1 /* Build expressions with type checking for C++ compiler. 2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 4 2011, 2012 5 Free Software Foundation, Inc. 6 Hacked by Michael Tiemann (tiemann@cygnus.com) 7 8 This file is part of GCC. 9 10 GCC is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3, or (at your option) 13 any later version. 14 15 GCC is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with GCC; see the file COPYING3. If not see 22 <http://www.gnu.org/licenses/>. */ 23 24 25 /* This file is part of the C++ front end. 26 It contains routines to build C++ expressions given their operands, 27 including computing the types of the result, C and C++ specific error 28 checks, and some optimization. */ 29 30 #include "config.h" 31 #include "system.h" 32 #include "coretypes.h" 33 #include "tm.h" 34 #include "tree.h" 35 #include "cp-tree.h" 36 #include "flags.h" 37 #include "output.h" 38 #include "diagnostic.h" 39 #include "intl.h" 40 #include "target.h" 41 #include "convert.h" 42 #include "c-family/c-common.h" 43 #include "c-family/c-objc.h" 44 #include "params.h" 45 46 static tree pfn_from_ptrmemfunc (tree); 47 static tree delta_from_ptrmemfunc (tree); 48 static tree convert_for_assignment (tree, tree, impl_conv_rhs, tree, int, 49 tsubst_flags_t, int); 50 static tree cp_pointer_int_sum (enum tree_code, tree, tree); 51 static tree rationalize_conditional_expr (enum tree_code, tree, 52 tsubst_flags_t); 53 static int comp_ptr_ttypes_real (tree, tree, int); 54 static bool comp_except_types (tree, tree, bool); 55 static bool comp_array_types (const_tree, const_tree, bool); 56 static tree pointer_diff (tree, tree, tree); 57 static tree get_delta_difference (tree, tree, bool, bool, tsubst_flags_t); 58 static void casts_away_constness_r (tree *, tree *); 59 static bool casts_away_constness (tree, tree); 60 static void maybe_warn_about_returning_address_of_local (tree); 61 static tree lookup_destructor (tree, tree, tree); 62 static void warn_args_num (location_t, tree, bool); 63 static int convert_arguments (tree, VEC(tree,gc) **, tree, int, 64 tsubst_flags_t); 65 66 /* Do `exp = require_complete_type (exp);' to make sure exp 67 does not have an incomplete type. (That includes void types.) 68 Returns error_mark_node if the VALUE does not have 69 complete type when this function returns. */ 70 71 tree 72 require_complete_type_sfinae (tree value, tsubst_flags_t complain) 73 { 74 tree type; 75 76 if (processing_template_decl || value == error_mark_node) 77 return value; 78 79 if (TREE_CODE (value) == OVERLOAD) 80 type = unknown_type_node; 81 else 82 type = TREE_TYPE (value); 83 84 if (type == error_mark_node) 85 return error_mark_node; 86 87 /* First, detect a valid value with a complete type. */ 88 if (COMPLETE_TYPE_P (type)) 89 return value; 90 91 if (complete_type_or_maybe_complain (type, value, complain)) 92 return value; 93 else 94 return error_mark_node; 95 } 96 97 tree 98 require_complete_type (tree value) 99 { 100 return require_complete_type_sfinae (value, tf_warning_or_error); 101 } 102 103 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is 104 a template instantiation, do the instantiation. Returns TYPE, 105 whether or not it could be completed, unless something goes 106 horribly wrong, in which case the error_mark_node is returned. */ 107 108 tree 109 complete_type (tree type) 110 { 111 if (type == NULL_TREE) 112 /* Rather than crash, we return something sure to cause an error 113 at some point. */ 114 return error_mark_node; 115 116 if (type == error_mark_node || COMPLETE_TYPE_P (type)) 117 ; 118 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type)) 119 { 120 tree t = complete_type (TREE_TYPE (type)); 121 unsigned int needs_constructing, has_nontrivial_dtor; 122 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type)) 123 layout_type (type); 124 needs_constructing 125 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t)); 126 has_nontrivial_dtor 127 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t)); 128 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t)) 129 { 130 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing; 131 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor; 132 } 133 } 134 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type)) 135 instantiate_class_template (TYPE_MAIN_VARIANT (type)); 136 137 return type; 138 } 139 140 /* Like complete_type, but issue an error if the TYPE cannot be completed. 141 VALUE is used for informative diagnostics. 142 Returns NULL_TREE if the type cannot be made complete. */ 143 144 tree 145 complete_type_or_maybe_complain (tree type, tree value, tsubst_flags_t complain) 146 { 147 type = complete_type (type); 148 if (type == error_mark_node) 149 /* We already issued an error. */ 150 return NULL_TREE; 151 else if (!COMPLETE_TYPE_P (type)) 152 { 153 if (complain & tf_error) 154 cxx_incomplete_type_diagnostic (value, type, DK_ERROR); 155 return NULL_TREE; 156 } 157 else 158 return type; 159 } 160 161 tree 162 complete_type_or_else (tree type, tree value) 163 { 164 return complete_type_or_maybe_complain (type, value, tf_warning_or_error); 165 } 166 167 /* Return truthvalue of whether type of EXP is instantiated. */ 168 169 int 170 type_unknown_p (const_tree exp) 171 { 172 return (TREE_CODE (exp) == TREE_LIST 173 || TREE_TYPE (exp) == unknown_type_node); 174 } 175 176 177 /* Return the common type of two parameter lists. 178 We assume that comptypes has already been done and returned 1; 179 if that isn't so, this may crash. 180 181 As an optimization, free the space we allocate if the parameter 182 lists are already common. */ 183 184 static tree 185 commonparms (tree p1, tree p2) 186 { 187 tree oldargs = p1, newargs, n; 188 int i, len; 189 int any_change = 0; 190 191 len = list_length (p1); 192 newargs = tree_last (p1); 193 194 if (newargs == void_list_node) 195 i = 1; 196 else 197 { 198 i = 0; 199 newargs = 0; 200 } 201 202 for (; i < len; i++) 203 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs); 204 205 n = newargs; 206 207 for (i = 0; p1; 208 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++) 209 { 210 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2)) 211 { 212 TREE_PURPOSE (n) = TREE_PURPOSE (p1); 213 any_change = 1; 214 } 215 else if (! TREE_PURPOSE (p1)) 216 { 217 if (TREE_PURPOSE (p2)) 218 { 219 TREE_PURPOSE (n) = TREE_PURPOSE (p2); 220 any_change = 1; 221 } 222 } 223 else 224 { 225 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2))) 226 any_change = 1; 227 TREE_PURPOSE (n) = TREE_PURPOSE (p2); 228 } 229 if (TREE_VALUE (p1) != TREE_VALUE (p2)) 230 { 231 any_change = 1; 232 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2)); 233 } 234 else 235 TREE_VALUE (n) = TREE_VALUE (p1); 236 } 237 if (! any_change) 238 return oldargs; 239 240 return newargs; 241 } 242 243 /* Given a type, perhaps copied for a typedef, 244 find the "original" version of it. */ 245 static tree 246 original_type (tree t) 247 { 248 int quals = cp_type_quals (t); 249 while (t != error_mark_node 250 && TYPE_NAME (t) != NULL_TREE) 251 { 252 tree x = TYPE_NAME (t); 253 if (TREE_CODE (x) != TYPE_DECL) 254 break; 255 x = DECL_ORIGINAL_TYPE (x); 256 if (x == NULL_TREE) 257 break; 258 t = x; 259 } 260 return cp_build_qualified_type (t, quals); 261 } 262 263 /* Return the common type for two arithmetic types T1 and T2 under the 264 usual arithmetic conversions. The default conversions have already 265 been applied, and enumerated types converted to their compatible 266 integer types. */ 267 268 static tree 269 cp_common_type (tree t1, tree t2) 270 { 271 enum tree_code code1 = TREE_CODE (t1); 272 enum tree_code code2 = TREE_CODE (t2); 273 tree attributes; 274 275 276 /* In what follows, we slightly generalize the rules given in [expr] so 277 as to deal with `long long' and `complex'. First, merge the 278 attributes. */ 279 attributes = (*targetm.merge_type_attributes) (t1, t2); 280 281 if (SCOPED_ENUM_P (t1) || SCOPED_ENUM_P (t2)) 282 { 283 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) 284 return build_type_attribute_variant (t1, attributes); 285 else 286 return NULL_TREE; 287 } 288 289 /* FIXME: Attributes. */ 290 gcc_assert (ARITHMETIC_TYPE_P (t1) 291 || TREE_CODE (t1) == VECTOR_TYPE 292 || UNSCOPED_ENUM_P (t1)); 293 gcc_assert (ARITHMETIC_TYPE_P (t2) 294 || TREE_CODE (t2) == VECTOR_TYPE 295 || UNSCOPED_ENUM_P (t2)); 296 297 /* If one type is complex, form the common type of the non-complex 298 components, then make that complex. Use T1 or T2 if it is the 299 required type. */ 300 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) 301 { 302 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1; 303 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2; 304 tree subtype 305 = type_after_usual_arithmetic_conversions (subtype1, subtype2); 306 307 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype) 308 return build_type_attribute_variant (t1, attributes); 309 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype) 310 return build_type_attribute_variant (t2, attributes); 311 else 312 return build_type_attribute_variant (build_complex_type (subtype), 313 attributes); 314 } 315 316 if (code1 == VECTOR_TYPE) 317 { 318 /* When we get here we should have two vectors of the same size. 319 Just prefer the unsigned one if present. */ 320 if (TYPE_UNSIGNED (t1)) 321 return build_type_attribute_variant (t1, attributes); 322 else 323 return build_type_attribute_variant (t2, attributes); 324 } 325 326 /* If only one is real, use it as the result. */ 327 if (code1 == REAL_TYPE && code2 != REAL_TYPE) 328 return build_type_attribute_variant (t1, attributes); 329 if (code2 == REAL_TYPE && code1 != REAL_TYPE) 330 return build_type_attribute_variant (t2, attributes); 331 332 /* Both real or both integers; use the one with greater precision. */ 333 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2)) 334 return build_type_attribute_variant (t1, attributes); 335 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1)) 336 return build_type_attribute_variant (t2, attributes); 337 338 /* The types are the same; no need to do anything fancy. */ 339 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) 340 return build_type_attribute_variant (t1, attributes); 341 342 if (code1 != REAL_TYPE) 343 { 344 /* If one is unsigned long long, then convert the other to unsigned 345 long long. */ 346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node) 347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node)) 348 return build_type_attribute_variant (long_long_unsigned_type_node, 349 attributes); 350 /* If one is a long long, and the other is an unsigned long, and 351 long long can represent all the values of an unsigned long, then 352 convert to a long long. Otherwise, convert to an unsigned long 353 long. Otherwise, if either operand is long long, convert the 354 other to long long. 355 356 Since we're here, we know the TYPE_PRECISION is the same; 357 therefore converting to long long cannot represent all the values 358 of an unsigned long, so we choose unsigned long long in that 359 case. */ 360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node) 361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node)) 362 { 363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) 364 ? long_long_unsigned_type_node 365 : long_long_integer_type_node); 366 return build_type_attribute_variant (t, attributes); 367 } 368 if (int128_integer_type_node != NULL_TREE 369 && (same_type_p (TYPE_MAIN_VARIANT (t1), 370 int128_integer_type_node) 371 || same_type_p (TYPE_MAIN_VARIANT (t2), 372 int128_integer_type_node))) 373 { 374 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) 375 ? int128_unsigned_type_node 376 : int128_integer_type_node); 377 return build_type_attribute_variant (t, attributes); 378 } 379 380 /* Go through the same procedure, but for longs. */ 381 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node) 382 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node)) 383 return build_type_attribute_variant (long_unsigned_type_node, 384 attributes); 385 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node) 386 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node)) 387 { 388 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) 389 ? long_unsigned_type_node : long_integer_type_node); 390 return build_type_attribute_variant (t, attributes); 391 } 392 /* Otherwise prefer the unsigned one. */ 393 if (TYPE_UNSIGNED (t1)) 394 return build_type_attribute_variant (t1, attributes); 395 else 396 return build_type_attribute_variant (t2, attributes); 397 } 398 else 399 { 400 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node) 401 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node)) 402 return build_type_attribute_variant (long_double_type_node, 403 attributes); 404 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node) 405 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node)) 406 return build_type_attribute_variant (double_type_node, 407 attributes); 408 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node) 409 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node)) 410 return build_type_attribute_variant (float_type_node, 411 attributes); 412 413 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of 414 the standard C++ floating-point types. Logic earlier in this 415 function has already eliminated the possibility that 416 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no 417 compelling reason to choose one or the other. */ 418 return build_type_attribute_variant (t1, attributes); 419 } 420 } 421 422 /* T1 and T2 are arithmetic or enumeration types. Return the type 423 that will result from the "usual arithmetic conversions" on T1 and 424 T2 as described in [expr]. */ 425 426 tree 427 type_after_usual_arithmetic_conversions (tree t1, tree t2) 428 { 429 gcc_assert (ARITHMETIC_TYPE_P (t1) 430 || TREE_CODE (t1) == VECTOR_TYPE 431 || UNSCOPED_ENUM_P (t1)); 432 gcc_assert (ARITHMETIC_TYPE_P (t2) 433 || TREE_CODE (t2) == VECTOR_TYPE 434 || UNSCOPED_ENUM_P (t2)); 435 436 /* Perform the integral promotions. We do not promote real types here. */ 437 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t1) 438 && INTEGRAL_OR_ENUMERATION_TYPE_P (t2)) 439 { 440 t1 = type_promotes_to (t1); 441 t2 = type_promotes_to (t2); 442 } 443 444 return cp_common_type (t1, t2); 445 } 446 447 static void 448 composite_pointer_error (diagnostic_t kind, tree t1, tree t2, 449 composite_pointer_operation operation) 450 { 451 switch (operation) 452 { 453 case CPO_COMPARISON: 454 emit_diagnostic (kind, input_location, 0, 455 "comparison between " 456 "distinct pointer types %qT and %qT lacks a cast", 457 t1, t2); 458 break; 459 case CPO_CONVERSION: 460 emit_diagnostic (kind, input_location, 0, 461 "conversion between " 462 "distinct pointer types %qT and %qT lacks a cast", 463 t1, t2); 464 break; 465 case CPO_CONDITIONAL_EXPR: 466 emit_diagnostic (kind, input_location, 0, 467 "conditional expression between " 468 "distinct pointer types %qT and %qT lacks a cast", 469 t1, t2); 470 break; 471 default: 472 gcc_unreachable (); 473 } 474 } 475 476 /* Subroutine of composite_pointer_type to implement the recursive 477 case. See that function for documentation of the parameters. */ 478 479 static tree 480 composite_pointer_type_r (tree t1, tree t2, 481 composite_pointer_operation operation, 482 tsubst_flags_t complain) 483 { 484 tree pointee1; 485 tree pointee2; 486 tree result_type; 487 tree attributes; 488 489 /* Determine the types pointed to by T1 and T2. */ 490 if (TREE_CODE (t1) == POINTER_TYPE) 491 { 492 pointee1 = TREE_TYPE (t1); 493 pointee2 = TREE_TYPE (t2); 494 } 495 else 496 { 497 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1); 498 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2); 499 } 500 501 /* [expr.rel] 502 503 Otherwise, the composite pointer type is a pointer type 504 similar (_conv.qual_) to the type of one of the operands, 505 with a cv-qualification signature (_conv.qual_) that is the 506 union of the cv-qualification signatures of the operand 507 types. */ 508 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2)) 509 result_type = pointee1; 510 else if ((TREE_CODE (pointee1) == POINTER_TYPE 511 && TREE_CODE (pointee2) == POINTER_TYPE) 512 || (TYPE_PTR_TO_MEMBER_P (pointee1) 513 && TYPE_PTR_TO_MEMBER_P (pointee2))) 514 { 515 result_type = composite_pointer_type_r (pointee1, pointee2, operation, 516 complain); 517 if (result_type == error_mark_node) 518 return error_mark_node; 519 } 520 else 521 { 522 if (complain & tf_error) 523 composite_pointer_error (DK_PERMERROR, t1, t2, operation); 524 else 525 return error_mark_node; 526 result_type = void_type_node; 527 } 528 result_type = cp_build_qualified_type (result_type, 529 (cp_type_quals (pointee1) 530 | cp_type_quals (pointee2))); 531 /* If the original types were pointers to members, so is the 532 result. */ 533 if (TYPE_PTR_TO_MEMBER_P (t1)) 534 { 535 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1), 536 TYPE_PTRMEM_CLASS_TYPE (t2))) 537 { 538 if (complain & tf_error) 539 composite_pointer_error (DK_PERMERROR, t1, t2, operation); 540 else 541 return error_mark_node; 542 } 543 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1), 544 result_type); 545 } 546 else 547 result_type = build_pointer_type (result_type); 548 549 /* Merge the attributes. */ 550 attributes = (*targetm.merge_type_attributes) (t1, t2); 551 return build_type_attribute_variant (result_type, attributes); 552 } 553 554 /* Return the composite pointer type (see [expr.rel]) for T1 and T2. 555 ARG1 and ARG2 are the values with those types. The OPERATION is to 556 describe the operation between the pointer types, 557 in case an error occurs. 558 559 This routine also implements the computation of a common type for 560 pointers-to-members as per [expr.eq]. */ 561 562 tree 563 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2, 564 composite_pointer_operation operation, 565 tsubst_flags_t complain) 566 { 567 tree class1; 568 tree class2; 569 570 /* [expr.rel] 571 572 If one operand is a null pointer constant, the composite pointer 573 type is the type of the other operand. */ 574 if (null_ptr_cst_p (arg1)) 575 return t2; 576 if (null_ptr_cst_p (arg2)) 577 return t1; 578 579 /* We have: 580 581 [expr.rel] 582 583 If one of the operands has type "pointer to cv1 void*", then 584 the other has type "pointer to cv2T", and the composite pointer 585 type is "pointer to cv12 void", where cv12 is the union of cv1 586 and cv2. 587 588 If either type is a pointer to void, make sure it is T1. */ 589 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2))) 590 { 591 tree t; 592 t = t1; 593 t1 = t2; 594 t2 = t; 595 } 596 597 /* Now, if T1 is a pointer to void, merge the qualifiers. */ 598 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1))) 599 { 600 tree attributes; 601 tree result_type; 602 603 if (TYPE_PTRFN_P (t2) && (complain & tf_error)) 604 { 605 switch (operation) 606 { 607 case CPO_COMPARISON: 608 pedwarn (input_location, OPT_pedantic, 609 "ISO C++ forbids comparison between " 610 "pointer of type %<void *%> and pointer-to-function"); 611 break; 612 case CPO_CONVERSION: 613 pedwarn (input_location, OPT_pedantic, 614 "ISO C++ forbids conversion between " 615 "pointer of type %<void *%> and pointer-to-function"); 616 break; 617 case CPO_CONDITIONAL_EXPR: 618 pedwarn (input_location, OPT_pedantic, 619 "ISO C++ forbids conditional expression between " 620 "pointer of type %<void *%> and pointer-to-function"); 621 break; 622 default: 623 gcc_unreachable (); 624 } 625 } 626 result_type 627 = cp_build_qualified_type (void_type_node, 628 (cp_type_quals (TREE_TYPE (t1)) 629 | cp_type_quals (TREE_TYPE (t2)))); 630 result_type = build_pointer_type (result_type); 631 /* Merge the attributes. */ 632 attributes = (*targetm.merge_type_attributes) (t1, t2); 633 return build_type_attribute_variant (result_type, attributes); 634 } 635 636 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE 637 && TREE_CODE (t2) == POINTER_TYPE) 638 { 639 if (objc_have_common_type (t1, t2, -3, NULL_TREE)) 640 return objc_common_type (t1, t2); 641 } 642 643 /* [expr.eq] permits the application of a pointer conversion to 644 bring the pointers to a common type. */ 645 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE 646 && CLASS_TYPE_P (TREE_TYPE (t1)) 647 && CLASS_TYPE_P (TREE_TYPE (t2)) 648 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1), 649 TREE_TYPE (t2))) 650 { 651 class1 = TREE_TYPE (t1); 652 class2 = TREE_TYPE (t2); 653 654 if (DERIVED_FROM_P (class1, class2)) 655 t2 = (build_pointer_type 656 (cp_build_qualified_type (class1, cp_type_quals (class2)))); 657 else if (DERIVED_FROM_P (class2, class1)) 658 t1 = (build_pointer_type 659 (cp_build_qualified_type (class2, cp_type_quals (class1)))); 660 else 661 { 662 if (complain & tf_error) 663 composite_pointer_error (DK_ERROR, t1, t2, operation); 664 return error_mark_node; 665 } 666 } 667 /* [expr.eq] permits the application of a pointer-to-member 668 conversion to change the class type of one of the types. */ 669 else if (TYPE_PTR_TO_MEMBER_P (t1) 670 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1), 671 TYPE_PTRMEM_CLASS_TYPE (t2))) 672 { 673 class1 = TYPE_PTRMEM_CLASS_TYPE (t1); 674 class2 = TYPE_PTRMEM_CLASS_TYPE (t2); 675 676 if (DERIVED_FROM_P (class1, class2)) 677 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1)); 678 else if (DERIVED_FROM_P (class2, class1)) 679 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2)); 680 else 681 { 682 if (complain & tf_error) 683 switch (operation) 684 { 685 case CPO_COMPARISON: 686 error ("comparison between distinct " 687 "pointer-to-member types %qT and %qT lacks a cast", 688 t1, t2); 689 break; 690 case CPO_CONVERSION: 691 error ("conversion between distinct " 692 "pointer-to-member types %qT and %qT lacks a cast", 693 t1, t2); 694 break; 695 case CPO_CONDITIONAL_EXPR: 696 error ("conditional expression between distinct " 697 "pointer-to-member types %qT and %qT lacks a cast", 698 t1, t2); 699 break; 700 default: 701 gcc_unreachable (); 702 } 703 return error_mark_node; 704 } 705 } 706 707 return composite_pointer_type_r (t1, t2, operation, complain); 708 } 709 710 /* Return the merged type of two types. 711 We assume that comptypes has already been done and returned 1; 712 if that isn't so, this may crash. 713 714 This just combines attributes and default arguments; any other 715 differences would cause the two types to compare unalike. */ 716 717 tree 718 merge_types (tree t1, tree t2) 719 { 720 enum tree_code code1; 721 enum tree_code code2; 722 tree attributes; 723 724 /* Save time if the two types are the same. */ 725 if (t1 == t2) 726 return t1; 727 if (original_type (t1) == original_type (t2)) 728 return t1; 729 730 /* If one type is nonsense, use the other. */ 731 if (t1 == error_mark_node) 732 return t2; 733 if (t2 == error_mark_node) 734 return t1; 735 736 /* Merge the attributes. */ 737 attributes = (*targetm.merge_type_attributes) (t1, t2); 738 739 if (TYPE_PTRMEMFUNC_P (t1)) 740 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1); 741 if (TYPE_PTRMEMFUNC_P (t2)) 742 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2); 743 744 code1 = TREE_CODE (t1); 745 code2 = TREE_CODE (t2); 746 if (code1 != code2) 747 { 748 gcc_assert (code1 == TYPENAME_TYPE || code2 == TYPENAME_TYPE); 749 if (code1 == TYPENAME_TYPE) 750 { 751 t1 = resolve_typename_type (t1, /*only_current_p=*/true); 752 code1 = TREE_CODE (t1); 753 } 754 else 755 { 756 t2 = resolve_typename_type (t2, /*only_current_p=*/true); 757 code2 = TREE_CODE (t2); 758 } 759 } 760 761 switch (code1) 762 { 763 case POINTER_TYPE: 764 case REFERENCE_TYPE: 765 /* For two pointers, do this recursively on the target type. */ 766 { 767 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); 768 int quals = cp_type_quals (t1); 769 770 if (code1 == POINTER_TYPE) 771 t1 = build_pointer_type (target); 772 else 773 t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1)); 774 t1 = build_type_attribute_variant (t1, attributes); 775 t1 = cp_build_qualified_type (t1, quals); 776 777 if (TREE_CODE (target) == METHOD_TYPE) 778 t1 = build_ptrmemfunc_type (t1); 779 780 return t1; 781 } 782 783 case OFFSET_TYPE: 784 { 785 int quals; 786 tree pointee; 787 quals = cp_type_quals (t1); 788 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1), 789 TYPE_PTRMEM_POINTED_TO_TYPE (t2)); 790 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1), 791 pointee); 792 t1 = cp_build_qualified_type (t1, quals); 793 break; 794 } 795 796 case ARRAY_TYPE: 797 { 798 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); 799 /* Save space: see if the result is identical to one of the args. */ 800 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)) 801 return build_type_attribute_variant (t1, attributes); 802 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)) 803 return build_type_attribute_variant (t2, attributes); 804 /* Merge the element types, and have a size if either arg has one. */ 805 t1 = build_cplus_array_type 806 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2)); 807 break; 808 } 809 810 case FUNCTION_TYPE: 811 /* Function types: prefer the one that specified arg types. 812 If both do, merge the arg types. Also merge the return types. */ 813 { 814 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); 815 tree p1 = TYPE_ARG_TYPES (t1); 816 tree p2 = TYPE_ARG_TYPES (t2); 817 tree parms; 818 tree rval, raises; 819 820 /* Save space: see if the result is identical to one of the args. */ 821 if (valtype == TREE_TYPE (t1) && ! p2) 822 return cp_build_type_attribute_variant (t1, attributes); 823 if (valtype == TREE_TYPE (t2) && ! p1) 824 return cp_build_type_attribute_variant (t2, attributes); 825 826 /* Simple way if one arg fails to specify argument types. */ 827 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node) 828 parms = p2; 829 else if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node) 830 parms = p1; 831 else 832 parms = commonparms (p1, p2); 833 834 rval = build_function_type (valtype, parms); 835 gcc_assert (type_memfn_quals (t1) == type_memfn_quals (t2)); 836 rval = apply_memfn_quals (rval, type_memfn_quals (t1)); 837 raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1), 838 TYPE_RAISES_EXCEPTIONS (t2), 839 NULL_TREE); 840 t1 = build_exception_variant (rval, raises); 841 break; 842 } 843 844 case METHOD_TYPE: 845 { 846 /* Get this value the long way, since TYPE_METHOD_BASETYPE 847 is just the main variant of this. */ 848 tree basetype = class_of_this_parm (t2); 849 tree raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1), 850 TYPE_RAISES_EXCEPTIONS (t2), 851 NULL_TREE); 852 tree t3; 853 854 /* If this was a member function type, get back to the 855 original type of type member function (i.e., without 856 the class instance variable up front. */ 857 t1 = build_function_type (TREE_TYPE (t1), 858 TREE_CHAIN (TYPE_ARG_TYPES (t1))); 859 t2 = build_function_type (TREE_TYPE (t2), 860 TREE_CHAIN (TYPE_ARG_TYPES (t2))); 861 t3 = merge_types (t1, t2); 862 t3 = build_method_type_directly (basetype, TREE_TYPE (t3), 863 TYPE_ARG_TYPES (t3)); 864 t1 = build_exception_variant (t3, raises); 865 break; 866 } 867 868 case TYPENAME_TYPE: 869 /* There is no need to merge attributes into a TYPENAME_TYPE. 870 When the type is instantiated it will have whatever 871 attributes result from the instantiation. */ 872 return t1; 873 874 default:; 875 } 876 877 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes)) 878 return t1; 879 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes)) 880 return t2; 881 else 882 return cp_build_type_attribute_variant (t1, attributes); 883 } 884 885 /* Return the ARRAY_TYPE type without its domain. */ 886 887 tree 888 strip_array_domain (tree type) 889 { 890 tree t2; 891 gcc_assert (TREE_CODE (type) == ARRAY_TYPE); 892 if (TYPE_DOMAIN (type) == NULL_TREE) 893 return type; 894 t2 = build_cplus_array_type (TREE_TYPE (type), NULL_TREE); 895 return cp_build_type_attribute_variant (t2, TYPE_ATTRIBUTES (type)); 896 } 897 898 /* Wrapper around cp_common_type that is used by c-common.c and other 899 front end optimizations that remove promotions. 900 901 Return the common type for two arithmetic types T1 and T2 under the 902 usual arithmetic conversions. The default conversions have already 903 been applied, and enumerated types converted to their compatible 904 integer types. */ 905 906 tree 907 common_type (tree t1, tree t2) 908 { 909 /* If one type is nonsense, use the other */ 910 if (t1 == error_mark_node) 911 return t2; 912 if (t2 == error_mark_node) 913 return t1; 914 915 return cp_common_type (t1, t2); 916 } 917 918 /* Return the common type of two pointer types T1 and T2. This is the 919 type for the result of most arithmetic operations if the operands 920 have the given two types. 921 922 We assume that comp_target_types has already been done and returned 923 nonzero; if that isn't so, this may crash. */ 924 925 tree 926 common_pointer_type (tree t1, tree t2) 927 { 928 gcc_assert ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2)) 929 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2)) 930 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2))); 931 932 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node, 933 CPO_CONVERSION, tf_warning_or_error); 934 } 935 936 /* Compare two exception specifier types for exactness or subsetness, if 937 allowed. Returns false for mismatch, true for match (same, or 938 derived and !exact). 939 940 [except.spec] "If a class X ... objects of class X or any class publicly 941 and unambiguously derived from X. Similarly, if a pointer type Y * ... 942 exceptions of type Y * or that are pointers to any type publicly and 943 unambiguously derived from Y. Otherwise a function only allows exceptions 944 that have the same type ..." 945 This does not mention cv qualifiers and is different to what throw 946 [except.throw] and catch [except.catch] will do. They will ignore the 947 top level cv qualifiers, and allow qualifiers in the pointer to class 948 example. 949 950 We implement the letter of the standard. */ 951 952 static bool 953 comp_except_types (tree a, tree b, bool exact) 954 { 955 if (same_type_p (a, b)) 956 return true; 957 else if (!exact) 958 { 959 if (cp_type_quals (a) || cp_type_quals (b)) 960 return false; 961 962 if (TREE_CODE (a) == POINTER_TYPE 963 && TREE_CODE (b) == POINTER_TYPE) 964 { 965 a = TREE_TYPE (a); 966 b = TREE_TYPE (b); 967 if (cp_type_quals (a) || cp_type_quals (b)) 968 return false; 969 } 970 971 if (TREE_CODE (a) != RECORD_TYPE 972 || TREE_CODE (b) != RECORD_TYPE) 973 return false; 974 975 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b)) 976 return true; 977 } 978 return false; 979 } 980 981 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers. 982 If EXACT is ce_derived, T2 can be stricter than T1 (according to 15.4/5). 983 If EXACT is ce_normal, the compatibility rules in 15.4/3 apply. 984 If EXACT is ce_exact, the specs must be exactly the same. Exception lists 985 are unordered, but we've already filtered out duplicates. Most lists will 986 be in order, we should try to make use of that. */ 987 988 bool 989 comp_except_specs (const_tree t1, const_tree t2, int exact) 990 { 991 const_tree probe; 992 const_tree base; 993 int length = 0; 994 995 if (t1 == t2) 996 return true; 997 998 /* First handle noexcept. */ 999 if (exact < ce_exact) 1000 { 1001 /* noexcept(false) is compatible with no exception-specification, 1002 and stricter than any spec. */ 1003 if (t1 == noexcept_false_spec) 1004 return t2 == NULL_TREE || exact == ce_derived; 1005 /* Even a derived noexcept(false) is compatible with no 1006 exception-specification. */ 1007 if (t2 == noexcept_false_spec) 1008 return t1 == NULL_TREE; 1009 1010 /* Otherwise, if we aren't looking for an exact match, noexcept is 1011 equivalent to throw(). */ 1012 if (t1 == noexcept_true_spec) 1013 t1 = empty_except_spec; 1014 if (t2 == noexcept_true_spec) 1015 t2 = empty_except_spec; 1016 } 1017 1018 /* If any noexcept is left, it is only comparable to itself; 1019 either we're looking for an exact match or we're redeclaring a 1020 template with dependent noexcept. */ 1021 if ((t1 && TREE_PURPOSE (t1)) 1022 || (t2 && TREE_PURPOSE (t2))) 1023 return (t1 && t2 1024 && cp_tree_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))); 1025 1026 if (t1 == NULL_TREE) /* T1 is ... */ 1027 return t2 == NULL_TREE || exact == ce_derived; 1028 if (!TREE_VALUE (t1)) /* t1 is EMPTY */ 1029 return t2 != NULL_TREE && !TREE_VALUE (t2); 1030 if (t2 == NULL_TREE) /* T2 is ... */ 1031 return false; 1032 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */ 1033 return exact == ce_derived; 1034 1035 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1. 1036 Count how many we find, to determine exactness. For exact matching and 1037 ordered T1, T2, this is an O(n) operation, otherwise its worst case is 1038 O(nm). */ 1039 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2)) 1040 { 1041 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe)) 1042 { 1043 tree a = TREE_VALUE (probe); 1044 tree b = TREE_VALUE (t2); 1045 1046 if (comp_except_types (a, b, exact)) 1047 { 1048 if (probe == base && exact > ce_derived) 1049 base = TREE_CHAIN (probe); 1050 length++; 1051 break; 1052 } 1053 } 1054 if (probe == NULL_TREE) 1055 return false; 1056 } 1057 return exact == ce_derived || base == NULL_TREE || length == list_length (t1); 1058 } 1059 1060 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if 1061 [] can match [size]. */ 1062 1063 static bool 1064 comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration) 1065 { 1066 tree d1; 1067 tree d2; 1068 tree max1, max2; 1069 1070 if (t1 == t2) 1071 return true; 1072 1073 /* The type of the array elements must be the same. */ 1074 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1075 return false; 1076 1077 d1 = TYPE_DOMAIN (t1); 1078 d2 = TYPE_DOMAIN (t2); 1079 1080 if (d1 == d2) 1081 return true; 1082 1083 /* If one of the arrays is dimensionless, and the other has a 1084 dimension, they are of different types. However, it is valid to 1085 write: 1086 1087 extern int a[]; 1088 int a[3]; 1089 1090 by [basic.link]: 1091 1092 declarations for an array object can specify 1093 array types that differ by the presence or absence of a major 1094 array bound (_dcl.array_). */ 1095 if (!d1 || !d2) 1096 return allow_redeclaration; 1097 1098 /* Check that the dimensions are the same. */ 1099 1100 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))) 1101 return false; 1102 max1 = TYPE_MAX_VALUE (d1); 1103 max2 = TYPE_MAX_VALUE (d2); 1104 if (processing_template_decl && !abi_version_at_least (2) 1105 && !value_dependent_expression_p (max1) 1106 && !value_dependent_expression_p (max2)) 1107 { 1108 /* With abi-1 we do not fold non-dependent array bounds, (and 1109 consequently mangle them incorrectly). We must therefore 1110 fold them here, to verify the domains have the same 1111 value. */ 1112 max1 = fold (max1); 1113 max2 = fold (max2); 1114 } 1115 1116 if (!cp_tree_equal (max1, max2)) 1117 return false; 1118 1119 return true; 1120 } 1121 1122 /* Compare the relative position of T1 and T2 into their respective 1123 template parameter list. 1124 T1 and T2 must be template parameter types. 1125 Return TRUE if T1 and T2 have the same position, FALSE otherwise. */ 1126 1127 static bool 1128 comp_template_parms_position (tree t1, tree t2) 1129 { 1130 tree index1, index2; 1131 gcc_assert (t1 && t2 1132 && TREE_CODE (t1) == TREE_CODE (t2) 1133 && (TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM 1134 || TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM 1135 || TREE_CODE (t1) == TEMPLATE_TYPE_PARM)); 1136 1137 index1 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t1)); 1138 index2 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t2)); 1139 1140 /* If T1 and T2 belong to template parm lists of different size, 1141 let's assume they are different. */ 1142 if (TEMPLATE_PARM_NUM_SIBLINGS (index1) 1143 != TEMPLATE_PARM_NUM_SIBLINGS (index2)) 1144 return false; 1145 1146 /* Then compare their relative position. */ 1147 if (TEMPLATE_PARM_IDX (index1) != TEMPLATE_PARM_IDX (index2) 1148 || TEMPLATE_PARM_LEVEL (index1) != TEMPLATE_PARM_LEVEL (index2) 1149 || (TEMPLATE_PARM_PARAMETER_PACK (index1) 1150 != TEMPLATE_PARM_PARAMETER_PACK (index2))) 1151 return false; 1152 1153 return true; 1154 } 1155 1156 /* Subroutine in comptypes. */ 1157 1158 static bool 1159 structural_comptypes (tree t1, tree t2, int strict) 1160 { 1161 if (t1 == t2) 1162 return true; 1163 1164 /* Suppress errors caused by previously reported errors. */ 1165 if (t1 == error_mark_node || t2 == error_mark_node) 1166 return false; 1167 1168 gcc_assert (TYPE_P (t1) && TYPE_P (t2)); 1169 1170 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the 1171 current instantiation. */ 1172 if (TREE_CODE (t1) == TYPENAME_TYPE) 1173 t1 = resolve_typename_type (t1, /*only_current_p=*/true); 1174 1175 if (TREE_CODE (t2) == TYPENAME_TYPE) 1176 t2 = resolve_typename_type (t2, /*only_current_p=*/true); 1177 1178 if (TYPE_PTRMEMFUNC_P (t1)) 1179 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1); 1180 if (TYPE_PTRMEMFUNC_P (t2)) 1181 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2); 1182 1183 /* Different classes of types can't be compatible. */ 1184 if (TREE_CODE (t1) != TREE_CODE (t2)) 1185 return false; 1186 1187 /* Qualifiers must match. For array types, we will check when we 1188 recur on the array element types. */ 1189 if (TREE_CODE (t1) != ARRAY_TYPE 1190 && cp_type_quals (t1) != cp_type_quals (t2)) 1191 return false; 1192 if (TREE_CODE (t1) == FUNCTION_TYPE 1193 && type_memfn_quals (t1) != type_memfn_quals (t2)) 1194 return false; 1195 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2)) 1196 return false; 1197 1198 /* Allow for two different type nodes which have essentially the same 1199 definition. Note that we already checked for equality of the type 1200 qualifiers (just above). */ 1201 1202 if (TREE_CODE (t1) != ARRAY_TYPE 1203 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) 1204 return true; 1205 1206 1207 /* Compare the types. Break out if they could be the same. */ 1208 switch (TREE_CODE (t1)) 1209 { 1210 case VOID_TYPE: 1211 case BOOLEAN_TYPE: 1212 /* All void and bool types are the same. */ 1213 break; 1214 1215 case INTEGER_TYPE: 1216 case FIXED_POINT_TYPE: 1217 case REAL_TYPE: 1218 /* With these nodes, we can't determine type equivalence by 1219 looking at what is stored in the nodes themselves, because 1220 two nodes might have different TYPE_MAIN_VARIANTs but still 1221 represent the same type. For example, wchar_t and int could 1222 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE, 1223 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs 1224 and are distinct types. On the other hand, int and the 1225 following typedef 1226 1227 typedef int INT __attribute((may_alias)); 1228 1229 have identical properties, different TYPE_MAIN_VARIANTs, but 1230 represent the same type. The canonical type system keeps 1231 track of equivalence in this case, so we fall back on it. */ 1232 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2); 1233 1234 case TEMPLATE_TEMPLATE_PARM: 1235 case BOUND_TEMPLATE_TEMPLATE_PARM: 1236 if (!comp_template_parms_position (t1, t2)) 1237 return false; 1238 if (!comp_template_parms 1239 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)), 1240 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2)))) 1241 return false; 1242 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM) 1243 break; 1244 /* Don't check inheritance. */ 1245 strict = COMPARE_STRICT; 1246 /* Fall through. */ 1247 1248 case RECORD_TYPE: 1249 case UNION_TYPE: 1250 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2) 1251 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2) 1252 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM) 1253 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2))) 1254 break; 1255 1256 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2)) 1257 break; 1258 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1)) 1259 break; 1260 1261 return false; 1262 1263 case OFFSET_TYPE: 1264 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2), 1265 strict & ~COMPARE_REDECLARATION)) 1266 return false; 1267 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1268 return false; 1269 break; 1270 1271 case REFERENCE_TYPE: 1272 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2)) 1273 return false; 1274 /* fall through to checks for pointer types */ 1275 1276 case POINTER_TYPE: 1277 if (TYPE_MODE (t1) != TYPE_MODE (t2) 1278 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2) 1279 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1280 return false; 1281 break; 1282 1283 case METHOD_TYPE: 1284 case FUNCTION_TYPE: 1285 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1286 return false; 1287 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2))) 1288 return false; 1289 break; 1290 1291 case ARRAY_TYPE: 1292 /* Target types must match incl. qualifiers. */ 1293 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION))) 1294 return false; 1295 break; 1296 1297 case TEMPLATE_TYPE_PARM: 1298 /* If T1 and T2 don't have the same relative position in their 1299 template parameters set, they can't be equal. */ 1300 if (!comp_template_parms_position (t1, t2)) 1301 return false; 1302 break; 1303 1304 case TYPENAME_TYPE: 1305 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1), 1306 TYPENAME_TYPE_FULLNAME (t2))) 1307 return false; 1308 /* Qualifiers don't matter on scopes. */ 1309 if (!same_type_ignoring_top_level_qualifiers_p (TYPE_CONTEXT (t1), 1310 TYPE_CONTEXT (t2))) 1311 return false; 1312 break; 1313 1314 case UNBOUND_CLASS_TEMPLATE: 1315 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2))) 1316 return false; 1317 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2))) 1318 return false; 1319 break; 1320 1321 case COMPLEX_TYPE: 1322 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1323 return false; 1324 break; 1325 1326 case VECTOR_TYPE: 1327 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2) 1328 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) 1329 return false; 1330 break; 1331 1332 case TYPE_PACK_EXPANSION: 1333 return (same_type_p (PACK_EXPANSION_PATTERN (t1), 1334 PACK_EXPANSION_PATTERN (t2)) 1335 && comp_template_args (PACK_EXPANSION_EXTRA_ARGS (t1), 1336 PACK_EXPANSION_EXTRA_ARGS (t2))); 1337 1338 case DECLTYPE_TYPE: 1339 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1) 1340 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2) 1341 || (DECLTYPE_FOR_LAMBDA_CAPTURE (t1) 1342 != DECLTYPE_FOR_LAMBDA_CAPTURE (t2)) 1343 || (DECLTYPE_FOR_LAMBDA_PROXY (t1) 1344 != DECLTYPE_FOR_LAMBDA_PROXY (t2)) 1345 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1), 1346 DECLTYPE_TYPE_EXPR (t2))) 1347 return false; 1348 break; 1349 1350 case UNDERLYING_TYPE: 1351 return same_type_p (UNDERLYING_TYPE_TYPE (t1), 1352 UNDERLYING_TYPE_TYPE (t2)); 1353 1354 default: 1355 return false; 1356 } 1357 1358 /* If we get here, we know that from a target independent POV the 1359 types are the same. Make sure the target attributes are also 1360 the same. */ 1361 return comp_type_attributes (t1, t2); 1362 } 1363 1364 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT 1365 is a bitwise-or of the COMPARE_* flags. */ 1366 1367 bool 1368 comptypes (tree t1, tree t2, int strict) 1369 { 1370 if (strict == COMPARE_STRICT) 1371 { 1372 if (t1 == t2) 1373 return true; 1374 1375 if (t1 == error_mark_node || t2 == error_mark_node) 1376 return false; 1377 1378 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2)) 1379 /* At least one of the types requires structural equality, so 1380 perform a deep check. */ 1381 return structural_comptypes (t1, t2, strict); 1382 1383 #ifdef ENABLE_CHECKING 1384 if (USE_CANONICAL_TYPES) 1385 { 1386 bool result = structural_comptypes (t1, t2, strict); 1387 1388 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2)) 1389 /* The two types are structurally equivalent, but their 1390 canonical types were different. This is a failure of the 1391 canonical type propagation code.*/ 1392 internal_error 1393 ("canonical types differ for identical types %T and %T", 1394 t1, t2); 1395 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2)) 1396 /* Two types are structurally different, but the canonical 1397 types are the same. This means we were over-eager in 1398 assigning canonical types. */ 1399 internal_error 1400 ("same canonical type node for different types %T and %T", 1401 t1, t2); 1402 1403 return result; 1404 } 1405 #else 1406 if (USE_CANONICAL_TYPES) 1407 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2); 1408 #endif 1409 else 1410 return structural_comptypes (t1, t2, strict); 1411 } 1412 else if (strict == COMPARE_STRUCTURAL) 1413 return structural_comptypes (t1, t2, COMPARE_STRICT); 1414 else 1415 return structural_comptypes (t1, t2, strict); 1416 } 1417 1418 /* Returns nonzero iff TYPE1 and TYPE2 are the same type, ignoring 1419 top-level qualifiers. */ 1420 1421 bool 1422 same_type_ignoring_top_level_qualifiers_p (tree type1, tree type2) 1423 { 1424 if (type1 == error_mark_node || type2 == error_mark_node) 1425 return false; 1426 1427 return same_type_p (TYPE_MAIN_VARIANT (type1), TYPE_MAIN_VARIANT (type2)); 1428 } 1429 1430 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */ 1431 1432 bool 1433 at_least_as_qualified_p (const_tree type1, const_tree type2) 1434 { 1435 int q1 = cp_type_quals (type1); 1436 int q2 = cp_type_quals (type2); 1437 1438 /* All qualifiers for TYPE2 must also appear in TYPE1. */ 1439 return (q1 & q2) == q2; 1440 } 1441 1442 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is 1443 more cv-qualified that TYPE1, and 0 otherwise. */ 1444 1445 int 1446 comp_cv_qualification (const_tree type1, const_tree type2) 1447 { 1448 int q1 = cp_type_quals (type1); 1449 int q2 = cp_type_quals (type2); 1450 1451 if (q1 == q2) 1452 return 0; 1453 1454 if ((q1 & q2) == q2) 1455 return 1; 1456 else if ((q1 & q2) == q1) 1457 return -1; 1458 1459 return 0; 1460 } 1461 1462 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper 1463 subset of the cv-qualification signature of TYPE2, and the types 1464 are similar. Returns -1 if the other way 'round, and 0 otherwise. */ 1465 1466 int 1467 comp_cv_qual_signature (tree type1, tree type2) 1468 { 1469 if (comp_ptr_ttypes_real (type2, type1, -1)) 1470 return 1; 1471 else if (comp_ptr_ttypes_real (type1, type2, -1)) 1472 return -1; 1473 else 1474 return 0; 1475 } 1476 1477 /* Subroutines of `comptypes'. */ 1478 1479 /* Return true if two parameter type lists PARMS1 and PARMS2 are 1480 equivalent in the sense that functions with those parameter types 1481 can have equivalent types. The two lists must be equivalent, 1482 element by element. */ 1483 1484 bool 1485 compparms (const_tree parms1, const_tree parms2) 1486 { 1487 const_tree t1, t2; 1488 1489 /* An unspecified parmlist matches any specified parmlist 1490 whose argument types don't need default promotions. */ 1491 1492 for (t1 = parms1, t2 = parms2; 1493 t1 || t2; 1494 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2)) 1495 { 1496 /* If one parmlist is shorter than the other, 1497 they fail to match. */ 1498 if (!t1 || !t2) 1499 return false; 1500 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2))) 1501 return false; 1502 } 1503 return true; 1504 } 1505 1506 1507 /* Process a sizeof or alignof expression where the operand is a 1508 type. */ 1509 1510 tree 1511 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain) 1512 { 1513 tree value; 1514 bool dependent_p; 1515 1516 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR); 1517 if (type == error_mark_node) 1518 return error_mark_node; 1519 1520 type = non_reference (type); 1521 if (TREE_CODE (type) == METHOD_TYPE) 1522 { 1523 if (complain) 1524 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith, 1525 "invalid application of %qs to a member function", 1526 operator_name_info[(int) op].name); 1527 value = size_one_node; 1528 } 1529 1530 dependent_p = dependent_type_p (type); 1531 if (!dependent_p) 1532 complete_type (type); 1533 if (dependent_p 1534 /* VLA types will have a non-constant size. In the body of an 1535 uninstantiated template, we don't need to try to compute the 1536 value, because the sizeof expression is not an integral 1537 constant expression in that case. And, if we do try to 1538 compute the value, we'll likely end up with SAVE_EXPRs, which 1539 the template substitution machinery does not expect to see. */ 1540 || (processing_template_decl 1541 && COMPLETE_TYPE_P (type) 1542 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)) 1543 { 1544 value = build_min (op, size_type_node, type); 1545 TREE_READONLY (value) = 1; 1546 return value; 1547 } 1548 1549 return c_sizeof_or_alignof_type (input_location, complete_type (type), 1550 op == SIZEOF_EXPR, 1551 complain); 1552 } 1553 1554 /* Return the size of the type, without producing any warnings for 1555 types whose size cannot be taken. This routine should be used only 1556 in some other routine that has already produced a diagnostic about 1557 using the size of such a type. */ 1558 tree 1559 cxx_sizeof_nowarn (tree type) 1560 { 1561 if (TREE_CODE (type) == FUNCTION_TYPE 1562 || TREE_CODE (type) == VOID_TYPE 1563 || TREE_CODE (type) == ERROR_MARK) 1564 return size_one_node; 1565 else if (!COMPLETE_TYPE_P (type)) 1566 return size_zero_node; 1567 else 1568 return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false); 1569 } 1570 1571 /* Process a sizeof expression where the operand is an expression. */ 1572 1573 static tree 1574 cxx_sizeof_expr (tree e, tsubst_flags_t complain) 1575 { 1576 if (e == error_mark_node) 1577 return error_mark_node; 1578 1579 if (processing_template_decl) 1580 { 1581 e = build_min (SIZEOF_EXPR, size_type_node, e); 1582 TREE_SIDE_EFFECTS (e) = 0; 1583 TREE_READONLY (e) = 1; 1584 1585 return e; 1586 } 1587 1588 /* To get the size of a static data member declared as an array of 1589 unknown bound, we need to instantiate it. */ 1590 if (TREE_CODE (e) == VAR_DECL 1591 && VAR_HAD_UNKNOWN_BOUND (e) 1592 && DECL_TEMPLATE_INSTANTIATION (e)) 1593 instantiate_decl (e, /*defer_ok*/true, /*expl_inst_mem*/false); 1594 1595 e = mark_type_use (e); 1596 1597 if (TREE_CODE (e) == COMPONENT_REF 1598 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL 1599 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1))) 1600 { 1601 if (complain & tf_error) 1602 error ("invalid application of %<sizeof%> to a bit-field"); 1603 else 1604 return error_mark_node; 1605 e = char_type_node; 1606 } 1607 else if (is_overloaded_fn (e)) 1608 { 1609 if (complain & tf_error) 1610 permerror (input_location, "ISO C++ forbids applying %<sizeof%> to an expression of " 1611 "function type"); 1612 else 1613 return error_mark_node; 1614 e = char_type_node; 1615 } 1616 else if (type_unknown_p (e)) 1617 { 1618 if (complain & tf_error) 1619 cxx_incomplete_type_error (e, TREE_TYPE (e)); 1620 else 1621 return error_mark_node; 1622 e = char_type_node; 1623 } 1624 else 1625 e = TREE_TYPE (e); 1626 1627 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error); 1628 } 1629 1630 /* Implement the __alignof keyword: Return the minimum required 1631 alignment of E, measured in bytes. For VAR_DECL's and 1632 FIELD_DECL's return DECL_ALIGN (which can be set from an 1633 "aligned" __attribute__ specification). */ 1634 1635 static tree 1636 cxx_alignof_expr (tree e, tsubst_flags_t complain) 1637 { 1638 tree t; 1639 1640 if (e == error_mark_node) 1641 return error_mark_node; 1642 1643 if (processing_template_decl) 1644 { 1645 e = build_min (ALIGNOF_EXPR, size_type_node, e); 1646 TREE_SIDE_EFFECTS (e) = 0; 1647 TREE_READONLY (e) = 1; 1648 1649 return e; 1650 } 1651 1652 e = mark_type_use (e); 1653 1654 if (TREE_CODE (e) == VAR_DECL) 1655 t = size_int (DECL_ALIGN_UNIT (e)); 1656 else if (TREE_CODE (e) == COMPONENT_REF 1657 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL 1658 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1))) 1659 { 1660 if (complain & tf_error) 1661 error ("invalid application of %<__alignof%> to a bit-field"); 1662 else 1663 return error_mark_node; 1664 t = size_one_node; 1665 } 1666 else if (TREE_CODE (e) == COMPONENT_REF 1667 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL) 1668 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1))); 1669 else if (is_overloaded_fn (e)) 1670 { 1671 if (complain & tf_error) 1672 permerror (input_location, "ISO C++ forbids applying %<__alignof%> to an expression of " 1673 "function type"); 1674 else 1675 return error_mark_node; 1676 if (TREE_CODE (e) == FUNCTION_DECL) 1677 t = size_int (DECL_ALIGN_UNIT (e)); 1678 else 1679 t = size_one_node; 1680 } 1681 else if (type_unknown_p (e)) 1682 { 1683 if (complain & tf_error) 1684 cxx_incomplete_type_error (e, TREE_TYPE (e)); 1685 else 1686 return error_mark_node; 1687 t = size_one_node; 1688 } 1689 else 1690 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, 1691 complain & tf_error); 1692 1693 return fold_convert (size_type_node, t); 1694 } 1695 1696 /* Process a sizeof or alignof expression E with code OP where the operand 1697 is an expression. */ 1698 1699 tree 1700 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain) 1701 { 1702 if (op == SIZEOF_EXPR) 1703 return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none); 1704 else 1705 return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none); 1706 } 1707 1708 /* EXPR is being used in a context that is not a function call. 1709 Enforce: 1710 1711 [expr.ref] 1712 1713 The expression can be used only as the left-hand operand of a 1714 member function call. 1715 1716 [expr.mptr.operator] 1717 1718 If the result of .* or ->* is a function, then that result can be 1719 used only as the operand for the function call operator (). 1720 1721 by issuing an error message if appropriate. Returns true iff EXPR 1722 violates these rules. */ 1723 1724 bool 1725 invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain) 1726 { 1727 if (expr && DECL_NONSTATIC_MEMBER_FUNCTION_P (expr)) 1728 { 1729 if (complain & tf_error) 1730 error ("invalid use of non-static member function"); 1731 return true; 1732 } 1733 return false; 1734 } 1735 1736 /* If EXP is a reference to a bitfield, and the type of EXP does not 1737 match the declared type of the bitfield, return the declared type 1738 of the bitfield. Otherwise, return NULL_TREE. */ 1739 1740 tree 1741 is_bitfield_expr_with_lowered_type (const_tree exp) 1742 { 1743 switch (TREE_CODE (exp)) 1744 { 1745 case COND_EXPR: 1746 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1) 1747 ? TREE_OPERAND (exp, 1) 1748 : TREE_OPERAND (exp, 0))) 1749 return NULL_TREE; 1750 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2)); 1751 1752 case COMPOUND_EXPR: 1753 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)); 1754 1755 case MODIFY_EXPR: 1756 case SAVE_EXPR: 1757 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0)); 1758 1759 case COMPONENT_REF: 1760 { 1761 tree field; 1762 1763 field = TREE_OPERAND (exp, 1); 1764 if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field)) 1765 return NULL_TREE; 1766 if (same_type_ignoring_top_level_qualifiers_p 1767 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field))) 1768 return NULL_TREE; 1769 return DECL_BIT_FIELD_TYPE (field); 1770 } 1771 1772 CASE_CONVERT: 1773 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0))) 1774 == TYPE_MAIN_VARIANT (TREE_TYPE (exp))) 1775 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0)); 1776 /* Fallthrough. */ 1777 1778 default: 1779 return NULL_TREE; 1780 } 1781 } 1782 1783 /* Like is_bitfield_with_lowered_type, except that if EXP is not a 1784 bitfield with a lowered type, the type of EXP is returned, rather 1785 than NULL_TREE. */ 1786 1787 tree 1788 unlowered_expr_type (const_tree exp) 1789 { 1790 tree type; 1791 tree etype = TREE_TYPE (exp); 1792 1793 type = is_bitfield_expr_with_lowered_type (exp); 1794 if (type) 1795 type = cp_build_qualified_type (type, cp_type_quals (etype)); 1796 else 1797 type = etype; 1798 1799 return type; 1800 } 1801 1802 /* Perform the conversions in [expr] that apply when an lvalue appears 1803 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and 1804 function-to-pointer conversions. In addition, manifest constants 1805 are replaced by their values, and bitfield references are converted 1806 to their declared types. Note that this function does not perform the 1807 lvalue-to-rvalue conversion for class types. If you need that conversion 1808 to for class types, then you probably need to use force_rvalue. 1809 1810 Although the returned value is being used as an rvalue, this 1811 function does not wrap the returned expression in a 1812 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact 1813 that the return value is no longer an lvalue. */ 1814 1815 tree 1816 decay_conversion (tree exp) 1817 { 1818 tree type; 1819 enum tree_code code; 1820 1821 type = TREE_TYPE (exp); 1822 if (type == error_mark_node) 1823 return error_mark_node; 1824 1825 exp = mark_rvalue_use (exp); 1826 1827 exp = resolve_nondeduced_context (exp); 1828 if (type_unknown_p (exp)) 1829 { 1830 cxx_incomplete_type_error (exp, TREE_TYPE (exp)); 1831 return error_mark_node; 1832 } 1833 1834 /* FIXME remove? at least need to remember that this isn't really a 1835 constant expression if EXP isn't decl_constant_var_p, like with 1836 C_MAYBE_CONST_EXPR. */ 1837 exp = decl_constant_value_safe (exp); 1838 if (error_operand_p (exp)) 1839 return error_mark_node; 1840 1841 if (NULLPTR_TYPE_P (type) && !TREE_SIDE_EFFECTS (exp)) 1842 return nullptr_node; 1843 1844 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 1845 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */ 1846 code = TREE_CODE (type); 1847 if (code == VOID_TYPE) 1848 { 1849 error ("void value not ignored as it ought to be"); 1850 return error_mark_node; 1851 } 1852 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error)) 1853 return error_mark_node; 1854 if (code == FUNCTION_TYPE || is_overloaded_fn (exp)) 1855 return cp_build_addr_expr (exp, tf_warning_or_error); 1856 if (code == ARRAY_TYPE) 1857 { 1858 tree adr; 1859 tree ptrtype; 1860 1861 if (TREE_CODE (exp) == INDIRECT_REF) 1862 return build_nop (build_pointer_type (TREE_TYPE (type)), 1863 TREE_OPERAND (exp, 0)); 1864 1865 if (TREE_CODE (exp) == COMPOUND_EXPR) 1866 { 1867 tree op1 = decay_conversion (TREE_OPERAND (exp, 1)); 1868 return build2 (COMPOUND_EXPR, TREE_TYPE (op1), 1869 TREE_OPERAND (exp, 0), op1); 1870 } 1871 1872 if (!lvalue_p (exp) 1873 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp))) 1874 { 1875 error ("invalid use of non-lvalue array"); 1876 return error_mark_node; 1877 } 1878 1879 /* Don't let an array compound literal decay to a pointer. It can 1880 still be used to initialize an array or bind to a reference. */ 1881 if (TREE_CODE (exp) == TARGET_EXPR) 1882 { 1883 error ("taking address of temporary array"); 1884 return error_mark_node; 1885 } 1886 1887 ptrtype = build_pointer_type (TREE_TYPE (type)); 1888 1889 if (TREE_CODE (exp) == VAR_DECL) 1890 { 1891 if (!cxx_mark_addressable (exp)) 1892 return error_mark_node; 1893 adr = build_nop (ptrtype, build_address (exp)); 1894 return adr; 1895 } 1896 /* This way is better for a COMPONENT_REF since it can 1897 simplify the offset for a component. */ 1898 adr = cp_build_addr_expr (exp, tf_warning_or_error); 1899 return cp_convert (ptrtype, adr); 1900 } 1901 1902 /* If a bitfield is used in a context where integral promotion 1903 applies, then the caller is expected to have used 1904 default_conversion. That function promotes bitfields correctly 1905 before calling this function. At this point, if we have a 1906 bitfield referenced, we may assume that is not subject to 1907 promotion, and that, therefore, the type of the resulting rvalue 1908 is the declared type of the bitfield. */ 1909 exp = convert_bitfield_to_declared_type (exp); 1910 1911 /* We do not call rvalue() here because we do not want to wrap EXP 1912 in a NON_LVALUE_EXPR. */ 1913 1914 /* [basic.lval] 1915 1916 Non-class rvalues always have cv-unqualified types. */ 1917 type = TREE_TYPE (exp); 1918 if (!CLASS_TYPE_P (type) && cv_qualified_p (type)) 1919 exp = build_nop (cv_unqualified (type), exp); 1920 1921 return exp; 1922 } 1923 1924 /* Perform preparatory conversions, as part of the "usual arithmetic 1925 conversions". In particular, as per [expr]: 1926 1927 Whenever an lvalue expression appears as an operand of an 1928 operator that expects the rvalue for that operand, the 1929 lvalue-to-rvalue, array-to-pointer, or function-to-pointer 1930 standard conversions are applied to convert the expression to an 1931 rvalue. 1932 1933 In addition, we perform integral promotions here, as those are 1934 applied to both operands to a binary operator before determining 1935 what additional conversions should apply. */ 1936 1937 tree 1938 default_conversion (tree exp) 1939 { 1940 /* Check for target-specific promotions. */ 1941 tree promoted_type = targetm.promoted_type (TREE_TYPE (exp)); 1942 if (promoted_type) 1943 exp = cp_convert (promoted_type, exp); 1944 /* Perform the integral promotions first so that bitfield 1945 expressions (which may promote to "int", even if the bitfield is 1946 declared "unsigned") are promoted correctly. */ 1947 else if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (exp))) 1948 exp = perform_integral_promotions (exp); 1949 /* Perform the other conversions. */ 1950 exp = decay_conversion (exp); 1951 1952 return exp; 1953 } 1954 1955 /* EXPR is an expression with an integral or enumeration type. 1956 Perform the integral promotions in [conv.prom], and return the 1957 converted value. */ 1958 1959 tree 1960 perform_integral_promotions (tree expr) 1961 { 1962 tree type; 1963 tree promoted_type; 1964 1965 expr = mark_rvalue_use (expr); 1966 1967 /* [conv.prom] 1968 1969 If the bitfield has an enumerated type, it is treated as any 1970 other value of that type for promotion purposes. */ 1971 type = is_bitfield_expr_with_lowered_type (expr); 1972 if (!type || TREE_CODE (type) != ENUMERAL_TYPE) 1973 type = TREE_TYPE (expr); 1974 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type)); 1975 /* Scoped enums don't promote. */ 1976 if (SCOPED_ENUM_P (type)) 1977 return expr; 1978 promoted_type = type_promotes_to (type); 1979 if (type != promoted_type) 1980 expr = cp_convert (promoted_type, expr); 1981 return expr; 1982 } 1983 1984 /* Returns nonzero iff exp is a STRING_CST or the result of applying 1985 decay_conversion to one. */ 1986 1987 int 1988 string_conv_p (const_tree totype, const_tree exp, int warn) 1989 { 1990 tree t; 1991 1992 if (TREE_CODE (totype) != POINTER_TYPE) 1993 return 0; 1994 1995 t = TREE_TYPE (totype); 1996 if (!same_type_p (t, char_type_node) 1997 && !same_type_p (t, char16_type_node) 1998 && !same_type_p (t, char32_type_node) 1999 && !same_type_p (t, wchar_type_node)) 2000 return 0; 2001 2002 if (TREE_CODE (exp) == STRING_CST) 2003 { 2004 /* Make sure that we don't try to convert between char and wide chars. */ 2005 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t)) 2006 return 0; 2007 } 2008 else 2009 { 2010 /* Is this a string constant which has decayed to 'const char *'? */ 2011 t = build_pointer_type (cp_build_qualified_type (t, TYPE_QUAL_CONST)); 2012 if (!same_type_p (TREE_TYPE (exp), t)) 2013 return 0; 2014 STRIP_NOPS (exp); 2015 if (TREE_CODE (exp) != ADDR_EXPR 2016 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST) 2017 return 0; 2018 } 2019 2020 /* This warning is not very useful, as it complains about printf. */ 2021 if (warn) 2022 warning (OPT_Wwrite_strings, 2023 "deprecated conversion from string constant to %qT", 2024 totype); 2025 2026 return 1; 2027 } 2028 2029 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we 2030 can, for example, use as an lvalue. This code used to be in 2031 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c' 2032 expressions, where we're dealing with aggregates. But now it's again only 2033 called from unary_complex_lvalue. The case (in particular) that led to 2034 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd 2035 get it there. */ 2036 2037 static tree 2038 rationalize_conditional_expr (enum tree_code code, tree t, 2039 tsubst_flags_t complain) 2040 { 2041 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that 2042 the first operand is always the one to be used if both operands 2043 are equal, so we know what conditional expression this used to be. */ 2044 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR) 2045 { 2046 tree op0 = TREE_OPERAND (t, 0); 2047 tree op1 = TREE_OPERAND (t, 1); 2048 2049 /* The following code is incorrect if either operand side-effects. */ 2050 gcc_assert (!TREE_SIDE_EFFECTS (op0) 2051 && !TREE_SIDE_EFFECTS (op1)); 2052 return 2053 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR 2054 ? LE_EXPR : GE_EXPR), 2055 op0, TREE_CODE (op0), 2056 op1, TREE_CODE (op1), 2057 /*overload=*/NULL, 2058 complain), 2059 cp_build_unary_op (code, op0, 0, complain), 2060 cp_build_unary_op (code, op1, 0, complain), 2061 complain); 2062 } 2063 2064 return 2065 build_conditional_expr (TREE_OPERAND (t, 0), 2066 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0, 2067 complain), 2068 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0, 2069 complain), 2070 complain); 2071 } 2072 2073 /* Given the TYPE of an anonymous union field inside T, return the 2074 FIELD_DECL for the field. If not found return NULL_TREE. Because 2075 anonymous unions can nest, we must also search all anonymous unions 2076 that are directly reachable. */ 2077 2078 tree 2079 lookup_anon_field (tree t, tree type) 2080 { 2081 tree field; 2082 2083 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) 2084 { 2085 if (TREE_STATIC (field)) 2086 continue; 2087 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field)) 2088 continue; 2089 2090 /* If we find it directly, return the field. */ 2091 if (DECL_NAME (field) == NULL_TREE 2092 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field))) 2093 { 2094 return field; 2095 } 2096 2097 /* Otherwise, it could be nested, search harder. */ 2098 if (DECL_NAME (field) == NULL_TREE 2099 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 2100 { 2101 tree subfield = lookup_anon_field (TREE_TYPE (field), type); 2102 if (subfield) 2103 return subfield; 2104 } 2105 } 2106 return NULL_TREE; 2107 } 2108 2109 /* Build an expression representing OBJECT.MEMBER. OBJECT is an 2110 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is 2111 non-NULL, it indicates the path to the base used to name MEMBER. 2112 If PRESERVE_REFERENCE is true, the expression returned will have 2113 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression 2114 returned will have the type referred to by the reference. 2115 2116 This function does not perform access control; that is either done 2117 earlier by the parser when the name of MEMBER is resolved to MEMBER 2118 itself, or later when overload resolution selects one of the 2119 functions indicated by MEMBER. */ 2120 2121 tree 2122 build_class_member_access_expr (tree object, tree member, 2123 tree access_path, bool preserve_reference, 2124 tsubst_flags_t complain) 2125 { 2126 tree object_type; 2127 tree member_scope; 2128 tree result = NULL_TREE; 2129 tree using_decl = NULL_TREE; 2130 2131 if (error_operand_p (object) || error_operand_p (member)) 2132 return error_mark_node; 2133 2134 gcc_assert (DECL_P (member) || BASELINK_P (member)); 2135 2136 /* [expr.ref] 2137 2138 The type of the first expression shall be "class object" (of a 2139 complete type). */ 2140 object_type = TREE_TYPE (object); 2141 if (!currently_open_class (object_type) 2142 && !complete_type_or_maybe_complain (object_type, object, complain)) 2143 return error_mark_node; 2144 if (!CLASS_TYPE_P (object_type)) 2145 { 2146 if (complain & tf_error) 2147 { 2148 if (POINTER_TYPE_P (object_type) 2149 && CLASS_TYPE_P (TREE_TYPE (object_type))) 2150 error ("request for member %qD in %qE, which is of pointer " 2151 "type %qT (maybe you meant to use %<->%> ?)", 2152 member, object, object_type); 2153 else 2154 error ("request for member %qD in %qE, which is of non-class " 2155 "type %qT", member, object, object_type); 2156 } 2157 return error_mark_node; 2158 } 2159 2160 /* The standard does not seem to actually say that MEMBER must be a 2161 member of OBJECT_TYPE. However, that is clearly what is 2162 intended. */ 2163 if (DECL_P (member)) 2164 { 2165 member_scope = DECL_CLASS_CONTEXT (member); 2166 mark_used (member); 2167 if (TREE_DEPRECATED (member)) 2168 warn_deprecated_use (member, NULL_TREE); 2169 } 2170 else 2171 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member)); 2172 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will 2173 presently be the anonymous union. Go outwards until we find a 2174 type related to OBJECT_TYPE. */ 2175 while (ANON_AGGR_TYPE_P (member_scope) 2176 && !same_type_ignoring_top_level_qualifiers_p (member_scope, 2177 object_type)) 2178 member_scope = TYPE_CONTEXT (member_scope); 2179 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type)) 2180 { 2181 if (complain & tf_error) 2182 { 2183 if (TREE_CODE (member) == FIELD_DECL) 2184 error ("invalid use of nonstatic data member %qE", member); 2185 else 2186 error ("%qD is not a member of %qT", member, object_type); 2187 } 2188 return error_mark_node; 2189 } 2190 2191 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into 2192 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue 2193 in the front end; only _DECLs and _REFs are lvalues in the back end. */ 2194 { 2195 tree temp = unary_complex_lvalue (ADDR_EXPR, object); 2196 if (temp) 2197 object = cp_build_indirect_ref (temp, RO_NULL, complain); 2198 } 2199 2200 /* In [expr.ref], there is an explicit list of the valid choices for 2201 MEMBER. We check for each of those cases here. */ 2202 if (TREE_CODE (member) == VAR_DECL) 2203 { 2204 /* A static data member. */ 2205 result = member; 2206 mark_exp_read (object); 2207 /* If OBJECT has side-effects, they are supposed to occur. */ 2208 if (TREE_SIDE_EFFECTS (object)) 2209 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result); 2210 } 2211 else if (TREE_CODE (member) == FIELD_DECL) 2212 { 2213 /* A non-static data member. */ 2214 bool null_object_p; 2215 int type_quals; 2216 tree member_type; 2217 2218 null_object_p = (TREE_CODE (object) == INDIRECT_REF 2219 && integer_zerop (TREE_OPERAND (object, 0))); 2220 2221 /* Convert OBJECT to the type of MEMBER. */ 2222 if (!same_type_p (TYPE_MAIN_VARIANT (object_type), 2223 TYPE_MAIN_VARIANT (member_scope))) 2224 { 2225 tree binfo; 2226 base_kind kind; 2227 2228 binfo = lookup_base (access_path ? access_path : object_type, 2229 member_scope, ba_unique, &kind); 2230 if (binfo == error_mark_node) 2231 return error_mark_node; 2232 2233 /* It is invalid to try to get to a virtual base of a 2234 NULL object. The most common cause is invalid use of 2235 offsetof macro. */ 2236 if (null_object_p && kind == bk_via_virtual) 2237 { 2238 if (complain & tf_error) 2239 { 2240 error ("invalid access to non-static data member %qD of " 2241 "NULL object", 2242 member); 2243 error ("(perhaps the %<offsetof%> macro was used incorrectly)"); 2244 } 2245 return error_mark_node; 2246 } 2247 2248 /* Convert to the base. */ 2249 object = build_base_path (PLUS_EXPR, object, binfo, 2250 /*nonnull=*/1, complain); 2251 /* If we found the base successfully then we should be able 2252 to convert to it successfully. */ 2253 gcc_assert (object != error_mark_node); 2254 } 2255 2256 /* Complain about other invalid uses of offsetof, even though they will 2257 give the right answer. Note that we complain whether or not they 2258 actually used the offsetof macro, since there's no way to know at this 2259 point. So we just give a warning, instead of a pedwarn. */ 2260 /* Do not produce this warning for base class field references, because 2261 we know for a fact that didn't come from offsetof. This does occur 2262 in various testsuite cases where a null object is passed where a 2263 vtable access is required. */ 2264 if (null_object_p && warn_invalid_offsetof 2265 && CLASSTYPE_NON_STD_LAYOUT (object_type) 2266 && !DECL_FIELD_IS_BASE (member) 2267 && cp_unevaluated_operand == 0 2268 && (complain & tf_warning)) 2269 { 2270 warning (OPT_Winvalid_offsetof, 2271 "invalid access to non-static data member %qD " 2272 " of NULL object", member); 2273 warning (OPT_Winvalid_offsetof, 2274 "(perhaps the %<offsetof%> macro was used incorrectly)"); 2275 } 2276 2277 /* If MEMBER is from an anonymous aggregate, we have converted 2278 OBJECT so that it refers to the class containing the 2279 anonymous union. Generate a reference to the anonymous union 2280 itself, and recur to find MEMBER. */ 2281 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member)) 2282 /* When this code is called from build_field_call, the 2283 object already has the type of the anonymous union. 2284 That is because the COMPONENT_REF was already 2285 constructed, and was then disassembled before calling 2286 build_field_call. After the function-call code is 2287 cleaned up, this waste can be eliminated. */ 2288 && (!same_type_ignoring_top_level_qualifiers_p 2289 (TREE_TYPE (object), DECL_CONTEXT (member)))) 2290 { 2291 tree anonymous_union; 2292 2293 anonymous_union = lookup_anon_field (TREE_TYPE (object), 2294 DECL_CONTEXT (member)); 2295 object = build_class_member_access_expr (object, 2296 anonymous_union, 2297 /*access_path=*/NULL_TREE, 2298 preserve_reference, 2299 complain); 2300 } 2301 2302 /* Compute the type of the field, as described in [expr.ref]. */ 2303 type_quals = TYPE_UNQUALIFIED; 2304 member_type = TREE_TYPE (member); 2305 if (TREE_CODE (member_type) != REFERENCE_TYPE) 2306 { 2307 type_quals = (cp_type_quals (member_type) 2308 | cp_type_quals (object_type)); 2309 2310 /* A field is const (volatile) if the enclosing object, or the 2311 field itself, is const (volatile). But, a mutable field is 2312 not const, even within a const object. */ 2313 if (DECL_MUTABLE_P (member)) 2314 type_quals &= ~TYPE_QUAL_CONST; 2315 member_type = cp_build_qualified_type (member_type, type_quals); 2316 } 2317 2318 result = build3 (COMPONENT_REF, member_type, object, member, 2319 NULL_TREE); 2320 result = fold_if_not_in_template (result); 2321 2322 /* Mark the expression const or volatile, as appropriate. Even 2323 though we've dealt with the type above, we still have to mark the 2324 expression itself. */ 2325 if (type_quals & TYPE_QUAL_CONST) 2326 TREE_READONLY (result) = 1; 2327 if (type_quals & TYPE_QUAL_VOLATILE) 2328 TREE_THIS_VOLATILE (result) = 1; 2329 } 2330 else if (BASELINK_P (member)) 2331 { 2332 /* The member is a (possibly overloaded) member function. */ 2333 tree functions; 2334 tree type; 2335 2336 /* If the MEMBER is exactly one static member function, then we 2337 know the type of the expression. Otherwise, we must wait 2338 until overload resolution has been performed. */ 2339 functions = BASELINK_FUNCTIONS (member); 2340 if (TREE_CODE (functions) == FUNCTION_DECL 2341 && DECL_STATIC_FUNCTION_P (functions)) 2342 type = TREE_TYPE (functions); 2343 else 2344 type = unknown_type_node; 2345 /* Note that we do not convert OBJECT to the BASELINK_BINFO 2346 base. That will happen when the function is called. */ 2347 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE); 2348 } 2349 else if (TREE_CODE (member) == CONST_DECL) 2350 { 2351 /* The member is an enumerator. */ 2352 result = member; 2353 /* If OBJECT has side-effects, they are supposed to occur. */ 2354 if (TREE_SIDE_EFFECTS (object)) 2355 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), 2356 object, result); 2357 } 2358 else if ((using_decl = strip_using_decl (member)) != member) 2359 result = build_class_member_access_expr (object, 2360 using_decl, 2361 access_path, preserve_reference, 2362 complain); 2363 else 2364 { 2365 if (complain & tf_error) 2366 error ("invalid use of %qD", member); 2367 return error_mark_node; 2368 } 2369 2370 if (!preserve_reference) 2371 /* [expr.ref] 2372 2373 If E2 is declared to have type "reference to T", then ... the 2374 type of E1.E2 is T. */ 2375 result = convert_from_reference (result); 2376 2377 return result; 2378 } 2379 2380 /* Return the destructor denoted by OBJECT.SCOPE::DTOR_NAME, or, if 2381 SCOPE is NULL, by OBJECT.DTOR_NAME, where DTOR_NAME is ~type. */ 2382 2383 static tree 2384 lookup_destructor (tree object, tree scope, tree dtor_name) 2385 { 2386 tree object_type = TREE_TYPE (object); 2387 tree dtor_type = TREE_OPERAND (dtor_name, 0); 2388 tree expr; 2389 2390 if (scope && !check_dtor_name (scope, dtor_type)) 2391 { 2392 error ("qualified type %qT does not match destructor name ~%qT", 2393 scope, dtor_type); 2394 return error_mark_node; 2395 } 2396 if (TREE_CODE (dtor_type) == IDENTIFIER_NODE) 2397 { 2398 /* In a template, names we can't find a match for are still accepted 2399 destructor names, and we check them here. */ 2400 if (check_dtor_name (object_type, dtor_type)) 2401 dtor_type = object_type; 2402 else 2403 { 2404 error ("object type %qT does not match destructor name ~%qT", 2405 object_type, dtor_type); 2406 return error_mark_node; 2407 } 2408 2409 } 2410 else if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type))) 2411 { 2412 error ("the type being destroyed is %qT, but the destructor refers to %qT", 2413 TYPE_MAIN_VARIANT (object_type), dtor_type); 2414 return error_mark_node; 2415 } 2416 expr = lookup_member (dtor_type, complete_dtor_identifier, 2417 /*protect=*/1, /*want_type=*/false, 2418 tf_warning_or_error); 2419 expr = (adjust_result_of_qualified_name_lookup 2420 (expr, dtor_type, object_type)); 2421 if (scope == NULL_TREE) 2422 /* We need to call adjust_result_of_qualified_name_lookup in case the 2423 destructor names a base class, but we unset BASELINK_QUALIFIED_P so 2424 that we still get virtual function binding. */ 2425 BASELINK_QUALIFIED_P (expr) = false; 2426 return expr; 2427 } 2428 2429 /* An expression of the form "A::template B" has been resolved to 2430 DECL. Issue a diagnostic if B is not a template or template 2431 specialization. */ 2432 2433 void 2434 check_template_keyword (tree decl) 2435 { 2436 /* The standard says: 2437 2438 [temp.names] 2439 2440 If a name prefixed by the keyword template is not a member 2441 template, the program is ill-formed. 2442 2443 DR 228 removed the restriction that the template be a member 2444 template. 2445 2446 DR 96, if accepted would add the further restriction that explicit 2447 template arguments must be provided if the template keyword is 2448 used, but, as of 2005-10-16, that DR is still in "drafting". If 2449 this DR is accepted, then the semantic checks here can be 2450 simplified, as the entity named must in fact be a template 2451 specialization, rather than, as at present, a set of overloaded 2452 functions containing at least one template function. */ 2453 if (TREE_CODE (decl) != TEMPLATE_DECL 2454 && TREE_CODE (decl) != TEMPLATE_ID_EXPR) 2455 { 2456 if (!is_overloaded_fn (decl)) 2457 permerror (input_location, "%qD is not a template", decl); 2458 else 2459 { 2460 tree fns; 2461 fns = decl; 2462 if (BASELINK_P (fns)) 2463 fns = BASELINK_FUNCTIONS (fns); 2464 while (fns) 2465 { 2466 tree fn = OVL_CURRENT (fns); 2467 if (TREE_CODE (fn) == TEMPLATE_DECL 2468 || TREE_CODE (fn) == TEMPLATE_ID_EXPR) 2469 break; 2470 if (TREE_CODE (fn) == FUNCTION_DECL 2471 && DECL_USE_TEMPLATE (fn) 2472 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 2473 break; 2474 fns = OVL_NEXT (fns); 2475 } 2476 if (!fns) 2477 permerror (input_location, "%qD is not a template", decl); 2478 } 2479 } 2480 } 2481 2482 /* This function is called by the parser to process a class member 2483 access expression of the form OBJECT.NAME. NAME is a node used by 2484 the parser to represent a name; it is not yet a DECL. It may, 2485 however, be a BASELINK where the BASELINK_FUNCTIONS is a 2486 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and 2487 there is no reason to do the lookup twice, so the parser keeps the 2488 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to 2489 be a template via the use of the "A::template B" syntax. */ 2490 2491 tree 2492 finish_class_member_access_expr (tree object, tree name, bool template_p, 2493 tsubst_flags_t complain) 2494 { 2495 tree expr; 2496 tree object_type; 2497 tree member; 2498 tree access_path = NULL_TREE; 2499 tree orig_object = object; 2500 tree orig_name = name; 2501 2502 if (object == error_mark_node || name == error_mark_node) 2503 return error_mark_node; 2504 2505 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */ 2506 if (!objc_is_public (object, name)) 2507 return error_mark_node; 2508 2509 object_type = TREE_TYPE (object); 2510 2511 if (processing_template_decl) 2512 { 2513 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */ 2514 dependent_type_p (object_type) 2515 /* If NAME is just an IDENTIFIER_NODE, then the expression 2516 is dependent. */ 2517 || TREE_CODE (object) == IDENTIFIER_NODE 2518 /* If NAME is "f<args>", where either 'f' or 'args' is 2519 dependent, then the expression is dependent. */ 2520 || (TREE_CODE (name) == TEMPLATE_ID_EXPR 2521 && dependent_template_id_p (TREE_OPERAND (name, 0), 2522 TREE_OPERAND (name, 1))) 2523 /* If NAME is "T::X" where "T" is dependent, then the 2524 expression is dependent. */ 2525 || (TREE_CODE (name) == SCOPE_REF 2526 && TYPE_P (TREE_OPERAND (name, 0)) 2527 && dependent_type_p (TREE_OPERAND (name, 0)))) 2528 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE); 2529 object = build_non_dependent_expr (object); 2530 } 2531 else if (c_dialect_objc () 2532 && TREE_CODE (name) == IDENTIFIER_NODE 2533 && (expr = objc_maybe_build_component_ref (object, name))) 2534 return expr; 2535 2536 /* [expr.ref] 2537 2538 The type of the first expression shall be "class object" (of a 2539 complete type). */ 2540 if (!currently_open_class (object_type) 2541 && !complete_type_or_maybe_complain (object_type, object, complain)) 2542 return error_mark_node; 2543 if (!CLASS_TYPE_P (object_type)) 2544 { 2545 if (complain & tf_error) 2546 { 2547 if (POINTER_TYPE_P (object_type) 2548 && CLASS_TYPE_P (TREE_TYPE (object_type))) 2549 error ("request for member %qD in %qE, which is of pointer " 2550 "type %qT (maybe you meant to use %<->%> ?)", 2551 name, object, object_type); 2552 else 2553 error ("request for member %qD in %qE, which is of non-class " 2554 "type %qT", name, object, object_type); 2555 } 2556 return error_mark_node; 2557 } 2558 2559 if (BASELINK_P (name)) 2560 /* A member function that has already been looked up. */ 2561 member = name; 2562 else 2563 { 2564 bool is_template_id = false; 2565 tree template_args = NULL_TREE; 2566 tree scope; 2567 2568 if (TREE_CODE (name) == TEMPLATE_ID_EXPR) 2569 { 2570 is_template_id = true; 2571 template_args = TREE_OPERAND (name, 1); 2572 name = TREE_OPERAND (name, 0); 2573 2574 if (TREE_CODE (name) == OVERLOAD) 2575 name = DECL_NAME (get_first_fn (name)); 2576 else if (DECL_P (name)) 2577 name = DECL_NAME (name); 2578 } 2579 2580 if (TREE_CODE (name) == SCOPE_REF) 2581 { 2582 /* A qualified name. The qualifying class or namespace `S' 2583 has already been looked up; it is either a TYPE or a 2584 NAMESPACE_DECL. */ 2585 scope = TREE_OPERAND (name, 0); 2586 name = TREE_OPERAND (name, 1); 2587 2588 /* If SCOPE is a namespace, then the qualified name does not 2589 name a member of OBJECT_TYPE. */ 2590 if (TREE_CODE (scope) == NAMESPACE_DECL) 2591 { 2592 if (complain & tf_error) 2593 error ("%<%D::%D%> is not a member of %qT", 2594 scope, name, object_type); 2595 return error_mark_node; 2596 } 2597 2598 gcc_assert (CLASS_TYPE_P (scope)); 2599 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE 2600 || TREE_CODE (name) == BIT_NOT_EXPR); 2601 2602 if (constructor_name_p (name, scope)) 2603 { 2604 if (complain & tf_error) 2605 error ("cannot call constructor %<%T::%D%> directly", 2606 scope, name); 2607 return error_mark_node; 2608 } 2609 2610 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */ 2611 access_path = lookup_base (object_type, scope, ba_check, NULL); 2612 if (access_path == error_mark_node) 2613 return error_mark_node; 2614 if (!access_path) 2615 { 2616 if (complain & tf_error) 2617 error ("%qT is not a base of %qT", scope, object_type); 2618 return error_mark_node; 2619 } 2620 } 2621 else 2622 { 2623 scope = NULL_TREE; 2624 access_path = object_type; 2625 } 2626 2627 if (TREE_CODE (name) == BIT_NOT_EXPR) 2628 member = lookup_destructor (object, scope, name); 2629 else 2630 { 2631 /* Look up the member. */ 2632 member = lookup_member (access_path, name, /*protect=*/1, 2633 /*want_type=*/false, complain); 2634 if (member == NULL_TREE) 2635 { 2636 if (complain & tf_error) 2637 error ("%qD has no member named %qE", 2638 TREE_CODE (access_path) == TREE_BINFO 2639 ? TREE_TYPE (access_path) : object_type, name); 2640 return error_mark_node; 2641 } 2642 if (member == error_mark_node) 2643 return error_mark_node; 2644 } 2645 2646 if (is_template_id) 2647 { 2648 tree templ = member; 2649 2650 if (BASELINK_P (templ)) 2651 templ = lookup_template_function (templ, template_args); 2652 else 2653 { 2654 if (complain & tf_error) 2655 error ("%qD is not a member template function", name); 2656 return error_mark_node; 2657 } 2658 } 2659 } 2660 2661 if (TREE_DEPRECATED (member)) 2662 warn_deprecated_use (member, NULL_TREE); 2663 2664 if (template_p) 2665 check_template_keyword (member); 2666 2667 expr = build_class_member_access_expr (object, member, access_path, 2668 /*preserve_reference=*/false, 2669 complain); 2670 if (processing_template_decl && expr != error_mark_node) 2671 { 2672 if (BASELINK_P (member)) 2673 { 2674 if (TREE_CODE (orig_name) == SCOPE_REF) 2675 BASELINK_QUALIFIED_P (member) = 1; 2676 orig_name = member; 2677 } 2678 return build_min_non_dep (COMPONENT_REF, expr, 2679 orig_object, orig_name, 2680 NULL_TREE); 2681 } 2682 2683 return expr; 2684 } 2685 2686 /* Return an expression for the MEMBER_NAME field in the internal 2687 representation of PTRMEM, a pointer-to-member function. (Each 2688 pointer-to-member function type gets its own RECORD_TYPE so it is 2689 more convenient to access the fields by name than by FIELD_DECL.) 2690 This routine converts the NAME to a FIELD_DECL and then creates the 2691 node for the complete expression. */ 2692 2693 tree 2694 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name) 2695 { 2696 tree ptrmem_type; 2697 tree member; 2698 tree member_type; 2699 2700 /* This code is a stripped down version of 2701 build_class_member_access_expr. It does not work to use that 2702 routine directly because it expects the object to be of class 2703 type. */ 2704 ptrmem_type = TREE_TYPE (ptrmem); 2705 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type)); 2706 member = lookup_member (ptrmem_type, member_name, /*protect=*/0, 2707 /*want_type=*/false, tf_warning_or_error); 2708 member_type = cp_build_qualified_type (TREE_TYPE (member), 2709 cp_type_quals (ptrmem_type)); 2710 return fold_build3_loc (input_location, 2711 COMPONENT_REF, member_type, 2712 ptrmem, member, NULL_TREE); 2713 } 2714 2715 /* Given an expression PTR for a pointer, return an expression 2716 for the value pointed to. 2717 ERRORSTRING is the name of the operator to appear in error messages. 2718 2719 This function may need to overload OPERATOR_FNNAME. 2720 Must also handle REFERENCE_TYPEs for C++. */ 2721 2722 tree 2723 build_x_indirect_ref (tree expr, ref_operator errorstring, 2724 tsubst_flags_t complain) 2725 { 2726 tree orig_expr = expr; 2727 tree rval; 2728 2729 if (processing_template_decl) 2730 { 2731 /* Retain the type if we know the operand is a pointer. */ 2732 if (TREE_TYPE (expr) && POINTER_TYPE_P (TREE_TYPE (expr))) 2733 return build_min (INDIRECT_REF, TREE_TYPE (TREE_TYPE (expr)), expr); 2734 if (type_dependent_expression_p (expr)) 2735 return build_min_nt (INDIRECT_REF, expr); 2736 expr = build_non_dependent_expr (expr); 2737 } 2738 2739 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE, 2740 NULL_TREE, /*overload=*/NULL, complain); 2741 if (!rval) 2742 rval = cp_build_indirect_ref (expr, errorstring, complain); 2743 2744 if (processing_template_decl && rval != error_mark_node) 2745 return build_min_non_dep (INDIRECT_REF, rval, orig_expr); 2746 else 2747 return rval; 2748 } 2749 2750 /* Helper function called from c-common. */ 2751 tree 2752 build_indirect_ref (location_t loc ATTRIBUTE_UNUSED, 2753 tree ptr, ref_operator errorstring) 2754 { 2755 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error); 2756 } 2757 2758 tree 2759 cp_build_indirect_ref (tree ptr, ref_operator errorstring, 2760 tsubst_flags_t complain) 2761 { 2762 tree pointer, type; 2763 2764 if (ptr == error_mark_node) 2765 return error_mark_node; 2766 2767 if (ptr == current_class_ptr) 2768 return current_class_ref; 2769 2770 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE 2771 ? ptr : decay_conversion (ptr)); 2772 type = TREE_TYPE (pointer); 2773 2774 if (POINTER_TYPE_P (type)) 2775 { 2776 /* [expr.unary.op] 2777 2778 If the type of the expression is "pointer to T," the type 2779 of the result is "T." */ 2780 tree t = TREE_TYPE (type); 2781 2782 if (CONVERT_EXPR_P (ptr) 2783 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR) 2784 { 2785 /* If a warning is issued, mark it to avoid duplicates from 2786 the backend. This only needs to be done at 2787 warn_strict_aliasing > 2. */ 2788 if (warn_strict_aliasing > 2) 2789 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)), 2790 type, TREE_OPERAND (ptr, 0))) 2791 TREE_NO_WARNING (ptr) = 1; 2792 } 2793 2794 if (VOID_TYPE_P (t)) 2795 { 2796 /* A pointer to incomplete type (other than cv void) can be 2797 dereferenced [expr.unary.op]/1 */ 2798 if (complain & tf_error) 2799 error ("%qT is not a pointer-to-object type", type); 2800 return error_mark_node; 2801 } 2802 else if (TREE_CODE (pointer) == ADDR_EXPR 2803 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0)))) 2804 /* The POINTER was something like `&x'. We simplify `*&x' to 2805 `x'. */ 2806 return TREE_OPERAND (pointer, 0); 2807 else 2808 { 2809 tree ref = build1 (INDIRECT_REF, t, pointer); 2810 2811 /* We *must* set TREE_READONLY when dereferencing a pointer to const, 2812 so that we get the proper error message if the result is used 2813 to assign to. Also, &* is supposed to be a no-op. */ 2814 TREE_READONLY (ref) = CP_TYPE_CONST_P (t); 2815 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t); 2816 TREE_SIDE_EFFECTS (ref) 2817 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer)); 2818 return ref; 2819 } 2820 } 2821 else if (!(complain & tf_error)) 2822 /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */ 2823 ; 2824 /* `pointer' won't be an error_mark_node if we were given a 2825 pointer to member, so it's cool to check for this here. */ 2826 else if (TYPE_PTR_TO_MEMBER_P (type)) 2827 switch (errorstring) 2828 { 2829 case RO_ARRAY_INDEXING: 2830 error ("invalid use of array indexing on pointer to member"); 2831 break; 2832 case RO_UNARY_STAR: 2833 error ("invalid use of unary %<*%> on pointer to member"); 2834 break; 2835 case RO_IMPLICIT_CONVERSION: 2836 error ("invalid use of implicit conversion on pointer to member"); 2837 break; 2838 default: 2839 gcc_unreachable (); 2840 } 2841 else if (pointer != error_mark_node) 2842 invalid_indirection_error (input_location, type, errorstring); 2843 2844 return error_mark_node; 2845 } 2846 2847 /* This handles expressions of the form "a[i]", which denotes 2848 an array reference. 2849 2850 This is logically equivalent in C to *(a+i), but we may do it differently. 2851 If A is a variable or a member, we generate a primitive ARRAY_REF. 2852 This avoids forcing the array out of registers, and can work on 2853 arrays that are not lvalues (for example, members of structures returned 2854 by functions). 2855 2856 If INDEX is of some user-defined type, it must be converted to 2857 integer type. Otherwise, to make a compatible PLUS_EXPR, it 2858 will inherit the type of the array, which will be some pointer type. 2859 2860 LOC is the location to use in building the array reference. */ 2861 2862 tree 2863 cp_build_array_ref (location_t loc, tree array, tree idx, 2864 tsubst_flags_t complain) 2865 { 2866 tree ret; 2867 2868 if (idx == 0) 2869 { 2870 if (complain & tf_error) 2871 error_at (loc, "subscript missing in array reference"); 2872 return error_mark_node; 2873 } 2874 2875 if (TREE_TYPE (array) == error_mark_node 2876 || TREE_TYPE (idx) == error_mark_node) 2877 return error_mark_node; 2878 2879 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference 2880 inside it. */ 2881 switch (TREE_CODE (array)) 2882 { 2883 case COMPOUND_EXPR: 2884 { 2885 tree value = cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx, 2886 complain); 2887 ret = build2 (COMPOUND_EXPR, TREE_TYPE (value), 2888 TREE_OPERAND (array, 0), value); 2889 SET_EXPR_LOCATION (ret, loc); 2890 return ret; 2891 } 2892 2893 case COND_EXPR: 2894 ret = build_conditional_expr 2895 (TREE_OPERAND (array, 0), 2896 cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx, 2897 complain), 2898 cp_build_array_ref (loc, TREE_OPERAND (array, 2), idx, 2899 complain), 2900 tf_warning_or_error); 2901 protected_set_expr_location (ret, loc); 2902 return ret; 2903 2904 default: 2905 break; 2906 } 2907 2908 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE) 2909 { 2910 tree rval, type; 2911 2912 warn_array_subscript_with_type_char (idx); 2913 2914 if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (idx))) 2915 { 2916 if (complain & tf_error) 2917 error_at (loc, "array subscript is not an integer"); 2918 return error_mark_node; 2919 } 2920 2921 /* Apply integral promotions *after* noticing character types. 2922 (It is unclear why we do these promotions -- the standard 2923 does not say that we should. In fact, the natural thing would 2924 seem to be to convert IDX to ptrdiff_t; we're performing 2925 pointer arithmetic.) */ 2926 idx = perform_integral_promotions (idx); 2927 2928 /* An array that is indexed by a non-constant 2929 cannot be stored in a register; we must be able to do 2930 address arithmetic on its address. 2931 Likewise an array of elements of variable size. */ 2932 if (TREE_CODE (idx) != INTEGER_CST 2933 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) 2934 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) 2935 != INTEGER_CST))) 2936 { 2937 if (!cxx_mark_addressable (array)) 2938 return error_mark_node; 2939 } 2940 2941 /* An array that is indexed by a constant value which is not within 2942 the array bounds cannot be stored in a register either; because we 2943 would get a crash in store_bit_field/extract_bit_field when trying 2944 to access a non-existent part of the register. */ 2945 if (TREE_CODE (idx) == INTEGER_CST 2946 && TYPE_DOMAIN (TREE_TYPE (array)) 2947 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array)))) 2948 { 2949 if (!cxx_mark_addressable (array)) 2950 return error_mark_node; 2951 } 2952 2953 if (!lvalue_p (array) && (complain & tf_error)) 2954 pedwarn (loc, OPT_pedantic, 2955 "ISO C++ forbids subscripting non-lvalue array"); 2956 2957 /* Note in C++ it is valid to subscript a `register' array, since 2958 it is valid to take the address of something with that 2959 storage specification. */ 2960 if (extra_warnings) 2961 { 2962 tree foo = array; 2963 while (TREE_CODE (foo) == COMPONENT_REF) 2964 foo = TREE_OPERAND (foo, 0); 2965 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo) 2966 && (complain & tf_warning)) 2967 warning_at (loc, OPT_Wextra, 2968 "subscripting array declared %<register%>"); 2969 } 2970 2971 type = TREE_TYPE (TREE_TYPE (array)); 2972 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE); 2973 /* Array ref is const/volatile if the array elements are 2974 or if the array is.. */ 2975 TREE_READONLY (rval) 2976 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array)); 2977 TREE_SIDE_EFFECTS (rval) 2978 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array)); 2979 TREE_THIS_VOLATILE (rval) 2980 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array)); 2981 ret = require_complete_type_sfinae (fold_if_not_in_template (rval), 2982 complain); 2983 protected_set_expr_location (ret, loc); 2984 return ret; 2985 } 2986 2987 { 2988 tree ar = default_conversion (array); 2989 tree ind = default_conversion (idx); 2990 2991 /* Put the integer in IND to simplify error checking. */ 2992 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE) 2993 { 2994 tree temp = ar; 2995 ar = ind; 2996 ind = temp; 2997 } 2998 2999 if (ar == error_mark_node) 3000 return ar; 3001 3002 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE) 3003 { 3004 if (complain & tf_error) 3005 error_at (loc, "subscripted value is neither array nor pointer"); 3006 return error_mark_node; 3007 } 3008 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE) 3009 { 3010 if (complain & tf_error) 3011 error_at (loc, "array subscript is not an integer"); 3012 return error_mark_node; 3013 } 3014 3015 warn_array_subscript_with_type_char (idx); 3016 3017 ret = cp_build_indirect_ref (cp_build_binary_op (input_location, 3018 PLUS_EXPR, ar, ind, 3019 complain), 3020 RO_ARRAY_INDEXING, 3021 complain); 3022 protected_set_expr_location (ret, loc); 3023 return ret; 3024 } 3025 } 3026 3027 /* Entry point for Obj-C++. */ 3028 3029 tree 3030 build_array_ref (location_t loc, tree array, tree idx) 3031 { 3032 return cp_build_array_ref (loc, array, idx, tf_warning_or_error); 3033 } 3034 3035 /* Resolve a pointer to member function. INSTANCE is the object 3036 instance to use, if the member points to a virtual member. 3037 3038 This used to avoid checking for virtual functions if basetype 3039 has no virtual functions, according to an earlier ANSI draft. 3040 With the final ISO C++ rules, such an optimization is 3041 incorrect: A pointer to a derived member can be static_cast 3042 to pointer-to-base-member, as long as the dynamic object 3043 later has the right member. */ 3044 3045 tree 3046 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function) 3047 { 3048 if (TREE_CODE (function) == OFFSET_REF) 3049 function = TREE_OPERAND (function, 1); 3050 3051 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function))) 3052 { 3053 tree idx, delta, e1, e2, e3, vtbl, basetype; 3054 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function)); 3055 3056 tree instance_ptr = *instance_ptrptr; 3057 tree instance_save_expr = 0; 3058 if (instance_ptr == error_mark_node) 3059 { 3060 if (TREE_CODE (function) == PTRMEM_CST) 3061 { 3062 /* Extracting the function address from a pmf is only 3063 allowed with -Wno-pmf-conversions. It only works for 3064 pmf constants. */ 3065 e1 = build_addr_func (PTRMEM_CST_MEMBER (function)); 3066 e1 = convert (fntype, e1); 3067 return e1; 3068 } 3069 else 3070 { 3071 error ("object missing in use of %qE", function); 3072 return error_mark_node; 3073 } 3074 } 3075 3076 if (TREE_SIDE_EFFECTS (instance_ptr)) 3077 instance_ptr = instance_save_expr = save_expr (instance_ptr); 3078 3079 if (TREE_SIDE_EFFECTS (function)) 3080 function = save_expr (function); 3081 3082 /* Start by extracting all the information from the PMF itself. */ 3083 e3 = pfn_from_ptrmemfunc (function); 3084 delta = delta_from_ptrmemfunc (function); 3085 idx = build1 (NOP_EXPR, vtable_index_type, e3); 3086 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION) 3087 { 3088 case ptrmemfunc_vbit_in_pfn: 3089 e1 = cp_build_binary_op (input_location, 3090 BIT_AND_EXPR, idx, integer_one_node, 3091 tf_warning_or_error); 3092 idx = cp_build_binary_op (input_location, 3093 MINUS_EXPR, idx, integer_one_node, 3094 tf_warning_or_error); 3095 break; 3096 3097 case ptrmemfunc_vbit_in_delta: 3098 e1 = cp_build_binary_op (input_location, 3099 BIT_AND_EXPR, delta, integer_one_node, 3100 tf_warning_or_error); 3101 delta = cp_build_binary_op (input_location, 3102 RSHIFT_EXPR, delta, integer_one_node, 3103 tf_warning_or_error); 3104 break; 3105 3106 default: 3107 gcc_unreachable (); 3108 } 3109 3110 /* Convert down to the right base before using the instance. A 3111 special case is that in a pointer to member of class C, C may 3112 be incomplete. In that case, the function will of course be 3113 a member of C, and no conversion is required. In fact, 3114 lookup_base will fail in that case, because incomplete 3115 classes do not have BINFOs. */ 3116 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype)); 3117 if (!same_type_ignoring_top_level_qualifiers_p 3118 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr)))) 3119 { 3120 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)), 3121 basetype, ba_check, NULL); 3122 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 3123 1, tf_warning_or_error); 3124 if (instance_ptr == error_mark_node) 3125 return error_mark_node; 3126 } 3127 /* ...and then the delta in the PMF. */ 3128 instance_ptr = fold_build_pointer_plus (instance_ptr, delta); 3129 3130 /* Hand back the adjusted 'this' argument to our caller. */ 3131 *instance_ptrptr = instance_ptr; 3132 3133 /* Next extract the vtable pointer from the object. */ 3134 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node), 3135 instance_ptr); 3136 vtbl = cp_build_indirect_ref (vtbl, RO_NULL, tf_warning_or_error); 3137 /* If the object is not dynamic the access invokes undefined 3138 behavior. As it is not executed in this case silence the 3139 spurious warnings it may provoke. */ 3140 TREE_NO_WARNING (vtbl) = 1; 3141 3142 /* Finally, extract the function pointer from the vtable. */ 3143 e2 = fold_build_pointer_plus_loc (input_location, vtbl, idx); 3144 e2 = cp_build_indirect_ref (e2, RO_NULL, tf_warning_or_error); 3145 TREE_CONSTANT (e2) = 1; 3146 3147 /* When using function descriptors, the address of the 3148 vtable entry is treated as a function pointer. */ 3149 if (TARGET_VTABLE_USES_DESCRIPTORS) 3150 e2 = build1 (NOP_EXPR, TREE_TYPE (e2), 3151 cp_build_addr_expr (e2, tf_warning_or_error)); 3152 3153 e2 = fold_convert (TREE_TYPE (e3), e2); 3154 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error); 3155 3156 /* Make sure this doesn't get evaluated first inside one of the 3157 branches of the COND_EXPR. */ 3158 if (instance_save_expr) 3159 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1), 3160 instance_save_expr, e1); 3161 3162 function = e1; 3163 } 3164 return function; 3165 } 3166 3167 /* Used by the C-common bits. */ 3168 tree 3169 build_function_call (location_t loc ATTRIBUTE_UNUSED, 3170 tree function, tree params) 3171 { 3172 return cp_build_function_call (function, params, tf_warning_or_error); 3173 } 3174 3175 /* Used by the C-common bits. */ 3176 tree 3177 build_function_call_vec (location_t loc ATTRIBUTE_UNUSED, 3178 tree function, VEC(tree,gc) *params, 3179 VEC(tree,gc) *origtypes ATTRIBUTE_UNUSED) 3180 { 3181 VEC(tree,gc) *orig_params = params; 3182 tree ret = cp_build_function_call_vec (function, ¶ms, 3183 tf_warning_or_error); 3184 3185 /* cp_build_function_call_vec can reallocate PARAMS by adding 3186 default arguments. That should never happen here. Verify 3187 that. */ 3188 gcc_assert (params == orig_params); 3189 3190 return ret; 3191 } 3192 3193 /* Build a function call using a tree list of arguments. */ 3194 3195 tree 3196 cp_build_function_call (tree function, tree params, tsubst_flags_t complain) 3197 { 3198 VEC(tree,gc) *vec; 3199 tree ret; 3200 3201 vec = make_tree_vector (); 3202 for (; params != NULL_TREE; params = TREE_CHAIN (params)) 3203 VEC_safe_push (tree, gc, vec, TREE_VALUE (params)); 3204 ret = cp_build_function_call_vec (function, &vec, complain); 3205 release_tree_vector (vec); 3206 return ret; 3207 } 3208 3209 /* Build a function call using varargs. */ 3210 3211 tree 3212 cp_build_function_call_nary (tree function, tsubst_flags_t complain, ...) 3213 { 3214 VEC(tree,gc) *vec; 3215 va_list args; 3216 tree ret, t; 3217 3218 vec = make_tree_vector (); 3219 va_start (args, complain); 3220 for (t = va_arg (args, tree); t != NULL_TREE; t = va_arg (args, tree)) 3221 VEC_safe_push (tree, gc, vec, t); 3222 va_end (args); 3223 ret = cp_build_function_call_vec (function, &vec, complain); 3224 release_tree_vector (vec); 3225 return ret; 3226 } 3227 3228 /* Build a function call using a vector of arguments. PARAMS may be 3229 NULL if there are no parameters. This changes the contents of 3230 PARAMS. */ 3231 3232 tree 3233 cp_build_function_call_vec (tree function, VEC(tree,gc) **params, 3234 tsubst_flags_t complain) 3235 { 3236 tree fntype, fndecl; 3237 int is_method; 3238 tree original = function; 3239 int nargs; 3240 tree *argarray; 3241 tree parm_types; 3242 VEC(tree,gc) *allocated = NULL; 3243 tree ret; 3244 3245 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF 3246 expressions, like those used for ObjC messenger dispatches. */ 3247 if (params != NULL && !VEC_empty (tree, *params)) 3248 function = objc_rewrite_function_call (function, 3249 VEC_index (tree, *params, 0)); 3250 3251 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 3252 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */ 3253 if (TREE_CODE (function) == NOP_EXPR 3254 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0))) 3255 function = TREE_OPERAND (function, 0); 3256 3257 if (TREE_CODE (function) == FUNCTION_DECL) 3258 { 3259 mark_used (function); 3260 fndecl = function; 3261 3262 /* Convert anything with function type to a pointer-to-function. */ 3263 if (DECL_MAIN_P (function) && (complain & tf_error)) 3264 pedwarn (input_location, OPT_pedantic, 3265 "ISO C++ forbids calling %<::main%> from within program"); 3266 3267 function = build_addr_func (function); 3268 } 3269 else 3270 { 3271 fndecl = NULL_TREE; 3272 3273 function = build_addr_func (function); 3274 } 3275 3276 if (function == error_mark_node) 3277 return error_mark_node; 3278 3279 fntype = TREE_TYPE (function); 3280 3281 if (TYPE_PTRMEMFUNC_P (fntype)) 3282 { 3283 if (complain & tf_error) 3284 error ("must use %<.*%> or %<->*%> to call pointer-to-member " 3285 "function in %<%E (...)%>, e.g. %<(... ->* %E) (...)%>", 3286 original, original); 3287 return error_mark_node; 3288 } 3289 3290 is_method = (TREE_CODE (fntype) == POINTER_TYPE 3291 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE); 3292 3293 if (!((TREE_CODE (fntype) == POINTER_TYPE 3294 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE) 3295 || is_method 3296 || TREE_CODE (function) == TEMPLATE_ID_EXPR)) 3297 { 3298 if (complain & tf_error) 3299 error ("%qE cannot be used as a function", original); 3300 return error_mark_node; 3301 } 3302 3303 /* fntype now gets the type of function pointed to. */ 3304 fntype = TREE_TYPE (fntype); 3305 parm_types = TYPE_ARG_TYPES (fntype); 3306 3307 if (params == NULL) 3308 { 3309 allocated = make_tree_vector (); 3310 params = &allocated; 3311 } 3312 3313 nargs = convert_arguments (parm_types, params, fndecl, LOOKUP_NORMAL, 3314 complain); 3315 if (nargs < 0) 3316 return error_mark_node; 3317 3318 argarray = VEC_address (tree, *params); 3319 3320 /* Check for errors in format strings and inappropriately 3321 null parameters. */ 3322 check_function_arguments (fntype, nargs, argarray); 3323 3324 ret = build_cxx_call (function, nargs, argarray); 3325 3326 if (allocated != NULL) 3327 release_tree_vector (allocated); 3328 3329 return ret; 3330 } 3331 3332 /* Subroutine of convert_arguments. 3333 Warn about wrong number of args are genereted. */ 3334 3335 static void 3336 warn_args_num (location_t loc, tree fndecl, bool too_many_p) 3337 { 3338 if (fndecl) 3339 { 3340 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE) 3341 { 3342 if (DECL_NAME (fndecl) == NULL_TREE 3343 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl))) 3344 error_at (loc, 3345 too_many_p 3346 ? G_("too many arguments to constructor %q#D") 3347 : G_("too few arguments to constructor %q#D"), 3348 fndecl); 3349 else 3350 error_at (loc, 3351 too_many_p 3352 ? G_("too many arguments to member function %q#D") 3353 : G_("too few arguments to member function %q#D"), 3354 fndecl); 3355 } 3356 else 3357 error_at (loc, 3358 too_many_p 3359 ? G_("too many arguments to function %q#D") 3360 : G_("too few arguments to function %q#D"), 3361 fndecl); 3362 inform (DECL_SOURCE_LOCATION (fndecl), 3363 "declared here"); 3364 } 3365 else 3366 { 3367 if (c_dialect_objc () && objc_message_selector ()) 3368 error_at (loc, 3369 too_many_p 3370 ? G_("too many arguments to method %q#D") 3371 : G_("too few arguments to method %q#D"), 3372 objc_message_selector ()); 3373 else 3374 error_at (loc, too_many_p ? G_("too many arguments to function") 3375 : G_("too few arguments to function")); 3376 } 3377 } 3378 3379 /* Convert the actual parameter expressions in the list VALUES to the 3380 types in the list TYPELIST. The converted expressions are stored 3381 back in the VALUES vector. 3382 If parmdecls is exhausted, or when an element has NULL as its type, 3383 perform the default conversions. 3384 3385 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages. 3386 3387 This is also where warnings about wrong number of args are generated. 3388 3389 Returns the actual number of arguments processed (which might be less 3390 than the length of the vector), or -1 on error. 3391 3392 In C++, unspecified trailing parameters can be filled in with their 3393 default arguments, if such were specified. Do so here. */ 3394 3395 static int 3396 convert_arguments (tree typelist, VEC(tree,gc) **values, tree fndecl, 3397 int flags, tsubst_flags_t complain) 3398 { 3399 tree typetail; 3400 unsigned int i; 3401 3402 /* Argument passing is always copy-initialization. */ 3403 flags |= LOOKUP_ONLYCONVERTING; 3404 3405 for (i = 0, typetail = typelist; 3406 i < VEC_length (tree, *values); 3407 i++) 3408 { 3409 tree type = typetail ? TREE_VALUE (typetail) : 0; 3410 tree val = VEC_index (tree, *values, i); 3411 3412 if (val == error_mark_node || type == error_mark_node) 3413 return -1; 3414 3415 if (type == void_type_node) 3416 { 3417 if (complain & tf_error) 3418 { 3419 warn_args_num (input_location, fndecl, /*too_many_p=*/true); 3420 return i; 3421 } 3422 else 3423 return -1; 3424 } 3425 3426 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 3427 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */ 3428 if (TREE_CODE (val) == NOP_EXPR 3429 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)) 3430 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)) 3431 val = TREE_OPERAND (val, 0); 3432 3433 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE) 3434 { 3435 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE 3436 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE 3437 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE) 3438 val = decay_conversion (val); 3439 } 3440 3441 if (val == error_mark_node) 3442 return -1; 3443 3444 if (type != 0) 3445 { 3446 /* Formal parm type is specified by a function prototype. */ 3447 tree parmval; 3448 3449 if (!COMPLETE_TYPE_P (complete_type (type))) 3450 { 3451 if (complain & tf_error) 3452 { 3453 if (fndecl) 3454 error ("parameter %P of %qD has incomplete type %qT", 3455 i, fndecl, type); 3456 else 3457 error ("parameter %P has incomplete type %qT", i, type); 3458 } 3459 parmval = error_mark_node; 3460 } 3461 else 3462 { 3463 parmval = convert_for_initialization 3464 (NULL_TREE, type, val, flags, 3465 ICR_ARGPASS, fndecl, i, complain); 3466 parmval = convert_for_arg_passing (type, parmval); 3467 } 3468 3469 if (parmval == error_mark_node) 3470 return -1; 3471 3472 VEC_replace (tree, *values, i, parmval); 3473 } 3474 else 3475 { 3476 if (fndecl && DECL_BUILT_IN (fndecl) 3477 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P) 3478 /* Don't do ellipsis conversion for __built_in_constant_p 3479 as this will result in spurious errors for non-trivial 3480 types. */ 3481 val = require_complete_type_sfinae (val, complain); 3482 else 3483 val = convert_arg_to_ellipsis (val); 3484 3485 VEC_replace (tree, *values, i, val); 3486 } 3487 3488 if (typetail) 3489 typetail = TREE_CHAIN (typetail); 3490 } 3491 3492 if (typetail != 0 && typetail != void_list_node) 3493 { 3494 /* See if there are default arguments that can be used. Because 3495 we hold default arguments in the FUNCTION_TYPE (which is so 3496 wrong), we can see default parameters here from deduced 3497 contexts (and via typeof) for indirect function calls. 3498 Fortunately we know whether we have a function decl to 3499 provide default arguments in a language conformant 3500 manner. */ 3501 if (fndecl && TREE_PURPOSE (typetail) 3502 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG) 3503 { 3504 for (; typetail != void_list_node; ++i) 3505 { 3506 tree parmval 3507 = convert_default_arg (TREE_VALUE (typetail), 3508 TREE_PURPOSE (typetail), 3509 fndecl, i); 3510 3511 if (parmval == error_mark_node) 3512 return -1; 3513 3514 VEC_safe_push (tree, gc, *values, parmval); 3515 typetail = TREE_CHAIN (typetail); 3516 /* ends with `...'. */ 3517 if (typetail == NULL_TREE) 3518 break; 3519 } 3520 } 3521 else 3522 { 3523 if (complain & tf_error) 3524 warn_args_num (input_location, fndecl, /*too_many_p=*/false); 3525 return -1; 3526 } 3527 } 3528 3529 return (int) i; 3530 } 3531 3532 /* Build a binary-operation expression, after performing default 3533 conversions on the operands. CODE is the kind of expression to 3534 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE 3535 are the tree codes which correspond to ARG1 and ARG2 when issuing 3536 warnings about possibly misplaced parentheses. They may differ 3537 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant 3538 folding (e.g., if the parser sees "a | 1 + 1", it may call this 3539 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR). 3540 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or 3541 ARG2_CODE as ERROR_MARK. */ 3542 3543 tree 3544 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code, 3545 tree arg2, enum tree_code arg2_code, tree *overload, 3546 tsubst_flags_t complain) 3547 { 3548 tree orig_arg1; 3549 tree orig_arg2; 3550 tree expr; 3551 3552 orig_arg1 = arg1; 3553 orig_arg2 = arg2; 3554 3555 if (processing_template_decl) 3556 { 3557 if (type_dependent_expression_p (arg1) 3558 || type_dependent_expression_p (arg2)) 3559 return build_min_nt (code, arg1, arg2); 3560 arg1 = build_non_dependent_expr (arg1); 3561 arg2 = build_non_dependent_expr (arg2); 3562 } 3563 3564 if (code == DOTSTAR_EXPR) 3565 expr = build_m_component_ref (arg1, arg2); 3566 else 3567 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE, 3568 overload, complain); 3569 3570 /* Check for cases such as x+y<<z which users are likely to 3571 misinterpret. But don't warn about obj << x + y, since that is a 3572 common idiom for I/O. */ 3573 if (warn_parentheses 3574 && (complain & tf_warning) 3575 && !processing_template_decl 3576 && !error_operand_p (arg1) 3577 && !error_operand_p (arg2) 3578 && (code != LSHIFT_EXPR 3579 || !CLASS_TYPE_P (TREE_TYPE (arg1)))) 3580 warn_about_parentheses (code, arg1_code, orig_arg1, arg2_code, orig_arg2); 3581 3582 if (processing_template_decl && expr != error_mark_node) 3583 return build_min_non_dep (code, expr, orig_arg1, orig_arg2); 3584 3585 return expr; 3586 } 3587 3588 /* Build and return an ARRAY_REF expression. */ 3589 3590 tree 3591 build_x_array_ref (tree arg1, tree arg2, tsubst_flags_t complain) 3592 { 3593 tree orig_arg1 = arg1; 3594 tree orig_arg2 = arg2; 3595 tree expr; 3596 3597 if (processing_template_decl) 3598 { 3599 if (type_dependent_expression_p (arg1) 3600 || type_dependent_expression_p (arg2)) 3601 return build_min_nt (ARRAY_REF, arg1, arg2, 3602 NULL_TREE, NULL_TREE); 3603 arg1 = build_non_dependent_expr (arg1); 3604 arg2 = build_non_dependent_expr (arg2); 3605 } 3606 3607 expr = build_new_op (ARRAY_REF, LOOKUP_NORMAL, arg1, arg2, NULL_TREE, 3608 /*overload=*/NULL, complain); 3609 3610 if (processing_template_decl && expr != error_mark_node) 3611 return build_min_non_dep (ARRAY_REF, expr, orig_arg1, orig_arg2, 3612 NULL_TREE, NULL_TREE); 3613 return expr; 3614 } 3615 3616 /* Return whether OP is an expression of enum type cast to integer 3617 type. In C++ even unsigned enum types are cast to signed integer 3618 types. We do not want to issue warnings about comparisons between 3619 signed and unsigned types when one of the types is an enum type. 3620 Those warnings are always false positives in practice. */ 3621 3622 static bool 3623 enum_cast_to_int (tree op) 3624 { 3625 if (TREE_CODE (op) == NOP_EXPR 3626 && TREE_TYPE (op) == integer_type_node 3627 && TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == ENUMERAL_TYPE 3628 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 0)))) 3629 return true; 3630 3631 /* The cast may have been pushed into a COND_EXPR. */ 3632 if (TREE_CODE (op) == COND_EXPR) 3633 return (enum_cast_to_int (TREE_OPERAND (op, 1)) 3634 || enum_cast_to_int (TREE_OPERAND (op, 2))); 3635 3636 return false; 3637 } 3638 3639 /* For the c-common bits. */ 3640 tree 3641 build_binary_op (location_t location, enum tree_code code, tree op0, tree op1, 3642 int convert_p ATTRIBUTE_UNUSED) 3643 { 3644 return cp_build_binary_op (location, code, op0, op1, tf_warning_or_error); 3645 } 3646 3647 3648 /* Build a binary-operation expression without default conversions. 3649 CODE is the kind of expression to build. 3650 LOCATION is the location_t of the operator in the source code. 3651 This function differs from `build' in several ways: 3652 the data type of the result is computed and recorded in it, 3653 warnings are generated if arg data types are invalid, 3654 special handling for addition and subtraction of pointers is known, 3655 and some optimization is done (operations on narrow ints 3656 are done in the narrower type when that gives the same result). 3657 Constant folding is also done before the result is returned. 3658 3659 Note that the operands will never have enumeral types 3660 because either they have just had the default conversions performed 3661 or they have both just been converted to some other type in which 3662 the arithmetic is to be done. 3663 3664 C++: must do special pointer arithmetic when implementing 3665 multiple inheritance, and deal with pointer to member functions. */ 3666 3667 tree 3668 cp_build_binary_op (location_t location, 3669 enum tree_code code, tree orig_op0, tree orig_op1, 3670 tsubst_flags_t complain) 3671 { 3672 tree op0, op1; 3673 enum tree_code code0, code1; 3674 tree type0, type1; 3675 const char *invalid_op_diag; 3676 3677 /* Expression code to give to the expression when it is built. 3678 Normally this is CODE, which is what the caller asked for, 3679 but in some special cases we change it. */ 3680 enum tree_code resultcode = code; 3681 3682 /* Data type in which the computation is to be performed. 3683 In the simplest cases this is the common type of the arguments. */ 3684 tree result_type = NULL; 3685 3686 /* Nonzero means operands have already been type-converted 3687 in whatever way is necessary. 3688 Zero means they need to be converted to RESULT_TYPE. */ 3689 int converted = 0; 3690 3691 /* Nonzero means create the expression with this type, rather than 3692 RESULT_TYPE. */ 3693 tree build_type = 0; 3694 3695 /* Nonzero means after finally constructing the expression 3696 convert it to this type. */ 3697 tree final_type = 0; 3698 3699 tree result; 3700 3701 /* Nonzero if this is an operation like MIN or MAX which can 3702 safely be computed in short if both args are promoted shorts. 3703 Also implies COMMON. 3704 -1 indicates a bitwise operation; this makes a difference 3705 in the exact conditions for when it is safe to do the operation 3706 in a narrower mode. */ 3707 int shorten = 0; 3708 3709 /* Nonzero if this is a comparison operation; 3710 if both args are promoted shorts, compare the original shorts. 3711 Also implies COMMON. */ 3712 int short_compare = 0; 3713 3714 /* Nonzero means set RESULT_TYPE to the common type of the args. */ 3715 int common = 0; 3716 3717 /* True if both operands have arithmetic type. */ 3718 bool arithmetic_types_p; 3719 3720 /* Apply default conversions. */ 3721 op0 = orig_op0; 3722 op1 = orig_op1; 3723 3724 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR 3725 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR 3726 || code == TRUTH_XOR_EXPR) 3727 { 3728 if (!really_overloaded_fn (op0) && !VOID_TYPE_P (TREE_TYPE (op0))) 3729 op0 = decay_conversion (op0); 3730 if (!really_overloaded_fn (op1) && !VOID_TYPE_P (TREE_TYPE (op1))) 3731 op1 = decay_conversion (op1); 3732 } 3733 else 3734 { 3735 if (!really_overloaded_fn (op0) && !VOID_TYPE_P (TREE_TYPE (op0))) 3736 op0 = default_conversion (op0); 3737 if (!really_overloaded_fn (op1) && !VOID_TYPE_P (TREE_TYPE (op1))) 3738 op1 = default_conversion (op1); 3739 } 3740 3741 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ 3742 STRIP_TYPE_NOPS (op0); 3743 STRIP_TYPE_NOPS (op1); 3744 3745 /* DTRT if one side is an overloaded function, but complain about it. */ 3746 if (type_unknown_p (op0)) 3747 { 3748 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none); 3749 if (t != error_mark_node) 3750 { 3751 if (complain & tf_error) 3752 permerror (input_location, "assuming cast to type %qT from overloaded function", 3753 TREE_TYPE (t)); 3754 op0 = t; 3755 } 3756 } 3757 if (type_unknown_p (op1)) 3758 { 3759 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none); 3760 if (t != error_mark_node) 3761 { 3762 if (complain & tf_error) 3763 permerror (input_location, "assuming cast to type %qT from overloaded function", 3764 TREE_TYPE (t)); 3765 op1 = t; 3766 } 3767 } 3768 3769 type0 = TREE_TYPE (op0); 3770 type1 = TREE_TYPE (op1); 3771 3772 /* The expression codes of the data types of the arguments tell us 3773 whether the arguments are integers, floating, pointers, etc. */ 3774 code0 = TREE_CODE (type0); 3775 code1 = TREE_CODE (type1); 3776 3777 /* If an error was already reported for one of the arguments, 3778 avoid reporting another error. */ 3779 if (code0 == ERROR_MARK || code1 == ERROR_MARK) 3780 return error_mark_node; 3781 3782 if ((invalid_op_diag 3783 = targetm.invalid_binary_op (code, type0, type1))) 3784 { 3785 error (invalid_op_diag); 3786 return error_mark_node; 3787 } 3788 3789 /* Issue warnings about peculiar, but valid, uses of NULL. */ 3790 if ((orig_op0 == null_node || orig_op1 == null_node) 3791 /* It's reasonable to use pointer values as operands of && 3792 and ||, so NULL is no exception. */ 3793 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR 3794 && ( /* Both are NULL (or 0) and the operation was not a 3795 comparison or a pointer subtraction. */ 3796 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1) 3797 && code != EQ_EXPR && code != NE_EXPR && code != MINUS_EXPR) 3798 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */ 3799 || (!null_ptr_cst_p (orig_op0) 3800 && !TYPE_PTR_P (type0) && !TYPE_PTR_TO_MEMBER_P (type0)) 3801 || (!null_ptr_cst_p (orig_op1) 3802 && !TYPE_PTR_P (type1) && !TYPE_PTR_TO_MEMBER_P (type1))) 3803 && (complain & tf_warning)) 3804 /* Some sort of arithmetic operation involving NULL was 3805 performed. */ 3806 warning (OPT_Wpointer_arith, "NULL used in arithmetic"); 3807 3808 switch (code) 3809 { 3810 case MINUS_EXPR: 3811 /* Subtraction of two similar pointers. 3812 We must subtract them as integers, then divide by object size. */ 3813 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE 3814 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0), 3815 TREE_TYPE (type1))) 3816 return pointer_diff (op0, op1, common_pointer_type (type0, type1)); 3817 /* In all other cases except pointer - int, the usual arithmetic 3818 rules apply. */ 3819 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE)) 3820 { 3821 common = 1; 3822 break; 3823 } 3824 /* The pointer - int case is just like pointer + int; fall 3825 through. */ 3826 case PLUS_EXPR: 3827 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE) 3828 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE)) 3829 { 3830 tree ptr_operand; 3831 tree int_operand; 3832 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1); 3833 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1); 3834 if (processing_template_decl) 3835 { 3836 result_type = TREE_TYPE (ptr_operand); 3837 break; 3838 } 3839 return cp_pointer_int_sum (code, 3840 ptr_operand, 3841 int_operand); 3842 } 3843 common = 1; 3844 break; 3845 3846 case MULT_EXPR: 3847 common = 1; 3848 break; 3849 3850 case TRUNC_DIV_EXPR: 3851 case CEIL_DIV_EXPR: 3852 case FLOOR_DIV_EXPR: 3853 case ROUND_DIV_EXPR: 3854 case EXACT_DIV_EXPR: 3855 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 3856 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) 3857 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 3858 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) 3859 { 3860 enum tree_code tcode0 = code0, tcode1 = code1; 3861 3862 warn_for_div_by_zero (location, op1); 3863 3864 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE) 3865 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); 3866 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE) 3867 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); 3868 3869 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)) 3870 resultcode = RDIV_EXPR; 3871 else 3872 /* When dividing two signed integers, we have to promote to int. 3873 unless we divide by a constant != -1. Note that default 3874 conversion will have been performed on the operands at this 3875 point, so we have to dig out the original type to find out if 3876 it was unsigned. */ 3877 shorten = ((TREE_CODE (op0) == NOP_EXPR 3878 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0)))) 3879 || (TREE_CODE (op1) == INTEGER_CST 3880 && ! integer_all_onesp (op1))); 3881 3882 common = 1; 3883 } 3884 break; 3885 3886 case BIT_AND_EXPR: 3887 case BIT_IOR_EXPR: 3888 case BIT_XOR_EXPR: 3889 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 3890 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE 3891 && !VECTOR_FLOAT_TYPE_P (type0) 3892 && !VECTOR_FLOAT_TYPE_P (type1))) 3893 shorten = -1; 3894 break; 3895 3896 case TRUNC_MOD_EXPR: 3897 case FLOOR_MOD_EXPR: 3898 warn_for_div_by_zero (location, op1); 3899 3900 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE 3901 && TREE_CODE (TREE_TYPE (type0)) == INTEGER_TYPE 3902 && TREE_CODE (TREE_TYPE (type1)) == INTEGER_TYPE) 3903 common = 1; 3904 else if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 3905 { 3906 /* Although it would be tempting to shorten always here, that loses 3907 on some targets, since the modulo instruction is undefined if the 3908 quotient can't be represented in the computation mode. We shorten 3909 only if unsigned or if dividing by something we know != -1. */ 3910 shorten = ((TREE_CODE (op0) == NOP_EXPR 3911 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0)))) 3912 || (TREE_CODE (op1) == INTEGER_CST 3913 && ! integer_all_onesp (op1))); 3914 common = 1; 3915 } 3916 break; 3917 3918 case TRUTH_ANDIF_EXPR: 3919 case TRUTH_ORIF_EXPR: 3920 case TRUTH_AND_EXPR: 3921 case TRUTH_OR_EXPR: 3922 result_type = boolean_type_node; 3923 break; 3924 3925 /* Shift operations: result has same type as first operand; 3926 always convert second operand to int. 3927 Also set SHORT_SHIFT if shifting rightward. */ 3928 3929 case RSHIFT_EXPR: 3930 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 3931 { 3932 result_type = type0; 3933 if (TREE_CODE (op1) == INTEGER_CST) 3934 { 3935 if (tree_int_cst_lt (op1, integer_zero_node)) 3936 { 3937 if ((complain & tf_warning) 3938 && c_inhibit_evaluation_warnings == 0) 3939 warning (0, "right shift count is negative"); 3940 } 3941 else 3942 { 3943 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0 3944 && (complain & tf_warning) 3945 && c_inhibit_evaluation_warnings == 0) 3946 warning (0, "right shift count >= width of type"); 3947 } 3948 } 3949 /* Convert the shift-count to an integer, regardless of 3950 size of value being shifted. */ 3951 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 3952 op1 = cp_convert (integer_type_node, op1); 3953 /* Avoid converting op1 to result_type later. */ 3954 converted = 1; 3955 } 3956 break; 3957 3958 case LSHIFT_EXPR: 3959 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 3960 { 3961 result_type = type0; 3962 if (TREE_CODE (op1) == INTEGER_CST) 3963 { 3964 if (tree_int_cst_lt (op1, integer_zero_node)) 3965 { 3966 if ((complain & tf_warning) 3967 && c_inhibit_evaluation_warnings == 0) 3968 warning (0, "left shift count is negative"); 3969 } 3970 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 3971 { 3972 if ((complain & tf_warning) 3973 && c_inhibit_evaluation_warnings == 0) 3974 warning (0, "left shift count >= width of type"); 3975 } 3976 } 3977 /* Convert the shift-count to an integer, regardless of 3978 size of value being shifted. */ 3979 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 3980 op1 = cp_convert (integer_type_node, op1); 3981 /* Avoid converting op1 to result_type later. */ 3982 converted = 1; 3983 } 3984 break; 3985 3986 case RROTATE_EXPR: 3987 case LROTATE_EXPR: 3988 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) 3989 { 3990 result_type = type0; 3991 if (TREE_CODE (op1) == INTEGER_CST) 3992 { 3993 if (tree_int_cst_lt (op1, integer_zero_node)) 3994 { 3995 if (complain & tf_warning) 3996 warning (0, (code == LROTATE_EXPR) 3997 ? G_("left rotate count is negative") 3998 : G_("right rotate count is negative")); 3999 } 4000 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) 4001 { 4002 if (complain & tf_warning) 4003 warning (0, (code == LROTATE_EXPR) 4004 ? G_("left rotate count >= width of type") 4005 : G_("right rotate count >= width of type")); 4006 } 4007 } 4008 /* Convert the shift-count to an integer, regardless of 4009 size of value being shifted. */ 4010 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) 4011 op1 = cp_convert (integer_type_node, op1); 4012 } 4013 break; 4014 4015 case EQ_EXPR: 4016 case NE_EXPR: 4017 if ((complain & tf_warning) 4018 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1))) 4019 warning (OPT_Wfloat_equal, 4020 "comparing floating point with == or != is unsafe"); 4021 if ((complain & tf_warning) 4022 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1)) 4023 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))) 4024 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour"); 4025 4026 build_type = boolean_type_node; 4027 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 4028 || code0 == COMPLEX_TYPE || code0 == ENUMERAL_TYPE) 4029 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 4030 || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE)) 4031 short_compare = 1; 4032 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE) 4033 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1))) 4034 result_type = composite_pointer_type (type0, type1, op0, op1, 4035 CPO_COMPARISON, complain); 4036 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0)) 4037 && null_ptr_cst_p (op1)) 4038 { 4039 if (TREE_CODE (op0) == ADDR_EXPR 4040 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0))) 4041 { 4042 if (complain & tf_warning) 4043 warning (OPT_Waddress, "the address of %qD will never be NULL", 4044 TREE_OPERAND (op0, 0)); 4045 } 4046 result_type = type0; 4047 } 4048 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1)) 4049 && null_ptr_cst_p (op0)) 4050 { 4051 if (TREE_CODE (op1) == ADDR_EXPR 4052 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0))) 4053 { 4054 if (complain & tf_warning) 4055 warning (OPT_Waddress, "the address of %qD will never be NULL", 4056 TREE_OPERAND (op1, 0)); 4057 } 4058 result_type = type1; 4059 } 4060 else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1)) 4061 /* One of the operands must be of nullptr_t type. */ 4062 result_type = TREE_TYPE (nullptr_node); 4063 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 4064 { 4065 result_type = type0; 4066 if (complain & tf_error) 4067 permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); 4068 else 4069 return error_mark_node; 4070 } 4071 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 4072 { 4073 result_type = type1; 4074 if (complain & tf_error) 4075 permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); 4076 else 4077 return error_mark_node; 4078 } 4079 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1)) 4080 { 4081 if (TARGET_PTRMEMFUNC_VBIT_LOCATION 4082 == ptrmemfunc_vbit_in_delta) 4083 { 4084 tree pfn0 = pfn_from_ptrmemfunc (op0); 4085 tree delta0 = delta_from_ptrmemfunc (op0); 4086 tree e1 = cp_build_binary_op (location, 4087 EQ_EXPR, 4088 pfn0, 4089 build_zero_cst (TREE_TYPE (pfn0)), 4090 complain); 4091 tree e2 = cp_build_binary_op (location, 4092 BIT_AND_EXPR, 4093 delta0, 4094 integer_one_node, 4095 complain); 4096 4097 if ((complain & tf_warning) 4098 && c_inhibit_evaluation_warnings == 0 4099 && !NULLPTR_TYPE_P (TREE_TYPE (op1))) 4100 warning (OPT_Wzero_as_null_pointer_constant, 4101 "zero as null pointer constant"); 4102 4103 e2 = cp_build_binary_op (location, 4104 EQ_EXPR, e2, integer_zero_node, 4105 complain); 4106 op0 = cp_build_binary_op (location, 4107 TRUTH_ANDIF_EXPR, e1, e2, 4108 complain); 4109 op1 = cp_convert (TREE_TYPE (op0), integer_one_node); 4110 } 4111 else 4112 { 4113 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier); 4114 op1 = cp_convert (TREE_TYPE (op0), op1); 4115 } 4116 result_type = TREE_TYPE (op0); 4117 } 4118 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0)) 4119 return cp_build_binary_op (location, code, op1, op0, complain); 4120 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)) 4121 { 4122 tree type; 4123 /* E will be the final comparison. */ 4124 tree e; 4125 /* E1 and E2 are for scratch. */ 4126 tree e1; 4127 tree e2; 4128 tree pfn0; 4129 tree pfn1; 4130 tree delta0; 4131 tree delta1; 4132 4133 type = composite_pointer_type (type0, type1, op0, op1, 4134 CPO_COMPARISON, complain); 4135 4136 if (!same_type_p (TREE_TYPE (op0), type)) 4137 op0 = cp_convert_and_check (type, op0); 4138 if (!same_type_p (TREE_TYPE (op1), type)) 4139 op1 = cp_convert_and_check (type, op1); 4140 4141 if (op0 == error_mark_node || op1 == error_mark_node) 4142 return error_mark_node; 4143 4144 if (TREE_SIDE_EFFECTS (op0)) 4145 op0 = save_expr (op0); 4146 if (TREE_SIDE_EFFECTS (op1)) 4147 op1 = save_expr (op1); 4148 4149 pfn0 = pfn_from_ptrmemfunc (op0); 4150 pfn1 = pfn_from_ptrmemfunc (op1); 4151 delta0 = delta_from_ptrmemfunc (op0); 4152 delta1 = delta_from_ptrmemfunc (op1); 4153 if (TARGET_PTRMEMFUNC_VBIT_LOCATION 4154 == ptrmemfunc_vbit_in_delta) 4155 { 4156 /* We generate: 4157 4158 (op0.pfn == op1.pfn 4159 && ((op0.delta == op1.delta) 4160 || (!op0.pfn && op0.delta & 1 == 0 4161 && op1.delta & 1 == 0)) 4162 4163 The reason for the `!op0.pfn' bit is that a NULL 4164 pointer-to-member is any member with a zero PFN and 4165 LSB of the DELTA field is 0. */ 4166 4167 e1 = cp_build_binary_op (location, BIT_AND_EXPR, 4168 delta0, 4169 integer_one_node, 4170 complain); 4171 e1 = cp_build_binary_op (location, 4172 EQ_EXPR, e1, integer_zero_node, 4173 complain); 4174 e2 = cp_build_binary_op (location, BIT_AND_EXPR, 4175 delta1, 4176 integer_one_node, 4177 complain); 4178 e2 = cp_build_binary_op (location, 4179 EQ_EXPR, e2, integer_zero_node, 4180 complain); 4181 e1 = cp_build_binary_op (location, 4182 TRUTH_ANDIF_EXPR, e2, e1, 4183 complain); 4184 e2 = cp_build_binary_op (location, EQ_EXPR, 4185 pfn0, 4186 build_zero_cst (TREE_TYPE (pfn0)), 4187 complain); 4188 e2 = cp_build_binary_op (location, 4189 TRUTH_ANDIF_EXPR, e2, e1, complain); 4190 e1 = cp_build_binary_op (location, 4191 EQ_EXPR, delta0, delta1, complain); 4192 e1 = cp_build_binary_op (location, 4193 TRUTH_ORIF_EXPR, e1, e2, complain); 4194 } 4195 else 4196 { 4197 /* We generate: 4198 4199 (op0.pfn == op1.pfn 4200 && (!op0.pfn || op0.delta == op1.delta)) 4201 4202 The reason for the `!op0.pfn' bit is that a NULL 4203 pointer-to-member is any member with a zero PFN; the 4204 DELTA field is unspecified. */ 4205 4206 e1 = cp_build_binary_op (location, 4207 EQ_EXPR, delta0, delta1, complain); 4208 e2 = cp_build_binary_op (location, 4209 EQ_EXPR, 4210 pfn0, 4211 build_zero_cst (TREE_TYPE (pfn0)), 4212 complain); 4213 e1 = cp_build_binary_op (location, 4214 TRUTH_ORIF_EXPR, e1, e2, complain); 4215 } 4216 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1); 4217 e = cp_build_binary_op (location, 4218 TRUTH_ANDIF_EXPR, e2, e1, complain); 4219 if (code == EQ_EXPR) 4220 return e; 4221 return cp_build_binary_op (location, 4222 EQ_EXPR, e, integer_zero_node, complain); 4223 } 4224 else 4225 { 4226 gcc_assert (!TYPE_PTRMEMFUNC_P (type0) 4227 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), 4228 type1)); 4229 gcc_assert (!TYPE_PTRMEMFUNC_P (type1) 4230 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), 4231 type0)); 4232 } 4233 4234 break; 4235 4236 case MAX_EXPR: 4237 case MIN_EXPR: 4238 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) 4239 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) 4240 shorten = 1; 4241 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 4242 result_type = composite_pointer_type (type0, type1, op0, op1, 4243 CPO_COMPARISON, complain); 4244 break; 4245 4246 case LE_EXPR: 4247 case GE_EXPR: 4248 case LT_EXPR: 4249 case GT_EXPR: 4250 if (TREE_CODE (orig_op0) == STRING_CST 4251 || TREE_CODE (orig_op1) == STRING_CST) 4252 { 4253 if (complain & tf_warning) 4254 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour"); 4255 } 4256 4257 build_type = boolean_type_node; 4258 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE 4259 || code0 == ENUMERAL_TYPE) 4260 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 4261 || code1 == ENUMERAL_TYPE)) 4262 short_compare = 1; 4263 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) 4264 result_type = composite_pointer_type (type0, type1, op0, op1, 4265 CPO_COMPARISON, complain); 4266 else if (code0 == POINTER_TYPE && null_ptr_cst_p (op1)) 4267 { 4268 result_type = type0; 4269 if (extra_warnings && (complain & tf_warning)) 4270 warning (OPT_Wextra, 4271 "ordered comparison of pointer with integer zero"); 4272 } 4273 else if (code1 == POINTER_TYPE && null_ptr_cst_p (op0)) 4274 { 4275 result_type = type1; 4276 if (extra_warnings && (complain & tf_warning)) 4277 warning (OPT_Wextra, 4278 "ordered comparison of pointer with integer zero"); 4279 } 4280 else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1)) 4281 /* One of the operands must be of nullptr_t type. */ 4282 result_type = TREE_TYPE (nullptr_node); 4283 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) 4284 { 4285 result_type = type0; 4286 if (complain & tf_error) 4287 permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); 4288 else 4289 return error_mark_node; 4290 } 4291 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) 4292 { 4293 result_type = type1; 4294 if (complain & tf_error) 4295 permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); 4296 else 4297 return error_mark_node; 4298 } 4299 break; 4300 4301 case UNORDERED_EXPR: 4302 case ORDERED_EXPR: 4303 case UNLT_EXPR: 4304 case UNLE_EXPR: 4305 case UNGT_EXPR: 4306 case UNGE_EXPR: 4307 case UNEQ_EXPR: 4308 build_type = integer_type_node; 4309 if (code0 != REAL_TYPE || code1 != REAL_TYPE) 4310 { 4311 if (complain & tf_error) 4312 error ("unordered comparison on non-floating point argument"); 4313 return error_mark_node; 4314 } 4315 common = 1; 4316 break; 4317 4318 default: 4319 break; 4320 } 4321 4322 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE 4323 || code0 == ENUMERAL_TYPE) 4324 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE 4325 || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE))) 4326 arithmetic_types_p = 1; 4327 else 4328 { 4329 arithmetic_types_p = 0; 4330 /* Vector arithmetic is only allowed when both sides are vectors. */ 4331 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) 4332 { 4333 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)) 4334 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0), 4335 TREE_TYPE (type1))) 4336 { 4337 binary_op_error (location, code, type0, type1); 4338 return error_mark_node; 4339 } 4340 arithmetic_types_p = 1; 4341 } 4342 } 4343 /* Determine the RESULT_TYPE, if it is not already known. */ 4344 if (!result_type 4345 && arithmetic_types_p 4346 && (shorten || common || short_compare)) 4347 { 4348 result_type = cp_common_type (type0, type1); 4349 do_warn_double_promotion (result_type, type0, type1, 4350 "implicit conversion from %qT to %qT " 4351 "to match other operand of binary " 4352 "expression", 4353 location); 4354 } 4355 4356 if (!result_type) 4357 { 4358 if (complain & tf_error) 4359 error ("invalid operands of types %qT and %qT to binary %qO", 4360 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code); 4361 return error_mark_node; 4362 } 4363 4364 /* If we're in a template, the only thing we need to know is the 4365 RESULT_TYPE. */ 4366 if (processing_template_decl) 4367 { 4368 /* Since the middle-end checks the type when doing a build2, we 4369 need to build the tree in pieces. This built tree will never 4370 get out of the front-end as we replace it when instantiating 4371 the template. */ 4372 tree tmp = build2 (resultcode, 4373 build_type ? build_type : result_type, 4374 NULL_TREE, op1); 4375 TREE_OPERAND (tmp, 0) = op0; 4376 return tmp; 4377 } 4378 4379 if (arithmetic_types_p) 4380 { 4381 bool first_complex = (code0 == COMPLEX_TYPE); 4382 bool second_complex = (code1 == COMPLEX_TYPE); 4383 int none_complex = (!first_complex && !second_complex); 4384 4385 /* Adapted from patch for c/24581. */ 4386 if (first_complex != second_complex 4387 && (code == PLUS_EXPR 4388 || code == MINUS_EXPR 4389 || code == MULT_EXPR 4390 || (code == TRUNC_DIV_EXPR && first_complex)) 4391 && TREE_CODE (TREE_TYPE (result_type)) == REAL_TYPE 4392 && flag_signed_zeros) 4393 { 4394 /* An operation on mixed real/complex operands must be 4395 handled specially, but the language-independent code can 4396 more easily optimize the plain complex arithmetic if 4397 -fno-signed-zeros. */ 4398 tree real_type = TREE_TYPE (result_type); 4399 tree real, imag; 4400 if (first_complex) 4401 { 4402 if (TREE_TYPE (op0) != result_type) 4403 op0 = cp_convert_and_check (result_type, op0); 4404 if (TREE_TYPE (op1) != real_type) 4405 op1 = cp_convert_and_check (real_type, op1); 4406 } 4407 else 4408 { 4409 if (TREE_TYPE (op0) != real_type) 4410 op0 = cp_convert_and_check (real_type, op0); 4411 if (TREE_TYPE (op1) != result_type) 4412 op1 = cp_convert_and_check (result_type, op1); 4413 } 4414 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) 4415 return error_mark_node; 4416 if (first_complex) 4417 { 4418 op0 = save_expr (op0); 4419 real = cp_build_unary_op (REALPART_EXPR, op0, 1, complain); 4420 imag = cp_build_unary_op (IMAGPART_EXPR, op0, 1, complain); 4421 switch (code) 4422 { 4423 case MULT_EXPR: 4424 case TRUNC_DIV_EXPR: 4425 op1 = save_expr (op1); 4426 imag = build2 (resultcode, real_type, imag, op1); 4427 /* Fall through. */ 4428 case PLUS_EXPR: 4429 case MINUS_EXPR: 4430 real = build2 (resultcode, real_type, real, op1); 4431 break; 4432 default: 4433 gcc_unreachable(); 4434 } 4435 } 4436 else 4437 { 4438 op1 = save_expr (op1); 4439 real = cp_build_unary_op (REALPART_EXPR, op1, 1, complain); 4440 imag = cp_build_unary_op (IMAGPART_EXPR, op1, 1, complain); 4441 switch (code) 4442 { 4443 case MULT_EXPR: 4444 op0 = save_expr (op0); 4445 imag = build2 (resultcode, real_type, op0, imag); 4446 /* Fall through. */ 4447 case PLUS_EXPR: 4448 real = build2 (resultcode, real_type, op0, real); 4449 break; 4450 case MINUS_EXPR: 4451 real = build2 (resultcode, real_type, op0, real); 4452 imag = build1 (NEGATE_EXPR, real_type, imag); 4453 break; 4454 default: 4455 gcc_unreachable(); 4456 } 4457 } 4458 real = fold_if_not_in_template (real); 4459 imag = fold_if_not_in_template (imag); 4460 result = build2 (COMPLEX_EXPR, result_type, real, imag); 4461 result = fold_if_not_in_template (result); 4462 return result; 4463 } 4464 4465 /* For certain operations (which identify themselves by shorten != 0) 4466 if both args were extended from the same smaller type, 4467 do the arithmetic in that type and then extend. 4468 4469 shorten !=0 and !=1 indicates a bitwise operation. 4470 For them, this optimization is safe only if 4471 both args are zero-extended or both are sign-extended. 4472 Otherwise, we might change the result. 4473 E.g., (short)-1 | (unsigned short)-1 is (int)-1 4474 but calculated in (unsigned short) it would be (unsigned short)-1. */ 4475 4476 if (shorten && none_complex) 4477 { 4478 final_type = result_type; 4479 result_type = shorten_binary_op (result_type, op0, op1, 4480 shorten == -1); 4481 } 4482 4483 /* Comparison operations are shortened too but differently. 4484 They identify themselves by setting short_compare = 1. */ 4485 4486 if (short_compare) 4487 { 4488 /* Don't write &op0, etc., because that would prevent op0 4489 from being kept in a register. 4490 Instead, make copies of the our local variables and 4491 pass the copies by reference, then copy them back afterward. */ 4492 tree xop0 = op0, xop1 = op1, xresult_type = result_type; 4493 enum tree_code xresultcode = resultcode; 4494 tree val 4495 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); 4496 if (val != 0) 4497 return cp_convert (boolean_type_node, val); 4498 op0 = xop0, op1 = xop1; 4499 converted = 1; 4500 resultcode = xresultcode; 4501 } 4502 4503 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR) 4504 && warn_sign_compare 4505 /* Do not warn until the template is instantiated; we cannot 4506 bound the ranges of the arguments until that point. */ 4507 && !processing_template_decl 4508 && (complain & tf_warning) 4509 && c_inhibit_evaluation_warnings == 0 4510 /* Even unsigned enum types promote to signed int. We don't 4511 want to issue -Wsign-compare warnings for this case. */ 4512 && !enum_cast_to_int (orig_op0) 4513 && !enum_cast_to_int (orig_op1)) 4514 { 4515 warn_for_sign_compare (location, orig_op0, orig_op1, op0, op1, 4516 result_type, resultcode); 4517 } 4518 } 4519 4520 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE. 4521 Then the expression will be built. 4522 It will be given type FINAL_TYPE if that is nonzero; 4523 otherwise, it will be given type RESULT_TYPE. */ 4524 if (! converted) 4525 { 4526 if (TREE_TYPE (op0) != result_type) 4527 op0 = cp_convert_and_check (result_type, op0); 4528 if (TREE_TYPE (op1) != result_type) 4529 op1 = cp_convert_and_check (result_type, op1); 4530 4531 if (op0 == error_mark_node || op1 == error_mark_node) 4532 return error_mark_node; 4533 } 4534 4535 if (build_type == NULL_TREE) 4536 build_type = result_type; 4537 4538 result = build2 (resultcode, build_type, op0, op1); 4539 result = fold_if_not_in_template (result); 4540 if (final_type != 0) 4541 result = cp_convert (final_type, result); 4542 4543 if (TREE_OVERFLOW_P (result) 4544 && !TREE_OVERFLOW_P (op0) 4545 && !TREE_OVERFLOW_P (op1)) 4546 overflow_warning (location, result); 4547 4548 return result; 4549 } 4550 4551 /* Return a tree for the sum or difference (RESULTCODE says which) 4552 of pointer PTROP and integer INTOP. */ 4553 4554 static tree 4555 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop) 4556 { 4557 tree res_type = TREE_TYPE (ptrop); 4558 4559 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type) 4560 in certain circumstance (when it's valid to do so). So we need 4561 to make sure it's complete. We don't need to check here, if we 4562 can actually complete it at all, as those checks will be done in 4563 pointer_int_sum() anyway. */ 4564 complete_type (TREE_TYPE (res_type)); 4565 4566 return pointer_int_sum (input_location, resultcode, ptrop, 4567 fold_if_not_in_template (intop)); 4568 } 4569 4570 /* Return a tree for the difference of pointers OP0 and OP1. 4571 The resulting tree has type int. */ 4572 4573 static tree 4574 pointer_diff (tree op0, tree op1, tree ptrtype) 4575 { 4576 tree result; 4577 tree restype = ptrdiff_type_node; 4578 tree target_type = TREE_TYPE (ptrtype); 4579 4580 if (!complete_type_or_else (target_type, NULL_TREE)) 4581 return error_mark_node; 4582 4583 if (TREE_CODE (target_type) == VOID_TYPE) 4584 permerror (input_location, "ISO C++ forbids using pointer of type %<void *%> in subtraction"); 4585 if (TREE_CODE (target_type) == FUNCTION_TYPE) 4586 permerror (input_location, "ISO C++ forbids using pointer to a function in subtraction"); 4587 if (TREE_CODE (target_type) == METHOD_TYPE) 4588 permerror (input_location, "ISO C++ forbids using pointer to a method in subtraction"); 4589 4590 /* First do the subtraction as integers; 4591 then drop through to build the divide operator. */ 4592 4593 op0 = cp_build_binary_op (input_location, 4594 MINUS_EXPR, 4595 cp_convert (restype, op0), 4596 cp_convert (restype, op1), 4597 tf_warning_or_error); 4598 4599 /* This generates an error if op1 is a pointer to an incomplete type. */ 4600 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1)))) 4601 error ("invalid use of a pointer to an incomplete type in pointer arithmetic"); 4602 4603 op1 = (TYPE_PTROB_P (ptrtype) 4604 ? size_in_bytes (target_type) 4605 : integer_one_node); 4606 4607 /* Do the division. */ 4608 4609 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1)); 4610 return fold_if_not_in_template (result); 4611 } 4612 4613 /* Construct and perhaps optimize a tree representation 4614 for a unary operation. CODE, a tree_code, specifies the operation 4615 and XARG is the operand. */ 4616 4617 tree 4618 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain) 4619 { 4620 tree orig_expr = xarg; 4621 tree exp; 4622 int ptrmem = 0; 4623 4624 if (processing_template_decl) 4625 { 4626 if (type_dependent_expression_p (xarg)) 4627 return build_min_nt (code, xarg, NULL_TREE); 4628 4629 xarg = build_non_dependent_expr (xarg); 4630 } 4631 4632 exp = NULL_TREE; 4633 4634 /* [expr.unary.op] says: 4635 4636 The address of an object of incomplete type can be taken. 4637 4638 (And is just the ordinary address operator, not an overloaded 4639 "operator &".) However, if the type is a template 4640 specialization, we must complete the type at this point so that 4641 an overloaded "operator &" will be available if required. */ 4642 if (code == ADDR_EXPR 4643 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR 4644 && ((CLASS_TYPE_P (TREE_TYPE (xarg)) 4645 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg)))) 4646 || (TREE_CODE (xarg) == OFFSET_REF))) 4647 /* Don't look for a function. */; 4648 else 4649 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE, 4650 /*overload=*/NULL, complain); 4651 if (!exp && code == ADDR_EXPR) 4652 { 4653 if (is_overloaded_fn (xarg)) 4654 { 4655 tree fn = get_first_fn (xarg); 4656 if (DECL_CONSTRUCTOR_P (fn) || DECL_DESTRUCTOR_P (fn)) 4657 { 4658 error (DECL_CONSTRUCTOR_P (fn) 4659 ? G_("taking address of constructor %qE") 4660 : G_("taking address of destructor %qE"), 4661 xarg); 4662 return error_mark_node; 4663 } 4664 } 4665 4666 /* A pointer to member-function can be formed only by saying 4667 &X::mf. */ 4668 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE 4669 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg))) 4670 { 4671 if (TREE_CODE (xarg) != OFFSET_REF 4672 || !TYPE_P (TREE_OPERAND (xarg, 0))) 4673 { 4674 error ("invalid use of %qE to form a pointer-to-member-function", 4675 xarg); 4676 if (TREE_CODE (xarg) != OFFSET_REF) 4677 inform (input_location, " a qualified-id is required"); 4678 return error_mark_node; 4679 } 4680 else 4681 { 4682 error ("parentheses around %qE cannot be used to form a" 4683 " pointer-to-member-function", 4684 xarg); 4685 PTRMEM_OK_P (xarg) = 1; 4686 } 4687 } 4688 4689 if (TREE_CODE (xarg) == OFFSET_REF) 4690 { 4691 ptrmem = PTRMEM_OK_P (xarg); 4692 4693 if (!ptrmem && !flag_ms_extensions 4694 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE) 4695 { 4696 /* A single non-static member, make sure we don't allow a 4697 pointer-to-member. */ 4698 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg), 4699 TREE_OPERAND (xarg, 0), 4700 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE)); 4701 PTRMEM_OK_P (xarg) = ptrmem; 4702 } 4703 } 4704 4705 exp = cp_build_addr_expr_strict (xarg, complain); 4706 } 4707 4708 if (processing_template_decl && exp != error_mark_node) 4709 exp = build_min_non_dep (code, exp, orig_expr, 4710 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE); 4711 if (TREE_CODE (exp) == ADDR_EXPR) 4712 PTRMEM_OK_P (exp) = ptrmem; 4713 return exp; 4714 } 4715 4716 /* Like c_common_truthvalue_conversion, but handle pointer-to-member 4717 constants, where a null value is represented by an INTEGER_CST of 4718 -1. */ 4719 4720 tree 4721 cp_truthvalue_conversion (tree expr) 4722 { 4723 tree type = TREE_TYPE (expr); 4724 if (TYPE_PTRMEM_P (type)) 4725 return build_binary_op (EXPR_LOCATION (expr), 4726 NE_EXPR, expr, nullptr_node, 1); 4727 else if (TYPE_PTR_P (type) || TYPE_PTRMEMFUNC_P (type)) 4728 { 4729 /* With -Wzero-as-null-pointer-constant do not warn for an 4730 'if (p)' or a 'while (!p)', where p is a pointer. */ 4731 tree ret; 4732 ++c_inhibit_evaluation_warnings; 4733 ret = c_common_truthvalue_conversion (input_location, expr); 4734 --c_inhibit_evaluation_warnings; 4735 return ret; 4736 } 4737 else 4738 return c_common_truthvalue_conversion (input_location, expr); 4739 } 4740 4741 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */ 4742 4743 tree 4744 condition_conversion (tree expr) 4745 { 4746 tree t; 4747 if (processing_template_decl) 4748 return expr; 4749 t = perform_implicit_conversion_flags (boolean_type_node, expr, 4750 tf_warning_or_error, LOOKUP_NORMAL); 4751 t = fold_build_cleanup_point_expr (boolean_type_node, t); 4752 return t; 4753 } 4754 4755 /* Returns the address of T. This function will fold away 4756 ADDR_EXPR of INDIRECT_REF. */ 4757 4758 tree 4759 build_address (tree t) 4760 { 4761 if (error_operand_p (t) || !cxx_mark_addressable (t)) 4762 return error_mark_node; 4763 t = build_fold_addr_expr (t); 4764 if (TREE_CODE (t) != ADDR_EXPR) 4765 t = rvalue (t); 4766 return t; 4767 } 4768 4769 /* Returns the address of T with type TYPE. */ 4770 4771 tree 4772 build_typed_address (tree t, tree type) 4773 { 4774 if (error_operand_p (t) || !cxx_mark_addressable (t)) 4775 return error_mark_node; 4776 t = build_fold_addr_expr_with_type (t, type); 4777 if (TREE_CODE (t) != ADDR_EXPR) 4778 t = rvalue (t); 4779 return t; 4780 } 4781 4782 /* Return a NOP_EXPR converting EXPR to TYPE. */ 4783 4784 tree 4785 build_nop (tree type, tree expr) 4786 { 4787 if (type == error_mark_node || error_operand_p (expr)) 4788 return expr; 4789 return build1 (NOP_EXPR, type, expr); 4790 } 4791 4792 /* Take the address of ARG, whatever that means under C++ semantics. 4793 If STRICT_LVALUE is true, require an lvalue; otherwise, allow xvalues 4794 and class rvalues as well. 4795 4796 Nothing should call this function directly; instead, callers should use 4797 cp_build_addr_expr or cp_build_addr_expr_strict. */ 4798 4799 static tree 4800 cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain) 4801 { 4802 tree argtype; 4803 tree val; 4804 4805 if (!arg || error_operand_p (arg)) 4806 return error_mark_node; 4807 4808 arg = mark_lvalue_use (arg); 4809 argtype = lvalue_type (arg); 4810 4811 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE 4812 || !IDENTIFIER_OPNAME_P (arg)); 4813 4814 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg) 4815 && !really_overloaded_fn (TREE_OPERAND (arg, 1))) 4816 { 4817 /* They're trying to take the address of a unique non-static 4818 member function. This is ill-formed (except in MS-land), 4819 but let's try to DTRT. 4820 Note: We only handle unique functions here because we don't 4821 want to complain if there's a static overload; non-unique 4822 cases will be handled by instantiate_type. But we need to 4823 handle this case here to allow casts on the resulting PMF. 4824 We could defer this in non-MS mode, but it's easier to give 4825 a useful error here. */ 4826 4827 /* Inside constant member functions, the `this' pointer 4828 contains an extra const qualifier. TYPE_MAIN_VARIANT 4829 is used here to remove this const from the diagnostics 4830 and the created OFFSET_REF. */ 4831 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0))); 4832 tree fn = get_first_fn (TREE_OPERAND (arg, 1)); 4833 mark_used (fn); 4834 4835 if (! flag_ms_extensions) 4836 { 4837 tree name = DECL_NAME (fn); 4838 if (!(complain & tf_error)) 4839 return error_mark_node; 4840 else if (current_class_type 4841 && TREE_OPERAND (arg, 0) == current_class_ref) 4842 /* An expression like &memfn. */ 4843 permerror (input_location, "ISO C++ forbids taking the address of an unqualified" 4844 " or parenthesized non-static member function to form" 4845 " a pointer to member function. Say %<&%T::%D%>", 4846 base, name); 4847 else 4848 permerror (input_location, "ISO C++ forbids taking the address of a bound member" 4849 " function to form a pointer to member function." 4850 " Say %<&%T::%D%>", 4851 base, name); 4852 } 4853 arg = build_offset_ref (base, fn, /*address_p=*/true); 4854 } 4855 4856 /* Uninstantiated types are all functions. Taking the 4857 address of a function is a no-op, so just return the 4858 argument. */ 4859 if (type_unknown_p (arg)) 4860 return build1 (ADDR_EXPR, unknown_type_node, arg); 4861 4862 if (TREE_CODE (arg) == OFFSET_REF) 4863 /* We want a pointer to member; bypass all the code for actually taking 4864 the address of something. */ 4865 goto offset_ref; 4866 4867 /* Anything not already handled and not a true memory reference 4868 is an error. */ 4869 if (TREE_CODE (argtype) != FUNCTION_TYPE 4870 && TREE_CODE (argtype) != METHOD_TYPE) 4871 { 4872 cp_lvalue_kind kind = lvalue_kind (arg); 4873 if (kind == clk_none) 4874 { 4875 if (complain & tf_error) 4876 lvalue_error (input_location, lv_addressof); 4877 return error_mark_node; 4878 } 4879 if (strict_lvalue && (kind & (clk_rvalueref|clk_class))) 4880 { 4881 if (!(complain & tf_error)) 4882 return error_mark_node; 4883 if (kind & clk_class) 4884 /* Make this a permerror because we used to accept it. */ 4885 permerror (input_location, "taking address of temporary"); 4886 else 4887 error ("taking address of xvalue (rvalue reference)"); 4888 } 4889 } 4890 4891 if (TREE_CODE (argtype) == REFERENCE_TYPE) 4892 { 4893 tree type = build_pointer_type (TREE_TYPE (argtype)); 4894 arg = build1 (CONVERT_EXPR, type, arg); 4895 return arg; 4896 } 4897 else if (pedantic && DECL_MAIN_P (arg)) 4898 { 4899 /* ARM $3.4 */ 4900 /* Apparently a lot of autoconf scripts for C++ packages do this, 4901 so only complain if -pedantic. */ 4902 if (complain & (flag_pedantic_errors ? tf_error : tf_warning)) 4903 pedwarn (input_location, OPT_pedantic, 4904 "ISO C++ forbids taking address of function %<::main%>"); 4905 else if (flag_pedantic_errors) 4906 return error_mark_node; 4907 } 4908 4909 /* Let &* cancel out to simplify resulting code. */ 4910 if (TREE_CODE (arg) == INDIRECT_REF) 4911 { 4912 /* We don't need to have `current_class_ptr' wrapped in a 4913 NON_LVALUE_EXPR node. */ 4914 if (arg == current_class_ref) 4915 return current_class_ptr; 4916 4917 arg = TREE_OPERAND (arg, 0); 4918 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE) 4919 { 4920 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg))); 4921 arg = build1 (CONVERT_EXPR, type, arg); 4922 } 4923 else 4924 /* Don't let this be an lvalue. */ 4925 arg = rvalue (arg); 4926 return arg; 4927 } 4928 4929 /* ??? Cope with user tricks that amount to offsetof. */ 4930 if (TREE_CODE (argtype) != FUNCTION_TYPE 4931 && TREE_CODE (argtype) != METHOD_TYPE 4932 && argtype != unknown_type_node 4933 && (val = get_base_address (arg)) 4934 && COMPLETE_TYPE_P (TREE_TYPE (val)) 4935 && TREE_CODE (val) == INDIRECT_REF 4936 && TREE_CONSTANT (TREE_OPERAND (val, 0))) 4937 { 4938 tree type = build_pointer_type (argtype); 4939 return fold_convert (type, fold_offsetof_1 (arg)); 4940 } 4941 4942 /* Handle complex lvalues (when permitted) 4943 by reduction to simpler cases. */ 4944 val = unary_complex_lvalue (ADDR_EXPR, arg); 4945 if (val != 0) 4946 return val; 4947 4948 switch (TREE_CODE (arg)) 4949 { 4950 CASE_CONVERT: 4951 case FLOAT_EXPR: 4952 case FIX_TRUNC_EXPR: 4953 /* Even if we're not being pedantic, we cannot allow this 4954 extension when we're instantiating in a SFINAE 4955 context. */ 4956 if (! lvalue_p (arg) && complain == tf_none) 4957 { 4958 if (complain & tf_error) 4959 permerror (input_location, "ISO C++ forbids taking the address of a cast to a non-lvalue expression"); 4960 else 4961 return error_mark_node; 4962 } 4963 break; 4964 4965 case BASELINK: 4966 arg = BASELINK_FUNCTIONS (arg); 4967 /* Fall through. */ 4968 4969 case OVERLOAD: 4970 arg = OVL_CURRENT (arg); 4971 break; 4972 4973 case OFFSET_REF: 4974 offset_ref: 4975 /* Turn a reference to a non-static data member into a 4976 pointer-to-member. */ 4977 { 4978 tree type; 4979 tree t; 4980 4981 gcc_assert (PTRMEM_OK_P (arg)); 4982 4983 t = TREE_OPERAND (arg, 1); 4984 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE) 4985 { 4986 if (complain & tf_error) 4987 error ("cannot create pointer to reference member %qD", t); 4988 return error_mark_node; 4989 } 4990 4991 type = build_ptrmem_type (context_for_name_lookup (t), 4992 TREE_TYPE (t)); 4993 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1)); 4994 return t; 4995 } 4996 4997 default: 4998 break; 4999 } 5000 5001 if (argtype != error_mark_node) 5002 argtype = build_pointer_type (argtype); 5003 5004 /* In a template, we are processing a non-dependent expression 5005 so we can just form an ADDR_EXPR with the correct type. */ 5006 if (processing_template_decl || TREE_CODE (arg) != COMPONENT_REF) 5007 { 5008 val = build_address (arg); 5009 if (TREE_CODE (arg) == OFFSET_REF) 5010 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg); 5011 } 5012 else if (BASELINK_P (TREE_OPERAND (arg, 1))) 5013 { 5014 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1)); 5015 5016 /* We can only get here with a single static member 5017 function. */ 5018 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 5019 && DECL_STATIC_FUNCTION_P (fn)); 5020 mark_used (fn); 5021 val = build_address (fn); 5022 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0))) 5023 /* Do not lose object's side effects. */ 5024 val = build2 (COMPOUND_EXPR, TREE_TYPE (val), 5025 TREE_OPERAND (arg, 0), val); 5026 } 5027 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))) 5028 { 5029 if (complain & tf_error) 5030 error ("attempt to take address of bit-field structure member %qD", 5031 TREE_OPERAND (arg, 1)); 5032 return error_mark_node; 5033 } 5034 else 5035 { 5036 tree object = TREE_OPERAND (arg, 0); 5037 tree field = TREE_OPERAND (arg, 1); 5038 gcc_assert (same_type_ignoring_top_level_qualifiers_p 5039 (TREE_TYPE (object), decl_type_context (field))); 5040 val = build_address (arg); 5041 } 5042 5043 if (TREE_CODE (argtype) == POINTER_TYPE 5044 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE) 5045 { 5046 build_ptrmemfunc_type (argtype); 5047 val = build_ptrmemfunc (argtype, val, 0, 5048 /*c_cast_p=*/false, 5049 tf_warning_or_error); 5050 } 5051 5052 return val; 5053 } 5054 5055 /* Take the address of ARG if it has one, even if it's an rvalue. */ 5056 5057 tree 5058 cp_build_addr_expr (tree arg, tsubst_flags_t complain) 5059 { 5060 return cp_build_addr_expr_1 (arg, 0, complain); 5061 } 5062 5063 /* Take the address of ARG, but only if it's an lvalue. */ 5064 5065 tree 5066 cp_build_addr_expr_strict (tree arg, tsubst_flags_t complain) 5067 { 5068 return cp_build_addr_expr_1 (arg, 1, complain); 5069 } 5070 5071 /* C++: Must handle pointers to members. 5072 5073 Perhaps type instantiation should be extended to handle conversion 5074 from aggregates to types we don't yet know we want? (Or are those 5075 cases typically errors which should be reported?) 5076 5077 NOCONVERT nonzero suppresses the default promotions 5078 (such as from short to int). */ 5079 5080 tree 5081 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert, 5082 tsubst_flags_t complain) 5083 { 5084 /* No default_conversion here. It causes trouble for ADDR_EXPR. */ 5085 tree arg = xarg; 5086 tree argtype = 0; 5087 const char *errstring = NULL; 5088 tree val; 5089 const char *invalid_op_diag; 5090 5091 if (!arg || error_operand_p (arg)) 5092 return error_mark_node; 5093 5094 if ((invalid_op_diag 5095 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR 5096 ? CONVERT_EXPR 5097 : code), 5098 TREE_TYPE (xarg)))) 5099 { 5100 error (invalid_op_diag); 5101 return error_mark_node; 5102 } 5103 5104 switch (code) 5105 { 5106 case UNARY_PLUS_EXPR: 5107 case NEGATE_EXPR: 5108 { 5109 int flags = WANT_ARITH | WANT_ENUM; 5110 /* Unary plus (but not unary minus) is allowed on pointers. */ 5111 if (code == UNARY_PLUS_EXPR) 5112 flags |= WANT_POINTER; 5113 arg = build_expr_type_conversion (flags, arg, true); 5114 if (!arg) 5115 errstring = (code == NEGATE_EXPR 5116 ? _("wrong type argument to unary minus") 5117 : _("wrong type argument to unary plus")); 5118 else 5119 { 5120 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg))) 5121 arg = perform_integral_promotions (arg); 5122 5123 /* Make sure the result is not an lvalue: a unary plus or minus 5124 expression is always a rvalue. */ 5125 arg = rvalue (arg); 5126 } 5127 } 5128 break; 5129 5130 case BIT_NOT_EXPR: 5131 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 5132 { 5133 code = CONJ_EXPR; 5134 if (!noconvert) 5135 arg = default_conversion (arg); 5136 } 5137 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM 5138 | WANT_VECTOR_OR_COMPLEX, 5139 arg, true))) 5140 errstring = _("wrong type argument to bit-complement"); 5141 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg))) 5142 arg = perform_integral_promotions (arg); 5143 break; 5144 5145 case ABS_EXPR: 5146 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true))) 5147 errstring = _("wrong type argument to abs"); 5148 else if (!noconvert) 5149 arg = default_conversion (arg); 5150 break; 5151 5152 case CONJ_EXPR: 5153 /* Conjugating a real value is a no-op, but allow it anyway. */ 5154 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true))) 5155 errstring = _("wrong type argument to conjugation"); 5156 else if (!noconvert) 5157 arg = default_conversion (arg); 5158 break; 5159 5160 case TRUTH_NOT_EXPR: 5161 arg = perform_implicit_conversion (boolean_type_node, arg, 5162 complain); 5163 val = invert_truthvalue_loc (input_location, arg); 5164 if (arg != error_mark_node) 5165 return val; 5166 errstring = _("in argument to unary !"); 5167 break; 5168 5169 case NOP_EXPR: 5170 break; 5171 5172 case REALPART_EXPR: 5173 case IMAGPART_EXPR: 5174 arg = build_real_imag_expr (input_location, code, arg); 5175 if (arg == error_mark_node) 5176 return arg; 5177 else 5178 return fold_if_not_in_template (arg); 5179 5180 case PREINCREMENT_EXPR: 5181 case POSTINCREMENT_EXPR: 5182 case PREDECREMENT_EXPR: 5183 case POSTDECREMENT_EXPR: 5184 /* Handle complex lvalues (when permitted) 5185 by reduction to simpler cases. */ 5186 5187 val = unary_complex_lvalue (code, arg); 5188 if (val != 0) 5189 return val; 5190 5191 arg = mark_lvalue_use (arg); 5192 5193 /* Increment or decrement the real part of the value, 5194 and don't change the imaginary part. */ 5195 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) 5196 { 5197 tree real, imag; 5198 5199 arg = stabilize_reference (arg); 5200 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain); 5201 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain); 5202 real = cp_build_unary_op (code, real, 1, complain); 5203 if (real == error_mark_node || imag == error_mark_node) 5204 return error_mark_node; 5205 return build2 (COMPLEX_EXPR, TREE_TYPE (arg), 5206 real, imag); 5207 } 5208 5209 /* Report invalid types. */ 5210 5211 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER, 5212 arg, true))) 5213 { 5214 if (code == PREINCREMENT_EXPR) 5215 errstring = _("no pre-increment operator for type"); 5216 else if (code == POSTINCREMENT_EXPR) 5217 errstring = _("no post-increment operator for type"); 5218 else if (code == PREDECREMENT_EXPR) 5219 errstring = _("no pre-decrement operator for type"); 5220 else 5221 errstring = _("no post-decrement operator for type"); 5222 break; 5223 } 5224 else if (arg == error_mark_node) 5225 return error_mark_node; 5226 5227 /* Report something read-only. */ 5228 5229 if (CP_TYPE_CONST_P (TREE_TYPE (arg)) 5230 || TREE_READONLY (arg)) 5231 { 5232 if (complain & tf_error) 5233 cxx_readonly_error (arg, ((code == PREINCREMENT_EXPR 5234 || code == POSTINCREMENT_EXPR) 5235 ? lv_increment : lv_decrement)); 5236 else 5237 return error_mark_node; 5238 } 5239 5240 { 5241 tree inc; 5242 tree declared_type = unlowered_expr_type (arg); 5243 5244 argtype = TREE_TYPE (arg); 5245 5246 /* ARM $5.2.5 last annotation says this should be forbidden. */ 5247 if (TREE_CODE (argtype) == ENUMERAL_TYPE) 5248 { 5249 if (complain & tf_error) 5250 permerror (input_location, (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) 5251 ? G_("ISO C++ forbids incrementing an enum") 5252 : G_("ISO C++ forbids decrementing an enum")); 5253 else 5254 return error_mark_node; 5255 } 5256 5257 /* Compute the increment. */ 5258 5259 if (TREE_CODE (argtype) == POINTER_TYPE) 5260 { 5261 tree type = complete_type (TREE_TYPE (argtype)); 5262 5263 if (!COMPLETE_OR_VOID_TYPE_P (type)) 5264 { 5265 if (complain & tf_error) 5266 error (((code == PREINCREMENT_EXPR 5267 || code == POSTINCREMENT_EXPR)) 5268 ? G_("cannot increment a pointer to incomplete type %qT") 5269 : G_("cannot decrement a pointer to incomplete type %qT"), 5270 TREE_TYPE (argtype)); 5271 else 5272 return error_mark_node; 5273 } 5274 else if ((pedantic || warn_pointer_arith) 5275 && !TYPE_PTROB_P (argtype)) 5276 { 5277 if (complain & tf_error) 5278 permerror (input_location, (code == PREINCREMENT_EXPR 5279 || code == POSTINCREMENT_EXPR) 5280 ? G_("ISO C++ forbids incrementing a pointer of type %qT") 5281 : G_("ISO C++ forbids decrementing a pointer of type %qT"), 5282 argtype); 5283 else 5284 return error_mark_node; 5285 } 5286 5287 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype)); 5288 } 5289 else 5290 inc = integer_one_node; 5291 5292 inc = cp_convert (argtype, inc); 5293 5294 /* If 'arg' is an Objective-C PROPERTY_REF expression, then we 5295 need to ask Objective-C to build the increment or decrement 5296 expression for it. */ 5297 if (objc_is_property_ref (arg)) 5298 return objc_build_incr_expr_for_property_ref (input_location, code, 5299 arg, inc); 5300 5301 /* Complain about anything else that is not a true lvalue. */ 5302 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR 5303 || code == POSTINCREMENT_EXPR) 5304 ? lv_increment : lv_decrement), 5305 complain)) 5306 return error_mark_node; 5307 5308 /* Forbid using -- on `bool'. */ 5309 if (TREE_CODE (declared_type) == BOOLEAN_TYPE) 5310 { 5311 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR) 5312 { 5313 if (complain & tf_error) 5314 error ("invalid use of Boolean expression as operand " 5315 "to %<operator--%>"); 5316 return error_mark_node; 5317 } 5318 val = boolean_increment (code, arg); 5319 } 5320 else if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 5321 /* An rvalue has no cv-qualifiers. */ 5322 val = build2 (code, cv_unqualified (TREE_TYPE (arg)), arg, inc); 5323 else 5324 val = build2 (code, TREE_TYPE (arg), arg, inc); 5325 5326 TREE_SIDE_EFFECTS (val) = 1; 5327 return val; 5328 } 5329 5330 case ADDR_EXPR: 5331 /* Note that this operation never does default_conversion 5332 regardless of NOCONVERT. */ 5333 return cp_build_addr_expr (arg, complain); 5334 5335 default: 5336 break; 5337 } 5338 5339 if (!errstring) 5340 { 5341 if (argtype == 0) 5342 argtype = TREE_TYPE (arg); 5343 return fold_if_not_in_template (build1 (code, argtype, arg)); 5344 } 5345 5346 if (complain & tf_error) 5347 error ("%s", errstring); 5348 return error_mark_node; 5349 } 5350 5351 /* Hook for the c-common bits that build a unary op. */ 5352 tree 5353 build_unary_op (location_t location ATTRIBUTE_UNUSED, 5354 enum tree_code code, tree xarg, int noconvert) 5355 { 5356 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error); 5357 } 5358 5359 /* Apply unary lvalue-demanding operator CODE to the expression ARG 5360 for certain kinds of expressions which are not really lvalues 5361 but which we can accept as lvalues. 5362 5363 If ARG is not a kind of expression we can handle, return 5364 NULL_TREE. */ 5365 5366 tree 5367 unary_complex_lvalue (enum tree_code code, tree arg) 5368 { 5369 /* Inside a template, making these kinds of adjustments is 5370 pointless; we are only concerned with the type of the 5371 expression. */ 5372 if (processing_template_decl) 5373 return NULL_TREE; 5374 5375 /* Handle (a, b) used as an "lvalue". */ 5376 if (TREE_CODE (arg) == COMPOUND_EXPR) 5377 { 5378 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0, 5379 tf_warning_or_error); 5380 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result), 5381 TREE_OPERAND (arg, 0), real_result); 5382 } 5383 5384 /* Handle (a ? b : c) used as an "lvalue". */ 5385 if (TREE_CODE (arg) == COND_EXPR 5386 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR) 5387 return rationalize_conditional_expr (code, arg, tf_warning_or_error); 5388 5389 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */ 5390 if (TREE_CODE (arg) == MODIFY_EXPR 5391 || TREE_CODE (arg) == PREINCREMENT_EXPR 5392 || TREE_CODE (arg) == PREDECREMENT_EXPR) 5393 { 5394 tree lvalue = TREE_OPERAND (arg, 0); 5395 if (TREE_SIDE_EFFECTS (lvalue)) 5396 { 5397 lvalue = stabilize_reference (lvalue); 5398 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg), 5399 lvalue, TREE_OPERAND (arg, 1)); 5400 } 5401 return unary_complex_lvalue 5402 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue)); 5403 } 5404 5405 if (code != ADDR_EXPR) 5406 return NULL_TREE; 5407 5408 /* Handle (a = b) used as an "lvalue" for `&'. */ 5409 if (TREE_CODE (arg) == MODIFY_EXPR 5410 || TREE_CODE (arg) == INIT_EXPR) 5411 { 5412 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0, 5413 tf_warning_or_error); 5414 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result), 5415 arg, real_result); 5416 TREE_NO_WARNING (arg) = 1; 5417 return arg; 5418 } 5419 5420 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE 5421 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE 5422 || TREE_CODE (arg) == OFFSET_REF) 5423 return NULL_TREE; 5424 5425 /* We permit compiler to make function calls returning 5426 objects of aggregate type look like lvalues. */ 5427 { 5428 tree targ = arg; 5429 5430 if (TREE_CODE (targ) == SAVE_EXPR) 5431 targ = TREE_OPERAND (targ, 0); 5432 5433 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ))) 5434 { 5435 if (TREE_CODE (arg) == SAVE_EXPR) 5436 targ = arg; 5437 else 5438 targ = build_cplus_new (TREE_TYPE (arg), arg, tf_warning_or_error); 5439 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ); 5440 } 5441 5442 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF) 5443 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)), 5444 TREE_OPERAND (targ, 0), current_function_decl, NULL); 5445 } 5446 5447 /* Don't let anything else be handled specially. */ 5448 return NULL_TREE; 5449 } 5450 5451 /* Mark EXP saying that we need to be able to take the 5452 address of it; it should not be allocated in a register. 5453 Value is true if successful. 5454 5455 C++: we do not allow `current_class_ptr' to be addressable. */ 5456 5457 bool 5458 cxx_mark_addressable (tree exp) 5459 { 5460 tree x = exp; 5461 5462 while (1) 5463 switch (TREE_CODE (x)) 5464 { 5465 case ADDR_EXPR: 5466 case COMPONENT_REF: 5467 case ARRAY_REF: 5468 case REALPART_EXPR: 5469 case IMAGPART_EXPR: 5470 x = TREE_OPERAND (x, 0); 5471 break; 5472 5473 case PARM_DECL: 5474 if (x == current_class_ptr) 5475 { 5476 error ("cannot take the address of %<this%>, which is an rvalue expression"); 5477 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */ 5478 return true; 5479 } 5480 /* Fall through. */ 5481 5482 case VAR_DECL: 5483 /* Caller should not be trying to mark initialized 5484 constant fields addressable. */ 5485 gcc_assert (DECL_LANG_SPECIFIC (x) == 0 5486 || DECL_IN_AGGR_P (x) == 0 5487 || TREE_STATIC (x) 5488 || DECL_EXTERNAL (x)); 5489 /* Fall through. */ 5490 5491 case RESULT_DECL: 5492 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x) 5493 && !DECL_ARTIFICIAL (x)) 5494 { 5495 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x)) 5496 { 5497 error 5498 ("address of explicit register variable %qD requested", x); 5499 return false; 5500 } 5501 else if (extra_warnings) 5502 warning 5503 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x); 5504 } 5505 TREE_ADDRESSABLE (x) = 1; 5506 return true; 5507 5508 case CONST_DECL: 5509 case FUNCTION_DECL: 5510 TREE_ADDRESSABLE (x) = 1; 5511 return true; 5512 5513 case CONSTRUCTOR: 5514 TREE_ADDRESSABLE (x) = 1; 5515 return true; 5516 5517 case TARGET_EXPR: 5518 TREE_ADDRESSABLE (x) = 1; 5519 cxx_mark_addressable (TREE_OPERAND (x, 0)); 5520 return true; 5521 5522 default: 5523 return true; 5524 } 5525 } 5526 5527 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */ 5528 5529 tree 5530 build_x_conditional_expr (tree ifexp, tree op1, tree op2, 5531 tsubst_flags_t complain) 5532 { 5533 tree orig_ifexp = ifexp; 5534 tree orig_op1 = op1; 5535 tree orig_op2 = op2; 5536 tree expr; 5537 5538 if (processing_template_decl) 5539 { 5540 /* The standard says that the expression is type-dependent if 5541 IFEXP is type-dependent, even though the eventual type of the 5542 expression doesn't dependent on IFEXP. */ 5543 if (type_dependent_expression_p (ifexp) 5544 /* As a GNU extension, the middle operand may be omitted. */ 5545 || (op1 && type_dependent_expression_p (op1)) 5546 || type_dependent_expression_p (op2)) 5547 return build_min_nt (COND_EXPR, ifexp, op1, op2); 5548 ifexp = build_non_dependent_expr (ifexp); 5549 if (op1) 5550 op1 = build_non_dependent_expr (op1); 5551 op2 = build_non_dependent_expr (op2); 5552 } 5553 5554 expr = build_conditional_expr (ifexp, op1, op2, complain); 5555 if (processing_template_decl && expr != error_mark_node) 5556 { 5557 tree min = build_min_non_dep (COND_EXPR, expr, 5558 orig_ifexp, orig_op1, orig_op2); 5559 /* In C++11, remember that the result is an lvalue or xvalue. 5560 In C++98, lvalue_kind can just assume lvalue in a template. */ 5561 if (cxx_dialect >= cxx0x 5562 && lvalue_or_rvalue_with_address_p (expr) 5563 && !lvalue_or_rvalue_with_address_p (min)) 5564 TREE_TYPE (min) = cp_build_reference_type (TREE_TYPE (min), 5565 !real_lvalue_p (expr)); 5566 expr = convert_from_reference (min); 5567 } 5568 return expr; 5569 } 5570 5571 /* Given a list of expressions, return a compound expression 5572 that performs them all and returns the value of the last of them. */ 5573 5574 tree 5575 build_x_compound_expr_from_list (tree list, expr_list_kind exp, 5576 tsubst_flags_t complain) 5577 { 5578 tree expr = TREE_VALUE (list); 5579 5580 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 5581 && !CONSTRUCTOR_IS_DIRECT_INIT (expr)) 5582 { 5583 if (complain & tf_error) 5584 pedwarn (EXPR_LOC_OR_HERE (expr), 0, "list-initializer for " 5585 "non-class type must not be parenthesized"); 5586 else 5587 return error_mark_node; 5588 } 5589 5590 if (TREE_CHAIN (list)) 5591 { 5592 if (complain & tf_error) 5593 switch (exp) 5594 { 5595 case ELK_INIT: 5596 permerror (input_location, "expression list treated as compound " 5597 "expression in initializer"); 5598 break; 5599 case ELK_MEM_INIT: 5600 permerror (input_location, "expression list treated as compound " 5601 "expression in mem-initializer"); 5602 break; 5603 case ELK_FUNC_CAST: 5604 permerror (input_location, "expression list treated as compound " 5605 "expression in functional cast"); 5606 break; 5607 default: 5608 gcc_unreachable (); 5609 } 5610 else 5611 return error_mark_node; 5612 5613 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list)) 5614 expr = build_x_compound_expr (expr, TREE_VALUE (list), 5615 complain); 5616 } 5617 5618 return expr; 5619 } 5620 5621 /* Like build_x_compound_expr_from_list, but using a VEC. */ 5622 5623 tree 5624 build_x_compound_expr_from_vec (VEC(tree,gc) *vec, const char *msg) 5625 { 5626 if (VEC_empty (tree, vec)) 5627 return NULL_TREE; 5628 else if (VEC_length (tree, vec) == 1) 5629 return VEC_index (tree, vec, 0); 5630 else 5631 { 5632 tree expr; 5633 unsigned int ix; 5634 tree t; 5635 5636 if (msg != NULL) 5637 permerror (input_location, 5638 "%s expression list treated as compound expression", 5639 msg); 5640 5641 expr = VEC_index (tree, vec, 0); 5642 for (ix = 1; VEC_iterate (tree, vec, ix, t); ++ix) 5643 expr = build_x_compound_expr (expr, t, tf_warning_or_error); 5644 5645 return expr; 5646 } 5647 } 5648 5649 /* Handle overloading of the ',' operator when needed. */ 5650 5651 tree 5652 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain) 5653 { 5654 tree result; 5655 tree orig_op1 = op1; 5656 tree orig_op2 = op2; 5657 5658 if (processing_template_decl) 5659 { 5660 if (type_dependent_expression_p (op1) 5661 || type_dependent_expression_p (op2)) 5662 return build_min_nt (COMPOUND_EXPR, op1, op2); 5663 op1 = build_non_dependent_expr (op1); 5664 op2 = build_non_dependent_expr (op2); 5665 } 5666 5667 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE, 5668 /*overload=*/NULL, complain); 5669 if (!result) 5670 result = cp_build_compound_expr (op1, op2, complain); 5671 5672 if (processing_template_decl && result != error_mark_node) 5673 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2); 5674 5675 return result; 5676 } 5677 5678 /* Like cp_build_compound_expr, but for the c-common bits. */ 5679 5680 tree 5681 build_compound_expr (location_t loc ATTRIBUTE_UNUSED, tree lhs, tree rhs) 5682 { 5683 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error); 5684 } 5685 5686 /* Build a compound expression. */ 5687 5688 tree 5689 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain) 5690 { 5691 lhs = convert_to_void (lhs, ICV_LEFT_OF_COMMA, complain); 5692 5693 if (lhs == error_mark_node || rhs == error_mark_node) 5694 return error_mark_node; 5695 5696 if (TREE_CODE (rhs) == TARGET_EXPR) 5697 { 5698 /* If the rhs is a TARGET_EXPR, then build the compound 5699 expression inside the target_expr's initializer. This 5700 helps the compiler to eliminate unnecessary temporaries. */ 5701 tree init = TREE_OPERAND (rhs, 1); 5702 5703 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init); 5704 TREE_OPERAND (rhs, 1) = init; 5705 5706 return rhs; 5707 } 5708 5709 if (type_unknown_p (rhs)) 5710 { 5711 error ("no context to resolve type of %qE", rhs); 5712 return error_mark_node; 5713 } 5714 5715 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs); 5716 } 5717 5718 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE 5719 casts away constness. CAST gives the type of cast. Returns true 5720 if the cast is ill-formed, false if it is well-formed. 5721 5722 ??? This function warns for casting away any qualifier not just 5723 const. We would like to specify exactly what qualifiers are casted 5724 away. 5725 */ 5726 5727 static bool 5728 check_for_casting_away_constness (tree src_type, tree dest_type, 5729 enum tree_code cast, tsubst_flags_t complain) 5730 { 5731 /* C-style casts are allowed to cast away constness. With 5732 WARN_CAST_QUAL, we still want to issue a warning. */ 5733 if (cast == CAST_EXPR && !warn_cast_qual) 5734 return false; 5735 5736 if (!casts_away_constness (src_type, dest_type)) 5737 return false; 5738 5739 switch (cast) 5740 { 5741 case CAST_EXPR: 5742 if (complain & tf_warning) 5743 warning (OPT_Wcast_qual, 5744 "cast from type %qT to type %qT casts away qualifiers", 5745 src_type, dest_type); 5746 return false; 5747 5748 case STATIC_CAST_EXPR: 5749 if (complain & tf_error) 5750 error ("static_cast from type %qT to type %qT casts away qualifiers", 5751 src_type, dest_type); 5752 return true; 5753 5754 case REINTERPRET_CAST_EXPR: 5755 if (complain & tf_error) 5756 error ("reinterpret_cast from type %qT to type %qT casts away qualifiers", 5757 src_type, dest_type); 5758 return true; 5759 5760 default: 5761 gcc_unreachable(); 5762 } 5763 } 5764 5765 /* Convert EXPR (an expression with pointer-to-member type) to TYPE 5766 (another pointer-to-member type in the same hierarchy) and return 5767 the converted expression. If ALLOW_INVERSE_P is permitted, a 5768 pointer-to-derived may be converted to pointer-to-base; otherwise, 5769 only the other direction is permitted. If C_CAST_P is true, this 5770 conversion is taking place as part of a C-style cast. */ 5771 5772 tree 5773 convert_ptrmem (tree type, tree expr, bool allow_inverse_p, 5774 bool c_cast_p, tsubst_flags_t complain) 5775 { 5776 if (TYPE_PTRMEM_P (type)) 5777 { 5778 tree delta; 5779 5780 if (TREE_CODE (expr) == PTRMEM_CST) 5781 expr = cplus_expand_constant (expr); 5782 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)), 5783 TYPE_PTRMEM_CLASS_TYPE (type), 5784 allow_inverse_p, 5785 c_cast_p, complain); 5786 if (delta == error_mark_node) 5787 return error_mark_node; 5788 5789 if (!integer_zerop (delta)) 5790 { 5791 tree cond, op1, op2; 5792 5793 cond = cp_build_binary_op (input_location, 5794 EQ_EXPR, 5795 expr, 5796 build_int_cst (TREE_TYPE (expr), -1), 5797 tf_warning_or_error); 5798 op1 = build_nop (ptrdiff_type_node, expr); 5799 op2 = cp_build_binary_op (input_location, 5800 PLUS_EXPR, op1, delta, 5801 tf_warning_or_error); 5802 5803 expr = fold_build3_loc (input_location, 5804 COND_EXPR, ptrdiff_type_node, cond, op1, op2); 5805 5806 } 5807 5808 return build_nop (type, expr); 5809 } 5810 else 5811 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 5812 allow_inverse_p, c_cast_p, complain); 5813 } 5814 5815 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true, 5816 this static_cast is being attempted as one of the possible casts 5817 allowed by a C-style cast. (In that case, accessibility of base 5818 classes is not considered, and it is OK to cast away 5819 constness.) Return the result of the cast. *VALID_P is set to 5820 indicate whether or not the cast was valid. */ 5821 5822 static tree 5823 build_static_cast_1 (tree type, tree expr, bool c_cast_p, 5824 bool *valid_p, tsubst_flags_t complain) 5825 { 5826 tree intype; 5827 tree result; 5828 cp_lvalue_kind clk; 5829 5830 /* Assume the cast is valid. */ 5831 *valid_p = true; 5832 5833 intype = unlowered_expr_type (expr); 5834 5835 /* Save casted types in the function's used types hash table. */ 5836 used_types_insert (type); 5837 5838 /* [expr.static.cast] 5839 5840 An lvalue of type "cv1 B", where B is a class type, can be cast 5841 to type "reference to cv2 D", where D is a class derived (clause 5842 _class.derived_) from B, if a valid standard conversion from 5843 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the 5844 same cv-qualification as, or greater cv-qualification than, cv1, 5845 and B is not a virtual base class of D. */ 5846 /* We check this case before checking the validity of "TYPE t = 5847 EXPR;" below because for this case: 5848 5849 struct B {}; 5850 struct D : public B { D(const B&); }; 5851 extern B& b; 5852 void f() { static_cast<const D&>(b); } 5853 5854 we want to avoid constructing a new D. The standard is not 5855 completely clear about this issue, but our interpretation is 5856 consistent with other compilers. */ 5857 if (TREE_CODE (type) == REFERENCE_TYPE 5858 && CLASS_TYPE_P (TREE_TYPE (type)) 5859 && CLASS_TYPE_P (intype) 5860 && (TYPE_REF_IS_RVALUE (type) || real_lvalue_p (expr)) 5861 && DERIVED_FROM_P (intype, TREE_TYPE (type)) 5862 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)), 5863 build_pointer_type (TYPE_MAIN_VARIANT 5864 (TREE_TYPE (type)))) 5865 && (c_cast_p 5866 || at_least_as_qualified_p (TREE_TYPE (type), intype))) 5867 { 5868 tree base; 5869 5870 /* There is a standard conversion from "D*" to "B*" even if "B" 5871 is ambiguous or inaccessible. If this is really a 5872 static_cast, then we check both for inaccessibility and 5873 ambiguity. However, if this is a static_cast being performed 5874 because the user wrote a C-style cast, then accessibility is 5875 not considered. */ 5876 base = lookup_base (TREE_TYPE (type), intype, 5877 c_cast_p ? ba_unique : ba_check, 5878 NULL); 5879 5880 /* Convert from "B*" to "D*". This function will check that "B" 5881 is not a virtual base of "D". */ 5882 expr = build_base_path (MINUS_EXPR, build_address (expr), 5883 base, /*nonnull=*/false, complain); 5884 /* Convert the pointer to a reference -- but then remember that 5885 there are no expressions with reference type in C++. 5886 5887 We call rvalue so that there's an actual tree code 5888 (NON_LVALUE_EXPR) for the static_cast; otherwise, if the operand 5889 is a variable with the same type, the conversion would get folded 5890 away, leaving just the variable and causing lvalue_kind to give 5891 the wrong answer. */ 5892 return convert_from_reference (rvalue (cp_fold_convert (type, expr))); 5893 } 5894 5895 /* "A glvalue of type cv1 T1 can be cast to type rvalue reference to 5896 cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */ 5897 if (TREE_CODE (type) == REFERENCE_TYPE 5898 && TYPE_REF_IS_RVALUE (type) 5899 && (clk = real_lvalue_p (expr)) 5900 && reference_related_p (TREE_TYPE (type), intype) 5901 && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype))) 5902 { 5903 if (clk == clk_ordinary) 5904 { 5905 /* Handle the (non-bit-field) lvalue case here by casting to 5906 lvalue reference and then changing it to an rvalue reference. 5907 Casting an xvalue to rvalue reference will be handled by the 5908 main code path. */ 5909 tree lref = cp_build_reference_type (TREE_TYPE (type), false); 5910 result = (perform_direct_initialization_if_possible 5911 (lref, expr, c_cast_p, complain)); 5912 result = cp_fold_convert (type, result); 5913 /* Make sure we don't fold back down to a named rvalue reference, 5914 because that would be an lvalue. */ 5915 if (DECL_P (result)) 5916 result = build1 (NON_LVALUE_EXPR, type, result); 5917 return convert_from_reference (result); 5918 } 5919 else 5920 /* For a bit-field or packed field, bind to a temporary. */ 5921 expr = rvalue (expr); 5922 } 5923 5924 /* Resolve overloaded address here rather than once in 5925 implicit_conversion and again in the inverse code below. */ 5926 if (TYPE_PTRMEMFUNC_P (type) && type_unknown_p (expr)) 5927 { 5928 expr = instantiate_type (type, expr, complain); 5929 intype = TREE_TYPE (expr); 5930 } 5931 5932 /* [expr.static.cast] 5933 5934 An expression e can be explicitly converted to a type T using a 5935 static_cast of the form static_cast<T>(e) if the declaration T 5936 t(e);" is well-formed, for some invented temporary variable 5937 t. */ 5938 result = perform_direct_initialization_if_possible (type, expr, 5939 c_cast_p, complain); 5940 if (result) 5941 { 5942 result = convert_from_reference (result); 5943 5944 /* [expr.static.cast] 5945 5946 If T is a reference type, the result is an lvalue; otherwise, 5947 the result is an rvalue. */ 5948 if (TREE_CODE (type) != REFERENCE_TYPE) 5949 result = rvalue (result); 5950 return result; 5951 } 5952 5953 /* [expr.static.cast] 5954 5955 Any expression can be explicitly converted to type cv void. */ 5956 if (TREE_CODE (type) == VOID_TYPE) 5957 return convert_to_void (expr, ICV_CAST, complain); 5958 5959 /* [expr.static.cast] 5960 5961 The inverse of any standard conversion sequence (clause _conv_), 5962 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer 5963 (_conv.array_), function-to-pointer (_conv.func_), and boolean 5964 (_conv.bool_) conversions, can be performed explicitly using 5965 static_cast subject to the restriction that the explicit 5966 conversion does not cast away constness (_expr.const.cast_), and 5967 the following additional rules for specific cases: */ 5968 /* For reference, the conversions not excluded are: integral 5969 promotions, floating point promotion, integral conversions, 5970 floating point conversions, floating-integral conversions, 5971 pointer conversions, and pointer to member conversions. */ 5972 /* DR 128 5973 5974 A value of integral _or enumeration_ type can be explicitly 5975 converted to an enumeration type. */ 5976 /* The effect of all that is that any conversion between any two 5977 types which are integral, floating, or enumeration types can be 5978 performed. */ 5979 if ((INTEGRAL_OR_ENUMERATION_TYPE_P (type) 5980 || SCALAR_FLOAT_TYPE_P (type)) 5981 && (INTEGRAL_OR_ENUMERATION_TYPE_P (intype) 5982 || SCALAR_FLOAT_TYPE_P (intype))) 5983 return ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL); 5984 5985 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype) 5986 && CLASS_TYPE_P (TREE_TYPE (type)) 5987 && CLASS_TYPE_P (TREE_TYPE (intype)) 5988 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT 5989 (TREE_TYPE (intype))), 5990 build_pointer_type (TYPE_MAIN_VARIANT 5991 (TREE_TYPE (type))))) 5992 { 5993 tree base; 5994 5995 if (!c_cast_p 5996 && check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR, 5997 complain)) 5998 return error_mark_node; 5999 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), 6000 c_cast_p ? ba_unique : ba_check, 6001 NULL); 6002 expr = build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false, 6003 complain); 6004 return cp_fold_convert(type, expr); 6005 } 6006 6007 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) 6008 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) 6009 { 6010 tree c1; 6011 tree c2; 6012 tree t1; 6013 tree t2; 6014 6015 c1 = TYPE_PTRMEM_CLASS_TYPE (intype); 6016 c2 = TYPE_PTRMEM_CLASS_TYPE (type); 6017 6018 if (TYPE_PTRMEM_P (type)) 6019 { 6020 t1 = (build_ptrmem_type 6021 (c1, 6022 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype)))); 6023 t2 = (build_ptrmem_type 6024 (c2, 6025 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type)))); 6026 } 6027 else 6028 { 6029 t1 = intype; 6030 t2 = type; 6031 } 6032 if (can_convert (t1, t2) || can_convert (t2, t1)) 6033 { 6034 if (!c_cast_p 6035 && check_for_casting_away_constness (intype, type, 6036 STATIC_CAST_EXPR, 6037 complain)) 6038 return error_mark_node; 6039 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1, 6040 c_cast_p, complain); 6041 } 6042 } 6043 6044 /* [expr.static.cast] 6045 6046 An rvalue of type "pointer to cv void" can be explicitly 6047 converted to a pointer to object type. A value of type pointer 6048 to object converted to "pointer to cv void" and back to the 6049 original pointer type will have its original value. */ 6050 if (TREE_CODE (intype) == POINTER_TYPE 6051 && VOID_TYPE_P (TREE_TYPE (intype)) 6052 && TYPE_PTROB_P (type)) 6053 { 6054 if (!c_cast_p 6055 && check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR, 6056 complain)) 6057 return error_mark_node; 6058 return build_nop (type, expr); 6059 } 6060 6061 *valid_p = false; 6062 return error_mark_node; 6063 } 6064 6065 /* Return an expression representing static_cast<TYPE>(EXPR). */ 6066 6067 tree 6068 build_static_cast (tree type, tree expr, tsubst_flags_t complain) 6069 { 6070 tree result; 6071 bool valid_p; 6072 6073 if (type == error_mark_node || expr == error_mark_node) 6074 return error_mark_node; 6075 6076 if (processing_template_decl) 6077 { 6078 expr = build_min (STATIC_CAST_EXPR, type, expr); 6079 /* We don't know if it will or will not have side effects. */ 6080 TREE_SIDE_EFFECTS (expr) = 1; 6081 return convert_from_reference (expr); 6082 } 6083 6084 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 6085 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ 6086 if (TREE_CODE (type) != REFERENCE_TYPE 6087 && TREE_CODE (expr) == NOP_EXPR 6088 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) 6089 expr = TREE_OPERAND (expr, 0); 6090 6091 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p, 6092 complain); 6093 if (valid_p) 6094 return result; 6095 6096 if (complain & tf_error) 6097 error ("invalid static_cast from type %qT to type %qT", 6098 TREE_TYPE (expr), type); 6099 return error_mark_node; 6100 } 6101 6102 /* EXPR is an expression with member function or pointer-to-member 6103 function type. TYPE is a pointer type. Converting EXPR to TYPE is 6104 not permitted by ISO C++, but we accept it in some modes. If we 6105 are not in one of those modes, issue a diagnostic. Return the 6106 converted expression. */ 6107 6108 tree 6109 convert_member_func_to_ptr (tree type, tree expr) 6110 { 6111 tree intype; 6112 tree decl; 6113 6114 intype = TREE_TYPE (expr); 6115 gcc_assert (TYPE_PTRMEMFUNC_P (intype) 6116 || TREE_CODE (intype) == METHOD_TYPE); 6117 6118 if (pedantic || warn_pmf2ptr) 6119 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpmf_conversions, 6120 "converting from %qT to %qT", intype, type); 6121 6122 if (TREE_CODE (intype) == METHOD_TYPE) 6123 expr = build_addr_func (expr); 6124 else if (TREE_CODE (expr) == PTRMEM_CST) 6125 expr = build_address (PTRMEM_CST_MEMBER (expr)); 6126 else 6127 { 6128 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0); 6129 decl = build_address (decl); 6130 expr = get_member_function_from_ptrfunc (&decl, expr); 6131 } 6132 6133 return build_nop (type, expr); 6134 } 6135 6136 /* Return a representation for a reinterpret_cast from EXPR to TYPE. 6137 If C_CAST_P is true, this reinterpret cast is being done as part of 6138 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to 6139 indicate whether or not reinterpret_cast was valid. */ 6140 6141 static tree 6142 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p, 6143 bool *valid_p, tsubst_flags_t complain) 6144 { 6145 tree intype; 6146 6147 /* Assume the cast is invalid. */ 6148 if (valid_p) 6149 *valid_p = true; 6150 6151 if (type == error_mark_node || error_operand_p (expr)) 6152 return error_mark_node; 6153 6154 intype = TREE_TYPE (expr); 6155 6156 /* Save casted types in the function's used types hash table. */ 6157 used_types_insert (type); 6158 6159 /* [expr.reinterpret.cast] 6160 An lvalue expression of type T1 can be cast to the type 6161 "reference to T2" if an expression of type "pointer to T1" can be 6162 explicitly converted to the type "pointer to T2" using a 6163 reinterpret_cast. */ 6164 if (TREE_CODE (type) == REFERENCE_TYPE) 6165 { 6166 if (! real_lvalue_p (expr)) 6167 { 6168 if (complain & tf_error) 6169 error ("invalid cast of an rvalue expression of type " 6170 "%qT to type %qT", 6171 intype, type); 6172 return error_mark_node; 6173 } 6174 6175 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and 6176 "B" are related class types; the reinterpret_cast does not 6177 adjust the pointer. */ 6178 if (TYPE_PTR_P (intype) 6179 && (complain & tf_warning) 6180 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type), 6181 COMPARE_BASE | COMPARE_DERIVED))) 6182 warning (0, "casting %qT to %qT does not dereference pointer", 6183 intype, type); 6184 6185 expr = cp_build_addr_expr (expr, complain); 6186 6187 if (warn_strict_aliasing > 2) 6188 strict_aliasing_warning (TREE_TYPE (expr), type, expr); 6189 6190 if (expr != error_mark_node) 6191 expr = build_reinterpret_cast_1 6192 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p, 6193 valid_p, complain); 6194 if (expr != error_mark_node) 6195 /* cp_build_indirect_ref isn't right for rvalue refs. */ 6196 expr = convert_from_reference (fold_convert (type, expr)); 6197 return expr; 6198 } 6199 6200 /* As a G++ extension, we consider conversions from member 6201 functions, and pointers to member functions to 6202 pointer-to-function and pointer-to-void types. If 6203 -Wno-pmf-conversions has not been specified, 6204 convert_member_func_to_ptr will issue an error message. */ 6205 if ((TYPE_PTRMEMFUNC_P (intype) 6206 || TREE_CODE (intype) == METHOD_TYPE) 6207 && TYPE_PTR_P (type) 6208 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE 6209 || VOID_TYPE_P (TREE_TYPE (type)))) 6210 return convert_member_func_to_ptr (type, expr); 6211 6212 /* If the cast is not to a reference type, the lvalue-to-rvalue, 6213 array-to-pointer, and function-to-pointer conversions are 6214 performed. */ 6215 expr = decay_conversion (expr); 6216 6217 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 6218 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ 6219 if (TREE_CODE (expr) == NOP_EXPR 6220 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) 6221 expr = TREE_OPERAND (expr, 0); 6222 6223 if (error_operand_p (expr)) 6224 return error_mark_node; 6225 6226 intype = TREE_TYPE (expr); 6227 6228 /* [expr.reinterpret.cast] 6229 A pointer can be converted to any integral type large enough to 6230 hold it. ... A value of type std::nullptr_t can be converted to 6231 an integral type; the conversion has the same meaning and 6232 validity as a conversion of (void*)0 to the integral type. */ 6233 if (CP_INTEGRAL_TYPE_P (type) 6234 && (TYPE_PTR_P (intype) || NULLPTR_TYPE_P (intype))) 6235 { 6236 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype)) 6237 { 6238 if (complain & tf_error) 6239 permerror (input_location, "cast from %qT to %qT loses precision", 6240 intype, type); 6241 else 6242 return error_mark_node; 6243 } 6244 if (NULLPTR_TYPE_P (intype)) 6245 return build_int_cst (type, 0); 6246 } 6247 /* [expr.reinterpret.cast] 6248 A value of integral or enumeration type can be explicitly 6249 converted to a pointer. */ 6250 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)) 6251 /* OK */ 6252 ; 6253 else if ((INTEGRAL_OR_ENUMERATION_TYPE_P (type) 6254 || TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)) 6255 && same_type_p (type, intype)) 6256 /* DR 799 */ 6257 return fold_if_not_in_template (build_nop (type, expr)); 6258 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype)) 6259 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) 6260 return fold_if_not_in_template (build_nop (type, expr)); 6261 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) 6262 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype))) 6263 { 6264 tree sexpr = expr; 6265 6266 if (!c_cast_p 6267 && check_for_casting_away_constness (intype, type, 6268 REINTERPRET_CAST_EXPR, 6269 complain)) 6270 return error_mark_node; 6271 /* Warn about possible alignment problems. */ 6272 if (STRICT_ALIGNMENT && warn_cast_align 6273 && (complain & tf_warning) 6274 && !VOID_TYPE_P (type) 6275 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE 6276 && COMPLETE_TYPE_P (TREE_TYPE (type)) 6277 && COMPLETE_TYPE_P (TREE_TYPE (intype)) 6278 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype))) 6279 warning (OPT_Wcast_align, "cast from %qT to %qT " 6280 "increases required alignment of target type", intype, type); 6281 6282 /* We need to strip nops here, because the front end likes to 6283 create (int *)&a for array-to-pointer decay, instead of &a[0]. */ 6284 STRIP_NOPS (sexpr); 6285 if (warn_strict_aliasing <= 2) 6286 strict_aliasing_warning (intype, type, sexpr); 6287 6288 return fold_if_not_in_template (build_nop (type, expr)); 6289 } 6290 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype)) 6291 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type))) 6292 { 6293 if (pedantic && (complain & tf_warning)) 6294 /* Only issue a warning, as we have always supported this 6295 where possible, and it is necessary in some cases. DR 195 6296 addresses this issue, but as of 2004/10/26 is still in 6297 drafting. */ 6298 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object"); 6299 return fold_if_not_in_template (build_nop (type, expr)); 6300 } 6301 else if (TREE_CODE (type) == VECTOR_TYPE) 6302 return fold_if_not_in_template (convert_to_vector (type, expr)); 6303 else if (TREE_CODE (intype) == VECTOR_TYPE 6304 && INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 6305 return fold_if_not_in_template (convert_to_integer (type, expr)); 6306 else 6307 { 6308 if (valid_p) 6309 *valid_p = false; 6310 if (complain & tf_error) 6311 error ("invalid cast from type %qT to type %qT", intype, type); 6312 return error_mark_node; 6313 } 6314 6315 return cp_convert (type, expr); 6316 } 6317 6318 tree 6319 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain) 6320 { 6321 if (type == error_mark_node || expr == error_mark_node) 6322 return error_mark_node; 6323 6324 if (processing_template_decl) 6325 { 6326 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr); 6327 6328 if (!TREE_SIDE_EFFECTS (t) 6329 && type_dependent_expression_p (expr)) 6330 /* There might turn out to be side effects inside expr. */ 6331 TREE_SIDE_EFFECTS (t) = 1; 6332 return convert_from_reference (t); 6333 } 6334 6335 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false, 6336 /*valid_p=*/NULL, complain); 6337 } 6338 6339 /* Perform a const_cast from EXPR to TYPE. If the cast is valid, 6340 return an appropriate expression. Otherwise, return 6341 error_mark_node. If the cast is not valid, and COMPLAIN is true, 6342 then a diagnostic will be issued. If VALID_P is non-NULL, we are 6343 performing a C-style cast, its value upon return will indicate 6344 whether or not the conversion succeeded. */ 6345 6346 static tree 6347 build_const_cast_1 (tree dst_type, tree expr, tsubst_flags_t complain, 6348 bool *valid_p) 6349 { 6350 tree src_type; 6351 tree reference_type; 6352 6353 /* Callers are responsible for handling error_mark_node as a 6354 destination type. */ 6355 gcc_assert (dst_type != error_mark_node); 6356 /* In a template, callers should be building syntactic 6357 representations of casts, not using this machinery. */ 6358 gcc_assert (!processing_template_decl); 6359 6360 /* Assume the conversion is invalid. */ 6361 if (valid_p) 6362 *valid_p = false; 6363 6364 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type)) 6365 { 6366 if (complain & tf_error) 6367 error ("invalid use of const_cast with type %qT, " 6368 "which is not a pointer, " 6369 "reference, nor a pointer-to-data-member type", dst_type); 6370 return error_mark_node; 6371 } 6372 6373 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE) 6374 { 6375 if (complain & tf_error) 6376 error ("invalid use of const_cast with type %qT, which is a pointer " 6377 "or reference to a function type", dst_type); 6378 return error_mark_node; 6379 } 6380 6381 /* Save casted types in the function's used types hash table. */ 6382 used_types_insert (dst_type); 6383 6384 src_type = TREE_TYPE (expr); 6385 /* Expressions do not really have reference types. */ 6386 if (TREE_CODE (src_type) == REFERENCE_TYPE) 6387 src_type = TREE_TYPE (src_type); 6388 6389 /* [expr.const.cast] 6390 6391 For two object types T1 and T2, if a pointer to T1 can be explicitly 6392 converted to the type "pointer to T2" using a const_cast, then the 6393 following conversions can also be made: 6394 6395 -- an lvalue of type T1 can be explicitly converted to an lvalue of 6396 type T2 using the cast const_cast<T2&>; 6397 6398 -- a glvalue of type T1 can be explicitly converted to an xvalue of 6399 type T2 using the cast const_cast<T2&&>; and 6400 6401 -- if T1 is a class type, a prvalue of type T1 can be explicitly 6402 converted to an xvalue of type T2 using the cast const_cast<T2&&>. */ 6403 6404 if (TREE_CODE (dst_type) == REFERENCE_TYPE) 6405 { 6406 reference_type = dst_type; 6407 if (!TYPE_REF_IS_RVALUE (dst_type) 6408 ? real_lvalue_p (expr) 6409 : (CLASS_TYPE_P (TREE_TYPE (dst_type)) 6410 ? lvalue_p (expr) 6411 : lvalue_or_rvalue_with_address_p (expr))) 6412 /* OK. */; 6413 else 6414 { 6415 if (complain & tf_error) 6416 error ("invalid const_cast of an rvalue of type %qT to type %qT", 6417 src_type, dst_type); 6418 return error_mark_node; 6419 } 6420 dst_type = build_pointer_type (TREE_TYPE (dst_type)); 6421 src_type = build_pointer_type (src_type); 6422 } 6423 else 6424 { 6425 reference_type = NULL_TREE; 6426 /* If the destination type is not a reference type, the 6427 lvalue-to-rvalue, array-to-pointer, and function-to-pointer 6428 conversions are performed. */ 6429 src_type = type_decays_to (src_type); 6430 if (src_type == error_mark_node) 6431 return error_mark_node; 6432 } 6433 6434 if (TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type)) 6435 { 6436 if (comp_ptr_ttypes_const (dst_type, src_type)) 6437 { 6438 if (valid_p) 6439 { 6440 *valid_p = true; 6441 /* This cast is actually a C-style cast. Issue a warning if 6442 the user is making a potentially unsafe cast. */ 6443 check_for_casting_away_constness (src_type, dst_type, 6444 CAST_EXPR, complain); 6445 } 6446 if (reference_type) 6447 { 6448 expr = cp_build_addr_expr (expr, complain); 6449 expr = build_nop (reference_type, expr); 6450 return convert_from_reference (expr); 6451 } 6452 else 6453 { 6454 expr = decay_conversion (expr); 6455 /* build_c_cast puts on a NOP_EXPR to make the result not an 6456 lvalue. Strip such NOP_EXPRs if VALUE is being used in 6457 non-lvalue context. */ 6458 if (TREE_CODE (expr) == NOP_EXPR 6459 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) 6460 expr = TREE_OPERAND (expr, 0); 6461 return build_nop (dst_type, expr); 6462 } 6463 } 6464 else if (valid_p 6465 && !at_least_as_qualified_p (TREE_TYPE (dst_type), 6466 TREE_TYPE (src_type))) 6467 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR, 6468 complain); 6469 } 6470 6471 if (complain & tf_error) 6472 error ("invalid const_cast from type %qT to type %qT", 6473 src_type, dst_type); 6474 return error_mark_node; 6475 } 6476 6477 tree 6478 build_const_cast (tree type, tree expr, tsubst_flags_t complain) 6479 { 6480 if (type == error_mark_node || error_operand_p (expr)) 6481 return error_mark_node; 6482 6483 if (processing_template_decl) 6484 { 6485 tree t = build_min (CONST_CAST_EXPR, type, expr); 6486 6487 if (!TREE_SIDE_EFFECTS (t) 6488 && type_dependent_expression_p (expr)) 6489 /* There might turn out to be side effects inside expr. */ 6490 TREE_SIDE_EFFECTS (t) = 1; 6491 return convert_from_reference (t); 6492 } 6493 6494 return build_const_cast_1 (type, expr, complain, 6495 /*valid_p=*/NULL); 6496 } 6497 6498 /* Like cp_build_c_cast, but for the c-common bits. */ 6499 6500 tree 6501 build_c_cast (location_t loc ATTRIBUTE_UNUSED, tree type, tree expr) 6502 { 6503 return cp_build_c_cast (type, expr, tf_warning_or_error); 6504 } 6505 6506 /* Build an expression representing an explicit C-style cast to type 6507 TYPE of expression EXPR. */ 6508 6509 tree 6510 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain) 6511 { 6512 tree value = expr; 6513 tree result; 6514 bool valid_p; 6515 6516 if (type == error_mark_node || error_operand_p (expr)) 6517 return error_mark_node; 6518 6519 if (processing_template_decl) 6520 { 6521 tree t = build_min (CAST_EXPR, type, 6522 tree_cons (NULL_TREE, value, NULL_TREE)); 6523 /* We don't know if it will or will not have side effects. */ 6524 TREE_SIDE_EFFECTS (t) = 1; 6525 return convert_from_reference (t); 6526 } 6527 6528 /* Casts to a (pointer to a) specific ObjC class (or 'id' or 6529 'Class') should always be retained, because this information aids 6530 in method lookup. */ 6531 if (objc_is_object_ptr (type) 6532 && objc_is_object_ptr (TREE_TYPE (expr))) 6533 return build_nop (type, expr); 6534 6535 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 6536 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ 6537 if (TREE_CODE (type) != REFERENCE_TYPE 6538 && TREE_CODE (value) == NOP_EXPR 6539 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0))) 6540 value = TREE_OPERAND (value, 0); 6541 6542 if (TREE_CODE (type) == ARRAY_TYPE) 6543 { 6544 /* Allow casting from T1* to T2[] because Cfront allows it. 6545 NIHCL uses it. It is not valid ISO C++ however. */ 6546 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE) 6547 { 6548 if (complain & tf_error) 6549 permerror (input_location, "ISO C++ forbids casting to an array type %qT", type); 6550 else 6551 return error_mark_node; 6552 type = build_pointer_type (TREE_TYPE (type)); 6553 } 6554 else 6555 { 6556 if (complain & tf_error) 6557 error ("ISO C++ forbids casting to an array type %qT", type); 6558 return error_mark_node; 6559 } 6560 } 6561 6562 if (TREE_CODE (type) == FUNCTION_TYPE 6563 || TREE_CODE (type) == METHOD_TYPE) 6564 { 6565 if (complain & tf_error) 6566 error ("invalid cast to function type %qT", type); 6567 return error_mark_node; 6568 } 6569 6570 if (TREE_CODE (type) == POINTER_TYPE 6571 && TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE 6572 /* Casting to an integer of smaller size is an error detected elsewhere. */ 6573 && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (value)) 6574 /* Don't warn about converting any constant. */ 6575 && !TREE_CONSTANT (value)) 6576 warning_at (input_location, OPT_Wint_to_pointer_cast, 6577 "cast to pointer from integer of different size"); 6578 6579 /* A C-style cast can be a const_cast. */ 6580 result = build_const_cast_1 (type, value, complain & tf_warning, 6581 &valid_p); 6582 if (valid_p) 6583 return result; 6584 6585 /* Or a static cast. */ 6586 result = build_static_cast_1 (type, value, /*c_cast_p=*/true, 6587 &valid_p, complain); 6588 /* Or a reinterpret_cast. */ 6589 if (!valid_p) 6590 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true, 6591 &valid_p, complain); 6592 /* The static_cast or reinterpret_cast may be followed by a 6593 const_cast. */ 6594 if (valid_p 6595 /* A valid cast may result in errors if, for example, a 6596 conversion to am ambiguous base class is required. */ 6597 && !error_operand_p (result)) 6598 { 6599 tree result_type; 6600 6601 /* Non-class rvalues always have cv-unqualified type. */ 6602 if (!CLASS_TYPE_P (type)) 6603 type = TYPE_MAIN_VARIANT (type); 6604 result_type = TREE_TYPE (result); 6605 if (!CLASS_TYPE_P (result_type) && TREE_CODE (type) != REFERENCE_TYPE) 6606 result_type = TYPE_MAIN_VARIANT (result_type); 6607 /* If the type of RESULT does not match TYPE, perform a 6608 const_cast to make it match. If the static_cast or 6609 reinterpret_cast succeeded, we will differ by at most 6610 cv-qualification, so the follow-on const_cast is guaranteed 6611 to succeed. */ 6612 if (!same_type_p (non_reference (type), non_reference (result_type))) 6613 { 6614 result = build_const_cast_1 (type, result, false, &valid_p); 6615 gcc_assert (valid_p); 6616 } 6617 return result; 6618 } 6619 6620 return error_mark_node; 6621 } 6622 6623 /* For use from the C common bits. */ 6624 tree 6625 build_modify_expr (location_t location ATTRIBUTE_UNUSED, 6626 tree lhs, tree lhs_origtype ATTRIBUTE_UNUSED, 6627 enum tree_code modifycode, 6628 location_t rhs_location ATTRIBUTE_UNUSED, tree rhs, 6629 tree rhs_origtype ATTRIBUTE_UNUSED) 6630 { 6631 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error); 6632 } 6633 6634 /* Build an assignment expression of lvalue LHS from value RHS. 6635 MODIFYCODE is the code for a binary operator that we use 6636 to combine the old value of LHS with RHS to get the new value. 6637 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. 6638 6639 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */ 6640 6641 tree 6642 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs, 6643 tsubst_flags_t complain) 6644 { 6645 tree result; 6646 tree newrhs = rhs; 6647 tree lhstype = TREE_TYPE (lhs); 6648 tree olhstype = lhstype; 6649 bool plain_assign = (modifycode == NOP_EXPR); 6650 6651 /* Avoid duplicate error messages from operands that had errors. */ 6652 if (error_operand_p (lhs) || error_operand_p (rhs)) 6653 return error_mark_node; 6654 6655 /* Handle control structure constructs used as "lvalues". */ 6656 switch (TREE_CODE (lhs)) 6657 { 6658 /* Handle --foo = 5; as these are valid constructs in C++. */ 6659 case PREDECREMENT_EXPR: 6660 case PREINCREMENT_EXPR: 6661 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))) 6662 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs), 6663 stabilize_reference (TREE_OPERAND (lhs, 0)), 6664 TREE_OPERAND (lhs, 1)); 6665 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), 6666 modifycode, rhs, complain); 6667 if (newrhs == error_mark_node) 6668 return error_mark_node; 6669 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs); 6670 6671 /* Handle (a, b) used as an "lvalue". */ 6672 case COMPOUND_EXPR: 6673 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1), 6674 modifycode, rhs, complain); 6675 if (newrhs == error_mark_node) 6676 return error_mark_node; 6677 return build2 (COMPOUND_EXPR, lhstype, 6678 TREE_OPERAND (lhs, 0), newrhs); 6679 6680 case MODIFY_EXPR: 6681 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))) 6682 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs), 6683 stabilize_reference (TREE_OPERAND (lhs, 0)), 6684 TREE_OPERAND (lhs, 1)); 6685 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs, 6686 complain); 6687 if (newrhs == error_mark_node) 6688 return error_mark_node; 6689 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs); 6690 6691 case MIN_EXPR: 6692 case MAX_EXPR: 6693 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues, 6694 when neither operand has side-effects. */ 6695 if (!lvalue_or_else (lhs, lv_assign, complain)) 6696 return error_mark_node; 6697 6698 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)) 6699 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1))); 6700 6701 lhs = build3 (COND_EXPR, TREE_TYPE (lhs), 6702 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR, 6703 boolean_type_node, 6704 TREE_OPERAND (lhs, 0), 6705 TREE_OPERAND (lhs, 1)), 6706 TREE_OPERAND (lhs, 0), 6707 TREE_OPERAND (lhs, 1)); 6708 /* Fall through. */ 6709 6710 /* Handle (a ? b : c) used as an "lvalue". */ 6711 case COND_EXPR: 6712 { 6713 /* Produce (a ? (b = rhs) : (c = rhs)) 6714 except that the RHS goes through a save-expr 6715 so the code to compute it is only emitted once. */ 6716 tree cond; 6717 tree preeval = NULL_TREE; 6718 6719 if (VOID_TYPE_P (TREE_TYPE (rhs))) 6720 { 6721 if (complain & tf_error) 6722 error ("void value not ignored as it ought to be"); 6723 return error_mark_node; 6724 } 6725 6726 rhs = stabilize_expr (rhs, &preeval); 6727 6728 /* Check this here to avoid odd errors when trying to convert 6729 a throw to the type of the COND_EXPR. */ 6730 if (!lvalue_or_else (lhs, lv_assign, complain)) 6731 return error_mark_node; 6732 6733 cond = build_conditional_expr 6734 (TREE_OPERAND (lhs, 0), 6735 cp_build_modify_expr (TREE_OPERAND (lhs, 1), 6736 modifycode, rhs, complain), 6737 cp_build_modify_expr (TREE_OPERAND (lhs, 2), 6738 modifycode, rhs, complain), 6739 complain); 6740 6741 if (cond == error_mark_node) 6742 return cond; 6743 /* Make sure the code to compute the rhs comes out 6744 before the split. */ 6745 if (preeval) 6746 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond); 6747 return cond; 6748 } 6749 6750 default: 6751 break; 6752 } 6753 6754 if (modifycode == INIT_EXPR) 6755 { 6756 if (BRACE_ENCLOSED_INITIALIZER_P (rhs)) 6757 /* Do the default thing. */; 6758 else if (TREE_CODE (rhs) == CONSTRUCTOR) 6759 { 6760 /* Compound literal. */ 6761 if (! same_type_p (TREE_TYPE (rhs), lhstype)) 6762 /* Call convert to generate an error; see PR 11063. */ 6763 rhs = convert (lhstype, rhs); 6764 result = build2 (INIT_EXPR, lhstype, lhs, rhs); 6765 TREE_SIDE_EFFECTS (result) = 1; 6766 return result; 6767 } 6768 else if (! MAYBE_CLASS_TYPE_P (lhstype)) 6769 /* Do the default thing. */; 6770 else 6771 { 6772 VEC(tree,gc) *rhs_vec = make_tree_vector_single (rhs); 6773 result = build_special_member_call (lhs, complete_ctor_identifier, 6774 &rhs_vec, lhstype, LOOKUP_NORMAL, 6775 complain); 6776 release_tree_vector (rhs_vec); 6777 if (result == NULL_TREE) 6778 return error_mark_node; 6779 return result; 6780 } 6781 } 6782 else 6783 { 6784 lhs = require_complete_type_sfinae (lhs, complain); 6785 if (lhs == error_mark_node) 6786 return error_mark_node; 6787 6788 if (modifycode == NOP_EXPR) 6789 { 6790 if (c_dialect_objc ()) 6791 { 6792 result = objc_maybe_build_modify_expr (lhs, rhs); 6793 if (result) 6794 return result; 6795 } 6796 6797 /* `operator=' is not an inheritable operator. */ 6798 if (! MAYBE_CLASS_TYPE_P (lhstype)) 6799 /* Do the default thing. */; 6800 else 6801 { 6802 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, 6803 lhs, rhs, make_node (NOP_EXPR), 6804 /*overload=*/NULL, 6805 complain); 6806 if (result == NULL_TREE) 6807 return error_mark_node; 6808 return result; 6809 } 6810 lhstype = olhstype; 6811 } 6812 else 6813 { 6814 tree init = NULL_TREE; 6815 6816 /* A binary op has been requested. Combine the old LHS 6817 value with the RHS producing the value we should actually 6818 store into the LHS. */ 6819 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE 6820 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype))) 6821 || MAYBE_CLASS_TYPE_P (lhstype))); 6822 6823 /* Preevaluate the RHS to make sure its evaluation is complete 6824 before the lvalue-to-rvalue conversion of the LHS: 6825 6826 [expr.ass] With respect to an indeterminately-sequenced 6827 function call, the operation of a compound assignment is a 6828 single evaluation. [ Note: Therefore, a function call shall 6829 not intervene between the lvalue-to-rvalue conversion and the 6830 side effect associated with any single compound assignment 6831 operator. -- end note ] */ 6832 lhs = stabilize_reference (lhs); 6833 if (TREE_SIDE_EFFECTS (rhs)) 6834 rhs = mark_rvalue_use (rhs); 6835 rhs = stabilize_expr (rhs, &init); 6836 newrhs = cp_build_binary_op (input_location, 6837 modifycode, lhs, rhs, 6838 complain); 6839 if (newrhs == error_mark_node) 6840 { 6841 if (complain & tf_error) 6842 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode, 6843 TREE_TYPE (lhs), TREE_TYPE (rhs)); 6844 return error_mark_node; 6845 } 6846 6847 if (init) 6848 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), init, newrhs); 6849 6850 /* Now it looks like a plain assignment. */ 6851 modifycode = NOP_EXPR; 6852 if (c_dialect_objc ()) 6853 { 6854 result = objc_maybe_build_modify_expr (lhs, newrhs); 6855 if (result) 6856 return result; 6857 } 6858 } 6859 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE); 6860 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE); 6861 } 6862 6863 /* The left-hand side must be an lvalue. */ 6864 if (!lvalue_or_else (lhs, lv_assign, complain)) 6865 return error_mark_node; 6866 6867 /* Warn about modifying something that is `const'. Don't warn if 6868 this is initialization. */ 6869 if (modifycode != INIT_EXPR 6870 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype) 6871 /* Functions are not modifiable, even though they are 6872 lvalues. */ 6873 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE 6874 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE 6875 /* If it's an aggregate and any field is const, then it is 6876 effectively const. */ 6877 || (CLASS_TYPE_P (lhstype) 6878 && C_TYPE_FIELDS_READONLY (lhstype)))) 6879 { 6880 if (complain & tf_error) 6881 cxx_readonly_error (lhs, lv_assign); 6882 else 6883 return error_mark_node; 6884 } 6885 6886 /* If storing into a structure or union member, it may have been given a 6887 lowered bitfield type. We need to convert to the declared type first, 6888 so retrieve it now. */ 6889 6890 olhstype = unlowered_expr_type (lhs); 6891 6892 /* Convert new value to destination type. */ 6893 6894 if (TREE_CODE (lhstype) == ARRAY_TYPE) 6895 { 6896 int from_array; 6897 6898 if (BRACE_ENCLOSED_INITIALIZER_P (newrhs)) 6899 { 6900 if (modifycode != INIT_EXPR) 6901 { 6902 if (complain & tf_error) 6903 error ("assigning to an array from an initializer list"); 6904 return error_mark_node; 6905 } 6906 if (check_array_initializer (lhs, lhstype, newrhs)) 6907 return error_mark_node; 6908 newrhs = digest_init (lhstype, newrhs, complain); 6909 if (newrhs == error_mark_node) 6910 return error_mark_node; 6911 } 6912 6913 else if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype), 6914 TYPE_MAIN_VARIANT (TREE_TYPE (newrhs)))) 6915 { 6916 if (complain & tf_error) 6917 error ("incompatible types in assignment of %qT to %qT", 6918 TREE_TYPE (rhs), lhstype); 6919 return error_mark_node; 6920 } 6921 6922 /* Allow array assignment in compiler-generated code. */ 6923 else if (!current_function_decl 6924 || !DECL_DEFAULTED_FN (current_function_decl)) 6925 { 6926 /* This routine is used for both initialization and assignment. 6927 Make sure the diagnostic message differentiates the context. */ 6928 if (complain & tf_error) 6929 { 6930 if (modifycode == INIT_EXPR) 6931 error ("array used as initializer"); 6932 else 6933 error ("invalid array assignment"); 6934 } 6935 return error_mark_node; 6936 } 6937 6938 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE 6939 ? 1 + (modifycode != INIT_EXPR): 0; 6940 return build_vec_init (lhs, NULL_TREE, newrhs, 6941 /*explicit_value_init_p=*/false, 6942 from_array, complain); 6943 } 6944 6945 if (modifycode == INIT_EXPR) 6946 /* Calls with INIT_EXPR are all direct-initialization, so don't set 6947 LOOKUP_ONLYCONVERTING. */ 6948 newrhs = convert_for_initialization (lhs, olhstype, newrhs, LOOKUP_NORMAL, 6949 ICR_INIT, NULL_TREE, 0, 6950 complain); 6951 else 6952 newrhs = convert_for_assignment (olhstype, newrhs, ICR_ASSIGN, 6953 NULL_TREE, 0, complain, LOOKUP_IMPLICIT); 6954 6955 if (!same_type_p (lhstype, olhstype)) 6956 newrhs = cp_convert_and_check (lhstype, newrhs); 6957 6958 if (modifycode != INIT_EXPR) 6959 { 6960 if (TREE_CODE (newrhs) == CALL_EXPR 6961 && TYPE_NEEDS_CONSTRUCTING (lhstype)) 6962 newrhs = build_cplus_new (lhstype, newrhs, complain); 6963 6964 /* Can't initialize directly from a TARGET_EXPR, since that would 6965 cause the lhs to be constructed twice, and possibly result in 6966 accidental self-initialization. So we force the TARGET_EXPR to be 6967 expanded without a target. */ 6968 if (TREE_CODE (newrhs) == TARGET_EXPR) 6969 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs, 6970 TREE_OPERAND (newrhs, 0)); 6971 } 6972 6973 if (newrhs == error_mark_node) 6974 return error_mark_node; 6975 6976 if (c_dialect_objc () && flag_objc_gc) 6977 { 6978 result = objc_generate_write_barrier (lhs, modifycode, newrhs); 6979 6980 if (result) 6981 return result; 6982 } 6983 6984 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR, 6985 lhstype, lhs, newrhs); 6986 6987 TREE_SIDE_EFFECTS (result) = 1; 6988 if (!plain_assign) 6989 TREE_NO_WARNING (result) = 1; 6990 6991 return result; 6992 } 6993 6994 tree 6995 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs, 6996 tsubst_flags_t complain) 6997 { 6998 if (processing_template_decl) 6999 return build_min_nt (MODOP_EXPR, lhs, 7000 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs); 7001 7002 if (modifycode != NOP_EXPR) 7003 { 7004 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs, 7005 make_node (modifycode), 7006 /*overload=*/NULL, 7007 complain); 7008 if (rval) 7009 { 7010 TREE_NO_WARNING (rval) = 1; 7011 return rval; 7012 } 7013 } 7014 return cp_build_modify_expr (lhs, modifycode, rhs, complain); 7015 } 7016 7017 /* Helper function for get_delta_difference which assumes FROM is a base 7018 class of TO. Returns a delta for the conversion of pointer-to-member 7019 of FROM to pointer-to-member of TO. If the conversion is invalid and 7020 tf_error is not set in COMPLAIN returns error_mark_node, otherwise 7021 returns zero. If FROM is not a base class of TO, returns NULL_TREE. 7022 If C_CAST_P is true, this conversion is taking place as part of a 7023 C-style cast. */ 7024 7025 static tree 7026 get_delta_difference_1 (tree from, tree to, bool c_cast_p, 7027 tsubst_flags_t complain) 7028 { 7029 tree binfo; 7030 base_kind kind; 7031 base_access access = c_cast_p ? ba_unique : ba_check; 7032 7033 /* Note: ba_quiet does not distinguish between access control and 7034 ambiguity. */ 7035 if (!(complain & tf_error)) 7036 access |= ba_quiet; 7037 7038 binfo = lookup_base (to, from, access, &kind); 7039 7040 if (kind == bk_inaccessible || kind == bk_ambig) 7041 { 7042 if (!(complain & tf_error)) 7043 return error_mark_node; 7044 7045 error (" in pointer to member function conversion"); 7046 return size_zero_node; 7047 } 7048 else if (binfo) 7049 { 7050 if (kind != bk_via_virtual) 7051 return BINFO_OFFSET (binfo); 7052 else 7053 /* FROM is a virtual base class of TO. Issue an error or warning 7054 depending on whether or not this is a reinterpret cast. */ 7055 { 7056 if (!(complain & tf_error)) 7057 return error_mark_node; 7058 7059 error ("pointer to member conversion via virtual base %qT", 7060 BINFO_TYPE (binfo_from_vbase (binfo))); 7061 7062 return size_zero_node; 7063 } 7064 } 7065 else 7066 return NULL_TREE; 7067 } 7068 7069 /* Get difference in deltas for different pointer to member function 7070 types. If the conversion is invalid and tf_error is not set in 7071 COMPLAIN, returns error_mark_node, otherwise returns an integer 7072 constant of type PTRDIFF_TYPE_NODE and its value is zero if the 7073 conversion is invalid. If ALLOW_INVERSE_P is true, then allow reverse 7074 conversions as well. If C_CAST_P is true this conversion is taking 7075 place as part of a C-style cast. 7076 7077 Note that the naming of FROM and TO is kind of backwards; the return 7078 value is what we add to a TO in order to get a FROM. They are named 7079 this way because we call this function to find out how to convert from 7080 a pointer to member of FROM to a pointer to member of TO. */ 7081 7082 static tree 7083 get_delta_difference (tree from, tree to, 7084 bool allow_inverse_p, 7085 bool c_cast_p, tsubst_flags_t complain) 7086 { 7087 tree result; 7088 7089 if (same_type_ignoring_top_level_qualifiers_p (from, to)) 7090 /* Pointer to member of incomplete class is permitted*/ 7091 result = size_zero_node; 7092 else 7093 result = get_delta_difference_1 (from, to, c_cast_p, complain); 7094 7095 if (result == error_mark_node) 7096 return error_mark_node; 7097 7098 if (!result) 7099 { 7100 if (!allow_inverse_p) 7101 { 7102 if (!(complain & tf_error)) 7103 return error_mark_node; 7104 7105 error_not_base_type (from, to); 7106 error (" in pointer to member conversion"); 7107 result = size_zero_node; 7108 } 7109 else 7110 { 7111 result = get_delta_difference_1 (to, from, c_cast_p, complain); 7112 7113 if (result == error_mark_node) 7114 return error_mark_node; 7115 7116 if (result) 7117 result = size_diffop_loc (input_location, 7118 size_zero_node, result); 7119 else 7120 { 7121 if (!(complain & tf_error)) 7122 return error_mark_node; 7123 7124 error_not_base_type (from, to); 7125 error (" in pointer to member conversion"); 7126 result = size_zero_node; 7127 } 7128 } 7129 } 7130 7131 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node, 7132 result)); 7133 } 7134 7135 /* Return a constructor for the pointer-to-member-function TYPE using 7136 the other components as specified. */ 7137 7138 tree 7139 build_ptrmemfunc1 (tree type, tree delta, tree pfn) 7140 { 7141 tree u = NULL_TREE; 7142 tree delta_field; 7143 tree pfn_field; 7144 VEC(constructor_elt, gc) *v; 7145 7146 /* Pull the FIELD_DECLs out of the type. */ 7147 pfn_field = TYPE_FIELDS (type); 7148 delta_field = DECL_CHAIN (pfn_field); 7149 7150 /* Make sure DELTA has the type we want. */ 7151 delta = convert_and_check (delta_type_node, delta); 7152 7153 /* Convert to the correct target type if necessary. */ 7154 pfn = fold_convert (TREE_TYPE (pfn_field), pfn); 7155 7156 /* Finish creating the initializer. */ 7157 v = VEC_alloc(constructor_elt, gc, 2); 7158 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn); 7159 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta); 7160 u = build_constructor (type, v); 7161 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta); 7162 TREE_STATIC (u) = (TREE_CONSTANT (u) 7163 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn)) 7164 != NULL_TREE) 7165 && (initializer_constant_valid_p (delta, TREE_TYPE (delta)) 7166 != NULL_TREE)); 7167 return u; 7168 } 7169 7170 /* Build a constructor for a pointer to member function. It can be 7171 used to initialize global variables, local variable, or used 7172 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we 7173 want to be. 7174 7175 If FORCE is nonzero, then force this conversion, even if 7176 we would rather not do it. Usually set when using an explicit 7177 cast. A C-style cast is being processed iff C_CAST_P is true. 7178 7179 Return error_mark_node, if something goes wrong. */ 7180 7181 tree 7182 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p, 7183 tsubst_flags_t complain) 7184 { 7185 tree fn; 7186 tree pfn_type; 7187 tree to_type; 7188 7189 if (error_operand_p (pfn)) 7190 return error_mark_node; 7191 7192 pfn_type = TREE_TYPE (pfn); 7193 to_type = build_ptrmemfunc_type (type); 7194 7195 /* Handle multiple conversions of pointer to member functions. */ 7196 if (TYPE_PTRMEMFUNC_P (pfn_type)) 7197 { 7198 tree delta = NULL_TREE; 7199 tree npfn = NULL_TREE; 7200 tree n; 7201 7202 if (!force 7203 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL)) 7204 error ("invalid conversion to type %qT from type %qT", 7205 to_type, pfn_type); 7206 7207 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type), 7208 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type), 7209 force, 7210 c_cast_p, complain); 7211 if (n == error_mark_node) 7212 return error_mark_node; 7213 7214 /* We don't have to do any conversion to convert a 7215 pointer-to-member to its own type. But, we don't want to 7216 just return a PTRMEM_CST if there's an explicit cast; that 7217 cast should make the expression an invalid template argument. */ 7218 if (TREE_CODE (pfn) != PTRMEM_CST) 7219 { 7220 if (same_type_p (to_type, pfn_type)) 7221 return pfn; 7222 else if (integer_zerop (n)) 7223 return build_reinterpret_cast (to_type, pfn, 7224 tf_warning_or_error); 7225 } 7226 7227 if (TREE_SIDE_EFFECTS (pfn)) 7228 pfn = save_expr (pfn); 7229 7230 /* Obtain the function pointer and the current DELTA. */ 7231 if (TREE_CODE (pfn) == PTRMEM_CST) 7232 expand_ptrmemfunc_cst (pfn, &delta, &npfn); 7233 else 7234 { 7235 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier); 7236 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier); 7237 } 7238 7239 /* Just adjust the DELTA field. */ 7240 gcc_assert (same_type_ignoring_top_level_qualifiers_p 7241 (TREE_TYPE (delta), ptrdiff_type_node)); 7242 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta) 7243 n = cp_build_binary_op (input_location, 7244 LSHIFT_EXPR, n, integer_one_node, 7245 tf_warning_or_error); 7246 delta = cp_build_binary_op (input_location, 7247 PLUS_EXPR, delta, n, tf_warning_or_error); 7248 return build_ptrmemfunc1 (to_type, delta, npfn); 7249 } 7250 7251 /* Handle null pointer to member function conversions. */ 7252 if (null_ptr_cst_p (pfn)) 7253 { 7254 pfn = build_c_cast (input_location, type, nullptr_node); 7255 return build_ptrmemfunc1 (to_type, 7256 integer_zero_node, 7257 pfn); 7258 } 7259 7260 if (type_unknown_p (pfn)) 7261 return instantiate_type (type, pfn, tf_warning_or_error); 7262 7263 fn = TREE_OPERAND (pfn, 0); 7264 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 7265 /* In a template, we will have preserved the 7266 OFFSET_REF. */ 7267 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF)); 7268 return make_ptrmem_cst (to_type, fn); 7269 } 7270 7271 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST 7272 given by CST. 7273 7274 ??? There is no consistency as to the types returned for the above 7275 values. Some code acts as if it were a sizetype and some as if it were 7276 integer_type_node. */ 7277 7278 void 7279 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn) 7280 { 7281 tree type = TREE_TYPE (cst); 7282 tree fn = PTRMEM_CST_MEMBER (cst); 7283 tree ptr_class, fn_class; 7284 7285 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7286 7287 /* The class that the function belongs to. */ 7288 fn_class = DECL_CONTEXT (fn); 7289 7290 /* The class that we're creating a pointer to member of. */ 7291 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type); 7292 7293 /* First, calculate the adjustment to the function's class. */ 7294 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0, 7295 /*c_cast_p=*/0, tf_warning_or_error); 7296 7297 if (!DECL_VIRTUAL_P (fn)) 7298 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn)); 7299 else 7300 { 7301 /* If we're dealing with a virtual function, we have to adjust 'this' 7302 again, to point to the base which provides the vtable entry for 7303 fn; the call will do the opposite adjustment. */ 7304 tree orig_class = DECL_CONTEXT (fn); 7305 tree binfo = binfo_or_else (orig_class, fn_class); 7306 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta), 7307 *delta, BINFO_OFFSET (binfo)); 7308 *delta = fold_if_not_in_template (*delta); 7309 7310 /* We set PFN to the vtable offset at which the function can be 7311 found, plus one (unless ptrmemfunc_vbit_in_delta, in which 7312 case delta is shifted left, and then incremented). */ 7313 *pfn = DECL_VINDEX (fn); 7314 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn, 7315 TYPE_SIZE_UNIT (vtable_entry_type)); 7316 *pfn = fold_if_not_in_template (*pfn); 7317 7318 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION) 7319 { 7320 case ptrmemfunc_vbit_in_pfn: 7321 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn, 7322 integer_one_node); 7323 *pfn = fold_if_not_in_template (*pfn); 7324 break; 7325 7326 case ptrmemfunc_vbit_in_delta: 7327 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta), 7328 *delta, integer_one_node); 7329 *delta = fold_if_not_in_template (*delta); 7330 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta), 7331 *delta, integer_one_node); 7332 *delta = fold_if_not_in_template (*delta); 7333 break; 7334 7335 default: 7336 gcc_unreachable (); 7337 } 7338 7339 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn); 7340 *pfn = fold_if_not_in_template (*pfn); 7341 } 7342 } 7343 7344 /* Return an expression for PFN from the pointer-to-member function 7345 given by T. */ 7346 7347 static tree 7348 pfn_from_ptrmemfunc (tree t) 7349 { 7350 if (TREE_CODE (t) == PTRMEM_CST) 7351 { 7352 tree delta; 7353 tree pfn; 7354 7355 expand_ptrmemfunc_cst (t, &delta, &pfn); 7356 if (pfn) 7357 return pfn; 7358 } 7359 7360 return build_ptrmemfunc_access_expr (t, pfn_identifier); 7361 } 7362 7363 /* Return an expression for DELTA from the pointer-to-member function 7364 given by T. */ 7365 7366 static tree 7367 delta_from_ptrmemfunc (tree t) 7368 { 7369 if (TREE_CODE (t) == PTRMEM_CST) 7370 { 7371 tree delta; 7372 tree pfn; 7373 7374 expand_ptrmemfunc_cst (t, &delta, &pfn); 7375 if (delta) 7376 return delta; 7377 } 7378 7379 return build_ptrmemfunc_access_expr (t, delta_identifier); 7380 } 7381 7382 /* Convert value RHS to type TYPE as preparation for an assignment to 7383 an lvalue of type TYPE. ERRTYPE indicates what kind of error the 7384 implicit conversion is. If FNDECL is non-NULL, we are doing the 7385 conversion in order to pass the PARMNUMth argument of FNDECL. 7386 If FNDECL is NULL, we are doing the conversion in function pointer 7387 argument passing, conversion in initialization, etc. */ 7388 7389 static tree 7390 convert_for_assignment (tree type, tree rhs, 7391 impl_conv_rhs errtype, tree fndecl, int parmnum, 7392 tsubst_flags_t complain, int flags) 7393 { 7394 tree rhstype; 7395 enum tree_code coder; 7396 7397 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ 7398 if (TREE_CODE (rhs) == NON_LVALUE_EXPR) 7399 rhs = TREE_OPERAND (rhs, 0); 7400 7401 rhstype = TREE_TYPE (rhs); 7402 coder = TREE_CODE (rhstype); 7403 7404 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE 7405 && vector_types_convertible_p (type, rhstype, true)) 7406 { 7407 rhs = mark_rvalue_use (rhs); 7408 return convert (type, rhs); 7409 } 7410 7411 if (rhs == error_mark_node || rhstype == error_mark_node) 7412 return error_mark_node; 7413 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node) 7414 return error_mark_node; 7415 7416 /* The RHS of an assignment cannot have void type. */ 7417 if (coder == VOID_TYPE) 7418 { 7419 if (complain & tf_error) 7420 error ("void value not ignored as it ought to be"); 7421 return error_mark_node; 7422 } 7423 7424 /* Simplify the RHS if possible. */ 7425 if (TREE_CODE (rhs) == CONST_DECL) 7426 rhs = DECL_INITIAL (rhs); 7427 7428 if (c_dialect_objc ()) 7429 { 7430 int parmno; 7431 tree selector; 7432 tree rname = fndecl; 7433 7434 switch (errtype) 7435 { 7436 case ICR_ASSIGN: 7437 parmno = -1; 7438 break; 7439 case ICR_INIT: 7440 parmno = -2; 7441 break; 7442 default: 7443 selector = objc_message_selector (); 7444 parmno = parmnum; 7445 if (selector && parmno > 1) 7446 { 7447 rname = selector; 7448 parmno -= 1; 7449 } 7450 } 7451 7452 if (objc_compare_types (type, rhstype, parmno, rname)) 7453 { 7454 rhs = mark_rvalue_use (rhs); 7455 return convert (type, rhs); 7456 } 7457 } 7458 7459 /* [expr.ass] 7460 7461 The expression is implicitly converted (clause _conv_) to the 7462 cv-unqualified type of the left operand. 7463 7464 We allow bad conversions here because by the time we get to this point 7465 we are committed to doing the conversion. If we end up doing a bad 7466 conversion, convert_like will complain. */ 7467 if (!can_convert_arg_bad (type, rhstype, rhs, flags)) 7468 { 7469 /* When -Wno-pmf-conversions is use, we just silently allow 7470 conversions from pointers-to-members to plain pointers. If 7471 the conversion doesn't work, cp_convert will complain. */ 7472 if (!warn_pmf2ptr 7473 && TYPE_PTR_P (type) 7474 && TYPE_PTRMEMFUNC_P (rhstype)) 7475 rhs = cp_convert (strip_top_quals (type), rhs); 7476 else 7477 { 7478 if (complain & tf_error) 7479 { 7480 /* If the right-hand side has unknown type, then it is an 7481 overloaded function. Call instantiate_type to get error 7482 messages. */ 7483 if (rhstype == unknown_type_node) 7484 instantiate_type (type, rhs, tf_warning_or_error); 7485 else if (fndecl) 7486 error ("cannot convert %qT to %qT for argument %qP to %qD", 7487 rhstype, type, parmnum, fndecl); 7488 else 7489 switch (errtype) 7490 { 7491 case ICR_DEFAULT_ARGUMENT: 7492 error ("cannot convert %qT to %qT in default argument", 7493 rhstype, type); 7494 break; 7495 case ICR_ARGPASS: 7496 error ("cannot convert %qT to %qT in argument passing", 7497 rhstype, type); 7498 break; 7499 case ICR_CONVERTING: 7500 error ("cannot convert %qT to %qT", 7501 rhstype, type); 7502 break; 7503 case ICR_INIT: 7504 error ("cannot convert %qT to %qT in initialization", 7505 rhstype, type); 7506 break; 7507 case ICR_RETURN: 7508 error ("cannot convert %qT to %qT in return", 7509 rhstype, type); 7510 break; 7511 case ICR_ASSIGN: 7512 error ("cannot convert %qT to %qT in assignment", 7513 rhstype, type); 7514 break; 7515 default: 7516 gcc_unreachable(); 7517 } 7518 } 7519 return error_mark_node; 7520 } 7521 } 7522 if (warn_missing_format_attribute) 7523 { 7524 const enum tree_code codel = TREE_CODE (type); 7525 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 7526 && coder == codel 7527 && check_missing_format_attribute (type, rhstype) 7528 && (complain & tf_warning)) 7529 switch (errtype) 7530 { 7531 case ICR_ARGPASS: 7532 case ICR_DEFAULT_ARGUMENT: 7533 if (fndecl) 7534 warning (OPT_Wmissing_format_attribute, 7535 "parameter %qP of %qD might be a candidate " 7536 "for a format attribute", parmnum, fndecl); 7537 else 7538 warning (OPT_Wmissing_format_attribute, 7539 "parameter might be a candidate " 7540 "for a format attribute"); 7541 break; 7542 case ICR_CONVERTING: 7543 warning (OPT_Wmissing_format_attribute, 7544 "target of conversion might be a candidate " 7545 "for a format attribute"); 7546 break; 7547 case ICR_INIT: 7548 warning (OPT_Wmissing_format_attribute, 7549 "target of initialization might be a candidate " 7550 "for a format attribute"); 7551 break; 7552 case ICR_RETURN: 7553 warning (OPT_Wmissing_format_attribute, 7554 "return type might be a candidate " 7555 "for a format attribute"); 7556 break; 7557 case ICR_ASSIGN: 7558 warning (OPT_Wmissing_format_attribute, 7559 "left-hand side of assignment might be a candidate " 7560 "for a format attribute"); 7561 break; 7562 default: 7563 gcc_unreachable(); 7564 } 7565 } 7566 7567 /* If -Wparentheses, warn about a = b = c when a has type bool and b 7568 does not. */ 7569 if (warn_parentheses 7570 && TREE_CODE (type) == BOOLEAN_TYPE 7571 && TREE_CODE (rhs) == MODIFY_EXPR 7572 && !TREE_NO_WARNING (rhs) 7573 && TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE 7574 && (complain & tf_warning)) 7575 { 7576 location_t loc = EXPR_LOC_OR_HERE (rhs); 7577 7578 warning_at (loc, OPT_Wparentheses, 7579 "suggest parentheses around assignment used as truth value"); 7580 TREE_NO_WARNING (rhs) = 1; 7581 } 7582 7583 return perform_implicit_conversion_flags (strip_top_quals (type), rhs, 7584 complain, flags); 7585 } 7586 7587 /* Convert RHS to be of type TYPE. 7588 If EXP is nonzero, it is the target of the initialization. 7589 ERRTYPE indicates what kind of error the implicit conversion is. 7590 7591 Two major differences between the behavior of 7592 `convert_for_assignment' and `convert_for_initialization' 7593 are that references are bashed in the former, while 7594 copied in the latter, and aggregates are assigned in 7595 the former (operator=) while initialized in the 7596 latter (X(X&)). 7597 7598 If using constructor make sure no conversion operator exists, if one does 7599 exist, an ambiguity exists. 7600 7601 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */ 7602 7603 tree 7604 convert_for_initialization (tree exp, tree type, tree rhs, int flags, 7605 impl_conv_rhs errtype, tree fndecl, int parmnum, 7606 tsubst_flags_t complain) 7607 { 7608 enum tree_code codel = TREE_CODE (type); 7609 tree rhstype; 7610 enum tree_code coder; 7611 7612 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. 7613 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */ 7614 if (TREE_CODE (rhs) == NOP_EXPR 7615 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0)) 7616 && codel != REFERENCE_TYPE) 7617 rhs = TREE_OPERAND (rhs, 0); 7618 7619 if (type == error_mark_node 7620 || rhs == error_mark_node 7621 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)) 7622 return error_mark_node; 7623 7624 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE 7625 && TREE_CODE (type) != ARRAY_TYPE 7626 && (TREE_CODE (type) != REFERENCE_TYPE 7627 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE)) 7628 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE 7629 && (TREE_CODE (type) != REFERENCE_TYPE 7630 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)) 7631 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE) 7632 rhs = decay_conversion (rhs); 7633 7634 rhstype = TREE_TYPE (rhs); 7635 coder = TREE_CODE (rhstype); 7636 7637 if (coder == ERROR_MARK) 7638 return error_mark_node; 7639 7640 /* We accept references to incomplete types, so we can 7641 return here before checking if RHS is of complete type. */ 7642 7643 if (codel == REFERENCE_TYPE) 7644 { 7645 /* This should eventually happen in convert_arguments. */ 7646 int savew = 0, savee = 0; 7647 7648 if (fndecl) 7649 savew = warningcount, savee = errorcount; 7650 rhs = initialize_reference (type, rhs, flags, complain); 7651 if (fndecl) 7652 { 7653 if (warningcount > savew) 7654 warning (0, "in passing argument %P of %q+D", parmnum, fndecl); 7655 else if (errorcount > savee) 7656 error ("in passing argument %P of %q+D", parmnum, fndecl); 7657 } 7658 return rhs; 7659 } 7660 7661 if (exp != 0) 7662 exp = require_complete_type_sfinae (exp, complain); 7663 if (exp == error_mark_node) 7664 return error_mark_node; 7665 7666 rhstype = non_reference (rhstype); 7667 7668 type = complete_type (type); 7669 7670 if (DIRECT_INIT_EXPR_P (type, rhs)) 7671 /* Don't try to do copy-initialization if we already have 7672 direct-initialization. */ 7673 return rhs; 7674 7675 if (MAYBE_CLASS_TYPE_P (type)) 7676 return perform_implicit_conversion_flags (type, rhs, complain, flags); 7677 7678 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum, 7679 complain, flags); 7680 } 7681 7682 /* If RETVAL is the address of, or a reference to, a local variable or 7683 temporary give an appropriate warning. */ 7684 7685 static void 7686 maybe_warn_about_returning_address_of_local (tree retval) 7687 { 7688 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl)); 7689 tree whats_returned = retval; 7690 7691 for (;;) 7692 { 7693 if (TREE_CODE (whats_returned) == COMPOUND_EXPR) 7694 whats_returned = TREE_OPERAND (whats_returned, 1); 7695 else if (CONVERT_EXPR_P (whats_returned) 7696 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR) 7697 whats_returned = TREE_OPERAND (whats_returned, 0); 7698 else 7699 break; 7700 } 7701 7702 if (TREE_CODE (whats_returned) != ADDR_EXPR) 7703 return; 7704 whats_returned = TREE_OPERAND (whats_returned, 0); 7705 7706 if (TREE_CODE (valtype) == REFERENCE_TYPE) 7707 { 7708 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR 7709 || TREE_CODE (whats_returned) == TARGET_EXPR) 7710 { 7711 warning (0, "returning reference to temporary"); 7712 return; 7713 } 7714 if (TREE_CODE (whats_returned) == VAR_DECL 7715 && DECL_NAME (whats_returned) 7716 && TEMP_NAME_P (DECL_NAME (whats_returned))) 7717 { 7718 warning (0, "reference to non-lvalue returned"); 7719 return; 7720 } 7721 } 7722 7723 while (TREE_CODE (whats_returned) == COMPONENT_REF 7724 || TREE_CODE (whats_returned) == ARRAY_REF) 7725 whats_returned = TREE_OPERAND (whats_returned, 0); 7726 7727 if (DECL_P (whats_returned) 7728 && DECL_NAME (whats_returned) 7729 && DECL_FUNCTION_SCOPE_P (whats_returned) 7730 && !(TREE_STATIC (whats_returned) 7731 || TREE_PUBLIC (whats_returned))) 7732 { 7733 if (TREE_CODE (valtype) == REFERENCE_TYPE) 7734 warning (0, "reference to local variable %q+D returned", 7735 whats_returned); 7736 else 7737 warning (0, "address of local variable %q+D returned", 7738 whats_returned); 7739 return; 7740 } 7741 } 7742 7743 /* Check that returning RETVAL from the current function is valid. 7744 Return an expression explicitly showing all conversions required to 7745 change RETVAL into the function return type, and to assign it to 7746 the DECL_RESULT for the function. Set *NO_WARNING to true if 7747 code reaches end of non-void function warning shouldn't be issued 7748 on this RETURN_EXPR. */ 7749 7750 tree 7751 check_return_expr (tree retval, bool *no_warning) 7752 { 7753 tree result; 7754 /* The type actually returned by the function, after any 7755 promotions. */ 7756 tree valtype; 7757 int fn_returns_value_p; 7758 bool named_return_value_okay_p; 7759 7760 *no_warning = false; 7761 7762 /* A `volatile' function is one that isn't supposed to return, ever. 7763 (This is a G++ extension, used to get better code for functions 7764 that call the `volatile' function.) */ 7765 if (TREE_THIS_VOLATILE (current_function_decl)) 7766 warning (0, "function declared %<noreturn%> has a %<return%> statement"); 7767 7768 /* Check for various simple errors. */ 7769 if (DECL_DESTRUCTOR_P (current_function_decl)) 7770 { 7771 if (retval) 7772 error ("returning a value from a destructor"); 7773 return NULL_TREE; 7774 } 7775 else if (DECL_CONSTRUCTOR_P (current_function_decl)) 7776 { 7777 if (in_function_try_handler) 7778 /* If a return statement appears in a handler of the 7779 function-try-block of a constructor, the program is ill-formed. */ 7780 error ("cannot return from a handler of a function-try-block of a constructor"); 7781 else if (retval) 7782 /* You can't return a value from a constructor. */ 7783 error ("returning a value from a constructor"); 7784 return NULL_TREE; 7785 } 7786 7787 /* As an extension, deduce lambda return type from a return statement 7788 anywhere in the body. */ 7789 if (retval && LAMBDA_FUNCTION_P (current_function_decl)) 7790 { 7791 tree lambda = CLASSTYPE_LAMBDA_EXPR (current_class_type); 7792 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda)) 7793 { 7794 tree type = lambda_return_type (retval); 7795 tree oldtype = LAMBDA_EXPR_RETURN_TYPE (lambda); 7796 7797 if (oldtype == NULL_TREE) 7798 apply_lambda_return_type (lambda, type); 7799 /* If one of the answers is type-dependent, we can't do any 7800 better until instantiation time. */ 7801 else if (oldtype == dependent_lambda_return_type_node) 7802 /* Leave it. */; 7803 else if (type == dependent_lambda_return_type_node) 7804 apply_lambda_return_type (lambda, type); 7805 else if (!same_type_p (type, oldtype)) 7806 error ("inconsistent types %qT and %qT deduced for " 7807 "lambda return type", type, oldtype); 7808 } 7809 } 7810 7811 if (processing_template_decl) 7812 { 7813 current_function_returns_value = 1; 7814 if (check_for_bare_parameter_packs (retval)) 7815 retval = error_mark_node; 7816 return retval; 7817 } 7818 7819 /* When no explicit return-value is given in a function with a named 7820 return value, the named return value is used. */ 7821 result = DECL_RESULT (current_function_decl); 7822 valtype = TREE_TYPE (result); 7823 gcc_assert (valtype != NULL_TREE); 7824 fn_returns_value_p = !VOID_TYPE_P (valtype); 7825 if (!retval && DECL_NAME (result) && fn_returns_value_p) 7826 retval = result; 7827 7828 /* Check for a return statement with no return value in a function 7829 that's supposed to return a value. */ 7830 if (!retval && fn_returns_value_p) 7831 { 7832 permerror (input_location, "return-statement with no value, in function returning %qT", 7833 valtype); 7834 /* Clear this, so finish_function won't say that we reach the 7835 end of a non-void function (which we don't, we gave a 7836 return!). */ 7837 current_function_returns_null = 0; 7838 /* And signal caller that TREE_NO_WARNING should be set on the 7839 RETURN_EXPR to avoid control reaches end of non-void function 7840 warnings in tree-cfg.c. */ 7841 *no_warning = true; 7842 } 7843 /* Check for a return statement with a value in a function that 7844 isn't supposed to return a value. */ 7845 else if (retval && !fn_returns_value_p) 7846 { 7847 if (VOID_TYPE_P (TREE_TYPE (retval))) 7848 /* You can return a `void' value from a function of `void' 7849 type. In that case, we have to evaluate the expression for 7850 its side-effects. */ 7851 finish_expr_stmt (retval); 7852 else 7853 permerror (input_location, "return-statement with a value, in function " 7854 "returning 'void'"); 7855 current_function_returns_null = 1; 7856 7857 /* There's really no value to return, after all. */ 7858 return NULL_TREE; 7859 } 7860 else if (!retval) 7861 /* Remember that this function can sometimes return without a 7862 value. */ 7863 current_function_returns_null = 1; 7864 else 7865 /* Remember that this function did return a value. */ 7866 current_function_returns_value = 1; 7867 7868 /* Check for erroneous operands -- but after giving ourselves a 7869 chance to provide an error about returning a value from a void 7870 function. */ 7871 if (error_operand_p (retval)) 7872 { 7873 current_function_return_value = error_mark_node; 7874 return error_mark_node; 7875 } 7876 7877 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */ 7878 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR 7879 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR) 7880 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl)) 7881 && ! flag_check_new 7882 && retval && null_ptr_cst_p (retval)) 7883 warning (0, "%<operator new%> must not return NULL unless it is " 7884 "declared %<throw()%> (or -fcheck-new is in effect)"); 7885 7886 /* Effective C++ rule 15. See also start_function. */ 7887 if (warn_ecpp 7888 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)) 7889 { 7890 bool warn = true; 7891 7892 /* The function return type must be a reference to the current 7893 class. */ 7894 if (TREE_CODE (valtype) == REFERENCE_TYPE 7895 && same_type_ignoring_top_level_qualifiers_p 7896 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref))) 7897 { 7898 /* Returning '*this' is obviously OK. */ 7899 if (retval == current_class_ref) 7900 warn = false; 7901 /* If we are calling a function whose return type is the same of 7902 the current class reference, it is ok. */ 7903 else if (TREE_CODE (retval) == INDIRECT_REF 7904 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR) 7905 warn = false; 7906 } 7907 7908 if (warn) 7909 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>"); 7910 } 7911 7912 /* The fabled Named Return Value optimization, as per [class.copy]/15: 7913 7914 [...] For a function with a class return type, if the expression 7915 in the return statement is the name of a local object, and the cv- 7916 unqualified type of the local object is the same as the function 7917 return type, an implementation is permitted to omit creating the tem- 7918 porary object to hold the function return value [...] 7919 7920 So, if this is a value-returning function that always returns the same 7921 local variable, remember it. 7922 7923 It might be nice to be more flexible, and choose the first suitable 7924 variable even if the function sometimes returns something else, but 7925 then we run the risk of clobbering the variable we chose if the other 7926 returned expression uses the chosen variable somehow. And people expect 7927 this restriction, anyway. (jason 2000-11-19) 7928 7929 See finish_function and finalize_nrv for the rest of this optimization. */ 7930 7931 named_return_value_okay_p = 7932 (retval != NULL_TREE 7933 /* Must be a local, automatic variable. */ 7934 && TREE_CODE (retval) == VAR_DECL 7935 && DECL_CONTEXT (retval) == current_function_decl 7936 && ! TREE_STATIC (retval) 7937 && ! DECL_ANON_UNION_VAR_P (retval) 7938 && (DECL_ALIGN (retval) 7939 >= DECL_ALIGN (DECL_RESULT (current_function_decl))) 7940 /* The cv-unqualified type of the returned value must be the 7941 same as the cv-unqualified return type of the 7942 function. */ 7943 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))), 7944 (TYPE_MAIN_VARIANT 7945 (TREE_TYPE (TREE_TYPE (current_function_decl))))) 7946 /* And the returned value must be non-volatile. */ 7947 && ! TYPE_VOLATILE (TREE_TYPE (retval))); 7948 7949 if (fn_returns_value_p && flag_elide_constructors) 7950 { 7951 if (named_return_value_okay_p 7952 && (current_function_return_value == NULL_TREE 7953 || current_function_return_value == retval)) 7954 current_function_return_value = retval; 7955 else 7956 current_function_return_value = error_mark_node; 7957 } 7958 7959 /* We don't need to do any conversions when there's nothing being 7960 returned. */ 7961 if (!retval) 7962 return NULL_TREE; 7963 7964 /* Do any required conversions. */ 7965 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl)) 7966 /* No conversions are required. */ 7967 ; 7968 else 7969 { 7970 /* The type the function is declared to return. */ 7971 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl)); 7972 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING; 7973 7974 /* The functype's return type will have been set to void, if it 7975 was an incomplete type. Just treat this as 'return;' */ 7976 if (VOID_TYPE_P (functype)) 7977 return error_mark_node; 7978 7979 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes 7980 treated as an rvalue for the purposes of overload resolution to 7981 favor move constructors over copy constructors. 7982 7983 Note that these conditions are similar to, but not as strict as, 7984 the conditions for the named return value optimization. */ 7985 if ((cxx_dialect != cxx98) 7986 && (TREE_CODE (retval) == VAR_DECL 7987 || TREE_CODE (retval) == PARM_DECL) 7988 && DECL_CONTEXT (retval) == current_function_decl 7989 && !TREE_STATIC (retval) 7990 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))), 7991 (TYPE_MAIN_VARIANT 7992 (TREE_TYPE (TREE_TYPE (current_function_decl))))) 7993 /* This is only interesting for class type. */ 7994 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl)))) 7995 flags = flags | LOOKUP_PREFER_RVALUE; 7996 7997 /* First convert the value to the function's return type, then 7998 to the type of return value's location to handle the 7999 case that functype is smaller than the valtype. */ 8000 retval = convert_for_initialization 8001 (NULL_TREE, functype, retval, flags, ICR_RETURN, NULL_TREE, 0, 8002 tf_warning_or_error); 8003 retval = convert (valtype, retval); 8004 8005 /* If the conversion failed, treat this just like `return;'. */ 8006 if (retval == error_mark_node) 8007 return retval; 8008 /* We can't initialize a register from a AGGR_INIT_EXPR. */ 8009 else if (! cfun->returns_struct 8010 && TREE_CODE (retval) == TARGET_EXPR 8011 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR) 8012 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval, 8013 TREE_OPERAND (retval, 0)); 8014 else 8015 maybe_warn_about_returning_address_of_local (retval); 8016 } 8017 8018 /* Actually copy the value returned into the appropriate location. */ 8019 if (retval && retval != result) 8020 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval); 8021 8022 return retval; 8023 } 8024 8025 8026 /* Returns nonzero if the pointer-type FROM can be converted to the 8027 pointer-type TO via a qualification conversion. If CONSTP is -1, 8028 then we return nonzero if the pointers are similar, and the 8029 cv-qualification signature of FROM is a proper subset of that of TO. 8030 8031 If CONSTP is positive, then all outer pointers have been 8032 const-qualified. */ 8033 8034 static int 8035 comp_ptr_ttypes_real (tree to, tree from, int constp) 8036 { 8037 bool to_more_cv_qualified = false; 8038 bool is_opaque_pointer = false; 8039 8040 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) 8041 { 8042 if (TREE_CODE (to) != TREE_CODE (from)) 8043 return 0; 8044 8045 if (TREE_CODE (from) == OFFSET_TYPE 8046 && !same_type_p (TYPE_OFFSET_BASETYPE (from), 8047 TYPE_OFFSET_BASETYPE (to))) 8048 return 0; 8049 8050 /* Const and volatile mean something different for function types, 8051 so the usual checks are not appropriate. */ 8052 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE) 8053 { 8054 if (!at_least_as_qualified_p (to, from)) 8055 return 0; 8056 8057 if (!at_least_as_qualified_p (from, to)) 8058 { 8059 if (constp == 0) 8060 return 0; 8061 to_more_cv_qualified = true; 8062 } 8063 8064 if (constp > 0) 8065 constp &= TYPE_READONLY (to); 8066 } 8067 8068 if (TREE_CODE (to) == VECTOR_TYPE) 8069 is_opaque_pointer = vector_targets_convertible_p (to, from); 8070 8071 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to)) 8072 return ((constp >= 0 || to_more_cv_qualified) 8073 && (is_opaque_pointer 8074 || same_type_ignoring_top_level_qualifiers_p (to, from))); 8075 } 8076 } 8077 8078 /* When comparing, say, char ** to char const **, this function takes 8079 the 'char *' and 'char const *'. Do not pass non-pointer/reference 8080 types to this function. */ 8081 8082 int 8083 comp_ptr_ttypes (tree to, tree from) 8084 { 8085 return comp_ptr_ttypes_real (to, from, 1); 8086 } 8087 8088 /* Returns true iff FNTYPE is a non-class type that involves 8089 error_mark_node. We can get FUNCTION_TYPE with buried error_mark_node 8090 if a parameter type is ill-formed. */ 8091 8092 bool 8093 error_type_p (const_tree type) 8094 { 8095 tree t; 8096 8097 switch (TREE_CODE (type)) 8098 { 8099 case ERROR_MARK: 8100 return true; 8101 8102 case POINTER_TYPE: 8103 case REFERENCE_TYPE: 8104 case OFFSET_TYPE: 8105 return error_type_p (TREE_TYPE (type)); 8106 8107 case FUNCTION_TYPE: 8108 case METHOD_TYPE: 8109 if (error_type_p (TREE_TYPE (type))) 8110 return true; 8111 for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t)) 8112 if (error_type_p (TREE_VALUE (t))) 8113 return true; 8114 return false; 8115 8116 case RECORD_TYPE: 8117 if (TYPE_PTRMEMFUNC_P (type)) 8118 return error_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type)); 8119 return false; 8120 8121 default: 8122 return false; 8123 } 8124 } 8125 8126 /* Returns 1 if to and from are (possibly multi-level) pointers to the same 8127 type or inheritance-related types, regardless of cv-quals. */ 8128 8129 int 8130 ptr_reasonably_similar (const_tree to, const_tree from) 8131 { 8132 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) 8133 { 8134 /* Any target type is similar enough to void. */ 8135 if (TREE_CODE (to) == VOID_TYPE) 8136 return !error_type_p (from); 8137 if (TREE_CODE (from) == VOID_TYPE) 8138 return !error_type_p (to); 8139 8140 if (TREE_CODE (to) != TREE_CODE (from)) 8141 return 0; 8142 8143 if (TREE_CODE (from) == OFFSET_TYPE 8144 && comptypes (TYPE_OFFSET_BASETYPE (to), 8145 TYPE_OFFSET_BASETYPE (from), 8146 COMPARE_BASE | COMPARE_DERIVED)) 8147 continue; 8148 8149 if (TREE_CODE (to) == VECTOR_TYPE 8150 && vector_types_convertible_p (to, from, false)) 8151 return 1; 8152 8153 if (TREE_CODE (to) == INTEGER_TYPE 8154 && TYPE_PRECISION (to) == TYPE_PRECISION (from)) 8155 return 1; 8156 8157 if (TREE_CODE (to) == FUNCTION_TYPE) 8158 return !error_type_p (to) && !error_type_p (from); 8159 8160 if (TREE_CODE (to) != POINTER_TYPE) 8161 return comptypes 8162 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from), 8163 COMPARE_BASE | COMPARE_DERIVED); 8164 } 8165 } 8166 8167 /* Return true if TO and FROM (both of which are POINTER_TYPEs or 8168 pointer-to-member types) are the same, ignoring cv-qualification at 8169 all levels. */ 8170 8171 bool 8172 comp_ptr_ttypes_const (tree to, tree from) 8173 { 8174 bool is_opaque_pointer = false; 8175 8176 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) 8177 { 8178 if (TREE_CODE (to) != TREE_CODE (from)) 8179 return false; 8180 8181 if (TREE_CODE (from) == OFFSET_TYPE 8182 && same_type_p (TYPE_OFFSET_BASETYPE (from), 8183 TYPE_OFFSET_BASETYPE (to))) 8184 continue; 8185 8186 if (TREE_CODE (to) == VECTOR_TYPE) 8187 is_opaque_pointer = vector_targets_convertible_p (to, from); 8188 8189 if (TREE_CODE (to) != POINTER_TYPE) 8190 return (is_opaque_pointer 8191 || same_type_ignoring_top_level_qualifiers_p (to, from)); 8192 } 8193 } 8194 8195 /* Returns the type qualifiers for this type, including the qualifiers on the 8196 elements for an array type. */ 8197 8198 int 8199 cp_type_quals (const_tree type) 8200 { 8201 int quals; 8202 /* This CONST_CAST is okay because strip_array_types returns its 8203 argument unmodified and we assign it to a const_tree. */ 8204 type = strip_array_types (CONST_CAST_TREE (type)); 8205 if (type == error_mark_node 8206 /* Quals on a FUNCTION_TYPE are memfn quals. */ 8207 || TREE_CODE (type) == FUNCTION_TYPE) 8208 return TYPE_UNQUALIFIED; 8209 quals = TYPE_QUALS (type); 8210 /* METHOD and REFERENCE_TYPEs should never have quals. */ 8211 gcc_assert ((TREE_CODE (type) != METHOD_TYPE 8212 && TREE_CODE (type) != REFERENCE_TYPE) 8213 || ((quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE)) 8214 == TYPE_UNQUALIFIED)); 8215 return quals; 8216 } 8217 8218 /* Returns the function-cv-quals for TYPE, which must be a FUNCTION_TYPE or 8219 METHOD_TYPE. */ 8220 8221 int 8222 type_memfn_quals (const_tree type) 8223 { 8224 if (TREE_CODE (type) == FUNCTION_TYPE) 8225 return TYPE_QUALS (type); 8226 else if (TREE_CODE (type) == METHOD_TYPE) 8227 return cp_type_quals (class_of_this_parm (type)); 8228 else 8229 gcc_unreachable (); 8230 } 8231 8232 /* Returns the FUNCTION_TYPE TYPE with its function-cv-quals changed to 8233 MEMFN_QUALS. */ 8234 8235 tree 8236 apply_memfn_quals (tree type, cp_cv_quals memfn_quals) 8237 { 8238 /* Could handle METHOD_TYPE here if necessary. */ 8239 gcc_assert (TREE_CODE (type) == FUNCTION_TYPE); 8240 if (TYPE_QUALS (type) == memfn_quals) 8241 return type; 8242 /* This should really have a different TYPE_MAIN_VARIANT, but that gets 8243 complex. */ 8244 return build_qualified_type (type, memfn_quals); 8245 } 8246 8247 /* Returns nonzero if TYPE is const or volatile. */ 8248 8249 bool 8250 cv_qualified_p (const_tree type) 8251 { 8252 int quals = cp_type_quals (type); 8253 return (quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE)) != 0; 8254 } 8255 8256 /* Returns nonzero if the TYPE contains a mutable member. */ 8257 8258 bool 8259 cp_has_mutable_p (const_tree type) 8260 { 8261 /* This CONST_CAST is okay because strip_array_types returns its 8262 argument unmodified and we assign it to a const_tree. */ 8263 type = strip_array_types (CONST_CAST_TREE(type)); 8264 8265 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type); 8266 } 8267 8268 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the 8269 TYPE_QUALS. For a VAR_DECL, this may be an optimistic 8270 approximation. In particular, consider: 8271 8272 int f(); 8273 struct S { int i; }; 8274 const S s = { f(); } 8275 8276 Here, we will make "s" as TREE_READONLY (because it is declared 8277 "const") -- only to reverse ourselves upon seeing that the 8278 initializer is non-constant. */ 8279 8280 void 8281 cp_apply_type_quals_to_decl (int type_quals, tree decl) 8282 { 8283 tree type = TREE_TYPE (decl); 8284 8285 if (type == error_mark_node) 8286 return; 8287 8288 if (TREE_CODE (decl) == TYPE_DECL) 8289 return; 8290 8291 gcc_assert (!(TREE_CODE (type) == FUNCTION_TYPE 8292 && type_quals != TYPE_UNQUALIFIED)); 8293 8294 /* Avoid setting TREE_READONLY incorrectly. */ 8295 /* We used to check TYPE_NEEDS_CONSTRUCTING here, but now a constexpr 8296 constructor can produce constant init, so rely on cp_finish_decl to 8297 clear TREE_READONLY if the variable has non-constant init. */ 8298 8299 /* If the type has (or might have) a mutable component, that component 8300 might be modified. */ 8301 if (TYPE_HAS_MUTABLE_P (type) || !COMPLETE_TYPE_P (type)) 8302 type_quals &= ~TYPE_QUAL_CONST; 8303 8304 c_apply_type_quals_to_decl (type_quals, decl); 8305 } 8306 8307 /* Subroutine of casts_away_constness. Make T1 and T2 point at 8308 exemplar types such that casting T1 to T2 is casting away constness 8309 if and only if there is no implicit conversion from T1 to T2. */ 8310 8311 static void 8312 casts_away_constness_r (tree *t1, tree *t2) 8313 { 8314 int quals1; 8315 int quals2; 8316 8317 /* [expr.const.cast] 8318 8319 For multi-level pointer to members and multi-level mixed pointers 8320 and pointers to members (conv.qual), the "member" aspect of a 8321 pointer to member level is ignored when determining if a const 8322 cv-qualifier has been cast away. */ 8323 /* [expr.const.cast] 8324 8325 For two pointer types: 8326 8327 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type 8328 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type 8329 K is min(N,M) 8330 8331 casting from X1 to X2 casts away constness if, for a non-pointer 8332 type T there does not exist an implicit conversion (clause 8333 _conv_) from: 8334 8335 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N * 8336 8337 to 8338 8339 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */ 8340 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1)) 8341 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2))) 8342 { 8343 *t1 = cp_build_qualified_type (void_type_node, 8344 cp_type_quals (*t1)); 8345 *t2 = cp_build_qualified_type (void_type_node, 8346 cp_type_quals (*t2)); 8347 return; 8348 } 8349 8350 quals1 = cp_type_quals (*t1); 8351 quals2 = cp_type_quals (*t2); 8352 8353 if (TYPE_PTRMEM_P (*t1)) 8354 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1); 8355 else 8356 *t1 = TREE_TYPE (*t1); 8357 if (TYPE_PTRMEM_P (*t2)) 8358 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2); 8359 else 8360 *t2 = TREE_TYPE (*t2); 8361 8362 casts_away_constness_r (t1, t2); 8363 *t1 = build_pointer_type (*t1); 8364 *t2 = build_pointer_type (*t2); 8365 *t1 = cp_build_qualified_type (*t1, quals1); 8366 *t2 = cp_build_qualified_type (*t2, quals2); 8367 } 8368 8369 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away 8370 constness. 8371 8372 ??? This function returns non-zero if casting away qualifiers not 8373 just const. We would like to return to the caller exactly which 8374 qualifiers are casted away to give more accurate diagnostics. 8375 */ 8376 8377 static bool 8378 casts_away_constness (tree t1, tree t2) 8379 { 8380 if (TREE_CODE (t2) == REFERENCE_TYPE) 8381 { 8382 /* [expr.const.cast] 8383 8384 Casting from an lvalue of type T1 to an lvalue of type T2 8385 using a reference cast casts away constness if a cast from an 8386 rvalue of type "pointer to T1" to the type "pointer to T2" 8387 casts away constness. */ 8388 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1); 8389 return casts_away_constness (build_pointer_type (t1), 8390 build_pointer_type (TREE_TYPE (t2))); 8391 } 8392 8393 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2)) 8394 /* [expr.const.cast] 8395 8396 Casting from an rvalue of type "pointer to data member of X 8397 of type T1" to the type "pointer to data member of Y of type 8398 T2" casts away constness if a cast from an rvalue of type 8399 "pointer to T1" to the type "pointer to T2" casts away 8400 constness. */ 8401 return casts_away_constness 8402 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)), 8403 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2))); 8404 8405 /* Casting away constness is only something that makes sense for 8406 pointer or reference types. */ 8407 if (TREE_CODE (t1) != POINTER_TYPE 8408 || TREE_CODE (t2) != POINTER_TYPE) 8409 return false; 8410 8411 /* Top-level qualifiers don't matter. */ 8412 t1 = TYPE_MAIN_VARIANT (t1); 8413 t2 = TYPE_MAIN_VARIANT (t2); 8414 casts_away_constness_r (&t1, &t2); 8415 if (!can_convert (t2, t1)) 8416 return true; 8417 8418 return false; 8419 } 8420 8421 /* If T is a REFERENCE_TYPE return the type to which T refers. 8422 Otherwise, return T itself. */ 8423 8424 tree 8425 non_reference (tree t) 8426 { 8427 if (t && TREE_CODE (t) == REFERENCE_TYPE) 8428 t = TREE_TYPE (t); 8429 return t; 8430 } 8431 8432 8433 /* Return nonzero if REF is an lvalue valid for this language; 8434 otherwise, print an error message and return zero. USE says 8435 how the lvalue is being used and so selects the error message. */ 8436 8437 int 8438 lvalue_or_else (tree ref, enum lvalue_use use, tsubst_flags_t complain) 8439 { 8440 cp_lvalue_kind kind = lvalue_kind (ref); 8441 8442 if (kind == clk_none) 8443 { 8444 if (complain & tf_error) 8445 lvalue_error (input_location, use); 8446 return 0; 8447 } 8448 else if (kind & (clk_rvalueref|clk_class)) 8449 { 8450 if (!(complain & tf_error)) 8451 return 0; 8452 if (kind & clk_class) 8453 /* Make this a permerror because we used to accept it. */ 8454 permerror (input_location, "using temporary as lvalue"); 8455 else 8456 error ("using xvalue (rvalue reference) as lvalue"); 8457 } 8458 return 1; 8459 } 8460 8461 /* Return true if a user-defined literal operator is a raw operator. */ 8462 8463 bool 8464 check_raw_literal_operator (const_tree decl) 8465 { 8466 tree argtypes = TYPE_ARG_TYPES (TREE_TYPE (decl)); 8467 tree argtype; 8468 int arity; 8469 bool maybe_raw_p = false; 8470 8471 /* Count the number and type of arguments and check for ellipsis. */ 8472 for (argtype = argtypes, arity = 0; 8473 argtype && argtype != void_list_node; 8474 ++arity, argtype = TREE_CHAIN (argtype)) 8475 { 8476 tree t = TREE_VALUE (argtype); 8477 8478 if (same_type_p (t, const_string_type_node)) 8479 maybe_raw_p = true; 8480 } 8481 if (!argtype) 8482 return false; /* Found ellipsis. */ 8483 8484 if (!maybe_raw_p || arity != 1) 8485 return false; 8486 8487 return true; 8488 } 8489 8490 8491 /* Return true if a user-defined literal operator has one of the allowed 8492 argument types. */ 8493 8494 bool 8495 check_literal_operator_args (const_tree decl, 8496 bool *long_long_unsigned_p, bool *long_double_p) 8497 { 8498 tree argtypes = TYPE_ARG_TYPES (TREE_TYPE (decl)); 8499 8500 *long_long_unsigned_p = false; 8501 *long_double_p = false; 8502 if (processing_template_decl || processing_specialization) 8503 return argtypes == void_list_node; 8504 else 8505 { 8506 tree argtype; 8507 int arity; 8508 int max_arity = 2; 8509 8510 /* Count the number and type of arguments and check for ellipsis. */ 8511 for (argtype = argtypes, arity = 0; 8512 argtype && argtype != void_list_node; 8513 argtype = TREE_CHAIN (argtype)) 8514 { 8515 tree t = TREE_VALUE (argtype); 8516 ++arity; 8517 8518 if (TREE_CODE (t) == POINTER_TYPE) 8519 { 8520 bool maybe_raw_p = false; 8521 t = TREE_TYPE (t); 8522 if (cp_type_quals (t) != TYPE_QUAL_CONST) 8523 return false; 8524 t = TYPE_MAIN_VARIANT (t); 8525 if ((maybe_raw_p = same_type_p (t, char_type_node)) 8526 || same_type_p (t, wchar_type_node) 8527 || same_type_p (t, char16_type_node) 8528 || same_type_p (t, char32_type_node)) 8529 { 8530 argtype = TREE_CHAIN (argtype); 8531 if (!argtype) 8532 return false; 8533 t = TREE_VALUE (argtype); 8534 if (maybe_raw_p && argtype == void_list_node) 8535 return true; 8536 else if (same_type_p (t, size_type_node)) 8537 { 8538 ++arity; 8539 continue; 8540 } 8541 else 8542 return false; 8543 } 8544 } 8545 else if (same_type_p (t, long_long_unsigned_type_node)) 8546 { 8547 max_arity = 1; 8548 *long_long_unsigned_p = true; 8549 } 8550 else if (same_type_p (t, long_double_type_node)) 8551 { 8552 max_arity = 1; 8553 *long_double_p = true; 8554 } 8555 else if (same_type_p (t, char_type_node)) 8556 max_arity = 1; 8557 else if (same_type_p (t, wchar_type_node)) 8558 max_arity = 1; 8559 else if (same_type_p (t, char16_type_node)) 8560 max_arity = 1; 8561 else if (same_type_p (t, char32_type_node)) 8562 max_arity = 1; 8563 else 8564 return false; 8565 } 8566 if (!argtype) 8567 return false; /* Found ellipsis. */ 8568 8569 if (arity != max_arity) 8570 return false; 8571 8572 return true; 8573 } 8574 } 8575