c-typeck.c revision 169689
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 2113 return ref; 2114} 2115 2116/* Record details of decls possibly used inside sizeof or typeof. */ 2117struct maybe_used_decl 2118{ 2119 /* The decl. */ 2120 tree decl; 2121 /* The level seen at (in_sizeof + in_typeof). */ 2122 int level; 2123 /* The next one at this level or above, or NULL. */ 2124 struct maybe_used_decl *next; 2125}; 2126 2127static struct maybe_used_decl *maybe_used_decls; 2128 2129/* Record that DECL, an undefined static function reference seen 2130 inside sizeof or typeof, might be used if the operand of sizeof is 2131 a VLA type or the operand of typeof is a variably modified 2132 type. */ 2133 2134static void 2135record_maybe_used_decl (tree decl) 2136{ 2137 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl); 2138 t->decl = decl; 2139 t->level = in_sizeof + in_typeof; 2140 t->next = maybe_used_decls; 2141 maybe_used_decls = t; 2142} 2143 2144/* Pop the stack of decls possibly used inside sizeof or typeof. If 2145 USED is false, just discard them. If it is true, mark them used 2146 (if no longer inside sizeof or typeof) or move them to the next 2147 level up (if still inside sizeof or typeof). */ 2148 2149void 2150pop_maybe_used (bool used) 2151{ 2152 struct maybe_used_decl *p = maybe_used_decls; 2153 int cur_level = in_sizeof + in_typeof; 2154 while (p && p->level > cur_level) 2155 { 2156 if (used) 2157 { 2158 if (cur_level == 0) 2159 C_DECL_USED (p->decl) = 1; 2160 else 2161 p->level = cur_level; 2162 } 2163 p = p->next; 2164 } 2165 if (!used || cur_level == 0) 2166 maybe_used_decls = p; 2167} 2168 2169/* Return the result of sizeof applied to EXPR. */ 2170 2171struct c_expr 2172c_expr_sizeof_expr (struct c_expr expr) 2173{ 2174 struct c_expr ret; 2175 if (expr.value == error_mark_node) 2176 { 2177 ret.value = error_mark_node; 2178 ret.original_code = ERROR_MARK; 2179 pop_maybe_used (false); 2180 } 2181 else 2182 { 2183 ret.value = c_sizeof (TREE_TYPE (expr.value)); 2184 ret.original_code = ERROR_MARK; 2185 if (c_vla_type_p (TREE_TYPE (expr.value))) 2186 { 2187 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */ 2188 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value); 2189 } 2190 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value))); 2191 } 2192 return ret; 2193} 2194 2195/* Return the result of sizeof applied to T, a structure for the type 2196 name passed to sizeof (rather than the type itself). */ 2197 2198struct c_expr 2199c_expr_sizeof_type (struct c_type_name *t) 2200{ 2201 tree type; 2202 struct c_expr ret; 2203 type = groktypename (t); 2204 ret.value = c_sizeof (type); 2205 ret.original_code = ERROR_MARK; 2206 pop_maybe_used (type != error_mark_node 2207 ? C_TYPE_VARIABLE_SIZE (type) : false); 2208 return ret; 2209} 2210 2211/* Build a function call to function FUNCTION with parameters PARAMS. 2212 PARAMS is a list--a chain of TREE_LIST nodes--in which the 2213 TREE_VALUE of each node is a parameter-expression. 2214 FUNCTION's data type may be a function type or a pointer-to-function. */ 2215 2216tree 2217build_function_call (tree function, tree params) 2218{ 2219 tree fntype, fundecl = 0; 2220 tree coerced_params; 2221 tree name = NULL_TREE, result; 2222 tree tem; 2223 2224 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 2225 STRIP_TYPE_NOPS (function); 2226 2227 /* Convert anything with function type to a pointer-to-function. */ 2228 if (TREE_CODE (function) == FUNCTION_DECL) 2229 { 2230 /* Implement type-directed function overloading for builtins. 2231 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin 2232 handle all the type checking. The result is a complete expression 2233 that implements this function call. */ 2234 tem = resolve_overloaded_builtin (function, params); 2235 if (tem) 2236 return tem; 2237 2238 name = DECL_NAME (function); 2239 fundecl = function; 2240 } 2241 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE) 2242 function = function_to_pointer_conversion (function); 2243 2244 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF 2245 expressions, like those used for ObjC messenger dispatches. */ 2246 function = objc_rewrite_function_call (function, params); 2247 2248 fntype = TREE_TYPE (function); 2249 2250 if (TREE_CODE (fntype) == ERROR_MARK) 2251 return error_mark_node; 2252 2253 if (!(TREE_CODE (fntype) == POINTER_TYPE 2254 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) 2255 { 2256 error ("called object %qE is not a function", function); 2257 return error_mark_node; 2258 } 2259 2260 if (fundecl && TREE_THIS_VOLATILE (fundecl)) 2261 current_function_returns_abnormally = 1; 2262 2263 /* fntype now gets the type of function pointed to. */ 2264 fntype = TREE_TYPE (fntype); 2265 2266 /* Check that the function is called through a compatible prototype. 2267 If it is not, replace the call by a trap, wrapped up in a compound 2268 expression if necessary. This has the nice side-effect to prevent 2269 the tree-inliner from generating invalid assignment trees which may 2270 blow up in the RTL expander later. */ 2271 if ((TREE_CODE (function) == NOP_EXPR 2272 || TREE_CODE (function) == CONVERT_EXPR) 2273 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR 2274 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL 2275 && !comptypes (fntype, TREE_TYPE (tem))) 2276 { 2277 tree return_type = TREE_TYPE (fntype); 2278 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], 2279 NULL_TREE); 2280 2281 /* This situation leads to run-time undefined behavior. We can't, 2282 therefore, simply error unless we can prove that all possible 2283 executions of the program must execute the code. */ 2284 warning (0, "function called through a non-compatible type"); 2285 2286 /* We can, however, treat "undefined" any way we please. 2287 Call abort to encourage the user to fix the program. */ 2288 inform ("if this code is reached, the program will abort"); 2289 2290 if (VOID_TYPE_P (return_type)) 2291 return trap; 2292 else 2293 { 2294 tree rhs; 2295 2296 if (AGGREGATE_TYPE_P (return_type)) 2297 rhs = build_compound_literal (return_type, 2298 build_constructor (return_type, 0)); 2299 else 2300 rhs = fold_convert (return_type, integer_zero_node); 2301 2302 return build2 (COMPOUND_EXPR, return_type, trap, rhs); 2303 } 2304 } 2305 2306 /* Convert the parameters to the types declared in the 2307 function prototype, or apply default promotions. */ 2308 2309 coerced_params 2310 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl); 2311 2312 if (coerced_params == error_mark_node) 2313 return error_mark_node; 2314 2315 /* Check that the arguments to the function are valid. */ 2316 2317 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params, 2318 TYPE_ARG_TYPES (fntype)); 2319 2320 if (require_constant_value) 2321 { 2322 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype), 2323 function, coerced_params, NULL_TREE); 2324 2325 if (TREE_CONSTANT (result) 2326 && (name == NULL_TREE 2327 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) 2328 pedwarn_init ("initializer element is not constant"); 2329 } 2330 else 2331 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype), 2332 function, coerced_params, NULL_TREE); 2333 2334 if (VOID_TYPE_P (TREE_TYPE (result))) 2335 return result; 2336 return require_complete_type (result); 2337} 2338 2339/* Convert the argument expressions in the list VALUES 2340 to the types in the list TYPELIST. The result is a list of converted 2341 argument expressions, unless there are too few arguments in which 2342 case it is error_mark_node. 2343 2344 If TYPELIST is exhausted, or when an element has NULL as its type, 2345 perform the default conversions. 2346 2347 PARMLIST is the chain of parm decls for the function being called. 2348 It may be 0, if that info is not available. 2349 It is used only for generating error messages. 2350 2351 FUNCTION is a tree for the called function. It is used only for 2352 error messages, where it is formatted with %qE. 2353 2354 This is also where warnings about wrong number of args are generated. 2355 2356 Both VALUES and the returned value are chains of TREE_LIST nodes 2357 with the elements of the list in the TREE_VALUE slots of those nodes. */ 2358 2359static tree 2360convert_arguments (tree typelist, tree values, tree function, tree fundecl) 2361{ 2362 tree typetail, valtail; 2363 tree result = NULL; 2364 int parmnum; 2365 tree selector; 2366 2367 /* Change pointer to function to the function itself for 2368 diagnostics. */ 2369 if (TREE_CODE (function) == ADDR_EXPR 2370 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 2371 function = TREE_OPERAND (function, 0); 2372 2373 /* Handle an ObjC selector specially for diagnostics. */ 2374 selector = objc_message_selector (); 2375 2376 /* Scan the given expressions and types, producing individual 2377 converted arguments and pushing them on RESULT in reverse order. */ 2378 2379 for (valtail = values, typetail = typelist, parmnum = 0; 2380 valtail; 2381 valtail = TREE_CHAIN (valtail), parmnum++) 2382 { 2383 tree type = typetail ? TREE_VALUE (typetail) : 0; 2384 tree val = TREE_VALUE (valtail); 2385 tree rname = function; 2386 int argnum = parmnum + 1; 2387 const char *invalid_func_diag; 2388 2389 if (type == void_type_node) 2390 { 2391 error ("too many arguments to function %qE", function); 2392 break; 2393 } 2394 2395 if (selector && argnum > 2) 2396 { 2397 rname = selector; 2398 argnum -= 2; 2399 } 2400 2401 STRIP_TYPE_NOPS (val); 2402 2403 val = require_complete_type (val); 2404 2405 if (type != 0) 2406 { 2407 /* Formal parm type is specified by a function prototype. */ 2408 tree parmval; 2409 2410 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 2411 { 2412 error ("type of formal parameter %d is incomplete", parmnum + 1); 2413 parmval = val; 2414 } 2415 else 2416 { 2417 /* Optionally warn about conversions that 2418 differ from the default conversions. */ 2419 if (warn_conversion || warn_traditional) 2420 { 2421 unsigned int formal_prec = TYPE_PRECISION (type); 2422 2423 if (INTEGRAL_TYPE_P (type) 2424 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2425 warning (0, "passing argument %d of %qE as integer " 2426 "rather than floating due to prototype", 2427 argnum, rname); 2428 if (INTEGRAL_TYPE_P (type) 2429 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2430 warning (0, "passing argument %d of %qE as integer " 2431 "rather than complex due to prototype", 2432 argnum, rname); 2433 else if (TREE_CODE (type) == COMPLEX_TYPE 2434 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2435 warning (0, "passing argument %d of %qE as complex " 2436 "rather than floating due to prototype", 2437 argnum, rname); 2438 else if (TREE_CODE (type) == REAL_TYPE 2439 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2440 warning (0, "passing argument %d of %qE as floating " 2441 "rather than integer due to prototype", 2442 argnum, rname); 2443 else if (TREE_CODE (type) == COMPLEX_TYPE 2444 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2445 warning (0, "passing argument %d of %qE as complex " 2446 "rather than integer due to prototype", 2447 argnum, rname); 2448 else if (TREE_CODE (type) == REAL_TYPE 2449 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 2450 warning (0, "passing argument %d of %qE as floating " 2451 "rather than complex due to prototype", 2452 argnum, rname); 2453 /* ??? At some point, messages should be written about 2454 conversions between complex types, but that's too messy 2455 to do now. */ 2456 else if (TREE_CODE (type) == REAL_TYPE 2457 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 2458 { 2459 /* Warn if any argument is passed as `float', 2460 since without a prototype it would be `double'. */ 2461 if (formal_prec == TYPE_PRECISION (float_type_node) 2462 && type != dfloat32_type_node) 2463 warning (0, "passing argument %d of %qE as %<float%> " 2464 "rather than %<double%> due to prototype", 2465 argnum, rname); 2466 2467 /* Warn if mismatch between argument and prototype 2468 for decimal float types. Warn of conversions with 2469 binary float types and of precision narrowing due to 2470 prototype. */ 2471 else if (type != TREE_TYPE (val) 2472 && (type == dfloat32_type_node 2473 || type == dfloat64_type_node 2474 || type == dfloat128_type_node 2475 || TREE_TYPE (val) == dfloat32_type_node 2476 || TREE_TYPE (val) == dfloat64_type_node 2477 || TREE_TYPE (val) == dfloat128_type_node) 2478 && (formal_prec 2479 <= TYPE_PRECISION (TREE_TYPE (val)) 2480 || (type == dfloat128_type_node 2481 && (TREE_TYPE (val) 2482 != dfloat64_type_node 2483 && (TREE_TYPE (val) 2484 != dfloat32_type_node))) 2485 || (type == dfloat64_type_node 2486 && (TREE_TYPE (val) 2487 != dfloat32_type_node)))) 2488 warning (0, "passing argument %d of %qE as %qT " 2489 "rather than %qT due to prototype", 2490 argnum, rname, type, TREE_TYPE (val)); 2491 2492 } 2493 /* Detect integer changing in width or signedness. 2494 These warnings are only activated with 2495 -Wconversion, not with -Wtraditional. */ 2496 else if (warn_conversion && INTEGRAL_TYPE_P (type) 2497 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 2498 { 2499 tree would_have_been = default_conversion (val); 2500 tree type1 = TREE_TYPE (would_have_been); 2501 2502 if (TREE_CODE (type) == ENUMERAL_TYPE 2503 && (TYPE_MAIN_VARIANT (type) 2504 == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) 2505 /* No warning if function asks for enum 2506 and the actual arg is that enum type. */ 2507 ; 2508 else if (formal_prec != TYPE_PRECISION (type1)) 2509 warning (OPT_Wconversion, "passing argument %d of %qE " 2510 "with different width due to prototype", 2511 argnum, rname); 2512 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1)) 2513 ; 2514 /* Don't complain if the formal parameter type 2515 is an enum, because we can't tell now whether 2516 the value was an enum--even the same enum. */ 2517 else if (TREE_CODE (type) == ENUMERAL_TYPE) 2518 ; 2519 else if (TREE_CODE (val) == INTEGER_CST 2520 && int_fits_type_p (val, type)) 2521 /* Change in signedness doesn't matter 2522 if a constant value is unaffected. */ 2523 ; 2524 /* If the value is extended from a narrower 2525 unsigned type, it doesn't matter whether we 2526 pass it as signed or unsigned; the value 2527 certainly is the same either way. */ 2528 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) 2529 && TYPE_UNSIGNED (TREE_TYPE (val))) 2530 ; 2531 else if (TYPE_UNSIGNED (type)) 2532 warning (OPT_Wconversion, "passing argument %d of %qE " 2533 "as unsigned due to prototype", 2534 argnum, rname); 2535 else 2536 warning (OPT_Wconversion, "passing argument %d of %qE " 2537 "as signed due to prototype", argnum, rname); 2538 } 2539 } 2540 2541 parmval = convert_for_assignment (type, val, ic_argpass, 2542 fundecl, function, 2543 parmnum + 1); 2544 2545 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) 2546 && INTEGRAL_TYPE_P (type) 2547 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 2548 parmval = default_conversion (parmval); 2549 } 2550 result = tree_cons (NULL_TREE, parmval, result); 2551 } 2552 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE 2553 && (TYPE_PRECISION (TREE_TYPE (val)) 2554 < TYPE_PRECISION (double_type_node)) 2555 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val)))) 2556 /* Convert `float' to `double'. */ 2557 result = tree_cons (NULL_TREE, convert (double_type_node, val), result); 2558 else if ((invalid_func_diag = 2559 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val))) 2560 { 2561 error (invalid_func_diag); 2562 return error_mark_node; 2563 } 2564 else 2565 /* Convert `short' and `char' to full-size `int'. */ 2566 result = tree_cons (NULL_TREE, default_conversion (val), result); 2567 2568 if (typetail) 2569 typetail = TREE_CHAIN (typetail); 2570 } 2571 2572 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) 2573 { 2574 error ("too few arguments to function %qE", function); 2575 return error_mark_node; 2576 } 2577 2578 return nreverse (result); 2579} 2580 2581/* This is the entry point used by the parser to build unary operators 2582 in the input. CODE, a tree_code, specifies the unary operator, and 2583 ARG is the operand. For unary plus, the C parser currently uses 2584 CONVERT_EXPR for code. */ 2585 2586struct c_expr 2587parser_build_unary_op (enum tree_code code, struct c_expr arg) 2588{ 2589 struct c_expr result; 2590 2591 result.original_code = ERROR_MARK; 2592 result.value = build_unary_op (code, arg.value, 0); 2593 overflow_warning (result.value); 2594 return result; 2595} 2596 2597/* This is the entry point used by the parser to build binary operators 2598 in the input. CODE, a tree_code, specifies the binary operator, and 2599 ARG1 and ARG2 are the operands. In addition to constructing the 2600 expression, we check for operands that were written with other binary 2601 operators in a way that is likely to confuse the user. */ 2602 2603struct c_expr 2604parser_build_binary_op (enum tree_code code, struct c_expr arg1, 2605 struct c_expr arg2) 2606{ 2607 struct c_expr result; 2608 2609 enum tree_code code1 = arg1.original_code; 2610 enum tree_code code2 = arg2.original_code; 2611 2612 result.value = build_binary_op (code, arg1.value, arg2.value, 1); 2613 result.original_code = code; 2614 2615 if (TREE_CODE (result.value) == ERROR_MARK) 2616 return result; 2617 2618 /* Check for cases such as x+y<<z which users are likely 2619 to misinterpret. */ 2620 if (warn_parentheses) 2621 { 2622 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 2623 { 2624 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2625 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2626 warning (OPT_Wparentheses, 2627 "suggest parentheses around + or - inside shift"); 2628 } 2629 2630 if (code == TRUTH_ORIF_EXPR) 2631 { 2632 if (code1 == TRUTH_ANDIF_EXPR 2633 || code2 == TRUTH_ANDIF_EXPR) 2634 warning (OPT_Wparentheses, 2635 "suggest parentheses around && within ||"); 2636 } 2637 2638 if (code == BIT_IOR_EXPR) 2639 { 2640 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR 2641 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2642 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR 2643 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2644 warning (OPT_Wparentheses, 2645 "suggest parentheses around arithmetic in operand of |"); 2646 /* Check cases like x|y==z */ 2647 if (TREE_CODE_CLASS (code1) == tcc_comparison 2648 || TREE_CODE_CLASS (code2) == tcc_comparison) 2649 warning (OPT_Wparentheses, 2650 "suggest parentheses around comparison in operand of |"); 2651 } 2652 2653 if (code == BIT_XOR_EXPR) 2654 { 2655 if (code1 == BIT_AND_EXPR 2656 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2657 || code2 == BIT_AND_EXPR 2658 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2659 warning (OPT_Wparentheses, 2660 "suggest parentheses around arithmetic in operand of ^"); 2661 /* Check cases like x^y==z */ 2662 if (TREE_CODE_CLASS (code1) == tcc_comparison 2663 || TREE_CODE_CLASS (code2) == tcc_comparison) 2664 warning (OPT_Wparentheses, 2665 "suggest parentheses around comparison in operand of ^"); 2666 } 2667 2668 if (code == BIT_AND_EXPR) 2669 { 2670 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2671 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2672 warning (OPT_Wparentheses, 2673 "suggest parentheses around + or - 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 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 2681 if (TREE_CODE_CLASS (code) == tcc_comparison 2682 && (TREE_CODE_CLASS (code1) == tcc_comparison 2683 || TREE_CODE_CLASS (code2) == tcc_comparison)) 2684 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not " 2685 "have their mathematical meaning"); 2686 2687 } 2688 2689 /* Warn about comparisons against string literals, with the exception 2690 of testing for equality or inequality of a string literal with NULL. */ 2691 if (code == EQ_EXPR || code == NE_EXPR) 2692 { 2693 if ((code1 == STRING_CST && !integer_zerop (arg2.value)) 2694 || (code2 == STRING_CST && !integer_zerop (arg1.value))) 2695 warning (OPT_Waddress, 2696 "comparison with string literal results in unspecified behaviour"); 2697 } 2698 else if (TREE_CODE_CLASS (code) == tcc_comparison 2699 && (code1 == STRING_CST || code2 == STRING_CST)) 2700 warning (OPT_Waddress, 2701 "comparison with string literal results in unspecified behaviour"); 2702 2703 overflow_warning (result.value); 2704 2705 return result; 2706} 2707 2708/* Return a tree for the difference of pointers OP0 and OP1. 2709 The resulting tree has type int. */ 2710 2711static tree 2712pointer_diff (tree op0, tree op1) 2713{ 2714 tree restype = ptrdiff_type_node; 2715 2716 tree target_type = TREE_TYPE (TREE_TYPE (op0)); 2717 tree con0, con1, lit0, lit1; 2718 tree orig_op1 = op1; 2719 2720 if (pedantic || warn_pointer_arith) 2721 { 2722 if (TREE_CODE (target_type) == VOID_TYPE) 2723 pedwarn ("pointer of type %<void *%> used in subtraction"); 2724 if (TREE_CODE (target_type) == FUNCTION_TYPE) 2725 pedwarn ("pointer to a function used in subtraction"); 2726 } 2727 2728 /* If the conversion to ptrdiff_type does anything like widening or 2729 converting a partial to an integral mode, we get a convert_expression 2730 that is in the way to do any simplifications. 2731 (fold-const.c doesn't know that the extra bits won't be needed. 2732 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a 2733 different mode in place.) 2734 So first try to find a common term here 'by hand'; we want to cover 2735 at least the cases that occur in legal static initializers. */ 2736 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR) 2737 && (TYPE_PRECISION (TREE_TYPE (op0)) 2738 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0))))) 2739 con0 = TREE_OPERAND (op0, 0); 2740 else 2741 con0 = op0; 2742 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR) 2743 && (TYPE_PRECISION (TREE_TYPE (op1)) 2744 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0))))) 2745 con1 = TREE_OPERAND (op1, 0); 2746 else 2747 con1 = op1; 2748 2749 if (TREE_CODE (con0) == PLUS_EXPR) 2750 { 2751 lit0 = TREE_OPERAND (con0, 1); 2752 con0 = TREE_OPERAND (con0, 0); 2753 } 2754 else 2755 lit0 = integer_zero_node; 2756 2757 if (TREE_CODE (con1) == PLUS_EXPR) 2758 { 2759 lit1 = TREE_OPERAND (con1, 1); 2760 con1 = TREE_OPERAND (con1, 0); 2761 } 2762 else 2763 lit1 = integer_zero_node; 2764 2765 if (operand_equal_p (con0, con1, 0)) 2766 { 2767 op0 = lit0; 2768 op1 = lit1; 2769 } 2770 2771 2772 /* First do the subtraction as integers; 2773 then drop through to build the divide operator. 2774 Do not do default conversions on the minus operator 2775 in case restype is a short type. */ 2776 2777 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), 2778 convert (restype, op1), 0); 2779 /* This generates an error if op1 is pointer to incomplete type. */ 2780 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) 2781 error ("arithmetic on pointer to an incomplete type"); 2782 2783 /* This generates an error if op0 is pointer to incomplete type. */ 2784 op1 = c_size_in_bytes (target_type); 2785 2786 /* Divide by the size, in easiest possible way. */ 2787 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1)); 2788} 2789 2790/* Construct and perhaps optimize a tree representation 2791 for a unary operation. CODE, a tree_code, specifies the operation 2792 and XARG is the operand. 2793 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses 2794 the default promotions (such as from short to int). 2795 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero 2796 allows non-lvalues; this is only used to handle conversion of non-lvalue 2797 arrays to pointers in C99. */ 2798 2799tree 2800build_unary_op (enum tree_code code, tree xarg, int flag) 2801{ 2802 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 2803 tree arg = xarg; 2804 tree argtype = 0; 2805 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); 2806 tree val; 2807 int noconvert = flag; 2808 const char *invalid_op_diag; 2809 2810 if (typecode == ERROR_MARK) 2811 return error_mark_node; 2812 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) 2813 typecode = INTEGER_TYPE; 2814 2815 if ((invalid_op_diag 2816 = targetm.invalid_unary_op (code, TREE_TYPE (xarg)))) 2817 { 2818 error (invalid_op_diag); 2819 return error_mark_node; 2820 } 2821 2822 switch (code) 2823 { 2824 case CONVERT_EXPR: 2825 /* This is used for unary plus, because a CONVERT_EXPR 2826 is enough to prevent anybody from looking inside for 2827 associativity, but won't generate any code. */ 2828 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2829 || typecode == COMPLEX_TYPE 2830 || typecode == VECTOR_TYPE)) 2831 { 2832 error ("wrong type argument to unary plus"); 2833 return error_mark_node; 2834 } 2835 else if (!noconvert) 2836 arg = default_conversion (arg); 2837 arg = non_lvalue (arg); 2838 break; 2839 2840 case NEGATE_EXPR: 2841 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2842 || typecode == COMPLEX_TYPE 2843 || typecode == VECTOR_TYPE)) 2844 { 2845 error ("wrong type argument to unary minus"); 2846 return error_mark_node; 2847 } 2848 else if (!noconvert) 2849 arg = default_conversion (arg); 2850 break; 2851 2852 case BIT_NOT_EXPR: 2853 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) 2854 { 2855 if (!noconvert) 2856 arg = default_conversion (arg); 2857 } 2858 else if (typecode == COMPLEX_TYPE) 2859 { 2860 code = CONJ_EXPR; 2861 if (pedantic) 2862 pedwarn ("ISO C does not support %<~%> for complex conjugation"); 2863 if (!noconvert) 2864 arg = default_conversion (arg); 2865 } 2866 else 2867 { 2868 error ("wrong type argument to bit-complement"); 2869 return error_mark_node; 2870 } 2871 break; 2872 2873 case ABS_EXPR: 2874 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) 2875 { 2876 error ("wrong type argument to abs"); 2877 return error_mark_node; 2878 } 2879 else if (!noconvert) 2880 arg = default_conversion (arg); 2881 break; 2882 2883 case CONJ_EXPR: 2884 /* Conjugating a real value is a no-op, but allow it anyway. */ 2885 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2886 || typecode == COMPLEX_TYPE)) 2887 { 2888 error ("wrong type argument to conjugation"); 2889 return error_mark_node; 2890 } 2891 else if (!noconvert) 2892 arg = default_conversion (arg); 2893 break; 2894 2895 case TRUTH_NOT_EXPR: 2896 if (typecode != INTEGER_TYPE 2897 && typecode != REAL_TYPE && typecode != POINTER_TYPE 2898 && typecode != COMPLEX_TYPE) 2899 { 2900 error ("wrong type argument to unary exclamation mark"); 2901 return error_mark_node; 2902 } 2903 arg = c_objc_common_truthvalue_conversion (arg); 2904 return invert_truthvalue (arg); 2905 2906 case REALPART_EXPR: 2907 if (TREE_CODE (arg) == COMPLEX_CST) 2908 return TREE_REALPART (arg); 2909 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2910 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2911 else 2912 return arg; 2913 2914 case IMAGPART_EXPR: 2915 if (TREE_CODE (arg) == COMPLEX_CST) 2916 return TREE_IMAGPART (arg); 2917 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2918 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg); 2919 else 2920 return convert (TREE_TYPE (arg), integer_zero_node); 2921 2922 case PREINCREMENT_EXPR: 2923 case POSTINCREMENT_EXPR: 2924 case PREDECREMENT_EXPR: 2925 case POSTDECREMENT_EXPR: 2926 2927 /* Increment or decrement the real part of the value, 2928 and don't change the imaginary part. */ 2929 if (typecode == COMPLEX_TYPE) 2930 { 2931 tree real, imag; 2932 2933 if (pedantic) 2934 pedwarn ("ISO C does not support %<++%> and %<--%>" 2935 " on complex types"); 2936 2937 arg = stabilize_reference (arg); 2938 real = build_unary_op (REALPART_EXPR, arg, 1); 2939 imag = build_unary_op (IMAGPART_EXPR, arg, 1); 2940 return build2 (COMPLEX_EXPR, TREE_TYPE (arg), 2941 build_unary_op (code, real, 1), imag); 2942 } 2943 2944 /* Report invalid types. */ 2945 2946 if (typecode != POINTER_TYPE 2947 && typecode != INTEGER_TYPE && typecode != REAL_TYPE) 2948 { 2949 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2950 error ("wrong type argument to increment"); 2951 else 2952 error ("wrong type argument to decrement"); 2953 2954 return error_mark_node; 2955 } 2956 2957 { 2958 tree inc; 2959 tree result_type = TREE_TYPE (arg); 2960 2961 arg = get_unwidened (arg, 0); 2962 argtype = TREE_TYPE (arg); 2963 2964 /* Compute the increment. */ 2965 2966 if (typecode == POINTER_TYPE) 2967 { 2968 /* If pointer target is an undefined struct, 2969 we just cannot know how to do the arithmetic. */ 2970 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) 2971 { 2972 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2973 error ("increment of pointer to unknown structure"); 2974 else 2975 error ("decrement of pointer to unknown structure"); 2976 } 2977 else if ((pedantic || warn_pointer_arith) 2978 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE 2979 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) 2980 { 2981 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2982 pedwarn ("wrong type argument to increment"); 2983 else 2984 pedwarn ("wrong type argument to decrement"); 2985 } 2986 2987 inc = c_size_in_bytes (TREE_TYPE (result_type)); 2988 } 2989 else 2990 inc = integer_one_node; 2991 2992 inc = convert (argtype, inc); 2993 2994 /* Complain about anything else that is not a true lvalue. */ 2995 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 2996 || code == POSTINCREMENT_EXPR) 2997 ? lv_increment 2998 : lv_decrement))) 2999 return error_mark_node; 3000 3001 /* Report a read-only lvalue. */ 3002 if (TREE_READONLY (arg)) 3003 { 3004 readonly_error (arg, 3005 ((code == PREINCREMENT_EXPR 3006 || code == POSTINCREMENT_EXPR) 3007 ? lv_increment : lv_decrement)); 3008 return error_mark_node; 3009 } 3010 3011 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 3012 val = boolean_increment (code, arg); 3013 else 3014 val = build2 (code, TREE_TYPE (arg), arg, inc); 3015 TREE_SIDE_EFFECTS (val) = 1; 3016 val = convert (result_type, val); 3017 if (TREE_CODE (val) != code) 3018 TREE_NO_WARNING (val) = 1; 3019 return val; 3020 } 3021 3022 case ADDR_EXPR: 3023 /* Note that this operation never does default_conversion. */ 3024 3025 /* Let &* cancel out to simplify resulting code. */ 3026 if (TREE_CODE (arg) == INDIRECT_REF) 3027 { 3028 /* Don't let this be an lvalue. */ 3029 if (lvalue_p (TREE_OPERAND (arg, 0))) 3030 return non_lvalue (TREE_OPERAND (arg, 0)); 3031 return TREE_OPERAND (arg, 0); 3032 } 3033 3034 /* For &x[y], return x+y */ 3035 if (TREE_CODE (arg) == ARRAY_REF) 3036 { 3037 tree op0 = TREE_OPERAND (arg, 0); 3038 if (!c_mark_addressable (op0)) 3039 return error_mark_node; 3040 return build_binary_op (PLUS_EXPR, 3041 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE 3042 ? array_to_pointer_conversion (op0) 3043 : op0), 3044 TREE_OPERAND (arg, 1), 1); 3045 } 3046 3047 /* Anything not already handled and not a true memory reference 3048 or a non-lvalue array is an error. */ 3049 else if (typecode != FUNCTION_TYPE && !flag 3050 && !lvalue_or_else (arg, lv_addressof)) 3051 return error_mark_node; 3052 3053 /* Ordinary case; arg is a COMPONENT_REF or a decl. */ 3054 argtype = TREE_TYPE (arg); 3055 3056 /* If the lvalue is const or volatile, merge that into the type 3057 to which the address will point. Note that you can't get a 3058 restricted pointer by taking the address of something, so we 3059 only have to deal with `const' and `volatile' here. */ 3060 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg)) 3061 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) 3062 argtype = c_build_type_variant (argtype, 3063 TREE_READONLY (arg), 3064 TREE_THIS_VOLATILE (arg)); 3065 3066 if (!c_mark_addressable (arg)) 3067 return error_mark_node; 3068 3069 gcc_assert (TREE_CODE (arg) != COMPONENT_REF 3070 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))); 3071 3072 argtype = build_pointer_type (argtype); 3073 3074 /* ??? Cope with user tricks that amount to offsetof. Delete this 3075 when we have proper support for integer constant expressions. */ 3076 val = get_base_address (arg); 3077 if (val && TREE_CODE (val) == INDIRECT_REF 3078 && TREE_CONSTANT (TREE_OPERAND (val, 0))) 3079 { 3080 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1; 3081 3082 op1 = fold_convert (argtype, TREE_OPERAND (val, 0)); 3083 return fold_build2 (PLUS_EXPR, argtype, op0, op1); 3084 } 3085 3086 val = build1 (ADDR_EXPR, argtype, arg); 3087 3088 return val; 3089 3090 default: 3091 gcc_unreachable (); 3092 } 3093 3094 if (argtype == 0) 3095 argtype = TREE_TYPE (arg); 3096 return require_constant_value ? fold_build1_initializer (code, argtype, arg) 3097 : fold_build1 (code, argtype, arg); 3098} 3099 3100/* Return nonzero if REF is an lvalue valid for this language. 3101 Lvalues can be assigned, unless their type has TYPE_READONLY. 3102 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */ 3103 3104static int 3105lvalue_p (tree ref) 3106{ 3107 enum tree_code code = TREE_CODE (ref); 3108 3109 switch (code) 3110 { 3111 case REALPART_EXPR: 3112 case IMAGPART_EXPR: 3113 case COMPONENT_REF: 3114 return lvalue_p (TREE_OPERAND (ref, 0)); 3115 3116 case COMPOUND_LITERAL_EXPR: 3117 case STRING_CST: 3118 return 1; 3119 3120 case INDIRECT_REF: 3121 case ARRAY_REF: 3122 case VAR_DECL: 3123 case PARM_DECL: 3124 case RESULT_DECL: 3125 case ERROR_MARK: 3126 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE 3127 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); 3128 3129 case BIND_EXPR: 3130 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; 3131 3132 default: 3133 return 0; 3134 } 3135} 3136 3137/* Give an error for storing in something that is 'const'. */ 3138 3139static void 3140readonly_error (tree arg, enum lvalue_use use) 3141{ 3142 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement 3143 || use == lv_asm); 3144 /* Using this macro rather than (for example) arrays of messages 3145 ensures that all the format strings are checked at compile 3146 time. */ 3147#define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \ 3148 : (use == lv_increment ? (I) \ 3149 : (use == lv_decrement ? (D) : (AS)))) 3150 if (TREE_CODE (arg) == COMPONENT_REF) 3151 { 3152 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) 3153 readonly_error (TREE_OPERAND (arg, 0), use); 3154 else 3155 error (READONLY_MSG (G_("assignment of read-only member %qD"), 3156 G_("increment of read-only member %qD"), 3157 G_("decrement of read-only member %qD"), 3158 G_("read-only member %qD used as %<asm%> output")), 3159 TREE_OPERAND (arg, 1)); 3160 } 3161 else if (TREE_CODE (arg) == VAR_DECL) 3162 error (READONLY_MSG (G_("assignment of read-only variable %qD"), 3163 G_("increment of read-only variable %qD"), 3164 G_("decrement of read-only variable %qD"), 3165 G_("read-only variable %qD used as %<asm%> output")), 3166 arg); 3167 else 3168 error (READONLY_MSG (G_("assignment of read-only location"), 3169 G_("increment of read-only location"), 3170 G_("decrement of read-only location"), 3171 G_("read-only location used as %<asm%> output"))); 3172} 3173 3174 3175/* Return nonzero if REF is an lvalue valid for this language; 3176 otherwise, print an error message and return zero. USE says 3177 how the lvalue is being used and so selects the error message. */ 3178 3179static int 3180lvalue_or_else (tree ref, enum lvalue_use use) 3181{ 3182 int win = lvalue_p (ref); 3183 3184 if (!win) 3185 lvalue_error (use); 3186 3187 return win; 3188} 3189 3190/* Mark EXP saying that we need to be able to take the 3191 address of it; it should not be allocated in a register. 3192 Returns true if successful. */ 3193 3194bool 3195c_mark_addressable (tree exp) 3196{ 3197 tree x = exp; 3198 3199 while (1) 3200 switch (TREE_CODE (x)) 3201 { 3202 case COMPONENT_REF: 3203 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) 3204 { 3205 error 3206 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1)); 3207 return false; 3208 } 3209 3210 /* ... fall through ... */ 3211 3212 case ADDR_EXPR: 3213 case ARRAY_REF: 3214 case REALPART_EXPR: 3215 case IMAGPART_EXPR: 3216 x = TREE_OPERAND (x, 0); 3217 break; 3218 3219 case COMPOUND_LITERAL_EXPR: 3220 case CONSTRUCTOR: 3221 TREE_ADDRESSABLE (x) = 1; 3222 return true; 3223 3224 case VAR_DECL: 3225 case CONST_DECL: 3226 case PARM_DECL: 3227 case RESULT_DECL: 3228 if (C_DECL_REGISTER (x) 3229 && DECL_NONLOCAL (x)) 3230 { 3231 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3232 { 3233 error 3234 ("global register variable %qD used in nested function", x); 3235 return false; 3236 } 3237 pedwarn ("register variable %qD used in nested function", x); 3238 } 3239 else if (C_DECL_REGISTER (x)) 3240 { 3241 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 3242 error ("address of global register variable %qD requested", x); 3243 else 3244 error ("address of register variable %qD requested", x); 3245 return false; 3246 } 3247 3248 /* drops in */ 3249 case FUNCTION_DECL: 3250 TREE_ADDRESSABLE (x) = 1; 3251 /* drops out */ 3252 default: 3253 return true; 3254 } 3255} 3256 3257/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 3258 3259tree 3260build_conditional_expr (tree ifexp, tree op1, tree op2) 3261{ 3262 tree type1; 3263 tree type2; 3264 enum tree_code code1; 3265 enum tree_code code2; 3266 tree result_type = NULL; 3267 tree orig_op1 = op1, orig_op2 = op2; 3268 3269 /* Promote both alternatives. */ 3270 3271 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) 3272 op1 = default_conversion (op1); 3273 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) 3274 op2 = default_conversion (op2); 3275 3276 if (TREE_CODE (ifexp) == ERROR_MARK 3277 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK 3278 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) 3279 return error_mark_node; 3280 3281 type1 = TREE_TYPE (op1); 3282 code1 = TREE_CODE (type1); 3283 type2 = TREE_TYPE (op2); 3284 code2 = TREE_CODE (type2); 3285 3286 /* C90 does not permit non-lvalue arrays in conditional expressions. 3287 In C99 they will be pointers by now. */ 3288 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE) 3289 { 3290 error ("non-lvalue array in conditional expression"); 3291 return error_mark_node; 3292 } 3293 3294 /* Quickly detect the usual case where op1 and op2 have the same type 3295 after promotion. */ 3296 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) 3297 { 3298 if (type1 == type2) 3299 result_type = type1; 3300 else 3301 result_type = TYPE_MAIN_VARIANT (type1); 3302 } 3303 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE 3304 || code1 == COMPLEX_TYPE) 3305 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE 3306 || code2 == COMPLEX_TYPE)) 3307 { 3308 result_type = c_common_type (type1, type2); 3309 3310 /* If -Wsign-compare, warn here if type1 and type2 have 3311 different signedness. We'll promote the signed to unsigned 3312 and later code won't know it used to be different. 3313 Do this check on the original types, so that explicit casts 3314 will be considered, but default promotions won't. */ 3315 if (warn_sign_compare && !skip_evaluation) 3316 { 3317 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 3318 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2)); 3319 3320 if (unsigned_op1 ^ unsigned_op2) 3321 { 3322 bool ovf; 3323 3324 /* Do not warn if the result type is signed, since the 3325 signed type will only be chosen if it can represent 3326 all the values of the unsigned type. */ 3327 if (!TYPE_UNSIGNED (result_type)) 3328 /* OK */; 3329 /* Do not warn if the signed quantity is an unsuffixed 3330 integer literal (or some static constant expression 3331 involving such literals) and it is non-negative. */ 3332 else if ((unsigned_op2 3333 && tree_expr_nonnegative_warnv_p (op1, &ovf)) 3334 || (unsigned_op1 3335 && tree_expr_nonnegative_warnv_p (op2, &ovf))) 3336 /* OK */; 3337 else 3338 warning (0, "signed and unsigned type in conditional expression"); 3339 } 3340 } 3341 } 3342 else if (code1 == VOID_TYPE || code2 == VOID_TYPE) 3343 { 3344 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) 3345 pedwarn ("ISO C forbids conditional expr with only one void side"); 3346 result_type = void_type_node; 3347 } 3348 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) 3349 { 3350 if (comp_target_types (type1, type2)) 3351 result_type = common_pointer_type (type1, type2); 3352 else if (null_pointer_constant_p (orig_op1)) 3353 result_type = qualify_type (type2, type1); 3354 else if (null_pointer_constant_p (orig_op2)) 3355 result_type = qualify_type (type1, type2); 3356 else if (VOID_TYPE_P (TREE_TYPE (type1))) 3357 { 3358 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) 3359 pedwarn ("ISO C forbids conditional expr between " 3360 "%<void *%> and function pointer"); 3361 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), 3362 TREE_TYPE (type2))); 3363 } 3364 else if (VOID_TYPE_P (TREE_TYPE (type2))) 3365 { 3366 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) 3367 pedwarn ("ISO C forbids conditional expr between " 3368 "%<void *%> and function pointer"); 3369 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), 3370 TREE_TYPE (type1))); 3371 } 3372 else 3373 { 3374 pedwarn ("pointer type mismatch in conditional expression"); 3375 result_type = build_pointer_type (void_type_node); 3376 } 3377 } 3378 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) 3379 { 3380 if (!null_pointer_constant_p (orig_op2)) 3381 pedwarn ("pointer/integer type mismatch in conditional expression"); 3382 else 3383 { 3384 op2 = null_pointer_node; 3385 } 3386 result_type = type1; 3387 } 3388 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) 3389 { 3390 if (!null_pointer_constant_p (orig_op1)) 3391 pedwarn ("pointer/integer type mismatch in conditional expression"); 3392 else 3393 { 3394 op1 = null_pointer_node; 3395 } 3396 result_type = type2; 3397 } 3398 3399 if (!result_type) 3400 { 3401 if (flag_cond_mismatch) 3402 result_type = void_type_node; 3403 else 3404 { 3405 error ("type mismatch in conditional expression"); 3406 return error_mark_node; 3407 } 3408 } 3409 3410 /* Merge const and volatile flags of the incoming types. */ 3411 result_type 3412 = build_type_variant (result_type, 3413 TREE_READONLY (op1) || TREE_READONLY (op2), 3414 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); 3415 3416 if (result_type != TREE_TYPE (op1)) 3417 op1 = convert_and_check (result_type, op1); 3418 if (result_type != TREE_TYPE (op2)) 3419 op2 = convert_and_check (result_type, op2); 3420 3421 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2); 3422} 3423 3424/* Return a compound expression that performs two expressions and 3425 returns the value of the second of them. */ 3426 3427tree 3428build_compound_expr (tree expr1, tree expr2) 3429{ 3430 if (!TREE_SIDE_EFFECTS (expr1)) 3431 { 3432 /* The left-hand operand of a comma expression is like an expression 3433 statement: with -Wextra or -Wunused, we should warn if it doesn't have 3434 any side-effects, unless it was explicitly cast to (void). */ 3435 if (warn_unused_value) 3436 { 3437 if (VOID_TYPE_P (TREE_TYPE (expr1)) 3438 && (TREE_CODE (expr1) == NOP_EXPR 3439 || TREE_CODE (expr1) == CONVERT_EXPR)) 3440 ; /* (void) a, b */ 3441 else if (VOID_TYPE_P (TREE_TYPE (expr1)) 3442 && TREE_CODE (expr1) == COMPOUND_EXPR 3443 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR 3444 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR)) 3445 ; /* (void) a, (void) b, c */ 3446 else 3447 warning (0, "left-hand operand of comma expression has no effect"); 3448 } 3449 } 3450 3451 /* With -Wunused, we should also warn if the left-hand operand does have 3452 side-effects, but computes a value which is not used. For example, in 3453 `foo() + bar(), baz()' the result of the `+' operator is not used, 3454 so we should issue a warning. */ 3455 else if (warn_unused_value) 3456 warn_if_unused_value (expr1, input_location); 3457 3458 if (expr2 == error_mark_node) 3459 return error_mark_node; 3460 3461 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2); 3462} 3463 3464/* Build an expression representing a cast to type TYPE of expression EXPR. */ 3465 3466tree 3467build_c_cast (tree type, tree expr) 3468{ 3469 tree value = expr; 3470 3471 if (type == error_mark_node || expr == error_mark_node) 3472 return error_mark_node; 3473 3474 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing 3475 only in <protocol> qualifications. But when constructing cast expressions, 3476 the protocols do matter and must be kept around. */ 3477 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr))) 3478 return build1 (NOP_EXPR, type, expr); 3479 3480 type = TYPE_MAIN_VARIANT (type); 3481 3482 if (TREE_CODE (type) == ARRAY_TYPE) 3483 { 3484 error ("cast specifies array type"); 3485 return error_mark_node; 3486 } 3487 3488 if (TREE_CODE (type) == FUNCTION_TYPE) 3489 { 3490 error ("cast specifies function type"); 3491 return error_mark_node; 3492 } 3493 3494 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) 3495 { 3496 if (pedantic) 3497 { 3498 if (TREE_CODE (type) == RECORD_TYPE 3499 || TREE_CODE (type) == UNION_TYPE) 3500 pedwarn ("ISO C forbids casting nonscalar to the same type"); 3501 } 3502 } 3503 else if (TREE_CODE (type) == UNION_TYPE) 3504 { 3505 tree field; 3506 3507 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3508 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), 3509 TYPE_MAIN_VARIANT (TREE_TYPE (value)))) 3510 break; 3511 3512 if (field) 3513 { 3514 tree t; 3515 3516 if (pedantic) 3517 pedwarn ("ISO C forbids casts to union type"); 3518 t = digest_init (type, 3519 build_constructor_single (type, field, value), 3520 true, 0); 3521 TREE_CONSTANT (t) = TREE_CONSTANT (value); 3522 TREE_INVARIANT (t) = TREE_INVARIANT (value); 3523 return t; 3524 } 3525 error ("cast to union type from type not present in union"); 3526 return error_mark_node; 3527 } 3528 else 3529 { 3530 tree otype, ovalue; 3531 3532 if (type == void_type_node) 3533 return build1 (CONVERT_EXPR, type, value); 3534 3535 otype = TREE_TYPE (value); 3536 3537 /* Optionally warn about potentially worrisome casts. */ 3538 3539 if (warn_cast_qual 3540 && TREE_CODE (type) == POINTER_TYPE 3541 && TREE_CODE (otype) == POINTER_TYPE) 3542 { 3543 tree in_type = type; 3544 tree in_otype = otype; 3545 int added = 0; 3546 int discarded = 0; 3547 3548 /* Check that the qualifiers on IN_TYPE are a superset of 3549 the qualifiers of IN_OTYPE. The outermost level of 3550 POINTER_TYPE nodes is uninteresting and we stop as soon 3551 as we hit a non-POINTER_TYPE node on either type. */ 3552 do 3553 { 3554 in_otype = TREE_TYPE (in_otype); 3555 in_type = TREE_TYPE (in_type); 3556 3557 /* GNU C allows cv-qualified function types. 'const' 3558 means the function is very pure, 'volatile' means it 3559 can't return. We need to warn when such qualifiers 3560 are added, not when they're taken away. */ 3561 if (TREE_CODE (in_otype) == FUNCTION_TYPE 3562 && TREE_CODE (in_type) == FUNCTION_TYPE) 3563 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); 3564 else 3565 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); 3566 } 3567 while (TREE_CODE (in_type) == POINTER_TYPE 3568 && TREE_CODE (in_otype) == POINTER_TYPE); 3569 3570 if (added) 3571 warning (0, "cast adds new qualifiers to function type"); 3572 3573 if (discarded) 3574 /* There are qualifiers present in IN_OTYPE that are not 3575 present in IN_TYPE. */ 3576 warning (0, "cast discards qualifiers from pointer target type"); 3577 } 3578 3579 /* Warn about possible alignment problems. */ 3580 if (STRICT_ALIGNMENT 3581 && TREE_CODE (type) == POINTER_TYPE 3582 && TREE_CODE (otype) == POINTER_TYPE 3583 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE 3584 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3585 /* Don't warn about opaque types, where the actual alignment 3586 restriction is unknown. */ 3587 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE 3588 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) 3589 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) 3590 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) 3591 warning (OPT_Wcast_align, 3592 "cast increases required alignment of target type"); 3593 3594 if (TREE_CODE (type) == INTEGER_TYPE 3595 && TREE_CODE (otype) == POINTER_TYPE 3596 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)) 3597 /* Unlike conversion of integers to pointers, where the 3598 warning is disabled for converting constants because 3599 of cases such as SIG_*, warn about converting constant 3600 pointers to integers. In some cases it may cause unwanted 3601 sign extension, and a warning is appropriate. */ 3602 warning (OPT_Wpointer_to_int_cast, 3603 "cast from pointer to integer of different size"); 3604 3605 if (TREE_CODE (value) == CALL_EXPR 3606 && TREE_CODE (type) != TREE_CODE (otype)) 3607 warning (OPT_Wbad_function_cast, "cast from function call of type %qT " 3608 "to non-matching type %qT", otype, type); 3609 3610 if (TREE_CODE (type) == POINTER_TYPE 3611 && TREE_CODE (otype) == INTEGER_TYPE 3612 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3613 /* Don't warn about converting any constant. */ 3614 && !TREE_CONSTANT (value)) 3615 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer " 3616 "of different size"); 3617 3618 strict_aliasing_warning (otype, type, expr); 3619 3620 /* If pedantic, warn for conversions between function and object 3621 pointer types, except for converting a null pointer constant 3622 to function pointer type. */ 3623 if (pedantic 3624 && TREE_CODE (type) == POINTER_TYPE 3625 && TREE_CODE (otype) == POINTER_TYPE 3626 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE 3627 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) 3628 pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); 3629 3630 if (pedantic 3631 && TREE_CODE (type) == POINTER_TYPE 3632 && TREE_CODE (otype) == POINTER_TYPE 3633 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 3634 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3635 && !null_pointer_constant_p (value)) 3636 pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); 3637 3638 ovalue = value; 3639 value = convert (type, value); 3640 3641 /* Ignore any integer overflow caused by the cast. */ 3642 if (TREE_CODE (value) == INTEGER_CST) 3643 { 3644 if (CONSTANT_CLASS_P (ovalue) 3645 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue))) 3646 { 3647 /* Avoid clobbering a shared constant. */ 3648 value = copy_node (value); 3649 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); 3650 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); 3651 } 3652 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value)) 3653 /* Reset VALUE's overflow flags, ensuring constant sharing. */ 3654 value = build_int_cst_wide (TREE_TYPE (value), 3655 TREE_INT_CST_LOW (value), 3656 TREE_INT_CST_HIGH (value)); 3657 } 3658 } 3659 3660 /* Don't let a cast be an lvalue. */ 3661 if (value == expr) 3662 value = non_lvalue (value); 3663 3664 return value; 3665} 3666 3667/* Interpret a cast of expression EXPR to type TYPE. */ 3668tree 3669c_cast_expr (struct c_type_name *type_name, tree expr) 3670{ 3671 tree type; 3672 int saved_wsp = warn_strict_prototypes; 3673 3674 /* This avoids warnings about unprototyped casts on 3675 integers. E.g. "#define SIG_DFL (void(*)())0". */ 3676 if (TREE_CODE (expr) == INTEGER_CST) 3677 warn_strict_prototypes = 0; 3678 type = groktypename (type_name); 3679 warn_strict_prototypes = saved_wsp; 3680 3681 return build_c_cast (type, expr); 3682} 3683 3684/* Build an assignment expression of lvalue LHS from value RHS. 3685 MODIFYCODE is the code for a binary operator that we use 3686 to combine the old value of LHS with RHS to get the new value. 3687 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ 3688 3689tree 3690build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) 3691{ 3692 tree result; 3693 tree newrhs; 3694 tree lhstype = TREE_TYPE (lhs); 3695 tree olhstype = lhstype; 3696 3697 /* Types that aren't fully specified cannot be used in assignments. */ 3698 lhs = require_complete_type (lhs); 3699 3700 /* Avoid duplicate error messages from operands that had errors. */ 3701 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) 3702 return error_mark_node; 3703 3704 if (!lvalue_or_else (lhs, lv_assign)) 3705 return error_mark_node; 3706 3707 STRIP_TYPE_NOPS (rhs); 3708 3709 newrhs = rhs; 3710 3711 /* If a binary op has been requested, combine the old LHS value with the RHS 3712 producing the value we should actually store into the LHS. */ 3713 3714 if (modifycode != NOP_EXPR) 3715 { 3716 lhs = stabilize_reference (lhs); 3717 newrhs = build_binary_op (modifycode, lhs, rhs, 1); 3718 } 3719 3720 /* Give an error for storing in something that is 'const'. */ 3721 3722 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) 3723 || ((TREE_CODE (lhstype) == RECORD_TYPE 3724 || TREE_CODE (lhstype) == UNION_TYPE) 3725 && C_TYPE_FIELDS_READONLY (lhstype))) 3726 { 3727 readonly_error (lhs, lv_assign); 3728 return error_mark_node; 3729 } 3730 3731 /* If storing into a structure or union member, 3732 it has probably been given type `int'. 3733 Compute the type that would go with 3734 the actual amount of storage the member occupies. */ 3735 3736 if (TREE_CODE (lhs) == COMPONENT_REF 3737 && (TREE_CODE (lhstype) == INTEGER_TYPE 3738 || TREE_CODE (lhstype) == BOOLEAN_TYPE 3739 || TREE_CODE (lhstype) == REAL_TYPE 3740 || TREE_CODE (lhstype) == ENUMERAL_TYPE)) 3741 lhstype = TREE_TYPE (get_unwidened (lhs, 0)); 3742 3743 /* If storing in a field that is in actuality a short or narrower than one, 3744 we must store in the field in its actual type. */ 3745 3746 if (lhstype != TREE_TYPE (lhs)) 3747 { 3748 lhs = copy_node (lhs); 3749 TREE_TYPE (lhs) = lhstype; 3750 } 3751 3752 /* Convert new value to destination type. */ 3753 3754 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign, 3755 NULL_TREE, NULL_TREE, 0); 3756 if (TREE_CODE (newrhs) == ERROR_MARK) 3757 return error_mark_node; 3758 3759 /* Emit ObjC write barrier, if necessary. */ 3760 if (c_dialect_objc () && flag_objc_gc) 3761 { 3762 result = objc_generate_write_barrier (lhs, modifycode, newrhs); 3763 if (result) 3764 return result; 3765 } 3766 3767 /* Scan operands. */ 3768 3769 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs); 3770 TREE_SIDE_EFFECTS (result) = 1; 3771 3772 /* If we got the LHS in a different type for storing in, 3773 convert the result back to the nominal type of LHS 3774 so that the value we return always has the same type 3775 as the LHS argument. */ 3776 3777 if (olhstype == TREE_TYPE (result)) 3778 return result; 3779 return convert_for_assignment (olhstype, result, ic_assign, 3780 NULL_TREE, NULL_TREE, 0); 3781} 3782 3783/* Convert value RHS to type TYPE as preparation for an assignment 3784 to an lvalue of type TYPE. 3785 The real work of conversion is done by `convert'. 3786 The purpose of this function is to generate error messages 3787 for assignments that are not allowed in C. 3788 ERRTYPE says whether it is argument passing, assignment, 3789 initialization or return. 3790 3791 FUNCTION is a tree for the function being called. 3792 PARMNUM is the number of the argument, for printing in error messages. */ 3793 3794static tree 3795convert_for_assignment (tree type, tree rhs, enum impl_conv errtype, 3796 tree fundecl, tree function, int parmnum) 3797{ 3798 enum tree_code codel = TREE_CODE (type); 3799 tree rhstype; 3800 enum tree_code coder; 3801 tree rname = NULL_TREE; 3802 bool objc_ok = false; 3803 3804 if (errtype == ic_argpass || errtype == ic_argpass_nonproto) 3805 { 3806 tree selector; 3807 /* Change pointer to function to the function itself for 3808 diagnostics. */ 3809 if (TREE_CODE (function) == ADDR_EXPR 3810 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 3811 function = TREE_OPERAND (function, 0); 3812 3813 /* Handle an ObjC selector specially for diagnostics. */ 3814 selector = objc_message_selector (); 3815 rname = function; 3816 if (selector && parmnum > 2) 3817 { 3818 rname = selector; 3819 parmnum -= 2; 3820 } 3821 } 3822 3823 /* This macro is used to emit diagnostics to ensure that all format 3824 strings are complete sentences, visible to gettext and checked at 3825 compile time. */ 3826#define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \ 3827 do { \ 3828 switch (errtype) \ 3829 { \ 3830 case ic_argpass: \ 3831 pedwarn (AR, parmnum, rname); \ 3832 break; \ 3833 case ic_argpass_nonproto: \ 3834 warning (0, AR, parmnum, rname); \ 3835 break; \ 3836 case ic_assign: \ 3837 pedwarn (AS); \ 3838 break; \ 3839 case ic_init: \ 3840 pedwarn (IN); \ 3841 break; \ 3842 case ic_return: \ 3843 pedwarn (RE); \ 3844 break; \ 3845 default: \ 3846 gcc_unreachable (); \ 3847 } \ 3848 } while (0) 3849 3850 STRIP_TYPE_NOPS (rhs); 3851 3852 if (optimize && TREE_CODE (rhs) == VAR_DECL 3853 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE) 3854 rhs = decl_constant_value_for_broken_optimization (rhs); 3855 3856 rhstype = TREE_TYPE (rhs); 3857 coder = TREE_CODE (rhstype); 3858 3859 if (coder == ERROR_MARK) 3860 return error_mark_node; 3861 3862 if (c_dialect_objc ()) 3863 { 3864 int parmno; 3865 3866 switch (errtype) 3867 { 3868 case ic_return: 3869 parmno = 0; 3870 break; 3871 3872 case ic_assign: 3873 parmno = -1; 3874 break; 3875 3876 case ic_init: 3877 parmno = -2; 3878 break; 3879 3880 default: 3881 parmno = parmnum; 3882 break; 3883 } 3884 3885 objc_ok = objc_compare_types (type, rhstype, parmno, rname); 3886 } 3887 3888 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) 3889 { 3890 overflow_warning (rhs); 3891 return rhs; 3892 } 3893 3894 if (coder == VOID_TYPE) 3895 { 3896 /* Except for passing an argument to an unprototyped function, 3897 this is a constraint violation. When passing an argument to 3898 an unprototyped function, it is compile-time undefined; 3899 making it a constraint in that case was rejected in 3900 DR#252. */ 3901 error ("void value not ignored as it ought to be"); 3902 return error_mark_node; 3903 } 3904 /* A type converts to a reference to it. 3905 This code doesn't fully support references, it's just for the 3906 special case of va_start and va_copy. */ 3907 if (codel == REFERENCE_TYPE 3908 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1) 3909 { 3910 if (!lvalue_p (rhs)) 3911 { 3912 error ("cannot pass rvalue to reference parameter"); 3913 return error_mark_node; 3914 } 3915 if (!c_mark_addressable (rhs)) 3916 return error_mark_node; 3917 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); 3918 3919 /* We already know that these two types are compatible, but they 3920 may not be exactly identical. In fact, `TREE_TYPE (type)' is 3921 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is 3922 likely to be va_list, a typedef to __builtin_va_list, which 3923 is different enough that it will cause problems later. */ 3924 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) 3925 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); 3926 3927 rhs = build1 (NOP_EXPR, type, rhs); 3928 return rhs; 3929 } 3930 /* Some types can interconvert without explicit casts. */ 3931 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE 3932 && vector_types_convertible_p (type, TREE_TYPE (rhs))) 3933 return convert (type, rhs); 3934 /* Arithmetic types all interconvert, and enum is treated like int. */ 3935 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 3936 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE 3937 || codel == BOOLEAN_TYPE) 3938 && (coder == INTEGER_TYPE || coder == REAL_TYPE 3939 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE 3940 || coder == BOOLEAN_TYPE)) 3941 return convert_and_check (type, rhs); 3942 3943 /* Aggregates in different TUs might need conversion. */ 3944 if ((codel == RECORD_TYPE || codel == UNION_TYPE) 3945 && codel == coder 3946 && comptypes (type, rhstype)) 3947 return convert_and_check (type, rhs); 3948 3949 /* Conversion to a transparent union from its member types. 3950 This applies only to function arguments. */ 3951 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) 3952 && (errtype == ic_argpass || errtype == ic_argpass_nonproto)) 3953 { 3954 tree memb, marginal_memb = NULL_TREE; 3955 3956 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb)) 3957 { 3958 tree memb_type = TREE_TYPE (memb); 3959 3960 if (comptypes (TYPE_MAIN_VARIANT (memb_type), 3961 TYPE_MAIN_VARIANT (rhstype))) 3962 break; 3963 3964 if (TREE_CODE (memb_type) != POINTER_TYPE) 3965 continue; 3966 3967 if (coder == POINTER_TYPE) 3968 { 3969 tree ttl = TREE_TYPE (memb_type); 3970 tree ttr = TREE_TYPE (rhstype); 3971 3972 /* Any non-function converts to a [const][volatile] void * 3973 and vice versa; otherwise, targets must be the same. 3974 Meanwhile, the lhs target must have all the qualifiers of 3975 the rhs. */ 3976 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3977 || comp_target_types (memb_type, rhstype)) 3978 { 3979 /* If this type won't generate any warnings, use it. */ 3980 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) 3981 || ((TREE_CODE (ttr) == FUNCTION_TYPE 3982 && TREE_CODE (ttl) == FUNCTION_TYPE) 3983 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3984 == TYPE_QUALS (ttr)) 3985 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3986 == TYPE_QUALS (ttl)))) 3987 break; 3988 3989 /* Keep looking for a better type, but remember this one. */ 3990 if (!marginal_memb) 3991 marginal_memb = memb; 3992 } 3993 } 3994 3995 /* Can convert integer zero to any pointer type. */ 3996 if (null_pointer_constant_p (rhs)) 3997 { 3998 rhs = null_pointer_node; 3999 break; 4000 } 4001 } 4002 4003 if (memb || marginal_memb) 4004 { 4005 if (!memb) 4006 { 4007 /* We have only a marginally acceptable member type; 4008 it needs a warning. */ 4009 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb)); 4010 tree ttr = TREE_TYPE (rhstype); 4011 4012 /* Const and volatile mean something different for function 4013 types, so the usual warnings are not appropriate. */ 4014 if (TREE_CODE (ttr) == FUNCTION_TYPE 4015 && TREE_CODE (ttl) == FUNCTION_TYPE) 4016 { 4017 /* Because const and volatile on functions are 4018 restrictions that say the function will not do 4019 certain things, it is okay to use a const or volatile 4020 function where an ordinary one is wanted, but not 4021 vice-versa. */ 4022 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 4023 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE " 4024 "makes qualified function " 4025 "pointer from unqualified"), 4026 G_("assignment makes qualified " 4027 "function pointer from " 4028 "unqualified"), 4029 G_("initialization makes qualified " 4030 "function pointer from " 4031 "unqualified"), 4032 G_("return makes qualified function " 4033 "pointer from unqualified")); 4034 } 4035 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4036 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4037 "qualifiers from pointer target type"), 4038 G_("assignment discards qualifiers " 4039 "from pointer target type"), 4040 G_("initialization discards qualifiers " 4041 "from pointer target type"), 4042 G_("return discards qualifiers from " 4043 "pointer target type")); 4044 4045 memb = marginal_memb; 4046 } 4047 4048 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))) 4049 pedwarn ("ISO C prohibits argument conversion to union type"); 4050 4051 return build_constructor_single (type, memb, rhs); 4052 } 4053 } 4054 4055 /* Conversions among pointers */ 4056 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 4057 && (coder == codel)) 4058 { 4059 tree ttl = TREE_TYPE (type); 4060 tree ttr = TREE_TYPE (rhstype); 4061 tree mvl = ttl; 4062 tree mvr = ttr; 4063 bool is_opaque_pointer; 4064 int target_cmp = 0; /* Cache comp_target_types () result. */ 4065 4066 if (TREE_CODE (mvl) != ARRAY_TYPE) 4067 mvl = TYPE_MAIN_VARIANT (mvl); 4068 if (TREE_CODE (mvr) != ARRAY_TYPE) 4069 mvr = TYPE_MAIN_VARIANT (mvr); 4070 /* Opaque pointers are treated like void pointers. */ 4071 is_opaque_pointer = (targetm.vector_opaque_p (type) 4072 || targetm.vector_opaque_p (rhstype)) 4073 && TREE_CODE (ttl) == VECTOR_TYPE 4074 && TREE_CODE (ttr) == VECTOR_TYPE; 4075 4076 /* C++ does not allow the implicit conversion void* -> T*. However, 4077 for the purpose of reducing the number of false positives, we 4078 tolerate the special case of 4079 4080 int *p = NULL; 4081 4082 where NULL is typically defined in C to be '(void *) 0'. */ 4083 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl)) 4084 warning (OPT_Wc___compat, "request for implicit conversion from " 4085 "%qT to %qT not permitted in C++", rhstype, type); 4086 4087 /* Check if the right-hand side has a format attribute but the 4088 left-hand side doesn't. */ 4089 if (warn_missing_format_attribute 4090 && check_missing_format_attribute (type, rhstype)) 4091 { 4092 switch (errtype) 4093 { 4094 case ic_argpass: 4095 case ic_argpass_nonproto: 4096 warning (OPT_Wmissing_format_attribute, 4097 "argument %d of %qE might be " 4098 "a candidate for a format attribute", 4099 parmnum, rname); 4100 break; 4101 case ic_assign: 4102 warning (OPT_Wmissing_format_attribute, 4103 "assignment left-hand side might be " 4104 "a candidate for a format attribute"); 4105 break; 4106 case ic_init: 4107 warning (OPT_Wmissing_format_attribute, 4108 "initialization left-hand side might be " 4109 "a candidate for a format attribute"); 4110 break; 4111 case ic_return: 4112 warning (OPT_Wmissing_format_attribute, 4113 "return type might be " 4114 "a candidate for a format attribute"); 4115 break; 4116 default: 4117 gcc_unreachable (); 4118 } 4119 } 4120 4121 /* Any non-function converts to a [const][volatile] void * 4122 and vice versa; otherwise, targets must be the same. 4123 Meanwhile, the lhs target must have all the qualifiers of the rhs. */ 4124 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4125 || (target_cmp = comp_target_types (type, rhstype)) 4126 || is_opaque_pointer 4127 || (c_common_unsigned_type (mvl) 4128 == c_common_unsigned_type (mvr))) 4129 { 4130 if (pedantic 4131 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) 4132 || 4133 (VOID_TYPE_P (ttr) 4134 && !null_pointer_constant_p (rhs) 4135 && TREE_CODE (ttl) == FUNCTION_TYPE))) 4136 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of " 4137 "%qE between function pointer " 4138 "and %<void *%>"), 4139 G_("ISO C forbids assignment between " 4140 "function pointer and %<void *%>"), 4141 G_("ISO C forbids initialization between " 4142 "function pointer and %<void *%>"), 4143 G_("ISO C forbids return between function " 4144 "pointer and %<void *%>")); 4145 /* Const and volatile mean something different for function types, 4146 so the usual warnings are not appropriate. */ 4147 else if (TREE_CODE (ttr) != FUNCTION_TYPE 4148 && TREE_CODE (ttl) != FUNCTION_TYPE) 4149 { 4150 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 4151 { 4152 /* Types differing only by the presence of the 'volatile' 4153 qualifier are acceptable if the 'volatile' has been added 4154 in by the Objective-C EH machinery. */ 4155 if (!objc_type_quals_match (ttl, ttr)) 4156 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards " 4157 "qualifiers from pointer target type"), 4158 G_("assignment discards qualifiers " 4159 "from pointer target type"), 4160 G_("initialization discards qualifiers " 4161 "from pointer target type"), 4162 G_("return discards qualifiers from " 4163 "pointer target type")); 4164 } 4165 /* If this is not a case of ignoring a mismatch in signedness, 4166 no warning. */ 4167 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 4168 || target_cmp) 4169 ; 4170 /* If there is a mismatch, do warn. */ 4171 else if (warn_pointer_sign) 4172 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument " 4173 "%d of %qE differ in signedness"), 4174 G_("pointer targets in assignment " 4175 "differ in signedness"), 4176 G_("pointer targets in initialization " 4177 "differ in signedness"), 4178 G_("pointer targets in return differ " 4179 "in signedness")); 4180 } 4181 else if (TREE_CODE (ttl) == FUNCTION_TYPE 4182 && TREE_CODE (ttr) == FUNCTION_TYPE) 4183 { 4184 /* Because const and volatile on functions are restrictions 4185 that say the function will not do certain things, 4186 it is okay to use a const or volatile function 4187 where an ordinary one is wanted, but not vice-versa. */ 4188 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 4189 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4190 "qualified function pointer " 4191 "from unqualified"), 4192 G_("assignment makes qualified function " 4193 "pointer from unqualified"), 4194 G_("initialization makes qualified " 4195 "function pointer from unqualified"), 4196 G_("return makes qualified function " 4197 "pointer from unqualified")); 4198 } 4199 } 4200 else 4201 /* Avoid warning about the volatile ObjC EH puts on decls. */ 4202 if (!objc_ok) 4203 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from " 4204 "incompatible pointer type"), 4205 G_("assignment from incompatible pointer type"), 4206 G_("initialization from incompatible " 4207 "pointer type"), 4208 G_("return from incompatible pointer type")); 4209 4210 return convert (type, rhs); 4211 } 4212 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) 4213 { 4214 /* ??? This should not be an error when inlining calls to 4215 unprototyped functions. */ 4216 error ("invalid use of non-lvalue array"); 4217 return error_mark_node; 4218 } 4219 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) 4220 { 4221 /* An explicit constant 0 can convert to a pointer, 4222 or one that results from arithmetic, even including 4223 a cast to integer type. */ 4224 if (!null_pointer_constant_p (rhs)) 4225 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes " 4226 "pointer from integer without a cast"), 4227 G_("assignment makes pointer from integer " 4228 "without a cast"), 4229 G_("initialization makes pointer from " 4230 "integer without a cast"), 4231 G_("return makes pointer from integer " 4232 "without a cast")); 4233 4234 return convert (type, rhs); 4235 } 4236 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) 4237 { 4238 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer " 4239 "from pointer without a cast"), 4240 G_("assignment makes integer from pointer " 4241 "without a cast"), 4242 G_("initialization makes integer from pointer " 4243 "without a cast"), 4244 G_("return makes integer from pointer " 4245 "without a cast")); 4246 return convert (type, rhs); 4247 } 4248 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) 4249 return convert (type, rhs); 4250 4251 switch (errtype) 4252 { 4253 case ic_argpass: 4254 case ic_argpass_nonproto: 4255 /* ??? This should not be an error when inlining calls to 4256 unprototyped functions. */ 4257 error ("incompatible type for argument %d of %qE", parmnum, rname); 4258 break; 4259 case ic_assign: 4260 error ("incompatible types in assignment"); 4261 break; 4262 case ic_init: 4263 error ("incompatible types in initialization"); 4264 break; 4265 case ic_return: 4266 error ("incompatible types in return"); 4267 break; 4268 default: 4269 gcc_unreachable (); 4270 } 4271 4272 return error_mark_node; 4273} 4274 4275/* Convert VALUE for assignment into inlined parameter PARM. ARGNUM 4276 is used for error and warning reporting and indicates which argument 4277 is being processed. */ 4278 4279tree 4280c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) 4281{ 4282 tree ret, type; 4283 4284 /* If FN was prototyped at the call site, the value has been converted 4285 already in convert_arguments. 4286 However, we might see a prototype now that was not in place when 4287 the function call was seen, so check that the VALUE actually matches 4288 PARM before taking an early exit. */ 4289 if (!value 4290 || (TYPE_ARG_TYPES (TREE_TYPE (fn)) 4291 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) 4292 == TYPE_MAIN_VARIANT (TREE_TYPE (value))))) 4293 return value; 4294 4295 type = TREE_TYPE (parm); 4296 ret = convert_for_assignment (type, value, 4297 ic_argpass_nonproto, fn, 4298 fn, argnum); 4299 if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) 4300 && INTEGRAL_TYPE_P (type) 4301 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 4302 ret = default_conversion (ret); 4303 return ret; 4304} 4305 4306/* If VALUE is a compound expr all of whose expressions are constant, then 4307 return its value. Otherwise, return error_mark_node. 4308 4309 This is for handling COMPOUND_EXPRs as initializer elements 4310 which is allowed with a warning when -pedantic is specified. */ 4311 4312static tree 4313valid_compound_expr_initializer (tree value, tree endtype) 4314{ 4315 if (TREE_CODE (value) == COMPOUND_EXPR) 4316 { 4317 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) 4318 == error_mark_node) 4319 return error_mark_node; 4320 return valid_compound_expr_initializer (TREE_OPERAND (value, 1), 4321 endtype); 4322 } 4323 else if (!initializer_constant_valid_p (value, endtype)) 4324 return error_mark_node; 4325 else 4326 return value; 4327} 4328 4329/* Perform appropriate conversions on the initial value of a variable, 4330 store it in the declaration DECL, 4331 and print any error messages that are appropriate. 4332 If the init is invalid, store an ERROR_MARK. */ 4333 4334void 4335store_init_value (tree decl, tree init) 4336{ 4337 tree value, type; 4338 4339 /* If variable's type was invalidly declared, just ignore it. */ 4340 4341 type = TREE_TYPE (decl); 4342 if (TREE_CODE (type) == ERROR_MARK) 4343 return; 4344 4345 /* Digest the specified initializer into an expression. */ 4346 4347 value = digest_init (type, init, true, TREE_STATIC (decl)); 4348 4349 /* Store the expression if valid; else report error. */ 4350 4351 if (!in_system_header 4352 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl)) 4353 warning (OPT_Wtraditional, "traditional C rejects automatic " 4354 "aggregate initialization"); 4355 4356 DECL_INITIAL (decl) = value; 4357 4358 /* ANSI wants warnings about out-of-range constant initializers. */ 4359 STRIP_TYPE_NOPS (value); 4360 constant_expression_warning (value); 4361 4362 /* Check if we need to set array size from compound literal size. */ 4363 if (TREE_CODE (type) == ARRAY_TYPE 4364 && TYPE_DOMAIN (type) == 0 4365 && value != error_mark_node) 4366 { 4367 tree inside_init = init; 4368 4369 STRIP_TYPE_NOPS (inside_init); 4370 inside_init = fold (inside_init); 4371 4372 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4373 { 4374 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4375 4376 if (TYPE_DOMAIN (TREE_TYPE (cldecl))) 4377 { 4378 /* For int foo[] = (int [3]){1}; we need to set array size 4379 now since later on array initializer will be just the 4380 brace enclosed list of the compound literal. */ 4381 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 4382 TREE_TYPE (decl) = type; 4383 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl)); 4384 layout_type (type); 4385 layout_decl (cldecl, 0); 4386 } 4387 } 4388 } 4389} 4390 4391/* Methods for storing and printing names for error messages. */ 4392 4393/* Implement a spelling stack that allows components of a name to be pushed 4394 and popped. Each element on the stack is this structure. */ 4395 4396struct spelling 4397{ 4398 int kind; 4399 union 4400 { 4401 unsigned HOST_WIDE_INT i; 4402 const char *s; 4403 } u; 4404}; 4405 4406#define SPELLING_STRING 1 4407#define SPELLING_MEMBER 2 4408#define SPELLING_BOUNDS 3 4409 4410static struct spelling *spelling; /* Next stack element (unused). */ 4411static struct spelling *spelling_base; /* Spelling stack base. */ 4412static int spelling_size; /* Size of the spelling stack. */ 4413 4414/* Macros to save and restore the spelling stack around push_... functions. 4415 Alternative to SAVE_SPELLING_STACK. */ 4416 4417#define SPELLING_DEPTH() (spelling - spelling_base) 4418#define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) 4419 4420/* Push an element on the spelling stack with type KIND and assign VALUE 4421 to MEMBER. */ 4422 4423#define PUSH_SPELLING(KIND, VALUE, MEMBER) \ 4424{ \ 4425 int depth = SPELLING_DEPTH (); \ 4426 \ 4427 if (depth >= spelling_size) \ 4428 { \ 4429 spelling_size += 10; \ 4430 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \ 4431 spelling_size); \ 4432 RESTORE_SPELLING_DEPTH (depth); \ 4433 } \ 4434 \ 4435 spelling->kind = (KIND); \ 4436 spelling->MEMBER = (VALUE); \ 4437 spelling++; \ 4438} 4439 4440/* Push STRING on the stack. Printed literally. */ 4441 4442static void 4443push_string (const char *string) 4444{ 4445 PUSH_SPELLING (SPELLING_STRING, string, u.s); 4446} 4447 4448/* Push a member name on the stack. Printed as '.' STRING. */ 4449 4450static void 4451push_member_name (tree decl) 4452{ 4453 const char *const string 4454 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>"; 4455 PUSH_SPELLING (SPELLING_MEMBER, string, u.s); 4456} 4457 4458/* Push an array bounds on the stack. Printed as [BOUNDS]. */ 4459 4460static void 4461push_array_bounds (unsigned HOST_WIDE_INT bounds) 4462{ 4463 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); 4464} 4465 4466/* Compute the maximum size in bytes of the printed spelling. */ 4467 4468static int 4469spelling_length (void) 4470{ 4471 int size = 0; 4472 struct spelling *p; 4473 4474 for (p = spelling_base; p < spelling; p++) 4475 { 4476 if (p->kind == SPELLING_BOUNDS) 4477 size += 25; 4478 else 4479 size += strlen (p->u.s) + 1; 4480 } 4481 4482 return size; 4483} 4484 4485/* Print the spelling to BUFFER and return it. */ 4486 4487static char * 4488print_spelling (char *buffer) 4489{ 4490 char *d = buffer; 4491 struct spelling *p; 4492 4493 for (p = spelling_base; p < spelling; p++) 4494 if (p->kind == SPELLING_BOUNDS) 4495 { 4496 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i); 4497 d += strlen (d); 4498 } 4499 else 4500 { 4501 const char *s; 4502 if (p->kind == SPELLING_MEMBER) 4503 *d++ = '.'; 4504 for (s = p->u.s; (*d = *s++); d++) 4505 ; 4506 } 4507 *d++ = '\0'; 4508 return buffer; 4509} 4510 4511/* Issue an error message for a bad initializer component. 4512 MSGID identifies the message. 4513 The component name is taken from the spelling stack. */ 4514 4515void 4516error_init (const char *msgid) 4517{ 4518 char *ofwhat; 4519 4520 error ("%s", _(msgid)); 4521 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4522 if (*ofwhat) 4523 error ("(near initialization for %qs)", ofwhat); 4524} 4525 4526/* Issue a pedantic warning for a bad initializer component. 4527 MSGID identifies the message. 4528 The component name is taken from the spelling stack. */ 4529 4530void 4531pedwarn_init (const char *msgid) 4532{ 4533 char *ofwhat; 4534 4535 pedwarn ("%s", _(msgid)); 4536 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4537 if (*ofwhat) 4538 pedwarn ("(near initialization for %qs)", ofwhat); 4539} 4540 4541/* Issue a warning for a bad initializer component. 4542 MSGID identifies the message. 4543 The component name is taken from the spelling stack. */ 4544 4545static void 4546warning_init (const char *msgid) 4547{ 4548 char *ofwhat; 4549 4550 warning (0, "%s", _(msgid)); 4551 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); 4552 if (*ofwhat) 4553 warning (0, "(near initialization for %qs)", ofwhat); 4554} 4555 4556/* If TYPE is an array type and EXPR is a parenthesized string 4557 constant, warn if pedantic that EXPR is being used to initialize an 4558 object of type TYPE. */ 4559 4560void 4561maybe_warn_string_init (tree type, struct c_expr expr) 4562{ 4563 if (pedantic 4564 && TREE_CODE (type) == ARRAY_TYPE 4565 && TREE_CODE (expr.value) == STRING_CST 4566 && expr.original_code != STRING_CST) 4567 pedwarn_init ("array initialized from parenthesized string constant"); 4568} 4569 4570/* Digest the parser output INIT as an initializer for type TYPE. 4571 Return a C expression of type TYPE to represent the initial value. 4572 4573 If INIT is a string constant, STRICT_STRING is true if it is 4574 unparenthesized or we should not warn here for it being parenthesized. 4575 For other types of INIT, STRICT_STRING is not used. 4576 4577 REQUIRE_CONSTANT requests an error if non-constant initializers or 4578 elements are seen. */ 4579 4580static tree 4581digest_init (tree type, tree init, bool strict_string, int require_constant) 4582{ 4583 enum tree_code code = TREE_CODE (type); 4584 tree inside_init = init; 4585 4586 if (type == error_mark_node 4587 || !init 4588 || init == error_mark_node 4589 || TREE_TYPE (init) == error_mark_node) 4590 return error_mark_node; 4591 4592 STRIP_TYPE_NOPS (inside_init); 4593 4594 inside_init = fold (inside_init); 4595 4596 /* Initialization of an array of chars from a string constant 4597 optionally enclosed in braces. */ 4598 4599 if (code == ARRAY_TYPE && inside_init 4600 && TREE_CODE (inside_init) == STRING_CST) 4601 { 4602 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); 4603 /* Note that an array could be both an array of character type 4604 and an array of wchar_t if wchar_t is signed char or unsigned 4605 char. */ 4606 bool char_array = (typ1 == char_type_node 4607 || typ1 == signed_char_type_node 4608 || typ1 == unsigned_char_type_node); 4609 bool wchar_array = !!comptypes (typ1, wchar_type_node); 4610 if (char_array || wchar_array) 4611 { 4612 struct c_expr expr; 4613 bool char_string; 4614 expr.value = inside_init; 4615 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK); 4616 maybe_warn_string_init (type, expr); 4617 4618 char_string 4619 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4620 == char_type_node); 4621 4622 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4623 TYPE_MAIN_VARIANT (type))) 4624 return inside_init; 4625 4626 if (!wchar_array && !char_string) 4627 { 4628 error_init ("char-array initialized from wide string"); 4629 return error_mark_node; 4630 } 4631 if (char_string && !char_array) 4632 { 4633 error_init ("wchar_t-array initialized from non-wide string"); 4634 return error_mark_node; 4635 } 4636 4637 TREE_TYPE (inside_init) = type; 4638 if (TYPE_DOMAIN (type) != 0 4639 && TYPE_SIZE (type) != 0 4640 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST 4641 /* Subtract 1 (or sizeof (wchar_t)) 4642 because it's ok to ignore the terminating null char 4643 that is counted in the length of the constant. */ 4644 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), 4645 TREE_STRING_LENGTH (inside_init) 4646 - ((TYPE_PRECISION (typ1) 4647 != TYPE_PRECISION (char_type_node)) 4648 ? (TYPE_PRECISION (wchar_type_node) 4649 / BITS_PER_UNIT) 4650 : 1))) 4651 pedwarn_init ("initializer-string for array of chars is too long"); 4652 4653 return inside_init; 4654 } 4655 else if (INTEGRAL_TYPE_P (typ1)) 4656 { 4657 error_init ("array of inappropriate type initialized " 4658 "from string constant"); 4659 return error_mark_node; 4660 } 4661 } 4662 4663 /* Build a VECTOR_CST from a *constant* vector constructor. If the 4664 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt 4665 below and handle as a constructor. */ 4666 if (code == VECTOR_TYPE 4667 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE 4668 && vector_types_convertible_p (TREE_TYPE (inside_init), type) 4669 && TREE_CONSTANT (inside_init)) 4670 { 4671 if (TREE_CODE (inside_init) == VECTOR_CST 4672 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4673 TYPE_MAIN_VARIANT (type))) 4674 return inside_init; 4675 4676 if (TREE_CODE (inside_init) == CONSTRUCTOR) 4677 { 4678 unsigned HOST_WIDE_INT ix; 4679 tree value; 4680 bool constant_p = true; 4681 4682 /* Iterate through elements and check if all constructor 4683 elements are *_CSTs. */ 4684 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value) 4685 if (!CONSTANT_CLASS_P (value)) 4686 { 4687 constant_p = false; 4688 break; 4689 } 4690 4691 if (constant_p) 4692 return build_vector_from_ctor (type, 4693 CONSTRUCTOR_ELTS (inside_init)); 4694 } 4695 } 4696 4697 /* Any type can be initialized 4698 from an expression of the same type, optionally with braces. */ 4699 4700 if (inside_init && TREE_TYPE (inside_init) != 0 4701 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4702 TYPE_MAIN_VARIANT (type)) 4703 || (code == ARRAY_TYPE 4704 && comptypes (TREE_TYPE (inside_init), type)) 4705 || (code == VECTOR_TYPE 4706 && comptypes (TREE_TYPE (inside_init), type)) 4707 || (code == POINTER_TYPE 4708 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4709 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4710 TREE_TYPE (type))))) 4711 { 4712 if (code == POINTER_TYPE) 4713 { 4714 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4715 { 4716 if (TREE_CODE (inside_init) == STRING_CST 4717 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4718 inside_init = array_to_pointer_conversion (inside_init); 4719 else 4720 { 4721 error_init ("invalid use of non-lvalue array"); 4722 return error_mark_node; 4723 } 4724 } 4725 } 4726 4727 if (code == VECTOR_TYPE) 4728 /* Although the types are compatible, we may require a 4729 conversion. */ 4730 inside_init = convert (type, inside_init); 4731 4732 if (require_constant 4733 && (code == VECTOR_TYPE || !flag_isoc99) 4734 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4735 { 4736 /* As an extension, allow initializing objects with static storage 4737 duration with compound literals (which are then treated just as 4738 the brace enclosed list they contain). Also allow this for 4739 vectors, as we can only assign them with compound literals. */ 4740 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4741 inside_init = DECL_INITIAL (decl); 4742 } 4743 4744 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4745 && TREE_CODE (inside_init) != CONSTRUCTOR) 4746 { 4747 error_init ("array initialized from non-constant array expression"); 4748 return error_mark_node; 4749 } 4750 4751 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4752 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4753 4754 /* Compound expressions can only occur here if -pedantic or 4755 -pedantic-errors is specified. In the later case, we always want 4756 an error. In the former case, we simply want a warning. */ 4757 if (require_constant && pedantic 4758 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4759 { 4760 inside_init 4761 = valid_compound_expr_initializer (inside_init, 4762 TREE_TYPE (inside_init)); 4763 if (inside_init == error_mark_node) 4764 error_init ("initializer element is not constant"); 4765 else 4766 pedwarn_init ("initializer element is not constant"); 4767 if (flag_pedantic_errors) 4768 inside_init = error_mark_node; 4769 } 4770 else if (require_constant 4771 && !initializer_constant_valid_p (inside_init, 4772 TREE_TYPE (inside_init))) 4773 { 4774 error_init ("initializer element is not constant"); 4775 inside_init = error_mark_node; 4776 } 4777 4778 /* Added to enable additional -Wmissing-format-attribute warnings. */ 4779 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE) 4780 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE, 4781 NULL_TREE, 0); 4782 return inside_init; 4783 } 4784 4785 /* Handle scalar types, including conversions. */ 4786 4787 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4788 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE 4789 || code == VECTOR_TYPE) 4790 { 4791 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE 4792 && (TREE_CODE (init) == STRING_CST 4793 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR)) 4794 init = array_to_pointer_conversion (init); 4795 inside_init 4796 = convert_for_assignment (type, init, ic_init, 4797 NULL_TREE, NULL_TREE, 0); 4798 4799 /* Check to see if we have already given an error message. */ 4800 if (inside_init == error_mark_node) 4801 ; 4802 else if (require_constant && !TREE_CONSTANT (inside_init)) 4803 { 4804 error_init ("initializer element is not constant"); 4805 inside_init = error_mark_node; 4806 } 4807 else if (require_constant 4808 && !initializer_constant_valid_p (inside_init, 4809 TREE_TYPE (inside_init))) 4810 { 4811 error_init ("initializer element is not computable at load time"); 4812 inside_init = error_mark_node; 4813 } 4814 4815 return inside_init; 4816 } 4817 4818 /* Come here only for records and arrays. */ 4819 4820 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4821 { 4822 error_init ("variable-sized object may not be initialized"); 4823 return error_mark_node; 4824 } 4825 4826 error_init ("invalid initializer"); 4827 return error_mark_node; 4828} 4829 4830/* Handle initializers that use braces. */ 4831 4832/* Type of object we are accumulating a constructor for. 4833 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4834static tree constructor_type; 4835 4836/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4837 left to fill. */ 4838static tree constructor_fields; 4839 4840/* For an ARRAY_TYPE, this is the specified index 4841 at which to store the next element we get. */ 4842static tree constructor_index; 4843 4844/* For an ARRAY_TYPE, this is the maximum index. */ 4845static tree constructor_max_index; 4846 4847/* For a RECORD_TYPE, this is the first field not yet written out. */ 4848static tree constructor_unfilled_fields; 4849 4850/* For an ARRAY_TYPE, this is the index of the first element 4851 not yet written out. */ 4852static tree constructor_unfilled_index; 4853 4854/* In a RECORD_TYPE, the byte index of the next consecutive field. 4855 This is so we can generate gaps between fields, when appropriate. */ 4856static tree constructor_bit_index; 4857 4858/* If we are saving up the elements rather than allocating them, 4859 this is the list of elements so far (in reverse order, 4860 most recent first). */ 4861static VEC(constructor_elt,gc) *constructor_elements; 4862 4863/* 1 if constructor should be incrementally stored into a constructor chain, 4864 0 if all the elements should be kept in AVL tree. */ 4865static int constructor_incremental; 4866 4867/* 1 if so far this constructor's elements are all compile-time constants. */ 4868static int constructor_constant; 4869 4870/* 1 if so far this constructor's elements are all valid address constants. */ 4871static int constructor_simple; 4872 4873/* 1 if this constructor is erroneous so far. */ 4874static int constructor_erroneous; 4875 4876/* Structure for managing pending initializer elements, organized as an 4877 AVL tree. */ 4878 4879struct init_node 4880{ 4881 struct init_node *left, *right; 4882 struct init_node *parent; 4883 int balance; 4884 tree purpose; 4885 tree value; 4886}; 4887 4888/* Tree of pending elements at this constructor level. 4889 These are elements encountered out of order 4890 which belong at places we haven't reached yet in actually 4891 writing the output. 4892 Will never hold tree nodes across GC runs. */ 4893static struct init_node *constructor_pending_elts; 4894 4895/* The SPELLING_DEPTH of this constructor. */ 4896static int constructor_depth; 4897 4898/* DECL node for which an initializer is being read. 4899 0 means we are reading a constructor expression 4900 such as (struct foo) {...}. */ 4901static tree constructor_decl; 4902 4903/* Nonzero if this is an initializer for a top-level decl. */ 4904static int constructor_top_level; 4905 4906/* Nonzero if there were any member designators in this initializer. */ 4907static int constructor_designated; 4908 4909/* Nesting depth of designator list. */ 4910static int designator_depth; 4911 4912/* Nonzero if there were diagnosed errors in this designator list. */ 4913static int designator_erroneous; 4914 4915 4916/* This stack has a level for each implicit or explicit level of 4917 structuring in the initializer, including the outermost one. It 4918 saves the values of most of the variables above. */ 4919 4920struct constructor_range_stack; 4921 4922struct constructor_stack 4923{ 4924 struct constructor_stack *next; 4925 tree type; 4926 tree fields; 4927 tree index; 4928 tree max_index; 4929 tree unfilled_index; 4930 tree unfilled_fields; 4931 tree bit_index; 4932 VEC(constructor_elt,gc) *elements; 4933 struct init_node *pending_elts; 4934 int offset; 4935 int depth; 4936 /* If value nonzero, this value should replace the entire 4937 constructor at this level. */ 4938 struct c_expr replacement_value; 4939 struct constructor_range_stack *range_stack; 4940 char constant; 4941 char simple; 4942 char implicit; 4943 char erroneous; 4944 char outer; 4945 char incremental; 4946 char designated; 4947}; 4948 4949static struct constructor_stack *constructor_stack; 4950 4951/* This stack represents designators from some range designator up to 4952 the last designator in the list. */ 4953 4954struct constructor_range_stack 4955{ 4956 struct constructor_range_stack *next, *prev; 4957 struct constructor_stack *stack; 4958 tree range_start; 4959 tree index; 4960 tree range_end; 4961 tree fields; 4962}; 4963 4964static struct constructor_range_stack *constructor_range_stack; 4965 4966/* This stack records separate initializers that are nested. 4967 Nested initializers can't happen in ANSI C, but GNU C allows them 4968 in cases like { ... (struct foo) { ... } ... }. */ 4969 4970struct initializer_stack 4971{ 4972 struct initializer_stack *next; 4973 tree decl; 4974 struct constructor_stack *constructor_stack; 4975 struct constructor_range_stack *constructor_range_stack; 4976 VEC(constructor_elt,gc) *elements; 4977 struct spelling *spelling; 4978 struct spelling *spelling_base; 4979 int spelling_size; 4980 char top_level; 4981 char require_constant_value; 4982 char require_constant_elements; 4983}; 4984 4985static struct initializer_stack *initializer_stack; 4986 4987/* Prepare to parse and output the initializer for variable DECL. */ 4988 4989void 4990start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level) 4991{ 4992 const char *locus; 4993 struct initializer_stack *p = XNEW (struct initializer_stack); 4994 4995 p->decl = constructor_decl; 4996 p->require_constant_value = require_constant_value; 4997 p->require_constant_elements = require_constant_elements; 4998 p->constructor_stack = constructor_stack; 4999 p->constructor_range_stack = constructor_range_stack; 5000 p->elements = constructor_elements; 5001 p->spelling = spelling; 5002 p->spelling_base = spelling_base; 5003 p->spelling_size = spelling_size; 5004 p->top_level = constructor_top_level; 5005 p->next = initializer_stack; 5006 initializer_stack = p; 5007 5008 constructor_decl = decl; 5009 constructor_designated = 0; 5010 constructor_top_level = top_level; 5011 5012 if (decl != 0 && decl != error_mark_node) 5013 { 5014 require_constant_value = TREE_STATIC (decl); 5015 require_constant_elements 5016 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 5017 /* For a scalar, you can always use any value to initialize, 5018 even within braces. */ 5019 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 5020 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 5021 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 5022 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 5023 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 5024 } 5025 else 5026 { 5027 require_constant_value = 0; 5028 require_constant_elements = 0; 5029 locus = "(anonymous)"; 5030 } 5031 5032 constructor_stack = 0; 5033 constructor_range_stack = 0; 5034 5035 missing_braces_mentioned = 0; 5036 5037 spelling_base = 0; 5038 spelling_size = 0; 5039 RESTORE_SPELLING_DEPTH (0); 5040 5041 if (locus) 5042 push_string (locus); 5043} 5044 5045void 5046finish_init (void) 5047{ 5048 struct initializer_stack *p = initializer_stack; 5049 5050 /* Free the whole constructor stack of this initializer. */ 5051 while (constructor_stack) 5052 { 5053 struct constructor_stack *q = constructor_stack; 5054 constructor_stack = q->next; 5055 free (q); 5056 } 5057 5058 gcc_assert (!constructor_range_stack); 5059 5060 /* Pop back to the data of the outer initializer (if any). */ 5061 free (spelling_base); 5062 5063 constructor_decl = p->decl; 5064 require_constant_value = p->require_constant_value; 5065 require_constant_elements = p->require_constant_elements; 5066 constructor_stack = p->constructor_stack; 5067 constructor_range_stack = p->constructor_range_stack; 5068 constructor_elements = p->elements; 5069 spelling = p->spelling; 5070 spelling_base = p->spelling_base; 5071 spelling_size = p->spelling_size; 5072 constructor_top_level = p->top_level; 5073 initializer_stack = p->next; 5074 free (p); 5075} 5076 5077/* Call here when we see the initializer is surrounded by braces. 5078 This is instead of a call to push_init_level; 5079 it is matched by a call to pop_init_level. 5080 5081 TYPE is the type to initialize, for a constructor expression. 5082 For an initializer for a decl, TYPE is zero. */ 5083 5084void 5085really_start_incremental_init (tree type) 5086{ 5087 struct constructor_stack *p = XNEW (struct constructor_stack); 5088 5089 if (type == 0) 5090 type = TREE_TYPE (constructor_decl); 5091 5092 if (targetm.vector_opaque_p (type)) 5093 error ("opaque vector types cannot be initialized"); 5094 5095 p->type = constructor_type; 5096 p->fields = constructor_fields; 5097 p->index = constructor_index; 5098 p->max_index = constructor_max_index; 5099 p->unfilled_index = constructor_unfilled_index; 5100 p->unfilled_fields = constructor_unfilled_fields; 5101 p->bit_index = constructor_bit_index; 5102 p->elements = constructor_elements; 5103 p->constant = constructor_constant; 5104 p->simple = constructor_simple; 5105 p->erroneous = constructor_erroneous; 5106 p->pending_elts = constructor_pending_elts; 5107 p->depth = constructor_depth; 5108 p->replacement_value.value = 0; 5109 p->replacement_value.original_code = ERROR_MARK; 5110 p->implicit = 0; 5111 p->range_stack = 0; 5112 p->outer = 0; 5113 p->incremental = constructor_incremental; 5114 p->designated = constructor_designated; 5115 p->next = 0; 5116 constructor_stack = p; 5117 5118 constructor_constant = 1; 5119 constructor_simple = 1; 5120 constructor_depth = SPELLING_DEPTH (); 5121 constructor_elements = 0; 5122 constructor_pending_elts = 0; 5123 constructor_type = type; 5124 constructor_incremental = 1; 5125 constructor_designated = 0; 5126 designator_depth = 0; 5127 designator_erroneous = 0; 5128 5129 if (TREE_CODE (constructor_type) == RECORD_TYPE 5130 || TREE_CODE (constructor_type) == UNION_TYPE) 5131 { 5132 constructor_fields = TYPE_FIELDS (constructor_type); 5133 /* Skip any nameless bit fields at the beginning. */ 5134 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5135 && DECL_NAME (constructor_fields) == 0) 5136 constructor_fields = TREE_CHAIN (constructor_fields); 5137 5138 constructor_unfilled_fields = constructor_fields; 5139 constructor_bit_index = bitsize_zero_node; 5140 } 5141 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5142 { 5143 if (TYPE_DOMAIN (constructor_type)) 5144 { 5145 constructor_max_index 5146 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5147 5148 /* Detect non-empty initializations of zero-length arrays. */ 5149 if (constructor_max_index == NULL_TREE 5150 && TYPE_SIZE (constructor_type)) 5151 constructor_max_index = build_int_cst (NULL_TREE, -1); 5152 5153 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5154 to initialize VLAs will cause a proper error; avoid tree 5155 checking errors as well by setting a safe value. */ 5156 if (constructor_max_index 5157 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5158 constructor_max_index = build_int_cst (NULL_TREE, -1); 5159 5160 constructor_index 5161 = convert (bitsizetype, 5162 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5163 } 5164 else 5165 { 5166 constructor_index = bitsize_zero_node; 5167 constructor_max_index = NULL_TREE; 5168 } 5169 5170 constructor_unfilled_index = constructor_index; 5171 } 5172 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5173 { 5174 /* Vectors are like simple fixed-size arrays. */ 5175 constructor_max_index = 5176 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5177 constructor_index = bitsize_zero_node; 5178 constructor_unfilled_index = constructor_index; 5179 } 5180 else 5181 { 5182 /* Handle the case of int x = {5}; */ 5183 constructor_fields = constructor_type; 5184 constructor_unfilled_fields = constructor_type; 5185 } 5186} 5187 5188/* Push down into a subobject, for initialization. 5189 If this is for an explicit set of braces, IMPLICIT is 0. 5190 If it is because the next element belongs at a lower level, 5191 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 5192 5193void 5194push_init_level (int implicit) 5195{ 5196 struct constructor_stack *p; 5197 tree value = NULL_TREE; 5198 5199 /* If we've exhausted any levels that didn't have braces, 5200 pop them now. If implicit == 1, this will have been done in 5201 process_init_element; do not repeat it here because in the case 5202 of excess initializers for an empty aggregate this leads to an 5203 infinite cycle of popping a level and immediately recreating 5204 it. */ 5205 if (implicit != 1) 5206 { 5207 while (constructor_stack->implicit) 5208 { 5209 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5210 || TREE_CODE (constructor_type) == UNION_TYPE) 5211 && constructor_fields == 0) 5212 process_init_element (pop_init_level (1)); 5213 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5214 && constructor_max_index 5215 && tree_int_cst_lt (constructor_max_index, 5216 constructor_index)) 5217 process_init_element (pop_init_level (1)); 5218 else 5219 break; 5220 } 5221 } 5222 5223 /* Unless this is an explicit brace, we need to preserve previous 5224 content if any. */ 5225 if (implicit) 5226 { 5227 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5228 || TREE_CODE (constructor_type) == UNION_TYPE) 5229 && constructor_fields) 5230 value = find_init_member (constructor_fields); 5231 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5232 value = find_init_member (constructor_index); 5233 } 5234 5235 p = XNEW (struct constructor_stack); 5236 p->type = constructor_type; 5237 p->fields = constructor_fields; 5238 p->index = constructor_index; 5239 p->max_index = constructor_max_index; 5240 p->unfilled_index = constructor_unfilled_index; 5241 p->unfilled_fields = constructor_unfilled_fields; 5242 p->bit_index = constructor_bit_index; 5243 p->elements = constructor_elements; 5244 p->constant = constructor_constant; 5245 p->simple = constructor_simple; 5246 p->erroneous = constructor_erroneous; 5247 p->pending_elts = constructor_pending_elts; 5248 p->depth = constructor_depth; 5249 p->replacement_value.value = 0; 5250 p->replacement_value.original_code = ERROR_MARK; 5251 p->implicit = implicit; 5252 p->outer = 0; 5253 p->incremental = constructor_incremental; 5254 p->designated = constructor_designated; 5255 p->next = constructor_stack; 5256 p->range_stack = 0; 5257 constructor_stack = p; 5258 5259 constructor_constant = 1; 5260 constructor_simple = 1; 5261 constructor_depth = SPELLING_DEPTH (); 5262 constructor_elements = 0; 5263 constructor_incremental = 1; 5264 constructor_designated = 0; 5265 constructor_pending_elts = 0; 5266 if (!implicit) 5267 { 5268 p->range_stack = constructor_range_stack; 5269 constructor_range_stack = 0; 5270 designator_depth = 0; 5271 designator_erroneous = 0; 5272 } 5273 5274 /* Don't die if an entire brace-pair level is superfluous 5275 in the containing level. */ 5276 if (constructor_type == 0) 5277 ; 5278 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5279 || TREE_CODE (constructor_type) == UNION_TYPE) 5280 { 5281 /* Don't die if there are extra init elts at the end. */ 5282 if (constructor_fields == 0) 5283 constructor_type = 0; 5284 else 5285 { 5286 constructor_type = TREE_TYPE (constructor_fields); 5287 push_member_name (constructor_fields); 5288 constructor_depth++; 5289 } 5290 } 5291 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5292 { 5293 constructor_type = TREE_TYPE (constructor_type); 5294 push_array_bounds (tree_low_cst (constructor_index, 1)); 5295 constructor_depth++; 5296 } 5297 5298 if (constructor_type == 0) 5299 { 5300 error_init ("extra brace group at end of initializer"); 5301 constructor_fields = 0; 5302 constructor_unfilled_fields = 0; 5303 return; 5304 } 5305 5306 if (value && TREE_CODE (value) == CONSTRUCTOR) 5307 { 5308 constructor_constant = TREE_CONSTANT (value); 5309 constructor_simple = TREE_STATIC (value); 5310 constructor_elements = CONSTRUCTOR_ELTS (value); 5311 if (!VEC_empty (constructor_elt, constructor_elements) 5312 && (TREE_CODE (constructor_type) == RECORD_TYPE 5313 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 5314 set_nonincremental_init (); 5315 } 5316 5317 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 5318 { 5319 missing_braces_mentioned = 1; 5320 warning_init ("missing braces around initializer"); 5321 } 5322 5323 if (TREE_CODE (constructor_type) == RECORD_TYPE 5324 || TREE_CODE (constructor_type) == UNION_TYPE) 5325 { 5326 constructor_fields = TYPE_FIELDS (constructor_type); 5327 /* Skip any nameless bit fields at the beginning. */ 5328 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 5329 && DECL_NAME (constructor_fields) == 0) 5330 constructor_fields = TREE_CHAIN (constructor_fields); 5331 5332 constructor_unfilled_fields = constructor_fields; 5333 constructor_bit_index = bitsize_zero_node; 5334 } 5335 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 5336 { 5337 /* Vectors are like simple fixed-size arrays. */ 5338 constructor_max_index = 5339 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); 5340 constructor_index = convert (bitsizetype, integer_zero_node); 5341 constructor_unfilled_index = constructor_index; 5342 } 5343 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5344 { 5345 if (TYPE_DOMAIN (constructor_type)) 5346 { 5347 constructor_max_index 5348 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 5349 5350 /* Detect non-empty initializations of zero-length arrays. */ 5351 if (constructor_max_index == NULL_TREE 5352 && TYPE_SIZE (constructor_type)) 5353 constructor_max_index = build_int_cst (NULL_TREE, -1); 5354 5355 /* constructor_max_index needs to be an INTEGER_CST. Attempts 5356 to initialize VLAs will cause a proper error; avoid tree 5357 checking errors as well by setting a safe value. */ 5358 if (constructor_max_index 5359 && TREE_CODE (constructor_max_index) != INTEGER_CST) 5360 constructor_max_index = build_int_cst (NULL_TREE, -1); 5361 5362 constructor_index 5363 = convert (bitsizetype, 5364 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5365 } 5366 else 5367 constructor_index = bitsize_zero_node; 5368 5369 constructor_unfilled_index = constructor_index; 5370 if (value && TREE_CODE (value) == STRING_CST) 5371 { 5372 /* We need to split the char/wchar array into individual 5373 characters, so that we don't have to special case it 5374 everywhere. */ 5375 set_nonincremental_init_from_string (value); 5376 } 5377 } 5378 else 5379 { 5380 if (constructor_type != error_mark_node) 5381 warning_init ("braces around scalar initializer"); 5382 constructor_fields = constructor_type; 5383 constructor_unfilled_fields = constructor_type; 5384 } 5385} 5386 5387/* At the end of an implicit or explicit brace level, 5388 finish up that level of constructor. If a single expression 5389 with redundant braces initialized that level, return the 5390 c_expr structure for that expression. Otherwise, the original_code 5391 element is set to ERROR_MARK. 5392 If we were outputting the elements as they are read, return 0 as the value 5393 from inner levels (process_init_element ignores that), 5394 but return error_mark_node as the value from the outermost level 5395 (that's what we want to put in DECL_INITIAL). 5396 Otherwise, return a CONSTRUCTOR expression as the value. */ 5397 5398struct c_expr 5399pop_init_level (int implicit) 5400{ 5401 struct constructor_stack *p; 5402 struct c_expr ret; 5403 ret.value = 0; 5404 ret.original_code = ERROR_MARK; 5405 5406 if (implicit == 0) 5407 { 5408 /* When we come to an explicit close brace, 5409 pop any inner levels that didn't have explicit braces. */ 5410 while (constructor_stack->implicit) 5411 process_init_element (pop_init_level (1)); 5412 5413 gcc_assert (!constructor_range_stack); 5414 } 5415 5416 /* Now output all pending elements. */ 5417 constructor_incremental = 1; 5418 output_pending_init_elements (1); 5419 5420 p = constructor_stack; 5421 5422 /* Error for initializing a flexible array member, or a zero-length 5423 array member in an inappropriate context. */ 5424 if (constructor_type && constructor_fields 5425 && TREE_CODE (constructor_type) == ARRAY_TYPE 5426 && TYPE_DOMAIN (constructor_type) 5427 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 5428 { 5429 /* Silently discard empty initializations. The parser will 5430 already have pedwarned for empty brackets. */ 5431 if (integer_zerop (constructor_unfilled_index)) 5432 constructor_type = NULL_TREE; 5433 else 5434 { 5435 gcc_assert (!TYPE_SIZE (constructor_type)); 5436 5437 if (constructor_depth > 2) 5438 error_init ("initialization of flexible array member in a nested context"); 5439 else if (pedantic) 5440 pedwarn_init ("initialization of a flexible array member"); 5441 5442 /* We have already issued an error message for the existence 5443 of a flexible array member not at the end of the structure. 5444 Discard the initializer so that we do not die later. */ 5445 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 5446 constructor_type = NULL_TREE; 5447 } 5448 } 5449 5450 /* Warn when some struct elements are implicitly initialized to zero. */ 5451 if (warn_missing_field_initializers 5452 && constructor_type 5453 && TREE_CODE (constructor_type) == RECORD_TYPE 5454 && constructor_unfilled_fields) 5455 { 5456 /* Do not warn for flexible array members or zero-length arrays. */ 5457 while (constructor_unfilled_fields 5458 && (!DECL_SIZE (constructor_unfilled_fields) 5459 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 5460 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5461 5462 /* Do not warn if this level of the initializer uses member 5463 designators; it is likely to be deliberate. */ 5464 if (constructor_unfilled_fields && !constructor_designated) 5465 { 5466 push_member_name (constructor_unfilled_fields); 5467 warning_init ("missing initializer"); 5468 RESTORE_SPELLING_DEPTH (constructor_depth); 5469 } 5470 } 5471 5472 /* Pad out the end of the structure. */ 5473 if (p->replacement_value.value) 5474 /* If this closes a superfluous brace pair, 5475 just pass out the element between them. */ 5476 ret = p->replacement_value; 5477 else if (constructor_type == 0) 5478 ; 5479 else if (TREE_CODE (constructor_type) != RECORD_TYPE 5480 && TREE_CODE (constructor_type) != UNION_TYPE 5481 && TREE_CODE (constructor_type) != ARRAY_TYPE 5482 && TREE_CODE (constructor_type) != VECTOR_TYPE) 5483 { 5484 /* A nonincremental scalar initializer--just return 5485 the element, after verifying there is just one. */ 5486 if (VEC_empty (constructor_elt,constructor_elements)) 5487 { 5488 if (!constructor_erroneous) 5489 error_init ("empty scalar initializer"); 5490 ret.value = error_mark_node; 5491 } 5492 else if (VEC_length (constructor_elt,constructor_elements) != 1) 5493 { 5494 error_init ("extra elements in scalar initializer"); 5495 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5496 } 5497 else 5498 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value; 5499 } 5500 else 5501 { 5502 if (constructor_erroneous) 5503 ret.value = error_mark_node; 5504 else 5505 { 5506 ret.value = build_constructor (constructor_type, 5507 constructor_elements); 5508 if (constructor_constant) 5509 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1; 5510 if (constructor_constant && constructor_simple) 5511 TREE_STATIC (ret.value) = 1; 5512 } 5513 } 5514 5515 constructor_type = p->type; 5516 constructor_fields = p->fields; 5517 constructor_index = p->index; 5518 constructor_max_index = p->max_index; 5519 constructor_unfilled_index = p->unfilled_index; 5520 constructor_unfilled_fields = p->unfilled_fields; 5521 constructor_bit_index = p->bit_index; 5522 constructor_elements = p->elements; 5523 constructor_constant = p->constant; 5524 constructor_simple = p->simple; 5525 constructor_erroneous = p->erroneous; 5526 constructor_incremental = p->incremental; 5527 constructor_designated = p->designated; 5528 constructor_pending_elts = p->pending_elts; 5529 constructor_depth = p->depth; 5530 if (!p->implicit) 5531 constructor_range_stack = p->range_stack; 5532 RESTORE_SPELLING_DEPTH (constructor_depth); 5533 5534 constructor_stack = p->next; 5535 free (p); 5536 5537 if (ret.value == 0 && constructor_stack == 0) 5538 ret.value = error_mark_node; 5539 return ret; 5540} 5541 5542/* Common handling for both array range and field name designators. 5543 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 5544 5545static int 5546set_designator (int array) 5547{ 5548 tree subtype; 5549 enum tree_code subcode; 5550 5551 /* Don't die if an entire brace-pair level is superfluous 5552 in the containing level. */ 5553 if (constructor_type == 0) 5554 return 1; 5555 5556 /* If there were errors in this designator list already, bail out 5557 silently. */ 5558 if (designator_erroneous) 5559 return 1; 5560 5561 if (!designator_depth) 5562 { 5563 gcc_assert (!constructor_range_stack); 5564 5565 /* Designator list starts at the level of closest explicit 5566 braces. */ 5567 while (constructor_stack->implicit) 5568 process_init_element (pop_init_level (1)); 5569 constructor_designated = 1; 5570 return 0; 5571 } 5572 5573 switch (TREE_CODE (constructor_type)) 5574 { 5575 case RECORD_TYPE: 5576 case UNION_TYPE: 5577 subtype = TREE_TYPE (constructor_fields); 5578 if (subtype != error_mark_node) 5579 subtype = TYPE_MAIN_VARIANT (subtype); 5580 break; 5581 case ARRAY_TYPE: 5582 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5583 break; 5584 default: 5585 gcc_unreachable (); 5586 } 5587 5588 subcode = TREE_CODE (subtype); 5589 if (array && subcode != ARRAY_TYPE) 5590 { 5591 error_init ("array index in non-array initializer"); 5592 return 1; 5593 } 5594 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5595 { 5596 error_init ("field name not in record or union initializer"); 5597 return 1; 5598 } 5599 5600 constructor_designated = 1; 5601 push_init_level (2); 5602 return 0; 5603} 5604 5605/* If there are range designators in designator list, push a new designator 5606 to constructor_range_stack. RANGE_END is end of such stack range or 5607 NULL_TREE if there is no range designator at this level. */ 5608 5609static void 5610push_range_stack (tree range_end) 5611{ 5612 struct constructor_range_stack *p; 5613 5614 p = GGC_NEW (struct constructor_range_stack); 5615 p->prev = constructor_range_stack; 5616 p->next = 0; 5617 p->fields = constructor_fields; 5618 p->range_start = constructor_index; 5619 p->index = constructor_index; 5620 p->stack = constructor_stack; 5621 p->range_end = range_end; 5622 if (constructor_range_stack) 5623 constructor_range_stack->next = p; 5624 constructor_range_stack = p; 5625} 5626 5627/* Within an array initializer, specify the next index to be initialized. 5628 FIRST is that index. If LAST is nonzero, then initialize a range 5629 of indices, running from FIRST through LAST. */ 5630 5631void 5632set_init_index (tree first, tree last) 5633{ 5634 if (set_designator (1)) 5635 return; 5636 5637 designator_erroneous = 1; 5638 5639 if (!INTEGRAL_TYPE_P (TREE_TYPE (first)) 5640 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last)))) 5641 { 5642 error_init ("array index in initializer not of integer type"); 5643 return; 5644 } 5645 5646 if (TREE_CODE (first) != INTEGER_CST) 5647 error_init ("nonconstant array index in initializer"); 5648 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5649 error_init ("nonconstant array index in initializer"); 5650 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5651 error_init ("array index in non-array initializer"); 5652 else if (tree_int_cst_sgn (first) == -1) 5653 error_init ("array index in initializer exceeds array bounds"); 5654 else if (constructor_max_index 5655 && tree_int_cst_lt (constructor_max_index, first)) 5656 error_init ("array index in initializer exceeds array bounds"); 5657 else 5658 { 5659 constructor_index = convert (bitsizetype, first); 5660 5661 if (last) 5662 { 5663 if (tree_int_cst_equal (first, last)) 5664 last = 0; 5665 else if (tree_int_cst_lt (last, first)) 5666 { 5667 error_init ("empty index range in initializer"); 5668 last = 0; 5669 } 5670 else 5671 { 5672 last = convert (bitsizetype, last); 5673 if (constructor_max_index != 0 5674 && tree_int_cst_lt (constructor_max_index, last)) 5675 { 5676 error_init ("array index range in initializer exceeds array bounds"); 5677 last = 0; 5678 } 5679 } 5680 } 5681 5682 designator_depth++; 5683 designator_erroneous = 0; 5684 if (constructor_range_stack || last) 5685 push_range_stack (last); 5686 } 5687} 5688 5689/* Within a struct initializer, specify the next field to be initialized. */ 5690 5691void 5692set_init_label (tree fieldname) 5693{ 5694 tree tail; 5695 5696 if (set_designator (0)) 5697 return; 5698 5699 designator_erroneous = 1; 5700 5701 if (TREE_CODE (constructor_type) != RECORD_TYPE 5702 && TREE_CODE (constructor_type) != UNION_TYPE) 5703 { 5704 error_init ("field name not in record or union initializer"); 5705 return; 5706 } 5707 5708 for (tail = TYPE_FIELDS (constructor_type); tail; 5709 tail = TREE_CHAIN (tail)) 5710 { 5711 if (DECL_NAME (tail) == fieldname) 5712 break; 5713 } 5714 5715 if (tail == 0) 5716 error ("unknown field %qE specified in initializer", fieldname); 5717 else 5718 { 5719 constructor_fields = tail; 5720 designator_depth++; 5721 designator_erroneous = 0; 5722 if (constructor_range_stack) 5723 push_range_stack (NULL_TREE); 5724 } 5725} 5726 5727/* Add a new initializer to the tree of pending initializers. PURPOSE 5728 identifies the initializer, either array index or field in a structure. 5729 VALUE is the value of that index or field. */ 5730 5731static void 5732add_pending_init (tree purpose, tree value) 5733{ 5734 struct init_node *p, **q, *r; 5735 5736 q = &constructor_pending_elts; 5737 p = 0; 5738 5739 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5740 { 5741 while (*q != 0) 5742 { 5743 p = *q; 5744 if (tree_int_cst_lt (purpose, p->purpose)) 5745 q = &p->left; 5746 else if (tree_int_cst_lt (p->purpose, purpose)) 5747 q = &p->right; 5748 else 5749 { 5750 if (TREE_SIDE_EFFECTS (p->value)) 5751 warning_init ("initialized field with side-effects overwritten"); 5752 else if (warn_override_init) 5753 warning_init ("initialized field overwritten"); 5754 p->value = value; 5755 return; 5756 } 5757 } 5758 } 5759 else 5760 { 5761 tree bitpos; 5762 5763 bitpos = bit_position (purpose); 5764 while (*q != NULL) 5765 { 5766 p = *q; 5767 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5768 q = &p->left; 5769 else if (p->purpose != purpose) 5770 q = &p->right; 5771 else 5772 { 5773 if (TREE_SIDE_EFFECTS (p->value)) 5774 warning_init ("initialized field with side-effects overwritten"); 5775 else if (warn_override_init) 5776 warning_init ("initialized field overwritten"); 5777 p->value = value; 5778 return; 5779 } 5780 } 5781 } 5782 5783 r = GGC_NEW (struct init_node); 5784 r->purpose = purpose; 5785 r->value = value; 5786 5787 *q = r; 5788 r->parent = p; 5789 r->left = 0; 5790 r->right = 0; 5791 r->balance = 0; 5792 5793 while (p) 5794 { 5795 struct init_node *s; 5796 5797 if (r == p->left) 5798 { 5799 if (p->balance == 0) 5800 p->balance = -1; 5801 else if (p->balance < 0) 5802 { 5803 if (r->balance < 0) 5804 { 5805 /* L rotation. */ 5806 p->left = r->right; 5807 if (p->left) 5808 p->left->parent = p; 5809 r->right = p; 5810 5811 p->balance = 0; 5812 r->balance = 0; 5813 5814 s = p->parent; 5815 p->parent = r; 5816 r->parent = s; 5817 if (s) 5818 { 5819 if (s->left == p) 5820 s->left = r; 5821 else 5822 s->right = r; 5823 } 5824 else 5825 constructor_pending_elts = r; 5826 } 5827 else 5828 { 5829 /* LR rotation. */ 5830 struct init_node *t = r->right; 5831 5832 r->right = t->left; 5833 if (r->right) 5834 r->right->parent = r; 5835 t->left = r; 5836 5837 p->left = t->right; 5838 if (p->left) 5839 p->left->parent = p; 5840 t->right = p; 5841 5842 p->balance = t->balance < 0; 5843 r->balance = -(t->balance > 0); 5844 t->balance = 0; 5845 5846 s = p->parent; 5847 p->parent = t; 5848 r->parent = t; 5849 t->parent = s; 5850 if (s) 5851 { 5852 if (s->left == p) 5853 s->left = t; 5854 else 5855 s->right = t; 5856 } 5857 else 5858 constructor_pending_elts = t; 5859 } 5860 break; 5861 } 5862 else 5863 { 5864 /* p->balance == +1; growth of left side balances the node. */ 5865 p->balance = 0; 5866 break; 5867 } 5868 } 5869 else /* r == p->right */ 5870 { 5871 if (p->balance == 0) 5872 /* Growth propagation from right side. */ 5873 p->balance++; 5874 else if (p->balance > 0) 5875 { 5876 if (r->balance > 0) 5877 { 5878 /* R rotation. */ 5879 p->right = r->left; 5880 if (p->right) 5881 p->right->parent = p; 5882 r->left = p; 5883 5884 p->balance = 0; 5885 r->balance = 0; 5886 5887 s = p->parent; 5888 p->parent = r; 5889 r->parent = s; 5890 if (s) 5891 { 5892 if (s->left == p) 5893 s->left = r; 5894 else 5895 s->right = r; 5896 } 5897 else 5898 constructor_pending_elts = r; 5899 } 5900 else /* r->balance == -1 */ 5901 { 5902 /* RL rotation */ 5903 struct init_node *t = r->left; 5904 5905 r->left = t->right; 5906 if (r->left) 5907 r->left->parent = r; 5908 t->right = r; 5909 5910 p->right = t->left; 5911 if (p->right) 5912 p->right->parent = p; 5913 t->left = p; 5914 5915 r->balance = (t->balance < 0); 5916 p->balance = -(t->balance > 0); 5917 t->balance = 0; 5918 5919 s = p->parent; 5920 p->parent = t; 5921 r->parent = t; 5922 t->parent = s; 5923 if (s) 5924 { 5925 if (s->left == p) 5926 s->left = t; 5927 else 5928 s->right = t; 5929 } 5930 else 5931 constructor_pending_elts = t; 5932 } 5933 break; 5934 } 5935 else 5936 { 5937 /* p->balance == -1; growth of right side balances the node. */ 5938 p->balance = 0; 5939 break; 5940 } 5941 } 5942 5943 r = p; 5944 p = p->parent; 5945 } 5946} 5947 5948/* Build AVL tree from a sorted chain. */ 5949 5950static void 5951set_nonincremental_init (void) 5952{ 5953 unsigned HOST_WIDE_INT ix; 5954 tree index, value; 5955 5956 if (TREE_CODE (constructor_type) != RECORD_TYPE 5957 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5958 return; 5959 5960 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value) 5961 add_pending_init (index, value); 5962 constructor_elements = 0; 5963 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5964 { 5965 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5966 /* Skip any nameless bit fields at the beginning. */ 5967 while (constructor_unfilled_fields != 0 5968 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5969 && DECL_NAME (constructor_unfilled_fields) == 0) 5970 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5971 5972 } 5973 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5974 { 5975 if (TYPE_DOMAIN (constructor_type)) 5976 constructor_unfilled_index 5977 = convert (bitsizetype, 5978 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5979 else 5980 constructor_unfilled_index = bitsize_zero_node; 5981 } 5982 constructor_incremental = 0; 5983} 5984 5985/* Build AVL tree from a string constant. */ 5986 5987static void 5988set_nonincremental_init_from_string (tree str) 5989{ 5990 tree value, purpose, type; 5991 HOST_WIDE_INT val[2]; 5992 const char *p, *end; 5993 int byte, wchar_bytes, charwidth, bitpos; 5994 5995 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE); 5996 5997 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5998 == TYPE_PRECISION (char_type_node)) 5999 wchar_bytes = 1; 6000 else 6001 { 6002 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 6003 == TYPE_PRECISION (wchar_type_node)); 6004 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 6005 } 6006 charwidth = TYPE_PRECISION (char_type_node); 6007 type = TREE_TYPE (constructor_type); 6008 p = TREE_STRING_POINTER (str); 6009 end = p + TREE_STRING_LENGTH (str); 6010 6011 for (purpose = bitsize_zero_node; 6012 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 6013 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 6014 { 6015 if (wchar_bytes == 1) 6016 { 6017 val[1] = (unsigned char) *p++; 6018 val[0] = 0; 6019 } 6020 else 6021 { 6022 val[0] = 0; 6023 val[1] = 0; 6024 for (byte = 0; byte < wchar_bytes; byte++) 6025 { 6026 if (BYTES_BIG_ENDIAN) 6027 bitpos = (wchar_bytes - byte - 1) * charwidth; 6028 else 6029 bitpos = byte * charwidth; 6030 val[bitpos < HOST_BITS_PER_WIDE_INT] 6031 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 6032 << (bitpos % HOST_BITS_PER_WIDE_INT); 6033 } 6034 } 6035 6036 if (!TYPE_UNSIGNED (type)) 6037 { 6038 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 6039 if (bitpos < HOST_BITS_PER_WIDE_INT) 6040 { 6041 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 6042 { 6043 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 6044 val[0] = -1; 6045 } 6046 } 6047 else if (bitpos == HOST_BITS_PER_WIDE_INT) 6048 { 6049 if (val[1] < 0) 6050 val[0] = -1; 6051 } 6052 else if (val[0] & (((HOST_WIDE_INT) 1) 6053 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 6054 val[0] |= ((HOST_WIDE_INT) -1) 6055 << (bitpos - HOST_BITS_PER_WIDE_INT); 6056 } 6057 6058 value = build_int_cst_wide (type, val[1], val[0]); 6059 add_pending_init (purpose, value); 6060 } 6061 6062 constructor_incremental = 0; 6063} 6064 6065/* Return value of FIELD in pending initializer or zero if the field was 6066 not initialized yet. */ 6067 6068static tree 6069find_init_member (tree field) 6070{ 6071 struct init_node *p; 6072 6073 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6074 { 6075 if (constructor_incremental 6076 && tree_int_cst_lt (field, constructor_unfilled_index)) 6077 set_nonincremental_init (); 6078 6079 p = constructor_pending_elts; 6080 while (p) 6081 { 6082 if (tree_int_cst_lt (field, p->purpose)) 6083 p = p->left; 6084 else if (tree_int_cst_lt (p->purpose, field)) 6085 p = p->right; 6086 else 6087 return p->value; 6088 } 6089 } 6090 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6091 { 6092 tree bitpos = bit_position (field); 6093 6094 if (constructor_incremental 6095 && (!constructor_unfilled_fields 6096 || tree_int_cst_lt (bitpos, 6097 bit_position (constructor_unfilled_fields)))) 6098 set_nonincremental_init (); 6099 6100 p = constructor_pending_elts; 6101 while (p) 6102 { 6103 if (field == p->purpose) 6104 return p->value; 6105 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 6106 p = p->left; 6107 else 6108 p = p->right; 6109 } 6110 } 6111 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6112 { 6113 if (!VEC_empty (constructor_elt, constructor_elements) 6114 && (VEC_last (constructor_elt, constructor_elements)->index 6115 == field)) 6116 return VEC_last (constructor_elt, constructor_elements)->value; 6117 } 6118 return 0; 6119} 6120 6121/* "Output" the next constructor element. 6122 At top level, really output it to assembler code now. 6123 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 6124 TYPE is the data type that the containing data type wants here. 6125 FIELD is the field (a FIELD_DECL) or the index that this element fills. 6126 If VALUE is a string constant, STRICT_STRING is true if it is 6127 unparenthesized or we should not warn here for it being parenthesized. 6128 For other types of VALUE, STRICT_STRING is not used. 6129 6130 PENDING if non-nil means output pending elements that belong 6131 right after this element. (PENDING is normally 1; 6132 it is 0 while outputting pending elements, to avoid recursion.) */ 6133 6134static void 6135output_init_element (tree value, bool strict_string, tree type, tree field, 6136 int pending) 6137{ 6138 constructor_elt *celt; 6139 6140 if (type == error_mark_node || value == error_mark_node) 6141 { 6142 constructor_erroneous = 1; 6143 return; 6144 } 6145 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 6146 && (TREE_CODE (value) == STRING_CST 6147 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR) 6148 && !(TREE_CODE (value) == STRING_CST 6149 && TREE_CODE (type) == ARRAY_TYPE 6150 && INTEGRAL_TYPE_P (TREE_TYPE (type))) 6151 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 6152 TYPE_MAIN_VARIANT (type))) 6153 value = array_to_pointer_conversion (value); 6154 6155 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 6156 && require_constant_value && !flag_isoc99 && pending) 6157 { 6158 /* As an extension, allow initializing objects with static storage 6159 duration with compound literals (which are then treated just as 6160 the brace enclosed list they contain). */ 6161 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 6162 value = DECL_INITIAL (decl); 6163 } 6164 6165 if (value == error_mark_node) 6166 constructor_erroneous = 1; 6167 else if (!TREE_CONSTANT (value)) 6168 constructor_constant = 0; 6169 else if (!initializer_constant_valid_p (value, TREE_TYPE (value)) 6170 || ((TREE_CODE (constructor_type) == RECORD_TYPE 6171 || TREE_CODE (constructor_type) == UNION_TYPE) 6172 && DECL_C_BIT_FIELD (field) 6173 && TREE_CODE (value) != INTEGER_CST)) 6174 constructor_simple = 0; 6175 6176 if (!initializer_constant_valid_p (value, TREE_TYPE (value))) 6177 { 6178 if (require_constant_value) 6179 { 6180 error_init ("initializer element is not constant"); 6181 value = error_mark_node; 6182 } 6183 else if (require_constant_elements) 6184 pedwarn ("initializer element is not computable at load time"); 6185 } 6186 6187 /* If this field is empty (and not at the end of structure), 6188 don't do anything other than checking the initializer. */ 6189 if (field 6190 && (TREE_TYPE (field) == error_mark_node 6191 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 6192 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 6193 && (TREE_CODE (constructor_type) == ARRAY_TYPE 6194 || TREE_CHAIN (field))))) 6195 return; 6196 6197 value = digest_init (type, value, strict_string, require_constant_value); 6198 if (value == error_mark_node) 6199 { 6200 constructor_erroneous = 1; 6201 return; 6202 } 6203 6204 /* If this element doesn't come next in sequence, 6205 put it on constructor_pending_elts. */ 6206 if (TREE_CODE (constructor_type) == ARRAY_TYPE 6207 && (!constructor_incremental 6208 || !tree_int_cst_equal (field, constructor_unfilled_index))) 6209 { 6210 if (constructor_incremental 6211 && tree_int_cst_lt (field, constructor_unfilled_index)) 6212 set_nonincremental_init (); 6213 6214 add_pending_init (field, value); 6215 return; 6216 } 6217 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6218 && (!constructor_incremental 6219 || field != constructor_unfilled_fields)) 6220 { 6221 /* We do this for records but not for unions. In a union, 6222 no matter which field is specified, it can be initialized 6223 right away since it starts at the beginning of the union. */ 6224 if (constructor_incremental) 6225 { 6226 if (!constructor_unfilled_fields) 6227 set_nonincremental_init (); 6228 else 6229 { 6230 tree bitpos, unfillpos; 6231 6232 bitpos = bit_position (field); 6233 unfillpos = bit_position (constructor_unfilled_fields); 6234 6235 if (tree_int_cst_lt (bitpos, unfillpos)) 6236 set_nonincremental_init (); 6237 } 6238 } 6239 6240 add_pending_init (field, value); 6241 return; 6242 } 6243 else if (TREE_CODE (constructor_type) == UNION_TYPE 6244 && !VEC_empty (constructor_elt, constructor_elements)) 6245 { 6246 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt, 6247 constructor_elements)->value)) 6248 warning_init ("initialized field with side-effects overwritten"); 6249 else if (warn_override_init) 6250 warning_init ("initialized field overwritten"); 6251 6252 /* We can have just one union field set. */ 6253 constructor_elements = 0; 6254 } 6255 6256 /* Otherwise, output this element either to 6257 constructor_elements or to the assembler file. */ 6258 6259 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL); 6260 celt->index = field; 6261 celt->value = value; 6262 6263 /* Advance the variable that indicates sequential elements output. */ 6264 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6265 constructor_unfilled_index 6266 = size_binop (PLUS_EXPR, constructor_unfilled_index, 6267 bitsize_one_node); 6268 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 6269 { 6270 constructor_unfilled_fields 6271 = TREE_CHAIN (constructor_unfilled_fields); 6272 6273 /* Skip any nameless bit fields. */ 6274 while (constructor_unfilled_fields != 0 6275 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6276 && DECL_NAME (constructor_unfilled_fields) == 0) 6277 constructor_unfilled_fields = 6278 TREE_CHAIN (constructor_unfilled_fields); 6279 } 6280 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6281 constructor_unfilled_fields = 0; 6282 6283 /* Now output any pending elements which have become next. */ 6284 if (pending) 6285 output_pending_init_elements (0); 6286} 6287 6288/* Output any pending elements which have become next. 6289 As we output elements, constructor_unfilled_{fields,index} 6290 advances, which may cause other elements to become next; 6291 if so, they too are output. 6292 6293 If ALL is 0, we return when there are 6294 no more pending elements to output now. 6295 6296 If ALL is 1, we output space as necessary so that 6297 we can output all the pending elements. */ 6298 6299static void 6300output_pending_init_elements (int all) 6301{ 6302 struct init_node *elt = constructor_pending_elts; 6303 tree next; 6304 6305 retry: 6306 6307 /* Look through the whole pending tree. 6308 If we find an element that should be output now, 6309 output it. Otherwise, set NEXT to the element 6310 that comes first among those still pending. */ 6311 6312 next = 0; 6313 while (elt) 6314 { 6315 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6316 { 6317 if (tree_int_cst_equal (elt->purpose, 6318 constructor_unfilled_index)) 6319 output_init_element (elt->value, true, 6320 TREE_TYPE (constructor_type), 6321 constructor_unfilled_index, 0); 6322 else if (tree_int_cst_lt (constructor_unfilled_index, 6323 elt->purpose)) 6324 { 6325 /* Advance to the next smaller node. */ 6326 if (elt->left) 6327 elt = elt->left; 6328 else 6329 { 6330 /* We have reached the smallest node bigger than the 6331 current unfilled index. Fill the space first. */ 6332 next = elt->purpose; 6333 break; 6334 } 6335 } 6336 else 6337 { 6338 /* Advance to the next bigger node. */ 6339 if (elt->right) 6340 elt = elt->right; 6341 else 6342 { 6343 /* We have reached the biggest node in a subtree. Find 6344 the parent of it, which is the next bigger node. */ 6345 while (elt->parent && elt->parent->right == elt) 6346 elt = elt->parent; 6347 elt = elt->parent; 6348 if (elt && tree_int_cst_lt (constructor_unfilled_index, 6349 elt->purpose)) 6350 { 6351 next = elt->purpose; 6352 break; 6353 } 6354 } 6355 } 6356 } 6357 else if (TREE_CODE (constructor_type) == RECORD_TYPE 6358 || TREE_CODE (constructor_type) == UNION_TYPE) 6359 { 6360 tree ctor_unfilled_bitpos, elt_bitpos; 6361 6362 /* If the current record is complete we are done. */ 6363 if (constructor_unfilled_fields == 0) 6364 break; 6365 6366 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 6367 elt_bitpos = bit_position (elt->purpose); 6368 /* We can't compare fields here because there might be empty 6369 fields in between. */ 6370 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 6371 { 6372 constructor_unfilled_fields = elt->purpose; 6373 output_init_element (elt->value, true, TREE_TYPE (elt->purpose), 6374 elt->purpose, 0); 6375 } 6376 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 6377 { 6378 /* Advance to the next smaller node. */ 6379 if (elt->left) 6380 elt = elt->left; 6381 else 6382 { 6383 /* We have reached the smallest node bigger than the 6384 current unfilled field. Fill the space first. */ 6385 next = elt->purpose; 6386 break; 6387 } 6388 } 6389 else 6390 { 6391 /* Advance to the next bigger node. */ 6392 if (elt->right) 6393 elt = elt->right; 6394 else 6395 { 6396 /* We have reached the biggest node in a subtree. Find 6397 the parent of it, which is the next bigger node. */ 6398 while (elt->parent && elt->parent->right == elt) 6399 elt = elt->parent; 6400 elt = elt->parent; 6401 if (elt 6402 && (tree_int_cst_lt (ctor_unfilled_bitpos, 6403 bit_position (elt->purpose)))) 6404 { 6405 next = elt->purpose; 6406 break; 6407 } 6408 } 6409 } 6410 } 6411 } 6412 6413 /* Ordinarily return, but not if we want to output all 6414 and there are elements left. */ 6415 if (!(all && next != 0)) 6416 return; 6417 6418 /* If it's not incremental, just skip over the gap, so that after 6419 jumping to retry we will output the next successive element. */ 6420 if (TREE_CODE (constructor_type) == RECORD_TYPE 6421 || TREE_CODE (constructor_type) == UNION_TYPE) 6422 constructor_unfilled_fields = next; 6423 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6424 constructor_unfilled_index = next; 6425 6426 /* ELT now points to the node in the pending tree with the next 6427 initializer to output. */ 6428 goto retry; 6429} 6430 6431/* Add one non-braced element to the current constructor level. 6432 This adjusts the current position within the constructor's type. 6433 This may also start or terminate implicit levels 6434 to handle a partly-braced initializer. 6435 6436 Once this has found the correct level for the new element, 6437 it calls output_init_element. */ 6438 6439void 6440process_init_element (struct c_expr value) 6441{ 6442 tree orig_value = value.value; 6443 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST; 6444 bool strict_string = value.original_code == STRING_CST; 6445 6446 designator_depth = 0; 6447 designator_erroneous = 0; 6448 6449 /* Handle superfluous braces around string cst as in 6450 char x[] = {"foo"}; */ 6451 if (string_flag 6452 && constructor_type 6453 && TREE_CODE (constructor_type) == ARRAY_TYPE 6454 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type)) 6455 && integer_zerop (constructor_unfilled_index)) 6456 { 6457 if (constructor_stack->replacement_value.value) 6458 error_init ("excess elements in char array initializer"); 6459 constructor_stack->replacement_value = value; 6460 return; 6461 } 6462 6463 if (constructor_stack->replacement_value.value != 0) 6464 { 6465 error_init ("excess elements in struct initializer"); 6466 return; 6467 } 6468 6469 /* Ignore elements of a brace group if it is entirely superfluous 6470 and has already been diagnosed. */ 6471 if (constructor_type == 0) 6472 return; 6473 6474 /* If we've exhausted any levels that didn't have braces, 6475 pop them now. */ 6476 while (constructor_stack->implicit) 6477 { 6478 if ((TREE_CODE (constructor_type) == RECORD_TYPE 6479 || TREE_CODE (constructor_type) == UNION_TYPE) 6480 && constructor_fields == 0) 6481 process_init_element (pop_init_level (1)); 6482 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 6483 && (constructor_max_index == 0 6484 || tree_int_cst_lt (constructor_max_index, 6485 constructor_index))) 6486 process_init_element (pop_init_level (1)); 6487 else 6488 break; 6489 } 6490 6491 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 6492 if (constructor_range_stack) 6493 { 6494 /* If value is a compound literal and we'll be just using its 6495 content, don't put it into a SAVE_EXPR. */ 6496 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR 6497 || !require_constant_value 6498 || flag_isoc99) 6499 value.value = save_expr (value.value); 6500 } 6501 6502 while (1) 6503 { 6504 if (TREE_CODE (constructor_type) == RECORD_TYPE) 6505 { 6506 tree fieldtype; 6507 enum tree_code fieldcode; 6508 6509 if (constructor_fields == 0) 6510 { 6511 pedwarn_init ("excess elements in struct initializer"); 6512 break; 6513 } 6514 6515 fieldtype = TREE_TYPE (constructor_fields); 6516 if (fieldtype != error_mark_node) 6517 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6518 fieldcode = TREE_CODE (fieldtype); 6519 6520 /* Error for non-static initialization of a flexible array member. */ 6521 if (fieldcode == ARRAY_TYPE 6522 && !require_constant_value 6523 && TYPE_SIZE (fieldtype) == NULL_TREE 6524 && TREE_CHAIN (constructor_fields) == NULL_TREE) 6525 { 6526 error_init ("non-static initialization of a flexible array member"); 6527 break; 6528 } 6529 6530 /* Accept a string constant to initialize a subarray. */ 6531 if (value.value != 0 6532 && fieldcode == ARRAY_TYPE 6533 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6534 && string_flag) 6535 value.value = orig_value; 6536 /* Otherwise, if we have come to a subaggregate, 6537 and we don't have an element of its type, push into it. */ 6538 else if (value.value != 0 6539 && value.value != error_mark_node 6540 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6541 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6542 || fieldcode == UNION_TYPE)) 6543 { 6544 push_init_level (1); 6545 continue; 6546 } 6547 6548 if (value.value) 6549 { 6550 push_member_name (constructor_fields); 6551 output_init_element (value.value, strict_string, 6552 fieldtype, constructor_fields, 1); 6553 RESTORE_SPELLING_DEPTH (constructor_depth); 6554 } 6555 else 6556 /* Do the bookkeeping for an element that was 6557 directly output as a constructor. */ 6558 { 6559 /* For a record, keep track of end position of last field. */ 6560 if (DECL_SIZE (constructor_fields)) 6561 constructor_bit_index 6562 = size_binop (PLUS_EXPR, 6563 bit_position (constructor_fields), 6564 DECL_SIZE (constructor_fields)); 6565 6566 /* If the current field was the first one not yet written out, 6567 it isn't now, so update. */ 6568 if (constructor_unfilled_fields == constructor_fields) 6569 { 6570 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6571 /* Skip any nameless bit fields. */ 6572 while (constructor_unfilled_fields != 0 6573 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6574 && DECL_NAME (constructor_unfilled_fields) == 0) 6575 constructor_unfilled_fields = 6576 TREE_CHAIN (constructor_unfilled_fields); 6577 } 6578 } 6579 6580 constructor_fields = TREE_CHAIN (constructor_fields); 6581 /* Skip any nameless bit fields at the beginning. */ 6582 while (constructor_fields != 0 6583 && DECL_C_BIT_FIELD (constructor_fields) 6584 && DECL_NAME (constructor_fields) == 0) 6585 constructor_fields = TREE_CHAIN (constructor_fields); 6586 } 6587 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6588 { 6589 tree fieldtype; 6590 enum tree_code fieldcode; 6591 6592 if (constructor_fields == 0) 6593 { 6594 pedwarn_init ("excess elements in union initializer"); 6595 break; 6596 } 6597 6598 fieldtype = TREE_TYPE (constructor_fields); 6599 if (fieldtype != error_mark_node) 6600 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6601 fieldcode = TREE_CODE (fieldtype); 6602 6603 /* Warn that traditional C rejects initialization of unions. 6604 We skip the warning if the value is zero. This is done 6605 under the assumption that the zero initializer in user 6606 code appears conditioned on e.g. __STDC__ to avoid 6607 "missing initializer" warnings and relies on default 6608 initialization to zero in the traditional C case. 6609 We also skip the warning if the initializer is designated, 6610 again on the assumption that this must be conditional on 6611 __STDC__ anyway (and we've already complained about the 6612 member-designator already). */ 6613 if (!in_system_header && !constructor_designated 6614 && !(value.value && (integer_zerop (value.value) 6615 || real_zerop (value.value)))) 6616 warning (OPT_Wtraditional, "traditional C rejects initialization " 6617 "of unions"); 6618 6619 /* Accept a string constant to initialize a subarray. */ 6620 if (value.value != 0 6621 && fieldcode == ARRAY_TYPE 6622 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) 6623 && string_flag) 6624 value.value = orig_value; 6625 /* Otherwise, if we have come to a subaggregate, 6626 and we don't have an element of its type, push into it. */ 6627 else if (value.value != 0 6628 && value.value != error_mark_node 6629 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype 6630 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6631 || fieldcode == UNION_TYPE)) 6632 { 6633 push_init_level (1); 6634 continue; 6635 } 6636 6637 if (value.value) 6638 { 6639 push_member_name (constructor_fields); 6640 output_init_element (value.value, strict_string, 6641 fieldtype, constructor_fields, 1); 6642 RESTORE_SPELLING_DEPTH (constructor_depth); 6643 } 6644 else 6645 /* Do the bookkeeping for an element that was 6646 directly output as a constructor. */ 6647 { 6648 constructor_bit_index = DECL_SIZE (constructor_fields); 6649 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6650 } 6651 6652 constructor_fields = 0; 6653 } 6654 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6655 { 6656 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6657 enum tree_code eltcode = TREE_CODE (elttype); 6658 6659 /* Accept a string constant to initialize a subarray. */ 6660 if (value.value != 0 6661 && eltcode == ARRAY_TYPE 6662 && INTEGRAL_TYPE_P (TREE_TYPE (elttype)) 6663 && string_flag) 6664 value.value = orig_value; 6665 /* Otherwise, if we have come to a subaggregate, 6666 and we don't have an element of its type, push into it. */ 6667 else if (value.value != 0 6668 && value.value != error_mark_node 6669 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype 6670 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6671 || eltcode == UNION_TYPE)) 6672 { 6673 push_init_level (1); 6674 continue; 6675 } 6676 6677 if (constructor_max_index != 0 6678 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6679 || integer_all_onesp (constructor_max_index))) 6680 { 6681 pedwarn_init ("excess elements in array initializer"); 6682 break; 6683 } 6684 6685 /* Now output the actual element. */ 6686 if (value.value) 6687 { 6688 push_array_bounds (tree_low_cst (constructor_index, 1)); 6689 output_init_element (value.value, strict_string, 6690 elttype, constructor_index, 1); 6691 RESTORE_SPELLING_DEPTH (constructor_depth); 6692 } 6693 6694 constructor_index 6695 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6696 6697 if (!value.value) 6698 /* If we are doing the bookkeeping for an element that was 6699 directly output as a constructor, we must update 6700 constructor_unfilled_index. */ 6701 constructor_unfilled_index = constructor_index; 6702 } 6703 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6704 { 6705 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6706 6707 /* Do a basic check of initializer size. Note that vectors 6708 always have a fixed size derived from their type. */ 6709 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6710 { 6711 pedwarn_init ("excess elements in vector initializer"); 6712 break; 6713 } 6714 6715 /* Now output the actual element. */ 6716 if (value.value) 6717 output_init_element (value.value, strict_string, 6718 elttype, constructor_index, 1); 6719 6720 constructor_index 6721 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6722 6723 if (!value.value) 6724 /* If we are doing the bookkeeping for an element that was 6725 directly output as a constructor, we must update 6726 constructor_unfilled_index. */ 6727 constructor_unfilled_index = constructor_index; 6728 } 6729 6730 /* Handle the sole element allowed in a braced initializer 6731 for a scalar variable. */ 6732 else if (constructor_type != error_mark_node 6733 && constructor_fields == 0) 6734 { 6735 pedwarn_init ("excess elements in scalar initializer"); 6736 break; 6737 } 6738 else 6739 { 6740 if (value.value) 6741 output_init_element (value.value, strict_string, 6742 constructor_type, NULL_TREE, 1); 6743 constructor_fields = 0; 6744 } 6745 6746 /* Handle range initializers either at this level or anywhere higher 6747 in the designator stack. */ 6748 if (constructor_range_stack) 6749 { 6750 struct constructor_range_stack *p, *range_stack; 6751 int finish = 0; 6752 6753 range_stack = constructor_range_stack; 6754 constructor_range_stack = 0; 6755 while (constructor_stack != range_stack->stack) 6756 { 6757 gcc_assert (constructor_stack->implicit); 6758 process_init_element (pop_init_level (1)); 6759 } 6760 for (p = range_stack; 6761 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6762 p = p->prev) 6763 { 6764 gcc_assert (constructor_stack->implicit); 6765 process_init_element (pop_init_level (1)); 6766 } 6767 6768 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6769 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6770 finish = 1; 6771 6772 while (1) 6773 { 6774 constructor_index = p->index; 6775 constructor_fields = p->fields; 6776 if (finish && p->range_end && p->index == p->range_start) 6777 { 6778 finish = 0; 6779 p->prev = 0; 6780 } 6781 p = p->next; 6782 if (!p) 6783 break; 6784 push_init_level (2); 6785 p->stack = constructor_stack; 6786 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6787 p->index = p->range_start; 6788 } 6789 6790 if (!finish) 6791 constructor_range_stack = range_stack; 6792 continue; 6793 } 6794 6795 break; 6796 } 6797 6798 constructor_range_stack = 0; 6799} 6800 6801/* Build a complete asm-statement, whose components are a CV_QUALIFIER 6802 (guaranteed to be 'volatile' or null) and ARGS (represented using 6803 an ASM_EXPR node). */ 6804tree 6805build_asm_stmt (tree cv_qualifier, tree args) 6806{ 6807 if (!ASM_VOLATILE_P (args) && cv_qualifier) 6808 ASM_VOLATILE_P (args) = 1; 6809 return add_stmt (args); 6810} 6811 6812/* Build an asm-expr, whose components are a STRING, some OUTPUTS, 6813 some INPUTS, and some CLOBBERS. The latter three may be NULL. 6814 SIMPLE indicates whether there was anything at all after the 6815 string in the asm expression -- asm("blah") and asm("blah" : ) 6816 are subtly different. We use a ASM_EXPR node to represent this. */ 6817tree 6818build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers, 6819 bool simple) 6820{ 6821 tree tail; 6822 tree args; 6823 int i; 6824 const char *constraint; 6825 const char **oconstraints; 6826 bool allows_mem, allows_reg, is_inout; 6827 int ninputs, noutputs; 6828 6829 ninputs = list_length (inputs); 6830 noutputs = list_length (outputs); 6831 oconstraints = (const char **) alloca (noutputs * sizeof (const char *)); 6832 6833 string = resolve_asm_operand_names (string, outputs, inputs); 6834 6835 /* Remove output conversions that change the type but not the mode. */ 6836 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail)) 6837 { 6838 tree output = TREE_VALUE (tail); 6839 6840 /* ??? Really, this should not be here. Users should be using a 6841 proper lvalue, dammit. But there's a long history of using casts 6842 in the output operands. In cases like longlong.h, this becomes a 6843 primitive form of typechecking -- if the cast can be removed, then 6844 the output operand had a type of the proper width; otherwise we'll 6845 get an error. Gross, but ... */ 6846 STRIP_NOPS (output); 6847 6848 if (!lvalue_or_else (output, lv_asm)) 6849 output = error_mark_node; 6850 6851 if (output != error_mark_node 6852 && (TREE_READONLY (output) 6853 || TYPE_READONLY (TREE_TYPE (output)) 6854 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE 6855 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE) 6856 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output))))) 6857 readonly_error (output, lv_asm); 6858 6859 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6860 oconstraints[i] = constraint; 6861 6862 if (parse_output_constraint (&constraint, i, ninputs, noutputs, 6863 &allows_mem, &allows_reg, &is_inout)) 6864 { 6865 /* If the operand is going to end up in memory, 6866 mark it addressable. */ 6867 if (!allows_reg && !c_mark_addressable (output)) 6868 output = error_mark_node; 6869 } 6870 else 6871 output = error_mark_node; 6872 6873 TREE_VALUE (tail) = output; 6874 } 6875 6876 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail)) 6877 { 6878 tree input; 6879 6880 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); 6881 input = TREE_VALUE (tail); 6882 6883 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0, 6884 oconstraints, &allows_mem, &allows_reg)) 6885 { 6886 /* If the operand is going to end up in memory, 6887 mark it addressable. */ 6888 if (!allows_reg && allows_mem) 6889 { 6890 /* Strip the nops as we allow this case. FIXME, this really 6891 should be rejected or made deprecated. */ 6892 STRIP_NOPS (input); 6893 if (!c_mark_addressable (input)) 6894 input = error_mark_node; 6895 } 6896 } 6897 else 6898 input = error_mark_node; 6899 6900 TREE_VALUE (tail) = input; 6901 } 6902 6903 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers); 6904 6905 /* asm statements without outputs, including simple ones, are treated 6906 as volatile. */ 6907 ASM_INPUT_P (args) = simple; 6908 ASM_VOLATILE_P (args) = (noutputs == 0); 6909 6910 return args; 6911} 6912 6913/* Generate a goto statement to LABEL. */ 6914 6915tree 6916c_finish_goto_label (tree label) 6917{ 6918 tree decl = lookup_label (label); 6919 if (!decl) 6920 return NULL_TREE; 6921 6922 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl)) 6923 { 6924 error ("jump into statement expression"); 6925 return NULL_TREE; 6926 } 6927 6928 if (C_DECL_UNJUMPABLE_VM (decl)) 6929 { 6930 error ("jump into scope of identifier with variably modified type"); 6931 return NULL_TREE; 6932 } 6933 6934 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl)) 6935 { 6936 /* No jump from outside this statement expression context, so 6937 record that there is a jump from within this context. */ 6938 struct c_label_list *nlist; 6939 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6940 nlist->next = label_context_stack_se->labels_used; 6941 nlist->label = decl; 6942 label_context_stack_se->labels_used = nlist; 6943 } 6944 6945 if (!C_DECL_UNDEFINABLE_VM (decl)) 6946 { 6947 /* No jump from outside this context context of identifiers with 6948 variably modified type, so record that there is a jump from 6949 within this context. */ 6950 struct c_label_list *nlist; 6951 nlist = XOBNEW (&parser_obstack, struct c_label_list); 6952 nlist->next = label_context_stack_vm->labels_used; 6953 nlist->label = decl; 6954 label_context_stack_vm->labels_used = nlist; 6955 } 6956 6957 TREE_USED (decl) = 1; 6958 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl)); 6959} 6960 6961/* Generate a computed goto statement to EXPR. */ 6962 6963tree 6964c_finish_goto_ptr (tree expr) 6965{ 6966 if (pedantic) 6967 pedwarn ("ISO C forbids %<goto *expr;%>"); 6968 expr = convert (ptr_type_node, expr); 6969 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr)); 6970} 6971 6972/* Generate a C `return' statement. RETVAL is the expression for what 6973 to return, or a null pointer for `return;' with no value. */ 6974 6975tree 6976c_finish_return (tree retval) 6977{ 6978 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt; 6979 bool no_warning = false; 6980 6981 if (TREE_THIS_VOLATILE (current_function_decl)) 6982 warning (0, "function declared %<noreturn%> has a %<return%> statement"); 6983 6984 if (!retval) 6985 { 6986 current_function_returns_null = 1; 6987 if ((warn_return_type || flag_isoc99) 6988 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 6989 { 6990 pedwarn_c99 ("%<return%> with no value, in " 6991 "function returning non-void"); 6992 no_warning = true; 6993 } 6994 } 6995 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 6996 { 6997 current_function_returns_null = 1; 6998 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 6999 pedwarn ("%<return%> with a value, in function returning void"); 7000 } 7001 else 7002 { 7003 tree t = convert_for_assignment (valtype, retval, ic_return, 7004 NULL_TREE, NULL_TREE, 0); 7005 tree res = DECL_RESULT (current_function_decl); 7006 tree inner; 7007 7008 current_function_returns_value = 1; 7009 if (t == error_mark_node) 7010 return NULL_TREE; 7011 7012 inner = t = convert (TREE_TYPE (res), t); 7013 7014 /* Strip any conversions, additions, and subtractions, and see if 7015 we are returning the address of a local variable. Warn if so. */ 7016 while (1) 7017 { 7018 switch (TREE_CODE (inner)) 7019 { 7020 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 7021 case PLUS_EXPR: 7022 inner = TREE_OPERAND (inner, 0); 7023 continue; 7024 7025 case MINUS_EXPR: 7026 /* If the second operand of the MINUS_EXPR has a pointer 7027 type (or is converted from it), this may be valid, so 7028 don't give a warning. */ 7029 { 7030 tree op1 = TREE_OPERAND (inner, 1); 7031 7032 while (!POINTER_TYPE_P (TREE_TYPE (op1)) 7033 && (TREE_CODE (op1) == NOP_EXPR 7034 || TREE_CODE (op1) == NON_LVALUE_EXPR 7035 || TREE_CODE (op1) == CONVERT_EXPR)) 7036 op1 = TREE_OPERAND (op1, 0); 7037 7038 if (POINTER_TYPE_P (TREE_TYPE (op1))) 7039 break; 7040 7041 inner = TREE_OPERAND (inner, 0); 7042 continue; 7043 } 7044 7045 case ADDR_EXPR: 7046 inner = TREE_OPERAND (inner, 0); 7047 7048 while (REFERENCE_CLASS_P (inner) 7049 && TREE_CODE (inner) != INDIRECT_REF) 7050 inner = TREE_OPERAND (inner, 0); 7051 7052 if (DECL_P (inner) 7053 && !DECL_EXTERNAL (inner) 7054 && !TREE_STATIC (inner) 7055 && DECL_CONTEXT (inner) == current_function_decl) 7056 warning (0, "function returns address of local variable"); 7057 break; 7058 7059 default: 7060 break; 7061 } 7062 7063 break; 7064 } 7065 7066 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t); 7067 } 7068 7069 ret_stmt = build_stmt (RETURN_EXPR, retval); 7070 TREE_NO_WARNING (ret_stmt) |= no_warning; 7071 return add_stmt (ret_stmt); 7072} 7073 7074struct c_switch { 7075 /* The SWITCH_EXPR being built. */ 7076 tree switch_expr; 7077 7078 /* The original type of the testing expression, i.e. before the 7079 default conversion is applied. */ 7080 tree orig_type; 7081 7082 /* A splay-tree mapping the low element of a case range to the high 7083 element, or NULL_TREE if there is no high element. Used to 7084 determine whether or not a new case label duplicates an old case 7085 label. We need a tree, rather than simply a hash table, because 7086 of the GNU case range extension. */ 7087 splay_tree cases; 7088 7089 /* Number of nested statement expressions within this switch 7090 statement; if nonzero, case and default labels may not 7091 appear. */ 7092 unsigned int blocked_stmt_expr; 7093 7094 /* Scope of outermost declarations of identifiers with variably 7095 modified type within this switch statement; if nonzero, case and 7096 default labels may not appear. */ 7097 unsigned int blocked_vm; 7098 7099 /* The next node on the stack. */ 7100 struct c_switch *next; 7101}; 7102 7103/* A stack of the currently active switch statements. The innermost 7104 switch statement is on the top of the stack. There is no need to 7105 mark the stack for garbage collection because it is only active 7106 during the processing of the body of a function, and we never 7107 collect at that point. */ 7108 7109struct c_switch *c_switch_stack; 7110 7111/* Start a C switch statement, testing expression EXP. Return the new 7112 SWITCH_EXPR. */ 7113 7114tree 7115c_start_case (tree exp) 7116{ 7117 tree orig_type = error_mark_node; 7118 struct c_switch *cs; 7119 7120 if (exp != error_mark_node) 7121 { 7122 orig_type = TREE_TYPE (exp); 7123 7124 if (!INTEGRAL_TYPE_P (orig_type)) 7125 { 7126 if (orig_type != error_mark_node) 7127 { 7128 error ("switch quantity not an integer"); 7129 orig_type = error_mark_node; 7130 } 7131 exp = integer_zero_node; 7132 } 7133 else 7134 { 7135 tree type = TYPE_MAIN_VARIANT (orig_type); 7136 7137 if (!in_system_header 7138 && (type == long_integer_type_node 7139 || type == long_unsigned_type_node)) 7140 warning (OPT_Wtraditional, "%<long%> switch expression not " 7141 "converted to %<int%> in ISO C"); 7142 7143 exp = default_conversion (exp); 7144 } 7145 } 7146 7147 /* Add this new SWITCH_EXPR to the stack. */ 7148 cs = XNEW (struct c_switch); 7149 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE); 7150 cs->orig_type = orig_type; 7151 cs->cases = splay_tree_new (case_compare, NULL, NULL); 7152 cs->blocked_stmt_expr = 0; 7153 cs->blocked_vm = 0; 7154 cs->next = c_switch_stack; 7155 c_switch_stack = cs; 7156 7157 return add_stmt (cs->switch_expr); 7158} 7159 7160/* Process a case label. */ 7161 7162tree 7163do_case (tree low_value, tree high_value) 7164{ 7165 tree label = NULL_TREE; 7166 7167 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr 7168 && !c_switch_stack->blocked_vm) 7169 { 7170 label = c_add_case_label (c_switch_stack->cases, 7171 SWITCH_COND (c_switch_stack->switch_expr), 7172 c_switch_stack->orig_type, 7173 low_value, high_value); 7174 if (label == error_mark_node) 7175 label = NULL_TREE; 7176 } 7177 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr) 7178 { 7179 if (low_value) 7180 error ("case label in statement expression not containing " 7181 "enclosing switch statement"); 7182 else 7183 error ("%<default%> label in statement expression not containing " 7184 "enclosing switch statement"); 7185 } 7186 else if (c_switch_stack && c_switch_stack->blocked_vm) 7187 { 7188 if (low_value) 7189 error ("case label in scope of identifier with variably modified " 7190 "type not containing enclosing switch statement"); 7191 else 7192 error ("%<default%> label in scope of identifier with variably " 7193 "modified type not containing enclosing switch statement"); 7194 } 7195 else if (low_value) 7196 error ("case label not within a switch statement"); 7197 else 7198 error ("%<default%> label not within a switch statement"); 7199 7200 return label; 7201} 7202 7203/* Finish the switch statement. */ 7204 7205void 7206c_finish_case (tree body) 7207{ 7208 struct c_switch *cs = c_switch_stack; 7209 location_t switch_location; 7210 7211 SWITCH_BODY (cs->switch_expr) = body; 7212 7213 /* We must not be within a statement expression nested in the switch 7214 at this point; we might, however, be within the scope of an 7215 identifier with variably modified type nested in the switch. */ 7216 gcc_assert (!cs->blocked_stmt_expr); 7217 7218 /* Emit warnings as needed. */ 7219 if (EXPR_HAS_LOCATION (cs->switch_expr)) 7220 switch_location = EXPR_LOCATION (cs->switch_expr); 7221 else 7222 switch_location = input_location; 7223 c_do_switch_warnings (cs->cases, switch_location, 7224 TREE_TYPE (cs->switch_expr), 7225 SWITCH_COND (cs->switch_expr)); 7226 7227 /* Pop the stack. */ 7228 c_switch_stack = cs->next; 7229 splay_tree_delete (cs->cases); 7230 XDELETE (cs); 7231} 7232 7233/* Emit an if statement. IF_LOCUS is the location of the 'if'. COND, 7234 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK 7235 may be null. NESTED_IF is true if THEN_BLOCK contains another IF 7236 statement, and was not surrounded with parenthesis. */ 7237 7238void 7239c_finish_if_stmt (location_t if_locus, tree cond, tree then_block, 7240 tree else_block, bool nested_if) 7241{ 7242 tree stmt; 7243 7244 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */ 7245 if (warn_parentheses && nested_if && else_block == NULL) 7246 { 7247 tree inner_if = then_block; 7248 7249 /* We know from the grammar productions that there is an IF nested 7250 within THEN_BLOCK. Due to labels and c99 conditional declarations, 7251 it might not be exactly THEN_BLOCK, but should be the last 7252 non-container statement within. */ 7253 while (1) 7254 switch (TREE_CODE (inner_if)) 7255 { 7256 case COND_EXPR: 7257 goto found; 7258 case BIND_EXPR: 7259 inner_if = BIND_EXPR_BODY (inner_if); 7260 break; 7261 case STATEMENT_LIST: 7262 inner_if = expr_last (then_block); 7263 break; 7264 case TRY_FINALLY_EXPR: 7265 case TRY_CATCH_EXPR: 7266 inner_if = TREE_OPERAND (inner_if, 0); 7267 break; 7268 default: 7269 gcc_unreachable (); 7270 } 7271 found: 7272 7273 if (COND_EXPR_ELSE (inner_if)) 7274 warning (OPT_Wparentheses, 7275 "%Hsuggest explicit braces to avoid ambiguous %<else%>", 7276 &if_locus); 7277 } 7278 7279 empty_body_warning (then_block, else_block); 7280 7281 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block); 7282 SET_EXPR_LOCATION (stmt, if_locus); 7283 add_stmt (stmt); 7284} 7285 7286/* Emit a general-purpose loop construct. START_LOCUS is the location of 7287 the beginning of the loop. COND is the loop condition. COND_IS_FIRST 7288 is false for DO loops. INCR is the FOR increment expression. BODY is 7289 the statement controlled by the loop. BLAB is the break label. CLAB is 7290 the continue label. Everything is allowed to be NULL. */ 7291 7292void 7293c_finish_loop (location_t start_locus, tree cond, tree incr, tree body, 7294 tree blab, tree clab, bool cond_is_first) 7295{ 7296 tree entry = NULL, exit = NULL, t; 7297 7298 /* If the condition is zero don't generate a loop construct. */ 7299 if (cond && integer_zerop (cond)) 7300 { 7301 if (cond_is_first) 7302 { 7303 t = build_and_jump (&blab); 7304 SET_EXPR_LOCATION (t, start_locus); 7305 add_stmt (t); 7306 } 7307 } 7308 else 7309 { 7310 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7311 7312 /* If we have an exit condition, then we build an IF with gotos either 7313 out of the loop, or to the top of it. If there's no exit condition, 7314 then we just build a jump back to the top. */ 7315 exit = build_and_jump (&LABEL_EXPR_LABEL (top)); 7316 7317 if (cond && !integer_nonzerop (cond)) 7318 { 7319 /* Canonicalize the loop condition to the end. This means 7320 generating a branch to the loop condition. Reuse the 7321 continue label, if possible. */ 7322 if (cond_is_first) 7323 { 7324 if (incr || !clab) 7325 { 7326 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE); 7327 t = build_and_jump (&LABEL_EXPR_LABEL (entry)); 7328 } 7329 else 7330 t = build1 (GOTO_EXPR, void_type_node, clab); 7331 SET_EXPR_LOCATION (t, start_locus); 7332 add_stmt (t); 7333 } 7334 7335 t = build_and_jump (&blab); 7336 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t); 7337 if (cond_is_first) 7338 SET_EXPR_LOCATION (exit, start_locus); 7339 else 7340 SET_EXPR_LOCATION (exit, input_location); 7341 } 7342 7343 add_stmt (top); 7344 } 7345 7346 if (body) 7347 add_stmt (body); 7348 if (clab) 7349 add_stmt (build1 (LABEL_EXPR, void_type_node, clab)); 7350 if (incr) 7351 add_stmt (incr); 7352 if (entry) 7353 add_stmt (entry); 7354 if (exit) 7355 add_stmt (exit); 7356 if (blab) 7357 add_stmt (build1 (LABEL_EXPR, void_type_node, blab)); 7358} 7359 7360tree 7361c_finish_bc_stmt (tree *label_p, bool is_break) 7362{ 7363 bool skip; 7364 tree label = *label_p; 7365 7366 /* In switch statements break is sometimes stylistically used after 7367 a return statement. This can lead to spurious warnings about 7368 control reaching the end of a non-void function when it is 7369 inlined. Note that we are calling block_may_fallthru with 7370 language specific tree nodes; this works because 7371 block_may_fallthru returns true when given something it does not 7372 understand. */ 7373 skip = !block_may_fallthru (cur_stmt_list); 7374 7375 if (!label) 7376 { 7377 if (!skip) 7378 *label_p = label = create_artificial_label (); 7379 } 7380 else if (TREE_CODE (label) == LABEL_DECL) 7381 ; 7382 else switch (TREE_INT_CST_LOW (label)) 7383 { 7384 case 0: 7385 if (is_break) 7386 error ("break statement not within loop or switch"); 7387 else 7388 error ("continue statement not within a loop"); 7389 return NULL_TREE; 7390 7391 case 1: 7392 gcc_assert (is_break); 7393 error ("break statement used with OpenMP for loop"); 7394 return NULL_TREE; 7395 7396 default: 7397 gcc_unreachable (); 7398 } 7399 7400 if (skip) 7401 return NULL_TREE; 7402 7403 return add_stmt (build1 (GOTO_EXPR, void_type_node, label)); 7404} 7405 7406/* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */ 7407 7408static void 7409emit_side_effect_warnings (tree expr) 7410{ 7411 if (expr == error_mark_node) 7412 ; 7413 else if (!TREE_SIDE_EFFECTS (expr)) 7414 { 7415 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr)) 7416 warning (0, "%Hstatement with no effect", 7417 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location); 7418 } 7419 else if (warn_unused_value) 7420 warn_if_unused_value (expr, input_location); 7421} 7422 7423/* Process an expression as if it were a complete statement. Emit 7424 diagnostics, but do not call ADD_STMT. */ 7425 7426tree 7427c_process_expr_stmt (tree expr) 7428{ 7429 if (!expr) 7430 return NULL_TREE; 7431 7432 if (warn_sequence_point) 7433 verify_sequence_points (expr); 7434 7435 if (TREE_TYPE (expr) != error_mark_node 7436 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr)) 7437 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE) 7438 error ("expression statement has incomplete type"); 7439 7440 /* If we're not processing a statement expression, warn about unused values. 7441 Warnings for statement expressions will be emitted later, once we figure 7442 out which is the result. */ 7443 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7444 && (extra_warnings || warn_unused_value)) 7445 emit_side_effect_warnings (expr); 7446 7447 /* If the expression is not of a type to which we cannot assign a line 7448 number, wrap the thing in a no-op NOP_EXPR. */ 7449 if (DECL_P (expr) || CONSTANT_CLASS_P (expr)) 7450 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr); 7451 7452 if (EXPR_P (expr)) 7453 SET_EXPR_LOCATION (expr, input_location); 7454 7455 return expr; 7456} 7457 7458/* Emit an expression as a statement. */ 7459 7460tree 7461c_finish_expr_stmt (tree expr) 7462{ 7463 if (expr) 7464 return add_stmt (c_process_expr_stmt (expr)); 7465 else 7466 return NULL; 7467} 7468 7469/* Do the opposite and emit a statement as an expression. To begin, 7470 create a new binding level and return it. */ 7471 7472tree 7473c_begin_stmt_expr (void) 7474{ 7475 tree ret; 7476 struct c_label_context_se *nstack; 7477 struct c_label_list *glist; 7478 7479 /* We must force a BLOCK for this level so that, if it is not expanded 7480 later, there is a way to turn off the entire subtree of blocks that 7481 are contained in it. */ 7482 keep_next_level (); 7483 ret = c_begin_compound_stmt (true); 7484 if (c_switch_stack) 7485 { 7486 c_switch_stack->blocked_stmt_expr++; 7487 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7488 } 7489 for (glist = label_context_stack_se->labels_used; 7490 glist != NULL; 7491 glist = glist->next) 7492 { 7493 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1; 7494 } 7495 nstack = XOBNEW (&parser_obstack, struct c_label_context_se); 7496 nstack->labels_def = NULL; 7497 nstack->labels_used = NULL; 7498 nstack->next = label_context_stack_se; 7499 label_context_stack_se = nstack; 7500 7501 /* Mark the current statement list as belonging to a statement list. */ 7502 STATEMENT_LIST_STMT_EXPR (ret) = 1; 7503 7504 return ret; 7505} 7506 7507tree 7508c_finish_stmt_expr (tree body) 7509{ 7510 tree last, type, tmp, val; 7511 tree *last_p; 7512 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7513 7514 body = c_end_compound_stmt (body, true); 7515 if (c_switch_stack) 7516 { 7517 gcc_assert (c_switch_stack->blocked_stmt_expr != 0); 7518 c_switch_stack->blocked_stmt_expr--; 7519 } 7520 /* It is no longer possible to jump to labels defined within this 7521 statement expression. */ 7522 for (dlist = label_context_stack_se->labels_def; 7523 dlist != NULL; 7524 dlist = dlist->next) 7525 { 7526 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1; 7527 } 7528 /* It is again possible to define labels with a goto just outside 7529 this statement expression. */ 7530 for (glist = label_context_stack_se->next->labels_used; 7531 glist != NULL; 7532 glist = glist->next) 7533 { 7534 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0; 7535 glist_prev = glist; 7536 } 7537 if (glist_prev != NULL) 7538 glist_prev->next = label_context_stack_se->labels_used; 7539 else 7540 label_context_stack_se->next->labels_used 7541 = label_context_stack_se->labels_used; 7542 label_context_stack_se = label_context_stack_se->next; 7543 7544 /* Locate the last statement in BODY. See c_end_compound_stmt 7545 about always returning a BIND_EXPR. */ 7546 last_p = &BIND_EXPR_BODY (body); 7547 last = BIND_EXPR_BODY (body); 7548 7549 continue_searching: 7550 if (TREE_CODE (last) == STATEMENT_LIST) 7551 { 7552 tree_stmt_iterator i; 7553 7554 /* This can happen with degenerate cases like ({ }). No value. */ 7555 if (!TREE_SIDE_EFFECTS (last)) 7556 return body; 7557 7558 /* If we're supposed to generate side effects warnings, process 7559 all of the statements except the last. */ 7560 if (extra_warnings || warn_unused_value) 7561 { 7562 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i)) 7563 emit_side_effect_warnings (tsi_stmt (i)); 7564 } 7565 else 7566 i = tsi_last (last); 7567 last_p = tsi_stmt_ptr (i); 7568 last = *last_p; 7569 } 7570 7571 /* If the end of the list is exception related, then the list was split 7572 by a call to push_cleanup. Continue searching. */ 7573 if (TREE_CODE (last) == TRY_FINALLY_EXPR 7574 || TREE_CODE (last) == TRY_CATCH_EXPR) 7575 { 7576 last_p = &TREE_OPERAND (last, 0); 7577 last = *last_p; 7578 goto continue_searching; 7579 } 7580 7581 /* In the case that the BIND_EXPR is not necessary, return the 7582 expression out from inside it. */ 7583 if (last == error_mark_node 7584 || (last == BIND_EXPR_BODY (body) 7585 && BIND_EXPR_VARS (body) == NULL)) 7586 { 7587 /* Do not warn if the return value of a statement expression is 7588 unused. */ 7589 if (EXPR_P (last)) 7590 TREE_NO_WARNING (last) = 1; 7591 return last; 7592 } 7593 7594 /* Extract the type of said expression. */ 7595 type = TREE_TYPE (last); 7596 7597 /* If we're not returning a value at all, then the BIND_EXPR that 7598 we already have is a fine expression to return. */ 7599 if (!type || VOID_TYPE_P (type)) 7600 return body; 7601 7602 /* Now that we've located the expression containing the value, it seems 7603 silly to make voidify_wrapper_expr repeat the process. Create a 7604 temporary of the appropriate type and stick it in a TARGET_EXPR. */ 7605 tmp = create_tmp_var_raw (type, NULL); 7606 7607 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids 7608 tree_expr_nonnegative_p giving up immediately. */ 7609 val = last; 7610 if (TREE_CODE (val) == NOP_EXPR 7611 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))) 7612 val = TREE_OPERAND (val, 0); 7613 7614 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val); 7615 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last)); 7616 7617 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE); 7618} 7619 7620/* Begin the scope of an identifier of variably modified type, scope 7621 number SCOPE. Jumping from outside this scope to inside it is not 7622 permitted. */ 7623 7624void 7625c_begin_vm_scope (unsigned int scope) 7626{ 7627 struct c_label_context_vm *nstack; 7628 struct c_label_list *glist; 7629 7630 gcc_assert (scope > 0); 7631 7632 /* At file_scope, we don't have to do any processing. */ 7633 if (label_context_stack_vm == NULL) 7634 return; 7635 7636 if (c_switch_stack && !c_switch_stack->blocked_vm) 7637 c_switch_stack->blocked_vm = scope; 7638 for (glist = label_context_stack_vm->labels_used; 7639 glist != NULL; 7640 glist = glist->next) 7641 { 7642 C_DECL_UNDEFINABLE_VM (glist->label) = 1; 7643 } 7644 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm); 7645 nstack->labels_def = NULL; 7646 nstack->labels_used = NULL; 7647 nstack->scope = scope; 7648 nstack->next = label_context_stack_vm; 7649 label_context_stack_vm = nstack; 7650} 7651 7652/* End a scope which may contain identifiers of variably modified 7653 type, scope number SCOPE. */ 7654 7655void 7656c_end_vm_scope (unsigned int scope) 7657{ 7658 if (label_context_stack_vm == NULL) 7659 return; 7660 if (c_switch_stack && c_switch_stack->blocked_vm == scope) 7661 c_switch_stack->blocked_vm = 0; 7662 /* We may have a number of nested scopes of identifiers with 7663 variably modified type, all at this depth. Pop each in turn. */ 7664 while (label_context_stack_vm->scope == scope) 7665 { 7666 struct c_label_list *dlist, *glist, *glist_prev = NULL; 7667 7668 /* It is no longer possible to jump to labels defined within this 7669 scope. */ 7670 for (dlist = label_context_stack_vm->labels_def; 7671 dlist != NULL; 7672 dlist = dlist->next) 7673 { 7674 C_DECL_UNJUMPABLE_VM (dlist->label) = 1; 7675 } 7676 /* It is again possible to define labels with a goto just outside 7677 this scope. */ 7678 for (glist = label_context_stack_vm->next->labels_used; 7679 glist != NULL; 7680 glist = glist->next) 7681 { 7682 C_DECL_UNDEFINABLE_VM (glist->label) = 0; 7683 glist_prev = glist; 7684 } 7685 if (glist_prev != NULL) 7686 glist_prev->next = label_context_stack_vm->labels_used; 7687 else 7688 label_context_stack_vm->next->labels_used 7689 = label_context_stack_vm->labels_used; 7690 label_context_stack_vm = label_context_stack_vm->next; 7691 } 7692} 7693 7694/* Begin and end compound statements. This is as simple as pushing 7695 and popping new statement lists from the tree. */ 7696 7697tree 7698c_begin_compound_stmt (bool do_scope) 7699{ 7700 tree stmt = push_stmt_list (); 7701 if (do_scope) 7702 push_scope (); 7703 return stmt; 7704} 7705 7706tree 7707c_end_compound_stmt (tree stmt, bool do_scope) 7708{ 7709 tree block = NULL; 7710 7711 if (do_scope) 7712 { 7713 if (c_dialect_objc ()) 7714 objc_clear_super_receiver (); 7715 block = pop_scope (); 7716 } 7717 7718 stmt = pop_stmt_list (stmt); 7719 stmt = c_build_bind_expr (block, stmt); 7720 7721 /* If this compound statement is nested immediately inside a statement 7722 expression, then force a BIND_EXPR to be created. Otherwise we'll 7723 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular, 7724 STATEMENT_LISTs merge, and thus we can lose track of what statement 7725 was really last. */ 7726 if (cur_stmt_list 7727 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list) 7728 && TREE_CODE (stmt) != BIND_EXPR) 7729 { 7730 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL); 7731 TREE_SIDE_EFFECTS (stmt) = 1; 7732 } 7733 7734 return stmt; 7735} 7736 7737/* Queue a cleanup. CLEANUP is an expression/statement to be executed 7738 when the current scope is exited. EH_ONLY is true when this is not 7739 meant to apply to normal control flow transfer. */ 7740 7741void 7742push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only) 7743{ 7744 enum tree_code code; 7745 tree stmt, list; 7746 bool stmt_expr; 7747 7748 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR; 7749 stmt = build_stmt (code, NULL, cleanup); 7750 add_stmt (stmt); 7751 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list); 7752 list = push_stmt_list (); 7753 TREE_OPERAND (stmt, 0) = list; 7754 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr; 7755} 7756 7757/* Build a binary-operation expression without default conversions. 7758 CODE is the kind of expression to build. 7759 This function differs from `build' in several ways: 7760 the data type of the result is computed and recorded in it, 7761 warnings are generated if arg data types are invalid, 7762 special handling for addition and subtraction of pointers is known, 7763 and some optimization is done (operations on narrow ints 7764 are done in the narrower type when that gives the same result). 7765 Constant folding is also done before the result is returned. 7766 7767 Note that the operands will never have enumeral types, or function 7768 or array types, because either they will have the default conversions 7769 performed or they have both just been converted to some other type in which 7770 the arithmetic is to be done. */ 7771 7772tree 7773build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 7774 int convert_p) 7775{ 7776 tree type0, type1; 7777 enum tree_code code0, code1; 7778 tree op0, op1; 7779 const char *invalid_op_diag; 7780 7781 /* Expression code to give to the expression when it is built. 7782 Normally this is CODE, which is what the caller asked for, 7783 but in some special cases we change it. */ 7784 enum tree_code resultcode = code; 7785 7786 /* Data type in which the computation is to be performed. 7787 In the simplest cases this is the common type of the arguments. */ 7788 tree result_type = NULL; 7789 7790 /* Nonzero means operands have already been type-converted 7791 in whatever way is necessary. 7792 Zero means they need to be converted to RESULT_TYPE. */ 7793 int converted = 0; 7794 7795 /* Nonzero means create the expression with this type, rather than 7796 RESULT_TYPE. */ 7797 tree build_type = 0; 7798 7799 /* Nonzero means after finally constructing the expression 7800 convert it to this type. */ 7801 tree final_type = 0; 7802 7803 /* Nonzero if this is an operation like MIN or MAX which can 7804 safely be computed in short if both args are promoted shorts. 7805 Also implies COMMON. 7806 -1 indicates a bitwise operation; this makes a difference 7807 in the exact conditions for when it is safe to do the operation 7808 in a narrower mode. */ 7809 int shorten = 0; 7810 7811 /* Nonzero if this is a comparison operation; 7812 if both args are promoted shorts, compare the original shorts. 7813 Also implies COMMON. */ 7814 int short_compare = 0; 7815 7816 /* Nonzero if this is a right-shift operation, which can be computed on the 7817 original short and then promoted if the operand is a promoted short. */ 7818 int short_shift = 0; 7819 7820 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 7821 int common = 0; 7822 7823 /* True means types are compatible as far as ObjC is concerned. */ 7824 bool objc_ok; 7825 7826 if (convert_p) 7827 { 7828 op0 = default_conversion (orig_op0); 7829 op1 = default_conversion (orig_op1); 7830 } 7831 else 7832 { 7833 op0 = orig_op0; 7834 op1 = orig_op1; 7835 } 7836 7837 type0 = TREE_TYPE (op0); 7838 type1 = TREE_TYPE (op1); 7839 7840 /* The expression codes of the data types of the arguments tell us 7841 whether the arguments are integers, floating, pointers, etc. */ 7842 code0 = TREE_CODE (type0); 7843 code1 = TREE_CODE (type1); 7844 7845 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 7846 STRIP_TYPE_NOPS (op0); 7847 STRIP_TYPE_NOPS (op1); 7848 7849 /* If an error was already reported for one of the arguments, 7850 avoid reporting another error. */ 7851 7852 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 7853 return error_mark_node; 7854 7855 if ((invalid_op_diag 7856 = targetm.invalid_binary_op (code, type0, type1))) 7857 { 7858 error (invalid_op_diag); 7859 return error_mark_node; 7860 } 7861 7862 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE); 7863 7864 switch (code) 7865 { 7866 case PLUS_EXPR: 7867 /* Handle the pointer + int case. */ 7868 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7869 return pointer_int_sum (PLUS_EXPR, op0, op1); 7870 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 7871 return pointer_int_sum (PLUS_EXPR, op1, op0); 7872 else 7873 common = 1; 7874 break; 7875 7876 case MINUS_EXPR: 7877 /* Subtraction of two similar pointers. 7878 We must subtract them as integers, then divide by object size. */ 7879 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 7880 && comp_target_types (type0, type1)) 7881 return pointer_diff (op0, op1); 7882 /* Handle pointer minus int. Just like pointer plus int. */ 7883 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 7884 return pointer_int_sum (MINUS_EXPR, op0, op1); 7885 else 7886 common = 1; 7887 break; 7888 7889 case MULT_EXPR: 7890 common = 1; 7891 break; 7892 7893 case TRUNC_DIV_EXPR: 7894 case CEIL_DIV_EXPR: 7895 case FLOOR_DIV_EXPR: 7896 case ROUND_DIV_EXPR: 7897 case EXACT_DIV_EXPR: 7898 /* Floating point division by zero is a legitimate way to obtain 7899 infinities and NaNs. */ 7900 if (skip_evaluation == 0 && integer_zerop (op1)) 7901 warning (OPT_Wdiv_by_zero, "division by zero"); 7902 7903 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 7904 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7905 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 7906 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 7907 { 7908 enum tree_code tcode0 = code0, tcode1 = code1; 7909 7910 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 7911 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); 7912 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE) 7913 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); 7914 7915 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)) 7916 resultcode = RDIV_EXPR; 7917 else 7918 /* Although it would be tempting to shorten always here, that 7919 loses on some targets, since the modulo instruction is 7920 undefined if the quotient can't be represented in the 7921 computation mode. We shorten only if unsigned or if 7922 dividing by something we know != -1. */ 7923 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7924 || (TREE_CODE (op1) == INTEGER_CST 7925 && !integer_all_onesp (op1))); 7926 common = 1; 7927 } 7928 break; 7929 7930 case BIT_AND_EXPR: 7931 case BIT_IOR_EXPR: 7932 case BIT_XOR_EXPR: 7933 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7934 shorten = -1; 7935 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 7936 common = 1; 7937 break; 7938 7939 case TRUNC_MOD_EXPR: 7940 case FLOOR_MOD_EXPR: 7941 if (skip_evaluation == 0 && integer_zerop (op1)) 7942 warning (OPT_Wdiv_by_zero, "division by zero"); 7943 7944 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7945 { 7946 /* Although it would be tempting to shorten always here, that loses 7947 on some targets, since the modulo instruction is undefined if the 7948 quotient can't be represented in the computation mode. We shorten 7949 only if unsigned or if dividing by something we know != -1. */ 7950 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) 7951 || (TREE_CODE (op1) == INTEGER_CST 7952 && !integer_all_onesp (op1))); 7953 common = 1; 7954 } 7955 break; 7956 7957 case TRUTH_ANDIF_EXPR: 7958 case TRUTH_ORIF_EXPR: 7959 case TRUTH_AND_EXPR: 7960 case TRUTH_OR_EXPR: 7961 case TRUTH_XOR_EXPR: 7962 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 7963 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 7964 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 7965 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 7966 { 7967 /* Result of these operations is always an int, 7968 but that does not mean the operands should be 7969 converted to ints! */ 7970 result_type = integer_type_node; 7971 op0 = c_common_truthvalue_conversion (op0); 7972 op1 = c_common_truthvalue_conversion (op1); 7973 converted = 1; 7974 } 7975 break; 7976 7977 /* Shift operations: result has same type as first operand; 7978 always convert second operand to int. 7979 Also set SHORT_SHIFT if shifting rightward. */ 7980 7981 case RSHIFT_EXPR: 7982 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 7983 { 7984 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 7985 { 7986 if (tree_int_cst_sgn (op1) < 0) 7987 warning (0, "right shift count is negative"); 7988 else 7989 { 7990 if (!integer_zerop (op1)) 7991 short_shift = 1; 7992 7993 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 7994 warning (0, "right shift count >= width of type"); 7995 } 7996 } 7997 7998 /* Use the type of the value to be shifted. */ 7999 result_type = type0; 8000 /* Convert the shift-count to an integer, regardless of size 8001 of value being shifted. */ 8002 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 8003 op1 = convert (integer_type_node, op1); 8004 /* Avoid converting op1 to result_type later. */ 8005 converted = 1; 8006 } 8007 break; 8008 8009 case LSHIFT_EXPR: 8010 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 8011 { 8012 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 8013 { 8014 if (tree_int_cst_sgn (op1) < 0) 8015 warning (0, "left shift count is negative"); 8016 8017 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 8018 warning (0, "left shift count >= width of type"); 8019 } 8020 8021 /* Use the type of the value to be shifted. */ 8022 result_type = type0; 8023 /* Convert the shift-count to an integer, regardless of size 8024 of value being shifted. */ 8025 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 8026 op1 = convert (integer_type_node, op1); 8027 /* Avoid converting op1 to result_type later. */ 8028 converted = 1; 8029 } 8030 break; 8031 8032 case EQ_EXPR: 8033 case NE_EXPR: 8034 if (code0 == REAL_TYPE || code1 == REAL_TYPE) 8035 warning (OPT_Wfloat_equal, 8036 "comparing floating point with == or != is unsafe"); 8037 /* Result of comparison is always int, 8038 but don't convert the args to int! */ 8039 build_type = integer_type_node; 8040 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 8041 || code0 == COMPLEX_TYPE) 8042 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 8043 || code1 == COMPLEX_TYPE)) 8044 short_compare = 1; 8045 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8046 { 8047 tree tt0 = TREE_TYPE (type0); 8048 tree tt1 = TREE_TYPE (type1); 8049 /* Anything compares with void *. void * compares with anything. 8050 Otherwise, the targets must be compatible 8051 and both must be object or both incomplete. */ 8052 if (comp_target_types (type0, type1)) 8053 result_type = common_pointer_type (type0, type1); 8054 else if (VOID_TYPE_P (tt0)) 8055 { 8056 /* op0 != orig_op0 detects the case of something 8057 whose value is 0 but which isn't a valid null ptr const. */ 8058 if (pedantic && !null_pointer_constant_p (orig_op0) 8059 && TREE_CODE (tt1) == FUNCTION_TYPE) 8060 pedwarn ("ISO C forbids comparison of %<void *%>" 8061 " with function pointer"); 8062 } 8063 else if (VOID_TYPE_P (tt1)) 8064 { 8065 if (pedantic && !null_pointer_constant_p (orig_op1) 8066 && TREE_CODE (tt0) == FUNCTION_TYPE) 8067 pedwarn ("ISO C forbids comparison of %<void *%>" 8068 " with function pointer"); 8069 } 8070 else 8071 /* Avoid warning about the volatile ObjC EH puts on decls. */ 8072 if (!objc_ok) 8073 pedwarn ("comparison of distinct pointer types lacks a cast"); 8074 8075 if (result_type == NULL_TREE) 8076 result_type = ptr_type_node; 8077 } 8078 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8079 { 8080 if (TREE_CODE (op0) == ADDR_EXPR 8081 && DECL_P (TREE_OPERAND (op0, 0)) 8082 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL 8083 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL 8084 || !DECL_WEAK (TREE_OPERAND (op0, 0)))) 8085 warning (OPT_Waddress, "the address of %qD will never be NULL", 8086 TREE_OPERAND (op0, 0)); 8087 result_type = type0; 8088 } 8089 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8090 { 8091 if (TREE_CODE (op1) == ADDR_EXPR 8092 && DECL_P (TREE_OPERAND (op1, 0)) 8093 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL 8094 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL 8095 || !DECL_WEAK (TREE_OPERAND (op1, 0)))) 8096 warning (OPT_Waddress, "the address of %qD will never be NULL", 8097 TREE_OPERAND (op1, 0)); 8098 result_type = type1; 8099 } 8100 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8101 { 8102 result_type = type0; 8103 pedwarn ("comparison between pointer and integer"); 8104 } 8105 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8106 { 8107 result_type = type1; 8108 pedwarn ("comparison between pointer and integer"); 8109 } 8110 break; 8111 8112 case LE_EXPR: 8113 case GE_EXPR: 8114 case LT_EXPR: 8115 case GT_EXPR: 8116 build_type = integer_type_node; 8117 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 8118 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 8119 short_compare = 1; 8120 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 8121 { 8122 if (comp_target_types (type0, type1)) 8123 { 8124 result_type = common_pointer_type (type0, type1); 8125 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 8126 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 8127 pedwarn ("comparison of complete and incomplete pointers"); 8128 else if (pedantic 8129 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 8130 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 8131 } 8132 else 8133 { 8134 result_type = ptr_type_node; 8135 pedwarn ("comparison of distinct pointer types lacks a cast"); 8136 } 8137 } 8138 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1)) 8139 { 8140 result_type = type0; 8141 if (pedantic || extra_warnings) 8142 pedwarn ("ordered comparison of pointer with integer zero"); 8143 } 8144 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0)) 8145 { 8146 result_type = type1; 8147 if (pedantic) 8148 pedwarn ("ordered comparison of pointer with integer zero"); 8149 } 8150 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 8151 { 8152 result_type = type0; 8153 pedwarn ("comparison between pointer and integer"); 8154 } 8155 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 8156 { 8157 result_type = type1; 8158 pedwarn ("comparison between pointer and integer"); 8159 } 8160 break; 8161 8162 default: 8163 gcc_unreachable (); 8164 } 8165 8166 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 8167 return error_mark_node; 8168 8169 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE 8170 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)) 8171 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0), 8172 TREE_TYPE (type1)))) 8173 { 8174 binary_op_error (code); 8175 return error_mark_node; 8176 } 8177 8178 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 8179 || code0 == VECTOR_TYPE) 8180 && 8181 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 8182 || code1 == VECTOR_TYPE)) 8183 { 8184 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 8185 8186 if (shorten || common || short_compare) 8187 result_type = c_common_type (type0, type1); 8188 8189 /* For certain operations (which identify themselves by shorten != 0) 8190 if both args were extended from the same smaller type, 8191 do the arithmetic in that type and then extend. 8192 8193 shorten !=0 and !=1 indicates a bitwise operation. 8194 For them, this optimization is safe only if 8195 both args are zero-extended or both are sign-extended. 8196 Otherwise, we might change the result. 8197 Eg, (short)-1 | (unsigned short)-1 is (int)-1 8198 but calculated in (unsigned short) it would be (unsigned short)-1. */ 8199 8200 if (shorten && none_complex) 8201 { 8202 int unsigned0, unsigned1; 8203 tree arg0, arg1; 8204 int uns; 8205 tree type; 8206 8207 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents 8208 excessive narrowing when we call get_narrower below. For 8209 example, suppose that OP0 is of unsigned int extended 8210 from signed char and that RESULT_TYPE is long long int. 8211 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look 8212 like 8213 8214 (long long int) (unsigned int) signed_char 8215 8216 which get_narrower would narrow down to 8217 8218 (unsigned int) signed char 8219 8220 If we do not cast OP0 first, get_narrower would return 8221 signed_char, which is inconsistent with the case of the 8222 explicit cast. */ 8223 op0 = convert (result_type, op0); 8224 op1 = convert (result_type, op1); 8225 8226 arg0 = get_narrower (op0, &unsigned0); 8227 arg1 = get_narrower (op1, &unsigned1); 8228 8229 /* UNS is 1 if the operation to be done is an unsigned one. */ 8230 uns = TYPE_UNSIGNED (result_type); 8231 8232 final_type = result_type; 8233 8234 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 8235 but it *requires* conversion to FINAL_TYPE. */ 8236 8237 if ((TYPE_PRECISION (TREE_TYPE (op0)) 8238 == TYPE_PRECISION (TREE_TYPE (arg0))) 8239 && TREE_TYPE (op0) != final_type) 8240 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 8241 if ((TYPE_PRECISION (TREE_TYPE (op1)) 8242 == TYPE_PRECISION (TREE_TYPE (arg1))) 8243 && TREE_TYPE (op1) != final_type) 8244 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 8245 8246 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 8247 8248 /* For bitwise operations, signedness of nominal type 8249 does not matter. Consider only how operands were extended. */ 8250 if (shorten == -1) 8251 uns = unsigned0; 8252 8253 /* Note that in all three cases below we refrain from optimizing 8254 an unsigned operation on sign-extended args. 8255 That would not be valid. */ 8256 8257 /* Both args variable: if both extended in same way 8258 from same width, do it in that width. 8259 Do it unsigned if args were zero-extended. */ 8260 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 8261 < TYPE_PRECISION (result_type)) 8262 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8263 == TYPE_PRECISION (TREE_TYPE (arg0))) 8264 && unsigned0 == unsigned1 8265 && (unsigned0 || !uns)) 8266 result_type 8267 = c_common_signed_or_unsigned_type 8268 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 8269 else if (TREE_CODE (arg0) == INTEGER_CST 8270 && (unsigned1 || !uns) 8271 && (TYPE_PRECISION (TREE_TYPE (arg1)) 8272 < TYPE_PRECISION (result_type)) 8273 && (type 8274 = c_common_signed_or_unsigned_type (unsigned1, 8275 TREE_TYPE (arg1)), 8276 int_fits_type_p (arg0, type))) 8277 result_type = type; 8278 else if (TREE_CODE (arg1) == INTEGER_CST 8279 && (unsigned0 || !uns) 8280 && (TYPE_PRECISION (TREE_TYPE (arg0)) 8281 < TYPE_PRECISION (result_type)) 8282 && (type 8283 = c_common_signed_or_unsigned_type (unsigned0, 8284 TREE_TYPE (arg0)), 8285 int_fits_type_p (arg1, type))) 8286 result_type = type; 8287 } 8288 8289 /* Shifts can be shortened if shifting right. */ 8290 8291 if (short_shift) 8292 { 8293 int unsigned_arg; 8294 tree arg0 = get_narrower (op0, &unsigned_arg); 8295 8296 final_type = result_type; 8297 8298 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 8299 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0)); 8300 8301 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 8302 /* We can shorten only if the shift count is less than the 8303 number of bits in the smaller type size. */ 8304 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 8305 /* We cannot drop an unsigned shift after sign-extension. */ 8306 && (!TYPE_UNSIGNED (final_type) || unsigned_arg)) 8307 { 8308 /* Do an unsigned shift if the operand was zero-extended. */ 8309 result_type 8310 = c_common_signed_or_unsigned_type (unsigned_arg, 8311 TREE_TYPE (arg0)); 8312 /* Convert value-to-be-shifted to that type. */ 8313 if (TREE_TYPE (op0) != result_type) 8314 op0 = convert (result_type, op0); 8315 converted = 1; 8316 } 8317 } 8318 8319 /* Comparison operations are shortened too but differently. 8320 They identify themselves by setting short_compare = 1. */ 8321 8322 if (short_compare) 8323 { 8324 /* Don't write &op0, etc., because that would prevent op0 8325 from being kept in a register. 8326 Instead, make copies of the our local variables and 8327 pass the copies by reference, then copy them back afterward. */ 8328 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 8329 enum tree_code xresultcode = resultcode; 8330 tree val 8331 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 8332 8333 if (val != 0) 8334 return val; 8335 8336 op0 = xop0, op1 = xop1; 8337 converted = 1; 8338 resultcode = xresultcode; 8339 8340 if (warn_sign_compare && skip_evaluation == 0) 8341 { 8342 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0)); 8343 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); 8344 int unsignedp0, unsignedp1; 8345 tree primop0 = get_narrower (op0, &unsignedp0); 8346 tree primop1 = get_narrower (op1, &unsignedp1); 8347 8348 xop0 = orig_op0; 8349 xop1 = orig_op1; 8350 STRIP_TYPE_NOPS (xop0); 8351 STRIP_TYPE_NOPS (xop1); 8352 8353 /* Give warnings for comparisons between signed and unsigned 8354 quantities that may fail. 8355 8356 Do the checking based on the original operand trees, so that 8357 casts will be considered, but default promotions won't be. 8358 8359 Do not warn if the comparison is being done in a signed type, 8360 since the signed type will only be chosen if it can represent 8361 all the values of the unsigned type. */ 8362 if (!TYPE_UNSIGNED (result_type)) 8363 /* OK */; 8364 /* Do not warn if both operands are the same signedness. */ 8365 else if (op0_signed == op1_signed) 8366 /* OK */; 8367 else 8368 { 8369 tree sop, uop; 8370 bool ovf; 8371 8372 if (op0_signed) 8373 sop = xop0, uop = xop1; 8374 else 8375 sop = xop1, uop = xop0; 8376 8377 /* Do not warn if the signed quantity is an 8378 unsuffixed integer literal (or some static 8379 constant expression involving such literals or a 8380 conditional expression involving such literals) 8381 and it is non-negative. */ 8382 if (tree_expr_nonnegative_warnv_p (sop, &ovf)) 8383 /* OK */; 8384 /* Do not warn if the comparison is an equality operation, 8385 the unsigned quantity is an integral constant, and it 8386 would fit in the result if the result were signed. */ 8387 else if (TREE_CODE (uop) == INTEGER_CST 8388 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 8389 && int_fits_type_p 8390 (uop, c_common_signed_type (result_type))) 8391 /* OK */; 8392 /* Do not warn if the unsigned quantity is an enumeration 8393 constant and its maximum value would fit in the result 8394 if the result were signed. */ 8395 else if (TREE_CODE (uop) == INTEGER_CST 8396 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 8397 && int_fits_type_p 8398 (TYPE_MAX_VALUE (TREE_TYPE (uop)), 8399 c_common_signed_type (result_type))) 8400 /* OK */; 8401 else 8402 warning (0, "comparison between signed and unsigned"); 8403 } 8404 8405 /* Warn if two unsigned values are being compared in a size 8406 larger than their original size, and one (and only one) is the 8407 result of a `~' operator. This comparison will always fail. 8408 8409 Also warn if one operand is a constant, and the constant 8410 does not have all bits set that are set in the ~ operand 8411 when it is extended. */ 8412 8413 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 8414 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 8415 { 8416 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 8417 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 8418 &unsignedp0); 8419 else 8420 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 8421 &unsignedp1); 8422 8423 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 8424 { 8425 tree primop; 8426 HOST_WIDE_INT constant, mask; 8427 int unsignedp, bits; 8428 8429 if (host_integerp (primop0, 0)) 8430 { 8431 primop = primop1; 8432 unsignedp = unsignedp1; 8433 constant = tree_low_cst (primop0, 0); 8434 } 8435 else 8436 { 8437 primop = primop0; 8438 unsignedp = unsignedp0; 8439 constant = tree_low_cst (primop1, 0); 8440 } 8441 8442 bits = TYPE_PRECISION (TREE_TYPE (primop)); 8443 if (bits < TYPE_PRECISION (result_type) 8444 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 8445 { 8446 mask = (~(HOST_WIDE_INT) 0) << bits; 8447 if ((mask & constant) != mask) 8448 warning (0, "comparison of promoted ~unsigned with constant"); 8449 } 8450 } 8451 else if (unsignedp0 && unsignedp1 8452 && (TYPE_PRECISION (TREE_TYPE (primop0)) 8453 < TYPE_PRECISION (result_type)) 8454 && (TYPE_PRECISION (TREE_TYPE (primop1)) 8455 < TYPE_PRECISION (result_type))) 8456 warning (0, "comparison of promoted ~unsigned with unsigned"); 8457 } 8458 } 8459 } 8460 } 8461 8462 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 8463 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 8464 Then the expression will be built. 8465 It will be given type FINAL_TYPE if that is nonzero; 8466 otherwise, it will be given type RESULT_TYPE. */ 8467 8468 if (!result_type) 8469 { 8470 binary_op_error (code); 8471 return error_mark_node; 8472 } 8473 8474 if (!converted) 8475 { 8476 if (TREE_TYPE (op0) != result_type) 8477 op0 = convert_and_check (result_type, op0); 8478 if (TREE_TYPE (op1) != result_type) 8479 op1 = convert_and_check (result_type, op1); 8480 8481 /* This can happen if one operand has a vector type, and the other 8482 has a different type. */ 8483 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) 8484 return error_mark_node; 8485 } 8486 8487 if (build_type == NULL_TREE) 8488 build_type = result_type; 8489 8490 { 8491 /* Treat expressions in initializers specially as they can't trap. */ 8492 tree result = require_constant_value ? fold_build2_initializer (resultcode, 8493 build_type, 8494 op0, op1) 8495 : fold_build2 (resultcode, build_type, 8496 op0, op1); 8497 8498 if (final_type != 0) 8499 result = convert (final_type, result); 8500 return result; 8501 } 8502} 8503 8504 8505/* Convert EXPR to be a truth-value, validating its type for this 8506 purpose. */ 8507 8508tree 8509c_objc_common_truthvalue_conversion (tree expr) 8510{ 8511 switch (TREE_CODE (TREE_TYPE (expr))) 8512 { 8513 case ARRAY_TYPE: 8514 error ("used array that cannot be converted to pointer where scalar is required"); 8515 return error_mark_node; 8516 8517 case RECORD_TYPE: 8518 error ("used struct type value where scalar is required"); 8519 return error_mark_node; 8520 8521 case UNION_TYPE: 8522 error ("used union type value where scalar is required"); 8523 return error_mark_node; 8524 8525 case FUNCTION_TYPE: 8526 gcc_unreachable (); 8527 8528 default: 8529 break; 8530 } 8531 8532 /* ??? Should we also give an error for void and vectors rather than 8533 leaving those to give errors later? */ 8534 return c_common_truthvalue_conversion (expr); 8535} 8536 8537 8538/* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as 8539 required. */ 8540 8541tree 8542c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, 8543 bool *ti ATTRIBUTE_UNUSED, bool *se) 8544{ 8545 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR) 8546 { 8547 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr); 8548 /* Executing a compound literal inside a function reinitializes 8549 it. */ 8550 if (!TREE_STATIC (decl)) 8551 *se = true; 8552 return decl; 8553 } 8554 else 8555 return expr; 8556} 8557 8558/* Like c_begin_compound_stmt, except force the retention of the BLOCK. */ 8559 8560tree 8561c_begin_omp_parallel (void) 8562{ 8563 tree block; 8564 8565 keep_next_level (); 8566 block = c_begin_compound_stmt (true); 8567 8568 return block; 8569} 8570 8571tree 8572c_finish_omp_parallel (tree clauses, tree block) 8573{ 8574 tree stmt; 8575 8576 block = c_end_compound_stmt (block, true); 8577 8578 stmt = make_node (OMP_PARALLEL); 8579 TREE_TYPE (stmt) = void_type_node; 8580 OMP_PARALLEL_CLAUSES (stmt) = clauses; 8581 OMP_PARALLEL_BODY (stmt) = block; 8582 8583 return add_stmt (stmt); 8584} 8585 8586/* For all elements of CLAUSES, validate them vs OpenMP constraints. 8587 Remove any elements from the list that are invalid. */ 8588 8589tree 8590c_finish_omp_clauses (tree clauses) 8591{ 8592 bitmap_head generic_head, firstprivate_head, lastprivate_head; 8593 tree c, t, *pc = &clauses; 8594 const char *name; 8595 8596 bitmap_obstack_initialize (NULL); 8597 bitmap_initialize (&generic_head, &bitmap_default_obstack); 8598 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack); 8599 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack); 8600 8601 for (pc = &clauses, c = clauses; c ; c = *pc) 8602 { 8603 bool remove = false; 8604 bool need_complete = false; 8605 bool need_implicitly_determined = false; 8606 8607 switch (OMP_CLAUSE_CODE (c)) 8608 { 8609 case OMP_CLAUSE_SHARED: 8610 name = "shared"; 8611 need_implicitly_determined = true; 8612 goto check_dup_generic; 8613 8614 case OMP_CLAUSE_PRIVATE: 8615 name = "private"; 8616 need_complete = true; 8617 need_implicitly_determined = true; 8618 goto check_dup_generic; 8619 8620 case OMP_CLAUSE_REDUCTION: 8621 name = "reduction"; 8622 need_implicitly_determined = true; 8623 t = OMP_CLAUSE_DECL (c); 8624 if (AGGREGATE_TYPE_P (TREE_TYPE (t)) 8625 || POINTER_TYPE_P (TREE_TYPE (t))) 8626 { 8627 error ("%qE has invalid type for %<reduction%>", t); 8628 remove = true; 8629 } 8630 else if (FLOAT_TYPE_P (TREE_TYPE (t))) 8631 { 8632 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c); 8633 const char *r_name = NULL; 8634 8635 switch (r_code) 8636 { 8637 case PLUS_EXPR: 8638 case MULT_EXPR: 8639 case MINUS_EXPR: 8640 break; 8641 case BIT_AND_EXPR: 8642 r_name = "&"; 8643 break; 8644 case BIT_XOR_EXPR: 8645 r_name = "^"; 8646 break; 8647 case BIT_IOR_EXPR: 8648 r_name = "|"; 8649 break; 8650 case TRUTH_ANDIF_EXPR: 8651 r_name = "&&"; 8652 break; 8653 case TRUTH_ORIF_EXPR: 8654 r_name = "||"; 8655 break; 8656 default: 8657 gcc_unreachable (); 8658 } 8659 if (r_name) 8660 { 8661 error ("%qE has invalid type for %<reduction(%s)%>", 8662 t, r_name); 8663 remove = true; 8664 } 8665 } 8666 goto check_dup_generic; 8667 8668 case OMP_CLAUSE_COPYPRIVATE: 8669 name = "copyprivate"; 8670 goto check_dup_generic; 8671 8672 case OMP_CLAUSE_COPYIN: 8673 name = "copyin"; 8674 t = OMP_CLAUSE_DECL (c); 8675 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t)) 8676 { 8677 error ("%qE must be %<threadprivate%> for %<copyin%>", t); 8678 remove = true; 8679 } 8680 goto check_dup_generic; 8681 8682 check_dup_generic: 8683 t = OMP_CLAUSE_DECL (c); 8684 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8685 { 8686 error ("%qE is not a variable in clause %qs", t, name); 8687 remove = true; 8688 } 8689 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8690 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)) 8691 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8692 { 8693 error ("%qE appears more than once in data clauses", t); 8694 remove = true; 8695 } 8696 else 8697 bitmap_set_bit (&generic_head, DECL_UID (t)); 8698 break; 8699 8700 case OMP_CLAUSE_FIRSTPRIVATE: 8701 name = "firstprivate"; 8702 t = OMP_CLAUSE_DECL (c); 8703 need_complete = true; 8704 need_implicitly_determined = true; 8705 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8706 { 8707 error ("%qE is not a variable in clause %<firstprivate%>", t); 8708 remove = true; 8709 } 8710 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8711 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))) 8712 { 8713 error ("%qE appears more than once in data clauses", t); 8714 remove = true; 8715 } 8716 else 8717 bitmap_set_bit (&firstprivate_head, DECL_UID (t)); 8718 break; 8719 8720 case OMP_CLAUSE_LASTPRIVATE: 8721 name = "lastprivate"; 8722 t = OMP_CLAUSE_DECL (c); 8723 need_complete = true; 8724 need_implicitly_determined = true; 8725 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL) 8726 { 8727 error ("%qE is not a variable in clause %<lastprivate%>", t); 8728 remove = true; 8729 } 8730 else if (bitmap_bit_p (&generic_head, DECL_UID (t)) 8731 || bitmap_bit_p (&lastprivate_head, DECL_UID (t))) 8732 { 8733 error ("%qE appears more than once in data clauses", t); 8734 remove = true; 8735 } 8736 else 8737 bitmap_set_bit (&lastprivate_head, DECL_UID (t)); 8738 break; 8739 8740 case OMP_CLAUSE_IF: 8741 case OMP_CLAUSE_NUM_THREADS: 8742 case OMP_CLAUSE_SCHEDULE: 8743 case OMP_CLAUSE_NOWAIT: 8744 case OMP_CLAUSE_ORDERED: 8745 case OMP_CLAUSE_DEFAULT: 8746 pc = &OMP_CLAUSE_CHAIN (c); 8747 continue; 8748 8749 default: 8750 gcc_unreachable (); 8751 } 8752 8753 if (!remove) 8754 { 8755 t = OMP_CLAUSE_DECL (c); 8756 8757 if (need_complete) 8758 { 8759 t = require_complete_type (t); 8760 if (t == error_mark_node) 8761 remove = true; 8762 } 8763 8764 if (need_implicitly_determined) 8765 { 8766 const char *share_name = NULL; 8767 8768 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t)) 8769 share_name = "threadprivate"; 8770 else switch (c_omp_predetermined_sharing (t)) 8771 { 8772 case OMP_CLAUSE_DEFAULT_UNSPECIFIED: 8773 break; 8774 case OMP_CLAUSE_DEFAULT_SHARED: 8775 share_name = "shared"; 8776 break; 8777 case OMP_CLAUSE_DEFAULT_PRIVATE: 8778 share_name = "private"; 8779 break; 8780 default: 8781 gcc_unreachable (); 8782 } 8783 if (share_name) 8784 { 8785 error ("%qE is predetermined %qs for %qs", 8786 t, share_name, name); 8787 remove = true; 8788 } 8789 } 8790 } 8791 8792 if (remove) 8793 *pc = OMP_CLAUSE_CHAIN (c); 8794 else 8795 pc = &OMP_CLAUSE_CHAIN (c); 8796 } 8797 8798 bitmap_obstack_release (NULL); 8799 return clauses; 8800} 8801