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