c-typeck.c revision 132718
1/* Build expressions with type checking for C compiler. 2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 59 Temple Place - Suite 330, Boston, MA 2002111-1307, USA. */ 21 22 23/* This file is part of the C front end. 24 It contains routines to build C expressions given their operands, 25 including computing the types of the result, C-specific error checks, 26 and some optimization. 27 28 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes, 29 and to process initializations in declarations (since they work 30 like a strange sort of assignment). */ 31 32#include "config.h" 33#include "system.h" 34#include "coretypes.h" 35#include "tm.h" 36#include "rtl.h" 37#include "tree.h" 38#include "c-tree.h" 39#include "tm_p.h" 40#include "flags.h" 41#include "output.h" 42#include "expr.h" 43#include "toplev.h" 44#include "intl.h" 45#include "ggc.h" 46#include "target.h" 47 48/* Nonzero if we've already printed a "missing braces around initializer" 49 message within this initializer. */ 50static int missing_braces_mentioned; 51 52static int require_constant_value; 53static int require_constant_elements; 54 55static tree qualify_type (tree, tree); 56static int same_translation_unit_p (tree, tree); 57static int tagged_types_tu_compatible_p (tree, tree, int); 58static int comp_target_types (tree, tree, int); 59static int function_types_compatible_p (tree, tree, int); 60static int type_lists_compatible_p (tree, tree, int); 61static tree decl_constant_value_for_broken_optimization (tree); 62static tree default_function_array_conversion (tree); 63static tree lookup_field (tree, tree); 64static tree convert_arguments (tree, tree, tree, tree); 65static tree pointer_diff (tree, tree); 66static tree unary_complex_lvalue (enum tree_code, tree, int); 67static void pedantic_lvalue_warning (enum tree_code); 68static tree internal_build_compound_expr (tree, int); 69static tree convert_for_assignment (tree, tree, const char *, tree, tree, 70 int); 71static void warn_for_assignment (const char *, const char *, tree, int); 72static tree valid_compound_expr_initializer (tree, tree); 73static void push_string (const char *); 74static void push_member_name (tree); 75static void push_array_bounds (int); 76static int spelling_length (void); 77static char *print_spelling (char *); 78static void warning_init (const char *); 79static tree digest_init (tree, tree, int); 80static void output_init_element (tree, tree, tree, int); 81static void output_pending_init_elements (int); 82static int set_designator (int); 83static void push_range_stack (tree); 84static void add_pending_init (tree, tree); 85static void set_nonincremental_init (void); 86static void set_nonincremental_init_from_string (tree); 87static tree find_init_member (tree); 88 89/* Do `exp = require_complete_type (exp);' to make sure exp 90 does not have an incomplete type. (That includes void types.) */ 91 92tree 93require_complete_type (tree value) 94{ 95 tree type = TREE_TYPE (value); 96 97 if (value == error_mark_node || type == error_mark_node) 98 return error_mark_node; 99 100 /* First, detect a valid value with a complete type. */ 101 if (COMPLETE_TYPE_P (type)) 102 return value; 103 104 c_incomplete_type_error (value, type); 105 return error_mark_node; 106} 107 108/* Print an error message for invalid use of an incomplete type. 109 VALUE is the expression that was used (or 0 if that isn't known) 110 and TYPE is the type that was invalid. */ 111 112void 113c_incomplete_type_error (tree value, tree type) 114{ 115 const char *type_code_string; 116 117 /* Avoid duplicate error message. */ 118 if (TREE_CODE (type) == ERROR_MARK) 119 return; 120 121 if (value != 0 && (TREE_CODE (value) == VAR_DECL 122 || TREE_CODE (value) == PARM_DECL)) 123 error ("`%s' has an incomplete type", 124 IDENTIFIER_POINTER (DECL_NAME (value))); 125 else 126 { 127 retry: 128 /* We must print an error message. Be clever about what it says. */ 129 130 switch (TREE_CODE (type)) 131 { 132 case RECORD_TYPE: 133 type_code_string = "struct"; 134 break; 135 136 case UNION_TYPE: 137 type_code_string = "union"; 138 break; 139 140 case ENUMERAL_TYPE: 141 type_code_string = "enum"; 142 break; 143 144 case VOID_TYPE: 145 error ("invalid use of void expression"); 146 return; 147 148 case ARRAY_TYPE: 149 if (TYPE_DOMAIN (type)) 150 { 151 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL) 152 { 153 error ("invalid use of flexible array member"); 154 return; 155 } 156 type = TREE_TYPE (type); 157 goto retry; 158 } 159 error ("invalid use of array with unspecified bounds"); 160 return; 161 162 default: 163 abort (); 164 } 165 166 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 167 error ("invalid use of undefined type `%s %s'", 168 type_code_string, IDENTIFIER_POINTER (TYPE_NAME (type))); 169 else 170 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */ 171 error ("invalid use of incomplete typedef `%s'", 172 IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type)))); 173 } 174} 175 176/* Given a type, apply default promotions wrt unnamed function 177 arguments and return the new type. */ 178 179tree 180c_type_promotes_to (tree type) 181{ 182 if (TYPE_MAIN_VARIANT (type) == float_type_node) 183 return double_type_node; 184 185 if (c_promoting_integer_type_p (type)) 186 { 187 /* Preserve unsignedness if not really getting any wider. */ 188 if (TREE_UNSIGNED (type) 189 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))) 190 return unsigned_type_node; 191 return integer_type_node; 192 } 193 194 return type; 195} 196 197/* Return a variant of TYPE which has all the type qualifiers of LIKE 198 as well as those of TYPE. */ 199 200static tree 201qualify_type (tree type, tree like) 202{ 203 return c_build_qualified_type (type, 204 TYPE_QUALS (type) | TYPE_QUALS (like)); 205} 206 207/* Return the common type of two types. 208 We assume that comptypes has already been done and returned 1; 209 if that isn't so, this may crash. In particular, we assume that qualifiers 210 match. 211 212 This is the type for the result of most arithmetic operations 213 if the operands have the given two types. */ 214 215tree 216common_type (tree t1, tree t2) 217{ 218 enum tree_code code1; 219 enum tree_code code2; 220 tree attributes; 221 222 /* Save time if the two types are the same. */ 223 224 if (t1 == t2) return t1; 225 226 /* If one type is nonsense, use the other. */ 227 if (t1 == error_mark_node) 228 return t2; 229 if (t2 == error_mark_node) 230 return t1; 231 232 /* Merge the attributes. */ 233 attributes = (*targetm.merge_type_attributes) (t1, t2); 234 235 /* Treat an enum type as the unsigned integer type of the same width. */ 236 237 if (TREE_CODE (t1) == ENUMERAL_TYPE) 238 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1); 239 if (TREE_CODE (t2) == ENUMERAL_TYPE) 240 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1); 241 242 code1 = TREE_CODE (t1); 243 code2 = TREE_CODE (t2); 244 245 /* If one type is complex, form the common type of the non-complex 246 components, then make that complex. Use T1 or T2 if it is the 247 required type. */ 248 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) 249 { 250 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1; 251 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2; 252 tree subtype = common_type (subtype1, subtype2); 253 254 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype) 255 return build_type_attribute_variant (t1, attributes); 256 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype) 257 return build_type_attribute_variant (t2, attributes); 258 else 259 return build_type_attribute_variant (build_complex_type (subtype), 260 attributes); 261 } 262 263 switch (code1) 264 { 265 case INTEGER_TYPE: 266 case REAL_TYPE: 267 /* If only one is real, use it as the result. */ 268 269 if (code1 == REAL_TYPE && code2 != REAL_TYPE) 270 return build_type_attribute_variant (t1, attributes); 271 272 if (code2 == REAL_TYPE && code1 != REAL_TYPE) 273 return build_type_attribute_variant (t2, attributes); 274 275 /* Both real or both integers; use the one with greater precision. */ 276 277 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2)) 278 return build_type_attribute_variant (t1, attributes); 279 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1)) 280 return build_type_attribute_variant (t2, attributes); 281 282 /* Same precision. Prefer longs to ints even when same size. */ 283 284 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node 285 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node) 286 { 287 t1 = build_qualified_type (long_unsigned_type_node, 288 TYPE_QUALS (t1)); 289 return build_type_attribute_variant (t1, attributes); 290 } 291 292 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node 293 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node) 294 { 295 tree ntype; 296 297 /* But preserve unsignedness from the other type, 298 since long cannot hold all the values of an unsigned int. */ 299 if (TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2)) 300 ntype = long_unsigned_type_node; 301 else 302 ntype = long_integer_type_node; 303 304 ntype = build_qualified_type (ntype, TYPE_QUALS (t1)); 305 return build_type_attribute_variant (ntype, attributes); 306 } 307 308 /* Likewise, prefer long double to double even if same size. */ 309 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node 310 || TYPE_MAIN_VARIANT (t2) == long_double_type_node) 311 { 312 t1 = build_qualified_type (long_double_type_node, 313 TYPE_QUALS (t1)); 314 return build_type_attribute_variant (t1, attributes); 315 } 316 317 /* Otherwise prefer the unsigned one. */ 318 319 if (TREE_UNSIGNED (t1)) 320 return build_type_attribute_variant (t1, attributes); 321 else 322 return build_type_attribute_variant (t2, attributes); 323 324 case POINTER_TYPE: 325 /* For two pointers, do this recursively on the target type, 326 and combine the qualifiers of the two types' targets. */ 327 /* This code was turned off; I don't know why. 328 But ANSI C specifies doing this with the qualifiers. 329 So I turned it on again. */ 330 { 331 tree pointed_to_1 = TREE_TYPE (t1); 332 tree pointed_to_2 = TREE_TYPE (t2); 333 tree target = common_type (TYPE_MAIN_VARIANT (pointed_to_1), 334 TYPE_MAIN_VARIANT (pointed_to_2)); 335 t1 = build_pointer_type (c_build_qualified_type 336 (target, 337 TYPE_QUALS (pointed_to_1) | 338 TYPE_QUALS (pointed_to_2))); 339 return build_type_attribute_variant (t1, attributes); 340 } 341 342 case ARRAY_TYPE: 343 { 344 tree elt = common_type (TREE_TYPE (t1), TREE_TYPE (t2)); 345 /* Save space: see if the result is identical to one of the args. */ 346 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)) 347 return build_type_attribute_variant (t1, attributes); 348 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)) 349 return build_type_attribute_variant (t2, attributes); 350 /* Merge the element types, and have a size if either arg has one. */ 351 t1 = build_array_type (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2)); 352 return build_type_attribute_variant (t1, attributes); 353 } 354 355 case FUNCTION_TYPE: 356 /* Function types: prefer the one that specified arg types. 357 If both do, merge the arg types. Also merge the return types. */ 358 { 359 tree valtype = common_type (TREE_TYPE (t1), TREE_TYPE (t2)); 360 tree p1 = TYPE_ARG_TYPES (t1); 361 tree p2 = TYPE_ARG_TYPES (t2); 362 int len; 363 tree newargs, n; 364 int i; 365 366 /* Save space: see if the result is identical to one of the args. */ 367 if (valtype == TREE_TYPE (t1) && ! TYPE_ARG_TYPES (t2)) 368 return build_type_attribute_variant (t1, attributes); 369 if (valtype == TREE_TYPE (t2) && ! TYPE_ARG_TYPES (t1)) 370 return build_type_attribute_variant (t2, attributes); 371 372 /* Simple way if one arg fails to specify argument types. */ 373 if (TYPE_ARG_TYPES (t1) == 0) 374 { 375 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2)); 376 return build_type_attribute_variant (t1, attributes); 377 } 378 if (TYPE_ARG_TYPES (t2) == 0) 379 { 380 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1)); 381 return build_type_attribute_variant (t1, attributes); 382 } 383 384 /* If both args specify argument types, we must merge the two 385 lists, argument by argument. */ 386 387 pushlevel (0); 388 declare_parm_level (); 389 390 len = list_length (p1); 391 newargs = 0; 392 393 for (i = 0; i < len; i++) 394 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs); 395 396 n = newargs; 397 398 for (; p1; 399 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n)) 400 { 401 /* A null type means arg type is not specified. 402 Take whatever the other function type has. */ 403 if (TREE_VALUE (p1) == 0) 404 { 405 TREE_VALUE (n) = TREE_VALUE (p2); 406 goto parm_done; 407 } 408 if (TREE_VALUE (p2) == 0) 409 { 410 TREE_VALUE (n) = TREE_VALUE (p1); 411 goto parm_done; 412 } 413 414 /* Given wait (union {union wait *u; int *i} *) 415 and wait (union wait *), 416 prefer union wait * as type of parm. */ 417 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE 418 && TREE_VALUE (p1) != TREE_VALUE (p2)) 419 { 420 tree memb; 421 for (memb = TYPE_FIELDS (TREE_VALUE (p1)); 422 memb; memb = TREE_CHAIN (memb)) 423 if (comptypes (TREE_TYPE (memb), TREE_VALUE (p2), 424 COMPARE_STRICT)) 425 { 426 TREE_VALUE (n) = TREE_VALUE (p2); 427 if (pedantic) 428 pedwarn ("function types not truly compatible in ISO C"); 429 goto parm_done; 430 } 431 } 432 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE 433 && TREE_VALUE (p2) != TREE_VALUE (p1)) 434 { 435 tree memb; 436 for (memb = TYPE_FIELDS (TREE_VALUE (p2)); 437 memb; memb = TREE_CHAIN (memb)) 438 if (comptypes (TREE_TYPE (memb), TREE_VALUE (p1), 439 COMPARE_STRICT)) 440 { 441 TREE_VALUE (n) = TREE_VALUE (p1); 442 if (pedantic) 443 pedwarn ("function types not truly compatible in ISO C"); 444 goto parm_done; 445 } 446 } 447 TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2)); 448 parm_done: ; 449 } 450 451 poplevel (0, 0, 0); 452 453 t1 = build_function_type (valtype, newargs); 454 /* ... falls through ... */ 455 } 456 457 default: 458 return build_type_attribute_variant (t1, attributes); 459 } 460 461} 462 463/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment 464 or various other operations. Return 2 if they are compatible 465 but a warning may be needed if you use them together. */ 466 467int 468comptypes (tree type1, tree type2, int flags) 469{ 470 tree t1 = type1; 471 tree t2 = type2; 472 int attrval, val; 473 474 /* Suppress errors caused by previously reported errors. */ 475 476 if (t1 == t2 || !t1 || !t2 477 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK) 478 return 1; 479 480 /* If either type is the internal version of sizetype, return the 481 language version. */ 482 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1) 483 && TYPE_DOMAIN (t1) != 0) 484 t1 = TYPE_DOMAIN (t1); 485 486 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2) 487 && TYPE_DOMAIN (t2) != 0) 488 t2 = TYPE_DOMAIN (t2); 489 490 /* Enumerated types are compatible with integer types, but this is 491 not transitive: two enumerated types in the same translation unit 492 are compatible with each other only if they are the same type. */ 493 494 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE) 495 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TREE_UNSIGNED (t1)); 496 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE) 497 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TREE_UNSIGNED (t2)); 498 499 if (t1 == t2) 500 return 1; 501 502 /* Different classes of types can't be compatible. */ 503 504 if (TREE_CODE (t1) != TREE_CODE (t2)) 505 return 0; 506 507 /* Qualifiers must match. */ 508 509 if (TYPE_QUALS (t1) != TYPE_QUALS (t2)) 510 return 0; 511 512 /* Allow for two different type nodes which have essentially the same 513 definition. Note that we already checked for equality of the type 514 qualifiers (just above). */ 515 516 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) 517 return 1; 518 519 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 520 if (! (attrval = (*targetm.comp_type_attributes) (t1, t2))) 521 return 0; 522 523 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 524 val = 0; 525 526 switch (TREE_CODE (t1)) 527 { 528 case POINTER_TYPE: 529 /* We must give ObjC the first crack at comparing pointers, since 530 protocol qualifiers may be involved. */ 531 if (c_dialect_objc () && (val = objc_comptypes (t1, t2, 0)) >= 0) 532 break; 533 val = (TREE_TYPE (t1) == TREE_TYPE (t2) 534 ? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2), flags)); 535 break; 536 537 case FUNCTION_TYPE: 538 val = function_types_compatible_p (t1, t2, flags); 539 break; 540 541 case ARRAY_TYPE: 542 { 543 tree d1 = TYPE_DOMAIN (t1); 544 tree d2 = TYPE_DOMAIN (t2); 545 bool d1_variable, d2_variable; 546 bool d1_zero, d2_zero; 547 val = 1; 548 549 /* Target types must match incl. qualifiers. */ 550 if (TREE_TYPE (t1) != TREE_TYPE (t2) 551 && 0 == (val = comptypes (TREE_TYPE (t1), TREE_TYPE (t2), 552 flags))) 553 return 0; 554 555 /* Sizes must match unless one is missing or variable. */ 556 if (d1 == 0 || d2 == 0 || d1 == d2) 557 break; 558 559 d1_zero = ! TYPE_MAX_VALUE (d1); 560 d2_zero = ! TYPE_MAX_VALUE (d2); 561 562 d1_variable = (! d1_zero 563 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST 564 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST)); 565 d2_variable = (! d2_zero 566 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST 567 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)); 568 569 if (d1_variable || d2_variable) 570 break; 571 if (d1_zero && d2_zero) 572 break; 573 if (d1_zero || d2_zero 574 || ! tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)) 575 || ! tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2))) 576 val = 0; 577 578 break; 579 } 580 581 case RECORD_TYPE: 582 /* We are dealing with two distinct structs. In assorted Objective-C 583 corner cases, however, these can still be deemed equivalent. */ 584 if (c_dialect_objc () && objc_comptypes (t1, t2, 0) == 1) 585 val = 1; 586 587 case ENUMERAL_TYPE: 588 case UNION_TYPE: 589 if (val != 1 && !same_translation_unit_p (t1, t2)) 590 val = tagged_types_tu_compatible_p (t1, t2, flags); 591 break; 592 593 case VECTOR_TYPE: 594 /* The target might allow certain vector types to be compatible. */ 595 val = (*targetm.vector_opaque_p) (t1) 596 || (*targetm.vector_opaque_p) (t2); 597 break; 598 599 default: 600 break; 601 } 602 return attrval == 2 && val == 1 ? 2 : val; 603} 604 605/* Return 1 if TTL and TTR are pointers to types that are equivalent, 606 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it 607 to 1 or 0 depending if the check of the pointer types is meant to 608 be reflexive or not (typically, assignments are not reflexive, 609 while comparisons are reflexive). 610*/ 611 612static int 613comp_target_types (tree ttl, tree ttr, int reflexive) 614{ 615 int val; 616 617 /* Give objc_comptypes a crack at letting these types through. */ 618 if ((val = objc_comptypes (ttl, ttr, reflexive)) >= 0) 619 return val; 620 621 val = comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (ttl)), 622 TYPE_MAIN_VARIANT (TREE_TYPE (ttr)), COMPARE_STRICT); 623 624 if (val == 2 && pedantic) 625 pedwarn ("types are not quite compatible"); 626 return val; 627} 628 629/* Subroutines of `comptypes'. */ 630 631/* Determine whether two types derive from the same translation unit. 632 If the CONTEXT chain ends in a null, that type's context is still 633 being parsed, so if two types have context chains ending in null, 634 they're in the same translation unit. */ 635static int 636same_translation_unit_p (tree t1, tree t2) 637{ 638 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL) 639 switch (TREE_CODE_CLASS (TREE_CODE (t1))) 640 { 641 case 'd': t1 = DECL_CONTEXT (t1); break; 642 case 't': t1 = TYPE_CONTEXT (t1); break; 643 case 'b': t1 = BLOCK_SUPERCONTEXT (t1); break; 644 default: abort (); 645 } 646 647 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL) 648 switch (TREE_CODE_CLASS (TREE_CODE (t2))) 649 { 650 case 'd': t2 = DECL_CONTEXT (t1); break; 651 case 't': t2 = TYPE_CONTEXT (t2); break; 652 case 'b': t2 = BLOCK_SUPERCONTEXT (t2); break; 653 default: abort (); 654 } 655 656 return t1 == t2; 657} 658 659/* The C standard says that two structures in different translation 660 units are compatible with each other only if the types of their 661 fields are compatible (among other things). So, consider two copies 662 of this structure: */ 663 664struct tagged_tu_seen { 665 const struct tagged_tu_seen * next; 666 tree t1; 667 tree t2; 668}; 669 670/* Can they be compatible with each other? We choose to break the 671 recursion by allowing those types to be compatible. */ 672 673static const struct tagged_tu_seen * tagged_tu_seen_base; 674 675/* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are 676 compatible. If the two types are not the same (which has been 677 checked earlier), this can only happen when multiple translation 678 units are being compiled. See C99 6.2.7 paragraph 1 for the exact 679 rules. */ 680 681static int 682tagged_types_tu_compatible_p (tree t1, tree t2, int flags) 683{ 684 tree s1, s2; 685 bool needs_warning = false; 686 687 /* We have to verify that the tags of the types are the same. This 688 is harder than it looks because this may be a typedef, so we have 689 to go look at the original type. It may even be a typedef of a 690 typedef... */ 691 while (TYPE_NAME (t1) 692 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL 693 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1))) 694 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1)); 695 696 while (TYPE_NAME (t2) 697 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL 698 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2))) 699 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2)); 700 701 /* C90 didn't have the requirement that the two tags be the same. */ 702 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2)) 703 return 0; 704 705 /* C90 didn't say what happened if one or both of the types were 706 incomplete; we choose to follow C99 rules here, which is that they 707 are compatible. */ 708 if (TYPE_SIZE (t1) == NULL 709 || TYPE_SIZE (t2) == NULL) 710 return 1; 711 712 { 713 const struct tagged_tu_seen * tts_i; 714 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next) 715 if (tts_i->t1 == t1 && tts_i->t2 == t2) 716 return 1; 717 } 718 719 switch (TREE_CODE (t1)) 720 { 721 case ENUMERAL_TYPE: 722 { 723 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2))) 724 return 0; 725 726 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1)) 727 { 728 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2)); 729 if (s2 == NULL 730 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1) 731 return 0; 732 } 733 return 1; 734 } 735 736 case UNION_TYPE: 737 { 738 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2))) 739 return 0; 740 741 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1)) 742 { 743 bool ok = false; 744 struct tagged_tu_seen tts; 745 746 tts.next = tagged_tu_seen_base; 747 tts.t1 = t1; 748 tts.t2 = t2; 749 tagged_tu_seen_base = &tts; 750 751 if (DECL_NAME (s1) != NULL) 752 for (s2 = TYPE_VALUES (t2); s2; s2 = TREE_CHAIN (s2)) 753 if (DECL_NAME (s1) == DECL_NAME (s2)) 754 { 755 int result; 756 result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2), flags); 757 if (result == 0) 758 break; 759 if (result == 2) 760 needs_warning = true; 761 762 if (TREE_CODE (s1) == FIELD_DECL 763 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), 764 DECL_FIELD_BIT_OFFSET (s2)) != 1) 765 break; 766 767 ok = true; 768 break; 769 } 770 tagged_tu_seen_base = tts.next; 771 if (! ok) 772 return 0; 773 } 774 return needs_warning ? 2 : 1; 775 } 776 777 case RECORD_TYPE: 778 { 779 struct tagged_tu_seen tts; 780 781 tts.next = tagged_tu_seen_base; 782 tts.t1 = t1; 783 tts.t2 = t2; 784 tagged_tu_seen_base = &tts; 785 786 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); 787 s1 && s2; 788 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2)) 789 { 790 int result; 791 if (TREE_CODE (s1) != TREE_CODE (s2) 792 || DECL_NAME (s1) != DECL_NAME (s2)) 793 break; 794 result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2), flags); 795 if (result == 0) 796 break; 797 if (result == 2) 798 needs_warning = true; 799 800 if (TREE_CODE (s1) == FIELD_DECL 801 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), 802 DECL_FIELD_BIT_OFFSET (s2)) != 1) 803 break; 804 } 805 tagged_tu_seen_base = tts.next; 806 if (s1 && s2) 807 return 0; 808 return needs_warning ? 2 : 1; 809 } 810 811 default: 812 abort (); 813 } 814} 815 816/* Return 1 if two function types F1 and F2 are compatible. 817 If either type specifies no argument types, 818 the other must specify a fixed number of self-promoting arg types. 819 Otherwise, if one type specifies only the number of arguments, 820 the other must specify that number of self-promoting arg types. 821 Otherwise, the argument types must match. */ 822 823static int 824function_types_compatible_p (tree f1, tree f2, int flags) 825{ 826 tree args1, args2; 827 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 828 int val = 1; 829 int val1; 830 tree ret1, ret2; 831 832 ret1 = TREE_TYPE (f1); 833 ret2 = TREE_TYPE (f2); 834 835 /* 'volatile' qualifiers on a function's return type mean the function 836 is noreturn. */ 837 if (pedantic && TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2)) 838 pedwarn ("function return types not compatible due to `volatile'"); 839 if (TYPE_VOLATILE (ret1)) 840 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1), 841 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE); 842 if (TYPE_VOLATILE (ret2)) 843 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2), 844 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE); 845 val = comptypes (ret1, ret2, flags); 846 if (val == 0) 847 return 0; 848 849 args1 = TYPE_ARG_TYPES (f1); 850 args2 = TYPE_ARG_TYPES (f2); 851 852 /* An unspecified parmlist matches any specified parmlist 853 whose argument types don't need default promotions. */ 854 855 if (args1 == 0) 856 { 857 if (!self_promoting_args_p (args2)) 858 return 0; 859 /* If one of these types comes from a non-prototype fn definition, 860 compare that with the other type's arglist. 861 If they don't match, ask for a warning (but no error). */ 862 if (TYPE_ACTUAL_ARG_TYPES (f1) 863 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1), 864 flags)) 865 val = 2; 866 return val; 867 } 868 if (args2 == 0) 869 { 870 if (!self_promoting_args_p (args1)) 871 return 0; 872 if (TYPE_ACTUAL_ARG_TYPES (f2) 873 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2), 874 flags)) 875 val = 2; 876 return val; 877 } 878 879 /* Both types have argument lists: compare them and propagate results. */ 880 val1 = type_lists_compatible_p (args1, args2, flags); 881 return val1 != 1 ? val1 : val; 882} 883 884/* Check two lists of types for compatibility, 885 returning 0 for incompatible, 1 for compatible, 886 or 2 for compatible with warning. */ 887 888static int 889type_lists_compatible_p (tree args1, tree args2, int flags) 890{ 891 /* 1 if no need for warning yet, 2 if warning cause has been seen. */ 892 int val = 1; 893 int newval = 0; 894 895 while (1) 896 { 897 if (args1 == 0 && args2 == 0) 898 return val; 899 /* If one list is shorter than the other, 900 they fail to match. */ 901 if (args1 == 0 || args2 == 0) 902 return 0; 903 /* A null pointer instead of a type 904 means there is supposed to be an argument 905 but nothing is specified about what type it has. 906 So match anything that self-promotes. */ 907 if (TREE_VALUE (args1) == 0) 908 { 909 if (c_type_promotes_to (TREE_VALUE (args2)) != TREE_VALUE (args2)) 910 return 0; 911 } 912 else if (TREE_VALUE (args2) == 0) 913 { 914 if (c_type_promotes_to (TREE_VALUE (args1)) != TREE_VALUE (args1)) 915 return 0; 916 } 917 /* If one of the lists has an error marker, ignore this arg. */ 918 else if (TREE_CODE (TREE_VALUE (args1)) == ERROR_MARK 919 || TREE_CODE (TREE_VALUE (args2)) == ERROR_MARK) 920 ; 921 else if (! (newval = comptypes (TYPE_MAIN_VARIANT (TREE_VALUE (args1)), 922 TYPE_MAIN_VARIANT (TREE_VALUE (args2)), 923 flags))) 924 { 925 /* Allow wait (union {union wait *u; int *i} *) 926 and wait (union wait *) to be compatible. */ 927 if (TREE_CODE (TREE_VALUE (args1)) == UNION_TYPE 928 && (TYPE_NAME (TREE_VALUE (args1)) == 0 929 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args1))) 930 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args1))) == INTEGER_CST 931 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args1)), 932 TYPE_SIZE (TREE_VALUE (args2)))) 933 { 934 tree memb; 935 for (memb = TYPE_FIELDS (TREE_VALUE (args1)); 936 memb; memb = TREE_CHAIN (memb)) 937 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args2), 938 flags)) 939 break; 940 if (memb == 0) 941 return 0; 942 } 943 else if (TREE_CODE (TREE_VALUE (args2)) == UNION_TYPE 944 && (TYPE_NAME (TREE_VALUE (args2)) == 0 945 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args2))) 946 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args2))) == INTEGER_CST 947 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args2)), 948 TYPE_SIZE (TREE_VALUE (args1)))) 949 { 950 tree memb; 951 for (memb = TYPE_FIELDS (TREE_VALUE (args2)); 952 memb; memb = TREE_CHAIN (memb)) 953 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args1), 954 flags)) 955 break; 956 if (memb == 0) 957 return 0; 958 } 959 else 960 return 0; 961 } 962 963 /* comptypes said ok, but record if it said to warn. */ 964 if (newval > val) 965 val = newval; 966 967 args1 = TREE_CHAIN (args1); 968 args2 = TREE_CHAIN (args2); 969 } 970} 971 972/* Compute the size to increment a pointer by. */ 973 974tree 975c_size_in_bytes (tree type) 976{ 977 enum tree_code code = TREE_CODE (type); 978 979 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK) 980 return size_one_node; 981 982 if (!COMPLETE_OR_VOID_TYPE_P (type)) 983 { 984 error ("arithmetic on pointer to an incomplete type"); 985 return size_one_node; 986 } 987 988 /* Convert in case a char is more than one unit. */ 989 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), 990 size_int (TYPE_PRECISION (char_type_node) 991 / BITS_PER_UNIT)); 992} 993 994/* Return either DECL or its known constant value (if it has one). */ 995 996tree 997decl_constant_value (tree decl) 998{ 999 if (/* Don't change a variable array bound or initial value to a constant 1000 in a place where a variable is invalid. */ 1001 current_function_decl != 0 1002 && ! TREE_THIS_VOLATILE (decl) 1003 && TREE_READONLY (decl) 1004 && DECL_INITIAL (decl) != 0 1005 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK 1006 /* This is invalid if initial value is not constant. 1007 If it has either a function call, a memory reference, 1008 or a variable, then re-evaluating it could give different results. */ 1009 && TREE_CONSTANT (DECL_INITIAL (decl)) 1010 /* Check for cases where this is sub-optimal, even though valid. */ 1011 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR) 1012 return DECL_INITIAL (decl); 1013 return decl; 1014} 1015 1016/* Return either DECL or its known constant value (if it has one), but 1017 return DECL if pedantic or DECL has mode BLKmode. This is for 1018 bug-compatibility with the old behavior of decl_constant_value 1019 (before GCC 3.0); every use of this function is a bug and it should 1020 be removed before GCC 3.1. It is not appropriate to use pedantic 1021 in a way that affects optimization, and BLKmode is probably not the 1022 right test for avoiding misoptimizations either. */ 1023 1024static tree 1025decl_constant_value_for_broken_optimization (tree decl) 1026{ 1027 if (pedantic || DECL_MODE (decl) == BLKmode) 1028 return decl; 1029 else 1030 return decl_constant_value (decl); 1031} 1032 1033 1034/* Perform the default conversion of arrays and functions to pointers. 1035 Return the result of converting EXP. For any other expression, just 1036 return EXP. */ 1037 1038static tree 1039default_function_array_conversion (tree exp) 1040{ 1041 tree orig_exp; 1042 tree type = TREE_TYPE (exp); 1043 enum tree_code code = TREE_CODE (type); 1044 int not_lvalue = 0; 1045 1046 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as 1047 an lvalue. 1048 1049 Do not use STRIP_NOPS here! It will remove conversions from pointer 1050 to integer and cause infinite recursion. */ 1051 orig_exp = exp; 1052 while (TREE_CODE (exp) == NON_LVALUE_EXPR 1053 || (TREE_CODE (exp) == NOP_EXPR 1054 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp))) 1055 { 1056 if (TREE_CODE (exp) == NON_LVALUE_EXPR) 1057 not_lvalue = 1; 1058 exp = TREE_OPERAND (exp, 0); 1059 } 1060 1061 /* Preserve the original expression code. */ 1062 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp)))) 1063 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp)); 1064 1065 if (code == FUNCTION_TYPE) 1066 { 1067 return build_unary_op (ADDR_EXPR, exp, 0); 1068 } 1069 if (code == ARRAY_TYPE) 1070 { 1071 tree adr; 1072 tree restype = TREE_TYPE (type); 1073 tree ptrtype; 1074 int constp = 0; 1075 int volatilep = 0; 1076 int lvalue_array_p; 1077 1078 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'r' || DECL_P (exp)) 1079 { 1080 constp = TREE_READONLY (exp); 1081 volatilep = TREE_THIS_VOLATILE (exp); 1082 } 1083 1084 if (TYPE_QUALS (type) || constp || volatilep) 1085 restype 1086 = c_build_qualified_type (restype, 1087 TYPE_QUALS (type) 1088 | (constp * TYPE_QUAL_CONST) 1089 | (volatilep * TYPE_QUAL_VOLATILE)); 1090 1091 if (TREE_CODE (exp) == INDIRECT_REF) 1092 return convert (TYPE_POINTER_TO (restype), 1093 TREE_OPERAND (exp, 0)); 1094 1095 if (TREE_CODE (exp) == COMPOUND_EXPR) 1096 { 1097 tree op1 = default_conversion (TREE_OPERAND (exp, 1)); 1098 return build (COMPOUND_EXPR, TREE_TYPE (op1), 1099 TREE_OPERAND (exp, 0), op1); 1100 } 1101 1102 lvalue_array_p = !not_lvalue && lvalue_p (exp); 1103 if (!flag_isoc99 && !lvalue_array_p) 1104 { 1105 /* Before C99, non-lvalue arrays do not decay to pointers. 1106 Normally, using such an array would be invalid; but it can 1107 be used correctly inside sizeof or as a statement expression. 1108 Thus, do not give an error here; an error will result later. */ 1109 return exp; 1110 } 1111 1112 ptrtype = build_pointer_type (restype); 1113 1114 if (TREE_CODE (exp) == VAR_DECL) 1115 { 1116 /* ??? This is not really quite correct 1117 in that the type of the operand of ADDR_EXPR 1118 is not the target type of the type of the ADDR_EXPR itself. 1119 Question is, can this lossage be avoided? */ 1120 adr = build1 (ADDR_EXPR, ptrtype, exp); 1121 if (!c_mark_addressable (exp)) 1122 return error_mark_node; 1123 TREE_CONSTANT (adr) = staticp (exp); 1124 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */ 1125 return adr; 1126 } 1127 /* This way is better for a COMPONENT_REF since it can 1128 simplify the offset for a component. */ 1129 adr = build_unary_op (ADDR_EXPR, exp, 1); 1130 return convert (ptrtype, adr); 1131 } 1132 return exp; 1133} 1134 1135/* Perform default promotions for C data used in expressions. 1136 Arrays and functions are converted to pointers; 1137 enumeral types or short or char, to int. 1138 In addition, manifest constants symbols are replaced by their values. */ 1139 1140tree 1141default_conversion (tree exp) 1142{ 1143 tree orig_exp; 1144 tree type = TREE_TYPE (exp); 1145 enum tree_code code = TREE_CODE (type); 1146 1147 if (code == FUNCTION_TYPE || code == ARRAY_TYPE) 1148 return default_function_array_conversion (exp); 1149 1150 /* Constants can be used directly unless they're not loadable. */ 1151 if (TREE_CODE (exp) == CONST_DECL) 1152 exp = DECL_INITIAL (exp); 1153 1154 /* Replace a nonvolatile const static variable with its value unless 1155 it is an array, in which case we must be sure that taking the 1156 address of the array produces consistent results. */ 1157 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE) 1158 { 1159 exp = decl_constant_value_for_broken_optimization (exp); 1160 type = TREE_TYPE (exp); 1161 } 1162 1163 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as 1164 an lvalue. 1165 1166 Do not use STRIP_NOPS here! It will remove conversions from pointer 1167 to integer and cause infinite recursion. */ 1168 orig_exp = exp; 1169 while (TREE_CODE (exp) == NON_LVALUE_EXPR 1170 || (TREE_CODE (exp) == NOP_EXPR 1171 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp))) 1172 exp = TREE_OPERAND (exp, 0); 1173 1174 /* Preserve the original expression code. */ 1175 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp)))) 1176 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp)); 1177 1178 /* Normally convert enums to int, 1179 but convert wide enums to something wider. */ 1180 if (code == ENUMERAL_TYPE) 1181 { 1182 type = c_common_type_for_size (MAX (TYPE_PRECISION (type), 1183 TYPE_PRECISION (integer_type_node)), 1184 ((TYPE_PRECISION (type) 1185 >= TYPE_PRECISION (integer_type_node)) 1186 && TREE_UNSIGNED (type))); 1187 1188 return convert (type, exp); 1189 } 1190 1191 if (TREE_CODE (exp) == COMPONENT_REF 1192 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1)) 1193 /* If it's thinner than an int, promote it like a 1194 c_promoting_integer_type_p, otherwise leave it alone. */ 1195 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)), 1196 TYPE_PRECISION (integer_type_node))) 1197 return convert (integer_type_node, exp); 1198 1199 if (c_promoting_integer_type_p (type)) 1200 { 1201 /* Preserve unsignedness if not really getting any wider. */ 1202 if (TREE_UNSIGNED (type) 1203 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) 1204 return convert (unsigned_type_node, exp); 1205 1206 return convert (integer_type_node, exp); 1207 } 1208 1209 if (code == VOID_TYPE) 1210 { 1211 error ("void value not ignored as it ought to be"); 1212 return error_mark_node; 1213 } 1214 return exp; 1215} 1216 1217/* Look up COMPONENT in a structure or union DECL. 1218 1219 If the component name is not found, returns NULL_TREE. Otherwise, 1220 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL 1221 stepping down the chain to the component, which is in the last 1222 TREE_VALUE of the list. Normally the list is of length one, but if 1223 the component is embedded within (nested) anonymous structures or 1224 unions, the list steps down the chain to the component. */ 1225 1226static tree 1227lookup_field (tree decl, tree component) 1228{ 1229 tree type = TREE_TYPE (decl); 1230 tree field; 1231 1232 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers 1233 to the field elements. Use a binary search on this array to quickly 1234 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC 1235 will always be set for structures which have many elements. */ 1236 1237 if (TYPE_LANG_SPECIFIC (type)) 1238 { 1239 int bot, top, half; 1240 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0]; 1241 1242 field = TYPE_FIELDS (type); 1243 bot = 0; 1244 top = TYPE_LANG_SPECIFIC (type)->s->len; 1245 while (top - bot > 1) 1246 { 1247 half = (top - bot + 1) >> 1; 1248 field = field_array[bot+half]; 1249 1250 if (DECL_NAME (field) == NULL_TREE) 1251 { 1252 /* Step through all anon unions in linear fashion. */ 1253 while (DECL_NAME (field_array[bot]) == NULL_TREE) 1254 { 1255 field = field_array[bot++]; 1256 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE 1257 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE) 1258 { 1259 tree anon = lookup_field (field, component); 1260 1261 if (anon) 1262 return tree_cons (NULL_TREE, field, anon); 1263 } 1264 } 1265 1266 /* Entire record is only anon unions. */ 1267 if (bot > top) 1268 return NULL_TREE; 1269 1270 /* Restart the binary search, with new lower bound. */ 1271 continue; 1272 } 1273 1274 if (DECL_NAME (field) == component) 1275 break; 1276 if (DECL_NAME (field) < component) 1277 bot += half; 1278 else 1279 top = bot + half; 1280 } 1281 1282 if (DECL_NAME (field_array[bot]) == component) 1283 field = field_array[bot]; 1284 else if (DECL_NAME (field) != component) 1285 return NULL_TREE; 1286 } 1287 else 1288 { 1289 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 1290 { 1291 if (DECL_NAME (field) == NULL_TREE 1292 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE 1293 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)) 1294 { 1295 tree anon = lookup_field (field, component); 1296 1297 if (anon) 1298 return tree_cons (NULL_TREE, field, anon); 1299 } 1300 1301 if (DECL_NAME (field) == component) 1302 break; 1303 } 1304 1305 if (field == NULL_TREE) 1306 return NULL_TREE; 1307 } 1308 1309 return tree_cons (NULL_TREE, field, NULL_TREE); 1310} 1311 1312/* Make an expression to refer to the COMPONENT field of 1313 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */ 1314 1315tree 1316build_component_ref (tree datum, tree component) 1317{ 1318 tree type = TREE_TYPE (datum); 1319 enum tree_code code = TREE_CODE (type); 1320 tree field = NULL; 1321 tree ref; 1322 1323 /* If DATUM is a COMPOUND_EXPR, move our reference inside it. 1324 If pedantic ensure that the arguments are not lvalues; otherwise, 1325 if the component is an array, it would wrongly decay to a pointer in 1326 C89 mode. 1327 We cannot do this with a COND_EXPR, because in a conditional expression 1328 the default promotions are applied to both sides, and this would yield 1329 the wrong type of the result; for example, if the components have 1330 type "char". */ 1331 switch (TREE_CODE (datum)) 1332 { 1333 case COMPOUND_EXPR: 1334 { 1335 tree value = build_component_ref (TREE_OPERAND (datum, 1), component); 1336 return build (COMPOUND_EXPR, TREE_TYPE (value), 1337 TREE_OPERAND (datum, 0), pedantic_non_lvalue (value)); 1338 } 1339 default: 1340 break; 1341 } 1342 1343 /* See if there is a field or component with name COMPONENT. */ 1344 1345 if (code == RECORD_TYPE || code == UNION_TYPE) 1346 { 1347 if (!COMPLETE_TYPE_P (type)) 1348 { 1349 c_incomplete_type_error (NULL_TREE, type); 1350 return error_mark_node; 1351 } 1352 1353 field = lookup_field (datum, component); 1354 1355 if (!field) 1356 { 1357 error ("%s has no member named `%s'", 1358 code == RECORD_TYPE ? "structure" : "union", 1359 IDENTIFIER_POINTER (component)); 1360 return error_mark_node; 1361 } 1362 1363 /* Chain the COMPONENT_REFs if necessary down to the FIELD. 1364 This might be better solved in future the way the C++ front 1365 end does it - by giving the anonymous entities each a 1366 separate name and type, and then have build_component_ref 1367 recursively call itself. We can't do that here. */ 1368 do 1369 { 1370 tree subdatum = TREE_VALUE (field); 1371 1372 if (TREE_TYPE (subdatum) == error_mark_node) 1373 return error_mark_node; 1374 1375 ref = build (COMPONENT_REF, TREE_TYPE (subdatum), datum, subdatum); 1376 if (TREE_READONLY (datum) || TREE_READONLY (subdatum)) 1377 TREE_READONLY (ref) = 1; 1378 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum)) 1379 TREE_THIS_VOLATILE (ref) = 1; 1380 1381 if (TREE_DEPRECATED (subdatum)) 1382 warn_deprecated_use (subdatum); 1383 1384 datum = ref; 1385 1386 field = TREE_CHAIN (field); 1387 } 1388 while (field); 1389 1390 return ref; 1391 } 1392 else if (code != ERROR_MARK) 1393 error ("request for member `%s' in something not a structure or union", 1394 IDENTIFIER_POINTER (component)); 1395 1396 return error_mark_node; 1397} 1398 1399/* Given an expression PTR for a pointer, return an expression 1400 for the value pointed to. 1401 ERRORSTRING is the name of the operator to appear in error messages. */ 1402 1403tree 1404build_indirect_ref (tree ptr, const char *errorstring) 1405{ 1406 tree pointer = default_conversion (ptr); 1407 tree type = TREE_TYPE (pointer); 1408 1409 if (TREE_CODE (type) == POINTER_TYPE) 1410 { 1411 if (TREE_CODE (pointer) == ADDR_EXPR 1412 && (TREE_TYPE (TREE_OPERAND (pointer, 0)) 1413 == TREE_TYPE (type))) 1414 return TREE_OPERAND (pointer, 0); 1415 else 1416 { 1417 tree t = TREE_TYPE (type); 1418 tree ref = build1 (INDIRECT_REF, TYPE_MAIN_VARIANT (t), pointer); 1419 1420 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) 1421 { 1422 error ("dereferencing pointer to incomplete type"); 1423 return error_mark_node; 1424 } 1425 if (VOID_TYPE_P (t) && skip_evaluation == 0) 1426 warning ("dereferencing `void *' pointer"); 1427 1428 /* We *must* set TREE_READONLY when dereferencing a pointer to const, 1429 so that we get the proper error message if the result is used 1430 to assign to. Also, &* is supposed to be a no-op. 1431 And ANSI C seems to specify that the type of the result 1432 should be the const type. */ 1433 /* A de-reference of a pointer to const is not a const. It is valid 1434 to change it via some other pointer. */ 1435 TREE_READONLY (ref) = TYPE_READONLY (t); 1436 TREE_SIDE_EFFECTS (ref) 1437 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer); 1438 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t); 1439 return ref; 1440 } 1441 } 1442 else if (TREE_CODE (pointer) != ERROR_MARK) 1443 error ("invalid type argument of `%s'", errorstring); 1444 return error_mark_node; 1445} 1446 1447/* This handles expressions of the form "a[i]", which denotes 1448 an array reference. 1449 1450 This is logically equivalent in C to *(a+i), but we may do it differently. 1451 If A is a variable or a member, we generate a primitive ARRAY_REF. 1452 This avoids forcing the array out of registers, and can work on 1453 arrays that are not lvalues (for example, members of structures returned 1454 by functions). */ 1455 1456tree 1457build_array_ref (tree array, tree index) 1458{ 1459 if (index == 0) 1460 { 1461 error ("subscript missing in array reference"); 1462 return error_mark_node; 1463 } 1464 1465 if (TREE_TYPE (array) == error_mark_node 1466 || TREE_TYPE (index) == error_mark_node) 1467 return error_mark_node; 1468 1469 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE 1470 && TREE_CODE (array) != INDIRECT_REF) 1471 { 1472 tree rval, type; 1473 1474 /* Subscripting with type char is likely to lose 1475 on a machine where chars are signed. 1476 So warn on any machine, but optionally. 1477 Don't warn for unsigned char since that type is safe. 1478 Don't warn for signed char because anyone who uses that 1479 must have done so deliberately. */ 1480 if (warn_char_subscripts 1481 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) 1482 warning ("array subscript has type `char'"); 1483 1484 /* Apply default promotions *after* noticing character types. */ 1485 index = default_conversion (index); 1486 1487 /* Require integer *after* promotion, for sake of enums. */ 1488 if (TREE_CODE (TREE_TYPE (index)) != INTEGER_TYPE) 1489 { 1490 error ("array subscript is not an integer"); 1491 return error_mark_node; 1492 } 1493 1494 /* An array that is indexed by a non-constant 1495 cannot be stored in a register; we must be able to do 1496 address arithmetic on its address. 1497 Likewise an array of elements of variable size. */ 1498 if (TREE_CODE (index) != INTEGER_CST 1499 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) 1500 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST)) 1501 { 1502 if (!c_mark_addressable (array)) 1503 return error_mark_node; 1504 } 1505 /* An array that is indexed by a constant value which is not within 1506 the array bounds cannot be stored in a register either; because we 1507 would get a crash in store_bit_field/extract_bit_field when trying 1508 to access a non-existent part of the register. */ 1509 if (TREE_CODE (index) == INTEGER_CST 1510 && TYPE_VALUES (TREE_TYPE (array)) 1511 && ! int_fits_type_p (index, TYPE_VALUES (TREE_TYPE (array)))) 1512 { 1513 if (!c_mark_addressable (array)) 1514 return error_mark_node; 1515 } 1516 1517 if (pedantic) 1518 { 1519 tree foo = array; 1520 while (TREE_CODE (foo) == COMPONENT_REF) 1521 foo = TREE_OPERAND (foo, 0); 1522 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo)) 1523 pedwarn ("ISO C forbids subscripting `register' array"); 1524 else if (! flag_isoc99 && ! lvalue_p (foo)) 1525 pedwarn ("ISO C90 forbids subscripting non-lvalue array"); 1526 } 1527 1528 type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (array))); 1529 rval = build (ARRAY_REF, type, array, index); 1530 /* Array ref is const/volatile if the array elements are 1531 or if the array is. */ 1532 TREE_READONLY (rval) 1533 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array))) 1534 | TREE_READONLY (array)); 1535 TREE_SIDE_EFFECTS (rval) 1536 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 1537 | TREE_SIDE_EFFECTS (array)); 1538 TREE_THIS_VOLATILE (rval) 1539 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 1540 /* This was added by rms on 16 Nov 91. 1541 It fixes vol struct foo *a; a->elts[1] 1542 in an inline function. 1543 Hope it doesn't break something else. */ 1544 | TREE_THIS_VOLATILE (array)); 1545 return require_complete_type (fold (rval)); 1546 } 1547 1548 { 1549 tree ar = default_conversion (array); 1550 tree ind = default_conversion (index); 1551 1552 /* Do the same warning check as above, but only on the part that's 1553 syntactically the index and only if it is also semantically 1554 the index. */ 1555 if (warn_char_subscripts 1556 && TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE 1557 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) 1558 warning ("subscript has type `char'"); 1559 1560 /* Put the integer in IND to simplify error checking. */ 1561 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE) 1562 { 1563 tree temp = ar; 1564 ar = ind; 1565 ind = temp; 1566 } 1567 1568 if (ar == error_mark_node) 1569 return ar; 1570 1571 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE 1572 || TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) == FUNCTION_TYPE) 1573 { 1574 error ("subscripted value is neither array nor pointer"); 1575 return error_mark_node; 1576 } 1577 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE) 1578 { 1579 error ("array subscript is not an integer"); 1580 return error_mark_node; 1581 } 1582 1583 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, ind, 0), 1584 "array indexing"); 1585 } 1586} 1587 1588/* Build an external reference to identifier ID. FUN indicates 1589 whether this will be used for a function call. */ 1590tree 1591build_external_ref (tree id, int fun) 1592{ 1593 tree ref; 1594 tree decl = lookup_name (id); 1595 tree objc_ivar = lookup_objc_ivar (id); 1596 1597 if (decl && decl != error_mark_node) 1598 { 1599 /* Properly declared variable or function reference. */ 1600 if (!objc_ivar) 1601 ref = decl; 1602 else if (decl != objc_ivar && !DECL_FILE_SCOPE_P (decl)) 1603 { 1604 warning ("local declaration of `%s' hides instance variable", 1605 IDENTIFIER_POINTER (id)); 1606 ref = decl; 1607 } 1608 else 1609 ref = objc_ivar; 1610 } 1611 else if (objc_ivar) 1612 ref = objc_ivar; 1613 else if (fun) 1614 /* Implicit function declaration. */ 1615 ref = implicitly_declare (id); 1616 else if (decl == error_mark_node) 1617 /* Don't complain about something that's already been 1618 complained about. */ 1619 return error_mark_node; 1620 else 1621 { 1622 undeclared_variable (id); 1623 return error_mark_node; 1624 } 1625 1626 if (TREE_TYPE (ref) == error_mark_node) 1627 return error_mark_node; 1628 1629 if (TREE_DEPRECATED (ref)) 1630 warn_deprecated_use (ref); 1631 1632 if (!skip_evaluation) 1633 assemble_external (ref); 1634 TREE_USED (ref) = 1; 1635 1636 if (TREE_CODE (ref) == CONST_DECL) 1637 { 1638 ref = DECL_INITIAL (ref); 1639 TREE_CONSTANT (ref) = 1; 1640 } 1641 else if (current_function_decl != 0 1642 && !DECL_FILE_SCOPE_P (current_function_decl) 1643 && (TREE_CODE (ref) == VAR_DECL 1644 || TREE_CODE (ref) == PARM_DECL 1645 || TREE_CODE (ref) == FUNCTION_DECL)) 1646 { 1647 tree context = decl_function_context (ref); 1648 1649 if (context != 0 && context != current_function_decl) 1650 DECL_NONLOCAL (ref) = 1; 1651 } 1652 1653 return ref; 1654} 1655 1656/* Build a function call to function FUNCTION with parameters PARAMS. 1657 PARAMS is a list--a chain of TREE_LIST nodes--in which the 1658 TREE_VALUE of each node is a parameter-expression. 1659 FUNCTION's data type may be a function type or a pointer-to-function. */ 1660 1661tree 1662build_function_call (tree function, tree params) 1663{ 1664 tree fntype, fundecl = 0; 1665 tree coerced_params; 1666 tree name = NULL_TREE, result; 1667 tree tem; 1668 1669 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 1670 STRIP_TYPE_NOPS (function); 1671 1672 /* Convert anything with function type to a pointer-to-function. */ 1673 if (TREE_CODE (function) == FUNCTION_DECL) 1674 { 1675 name = DECL_NAME (function); 1676 1677 /* Differs from default_conversion by not setting TREE_ADDRESSABLE 1678 (because calling an inline function does not mean the function 1679 needs to be separately compiled). */ 1680 fntype = build_type_variant (TREE_TYPE (function), 1681 TREE_READONLY (function), 1682 TREE_THIS_VOLATILE (function)); 1683 fundecl = function; 1684 function = build1 (ADDR_EXPR, build_pointer_type (fntype), function); 1685 } 1686 else 1687 function = default_conversion (function); 1688 1689 fntype = TREE_TYPE (function); 1690 1691 if (TREE_CODE (fntype) == ERROR_MARK) 1692 return error_mark_node; 1693 1694 if (!(TREE_CODE (fntype) == POINTER_TYPE 1695 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) 1696 { 1697 error ("called object is not a function"); 1698 return error_mark_node; 1699 } 1700 1701 if (fundecl && TREE_THIS_VOLATILE (fundecl)) 1702 current_function_returns_abnormally = 1; 1703 1704 /* fntype now gets the type of function pointed to. */ 1705 fntype = TREE_TYPE (fntype); 1706 1707 /* Check that the function is called through a compatible prototype. 1708 If it is not, replace the call by a trap, wrapped up in a compound 1709 expression if necessary. This has the nice side-effect to prevent 1710 the tree-inliner from generating invalid assignment trees which may 1711 blow up in the RTL expander later. 1712 1713 ??? This doesn't work for Objective-C because objc_comptypes 1714 refuses to compare function prototypes, yet the compiler appears 1715 to build calls that are flagged as invalid by C's comptypes. */ 1716 if (! c_dialect_objc () 1717 && TREE_CODE (function) == NOP_EXPR 1718 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR 1719 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL 1720 && ! comptypes (fntype, TREE_TYPE (tem), COMPARE_STRICT)) 1721 { 1722 tree return_type = TREE_TYPE (fntype); 1723 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], 1724 NULL_TREE); 1725 1726 /* This situation leads to run-time undefined behavior. We can't, 1727 therefore, simply error unless we can prove that all possible 1728 executions of the program must execute the code. */ 1729 warning ("function called through a non-compatible type"); 1730 1731 /* We can, however, treat "undefined" any way we please. 1732 Call abort to encourage the user to fix the program. */ 1733 inform ("if this code is reached, the program will abort"); 1734 1735 if (VOID_TYPE_P (return_type)) 1736 return trap; 1737 else 1738 { 1739 tree rhs; 1740 1741 if (AGGREGATE_TYPE_P (return_type)) 1742 rhs = build_compound_literal (return_type, 1743 build_constructor (return_type, 1744 NULL_TREE)); 1745 else 1746 rhs = fold (build1 (NOP_EXPR, return_type, integer_zero_node)); 1747 1748 return build (COMPOUND_EXPR, return_type, trap, rhs); 1749 } 1750 } 1751 1752 /* Convert the parameters to the types declared in the 1753 function prototype, or apply default promotions. */ 1754 1755 coerced_params 1756 = convert_arguments (TYPE_ARG_TYPES (fntype), params, name, fundecl); 1757 1758 /* Check that the arguments to the function are valid. */ 1759 1760 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params); 1761 1762 /* Recognize certain built-in functions so we can make tree-codes 1763 other than CALL_EXPR. We do this when it enables fold-const.c 1764 to do something useful. */ 1765 1766 if (TREE_CODE (function) == ADDR_EXPR 1767 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL 1768 && DECL_BUILT_IN (TREE_OPERAND (function, 0))) 1769 { 1770 result = expand_tree_builtin (TREE_OPERAND (function, 0), 1771 params, coerced_params); 1772 if (result) 1773 return result; 1774 } 1775 1776 result = build (CALL_EXPR, TREE_TYPE (fntype), 1777 function, coerced_params, NULL_TREE); 1778 TREE_SIDE_EFFECTS (result) = 1; 1779 1780 if (require_constant_value) 1781 { 1782 result = fold_initializer (result); 1783 1784 if (TREE_CONSTANT (result) 1785 && (name == NULL_TREE 1786 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) 1787 pedwarn_init ("initializer element is not constant"); 1788 } 1789 else 1790 result = fold (result); 1791 1792 if (VOID_TYPE_P (TREE_TYPE (result))) 1793 return result; 1794 return require_complete_type (result); 1795} 1796 1797/* Convert the argument expressions in the list VALUES 1798 to the types in the list TYPELIST. The result is a list of converted 1799 argument expressions. 1800 1801 If TYPELIST is exhausted, or when an element has NULL as its type, 1802 perform the default conversions. 1803 1804 PARMLIST is the chain of parm decls for the function being called. 1805 It may be 0, if that info is not available. 1806 It is used only for generating error messages. 1807 1808 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages. 1809 1810 This is also where warnings about wrong number of args are generated. 1811 1812 Both VALUES and the returned value are chains of TREE_LIST nodes 1813 with the elements of the list in the TREE_VALUE slots of those nodes. */ 1814 1815static tree 1816convert_arguments (tree typelist, tree values, tree name, tree fundecl) 1817{ 1818 tree typetail, valtail; 1819 tree result = NULL; 1820 int parmnum; 1821 1822 /* Scan the given expressions and types, producing individual 1823 converted arguments and pushing them on RESULT in reverse order. */ 1824 1825 for (valtail = values, typetail = typelist, parmnum = 0; 1826 valtail; 1827 valtail = TREE_CHAIN (valtail), parmnum++) 1828 { 1829 tree type = typetail ? TREE_VALUE (typetail) : 0; 1830 tree val = TREE_VALUE (valtail); 1831 1832 if (type == void_type_node) 1833 { 1834 if (name) 1835 error ("too many arguments to function `%s'", 1836 IDENTIFIER_POINTER (name)); 1837 else 1838 error ("too many arguments to function"); 1839 break; 1840 } 1841 1842 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 1843 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0 1844 to convert automatically to a pointer. */ 1845 if (TREE_CODE (val) == NON_LVALUE_EXPR) 1846 val = TREE_OPERAND (val, 0); 1847 1848 val = default_function_array_conversion (val); 1849 1850 val = require_complete_type (val); 1851 1852 if (type != 0) 1853 { 1854 /* Formal parm type is specified by a function prototype. */ 1855 tree parmval; 1856 1857 if (!COMPLETE_TYPE_P (type)) 1858 { 1859 error ("type of formal parameter %d is incomplete", parmnum + 1); 1860 parmval = val; 1861 } 1862 else 1863 { 1864 /* Optionally warn about conversions that 1865 differ from the default conversions. */ 1866 if (warn_conversion || warn_traditional) 1867 { 1868 int formal_prec = TYPE_PRECISION (type); 1869 1870 if (INTEGRAL_TYPE_P (type) 1871 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1872 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1); 1873 if (INTEGRAL_TYPE_P (type) 1874 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 1875 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1); 1876 else if (TREE_CODE (type) == COMPLEX_TYPE 1877 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1878 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1); 1879 else if (TREE_CODE (type) == REAL_TYPE 1880 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1881 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1); 1882 else if (TREE_CODE (type) == COMPLEX_TYPE 1883 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1884 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1); 1885 else if (TREE_CODE (type) == REAL_TYPE 1886 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 1887 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1); 1888 /* ??? At some point, messages should be written about 1889 conversions between complex types, but that's too messy 1890 to do now. */ 1891 else if (TREE_CODE (type) == REAL_TYPE 1892 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1893 { 1894 /* Warn if any argument is passed as `float', 1895 since without a prototype it would be `double'. */ 1896 if (formal_prec == TYPE_PRECISION (float_type_node)) 1897 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1); 1898 } 1899 /* Detect integer changing in width or signedness. 1900 These warnings are only activated with 1901 -Wconversion, not with -Wtraditional. */ 1902 else if (warn_conversion && INTEGRAL_TYPE_P (type) 1903 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1904 { 1905 tree would_have_been = default_conversion (val); 1906 tree type1 = TREE_TYPE (would_have_been); 1907 1908 if (TREE_CODE (type) == ENUMERAL_TYPE 1909 && (TYPE_MAIN_VARIANT (type) 1910 == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) 1911 /* No warning if function asks for enum 1912 and the actual arg is that enum type. */ 1913 ; 1914 else if (formal_prec != TYPE_PRECISION (type1)) 1915 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1); 1916 else if (TREE_UNSIGNED (type) == TREE_UNSIGNED (type1)) 1917 ; 1918 /* Don't complain if the formal parameter type 1919 is an enum, because we can't tell now whether 1920 the value was an enum--even the same enum. */ 1921 else if (TREE_CODE (type) == ENUMERAL_TYPE) 1922 ; 1923 else if (TREE_CODE (val) == INTEGER_CST 1924 && int_fits_type_p (val, type)) 1925 /* Change in signedness doesn't matter 1926 if a constant value is unaffected. */ 1927 ; 1928 /* Likewise for a constant in a NOP_EXPR. */ 1929 else if (TREE_CODE (val) == NOP_EXPR 1930 && TREE_CODE (TREE_OPERAND (val, 0)) == INTEGER_CST 1931 && int_fits_type_p (TREE_OPERAND (val, 0), type)) 1932 ; 1933 /* If the value is extended from a narrower 1934 unsigned type, it doesn't matter whether we 1935 pass it as signed or unsigned; the value 1936 certainly is the same either way. */ 1937 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) 1938 && TREE_UNSIGNED (TREE_TYPE (val))) 1939 ; 1940 else if (TREE_UNSIGNED (type)) 1941 warn_for_assignment ("%s as unsigned due to prototype", (char *) 0, name, parmnum + 1); 1942 else 1943 warn_for_assignment ("%s as signed due to prototype", (char *) 0, name, parmnum + 1); 1944 } 1945 } 1946 1947 parmval = convert_for_assignment (type, val, 1948 (char *) 0, /* arg passing */ 1949 fundecl, name, parmnum + 1); 1950 1951 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) 1952 && INTEGRAL_TYPE_P (type) 1953 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 1954 parmval = default_conversion (parmval); 1955 } 1956 result = tree_cons (NULL_TREE, parmval, result); 1957 } 1958 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE 1959 && (TYPE_PRECISION (TREE_TYPE (val)) 1960 < TYPE_PRECISION (double_type_node))) 1961 /* Convert `float' to `double'. */ 1962 result = tree_cons (NULL_TREE, convert (double_type_node, val), result); 1963 else 1964 /* Convert `short' and `char' to full-size `int'. */ 1965 result = tree_cons (NULL_TREE, default_conversion (val), result); 1966 1967 if (typetail) 1968 typetail = TREE_CHAIN (typetail); 1969 } 1970 1971 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) 1972 { 1973 if (name) 1974 error ("too few arguments to function `%s'", 1975 IDENTIFIER_POINTER (name)); 1976 else 1977 error ("too few arguments to function"); 1978 } 1979 1980 return nreverse (result); 1981} 1982 1983/* This is the entry point used by the parser 1984 for binary operators in the input. 1985 In addition to constructing the expression, 1986 we check for operands that were written with other binary operators 1987 in a way that is likely to confuse the user. */ 1988 1989tree 1990parser_build_binary_op (enum tree_code code, tree arg1, tree arg2) 1991{ 1992 tree result = build_binary_op (code, arg1, arg2, 1); 1993 1994 char class; 1995 char class1 = TREE_CODE_CLASS (TREE_CODE (arg1)); 1996 char class2 = TREE_CODE_CLASS (TREE_CODE (arg2)); 1997 enum tree_code code1 = ERROR_MARK; 1998 enum tree_code code2 = ERROR_MARK; 1999 2000 if (TREE_CODE (result) == ERROR_MARK) 2001 return error_mark_node; 2002 2003 if (IS_EXPR_CODE_CLASS (class1)) 2004 code1 = C_EXP_ORIGINAL_CODE (arg1); 2005 if (IS_EXPR_CODE_CLASS (class2)) 2006 code2 = C_EXP_ORIGINAL_CODE (arg2); 2007 2008 /* Check for cases such as x+y<<z which users are likely 2009 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE 2010 is cleared to prevent these warnings. */ 2011 if (warn_parentheses) 2012 { 2013 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 2014 { 2015 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2016 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2017 warning ("suggest parentheses around + or - inside shift"); 2018 } 2019 2020 if (code == TRUTH_ORIF_EXPR) 2021 { 2022 if (code1 == TRUTH_ANDIF_EXPR 2023 || code2 == TRUTH_ANDIF_EXPR) 2024 warning ("suggest parentheses around && within ||"); 2025 } 2026 2027 if (code == BIT_IOR_EXPR) 2028 { 2029 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR 2030 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2031 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR 2032 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2033 warning ("suggest parentheses around arithmetic in operand of |"); 2034 /* Check cases like x|y==z */ 2035 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2036 warning ("suggest parentheses around comparison in operand of |"); 2037 } 2038 2039 if (code == BIT_XOR_EXPR) 2040 { 2041 if (code1 == BIT_AND_EXPR 2042 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2043 || code2 == BIT_AND_EXPR 2044 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2045 warning ("suggest parentheses around arithmetic in operand of ^"); 2046 /* Check cases like x^y==z */ 2047 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2048 warning ("suggest parentheses around comparison in operand of ^"); 2049 } 2050 2051 if (code == BIT_AND_EXPR) 2052 { 2053 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2054 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2055 warning ("suggest parentheses around + or - in operand of &"); 2056 /* Check cases like x&y==z */ 2057 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2058 warning ("suggest parentheses around comparison in operand of &"); 2059 } 2060 } 2061 2062 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 2063 if (TREE_CODE_CLASS (code) == '<' && extra_warnings 2064 && (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')) 2065 warning ("comparisons like X<=Y<=Z do not have their mathematical meaning"); 2066 2067 unsigned_conversion_warning (result, arg1); 2068 unsigned_conversion_warning (result, arg2); 2069 overflow_warning (result); 2070 2071 class = TREE_CODE_CLASS (TREE_CODE (result)); 2072 2073 /* Record the code that was specified in the source, 2074 for the sake of warnings about confusing nesting. */ 2075 if (IS_EXPR_CODE_CLASS (class)) 2076 C_SET_EXP_ORIGINAL_CODE (result, code); 2077 else 2078 { 2079 int flag = TREE_CONSTANT (result); 2080 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR 2081 so that convert_for_assignment wouldn't strip it. 2082 That way, we got warnings for things like p = (1 - 1). 2083 But it turns out we should not get those warnings. */ 2084 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result); 2085 C_SET_EXP_ORIGINAL_CODE (result, code); 2086 TREE_CONSTANT (result) = flag; 2087 } 2088 2089 return result; 2090} 2091 2092 2093/* Return true if `t' is known to be non-negative. */ 2094 2095int 2096c_tree_expr_nonnegative_p (tree t) 2097{ 2098 if (TREE_CODE (t) == STMT_EXPR) 2099 { 2100 t = COMPOUND_BODY (STMT_EXPR_STMT (t)); 2101 2102 /* Find the last statement in the chain, ignoring the final 2103 * scope statement */ 2104 while (TREE_CHAIN (t) != NULL_TREE 2105 && TREE_CODE (TREE_CHAIN (t)) != SCOPE_STMT) 2106 t = TREE_CHAIN (t); 2107 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)); 2108 } 2109 return tree_expr_nonnegative_p (t); 2110} 2111 2112/* Return a tree for the difference of pointers OP0 and OP1. 2113 The resulting tree has type int. */ 2114 2115static tree 2116pointer_diff (tree op0, tree op1) 2117{ 2118 tree result, folded; 2119 tree restype = ptrdiff_type_node; 2120 2121 tree target_type = TREE_TYPE (TREE_TYPE (op0)); 2122 tree con0, con1, lit0, lit1; 2123 tree orig_op1 = op1; 2124 2125 if (pedantic || warn_pointer_arith) 2126 { 2127 if (TREE_CODE (target_type) == VOID_TYPE) 2128 pedwarn ("pointer of type `void *' used in subtraction"); 2129 if (TREE_CODE (target_type) == FUNCTION_TYPE) 2130 pedwarn ("pointer to a function used in subtraction"); 2131 } 2132 2133 /* If the conversion to ptrdiff_type does anything like widening or 2134 converting a partial to an integral mode, we get a convert_expression 2135 that is in the way to do any simplifications. 2136 (fold-const.c doesn't know that the extra bits won't be needed. 2137 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a 2138 different mode in place.) 2139 So first try to find a common term here 'by hand'; we want to cover 2140 at least the cases that occur in legal static initializers. */ 2141 con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0; 2142 con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1; 2143 2144 if (TREE_CODE (con0) == PLUS_EXPR) 2145 { 2146 lit0 = TREE_OPERAND (con0, 1); 2147 con0 = TREE_OPERAND (con0, 0); 2148 } 2149 else 2150 lit0 = integer_zero_node; 2151 2152 if (TREE_CODE (con1) == PLUS_EXPR) 2153 { 2154 lit1 = TREE_OPERAND (con1, 1); 2155 con1 = TREE_OPERAND (con1, 0); 2156 } 2157 else 2158 lit1 = integer_zero_node; 2159 2160 if (operand_equal_p (con0, con1, 0)) 2161 { 2162 op0 = lit0; 2163 op1 = lit1; 2164 } 2165 2166 2167 /* First do the subtraction as integers; 2168 then drop through to build the divide operator. 2169 Do not do default conversions on the minus operator 2170 in case restype is a short type. */ 2171 2172 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), 2173 convert (restype, op1), 0); 2174 /* This generates an error if op1 is pointer to incomplete type. */ 2175 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) 2176 error ("arithmetic on pointer to an incomplete type"); 2177 2178 /* This generates an error if op0 is pointer to incomplete type. */ 2179 op1 = c_size_in_bytes (target_type); 2180 2181 /* Divide by the size, in easiest possible way. */ 2182 2183 result = build (EXACT_DIV_EXPR, restype, op0, convert (restype, op1)); 2184 2185 folded = fold (result); 2186 if (folded == result) 2187 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1); 2188 return folded; 2189} 2190 2191/* Construct and perhaps optimize a tree representation 2192 for a unary operation. CODE, a tree_code, specifies the operation 2193 and XARG is the operand. 2194 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses 2195 the default promotions (such as from short to int). 2196 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero 2197 allows non-lvalues; this is only used to handle conversion of non-lvalue 2198 arrays to pointers in C99. */ 2199 2200tree 2201build_unary_op (enum tree_code code, tree xarg, int flag) 2202{ 2203 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 2204 tree arg = xarg; 2205 tree argtype = 0; 2206 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); 2207 tree val; 2208 int noconvert = flag; 2209 2210 if (typecode == ERROR_MARK) 2211 return error_mark_node; 2212 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) 2213 typecode = INTEGER_TYPE; 2214 2215 switch (code) 2216 { 2217 case CONVERT_EXPR: 2218 /* This is used for unary plus, because a CONVERT_EXPR 2219 is enough to prevent anybody from looking inside for 2220 associativity, but won't generate any code. */ 2221 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2222 || typecode == COMPLEX_TYPE)) 2223 { 2224 error ("wrong type argument to unary plus"); 2225 return error_mark_node; 2226 } 2227 else if (!noconvert) 2228 arg = default_conversion (arg); 2229 arg = non_lvalue (arg); 2230 break; 2231 2232 case NEGATE_EXPR: 2233 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2234 || typecode == COMPLEX_TYPE 2235 || typecode == VECTOR_TYPE)) 2236 { 2237 error ("wrong type argument to unary minus"); 2238 return error_mark_node; 2239 } 2240 else if (!noconvert) 2241 arg = default_conversion (arg); 2242 break; 2243 2244 case BIT_NOT_EXPR: 2245 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) 2246 { 2247 if (!noconvert) 2248 arg = default_conversion (arg); 2249 } 2250 else if (typecode == COMPLEX_TYPE) 2251 { 2252 code = CONJ_EXPR; 2253 if (pedantic) 2254 pedwarn ("ISO C does not support `~' for complex conjugation"); 2255 if (!noconvert) 2256 arg = default_conversion (arg); 2257 } 2258 else 2259 { 2260 error ("wrong type argument to bit-complement"); 2261 return error_mark_node; 2262 } 2263 break; 2264 2265 case ABS_EXPR: 2266 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) 2267 { 2268 error ("wrong type argument to abs"); 2269 return error_mark_node; 2270 } 2271 else if (!noconvert) 2272 arg = default_conversion (arg); 2273 break; 2274 2275 case CONJ_EXPR: 2276 /* Conjugating a real value is a no-op, but allow it anyway. */ 2277 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2278 || typecode == COMPLEX_TYPE)) 2279 { 2280 error ("wrong type argument to conjugation"); 2281 return error_mark_node; 2282 } 2283 else if (!noconvert) 2284 arg = default_conversion (arg); 2285 break; 2286 2287 case TRUTH_NOT_EXPR: 2288 if (typecode != INTEGER_TYPE 2289 && typecode != REAL_TYPE && typecode != POINTER_TYPE 2290 && typecode != COMPLEX_TYPE 2291 /* These will convert to a pointer. */ 2292 && typecode != ARRAY_TYPE && typecode != FUNCTION_TYPE) 2293 { 2294 error ("wrong type argument to unary exclamation mark"); 2295 return error_mark_node; 2296 } 2297 arg = c_common_truthvalue_conversion (arg); 2298 return invert_truthvalue (arg); 2299 2300 case NOP_EXPR: 2301 break; 2302 2303 case REALPART_EXPR: 2304 if (TREE_CODE (arg) == COMPLEX_CST) 2305 return TREE_REALPART (arg); 2306 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2307 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); 2308 else 2309 return arg; 2310 2311 case IMAGPART_EXPR: 2312 if (TREE_CODE (arg) == COMPLEX_CST) 2313 return TREE_IMAGPART (arg); 2314 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2315 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); 2316 else 2317 return convert (TREE_TYPE (arg), integer_zero_node); 2318 2319 case PREINCREMENT_EXPR: 2320 case POSTINCREMENT_EXPR: 2321 case PREDECREMENT_EXPR: 2322 case POSTDECREMENT_EXPR: 2323 /* Handle complex lvalues (when permitted) 2324 by reduction to simpler cases. */ 2325 2326 val = unary_complex_lvalue (code, arg, 0); 2327 if (val != 0) 2328 return val; 2329 2330 /* Increment or decrement the real part of the value, 2331 and don't change the imaginary part. */ 2332 if (typecode == COMPLEX_TYPE) 2333 { 2334 tree real, imag; 2335 2336 if (pedantic) 2337 pedwarn ("ISO C does not support `++' and `--' on complex types"); 2338 2339 arg = stabilize_reference (arg); 2340 real = build_unary_op (REALPART_EXPR, arg, 1); 2341 imag = build_unary_op (IMAGPART_EXPR, arg, 1); 2342 return build (COMPLEX_EXPR, TREE_TYPE (arg), 2343 build_unary_op (code, real, 1), imag); 2344 } 2345 2346 /* Report invalid types. */ 2347 2348 if (typecode != POINTER_TYPE 2349 && typecode != INTEGER_TYPE && typecode != REAL_TYPE) 2350 { 2351 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2352 error ("wrong type argument to increment"); 2353 else 2354 error ("wrong type argument to decrement"); 2355 2356 return error_mark_node; 2357 } 2358 2359 { 2360 tree inc; 2361 tree result_type = TREE_TYPE (arg); 2362 2363 arg = get_unwidened (arg, 0); 2364 argtype = TREE_TYPE (arg); 2365 2366 /* Compute the increment. */ 2367 2368 if (typecode == POINTER_TYPE) 2369 { 2370 /* If pointer target is an undefined struct, 2371 we just cannot know how to do the arithmetic. */ 2372 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) 2373 { 2374 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2375 error ("increment of pointer to unknown structure"); 2376 else 2377 error ("decrement of pointer to unknown structure"); 2378 } 2379 else if ((pedantic || warn_pointer_arith) 2380 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE 2381 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) 2382 { 2383 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2384 pedwarn ("wrong type argument to increment"); 2385 else 2386 pedwarn ("wrong type argument to decrement"); 2387 } 2388 2389 inc = c_size_in_bytes (TREE_TYPE (result_type)); 2390 } 2391 else 2392 inc = integer_one_node; 2393 2394 inc = convert (argtype, inc); 2395 2396 /* Handle incrementing a cast-expression. */ 2397 2398 while (1) 2399 switch (TREE_CODE (arg)) 2400 { 2401 case NOP_EXPR: 2402 case CONVERT_EXPR: 2403 case FLOAT_EXPR: 2404 case FIX_TRUNC_EXPR: 2405 case FIX_FLOOR_EXPR: 2406 case FIX_ROUND_EXPR: 2407 case FIX_CEIL_EXPR: 2408 pedantic_lvalue_warning (CONVERT_EXPR); 2409 /* If the real type has the same machine representation 2410 as the type it is cast to, we can make better output 2411 by adding directly to the inside of the cast. */ 2412 if ((TREE_CODE (TREE_TYPE (arg)) 2413 == TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0)))) 2414 && (TYPE_MODE (TREE_TYPE (arg)) 2415 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (arg, 0))))) 2416 arg = TREE_OPERAND (arg, 0); 2417 else 2418 { 2419 tree incremented, modify, value; 2420 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 2421 value = boolean_increment (code, arg); 2422 else 2423 { 2424 arg = stabilize_reference (arg); 2425 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) 2426 value = arg; 2427 else 2428 value = save_expr (arg); 2429 incremented = build (((code == PREINCREMENT_EXPR 2430 || code == POSTINCREMENT_EXPR) 2431 ? PLUS_EXPR : MINUS_EXPR), 2432 argtype, value, inc); 2433 TREE_SIDE_EFFECTS (incremented) = 1; 2434 modify = build_modify_expr (arg, NOP_EXPR, incremented); 2435 value = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value); 2436 } 2437 TREE_USED (value) = 1; 2438 return value; 2439 } 2440 break; 2441 2442 default: 2443 goto give_up; 2444 } 2445 give_up: 2446 2447 /* Complain about anything else that is not a true lvalue. */ 2448 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 2449 || code == POSTINCREMENT_EXPR) 2450 ? "invalid lvalue in increment" 2451 : "invalid lvalue in decrement"))) 2452 return error_mark_node; 2453 2454 /* Report a read-only lvalue. */ 2455 if (TREE_READONLY (arg)) 2456 readonly_error (arg, 2457 ((code == PREINCREMENT_EXPR 2458 || code == POSTINCREMENT_EXPR) 2459 ? "increment" : "decrement")); 2460 2461 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 2462 val = boolean_increment (code, arg); 2463 else 2464 val = build (code, TREE_TYPE (arg), arg, inc); 2465 TREE_SIDE_EFFECTS (val) = 1; 2466 val = convert (result_type, val); 2467 if (TREE_CODE (val) != code) 2468 TREE_NO_UNUSED_WARNING (val) = 1; 2469 return val; 2470 } 2471 2472 case ADDR_EXPR: 2473 /* Note that this operation never does default_conversion. */ 2474 2475 /* Let &* cancel out to simplify resulting code. */ 2476 if (TREE_CODE (arg) == INDIRECT_REF) 2477 { 2478 /* Don't let this be an lvalue. */ 2479 if (lvalue_p (TREE_OPERAND (arg, 0))) 2480 return non_lvalue (TREE_OPERAND (arg, 0)); 2481 return TREE_OPERAND (arg, 0); 2482 } 2483 2484 /* For &x[y], return x+y */ 2485 if (TREE_CODE (arg) == ARRAY_REF) 2486 { 2487 if (!c_mark_addressable (TREE_OPERAND (arg, 0))) 2488 return error_mark_node; 2489 return build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0), 2490 TREE_OPERAND (arg, 1), 1); 2491 } 2492 2493 /* Handle complex lvalues (when permitted) 2494 by reduction to simpler cases. */ 2495 val = unary_complex_lvalue (code, arg, flag); 2496 if (val != 0) 2497 return val; 2498 2499 /* Anything not already handled and not a true memory reference 2500 or a non-lvalue array is an error. */ 2501 else if (typecode != FUNCTION_TYPE && !flag 2502 && !lvalue_or_else (arg, "invalid lvalue in unary `&'")) 2503 return error_mark_node; 2504 2505 /* Ordinary case; arg is a COMPONENT_REF or a decl. */ 2506 argtype = TREE_TYPE (arg); 2507 2508 /* If the lvalue is const or volatile, merge that into the type 2509 to which the address will point. Note that you can't get a 2510 restricted pointer by taking the address of something, so we 2511 only have to deal with `const' and `volatile' here. */ 2512 if ((DECL_P (arg) || TREE_CODE_CLASS (TREE_CODE (arg)) == 'r') 2513 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) 2514 argtype = c_build_type_variant (argtype, 2515 TREE_READONLY (arg), 2516 TREE_THIS_VOLATILE (arg)); 2517 2518 argtype = build_pointer_type (argtype); 2519 2520 if (!c_mark_addressable (arg)) 2521 return error_mark_node; 2522 2523 { 2524 tree addr; 2525 2526 if (TREE_CODE (arg) == COMPONENT_REF) 2527 { 2528 tree field = TREE_OPERAND (arg, 1); 2529 2530 addr = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), flag); 2531 2532 if (DECL_C_BIT_FIELD (field)) 2533 { 2534 error ("attempt to take address of bit-field structure member `%s'", 2535 IDENTIFIER_POINTER (DECL_NAME (field))); 2536 return error_mark_node; 2537 } 2538 2539 addr = fold (build (PLUS_EXPR, argtype, 2540 convert (argtype, addr), 2541 convert (argtype, byte_position (field)))); 2542 } 2543 else 2544 addr = build1 (code, argtype, arg); 2545 2546 /* Address of a static or external variable or 2547 file-scope function counts as a constant. */ 2548 if (staticp (arg) 2549 && ! (TREE_CODE (arg) == FUNCTION_DECL 2550 && !DECL_FILE_SCOPE_P (arg))) 2551 TREE_CONSTANT (addr) = 1; 2552 return addr; 2553 } 2554 2555 default: 2556 break; 2557 } 2558 2559 if (argtype == 0) 2560 argtype = TREE_TYPE (arg); 2561 val = build1 (code, argtype, arg); 2562 return require_constant_value ? fold_initializer (val) : fold (val); 2563} 2564 2565/* Return nonzero if REF is an lvalue valid for this language. 2566 Lvalues can be assigned, unless their type has TYPE_READONLY. 2567 Lvalues can have their address taken, unless they have DECL_REGISTER. */ 2568 2569int 2570lvalue_p (tree ref) 2571{ 2572 enum tree_code code = TREE_CODE (ref); 2573 2574 switch (code) 2575 { 2576 case REALPART_EXPR: 2577 case IMAGPART_EXPR: 2578 case COMPONENT_REF: 2579 return lvalue_p (TREE_OPERAND (ref, 0)); 2580 2581 case COMPOUND_LITERAL_EXPR: 2582 case STRING_CST: 2583 return 1; 2584 2585 case INDIRECT_REF: 2586 case ARRAY_REF: 2587 case VAR_DECL: 2588 case PARM_DECL: 2589 case RESULT_DECL: 2590 case ERROR_MARK: 2591 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE 2592 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); 2593 2594 case BIND_EXPR: 2595 case RTL_EXPR: 2596 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; 2597 2598 default: 2599 return 0; 2600 } 2601} 2602 2603/* Return nonzero if REF is an lvalue valid for this language; 2604 otherwise, print an error message and return zero. */ 2605 2606int 2607lvalue_or_else (tree ref, const char *msgid) 2608{ 2609 int win = lvalue_p (ref); 2610 2611 if (! win) 2612 error ("%s", msgid); 2613 2614 return win; 2615} 2616 2617/* Apply unary lvalue-demanding operator CODE to the expression ARG 2618 for certain kinds of expressions which are not really lvalues 2619 but which we can accept as lvalues. If FLAG is nonzero, then 2620 non-lvalues are OK since we may be converting a non-lvalue array to 2621 a pointer in C99. 2622 2623 If ARG is not a kind of expression we can handle, return zero. */ 2624 2625static tree 2626unary_complex_lvalue (enum tree_code code, tree arg, int flag) 2627{ 2628 /* Handle (a, b) used as an "lvalue". */ 2629 if (TREE_CODE (arg) == COMPOUND_EXPR) 2630 { 2631 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0); 2632 2633 /* If this returns a function type, it isn't really being used as 2634 an lvalue, so don't issue a warning about it. */ 2635 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag) 2636 pedantic_lvalue_warning (COMPOUND_EXPR); 2637 2638 return build (COMPOUND_EXPR, TREE_TYPE (real_result), 2639 TREE_OPERAND (arg, 0), real_result); 2640 } 2641 2642 /* Handle (a ? b : c) used as an "lvalue". */ 2643 if (TREE_CODE (arg) == COND_EXPR) 2644 { 2645 if (!flag) 2646 pedantic_lvalue_warning (COND_EXPR); 2647 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag) 2648 pedantic_lvalue_warning (COMPOUND_EXPR); 2649 2650 return (build_conditional_expr 2651 (TREE_OPERAND (arg, 0), 2652 build_unary_op (code, TREE_OPERAND (arg, 1), flag), 2653 build_unary_op (code, TREE_OPERAND (arg, 2), flag))); 2654 } 2655 2656 return 0; 2657} 2658 2659/* If pedantic, warn about improper lvalue. CODE is either COND_EXPR 2660 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */ 2661 2662static void 2663pedantic_lvalue_warning (enum tree_code code) 2664{ 2665 switch (code) 2666 { 2667 case COND_EXPR: 2668 pedwarn ("use of conditional expressions as lvalues is deprecated"); 2669 break; 2670 case COMPOUND_EXPR: 2671 pedwarn ("use of compound expressions as lvalues is deprecated"); 2672 break; 2673 default: 2674 pedwarn ("use of cast expressions as lvalues is deprecated"); 2675 break; 2676 } 2677} 2678 2679/* Warn about storing in something that is `const'. */ 2680 2681void 2682readonly_error (tree arg, const char *msgid) 2683{ 2684 if (TREE_CODE (arg) == COMPONENT_REF) 2685 { 2686 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) 2687 readonly_error (TREE_OPERAND (arg, 0), msgid); 2688 else 2689 error ("%s of read-only member `%s'", _(msgid), 2690 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (arg, 1)))); 2691 } 2692 else if (TREE_CODE (arg) == VAR_DECL) 2693 error ("%s of read-only variable `%s'", _(msgid), 2694 IDENTIFIER_POINTER (DECL_NAME (arg))); 2695 else 2696 error ("%s of read-only location", _(msgid)); 2697} 2698 2699/* Mark EXP saying that we need to be able to take the 2700 address of it; it should not be allocated in a register. 2701 Returns true if successful. */ 2702 2703bool 2704c_mark_addressable (tree exp) 2705{ 2706 tree x = exp; 2707 2708 while (1) 2709 switch (TREE_CODE (x)) 2710 { 2711 case COMPONENT_REF: 2712 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) 2713 { 2714 error ("cannot take address of bit-field `%s'", 2715 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (x, 1)))); 2716 return false; 2717 } 2718 2719 /* ... fall through ... */ 2720 2721 case ADDR_EXPR: 2722 case ARRAY_REF: 2723 case REALPART_EXPR: 2724 case IMAGPART_EXPR: 2725 x = TREE_OPERAND (x, 0); 2726 break; 2727 2728 case COMPOUND_LITERAL_EXPR: 2729 case CONSTRUCTOR: 2730 TREE_ADDRESSABLE (x) = 1; 2731 return true; 2732 2733 case VAR_DECL: 2734 case CONST_DECL: 2735 case PARM_DECL: 2736 case RESULT_DECL: 2737 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x) 2738 && DECL_NONLOCAL (x)) 2739 { 2740 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 2741 { 2742 error ("global register variable `%s' used in nested function", 2743 IDENTIFIER_POINTER (DECL_NAME (x))); 2744 return false; 2745 } 2746 pedwarn ("register variable `%s' used in nested function", 2747 IDENTIFIER_POINTER (DECL_NAME (x))); 2748 } 2749 else if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)) 2750 { 2751 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 2752 { 2753 error ("address of global register variable `%s' requested", 2754 IDENTIFIER_POINTER (DECL_NAME (x))); 2755 return false; 2756 } 2757 2758 /* If we are making this addressable due to its having 2759 volatile components, give a different error message. Also 2760 handle the case of an unnamed parameter by not trying 2761 to give the name. */ 2762 2763 else if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (x))) 2764 { 2765 error ("cannot put object with volatile field into register"); 2766 return false; 2767 } 2768 2769 pedwarn ("address of register variable `%s' requested", 2770 IDENTIFIER_POINTER (DECL_NAME (x))); 2771 } 2772 put_var_into_stack (x, /*rescan=*/true); 2773 2774 /* drops in */ 2775 case FUNCTION_DECL: 2776 TREE_ADDRESSABLE (x) = 1; 2777 /* drops out */ 2778 default: 2779 return true; 2780 } 2781} 2782 2783/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 2784 2785tree 2786build_conditional_expr (tree ifexp, tree op1, tree op2) 2787{ 2788 tree type1; 2789 tree type2; 2790 enum tree_code code1; 2791 enum tree_code code2; 2792 tree result_type = NULL; 2793 tree orig_op1 = op1, orig_op2 = op2; 2794 2795 ifexp = c_common_truthvalue_conversion (default_conversion (ifexp)); 2796 2797 /* Promote both alternatives. */ 2798 2799 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) 2800 op1 = default_conversion (op1); 2801 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) 2802 op2 = default_conversion (op2); 2803 2804 if (TREE_CODE (ifexp) == ERROR_MARK 2805 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK 2806 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) 2807 return error_mark_node; 2808 2809 type1 = TREE_TYPE (op1); 2810 code1 = TREE_CODE (type1); 2811 type2 = TREE_TYPE (op2); 2812 code2 = TREE_CODE (type2); 2813 2814 /* Quickly detect the usual case where op1 and op2 have the same type 2815 after promotion. */ 2816 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) 2817 { 2818 if (type1 == type2) 2819 result_type = type1; 2820 else 2821 result_type = TYPE_MAIN_VARIANT (type1); 2822 } 2823 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE 2824 || code1 == COMPLEX_TYPE) 2825 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE 2826 || code2 == COMPLEX_TYPE)) 2827 { 2828 result_type = common_type (type1, type2); 2829 2830 /* If -Wsign-compare, warn here if type1 and type2 have 2831 different signedness. We'll promote the signed to unsigned 2832 and later code won't know it used to be different. 2833 Do this check on the original types, so that explicit casts 2834 will be considered, but default promotions won't. */ 2835 if (warn_sign_compare && !skip_evaluation) 2836 { 2837 int unsigned_op1 = TREE_UNSIGNED (TREE_TYPE (orig_op1)); 2838 int unsigned_op2 = TREE_UNSIGNED (TREE_TYPE (orig_op2)); 2839 2840 if (unsigned_op1 ^ unsigned_op2) 2841 { 2842 /* Do not warn if the result type is signed, since the 2843 signed type will only be chosen if it can represent 2844 all the values of the unsigned type. */ 2845 if (! TREE_UNSIGNED (result_type)) 2846 /* OK */; 2847 /* Do not warn if the signed quantity is an unsuffixed 2848 integer literal (or some static constant expression 2849 involving such literals) and it is non-negative. */ 2850 else if ((unsigned_op2 && c_tree_expr_nonnegative_p (op1)) 2851 || (unsigned_op1 && c_tree_expr_nonnegative_p (op2))) 2852 /* OK */; 2853 else 2854 warning ("signed and unsigned type in conditional expression"); 2855 } 2856 } 2857 } 2858 else if (code1 == VOID_TYPE || code2 == VOID_TYPE) 2859 { 2860 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) 2861 pedwarn ("ISO C forbids conditional expr with only one void side"); 2862 result_type = void_type_node; 2863 } 2864 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) 2865 { 2866 if (comp_target_types (type1, type2, 1)) 2867 result_type = common_type (type1, type2); 2868 else if (integer_zerop (op1) && TREE_TYPE (type1) == void_type_node 2869 && TREE_CODE (orig_op1) != NOP_EXPR) 2870 result_type = qualify_type (type2, type1); 2871 else if (integer_zerop (op2) && TREE_TYPE (type2) == void_type_node 2872 && TREE_CODE (orig_op2) != NOP_EXPR) 2873 result_type = qualify_type (type1, type2); 2874 else if (VOID_TYPE_P (TREE_TYPE (type1))) 2875 { 2876 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) 2877 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer"); 2878 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), 2879 TREE_TYPE (type2))); 2880 } 2881 else if (VOID_TYPE_P (TREE_TYPE (type2))) 2882 { 2883 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) 2884 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer"); 2885 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), 2886 TREE_TYPE (type1))); 2887 } 2888 else 2889 { 2890 pedwarn ("pointer type mismatch in conditional expression"); 2891 result_type = build_pointer_type (void_type_node); 2892 } 2893 } 2894 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) 2895 { 2896 if (! integer_zerop (op2)) 2897 pedwarn ("pointer/integer type mismatch in conditional expression"); 2898 else 2899 { 2900 op2 = null_pointer_node; 2901 } 2902 result_type = type1; 2903 } 2904 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) 2905 { 2906 if (!integer_zerop (op1)) 2907 pedwarn ("pointer/integer type mismatch in conditional expression"); 2908 else 2909 { 2910 op1 = null_pointer_node; 2911 } 2912 result_type = type2; 2913 } 2914 2915 if (!result_type) 2916 { 2917 if (flag_cond_mismatch) 2918 result_type = void_type_node; 2919 else 2920 { 2921 error ("type mismatch in conditional expression"); 2922 return error_mark_node; 2923 } 2924 } 2925 2926 /* Merge const and volatile flags of the incoming types. */ 2927 result_type 2928 = build_type_variant (result_type, 2929 TREE_READONLY (op1) || TREE_READONLY (op2), 2930 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); 2931 2932 if (result_type != TREE_TYPE (op1)) 2933 op1 = convert_and_check (result_type, op1); 2934 if (result_type != TREE_TYPE (op2)) 2935 op2 = convert_and_check (result_type, op2); 2936 2937 if (TREE_CODE (ifexp) == INTEGER_CST) 2938 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1); 2939 2940 return fold (build (COND_EXPR, result_type, ifexp, op1, op2)); 2941} 2942 2943/* Given a list of expressions, return a compound expression 2944 that performs them all and returns the value of the last of them. */ 2945 2946tree 2947build_compound_expr (tree list) 2948{ 2949 return internal_build_compound_expr (list, TRUE); 2950} 2951 2952static tree 2953internal_build_compound_expr (tree list, int first_p) 2954{ 2955 tree rest; 2956 2957 if (TREE_CHAIN (list) == 0) 2958 { 2959 /* Convert arrays and functions to pointers when there 2960 really is a comma operator. */ 2961 if (!first_p) 2962 TREE_VALUE (list) 2963 = default_function_array_conversion (TREE_VALUE (list)); 2964 2965 /* Don't let (0, 0) be null pointer constant. */ 2966 if (!first_p && integer_zerop (TREE_VALUE (list))) 2967 return non_lvalue (TREE_VALUE (list)); 2968 return TREE_VALUE (list); 2969 } 2970 2971 rest = internal_build_compound_expr (TREE_CHAIN (list), FALSE); 2972 2973 if (! TREE_SIDE_EFFECTS (TREE_VALUE (list))) 2974 { 2975 /* The left-hand operand of a comma expression is like an expression 2976 statement: with -Wextra or -Wunused, we should warn if it doesn't have 2977 any side-effects, unless it was explicitly cast to (void). */ 2978 if (warn_unused_value 2979 && ! (TREE_CODE (TREE_VALUE (list)) == CONVERT_EXPR 2980 && VOID_TYPE_P (TREE_TYPE (TREE_VALUE (list))))) 2981 warning ("left-hand operand of comma expression has no effect"); 2982 } 2983 2984 /* With -Wunused, we should also warn if the left-hand operand does have 2985 side-effects, but computes a value which is not used. For example, in 2986 `foo() + bar(), baz()' the result of the `+' operator is not used, 2987 so we should issue a warning. */ 2988 else if (warn_unused_value) 2989 warn_if_unused_value (TREE_VALUE (list)); 2990 2991 return build (COMPOUND_EXPR, TREE_TYPE (rest), TREE_VALUE (list), rest); 2992} 2993 2994/* Build an expression representing a cast to type TYPE of expression EXPR. */ 2995 2996tree 2997build_c_cast (tree type, tree expr) 2998{ 2999 tree value = expr; 3000 3001 if (type == error_mark_node || expr == error_mark_node) 3002 return error_mark_node; 3003 3004 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing 3005 only in <protocol> qualifications. But when constructing cast expressions, 3006 the protocols do matter and must be kept around. */ 3007 if (!c_dialect_objc () || !objc_is_object_ptr (type)) 3008 type = TYPE_MAIN_VARIANT (type); 3009 3010 if (TREE_CODE (type) == ARRAY_TYPE) 3011 { 3012 error ("cast specifies array type"); 3013 return error_mark_node; 3014 } 3015 3016 if (TREE_CODE (type) == FUNCTION_TYPE) 3017 { 3018 error ("cast specifies function type"); 3019 return error_mark_node; 3020 } 3021 3022 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) 3023 { 3024 if (pedantic) 3025 { 3026 if (TREE_CODE (type) == RECORD_TYPE 3027 || TREE_CODE (type) == UNION_TYPE) 3028 pedwarn ("ISO C forbids casting nonscalar to the same type"); 3029 } 3030 } 3031 else if (TREE_CODE (type) == UNION_TYPE) 3032 { 3033 tree field; 3034 value = default_function_array_conversion (value); 3035 3036 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3037 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), 3038 TYPE_MAIN_VARIANT (TREE_TYPE (value)), COMPARE_STRICT)) 3039 break; 3040 3041 if (field) 3042 { 3043 tree t; 3044 3045 if (pedantic) 3046 pedwarn ("ISO C forbids casts to union type"); 3047 t = digest_init (type, 3048 build_constructor (type, 3049 build_tree_list (field, value)), 3050 0); 3051 TREE_CONSTANT (t) = TREE_CONSTANT (value); 3052 return t; 3053 } 3054 error ("cast to union type from type not present in union"); 3055 return error_mark_node; 3056 } 3057 else 3058 { 3059 tree otype, ovalue; 3060 3061 /* If casting to void, avoid the error that would come 3062 from default_conversion in the case of a non-lvalue array. */ 3063 if (type == void_type_node) 3064 return build1 (CONVERT_EXPR, type, value); 3065 3066 /* Convert functions and arrays to pointers, 3067 but don't convert any other types. */ 3068 value = default_function_array_conversion (value); 3069 otype = TREE_TYPE (value); 3070 3071 /* Optionally warn about potentially worrisome casts. */ 3072 3073 if (warn_cast_qual 3074 && TREE_CODE (type) == POINTER_TYPE 3075 && TREE_CODE (otype) == POINTER_TYPE) 3076 { 3077 tree in_type = type; 3078 tree in_otype = otype; 3079 int added = 0; 3080 int discarded = 0; 3081 3082 /* Check that the qualifiers on IN_TYPE are a superset of 3083 the qualifiers of IN_OTYPE. The outermost level of 3084 POINTER_TYPE nodes is uninteresting and we stop as soon 3085 as we hit a non-POINTER_TYPE node on either type. */ 3086 do 3087 { 3088 in_otype = TREE_TYPE (in_otype); 3089 in_type = TREE_TYPE (in_type); 3090 3091 /* GNU C allows cv-qualified function types. 'const' 3092 means the function is very pure, 'volatile' means it 3093 can't return. We need to warn when such qualifiers 3094 are added, not when they're taken away. */ 3095 if (TREE_CODE (in_otype) == FUNCTION_TYPE 3096 && TREE_CODE (in_type) == FUNCTION_TYPE) 3097 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); 3098 else 3099 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); 3100 } 3101 while (TREE_CODE (in_type) == POINTER_TYPE 3102 && TREE_CODE (in_otype) == POINTER_TYPE); 3103 3104 if (added) 3105 warning ("cast adds new qualifiers to function type"); 3106 3107 if (discarded) 3108 /* There are qualifiers present in IN_OTYPE that are not 3109 present in IN_TYPE. */ 3110 warning ("cast discards qualifiers from pointer target type"); 3111 } 3112 3113 /* Warn about possible alignment problems. */ 3114 if (STRICT_ALIGNMENT && warn_cast_align 3115 && TREE_CODE (type) == POINTER_TYPE 3116 && TREE_CODE (otype) == POINTER_TYPE 3117 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE 3118 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3119 /* Don't warn about opaque types, where the actual alignment 3120 restriction is unknown. */ 3121 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE 3122 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) 3123 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) 3124 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) 3125 warning ("cast increases required alignment of target type"); 3126 3127 if (TREE_CODE (type) == INTEGER_TYPE 3128 && TREE_CODE (otype) == POINTER_TYPE 3129 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3130 && !TREE_CONSTANT (value)) 3131 warning ("cast from pointer to integer of different size"); 3132 3133 if (warn_bad_function_cast 3134 && TREE_CODE (value) == CALL_EXPR 3135 && TREE_CODE (type) != TREE_CODE (otype)) 3136 warning ("cast does not match function type"); 3137 3138 if (TREE_CODE (type) == POINTER_TYPE 3139 && TREE_CODE (otype) == INTEGER_TYPE 3140 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3141 /* Don't warn about converting any constant. */ 3142 && !TREE_CONSTANT (value)) 3143 warning ("cast to pointer from integer of different size"); 3144 3145 if (TREE_CODE (type) == POINTER_TYPE 3146 && TREE_CODE (otype) == POINTER_TYPE 3147 && TREE_CODE (expr) == ADDR_EXPR 3148 && DECL_P (TREE_OPERAND (expr, 0)) 3149 && flag_strict_aliasing && warn_strict_aliasing 3150 && !VOID_TYPE_P (TREE_TYPE (type))) 3151 { 3152 /* Casting the address of a decl to non void pointer. Warn 3153 if the cast breaks type based aliasing. */ 3154 if (!COMPLETE_TYPE_P (TREE_TYPE (type))) 3155 warning ("type-punning to incomplete type might break strict-aliasing rules"); 3156 else if (!alias_sets_conflict_p 3157 (get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))), 3158 get_alias_set (TREE_TYPE (type)))) 3159 warning ("dereferencing type-punned pointer will break strict-aliasing rules"); 3160 } 3161 3162 /* If pedantic, warn for conversions between function and object 3163 pointer types, except for converting a null pointer constant 3164 to function pointer type. */ 3165 if (pedantic 3166 && TREE_CODE (type) == POINTER_TYPE 3167 && TREE_CODE (otype) == POINTER_TYPE 3168 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE 3169 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) 3170 pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); 3171 3172 if (pedantic 3173 && TREE_CODE (type) == POINTER_TYPE 3174 && TREE_CODE (otype) == POINTER_TYPE 3175 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 3176 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3177 && !(integer_zerop (value) && TREE_TYPE (otype) == void_type_node 3178 && TREE_CODE (expr) != NOP_EXPR)) 3179 pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); 3180 3181 ovalue = value; 3182 /* Replace a nonvolatile const static variable with its value. */ 3183 if (optimize && TREE_CODE (value) == VAR_DECL) 3184 value = decl_constant_value (value); 3185 value = convert (type, value); 3186 3187 /* Ignore any integer overflow caused by the cast. */ 3188 if (TREE_CODE (value) == INTEGER_CST) 3189 { 3190 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); 3191 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); 3192 } 3193 } 3194 3195 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */ 3196 if (pedantic && TREE_CODE (value) == INTEGER_CST 3197 && TREE_CODE (expr) == INTEGER_CST 3198 && TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE) 3199 value = non_lvalue (value); 3200 3201 /* If pedantic, don't let a cast be an lvalue. */ 3202 if (value == expr && pedantic) 3203 value = non_lvalue (value); 3204 3205 return value; 3206} 3207 3208/* Interpret a cast of expression EXPR to type TYPE. */ 3209tree 3210c_cast_expr (tree type, tree expr) 3211{ 3212 int saved_wsp = warn_strict_prototypes; 3213 3214 /* This avoids warnings about unprototyped casts on 3215 integers. E.g. "#define SIG_DFL (void(*)())0". */ 3216 if (TREE_CODE (expr) == INTEGER_CST) 3217 warn_strict_prototypes = 0; 3218 type = groktypename (type); 3219 warn_strict_prototypes = saved_wsp; 3220 3221 return build_c_cast (type, expr); 3222} 3223 3224 3225/* Build an assignment expression of lvalue LHS from value RHS. 3226 MODIFYCODE is the code for a binary operator that we use 3227 to combine the old value of LHS with RHS to get the new value. 3228 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ 3229 3230tree 3231build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) 3232{ 3233 tree result; 3234 tree newrhs; 3235 tree lhstype = TREE_TYPE (lhs); 3236 tree olhstype = lhstype; 3237 3238 /* Types that aren't fully specified cannot be used in assignments. */ 3239 lhs = require_complete_type (lhs); 3240 3241 /* Avoid duplicate error messages from operands that had errors. */ 3242 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) 3243 return error_mark_node; 3244 3245 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 3246 /* Do not use STRIP_NOPS here. We do not want an enumerator 3247 whose value is 0 to count as a null pointer constant. */ 3248 if (TREE_CODE (rhs) == NON_LVALUE_EXPR) 3249 rhs = TREE_OPERAND (rhs, 0); 3250 3251 newrhs = rhs; 3252 3253 /* Handle control structure constructs used as "lvalues". */ 3254 3255 switch (TREE_CODE (lhs)) 3256 { 3257 /* Handle (a, b) used as an "lvalue". */ 3258 case COMPOUND_EXPR: 3259 pedantic_lvalue_warning (COMPOUND_EXPR); 3260 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1), modifycode, rhs); 3261 if (TREE_CODE (newrhs) == ERROR_MARK) 3262 return error_mark_node; 3263 return build (COMPOUND_EXPR, lhstype, 3264 TREE_OPERAND (lhs, 0), newrhs); 3265 3266 /* Handle (a ? b : c) used as an "lvalue". */ 3267 case COND_EXPR: 3268 pedantic_lvalue_warning (COND_EXPR); 3269 rhs = save_expr (rhs); 3270 { 3271 /* Produce (a ? (b = rhs) : (c = rhs)) 3272 except that the RHS goes through a save-expr 3273 so the code to compute it is only emitted once. */ 3274 tree cond 3275 = build_conditional_expr (TREE_OPERAND (lhs, 0), 3276 build_modify_expr (TREE_OPERAND (lhs, 1), 3277 modifycode, rhs), 3278 build_modify_expr (TREE_OPERAND (lhs, 2), 3279 modifycode, rhs)); 3280 if (TREE_CODE (cond) == ERROR_MARK) 3281 return cond; 3282 /* Make sure the code to compute the rhs comes out 3283 before the split. */ 3284 return build (COMPOUND_EXPR, TREE_TYPE (lhs), 3285 /* But cast it to void to avoid an "unused" error. */ 3286 convert (void_type_node, rhs), cond); 3287 } 3288 default: 3289 break; 3290 } 3291 3292 /* If a binary op has been requested, combine the old LHS value with the RHS 3293 producing the value we should actually store into the LHS. */ 3294 3295 if (modifycode != NOP_EXPR) 3296 { 3297 lhs = stabilize_reference (lhs); 3298 newrhs = build_binary_op (modifycode, lhs, rhs, 1); 3299 } 3300 3301 /* Handle a cast used as an "lvalue". 3302 We have already performed any binary operator using the value as cast. 3303 Now convert the result to the cast type of the lhs, 3304 and then true type of the lhs and store it there; 3305 then convert result back to the cast type to be the value 3306 of the assignment. */ 3307 3308 switch (TREE_CODE (lhs)) 3309 { 3310 case NOP_EXPR: 3311 case CONVERT_EXPR: 3312 case FLOAT_EXPR: 3313 case FIX_TRUNC_EXPR: 3314 case FIX_FLOOR_EXPR: 3315 case FIX_ROUND_EXPR: 3316 case FIX_CEIL_EXPR: 3317 newrhs = default_function_array_conversion (newrhs); 3318 { 3319 tree inner_lhs = TREE_OPERAND (lhs, 0); 3320 tree result; 3321 result = build_modify_expr (inner_lhs, NOP_EXPR, 3322 convert (TREE_TYPE (inner_lhs), 3323 convert (lhstype, newrhs))); 3324 if (TREE_CODE (result) == ERROR_MARK) 3325 return result; 3326 pedantic_lvalue_warning (CONVERT_EXPR); 3327 return convert (TREE_TYPE (lhs), result); 3328 } 3329 3330 default: 3331 break; 3332 } 3333 3334 /* Now we have handled acceptable kinds of LHS that are not truly lvalues. 3335 Reject anything strange now. */ 3336 3337 if (!lvalue_or_else (lhs, "invalid lvalue in assignment")) 3338 return error_mark_node; 3339 3340 /* Warn about storing in something that is `const'. */ 3341 3342 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) 3343 || ((TREE_CODE (lhstype) == RECORD_TYPE 3344 || TREE_CODE (lhstype) == UNION_TYPE) 3345 && C_TYPE_FIELDS_READONLY (lhstype))) 3346 readonly_error (lhs, "assignment"); 3347 3348 /* If storing into a structure or union member, 3349 it has probably been given type `int'. 3350 Compute the type that would go with 3351 the actual amount of storage the member occupies. */ 3352 3353 if (TREE_CODE (lhs) == COMPONENT_REF 3354 && (TREE_CODE (lhstype) == INTEGER_TYPE 3355 || TREE_CODE (lhstype) == BOOLEAN_TYPE 3356 || TREE_CODE (lhstype) == REAL_TYPE 3357 || TREE_CODE (lhstype) == ENUMERAL_TYPE)) 3358 lhstype = TREE_TYPE (get_unwidened (lhs, 0)); 3359 3360 /* If storing in a field that is in actuality a short or narrower than one, 3361 we must store in the field in its actual type. */ 3362 3363 if (lhstype != TREE_TYPE (lhs)) 3364 { 3365 lhs = copy_node (lhs); 3366 TREE_TYPE (lhs) = lhstype; 3367 } 3368 3369 /* Convert new value to destination type. */ 3370 3371 newrhs = convert_for_assignment (lhstype, newrhs, _("assignment"), 3372 NULL_TREE, NULL_TREE, 0); 3373 if (TREE_CODE (newrhs) == ERROR_MARK) 3374 return error_mark_node; 3375 3376 /* Scan operands */ 3377 3378 result = build (MODIFY_EXPR, lhstype, lhs, newrhs); 3379 TREE_SIDE_EFFECTS (result) = 1; 3380 3381 /* If we got the LHS in a different type for storing in, 3382 convert the result back to the nominal type of LHS 3383 so that the value we return always has the same type 3384 as the LHS argument. */ 3385 3386 if (olhstype == TREE_TYPE (result)) 3387 return result; 3388 return convert_for_assignment (olhstype, result, _("assignment"), 3389 NULL_TREE, NULL_TREE, 0); 3390} 3391 3392/* Convert value RHS to type TYPE as preparation for an assignment 3393 to an lvalue of type TYPE. 3394 The real work of conversion is done by `convert'. 3395 The purpose of this function is to generate error messages 3396 for assignments that are not allowed in C. 3397 ERRTYPE is a string to use in error messages: 3398 "assignment", "return", etc. If it is null, this is parameter passing 3399 for a function call (and different error messages are output). 3400 3401 FUNNAME is the name of the function being called, 3402 as an IDENTIFIER_NODE, or null. 3403 PARMNUM is the number of the argument, for printing in error messages. */ 3404 3405static tree 3406convert_for_assignment (tree type, tree rhs, const char *errtype, 3407 tree fundecl, tree funname, int parmnum) 3408{ 3409 enum tree_code codel = TREE_CODE (type); 3410 tree rhstype; 3411 enum tree_code coder; 3412 3413 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 3414 /* Do not use STRIP_NOPS here. We do not want an enumerator 3415 whose value is 0 to count as a null pointer constant. */ 3416 if (TREE_CODE (rhs) == NON_LVALUE_EXPR) 3417 rhs = TREE_OPERAND (rhs, 0); 3418 3419 if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE 3420 || TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE) 3421 rhs = default_conversion (rhs); 3422 else if (optimize && TREE_CODE (rhs) == VAR_DECL) 3423 rhs = decl_constant_value_for_broken_optimization (rhs); 3424 3425 rhstype = TREE_TYPE (rhs); 3426 coder = TREE_CODE (rhstype); 3427 3428 if (coder == ERROR_MARK) 3429 return error_mark_node; 3430 3431 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) 3432 { 3433 overflow_warning (rhs); 3434 /* Check for Objective-C protocols. This will automatically 3435 issue a warning if there are protocol violations. No need to 3436 use the return value. */ 3437 if (c_dialect_objc ()) 3438 objc_comptypes (type, rhstype, 0); 3439 return rhs; 3440 } 3441 3442 if (coder == VOID_TYPE) 3443 { 3444 error ("void value not ignored as it ought to be"); 3445 return error_mark_node; 3446 } 3447 /* A type converts to a reference to it. 3448 This code doesn't fully support references, it's just for the 3449 special case of va_start and va_copy. */ 3450 if (codel == REFERENCE_TYPE 3451 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs), COMPARE_STRICT) == 1) 3452 { 3453 if (!lvalue_p (rhs)) 3454 { 3455 error ("cannot pass rvalue to reference parameter"); 3456 return error_mark_node; 3457 } 3458 if (!c_mark_addressable (rhs)) 3459 return error_mark_node; 3460 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); 3461 3462 /* We already know that these two types are compatible, but they 3463 may not be exactly identical. In fact, `TREE_TYPE (type)' is 3464 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is 3465 likely to be va_list, a typedef to __builtin_va_list, which 3466 is different enough that it will cause problems later. */ 3467 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) 3468 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); 3469 3470 rhs = build1 (NOP_EXPR, type, rhs); 3471 return rhs; 3472 } 3473 /* Some types can interconvert without explicit casts. */ 3474 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE 3475 && ((*targetm.vector_opaque_p) (type) 3476 || (*targetm.vector_opaque_p) (rhstype))) 3477 return convert (type, rhs); 3478 /* Arithmetic types all interconvert, and enum is treated like int. */ 3479 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 3480 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE 3481 || codel == BOOLEAN_TYPE) 3482 && (coder == INTEGER_TYPE || coder == REAL_TYPE 3483 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE 3484 || coder == BOOLEAN_TYPE)) 3485 return convert_and_check (type, rhs); 3486 3487 /* Conversion to a transparent union from its member types. 3488 This applies only to function arguments. */ 3489 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) && ! errtype) 3490 { 3491 tree memb_types; 3492 tree marginal_memb_type = 0; 3493 3494 for (memb_types = TYPE_FIELDS (type); memb_types; 3495 memb_types = TREE_CHAIN (memb_types)) 3496 { 3497 tree memb_type = TREE_TYPE (memb_types); 3498 3499 if (comptypes (TYPE_MAIN_VARIANT (memb_type), 3500 TYPE_MAIN_VARIANT (rhstype), COMPARE_STRICT)) 3501 break; 3502 3503 if (TREE_CODE (memb_type) != POINTER_TYPE) 3504 continue; 3505 3506 if (coder == POINTER_TYPE) 3507 { 3508 tree ttl = TREE_TYPE (memb_type); 3509 tree ttr = TREE_TYPE (rhstype); 3510 3511 /* Any non-function converts to a [const][volatile] void * 3512 and vice versa; otherwise, targets must be the same. 3513 Meanwhile, the lhs target must have all the qualifiers of 3514 the rhs. */ 3515 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3516 || comp_target_types (memb_type, rhstype, 0)) 3517 { 3518 /* If this type won't generate any warnings, use it. */ 3519 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) 3520 || ((TREE_CODE (ttr) == FUNCTION_TYPE 3521 && TREE_CODE (ttl) == FUNCTION_TYPE) 3522 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3523 == TYPE_QUALS (ttr)) 3524 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3525 == TYPE_QUALS (ttl)))) 3526 break; 3527 3528 /* Keep looking for a better type, but remember this one. */ 3529 if (! marginal_memb_type) 3530 marginal_memb_type = memb_type; 3531 } 3532 } 3533 3534 /* Can convert integer zero to any pointer type. */ 3535 if (integer_zerop (rhs) 3536 || (TREE_CODE (rhs) == NOP_EXPR 3537 && integer_zerop (TREE_OPERAND (rhs, 0)))) 3538 { 3539 rhs = null_pointer_node; 3540 break; 3541 } 3542 } 3543 3544 if (memb_types || marginal_memb_type) 3545 { 3546 if (! memb_types) 3547 { 3548 /* We have only a marginally acceptable member type; 3549 it needs a warning. */ 3550 tree ttl = TREE_TYPE (marginal_memb_type); 3551 tree ttr = TREE_TYPE (rhstype); 3552 3553 /* Const and volatile mean something different for function 3554 types, so the usual warnings are not appropriate. */ 3555 if (TREE_CODE (ttr) == FUNCTION_TYPE 3556 && TREE_CODE (ttl) == FUNCTION_TYPE) 3557 { 3558 /* Because const and volatile on functions are 3559 restrictions that say the function will not do 3560 certain things, it is okay to use a const or volatile 3561 function where an ordinary one is wanted, but not 3562 vice-versa. */ 3563 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 3564 warn_for_assignment ("%s makes qualified function pointer from unqualified", 3565 errtype, funname, parmnum); 3566 } 3567 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 3568 warn_for_assignment ("%s discards qualifiers from pointer target type", 3569 errtype, funname, 3570 parmnum); 3571 } 3572 3573 if (pedantic && ! DECL_IN_SYSTEM_HEADER (fundecl)) 3574 pedwarn ("ISO C prohibits argument conversion to union type"); 3575 3576 return build1 (NOP_EXPR, type, rhs); 3577 } 3578 } 3579 3580 /* Conversions among pointers */ 3581 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 3582 && (coder == codel)) 3583 { 3584 tree ttl = TREE_TYPE (type); 3585 tree ttr = TREE_TYPE (rhstype); 3586 bool is_opaque_pointer; 3587 int target_cmp = 0; /* Cache comp_target_types () result. */ 3588 3589 /* Opaque pointers are treated like void pointers. */ 3590 is_opaque_pointer = ((*targetm.vector_opaque_p) (type) 3591 || (*targetm.vector_opaque_p) (rhstype)) 3592 && TREE_CODE (ttl) == VECTOR_TYPE 3593 && TREE_CODE (ttr) == VECTOR_TYPE; 3594 3595 /* Any non-function converts to a [const][volatile] void * 3596 and vice versa; otherwise, targets must be the same. 3597 Meanwhile, the lhs target must have all the qualifiers of the rhs. */ 3598 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3599 || (target_cmp = comp_target_types (type, rhstype, 0)) 3600 || is_opaque_pointer 3601 || (c_common_unsigned_type (TYPE_MAIN_VARIANT (ttl)) 3602 == c_common_unsigned_type (TYPE_MAIN_VARIANT (ttr)))) 3603 { 3604 if (pedantic 3605 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) 3606 || 3607 (VOID_TYPE_P (ttr) 3608 /* Check TREE_CODE to catch cases like (void *) (char *) 0 3609 which are not ANSI null ptr constants. */ 3610 && (!integer_zerop (rhs) || TREE_CODE (rhs) == NOP_EXPR) 3611 && TREE_CODE (ttl) == FUNCTION_TYPE))) 3612 warn_for_assignment ("ISO C forbids %s between function pointer and `void *'", 3613 errtype, funname, parmnum); 3614 /* Const and volatile mean something different for function types, 3615 so the usual warnings are not appropriate. */ 3616 else if (TREE_CODE (ttr) != FUNCTION_TYPE 3617 && TREE_CODE (ttl) != FUNCTION_TYPE) 3618 { 3619 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 3620 warn_for_assignment ("%s discards qualifiers from pointer target type", 3621 errtype, funname, parmnum); 3622 /* If this is not a case of ignoring a mismatch in signedness, 3623 no warning. */ 3624 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3625 || target_cmp) 3626 ; 3627 /* If there is a mismatch, do warn. */ 3628 else if (pedantic) 3629 warn_for_assignment ("pointer targets in %s differ in signedness", 3630 errtype, funname, parmnum); 3631 } 3632 else if (TREE_CODE (ttl) == FUNCTION_TYPE 3633 && TREE_CODE (ttr) == FUNCTION_TYPE) 3634 { 3635 /* Because const and volatile on functions are restrictions 3636 that say the function will not do certain things, 3637 it is okay to use a const or volatile function 3638 where an ordinary one is wanted, but not vice-versa. */ 3639 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 3640 warn_for_assignment ("%s makes qualified function pointer from unqualified", 3641 errtype, funname, parmnum); 3642 } 3643 } 3644 else 3645 warn_for_assignment ("%s from incompatible pointer type", 3646 errtype, funname, parmnum); 3647 return convert (type, rhs); 3648 } 3649 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) 3650 { 3651 error ("invalid use of non-lvalue array"); 3652 return error_mark_node; 3653 } 3654 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) 3655 { 3656 /* An explicit constant 0 can convert to a pointer, 3657 or one that results from arithmetic, even including 3658 a cast to integer type. */ 3659 if (! (TREE_CODE (rhs) == INTEGER_CST && integer_zerop (rhs)) 3660 && 3661 ! (TREE_CODE (rhs) == NOP_EXPR 3662 && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE 3663 && TREE_CODE (TREE_OPERAND (rhs, 0)) == INTEGER_CST 3664 && integer_zerop (TREE_OPERAND (rhs, 0)))) 3665 warn_for_assignment ("%s makes pointer from integer without a cast", 3666 errtype, funname, parmnum); 3667 3668 return convert (type, rhs); 3669 } 3670 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) 3671 { 3672 warn_for_assignment ("%s makes integer from pointer without a cast", 3673 errtype, funname, parmnum); 3674 return convert (type, rhs); 3675 } 3676 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) 3677 return convert (type, rhs); 3678 3679 if (!errtype) 3680 { 3681 if (funname) 3682 { 3683 tree selector = objc_message_selector (); 3684 3685 if (selector && parmnum > 2) 3686 error ("incompatible type for argument %d of `%s'", 3687 parmnum - 2, IDENTIFIER_POINTER (selector)); 3688 else 3689 error ("incompatible type for argument %d of `%s'", 3690 parmnum, IDENTIFIER_POINTER (funname)); 3691 } 3692 else 3693 error ("incompatible type for argument %d of indirect function call", 3694 parmnum); 3695 } 3696 else 3697 error ("incompatible types in %s", errtype); 3698 3699 return error_mark_node; 3700} 3701 3702/* Convert VALUE for assignment into inlined parameter PARM. ARGNUM 3703 is used for error and waring reporting and indicates which argument 3704 is being processed. */ 3705 3706tree 3707c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) 3708{ 3709 tree ret, type; 3710 3711 /* If FN was prototyped, the value has been converted already 3712 in convert_arguments. */ 3713 if (! value || TYPE_ARG_TYPES (TREE_TYPE (fn))) 3714 return value; 3715 3716 type = TREE_TYPE (parm); 3717 ret = convert_for_assignment (type, value, 3718 (char *) 0 /* arg passing */, fn, 3719 DECL_NAME (fn), argnum); 3720 if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) 3721 && INTEGRAL_TYPE_P (type) 3722 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 3723 ret = default_conversion (ret); 3724 return ret; 3725} 3726 3727/* Print a warning using MSGID. 3728 It gets OPNAME as its one parameter. 3729 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'". 3730 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'". 3731 FUNCTION and ARGNUM are handled specially if we are building an 3732 Objective-C selector. */ 3733 3734static void 3735warn_for_assignment (const char *msgid, const char *opname, tree function, 3736 int argnum) 3737{ 3738 if (opname == 0) 3739 { 3740 tree selector = objc_message_selector (); 3741 char * new_opname; 3742 3743 if (selector && argnum > 2) 3744 { 3745 function = selector; 3746 argnum -= 2; 3747 } 3748 if (argnum == 0) 3749 { 3750 if (function) 3751 { 3752 /* Function name is known; supply it. */ 3753 const char *const argstring = _("passing arg of `%s'"); 3754 new_opname = alloca (IDENTIFIER_LENGTH (function) 3755 + strlen (argstring) + 1 + 1); 3756 sprintf (new_opname, argstring, 3757 IDENTIFIER_POINTER (function)); 3758 } 3759 else 3760 { 3761 /* Function name unknown (call through ptr). */ 3762 const char *const argnofun = _("passing arg of pointer to function"); 3763 new_opname = alloca (strlen (argnofun) + 1 + 1); 3764 sprintf (new_opname, argnofun); 3765 } 3766 } 3767 else if (function) 3768 { 3769 /* Function name is known; supply it. */ 3770 const char *const argstring = _("passing arg %d of `%s'"); 3771 new_opname = alloca (IDENTIFIER_LENGTH (function) 3772 + strlen (argstring) + 1 + 25 /*%d*/ + 1); 3773 sprintf (new_opname, argstring, argnum, 3774 IDENTIFIER_POINTER (function)); 3775 } 3776 else 3777 { 3778 /* Function name unknown (call through ptr); just give arg number. */ 3779 const char *const argnofun = _("passing arg %d of pointer to function"); 3780 new_opname = alloca (strlen (argnofun) + 1 + 25 /*%d*/ + 1); 3781 sprintf (new_opname, argnofun, argnum); 3782 } 3783 opname = new_opname; 3784 } 3785 pedwarn (msgid, opname); 3786} 3787 3788/* If VALUE is a compound expr all of whose expressions are constant, then 3789 return its value. Otherwise, return error_mark_node. 3790 3791 This is for handling COMPOUND_EXPRs as initializer elements 3792 which is allowed with a warning when -pedantic is specified. */ 3793 3794static tree 3795valid_compound_expr_initializer (tree value, tree endtype) 3796{ 3797 if (TREE_CODE (value) == COMPOUND_EXPR) 3798 { 3799 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) 3800 == error_mark_node) 3801 return error_mark_node; 3802 return valid_compound_expr_initializer (TREE_OPERAND (value, 1), 3803 endtype); 3804 } 3805 else if (! TREE_CONSTANT (value) 3806 && ! initializer_constant_valid_p (value, endtype)) 3807 return error_mark_node; 3808 else 3809 return value; 3810} 3811 3812/* Perform appropriate conversions on the initial value of a variable, 3813 store it in the declaration DECL, 3814 and print any error messages that are appropriate. 3815 If the init is invalid, store an ERROR_MARK. */ 3816 3817void 3818store_init_value (tree decl, tree init) 3819{ 3820 tree value, type; 3821 3822 /* If variable's type was invalidly declared, just ignore it. */ 3823 3824 type = TREE_TYPE (decl); 3825 if (TREE_CODE (type) == ERROR_MARK) 3826 return; 3827 3828 /* Digest the specified initializer into an expression. */ 3829 3830 value = digest_init (type, init, TREE_STATIC (decl)); 3831 3832 /* Store the expression if valid; else report error. */ 3833 3834 if (warn_traditional && !in_system_header 3835 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && ! TREE_STATIC (decl)) 3836 warning ("traditional C rejects automatic aggregate initialization"); 3837 3838 DECL_INITIAL (decl) = value; 3839 3840 /* ANSI wants warnings about out-of-range constant initializers. */ 3841 STRIP_TYPE_NOPS (value); 3842 constant_expression_warning (value); 3843 3844 /* Check if we need to set array size from compound literal size. */ 3845 if (TREE_CODE (type) == ARRAY_TYPE 3846 && TYPE_DOMAIN (type) == 0 3847 && value != error_mark_node) 3848 { 3849 tree inside_init = init; 3850 3851 if (TREE_CODE (init) == NON_LVALUE_EXPR) 3852 inside_init = TREE_OPERAND (init, 0); 3853 inside_init = fold (inside_init); 3854 3855 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 3856 { 3857 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 3858 3859 if (TYPE_DOMAIN (TREE_TYPE (decl))) 3860 { 3861 /* For int foo[] = (int [3]){1}; we need to set array size 3862 now since later on array initializer will be just the 3863 brace enclosed list of the compound literal. */ 3864 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (decl)); 3865 layout_type (type); 3866 layout_decl (decl, 0); 3867 } 3868 } 3869 } 3870} 3871 3872/* Methods for storing and printing names for error messages. */ 3873 3874/* Implement a spelling stack that allows components of a name to be pushed 3875 and popped. Each element on the stack is this structure. */ 3876 3877struct spelling 3878{ 3879 int kind; 3880 union 3881 { 3882 int i; 3883 const char *s; 3884 } u; 3885}; 3886 3887#define SPELLING_STRING 1 3888#define SPELLING_MEMBER 2 3889#define SPELLING_BOUNDS 3 3890 3891static struct spelling *spelling; /* Next stack element (unused). */ 3892static struct spelling *spelling_base; /* Spelling stack base. */ 3893static int spelling_size; /* Size of the spelling stack. */ 3894 3895/* Macros to save and restore the spelling stack around push_... functions. 3896 Alternative to SAVE_SPELLING_STACK. */ 3897 3898#define SPELLING_DEPTH() (spelling - spelling_base) 3899#define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) 3900 3901/* Push an element on the spelling stack with type KIND and assign VALUE 3902 to MEMBER. */ 3903 3904#define PUSH_SPELLING(KIND, VALUE, MEMBER) \ 3905{ \ 3906 int depth = SPELLING_DEPTH (); \ 3907 \ 3908 if (depth >= spelling_size) \ 3909 { \ 3910 spelling_size += 10; \ 3911 if (spelling_base == 0) \ 3912 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \ 3913 else \ 3914 spelling_base = xrealloc (spelling_base, \ 3915 spelling_size * sizeof (struct spelling)); \ 3916 RESTORE_SPELLING_DEPTH (depth); \ 3917 } \ 3918 \ 3919 spelling->kind = (KIND); \ 3920 spelling->MEMBER = (VALUE); \ 3921 spelling++; \ 3922} 3923 3924/* Push STRING on the stack. Printed literally. */ 3925 3926static void 3927push_string (const char *string) 3928{ 3929 PUSH_SPELLING (SPELLING_STRING, string, u.s); 3930} 3931 3932/* Push a member name on the stack. Printed as '.' STRING. */ 3933 3934static void 3935push_member_name (tree decl) 3936{ 3937 const char *const string 3938 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>"; 3939 PUSH_SPELLING (SPELLING_MEMBER, string, u.s); 3940} 3941 3942/* Push an array bounds on the stack. Printed as [BOUNDS]. */ 3943 3944static void 3945push_array_bounds (int bounds) 3946{ 3947 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); 3948} 3949 3950/* Compute the maximum size in bytes of the printed spelling. */ 3951 3952static int 3953spelling_length (void) 3954{ 3955 int size = 0; 3956 struct spelling *p; 3957 3958 for (p = spelling_base; p < spelling; p++) 3959 { 3960 if (p->kind == SPELLING_BOUNDS) 3961 size += 25; 3962 else 3963 size += strlen (p->u.s) + 1; 3964 } 3965 3966 return size; 3967} 3968 3969/* Print the spelling to BUFFER and return it. */ 3970 3971static char * 3972print_spelling (char *buffer) 3973{ 3974 char *d = buffer; 3975 struct spelling *p; 3976 3977 for (p = spelling_base; p < spelling; p++) 3978 if (p->kind == SPELLING_BOUNDS) 3979 { 3980 sprintf (d, "[%d]", p->u.i); 3981 d += strlen (d); 3982 } 3983 else 3984 { 3985 const char *s; 3986 if (p->kind == SPELLING_MEMBER) 3987 *d++ = '.'; 3988 for (s = p->u.s; (*d = *s++); d++) 3989 ; 3990 } 3991 *d++ = '\0'; 3992 return buffer; 3993} 3994 3995/* Issue an error message for a bad initializer component. 3996 MSGID identifies the message. 3997 The component name is taken from the spelling stack. */ 3998 3999void 4000error_init (const char *msgid) 4001{ 4002 char *ofwhat; 4003 4004 error ("%s", _(msgid)); 4005 ofwhat = print_spelling (alloca (spelling_length () + 1)); 4006 if (*ofwhat) 4007 error ("(near initialization for `%s')", ofwhat); 4008} 4009 4010/* Issue a pedantic warning for a bad initializer component. 4011 MSGID identifies the message. 4012 The component name is taken from the spelling stack. */ 4013 4014void 4015pedwarn_init (const char *msgid) 4016{ 4017 char *ofwhat; 4018 4019 pedwarn ("%s", _(msgid)); 4020 ofwhat = print_spelling (alloca (spelling_length () + 1)); 4021 if (*ofwhat) 4022 pedwarn ("(near initialization for `%s')", ofwhat); 4023} 4024 4025/* Issue a warning for a bad initializer component. 4026 MSGID identifies the message. 4027 The component name is taken from the spelling stack. */ 4028 4029static void 4030warning_init (const char *msgid) 4031{ 4032 char *ofwhat; 4033 4034 warning ("%s", _(msgid)); 4035 ofwhat = print_spelling (alloca (spelling_length () + 1)); 4036 if (*ofwhat) 4037 warning ("(near initialization for `%s')", ofwhat); 4038} 4039 4040/* Digest the parser output INIT as an initializer for type TYPE. 4041 Return a C expression of type TYPE to represent the initial value. 4042 4043 REQUIRE_CONSTANT requests an error if non-constant initializers or 4044 elements are seen. */ 4045 4046static tree 4047digest_init (tree type, tree init, int require_constant) 4048{ 4049 enum tree_code code = TREE_CODE (type); 4050 tree inside_init = init; 4051 4052 if (type == error_mark_node 4053 || init == error_mark_node 4054 || TREE_TYPE (init) == error_mark_node) 4055 return error_mark_node; 4056 4057 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 4058 /* Do not use STRIP_NOPS here. We do not want an enumerator 4059 whose value is 0 to count as a null pointer constant. */ 4060 if (TREE_CODE (init) == NON_LVALUE_EXPR) 4061 inside_init = TREE_OPERAND (init, 0); 4062 4063 inside_init = fold (inside_init); 4064 4065 /* Initialization of an array of chars from a string constant 4066 optionally enclosed in braces. */ 4067 4068 if (code == ARRAY_TYPE) 4069 { 4070 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); 4071 if ((typ1 == char_type_node 4072 || typ1 == signed_char_type_node 4073 || typ1 == unsigned_char_type_node 4074 || typ1 == unsigned_wchar_type_node 4075 || typ1 == signed_wchar_type_node) 4076 && ((inside_init && TREE_CODE (inside_init) == STRING_CST))) 4077 { 4078 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4079 TYPE_MAIN_VARIANT (type), COMPARE_STRICT)) 4080 return inside_init; 4081 4082 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4083 != char_type_node) 4084 && TYPE_PRECISION (typ1) == TYPE_PRECISION (char_type_node)) 4085 { 4086 error_init ("char-array initialized from wide string"); 4087 return error_mark_node; 4088 } 4089 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4090 == char_type_node) 4091 && TYPE_PRECISION (typ1) != TYPE_PRECISION (char_type_node)) 4092 { 4093 error_init ("int-array initialized from non-wide string"); 4094 return error_mark_node; 4095 } 4096 4097 TREE_TYPE (inside_init) = type; 4098 if (TYPE_DOMAIN (type) != 0 4099 && TYPE_SIZE (type) != 0 4100 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST 4101 /* Subtract 1 (or sizeof (wchar_t)) 4102 because it's ok to ignore the terminating null char 4103 that is counted in the length of the constant. */ 4104 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), 4105 TREE_STRING_LENGTH (inside_init) 4106 - ((TYPE_PRECISION (typ1) 4107 != TYPE_PRECISION (char_type_node)) 4108 ? (TYPE_PRECISION (wchar_type_node) 4109 / BITS_PER_UNIT) 4110 : 1))) 4111 pedwarn_init ("initializer-string for array of chars is too long"); 4112 4113 return inside_init; 4114 } 4115 } 4116 4117 /* Build a VECTOR_CST from a *constant* vector constructor. If the 4118 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt 4119 below and handle as a constructor. */ 4120 if (code == VECTOR_TYPE 4121 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT) 4122 && TREE_CONSTANT (inside_init)) 4123 { 4124 if (TREE_CODE (inside_init) == VECTOR_CST 4125 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4126 TYPE_MAIN_VARIANT (type), 4127 COMPARE_STRICT)) 4128 return inside_init; 4129 else 4130 return build_vector (type, CONSTRUCTOR_ELTS (inside_init)); 4131 } 4132 4133 /* Any type can be initialized 4134 from an expression of the same type, optionally with braces. */ 4135 4136 if (inside_init && TREE_TYPE (inside_init) != 0 4137 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4138 TYPE_MAIN_VARIANT (type), COMPARE_STRICT) 4139 || (code == ARRAY_TYPE 4140 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4141 || (code == VECTOR_TYPE 4142 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4143 || (code == POINTER_TYPE 4144 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4145 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4146 TREE_TYPE (type), COMPARE_STRICT)) 4147 || (code == POINTER_TYPE 4148 && TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE 4149 && comptypes (TREE_TYPE (inside_init), 4150 TREE_TYPE (type), COMPARE_STRICT)))) 4151 { 4152 if (code == POINTER_TYPE) 4153 { 4154 inside_init = default_function_array_conversion (inside_init); 4155 4156 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4157 { 4158 error_init ("invalid use of non-lvalue array"); 4159 return error_mark_node; 4160 } 4161 } 4162 4163 if (code == VECTOR_TYPE) 4164 /* Although the types are compatible, we may require a 4165 conversion. */ 4166 inside_init = convert (type, inside_init); 4167 4168 if (require_constant && !flag_isoc99 4169 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4170 { 4171 /* As an extension, allow initializing objects with static storage 4172 duration with compound literals (which are then treated just as 4173 the brace enclosed list they contain). */ 4174 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4175 inside_init = DECL_INITIAL (decl); 4176 } 4177 4178 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4179 && TREE_CODE (inside_init) != CONSTRUCTOR) 4180 { 4181 error_init ("array initialized from non-constant array expression"); 4182 return error_mark_node; 4183 } 4184 4185 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4186 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4187 4188 /* Compound expressions can only occur here if -pedantic or 4189 -pedantic-errors is specified. In the later case, we always want 4190 an error. In the former case, we simply want a warning. */ 4191 if (require_constant && pedantic 4192 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4193 { 4194 inside_init 4195 = valid_compound_expr_initializer (inside_init, 4196 TREE_TYPE (inside_init)); 4197 if (inside_init == error_mark_node) 4198 error_init ("initializer element is not constant"); 4199 else 4200 pedwarn_init ("initializer element is not constant"); 4201 if (flag_pedantic_errors) 4202 inside_init = error_mark_node; 4203 } 4204 else if (require_constant 4205 && (!TREE_CONSTANT (inside_init) 4206 /* This test catches things like `7 / 0' which 4207 result in an expression for which TREE_CONSTANT 4208 is true, but which is not actually something 4209 that is a legal constant. We really should not 4210 be using this function, because it is a part of 4211 the back-end. Instead, the expression should 4212 already have been turned into ERROR_MARK_NODE. */ 4213 || !initializer_constant_valid_p (inside_init, 4214 TREE_TYPE (inside_init)))) 4215 { 4216 error_init ("initializer element is not constant"); 4217 inside_init = error_mark_node; 4218 } 4219 4220 return inside_init; 4221 } 4222 4223 /* Handle scalar types, including conversions. */ 4224 4225 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4226 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE) 4227 { 4228 /* Note that convert_for_assignment calls default_conversion 4229 for arrays and functions. We must not call it in the 4230 case where inside_init is a null pointer constant. */ 4231 inside_init 4232 = convert_for_assignment (type, init, _("initialization"), 4233 NULL_TREE, NULL_TREE, 0); 4234 4235 if (require_constant && ! TREE_CONSTANT (inside_init)) 4236 { 4237 error_init ("initializer element is not constant"); 4238 inside_init = error_mark_node; 4239 } 4240 else if (require_constant 4241 && initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init)) == 0) 4242 { 4243 error_init ("initializer element is not computable at load time"); 4244 inside_init = error_mark_node; 4245 } 4246 4247 return inside_init; 4248 } 4249 4250 /* Come here only for records and arrays. */ 4251 4252 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4253 { 4254 error_init ("variable-sized object may not be initialized"); 4255 return error_mark_node; 4256 } 4257 4258 error_init ("invalid initializer"); 4259 return error_mark_node; 4260} 4261 4262/* Handle initializers that use braces. */ 4263 4264/* Type of object we are accumulating a constructor for. 4265 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4266static tree constructor_type; 4267 4268/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4269 left to fill. */ 4270static tree constructor_fields; 4271 4272/* For an ARRAY_TYPE, this is the specified index 4273 at which to store the next element we get. */ 4274static tree constructor_index; 4275 4276/* For an ARRAY_TYPE, this is the maximum index. */ 4277static tree constructor_max_index; 4278 4279/* For a RECORD_TYPE, this is the first field not yet written out. */ 4280static tree constructor_unfilled_fields; 4281 4282/* For an ARRAY_TYPE, this is the index of the first element 4283 not yet written out. */ 4284static tree constructor_unfilled_index; 4285 4286/* In a RECORD_TYPE, the byte index of the next consecutive field. 4287 This is so we can generate gaps between fields, when appropriate. */ 4288static tree constructor_bit_index; 4289 4290/* If we are saving up the elements rather than allocating them, 4291 this is the list of elements so far (in reverse order, 4292 most recent first). */ 4293static tree constructor_elements; 4294 4295/* 1 if constructor should be incrementally stored into a constructor chain, 4296 0 if all the elements should be kept in AVL tree. */ 4297static int constructor_incremental; 4298 4299/* 1 if so far this constructor's elements are all compile-time constants. */ 4300static int constructor_constant; 4301 4302/* 1 if so far this constructor's elements are all valid address constants. */ 4303static int constructor_simple; 4304 4305/* 1 if this constructor is erroneous so far. */ 4306static int constructor_erroneous; 4307 4308/* Structure for managing pending initializer elements, organized as an 4309 AVL tree. */ 4310 4311struct init_node 4312{ 4313 struct init_node *left, *right; 4314 struct init_node *parent; 4315 int balance; 4316 tree purpose; 4317 tree value; 4318}; 4319 4320/* Tree of pending elements at this constructor level. 4321 These are elements encountered out of order 4322 which belong at places we haven't reached yet in actually 4323 writing the output. 4324 Will never hold tree nodes across GC runs. */ 4325static struct init_node *constructor_pending_elts; 4326 4327/* The SPELLING_DEPTH of this constructor. */ 4328static int constructor_depth; 4329 4330/* 0 if implicitly pushing constructor levels is allowed. */ 4331int constructor_no_implicit = 0; /* 0 for C; 1 for some other languages. */ 4332 4333/* DECL node for which an initializer is being read. 4334 0 means we are reading a constructor expression 4335 such as (struct foo) {...}. */ 4336static tree constructor_decl; 4337 4338/* start_init saves the ASMSPEC arg here for really_start_incremental_init. */ 4339static const char *constructor_asmspec; 4340 4341/* Nonzero if this is an initializer for a top-level decl. */ 4342static int constructor_top_level; 4343 4344/* Nonzero if there were any member designators in this initializer. */ 4345static int constructor_designated; 4346 4347/* Nesting depth of designator list. */ 4348static int designator_depth; 4349 4350/* Nonzero if there were diagnosed errors in this designator list. */ 4351static int designator_errorneous; 4352 4353 4354/* This stack has a level for each implicit or explicit level of 4355 structuring in the initializer, including the outermost one. It 4356 saves the values of most of the variables above. */ 4357 4358struct constructor_range_stack; 4359 4360struct constructor_stack 4361{ 4362 struct constructor_stack *next; 4363 tree type; 4364 tree fields; 4365 tree index; 4366 tree max_index; 4367 tree unfilled_index; 4368 tree unfilled_fields; 4369 tree bit_index; 4370 tree elements; 4371 struct init_node *pending_elts; 4372 int offset; 4373 int depth; 4374 /* If nonzero, this value should replace the entire 4375 constructor at this level. */ 4376 tree replacement_value; 4377 struct constructor_range_stack *range_stack; 4378 char constant; 4379 char simple; 4380 char implicit; 4381 char erroneous; 4382 char outer; 4383 char incremental; 4384 char designated; 4385}; 4386 4387struct constructor_stack *constructor_stack; 4388 4389/* This stack represents designators from some range designator up to 4390 the last designator in the list. */ 4391 4392struct constructor_range_stack 4393{ 4394 struct constructor_range_stack *next, *prev; 4395 struct constructor_stack *stack; 4396 tree range_start; 4397 tree index; 4398 tree range_end; 4399 tree fields; 4400}; 4401 4402struct constructor_range_stack *constructor_range_stack; 4403 4404/* This stack records separate initializers that are nested. 4405 Nested initializers can't happen in ANSI C, but GNU C allows them 4406 in cases like { ... (struct foo) { ... } ... }. */ 4407 4408struct initializer_stack 4409{ 4410 struct initializer_stack *next; 4411 tree decl; 4412 const char *asmspec; 4413 struct constructor_stack *constructor_stack; 4414 struct constructor_range_stack *constructor_range_stack; 4415 tree elements; 4416 struct spelling *spelling; 4417 struct spelling *spelling_base; 4418 int spelling_size; 4419 char top_level; 4420 char require_constant_value; 4421 char require_constant_elements; 4422}; 4423 4424struct initializer_stack *initializer_stack; 4425 4426/* Prepare to parse and output the initializer for variable DECL. */ 4427 4428void 4429start_init (tree decl, tree asmspec_tree, int top_level) 4430{ 4431 const char *locus; 4432 struct initializer_stack *p = xmalloc (sizeof (struct initializer_stack)); 4433 const char *asmspec = 0; 4434 4435 if (asmspec_tree) 4436 asmspec = TREE_STRING_POINTER (asmspec_tree); 4437 4438 p->decl = constructor_decl; 4439 p->asmspec = constructor_asmspec; 4440 p->require_constant_value = require_constant_value; 4441 p->require_constant_elements = require_constant_elements; 4442 p->constructor_stack = constructor_stack; 4443 p->constructor_range_stack = constructor_range_stack; 4444 p->elements = constructor_elements; 4445 p->spelling = spelling; 4446 p->spelling_base = spelling_base; 4447 p->spelling_size = spelling_size; 4448 p->top_level = constructor_top_level; 4449 p->next = initializer_stack; 4450 initializer_stack = p; 4451 4452 constructor_decl = decl; 4453 constructor_asmspec = asmspec; 4454 constructor_designated = 0; 4455 constructor_top_level = top_level; 4456 4457 if (decl != 0) 4458 { 4459 require_constant_value = TREE_STATIC (decl); 4460 require_constant_elements 4461 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 4462 /* For a scalar, you can always use any value to initialize, 4463 even within braces. */ 4464 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 4465 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 4466 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 4467 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 4468 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 4469 } 4470 else 4471 { 4472 require_constant_value = 0; 4473 require_constant_elements = 0; 4474 locus = "(anonymous)"; 4475 } 4476 4477 constructor_stack = 0; 4478 constructor_range_stack = 0; 4479 4480 missing_braces_mentioned = 0; 4481 4482 spelling_base = 0; 4483 spelling_size = 0; 4484 RESTORE_SPELLING_DEPTH (0); 4485 4486 if (locus) 4487 push_string (locus); 4488} 4489 4490void 4491finish_init (void) 4492{ 4493 struct initializer_stack *p = initializer_stack; 4494 4495 /* Free the whole constructor stack of this initializer. */ 4496 while (constructor_stack) 4497 { 4498 struct constructor_stack *q = constructor_stack; 4499 constructor_stack = q->next; 4500 free (q); 4501 } 4502 4503 if (constructor_range_stack) 4504 abort (); 4505 4506 /* Pop back to the data of the outer initializer (if any). */ 4507 free (spelling_base); 4508 4509 constructor_decl = p->decl; 4510 constructor_asmspec = p->asmspec; 4511 require_constant_value = p->require_constant_value; 4512 require_constant_elements = p->require_constant_elements; 4513 constructor_stack = p->constructor_stack; 4514 constructor_range_stack = p->constructor_range_stack; 4515 constructor_elements = p->elements; 4516 spelling = p->spelling; 4517 spelling_base = p->spelling_base; 4518 spelling_size = p->spelling_size; 4519 constructor_top_level = p->top_level; 4520 initializer_stack = p->next; 4521 free (p); 4522} 4523 4524/* Call here when we see the initializer is surrounded by braces. 4525 This is instead of a call to push_init_level; 4526 it is matched by a call to pop_init_level. 4527 4528 TYPE is the type to initialize, for a constructor expression. 4529 For an initializer for a decl, TYPE is zero. */ 4530 4531void 4532really_start_incremental_init (tree type) 4533{ 4534 struct constructor_stack *p = xmalloc (sizeof (struct constructor_stack)); 4535 4536 if (type == 0) 4537 type = TREE_TYPE (constructor_decl); 4538 4539 if ((*targetm.vector_opaque_p) (type)) 4540 error ("opaque vector types cannot be initialized"); 4541 4542 p->type = constructor_type; 4543 p->fields = constructor_fields; 4544 p->index = constructor_index; 4545 p->max_index = constructor_max_index; 4546 p->unfilled_index = constructor_unfilled_index; 4547 p->unfilled_fields = constructor_unfilled_fields; 4548 p->bit_index = constructor_bit_index; 4549 p->elements = constructor_elements; 4550 p->constant = constructor_constant; 4551 p->simple = constructor_simple; 4552 p->erroneous = constructor_erroneous; 4553 p->pending_elts = constructor_pending_elts; 4554 p->depth = constructor_depth; 4555 p->replacement_value = 0; 4556 p->implicit = 0; 4557 p->range_stack = 0; 4558 p->outer = 0; 4559 p->incremental = constructor_incremental; 4560 p->designated = constructor_designated; 4561 p->next = 0; 4562 constructor_stack = p; 4563 4564 constructor_constant = 1; 4565 constructor_simple = 1; 4566 constructor_depth = SPELLING_DEPTH (); 4567 constructor_elements = 0; 4568 constructor_pending_elts = 0; 4569 constructor_type = type; 4570 constructor_incremental = 1; 4571 constructor_designated = 0; 4572 designator_depth = 0; 4573 designator_errorneous = 0; 4574 4575 if (TREE_CODE (constructor_type) == RECORD_TYPE 4576 || TREE_CODE (constructor_type) == UNION_TYPE) 4577 { 4578 constructor_fields = TYPE_FIELDS (constructor_type); 4579 /* Skip any nameless bit fields at the beginning. */ 4580 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4581 && DECL_NAME (constructor_fields) == 0) 4582 constructor_fields = TREE_CHAIN (constructor_fields); 4583 4584 constructor_unfilled_fields = constructor_fields; 4585 constructor_bit_index = bitsize_zero_node; 4586 } 4587 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4588 { 4589 if (TYPE_DOMAIN (constructor_type)) 4590 { 4591 constructor_max_index 4592 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4593 4594 /* Detect non-empty initializations of zero-length arrays. */ 4595 if (constructor_max_index == NULL_TREE 4596 && TYPE_SIZE (constructor_type)) 4597 constructor_max_index = build_int_2 (-1, -1); 4598 4599 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4600 to initialize VLAs will cause a proper error; avoid tree 4601 checking errors as well by setting a safe value. */ 4602 if (constructor_max_index 4603 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4604 constructor_max_index = build_int_2 (-1, -1); 4605 4606 constructor_index 4607 = convert (bitsizetype, 4608 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4609 } 4610 else 4611 constructor_index = bitsize_zero_node; 4612 4613 constructor_unfilled_index = constructor_index; 4614 } 4615 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4616 { 4617 /* Vectors are like simple fixed-size arrays. */ 4618 constructor_max_index = 4619 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4620 constructor_index = convert (bitsizetype, bitsize_zero_node); 4621 constructor_unfilled_index = constructor_index; 4622 } 4623 else 4624 { 4625 /* Handle the case of int x = {5}; */ 4626 constructor_fields = constructor_type; 4627 constructor_unfilled_fields = constructor_type; 4628 } 4629} 4630 4631/* Push down into a subobject, for initialization. 4632 If this is for an explicit set of braces, IMPLICIT is 0. 4633 If it is because the next element belongs at a lower level, 4634 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 4635 4636void 4637push_init_level (int implicit) 4638{ 4639 struct constructor_stack *p; 4640 tree value = NULL_TREE; 4641 4642 /* If we've exhausted any levels that didn't have braces, 4643 pop them now. */ 4644 while (constructor_stack->implicit) 4645 { 4646 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4647 || TREE_CODE (constructor_type) == UNION_TYPE) 4648 && constructor_fields == 0) 4649 process_init_element (pop_init_level (1)); 4650 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 4651 && constructor_max_index 4652 && tree_int_cst_lt (constructor_max_index, constructor_index)) 4653 process_init_element (pop_init_level (1)); 4654 else 4655 break; 4656 } 4657 4658 /* Unless this is an explicit brace, we need to preserve previous 4659 content if any. */ 4660 if (implicit) 4661 { 4662 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4663 || TREE_CODE (constructor_type) == UNION_TYPE) 4664 && constructor_fields) 4665 value = find_init_member (constructor_fields); 4666 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4667 value = find_init_member (constructor_index); 4668 } 4669 4670 p = xmalloc (sizeof (struct constructor_stack)); 4671 p->type = constructor_type; 4672 p->fields = constructor_fields; 4673 p->index = constructor_index; 4674 p->max_index = constructor_max_index; 4675 p->unfilled_index = constructor_unfilled_index; 4676 p->unfilled_fields = constructor_unfilled_fields; 4677 p->bit_index = constructor_bit_index; 4678 p->elements = constructor_elements; 4679 p->constant = constructor_constant; 4680 p->simple = constructor_simple; 4681 p->erroneous = constructor_erroneous; 4682 p->pending_elts = constructor_pending_elts; 4683 p->depth = constructor_depth; 4684 p->replacement_value = 0; 4685 p->implicit = implicit; 4686 p->outer = 0; 4687 p->incremental = constructor_incremental; 4688 p->designated = constructor_designated; 4689 p->next = constructor_stack; 4690 p->range_stack = 0; 4691 constructor_stack = p; 4692 4693 constructor_constant = 1; 4694 constructor_simple = 1; 4695 constructor_depth = SPELLING_DEPTH (); 4696 constructor_elements = 0; 4697 constructor_incremental = 1; 4698 constructor_designated = 0; 4699 constructor_pending_elts = 0; 4700 if (!implicit) 4701 { 4702 p->range_stack = constructor_range_stack; 4703 constructor_range_stack = 0; 4704 designator_depth = 0; 4705 designator_errorneous = 0; 4706 } 4707 4708 /* Don't die if an entire brace-pair level is superfluous 4709 in the containing level. */ 4710 if (constructor_type == 0) 4711 ; 4712 else if (TREE_CODE (constructor_type) == RECORD_TYPE 4713 || TREE_CODE (constructor_type) == UNION_TYPE) 4714 { 4715 /* Don't die if there are extra init elts at the end. */ 4716 if (constructor_fields == 0) 4717 constructor_type = 0; 4718 else 4719 { 4720 constructor_type = TREE_TYPE (constructor_fields); 4721 push_member_name (constructor_fields); 4722 constructor_depth++; 4723 } 4724 } 4725 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4726 { 4727 constructor_type = TREE_TYPE (constructor_type); 4728 push_array_bounds (tree_low_cst (constructor_index, 0)); 4729 constructor_depth++; 4730 } 4731 4732 if (constructor_type == 0) 4733 { 4734 error_init ("extra brace group at end of initializer"); 4735 constructor_fields = 0; 4736 constructor_unfilled_fields = 0; 4737 return; 4738 } 4739 4740 if (value && TREE_CODE (value) == CONSTRUCTOR) 4741 { 4742 constructor_constant = TREE_CONSTANT (value); 4743 constructor_simple = TREE_STATIC (value); 4744 constructor_elements = CONSTRUCTOR_ELTS (value); 4745 if (constructor_elements 4746 && (TREE_CODE (constructor_type) == RECORD_TYPE 4747 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 4748 set_nonincremental_init (); 4749 } 4750 4751 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 4752 { 4753 missing_braces_mentioned = 1; 4754 warning_init ("missing braces around initializer"); 4755 } 4756 4757 if (TREE_CODE (constructor_type) == RECORD_TYPE 4758 || TREE_CODE (constructor_type) == UNION_TYPE) 4759 { 4760 constructor_fields = TYPE_FIELDS (constructor_type); 4761 /* Skip any nameless bit fields at the beginning. */ 4762 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4763 && DECL_NAME (constructor_fields) == 0) 4764 constructor_fields = TREE_CHAIN (constructor_fields); 4765 4766 constructor_unfilled_fields = constructor_fields; 4767 constructor_bit_index = bitsize_zero_node; 4768 } 4769 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4770 { 4771 /* Vectors are like simple fixed-size arrays. */ 4772 constructor_max_index = 4773 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4774 constructor_index = convert (bitsizetype, integer_zero_node); 4775 constructor_unfilled_index = constructor_index; 4776 } 4777 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4778 { 4779 if (TYPE_DOMAIN (constructor_type)) 4780 { 4781 constructor_max_index 4782 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4783 4784 /* Detect non-empty initializations of zero-length arrays. */ 4785 if (constructor_max_index == NULL_TREE 4786 && TYPE_SIZE (constructor_type)) 4787 constructor_max_index = build_int_2 (-1, -1); 4788 4789 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4790 to initialize VLAs will cause a proper error; avoid tree 4791 checking errors as well by setting a safe value. */ 4792 if (constructor_max_index 4793 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4794 constructor_max_index = build_int_2 (-1, -1); 4795 4796 constructor_index 4797 = convert (bitsizetype, 4798 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4799 } 4800 else 4801 constructor_index = bitsize_zero_node; 4802 4803 constructor_unfilled_index = constructor_index; 4804 if (value && TREE_CODE (value) == STRING_CST) 4805 { 4806 /* We need to split the char/wchar array into individual 4807 characters, so that we don't have to special case it 4808 everywhere. */ 4809 set_nonincremental_init_from_string (value); 4810 } 4811 } 4812 else 4813 { 4814 warning_init ("braces around scalar initializer"); 4815 constructor_fields = constructor_type; 4816 constructor_unfilled_fields = constructor_type; 4817 } 4818} 4819 4820/* At the end of an implicit or explicit brace level, 4821 finish up that level of constructor. 4822 If we were outputting the elements as they are read, return 0 4823 from inner levels (process_init_element ignores that), 4824 but return error_mark_node from the outermost level 4825 (that's what we want to put in DECL_INITIAL). 4826 Otherwise, return a CONSTRUCTOR expression. */ 4827 4828tree 4829pop_init_level (int implicit) 4830{ 4831 struct constructor_stack *p; 4832 tree constructor = 0; 4833 4834 if (implicit == 0) 4835 { 4836 /* When we come to an explicit close brace, 4837 pop any inner levels that didn't have explicit braces. */ 4838 while (constructor_stack->implicit) 4839 process_init_element (pop_init_level (1)); 4840 4841 if (constructor_range_stack) 4842 abort (); 4843 } 4844 4845 /* Now output all pending elements. */ 4846 constructor_incremental = 1; 4847 output_pending_init_elements (1); 4848 4849 p = constructor_stack; 4850 4851 /* Error for initializing a flexible array member, or a zero-length 4852 array member in an inappropriate context. */ 4853 if (constructor_type && constructor_fields 4854 && TREE_CODE (constructor_type) == ARRAY_TYPE 4855 && TYPE_DOMAIN (constructor_type) 4856 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 4857 { 4858 /* Silently discard empty initializations. The parser will 4859 already have pedwarned for empty brackets. */ 4860 if (integer_zerop (constructor_unfilled_index)) 4861 constructor_type = NULL_TREE; 4862 else if (! TYPE_SIZE (constructor_type)) 4863 { 4864 if (constructor_depth > 2) 4865 error_init ("initialization of flexible array member in a nested context"); 4866 else if (pedantic) 4867 pedwarn_init ("initialization of a flexible array member"); 4868 4869 /* We have already issued an error message for the existence 4870 of a flexible array member not at the end of the structure. 4871 Discard the initializer so that we do not abort later. */ 4872 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 4873 constructor_type = NULL_TREE; 4874 } 4875 else 4876 /* Zero-length arrays are no longer special, so we should no longer 4877 get here. */ 4878 abort (); 4879 } 4880 4881 /* Warn when some struct elements are implicitly initialized to zero. */ 4882 if (extra_warnings 4883 && constructor_type 4884 && TREE_CODE (constructor_type) == RECORD_TYPE 4885 && constructor_unfilled_fields) 4886 { 4887 /* Do not warn for flexible array members or zero-length arrays. */ 4888 while (constructor_unfilled_fields 4889 && (! DECL_SIZE (constructor_unfilled_fields) 4890 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 4891 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 4892 4893 /* Do not warn if this level of the initializer uses member 4894 designators; it is likely to be deliberate. */ 4895 if (constructor_unfilled_fields && !constructor_designated) 4896 { 4897 push_member_name (constructor_unfilled_fields); 4898 warning_init ("missing initializer"); 4899 RESTORE_SPELLING_DEPTH (constructor_depth); 4900 } 4901 } 4902 4903 /* Pad out the end of the structure. */ 4904 if (p->replacement_value) 4905 /* If this closes a superfluous brace pair, 4906 just pass out the element between them. */ 4907 constructor = p->replacement_value; 4908 else if (constructor_type == 0) 4909 ; 4910 else if (TREE_CODE (constructor_type) != RECORD_TYPE 4911 && TREE_CODE (constructor_type) != UNION_TYPE 4912 && TREE_CODE (constructor_type) != ARRAY_TYPE 4913 && TREE_CODE (constructor_type) != VECTOR_TYPE) 4914 { 4915 /* A nonincremental scalar initializer--just return 4916 the element, after verifying there is just one. */ 4917 if (constructor_elements == 0) 4918 { 4919 if (!constructor_erroneous) 4920 error_init ("empty scalar initializer"); 4921 constructor = error_mark_node; 4922 } 4923 else if (TREE_CHAIN (constructor_elements) != 0) 4924 { 4925 error_init ("extra elements in scalar initializer"); 4926 constructor = TREE_VALUE (constructor_elements); 4927 } 4928 else 4929 constructor = TREE_VALUE (constructor_elements); 4930 } 4931 else 4932 { 4933 if (constructor_erroneous) 4934 constructor = error_mark_node; 4935 else 4936 { 4937 constructor = build_constructor (constructor_type, 4938 nreverse (constructor_elements)); 4939 if (constructor_constant) 4940 TREE_CONSTANT (constructor) = 1; 4941 if (constructor_constant && constructor_simple) 4942 TREE_STATIC (constructor) = 1; 4943 } 4944 } 4945 4946 constructor_type = p->type; 4947 constructor_fields = p->fields; 4948 constructor_index = p->index; 4949 constructor_max_index = p->max_index; 4950 constructor_unfilled_index = p->unfilled_index; 4951 constructor_unfilled_fields = p->unfilled_fields; 4952 constructor_bit_index = p->bit_index; 4953 constructor_elements = p->elements; 4954 constructor_constant = p->constant; 4955 constructor_simple = p->simple; 4956 constructor_erroneous = p->erroneous; 4957 constructor_incremental = p->incremental; 4958 constructor_designated = p->designated; 4959 constructor_pending_elts = p->pending_elts; 4960 constructor_depth = p->depth; 4961 if (!p->implicit) 4962 constructor_range_stack = p->range_stack; 4963 RESTORE_SPELLING_DEPTH (constructor_depth); 4964 4965 constructor_stack = p->next; 4966 free (p); 4967 4968 if (constructor == 0) 4969 { 4970 if (constructor_stack == 0) 4971 return error_mark_node; 4972 return NULL_TREE; 4973 } 4974 return constructor; 4975} 4976 4977/* Common handling for both array range and field name designators. 4978 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 4979 4980static int 4981set_designator (int array) 4982{ 4983 tree subtype; 4984 enum tree_code subcode; 4985 4986 /* Don't die if an entire brace-pair level is superfluous 4987 in the containing level. */ 4988 if (constructor_type == 0) 4989 return 1; 4990 4991 /* If there were errors in this designator list already, bail out silently. */ 4992 if (designator_errorneous) 4993 return 1; 4994 4995 if (!designator_depth) 4996 { 4997 if (constructor_range_stack) 4998 abort (); 4999 5000 /* Designator list starts at the level of closest explicit 5001 braces. */ 5002 while (constructor_stack->implicit) 5003 process_init_element (pop_init_level (1)); 5004 constructor_designated = 1; 5005 return 0; 5006 } 5007 5008 if (constructor_no_implicit) 5009 { 5010 error_init ("initialization designators may not nest"); 5011 return 1; 5012 } 5013 5014 if (TREE_CODE (constructor_type) == RECORD_TYPE 5015 || TREE_CODE (constructor_type) == UNION_TYPE) 5016 { 5017 subtype = TREE_TYPE (constructor_fields); 5018 if (subtype != error_mark_node) 5019 subtype = TYPE_MAIN_VARIANT (subtype); 5020 } 5021 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5022 { 5023 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5024 } 5025 else 5026 abort (); 5027 5028 subcode = TREE_CODE (subtype); 5029 if (array && subcode != ARRAY_TYPE) 5030 { 5031 error_init ("array index in non-array initializer"); 5032 return 1; 5033 } 5034 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5035 { 5036 error_init ("field name not in record or union initializer"); 5037 return 1; 5038 } 5039 5040 constructor_designated = 1; 5041 push_init_level (2); 5042 return 0; 5043} 5044 5045/* If there are range designators in designator list, push a new designator 5046 to constructor_range_stack. RANGE_END is end of such stack range or 5047 NULL_TREE if there is no range designator at this level. */ 5048 5049static void 5050push_range_stack (tree range_end) 5051{ 5052 struct constructor_range_stack *p; 5053 5054 p = ggc_alloc (sizeof (struct constructor_range_stack)); 5055 p->prev = constructor_range_stack; 5056 p->next = 0; 5057 p->fields = constructor_fields; 5058 p->range_start = constructor_index; 5059 p->index = constructor_index; 5060 p->stack = constructor_stack; 5061 p->range_end = range_end; 5062 if (constructor_range_stack) 5063 constructor_range_stack->next = p; 5064 constructor_range_stack = p; 5065} 5066 5067/* Within an array initializer, specify the next index to be initialized. 5068 FIRST is that index. If LAST is nonzero, then initialize a range 5069 of indices, running from FIRST through LAST. */ 5070 5071void 5072set_init_index (tree first, tree last) 5073{ 5074 if (set_designator (1)) 5075 return; 5076 5077 designator_errorneous = 1; 5078 5079 while ((TREE_CODE (first) == NOP_EXPR 5080 || TREE_CODE (first) == CONVERT_EXPR 5081 || TREE_CODE (first) == NON_LVALUE_EXPR) 5082 && (TYPE_MODE (TREE_TYPE (first)) 5083 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (first, 0))))) 5084 first = TREE_OPERAND (first, 0); 5085 5086 if (last) 5087 while ((TREE_CODE (last) == NOP_EXPR 5088 || TREE_CODE (last) == CONVERT_EXPR 5089 || TREE_CODE (last) == NON_LVALUE_EXPR) 5090 && (TYPE_MODE (TREE_TYPE (last)) 5091 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (last, 0))))) 5092 last = TREE_OPERAND (last, 0); 5093 5094 if (TREE_CODE (first) != INTEGER_CST) 5095 error_init ("nonconstant array index in initializer"); 5096 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5097 error_init ("nonconstant array index in initializer"); 5098 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5099 error_init ("array index in non-array initializer"); 5100 else if (tree_int_cst_sgn (first) == -1) 5101 error_init ("array index in initializer exceeds array bounds"); 5102 else if (constructor_max_index 5103 && tree_int_cst_lt (constructor_max_index, first)) 5104 error_init ("array index in initializer exceeds array bounds"); 5105 else 5106 { 5107 constructor_index = convert (bitsizetype, first); 5108 5109 if (last) 5110 { 5111 if (tree_int_cst_equal (first, last)) 5112 last = 0; 5113 else if (tree_int_cst_lt (last, first)) 5114 { 5115 error_init ("empty index range in initializer"); 5116 last = 0; 5117 } 5118 else 5119 { 5120 last = convert (bitsizetype, last); 5121 if (constructor_max_index != 0 5122 && tree_int_cst_lt (constructor_max_index, last)) 5123 { 5124 error_init ("array index range in initializer exceeds array bounds"); 5125 last = 0; 5126 } 5127 } 5128 } 5129 5130 designator_depth++; 5131 designator_errorneous = 0; 5132 if (constructor_range_stack || last) 5133 push_range_stack (last); 5134 } 5135} 5136 5137/* Within a struct initializer, specify the next field to be initialized. */ 5138 5139void 5140set_init_label (tree fieldname) 5141{ 5142 tree tail; 5143 5144 if (set_designator (0)) 5145 return; 5146 5147 designator_errorneous = 1; 5148 5149 if (TREE_CODE (constructor_type) != RECORD_TYPE 5150 && TREE_CODE (constructor_type) != UNION_TYPE) 5151 { 5152 error_init ("field name not in record or union initializer"); 5153 return; 5154 } 5155 5156 for (tail = TYPE_FIELDS (constructor_type); tail; 5157 tail = TREE_CHAIN (tail)) 5158 { 5159 if (DECL_NAME (tail) == fieldname) 5160 break; 5161 } 5162 5163 if (tail == 0) 5164 error ("unknown field `%s' specified in initializer", 5165 IDENTIFIER_POINTER (fieldname)); 5166 else 5167 { 5168 constructor_fields = tail; 5169 designator_depth++; 5170 designator_errorneous = 0; 5171 if (constructor_range_stack) 5172 push_range_stack (NULL_TREE); 5173 } 5174} 5175 5176/* Add a new initializer to the tree of pending initializers. PURPOSE 5177 identifies the initializer, either array index or field in a structure. 5178 VALUE is the value of that index or field. */ 5179 5180static void 5181add_pending_init (tree purpose, tree value) 5182{ 5183 struct init_node *p, **q, *r; 5184 5185 q = &constructor_pending_elts; 5186 p = 0; 5187 5188 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5189 { 5190 while (*q != 0) 5191 { 5192 p = *q; 5193 if (tree_int_cst_lt (purpose, p->purpose)) 5194 q = &p->left; 5195 else if (tree_int_cst_lt (p->purpose, purpose)) 5196 q = &p->right; 5197 else 5198 { 5199 if (TREE_SIDE_EFFECTS (p->value)) 5200 warning_init ("initialized field with side-effects overwritten"); 5201 p->value = value; 5202 return; 5203 } 5204 } 5205 } 5206 else 5207 { 5208 tree bitpos; 5209 5210 bitpos = bit_position (purpose); 5211 while (*q != NULL) 5212 { 5213 p = *q; 5214 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5215 q = &p->left; 5216 else if (p->purpose != purpose) 5217 q = &p->right; 5218 else 5219 { 5220 if (TREE_SIDE_EFFECTS (p->value)) 5221 warning_init ("initialized field with side-effects overwritten"); 5222 p->value = value; 5223 return; 5224 } 5225 } 5226 } 5227 5228 r = ggc_alloc (sizeof (struct init_node)); 5229 r->purpose = purpose; 5230 r->value = value; 5231 5232 *q = r; 5233 r->parent = p; 5234 r->left = 0; 5235 r->right = 0; 5236 r->balance = 0; 5237 5238 while (p) 5239 { 5240 struct init_node *s; 5241 5242 if (r == p->left) 5243 { 5244 if (p->balance == 0) 5245 p->balance = -1; 5246 else if (p->balance < 0) 5247 { 5248 if (r->balance < 0) 5249 { 5250 /* L rotation. */ 5251 p->left = r->right; 5252 if (p->left) 5253 p->left->parent = p; 5254 r->right = p; 5255 5256 p->balance = 0; 5257 r->balance = 0; 5258 5259 s = p->parent; 5260 p->parent = r; 5261 r->parent = s; 5262 if (s) 5263 { 5264 if (s->left == p) 5265 s->left = r; 5266 else 5267 s->right = r; 5268 } 5269 else 5270 constructor_pending_elts = r; 5271 } 5272 else 5273 { 5274 /* LR rotation. */ 5275 struct init_node *t = r->right; 5276 5277 r->right = t->left; 5278 if (r->right) 5279 r->right->parent = r; 5280 t->left = r; 5281 5282 p->left = t->right; 5283 if (p->left) 5284 p->left->parent = p; 5285 t->right = p; 5286 5287 p->balance = t->balance < 0; 5288 r->balance = -(t->balance > 0); 5289 t->balance = 0; 5290 5291 s = p->parent; 5292 p->parent = t; 5293 r->parent = t; 5294 t->parent = s; 5295 if (s) 5296 { 5297 if (s->left == p) 5298 s->left = t; 5299 else 5300 s->right = t; 5301 } 5302 else 5303 constructor_pending_elts = t; 5304 } 5305 break; 5306 } 5307 else 5308 { 5309 /* p->balance == +1; growth of left side balances the node. */ 5310 p->balance = 0; 5311 break; 5312 } 5313 } 5314 else /* r == p->right */ 5315 { 5316 if (p->balance == 0) 5317 /* Growth propagation from right side. */ 5318 p->balance++; 5319 else if (p->balance > 0) 5320 { 5321 if (r->balance > 0) 5322 { 5323 /* R rotation. */ 5324 p->right = r->left; 5325 if (p->right) 5326 p->right->parent = p; 5327 r->left = p; 5328 5329 p->balance = 0; 5330 r->balance = 0; 5331 5332 s = p->parent; 5333 p->parent = r; 5334 r->parent = s; 5335 if (s) 5336 { 5337 if (s->left == p) 5338 s->left = r; 5339 else 5340 s->right = r; 5341 } 5342 else 5343 constructor_pending_elts = r; 5344 } 5345 else /* r->balance == -1 */ 5346 { 5347 /* RL rotation */ 5348 struct init_node *t = r->left; 5349 5350 r->left = t->right; 5351 if (r->left) 5352 r->left->parent = r; 5353 t->right = r; 5354 5355 p->right = t->left; 5356 if (p->right) 5357 p->right->parent = p; 5358 t->left = p; 5359 5360 r->balance = (t->balance < 0); 5361 p->balance = -(t->balance > 0); 5362 t->balance = 0; 5363 5364 s = p->parent; 5365 p->parent = t; 5366 r->parent = t; 5367 t->parent = s; 5368 if (s) 5369 { 5370 if (s->left == p) 5371 s->left = t; 5372 else 5373 s->right = t; 5374 } 5375 else 5376 constructor_pending_elts = t; 5377 } 5378 break; 5379 } 5380 else 5381 { 5382 /* p->balance == -1; growth of right side balances the node. */ 5383 p->balance = 0; 5384 break; 5385 } 5386 } 5387 5388 r = p; 5389 p = p->parent; 5390 } 5391} 5392 5393/* Build AVL tree from a sorted chain. */ 5394 5395static void 5396set_nonincremental_init (void) 5397{ 5398 tree chain; 5399 5400 if (TREE_CODE (constructor_type) != RECORD_TYPE 5401 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5402 return; 5403 5404 for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain)) 5405 add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain)); 5406 constructor_elements = 0; 5407 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5408 { 5409 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5410 /* Skip any nameless bit fields at the beginning. */ 5411 while (constructor_unfilled_fields != 0 5412 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5413 && DECL_NAME (constructor_unfilled_fields) == 0) 5414 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5415 5416 } 5417 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5418 { 5419 if (TYPE_DOMAIN (constructor_type)) 5420 constructor_unfilled_index 5421 = convert (bitsizetype, 5422 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5423 else 5424 constructor_unfilled_index = bitsize_zero_node; 5425 } 5426 constructor_incremental = 0; 5427} 5428 5429/* Build AVL tree from a string constant. */ 5430 5431static void 5432set_nonincremental_init_from_string (tree str) 5433{ 5434 tree value, purpose, type; 5435 HOST_WIDE_INT val[2]; 5436 const char *p, *end; 5437 int byte, wchar_bytes, charwidth, bitpos; 5438 5439 if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5440 abort (); 5441 5442 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5443 == TYPE_PRECISION (char_type_node)) 5444 wchar_bytes = 1; 5445 else if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5446 == TYPE_PRECISION (wchar_type_node)) 5447 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 5448 else 5449 abort (); 5450 5451 charwidth = TYPE_PRECISION (char_type_node); 5452 type = TREE_TYPE (constructor_type); 5453 p = TREE_STRING_POINTER (str); 5454 end = p + TREE_STRING_LENGTH (str); 5455 5456 for (purpose = bitsize_zero_node; 5457 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 5458 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 5459 { 5460 if (wchar_bytes == 1) 5461 { 5462 val[1] = (unsigned char) *p++; 5463 val[0] = 0; 5464 } 5465 else 5466 { 5467 val[0] = 0; 5468 val[1] = 0; 5469 for (byte = 0; byte < wchar_bytes; byte++) 5470 { 5471 if (BYTES_BIG_ENDIAN) 5472 bitpos = (wchar_bytes - byte - 1) * charwidth; 5473 else 5474 bitpos = byte * charwidth; 5475 val[bitpos < HOST_BITS_PER_WIDE_INT] 5476 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 5477 << (bitpos % HOST_BITS_PER_WIDE_INT); 5478 } 5479 } 5480 5481 if (!TREE_UNSIGNED (type)) 5482 { 5483 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 5484 if (bitpos < HOST_BITS_PER_WIDE_INT) 5485 { 5486 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 5487 { 5488 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 5489 val[0] = -1; 5490 } 5491 } 5492 else if (bitpos == HOST_BITS_PER_WIDE_INT) 5493 { 5494 if (val[1] < 0) 5495 val[0] = -1; 5496 } 5497 else if (val[0] & (((HOST_WIDE_INT) 1) 5498 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 5499 val[0] |= ((HOST_WIDE_INT) -1) 5500 << (bitpos - HOST_BITS_PER_WIDE_INT); 5501 } 5502 5503 value = build_int_2 (val[1], val[0]); 5504 TREE_TYPE (value) = type; 5505 add_pending_init (purpose, value); 5506 } 5507 5508 constructor_incremental = 0; 5509} 5510 5511/* Return value of FIELD in pending initializer or zero if the field was 5512 not initialized yet. */ 5513 5514static tree 5515find_init_member (tree field) 5516{ 5517 struct init_node *p; 5518 5519 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5520 { 5521 if (constructor_incremental 5522 && tree_int_cst_lt (field, constructor_unfilled_index)) 5523 set_nonincremental_init (); 5524 5525 p = constructor_pending_elts; 5526 while (p) 5527 { 5528 if (tree_int_cst_lt (field, p->purpose)) 5529 p = p->left; 5530 else if (tree_int_cst_lt (p->purpose, field)) 5531 p = p->right; 5532 else 5533 return p->value; 5534 } 5535 } 5536 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5537 { 5538 tree bitpos = bit_position (field); 5539 5540 if (constructor_incremental 5541 && (!constructor_unfilled_fields 5542 || tree_int_cst_lt (bitpos, 5543 bit_position (constructor_unfilled_fields)))) 5544 set_nonincremental_init (); 5545 5546 p = constructor_pending_elts; 5547 while (p) 5548 { 5549 if (field == p->purpose) 5550 return p->value; 5551 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5552 p = p->left; 5553 else 5554 p = p->right; 5555 } 5556 } 5557 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5558 { 5559 if (constructor_elements 5560 && TREE_PURPOSE (constructor_elements) == field) 5561 return TREE_VALUE (constructor_elements); 5562 } 5563 return 0; 5564} 5565 5566/* "Output" the next constructor element. 5567 At top level, really output it to assembler code now. 5568 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 5569 TYPE is the data type that the containing data type wants here. 5570 FIELD is the field (a FIELD_DECL) or the index that this element fills. 5571 5572 PENDING if non-nil means output pending elements that belong 5573 right after this element. (PENDING is normally 1; 5574 it is 0 while outputting pending elements, to avoid recursion.) */ 5575 5576static void 5577output_init_element (tree value, tree type, tree field, int pending) 5578{ 5579 if (type == error_mark_node) 5580 { 5581 constructor_erroneous = 1; 5582 return; 5583 } 5584 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE 5585 || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 5586 && !(TREE_CODE (value) == STRING_CST 5587 && TREE_CODE (type) == ARRAY_TYPE 5588 && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE) 5589 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 5590 TYPE_MAIN_VARIANT (type), COMPARE_STRICT))) 5591 value = default_conversion (value); 5592 5593 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 5594 && require_constant_value && !flag_isoc99 && pending) 5595 { 5596 /* As an extension, allow initializing objects with static storage 5597 duration with compound literals (which are then treated just as 5598 the brace enclosed list they contain). */ 5599 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 5600 value = DECL_INITIAL (decl); 5601 } 5602 5603 if (value == error_mark_node) 5604 constructor_erroneous = 1; 5605 else if (!TREE_CONSTANT (value)) 5606 constructor_constant = 0; 5607 else if (initializer_constant_valid_p (value, TREE_TYPE (value)) == 0 5608 || ((TREE_CODE (constructor_type) == RECORD_TYPE 5609 || TREE_CODE (constructor_type) == UNION_TYPE) 5610 && DECL_C_BIT_FIELD (field) 5611 && TREE_CODE (value) != INTEGER_CST)) 5612 constructor_simple = 0; 5613 5614 if (require_constant_value && ! TREE_CONSTANT (value)) 5615 { 5616 error_init ("initializer element is not constant"); 5617 value = error_mark_node; 5618 } 5619 else if (require_constant_elements 5620 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0) 5621 pedwarn ("initializer element is not computable at load time"); 5622 5623 /* If this field is empty (and not at the end of structure), 5624 don't do anything other than checking the initializer. */ 5625 if (field 5626 && (TREE_TYPE (field) == error_mark_node 5627 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 5628 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 5629 && (TREE_CODE (constructor_type) == ARRAY_TYPE 5630 || TREE_CHAIN (field))))) 5631 return; 5632 5633 value = digest_init (type, value, require_constant_value); 5634 if (value == error_mark_node) 5635 { 5636 constructor_erroneous = 1; 5637 return; 5638 } 5639 5640 /* If this element doesn't come next in sequence, 5641 put it on constructor_pending_elts. */ 5642 if (TREE_CODE (constructor_type) == ARRAY_TYPE 5643 && (!constructor_incremental 5644 || !tree_int_cst_equal (field, constructor_unfilled_index))) 5645 { 5646 if (constructor_incremental 5647 && tree_int_cst_lt (field, constructor_unfilled_index)) 5648 set_nonincremental_init (); 5649 5650 add_pending_init (field, value); 5651 return; 5652 } 5653 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5654 && (!constructor_incremental 5655 || field != constructor_unfilled_fields)) 5656 { 5657 /* We do this for records but not for unions. In a union, 5658 no matter which field is specified, it can be initialized 5659 right away since it starts at the beginning of the union. */ 5660 if (constructor_incremental) 5661 { 5662 if (!constructor_unfilled_fields) 5663 set_nonincremental_init (); 5664 else 5665 { 5666 tree bitpos, unfillpos; 5667 5668 bitpos = bit_position (field); 5669 unfillpos = bit_position (constructor_unfilled_fields); 5670 5671 if (tree_int_cst_lt (bitpos, unfillpos)) 5672 set_nonincremental_init (); 5673 } 5674 } 5675 5676 add_pending_init (field, value); 5677 return; 5678 } 5679 else if (TREE_CODE (constructor_type) == UNION_TYPE 5680 && constructor_elements) 5681 { 5682 if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements))) 5683 warning_init ("initialized field with side-effects overwritten"); 5684 5685 /* We can have just one union field set. */ 5686 constructor_elements = 0; 5687 } 5688 5689 /* Otherwise, output this element either to 5690 constructor_elements or to the assembler file. */ 5691 5692 if (field && TREE_CODE (field) == INTEGER_CST) 5693 field = copy_node (field); 5694 constructor_elements 5695 = tree_cons (field, value, constructor_elements); 5696 5697 /* Advance the variable that indicates sequential elements output. */ 5698 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5699 constructor_unfilled_index 5700 = size_binop (PLUS_EXPR, constructor_unfilled_index, 5701 bitsize_one_node); 5702 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5703 { 5704 constructor_unfilled_fields 5705 = TREE_CHAIN (constructor_unfilled_fields); 5706 5707 /* Skip any nameless bit fields. */ 5708 while (constructor_unfilled_fields != 0 5709 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5710 && DECL_NAME (constructor_unfilled_fields) == 0) 5711 constructor_unfilled_fields = 5712 TREE_CHAIN (constructor_unfilled_fields); 5713 } 5714 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5715 constructor_unfilled_fields = 0; 5716 5717 /* Now output any pending elements which have become next. */ 5718 if (pending) 5719 output_pending_init_elements (0); 5720} 5721 5722/* Output any pending elements which have become next. 5723 As we output elements, constructor_unfilled_{fields,index} 5724 advances, which may cause other elements to become next; 5725 if so, they too are output. 5726 5727 If ALL is 0, we return when there are 5728 no more pending elements to output now. 5729 5730 If ALL is 1, we output space as necessary so that 5731 we can output all the pending elements. */ 5732 5733static void 5734output_pending_init_elements (int all) 5735{ 5736 struct init_node *elt = constructor_pending_elts; 5737 tree next; 5738 5739 retry: 5740 5741 /* Look through the whole pending tree. 5742 If we find an element that should be output now, 5743 output it. Otherwise, set NEXT to the element 5744 that comes first among those still pending. */ 5745 5746 next = 0; 5747 while (elt) 5748 { 5749 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5750 { 5751 if (tree_int_cst_equal (elt->purpose, 5752 constructor_unfilled_index)) 5753 output_init_element (elt->value, 5754 TREE_TYPE (constructor_type), 5755 constructor_unfilled_index, 0); 5756 else if (tree_int_cst_lt (constructor_unfilled_index, 5757 elt->purpose)) 5758 { 5759 /* Advance to the next smaller node. */ 5760 if (elt->left) 5761 elt = elt->left; 5762 else 5763 { 5764 /* We have reached the smallest node bigger than the 5765 current unfilled index. Fill the space first. */ 5766 next = elt->purpose; 5767 break; 5768 } 5769 } 5770 else 5771 { 5772 /* Advance to the next bigger node. */ 5773 if (elt->right) 5774 elt = elt->right; 5775 else 5776 { 5777 /* We have reached the biggest node in a subtree. Find 5778 the parent of it, which is the next bigger node. */ 5779 while (elt->parent && elt->parent->right == elt) 5780 elt = elt->parent; 5781 elt = elt->parent; 5782 if (elt && tree_int_cst_lt (constructor_unfilled_index, 5783 elt->purpose)) 5784 { 5785 next = elt->purpose; 5786 break; 5787 } 5788 } 5789 } 5790 } 5791 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5792 || TREE_CODE (constructor_type) == UNION_TYPE) 5793 { 5794 tree ctor_unfilled_bitpos, elt_bitpos; 5795 5796 /* If the current record is complete we are done. */ 5797 if (constructor_unfilled_fields == 0) 5798 break; 5799 5800 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 5801 elt_bitpos = bit_position (elt->purpose); 5802 /* We can't compare fields here because there might be empty 5803 fields in between. */ 5804 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 5805 { 5806 constructor_unfilled_fields = elt->purpose; 5807 output_init_element (elt->value, TREE_TYPE (elt->purpose), 5808 elt->purpose, 0); 5809 } 5810 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 5811 { 5812 /* Advance to the next smaller node. */ 5813 if (elt->left) 5814 elt = elt->left; 5815 else 5816 { 5817 /* We have reached the smallest node bigger than the 5818 current unfilled field. Fill the space first. */ 5819 next = elt->purpose; 5820 break; 5821 } 5822 } 5823 else 5824 { 5825 /* Advance to the next bigger node. */ 5826 if (elt->right) 5827 elt = elt->right; 5828 else 5829 { 5830 /* We have reached the biggest node in a subtree. Find 5831 the parent of it, which is the next bigger node. */ 5832 while (elt->parent && elt->parent->right == elt) 5833 elt = elt->parent; 5834 elt = elt->parent; 5835 if (elt 5836 && (tree_int_cst_lt (ctor_unfilled_bitpos, 5837 bit_position (elt->purpose)))) 5838 { 5839 next = elt->purpose; 5840 break; 5841 } 5842 } 5843 } 5844 } 5845 } 5846 5847 /* Ordinarily return, but not if we want to output all 5848 and there are elements left. */ 5849 if (! (all && next != 0)) 5850 return; 5851 5852 /* If it's not incremental, just skip over the gap, so that after 5853 jumping to retry we will output the next successive element. */ 5854 if (TREE_CODE (constructor_type) == RECORD_TYPE 5855 || TREE_CODE (constructor_type) == UNION_TYPE) 5856 constructor_unfilled_fields = next; 5857 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5858 constructor_unfilled_index = next; 5859 5860 /* ELT now points to the node in the pending tree with the next 5861 initializer to output. */ 5862 goto retry; 5863} 5864 5865/* Add one non-braced element to the current constructor level. 5866 This adjusts the current position within the constructor's type. 5867 This may also start or terminate implicit levels 5868 to handle a partly-braced initializer. 5869 5870 Once this has found the correct level for the new element, 5871 it calls output_init_element. */ 5872 5873void 5874process_init_element (tree value) 5875{ 5876 tree orig_value = value; 5877 int string_flag = value != 0 && TREE_CODE (value) == STRING_CST; 5878 5879 designator_depth = 0; 5880 designator_errorneous = 0; 5881 5882 /* Handle superfluous braces around string cst as in 5883 char x[] = {"foo"}; */ 5884 if (string_flag 5885 && constructor_type 5886 && TREE_CODE (constructor_type) == ARRAY_TYPE 5887 && TREE_CODE (TREE_TYPE (constructor_type)) == INTEGER_TYPE 5888 && integer_zerop (constructor_unfilled_index)) 5889 { 5890 if (constructor_stack->replacement_value) 5891 error_init ("excess elements in char array initializer"); 5892 constructor_stack->replacement_value = value; 5893 return; 5894 } 5895 5896 if (constructor_stack->replacement_value != 0) 5897 { 5898 error_init ("excess elements in struct initializer"); 5899 return; 5900 } 5901 5902 /* Ignore elements of a brace group if it is entirely superfluous 5903 and has already been diagnosed. */ 5904 if (constructor_type == 0) 5905 return; 5906 5907 /* If we've exhausted any levels that didn't have braces, 5908 pop them now. */ 5909 while (constructor_stack->implicit) 5910 { 5911 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5912 || TREE_CODE (constructor_type) == UNION_TYPE) 5913 && constructor_fields == 0) 5914 process_init_element (pop_init_level (1)); 5915 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5916 && (constructor_max_index == 0 5917 || tree_int_cst_lt (constructor_max_index, 5918 constructor_index))) 5919 process_init_element (pop_init_level (1)); 5920 else 5921 break; 5922 } 5923 5924 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 5925 if (constructor_range_stack) 5926 { 5927 /* If value is a compound literal and we'll be just using its 5928 content, don't put it into a SAVE_EXPR. */ 5929 if (TREE_CODE (value) != COMPOUND_LITERAL_EXPR 5930 || !require_constant_value 5931 || flag_isoc99) 5932 value = save_expr (value); 5933 } 5934 5935 while (1) 5936 { 5937 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5938 { 5939 tree fieldtype; 5940 enum tree_code fieldcode; 5941 5942 if (constructor_fields == 0) 5943 { 5944 pedwarn_init ("excess elements in struct initializer"); 5945 break; 5946 } 5947 5948 fieldtype = TREE_TYPE (constructor_fields); 5949 if (fieldtype != error_mark_node) 5950 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 5951 fieldcode = TREE_CODE (fieldtype); 5952 5953 /* Error for non-static initialization of a flexible array member. */ 5954 if (fieldcode == ARRAY_TYPE 5955 && !require_constant_value 5956 && TYPE_SIZE (fieldtype) == NULL_TREE 5957 && TREE_CHAIN (constructor_fields) == NULL_TREE) 5958 { 5959 error_init ("non-static initialization of a flexible array member"); 5960 break; 5961 } 5962 5963 /* Accept a string constant to initialize a subarray. */ 5964 if (value != 0 5965 && fieldcode == ARRAY_TYPE 5966 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 5967 && string_flag) 5968 value = orig_value; 5969 /* Otherwise, if we have come to a subaggregate, 5970 and we don't have an element of its type, push into it. */ 5971 else if (value != 0 && !constructor_no_implicit 5972 && value != error_mark_node 5973 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 5974 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 5975 || fieldcode == UNION_TYPE)) 5976 { 5977 push_init_level (1); 5978 continue; 5979 } 5980 5981 if (value) 5982 { 5983 push_member_name (constructor_fields); 5984 output_init_element (value, fieldtype, constructor_fields, 1); 5985 RESTORE_SPELLING_DEPTH (constructor_depth); 5986 } 5987 else 5988 /* Do the bookkeeping for an element that was 5989 directly output as a constructor. */ 5990 { 5991 /* For a record, keep track of end position of last field. */ 5992 if (DECL_SIZE (constructor_fields)) 5993 constructor_bit_index 5994 = size_binop (PLUS_EXPR, 5995 bit_position (constructor_fields), 5996 DECL_SIZE (constructor_fields)); 5997 5998 /* If the current field was the first one not yet written out, 5999 it isn't now, so update. */ 6000 if (constructor_unfilled_fields == constructor_fields) 6001 { 6002 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6003 /* Skip any nameless bit fields. */ 6004 while (constructor_unfilled_fields != 0 6005 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6006 && DECL_NAME (constructor_unfilled_fields) == 0) 6007 constructor_unfilled_fields = 6008 TREE_CHAIN (constructor_unfilled_fields); 6009 } 6010 } 6011 6012 constructor_fields = TREE_CHAIN (constructor_fields); 6013 /* Skip any nameless bit fields at the beginning. */ 6014 while (constructor_fields != 0 6015 && DECL_C_BIT_FIELD (constructor_fields) 6016 && DECL_NAME (constructor_fields) == 0) 6017 constructor_fields = TREE_CHAIN (constructor_fields); 6018 } 6019 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6020 { 6021 tree fieldtype; 6022 enum tree_code fieldcode; 6023 6024 if (constructor_fields == 0) 6025 { 6026 pedwarn_init ("excess elements in union initializer"); 6027 break; 6028 } 6029 6030 fieldtype = TREE_TYPE (constructor_fields); 6031 if (fieldtype != error_mark_node) 6032 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6033 fieldcode = TREE_CODE (fieldtype); 6034 6035 /* Warn that traditional C rejects initialization of unions. 6036 We skip the warning if the value is zero. This is done 6037 under the assumption that the zero initializer in user 6038 code appears conditioned on e.g. __STDC__ to avoid 6039 "missing initializer" warnings and relies on default 6040 initialization to zero in the traditional C case. 6041 We also skip the warning if the initializer is designated, 6042 again on the assumption that this must be conditional on 6043 __STDC__ anyway (and we've already complained about the 6044 member-designator already). */ 6045 if (warn_traditional && !in_system_header && !constructor_designated 6046 && !(value && (integer_zerop (value) || real_zerop (value)))) 6047 warning ("traditional C rejects initialization of unions"); 6048 6049 /* Accept a string constant to initialize a subarray. */ 6050 if (value != 0 6051 && fieldcode == ARRAY_TYPE 6052 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 6053 && string_flag) 6054 value = orig_value; 6055 /* Otherwise, if we have come to a subaggregate, 6056 and we don't have an element of its type, push into it. */ 6057 else if (value != 0 && !constructor_no_implicit 6058 && value != error_mark_node 6059 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 6060 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6061 || fieldcode == UNION_TYPE)) 6062 { 6063 push_init_level (1); 6064 continue; 6065 } 6066 6067 if (value) 6068 { 6069 push_member_name (constructor_fields); 6070 output_init_element (value, fieldtype, constructor_fields, 1); 6071 RESTORE_SPELLING_DEPTH (constructor_depth); 6072 } 6073 else 6074 /* Do the bookkeeping for an element that was 6075 directly output as a constructor. */ 6076 { 6077 constructor_bit_index = DECL_SIZE (constructor_fields); 6078 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6079 } 6080 6081 constructor_fields = 0; 6082 } 6083 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6084 { 6085 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6086 enum tree_code eltcode = TREE_CODE (elttype); 6087 6088 /* Accept a string constant to initialize a subarray. */ 6089 if (value != 0 6090 && eltcode == ARRAY_TYPE 6091 && TREE_CODE (TREE_TYPE (elttype)) == INTEGER_TYPE 6092 && string_flag) 6093 value = orig_value; 6094 /* Otherwise, if we have come to a subaggregate, 6095 and we don't have an element of its type, push into it. */ 6096 else if (value != 0 && !constructor_no_implicit 6097 && value != error_mark_node 6098 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != elttype 6099 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6100 || eltcode == UNION_TYPE)) 6101 { 6102 push_init_level (1); 6103 continue; 6104 } 6105 6106 if (constructor_max_index != 0 6107 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6108 || integer_all_onesp (constructor_max_index))) 6109 { 6110 pedwarn_init ("excess elements in array initializer"); 6111 break; 6112 } 6113 6114 /* Now output the actual element. */ 6115 if (value) 6116 { 6117 push_array_bounds (tree_low_cst (constructor_index, 0)); 6118 output_init_element (value, elttype, constructor_index, 1); 6119 RESTORE_SPELLING_DEPTH (constructor_depth); 6120 } 6121 6122 constructor_index 6123 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6124 6125 if (! value) 6126 /* If we are doing the bookkeeping for an element that was 6127 directly output as a constructor, we must update 6128 constructor_unfilled_index. */ 6129 constructor_unfilled_index = constructor_index; 6130 } 6131 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6132 { 6133 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6134 6135 /* Do a basic check of initializer size. Note that vectors 6136 always have a fixed size derived from their type. */ 6137 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6138 { 6139 pedwarn_init ("excess elements in vector initializer"); 6140 break; 6141 } 6142 6143 /* Now output the actual element. */ 6144 if (value) 6145 output_init_element (value, elttype, constructor_index, 1); 6146 6147 constructor_index 6148 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6149 6150 if (! value) 6151 /* If we are doing the bookkeeping for an element that was 6152 directly output as a constructor, we must update 6153 constructor_unfilled_index. */ 6154 constructor_unfilled_index = constructor_index; 6155 } 6156 6157 /* Handle the sole element allowed in a braced initializer 6158 for a scalar variable. */ 6159 else if (constructor_fields == 0) 6160 { 6161 pedwarn_init ("excess elements in scalar initializer"); 6162 break; 6163 } 6164 else 6165 { 6166 if (value) 6167 output_init_element (value, constructor_type, NULL_TREE, 1); 6168 constructor_fields = 0; 6169 } 6170 6171 /* Handle range initializers either at this level or anywhere higher 6172 in the designator stack. */ 6173 if (constructor_range_stack) 6174 { 6175 struct constructor_range_stack *p, *range_stack; 6176 int finish = 0; 6177 6178 range_stack = constructor_range_stack; 6179 constructor_range_stack = 0; 6180 while (constructor_stack != range_stack->stack) 6181 { 6182 if (!constructor_stack->implicit) 6183 abort (); 6184 process_init_element (pop_init_level (1)); 6185 } 6186 for (p = range_stack; 6187 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6188 p = p->prev) 6189 { 6190 if (!constructor_stack->implicit) 6191 abort (); 6192 process_init_element (pop_init_level (1)); 6193 } 6194 6195 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6196 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6197 finish = 1; 6198 6199 while (1) 6200 { 6201 constructor_index = p->index; 6202 constructor_fields = p->fields; 6203 if (finish && p->range_end && p->index == p->range_start) 6204 { 6205 finish = 0; 6206 p->prev = 0; 6207 } 6208 p = p->next; 6209 if (!p) 6210 break; 6211 push_init_level (2); 6212 p->stack = constructor_stack; 6213 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6214 p->index = p->range_start; 6215 } 6216 6217 if (!finish) 6218 constructor_range_stack = range_stack; 6219 continue; 6220 } 6221 6222 break; 6223 } 6224 6225 constructor_range_stack = 0; 6226} 6227 6228/* Build a simple asm-statement, from one string literal. */ 6229tree 6230simple_asm_stmt (tree expr) 6231{ 6232 STRIP_NOPS (expr); 6233 6234 if (TREE_CODE (expr) == ADDR_EXPR) 6235 expr = TREE_OPERAND (expr, 0); 6236 6237 if (TREE_CODE (expr) == STRING_CST) 6238 { 6239 tree stmt; 6240 6241 /* Simple asm statements are treated as volatile. */ 6242 stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE], 6243 expr, NULL_TREE, NULL_TREE, NULL_TREE)); 6244 ASM_INPUT_P (stmt) = 1; 6245 return stmt; 6246 } 6247 6248 error ("argument of `asm' is not a constant string"); 6249 return NULL_TREE; 6250} 6251 6252/* Build an asm-statement, whose components are a CV_QUALIFIER, a 6253 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */ 6254 6255tree 6256build_asm_stmt (tree cv_qualifier, tree string, tree outputs, tree inputs, 6257 tree clobbers) 6258{ 6259 tree tail; 6260 6261 if (TREE_CODE (string) != STRING_CST) 6262 { 6263 error ("asm template is not a string constant"); 6264 return NULL_TREE; 6265 } 6266 6267 if (cv_qualifier != NULL_TREE 6268 && cv_qualifier != ridpointers[(int) RID_VOLATILE]) 6269 { 6270 warning ("%s qualifier ignored on asm", 6271 IDENTIFIER_POINTER (cv_qualifier)); 6272 cv_qualifier = NULL_TREE; 6273 } 6274 6275 /* We can remove output conversions that change the type, 6276 but not the mode. */ 6277 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6278 { 6279 tree output = TREE_VALUE (tail); 6280 6281 STRIP_NOPS (output); 6282 TREE_VALUE (tail) = output; 6283 6284 /* Allow conversions as LHS here. build_modify_expr as called below 6285 will do the right thing with them. */ 6286 while (TREE_CODE (output) == NOP_EXPR 6287 || TREE_CODE (output) == CONVERT_EXPR 6288 || TREE_CODE (output) == FLOAT_EXPR 6289 || TREE_CODE (output) == FIX_TRUNC_EXPR 6290 || TREE_CODE (output) == FIX_FLOOR_EXPR 6291 || TREE_CODE (output) == FIX_ROUND_EXPR 6292 || TREE_CODE (output) == FIX_CEIL_EXPR) 6293 output = TREE_OPERAND (output, 0); 6294 6295 lvalue_or_else (TREE_VALUE (tail), "invalid lvalue in asm statement"); 6296 } 6297 6298 /* Remove output conversions that change the type but not the mode. */ 6299 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6300 { 6301 tree output = TREE_VALUE (tail); 6302 STRIP_NOPS (output); 6303 TREE_VALUE (tail) = output; 6304 } 6305 6306 /* Perform default conversions on array and function inputs. 6307 Don't do this for other types as it would screw up operands 6308 expected to be in memory. */ 6309 for (tail = inputs; tail; tail = TREE_CHAIN (tail)) 6310 TREE_VALUE (tail) = default_function_array_conversion (TREE_VALUE (tail)); 6311 6312 return add_stmt (build_stmt (ASM_STMT, cv_qualifier, string, 6313 outputs, inputs, clobbers)); 6314} 6315 6316/* Expand an ASM statement with operands, handling output operands 6317 that are not variables or INDIRECT_REFS by transforming such 6318 cases into cases that expand_asm_operands can handle. 6319 6320 Arguments are same as for expand_asm_operands. */ 6321 6322void 6323c_expand_asm_operands (tree string, tree outputs, tree inputs, 6324 tree clobbers, int vol, location_t locus) 6325{ 6326 int noutputs = list_length (outputs); 6327 int i; 6328 /* o[I] is the place that output number I should be written. */ 6329 tree *o = alloca (noutputs * sizeof (tree)); 6330 tree tail; 6331 6332 /* Record the contents of OUTPUTS before it is modified. */ 6333 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6334 { 6335 o[i] = TREE_VALUE (tail); 6336 if (o[i] == error_mark_node) 6337 return; 6338 } 6339 6340 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of 6341 OUTPUTS some trees for where the values were actually stored. */ 6342 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus); 6343 6344 /* Copy all the intermediate outputs into the specified outputs. */ 6345 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6346 { 6347 if (o[i] != TREE_VALUE (tail)) 6348 { 6349 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)), 6350 NULL_RTX, VOIDmode, EXPAND_NORMAL); 6351 free_temp_slots (); 6352 6353 /* Restore the original value so that it's correct the next 6354 time we expand this function. */ 6355 TREE_VALUE (tail) = o[i]; 6356 } 6357 /* Detect modification of read-only values. 6358 (Otherwise done by build_modify_expr.) */ 6359 else 6360 { 6361 tree type = TREE_TYPE (o[i]); 6362 if (TREE_READONLY (o[i]) 6363 || TYPE_READONLY (type) 6364 || ((TREE_CODE (type) == RECORD_TYPE 6365 || TREE_CODE (type) == UNION_TYPE) 6366 && C_TYPE_FIELDS_READONLY (type))) 6367 readonly_error (o[i], "modification by `asm'"); 6368 } 6369 } 6370 6371 /* Those MODIFY_EXPRs could do autoincrements. */ 6372 emit_queue (); 6373} 6374 6375/* Expand a C `return' statement. 6376 RETVAL is the expression for what to return, 6377 or a null pointer for `return;' with no value. */ 6378 6379tree 6380c_expand_return (tree retval) 6381{ 6382 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6383 6384 if (TREE_THIS_VOLATILE (current_function_decl)) 6385 warning ("function declared `noreturn' has a `return' statement"); 6386 6387 if (!retval) 6388 { 6389 current_function_returns_null = 1; 6390 if ((warn_return_type || flag_isoc99) 6391 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 6392 pedwarn_c99 ("`return' with no value, in function returning non-void"); 6393 } 6394 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 6395 { 6396 current_function_returns_null = 1; 6397 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 6398 pedwarn ("`return' with a value, in function returning void"); 6399 } 6400 else 6401 { 6402 tree t = convert_for_assignment (valtype, retval, _("return"), 6403 NULL_TREE, NULL_TREE, 0); 6404 tree res = DECL_RESULT (current_function_decl); 6405 tree inner; 6406 6407 current_function_returns_value = 1; 6408 if (t == error_mark_node) 6409 return NULL_TREE; 6410 6411 inner = t = convert (TREE_TYPE (res), t); 6412 6413 /* Strip any conversions, additions, and subtractions, and see if 6414 we are returning the address of a local variable. Warn if so. */ 6415 while (1) 6416 { 6417 switch (TREE_CODE (inner)) 6418 { 6419 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 6420 case PLUS_EXPR: 6421 inner = TREE_OPERAND (inner, 0); 6422 continue; 6423 6424 case MINUS_EXPR: 6425 /* If the second operand of the MINUS_EXPR has a pointer 6426 type (or is converted from it), this may be valid, so 6427 don't give a warning. */ 6428 { 6429 tree op1 = TREE_OPERAND (inner, 1); 6430 6431 while (! POINTER_TYPE_P (TREE_TYPE (op1)) 6432 && (TREE_CODE (op1) == NOP_EXPR 6433 || TREE_CODE (op1) == NON_LVALUE_EXPR 6434 || TREE_CODE (op1) == CONVERT_EXPR)) 6435 op1 = TREE_OPERAND (op1, 0); 6436 6437 if (POINTER_TYPE_P (TREE_TYPE (op1))) 6438 break; 6439 6440 inner = TREE_OPERAND (inner, 0); 6441 continue; 6442 } 6443 6444 case ADDR_EXPR: 6445 inner = TREE_OPERAND (inner, 0); 6446 6447 while (TREE_CODE_CLASS (TREE_CODE (inner)) == 'r') 6448 inner = TREE_OPERAND (inner, 0); 6449 6450 if (TREE_CODE (inner) == VAR_DECL 6451 && ! DECL_EXTERNAL (inner) 6452 && ! TREE_STATIC (inner) 6453 && DECL_CONTEXT (inner) == current_function_decl) 6454 warning ("function returns address of local variable"); 6455 break; 6456 6457 default: 6458 break; 6459 } 6460 6461 break; 6462 } 6463 6464 retval = build (MODIFY_EXPR, TREE_TYPE (res), res, t); 6465 } 6466 6467 return add_stmt (build_return_stmt (retval)); 6468} 6469 6470struct c_switch { 6471 /* The SWITCH_STMT being built. */ 6472 tree switch_stmt; 6473 /* A splay-tree mapping the low element of a case range to the high 6474 element, or NULL_TREE if there is no high element. Used to 6475 determine whether or not a new case label duplicates an old case 6476 label. We need a tree, rather than simply a hash table, because 6477 of the GNU case range extension. */ 6478 splay_tree cases; 6479 /* The next node on the stack. */ 6480 struct c_switch *next; 6481}; 6482 6483/* A stack of the currently active switch statements. The innermost 6484 switch statement is on the top of the stack. There is no need to 6485 mark the stack for garbage collection because it is only active 6486 during the processing of the body of a function, and we never 6487 collect at that point. */ 6488 6489static struct c_switch *switch_stack; 6490 6491/* Start a C switch statement, testing expression EXP. Return the new 6492 SWITCH_STMT. */ 6493 6494tree 6495c_start_case (tree exp) 6496{ 6497 enum tree_code code; 6498 tree type, orig_type = error_mark_node; 6499 struct c_switch *cs; 6500 6501 if (exp != error_mark_node) 6502 { 6503 code = TREE_CODE (TREE_TYPE (exp)); 6504 orig_type = TREE_TYPE (exp); 6505 6506 if (! INTEGRAL_TYPE_P (orig_type) 6507 && code != ERROR_MARK) 6508 { 6509 error ("switch quantity not an integer"); 6510 exp = integer_zero_node; 6511 } 6512 else 6513 { 6514 type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 6515 6516 if (warn_traditional && !in_system_header 6517 && (type == long_integer_type_node 6518 || type == long_unsigned_type_node)) 6519 warning ("`long' switch expression not converted to `int' in ISO C"); 6520 6521 exp = default_conversion (exp); 6522 type = TREE_TYPE (exp); 6523 } 6524 } 6525 6526 /* Add this new SWITCH_STMT to the stack. */ 6527 cs = xmalloc (sizeof (*cs)); 6528 cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type); 6529 cs->cases = splay_tree_new (case_compare, NULL, NULL); 6530 cs->next = switch_stack; 6531 switch_stack = cs; 6532 6533 return add_stmt (switch_stack->switch_stmt); 6534} 6535 6536/* Process a case label. */ 6537 6538tree 6539do_case (tree low_value, tree high_value) 6540{ 6541 tree label = NULL_TREE; 6542 6543 if (switch_stack) 6544 { 6545 bool switch_was_empty_p = (SWITCH_BODY (switch_stack->switch_stmt) == NULL_TREE); 6546 6547 label = c_add_case_label (switch_stack->cases, 6548 SWITCH_COND (switch_stack->switch_stmt), 6549 low_value, high_value); 6550 if (label == error_mark_node) 6551 label = NULL_TREE; 6552 else if (switch_was_empty_p) 6553 { 6554 /* Attach the first case label to the SWITCH_BODY. */ 6555 SWITCH_BODY (switch_stack->switch_stmt) = TREE_CHAIN (switch_stack->switch_stmt); 6556 TREE_CHAIN (switch_stack->switch_stmt) = NULL_TREE; 6557 } 6558 } 6559 else if (low_value) 6560 error ("case label not within a switch statement"); 6561 else 6562 error ("`default' label not within a switch statement"); 6563 6564 return label; 6565} 6566 6567/* Finish the switch statement. */ 6568 6569void 6570c_finish_case (void) 6571{ 6572 struct c_switch *cs = switch_stack; 6573 6574 /* Rechain the next statements to the SWITCH_STMT. */ 6575 last_tree = cs->switch_stmt; 6576 6577 /* Pop the stack. */ 6578 switch_stack = switch_stack->next; 6579 splay_tree_delete (cs->cases); 6580 free (cs); 6581} 6582 6583/* Build a binary-operation expression without default conversions. 6584 CODE is the kind of expression to build. 6585 This function differs from `build' in several ways: 6586 the data type of the result is computed and recorded in it, 6587 warnings are generated if arg data types are invalid, 6588 special handling for addition and subtraction of pointers is known, 6589 and some optimization is done (operations on narrow ints 6590 are done in the narrower type when that gives the same result). 6591 Constant folding is also done before the result is returned. 6592 6593 Note that the operands will never have enumeral types, or function 6594 or array types, because either they will have the default conversions 6595 performed or they have both just been converted to some other type in which 6596 the arithmetic is to be done. */ 6597 6598tree 6599build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 6600 int convert_p) 6601{ 6602 tree type0, type1; 6603 enum tree_code code0, code1; 6604 tree op0, op1; 6605 6606 /* Expression code to give to the expression when it is built. 6607 Normally this is CODE, which is what the caller asked for, 6608 but in some special cases we change it. */ 6609 enum tree_code resultcode = code; 6610 6611 /* Data type in which the computation is to be performed. 6612 In the simplest cases this is the common type of the arguments. */ 6613 tree result_type = NULL; 6614 6615 /* Nonzero means operands have already been type-converted 6616 in whatever way is necessary. 6617 Zero means they need to be converted to RESULT_TYPE. */ 6618 int converted = 0; 6619 6620 /* Nonzero means create the expression with this type, rather than 6621 RESULT_TYPE. */ 6622 tree build_type = 0; 6623 6624 /* Nonzero means after finally constructing the expression 6625 convert it to this type. */ 6626 tree final_type = 0; 6627 6628 /* Nonzero if this is an operation like MIN or MAX which can 6629 safely be computed in short if both args are promoted shorts. 6630 Also implies COMMON. 6631 -1 indicates a bitwise operation; this makes a difference 6632 in the exact conditions for when it is safe to do the operation 6633 in a narrower mode. */ 6634 int shorten = 0; 6635 6636 /* Nonzero if this is a comparison operation; 6637 if both args are promoted shorts, compare the original shorts. 6638 Also implies COMMON. */ 6639 int short_compare = 0; 6640 6641 /* Nonzero if this is a right-shift operation, which can be computed on the 6642 original short and then promoted if the operand is a promoted short. */ 6643 int short_shift = 0; 6644 6645 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 6646 int common = 0; 6647 6648 if (convert_p) 6649 { 6650 op0 = default_conversion (orig_op0); 6651 op1 = default_conversion (orig_op1); 6652 } 6653 else 6654 { 6655 op0 = orig_op0; 6656 op1 = orig_op1; 6657 } 6658 6659 type0 = TREE_TYPE (op0); 6660 type1 = TREE_TYPE (op1); 6661 6662 /* The expression codes of the data types of the arguments tell us 6663 whether the arguments are integers, floating, pointers, etc. */ 6664 code0 = TREE_CODE (type0); 6665 code1 = TREE_CODE (type1); 6666 6667 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 6668 STRIP_TYPE_NOPS (op0); 6669 STRIP_TYPE_NOPS (op1); 6670 6671 /* If an error was already reported for one of the arguments, 6672 avoid reporting another error. */ 6673 6674 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 6675 return error_mark_node; 6676 6677 switch (code) 6678 { 6679 case PLUS_EXPR: 6680 /* Handle the pointer + int case. */ 6681 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6682 return pointer_int_sum (PLUS_EXPR, op0, op1); 6683 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 6684 return pointer_int_sum (PLUS_EXPR, op1, op0); 6685 else 6686 common = 1; 6687 break; 6688 6689 case MINUS_EXPR: 6690 /* Subtraction of two similar pointers. 6691 We must subtract them as integers, then divide by object size. */ 6692 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 6693 && comp_target_types (type0, type1, 1)) 6694 return pointer_diff (op0, op1); 6695 /* Handle pointer minus int. Just like pointer plus int. */ 6696 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6697 return pointer_int_sum (MINUS_EXPR, op0, op1); 6698 else 6699 common = 1; 6700 break; 6701 6702 case MULT_EXPR: 6703 common = 1; 6704 break; 6705 6706 case TRUNC_DIV_EXPR: 6707 case CEIL_DIV_EXPR: 6708 case FLOOR_DIV_EXPR: 6709 case ROUND_DIV_EXPR: 6710 case EXACT_DIV_EXPR: 6711 /* Floating point division by zero is a legitimate way to obtain 6712 infinities and NaNs. */ 6713 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6714 warning ("division by zero"); 6715 6716 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6717 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 6718 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6719 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 6720 { 6721 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)) 6722 resultcode = RDIV_EXPR; 6723 else 6724 /* Although it would be tempting to shorten always here, that 6725 loses on some targets, since the modulo instruction is 6726 undefined if the quotient can't be represented in the 6727 computation mode. We shorten only if unsigned or if 6728 dividing by something we know != -1. */ 6729 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6730 || (TREE_CODE (op1) == INTEGER_CST 6731 && ! integer_all_onesp (op1))); 6732 common = 1; 6733 } 6734 break; 6735 6736 case BIT_AND_EXPR: 6737 case BIT_IOR_EXPR: 6738 case BIT_XOR_EXPR: 6739 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6740 shorten = -1; 6741 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 6742 common = 1; 6743 break; 6744 6745 case TRUNC_MOD_EXPR: 6746 case FLOOR_MOD_EXPR: 6747 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6748 warning ("division by zero"); 6749 6750 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6751 { 6752 /* Although it would be tempting to shorten always here, that loses 6753 on some targets, since the modulo instruction is undefined if the 6754 quotient can't be represented in the computation mode. We shorten 6755 only if unsigned or if dividing by something we know != -1. */ 6756 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6757 || (TREE_CODE (op1) == INTEGER_CST 6758 && ! integer_all_onesp (op1))); 6759 common = 1; 6760 } 6761 break; 6762 6763 case TRUTH_ANDIF_EXPR: 6764 case TRUTH_ORIF_EXPR: 6765 case TRUTH_AND_EXPR: 6766 case TRUTH_OR_EXPR: 6767 case TRUTH_XOR_EXPR: 6768 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 6769 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 6770 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 6771 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 6772 { 6773 /* Result of these operations is always an int, 6774 but that does not mean the operands should be 6775 converted to ints! */ 6776 result_type = integer_type_node; 6777 op0 = c_common_truthvalue_conversion (op0); 6778 op1 = c_common_truthvalue_conversion (op1); 6779 converted = 1; 6780 } 6781 break; 6782 6783 /* Shift operations: result has same type as first operand; 6784 always convert second operand to int. 6785 Also set SHORT_SHIFT if shifting rightward. */ 6786 6787 case RSHIFT_EXPR: 6788 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6789 { 6790 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6791 { 6792 if (tree_int_cst_sgn (op1) < 0) 6793 warning ("right shift count is negative"); 6794 else 6795 { 6796 if (! integer_zerop (op1)) 6797 short_shift = 1; 6798 6799 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6800 warning ("right shift count >= width of type"); 6801 } 6802 } 6803 6804 /* Use the type of the value to be shifted. */ 6805 result_type = type0; 6806 /* Convert the shift-count to an integer, regardless of size 6807 of value being shifted. */ 6808 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6809 op1 = convert (integer_type_node, op1); 6810 /* Avoid converting op1 to result_type later. */ 6811 converted = 1; 6812 } 6813 break; 6814 6815 case LSHIFT_EXPR: 6816 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6817 { 6818 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6819 { 6820 if (tree_int_cst_sgn (op1) < 0) 6821 warning ("left shift count is negative"); 6822 6823 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6824 warning ("left shift count >= width of type"); 6825 } 6826 6827 /* Use the type of the value to be shifted. */ 6828 result_type = type0; 6829 /* Convert the shift-count to an integer, regardless of size 6830 of value being shifted. */ 6831 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6832 op1 = convert (integer_type_node, op1); 6833 /* Avoid converting op1 to result_type later. */ 6834 converted = 1; 6835 } 6836 break; 6837 6838 case RROTATE_EXPR: 6839 case LROTATE_EXPR: 6840 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6841 { 6842 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6843 { 6844 if (tree_int_cst_sgn (op1) < 0) 6845 warning ("shift count is negative"); 6846 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6847 warning ("shift count >= width of type"); 6848 } 6849 6850 /* Use the type of the value to be shifted. */ 6851 result_type = type0; 6852 /* Convert the shift-count to an integer, regardless of size 6853 of value being shifted. */ 6854 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6855 op1 = convert (integer_type_node, op1); 6856 /* Avoid converting op1 to result_type later. */ 6857 converted = 1; 6858 } 6859 break; 6860 6861 case EQ_EXPR: 6862 case NE_EXPR: 6863 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE)) 6864 warning ("comparing floating point with == or != is unsafe"); 6865 /* Result of comparison is always int, 6866 but don't convert the args to int! */ 6867 build_type = integer_type_node; 6868 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6869 || code0 == COMPLEX_TYPE) 6870 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6871 || code1 == COMPLEX_TYPE)) 6872 short_compare = 1; 6873 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6874 { 6875 tree tt0 = TREE_TYPE (type0); 6876 tree tt1 = TREE_TYPE (type1); 6877 /* Anything compares with void *. void * compares with anything. 6878 Otherwise, the targets must be compatible 6879 and both must be object or both incomplete. */ 6880 if (comp_target_types (type0, type1, 1)) 6881 result_type = common_type (type0, type1); 6882 else if (VOID_TYPE_P (tt0)) 6883 { 6884 /* op0 != orig_op0 detects the case of something 6885 whose value is 0 but which isn't a valid null ptr const. */ 6886 if (pedantic && (!integer_zerop (op0) || op0 != orig_op0) 6887 && TREE_CODE (tt1) == FUNCTION_TYPE) 6888 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6889 } 6890 else if (VOID_TYPE_P (tt1)) 6891 { 6892 if (pedantic && (!integer_zerop (op1) || op1 != orig_op1) 6893 && TREE_CODE (tt0) == FUNCTION_TYPE) 6894 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6895 } 6896 else 6897 pedwarn ("comparison of distinct pointer types lacks a cast"); 6898 6899 if (result_type == NULL_TREE) 6900 result_type = ptr_type_node; 6901 } 6902 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6903 && integer_zerop (op1)) 6904 result_type = type0; 6905 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6906 && integer_zerop (op0)) 6907 result_type = type1; 6908 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6909 { 6910 result_type = type0; 6911 pedwarn ("comparison between pointer and integer"); 6912 } 6913 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6914 { 6915 result_type = type1; 6916 pedwarn ("comparison between pointer and integer"); 6917 } 6918 break; 6919 6920 case MAX_EXPR: 6921 case MIN_EXPR: 6922 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6923 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6924 shorten = 1; 6925 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6926 { 6927 if (comp_target_types (type0, type1, 1)) 6928 { 6929 result_type = common_type (type0, type1); 6930 if (pedantic 6931 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6932 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6933 } 6934 else 6935 { 6936 result_type = ptr_type_node; 6937 pedwarn ("comparison of distinct pointer types lacks a cast"); 6938 } 6939 } 6940 break; 6941 6942 case LE_EXPR: 6943 case GE_EXPR: 6944 case LT_EXPR: 6945 case GT_EXPR: 6946 build_type = integer_type_node; 6947 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6948 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6949 short_compare = 1; 6950 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6951 { 6952 if (comp_target_types (type0, type1, 1)) 6953 { 6954 result_type = common_type (type0, type1); 6955 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 6956 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 6957 pedwarn ("comparison of complete and incomplete pointers"); 6958 else if (pedantic 6959 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6960 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6961 } 6962 else 6963 { 6964 result_type = ptr_type_node; 6965 pedwarn ("comparison of distinct pointer types lacks a cast"); 6966 } 6967 } 6968 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6969 && integer_zerop (op1)) 6970 { 6971 result_type = type0; 6972 if (pedantic || extra_warnings) 6973 pedwarn ("ordered comparison of pointer with integer zero"); 6974 } 6975 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6976 && integer_zerop (op0)) 6977 { 6978 result_type = type1; 6979 if (pedantic) 6980 pedwarn ("ordered comparison of pointer with integer zero"); 6981 } 6982 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6983 { 6984 result_type = type0; 6985 pedwarn ("comparison between pointer and integer"); 6986 } 6987 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6988 { 6989 result_type = type1; 6990 pedwarn ("comparison between pointer and integer"); 6991 } 6992 break; 6993 6994 case UNORDERED_EXPR: 6995 case ORDERED_EXPR: 6996 case UNLT_EXPR: 6997 case UNLE_EXPR: 6998 case UNGT_EXPR: 6999 case UNGE_EXPR: 7000 case UNEQ_EXPR: 7001 build_type = integer_type_node; 7002 if (code0 != REAL_TYPE || code1 != REAL_TYPE) 7003 { 7004 error ("unordered comparison on non-floating point argument"); 7005 return error_mark_node; 7006 } 7007 common = 1; 7008 break; 7009 7010 default: 7011 break; 7012 } 7013 7014 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 7015 || code0 == VECTOR_TYPE) 7016 && 7017 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 7018 || code1 == VECTOR_TYPE)) 7019 { 7020 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 7021 7022 if (shorten || common || short_compare) 7023 result_type = common_type (type0, type1); 7024 7025 /* For certain operations (which identify themselves by shorten != 0) 7026 if both args were extended from the same smaller type, 7027 do the arithmetic in that type and then extend. 7028 7029 shorten !=0 and !=1 indicates a bitwise operation. 7030 For them, this optimization is safe only if 7031 both args are zero-extended or both are sign-extended. 7032 Otherwise, we might change the result. 7033 Eg, (short)-1 | (unsigned short)-1 is (int)-1 7034 but calculated in (unsigned short) it would be (unsigned short)-1. */ 7035 7036 if (shorten && none_complex) 7037 { 7038 int unsigned0, unsigned1; 7039 tree arg0 = get_narrower (op0, &unsigned0); 7040 tree arg1 = get_narrower (op1, &unsigned1); 7041 /* UNS is 1 if the operation to be done is an unsigned one. */ 7042 int uns = TREE_UNSIGNED (result_type); 7043 tree type; 7044 7045 final_type = result_type; 7046 7047 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 7048 but it *requires* conversion to FINAL_TYPE. */ 7049 7050 if ((TYPE_PRECISION (TREE_TYPE (op0)) 7051 == TYPE_PRECISION (TREE_TYPE (arg0))) 7052 && TREE_TYPE (op0) != final_type) 7053 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0)); 7054 if ((TYPE_PRECISION (TREE_TYPE (op1)) 7055 == TYPE_PRECISION (TREE_TYPE (arg1))) 7056 && TREE_TYPE (op1) != final_type) 7057 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1)); 7058 7059 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 7060 7061 /* For bitwise operations, signedness of nominal type 7062 does not matter. Consider only how operands were extended. */ 7063 if (shorten == -1) 7064 uns = unsigned0; 7065 7066 /* Note that in all three cases below we refrain from optimizing 7067 an unsigned operation on sign-extended args. 7068 That would not be valid. */ 7069 7070 /* Both args variable: if both extended in same way 7071 from same width, do it in that width. 7072 Do it unsigned if args were zero-extended. */ 7073 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 7074 < TYPE_PRECISION (result_type)) 7075 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7076 == TYPE_PRECISION (TREE_TYPE (arg0))) 7077 && unsigned0 == unsigned1 7078 && (unsigned0 || !uns)) 7079 result_type 7080 = c_common_signed_or_unsigned_type 7081 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 7082 else if (TREE_CODE (arg0) == INTEGER_CST 7083 && (unsigned1 || !uns) 7084 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7085 < TYPE_PRECISION (result_type)) 7086 && (type 7087 = c_common_signed_or_unsigned_type (unsigned1, 7088 TREE_TYPE (arg1)), 7089 int_fits_type_p (arg0, type))) 7090 result_type = type; 7091 else if (TREE_CODE (arg1) == INTEGER_CST 7092 && (unsigned0 || !uns) 7093 && (TYPE_PRECISION (TREE_TYPE (arg0)) 7094 < TYPE_PRECISION (result_type)) 7095 && (type 7096 = c_common_signed_or_unsigned_type (unsigned0, 7097 TREE_TYPE (arg0)), 7098 int_fits_type_p (arg1, type))) 7099 result_type = type; 7100 } 7101 7102 /* Shifts can be shortened if shifting right. */ 7103 7104 if (short_shift) 7105 { 7106 int unsigned_arg; 7107 tree arg0 = get_narrower (op0, &unsigned_arg); 7108 7109 final_type = result_type; 7110 7111 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 7112 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0)); 7113 7114 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 7115 /* We can shorten only if the shift count is less than the 7116 number of bits in the smaller type size. */ 7117 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 7118 /* We cannot drop an unsigned shift after sign-extension. */ 7119 && (!TREE_UNSIGNED (final_type) || unsigned_arg)) 7120 { 7121 /* Do an unsigned shift if the operand was zero-extended. */ 7122 result_type 7123 = c_common_signed_or_unsigned_type (unsigned_arg, 7124 TREE_TYPE (arg0)); 7125 /* Convert value-to-be-shifted to that type. */ 7126 if (TREE_TYPE (op0) != result_type) 7127 op0 = convert (result_type, op0); 7128 converted = 1; 7129 } 7130 } 7131 7132 /* Comparison operations are shortened too but differently. 7133 They identify themselves by setting short_compare = 1. */ 7134 7135 if (short_compare) 7136 { 7137 /* Don't write &op0, etc., because that would prevent op0 7138 from being kept in a register. 7139 Instead, make copies of the our local variables and 7140 pass the copies by reference, then copy them back afterward. */ 7141 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 7142 enum tree_code xresultcode = resultcode; 7143 tree val 7144 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 7145 7146 if (val != 0) 7147 return val; 7148 7149 op0 = xop0, op1 = xop1; 7150 converted = 1; 7151 resultcode = xresultcode; 7152 7153 if (warn_sign_compare && skip_evaluation == 0) 7154 { 7155 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0)); 7156 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1)); 7157 int unsignedp0, unsignedp1; 7158 tree primop0 = get_narrower (op0, &unsignedp0); 7159 tree primop1 = get_narrower (op1, &unsignedp1); 7160 7161 xop0 = orig_op0; 7162 xop1 = orig_op1; 7163 STRIP_TYPE_NOPS (xop0); 7164 STRIP_TYPE_NOPS (xop1); 7165 7166 /* Give warnings for comparisons between signed and unsigned 7167 quantities that may fail. 7168 7169 Do the checking based on the original operand trees, so that 7170 casts will be considered, but default promotions won't be. 7171 7172 Do not warn if the comparison is being done in a signed type, 7173 since the signed type will only be chosen if it can represent 7174 all the values of the unsigned type. */ 7175 if (! TREE_UNSIGNED (result_type)) 7176 /* OK */; 7177 /* Do not warn if both operands are the same signedness. */ 7178 else if (op0_signed == op1_signed) 7179 /* OK */; 7180 else 7181 { 7182 tree sop, uop; 7183 7184 if (op0_signed) 7185 sop = xop0, uop = xop1; 7186 else 7187 sop = xop1, uop = xop0; 7188 7189 /* Do not warn if the signed quantity is an 7190 unsuffixed integer literal (or some static 7191 constant expression involving such literals or a 7192 conditional expression involving such literals) 7193 and it is non-negative. */ 7194 if (c_tree_expr_nonnegative_p (sop)) 7195 /* OK */; 7196 /* Do not warn if the comparison is an equality operation, 7197 the unsigned quantity is an integral constant, and it 7198 would fit in the result if the result were signed. */ 7199 else if (TREE_CODE (uop) == INTEGER_CST 7200 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 7201 && int_fits_type_p 7202 (uop, c_common_signed_type (result_type))) 7203 /* OK */; 7204 /* Do not warn if the unsigned quantity is an enumeration 7205 constant and its maximum value would fit in the result 7206 if the result were signed. */ 7207 else if (TREE_CODE (uop) == INTEGER_CST 7208 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 7209 && int_fits_type_p 7210 (TYPE_MAX_VALUE (TREE_TYPE(uop)), 7211 c_common_signed_type (result_type))) 7212 /* OK */; 7213 else 7214 warning ("comparison between signed and unsigned"); 7215 } 7216 7217 /* Warn if two unsigned values are being compared in a size 7218 larger than their original size, and one (and only one) is the 7219 result of a `~' operator. This comparison will always fail. 7220 7221 Also warn if one operand is a constant, and the constant 7222 does not have all bits set that are set in the ~ operand 7223 when it is extended. */ 7224 7225 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 7226 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 7227 { 7228 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 7229 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 7230 &unsignedp0); 7231 else 7232 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 7233 &unsignedp1); 7234 7235 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 7236 { 7237 tree primop; 7238 HOST_WIDE_INT constant, mask; 7239 int unsignedp, bits; 7240 7241 if (host_integerp (primop0, 0)) 7242 { 7243 primop = primop1; 7244 unsignedp = unsignedp1; 7245 constant = tree_low_cst (primop0, 0); 7246 } 7247 else 7248 { 7249 primop = primop0; 7250 unsignedp = unsignedp0; 7251 constant = tree_low_cst (primop1, 0); 7252 } 7253 7254 bits = TYPE_PRECISION (TREE_TYPE (primop)); 7255 if (bits < TYPE_PRECISION (result_type) 7256 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 7257 { 7258 mask = (~ (HOST_WIDE_INT) 0) << bits; 7259 if ((mask & constant) != mask) 7260 warning ("comparison of promoted ~unsigned with constant"); 7261 } 7262 } 7263 else if (unsignedp0 && unsignedp1 7264 && (TYPE_PRECISION (TREE_TYPE (primop0)) 7265 < TYPE_PRECISION (result_type)) 7266 && (TYPE_PRECISION (TREE_TYPE (primop1)) 7267 < TYPE_PRECISION (result_type))) 7268 warning ("comparison of promoted ~unsigned with unsigned"); 7269 } 7270 } 7271 } 7272 } 7273 7274 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 7275 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 7276 Then the expression will be built. 7277 It will be given type FINAL_TYPE if that is nonzero; 7278 otherwise, it will be given type RESULT_TYPE. */ 7279 7280 if (!result_type) 7281 { 7282 binary_op_error (code); 7283 return error_mark_node; 7284 } 7285 7286 if (! converted) 7287 { 7288 if (TREE_TYPE (op0) != result_type) 7289 op0 = convert (result_type, op0); 7290 if (TREE_TYPE (op1) != result_type) 7291 op1 = convert (result_type, op1); 7292 } 7293 7294 if (build_type == NULL_TREE) 7295 build_type = result_type; 7296 7297 { 7298 tree result = build (resultcode, build_type, op0, op1); 7299 tree folded; 7300 7301 /* Treat expressions in initializers specially as they can't trap. */ 7302 folded = require_constant_value ? fold_initializer (result) 7303 : fold (result); 7304 if (folded == result) 7305 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1); 7306 if (final_type != 0) 7307 return convert (final_type, folded); 7308 return folded; 7309 } 7310} 7311