c-typeck.c revision 161651
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 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE 4102 && vector_types_convertible_p (TREE_TYPE (inside_init), type) 4103 && TREE_CONSTANT (inside_init)) 4104 { 4105 if (TREE_CODE (inside_init) == VECTOR_CST 4106 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4107 TYPE_MAIN_VARIANT (type), 4108 COMPARE_STRICT)) 4109 return inside_init; 4110 4111 if (TREE_CODE (inside_init) == CONSTRUCTOR) 4112 { 4113 tree link; 4114 4115 /* Iterate through elements and check if all constructor 4116 elements are *_CSTs. */ 4117 for (link = CONSTRUCTOR_ELTS (inside_init); 4118 link; 4119 link = TREE_CHAIN (link)) 4120 if (TREE_CODE_CLASS (TREE_CODE (TREE_VALUE (link))) != 'c') 4121 break; 4122 4123 if (link == NULL) 4124 return build_vector (type, CONSTRUCTOR_ELTS (inside_init)); 4125 } 4126 } 4127 4128 /* Any type can be initialized 4129 from an expression of the same type, optionally with braces. */ 4130 4131 if (inside_init && TREE_TYPE (inside_init) != 0 4132 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), 4133 TYPE_MAIN_VARIANT (type), COMPARE_STRICT) 4134 || (code == ARRAY_TYPE 4135 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4136 || (code == VECTOR_TYPE 4137 && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT)) 4138 || (code == POINTER_TYPE 4139 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE 4140 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), 4141 TREE_TYPE (type), COMPARE_STRICT)) 4142 || (code == POINTER_TYPE 4143 && TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE 4144 && comptypes (TREE_TYPE (inside_init), 4145 TREE_TYPE (type), COMPARE_STRICT)))) 4146 { 4147 if (code == POINTER_TYPE) 4148 { 4149 inside_init = default_function_array_conversion (inside_init); 4150 4151 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) 4152 { 4153 error_init ("invalid use of non-lvalue array"); 4154 return error_mark_node; 4155 } 4156 } 4157 4158 if (code == VECTOR_TYPE) 4159 /* Although the types are compatible, we may require a 4160 conversion. */ 4161 inside_init = convert (type, inside_init); 4162 4163 if (require_constant && !flag_isoc99 4164 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) 4165 { 4166 /* As an extension, allow initializing objects with static storage 4167 duration with compound literals (which are then treated just as 4168 the brace enclosed list they contain). */ 4169 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); 4170 inside_init = DECL_INITIAL (decl); 4171 } 4172 4173 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST 4174 && TREE_CODE (inside_init) != CONSTRUCTOR) 4175 { 4176 error_init ("array initialized from non-constant array expression"); 4177 return error_mark_node; 4178 } 4179 4180 if (optimize && TREE_CODE (inside_init) == VAR_DECL) 4181 inside_init = decl_constant_value_for_broken_optimization (inside_init); 4182 4183 /* Compound expressions can only occur here if -pedantic or 4184 -pedantic-errors is specified. In the later case, we always want 4185 an error. In the former case, we simply want a warning. */ 4186 if (require_constant && pedantic 4187 && TREE_CODE (inside_init) == COMPOUND_EXPR) 4188 { 4189 inside_init 4190 = valid_compound_expr_initializer (inside_init, 4191 TREE_TYPE (inside_init)); 4192 if (inside_init == error_mark_node) 4193 error_init ("initializer element is not constant"); 4194 else 4195 pedwarn_init ("initializer element is not constant"); 4196 if (flag_pedantic_errors) 4197 inside_init = error_mark_node; 4198 } 4199 else if (require_constant 4200 && (!TREE_CONSTANT (inside_init) 4201 /* This test catches things like `7 / 0' which 4202 result in an expression for which TREE_CONSTANT 4203 is true, but which is not actually something 4204 that is a legal constant. We really should not 4205 be using this function, because it is a part of 4206 the back-end. Instead, the expression should 4207 already have been turned into ERROR_MARK_NODE. */ 4208 || !initializer_constant_valid_p (inside_init, 4209 TREE_TYPE (inside_init)))) 4210 { 4211 error_init ("initializer element is not constant"); 4212 inside_init = error_mark_node; 4213 } 4214 4215 return inside_init; 4216 } 4217 4218 /* Handle scalar types, including conversions. */ 4219 4220 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE 4221 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE) 4222 { 4223 /* Note that convert_for_assignment calls default_conversion 4224 for arrays and functions. We must not call it in the 4225 case where inside_init is a null pointer constant. */ 4226 inside_init 4227 = convert_for_assignment (type, init, _("initialization"), 4228 NULL_TREE, NULL_TREE, 0); 4229 4230 if (require_constant && ! TREE_CONSTANT (inside_init)) 4231 { 4232 error_init ("initializer element is not constant"); 4233 inside_init = error_mark_node; 4234 } 4235 else if (require_constant 4236 && initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init)) == 0) 4237 { 4238 error_init ("initializer element is not computable at load time"); 4239 inside_init = error_mark_node; 4240 } 4241 4242 return inside_init; 4243 } 4244 4245 /* Come here only for records and arrays. */ 4246 4247 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4248 { 4249 error_init ("variable-sized object may not be initialized"); 4250 return error_mark_node; 4251 } 4252 4253 error_init ("invalid initializer"); 4254 return error_mark_node; 4255} 4256 4257/* Handle initializers that use braces. */ 4258 4259/* Type of object we are accumulating a constructor for. 4260 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ 4261static tree constructor_type; 4262 4263/* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields 4264 left to fill. */ 4265static tree constructor_fields; 4266 4267/* For an ARRAY_TYPE, this is the specified index 4268 at which to store the next element we get. */ 4269static tree constructor_index; 4270 4271/* For an ARRAY_TYPE, this is the maximum index. */ 4272static tree constructor_max_index; 4273 4274/* For a RECORD_TYPE, this is the first field not yet written out. */ 4275static tree constructor_unfilled_fields; 4276 4277/* For an ARRAY_TYPE, this is the index of the first element 4278 not yet written out. */ 4279static tree constructor_unfilled_index; 4280 4281/* In a RECORD_TYPE, the byte index of the next consecutive field. 4282 This is so we can generate gaps between fields, when appropriate. */ 4283static tree constructor_bit_index; 4284 4285/* If we are saving up the elements rather than allocating them, 4286 this is the list of elements so far (in reverse order, 4287 most recent first). */ 4288static tree constructor_elements; 4289 4290/* 1 if constructor should be incrementally stored into a constructor chain, 4291 0 if all the elements should be kept in AVL tree. */ 4292static int constructor_incremental; 4293 4294/* 1 if so far this constructor's elements are all compile-time constants. */ 4295static int constructor_constant; 4296 4297/* 1 if so far this constructor's elements are all valid address constants. */ 4298static int constructor_simple; 4299 4300/* 1 if this constructor is erroneous so far. */ 4301static int constructor_erroneous; 4302 4303/* Structure for managing pending initializer elements, organized as an 4304 AVL tree. */ 4305 4306struct init_node 4307{ 4308 struct init_node *left, *right; 4309 struct init_node *parent; 4310 int balance; 4311 tree purpose; 4312 tree value; 4313}; 4314 4315/* Tree of pending elements at this constructor level. 4316 These are elements encountered out of order 4317 which belong at places we haven't reached yet in actually 4318 writing the output. 4319 Will never hold tree nodes across GC runs. */ 4320static struct init_node *constructor_pending_elts; 4321 4322/* The SPELLING_DEPTH of this constructor. */ 4323static int constructor_depth; 4324 4325/* 0 if implicitly pushing constructor levels is allowed. */ 4326int constructor_no_implicit = 0; /* 0 for C; 1 for some other languages. */ 4327 4328/* DECL node for which an initializer is being read. 4329 0 means we are reading a constructor expression 4330 such as (struct foo) {...}. */ 4331static tree constructor_decl; 4332 4333/* start_init saves the ASMSPEC arg here for really_start_incremental_init. */ 4334static const char *constructor_asmspec; 4335 4336/* Nonzero if this is an initializer for a top-level decl. */ 4337static int constructor_top_level; 4338 4339/* Nonzero if there were any member designators in this initializer. */ 4340static int constructor_designated; 4341 4342/* Nesting depth of designator list. */ 4343static int designator_depth; 4344 4345/* Nonzero if there were diagnosed errors in this designator list. */ 4346static int designator_errorneous; 4347 4348 4349/* This stack has a level for each implicit or explicit level of 4350 structuring in the initializer, including the outermost one. It 4351 saves the values of most of the variables above. */ 4352 4353struct constructor_range_stack; 4354 4355struct constructor_stack 4356{ 4357 struct constructor_stack *next; 4358 tree type; 4359 tree fields; 4360 tree index; 4361 tree max_index; 4362 tree unfilled_index; 4363 tree unfilled_fields; 4364 tree bit_index; 4365 tree elements; 4366 struct init_node *pending_elts; 4367 int offset; 4368 int depth; 4369 /* If nonzero, this value should replace the entire 4370 constructor at this level. */ 4371 tree replacement_value; 4372 struct constructor_range_stack *range_stack; 4373 char constant; 4374 char simple; 4375 char implicit; 4376 char erroneous; 4377 char outer; 4378 char incremental; 4379 char designated; 4380}; 4381 4382struct constructor_stack *constructor_stack; 4383 4384/* This stack represents designators from some range designator up to 4385 the last designator in the list. */ 4386 4387struct constructor_range_stack 4388{ 4389 struct constructor_range_stack *next, *prev; 4390 struct constructor_stack *stack; 4391 tree range_start; 4392 tree index; 4393 tree range_end; 4394 tree fields; 4395}; 4396 4397struct constructor_range_stack *constructor_range_stack; 4398 4399/* This stack records separate initializers that are nested. 4400 Nested initializers can't happen in ANSI C, but GNU C allows them 4401 in cases like { ... (struct foo) { ... } ... }. */ 4402 4403struct initializer_stack 4404{ 4405 struct initializer_stack *next; 4406 tree decl; 4407 const char *asmspec; 4408 struct constructor_stack *constructor_stack; 4409 struct constructor_range_stack *constructor_range_stack; 4410 tree elements; 4411 struct spelling *spelling; 4412 struct spelling *spelling_base; 4413 int spelling_size; 4414 char top_level; 4415 char require_constant_value; 4416 char require_constant_elements; 4417}; 4418 4419struct initializer_stack *initializer_stack; 4420 4421/* Prepare to parse and output the initializer for variable DECL. */ 4422 4423void 4424start_init (tree decl, tree asmspec_tree, int top_level) 4425{ 4426 const char *locus; 4427 struct initializer_stack *p = xmalloc (sizeof (struct initializer_stack)); 4428 const char *asmspec = 0; 4429 4430 if (asmspec_tree) 4431 asmspec = TREE_STRING_POINTER (asmspec_tree); 4432 4433 p->decl = constructor_decl; 4434 p->asmspec = constructor_asmspec; 4435 p->require_constant_value = require_constant_value; 4436 p->require_constant_elements = require_constant_elements; 4437 p->constructor_stack = constructor_stack; 4438 p->constructor_range_stack = constructor_range_stack; 4439 p->elements = constructor_elements; 4440 p->spelling = spelling; 4441 p->spelling_base = spelling_base; 4442 p->spelling_size = spelling_size; 4443 p->top_level = constructor_top_level; 4444 p->next = initializer_stack; 4445 initializer_stack = p; 4446 4447 constructor_decl = decl; 4448 constructor_asmspec = asmspec; 4449 constructor_designated = 0; 4450 constructor_top_level = top_level; 4451 4452 if (decl != 0) 4453 { 4454 require_constant_value = TREE_STATIC (decl); 4455 require_constant_elements 4456 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) 4457 /* For a scalar, you can always use any value to initialize, 4458 even within braces. */ 4459 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE 4460 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE 4461 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE 4462 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); 4463 locus = IDENTIFIER_POINTER (DECL_NAME (decl)); 4464 } 4465 else 4466 { 4467 require_constant_value = 0; 4468 require_constant_elements = 0; 4469 locus = "(anonymous)"; 4470 } 4471 4472 constructor_stack = 0; 4473 constructor_range_stack = 0; 4474 4475 missing_braces_mentioned = 0; 4476 4477 spelling_base = 0; 4478 spelling_size = 0; 4479 RESTORE_SPELLING_DEPTH (0); 4480 4481 if (locus) 4482 push_string (locus); 4483} 4484 4485void 4486finish_init (void) 4487{ 4488 struct initializer_stack *p = initializer_stack; 4489 4490 /* Free the whole constructor stack of this initializer. */ 4491 while (constructor_stack) 4492 { 4493 struct constructor_stack *q = constructor_stack; 4494 constructor_stack = q->next; 4495 free (q); 4496 } 4497 4498 if (constructor_range_stack) 4499 abort (); 4500 4501 /* Pop back to the data of the outer initializer (if any). */ 4502 free (spelling_base); 4503 4504 constructor_decl = p->decl; 4505 constructor_asmspec = p->asmspec; 4506 require_constant_value = p->require_constant_value; 4507 require_constant_elements = p->require_constant_elements; 4508 constructor_stack = p->constructor_stack; 4509 constructor_range_stack = p->constructor_range_stack; 4510 constructor_elements = p->elements; 4511 spelling = p->spelling; 4512 spelling_base = p->spelling_base; 4513 spelling_size = p->spelling_size; 4514 constructor_top_level = p->top_level; 4515 initializer_stack = p->next; 4516 free (p); 4517} 4518 4519/* Call here when we see the initializer is surrounded by braces. 4520 This is instead of a call to push_init_level; 4521 it is matched by a call to pop_init_level. 4522 4523 TYPE is the type to initialize, for a constructor expression. 4524 For an initializer for a decl, TYPE is zero. */ 4525 4526void 4527really_start_incremental_init (tree type) 4528{ 4529 struct constructor_stack *p = xmalloc (sizeof (struct constructor_stack)); 4530 4531 if (type == 0) 4532 type = TREE_TYPE (constructor_decl); 4533 4534 if ((*targetm.vector_opaque_p) (type)) 4535 error ("opaque vector types cannot be initialized"); 4536 4537 p->type = constructor_type; 4538 p->fields = constructor_fields; 4539 p->index = constructor_index; 4540 p->max_index = constructor_max_index; 4541 p->unfilled_index = constructor_unfilled_index; 4542 p->unfilled_fields = constructor_unfilled_fields; 4543 p->bit_index = constructor_bit_index; 4544 p->elements = constructor_elements; 4545 p->constant = constructor_constant; 4546 p->simple = constructor_simple; 4547 p->erroneous = constructor_erroneous; 4548 p->pending_elts = constructor_pending_elts; 4549 p->depth = constructor_depth; 4550 p->replacement_value = 0; 4551 p->implicit = 0; 4552 p->range_stack = 0; 4553 p->outer = 0; 4554 p->incremental = constructor_incremental; 4555 p->designated = constructor_designated; 4556 p->next = 0; 4557 constructor_stack = p; 4558 4559 constructor_constant = 1; 4560 constructor_simple = 1; 4561 constructor_depth = SPELLING_DEPTH (); 4562 constructor_elements = 0; 4563 constructor_pending_elts = 0; 4564 constructor_type = type; 4565 constructor_incremental = 1; 4566 constructor_designated = 0; 4567 designator_depth = 0; 4568 designator_errorneous = 0; 4569 4570 if (TREE_CODE (constructor_type) == RECORD_TYPE 4571 || TREE_CODE (constructor_type) == UNION_TYPE) 4572 { 4573 constructor_fields = TYPE_FIELDS (constructor_type); 4574 /* Skip any nameless bit fields at the beginning. */ 4575 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4576 && DECL_NAME (constructor_fields) == 0) 4577 constructor_fields = TREE_CHAIN (constructor_fields); 4578 4579 constructor_unfilled_fields = constructor_fields; 4580 constructor_bit_index = bitsize_zero_node; 4581 } 4582 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4583 { 4584 if (TYPE_DOMAIN (constructor_type)) 4585 { 4586 constructor_max_index 4587 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4588 4589 /* Detect non-empty initializations of zero-length arrays. */ 4590 if (constructor_max_index == NULL_TREE 4591 && TYPE_SIZE (constructor_type)) 4592 constructor_max_index = build_int_2 (-1, -1); 4593 4594 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4595 to initialize VLAs will cause a proper error; avoid tree 4596 checking errors as well by setting a safe value. */ 4597 if (constructor_max_index 4598 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4599 constructor_max_index = build_int_2 (-1, -1); 4600 4601 constructor_index 4602 = convert (bitsizetype, 4603 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4604 } 4605 else 4606 constructor_index = bitsize_zero_node; 4607 4608 constructor_unfilled_index = constructor_index; 4609 } 4610 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4611 { 4612 /* Vectors are like simple fixed-size arrays. */ 4613 constructor_max_index = 4614 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4615 constructor_index = convert (bitsizetype, bitsize_zero_node); 4616 constructor_unfilled_index = constructor_index; 4617 } 4618 else 4619 { 4620 /* Handle the case of int x = {5}; */ 4621 constructor_fields = constructor_type; 4622 constructor_unfilled_fields = constructor_type; 4623 } 4624} 4625 4626/* Push down into a subobject, for initialization. 4627 If this is for an explicit set of braces, IMPLICIT is 0. 4628 If it is because the next element belongs at a lower level, 4629 IMPLICIT is 1 (or 2 if the push is because of designator list). */ 4630 4631void 4632push_init_level (int implicit) 4633{ 4634 struct constructor_stack *p; 4635 tree value = NULL_TREE; 4636 4637 /* If we've exhausted any levels that didn't have braces, 4638 pop them now. If implicit == 1, this will have been done in 4639 process_init_element; do not repeat it here because in the case 4640 of excess initializers for an empty aggregate this leads to an 4641 infinite cycle of popping a level and immediately recreating 4642 it. */ 4643 if (implicit != 1) 4644 { 4645 while (constructor_stack->implicit) 4646 { 4647 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4648 || TREE_CODE (constructor_type) == UNION_TYPE) 4649 && constructor_fields == 0) 4650 process_init_element (pop_init_level (1)); 4651 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 4652 && constructor_max_index 4653 && tree_int_cst_lt (constructor_max_index, 4654 constructor_index)) 4655 process_init_element (pop_init_level (1)); 4656 else 4657 break; 4658 } 4659 } 4660 4661 /* Unless this is an explicit brace, we need to preserve previous 4662 content if any. */ 4663 if (implicit) 4664 { 4665 if ((TREE_CODE (constructor_type) == RECORD_TYPE 4666 || TREE_CODE (constructor_type) == UNION_TYPE) 4667 && constructor_fields) 4668 value = find_init_member (constructor_fields); 4669 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4670 value = find_init_member (constructor_index); 4671 } 4672 4673 p = xmalloc (sizeof (struct constructor_stack)); 4674 p->type = constructor_type; 4675 p->fields = constructor_fields; 4676 p->index = constructor_index; 4677 p->max_index = constructor_max_index; 4678 p->unfilled_index = constructor_unfilled_index; 4679 p->unfilled_fields = constructor_unfilled_fields; 4680 p->bit_index = constructor_bit_index; 4681 p->elements = constructor_elements; 4682 p->constant = constructor_constant; 4683 p->simple = constructor_simple; 4684 p->erroneous = constructor_erroneous; 4685 p->pending_elts = constructor_pending_elts; 4686 p->depth = constructor_depth; 4687 p->replacement_value = 0; 4688 p->implicit = implicit; 4689 p->outer = 0; 4690 p->incremental = constructor_incremental; 4691 p->designated = constructor_designated; 4692 p->next = constructor_stack; 4693 p->range_stack = 0; 4694 constructor_stack = p; 4695 4696 constructor_constant = 1; 4697 constructor_simple = 1; 4698 constructor_depth = SPELLING_DEPTH (); 4699 constructor_elements = 0; 4700 constructor_incremental = 1; 4701 constructor_designated = 0; 4702 constructor_pending_elts = 0; 4703 if (!implicit) 4704 { 4705 p->range_stack = constructor_range_stack; 4706 constructor_range_stack = 0; 4707 designator_depth = 0; 4708 designator_errorneous = 0; 4709 } 4710 4711 /* Don't die if an entire brace-pair level is superfluous 4712 in the containing level. */ 4713 if (constructor_type == 0) 4714 ; 4715 else if (TREE_CODE (constructor_type) == RECORD_TYPE 4716 || TREE_CODE (constructor_type) == UNION_TYPE) 4717 { 4718 /* Don't die if there are extra init elts at the end. */ 4719 if (constructor_fields == 0) 4720 constructor_type = 0; 4721 else 4722 { 4723 constructor_type = TREE_TYPE (constructor_fields); 4724 push_member_name (constructor_fields); 4725 constructor_depth++; 4726 } 4727 } 4728 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4729 { 4730 constructor_type = TREE_TYPE (constructor_type); 4731 push_array_bounds (tree_low_cst (constructor_index, 0)); 4732 constructor_depth++; 4733 } 4734 4735 if (constructor_type == 0) 4736 { 4737 error_init ("extra brace group at end of initializer"); 4738 constructor_fields = 0; 4739 constructor_unfilled_fields = 0; 4740 return; 4741 } 4742 4743 if (value && TREE_CODE (value) == CONSTRUCTOR) 4744 { 4745 constructor_constant = TREE_CONSTANT (value); 4746 constructor_simple = TREE_STATIC (value); 4747 constructor_elements = CONSTRUCTOR_ELTS (value); 4748 if (constructor_elements 4749 && (TREE_CODE (constructor_type) == RECORD_TYPE 4750 || TREE_CODE (constructor_type) == ARRAY_TYPE)) 4751 set_nonincremental_init (); 4752 } 4753 4754 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) 4755 { 4756 missing_braces_mentioned = 1; 4757 warning_init ("missing braces around initializer"); 4758 } 4759 4760 if (TREE_CODE (constructor_type) == RECORD_TYPE 4761 || TREE_CODE (constructor_type) == UNION_TYPE) 4762 { 4763 constructor_fields = TYPE_FIELDS (constructor_type); 4764 /* Skip any nameless bit fields at the beginning. */ 4765 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) 4766 && DECL_NAME (constructor_fields) == 0) 4767 constructor_fields = TREE_CHAIN (constructor_fields); 4768 4769 constructor_unfilled_fields = constructor_fields; 4770 constructor_bit_index = bitsize_zero_node; 4771 } 4772 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 4773 { 4774 /* Vectors are like simple fixed-size arrays. */ 4775 constructor_max_index = 4776 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0); 4777 constructor_index = convert (bitsizetype, integer_zero_node); 4778 constructor_unfilled_index = constructor_index; 4779 } 4780 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 4781 { 4782 if (TYPE_DOMAIN (constructor_type)) 4783 { 4784 constructor_max_index 4785 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); 4786 4787 /* Detect non-empty initializations of zero-length arrays. */ 4788 if (constructor_max_index == NULL_TREE 4789 && TYPE_SIZE (constructor_type)) 4790 constructor_max_index = build_int_2 (-1, -1); 4791 4792 /* constructor_max_index needs to be an INTEGER_CST. Attempts 4793 to initialize VLAs will cause a proper error; avoid tree 4794 checking errors as well by setting a safe value. */ 4795 if (constructor_max_index 4796 && TREE_CODE (constructor_max_index) != INTEGER_CST) 4797 constructor_max_index = build_int_2 (-1, -1); 4798 4799 constructor_index 4800 = convert (bitsizetype, 4801 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 4802 } 4803 else 4804 constructor_index = bitsize_zero_node; 4805 4806 constructor_unfilled_index = constructor_index; 4807 if (value && TREE_CODE (value) == STRING_CST) 4808 { 4809 /* We need to split the char/wchar array into individual 4810 characters, so that we don't have to special case it 4811 everywhere. */ 4812 set_nonincremental_init_from_string (value); 4813 } 4814 } 4815 else 4816 { 4817 warning_init ("braces around scalar initializer"); 4818 constructor_fields = constructor_type; 4819 constructor_unfilled_fields = constructor_type; 4820 } 4821} 4822 4823/* At the end of an implicit or explicit brace level, 4824 finish up that level of constructor. 4825 If we were outputting the elements as they are read, return 0 4826 from inner levels (process_init_element ignores that), 4827 but return error_mark_node from the outermost level 4828 (that's what we want to put in DECL_INITIAL). 4829 Otherwise, return a CONSTRUCTOR expression. */ 4830 4831tree 4832pop_init_level (int implicit) 4833{ 4834 struct constructor_stack *p; 4835 tree constructor = 0; 4836 4837 if (implicit == 0) 4838 { 4839 /* When we come to an explicit close brace, 4840 pop any inner levels that didn't have explicit braces. */ 4841 while (constructor_stack->implicit) 4842 process_init_element (pop_init_level (1)); 4843 4844 if (constructor_range_stack) 4845 abort (); 4846 } 4847 4848 /* Now output all pending elements. */ 4849 constructor_incremental = 1; 4850 output_pending_init_elements (1); 4851 4852 p = constructor_stack; 4853 4854 /* Error for initializing a flexible array member, or a zero-length 4855 array member in an inappropriate context. */ 4856 if (constructor_type && constructor_fields 4857 && TREE_CODE (constructor_type) == ARRAY_TYPE 4858 && TYPE_DOMAIN (constructor_type) 4859 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) 4860 { 4861 /* Silently discard empty initializations. The parser will 4862 already have pedwarned for empty brackets. */ 4863 if (integer_zerop (constructor_unfilled_index)) 4864 constructor_type = NULL_TREE; 4865 else if (! TYPE_SIZE (constructor_type)) 4866 { 4867 if (constructor_depth > 2) 4868 error_init ("initialization of flexible array member in a nested context"); 4869 else if (pedantic) 4870 pedwarn_init ("initialization of a flexible array member"); 4871 4872 /* We have already issued an error message for the existence 4873 of a flexible array member not at the end of the structure. 4874 Discard the initializer so that we do not abort later. */ 4875 if (TREE_CHAIN (constructor_fields) != NULL_TREE) 4876 constructor_type = NULL_TREE; 4877 } 4878 else 4879 /* Zero-length arrays are no longer special, so we should no longer 4880 get here. */ 4881 abort (); 4882 } 4883 4884 /* Warn when some struct elements are implicitly initialized to zero. */ 4885 if (extra_warnings 4886 && constructor_type 4887 && TREE_CODE (constructor_type) == RECORD_TYPE 4888 && constructor_unfilled_fields) 4889 { 4890 /* Do not warn for flexible array members or zero-length arrays. */ 4891 while (constructor_unfilled_fields 4892 && (! DECL_SIZE (constructor_unfilled_fields) 4893 || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) 4894 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 4895 4896 /* Do not warn if this level of the initializer uses member 4897 designators; it is likely to be deliberate. */ 4898 if (constructor_unfilled_fields && !constructor_designated) 4899 { 4900 push_member_name (constructor_unfilled_fields); 4901 warning_init ("missing initializer"); 4902 RESTORE_SPELLING_DEPTH (constructor_depth); 4903 } 4904 } 4905 4906 /* Pad out the end of the structure. */ 4907 if (p->replacement_value) 4908 /* If this closes a superfluous brace pair, 4909 just pass out the element between them. */ 4910 constructor = p->replacement_value; 4911 else if (constructor_type == 0) 4912 ; 4913 else if (TREE_CODE (constructor_type) != RECORD_TYPE 4914 && TREE_CODE (constructor_type) != UNION_TYPE 4915 && TREE_CODE (constructor_type) != ARRAY_TYPE 4916 && TREE_CODE (constructor_type) != VECTOR_TYPE) 4917 { 4918 /* A nonincremental scalar initializer--just return 4919 the element, after verifying there is just one. */ 4920 if (constructor_elements == 0) 4921 { 4922 if (!constructor_erroneous) 4923 error_init ("empty scalar initializer"); 4924 constructor = error_mark_node; 4925 } 4926 else if (TREE_CHAIN (constructor_elements) != 0) 4927 { 4928 error_init ("extra elements in scalar initializer"); 4929 constructor = TREE_VALUE (constructor_elements); 4930 } 4931 else 4932 constructor = TREE_VALUE (constructor_elements); 4933 } 4934 else 4935 { 4936 if (constructor_erroneous) 4937 constructor = error_mark_node; 4938 else 4939 { 4940 constructor = build_constructor (constructor_type, 4941 nreverse (constructor_elements)); 4942 if (constructor_constant) 4943 TREE_CONSTANT (constructor) = 1; 4944 if (constructor_constant && constructor_simple) 4945 TREE_STATIC (constructor) = 1; 4946 } 4947 } 4948 4949 constructor_type = p->type; 4950 constructor_fields = p->fields; 4951 constructor_index = p->index; 4952 constructor_max_index = p->max_index; 4953 constructor_unfilled_index = p->unfilled_index; 4954 constructor_unfilled_fields = p->unfilled_fields; 4955 constructor_bit_index = p->bit_index; 4956 constructor_elements = p->elements; 4957 constructor_constant = p->constant; 4958 constructor_simple = p->simple; 4959 constructor_erroneous = p->erroneous; 4960 constructor_incremental = p->incremental; 4961 constructor_designated = p->designated; 4962 constructor_pending_elts = p->pending_elts; 4963 constructor_depth = p->depth; 4964 if (!p->implicit) 4965 constructor_range_stack = p->range_stack; 4966 RESTORE_SPELLING_DEPTH (constructor_depth); 4967 4968 constructor_stack = p->next; 4969 free (p); 4970 4971 if (constructor == 0) 4972 { 4973 if (constructor_stack == 0) 4974 return error_mark_node; 4975 return NULL_TREE; 4976 } 4977 return constructor; 4978} 4979 4980/* Common handling for both array range and field name designators. 4981 ARRAY argument is nonzero for array ranges. Returns zero for success. */ 4982 4983static int 4984set_designator (int array) 4985{ 4986 tree subtype; 4987 enum tree_code subcode; 4988 4989 /* Don't die if an entire brace-pair level is superfluous 4990 in the containing level. */ 4991 if (constructor_type == 0) 4992 return 1; 4993 4994 /* If there were errors in this designator list already, bail out silently. */ 4995 if (designator_errorneous) 4996 return 1; 4997 4998 if (!designator_depth) 4999 { 5000 if (constructor_range_stack) 5001 abort (); 5002 5003 /* Designator list starts at the level of closest explicit 5004 braces. */ 5005 while (constructor_stack->implicit) 5006 process_init_element (pop_init_level (1)); 5007 constructor_designated = 1; 5008 return 0; 5009 } 5010 5011 if (constructor_no_implicit) 5012 { 5013 error_init ("initialization designators may not nest"); 5014 return 1; 5015 } 5016 5017 if (TREE_CODE (constructor_type) == RECORD_TYPE 5018 || TREE_CODE (constructor_type) == UNION_TYPE) 5019 { 5020 subtype = TREE_TYPE (constructor_fields); 5021 if (subtype != error_mark_node) 5022 subtype = TYPE_MAIN_VARIANT (subtype); 5023 } 5024 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5025 { 5026 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 5027 } 5028 else 5029 abort (); 5030 5031 subcode = TREE_CODE (subtype); 5032 if (array && subcode != ARRAY_TYPE) 5033 { 5034 error_init ("array index in non-array initializer"); 5035 return 1; 5036 } 5037 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) 5038 { 5039 error_init ("field name not in record or union initializer"); 5040 return 1; 5041 } 5042 5043 constructor_designated = 1; 5044 push_init_level (2); 5045 return 0; 5046} 5047 5048/* If there are range designators in designator list, push a new designator 5049 to constructor_range_stack. RANGE_END is end of such stack range or 5050 NULL_TREE if there is no range designator at this level. */ 5051 5052static void 5053push_range_stack (tree range_end) 5054{ 5055 struct constructor_range_stack *p; 5056 5057 p = ggc_alloc (sizeof (struct constructor_range_stack)); 5058 p->prev = constructor_range_stack; 5059 p->next = 0; 5060 p->fields = constructor_fields; 5061 p->range_start = constructor_index; 5062 p->index = constructor_index; 5063 p->stack = constructor_stack; 5064 p->range_end = range_end; 5065 if (constructor_range_stack) 5066 constructor_range_stack->next = p; 5067 constructor_range_stack = p; 5068} 5069 5070/* Within an array initializer, specify the next index to be initialized. 5071 FIRST is that index. If LAST is nonzero, then initialize a range 5072 of indices, running from FIRST through LAST. */ 5073 5074void 5075set_init_index (tree first, tree last) 5076{ 5077 if (set_designator (1)) 5078 return; 5079 5080 designator_errorneous = 1; 5081 5082 while ((TREE_CODE (first) == NOP_EXPR 5083 || TREE_CODE (first) == CONVERT_EXPR 5084 || TREE_CODE (first) == NON_LVALUE_EXPR) 5085 && (TYPE_MODE (TREE_TYPE (first)) 5086 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (first, 0))))) 5087 first = TREE_OPERAND (first, 0); 5088 5089 if (last) 5090 while ((TREE_CODE (last) == NOP_EXPR 5091 || TREE_CODE (last) == CONVERT_EXPR 5092 || TREE_CODE (last) == NON_LVALUE_EXPR) 5093 && (TYPE_MODE (TREE_TYPE (last)) 5094 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (last, 0))))) 5095 last = TREE_OPERAND (last, 0); 5096 5097 if (TREE_CODE (first) != INTEGER_CST) 5098 error_init ("nonconstant array index in initializer"); 5099 else if (last != 0 && TREE_CODE (last) != INTEGER_CST) 5100 error_init ("nonconstant array index in initializer"); 5101 else if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5102 error_init ("array index in non-array initializer"); 5103 else if (tree_int_cst_sgn (first) == -1) 5104 error_init ("array index in initializer exceeds array bounds"); 5105 else if (constructor_max_index 5106 && tree_int_cst_lt (constructor_max_index, first)) 5107 error_init ("array index in initializer exceeds array bounds"); 5108 else 5109 { 5110 constructor_index = convert (bitsizetype, first); 5111 5112 if (last) 5113 { 5114 if (tree_int_cst_equal (first, last)) 5115 last = 0; 5116 else if (tree_int_cst_lt (last, first)) 5117 { 5118 error_init ("empty index range in initializer"); 5119 last = 0; 5120 } 5121 else 5122 { 5123 last = convert (bitsizetype, last); 5124 if (constructor_max_index != 0 5125 && tree_int_cst_lt (constructor_max_index, last)) 5126 { 5127 error_init ("array index range in initializer exceeds array bounds"); 5128 last = 0; 5129 } 5130 } 5131 } 5132 5133 designator_depth++; 5134 designator_errorneous = 0; 5135 if (constructor_range_stack || last) 5136 push_range_stack (last); 5137 } 5138} 5139 5140/* Within a struct initializer, specify the next field to be initialized. */ 5141 5142void 5143set_init_label (tree fieldname) 5144{ 5145 tree tail; 5146 5147 if (set_designator (0)) 5148 return; 5149 5150 designator_errorneous = 1; 5151 5152 if (TREE_CODE (constructor_type) != RECORD_TYPE 5153 && TREE_CODE (constructor_type) != UNION_TYPE) 5154 { 5155 error_init ("field name not in record or union initializer"); 5156 return; 5157 } 5158 5159 for (tail = TYPE_FIELDS (constructor_type); tail; 5160 tail = TREE_CHAIN (tail)) 5161 { 5162 if (DECL_NAME (tail) == fieldname) 5163 break; 5164 } 5165 5166 if (tail == 0) 5167 error ("unknown field `%s' specified in initializer", 5168 IDENTIFIER_POINTER (fieldname)); 5169 else 5170 { 5171 constructor_fields = tail; 5172 designator_depth++; 5173 designator_errorneous = 0; 5174 if (constructor_range_stack) 5175 push_range_stack (NULL_TREE); 5176 } 5177} 5178 5179/* Add a new initializer to the tree of pending initializers. PURPOSE 5180 identifies the initializer, either array index or field in a structure. 5181 VALUE is the value of that index or field. */ 5182 5183static void 5184add_pending_init (tree purpose, tree value) 5185{ 5186 struct init_node *p, **q, *r; 5187 5188 q = &constructor_pending_elts; 5189 p = 0; 5190 5191 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5192 { 5193 while (*q != 0) 5194 { 5195 p = *q; 5196 if (tree_int_cst_lt (purpose, p->purpose)) 5197 q = &p->left; 5198 else if (tree_int_cst_lt (p->purpose, purpose)) 5199 q = &p->right; 5200 else 5201 { 5202 if (TREE_SIDE_EFFECTS (p->value)) 5203 warning_init ("initialized field with side-effects overwritten"); 5204 p->value = value; 5205 return; 5206 } 5207 } 5208 } 5209 else 5210 { 5211 tree bitpos; 5212 5213 bitpos = bit_position (purpose); 5214 while (*q != NULL) 5215 { 5216 p = *q; 5217 if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5218 q = &p->left; 5219 else if (p->purpose != purpose) 5220 q = &p->right; 5221 else 5222 { 5223 if (TREE_SIDE_EFFECTS (p->value)) 5224 warning_init ("initialized field with side-effects overwritten"); 5225 p->value = value; 5226 return; 5227 } 5228 } 5229 } 5230 5231 r = ggc_alloc (sizeof (struct init_node)); 5232 r->purpose = purpose; 5233 r->value = value; 5234 5235 *q = r; 5236 r->parent = p; 5237 r->left = 0; 5238 r->right = 0; 5239 r->balance = 0; 5240 5241 while (p) 5242 { 5243 struct init_node *s; 5244 5245 if (r == p->left) 5246 { 5247 if (p->balance == 0) 5248 p->balance = -1; 5249 else if (p->balance < 0) 5250 { 5251 if (r->balance < 0) 5252 { 5253 /* L rotation. */ 5254 p->left = r->right; 5255 if (p->left) 5256 p->left->parent = p; 5257 r->right = p; 5258 5259 p->balance = 0; 5260 r->balance = 0; 5261 5262 s = p->parent; 5263 p->parent = r; 5264 r->parent = s; 5265 if (s) 5266 { 5267 if (s->left == p) 5268 s->left = r; 5269 else 5270 s->right = r; 5271 } 5272 else 5273 constructor_pending_elts = r; 5274 } 5275 else 5276 { 5277 /* LR rotation. */ 5278 struct init_node *t = r->right; 5279 5280 r->right = t->left; 5281 if (r->right) 5282 r->right->parent = r; 5283 t->left = r; 5284 5285 p->left = t->right; 5286 if (p->left) 5287 p->left->parent = p; 5288 t->right = p; 5289 5290 p->balance = t->balance < 0; 5291 r->balance = -(t->balance > 0); 5292 t->balance = 0; 5293 5294 s = p->parent; 5295 p->parent = t; 5296 r->parent = t; 5297 t->parent = s; 5298 if (s) 5299 { 5300 if (s->left == p) 5301 s->left = t; 5302 else 5303 s->right = t; 5304 } 5305 else 5306 constructor_pending_elts = t; 5307 } 5308 break; 5309 } 5310 else 5311 { 5312 /* p->balance == +1; growth of left side balances the node. */ 5313 p->balance = 0; 5314 break; 5315 } 5316 } 5317 else /* r == p->right */ 5318 { 5319 if (p->balance == 0) 5320 /* Growth propagation from right side. */ 5321 p->balance++; 5322 else if (p->balance > 0) 5323 { 5324 if (r->balance > 0) 5325 { 5326 /* R rotation. */ 5327 p->right = r->left; 5328 if (p->right) 5329 p->right->parent = p; 5330 r->left = p; 5331 5332 p->balance = 0; 5333 r->balance = 0; 5334 5335 s = p->parent; 5336 p->parent = r; 5337 r->parent = s; 5338 if (s) 5339 { 5340 if (s->left == p) 5341 s->left = r; 5342 else 5343 s->right = r; 5344 } 5345 else 5346 constructor_pending_elts = r; 5347 } 5348 else /* r->balance == -1 */ 5349 { 5350 /* RL rotation */ 5351 struct init_node *t = r->left; 5352 5353 r->left = t->right; 5354 if (r->left) 5355 r->left->parent = r; 5356 t->right = r; 5357 5358 p->right = t->left; 5359 if (p->right) 5360 p->right->parent = p; 5361 t->left = p; 5362 5363 r->balance = (t->balance < 0); 5364 p->balance = -(t->balance > 0); 5365 t->balance = 0; 5366 5367 s = p->parent; 5368 p->parent = t; 5369 r->parent = t; 5370 t->parent = s; 5371 if (s) 5372 { 5373 if (s->left == p) 5374 s->left = t; 5375 else 5376 s->right = t; 5377 } 5378 else 5379 constructor_pending_elts = t; 5380 } 5381 break; 5382 } 5383 else 5384 { 5385 /* p->balance == -1; growth of right side balances the node. */ 5386 p->balance = 0; 5387 break; 5388 } 5389 } 5390 5391 r = p; 5392 p = p->parent; 5393 } 5394} 5395 5396/* Build AVL tree from a sorted chain. */ 5397 5398static void 5399set_nonincremental_init (void) 5400{ 5401 tree chain; 5402 5403 if (TREE_CODE (constructor_type) != RECORD_TYPE 5404 && TREE_CODE (constructor_type) != ARRAY_TYPE) 5405 return; 5406 5407 for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain)) 5408 add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain)); 5409 constructor_elements = 0; 5410 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5411 { 5412 constructor_unfilled_fields = TYPE_FIELDS (constructor_type); 5413 /* Skip any nameless bit fields at the beginning. */ 5414 while (constructor_unfilled_fields != 0 5415 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5416 && DECL_NAME (constructor_unfilled_fields) == 0) 5417 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); 5418 5419 } 5420 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5421 { 5422 if (TYPE_DOMAIN (constructor_type)) 5423 constructor_unfilled_index 5424 = convert (bitsizetype, 5425 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); 5426 else 5427 constructor_unfilled_index = bitsize_zero_node; 5428 } 5429 constructor_incremental = 0; 5430} 5431 5432/* Build AVL tree from a string constant. */ 5433 5434static void 5435set_nonincremental_init_from_string (tree str) 5436{ 5437 tree value, purpose, type; 5438 HOST_WIDE_INT val[2]; 5439 const char *p, *end; 5440 int byte, wchar_bytes, charwidth, bitpos; 5441 5442 if (TREE_CODE (constructor_type) != ARRAY_TYPE) 5443 abort (); 5444 5445 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5446 == TYPE_PRECISION (char_type_node)) 5447 wchar_bytes = 1; 5448 else if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) 5449 == TYPE_PRECISION (wchar_type_node)) 5450 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 5451 else 5452 abort (); 5453 5454 charwidth = TYPE_PRECISION (char_type_node); 5455 type = TREE_TYPE (constructor_type); 5456 p = TREE_STRING_POINTER (str); 5457 end = p + TREE_STRING_LENGTH (str); 5458 5459 for (purpose = bitsize_zero_node; 5460 p < end && !tree_int_cst_lt (constructor_max_index, purpose); 5461 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) 5462 { 5463 if (wchar_bytes == 1) 5464 { 5465 val[1] = (unsigned char) *p++; 5466 val[0] = 0; 5467 } 5468 else 5469 { 5470 val[0] = 0; 5471 val[1] = 0; 5472 for (byte = 0; byte < wchar_bytes; byte++) 5473 { 5474 if (BYTES_BIG_ENDIAN) 5475 bitpos = (wchar_bytes - byte - 1) * charwidth; 5476 else 5477 bitpos = byte * charwidth; 5478 val[bitpos < HOST_BITS_PER_WIDE_INT] 5479 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) 5480 << (bitpos % HOST_BITS_PER_WIDE_INT); 5481 } 5482 } 5483 5484 if (!TREE_UNSIGNED (type)) 5485 { 5486 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; 5487 if (bitpos < HOST_BITS_PER_WIDE_INT) 5488 { 5489 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) 5490 { 5491 val[1] |= ((HOST_WIDE_INT) -1) << bitpos; 5492 val[0] = -1; 5493 } 5494 } 5495 else if (bitpos == HOST_BITS_PER_WIDE_INT) 5496 { 5497 if (val[1] < 0) 5498 val[0] = -1; 5499 } 5500 else if (val[0] & (((HOST_WIDE_INT) 1) 5501 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) 5502 val[0] |= ((HOST_WIDE_INT) -1) 5503 << (bitpos - HOST_BITS_PER_WIDE_INT); 5504 } 5505 5506 value = build_int_2 (val[1], val[0]); 5507 TREE_TYPE (value) = type; 5508 add_pending_init (purpose, value); 5509 } 5510 5511 constructor_incremental = 0; 5512} 5513 5514/* Return value of FIELD in pending initializer or zero if the field was 5515 not initialized yet. */ 5516 5517static tree 5518find_init_member (tree field) 5519{ 5520 struct init_node *p; 5521 5522 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5523 { 5524 if (constructor_incremental 5525 && tree_int_cst_lt (field, constructor_unfilled_index)) 5526 set_nonincremental_init (); 5527 5528 p = constructor_pending_elts; 5529 while (p) 5530 { 5531 if (tree_int_cst_lt (field, p->purpose)) 5532 p = p->left; 5533 else if (tree_int_cst_lt (p->purpose, field)) 5534 p = p->right; 5535 else 5536 return p->value; 5537 } 5538 } 5539 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5540 { 5541 tree bitpos = bit_position (field); 5542 5543 if (constructor_incremental 5544 && (!constructor_unfilled_fields 5545 || tree_int_cst_lt (bitpos, 5546 bit_position (constructor_unfilled_fields)))) 5547 set_nonincremental_init (); 5548 5549 p = constructor_pending_elts; 5550 while (p) 5551 { 5552 if (field == p->purpose) 5553 return p->value; 5554 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) 5555 p = p->left; 5556 else 5557 p = p->right; 5558 } 5559 } 5560 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5561 { 5562 if (constructor_elements 5563 && TREE_PURPOSE (constructor_elements) == field) 5564 return TREE_VALUE (constructor_elements); 5565 } 5566 return 0; 5567} 5568 5569/* "Output" the next constructor element. 5570 At top level, really output it to assembler code now. 5571 Otherwise, collect it in a list from which we will make a CONSTRUCTOR. 5572 TYPE is the data type that the containing data type wants here. 5573 FIELD is the field (a FIELD_DECL) or the index that this element fills. 5574 5575 PENDING if non-nil means output pending elements that belong 5576 right after this element. (PENDING is normally 1; 5577 it is 0 while outputting pending elements, to avoid recursion.) */ 5578 5579static void 5580output_init_element (tree value, tree type, tree field, int pending) 5581{ 5582 if (type == error_mark_node) 5583 { 5584 constructor_erroneous = 1; 5585 return; 5586 } 5587 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE 5588 || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE 5589 && !(TREE_CODE (value) == STRING_CST 5590 && TREE_CODE (type) == ARRAY_TYPE 5591 && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE) 5592 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), 5593 TYPE_MAIN_VARIANT (type), COMPARE_STRICT))) 5594 value = default_conversion (value); 5595 5596 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR 5597 && require_constant_value && !flag_isoc99 && pending) 5598 { 5599 /* As an extension, allow initializing objects with static storage 5600 duration with compound literals (which are then treated just as 5601 the brace enclosed list they contain). */ 5602 tree decl = COMPOUND_LITERAL_EXPR_DECL (value); 5603 value = DECL_INITIAL (decl); 5604 } 5605 5606 if (value == error_mark_node) 5607 constructor_erroneous = 1; 5608 else if (!TREE_CONSTANT (value)) 5609 constructor_constant = 0; 5610 else if (initializer_constant_valid_p (value, TREE_TYPE (value)) == 0 5611 || ((TREE_CODE (constructor_type) == RECORD_TYPE 5612 || TREE_CODE (constructor_type) == UNION_TYPE) 5613 && DECL_C_BIT_FIELD (field) 5614 && TREE_CODE (value) != INTEGER_CST)) 5615 constructor_simple = 0; 5616 5617 if (require_constant_value && ! TREE_CONSTANT (value)) 5618 { 5619 error_init ("initializer element is not constant"); 5620 value = error_mark_node; 5621 } 5622 else if (require_constant_elements 5623 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0) 5624 pedwarn ("initializer element is not computable at load time"); 5625 5626 /* If this field is empty (and not at the end of structure), 5627 don't do anything other than checking the initializer. */ 5628 if (field 5629 && (TREE_TYPE (field) == error_mark_node 5630 || (COMPLETE_TYPE_P (TREE_TYPE (field)) 5631 && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) 5632 && (TREE_CODE (constructor_type) == ARRAY_TYPE 5633 || TREE_CHAIN (field))))) 5634 return; 5635 5636 value = digest_init (type, value, require_constant_value); 5637 if (value == error_mark_node) 5638 { 5639 constructor_erroneous = 1; 5640 return; 5641 } 5642 5643 /* If this element doesn't come next in sequence, 5644 put it on constructor_pending_elts. */ 5645 if (TREE_CODE (constructor_type) == ARRAY_TYPE 5646 && (!constructor_incremental 5647 || !tree_int_cst_equal (field, constructor_unfilled_index))) 5648 { 5649 if (constructor_incremental 5650 && tree_int_cst_lt (field, constructor_unfilled_index)) 5651 set_nonincremental_init (); 5652 5653 add_pending_init (field, value); 5654 return; 5655 } 5656 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5657 && (!constructor_incremental 5658 || field != constructor_unfilled_fields)) 5659 { 5660 /* We do this for records but not for unions. In a union, 5661 no matter which field is specified, it can be initialized 5662 right away since it starts at the beginning of the union. */ 5663 if (constructor_incremental) 5664 { 5665 if (!constructor_unfilled_fields) 5666 set_nonincremental_init (); 5667 else 5668 { 5669 tree bitpos, unfillpos; 5670 5671 bitpos = bit_position (field); 5672 unfillpos = bit_position (constructor_unfilled_fields); 5673 5674 if (tree_int_cst_lt (bitpos, unfillpos)) 5675 set_nonincremental_init (); 5676 } 5677 } 5678 5679 add_pending_init (field, value); 5680 return; 5681 } 5682 else if (TREE_CODE (constructor_type) == UNION_TYPE 5683 && constructor_elements) 5684 { 5685 if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements))) 5686 warning_init ("initialized field with side-effects overwritten"); 5687 5688 /* We can have just one union field set. */ 5689 constructor_elements = 0; 5690 } 5691 5692 /* Otherwise, output this element either to 5693 constructor_elements or to the assembler file. */ 5694 5695 if (field && TREE_CODE (field) == INTEGER_CST) 5696 field = copy_node (field); 5697 constructor_elements 5698 = tree_cons (field, value, constructor_elements); 5699 5700 /* Advance the variable that indicates sequential elements output. */ 5701 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5702 constructor_unfilled_index 5703 = size_binop (PLUS_EXPR, constructor_unfilled_index, 5704 bitsize_one_node); 5705 else if (TREE_CODE (constructor_type) == RECORD_TYPE) 5706 { 5707 constructor_unfilled_fields 5708 = TREE_CHAIN (constructor_unfilled_fields); 5709 5710 /* Skip any nameless bit fields. */ 5711 while (constructor_unfilled_fields != 0 5712 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 5713 && DECL_NAME (constructor_unfilled_fields) == 0) 5714 constructor_unfilled_fields = 5715 TREE_CHAIN (constructor_unfilled_fields); 5716 } 5717 else if (TREE_CODE (constructor_type) == UNION_TYPE) 5718 constructor_unfilled_fields = 0; 5719 5720 /* Now output any pending elements which have become next. */ 5721 if (pending) 5722 output_pending_init_elements (0); 5723} 5724 5725/* Output any pending elements which have become next. 5726 As we output elements, constructor_unfilled_{fields,index} 5727 advances, which may cause other elements to become next; 5728 if so, they too are output. 5729 5730 If ALL is 0, we return when there are 5731 no more pending elements to output now. 5732 5733 If ALL is 1, we output space as necessary so that 5734 we can output all the pending elements. */ 5735 5736static void 5737output_pending_init_elements (int all) 5738{ 5739 struct init_node *elt = constructor_pending_elts; 5740 tree next; 5741 5742 retry: 5743 5744 /* Look through the whole pending tree. 5745 If we find an element that should be output now, 5746 output it. Otherwise, set NEXT to the element 5747 that comes first among those still pending. */ 5748 5749 next = 0; 5750 while (elt) 5751 { 5752 if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5753 { 5754 if (tree_int_cst_equal (elt->purpose, 5755 constructor_unfilled_index)) 5756 output_init_element (elt->value, 5757 TREE_TYPE (constructor_type), 5758 constructor_unfilled_index, 0); 5759 else if (tree_int_cst_lt (constructor_unfilled_index, 5760 elt->purpose)) 5761 { 5762 /* Advance to the next smaller node. */ 5763 if (elt->left) 5764 elt = elt->left; 5765 else 5766 { 5767 /* We have reached the smallest node bigger than the 5768 current unfilled index. Fill the space first. */ 5769 next = elt->purpose; 5770 break; 5771 } 5772 } 5773 else 5774 { 5775 /* Advance to the next bigger node. */ 5776 if (elt->right) 5777 elt = elt->right; 5778 else 5779 { 5780 /* We have reached the biggest node in a subtree. Find 5781 the parent of it, which is the next bigger node. */ 5782 while (elt->parent && elt->parent->right == elt) 5783 elt = elt->parent; 5784 elt = elt->parent; 5785 if (elt && tree_int_cst_lt (constructor_unfilled_index, 5786 elt->purpose)) 5787 { 5788 next = elt->purpose; 5789 break; 5790 } 5791 } 5792 } 5793 } 5794 else if (TREE_CODE (constructor_type) == RECORD_TYPE 5795 || TREE_CODE (constructor_type) == UNION_TYPE) 5796 { 5797 tree ctor_unfilled_bitpos, elt_bitpos; 5798 5799 /* If the current record is complete we are done. */ 5800 if (constructor_unfilled_fields == 0) 5801 break; 5802 5803 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); 5804 elt_bitpos = bit_position (elt->purpose); 5805 /* We can't compare fields here because there might be empty 5806 fields in between. */ 5807 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) 5808 { 5809 constructor_unfilled_fields = elt->purpose; 5810 output_init_element (elt->value, TREE_TYPE (elt->purpose), 5811 elt->purpose, 0); 5812 } 5813 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) 5814 { 5815 /* Advance to the next smaller node. */ 5816 if (elt->left) 5817 elt = elt->left; 5818 else 5819 { 5820 /* We have reached the smallest node bigger than the 5821 current unfilled field. Fill the space first. */ 5822 next = elt->purpose; 5823 break; 5824 } 5825 } 5826 else 5827 { 5828 /* Advance to the next bigger node. */ 5829 if (elt->right) 5830 elt = elt->right; 5831 else 5832 { 5833 /* We have reached the biggest node in a subtree. Find 5834 the parent of it, which is the next bigger node. */ 5835 while (elt->parent && elt->parent->right == elt) 5836 elt = elt->parent; 5837 elt = elt->parent; 5838 if (elt 5839 && (tree_int_cst_lt (ctor_unfilled_bitpos, 5840 bit_position (elt->purpose)))) 5841 { 5842 next = elt->purpose; 5843 break; 5844 } 5845 } 5846 } 5847 } 5848 } 5849 5850 /* Ordinarily return, but not if we want to output all 5851 and there are elements left. */ 5852 if (! (all && next != 0)) 5853 return; 5854 5855 /* If it's not incremental, just skip over the gap, so that after 5856 jumping to retry we will output the next successive element. */ 5857 if (TREE_CODE (constructor_type) == RECORD_TYPE 5858 || TREE_CODE (constructor_type) == UNION_TYPE) 5859 constructor_unfilled_fields = next; 5860 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 5861 constructor_unfilled_index = next; 5862 5863 /* ELT now points to the node in the pending tree with the next 5864 initializer to output. */ 5865 goto retry; 5866} 5867 5868/* Add one non-braced element to the current constructor level. 5869 This adjusts the current position within the constructor's type. 5870 This may also start or terminate implicit levels 5871 to handle a partly-braced initializer. 5872 5873 Once this has found the correct level for the new element, 5874 it calls output_init_element. */ 5875 5876void 5877process_init_element (tree value) 5878{ 5879 tree orig_value = value; 5880 int string_flag = value != 0 && TREE_CODE (value) == STRING_CST; 5881 5882 designator_depth = 0; 5883 designator_errorneous = 0; 5884 5885 /* Handle superfluous braces around string cst as in 5886 char x[] = {"foo"}; */ 5887 if (string_flag 5888 && constructor_type 5889 && TREE_CODE (constructor_type) == ARRAY_TYPE 5890 && TREE_CODE (TREE_TYPE (constructor_type)) == INTEGER_TYPE 5891 && integer_zerop (constructor_unfilled_index)) 5892 { 5893 if (constructor_stack->replacement_value) 5894 error_init ("excess elements in char array initializer"); 5895 constructor_stack->replacement_value = value; 5896 return; 5897 } 5898 5899 if (constructor_stack->replacement_value != 0) 5900 { 5901 error_init ("excess elements in struct initializer"); 5902 return; 5903 } 5904 5905 /* Ignore elements of a brace group if it is entirely superfluous 5906 and has already been diagnosed. */ 5907 if (constructor_type == 0) 5908 return; 5909 5910 /* If we've exhausted any levels that didn't have braces, 5911 pop them now. */ 5912 while (constructor_stack->implicit) 5913 { 5914 if ((TREE_CODE (constructor_type) == RECORD_TYPE 5915 || TREE_CODE (constructor_type) == UNION_TYPE) 5916 && constructor_fields == 0) 5917 process_init_element (pop_init_level (1)); 5918 else if (TREE_CODE (constructor_type) == ARRAY_TYPE 5919 && (constructor_max_index == 0 5920 || tree_int_cst_lt (constructor_max_index, 5921 constructor_index))) 5922 process_init_element (pop_init_level (1)); 5923 else 5924 break; 5925 } 5926 5927 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ 5928 if (constructor_range_stack) 5929 { 5930 /* If value is a compound literal and we'll be just using its 5931 content, don't put it into a SAVE_EXPR. */ 5932 if (TREE_CODE (value) != COMPOUND_LITERAL_EXPR 5933 || !require_constant_value 5934 || flag_isoc99) 5935 value = save_expr (value); 5936 } 5937 5938 while (1) 5939 { 5940 if (TREE_CODE (constructor_type) == RECORD_TYPE) 5941 { 5942 tree fieldtype; 5943 enum tree_code fieldcode; 5944 5945 if (constructor_fields == 0) 5946 { 5947 pedwarn_init ("excess elements in struct initializer"); 5948 break; 5949 } 5950 5951 fieldtype = TREE_TYPE (constructor_fields); 5952 if (fieldtype != error_mark_node) 5953 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 5954 fieldcode = TREE_CODE (fieldtype); 5955 5956 /* Error for non-static initialization of a flexible array member. */ 5957 if (fieldcode == ARRAY_TYPE 5958 && !require_constant_value 5959 && TYPE_SIZE (fieldtype) == NULL_TREE 5960 && TREE_CHAIN (constructor_fields) == NULL_TREE) 5961 { 5962 error_init ("non-static initialization of a flexible array member"); 5963 break; 5964 } 5965 5966 /* Accept a string constant to initialize a subarray. */ 5967 if (value != 0 5968 && fieldcode == ARRAY_TYPE 5969 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 5970 && string_flag) 5971 value = orig_value; 5972 /* Otherwise, if we have come to a subaggregate, 5973 and we don't have an element of its type, push into it. */ 5974 else if (value != 0 && !constructor_no_implicit 5975 && value != error_mark_node 5976 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 5977 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 5978 || fieldcode == UNION_TYPE)) 5979 { 5980 push_init_level (1); 5981 continue; 5982 } 5983 5984 if (value) 5985 { 5986 push_member_name (constructor_fields); 5987 output_init_element (value, fieldtype, constructor_fields, 1); 5988 RESTORE_SPELLING_DEPTH (constructor_depth); 5989 } 5990 else 5991 /* Do the bookkeeping for an element that was 5992 directly output as a constructor. */ 5993 { 5994 /* For a record, keep track of end position of last field. */ 5995 if (DECL_SIZE (constructor_fields)) 5996 constructor_bit_index 5997 = size_binop (PLUS_EXPR, 5998 bit_position (constructor_fields), 5999 DECL_SIZE (constructor_fields)); 6000 6001 /* If the current field was the first one not yet written out, 6002 it isn't now, so update. */ 6003 if (constructor_unfilled_fields == constructor_fields) 6004 { 6005 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6006 /* Skip any nameless bit fields. */ 6007 while (constructor_unfilled_fields != 0 6008 && DECL_C_BIT_FIELD (constructor_unfilled_fields) 6009 && DECL_NAME (constructor_unfilled_fields) == 0) 6010 constructor_unfilled_fields = 6011 TREE_CHAIN (constructor_unfilled_fields); 6012 } 6013 } 6014 6015 constructor_fields = TREE_CHAIN (constructor_fields); 6016 /* Skip any nameless bit fields at the beginning. */ 6017 while (constructor_fields != 0 6018 && DECL_C_BIT_FIELD (constructor_fields) 6019 && DECL_NAME (constructor_fields) == 0) 6020 constructor_fields = TREE_CHAIN (constructor_fields); 6021 } 6022 else if (TREE_CODE (constructor_type) == UNION_TYPE) 6023 { 6024 tree fieldtype; 6025 enum tree_code fieldcode; 6026 6027 if (constructor_fields == 0) 6028 { 6029 pedwarn_init ("excess elements in union initializer"); 6030 break; 6031 } 6032 6033 fieldtype = TREE_TYPE (constructor_fields); 6034 if (fieldtype != error_mark_node) 6035 fieldtype = TYPE_MAIN_VARIANT (fieldtype); 6036 fieldcode = TREE_CODE (fieldtype); 6037 6038 /* Warn that traditional C rejects initialization of unions. 6039 We skip the warning if the value is zero. This is done 6040 under the assumption that the zero initializer in user 6041 code appears conditioned on e.g. __STDC__ to avoid 6042 "missing initializer" warnings and relies on default 6043 initialization to zero in the traditional C case. 6044 We also skip the warning if the initializer is designated, 6045 again on the assumption that this must be conditional on 6046 __STDC__ anyway (and we've already complained about the 6047 member-designator already). */ 6048 if (warn_traditional && !in_system_header && !constructor_designated 6049 && !(value && (integer_zerop (value) || real_zerop (value)))) 6050 warning ("traditional C rejects initialization of unions"); 6051 6052 /* Accept a string constant to initialize a subarray. */ 6053 if (value != 0 6054 && fieldcode == ARRAY_TYPE 6055 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE 6056 && string_flag) 6057 value = orig_value; 6058 /* Otherwise, if we have come to a subaggregate, 6059 and we don't have an element of its type, push into it. */ 6060 else if (value != 0 && !constructor_no_implicit 6061 && value != error_mark_node 6062 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype 6063 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE 6064 || fieldcode == UNION_TYPE)) 6065 { 6066 push_init_level (1); 6067 continue; 6068 } 6069 6070 if (value) 6071 { 6072 push_member_name (constructor_fields); 6073 output_init_element (value, fieldtype, constructor_fields, 1); 6074 RESTORE_SPELLING_DEPTH (constructor_depth); 6075 } 6076 else 6077 /* Do the bookkeeping for an element that was 6078 directly output as a constructor. */ 6079 { 6080 constructor_bit_index = DECL_SIZE (constructor_fields); 6081 constructor_unfilled_fields = TREE_CHAIN (constructor_fields); 6082 } 6083 6084 constructor_fields = 0; 6085 } 6086 else if (TREE_CODE (constructor_type) == ARRAY_TYPE) 6087 { 6088 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6089 enum tree_code eltcode = TREE_CODE (elttype); 6090 6091 /* Accept a string constant to initialize a subarray. */ 6092 if (value != 0 6093 && eltcode == ARRAY_TYPE 6094 && TREE_CODE (TREE_TYPE (elttype)) == INTEGER_TYPE 6095 && string_flag) 6096 value = orig_value; 6097 /* Otherwise, if we have come to a subaggregate, 6098 and we don't have an element of its type, push into it. */ 6099 else if (value != 0 && !constructor_no_implicit 6100 && value != error_mark_node 6101 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != elttype 6102 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE 6103 || eltcode == UNION_TYPE)) 6104 { 6105 push_init_level (1); 6106 continue; 6107 } 6108 6109 if (constructor_max_index != 0 6110 && (tree_int_cst_lt (constructor_max_index, constructor_index) 6111 || integer_all_onesp (constructor_max_index))) 6112 { 6113 pedwarn_init ("excess elements in array initializer"); 6114 break; 6115 } 6116 6117 /* Now output the actual element. */ 6118 if (value) 6119 { 6120 push_array_bounds (tree_low_cst (constructor_index, 0)); 6121 output_init_element (value, elttype, constructor_index, 1); 6122 RESTORE_SPELLING_DEPTH (constructor_depth); 6123 } 6124 6125 constructor_index 6126 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6127 6128 if (! value) 6129 /* If we are doing the bookkeeping for an element that was 6130 directly output as a constructor, we must update 6131 constructor_unfilled_index. */ 6132 constructor_unfilled_index = constructor_index; 6133 } 6134 else if (TREE_CODE (constructor_type) == VECTOR_TYPE) 6135 { 6136 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); 6137 6138 /* Do a basic check of initializer size. Note that vectors 6139 always have a fixed size derived from their type. */ 6140 if (tree_int_cst_lt (constructor_max_index, constructor_index)) 6141 { 6142 pedwarn_init ("excess elements in vector initializer"); 6143 break; 6144 } 6145 6146 /* Now output the actual element. */ 6147 if (value) 6148 output_init_element (value, elttype, constructor_index, 1); 6149 6150 constructor_index 6151 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); 6152 6153 if (! value) 6154 /* If we are doing the bookkeeping for an element that was 6155 directly output as a constructor, we must update 6156 constructor_unfilled_index. */ 6157 constructor_unfilled_index = constructor_index; 6158 } 6159 6160 /* Handle the sole element allowed in a braced initializer 6161 for a scalar variable. */ 6162 else if (constructor_fields == 0) 6163 { 6164 pedwarn_init ("excess elements in scalar initializer"); 6165 break; 6166 } 6167 else 6168 { 6169 if (value) 6170 output_init_element (value, constructor_type, NULL_TREE, 1); 6171 constructor_fields = 0; 6172 } 6173 6174 /* Handle range initializers either at this level or anywhere higher 6175 in the designator stack. */ 6176 if (constructor_range_stack) 6177 { 6178 struct constructor_range_stack *p, *range_stack; 6179 int finish = 0; 6180 6181 range_stack = constructor_range_stack; 6182 constructor_range_stack = 0; 6183 while (constructor_stack != range_stack->stack) 6184 { 6185 if (!constructor_stack->implicit) 6186 abort (); 6187 process_init_element (pop_init_level (1)); 6188 } 6189 for (p = range_stack; 6190 !p->range_end || tree_int_cst_equal (p->index, p->range_end); 6191 p = p->prev) 6192 { 6193 if (!constructor_stack->implicit) 6194 abort (); 6195 process_init_element (pop_init_level (1)); 6196 } 6197 6198 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); 6199 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) 6200 finish = 1; 6201 6202 while (1) 6203 { 6204 constructor_index = p->index; 6205 constructor_fields = p->fields; 6206 if (finish && p->range_end && p->index == p->range_start) 6207 { 6208 finish = 0; 6209 p->prev = 0; 6210 } 6211 p = p->next; 6212 if (!p) 6213 break; 6214 push_init_level (2); 6215 p->stack = constructor_stack; 6216 if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) 6217 p->index = p->range_start; 6218 } 6219 6220 if (!finish) 6221 constructor_range_stack = range_stack; 6222 continue; 6223 } 6224 6225 break; 6226 } 6227 6228 constructor_range_stack = 0; 6229} 6230 6231/* Build a simple asm-statement, from one string literal. */ 6232tree 6233simple_asm_stmt (tree expr) 6234{ 6235 STRIP_NOPS (expr); 6236 6237 if (TREE_CODE (expr) == ADDR_EXPR) 6238 expr = TREE_OPERAND (expr, 0); 6239 6240 if (TREE_CODE (expr) == STRING_CST) 6241 { 6242 tree stmt; 6243 6244 /* Simple asm statements are treated as volatile. */ 6245 stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE], 6246 expr, NULL_TREE, NULL_TREE, NULL_TREE)); 6247 ASM_INPUT_P (stmt) = 1; 6248 return stmt; 6249 } 6250 6251 error ("argument of `asm' is not a constant string"); 6252 return NULL_TREE; 6253} 6254 6255/* Build an asm-statement, whose components are a CV_QUALIFIER, a 6256 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */ 6257 6258tree 6259build_asm_stmt (tree cv_qualifier, tree string, tree outputs, tree inputs, 6260 tree clobbers) 6261{ 6262 tree tail; 6263 6264 if (TREE_CODE (string) != STRING_CST) 6265 { 6266 error ("asm template is not a string constant"); 6267 return NULL_TREE; 6268 } 6269 6270 if (cv_qualifier != NULL_TREE 6271 && cv_qualifier != ridpointers[(int) RID_VOLATILE]) 6272 { 6273 warning ("%s qualifier ignored on asm", 6274 IDENTIFIER_POINTER (cv_qualifier)); 6275 cv_qualifier = NULL_TREE; 6276 } 6277 6278 /* We can remove output conversions that change the type, 6279 but not the mode. */ 6280 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6281 { 6282 tree output = TREE_VALUE (tail); 6283 6284 STRIP_NOPS (output); 6285 TREE_VALUE (tail) = output; 6286 6287 /* Allow conversions as LHS here. build_modify_expr as called below 6288 will do the right thing with them. */ 6289 while (TREE_CODE (output) == NOP_EXPR 6290 || TREE_CODE (output) == CONVERT_EXPR 6291 || TREE_CODE (output) == FLOAT_EXPR 6292 || TREE_CODE (output) == FIX_TRUNC_EXPR 6293 || TREE_CODE (output) == FIX_FLOOR_EXPR 6294 || TREE_CODE (output) == FIX_ROUND_EXPR 6295 || TREE_CODE (output) == FIX_CEIL_EXPR) 6296 output = TREE_OPERAND (output, 0); 6297 6298 lvalue_or_else (TREE_VALUE (tail), "invalid lvalue in asm statement"); 6299 } 6300 6301 /* Remove output conversions that change the type but not the mode. */ 6302 for (tail = outputs; tail; tail = TREE_CHAIN (tail)) 6303 { 6304 tree output = TREE_VALUE (tail); 6305 STRIP_NOPS (output); 6306 TREE_VALUE (tail) = output; 6307 } 6308 6309 /* Perform default conversions on array and function inputs. 6310 Don't do this for other types as it would screw up operands 6311 expected to be in memory. */ 6312 for (tail = inputs; tail; tail = TREE_CHAIN (tail)) 6313 TREE_VALUE (tail) = default_function_array_conversion (TREE_VALUE (tail)); 6314 6315 return add_stmt (build_stmt (ASM_STMT, cv_qualifier, string, 6316 outputs, inputs, clobbers)); 6317} 6318 6319/* Expand an ASM statement with operands, handling output operands 6320 that are not variables or INDIRECT_REFS by transforming such 6321 cases into cases that expand_asm_operands can handle. 6322 6323 Arguments are same as for expand_asm_operands. */ 6324 6325void 6326c_expand_asm_operands (tree string, tree outputs, tree inputs, 6327 tree clobbers, int vol, location_t locus) 6328{ 6329 int noutputs = list_length (outputs); 6330 int i; 6331 /* o[I] is the place that output number I should be written. */ 6332 tree *o = alloca (noutputs * sizeof (tree)); 6333 tree tail; 6334 6335 /* Record the contents of OUTPUTS before it is modified. */ 6336 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6337 { 6338 o[i] = TREE_VALUE (tail); 6339 if (o[i] == error_mark_node) 6340 return; 6341 } 6342 6343 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of 6344 OUTPUTS some trees for where the values were actually stored. */ 6345 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus); 6346 6347 /* Copy all the intermediate outputs into the specified outputs. */ 6348 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) 6349 { 6350 if (o[i] != TREE_VALUE (tail)) 6351 { 6352 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)), 6353 NULL_RTX, VOIDmode, EXPAND_NORMAL); 6354 free_temp_slots (); 6355 6356 /* Restore the original value so that it's correct the next 6357 time we expand this function. */ 6358 TREE_VALUE (tail) = o[i]; 6359 } 6360 /* Detect modification of read-only values. 6361 (Otherwise done by build_modify_expr.) */ 6362 else 6363 { 6364 tree type = TREE_TYPE (o[i]); 6365 if (TREE_READONLY (o[i]) 6366 || TYPE_READONLY (type) 6367 || ((TREE_CODE (type) == RECORD_TYPE 6368 || TREE_CODE (type) == UNION_TYPE) 6369 && C_TYPE_FIELDS_READONLY (type))) 6370 readonly_error (o[i], "modification by `asm'"); 6371 } 6372 } 6373 6374 /* Those MODIFY_EXPRs could do autoincrements. */ 6375 emit_queue (); 6376} 6377 6378/* Expand a C `return' statement. 6379 RETVAL is the expression for what to return, 6380 or a null pointer for `return;' with no value. */ 6381 6382tree 6383c_expand_return (tree retval) 6384{ 6385 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)); 6386 6387 if (TREE_THIS_VOLATILE (current_function_decl)) 6388 warning ("function declared `noreturn' has a `return' statement"); 6389 6390 if (!retval) 6391 { 6392 current_function_returns_null = 1; 6393 if ((warn_return_type || flag_isoc99) 6394 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) 6395 pedwarn_c99 ("`return' with no value, in function returning non-void"); 6396 } 6397 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) 6398 { 6399 current_function_returns_null = 1; 6400 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) 6401 pedwarn ("`return' with a value, in function returning void"); 6402 } 6403 else 6404 { 6405 tree t = convert_for_assignment (valtype, retval, _("return"), 6406 NULL_TREE, NULL_TREE, 0); 6407 tree res = DECL_RESULT (current_function_decl); 6408 tree inner; 6409 6410 current_function_returns_value = 1; 6411 if (t == error_mark_node) 6412 return NULL_TREE; 6413 6414 inner = t = convert (TREE_TYPE (res), t); 6415 6416 /* Strip any conversions, additions, and subtractions, and see if 6417 we are returning the address of a local variable. Warn if so. */ 6418 while (1) 6419 { 6420 switch (TREE_CODE (inner)) 6421 { 6422 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: 6423 case PLUS_EXPR: 6424 inner = TREE_OPERAND (inner, 0); 6425 continue; 6426 6427 case MINUS_EXPR: 6428 /* If the second operand of the MINUS_EXPR has a pointer 6429 type (or is converted from it), this may be valid, so 6430 don't give a warning. */ 6431 { 6432 tree op1 = TREE_OPERAND (inner, 1); 6433 6434 while (! POINTER_TYPE_P (TREE_TYPE (op1)) 6435 && (TREE_CODE (op1) == NOP_EXPR 6436 || TREE_CODE (op1) == NON_LVALUE_EXPR 6437 || TREE_CODE (op1) == CONVERT_EXPR)) 6438 op1 = TREE_OPERAND (op1, 0); 6439 6440 if (POINTER_TYPE_P (TREE_TYPE (op1))) 6441 break; 6442 6443 inner = TREE_OPERAND (inner, 0); 6444 continue; 6445 } 6446 6447 case ADDR_EXPR: 6448 inner = TREE_OPERAND (inner, 0); 6449 6450 while (TREE_CODE_CLASS (TREE_CODE (inner)) == 'r') 6451 inner = TREE_OPERAND (inner, 0); 6452 6453 if (TREE_CODE (inner) == VAR_DECL 6454 && ! DECL_EXTERNAL (inner) 6455 && ! TREE_STATIC (inner) 6456 && DECL_CONTEXT (inner) == current_function_decl) 6457 warning ("function returns address of local variable"); 6458 break; 6459 6460 default: 6461 break; 6462 } 6463 6464 break; 6465 } 6466 6467 retval = build (MODIFY_EXPR, TREE_TYPE (res), res, t); 6468 } 6469 6470 return add_stmt (build_return_stmt (retval)); 6471} 6472 6473struct c_switch { 6474 /* The SWITCH_STMT being built. */ 6475 tree switch_stmt; 6476 /* A splay-tree mapping the low element of a case range to the high 6477 element, or NULL_TREE if there is no high element. Used to 6478 determine whether or not a new case label duplicates an old case 6479 label. We need a tree, rather than simply a hash table, because 6480 of the GNU case range extension. */ 6481 splay_tree cases; 6482 /* The next node on the stack. */ 6483 struct c_switch *next; 6484}; 6485 6486/* A stack of the currently active switch statements. The innermost 6487 switch statement is on the top of the stack. There is no need to 6488 mark the stack for garbage collection because it is only active 6489 during the processing of the body of a function, and we never 6490 collect at that point. */ 6491 6492static struct c_switch *switch_stack; 6493 6494/* Start a C switch statement, testing expression EXP. Return the new 6495 SWITCH_STMT. */ 6496 6497tree 6498c_start_case (tree exp) 6499{ 6500 enum tree_code code; 6501 tree type, orig_type = error_mark_node; 6502 struct c_switch *cs; 6503 6504 if (exp != error_mark_node) 6505 { 6506 code = TREE_CODE (TREE_TYPE (exp)); 6507 orig_type = TREE_TYPE (exp); 6508 6509 if (! INTEGRAL_TYPE_P (orig_type) 6510 && code != ERROR_MARK) 6511 { 6512 error ("switch quantity not an integer"); 6513 exp = integer_zero_node; 6514 } 6515 else 6516 { 6517 type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 6518 6519 if (warn_traditional && !in_system_header 6520 && (type == long_integer_type_node 6521 || type == long_unsigned_type_node)) 6522 warning ("`long' switch expression not converted to `int' in ISO C"); 6523 6524 exp = default_conversion (exp); 6525 type = TREE_TYPE (exp); 6526 } 6527 } 6528 6529 /* Add this new SWITCH_STMT to the stack. */ 6530 cs = xmalloc (sizeof (*cs)); 6531 cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type); 6532 cs->cases = splay_tree_new (case_compare, NULL, NULL); 6533 cs->next = switch_stack; 6534 switch_stack = cs; 6535 6536 return add_stmt (switch_stack->switch_stmt); 6537} 6538 6539/* Process a case label. */ 6540 6541tree 6542do_case (tree low_value, tree high_value) 6543{ 6544 tree label = NULL_TREE; 6545 6546 if (switch_stack) 6547 { 6548 bool switch_was_empty_p = (SWITCH_BODY (switch_stack->switch_stmt) == NULL_TREE); 6549 6550 label = c_add_case_label (switch_stack->cases, 6551 SWITCH_COND (switch_stack->switch_stmt), 6552 low_value, high_value); 6553 if (label == error_mark_node) 6554 label = NULL_TREE; 6555 else if (switch_was_empty_p) 6556 { 6557 /* Attach the first case label to the SWITCH_BODY. */ 6558 SWITCH_BODY (switch_stack->switch_stmt) = TREE_CHAIN (switch_stack->switch_stmt); 6559 TREE_CHAIN (switch_stack->switch_stmt) = NULL_TREE; 6560 } 6561 } 6562 else if (low_value) 6563 error ("case label not within a switch statement"); 6564 else 6565 error ("`default' label not within a switch statement"); 6566 6567 return label; 6568} 6569 6570/* Finish the switch statement. */ 6571 6572void 6573c_finish_case (void) 6574{ 6575 struct c_switch *cs = switch_stack; 6576 6577 /* If we've not seen any case labels (or a default), we may still 6578 need to chain any statements that were seen as the SWITCH_BODY. */ 6579 if (SWITCH_BODY (cs->switch_stmt) == NULL) 6580 { 6581 SWITCH_BODY (cs->switch_stmt) = TREE_CHAIN (cs->switch_stmt); 6582 TREE_CHAIN (cs->switch_stmt) = NULL_TREE; 6583 } 6584 6585 /* Rechain the next statements to the SWITCH_STMT. */ 6586 last_tree = cs->switch_stmt; 6587 6588 /* Pop the stack. */ 6589 switch_stack = switch_stack->next; 6590 splay_tree_delete (cs->cases); 6591 free (cs); 6592} 6593 6594/* Build a binary-operation expression without default conversions. 6595 CODE is the kind of expression to build. 6596 This function differs from `build' in several ways: 6597 the data type of the result is computed and recorded in it, 6598 warnings are generated if arg data types are invalid, 6599 special handling for addition and subtraction of pointers is known, 6600 and some optimization is done (operations on narrow ints 6601 are done in the narrower type when that gives the same result). 6602 Constant folding is also done before the result is returned. 6603 6604 Note that the operands will never have enumeral types, or function 6605 or array types, because either they will have the default conversions 6606 performed or they have both just been converted to some other type in which 6607 the arithmetic is to be done. */ 6608 6609tree 6610build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, 6611 int convert_p) 6612{ 6613 tree type0, type1; 6614 enum tree_code code0, code1; 6615 tree op0, op1; 6616 6617 /* Expression code to give to the expression when it is built. 6618 Normally this is CODE, which is what the caller asked for, 6619 but in some special cases we change it. */ 6620 enum tree_code resultcode = code; 6621 6622 /* Data type in which the computation is to be performed. 6623 In the simplest cases this is the common type of the arguments. */ 6624 tree result_type = NULL; 6625 6626 /* Nonzero means operands have already been type-converted 6627 in whatever way is necessary. 6628 Zero means they need to be converted to RESULT_TYPE. */ 6629 int converted = 0; 6630 6631 /* Nonzero means create the expression with this type, rather than 6632 RESULT_TYPE. */ 6633 tree build_type = 0; 6634 6635 /* Nonzero means after finally constructing the expression 6636 convert it to this type. */ 6637 tree final_type = 0; 6638 6639 /* Nonzero if this is an operation like MIN or MAX which can 6640 safely be computed in short if both args are promoted shorts. 6641 Also implies COMMON. 6642 -1 indicates a bitwise operation; this makes a difference 6643 in the exact conditions for when it is safe to do the operation 6644 in a narrower mode. */ 6645 int shorten = 0; 6646 6647 /* Nonzero if this is a comparison operation; 6648 if both args are promoted shorts, compare the original shorts. 6649 Also implies COMMON. */ 6650 int short_compare = 0; 6651 6652 /* Nonzero if this is a right-shift operation, which can be computed on the 6653 original short and then promoted if the operand is a promoted short. */ 6654 int short_shift = 0; 6655 6656 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 6657 int common = 0; 6658 6659 if (convert_p) 6660 { 6661 op0 = default_conversion (orig_op0); 6662 op1 = default_conversion (orig_op1); 6663 } 6664 else 6665 { 6666 op0 = orig_op0; 6667 op1 = orig_op1; 6668 } 6669 6670 type0 = TREE_TYPE (op0); 6671 type1 = TREE_TYPE (op1); 6672 6673 /* The expression codes of the data types of the arguments tell us 6674 whether the arguments are integers, floating, pointers, etc. */ 6675 code0 = TREE_CODE (type0); 6676 code1 = TREE_CODE (type1); 6677 6678 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 6679 STRIP_TYPE_NOPS (op0); 6680 STRIP_TYPE_NOPS (op1); 6681 6682 /* If an error was already reported for one of the arguments, 6683 avoid reporting another error. */ 6684 6685 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 6686 return error_mark_node; 6687 6688 switch (code) 6689 { 6690 case PLUS_EXPR: 6691 /* Handle the pointer + int case. */ 6692 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6693 return pointer_int_sum (PLUS_EXPR, op0, op1); 6694 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) 6695 return pointer_int_sum (PLUS_EXPR, op1, op0); 6696 else 6697 common = 1; 6698 break; 6699 6700 case MINUS_EXPR: 6701 /* Subtraction of two similar pointers. 6702 We must subtract them as integers, then divide by object size. */ 6703 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 6704 && comp_target_types (type0, type1, 1)) 6705 return pointer_diff (op0, op1); 6706 /* Handle pointer minus int. Just like pointer plus int. */ 6707 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6708 return pointer_int_sum (MINUS_EXPR, op0, op1); 6709 else 6710 common = 1; 6711 break; 6712 6713 case MULT_EXPR: 6714 common = 1; 6715 break; 6716 6717 case TRUNC_DIV_EXPR: 6718 case CEIL_DIV_EXPR: 6719 case FLOOR_DIV_EXPR: 6720 case ROUND_DIV_EXPR: 6721 case EXACT_DIV_EXPR: 6722 /* Floating point division by zero is a legitimate way to obtain 6723 infinities and NaNs. */ 6724 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6725 warning ("division by zero"); 6726 6727 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6728 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 6729 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6730 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 6731 { 6732 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)) 6733 resultcode = RDIV_EXPR; 6734 else 6735 /* Although it would be tempting to shorten always here, that 6736 loses on some targets, since the modulo instruction is 6737 undefined if the quotient can't be represented in the 6738 computation mode. We shorten only if unsigned or if 6739 dividing by something we know != -1. */ 6740 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6741 || (TREE_CODE (op1) == INTEGER_CST 6742 && ! integer_all_onesp (op1))); 6743 common = 1; 6744 } 6745 break; 6746 6747 case BIT_AND_EXPR: 6748 case BIT_IOR_EXPR: 6749 case BIT_XOR_EXPR: 6750 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6751 shorten = -1; 6752 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 6753 common = 1; 6754 break; 6755 6756 case TRUNC_MOD_EXPR: 6757 case FLOOR_MOD_EXPR: 6758 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) 6759 warning ("division by zero"); 6760 6761 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6762 { 6763 /* Although it would be tempting to shorten always here, that loses 6764 on some targets, since the modulo instruction is undefined if the 6765 quotient can't be represented in the computation mode. We shorten 6766 only if unsigned or if dividing by something we know != -1. */ 6767 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0)) 6768 || (TREE_CODE (op1) == INTEGER_CST 6769 && ! integer_all_onesp (op1))); 6770 common = 1; 6771 } 6772 break; 6773 6774 case TRUTH_ANDIF_EXPR: 6775 case TRUTH_ORIF_EXPR: 6776 case TRUTH_AND_EXPR: 6777 case TRUTH_OR_EXPR: 6778 case TRUTH_XOR_EXPR: 6779 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE 6780 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) 6781 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE 6782 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) 6783 { 6784 /* Result of these operations is always an int, 6785 but that does not mean the operands should be 6786 converted to ints! */ 6787 result_type = integer_type_node; 6788 op0 = c_common_truthvalue_conversion (op0); 6789 op1 = c_common_truthvalue_conversion (op1); 6790 converted = 1; 6791 } 6792 break; 6793 6794 /* Shift operations: result has same type as first operand; 6795 always convert second operand to int. 6796 Also set SHORT_SHIFT if shifting rightward. */ 6797 6798 case RSHIFT_EXPR: 6799 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6800 { 6801 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6802 { 6803 if (tree_int_cst_sgn (op1) < 0) 6804 warning ("right shift count is negative"); 6805 else 6806 { 6807 if (! integer_zerop (op1)) 6808 short_shift = 1; 6809 6810 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6811 warning ("right shift count >= width of type"); 6812 } 6813 } 6814 6815 /* Use the type of the value to be shifted. */ 6816 result_type = type0; 6817 /* Convert the shift-count to an integer, regardless of size 6818 of value being shifted. */ 6819 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6820 op1 = convert (integer_type_node, op1); 6821 /* Avoid converting op1 to result_type later. */ 6822 converted = 1; 6823 } 6824 break; 6825 6826 case LSHIFT_EXPR: 6827 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6828 { 6829 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6830 { 6831 if (tree_int_cst_sgn (op1) < 0) 6832 warning ("left shift count is negative"); 6833 6834 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6835 warning ("left shift count >= width of type"); 6836 } 6837 6838 /* Use the type of the value to be shifted. */ 6839 result_type = type0; 6840 /* Convert the shift-count to an integer, regardless of size 6841 of value being shifted. */ 6842 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6843 op1 = convert (integer_type_node, op1); 6844 /* Avoid converting op1 to result_type later. */ 6845 converted = 1; 6846 } 6847 break; 6848 6849 case RROTATE_EXPR: 6850 case LROTATE_EXPR: 6851 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 6852 { 6853 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) 6854 { 6855 if (tree_int_cst_sgn (op1) < 0) 6856 warning ("shift count is negative"); 6857 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 6858 warning ("shift count >= width of type"); 6859 } 6860 6861 /* Use the type of the value to be shifted. */ 6862 result_type = type0; 6863 /* Convert the shift-count to an integer, regardless of size 6864 of value being shifted. */ 6865 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 6866 op1 = convert (integer_type_node, op1); 6867 /* Avoid converting op1 to result_type later. */ 6868 converted = 1; 6869 } 6870 break; 6871 6872 case EQ_EXPR: 6873 case NE_EXPR: 6874 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE)) 6875 warning ("comparing floating point with == or != is unsafe"); 6876 /* Result of comparison is always int, 6877 but don't convert the args to int! */ 6878 build_type = integer_type_node; 6879 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 6880 || code0 == COMPLEX_TYPE) 6881 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 6882 || code1 == COMPLEX_TYPE)) 6883 short_compare = 1; 6884 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6885 { 6886 tree tt0 = TREE_TYPE (type0); 6887 tree tt1 = TREE_TYPE (type1); 6888 /* Anything compares with void *. void * compares with anything. 6889 Otherwise, the targets must be compatible 6890 and both must be object or both incomplete. */ 6891 if (comp_target_types (type0, type1, 1)) 6892 result_type = common_type (type0, type1); 6893 else if (VOID_TYPE_P (tt0)) 6894 { 6895 /* op0 != orig_op0 detects the case of something 6896 whose value is 0 but which isn't a valid null ptr const. */ 6897 if (pedantic && (!integer_zerop (op0) || op0 != orig_op0) 6898 && TREE_CODE (tt1) == FUNCTION_TYPE) 6899 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6900 } 6901 else if (VOID_TYPE_P (tt1)) 6902 { 6903 if (pedantic && (!integer_zerop (op1) || op1 != orig_op1) 6904 && TREE_CODE (tt0) == FUNCTION_TYPE) 6905 pedwarn ("ISO C forbids comparison of `void *' with function pointer"); 6906 } 6907 else 6908 pedwarn ("comparison of distinct pointer types lacks a cast"); 6909 6910 if (result_type == NULL_TREE) 6911 result_type = ptr_type_node; 6912 } 6913 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6914 && integer_zerop (op1)) 6915 result_type = type0; 6916 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6917 && integer_zerop (op0)) 6918 result_type = type1; 6919 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6920 { 6921 result_type = type0; 6922 pedwarn ("comparison between pointer and integer"); 6923 } 6924 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6925 { 6926 result_type = type1; 6927 pedwarn ("comparison between pointer and integer"); 6928 } 6929 break; 6930 6931 case MAX_EXPR: 6932 case MIN_EXPR: 6933 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6934 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6935 shorten = 1; 6936 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6937 { 6938 if (comp_target_types (type0, type1, 1)) 6939 { 6940 result_type = common_type (type0, type1); 6941 if (pedantic 6942 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6943 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6944 } 6945 else 6946 { 6947 result_type = ptr_type_node; 6948 pedwarn ("comparison of distinct pointer types lacks a cast"); 6949 } 6950 } 6951 break; 6952 6953 case LE_EXPR: 6954 case GE_EXPR: 6955 case LT_EXPR: 6956 case GT_EXPR: 6957 build_type = integer_type_node; 6958 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 6959 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 6960 short_compare = 1; 6961 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 6962 { 6963 if (comp_target_types (type0, type1, 1)) 6964 { 6965 result_type = common_type (type0, type1); 6966 if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) 6967 != !COMPLETE_TYPE_P (TREE_TYPE (type1))) 6968 pedwarn ("comparison of complete and incomplete pointers"); 6969 else if (pedantic 6970 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) 6971 pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); 6972 } 6973 else 6974 { 6975 result_type = ptr_type_node; 6976 pedwarn ("comparison of distinct pointer types lacks a cast"); 6977 } 6978 } 6979 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST 6980 && integer_zerop (op1)) 6981 { 6982 result_type = type0; 6983 if (pedantic || extra_warnings) 6984 pedwarn ("ordered comparison of pointer with integer zero"); 6985 } 6986 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST 6987 && integer_zerop (op0)) 6988 { 6989 result_type = type1; 6990 if (pedantic) 6991 pedwarn ("ordered comparison of pointer with integer zero"); 6992 } 6993 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 6994 { 6995 result_type = type0; 6996 pedwarn ("comparison between pointer and integer"); 6997 } 6998 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 6999 { 7000 result_type = type1; 7001 pedwarn ("comparison between pointer and integer"); 7002 } 7003 break; 7004 7005 case UNORDERED_EXPR: 7006 case ORDERED_EXPR: 7007 case UNLT_EXPR: 7008 case UNLE_EXPR: 7009 case UNGT_EXPR: 7010 case UNGE_EXPR: 7011 case UNEQ_EXPR: 7012 build_type = integer_type_node; 7013 if (code0 != REAL_TYPE || code1 != REAL_TYPE) 7014 { 7015 error ("unordered comparison on non-floating point argument"); 7016 return error_mark_node; 7017 } 7018 common = 1; 7019 break; 7020 7021 default: 7022 break; 7023 } 7024 7025 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 7026 || code0 == VECTOR_TYPE) 7027 && 7028 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE 7029 || code1 == VECTOR_TYPE)) 7030 { 7031 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); 7032 7033 if (shorten || common || short_compare) 7034 result_type = common_type (type0, type1); 7035 7036 /* For certain operations (which identify themselves by shorten != 0) 7037 if both args were extended from the same smaller type, 7038 do the arithmetic in that type and then extend. 7039 7040 shorten !=0 and !=1 indicates a bitwise operation. 7041 For them, this optimization is safe only if 7042 both args are zero-extended or both are sign-extended. 7043 Otherwise, we might change the result. 7044 Eg, (short)-1 | (unsigned short)-1 is (int)-1 7045 but calculated in (unsigned short) it would be (unsigned short)-1. */ 7046 7047 if (shorten && none_complex) 7048 { 7049 int unsigned0, unsigned1; 7050 tree arg0 = get_narrower (op0, &unsigned0); 7051 tree arg1 = get_narrower (op1, &unsigned1); 7052 /* UNS is 1 if the operation to be done is an unsigned one. */ 7053 int uns = TREE_UNSIGNED (result_type); 7054 tree type; 7055 7056 final_type = result_type; 7057 7058 /* Handle the case that OP0 (or OP1) does not *contain* a conversion 7059 but it *requires* conversion to FINAL_TYPE. */ 7060 7061 if ((TYPE_PRECISION (TREE_TYPE (op0)) 7062 == TYPE_PRECISION (TREE_TYPE (arg0))) 7063 && TREE_TYPE (op0) != final_type) 7064 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0)); 7065 if ((TYPE_PRECISION (TREE_TYPE (op1)) 7066 == TYPE_PRECISION (TREE_TYPE (arg1))) 7067 && TREE_TYPE (op1) != final_type) 7068 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1)); 7069 7070 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ 7071 7072 /* For bitwise operations, signedness of nominal type 7073 does not matter. Consider only how operands were extended. */ 7074 if (shorten == -1) 7075 uns = unsigned0; 7076 7077 /* Note that in all three cases below we refrain from optimizing 7078 an unsigned operation on sign-extended args. 7079 That would not be valid. */ 7080 7081 /* Both args variable: if both extended in same way 7082 from same width, do it in that width. 7083 Do it unsigned if args were zero-extended. */ 7084 if ((TYPE_PRECISION (TREE_TYPE (arg0)) 7085 < TYPE_PRECISION (result_type)) 7086 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7087 == TYPE_PRECISION (TREE_TYPE (arg0))) 7088 && unsigned0 == unsigned1 7089 && (unsigned0 || !uns)) 7090 result_type 7091 = c_common_signed_or_unsigned_type 7092 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); 7093 else if (TREE_CODE (arg0) == INTEGER_CST 7094 && (unsigned1 || !uns) 7095 && (TYPE_PRECISION (TREE_TYPE (arg1)) 7096 < TYPE_PRECISION (result_type)) 7097 && (type 7098 = c_common_signed_or_unsigned_type (unsigned1, 7099 TREE_TYPE (arg1)), 7100 int_fits_type_p (arg0, type))) 7101 result_type = type; 7102 else if (TREE_CODE (arg1) == INTEGER_CST 7103 && (unsigned0 || !uns) 7104 && (TYPE_PRECISION (TREE_TYPE (arg0)) 7105 < TYPE_PRECISION (result_type)) 7106 && (type 7107 = c_common_signed_or_unsigned_type (unsigned0, 7108 TREE_TYPE (arg0)), 7109 int_fits_type_p (arg1, type))) 7110 result_type = type; 7111 } 7112 7113 /* Shifts can be shortened if shifting right. */ 7114 7115 if (short_shift) 7116 { 7117 int unsigned_arg; 7118 tree arg0 = get_narrower (op0, &unsigned_arg); 7119 7120 final_type = result_type; 7121 7122 if (arg0 == op0 && final_type == TREE_TYPE (op0)) 7123 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0)); 7124 7125 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) 7126 /* We can shorten only if the shift count is less than the 7127 number of bits in the smaller type size. */ 7128 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 7129 /* We cannot drop an unsigned shift after sign-extension. */ 7130 && (!TREE_UNSIGNED (final_type) || unsigned_arg)) 7131 { 7132 /* Do an unsigned shift if the operand was zero-extended. */ 7133 result_type 7134 = c_common_signed_or_unsigned_type (unsigned_arg, 7135 TREE_TYPE (arg0)); 7136 /* Convert value-to-be-shifted to that type. */ 7137 if (TREE_TYPE (op0) != result_type) 7138 op0 = convert (result_type, op0); 7139 converted = 1; 7140 } 7141 } 7142 7143 /* Comparison operations are shortened too but differently. 7144 They identify themselves by setting short_compare = 1. */ 7145 7146 if (short_compare) 7147 { 7148 /* Don't write &op0, etc., because that would prevent op0 7149 from being kept in a register. 7150 Instead, make copies of the our local variables and 7151 pass the copies by reference, then copy them back afterward. */ 7152 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 7153 enum tree_code xresultcode = resultcode; 7154 tree val 7155 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 7156 7157 if (val != 0) 7158 return val; 7159 7160 op0 = xop0, op1 = xop1; 7161 converted = 1; 7162 resultcode = xresultcode; 7163 7164 if (warn_sign_compare && skip_evaluation == 0) 7165 { 7166 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0)); 7167 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1)); 7168 int unsignedp0, unsignedp1; 7169 tree primop0 = get_narrower (op0, &unsignedp0); 7170 tree primop1 = get_narrower (op1, &unsignedp1); 7171 7172 xop0 = orig_op0; 7173 xop1 = orig_op1; 7174 STRIP_TYPE_NOPS (xop0); 7175 STRIP_TYPE_NOPS (xop1); 7176 7177 /* Give warnings for comparisons between signed and unsigned 7178 quantities that may fail. 7179 7180 Do the checking based on the original operand trees, so that 7181 casts will be considered, but default promotions won't be. 7182 7183 Do not warn if the comparison is being done in a signed type, 7184 since the signed type will only be chosen if it can represent 7185 all the values of the unsigned type. */ 7186 if (! TREE_UNSIGNED (result_type)) 7187 /* OK */; 7188 /* Do not warn if both operands are the same signedness. */ 7189 else if (op0_signed == op1_signed) 7190 /* OK */; 7191 else 7192 { 7193 tree sop, uop; 7194 7195 if (op0_signed) 7196 sop = xop0, uop = xop1; 7197 else 7198 sop = xop1, uop = xop0; 7199 7200 /* Do not warn if the signed quantity is an 7201 unsuffixed integer literal (or some static 7202 constant expression involving such literals or a 7203 conditional expression involving such literals) 7204 and it is non-negative. */ 7205 if (c_tree_expr_nonnegative_p (sop)) 7206 /* OK */; 7207 /* Do not warn if the comparison is an equality operation, 7208 the unsigned quantity is an integral constant, and it 7209 would fit in the result if the result were signed. */ 7210 else if (TREE_CODE (uop) == INTEGER_CST 7211 && (resultcode == EQ_EXPR || resultcode == NE_EXPR) 7212 && int_fits_type_p 7213 (uop, c_common_signed_type (result_type))) 7214 /* OK */; 7215 /* Do not warn if the unsigned quantity is an enumeration 7216 constant and its maximum value would fit in the result 7217 if the result were signed. */ 7218 else if (TREE_CODE (uop) == INTEGER_CST 7219 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE 7220 && int_fits_type_p 7221 (TYPE_MAX_VALUE (TREE_TYPE(uop)), 7222 c_common_signed_type (result_type))) 7223 /* OK */; 7224 else 7225 warning ("comparison between signed and unsigned"); 7226 } 7227 7228 /* Warn if two unsigned values are being compared in a size 7229 larger than their original size, and one (and only one) is the 7230 result of a `~' operator. This comparison will always fail. 7231 7232 Also warn if one operand is a constant, and the constant 7233 does not have all bits set that are set in the ~ operand 7234 when it is extended. */ 7235 7236 if ((TREE_CODE (primop0) == BIT_NOT_EXPR) 7237 != (TREE_CODE (primop1) == BIT_NOT_EXPR)) 7238 { 7239 if (TREE_CODE (primop0) == BIT_NOT_EXPR) 7240 primop0 = get_narrower (TREE_OPERAND (primop0, 0), 7241 &unsignedp0); 7242 else 7243 primop1 = get_narrower (TREE_OPERAND (primop1, 0), 7244 &unsignedp1); 7245 7246 if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) 7247 { 7248 tree primop; 7249 HOST_WIDE_INT constant, mask; 7250 int unsignedp, bits; 7251 7252 if (host_integerp (primop0, 0)) 7253 { 7254 primop = primop1; 7255 unsignedp = unsignedp1; 7256 constant = tree_low_cst (primop0, 0); 7257 } 7258 else 7259 { 7260 primop = primop0; 7261 unsignedp = unsignedp0; 7262 constant = tree_low_cst (primop1, 0); 7263 } 7264 7265 bits = TYPE_PRECISION (TREE_TYPE (primop)); 7266 if (bits < TYPE_PRECISION (result_type) 7267 && bits < HOST_BITS_PER_WIDE_INT && unsignedp) 7268 { 7269 mask = (~ (HOST_WIDE_INT) 0) << bits; 7270 if ((mask & constant) != mask) 7271 warning ("comparison of promoted ~unsigned with constant"); 7272 } 7273 } 7274 else if (unsignedp0 && unsignedp1 7275 && (TYPE_PRECISION (TREE_TYPE (primop0)) 7276 < TYPE_PRECISION (result_type)) 7277 && (TYPE_PRECISION (TREE_TYPE (primop1)) 7278 < TYPE_PRECISION (result_type))) 7279 warning ("comparison of promoted ~unsigned with unsigned"); 7280 } 7281 } 7282 } 7283 } 7284 7285 /* At this point, RESULT_TYPE must be nonzero to avoid an error message. 7286 If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 7287 Then the expression will be built. 7288 It will be given type FINAL_TYPE if that is nonzero; 7289 otherwise, it will be given type RESULT_TYPE. */ 7290 7291 if (!result_type) 7292 { 7293 binary_op_error (code); 7294 return error_mark_node; 7295 } 7296 7297 if (! converted) 7298 { 7299 if (TREE_TYPE (op0) != result_type) 7300 op0 = convert (result_type, op0); 7301 if (TREE_TYPE (op1) != result_type) 7302 op1 = convert (result_type, op1); 7303 } 7304 7305 if (build_type == NULL_TREE) 7306 build_type = result_type; 7307 7308 { 7309 tree result = build (resultcode, build_type, op0, op1); 7310 tree folded; 7311 7312 /* Treat expressions in initializers specially as they can't trap. */ 7313 folded = require_constant_value ? fold_initializer (result) 7314 : fold (result); 7315 if (folded == result) 7316 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1); 7317 if (final_type != 0) 7318 return convert (final_type, folded); 7319 return folded; 7320 } 7321} 7322