c-typeck.c revision 146895
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 (t2); 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 /* See if there is a field or component with name COMPONENT. */ 1324 1325 if (code == RECORD_TYPE || code == UNION_TYPE) 1326 { 1327 if (!COMPLETE_TYPE_P (type)) 1328 { 1329 c_incomplete_type_error (NULL_TREE, type); 1330 return error_mark_node; 1331 } 1332 1333 field = lookup_field (datum, component); 1334 1335 if (!field) 1336 { 1337 error ("%s has no member named `%s'", 1338 code == RECORD_TYPE ? "structure" : "union", 1339 IDENTIFIER_POINTER (component)); 1340 return error_mark_node; 1341 } 1342 1343 /* Chain the COMPONENT_REFs if necessary down to the FIELD. 1344 This might be better solved in future the way the C++ front 1345 end does it - by giving the anonymous entities each a 1346 separate name and type, and then have build_component_ref 1347 recursively call itself. We can't do that here. */ 1348 do 1349 { 1350 tree subdatum = TREE_VALUE (field); 1351 1352 if (TREE_TYPE (subdatum) == error_mark_node) 1353 return error_mark_node; 1354 1355 ref = build (COMPONENT_REF, TREE_TYPE (subdatum), datum, subdatum); 1356 if (TREE_READONLY (datum) || TREE_READONLY (subdatum)) 1357 TREE_READONLY (ref) = 1; 1358 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum)) 1359 TREE_THIS_VOLATILE (ref) = 1; 1360 1361 if (TREE_DEPRECATED (subdatum)) 1362 warn_deprecated_use (subdatum); 1363 1364 datum = ref; 1365 1366 field = TREE_CHAIN (field); 1367 } 1368 while (field); 1369 1370 return ref; 1371 } 1372 else if (code != ERROR_MARK) 1373 error ("request for member `%s' in something not a structure or union", 1374 IDENTIFIER_POINTER (component)); 1375 1376 return error_mark_node; 1377} 1378 1379/* Given an expression PTR for a pointer, return an expression 1380 for the value pointed to. 1381 ERRORSTRING is the name of the operator to appear in error messages. */ 1382 1383tree 1384build_indirect_ref (tree ptr, const char *errorstring) 1385{ 1386 tree pointer = default_conversion (ptr); 1387 tree type = TREE_TYPE (pointer); 1388 1389 if (TREE_CODE (type) == POINTER_TYPE) 1390 { 1391 if (TREE_CODE (pointer) == ADDR_EXPR 1392 && (TREE_TYPE (TREE_OPERAND (pointer, 0)) 1393 == TREE_TYPE (type))) 1394 return TREE_OPERAND (pointer, 0); 1395 else 1396 { 1397 tree t = TREE_TYPE (type); 1398 tree ref = build1 (INDIRECT_REF, TYPE_MAIN_VARIANT (t), pointer); 1399 1400 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) 1401 { 1402 error ("dereferencing pointer to incomplete type"); 1403 return error_mark_node; 1404 } 1405 if (VOID_TYPE_P (t) && skip_evaluation == 0) 1406 warning ("dereferencing `void *' pointer"); 1407 1408 /* We *must* set TREE_READONLY when dereferencing a pointer to const, 1409 so that we get the proper error message if the result is used 1410 to assign to. Also, &* is supposed to be a no-op. 1411 And ANSI C seems to specify that the type of the result 1412 should be the const type. */ 1413 /* A de-reference of a pointer to const is not a const. It is valid 1414 to change it via some other pointer. */ 1415 TREE_READONLY (ref) = TYPE_READONLY (t); 1416 TREE_SIDE_EFFECTS (ref) 1417 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer); 1418 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t); 1419 return ref; 1420 } 1421 } 1422 else if (TREE_CODE (pointer) != ERROR_MARK) 1423 error ("invalid type argument of `%s'", errorstring); 1424 return error_mark_node; 1425} 1426 1427/* This handles expressions of the form "a[i]", which denotes 1428 an array reference. 1429 1430 This is logically equivalent in C to *(a+i), but we may do it differently. 1431 If A is a variable or a member, we generate a primitive ARRAY_REF. 1432 This avoids forcing the array out of registers, and can work on 1433 arrays that are not lvalues (for example, members of structures returned 1434 by functions). */ 1435 1436tree 1437build_array_ref (tree array, tree index) 1438{ 1439 if (index == 0) 1440 { 1441 error ("subscript missing in array reference"); 1442 return error_mark_node; 1443 } 1444 1445 if (TREE_TYPE (array) == error_mark_node 1446 || TREE_TYPE (index) == error_mark_node) 1447 return error_mark_node; 1448 1449 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE 1450 && TREE_CODE (array) != INDIRECT_REF) 1451 { 1452 tree rval, type; 1453 1454 /* Subscripting with type char is likely to lose 1455 on a machine where chars are signed. 1456 So warn on any machine, but optionally. 1457 Don't warn for unsigned char since that type is safe. 1458 Don't warn for signed char because anyone who uses that 1459 must have done so deliberately. */ 1460 if (warn_char_subscripts 1461 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) 1462 warning ("array subscript has type `char'"); 1463 1464 /* Apply default promotions *after* noticing character types. */ 1465 index = default_conversion (index); 1466 1467 /* Require integer *after* promotion, for sake of enums. */ 1468 if (TREE_CODE (TREE_TYPE (index)) != INTEGER_TYPE) 1469 { 1470 error ("array subscript is not an integer"); 1471 return error_mark_node; 1472 } 1473 1474 /* An array that is indexed by a non-constant 1475 cannot be stored in a register; we must be able to do 1476 address arithmetic on its address. 1477 Likewise an array of elements of variable size. */ 1478 if (TREE_CODE (index) != INTEGER_CST 1479 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) 1480 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST)) 1481 { 1482 if (!c_mark_addressable (array)) 1483 return error_mark_node; 1484 } 1485 /* An array that is indexed by a constant value which is not within 1486 the array bounds cannot be stored in a register either; because we 1487 would get a crash in store_bit_field/extract_bit_field when trying 1488 to access a non-existent part of the register. */ 1489 if (TREE_CODE (index) == INTEGER_CST 1490 && TYPE_VALUES (TREE_TYPE (array)) 1491 && ! int_fits_type_p (index, TYPE_VALUES (TREE_TYPE (array)))) 1492 { 1493 if (!c_mark_addressable (array)) 1494 return error_mark_node; 1495 } 1496 1497 if (pedantic) 1498 { 1499 tree foo = array; 1500 while (TREE_CODE (foo) == COMPONENT_REF) 1501 foo = TREE_OPERAND (foo, 0); 1502 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo)) 1503 pedwarn ("ISO C forbids subscripting `register' array"); 1504 else if (! flag_isoc99 && ! lvalue_p (foo)) 1505 pedwarn ("ISO C90 forbids subscripting non-lvalue array"); 1506 } 1507 1508 type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (array))); 1509 rval = build (ARRAY_REF, type, array, index); 1510 /* Array ref is const/volatile if the array elements are 1511 or if the array is. */ 1512 TREE_READONLY (rval) 1513 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array))) 1514 | TREE_READONLY (array)); 1515 TREE_SIDE_EFFECTS (rval) 1516 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 1517 | TREE_SIDE_EFFECTS (array)); 1518 TREE_THIS_VOLATILE (rval) 1519 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) 1520 /* This was added by rms on 16 Nov 91. 1521 It fixes vol struct foo *a; a->elts[1] 1522 in an inline function. 1523 Hope it doesn't break something else. */ 1524 | TREE_THIS_VOLATILE (array)); 1525 return require_complete_type (fold (rval)); 1526 } 1527 1528 { 1529 tree ar = default_conversion (array); 1530 tree ind = default_conversion (index); 1531 1532 /* Do the same warning check as above, but only on the part that's 1533 syntactically the index and only if it is also semantically 1534 the index. */ 1535 if (warn_char_subscripts 1536 && TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE 1537 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) 1538 warning ("subscript has type `char'"); 1539 1540 /* Put the integer in IND to simplify error checking. */ 1541 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE) 1542 { 1543 tree temp = ar; 1544 ar = ind; 1545 ind = temp; 1546 } 1547 1548 if (ar == error_mark_node) 1549 return ar; 1550 1551 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE 1552 || TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) == FUNCTION_TYPE) 1553 { 1554 error ("subscripted value is neither array nor pointer"); 1555 return error_mark_node; 1556 } 1557 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE) 1558 { 1559 error ("array subscript is not an integer"); 1560 return error_mark_node; 1561 } 1562 1563 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, ind, 0), 1564 "array indexing"); 1565 } 1566} 1567 1568/* Build an external reference to identifier ID. FUN indicates 1569 whether this will be used for a function call. */ 1570tree 1571build_external_ref (tree id, int fun) 1572{ 1573 tree ref; 1574 tree decl = lookup_name (id); 1575 tree objc_ivar = lookup_objc_ivar (id); 1576 1577 if (decl && decl != error_mark_node) 1578 { 1579 /* Properly declared variable or function reference. */ 1580 if (!objc_ivar) 1581 ref = decl; 1582 else if (decl != objc_ivar && !DECL_FILE_SCOPE_P (decl)) 1583 { 1584 warning ("local declaration of `%s' hides instance variable", 1585 IDENTIFIER_POINTER (id)); 1586 ref = decl; 1587 } 1588 else 1589 ref = objc_ivar; 1590 } 1591 else if (objc_ivar) 1592 ref = objc_ivar; 1593 else if (fun) 1594 /* Implicit function declaration. */ 1595 ref = implicitly_declare (id); 1596 else if (decl == error_mark_node) 1597 /* Don't complain about something that's already been 1598 complained about. */ 1599 return error_mark_node; 1600 else 1601 { 1602 undeclared_variable (id); 1603 return error_mark_node; 1604 } 1605 1606 if (TREE_TYPE (ref) == error_mark_node) 1607 return error_mark_node; 1608 1609 if (TREE_DEPRECATED (ref)) 1610 warn_deprecated_use (ref); 1611 1612 if (!skip_evaluation) 1613 assemble_external (ref); 1614 TREE_USED (ref) = 1; 1615 1616 if (TREE_CODE (ref) == CONST_DECL) 1617 { 1618 ref = DECL_INITIAL (ref); 1619 TREE_CONSTANT (ref) = 1; 1620 } 1621 else if (current_function_decl != 0 1622 && !DECL_FILE_SCOPE_P (current_function_decl) 1623 && (TREE_CODE (ref) == VAR_DECL 1624 || TREE_CODE (ref) == PARM_DECL 1625 || TREE_CODE (ref) == FUNCTION_DECL)) 1626 { 1627 tree context = decl_function_context (ref); 1628 1629 if (context != 0 && context != current_function_decl) 1630 DECL_NONLOCAL (ref) = 1; 1631 } 1632 1633 return ref; 1634} 1635 1636/* Build a function call to function FUNCTION with parameters PARAMS. 1637 PARAMS is a list--a chain of TREE_LIST nodes--in which the 1638 TREE_VALUE of each node is a parameter-expression. 1639 FUNCTION's data type may be a function type or a pointer-to-function. */ 1640 1641tree 1642build_function_call (tree function, tree params) 1643{ 1644 tree fntype, fundecl = 0; 1645 tree coerced_params; 1646 tree name = NULL_TREE, result; 1647 tree tem; 1648 1649 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 1650 STRIP_TYPE_NOPS (function); 1651 1652 /* Convert anything with function type to a pointer-to-function. */ 1653 if (TREE_CODE (function) == FUNCTION_DECL) 1654 { 1655 name = DECL_NAME (function); 1656 1657 /* Differs from default_conversion by not setting TREE_ADDRESSABLE 1658 (because calling an inline function does not mean the function 1659 needs to be separately compiled). */ 1660 fntype = build_type_variant (TREE_TYPE (function), 1661 TREE_READONLY (function), 1662 TREE_THIS_VOLATILE (function)); 1663 fundecl = function; 1664 function = build1 (ADDR_EXPR, build_pointer_type (fntype), function); 1665 } 1666 else 1667 function = default_conversion (function); 1668 1669 fntype = TREE_TYPE (function); 1670 1671 if (TREE_CODE (fntype) == ERROR_MARK) 1672 return error_mark_node; 1673 1674 if (!(TREE_CODE (fntype) == POINTER_TYPE 1675 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) 1676 { 1677 error ("called object is not a function"); 1678 return error_mark_node; 1679 } 1680 1681 if (fundecl && TREE_THIS_VOLATILE (fundecl)) 1682 current_function_returns_abnormally = 1; 1683 1684 /* fntype now gets the type of function pointed to. */ 1685 fntype = TREE_TYPE (fntype); 1686 1687 /* Check that the function is called through a compatible prototype. 1688 If it is not, replace the call by a trap, wrapped up in a compound 1689 expression if necessary. This has the nice side-effect to prevent 1690 the tree-inliner from generating invalid assignment trees which may 1691 blow up in the RTL expander later. 1692 1693 ??? This doesn't work for Objective-C because objc_comptypes 1694 refuses to compare function prototypes, yet the compiler appears 1695 to build calls that are flagged as invalid by C's comptypes. */ 1696 if (! c_dialect_objc () 1697 && TREE_CODE (function) == NOP_EXPR 1698 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR 1699 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL 1700 && ! comptypes (fntype, TREE_TYPE (tem), COMPARE_STRICT)) 1701 { 1702 tree return_type = TREE_TYPE (fntype); 1703 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], 1704 NULL_TREE); 1705 1706 /* This situation leads to run-time undefined behavior. We can't, 1707 therefore, simply error unless we can prove that all possible 1708 executions of the program must execute the code. */ 1709 warning ("function called through a non-compatible type"); 1710 1711 /* We can, however, treat "undefined" any way we please. 1712 Call abort to encourage the user to fix the program. */ 1713 inform ("if this code is reached, the program will abort"); 1714 1715 if (VOID_TYPE_P (return_type)) 1716 return trap; 1717 else 1718 { 1719 tree rhs; 1720 1721 if (AGGREGATE_TYPE_P (return_type)) 1722 rhs = build_compound_literal (return_type, 1723 build_constructor (return_type, 1724 NULL_TREE)); 1725 else 1726 rhs = fold (build1 (NOP_EXPR, return_type, integer_zero_node)); 1727 1728 return build (COMPOUND_EXPR, return_type, trap, rhs); 1729 } 1730 } 1731 1732 /* Convert the parameters to the types declared in the 1733 function prototype, or apply default promotions. */ 1734 1735 coerced_params 1736 = convert_arguments (TYPE_ARG_TYPES (fntype), params, name, fundecl); 1737 1738 /* Check that the arguments to the function are valid. */ 1739 1740 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params); 1741 1742 /* Recognize certain built-in functions so we can make tree-codes 1743 other than CALL_EXPR. We do this when it enables fold-const.c 1744 to do something useful. */ 1745 1746 if (TREE_CODE (function) == ADDR_EXPR 1747 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL 1748 && DECL_BUILT_IN (TREE_OPERAND (function, 0))) 1749 { 1750 result = expand_tree_builtin (TREE_OPERAND (function, 0), 1751 params, coerced_params); 1752 if (result) 1753 return result; 1754 } 1755 1756 result = build (CALL_EXPR, TREE_TYPE (fntype), 1757 function, coerced_params, NULL_TREE); 1758 TREE_SIDE_EFFECTS (result) = 1; 1759 1760 if (require_constant_value) 1761 { 1762 result = fold_initializer (result); 1763 1764 if (TREE_CONSTANT (result) 1765 && (name == NULL_TREE 1766 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) 1767 pedwarn_init ("initializer element is not constant"); 1768 } 1769 else 1770 result = fold (result); 1771 1772 if (VOID_TYPE_P (TREE_TYPE (result))) 1773 return result; 1774 return require_complete_type (result); 1775} 1776 1777/* Convert the argument expressions in the list VALUES 1778 to the types in the list TYPELIST. The result is a list of converted 1779 argument expressions. 1780 1781 If TYPELIST is exhausted, or when an element has NULL as its type, 1782 perform the default conversions. 1783 1784 PARMLIST is the chain of parm decls for the function being called. 1785 It may be 0, if that info is not available. 1786 It is used only for generating error messages. 1787 1788 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages. 1789 1790 This is also where warnings about wrong number of args are generated. 1791 1792 Both VALUES and the returned value are chains of TREE_LIST nodes 1793 with the elements of the list in the TREE_VALUE slots of those nodes. */ 1794 1795static tree 1796convert_arguments (tree typelist, tree values, tree name, tree fundecl) 1797{ 1798 tree typetail, valtail; 1799 tree result = NULL; 1800 int parmnum; 1801 1802 /* Scan the given expressions and types, producing individual 1803 converted arguments and pushing them on RESULT in reverse order. */ 1804 1805 for (valtail = values, typetail = typelist, parmnum = 0; 1806 valtail; 1807 valtail = TREE_CHAIN (valtail), parmnum++) 1808 { 1809 tree type = typetail ? TREE_VALUE (typetail) : 0; 1810 tree val = TREE_VALUE (valtail); 1811 1812 if (type == void_type_node) 1813 { 1814 if (name) 1815 error ("too many arguments to function `%s'", 1816 IDENTIFIER_POINTER (name)); 1817 else 1818 error ("too many arguments to function"); 1819 break; 1820 } 1821 1822 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 1823 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0 1824 to convert automatically to a pointer. */ 1825 if (TREE_CODE (val) == NON_LVALUE_EXPR) 1826 val = TREE_OPERAND (val, 0); 1827 1828 val = default_function_array_conversion (val); 1829 1830 val = require_complete_type (val); 1831 1832 if (type != 0) 1833 { 1834 /* Formal parm type is specified by a function prototype. */ 1835 tree parmval; 1836 1837 if (!COMPLETE_TYPE_P (type)) 1838 { 1839 error ("type of formal parameter %d is incomplete", parmnum + 1); 1840 parmval = val; 1841 } 1842 else 1843 { 1844 /* Optionally warn about conversions that 1845 differ from the default conversions. */ 1846 if (warn_conversion || warn_traditional) 1847 { 1848 int formal_prec = TYPE_PRECISION (type); 1849 1850 if (INTEGRAL_TYPE_P (type) 1851 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1852 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1); 1853 if (INTEGRAL_TYPE_P (type) 1854 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 1855 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1); 1856 else if (TREE_CODE (type) == COMPLEX_TYPE 1857 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1858 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1); 1859 else if (TREE_CODE (type) == REAL_TYPE 1860 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1861 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1); 1862 else if (TREE_CODE (type) == COMPLEX_TYPE 1863 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1864 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1); 1865 else if (TREE_CODE (type) == REAL_TYPE 1866 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) 1867 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1); 1868 /* ??? At some point, messages should be written about 1869 conversions between complex types, but that's too messy 1870 to do now. */ 1871 else if (TREE_CODE (type) == REAL_TYPE 1872 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) 1873 { 1874 /* Warn if any argument is passed as `float', 1875 since without a prototype it would be `double'. */ 1876 if (formal_prec == TYPE_PRECISION (float_type_node)) 1877 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1); 1878 } 1879 /* Detect integer changing in width or signedness. 1880 These warnings are only activated with 1881 -Wconversion, not with -Wtraditional. */ 1882 else if (warn_conversion && INTEGRAL_TYPE_P (type) 1883 && INTEGRAL_TYPE_P (TREE_TYPE (val))) 1884 { 1885 tree would_have_been = default_conversion (val); 1886 tree type1 = TREE_TYPE (would_have_been); 1887 1888 if (TREE_CODE (type) == ENUMERAL_TYPE 1889 && (TYPE_MAIN_VARIANT (type) 1890 == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) 1891 /* No warning if function asks for enum 1892 and the actual arg is that enum type. */ 1893 ; 1894 else if (formal_prec != TYPE_PRECISION (type1)) 1895 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1); 1896 else if (TREE_UNSIGNED (type) == TREE_UNSIGNED (type1)) 1897 ; 1898 /* Don't complain if the formal parameter type 1899 is an enum, because we can't tell now whether 1900 the value was an enum--even the same enum. */ 1901 else if (TREE_CODE (type) == ENUMERAL_TYPE) 1902 ; 1903 else if (TREE_CODE (val) == INTEGER_CST 1904 && int_fits_type_p (val, type)) 1905 /* Change in signedness doesn't matter 1906 if a constant value is unaffected. */ 1907 ; 1908 /* Likewise for a constant in a NOP_EXPR. */ 1909 else if (TREE_CODE (val) == NOP_EXPR 1910 && TREE_CODE (TREE_OPERAND (val, 0)) == INTEGER_CST 1911 && int_fits_type_p (TREE_OPERAND (val, 0), type)) 1912 ; 1913 /* If the value is extended from a narrower 1914 unsigned type, it doesn't matter whether we 1915 pass it as signed or unsigned; the value 1916 certainly is the same either way. */ 1917 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) 1918 && TREE_UNSIGNED (TREE_TYPE (val))) 1919 ; 1920 else if (TREE_UNSIGNED (type)) 1921 warn_for_assignment ("%s as unsigned due to prototype", (char *) 0, name, parmnum + 1); 1922 else 1923 warn_for_assignment ("%s as signed due to prototype", (char *) 0, name, parmnum + 1); 1924 } 1925 } 1926 1927 parmval = convert_for_assignment (type, val, 1928 (char *) 0, /* arg passing */ 1929 fundecl, name, parmnum + 1); 1930 1931 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) 1932 && INTEGRAL_TYPE_P (type) 1933 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 1934 parmval = default_conversion (parmval); 1935 } 1936 result = tree_cons (NULL_TREE, parmval, result); 1937 } 1938 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE 1939 && (TYPE_PRECISION (TREE_TYPE (val)) 1940 < TYPE_PRECISION (double_type_node))) 1941 /* Convert `float' to `double'. */ 1942 result = tree_cons (NULL_TREE, convert (double_type_node, val), result); 1943 else 1944 /* Convert `short' and `char' to full-size `int'. */ 1945 result = tree_cons (NULL_TREE, default_conversion (val), result); 1946 1947 if (typetail) 1948 typetail = TREE_CHAIN (typetail); 1949 } 1950 1951 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) 1952 { 1953 if (name) 1954 error ("too few arguments to function `%s'", 1955 IDENTIFIER_POINTER (name)); 1956 else 1957 error ("too few arguments to function"); 1958 } 1959 1960 return nreverse (result); 1961} 1962 1963/* This is the entry point used by the parser 1964 for binary operators in the input. 1965 In addition to constructing the expression, 1966 we check for operands that were written with other binary operators 1967 in a way that is likely to confuse the user. */ 1968 1969tree 1970parser_build_binary_op (enum tree_code code, tree arg1, tree arg2) 1971{ 1972 tree result = build_binary_op (code, arg1, arg2, 1); 1973 1974 char class; 1975 char class1 = TREE_CODE_CLASS (TREE_CODE (arg1)); 1976 char class2 = TREE_CODE_CLASS (TREE_CODE (arg2)); 1977 enum tree_code code1 = ERROR_MARK; 1978 enum tree_code code2 = ERROR_MARK; 1979 1980 if (TREE_CODE (result) == ERROR_MARK) 1981 return error_mark_node; 1982 1983 if (IS_EXPR_CODE_CLASS (class1)) 1984 code1 = C_EXP_ORIGINAL_CODE (arg1); 1985 if (IS_EXPR_CODE_CLASS (class2)) 1986 code2 = C_EXP_ORIGINAL_CODE (arg2); 1987 1988 /* Check for cases such as x+y<<z which users are likely 1989 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE 1990 is cleared to prevent these warnings. */ 1991 if (warn_parentheses) 1992 { 1993 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 1994 { 1995 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 1996 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 1997 warning ("suggest parentheses around + or - inside shift"); 1998 } 1999 2000 if (code == TRUTH_ORIF_EXPR) 2001 { 2002 if (code1 == TRUTH_ANDIF_EXPR 2003 || code2 == TRUTH_ANDIF_EXPR) 2004 warning ("suggest parentheses around && within ||"); 2005 } 2006 2007 if (code == BIT_IOR_EXPR) 2008 { 2009 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR 2010 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2011 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR 2012 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2013 warning ("suggest parentheses around arithmetic in operand of |"); 2014 /* Check cases like x|y==z */ 2015 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2016 warning ("suggest parentheses around comparison in operand of |"); 2017 } 2018 2019 if (code == BIT_XOR_EXPR) 2020 { 2021 if (code1 == BIT_AND_EXPR 2022 || code1 == PLUS_EXPR || code1 == MINUS_EXPR 2023 || code2 == BIT_AND_EXPR 2024 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2025 warning ("suggest parentheses around arithmetic in operand of ^"); 2026 /* Check cases like x^y==z */ 2027 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2028 warning ("suggest parentheses around comparison in operand of ^"); 2029 } 2030 2031 if (code == BIT_AND_EXPR) 2032 { 2033 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR 2034 || code2 == PLUS_EXPR || code2 == MINUS_EXPR) 2035 warning ("suggest parentheses around + or - in operand of &"); 2036 /* Check cases like x&y==z */ 2037 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<') 2038 warning ("suggest parentheses around comparison in operand of &"); 2039 } 2040 } 2041 2042 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 2043 if (TREE_CODE_CLASS (code) == '<' && extra_warnings 2044 && (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')) 2045 warning ("comparisons like X<=Y<=Z do not have their mathematical meaning"); 2046 2047 unsigned_conversion_warning (result, arg1); 2048 unsigned_conversion_warning (result, arg2); 2049 overflow_warning (result); 2050 2051 class = TREE_CODE_CLASS (TREE_CODE (result)); 2052 2053 /* Record the code that was specified in the source, 2054 for the sake of warnings about confusing nesting. */ 2055 if (IS_EXPR_CODE_CLASS (class)) 2056 C_SET_EXP_ORIGINAL_CODE (result, code); 2057 else 2058 { 2059 int flag = TREE_CONSTANT (result); 2060 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR 2061 so that convert_for_assignment wouldn't strip it. 2062 That way, we got warnings for things like p = (1 - 1). 2063 But it turns out we should not get those warnings. */ 2064 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result); 2065 C_SET_EXP_ORIGINAL_CODE (result, code); 2066 TREE_CONSTANT (result) = flag; 2067 } 2068 2069 return result; 2070} 2071 2072 2073/* Return true if `t' is known to be non-negative. */ 2074 2075int 2076c_tree_expr_nonnegative_p (tree t) 2077{ 2078 if (TREE_CODE (t) == STMT_EXPR) 2079 { 2080 t = COMPOUND_BODY (STMT_EXPR_STMT (t)); 2081 2082 /* Find the last statement in the chain, ignoring the final 2083 * scope statement */ 2084 while (TREE_CHAIN (t) != NULL_TREE 2085 && TREE_CODE (TREE_CHAIN (t)) != SCOPE_STMT) 2086 t = TREE_CHAIN (t); 2087 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0)); 2088 } 2089 return tree_expr_nonnegative_p (t); 2090} 2091 2092/* Return a tree for the difference of pointers OP0 and OP1. 2093 The resulting tree has type int. */ 2094 2095static tree 2096pointer_diff (tree op0, tree op1) 2097{ 2098 tree result, folded; 2099 tree restype = ptrdiff_type_node; 2100 2101 tree target_type = TREE_TYPE (TREE_TYPE (op0)); 2102 tree con0, con1, lit0, lit1; 2103 tree orig_op1 = op1; 2104 2105 if (pedantic || warn_pointer_arith) 2106 { 2107 if (TREE_CODE (target_type) == VOID_TYPE) 2108 pedwarn ("pointer of type `void *' used in subtraction"); 2109 if (TREE_CODE (target_type) == FUNCTION_TYPE) 2110 pedwarn ("pointer to a function used in subtraction"); 2111 } 2112 2113 /* If the conversion to ptrdiff_type does anything like widening or 2114 converting a partial to an integral mode, we get a convert_expression 2115 that is in the way to do any simplifications. 2116 (fold-const.c doesn't know that the extra bits won't be needed. 2117 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a 2118 different mode in place.) 2119 So first try to find a common term here 'by hand'; we want to cover 2120 at least the cases that occur in legal static initializers. */ 2121 con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0; 2122 con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1; 2123 2124 if (TREE_CODE (con0) == PLUS_EXPR) 2125 { 2126 lit0 = TREE_OPERAND (con0, 1); 2127 con0 = TREE_OPERAND (con0, 0); 2128 } 2129 else 2130 lit0 = integer_zero_node; 2131 2132 if (TREE_CODE (con1) == PLUS_EXPR) 2133 { 2134 lit1 = TREE_OPERAND (con1, 1); 2135 con1 = TREE_OPERAND (con1, 0); 2136 } 2137 else 2138 lit1 = integer_zero_node; 2139 2140 if (operand_equal_p (con0, con1, 0)) 2141 { 2142 op0 = lit0; 2143 op1 = lit1; 2144 } 2145 2146 2147 /* First do the subtraction as integers; 2148 then drop through to build the divide operator. 2149 Do not do default conversions on the minus operator 2150 in case restype is a short type. */ 2151 2152 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), 2153 convert (restype, op1), 0); 2154 /* This generates an error if op1 is pointer to incomplete type. */ 2155 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) 2156 error ("arithmetic on pointer to an incomplete type"); 2157 2158 /* This generates an error if op0 is pointer to incomplete type. */ 2159 op1 = c_size_in_bytes (target_type); 2160 2161 /* Divide by the size, in easiest possible way. */ 2162 2163 result = build (EXACT_DIV_EXPR, restype, op0, convert (restype, op1)); 2164 2165 folded = fold (result); 2166 if (folded == result) 2167 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1); 2168 return folded; 2169} 2170 2171/* Construct and perhaps optimize a tree representation 2172 for a unary operation. CODE, a tree_code, specifies the operation 2173 and XARG is the operand. 2174 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses 2175 the default promotions (such as from short to int). 2176 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero 2177 allows non-lvalues; this is only used to handle conversion of non-lvalue 2178 arrays to pointers in C99. */ 2179 2180tree 2181build_unary_op (enum tree_code code, tree xarg, int flag) 2182{ 2183 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 2184 tree arg = xarg; 2185 tree argtype = 0; 2186 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); 2187 tree val; 2188 int noconvert = flag; 2189 2190 if (typecode == ERROR_MARK) 2191 return error_mark_node; 2192 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) 2193 typecode = INTEGER_TYPE; 2194 2195 switch (code) 2196 { 2197 case CONVERT_EXPR: 2198 /* This is used for unary plus, because a CONVERT_EXPR 2199 is enough to prevent anybody from looking inside for 2200 associativity, but won't generate any code. */ 2201 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2202 || typecode == COMPLEX_TYPE)) 2203 { 2204 error ("wrong type argument to unary plus"); 2205 return error_mark_node; 2206 } 2207 else if (!noconvert) 2208 arg = default_conversion (arg); 2209 arg = non_lvalue (arg); 2210 break; 2211 2212 case NEGATE_EXPR: 2213 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2214 || typecode == COMPLEX_TYPE 2215 || typecode == VECTOR_TYPE)) 2216 { 2217 error ("wrong type argument to unary minus"); 2218 return error_mark_node; 2219 } 2220 else if (!noconvert) 2221 arg = default_conversion (arg); 2222 break; 2223 2224 case BIT_NOT_EXPR: 2225 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) 2226 { 2227 if (!noconvert) 2228 arg = default_conversion (arg); 2229 } 2230 else if (typecode == COMPLEX_TYPE) 2231 { 2232 code = CONJ_EXPR; 2233 if (pedantic) 2234 pedwarn ("ISO C does not support `~' for complex conjugation"); 2235 if (!noconvert) 2236 arg = default_conversion (arg); 2237 } 2238 else 2239 { 2240 error ("wrong type argument to bit-complement"); 2241 return error_mark_node; 2242 } 2243 break; 2244 2245 case ABS_EXPR: 2246 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) 2247 { 2248 error ("wrong type argument to abs"); 2249 return error_mark_node; 2250 } 2251 else if (!noconvert) 2252 arg = default_conversion (arg); 2253 break; 2254 2255 case CONJ_EXPR: 2256 /* Conjugating a real value is a no-op, but allow it anyway. */ 2257 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE 2258 || typecode == COMPLEX_TYPE)) 2259 { 2260 error ("wrong type argument to conjugation"); 2261 return error_mark_node; 2262 } 2263 else if (!noconvert) 2264 arg = default_conversion (arg); 2265 break; 2266 2267 case TRUTH_NOT_EXPR: 2268 if (typecode != INTEGER_TYPE 2269 && typecode != REAL_TYPE && typecode != POINTER_TYPE 2270 && typecode != COMPLEX_TYPE 2271 /* These will convert to a pointer. */ 2272 && typecode != ARRAY_TYPE && typecode != FUNCTION_TYPE) 2273 { 2274 error ("wrong type argument to unary exclamation mark"); 2275 return error_mark_node; 2276 } 2277 arg = c_common_truthvalue_conversion (arg); 2278 return invert_truthvalue (arg); 2279 2280 case NOP_EXPR: 2281 break; 2282 2283 case REALPART_EXPR: 2284 if (TREE_CODE (arg) == COMPLEX_CST) 2285 return TREE_REALPART (arg); 2286 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2287 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); 2288 else 2289 return arg; 2290 2291 case IMAGPART_EXPR: 2292 if (TREE_CODE (arg) == COMPLEX_CST) 2293 return TREE_IMAGPART (arg); 2294 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 2295 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); 2296 else 2297 return convert (TREE_TYPE (arg), integer_zero_node); 2298 2299 case PREINCREMENT_EXPR: 2300 case POSTINCREMENT_EXPR: 2301 case PREDECREMENT_EXPR: 2302 case POSTDECREMENT_EXPR: 2303 /* Handle complex lvalues (when permitted) 2304 by reduction to simpler cases. */ 2305 2306 val = unary_complex_lvalue (code, arg, 0); 2307 if (val != 0) 2308 return val; 2309 2310 /* Increment or decrement the real part of the value, 2311 and don't change the imaginary part. */ 2312 if (typecode == COMPLEX_TYPE) 2313 { 2314 tree real, imag; 2315 2316 if (pedantic) 2317 pedwarn ("ISO C does not support `++' and `--' on complex types"); 2318 2319 arg = stabilize_reference (arg); 2320 real = build_unary_op (REALPART_EXPR, arg, 1); 2321 imag = build_unary_op (IMAGPART_EXPR, arg, 1); 2322 return build (COMPLEX_EXPR, TREE_TYPE (arg), 2323 build_unary_op (code, real, 1), imag); 2324 } 2325 2326 /* Report invalid types. */ 2327 2328 if (typecode != POINTER_TYPE 2329 && typecode != INTEGER_TYPE && typecode != REAL_TYPE) 2330 { 2331 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2332 error ("wrong type argument to increment"); 2333 else 2334 error ("wrong type argument to decrement"); 2335 2336 return error_mark_node; 2337 } 2338 2339 { 2340 tree inc; 2341 tree result_type = TREE_TYPE (arg); 2342 2343 arg = get_unwidened (arg, 0); 2344 argtype = TREE_TYPE (arg); 2345 2346 /* Compute the increment. */ 2347 2348 if (typecode == POINTER_TYPE) 2349 { 2350 /* If pointer target is an undefined struct, 2351 we just cannot know how to do the arithmetic. */ 2352 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) 2353 { 2354 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2355 error ("increment of pointer to unknown structure"); 2356 else 2357 error ("decrement of pointer to unknown structure"); 2358 } 2359 else if ((pedantic || warn_pointer_arith) 2360 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE 2361 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) 2362 { 2363 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 2364 pedwarn ("wrong type argument to increment"); 2365 else 2366 pedwarn ("wrong type argument to decrement"); 2367 } 2368 2369 inc = c_size_in_bytes (TREE_TYPE (result_type)); 2370 } 2371 else 2372 inc = integer_one_node; 2373 2374 inc = convert (argtype, inc); 2375 2376 /* Handle incrementing a cast-expression. */ 2377 2378 while (1) 2379 switch (TREE_CODE (arg)) 2380 { 2381 case NOP_EXPR: 2382 case CONVERT_EXPR: 2383 case FLOAT_EXPR: 2384 case FIX_TRUNC_EXPR: 2385 case FIX_FLOOR_EXPR: 2386 case FIX_ROUND_EXPR: 2387 case FIX_CEIL_EXPR: 2388 pedantic_lvalue_warning (CONVERT_EXPR); 2389 /* If the real type has the same machine representation 2390 as the type it is cast to, we can make better output 2391 by adding directly to the inside of the cast. */ 2392 if ((TREE_CODE (TREE_TYPE (arg)) 2393 == TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0)))) 2394 && (TYPE_MODE (TREE_TYPE (arg)) 2395 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (arg, 0))))) 2396 arg = TREE_OPERAND (arg, 0); 2397 else 2398 { 2399 tree incremented, modify, value; 2400 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 2401 value = boolean_increment (code, arg); 2402 else 2403 { 2404 arg = stabilize_reference (arg); 2405 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) 2406 value = arg; 2407 else 2408 value = save_expr (arg); 2409 incremented = build (((code == PREINCREMENT_EXPR 2410 || code == POSTINCREMENT_EXPR) 2411 ? PLUS_EXPR : MINUS_EXPR), 2412 argtype, value, inc); 2413 TREE_SIDE_EFFECTS (incremented) = 1; 2414 modify = build_modify_expr (arg, NOP_EXPR, incremented); 2415 value = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value); 2416 } 2417 TREE_USED (value) = 1; 2418 return value; 2419 } 2420 break; 2421 2422 default: 2423 goto give_up; 2424 } 2425 give_up: 2426 2427 /* Complain about anything else that is not a true lvalue. */ 2428 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 2429 || code == POSTINCREMENT_EXPR) 2430 ? "invalid lvalue in increment" 2431 : "invalid lvalue in decrement"))) 2432 return error_mark_node; 2433 2434 /* Report a read-only lvalue. */ 2435 if (TREE_READONLY (arg)) 2436 readonly_error (arg, 2437 ((code == PREINCREMENT_EXPR 2438 || code == POSTINCREMENT_EXPR) 2439 ? "increment" : "decrement")); 2440 2441 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) 2442 val = boolean_increment (code, arg); 2443 else 2444 val = build (code, TREE_TYPE (arg), arg, inc); 2445 TREE_SIDE_EFFECTS (val) = 1; 2446 val = convert (result_type, val); 2447 if (TREE_CODE (val) != code) 2448 TREE_NO_UNUSED_WARNING (val) = 1; 2449 return val; 2450 } 2451 2452 case ADDR_EXPR: 2453 /* Note that this operation never does default_conversion. */ 2454 2455 /* Let &* cancel out to simplify resulting code. */ 2456 if (TREE_CODE (arg) == INDIRECT_REF) 2457 { 2458 /* Don't let this be an lvalue. */ 2459 if (lvalue_p (TREE_OPERAND (arg, 0))) 2460 return non_lvalue (TREE_OPERAND (arg, 0)); 2461 return TREE_OPERAND (arg, 0); 2462 } 2463 2464 /* For &x[y], return x+y */ 2465 if (TREE_CODE (arg) == ARRAY_REF) 2466 { 2467 if (!c_mark_addressable (TREE_OPERAND (arg, 0))) 2468 return error_mark_node; 2469 return build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0), 2470 TREE_OPERAND (arg, 1), 1); 2471 } 2472 2473 /* Handle complex lvalues (when permitted) 2474 by reduction to simpler cases. */ 2475 val = unary_complex_lvalue (code, arg, flag); 2476 if (val != 0) 2477 return val; 2478 2479 /* Anything not already handled and not a true memory reference 2480 or a non-lvalue array is an error. */ 2481 else if (typecode != FUNCTION_TYPE && !flag 2482 && !lvalue_or_else (arg, "invalid lvalue in unary `&'")) 2483 return error_mark_node; 2484 2485 /* Ordinary case; arg is a COMPONENT_REF or a decl. */ 2486 argtype = TREE_TYPE (arg); 2487 2488 /* If the lvalue is const or volatile, merge that into the type 2489 to which the address will point. Note that you can't get a 2490 restricted pointer by taking the address of something, so we 2491 only have to deal with `const' and `volatile' here. */ 2492 if ((DECL_P (arg) || TREE_CODE_CLASS (TREE_CODE (arg)) == 'r') 2493 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) 2494 argtype = c_build_type_variant (argtype, 2495 TREE_READONLY (arg), 2496 TREE_THIS_VOLATILE (arg)); 2497 2498 argtype = build_pointer_type (argtype); 2499 2500 if (!c_mark_addressable (arg)) 2501 return error_mark_node; 2502 2503 { 2504 tree addr; 2505 2506 if (TREE_CODE (arg) == COMPONENT_REF) 2507 { 2508 tree field = TREE_OPERAND (arg, 1); 2509 2510 addr = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), flag); 2511 2512 if (DECL_C_BIT_FIELD (field)) 2513 { 2514 error ("attempt to take address of bit-field structure member `%s'", 2515 IDENTIFIER_POINTER (DECL_NAME (field))); 2516 return error_mark_node; 2517 } 2518 2519 addr = fold (build (PLUS_EXPR, argtype, 2520 convert (argtype, addr), 2521 convert (argtype, byte_position (field)))); 2522 } 2523 else 2524 addr = build1 (code, argtype, arg); 2525 2526 /* Address of a static or external variable or 2527 file-scope function counts as a constant. */ 2528 if (staticp (arg) 2529 && ! (TREE_CODE (arg) == FUNCTION_DECL 2530 && !DECL_FILE_SCOPE_P (arg))) 2531 TREE_CONSTANT (addr) = 1; 2532 return addr; 2533 } 2534 2535 default: 2536 break; 2537 } 2538 2539 if (argtype == 0) 2540 argtype = TREE_TYPE (arg); 2541 val = build1 (code, argtype, arg); 2542 return require_constant_value ? fold_initializer (val) : fold (val); 2543} 2544 2545/* Return nonzero if REF is an lvalue valid for this language. 2546 Lvalues can be assigned, unless their type has TYPE_READONLY. 2547 Lvalues can have their address taken, unless they have DECL_REGISTER. */ 2548 2549int 2550lvalue_p (tree ref) 2551{ 2552 enum tree_code code = TREE_CODE (ref); 2553 2554 switch (code) 2555 { 2556 case REALPART_EXPR: 2557 case IMAGPART_EXPR: 2558 case COMPONENT_REF: 2559 return lvalue_p (TREE_OPERAND (ref, 0)); 2560 2561 case COMPOUND_LITERAL_EXPR: 2562 case STRING_CST: 2563 return 1; 2564 2565 case INDIRECT_REF: 2566 case ARRAY_REF: 2567 case VAR_DECL: 2568 case PARM_DECL: 2569 case RESULT_DECL: 2570 case ERROR_MARK: 2571 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE 2572 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); 2573 2574 case BIND_EXPR: 2575 case RTL_EXPR: 2576 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; 2577 2578 default: 2579 return 0; 2580 } 2581} 2582 2583/* Return nonzero if REF is an lvalue valid for this language; 2584 otherwise, print an error message and return zero. */ 2585 2586int 2587lvalue_or_else (tree ref, const char *msgid) 2588{ 2589 int win = lvalue_p (ref); 2590 2591 if (! win) 2592 error ("%s", msgid); 2593 2594 return win; 2595} 2596 2597/* Apply unary lvalue-demanding operator CODE to the expression ARG 2598 for certain kinds of expressions which are not really lvalues 2599 but which we can accept as lvalues. If FLAG is nonzero, then 2600 non-lvalues are OK since we may be converting a non-lvalue array to 2601 a pointer in C99. 2602 2603 If ARG is not a kind of expression we can handle, return zero. */ 2604 2605static tree 2606unary_complex_lvalue (enum tree_code code, tree arg, int flag) 2607{ 2608 /* Handle (a, b) used as an "lvalue". */ 2609 if (TREE_CODE (arg) == COMPOUND_EXPR) 2610 { 2611 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0); 2612 2613 /* If this returns a function type, it isn't really being used as 2614 an lvalue, so don't issue a warning about it. */ 2615 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag) 2616 pedantic_lvalue_warning (COMPOUND_EXPR); 2617 2618 return build (COMPOUND_EXPR, TREE_TYPE (real_result), 2619 TREE_OPERAND (arg, 0), real_result); 2620 } 2621 2622 /* Handle (a ? b : c) used as an "lvalue". */ 2623 if (TREE_CODE (arg) == COND_EXPR) 2624 { 2625 if (!flag) 2626 pedantic_lvalue_warning (COND_EXPR); 2627 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag) 2628 pedantic_lvalue_warning (COMPOUND_EXPR); 2629 2630 return (build_conditional_expr 2631 (TREE_OPERAND (arg, 0), 2632 build_unary_op (code, TREE_OPERAND (arg, 1), flag), 2633 build_unary_op (code, TREE_OPERAND (arg, 2), flag))); 2634 } 2635 2636 return 0; 2637} 2638 2639/* If pedantic, warn about improper lvalue. CODE is either COND_EXPR 2640 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */ 2641 2642static void 2643pedantic_lvalue_warning (enum tree_code code) 2644{ 2645 switch (code) 2646 { 2647 case COND_EXPR: 2648 pedwarn ("use of conditional expressions as lvalues is deprecated"); 2649 break; 2650 case COMPOUND_EXPR: 2651 pedwarn ("use of compound expressions as lvalues is deprecated"); 2652 break; 2653 default: 2654 pedwarn ("use of cast expressions as lvalues is deprecated"); 2655 break; 2656 } 2657} 2658 2659/* Warn about storing in something that is `const'. */ 2660 2661void 2662readonly_error (tree arg, const char *msgid) 2663{ 2664 if (TREE_CODE (arg) == COMPONENT_REF) 2665 { 2666 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) 2667 readonly_error (TREE_OPERAND (arg, 0), msgid); 2668 else 2669 error ("%s of read-only member `%s'", _(msgid), 2670 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (arg, 1)))); 2671 } 2672 else if (TREE_CODE (arg) == VAR_DECL) 2673 error ("%s of read-only variable `%s'", _(msgid), 2674 IDENTIFIER_POINTER (DECL_NAME (arg))); 2675 else 2676 error ("%s of read-only location", _(msgid)); 2677} 2678 2679/* Mark EXP saying that we need to be able to take the 2680 address of it; it should not be allocated in a register. 2681 Returns true if successful. */ 2682 2683bool 2684c_mark_addressable (tree exp) 2685{ 2686 tree x = exp; 2687 2688 while (1) 2689 switch (TREE_CODE (x)) 2690 { 2691 case COMPONENT_REF: 2692 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) 2693 { 2694 error ("cannot take address of bit-field `%s'", 2695 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (x, 1)))); 2696 return false; 2697 } 2698 2699 /* ... fall through ... */ 2700 2701 case ADDR_EXPR: 2702 case ARRAY_REF: 2703 case REALPART_EXPR: 2704 case IMAGPART_EXPR: 2705 x = TREE_OPERAND (x, 0); 2706 break; 2707 2708 case COMPOUND_LITERAL_EXPR: 2709 case CONSTRUCTOR: 2710 TREE_ADDRESSABLE (x) = 1; 2711 return true; 2712 2713 case VAR_DECL: 2714 case CONST_DECL: 2715 case PARM_DECL: 2716 case RESULT_DECL: 2717 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x) 2718 && DECL_NONLOCAL (x)) 2719 { 2720 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 2721 { 2722 error ("global register variable `%s' used in nested function", 2723 IDENTIFIER_POINTER (DECL_NAME (x))); 2724 return false; 2725 } 2726 pedwarn ("register variable `%s' used in nested function", 2727 IDENTIFIER_POINTER (DECL_NAME (x))); 2728 } 2729 else if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)) 2730 { 2731 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) 2732 { 2733 error ("address of global register variable `%s' requested", 2734 IDENTIFIER_POINTER (DECL_NAME (x))); 2735 return false; 2736 } 2737 2738 /* If we are making this addressable due to its having 2739 volatile components, give a different error message. Also 2740 handle the case of an unnamed parameter by not trying 2741 to give the name. */ 2742 2743 else if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (x))) 2744 { 2745 error ("cannot put object with volatile field into register"); 2746 return false; 2747 } 2748 2749 pedwarn ("address of register variable `%s' requested", 2750 IDENTIFIER_POINTER (DECL_NAME (x))); 2751 } 2752 put_var_into_stack (x, /*rescan=*/true); 2753 2754 /* drops in */ 2755 case FUNCTION_DECL: 2756 TREE_ADDRESSABLE (x) = 1; 2757 /* drops out */ 2758 default: 2759 return true; 2760 } 2761} 2762 2763/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 2764 2765tree 2766build_conditional_expr (tree ifexp, tree op1, tree op2) 2767{ 2768 tree type1; 2769 tree type2; 2770 enum tree_code code1; 2771 enum tree_code code2; 2772 tree result_type = NULL; 2773 tree orig_op1 = op1, orig_op2 = op2; 2774 2775 ifexp = c_common_truthvalue_conversion (default_conversion (ifexp)); 2776 2777 /* Promote both alternatives. */ 2778 2779 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) 2780 op1 = default_conversion (op1); 2781 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) 2782 op2 = default_conversion (op2); 2783 2784 if (TREE_CODE (ifexp) == ERROR_MARK 2785 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK 2786 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) 2787 return error_mark_node; 2788 2789 type1 = TREE_TYPE (op1); 2790 code1 = TREE_CODE (type1); 2791 type2 = TREE_TYPE (op2); 2792 code2 = TREE_CODE (type2); 2793 2794 /* Quickly detect the usual case where op1 and op2 have the same type 2795 after promotion. */ 2796 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) 2797 { 2798 if (type1 == type2) 2799 result_type = type1; 2800 else 2801 result_type = TYPE_MAIN_VARIANT (type1); 2802 } 2803 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE 2804 || code1 == COMPLEX_TYPE) 2805 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE 2806 || code2 == COMPLEX_TYPE)) 2807 { 2808 result_type = common_type (type1, type2); 2809 2810 /* If -Wsign-compare, warn here if type1 and type2 have 2811 different signedness. We'll promote the signed to unsigned 2812 and later code won't know it used to be different. 2813 Do this check on the original types, so that explicit casts 2814 will be considered, but default promotions won't. */ 2815 if (warn_sign_compare && !skip_evaluation) 2816 { 2817 int unsigned_op1 = TREE_UNSIGNED (TREE_TYPE (orig_op1)); 2818 int unsigned_op2 = TREE_UNSIGNED (TREE_TYPE (orig_op2)); 2819 2820 if (unsigned_op1 ^ unsigned_op2) 2821 { 2822 /* Do not warn if the result type is signed, since the 2823 signed type will only be chosen if it can represent 2824 all the values of the unsigned type. */ 2825 if (! TREE_UNSIGNED (result_type)) 2826 /* OK */; 2827 /* Do not warn if the signed quantity is an unsuffixed 2828 integer literal (or some static constant expression 2829 involving such literals) and it is non-negative. */ 2830 else if ((unsigned_op2 && c_tree_expr_nonnegative_p (op1)) 2831 || (unsigned_op1 && c_tree_expr_nonnegative_p (op2))) 2832 /* OK */; 2833 else 2834 warning ("signed and unsigned type in conditional expression"); 2835 } 2836 } 2837 } 2838 else if (code1 == VOID_TYPE || code2 == VOID_TYPE) 2839 { 2840 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) 2841 pedwarn ("ISO C forbids conditional expr with only one void side"); 2842 result_type = void_type_node; 2843 } 2844 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) 2845 { 2846 if (comp_target_types (type1, type2, 1)) 2847 result_type = common_type (type1, type2); 2848 else if (integer_zerop (op1) && TREE_TYPE (type1) == void_type_node 2849 && TREE_CODE (orig_op1) != NOP_EXPR) 2850 result_type = qualify_type (type2, type1); 2851 else if (integer_zerop (op2) && TREE_TYPE (type2) == void_type_node 2852 && TREE_CODE (orig_op2) != NOP_EXPR) 2853 result_type = qualify_type (type1, type2); 2854 else if (VOID_TYPE_P (TREE_TYPE (type1))) 2855 { 2856 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) 2857 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer"); 2858 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), 2859 TREE_TYPE (type2))); 2860 } 2861 else if (VOID_TYPE_P (TREE_TYPE (type2))) 2862 { 2863 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) 2864 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer"); 2865 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), 2866 TREE_TYPE (type1))); 2867 } 2868 else 2869 { 2870 pedwarn ("pointer type mismatch in conditional expression"); 2871 result_type = build_pointer_type (void_type_node); 2872 } 2873 } 2874 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) 2875 { 2876 if (! integer_zerop (op2)) 2877 pedwarn ("pointer/integer type mismatch in conditional expression"); 2878 else 2879 { 2880 op2 = null_pointer_node; 2881 } 2882 result_type = type1; 2883 } 2884 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) 2885 { 2886 if (!integer_zerop (op1)) 2887 pedwarn ("pointer/integer type mismatch in conditional expression"); 2888 else 2889 { 2890 op1 = null_pointer_node; 2891 } 2892 result_type = type2; 2893 } 2894 2895 if (!result_type) 2896 { 2897 if (flag_cond_mismatch) 2898 result_type = void_type_node; 2899 else 2900 { 2901 error ("type mismatch in conditional expression"); 2902 return error_mark_node; 2903 } 2904 } 2905 2906 /* Merge const and volatile flags of the incoming types. */ 2907 result_type 2908 = build_type_variant (result_type, 2909 TREE_READONLY (op1) || TREE_READONLY (op2), 2910 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); 2911 2912 if (result_type != TREE_TYPE (op1)) 2913 op1 = convert_and_check (result_type, op1); 2914 if (result_type != TREE_TYPE (op2)) 2915 op2 = convert_and_check (result_type, op2); 2916 2917 if (TREE_CODE (ifexp) == INTEGER_CST) 2918 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1); 2919 2920 return fold (build (COND_EXPR, result_type, ifexp, op1, op2)); 2921} 2922 2923/* Given a list of expressions, return a compound expression 2924 that performs them all and returns the value of the last of them. */ 2925 2926tree 2927build_compound_expr (tree list) 2928{ 2929 return internal_build_compound_expr (list, TRUE); 2930} 2931 2932static tree 2933internal_build_compound_expr (tree list, int first_p) 2934{ 2935 tree rest; 2936 2937 if (TREE_CHAIN (list) == 0) 2938 { 2939 /* Convert arrays and functions to pointers when there 2940 really is a comma operator. */ 2941 if (!first_p) 2942 TREE_VALUE (list) 2943 = default_function_array_conversion (TREE_VALUE (list)); 2944 2945 /* Don't let (0, 0) be null pointer constant. */ 2946 if (!first_p && integer_zerop (TREE_VALUE (list))) 2947 return non_lvalue (TREE_VALUE (list)); 2948 return TREE_VALUE (list); 2949 } 2950 2951 rest = internal_build_compound_expr (TREE_CHAIN (list), FALSE); 2952 2953 if (! TREE_SIDE_EFFECTS (TREE_VALUE (list))) 2954 { 2955 /* The left-hand operand of a comma expression is like an expression 2956 statement: with -Wextra or -Wunused, we should warn if it doesn't have 2957 any side-effects, unless it was explicitly cast to (void). */ 2958 if (warn_unused_value 2959 && ! (TREE_CODE (TREE_VALUE (list)) == CONVERT_EXPR 2960 && VOID_TYPE_P (TREE_TYPE (TREE_VALUE (list))))) 2961 warning ("left-hand operand of comma expression has no effect"); 2962 } 2963 2964 /* With -Wunused, we should also warn if the left-hand operand does have 2965 side-effects, but computes a value which is not used. For example, in 2966 `foo() + bar(), baz()' the result of the `+' operator is not used, 2967 so we should issue a warning. */ 2968 else if (warn_unused_value) 2969 warn_if_unused_value (TREE_VALUE (list)); 2970 2971 return build (COMPOUND_EXPR, TREE_TYPE (rest), TREE_VALUE (list), rest); 2972} 2973 2974/* Build an expression representing a cast to type TYPE of expression EXPR. */ 2975 2976tree 2977build_c_cast (tree type, tree expr) 2978{ 2979 tree value = expr; 2980 2981 if (type == error_mark_node || expr == error_mark_node) 2982 return error_mark_node; 2983 2984 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing 2985 only in <protocol> qualifications. But when constructing cast expressions, 2986 the protocols do matter and must be kept around. */ 2987 if (!c_dialect_objc () || !objc_is_object_ptr (type)) 2988 type = TYPE_MAIN_VARIANT (type); 2989 2990 if (TREE_CODE (type) == ARRAY_TYPE) 2991 { 2992 error ("cast specifies array type"); 2993 return error_mark_node; 2994 } 2995 2996 if (TREE_CODE (type) == FUNCTION_TYPE) 2997 { 2998 error ("cast specifies function type"); 2999 return error_mark_node; 3000 } 3001 3002 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) 3003 { 3004 if (pedantic) 3005 { 3006 if (TREE_CODE (type) == RECORD_TYPE 3007 || TREE_CODE (type) == UNION_TYPE) 3008 pedwarn ("ISO C forbids casting nonscalar to the same type"); 3009 } 3010 } 3011 else if (TREE_CODE (type) == UNION_TYPE) 3012 { 3013 tree field; 3014 value = default_function_array_conversion (value); 3015 3016 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3017 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), 3018 TYPE_MAIN_VARIANT (TREE_TYPE (value)), COMPARE_STRICT)) 3019 break; 3020 3021 if (field) 3022 { 3023 tree t; 3024 3025 if (pedantic) 3026 pedwarn ("ISO C forbids casts to union type"); 3027 t = digest_init (type, 3028 build_constructor (type, 3029 build_tree_list (field, value)), 3030 0); 3031 TREE_CONSTANT (t) = TREE_CONSTANT (value); 3032 return t; 3033 } 3034 error ("cast to union type from type not present in union"); 3035 return error_mark_node; 3036 } 3037 else 3038 { 3039 tree otype, ovalue; 3040 3041 /* If casting to void, avoid the error that would come 3042 from default_conversion in the case of a non-lvalue array. */ 3043 if (type == void_type_node) 3044 return build1 (CONVERT_EXPR, type, value); 3045 3046 /* Convert functions and arrays to pointers, 3047 but don't convert any other types. */ 3048 value = default_function_array_conversion (value); 3049 otype = TREE_TYPE (value); 3050 3051 /* Optionally warn about potentially worrisome casts. */ 3052 3053 if (warn_cast_qual 3054 && TREE_CODE (type) == POINTER_TYPE 3055 && TREE_CODE (otype) == POINTER_TYPE) 3056 { 3057 tree in_type = type; 3058 tree in_otype = otype; 3059 int added = 0; 3060 int discarded = 0; 3061 3062 /* Check that the qualifiers on IN_TYPE are a superset of 3063 the qualifiers of IN_OTYPE. The outermost level of 3064 POINTER_TYPE nodes is uninteresting and we stop as soon 3065 as we hit a non-POINTER_TYPE node on either type. */ 3066 do 3067 { 3068 in_otype = TREE_TYPE (in_otype); 3069 in_type = TREE_TYPE (in_type); 3070 3071 /* GNU C allows cv-qualified function types. 'const' 3072 means the function is very pure, 'volatile' means it 3073 can't return. We need to warn when such qualifiers 3074 are added, not when they're taken away. */ 3075 if (TREE_CODE (in_otype) == FUNCTION_TYPE 3076 && TREE_CODE (in_type) == FUNCTION_TYPE) 3077 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); 3078 else 3079 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); 3080 } 3081 while (TREE_CODE (in_type) == POINTER_TYPE 3082 && TREE_CODE (in_otype) == POINTER_TYPE); 3083 3084 if (added) 3085 warning ("cast adds new qualifiers to function type"); 3086 3087 if (discarded) 3088 /* There are qualifiers present in IN_OTYPE that are not 3089 present in IN_TYPE. */ 3090 warning ("cast discards qualifiers from pointer target type"); 3091 } 3092 3093 /* Warn about possible alignment problems. */ 3094 if (STRICT_ALIGNMENT && warn_cast_align 3095 && TREE_CODE (type) == POINTER_TYPE 3096 && TREE_CODE (otype) == POINTER_TYPE 3097 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE 3098 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3099 /* Don't warn about opaque types, where the actual alignment 3100 restriction is unknown. */ 3101 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE 3102 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) 3103 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) 3104 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) 3105 warning ("cast increases required alignment of target type"); 3106 3107 if (TREE_CODE (type) == INTEGER_TYPE 3108 && TREE_CODE (otype) == POINTER_TYPE 3109 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3110 && !TREE_CONSTANT (value)) 3111 warning ("cast from pointer to integer of different size"); 3112 3113 if (warn_bad_function_cast 3114 && TREE_CODE (value) == CALL_EXPR 3115 && TREE_CODE (type) != TREE_CODE (otype)) 3116 warning ("cast does not match function type"); 3117 3118 if (TREE_CODE (type) == POINTER_TYPE 3119 && TREE_CODE (otype) == INTEGER_TYPE 3120 && TYPE_PRECISION (type) != TYPE_PRECISION (otype) 3121 /* Don't warn about converting any constant. */ 3122 && !TREE_CONSTANT (value)) 3123 warning ("cast to pointer from integer of different size"); 3124 3125 if (TREE_CODE (type) == POINTER_TYPE 3126 && TREE_CODE (otype) == POINTER_TYPE 3127 && TREE_CODE (expr) == ADDR_EXPR 3128 && DECL_P (TREE_OPERAND (expr, 0)) 3129 && flag_strict_aliasing && warn_strict_aliasing 3130 && !VOID_TYPE_P (TREE_TYPE (type))) 3131 { 3132 /* Casting the address of a decl to non void pointer. Warn 3133 if the cast breaks type based aliasing. */ 3134 if (!COMPLETE_TYPE_P (TREE_TYPE (type))) 3135 warning ("type-punning to incomplete type might break strict-aliasing rules"); 3136 else if (!alias_sets_conflict_p 3137 (get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))), 3138 get_alias_set (TREE_TYPE (type)))) 3139 warning ("dereferencing type-punned pointer will break strict-aliasing rules"); 3140 } 3141 3142 /* If pedantic, warn for conversions between function and object 3143 pointer types, except for converting a null pointer constant 3144 to function pointer type. */ 3145 if (pedantic 3146 && TREE_CODE (type) == POINTER_TYPE 3147 && TREE_CODE (otype) == POINTER_TYPE 3148 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE 3149 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) 3150 pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); 3151 3152 if (pedantic 3153 && TREE_CODE (type) == POINTER_TYPE 3154 && TREE_CODE (otype) == POINTER_TYPE 3155 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 3156 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE 3157 && !(integer_zerop (value) && TREE_TYPE (otype) == void_type_node 3158 && TREE_CODE (expr) != NOP_EXPR)) 3159 pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); 3160 3161 ovalue = value; 3162 /* Replace a nonvolatile const static variable with its value. */ 3163 if (optimize && TREE_CODE (value) == VAR_DECL) 3164 value = decl_constant_value (value); 3165 value = convert (type, value); 3166 3167 /* Ignore any integer overflow caused by the cast. */ 3168 if (TREE_CODE (value) == INTEGER_CST) 3169 { 3170 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); 3171 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); 3172 } 3173 } 3174 3175 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */ 3176 if (pedantic && TREE_CODE (value) == INTEGER_CST 3177 && TREE_CODE (expr) == INTEGER_CST 3178 && TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE) 3179 value = non_lvalue (value); 3180 3181 /* If pedantic, don't let a cast be an lvalue. */ 3182 if (value == expr && pedantic) 3183 value = non_lvalue (value); 3184 3185 return value; 3186} 3187 3188/* Interpret a cast of expression EXPR to type TYPE. */ 3189tree 3190c_cast_expr (tree type, tree expr) 3191{ 3192 int saved_wsp = warn_strict_prototypes; 3193 3194 /* This avoids warnings about unprototyped casts on 3195 integers. E.g. "#define SIG_DFL (void(*)())0". */ 3196 if (TREE_CODE (expr) == INTEGER_CST) 3197 warn_strict_prototypes = 0; 3198 type = groktypename (type); 3199 warn_strict_prototypes = saved_wsp; 3200 3201 return build_c_cast (type, expr); 3202} 3203 3204 3205/* Build an assignment expression of lvalue LHS from value RHS. 3206 MODIFYCODE is the code for a binary operator that we use 3207 to combine the old value of LHS with RHS to get the new value. 3208 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ 3209 3210tree 3211build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) 3212{ 3213 tree result; 3214 tree newrhs; 3215 tree lhstype = TREE_TYPE (lhs); 3216 tree olhstype = lhstype; 3217 3218 /* Types that aren't fully specified cannot be used in assignments. */ 3219 lhs = require_complete_type (lhs); 3220 3221 /* Avoid duplicate error messages from operands that had errors. */ 3222 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) 3223 return error_mark_node; 3224 3225 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 3226 /* Do not use STRIP_NOPS here. We do not want an enumerator 3227 whose value is 0 to count as a null pointer constant. */ 3228 if (TREE_CODE (rhs) == NON_LVALUE_EXPR) 3229 rhs = TREE_OPERAND (rhs, 0); 3230 3231 newrhs = rhs; 3232 3233 /* Handle control structure constructs used as "lvalues". */ 3234 3235 switch (TREE_CODE (lhs)) 3236 { 3237 /* Handle (a, b) used as an "lvalue". */ 3238 case COMPOUND_EXPR: 3239 pedantic_lvalue_warning (COMPOUND_EXPR); 3240 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1), modifycode, rhs); 3241 if (TREE_CODE (newrhs) == ERROR_MARK) 3242 return error_mark_node; 3243 return build (COMPOUND_EXPR, lhstype, 3244 TREE_OPERAND (lhs, 0), newrhs); 3245 3246 /* Handle (a ? b : c) used as an "lvalue". */ 3247 case COND_EXPR: 3248 pedantic_lvalue_warning (COND_EXPR); 3249 rhs = save_expr (rhs); 3250 { 3251 /* Produce (a ? (b = rhs) : (c = rhs)) 3252 except that the RHS goes through a save-expr 3253 so the code to compute it is only emitted once. */ 3254 tree cond 3255 = build_conditional_expr (TREE_OPERAND (lhs, 0), 3256 build_modify_expr (TREE_OPERAND (lhs, 1), 3257 modifycode, rhs), 3258 build_modify_expr (TREE_OPERAND (lhs, 2), 3259 modifycode, rhs)); 3260 if (TREE_CODE (cond) == ERROR_MARK) 3261 return cond; 3262 /* Make sure the code to compute the rhs comes out 3263 before the split. */ 3264 return build (COMPOUND_EXPR, TREE_TYPE (lhs), 3265 /* But cast it to void to avoid an "unused" error. */ 3266 convert (void_type_node, rhs), cond); 3267 } 3268 default: 3269 break; 3270 } 3271 3272 /* If a binary op has been requested, combine the old LHS value with the RHS 3273 producing the value we should actually store into the LHS. */ 3274 3275 if (modifycode != NOP_EXPR) 3276 { 3277 lhs = stabilize_reference (lhs); 3278 newrhs = build_binary_op (modifycode, lhs, rhs, 1); 3279 } 3280 3281 /* Handle a cast used as an "lvalue". 3282 We have already performed any binary operator using the value as cast. 3283 Now convert the result to the cast type of the lhs, 3284 and then true type of the lhs and store it there; 3285 then convert result back to the cast type to be the value 3286 of the assignment. */ 3287 3288 switch (TREE_CODE (lhs)) 3289 { 3290 case NOP_EXPR: 3291 case CONVERT_EXPR: 3292 case FLOAT_EXPR: 3293 case FIX_TRUNC_EXPR: 3294 case FIX_FLOOR_EXPR: 3295 case FIX_ROUND_EXPR: 3296 case FIX_CEIL_EXPR: 3297 newrhs = default_function_array_conversion (newrhs); 3298 { 3299 tree inner_lhs = TREE_OPERAND (lhs, 0); 3300 tree result; 3301 result = build_modify_expr (inner_lhs, NOP_EXPR, 3302 convert (TREE_TYPE (inner_lhs), 3303 convert (lhstype, newrhs))); 3304 if (TREE_CODE (result) == ERROR_MARK) 3305 return result; 3306 pedantic_lvalue_warning (CONVERT_EXPR); 3307 return convert (TREE_TYPE (lhs), result); 3308 } 3309 3310 default: 3311 break; 3312 } 3313 3314 /* Now we have handled acceptable kinds of LHS that are not truly lvalues. 3315 Reject anything strange now. */ 3316 3317 if (!lvalue_or_else (lhs, "invalid lvalue in assignment")) 3318 return error_mark_node; 3319 3320 /* Warn about storing in something that is `const'. */ 3321 3322 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) 3323 || ((TREE_CODE (lhstype) == RECORD_TYPE 3324 || TREE_CODE (lhstype) == UNION_TYPE) 3325 && C_TYPE_FIELDS_READONLY (lhstype))) 3326 readonly_error (lhs, "assignment"); 3327 3328 /* If storing into a structure or union member, 3329 it has probably been given type `int'. 3330 Compute the type that would go with 3331 the actual amount of storage the member occupies. */ 3332 3333 if (TREE_CODE (lhs) == COMPONENT_REF 3334 && (TREE_CODE (lhstype) == INTEGER_TYPE 3335 || TREE_CODE (lhstype) == BOOLEAN_TYPE 3336 || TREE_CODE (lhstype) == REAL_TYPE 3337 || TREE_CODE (lhstype) == ENUMERAL_TYPE)) 3338 lhstype = TREE_TYPE (get_unwidened (lhs, 0)); 3339 3340 /* If storing in a field that is in actuality a short or narrower than one, 3341 we must store in the field in its actual type. */ 3342 3343 if (lhstype != TREE_TYPE (lhs)) 3344 { 3345 lhs = copy_node (lhs); 3346 TREE_TYPE (lhs) = lhstype; 3347 } 3348 3349 /* Convert new value to destination type. */ 3350 3351 newrhs = convert_for_assignment (lhstype, newrhs, _("assignment"), 3352 NULL_TREE, NULL_TREE, 0); 3353 if (TREE_CODE (newrhs) == ERROR_MARK) 3354 return error_mark_node; 3355 3356 /* Scan operands */ 3357 3358 result = build (MODIFY_EXPR, lhstype, lhs, newrhs); 3359 TREE_SIDE_EFFECTS (result) = 1; 3360 3361 /* If we got the LHS in a different type for storing in, 3362 convert the result back to the nominal type of LHS 3363 so that the value we return always has the same type 3364 as the LHS argument. */ 3365 3366 if (olhstype == TREE_TYPE (result)) 3367 return result; 3368 return convert_for_assignment (olhstype, result, _("assignment"), 3369 NULL_TREE, NULL_TREE, 0); 3370} 3371 3372/* Convert value RHS to type TYPE as preparation for an assignment 3373 to an lvalue of type TYPE. 3374 The real work of conversion is done by `convert'. 3375 The purpose of this function is to generate error messages 3376 for assignments that are not allowed in C. 3377 ERRTYPE is a string to use in error messages: 3378 "assignment", "return", etc. If it is null, this is parameter passing 3379 for a function call (and different error messages are output). 3380 3381 FUNNAME is the name of the function being called, 3382 as an IDENTIFIER_NODE, or null. 3383 PARMNUM is the number of the argument, for printing in error messages. */ 3384 3385static tree 3386convert_for_assignment (tree type, tree rhs, const char *errtype, 3387 tree fundecl, tree funname, int parmnum) 3388{ 3389 enum tree_code codel = TREE_CODE (type); 3390 tree rhstype; 3391 enum tree_code coder; 3392 3393 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 3394 /* Do not use STRIP_NOPS here. We do not want an enumerator 3395 whose value is 0 to count as a null pointer constant. */ 3396 if (TREE_CODE (rhs) == NON_LVALUE_EXPR) 3397 rhs = TREE_OPERAND (rhs, 0); 3398 3399 if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE 3400 || TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE) 3401 rhs = default_conversion (rhs); 3402 else if (optimize && TREE_CODE (rhs) == VAR_DECL) 3403 rhs = decl_constant_value_for_broken_optimization (rhs); 3404 3405 rhstype = TREE_TYPE (rhs); 3406 coder = TREE_CODE (rhstype); 3407 3408 if (coder == ERROR_MARK) 3409 return error_mark_node; 3410 3411 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) 3412 { 3413 overflow_warning (rhs); 3414 /* Check for Objective-C protocols. This will automatically 3415 issue a warning if there are protocol violations. No need to 3416 use the return value. */ 3417 if (c_dialect_objc ()) 3418 objc_comptypes (type, rhstype, 0); 3419 return rhs; 3420 } 3421 3422 if (coder == VOID_TYPE) 3423 { 3424 error ("void value not ignored as it ought to be"); 3425 return error_mark_node; 3426 } 3427 /* A type converts to a reference to it. 3428 This code doesn't fully support references, it's just for the 3429 special case of va_start and va_copy. */ 3430 if (codel == REFERENCE_TYPE 3431 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs), COMPARE_STRICT) == 1) 3432 { 3433 if (!lvalue_p (rhs)) 3434 { 3435 error ("cannot pass rvalue to reference parameter"); 3436 return error_mark_node; 3437 } 3438 if (!c_mark_addressable (rhs)) 3439 return error_mark_node; 3440 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); 3441 3442 /* We already know that these two types are compatible, but they 3443 may not be exactly identical. In fact, `TREE_TYPE (type)' is 3444 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is 3445 likely to be va_list, a typedef to __builtin_va_list, which 3446 is different enough that it will cause problems later. */ 3447 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) 3448 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); 3449 3450 rhs = build1 (NOP_EXPR, type, rhs); 3451 return rhs; 3452 } 3453 /* Some types can interconvert without explicit casts. */ 3454 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE 3455 && ((*targetm.vector_opaque_p) (type) 3456 || (*targetm.vector_opaque_p) (rhstype))) 3457 return convert (type, rhs); 3458 /* Arithmetic types all interconvert, and enum is treated like int. */ 3459 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 3460 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE 3461 || codel == BOOLEAN_TYPE) 3462 && (coder == INTEGER_TYPE || coder == REAL_TYPE 3463 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE 3464 || coder == BOOLEAN_TYPE)) 3465 return convert_and_check (type, rhs); 3466 3467 /* Conversion to a transparent union from its member types. 3468 This applies only to function arguments. */ 3469 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) && ! errtype) 3470 { 3471 tree memb_types; 3472 tree marginal_memb_type = 0; 3473 3474 for (memb_types = TYPE_FIELDS (type); memb_types; 3475 memb_types = TREE_CHAIN (memb_types)) 3476 { 3477 tree memb_type = TREE_TYPE (memb_types); 3478 3479 if (comptypes (TYPE_MAIN_VARIANT (memb_type), 3480 TYPE_MAIN_VARIANT (rhstype), COMPARE_STRICT)) 3481 break; 3482 3483 if (TREE_CODE (memb_type) != POINTER_TYPE) 3484 continue; 3485 3486 if (coder == POINTER_TYPE) 3487 { 3488 tree ttl = TREE_TYPE (memb_type); 3489 tree ttr = TREE_TYPE (rhstype); 3490 3491 /* Any non-function converts to a [const][volatile] void * 3492 and vice versa; otherwise, targets must be the same. 3493 Meanwhile, the lhs target must have all the qualifiers of 3494 the rhs. */ 3495 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3496 || comp_target_types (memb_type, rhstype, 0)) 3497 { 3498 /* If this type won't generate any warnings, use it. */ 3499 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) 3500 || ((TREE_CODE (ttr) == FUNCTION_TYPE 3501 && TREE_CODE (ttl) == FUNCTION_TYPE) 3502 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3503 == TYPE_QUALS (ttr)) 3504 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) 3505 == TYPE_QUALS (ttl)))) 3506 break; 3507 3508 /* Keep looking for a better type, but remember this one. */ 3509 if (! marginal_memb_type) 3510 marginal_memb_type = memb_type; 3511 } 3512 } 3513 3514 /* Can convert integer zero to any pointer type. */ 3515 if (integer_zerop (rhs) 3516 || (TREE_CODE (rhs) == NOP_EXPR 3517 && integer_zerop (TREE_OPERAND (rhs, 0)))) 3518 { 3519 rhs = null_pointer_node; 3520 break; 3521 } 3522 } 3523 3524 if (memb_types || marginal_memb_type) 3525 { 3526 if (! memb_types) 3527 { 3528 /* We have only a marginally acceptable member type; 3529 it needs a warning. */ 3530 tree ttl = TREE_TYPE (marginal_memb_type); 3531 tree ttr = TREE_TYPE (rhstype); 3532 3533 /* Const and volatile mean something different for function 3534 types, so the usual warnings are not appropriate. */ 3535 if (TREE_CODE (ttr) == FUNCTION_TYPE 3536 && TREE_CODE (ttl) == FUNCTION_TYPE) 3537 { 3538 /* Because const and volatile on functions are 3539 restrictions that say the function will not do 3540 certain things, it is okay to use a const or volatile 3541 function where an ordinary one is wanted, but not 3542 vice-versa. */ 3543 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 3544 warn_for_assignment ("%s makes qualified function pointer from unqualified", 3545 errtype, funname, parmnum); 3546 } 3547 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 3548 warn_for_assignment ("%s discards qualifiers from pointer target type", 3549 errtype, funname, 3550 parmnum); 3551 } 3552 3553 if (pedantic && ! DECL_IN_SYSTEM_HEADER (fundecl)) 3554 pedwarn ("ISO C prohibits argument conversion to union type"); 3555 3556 return build1 (NOP_EXPR, type, rhs); 3557 } 3558 } 3559 3560 /* Conversions among pointers */ 3561 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 3562 && (coder == codel)) 3563 { 3564 tree ttl = TREE_TYPE (type); 3565 tree ttr = TREE_TYPE (rhstype); 3566 bool is_opaque_pointer; 3567 int target_cmp = 0; /* Cache comp_target_types () result. */ 3568 3569 /* Opaque pointers are treated like void pointers. */ 3570 is_opaque_pointer = ((*targetm.vector_opaque_p) (type) 3571 || (*targetm.vector_opaque_p) (rhstype)) 3572 && TREE_CODE (ttl) == VECTOR_TYPE 3573 && TREE_CODE (ttr) == VECTOR_TYPE; 3574 3575 /* Any non-function converts to a [const][volatile] void * 3576 and vice versa; otherwise, targets must be the same. 3577 Meanwhile, the lhs target must have all the qualifiers of the rhs. */ 3578 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3579 || (target_cmp = comp_target_types (type, rhstype, 0)) 3580 || is_opaque_pointer 3581 || (c_common_unsigned_type (TYPE_MAIN_VARIANT (ttl)) 3582 == c_common_unsigned_type (TYPE_MAIN_VARIANT (ttr)))) 3583 { 3584 if (pedantic 3585 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) 3586 || 3587 (VOID_TYPE_P (ttr) 3588 /* Check TREE_CODE to catch cases like (void *) (char *) 0 3589 which are not ANSI null ptr constants. */ 3590 && (!integer_zerop (rhs) || TREE_CODE (rhs) == NOP_EXPR) 3591 && TREE_CODE (ttl) == FUNCTION_TYPE))) 3592 warn_for_assignment ("ISO C forbids %s between function pointer and `void *'", 3593 errtype, funname, parmnum); 3594 /* Const and volatile mean something different for function types, 3595 so the usual warnings are not appropriate. */ 3596 else if (TREE_CODE (ttr) != FUNCTION_TYPE 3597 && TREE_CODE (ttl) != FUNCTION_TYPE) 3598 { 3599 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) 3600 warn_for_assignment ("%s discards qualifiers from pointer target type", 3601 errtype, funname, parmnum); 3602 /* If this is not a case of ignoring a mismatch in signedness, 3603 no warning. */ 3604 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) 3605 || target_cmp) 3606 ; 3607 /* If there is a mismatch, do warn. */ 3608 else if (pedantic) 3609 warn_for_assignment ("pointer targets in %s differ in signedness", 3610 errtype, funname, parmnum); 3611 } 3612 else if (TREE_CODE (ttl) == FUNCTION_TYPE 3613 && TREE_CODE (ttr) == FUNCTION_TYPE) 3614 { 3615 /* Because const and volatile on functions are restrictions 3616 that say the function will not do certain things, 3617 it is okay to use a const or volatile function 3618 where an ordinary one is wanted, but not vice-versa. */ 3619 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) 3620 warn_for_assignment ("%s makes qualified function pointer from unqualified", 3621 errtype, funname, parmnum); 3622 } 3623 } 3624 else 3625 warn_for_assignment ("%s from incompatible pointer type", 3626 errtype, funname, parmnum); 3627 return convert (type, rhs); 3628 } 3629 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) 3630 { 3631 error ("invalid use of non-lvalue array"); 3632 return error_mark_node; 3633 } 3634 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) 3635 { 3636 /* An explicit constant 0 can convert to a pointer, 3637 or one that results from arithmetic, even including 3638 a cast to integer type. */ 3639 if (! (TREE_CODE (rhs) == INTEGER_CST && integer_zerop (rhs)) 3640 && 3641 ! (TREE_CODE (rhs) == NOP_EXPR 3642 && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE 3643 && TREE_CODE (TREE_OPERAND (rhs, 0)) == INTEGER_CST 3644 && integer_zerop (TREE_OPERAND (rhs, 0)))) 3645 warn_for_assignment ("%s makes pointer from integer without a cast", 3646 errtype, funname, parmnum); 3647 3648 return convert (type, rhs); 3649 } 3650 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) 3651 { 3652 warn_for_assignment ("%s makes integer from pointer without a cast", 3653 errtype, funname, parmnum); 3654 return convert (type, rhs); 3655 } 3656 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) 3657 return convert (type, rhs); 3658 3659 if (!errtype) 3660 { 3661 if (funname) 3662 { 3663 tree selector = objc_message_selector (); 3664 3665 if (selector && parmnum > 2) 3666 error ("incompatible type for argument %d of `%s'", 3667 parmnum - 2, IDENTIFIER_POINTER (selector)); 3668 else 3669 error ("incompatible type for argument %d of `%s'", 3670 parmnum, IDENTIFIER_POINTER (funname)); 3671 } 3672 else 3673 error ("incompatible type for argument %d of indirect function call", 3674 parmnum); 3675 } 3676 else 3677 error ("incompatible types in %s", errtype); 3678 3679 return error_mark_node; 3680} 3681 3682/* Convert VALUE for assignment into inlined parameter PARM. ARGNUM 3683 is used for error and waring reporting and indicates which argument 3684 is being processed. */ 3685 3686tree 3687c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) 3688{ 3689 tree ret, type; 3690 3691 /* If FN was prototyped, the value has been converted already 3692 in convert_arguments. */ 3693 if (! value || TYPE_ARG_TYPES (TREE_TYPE (fn))) 3694 return value; 3695 3696 type = TREE_TYPE (parm); 3697 ret = convert_for_assignment (type, value, 3698 (char *) 0 /* arg passing */, fn, 3699 DECL_NAME (fn), argnum); 3700 if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) 3701 && INTEGRAL_TYPE_P (type) 3702 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) 3703 ret = default_conversion (ret); 3704 return ret; 3705} 3706 3707/* Print a warning using MSGID. 3708 It gets OPNAME as its one parameter. 3709 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'". 3710 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'". 3711 FUNCTION and ARGNUM are handled specially if we are building an 3712 Objective-C selector. */ 3713 3714static void 3715warn_for_assignment (const char *msgid, const char *opname, tree function, 3716 int argnum) 3717{ 3718 if (opname == 0) 3719 { 3720 tree selector = objc_message_selector (); 3721 char * new_opname; 3722 3723 if (selector && argnum > 2) 3724 { 3725 function = selector; 3726 argnum -= 2; 3727 } 3728 if (argnum == 0) 3729 { 3730 if (function) 3731 { 3732 /* Function name is known; supply it. */ 3733 const char *const argstring = _("passing arg of `%s'"); 3734 new_opname = alloca (IDENTIFIER_LENGTH (function) 3735 + strlen (argstring) + 1 + 1); 3736 sprintf (new_opname, argstring, 3737 IDENTIFIER_POINTER (function)); 3738 } 3739 else 3740 { 3741 /* Function name unknown (call through ptr). */ 3742 const char *const argnofun = _("passing arg of pointer to function"); 3743 new_opname = alloca (strlen (argnofun) + 1 + 1); 3744 sprintf (new_opname, argnofun); 3745 } 3746 } 3747 else if (function) 3748 { 3749 /* Function name is known; supply it. */ 3750 const char *const argstring = _("passing arg %d of `%s'"); 3751 new_opname = alloca (IDENTIFIER_LENGTH (function) 3752 + strlen (argstring) + 1 + 25 /*%d*/ + 1); 3753 sprintf (new_opname, argstring, argnum, 3754 IDENTIFIER_POINTER (function)); 3755 } 3756 else 3757 { 3758 /* Function name unknown (call through ptr); just give arg number. */ 3759 const char *const argnofun = _("passing arg %d of pointer to function"); 3760 new_opname = alloca (strlen (argnofun) + 1 + 25 /*%d*/ + 1); 3761 sprintf (new_opname, argnofun, argnum); 3762 } 3763 opname = new_opname; 3764 } 3765 pedwarn (msgid, opname); 3766} 3767 3768/* If VALUE is a compound expr all of whose expressions are constant, then 3769 return its value. Otherwise, return error_mark_node. 3770 3771 This is for handling COMPOUND_EXPRs as initializer elements 3772 which is allowed with a warning when -pedantic is specified. */ 3773 3774static tree 3775valid_compound_expr_initializer (tree value, tree endtype) 3776{ 3777 if (TREE_CODE (value) == COMPOUND_EXPR) 3778 { 3779 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) 3780 == error_mark_node) 3781 return error_mark_node; 3782 return valid_compound_expr_initializer (TREE_OPERAND (value, 1), 3783 endtype); 3784 } 3785 else if (! TREE_CONSTANT (value) 3786 && ! initializer_constant_valid_p (value, endtype)) 3787 return error_mark_node; 3788 else 3789 return value; 3790} 3791 3792/* Perform appropriate conversions on the initial value of a variable, 3793 store it in the declaration DECL, 3794 and print any error messages that are appropriate. 3795 If the init is invalid, store an ERROR_MARK. */ 3796 3797void 3798store_init_value (tree decl, tree init) 3799{ 3800 tree value, type; 3801 3802 /* If variable's type was invalidly declared, just ignore it. */ 3803 3804 type = TREE_TYPE (decl); 3805 if (TREE_CODE (type) == ERROR_MARK) 3806 return; 3807 3808 /* Digest the specified initializer into an expression. */ 3809 3810 value = digest_init (type, init, TREE_STATIC (decl)); 3811 3812 /* Store the expression if valid; else report error. */ 3813 3814 if (warn_traditional && !in_system_header 3815 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && ! TREE_STATIC (decl)) 3816 warning ("traditional C rejects automatic aggregate initialization"); 3817 3818 DECL_INITIAL (decl) = value; 3819 3820 /* ANSI wants warnings about out-of-range constant initializers. */ 3821 STRIP_TYPE_NOPS (value); 3822 constant_expression_warning (value); 3823 3824 /* Check if we need to set array size from compound literal size. */ 3825 if (TREE_CODE (type) == ARRAY_TYPE 3826 && TYPE_DOMAIN (type) == 0 3827 && value != error_mark_node) 3828 { 3829 tree inside_init = init; 3830 3831 if (TREE_CODE (init) == NON_LVALUE_EXPR) 3832 inside_init = TREE_OPERAND (init, 0); 3833 inside_init = fold (inside_init); 3834 3835 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 3836 { 3837 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 3838 3839 if (TYPE_DOMAIN (TREE_TYPE (decl))) 3840 { 3841 /* For int foo[] = (int [3]){1}; we need to set array size 3842 now since later on array initializer will be just the 3843 brace enclosed list of the compound literal. */ 3844 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (decl)); 3845 layout_type (type); 3846 layout_decl (decl, 0); 3847 } 3848 } 3849 } 3850} 3851 3852/* Methods for storing and printing names for error messages. */ 3853 3854/* Implement a spelling stack that allows components of a name to be pushed 3855 and popped. Each element on the stack is this structure. */ 3856 3857struct spelling 3858{ 3859 int kind; 3860 union 3861 { 3862 int i; 3863 const char *s; 3864 } u; 3865}; 3866 3867#define SPELLING_STRING 1 3868#define SPELLING_MEMBER 2 3869#define SPELLING_BOUNDS 3 3870 3871static struct spelling *spelling; /* Next stack element (unused). */ 3872static struct spelling *spelling_base; /* Spelling stack base. */ 3873static int spelling_size; /* Size of the spelling stack. */ 3874 3875/* Macros to save and restore the spelling stack around push_... functions. 3876 Alternative to SAVE_SPELLING_STACK. */ 3877 3878#define SPELLING_DEPTH() (spelling - spelling_base) 3879#define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) 3880 3881/* Push an element on the spelling stack with type KIND and assign VALUE 3882 to MEMBER. */ 3883 3884#define PUSH_SPELLING(KIND, VALUE, MEMBER) \ 3885{ \ 3886 int depth = SPELLING_DEPTH (); \ 3887 \ 3888 if (depth >= spelling_size) \ 3889 { \ 3890 spelling_size += 10; \ 3891 if (spelling_base == 0) \ 3892 spelling_base = xmalloc (spelling_size * sizeof (struct spelling)); \ 3893 else \ 3894 spelling_base = xrealloc (spelling_base, \ 3895 spelling_size * sizeof (struct spelling)); \ 3896 RESTORE_SPELLING_DEPTH (depth); \ 3897 } \ 3898 \ 3899 spelling->kind = (KIND); \ 3900 spelling->MEMBER = (VALUE); \ 3901 spelling++; \ 3902} 3903 3904/* Push STRING on the stack. Printed literally. */ 3905 3906static void 3907push_string (const char *string) 3908{ 3909 PUSH_SPELLING (SPELLING_STRING, string, u.s); 3910} 3911 3912/* Push a member name on the stack. Printed as '.' STRING. */ 3913 3914static void 3915push_member_name (tree decl) 3916{ 3917 const char *const string 3918 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>"; 3919 PUSH_SPELLING (SPELLING_MEMBER, string, u.s); 3920} 3921 3922/* Push an array bounds on the stack. Printed as [BOUNDS]. */ 3923 3924static void 3925push_array_bounds (int bounds) 3926{ 3927 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); 3928} 3929 3930/* Compute the maximum size in bytes of the printed spelling. */ 3931 3932static int 3933spelling_length (void) 3934{ 3935 int size = 0; 3936 struct spelling *p; 3937 3938 for (p = spelling_base; p < spelling; p++) 3939 { 3940 if (p->kind == SPELLING_BOUNDS) 3941 size += 25; 3942 else 3943 size += strlen (p->u.s) + 1; 3944 } 3945 3946 return size; 3947} 3948 3949/* Print the spelling to BUFFER and return it. */ 3950 3951static char * 3952print_spelling (char *buffer) 3953{ 3954 char *d = buffer; 3955 struct spelling *p; 3956 3957 for (p = spelling_base; p < spelling; p++) 3958 if (p->kind == SPELLING_BOUNDS) 3959 { 3960 sprintf (d, "[%d]", p->u.i); 3961 d += strlen (d); 3962 } 3963 else 3964 { 3965 const char *s; 3966 if (p->kind == SPELLING_MEMBER) 3967 *d++ = '.'; 3968 for (s = p->u.s; (*d = *s++); d++) 3969 ; 3970 } 3971 *d++ = '\0'; 3972 return buffer; 3973} 3974 3975/* Issue an error message for a bad initializer component. 3976 MSGID identifies the message. 3977 The component name is taken from the spelling stack. */ 3978 3979void 3980error_init (const char *msgid) 3981{ 3982 char *ofwhat; 3983 3984 error ("%s", _(msgid)); 3985 ofwhat = print_spelling (alloca (spelling_length () + 1)); 3986 if (*ofwhat) 3987 error ("(near initialization for `%s')", ofwhat); 3988} 3989 3990/* Issue a pedantic warning for a bad initializer component. 3991 MSGID identifies the message. 3992 The component name is taken from the spelling stack. */ 3993 3994void 3995pedwarn_init (const char *msgid) 3996{ 3997 char *ofwhat; 3998 3999 pedwarn ("%s", _(msgid)); 4000 ofwhat = print_spelling (alloca (spelling_length () + 1)); 4001 if (*ofwhat) 4002 pedwarn ("(near initialization for `%s')", ofwhat); 4003} 4004 4005/* Issue a warning for a bad initializer component. 4006 MSGID identifies the message. 4007 The component name is taken from the spelling stack. */ 4008 4009static void 4010warning_init (const char *msgid) 4011{ 4012 char *ofwhat; 4013 4014 warning ("%s", _(msgid)); 4015 ofwhat = print_spelling (alloca (spelling_length () + 1)); 4016 if (*ofwhat) 4017 warning ("(near initialization for `%s')", ofwhat); 4018} 4019 4020/* Digest the parser output INIT as an initializer for type TYPE. 4021 Return a C expression of type TYPE to represent the initial value. 4022 4023 REQUIRE_CONSTANT requests an error if non-constant initializers or 4024 elements are seen. */ 4025 4026static tree 4027digest_init (tree type, tree init, int require_constant) 4028{ 4029 enum tree_code code = TREE_CODE (type); 4030 tree inside_init = init; 4031 4032 if (type == error_mark_node 4033 || init == error_mark_node 4034 || TREE_TYPE (init) == error_mark_node) 4035 return error_mark_node; 4036 4037 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 4038 /* Do not use STRIP_NOPS here. We do not want an enumerator 4039 whose value is 0 to count as a null pointer constant. */ 4040 if (TREE_CODE (init) == NON_LVALUE_EXPR) 4041 inside_init = TREE_OPERAND (init, 0); 4042 4043 inside_init = fold (inside_init); 4044 4045 /* Initialization of an array of chars from a string constant 4046 optionally enclosed in braces. */ 4047 4048 if (code == ARRAY_TYPE) 4049 { 4050 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); 4051 if ((typ1 == char_type_node 4052 || typ1 == signed_char_type_node 4053 || typ1 == unsigned_char_type_node 4054 || typ1 == unsigned_wchar_type_node 4055 || typ1 == signed_wchar_type_node) 4056 && ((inside_init && TREE_CODE (inside_init) == STRING_CST))) 4057 { 4058 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4059 TYPE_MAIN_VARIANT (type), COMPARE_STRICT)) 4060 return inside_init; 4061 4062 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4063 != char_type_node) 4064 && TYPE_PRECISION (typ1) == TYPE_PRECISION (char_type_node)) 4065 { 4066 error_init ("char-array initialized from wide string"); 4067 return error_mark_node; 4068 } 4069 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) 4070 == char_type_node) 4071 && TYPE_PRECISION (typ1) != TYPE_PRECISION (char_type_node)) 4072 { 4073 error_init ("int-array initialized from non-wide string"); 4074 return error_mark_node; 4075 } 4076 4077 TREE_TYPE (inside_init) = type; 4078 if (TYPE_DOMAIN (type) != 0 4079 && TYPE_SIZE (type) != 0 4080 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST 4081 /* Subtract 1 (or sizeof (wchar_t)) 4082 because it's ok to ignore the terminating null char 4083 that is counted in the length of the constant. */ 4084 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), 4085 TREE_STRING_LENGTH (inside_init) 4086 - ((TYPE_PRECISION (typ1) 4087 != TYPE_PRECISION (char_type_node)) 4088 ? (TYPE_PRECISION (wchar_type_node) 4089 / BITS_PER_UNIT) 4090 : 1))) 4091 pedwarn_init ("initializer-string for array of chars is too long"); 4092 4093 return inside_init; 4094 } 4095 } 4096 4097 /* Build a VECTOR_CST from a *constant* vector constructor. If the 4098 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt 4099 below and handle as a constructor. */ 4100 if (code == VECTOR_TYPE 4101 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT) 4102 && TREE_CONSTANT (inside_init)) 4103 { 4104 if (TREE_CODE (inside_init) == VECTOR_CST 4105 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4106 TYPE_MAIN_VARIANT (type), 4107 COMPARE_STRICT)) 4108 return inside_init; 4109 4110 if (TREE_CODE (inside_init) == CONSTRUCTOR) 4111 { 4112 tree link; 4113 4114 /* Iterate through elements and check if all constructor 4115 elements are *_CSTs. */ 4116 for (link = CONSTRUCTOR_ELTS (inside_init); 4117 link; 4118 link = TREE_CHAIN (link)) 4119 if (TREE_CODE_CLASS (TREE_CODE (TREE_VALUE (link))) != 'c') 4120 break; 4121 4122 if (link == NULL) 4123 return build_vector (type, CONSTRUCTOR_ELTS (inside_init)); 4124 } 4125 } 4126 4127 /* Any type can be initialized 4128 from an expression of the same type, optionally with braces. */ 4129 4130 if (inside_init && TREE_TYPE (inside_init) != 0 4131 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4132 TYPE_MAIN_VARIANT (type), COMPARE_STRICT) 4133 || (code == ARRAY_TYPE 4134 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4135 || (code == VECTOR_TYPE 4136 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4137 || (code == POINTER_TYPE 4138 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4139 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4140 TREE_TYPE (type), COMPARE_STRICT)) 4141 || (code == POINTER_TYPE 4142 && TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE 4143 && comptypes (TREE_TYPE (inside_init), 4144 TREE_TYPE (type), COMPARE_STRICT)))) 4145 { 4146 if (code == POINTER_TYPE) 4147 { 4148 inside_init = default_function_array_conversion (inside_init); 4149 4150 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4151 { 4152 error_init ("invalid use of non-lvalue array"); 4153 return error_mark_node; 4154 } 4155 } 4156 4157 if (code == VECTOR_TYPE) 4158 /* Although the types are compatible, we may require a 4159 conversion. */ 4160 inside_init = convert (type, inside_init); 4161 4162 if (require_constant && !flag_isoc99 4163 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4164 { 4165 /* As an extension, allow initializing objects with static storage 4166 duration with compound literals (which are then treated just as 4167 the brace enclosed list they contain). */ 4168 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4169 inside_init = DECL_INITIAL (decl); 4170 } 4171 4172 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4173 && TREE_CODE (inside_init) != CONSTRUCTOR) 4174 { 4175 error_init ("array initialized from non-constant array expression"); 4176 return error_mark_node; 4177 } 4178 4179 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4180 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4181 4182 /* Compound expressions can only occur here if -pedantic or 4183 -pedantic-errors is specified. In the later case, we always want 4184 an error. In the former case, we simply want a warning. */ 4185 if (require_constant && pedantic 4186 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4187 { 4188 inside_init 4189 = valid_compound_expr_initializer (inside_init, 4190 TREE_TYPE (inside_init)); 4191 if (inside_init == error_mark_node) 4192 error_init ("initializer element is not constant"); 4193 else 4194 pedwarn_init ("initializer element is not constant"); 4195 if (flag_pedantic_errors) 4196 inside_init = error_mark_node; 4197 } 4198 else if (require_constant 4199 && (!TREE_CONSTANT (inside_init) 4200 /* This test catches things like `7 / 0' which 4201 result in an expression for which TREE_CONSTANT 4202 is true, but which is not actually something 4203 that is a legal constant. We really should not 4204 be using this function, because it is a part of 4205 the back-end. Instead, the expression should 4206 already have been turned into ERROR_MARK_NODE. */ 4207 || !initializer_constant_valid_p (inside_init, 4208 TREE_TYPE (inside_init)))) 4209 { 4210 error_init ("initializer element is not constant"); 4211 inside_init = error_mark_node; 4212 } 4213 4214 return inside_init; 4215 } 4216 4217 /* Handle scalar types, including conversions. */ 4218 4219 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4220 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE) 4221 { 4222 /* Note that convert_for_assignment calls default_conversion 4223 for arrays and functions. We must not call it in the 4224 case where inside_init is a null pointer constant. */ 4225 inside_init 4226 = convert_for_assignment (type, init, _("initialization"), 4227 NULL_TREE, NULL_TREE, 0); 4228 4229 if (require_constant && ! TREE_CONSTANT (inside_init)) 4230 { 4231 error_init ("initializer element is not constant"); 4232 inside_init = error_mark_node; 4233 } 4234 else if (require_constant 4235 && initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init)) == 0) 4236 { 4237 error_init ("initializer element is not computable at load time"); 4238 inside_init = error_mark_node; 4239 } 4240 4241 return inside_init; 4242 } 4243 4244 /* Come here only for records and arrays. */ 4245 4246 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4247 { 4248 error_init ("variable-sized object may not be initialized"); 4249 return error_mark_node; 4250 } 4251 4252 error_init ("invalid initializer"); 4253 return error_mark_node; 4254} 4255 4256/* Handle initializers that use braces. */ 4257 4258/* Type of object we are accumulating a constructor for. 4259 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4260static tree constructor_type; 4261 4262/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4263 left to fill. */ 4264static tree constructor_fields; 4265 4266/* For an ARRAY_TYPE, this is the specified index 4267 at which to store the next element we get. */ 4268static tree constructor_index; 4269 4270/* For an ARRAY_TYPE, this is the maximum index. */ 4271static tree constructor_max_index; 4272 4273/* For a RECORD_TYPE, this is the first field not yet written out. */ 4274static tree constructor_unfilled_fields; 4275 4276/* For an ARRAY_TYPE, this is the index of the first element 4277 not yet written out. */ 4278static tree constructor_unfilled_index; 4279 4280/* In a RECORD_TYPE, the byte index of the next consecutive field. 4281 This is so we can generate gaps between fields, when appropriate. */ 4282static tree constructor_bit_index; 4283 4284/* If we are saving up the elements rather than allocating them, 4285 this is the list of elements so far (in reverse order, 4286 most recent first). */ 4287static tree constructor_elements; 4288 4289/* 1 if constructor should be incrementally stored into a constructor chain, 4290 0 if all the elements should be kept in AVL tree. */ 4291static int constructor_incremental; 4292 4293/* 1 if so far this constructor's elements are all compile-time constants. */ 4294static int constructor_constant; 4295 4296/* 1 if so far this constructor's elements are all valid address constants. */ 4297static int constructor_simple; 4298 4299/* 1 if this constructor is erroneous so far. */ 4300static int constructor_erroneous; 4301 4302/* Structure for managing pending initializer elements, organized as an 4303 AVL tree. */ 4304 4305struct init_node 4306{ 4307 struct init_node *left, *right; 4308 struct init_node *parent; 4309 int balance; 4310 tree purpose; 4311 tree value; 4312}; 4313 4314/* Tree of pending elements at this constructor level. 4315 These are elements encountered out of order 4316 which belong at places we haven't reached yet in actually 4317 writing the output. 4318 Will never hold tree nodes across GC runs. */ 4319static struct init_node *constructor_pending_elts; 4320 4321/* The SPELLING_DEPTH of this constructor. */ 4322static int constructor_depth; 4323 4324/* 0 if implicitly pushing constructor levels is allowed. */ 4325int constructor_no_implicit = 0; /* 0 for C; 1 for some other languages. */ 4326 4327/* DECL node for which an initializer is being read. 4328 0 means we are reading a constructor expression 4329 such as (struct foo) {...}. */ 4330static tree constructor_decl; 4331 4332/* start_init saves the ASMSPEC arg here for really_start_incremental_init. */ 4333static const char *constructor_asmspec; 4334 4335/* Nonzero if this is an initializer for a top-level decl. */ 4336static int constructor_top_level; 4337 4338/* Nonzero if there were any member designators in this initializer. */ 4339static int constructor_designated; 4340 4341/* Nesting depth of designator list. */ 4342static int designator_depth; 4343 4344/* Nonzero if there were diagnosed errors in this designator list. */ 4345static int designator_errorneous; 4346 4347 4348/* This stack has a level for each implicit or explicit level of 4349 structuring in the initializer, including the outermost one. It 4350 saves the values of most of the variables above. */ 4351 4352struct constructor_range_stack; 4353 4354struct constructor_stack 4355{ 4356 struct constructor_stack *next; 4357 tree type; 4358 tree fields; 4359 tree index; 4360 tree max_index; 4361 tree unfilled_index; 4362 tree unfilled_fields; 4363 tree bit_index; 4364 tree elements; 4365 struct init_node *pending_elts; 4366 int offset; 4367 int depth; 4368 /* If nonzero, this value should replace the entire 4369 constructor at this level. */ 4370 tree replacement_value; 4371 struct constructor_range_stack *range_stack; 4372 char constant; 4373 char simple; 4374 char implicit; 4375 char erroneous; 4376 char outer; 4377 char incremental; 4378 char designated; 4379}; 4380 4381struct constructor_stack *constructor_stack; 4382 4383/* This stack represents designators from some range designator up to 4384 the last designator in the list. */ 4385 4386struct constructor_range_stack 4387{ 4388 struct constructor_range_stack *next, *prev; 4389 struct constructor_stack *stack; 4390 tree range_start; 4391 tree index; 4392 tree range_end; 4393 tree fields; 4394}; 4395 4396struct constructor_range_stack *constructor_range_stack; 4397 4398/* This stack records separate initializers that are nested. 4399 Nested initializers can't happen in ANSI C, but GNU C allows them 4400 in cases like { ... (struct foo) { ... } ... }. */ 4401 4402struct initializer_stack 4403{ 4404 struct initializer_stack *next; 4405 tree decl; 4406 const char *asmspec; 4407 struct constructor_stack *constructor_stack; 4408 struct constructor_range_stack *constructor_range_stack; 4409 tree elements; 4410 struct spelling *spelling; 4411 struct spelling *spelling_base; 4412 int spelling_size; 4413 char top_level; 4414 char require_constant_value; 4415 char require_constant_elements; 4416}; 4417 4418struct initializer_stack *initializer_stack; 4419 4420/* Prepare to parse and output the initializer for variable DECL. */ 4421 4422void 4423start_init (tree decl, tree asmspec_tree, int top_level) 4424{ 4425 const char *locus; 4426 struct initializer_stack *p = xmalloc (sizeof (struct initializer_stack)); 4427 const char *asmspec = 0; 4428 4429 if (asmspec_tree) 4430 asmspec = TREE_STRING_POINTER (asmspec_tree); 4431 4432 p->decl = constructor_decl; 4433 p->asmspec = constructor_asmspec; 4434 p->require_constant_value = require_constant_value; 4435 p->require_constant_elements = require_constant_elements; 4436 p->constructor_stack = constructor_stack; 4437 p->constructor_range_stack = constructor_range_stack; 4438 p->elements = constructor_elements; 4439 p->spelling = spelling; 4440 p->spelling_base = spelling_base; 4441 p->spelling_size = spelling_size; 4442 p->top_level = constructor_top_level; 4443 p->next = initializer_stack; 4444 initializer_stack = p; 4445 4446 constructor_decl = decl; 4447 constructor_asmspec = asmspec; 4448 constructor_designated = 0; 4449 constructor_top_level = top_level; 4450 4451 if (decl != 0) 4452 { 4453 require_constant_value = TREE_STATIC (decl); 4454 require_constant_elements 4455 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 4456 /* For a scalar, you can always use any value to initialize, 4457 even within braces. */ 4458 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 4459 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 4460 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 4461 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 4462 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 4463 } 4464 else 4465 { 4466 require_constant_value = 0; 4467 require_constant_elements = 0; 4468 locus = "(anonymous)"; 4469 } 4470 4471 constructor_stack = 0; 4472 constructor_range_stack = 0; 4473 4474 missing_braces_mentioned = 0; 4475 4476 spelling_base = 0; 4477 spelling_size = 0; 4478 RESTORE_SPELLING_DEPTH (0); 4479 4480 if (locus) 4481 push_string (locus); 4482} 4483 4484void 4485finish_init (void) 4486{ 4487 struct initializer_stack *p = initializer_stack; 4488 4489 /* Free the whole constructor stack of this initializer. */ 4490 while (constructor_stack) 4491 { 4492 struct constructor_stack *q = constructor_stack; 4493 constructor_stack = q->next; 4494 free (q); 4495 } 4496 4497 if (constructor_range_stack) 4498 abort (); 4499 4500 /* Pop back to the data of the outer initializer (if any). */ 4501 free (spelling_base); 4502 4503 constructor_decl = p->decl; 4504 constructor_asmspec = p->asmspec; 4505 require_constant_value = p->require_constant_value; 4506 require_constant_elements = p->require_constant_elements; 4507 constructor_stack = p->constructor_stack; 4508 constructor_range_stack = p->constructor_range_stack; 4509 constructor_elements = p->elements; 4510 spelling = p->spelling; 4511 spelling_base = p->spelling_base; 4512 spelling_size = p->spelling_size; 4513 constructor_top_level = p->top_level; 4514 initializer_stack = p->next; 4515 free (p); 4516} 4517 4518/* Call here when we see the initializer is surrounded by braces. 4519 This is instead of a call to push_init_level; 4520 it is matched by a call to pop_init_level. 4521 4522 TYPE is the type to initialize, for a constructor expression. 4523 For an initializer for a decl, TYPE is zero. */ 4524 4525void 4526really_start_incremental_init (tree type) 4527{ 4528 struct constructor_stack *p = xmalloc (sizeof (struct constructor_stack)); 4529 4530 if (type == 0) 4531 type = TREE_TYPE (constructor_decl); 4532 4533 if ((*targetm.vector_opaque_p) (type)) 4534 error ("opaque vector types cannot be initialized"); 4535 4536 p->type = constructor_type; 4537 p->fields = constructor_fields; 4538 p->index = constructor_index; 4539 p->max_index = constructor_max_index; 4540 p->unfilled_index = constructor_unfilled_index; 4541 p->unfilled_fields = constructor_unfilled_fields; 4542 p->bit_index = constructor_bit_index; 4543 p->elements = constructor_elements; 4544 p->constant = constructor_constant; 4545 p->simple = constructor_simple; 4546 p->erroneous = constructor_erroneous; 4547 p->pending_elts = constructor_pending_elts; 4548 p->depth = constructor_depth; 4549 p->replacement_value = 0; 4550 p->implicit = 0; 4551 p->range_stack = 0; 4552 p->outer = 0; 4553 p->incremental = constructor_incremental; 4554 p->designated = constructor_designated; 4555 p->next = 0; 4556 constructor_stack = p; 4557 4558 constructor_constant = 1; 4559 constructor_simple = 1; 4560 constructor_depth = SPELLING_DEPTH (); 4561 constructor_elements = 0; 4562 constructor_pending_elts = 0; 4563 constructor_type = type; 4564 constructor_incremental = 1; 4565 constructor_designated = 0; 4566 designator_depth = 0; 4567 designator_errorneous = 0; 4568 4569 if (TREE_CODE (constructor_type) == RECORD_TYPE 4570 || TREE_CODE (constructor_type) == UNION_TYPE) 4571 { 4572 constructor_fields = TYPE_FIELDS (constructor_type); 4573 /* Skip any nameless bit fields at the beginning. */ 4574 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4575 && DECL_NAME (constructor_fields) == 0) 4576 constructor_fields = TREE_CHAIN (constructor_fields); 4577 4578 constructor_unfilled_fields = constructor_fields; 4579 constructor_bit_index = bitsize_zero_node; 4580 } 4581 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4582 { 4583 if (TYPE_DOMAIN (constructor_type)) 4584 { 4585 constructor_max_index 4586 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4587 4588 /* Detect non-empty initializations of zero-length arrays. */ 4589 if (constructor_max_index == NULL_TREE 4590 && TYPE_SIZE (constructor_type)) 4591 constructor_max_index = build_int_2 (-1, -1); 4592 4593 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4594 to initialize VLAs will cause a proper error; avoid tree 4595 checking errors as well by setting a safe value. */ 4596 if (constructor_max_index 4597 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4598 constructor_max_index = build_int_2 (-1, -1); 4599 4600 constructor_index 4601 = convert (bitsizetype, 4602 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4603 } 4604 else 4605 constructor_index = bitsize_zero_node; 4606 4607 constructor_unfilled_index = constructor_index; 4608 } 4609 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4610 { 4611 /* Vectors are like simple fixed-size arrays. */ 4612 constructor_max_index = 4613 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4614 constructor_index = convert (bitsizetype, bitsize_zero_node); 4615 constructor_unfilled_index = constructor_index; 4616 } 4617 else 4618 { 4619 /* Handle the case of int x = {5}; */ 4620 constructor_fields = constructor_type; 4621 constructor_unfilled_fields = constructor_type; 4622 } 4623} 4624 4625/* Push down into a subobject, for initialization. 4626 If this is for an explicit set of braces, IMPLICIT is 0. 4627 If it is because the next element belongs at a lower level, 4628 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 4629 4630void 4631push_init_level (int implicit) 4632{ 4633 struct constructor_stack *p; 4634 tree value = NULL_TREE; 4635 4636 /* If we've exhausted any levels that didn't have braces, 4637 pop them now. */ 4638 while (constructor_stack->implicit) 4639 { 4640 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4641 || TREE_CODE (constructor_type) == UNION_TYPE) 4642 && constructor_fields == 0) 4643 process_init_element (pop_init_level (1)); 4644 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 4645 && constructor_max_index 4646 && tree_int_cst_lt (constructor_max_index, constructor_index)) 4647 process_init_element (pop_init_level (1)); 4648 else 4649 break; 4650 } 4651 4652 /* Unless this is an explicit brace, we need to preserve previous 4653 content if any. */ 4654 if (implicit) 4655 { 4656 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4657 || TREE_CODE (constructor_type) == UNION_TYPE) 4658 && constructor_fields) 4659 value = find_init_member (constructor_fields); 4660 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4661 value = find_init_member (constructor_index); 4662 } 4663 4664 p = xmalloc (sizeof (struct constructor_stack)); 4665 p->type = constructor_type; 4666 p->fields = constructor_fields; 4667 p->index = constructor_index; 4668 p->max_index = constructor_max_index; 4669 p->unfilled_index = constructor_unfilled_index; 4670 p->unfilled_fields = constructor_unfilled_fields; 4671 p->bit_index = constructor_bit_index; 4672 p->elements = constructor_elements; 4673 p->constant = constructor_constant; 4674 p->simple = constructor_simple; 4675 p->erroneous = constructor_erroneous; 4676 p->pending_elts = constructor_pending_elts; 4677 p->depth = constructor_depth; 4678 p->replacement_value = 0; 4679 p->implicit = implicit; 4680 p->outer = 0; 4681 p->incremental = constructor_incremental; 4682 p->designated = constructor_designated; 4683 p->next = constructor_stack; 4684 p->range_stack = 0; 4685 constructor_stack = p; 4686 4687 constructor_constant = 1; 4688 constructor_simple = 1; 4689 constructor_depth = SPELLING_DEPTH (); 4690 constructor_elements = 0; 4691 constructor_incremental = 1; 4692 constructor_designated = 0; 4693 constructor_pending_elts = 0; 4694 if (!implicit) 4695 { 4696 p->range_stack = constructor_range_stack; 4697 constructor_range_stack = 0; 4698 designator_depth = 0; 4699 designator_errorneous = 0; 4700 } 4701 4702 /* Don't die if an entire brace-pair level is superfluous 4703 in the containing level. */ 4704 if (constructor_type == 0) 4705 ; 4706 else if (TREE_CODE (constructor_type) == RECORD_TYPE 4707 || TREE_CODE (constructor_type) == UNION_TYPE) 4708 { 4709 /* Don't die if there are extra init elts at the end. */ 4710 if (constructor_fields == 0) 4711 constructor_type = 0; 4712 else 4713 { 4714 constructor_type = TREE_TYPE (constructor_fields); 4715 push_member_name (constructor_fields); 4716 constructor_depth++; 4717 } 4718 } 4719 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4720 { 4721 constructor_type = TREE_TYPE (constructor_type); 4722 push_array_bounds (tree_low_cst (constructor_index, 0)); 4723 constructor_depth++; 4724 } 4725 4726 if (constructor_type == 0) 4727 { 4728 error_init ("extra brace group at end of initializer"); 4729 constructor_fields = 0; 4730 constructor_unfilled_fields = 0; 4731 return; 4732 } 4733 4734 if (value && TREE_CODE (value) == CONSTRUCTOR) 4735 { 4736 constructor_constant = TREE_CONSTANT (value); 4737 constructor_simple = TREE_STATIC (value); 4738 constructor_elements = CONSTRUCTOR_ELTS (value); 4739 if (constructor_elements 4740 && (TREE_CODE (constructor_type) == RECORD_TYPE 4741 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 4742 set_nonincremental_init (); 4743 } 4744 4745 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 4746 { 4747 missing_braces_mentioned = 1; 4748 warning_init ("missing braces around initializer"); 4749 } 4750 4751 if (TREE_CODE (constructor_type) == RECORD_TYPE 4752 || TREE_CODE (constructor_type) == UNION_TYPE) 4753 { 4754 constructor_fields = TYPE_FIELDS (constructor_type); 4755 /* Skip any nameless bit fields at the beginning. */ 4756 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4757 && DECL_NAME (constructor_fields) == 0) 4758 constructor_fields = TREE_CHAIN (constructor_fields); 4759 4760 constructor_unfilled_fields = constructor_fields; 4761 constructor_bit_index = bitsize_zero_node; 4762 } 4763 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4764 { 4765 /* Vectors are like simple fixed-size arrays. */ 4766 constructor_max_index = 4767 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4768 constructor_index = convert (bitsizetype, integer_zero_node); 4769 constructor_unfilled_index = constructor_index; 4770 } 4771 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4772 { 4773 if (TYPE_DOMAIN (constructor_type)) 4774 { 4775 constructor_max_index 4776 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4777 4778 /* Detect non-empty initializations of zero-length arrays. */ 4779 if (constructor_max_index == NULL_TREE 4780 && TYPE_SIZE (constructor_type)) 4781 constructor_max_index = build_int_2 (-1, -1); 4782 4783 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4784 to initialize VLAs will cause a proper error; avoid tree 4785 checking errors as well by setting a safe value. */ 4786 if (constructor_max_index 4787 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4788 constructor_max_index = build_int_2 (-1, -1); 4789 4790 constructor_index 4791 = convert (bitsizetype, 4792 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4793 } 4794 else 4795 constructor_index = bitsize_zero_node; 4796 4797 constructor_unfilled_index = constructor_index; 4798 if (value && TREE_CODE (value) == STRING_CST) 4799 { 4800 /* We need to split the char/wchar array into individual 4801 characters, so that we don't have to special case it 4802 everywhere. */ 4803 set_nonincremental_init_from_string (value); 4804 } 4805 } 4806 else 4807 { 4808 warning_init ("braces around scalar initializer"); 4809 constructor_fields = constructor_type; 4810 constructor_unfilled_fields = constructor_type; 4811 } 4812} 4813 4814/* At the end of an implicit or explicit brace level, 4815 finish up that level of constructor. 4816 If we were outputting the elements as they are read, return 0 4817 from inner levels (process_init_element ignores that), 4818 but return error_mark_node from the outermost level 4819 (that's what we want to put in DECL_INITIAL). 4820 Otherwise, return a CONSTRUCTOR expression. */ 4821 4822tree 4823pop_init_level (int implicit) 4824{ 4825 struct constructor_stack *p; 4826 tree constructor = 0; 4827 4828 if (implicit == 0) 4829 { 4830 /* When we come to an explicit close brace, 4831 pop any inner levels that didn't have explicit braces. */ 4832 while (constructor_stack->implicit) 4833 process_init_element (pop_init_level (1)); 4834 4835 if (constructor_range_stack) 4836 abort (); 4837 } 4838 4839 /* Now output all pending elements. */ 4840 constructor_incremental = 1; 4841 output_pending_init_elements (1); 4842 4843 p = constructor_stack; 4844 4845 /* Error for initializing a flexible array member, or a zero-length 4846 array member in an inappropriate context. */ 4847 if (constructor_type && constructor_fields 4848 && TREE_CODE (constructor_type) == ARRAY_TYPE 4849 && TYPE_DOMAIN (constructor_type) 4850 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 4851 { 4852 /* Silently discard empty initializations. The parser will 4853 already have pedwarned for empty brackets. */ 4854 if (integer_zerop (constructor_unfilled_index)) 4855 constructor_type = NULL_TREE; 4856 else if (! TYPE_SIZE (constructor_type)) 4857 { 4858 if (constructor_depth > 2) 4859 error_init ("initialization of flexible array member in a nested context"); 4860 else if (pedantic) 4861 pedwarn_init ("initialization of a flexible array member"); 4862 4863 /* We have already issued an error message for the existence 4864 of a flexible array member not at the end of the structure. 4865 Discard the initializer so that we do not abort later. */ 4866 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 4867 constructor_type = NULL_TREE; 4868 } 4869 else 4870 /* Zero-length arrays are no longer special, so we should no longer 4871 get here. */ 4872 abort (); 4873 } 4874 4875 /* Warn when some struct elements are implicitly initialized to zero. */ 4876 if (extra_warnings 4877 && constructor_type 4878 && TREE_CODE (constructor_type) == RECORD_TYPE 4879 && constructor_unfilled_fields) 4880 { 4881 /* Do not warn for flexible array members or zero-length arrays. */ 4882 while (constructor_unfilled_fields 4883 && (! DECL_SIZE (constructor_unfilled_fields) 4884 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 4885 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 4886 4887 /* Do not warn if this level of the initializer uses member 4888 designators; it is likely to be deliberate. */ 4889 if (constructor_unfilled_fields && !constructor_designated) 4890 { 4891 push_member_name (constructor_unfilled_fields); 4892 warning_init ("missing initializer"); 4893 RESTORE_SPELLING_DEPTH (constructor_depth); 4894 } 4895 } 4896 4897 /* Pad out the end of the structure. */ 4898 if (p->replacement_value) 4899 /* If this closes a superfluous brace pair, 4900 just pass out the element between them. */ 4901 constructor = p->replacement_value; 4902 else if (constructor_type == 0) 4903 ; 4904 else if (TREE_CODE (constructor_type) != RECORD_TYPE 4905 && TREE_CODE (constructor_type) != UNION_TYPE 4906 && TREE_CODE (constructor_type) != ARRAY_TYPE 4907 && TREE_CODE (constructor_type) != VECTOR_TYPE) 4908 { 4909 /* A nonincremental scalar initializer--just return 4910 the element, after verifying there is just one. */ 4911 if (constructor_elements == 0) 4912 { 4913 if (!constructor_erroneous) 4914 error_init ("empty scalar initializer"); 4915 constructor = error_mark_node; 4916 } 4917 else if (TREE_CHAIN (constructor_elements) != 0) 4918 { 4919 error_init ("extra elements in scalar initializer"); 4920 constructor = TREE_VALUE (constructor_elements); 4921 } 4922 else 4923 constructor = TREE_VALUE (constructor_elements); 4924 } 4925 else 4926 { 4927 if (constructor_erroneous) 4928 constructor = error_mark_node; 4929 else 4930 { 4931 constructor = build_constructor (constructor_type, 4932 nreverse (constructor_elements)); 4933 if (constructor_constant) 4934 TREE_CONSTANT (constructor) = 1; 4935 if (constructor_constant && constructor_simple) 4936 TREE_STATIC (constructor) = 1; 4937 } 4938 } 4939 4940 constructor_type = p->type; 4941 constructor_fields = p->fields; 4942 constructor_index = p->index; 4943 constructor_max_index = p->max_index; 4944 constructor_unfilled_index = p->unfilled_index; 4945 constructor_unfilled_fields = p->unfilled_fields; 4946 constructor_bit_index = p->bit_index; 4947 constructor_elements = p->elements; 4948 constructor_constant = p->constant; 4949 constructor_simple = p->simple; 4950 constructor_erroneous = p->erroneous; 4951 constructor_incremental = p->incremental; 4952 constructor_designated = p->designated; 4953 constructor_pending_elts = p->pending_elts; 4954 constructor_depth = p->depth; 4955 if (!p->implicit) 4956 constructor_range_stack = p->range_stack; 4957 RESTORE_SPELLING_DEPTH (constructor_depth); 4958 4959 constructor_stack = p->next; 4960 free (p); 4961 4962 if (constructor == 0) 4963 { 4964 if (constructor_stack == 0) 4965 return error_mark_node; 4966 return NULL_TREE; 4967 } 4968 return constructor; 4969} 4970 4971/* Common handling for both array range and field name designators. 4972 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 4973 4974static int 4975set_designator (int array) 4976{ 4977 tree subtype; 4978 enum tree_code subcode; 4979 4980 /* Don't die if an entire brace-pair level is superfluous 4981 in the containing level. */ 4982 if (constructor_type == 0) 4983 return 1; 4984 4985 /* If there were errors in this designator list already, bail out silently. */ 4986 if (designator_errorneous) 4987 return 1; 4988 4989 if (!designator_depth) 4990 { 4991 if (constructor_range_stack) 4992 abort (); 4993 4994 /* Designator list starts at the level of closest explicit 4995 braces. */ 4996 while (constructor_stack->implicit) 4997 process_init_element (pop_init_level (1)); 4998 constructor_designated = 1; 4999 return 0; 5000 } 5001 5002 if (constructor_no_implicit) 5003 { 5004 error_init ("initialization designators may not nest"); 5005 return 1; 5006 } 5007 5008 if (TREE_CODE (constructor_type) == RECORD_TYPE 5009 || TREE_CODE (constructor_type) == UNION_TYPE) 5010 { 5011 subtype = TREE_TYPE (constructor_fields); 5012 if (subtype != error_mark_node) 5013 subtype = TYPE_MAIN_VARIANT (subtype); 5014 } 5015 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5016 { 5017 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5018 } 5019 else 5020 abort (); 5021 5022 subcode = TREE_CODE (subtype); 5023 if (array && subcode != ARRAY_TYPE) 5024 { 5025 error_init ("array index in non-array initializer"); 5026 return 1; 5027 } 5028 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5029 { 5030 error_init ("field name not in record or union initializer"); 5031 return 1; 5032 } 5033 5034 constructor_designated = 1; 5035 push_init_level (2); 5036 return 0; 5037} 5038 5039/* If there are range designators in designator list, push a new designator 5040 to constructor_range_stack. RANGE_END is end of such stack range or 5041 NULL_TREE if there is no range designator at this level. */ 5042 5043static void 5044push_range_stack (tree range_end) 5045{ 5046 struct constructor_range_stack *p; 5047 5048 p = ggc_alloc (sizeof (struct constructor_range_stack)); 5049 p->prev = constructor_range_stack; 5050 p->next = 0; 5051 p->fields = constructor_fields; 5052 p->range_start = constructor_index; 5053 p->index = constructor_index; 5054 p->stack = constructor_stack; 5055 p->range_end = range_end; 5056 if (constructor_range_stack) 5057 constructor_range_stack->next = p; 5058 constructor_range_stack = p; 5059} 5060 5061/* Within an array initializer, specify the next index to be initialized. 5062 FIRST is that index. If LAST is nonzero, then initialize a range 5063 of indices, running from FIRST through LAST. */ 5064 5065void 5066set_init_index (tree first, tree last) 5067{ 5068 if (set_designator (1)) 5069 return; 5070 5071 designator_errorneous = 1; 5072 5073 while ((TREE_CODE (first) == NOP_EXPR 5074 || TREE_CODE (first) == CONVERT_EXPR 5075 || TREE_CODE (first) == NON_LVALUE_EXPR) 5076 && (TYPE_MODE (TREE_TYPE (first)) 5077 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (first, 0))))) 5078 first = TREE_OPERAND (first, 0); 5079 5080 if (last) 5081 while ((TREE_CODE (last) == NOP_EXPR 5082 || TREE_CODE (last) == CONVERT_EXPR 5083 || TREE_CODE (last) == NON_LVALUE_EXPR) 5084 && (TYPE_MODE (TREE_TYPE (last)) 5085 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (last, 0))))) 5086 last = TREE_OPERAND (last, 0); 5087 5088 if (TREE_CODE (first) != INTEGER_CST) 5089 error_init ("nonconstant array index in initializer"); 5090 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5091 error_init ("nonconstant array index in initializer"); 5092 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5093 error_init ("array index in non-array initializer"); 5094 else if (tree_int_cst_sgn (first) == -1) 5095 error_init ("array index in initializer exceeds array bounds"); 5096 else if (constructor_max_index 5097 && tree_int_cst_lt (constructor_max_index, first)) 5098 error_init ("array index in initializer exceeds array bounds"); 5099 else 5100 { 5101 constructor_index = convert (bitsizetype, first); 5102 5103 if (last) 5104 { 5105 if (tree_int_cst_equal (first, last)) 5106 last = 0; 5107 else if (tree_int_cst_lt (last, first)) 5108 { 5109 error_init ("empty index range in initializer"); 5110 last = 0; 5111 } 5112 else 5113 { 5114 last = convert (bitsizetype, last); 5115 if (constructor_max_index != 0 5116 && tree_int_cst_lt (constructor_max_index, last)) 5117 { 5118 error_init ("array index range in initializer exceeds array bounds"); 5119 last = 0; 5120 } 5121 } 5122 } 5123 5124 designator_depth++; 5125 designator_errorneous = 0; 5126 if (constructor_range_stack || last) 5127 push_range_stack (last); 5128 } 5129} 5130 5131/* Within a struct initializer, specify the next field to be initialized. */ 5132 5133void 5134set_init_label (tree fieldname) 5135{ 5136 tree tail; 5137 5138 if (set_designator (0)) 5139 return; 5140 5141 designator_errorneous = 1; 5142 5143 if (TREE_CODE (constructor_type) != RECORD_TYPE 5144 && TREE_CODE (constructor_type) != UNION_TYPE) 5145 { 5146 error_init ("field name not in record or union initializer"); 5147 return; 5148 } 5149 5150 for (tail = TYPE_FIELDS (constructor_type); tail; 5151 tail = TREE_CHAIN (tail)) 5152 { 5153 if (DECL_NAME (tail) == fieldname) 5154 break; 5155 } 5156 5157 if (tail == 0) 5158 error ("unknown field `%s' specified in initializer", 5159 IDENTIFIER_POINTER (fieldname)); 5160 else 5161 { 5162 constructor_fields = tail; 5163 designator_depth++; 5164 designator_errorneous = 0; 5165 if (constructor_range_stack) 5166 push_range_stack (NULL_TREE); 5167 } 5168} 5169 5170/* Add a new initializer to the tree of pending initializers. PURPOSE 5171 identifies the initializer, either array index or field in a structure. 5172 VALUE is the value of that index or field. */ 5173 5174static void 5175add_pending_init (tree purpose, tree value) 5176{ 5177 struct init_node *p, **q, *r; 5178 5179 q = &constructor_pending_elts; 5180 p = 0; 5181 5182 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5183 { 5184 while (*q != 0) 5185 { 5186 p = *q; 5187 if (tree_int_cst_lt (purpose, p->purpose)) 5188 q = &p->left; 5189 else if (tree_int_cst_lt (p->purpose, purpose)) 5190 q = &p->right; 5191 else 5192 { 5193 if (TREE_SIDE_EFFECTS (p->value)) 5194 warning_init ("initialized field with side-effects overwritten"); 5195 p->value = value; 5196 return; 5197 } 5198 } 5199 } 5200 else 5201 { 5202 tree bitpos; 5203 5204 bitpos = bit_position (purpose); 5205 while (*q != NULL) 5206 { 5207 p = *q; 5208 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5209 q = &p->left; 5210 else if (p->purpose != purpose) 5211 q = &p->right; 5212 else 5213 { 5214 if (TREE_SIDE_EFFECTS (p->value)) 5215 warning_init ("initialized field with side-effects overwritten"); 5216 p->value = value; 5217 return; 5218 } 5219 } 5220 } 5221 5222 r = ggc_alloc (sizeof (struct init_node)); 5223 r->purpose = purpose; 5224 r->value = value; 5225 5226 *q = r; 5227 r->parent = p; 5228 r->left = 0; 5229 r->right = 0; 5230 r->balance = 0; 5231 5232 while (p) 5233 { 5234 struct init_node *s; 5235 5236 if (r == p->left) 5237 { 5238 if (p->balance == 0) 5239 p->balance = -1; 5240 else if (p->balance < 0) 5241 { 5242 if (r->balance < 0) 5243 { 5244 /* L rotation. */ 5245 p->left = r->right; 5246 if (p->left) 5247 p->left->parent = p; 5248 r->right = p; 5249 5250 p->balance = 0; 5251 r->balance = 0; 5252 5253 s = p->parent; 5254 p->parent = r; 5255 r->parent = s; 5256 if (s) 5257 { 5258 if (s->left == p) 5259 s->left = r; 5260 else 5261 s->right = r; 5262 } 5263 else 5264 constructor_pending_elts = r; 5265 } 5266 else 5267 { 5268 /* LR rotation. */ 5269 struct init_node *t = r->right; 5270 5271 r->right = t->left; 5272 if (r->right) 5273 r->right->parent = r; 5274 t->left = r; 5275 5276 p->left = t->right; 5277 if (p->left) 5278 p->left->parent = p; 5279 t->right = p; 5280 5281 p->balance = t->balance < 0; 5282 r->balance = -(t->balance > 0); 5283 t->balance = 0; 5284 5285 s = p->parent; 5286 p->parent = t; 5287 r->parent = t; 5288 t->parent = s; 5289 if (s) 5290 { 5291 if (s->left == p) 5292 s->left = t; 5293 else 5294 s->right = t; 5295 } 5296 else 5297 constructor_pending_elts = t; 5298 } 5299 break; 5300 } 5301 else 5302 { 5303 /* p->balance == +1; growth of left side balances the node. */ 5304 p->balance = 0; 5305 break; 5306 } 5307 } 5308 else /* r == p->right */ 5309 { 5310 if (p->balance == 0) 5311 /* Growth propagation from right side. */ 5312 p->balance++; 5313 else if (p->balance > 0) 5314 { 5315 if (r->balance > 0) 5316 { 5317 /* R rotation. */ 5318 p->right = r->left; 5319 if (p->right) 5320 p->right->parent = p; 5321 r->left = p; 5322 5323 p->balance = 0; 5324 r->balance = 0; 5325 5326 s = p->parent; 5327 p->parent = r; 5328 r->parent = s; 5329 if (s) 5330 { 5331 if (s->left == p) 5332 s->left = r; 5333 else 5334 s->right = r; 5335 } 5336 else 5337 constructor_pending_elts = r; 5338 } 5339 else /* r->balance == -1 */ 5340 { 5341 /* RL rotation */ 5342 struct init_node *t = r->left; 5343 5344 r->left = t->right; 5345 if (r->left) 5346 r->left->parent = r; 5347 t->right = r; 5348 5349 p->right = t->left; 5350 if (p->right) 5351 p->right->parent = p; 5352 t->left = p; 5353 5354 r->balance = (t->balance < 0); 5355 p->balance = -(t->balance > 0); 5356 t->balance = 0; 5357 5358 s = p->parent; 5359 p->parent = t; 5360 r->parent = t; 5361 t->parent = s; 5362 if (s) 5363 { 5364 if (s->left == p) 5365 s->left = t; 5366 else 5367 s->right = t; 5368 } 5369 else 5370 constructor_pending_elts = t; 5371 } 5372 break; 5373 } 5374 else 5375 { 5376 /* p->balance == -1; growth of right side balances the node. */ 5377 p->balance = 0; 5378 break; 5379 } 5380 } 5381 5382 r = p; 5383 p = p->parent; 5384 } 5385} 5386 5387/* Build AVL tree from a sorted chain. */ 5388 5389static void 5390set_nonincremental_init (void) 5391{ 5392 tree chain; 5393 5394 if (TREE_CODE (constructor_type) != RECORD_TYPE 5395 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5396 return; 5397 5398 for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain)) 5399 add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain)); 5400 constructor_elements = 0; 5401 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5402 { 5403 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5404 /* Skip any nameless bit fields at the beginning. */ 5405 while (constructor_unfilled_fields != 0 5406 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5407 && DECL_NAME (constructor_unfilled_fields) == 0) 5408 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5409 5410 } 5411 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5412 { 5413 if (TYPE_DOMAIN (constructor_type)) 5414 constructor_unfilled_index 5415 = convert (bitsizetype, 5416 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5417 else 5418 constructor_unfilled_index = bitsize_zero_node; 5419 } 5420 constructor_incremental = 0; 5421} 5422 5423/* Build AVL tree from a string constant. */ 5424 5425static void 5426set_nonincremental_init_from_string (tree str) 5427{ 5428 tree value, purpose, type; 5429 HOST_WIDE_INT val[2]; 5430 const char *p, *end; 5431 int byte, wchar_bytes, charwidth, bitpos; 5432 5433 if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5434 abort (); 5435 5436 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5437 == TYPE_PRECISION (char_type_node)) 5438 wchar_bytes = 1; 5439 else if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5440 == TYPE_PRECISION (wchar_type_node)) 5441 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 5442 else 5443 abort (); 5444 5445 charwidth = TYPE_PRECISION (char_type_node); 5446 type = TREE_TYPE (constructor_type); 5447 p = TREE_STRING_POINTER (str); 5448 end = p + TREE_STRING_LENGTH (str); 5449 5450 for (purpose = bitsize_zero_node; 5451 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 5452 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 5453 { 5454 if (wchar_bytes == 1) 5455 { 5456 val[1] = (unsigned char) *p++; 5457 val[0] = 0; 5458 } 5459 else 5460 { 5461 val[0] = 0; 5462 val[1] = 0; 5463 for (byte = 0; byte < wchar_bytes; byte++) 5464 { 5465 if (BYTES_BIG_ENDIAN) 5466 bitpos = (wchar_bytes - byte - 1) * charwidth; 5467 else 5468 bitpos = byte * charwidth; 5469 val[bitpos < HOST_BITS_PER_WIDE_INT] 5470 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 5471 << (bitpos % HOST_BITS_PER_WIDE_INT); 5472 } 5473 } 5474 5475 if (!TREE_UNSIGNED (type)) 5476 { 5477 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 5478 if (bitpos < HOST_BITS_PER_WIDE_INT) 5479 { 5480 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 5481 { 5482 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 5483 val[0] = -1; 5484 } 5485 } 5486 else if (bitpos == HOST_BITS_PER_WIDE_INT) 5487 { 5488 if (val[1] < 0) 5489 val[0] = -1; 5490 } 5491 else if (val[0] & (((HOST_WIDE_INT) 1) 5492 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 5493 val[0] |= ((HOST_WIDE_INT) -1) 5494 << (bitpos - HOST_BITS_PER_WIDE_INT); 5495 } 5496 5497 value = build_int_2 (val[1], val[0]); 5498 TREE_TYPE (value) = type; 5499 add_pending_init (purpose, value); 5500 } 5501 5502 constructor_incremental = 0; 5503} 5504 5505/* Return value of FIELD in pending initializer or zero if the field was 5506 not initialized yet. */ 5507 5508static tree 5509find_init_member (tree field) 5510{ 5511 struct init_node *p; 5512 5513 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5514 { 5515 if (constructor_incremental 5516 && tree_int_cst_lt (field, constructor_unfilled_index)) 5517 set_nonincremental_init (); 5518 5519 p = constructor_pending_elts; 5520 while (p) 5521 { 5522 if (tree_int_cst_lt (field, p->purpose)) 5523 p = p->left; 5524 else if (tree_int_cst_lt (p->purpose, field)) 5525 p = p->right; 5526 else 5527 return p->value; 5528 } 5529 } 5530 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5531 { 5532 tree bitpos = bit_position (field); 5533 5534 if (constructor_incremental 5535 && (!constructor_unfilled_fields 5536 || tree_int_cst_lt (bitpos, 5537 bit_position (constructor_unfilled_fields)))) 5538 set_nonincremental_init (); 5539 5540 p = constructor_pending_elts; 5541 while (p) 5542 { 5543 if (field == p->purpose) 5544 return p->value; 5545 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5546 p = p->left; 5547 else 5548 p = p->right; 5549 } 5550 } 5551 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5552 { 5553 if (constructor_elements 5554 && TREE_PURPOSE (constructor_elements) == field) 5555 return TREE_VALUE (constructor_elements); 5556 } 5557 return 0; 5558} 5559 5560/* "Output" the next constructor element. 5561 At top level, really output it to assembler code now. 5562 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 5563 TYPE is the data type that the containing data type wants here. 5564 FIELD is the field (a FIELD_DECL) or the index that this element fills. 5565 5566 PENDING if non-nil means output pending elements that belong 5567 right after this element. (PENDING is normally 1; 5568 it is 0 while outputting pending elements, to avoid recursion.) */ 5569 5570static void 5571output_init_element (tree value, tree type, tree field, int pending) 5572{ 5573 if (type == error_mark_node) 5574 { 5575 constructor_erroneous = 1; 5576 return; 5577 } 5578 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE 5579 || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 5580 && !(TREE_CODE (value) == STRING_CST 5581 && TREE_CODE (type) == ARRAY_TYPE 5582 && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE) 5583 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 5584 TYPE_MAIN_VARIANT (type), COMPARE_STRICT))) 5585 value = default_conversion (value); 5586 5587 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 5588 && require_constant_value && !flag_isoc99 && pending) 5589 { 5590 /* As an extension, allow initializing objects with static storage 5591 duration with compound literals (which are then treated just as 5592 the brace enclosed list they contain). */ 5593 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 5594 value = DECL_INITIAL (decl); 5595 } 5596 5597 if (value == error_mark_node) 5598 constructor_erroneous = 1; 5599 else if (!TREE_CONSTANT (value)) 5600 constructor_constant = 0; 5601 else if (initializer_constant_valid_p (value, TREE_TYPE (value)) == 0 5602 || ((TREE_CODE (constructor_type) == RECORD_TYPE 5603 || TREE_CODE (constructor_type) == UNION_TYPE) 5604 && DECL_C_BIT_FIELD (field) 5605 && TREE_CODE (value) != INTEGER_CST)) 5606 constructor_simple = 0; 5607 5608 if (require_constant_value && ! TREE_CONSTANT (value)) 5609 { 5610 error_init ("initializer element is not constant"); 5611 value = error_mark_node; 5612 } 5613 else if (require_constant_elements 5614 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0) 5615 pedwarn ("initializer element is not computable at load time"); 5616 5617 /* If this field is empty (and not at the end of structure), 5618 don't do anything other than checking the initializer. */ 5619 if (field 5620 && (TREE_TYPE (field) == error_mark_node 5621 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 5622 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 5623 && (TREE_CODE (constructor_type) == ARRAY_TYPE 5624 || TREE_CHAIN (field))))) 5625 return; 5626 5627 value = digest_init (type, value, require_constant_value); 5628 if (value == error_mark_node) 5629 { 5630 constructor_erroneous = 1; 5631 return; 5632 } 5633 5634 /* If this element doesn't come next in sequence, 5635 put it on constructor_pending_elts. */ 5636 if (TREE_CODE (constructor_type) == ARRAY_TYPE 5637 && (!constructor_incremental 5638 || !tree_int_cst_equal (field, constructor_unfilled_index))) 5639 { 5640 if (constructor_incremental 5641 && tree_int_cst_lt (field, constructor_unfilled_index)) 5642 set_nonincremental_init (); 5643 5644 add_pending_init (field, value); 5645 return; 5646 } 5647 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5648 && (!constructor_incremental 5649 || field != constructor_unfilled_fields)) 5650 { 5651 /* We do this for records but not for unions. In a union, 5652 no matter which field is specified, it can be initialized 5653 right away since it starts at the beginning of the union. */ 5654 if (constructor_incremental) 5655 { 5656 if (!constructor_unfilled_fields) 5657 set_nonincremental_init (); 5658 else 5659 { 5660 tree bitpos, unfillpos; 5661 5662 bitpos = bit_position (field); 5663 unfillpos = bit_position (constructor_unfilled_fields); 5664 5665 if (tree_int_cst_lt (bitpos, unfillpos)) 5666 set_nonincremental_init (); 5667 } 5668 } 5669 5670 add_pending_init (field, value); 5671 return; 5672 } 5673 else if (TREE_CODE (constructor_type) == UNION_TYPE 5674 && constructor_elements) 5675 { 5676 if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements))) 5677 warning_init ("initialized field with side-effects overwritten"); 5678 5679 /* We can have just one union field set. */ 5680 constructor_elements = 0; 5681 } 5682 5683 /* Otherwise, output this element either to 5684 constructor_elements or to the assembler file. */ 5685 5686 if (field && TREE_CODE (field) == INTEGER_CST) 5687 field = copy_node (field); 5688 constructor_elements 5689 = tree_cons (field, value, constructor_elements); 5690 5691 /* Advance the variable that indicates sequential elements output. */ 5692 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5693 constructor_unfilled_index 5694 = size_binop (PLUS_EXPR, constructor_unfilled_index, 5695 bitsize_one_node); 5696 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5697 { 5698 constructor_unfilled_fields 5699 = TREE_CHAIN (constructor_unfilled_fields); 5700 5701 /* Skip any nameless bit fields. */ 5702 while (constructor_unfilled_fields != 0 5703 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5704 && DECL_NAME (constructor_unfilled_fields) == 0) 5705 constructor_unfilled_fields = 5706 TREE_CHAIN (constructor_unfilled_fields); 5707 } 5708 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5709 constructor_unfilled_fields = 0; 5710 5711 /* Now output any pending elements which have become next. */ 5712 if (pending) 5713 output_pending_init_elements (0); 5714} 5715 5716/* Output any pending elements which have become next. 5717 As we output elements, constructor_unfilled_{fields,index} 5718 advances, which may cause other elements to become next; 5719 if so, they too are output. 5720 5721 If ALL is 0, we return when there are 5722 no more pending elements to output now. 5723 5724 If ALL is 1, we output space as necessary so that 5725 we can output all the pending elements. */ 5726 5727static void 5728output_pending_init_elements (int all) 5729{ 5730 struct init_node *elt = constructor_pending_elts; 5731 tree next; 5732 5733 retry: 5734 5735 /* Look through the whole pending tree. 5736 If we find an element that should be output now, 5737 output it. Otherwise, set NEXT to the element 5738 that comes first among those still pending. */ 5739 5740 next = 0; 5741 while (elt) 5742 { 5743 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5744 { 5745 if (tree_int_cst_equal (elt->purpose, 5746 constructor_unfilled_index)) 5747 output_init_element (elt->value, 5748 TREE_TYPE (constructor_type), 5749 constructor_unfilled_index, 0); 5750 else if (tree_int_cst_lt (constructor_unfilled_index, 5751 elt->purpose)) 5752 { 5753 /* Advance to the next smaller node. */ 5754 if (elt->left) 5755 elt = elt->left; 5756 else 5757 { 5758 /* We have reached the smallest node bigger than the 5759 current unfilled index. Fill the space first. */ 5760 next = elt->purpose; 5761 break; 5762 } 5763 } 5764 else 5765 { 5766 /* Advance to the next bigger node. */ 5767 if (elt->right) 5768 elt = elt->right; 5769 else 5770 { 5771 /* We have reached the biggest node in a subtree. Find 5772 the parent of it, which is the next bigger node. */ 5773 while (elt->parent && elt->parent->right == elt) 5774 elt = elt->parent; 5775 elt = elt->parent; 5776 if (elt && tree_int_cst_lt (constructor_unfilled_index, 5777 elt->purpose)) 5778 { 5779 next = elt->purpose; 5780 break; 5781 } 5782 } 5783 } 5784 } 5785 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5786 || TREE_CODE (constructor_type) == UNION_TYPE) 5787 { 5788 tree ctor_unfilled_bitpos, elt_bitpos; 5789 5790 /* If the current record is complete we are done. */ 5791 if (constructor_unfilled_fields == 0) 5792 break; 5793 5794 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 5795 elt_bitpos = bit_position (elt->purpose); 5796 /* We can't compare fields here because there might be empty 5797 fields in between. */ 5798 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 5799 { 5800 constructor_unfilled_fields = elt->purpose; 5801 output_init_element (elt->value, TREE_TYPE (elt->purpose), 5802 elt->purpose, 0); 5803 } 5804 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 5805 { 5806 /* Advance to the next smaller node. */ 5807 if (elt->left) 5808 elt = elt->left; 5809 else 5810 { 5811 /* We have reached the smallest node bigger than the 5812 current unfilled field. Fill the space first. */ 5813 next = elt->purpose; 5814 break; 5815 } 5816 } 5817 else 5818 { 5819 /* Advance to the next bigger node. */ 5820 if (elt->right) 5821 elt = elt->right; 5822 else 5823 { 5824 /* We have reached the biggest node in a subtree. Find 5825 the parent of it, which is the next bigger node. */ 5826 while (elt->parent && elt->parent->right == elt) 5827 elt = elt->parent; 5828 elt = elt->parent; 5829 if (elt 5830 && (tree_int_cst_lt (ctor_unfilled_bitpos, 5831 bit_position (elt->purpose)))) 5832 { 5833 next = elt->purpose; 5834 break; 5835 } 5836 } 5837 } 5838 } 5839 } 5840 5841 /* Ordinarily return, but not if we want to output all 5842 and there are elements left. */ 5843 if (! (all && next != 0)) 5844 return; 5845 5846 /* If it's not incremental, just skip over the gap, so that after 5847 jumping to retry we will output the next successive element. */ 5848 if (TREE_CODE (constructor_type) == RECORD_TYPE 5849 || TREE_CODE (constructor_type) == UNION_TYPE) 5850 constructor_unfilled_fields = next; 5851 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5852 constructor_unfilled_index = next; 5853 5854 /* ELT now points to the node in the pending tree with the next 5855 initializer to output. */ 5856 goto retry; 5857} 5858 5859/* Add one non-braced element to the current constructor level. 5860 This adjusts the current position within the constructor's type. 5861 This may also start or terminate implicit levels 5862 to handle a partly-braced initializer. 5863 5864 Once this has found the correct level for the new element, 5865 it calls output_init_element. */ 5866 5867void 5868process_init_element (tree value) 5869{ 5870 tree orig_value = value; 5871 int string_flag = value != 0 && TREE_CODE (value) == STRING_CST; 5872 5873 designator_depth = 0; 5874 designator_errorneous = 0; 5875 5876 /* Handle superfluous braces around string cst as in 5877 char x[] = {"foo"}; */ 5878 if (string_flag 5879 && constructor_type 5880 && TREE_CODE (constructor_type) == ARRAY_TYPE 5881 && TREE_CODE (TREE_TYPE (constructor_type)) == INTEGER_TYPE 5882 && integer_zerop (constructor_unfilled_index)) 5883 { 5884 if (constructor_stack->replacement_value) 5885 error_init ("excess elements in char array initializer"); 5886 constructor_stack->replacement_value = value; 5887 return; 5888 } 5889 5890 if (constructor_stack->replacement_value != 0) 5891 { 5892 error_init ("excess elements in struct initializer"); 5893 return; 5894 } 5895 5896 /* Ignore elements of a brace group if it is entirely superfluous 5897 and has already been diagnosed. */ 5898 if (constructor_type == 0) 5899 return; 5900 5901 /* If we've exhausted any levels that didn't have braces, 5902 pop them now. */ 5903 while (constructor_stack->implicit) 5904 { 5905 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5906 || TREE_CODE (constructor_type) == UNION_TYPE) 5907 && constructor_fields == 0) 5908 process_init_element (pop_init_level (1)); 5909 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5910 && (constructor_max_index == 0 5911 || tree_int_cst_lt (constructor_max_index, 5912 constructor_index))) 5913 process_init_element (pop_init_level (1)); 5914 else 5915 break; 5916 } 5917 5918 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 5919 if (constructor_range_stack) 5920 { 5921 /* If value is a compound literal and we'll be just using its 5922 content, don't put it into a SAVE_EXPR. */ 5923 if (TREE_CODE (value) != COMPOUND_LITERAL_EXPR 5924 || !require_constant_value 5925 || flag_isoc99) 5926 value = save_expr (value); 5927 } 5928 5929 while (1) 5930 { 5931 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5932 { 5933 tree fieldtype; 5934 enum tree_code fieldcode; 5935 5936 if (constructor_fields == 0) 5937 { 5938 pedwarn_init ("excess elements in struct initializer"); 5939 break; 5940 } 5941 5942 fieldtype = TREE_TYPE (constructor_fields); 5943 if (fieldtype != error_mark_node) 5944 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 5945 fieldcode = TREE_CODE (fieldtype); 5946 5947 /* Error for non-static initialization of a flexible array member. */ 5948 if (fieldcode == ARRAY_TYPE 5949 && !require_constant_value 5950 && TYPE_SIZE (fieldtype) == NULL_TREE 5951 && TREE_CHAIN (constructor_fields) == NULL_TREE) 5952 { 5953 error_init ("non-static initialization of a flexible array member"); 5954 break; 5955 } 5956 5957 /* Accept a string constant to initialize a subarray. */ 5958 if (value != 0 5959 && fieldcode == ARRAY_TYPE 5960 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 5961 && string_flag) 5962 value = orig_value; 5963 /* Otherwise, if we have come to a subaggregate, 5964 and we don't have an element of its type, push into it. */ 5965 else if (value != 0 && !constructor_no_implicit 5966 && value != error_mark_node 5967 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 5968 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 5969 || fieldcode == UNION_TYPE)) 5970 { 5971 push_init_level (1); 5972 continue; 5973 } 5974 5975 if (value) 5976 { 5977 push_member_name (constructor_fields); 5978 output_init_element (value, fieldtype, constructor_fields, 1); 5979 RESTORE_SPELLING_DEPTH (constructor_depth); 5980 } 5981 else 5982 /* Do the bookkeeping for an element that was 5983 directly output as a constructor. */ 5984 { 5985 /* For a record, keep track of end position of last field. */ 5986 if (DECL_SIZE (constructor_fields)) 5987 constructor_bit_index 5988 = size_binop (PLUS_EXPR, 5989 bit_position (constructor_fields), 5990 DECL_SIZE (constructor_fields)); 5991 5992 /* If the current field was the first one not yet written out, 5993 it isn't now, so update. */ 5994 if (constructor_unfilled_fields == constructor_fields) 5995 { 5996 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 5997 /* Skip any nameless bit fields. */ 5998 while (constructor_unfilled_fields != 0 5999 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6000 && DECL_NAME (constructor_unfilled_fields) == 0) 6001 constructor_unfilled_fields = 6002 TREE_CHAIN (constructor_unfilled_fields); 6003 } 6004 } 6005 6006 constructor_fields = TREE_CHAIN (constructor_fields); 6007 /* Skip any nameless bit fields at the beginning. */ 6008 while (constructor_fields != 0 6009 && DECL_C_BIT_FIELD (constructor_fields) 6010 && DECL_NAME (constructor_fields) == 0) 6011 constructor_fields = TREE_CHAIN (constructor_fields); 6012 } 6013 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6014 { 6015 tree fieldtype; 6016 enum tree_code fieldcode; 6017 6018 if (constructor_fields == 0) 6019 { 6020 pedwarn_init ("excess elements in union initializer"); 6021 break; 6022 } 6023 6024 fieldtype = TREE_TYPE (constructor_fields); 6025 if (fieldtype != error_mark_node) 6026 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6027 fieldcode = TREE_CODE (fieldtype); 6028 6029 /* Warn that traditional C rejects initialization of unions. 6030 We skip the warning if the value is zero. This is done 6031 under the assumption that the zero initializer in user 6032 code appears conditioned on e.g. __STDC__ to avoid 6033 "missing initializer" warnings and relies on default 6034 initialization to zero in the traditional C case. 6035 We also skip the warning if the initializer is designated, 6036 again on the assumption that this must be conditional on 6037 __STDC__ anyway (and we've already complained about the 6038 member-designator already). */ 6039 if (warn_traditional && !in_system_header && !constructor_designated 6040 && !(value && (integer_zerop (value) || real_zerop (value)))) 6041 warning ("traditional C rejects initialization of unions"); 6042 6043 /* Accept a string constant to initialize a subarray. */ 6044 if (value != 0 6045 && fieldcode == ARRAY_TYPE 6046 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 6047 && string_flag) 6048 value = orig_value; 6049 /* Otherwise, if we have come to a subaggregate, 6050 and we don't have an element of its type, push into it. */ 6051 else if (value != 0 && !constructor_no_implicit 6052 && value != error_mark_node 6053 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 6054 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6055 || fieldcode == UNION_TYPE)) 6056 { 6057 push_init_level (1); 6058 continue; 6059 } 6060 6061 if (value) 6062 { 6063 push_member_name (constructor_fields); 6064 output_init_element (value, fieldtype, constructor_fields, 1); 6065 RESTORE_SPELLING_DEPTH (constructor_depth); 6066 } 6067 else 6068 /* Do the bookkeeping for an element that was 6069 directly output as a constructor. */ 6070 { 6071 constructor_bit_index = DECL_SIZE (constructor_fields); 6072 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6073 } 6074 6075 constructor_fields = 0; 6076 } 6077 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6078 { 6079 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6080 enum tree_code eltcode = TREE_CODE (elttype); 6081 6082 /* Accept a string constant to initialize a subarray. */ 6083 if (value != 0 6084 && eltcode == ARRAY_TYPE 6085 && TREE_CODE (TREE_TYPE (elttype)) == INTEGER_TYPE 6086 && string_flag) 6087 value = orig_value; 6088 /* Otherwise, if we have come to a subaggregate, 6089 and we don't have an element of its type, push into it. */ 6090 else if (value != 0 && !constructor_no_implicit 6091 && value != error_mark_node 6092 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != elttype 6093 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6094 || eltcode == UNION_TYPE)) 6095 { 6096 push_init_level (1); 6097 continue; 6098 } 6099 6100 if (constructor_max_index != 0 6101 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6102 || integer_all_onesp (constructor_max_index))) 6103 { 6104 pedwarn_init ("excess elements in array initializer"); 6105 break; 6106 } 6107 6108 /* Now output the actual element. */ 6109 if (value) 6110 { 6111 push_array_bounds (tree_low_cst (constructor_index, 0)); 6112 output_init_element (value, elttype, constructor_index, 1); 6113 RESTORE_SPELLING_DEPTH (constructor_depth); 6114 } 6115 6116 constructor_index 6117 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6118 6119 if (! value) 6120 /* If we are doing the bookkeeping for an element that was 6121 directly output as a constructor, we must update 6122 constructor_unfilled_index. */ 6123 constructor_unfilled_index = constructor_index; 6124 } 6125 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6126 { 6127 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6128 6129 /* Do a basic check of initializer size. Note that vectors 6130 always have a fixed size derived from their type. */ 6131 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6132 { 6133 pedwarn_init ("excess elements in vector initializer"); 6134 break; 6135 } 6136 6137 /* Now output the actual element. */ 6138 if (value) 6139 output_init_element (value, elttype, constructor_index, 1); 6140 6141 constructor_index 6142 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6143 6144 if (! value) 6145 /* If we are doing the bookkeeping for an element that was 6146 directly output as a constructor, we must update 6147 constructor_unfilled_index. */ 6148 constructor_unfilled_index = constructor_index; 6149 } 6150 6151 /* Handle the sole element allowed in a braced initializer 6152 for a scalar variable. */ 6153 else if (constructor_fields == 0) 6154 { 6155 pedwarn_init ("excess elements in scalar initializer"); 6156 break; 6157 } 6158 else 6159 { 6160 if (value) 6161 output_init_element (value, constructor_type, NULL_TREE, 1); 6162 constructor_fields = 0; 6163 } 6164 6165 /* Handle range initializers either at this level or anywhere higher 6166 in the designator stack. */ 6167 if (constructor_range_stack) 6168 { 6169 struct constructor_range_stack *p, *range_stack; 6170 int finish = 0; 6171 6172 range_stack = constructor_range_stack; 6173 constructor_range_stack = 0; 6174 while (constructor_stack != range_stack->stack) 6175 { 6176 if (!constructor_stack->implicit) 6177 abort (); 6178 process_init_element (pop_init_level (1)); 6179 } 6180 for (p = range_stack; 6181 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6182 p = p->prev) 6183 { 6184 if (!constructor_stack->implicit) 6185 abort (); 6186 process_init_element (pop_init_level (1)); 6187 } 6188 6189 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6190 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6191 finish = 1; 6192 6193 while (1) 6194 { 6195 constructor_index = p->index; 6196 constructor_fields = p->fields; 6197 if (finish && p->range_end && p->index == p->range_start) 6198 { 6199 finish = 0; 6200 p->prev = 0; 6201 } 6202 p = p->next; 6203 if (!p) 6204 break; 6205 push_init_level (2); 6206 p->stack = constructor_stack; 6207 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6208 p->index = p->range_start; 6209 } 6210 6211 if (!finish) 6212 constructor_range_stack = range_stack; 6213 continue; 6214 } 6215 6216 break; 6217 } 6218 6219 constructor_range_stack = 0; 6220} 6221 6222/* Build a simple asm-statement, from one string literal. */ 6223tree 6224simple_asm_stmt (tree expr) 6225{ 6226 STRIP_NOPS (expr); 6227 6228 if (TREE_CODE (expr) == ADDR_EXPR) 6229 expr = TREE_OPERAND (expr, 0); 6230 6231 if (TREE_CODE (expr) == STRING_CST) 6232 { 6233 tree stmt; 6234 6235 /* Simple asm statements are treated as volatile. */ 6236 stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE], 6237 expr, NULL_TREE, NULL_TREE, NULL_TREE)); 6238 ASM_INPUT_P (stmt) = 1; 6239 return stmt; 6240 } 6241 6242 error ("argument of `asm' is not a constant string"); 6243 return NULL_TREE; 6244} 6245 6246/* Build an asm-statement, whose components are a CV_QUALIFIER, a 6247 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */ 6248 6249tree 6250build_asm_stmt (tree cv_qualifier, tree string, tree outputs, tree inputs, 6251 tree clobbers) 6252{ 6253 tree tail; 6254 6255 if (TREE_CODE (string) != STRING_CST) 6256 { 6257 error ("asm template is not a string constant"); 6258 return NULL_TREE; 6259 } 6260 6261 if (cv_qualifier != NULL_TREE 6262 && cv_qualifier != ridpointers[(int) RID_VOLATILE]) 6263 { 6264 warning ("%s qualifier ignored on asm", 6265 IDENTIFIER_POINTER (cv_qualifier)); 6266 cv_qualifier = NULL_TREE; 6267 } 6268 6269 /* We can remove output conversions that change the type, 6270 but not the mode. */ 6271 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6272 { 6273 tree output = TREE_VALUE (tail); 6274 6275 STRIP_NOPS (output); 6276 TREE_VALUE (tail) = output; 6277 6278 /* Allow conversions as LHS here. build_modify_expr as called below 6279 will do the right thing with them. */ 6280 while (TREE_CODE (output) == NOP_EXPR 6281 || TREE_CODE (output) == CONVERT_EXPR 6282 || TREE_CODE (output) == FLOAT_EXPR 6283 || TREE_CODE (output) == FIX_TRUNC_EXPR 6284 || TREE_CODE (output) == FIX_FLOOR_EXPR 6285 || TREE_CODE (output) == FIX_ROUND_EXPR 6286 || TREE_CODE (output) == FIX_CEIL_EXPR) 6287 output = TREE_OPERAND (output, 0); 6288 6289 lvalue_or_else (TREE_VALUE (tail), "invalid lvalue in asm statement"); 6290 } 6291 6292 /* Remove output conversions that change the type but not the mode. */ 6293 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6294 { 6295 tree output = TREE_VALUE (tail); 6296 STRIP_NOPS (output); 6297 TREE_VALUE (tail) = output; 6298 } 6299 6300 /* Perform default conversions on array and function inputs. 6301 Don't do this for other types as it would screw up operands 6302 expected to be in memory. */ 6303 for (tail = inputs; tail; tail = TREE_CHAIN (tail)) 6304 TREE_VALUE (tail) = default_function_array_conversion (TREE_VALUE (tail)); 6305 6306 return add_stmt (build_stmt (ASM_STMT, cv_qualifier, string, 6307 outputs, inputs, clobbers)); 6308} 6309 6310/* Expand an ASM statement with operands, handling output operands 6311 that are not variables or INDIRECT_REFS by transforming such 6312 cases into cases that expand_asm_operands can handle. 6313 6314 Arguments are same as for expand_asm_operands. */ 6315 6316void 6317c_expand_asm_operands (tree string, tree outputs, tree inputs, 6318 tree clobbers, int vol, location_t locus) 6319{ 6320 int noutputs = list_length (outputs); 6321 int i; 6322 /* o[I] is the place that output number I should be written. */ 6323 tree *o = alloca (noutputs * sizeof (tree)); 6324 tree tail; 6325 6326 /* Record the contents of OUTPUTS before it is modified. */ 6327 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6328 { 6329 o[i] = TREE_VALUE (tail); 6330 if (o[i] == error_mark_node) 6331 return; 6332 } 6333 6334 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of 6335 OUTPUTS some trees for where the values were actually stored. */ 6336 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus); 6337 6338 /* Copy all the intermediate outputs into the specified outputs. */ 6339 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6340 { 6341 if (o[i] != TREE_VALUE (tail)) 6342 { 6343 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)), 6344 NULL_RTX, VOIDmode, EXPAND_NORMAL); 6345 free_temp_slots (); 6346 6347 /* Restore the original value so that it's correct the next 6348 time we expand this function. */ 6349 TREE_VALUE (tail) = o[i]; 6350 } 6351 /* Detect modification of read-only values. 6352 (Otherwise done by build_modify_expr.) */ 6353 else 6354 { 6355 tree type = TREE_TYPE (o[i]); 6356 if (TREE_READONLY (o[i]) 6357 || TYPE_READONLY (type) 6358 || ((TREE_CODE (type) == RECORD_TYPE 6359 || TREE_CODE (type) == UNION_TYPE) 6360 && C_TYPE_FIELDS_READONLY (type))) 6361 readonly_error (o[i], "modification by `asm'"); 6362 } 6363 } 6364 6365 /* Those MODIFY_EXPRs could do autoincrements. */ 6366 emit_queue (); 6367} 6368 6369/* Expand a C `return' statement. 6370 RETVAL is the expression for what to return, 6371 or a null pointer for `return;' with no value. */ 6372 6373tree 6374c_expand_return (tree retval) 6375{ 6376 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6377 6378 if (TREE_THIS_VOLATILE (current_function_decl)) 6379 warning ("function declared `noreturn' has a `return' statement"); 6380 6381 if (!retval) 6382 { 6383 current_function_returns_null = 1; 6384 if ((warn_return_type || flag_isoc99) 6385 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 6386 pedwarn_c99 ("`return' with no value, in function returning non-void"); 6387 } 6388 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 6389 { 6390 current_function_returns_null = 1; 6391 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 6392 pedwarn ("`return' with a value, in function returning void"); 6393 } 6394 else 6395 { 6396 tree t = convert_for_assignment (valtype, retval, _("return"), 6397 NULL_TREE, NULL_TREE, 0); 6398 tree res = DECL_RESULT (current_function_decl); 6399 tree inner; 6400 6401 current_function_returns_value = 1; 6402 if (t == error_mark_node) 6403 return NULL_TREE; 6404 6405 inner = t = convert (TREE_TYPE (res), t); 6406 6407 /* Strip any conversions, additions, and subtractions, and see if 6408 we are returning the address of a local variable. Warn if so. */ 6409 while (1) 6410 { 6411 switch (TREE_CODE (inner)) 6412 { 6413 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 6414 case PLUS_EXPR: 6415 inner = TREE_OPERAND (inner, 0); 6416 continue; 6417 6418 case MINUS_EXPR: 6419 /* If the second operand of the MINUS_EXPR has a pointer 6420 type (or is converted from it), this may be valid, so 6421 don't give a warning. */ 6422 { 6423 tree op1 = TREE_OPERAND (inner, 1); 6424 6425 while (! POINTER_TYPE_P (TREE_TYPE (op1)) 6426 && (TREE_CODE (op1) == NOP_EXPR 6427 || TREE_CODE (op1) == NON_LVALUE_EXPR 6428 || TREE_CODE (op1) == CONVERT_EXPR)) 6429 op1 = TREE_OPERAND (op1, 0); 6430 6431 if (POINTER_TYPE_P (TREE_TYPE (op1))) 6432 break; 6433 6434 inner = TREE_OPERAND (inner, 0); 6435 continue; 6436 } 6437 6438 case ADDR_EXPR: 6439 inner = TREE_OPERAND (inner, 0); 6440 6441 while (TREE_CODE_CLASS (TREE_CODE (inner)) == 'r') 6442 inner = TREE_OPERAND (inner, 0); 6443 6444 if (TREE_CODE (inner) == VAR_DECL 6445 && ! DECL_EXTERNAL (inner) 6446 && ! TREE_STATIC (inner) 6447 && DECL_CONTEXT (inner) == current_function_decl) 6448 warning ("function returns address of local variable"); 6449 break; 6450 6451 default: 6452 break; 6453 } 6454 6455 break; 6456 } 6457 6458 retval = build (MODIFY_EXPR, TREE_TYPE (res), res, t); 6459 } 6460 6461 return add_stmt (build_return_stmt (retval)); 6462} 6463 6464struct c_switch { 6465 /* The SWITCH_STMT being built. */ 6466 tree switch_stmt; 6467 /* A splay-tree mapping the low element of a case range to the high 6468 element, or NULL_TREE if there is no high element. Used to 6469 determine whether or not a new case label duplicates an old case 6470 label. We need a tree, rather than simply a hash table, because 6471 of the GNU case range extension. */ 6472 splay_tree cases; 6473 /* The next node on the stack. */ 6474 struct c_switch *next; 6475}; 6476 6477/* A stack of the currently active switch statements. The innermost 6478 switch statement is on the top of the stack. There is no need to 6479 mark the stack for garbage collection because it is only active 6480 during the processing of the body of a function, and we never 6481 collect at that point. */ 6482 6483static struct c_switch *switch_stack; 6484 6485/* Start a C switch statement, testing expression EXP. Return the new 6486 SWITCH_STMT. */ 6487 6488tree 6489c_start_case (tree exp) 6490{ 6491 enum tree_code code; 6492 tree type, orig_type = error_mark_node; 6493 struct c_switch *cs; 6494 6495 if (exp != error_mark_node) 6496 { 6497 code = TREE_CODE (TREE_TYPE (exp)); 6498 orig_type = TREE_TYPE (exp); 6499 6500 if (! INTEGRAL_TYPE_P (orig_type) 6501 && code != ERROR_MARK) 6502 { 6503 error ("switch quantity not an integer"); 6504 exp = integer_zero_node; 6505 } 6506 else 6507 { 6508 type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 6509 6510 if (warn_traditional && !in_system_header 6511 && (type == long_integer_type_node 6512 || type == long_unsigned_type_node)) 6513 warning ("`long' switch expression not converted to `int' in ISO C"); 6514 6515 exp = default_conversion (exp); 6516 type = TREE_TYPE (exp); 6517 } 6518 } 6519 6520 /* Add this new SWITCH_STMT to the stack. */ 6521 cs = xmalloc (sizeof (*cs)); 6522 cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type); 6523 cs->cases = splay_tree_new (case_compare, NULL, NULL); 6524 cs->next = switch_stack; 6525 switch_stack = cs; 6526 6527 return add_stmt (switch_stack->switch_stmt); 6528} 6529 6530/* Process a case label. */ 6531 6532tree 6533do_case (tree low_value, tree high_value) 6534{ 6535 tree label = NULL_TREE; 6536 6537 if (switch_stack) 6538 { 6539 bool switch_was_empty_p = (SWITCH_BODY (switch_stack->switch_stmt) == NULL_TREE); 6540 6541 label = c_add_case_label (switch_stack->cases, 6542 SWITCH_COND (switch_stack->switch_stmt), 6543 low_value, high_value); 6544 if (label == error_mark_node) 6545 label = NULL_TREE; 6546 else if (switch_was_empty_p) 6547 { 6548 /* Attach the first case label to the SWITCH_BODY. */ 6549 SWITCH_BODY (switch_stack->switch_stmt) = TREE_CHAIN (switch_stack->switch_stmt); 6550 TREE_CHAIN (switch_stack->switch_stmt) = NULL_TREE; 6551 } 6552 } 6553 else if (low_value) 6554 error ("case label not within a switch statement"); 6555 else 6556 error ("`default' label not within a switch statement"); 6557 6558 return label; 6559} 6560 6561/* Finish the switch statement. */ 6562 6563void 6564c_finish_case (void) 6565{ 6566 struct c_switch *cs = switch_stack; 6567 6568 /* If we've not seen any case labels (or a default), we may still 6569 need to chain any statements that were seen as the SWITCH_BODY. */ 6570 if (SWITCH_BODY (cs->switch_stmt) == NULL) 6571 { 6572 SWITCH_BODY (cs->switch_stmt) = TREE_CHAIN (cs->switch_stmt); 6573 TREE_CHAIN (cs->switch_stmt) = NULL_TREE; 6574 } 6575 6576 /* Rechain the next statements to the SWITCH_STMT. */ 6577 last_tree = cs->switch_stmt; 6578 6579 /* Pop the stack. */ 6580 switch_stack = switch_stack->next; 6581 splay_tree_delete (cs->cases); 6582 free (cs); 6583} 6584 6585/* Build a binary-operation expression without default conversions. 6586 CODE is the kind of expression to build. 6587 This function differs from `build' in several ways: 6588 the data type of the result is computed and recorded in it, 6589 warnings are generated if arg data types are invalid, 6590 special handling for addition and subtraction of pointers is known, 6591 and some optimization is done (operations on narrow ints 6592 are done in the narrower type when that gives the same result). 6593 Constant folding is also done before the result is returned. 6594 6595 Note that the operands will never have enumeral types, or function 6596 or array types, because either they will have the default conversions 6597 performed or they have both just been converted to some other type in which 6598 the arithmetic is to be done. */ 6599 6600tree 6601build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 6602 int convert_p) 6603{ 6604 tree type0, type1; 6605 enum tree_code code0, code1; 6606 tree op0, op1; 6607 6608 /* Expression code to give to the expression when it is built. 6609 Normally this is CODE, which is what the caller asked for, 6610 but in some special cases we change it. */ 6611 enum tree_code resultcode = code; 6612 6613 /* Data type in which the computation is to be performed. 6614 In the simplest cases this is the common type of the arguments. */ 6615 tree result_type = NULL; 6616 6617 /* Nonzero means operands have already been type-converted 6618 in whatever way is necessary. 6619 Zero means they need to be converted to RESULT_TYPE. */ 6620 int converted = 0; 6621 6622 /* Nonzero means create the expression with this type, rather than 6623 RESULT_TYPE. */ 6624 tree build_type = 0; 6625 6626 /* Nonzero means after finally constructing the expression 6627 convert it to this type. */ 6628 tree final_type = 0; 6629 6630 /* Nonzero if this is an operation like MIN or MAX which can 6631 safely be computed in short if both args are promoted shorts. 6632 Also implies COMMON. 6633 -1 indicates a bitwise operation; this makes a difference 6634 in the exact conditions for when it is safe to do the operation 6635 in a narrower mode. */ 6636 int shorten = 0; 6637 6638 /* Nonzero if this is a comparison operation; 6639 if both args are promoted shorts, compare the original shorts. 6640 Also implies COMMON. */ 6641 int short_compare = 0; 6642 6643 /* Nonzero if this is a right-shift operation, which can be computed on the 6644 original short and then promoted if the operand is a promoted short. */ 6645 int short_shift = 0; 6646 6647 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 6648 int common = 0; 6649 6650 if (convert_p) 6651 { 6652 op0 = default_conversion (orig_op0); 6653 op1 = default_conversion (orig_op1); 6654 } 6655 else 6656 { 6657 op0 = orig_op0; 6658 op1 = orig_op1; 6659 } 6660 6661 type0 = TREE_TYPE (op0); 6662 type1 = TREE_TYPE (op1); 6663 6664 /* The expression codes of the data types of the arguments tell us 6665 whether the arguments are integers, floating, pointers, etc. */ 6666 code0 = TREE_CODE (type0); 6667 code1 = TREE_CODE (type1); 6668 6669 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 6670 STRIP_TYPE_NOPS (op0); 6671 STRIP_TYPE_NOPS (op1); 6672 6673 /* If an error was already reported for one of the arguments, 6674 avoid reporting another error. */ 6675 6676 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 6677 return error_mark_node; 6678 6679 switch (code) 6680 { 6681 case PLUS_EXPR: 6682 /* Handle the pointer + int case. */ 6683 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6684 return pointer_int_sum (PLUS_EXPR, op0, op1); 6685 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 6686 return pointer_int_sum (PLUS_EXPR, op1, op0); 6687 else 6688 common = 1; 6689 break; 6690 6691 case MINUS_EXPR: 6692 /* Subtraction of two similar pointers. 6693 We must subtract them as integers, then divide by object size. */ 6694 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 6695 && comp_target_types (type0, type1, 1)) 6696 return pointer_diff (op0, op1); 6697 /* Handle pointer minus int. Just like pointer plus int. */ 6698 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6699 return pointer_int_sum (MINUS_EXPR, op0, op1); 6700 else 6701 common = 1; 6702 break; 6703 6704 case MULT_EXPR: 6705 common = 1; 6706 break; 6707 6708 case TRUNC_DIV_EXPR: 6709 case CEIL_DIV_EXPR: 6710 case FLOOR_DIV_EXPR: 6711 case ROUND_DIV_EXPR: 6712 case EXACT_DIV_EXPR: 6713 /* Floating point division by zero is a legitimate way to obtain 6714 infinities and NaNs. */ 6715 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6716 warning ("division by zero"); 6717 6718 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6719 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 6720 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6721 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 6722 { 6723 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)) 6724 resultcode = RDIV_EXPR; 6725 else 6726 /* Although it would be tempting to shorten always here, that 6727 loses on some targets, since the modulo instruction is 6728 undefined if the quotient can't be represented in the 6729 computation mode. We shorten only if unsigned or if 6730 dividing by something we know != -1. */ 6731 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6732 || (TREE_CODE (op1) == INTEGER_CST 6733 && ! integer_all_onesp (op1))); 6734 common = 1; 6735 } 6736 break; 6737 6738 case BIT_AND_EXPR: 6739 case BIT_IOR_EXPR: 6740 case BIT_XOR_EXPR: 6741 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6742 shorten = -1; 6743 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 6744 common = 1; 6745 break; 6746 6747 case TRUNC_MOD_EXPR: 6748 case FLOOR_MOD_EXPR: 6749 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6750 warning ("division by zero"); 6751 6752 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6753 { 6754 /* Although it would be tempting to shorten always here, that loses 6755 on some targets, since the modulo instruction is undefined if the 6756 quotient can't be represented in the computation mode. We shorten 6757 only if unsigned or if dividing by something we know != -1. */ 6758 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6759 || (TREE_CODE (op1) == INTEGER_CST 6760 && ! integer_all_onesp (op1))); 6761 common = 1; 6762 } 6763 break; 6764 6765 case TRUTH_ANDIF_EXPR: 6766 case TRUTH_ORIF_EXPR: 6767 case TRUTH_AND_EXPR: 6768 case TRUTH_OR_EXPR: 6769 case TRUTH_XOR_EXPR: 6770 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 6771 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 6772 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 6773 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 6774 { 6775 /* Result of these operations is always an int, 6776 but that does not mean the operands should be 6777 converted to ints! */ 6778 result_type = integer_type_node; 6779 op0 = c_common_truthvalue_conversion (op0); 6780 op1 = c_common_truthvalue_conversion (op1); 6781 converted = 1; 6782 } 6783 break; 6784 6785 /* Shift operations: result has same type as first operand; 6786 always convert second operand to int. 6787 Also set SHORT_SHIFT if shifting rightward. */ 6788 6789 case RSHIFT_EXPR: 6790 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6791 { 6792 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6793 { 6794 if (tree_int_cst_sgn (op1) < 0) 6795 warning ("right shift count is negative"); 6796 else 6797 { 6798 if (! integer_zerop (op1)) 6799 short_shift = 1; 6800 6801 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6802 warning ("right shift count >= width of type"); 6803 } 6804 } 6805 6806 /* Use the type of the value to be shifted. */ 6807 result_type = type0; 6808 /* Convert the shift-count to an integer, regardless of size 6809 of value being shifted. */ 6810 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6811 op1 = convert (integer_type_node, op1); 6812 /* Avoid converting op1 to result_type later. */ 6813 converted = 1; 6814 } 6815 break; 6816 6817 case LSHIFT_EXPR: 6818 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6819 { 6820 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6821 { 6822 if (tree_int_cst_sgn (op1) < 0) 6823 warning ("left shift count is negative"); 6824 6825 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6826 warning ("left shift count >= width of type"); 6827 } 6828 6829 /* Use the type of the value to be shifted. */ 6830 result_type = type0; 6831 /* Convert the shift-count to an integer, regardless of size 6832 of value being shifted. */ 6833 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6834 op1 = convert (integer_type_node, op1); 6835 /* Avoid converting op1 to result_type later. */ 6836 converted = 1; 6837 } 6838 break; 6839 6840 case RROTATE_EXPR: 6841 case LROTATE_EXPR: 6842 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6843 { 6844 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6845 { 6846 if (tree_int_cst_sgn (op1) < 0) 6847 warning ("shift count is negative"); 6848 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6849 warning ("shift count >= width of type"); 6850 } 6851 6852 /* Use the type of the value to be shifted. */ 6853 result_type = type0; 6854 /* Convert the shift-count to an integer, regardless of size 6855 of value being shifted. */ 6856 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6857 op1 = convert (integer_type_node, op1); 6858 /* Avoid converting op1 to result_type later. */ 6859 converted = 1; 6860 } 6861 break; 6862 6863 case EQ_EXPR: 6864 case NE_EXPR: 6865 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE)) 6866 warning ("comparing floating point with == or != is unsafe"); 6867 /* Result of comparison is always int, 6868 but don't convert the args to int! */ 6869 build_type = integer_type_node; 6870 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6871 || code0 == COMPLEX_TYPE) 6872 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6873 || code1 == COMPLEX_TYPE)) 6874 short_compare = 1; 6875 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6876 { 6877 tree tt0 = TREE_TYPE (type0); 6878 tree tt1 = TREE_TYPE (type1); 6879 /* Anything compares with void *. void * compares with anything. 6880 Otherwise, the targets must be compatible 6881 and both must be object or both incomplete. */ 6882 if (comp_target_types (type0, type1, 1)) 6883 result_type = common_type (type0, type1); 6884 else if (VOID_TYPE_P (tt0)) 6885 { 6886 /* op0 != orig_op0 detects the case of something 6887 whose value is 0 but which isn't a valid null ptr const. */ 6888 if (pedantic && (!integer_zerop (op0) || op0 != orig_op0) 6889 && TREE_CODE (tt1) == FUNCTION_TYPE) 6890 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6891 } 6892 else if (VOID_TYPE_P (tt1)) 6893 { 6894 if (pedantic && (!integer_zerop (op1) || op1 != orig_op1) 6895 && TREE_CODE (tt0) == FUNCTION_TYPE) 6896 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6897 } 6898 else 6899 pedwarn ("comparison of distinct pointer types lacks a cast"); 6900 6901 if (result_type == NULL_TREE) 6902 result_type = ptr_type_node; 6903 } 6904 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6905 && integer_zerop (op1)) 6906 result_type = type0; 6907 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6908 && integer_zerop (op0)) 6909 result_type = type1; 6910 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6911 { 6912 result_type = type0; 6913 pedwarn ("comparison between pointer and integer"); 6914 } 6915 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6916 { 6917 result_type = type1; 6918 pedwarn ("comparison between pointer and integer"); 6919 } 6920 break; 6921 6922 case MAX_EXPR: 6923 case MIN_EXPR: 6924 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6925 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6926 shorten = 1; 6927 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6928 { 6929 if (comp_target_types (type0, type1, 1)) 6930 { 6931 result_type = common_type (type0, type1); 6932 if (pedantic 6933 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6934 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6935 } 6936 else 6937 { 6938 result_type = ptr_type_node; 6939 pedwarn ("comparison of distinct pointer types lacks a cast"); 6940 } 6941 } 6942 break; 6943 6944 case LE_EXPR: 6945 case GE_EXPR: 6946 case LT_EXPR: 6947 case GT_EXPR: 6948 build_type = integer_type_node; 6949 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6950 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6951 short_compare = 1; 6952 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6953 { 6954 if (comp_target_types (type0, type1, 1)) 6955 { 6956 result_type = common_type (type0, type1); 6957 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 6958 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 6959 pedwarn ("comparison of complete and incomplete pointers"); 6960 else if (pedantic 6961 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6962 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6963 } 6964 else 6965 { 6966 result_type = ptr_type_node; 6967 pedwarn ("comparison of distinct pointer types lacks a cast"); 6968 } 6969 } 6970 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6971 && integer_zerop (op1)) 6972 { 6973 result_type = type0; 6974 if (pedantic || extra_warnings) 6975 pedwarn ("ordered comparison of pointer with integer zero"); 6976 } 6977 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6978 && integer_zerop (op0)) 6979 { 6980 result_type = type1; 6981 if (pedantic) 6982 pedwarn ("ordered comparison of pointer with integer zero"); 6983 } 6984 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6985 { 6986 result_type = type0; 6987 pedwarn ("comparison between pointer and integer"); 6988 } 6989 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6990 { 6991 result_type = type1; 6992 pedwarn ("comparison between pointer and integer"); 6993 } 6994 break; 6995 6996 case UNORDERED_EXPR: 6997 case ORDERED_EXPR: 6998 case UNLT_EXPR: 6999 case UNLE_EXPR: 7000 case UNGT_EXPR: 7001 case UNGE_EXPR: 7002 case UNEQ_EXPR: 7003 build_type = integer_type_node; 7004 if (code0 != REAL_TYPE || code1 != REAL_TYPE) 7005 { 7006 error ("unordered comparison on non-floating point argument"); 7007 return error_mark_node; 7008 } 7009 common = 1; 7010 break; 7011 7012 default: 7013 break; 7014 } 7015 7016 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 7017 || code0 == VECTOR_TYPE) 7018 && 7019 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 7020 || code1 == VECTOR_TYPE)) 7021 { 7022 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 7023 7024 if (shorten || common || short_compare) 7025 result_type = common_type (type0, type1); 7026 7027 /* For certain operations (which identify themselves by shorten != 0) 7028 if both args were extended from the same smaller type, 7029 do the arithmetic in that type and then extend. 7030 7031 shorten !=0 and !=1 indicates a bitwise operation. 7032 For them, this optimization is safe only if 7033 both args are zero-extended or both are sign-extended. 7034 Otherwise, we might change the result. 7035 Eg, (short)-1 | (unsigned short)-1 is (int)-1 7036 but calculated in (unsigned short) it would be (unsigned short)-1. */ 7037 7038 if (shorten && none_complex) 7039 { 7040 int unsigned0, unsigned1; 7041 tree arg0 = get_narrower (op0, &unsigned0); 7042 tree arg1 = get_narrower (op1, &unsigned1); 7043 /* UNS is 1 if the operation to be done is an unsigned one. */ 7044 int uns = TREE_UNSIGNED (result_type); 7045 tree type; 7046 7047 final_type = result_type; 7048 7049 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 7050 but it *requires* conversion to FINAL_TYPE. */ 7051 7052 if ((TYPE_PRECISION (TREE_TYPE (op0)) 7053 == TYPE_PRECISION (TREE_TYPE (arg0))) 7054 && TREE_TYPE (op0) != final_type) 7055 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0)); 7056 if ((TYPE_PRECISION (TREE_TYPE (op1)) 7057 == TYPE_PRECISION (TREE_TYPE (arg1))) 7058 && TREE_TYPE (op1) != final_type) 7059 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1)); 7060 7061 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 7062 7063 /* For bitwise operations, signedness of nominal type 7064 does not matter. Consider only how operands were extended. */ 7065 if (shorten == -1) 7066 uns = unsigned0; 7067 7068 /* Note that in all three cases below we refrain from optimizing 7069 an unsigned operation on sign-extended args. 7070 That would not be valid. */ 7071 7072 /* Both args variable: if both extended in same way 7073 from same width, do it in that width. 7074 Do it unsigned if args were zero-extended. */ 7075 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 7076 < TYPE_PRECISION (result_type)) 7077 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7078 == TYPE_PRECISION (TREE_TYPE (arg0))) 7079 && unsigned0 == unsigned1 7080 && (unsigned0 || !uns)) 7081 result_type 7082 = c_common_signed_or_unsigned_type 7083 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 7084 else if (TREE_CODE (arg0) == INTEGER_CST 7085 && (unsigned1 || !uns) 7086 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7087 < TYPE_PRECISION (result_type)) 7088 && (type 7089 = c_common_signed_or_unsigned_type (unsigned1, 7090 TREE_TYPE (arg1)), 7091 int_fits_type_p (arg0, type))) 7092 result_type = type; 7093 else if (TREE_CODE (arg1) == INTEGER_CST 7094 && (unsigned0 || !uns) 7095 && (TYPE_PRECISION (TREE_TYPE (arg0)) 7096 < TYPE_PRECISION (result_type)) 7097 && (type 7098 = c_common_signed_or_unsigned_type (unsigned0, 7099 TREE_TYPE (arg0)), 7100 int_fits_type_p (arg1, type))) 7101 result_type = type; 7102 } 7103 7104 /* Shifts can be shortened if shifting right. */ 7105 7106 if (short_shift) 7107 { 7108 int unsigned_arg; 7109 tree arg0 = get_narrower (op0, &unsigned_arg); 7110 7111 final_type = result_type; 7112 7113 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 7114 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0)); 7115 7116 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 7117 /* We can shorten only if the shift count is less than the 7118 number of bits in the smaller type size. */ 7119 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 7120 /* We cannot drop an unsigned shift after sign-extension. */ 7121 && (!TREE_UNSIGNED (final_type) || unsigned_arg)) 7122 { 7123 /* Do an unsigned shift if the operand was zero-extended. */ 7124 result_type 7125 = c_common_signed_or_unsigned_type (unsigned_arg, 7126 TREE_TYPE (arg0)); 7127 /* Convert value-to-be-shifted to that type. */ 7128 if (TREE_TYPE (op0) != result_type) 7129 op0 = convert (result_type, op0); 7130 converted = 1; 7131 } 7132 } 7133 7134 /* Comparison operations are shortened too but differently. 7135 They identify themselves by setting short_compare = 1. */ 7136 7137 if (short_compare) 7138 { 7139 /* Don't write &op0, etc., because that would prevent op0 7140 from being kept in a register. 7141 Instead, make copies of the our local variables and 7142 pass the copies by reference, then copy them back afterward. */ 7143 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 7144 enum tree_code xresultcode = resultcode; 7145 tree val 7146 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 7147 7148 if (val != 0) 7149 return val; 7150 7151 op0 = xop0, op1 = xop1; 7152 converted = 1; 7153 resultcode = xresultcode; 7154 7155 if (warn_sign_compare && skip_evaluation == 0) 7156 { 7157 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0)); 7158 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1)); 7159 int unsignedp0, unsignedp1; 7160 tree primop0 = get_narrower (op0, &unsignedp0); 7161 tree primop1 = get_narrower (op1, &unsignedp1); 7162 7163 xop0 = orig_op0; 7164 xop1 = orig_op1; 7165 STRIP_TYPE_NOPS (xop0); 7166 STRIP_TYPE_NOPS (xop1); 7167 7168 /* Give warnings for comparisons between signed and unsigned 7169 quantities that may fail. 7170 7171 Do the checking based on the original operand trees, so that 7172 casts will be considered, but default promotions won't be. 7173 7174 Do not warn if the comparison is being done in a signed type, 7175 since the signed type will only be chosen if it can represent 7176 all the values of the unsigned type. */ 7177 if (! TREE_UNSIGNED (result_type)) 7178 /* OK */; 7179 /* Do not warn if both operands are the same signedness. */ 7180 else if (op0_signed == op1_signed) 7181 /* OK */; 7182 else 7183 { 7184 tree sop, uop; 7185 7186 if (op0_signed) 7187 sop = xop0, uop = xop1; 7188 else 7189 sop = xop1, uop = xop0; 7190 7191 /* Do not warn if the signed quantity is an 7192 unsuffixed integer literal (or some static 7193 constant expression involving such literals or a 7194 conditional expression involving such literals) 7195 and it is non-negative. */ 7196 if (c_tree_expr_nonnegative_p (sop)) 7197 /* OK */; 7198 /* Do not warn if the comparison is an equality operation, 7199 the unsigned quantity is an integral constant, and it 7200 would fit in the result if the result were signed. */ 7201 else if (TREE_CODE (uop) == INTEGER_CST 7202 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 7203 && int_fits_type_p 7204 (uop, c_common_signed_type (result_type))) 7205 /* OK */; 7206 /* Do not warn if the unsigned quantity is an enumeration 7207 constant and its maximum value would fit in the result 7208 if the result were signed. */ 7209 else if (TREE_CODE (uop) == INTEGER_CST 7210 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 7211 && int_fits_type_p 7212 (TYPE_MAX_VALUE (TREE_TYPE(uop)), 7213 c_common_signed_type (result_type))) 7214 /* OK */; 7215 else 7216 warning ("comparison between signed and unsigned"); 7217 } 7218 7219 /* Warn if two unsigned values are being compared in a size 7220 larger than their original size, and one (and only one) is the 7221 result of a `~' operator. This comparison will always fail. 7222 7223 Also warn if one operand is a constant, and the constant 7224 does not have all bits set that are set in the ~ operand 7225 when it is extended. */ 7226 7227 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 7228 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 7229 { 7230 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 7231 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 7232 &unsignedp0); 7233 else 7234 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 7235 &unsignedp1); 7236 7237 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 7238 { 7239 tree primop; 7240 HOST_WIDE_INT constant, mask; 7241 int unsignedp, bits; 7242 7243 if (host_integerp (primop0, 0)) 7244 { 7245 primop = primop1; 7246 unsignedp = unsignedp1; 7247 constant = tree_low_cst (primop0, 0); 7248 } 7249 else 7250 { 7251 primop = primop0; 7252 unsignedp = unsignedp0; 7253 constant = tree_low_cst (primop1, 0); 7254 } 7255 7256 bits = TYPE_PRECISION (TREE_TYPE (primop)); 7257 if (bits < TYPE_PRECISION (result_type) 7258 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 7259 { 7260 mask = (~ (HOST_WIDE_INT) 0) << bits; 7261 if ((mask & constant) != mask) 7262 warning ("comparison of promoted ~unsigned with constant"); 7263 } 7264 } 7265 else if (unsignedp0 && unsignedp1 7266 && (TYPE_PRECISION (TREE_TYPE (primop0)) 7267 < TYPE_PRECISION (result_type)) 7268 && (TYPE_PRECISION (TREE_TYPE (primop1)) 7269 < TYPE_PRECISION (result_type))) 7270 warning ("comparison of promoted ~unsigned with unsigned"); 7271 } 7272 } 7273 } 7274 } 7275 7276 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 7277 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 7278 Then the expression will be built. 7279 It will be given type FINAL_TYPE if that is nonzero; 7280 otherwise, it will be given type RESULT_TYPE. */ 7281 7282 if (!result_type) 7283 { 7284 binary_op_error (code); 7285 return error_mark_node; 7286 } 7287 7288 if (! converted) 7289 { 7290 if (TREE_TYPE (op0) != result_type) 7291 op0 = convert (result_type, op0); 7292 if (TREE_TYPE (op1) != result_type) 7293 op1 = convert (result_type, op1); 7294 } 7295 7296 if (build_type == NULL_TREE) 7297 build_type = result_type; 7298 7299 { 7300 tree result = build (resultcode, build_type, op0, op1); 7301 tree folded; 7302 7303 /* Treat expressions in initializers specially as they can't trap. */ 7304 folded = require_constant_value ? fold_initializer (result) 7305 : fold (result); 7306 if (folded == result) 7307 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1); 7308 if (final_type != 0) 7309 return convert (final_type, folded); 7310 return folded; 7311 } 7312} 7313