) 8638 || POINTER_TYPE_P (TREE_TYPE (t))) 8639 { 8640 error ("%qE has invalid type for %<reduction%>", t); 8641 remove = true; 8642 } 8643 else if (FLOAT_TYPE_P (TREE_TYPE (t))) 8644 { 8645 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c); 8646 const char *r_name = NULL; 8647 8648 switch (r_code) 8649 { 8650 case PLUS_EXPR: 8651 case MULT_EXPR: 8652 case MINUS_EXPR: 8653 break; 8654 case BIT_AND_EXPR: 8655 r_name = "&"; 8656 break; 8657 case BIT_XOR_EXPR: 8658 r_name = "^"; 8659 break; 8660 case BIT_IOR_EXPR: 8661 r_name = "|"; 8662 break; 8663 case TRUTH_ANDIF_EXPR: 8664 r_name = "&&"; 8665 break; 8666 case TRUTH_ORIF_EXPR: 8667 r_name = "||"; 8668 break; 8669 default: 8670 gcc_unreachable (); 8671 } 8672 if (r_name) 8673 { 8674 error ("%qE has invalid type for %<reduction(%s)%>", 8675 t, r_name); 8676 remove = true; 8677 } 8678 } 8679 goto check_dup_generic; 8680 8681 case OMP_CLAUSE_COPYPRIVATE: 8682 name = "copyprivate"; 8683 goto check_dup_generic; 8684 8685 case OMP_CLAUSE_COPYIN: 8686 name = "copyin"; 8687 t = OMP_CLAUSE_DECL (c); 8688 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t)) 8689 { 8690 error ("%qE must be %<threadprivate%> for %<copyin%>", t); 8691 remove = true; 8692 } 8693 goto check_dup_generic; 8694 8695 check_dup_generic: 8696 t = OMP_CLAUSE_DECL (c); 8697 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8698 { 8699 error ("%qE is not a variable in clause %qs", t, name); 8700 remove = true; 8701 } 8702 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8703 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)) 8704 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8705 { 8706 error ("%qE appears more than once in data clauses", t); 8707 remove = true; 8708 } 8709 else 8710 bitmap_set_bit (&generic_head, DECL_UID (t)); 8711 break; 8712 8713 case OMP_CLAUSE_FIRSTPRIVATE: 8714 name = "firstprivate"; 8715 t = OMP_CLAUSE_DECL (c); 8716 need_complete = true; 8717 need_implicitly_determined = true; 8718 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8719 { 8720 error ("%qE is not a variable in clause %<firstprivate%>", t); 8721 remove = true; 8722 } 8723 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8724 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))) 8725 { 8726 error ("%qE appears more than once in data clauses", t); 8727 remove = true; 8728 } 8729 else 8730 bitmap_set_bit (&firstprivate_head, DECL_UID (t)); 8731 break; 8732 8733 case OMP_CLAUSE_LASTPRIVATE: 8734 name = "lastprivate"; 8735 t = OMP_CLAUSE_DECL (c); 8736 need_complete = true; 8737 need_implicitly_determined = true; 8738 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8739 { 8740 error ("%qE is not a variable in clause %<lastprivate%>", t); 8741 remove = true; 8742 } 8743 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8744 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8745 { 8746 error ("%qE appears more than once in data clauses", t); 8747 remove = true; 8748 } 8749 else 8750 bitmap_set_bit (&lastprivate_head, DECL_UID (t)); 8751 break; 8752 8753 case OMP_CLAUSE_IF: 8754 case OMP_CLAUSE_NUM_THREADS: 8755 case OMP_CLAUSE_SCHEDULE: 8756 case OMP_CLAUSE_NOWAIT: 8757 case OMP_CLAUSE_ORDERED: 8758 case OMP_CLAUSE_DEFAULT: 8759 pc = &OMP_CLAUSE_CHAIN (c); 8760 continue; 8761 8762 default: 8763 gcc_unreachable (); 8764 } 8765 8766 if (!remove) 8767 { 8768 t = OMP_CLAUSE_DECL (c); 8769 8770 if (need_complete) 8771 { 8772 t = require_complete_type (t); 8773 if (t == error_mark_node) 8774 remove = true; 8775 } 8776 8777 if (need_implicitly_determined) 8778 { 8779 const char *share_name = NULL; 8780 8781 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t)) 8782 share_name = "threadprivate"; 8783 else switch (c_omp_predetermined_sharing (t)) 8784 { 8785 case OMP_CLAUSE_DEFAULT_UNSPECIFIED: 8786 break; 8787 case OMP_CLAUSE_DEFAULT_SHARED: 8788 share_name = "shared"; 8789 break; 8790 case OMP_CLAUSE_DEFAULT_PRIVATE: 8791 share_name = "private"; 8792 break; 8793 default: 8794 gcc_unreachable (); 8795 } 8796 if (share_name) 8797 { 8798 error ("%qE is predetermined %qs for %qs", 8799 t, share_name, name); 8800 remove = true; 8801 } 8802 } 8803 } 8804 8805 if (remove) 8806 *pc = OMP_CLAUSE_CHAIN (c); 8807 else 8808 pc = &OMP_CLAUSE_CHAIN (c); 8809 } 8810 8811 bitmap_obstack_release (NULL); 8812 return clauses; 8813} 8814