1 /* Functions related to invoking methods and overloaded functions. 2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 4 Free Software Foundation, Inc. 5 Contributed by Michael Tiemann (tiemann@cygnus.com) and 6 modified by Brendan Kehoe (brendan@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 /* High-level class interface. */ 26 27 #include "config.h" 28 #include "system.h" 29 #include "coretypes.h" 30 #include "tm.h" 31 #include "tree.h" 32 #include "cp-tree.h" 33 #include "output.h" 34 #include "flags.h" 35 #include "rtl.h" 36 #include "toplev.h" 37 #include "expr.h" 38 #include "diagnostic.h" 39 #include "intl.h" 40 #include "target.h" 41 #include "convert.h" 42 #include "langhooks.h" 43 44 /* The various kinds of conversion. */ 45 46 typedef enum conversion_kind { 47 ck_identity, 48 ck_lvalue, 49 ck_qual, 50 ck_std, 51 ck_ptr, 52 ck_pmem, 53 ck_base, 54 ck_ref_bind, 55 ck_user, 56 ck_ambig, 57 ck_list, 58 ck_aggr, 59 ck_rvalue 60 } conversion_kind; 61 62 /* The rank of the conversion. Order of the enumerals matters; better 63 conversions should come earlier in the list. */ 64 65 typedef enum conversion_rank { 66 cr_identity, 67 cr_exact, 68 cr_promotion, 69 cr_std, 70 cr_pbool, 71 cr_user, 72 cr_ellipsis, 73 cr_bad 74 } conversion_rank; 75 76 /* An implicit conversion sequence, in the sense of [over.best.ics]. 77 The first conversion to be performed is at the end of the chain. 78 That conversion is always a cr_identity conversion. */ 79 80 typedef struct conversion conversion; 81 struct conversion { 82 /* The kind of conversion represented by this step. */ 83 conversion_kind kind; 84 /* The rank of this conversion. */ 85 conversion_rank rank; 86 BOOL_BITFIELD user_conv_p : 1; 87 BOOL_BITFIELD ellipsis_p : 1; 88 BOOL_BITFIELD this_p : 1; 89 BOOL_BITFIELD bad_p : 1; 90 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a 91 temporary should be created to hold the result of the 92 conversion. */ 93 BOOL_BITFIELD need_temporary_p : 1; 94 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 95 from a pointer-to-derived to pointer-to-base is being performed. */ 96 BOOL_BITFIELD base_p : 1; 97 /* If KIND is ck_ref_bind, true when either an lvalue reference is 98 being bound to an lvalue expression or an rvalue reference is 99 being bound to an rvalue expression. */ 100 BOOL_BITFIELD rvaluedness_matches_p: 1; 101 BOOL_BITFIELD check_narrowing: 1; 102 /* The type of the expression resulting from the conversion. */ 103 tree type; 104 union { 105 /* The next conversion in the chain. Since the conversions are 106 arranged from outermost to innermost, the NEXT conversion will 107 actually be performed before this conversion. This variant is 108 used only when KIND is neither ck_identity nor ck_ambig. */ 109 conversion *next; 110 /* The expression at the beginning of the conversion chain. This 111 variant is used only if KIND is ck_identity or ck_ambig. */ 112 tree expr; 113 /* The array of conversions for an initializer_list. */ 114 conversion **list; 115 } u; 116 /* The function candidate corresponding to this conversion 117 sequence. This field is only used if KIND is ck_user. */ 118 struct z_candidate *cand; 119 }; 120 121 #define CONVERSION_RANK(NODE) \ 122 ((NODE)->bad_p ? cr_bad \ 123 : (NODE)->ellipsis_p ? cr_ellipsis \ 124 : (NODE)->user_conv_p ? cr_user \ 125 : (NODE)->rank) 126 127 static struct obstack conversion_obstack; 128 static bool conversion_obstack_initialized; 129 130 static struct z_candidate * tourney (struct z_candidate *); 131 static int equal_functions (tree, tree); 132 static int joust (struct z_candidate *, struct z_candidate *, bool); 133 static int compare_ics (conversion *, conversion *); 134 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 135 static tree build_java_interface_fn_ref (tree, tree); 136 #define convert_like(CONV, EXPR, COMPLAIN) \ 137 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \ 138 /*issue_conversion_warnings=*/true, \ 139 /*c_cast_p=*/false, (COMPLAIN)) 140 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 141 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \ 142 /*issue_conversion_warnings=*/true, \ 143 /*c_cast_p=*/false, (COMPLAIN)) 144 static tree convert_like_real (conversion *, tree, tree, int, int, bool, 145 bool, tsubst_flags_t); 146 static void op_error (enum tree_code, enum tree_code, tree, tree, 147 tree, bool); 148 static VEC(tree,gc) *resolve_args (VEC(tree,gc) *); 149 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int); 150 static void print_z_candidate (const char *, struct z_candidate *); 151 static void print_z_candidates (struct z_candidate *); 152 static tree build_this (tree); 153 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 154 static bool any_strictly_viable (struct z_candidate *); 155 static struct z_candidate *add_template_candidate 156 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *, 157 tree, tree, tree, int, unification_kind_t); 158 static struct z_candidate *add_template_candidate_real 159 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *, 160 tree, tree, tree, int, tree, unification_kind_t); 161 static struct z_candidate *add_template_conv_candidate 162 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 163 tree, tree); 164 static void add_builtin_candidates 165 (struct z_candidate **, enum tree_code, enum tree_code, 166 tree, tree *, int); 167 static void add_builtin_candidate 168 (struct z_candidate **, enum tree_code, enum tree_code, 169 tree, tree, tree, tree *, tree *, int); 170 static bool is_complete (tree); 171 static void build_builtin_candidate 172 (struct z_candidate **, tree, tree, tree, tree *, tree *, 173 int); 174 static struct z_candidate *add_conv_candidate 175 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 176 tree); 177 static struct z_candidate *add_function_candidate 178 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 179 tree, int); 180 static conversion *implicit_conversion (tree, tree, tree, bool, int); 181 static conversion *standard_conversion (tree, tree, tree, bool, int); 182 static conversion *reference_binding (tree, tree, tree, bool, int); 183 static conversion *build_conv (conversion_kind, tree, conversion *); 184 static conversion *build_list_conv (tree, tree, int); 185 static bool is_subseq (conversion *, conversion *); 186 static conversion *maybe_handle_ref_bind (conversion **); 187 static void maybe_handle_implicit_object (conversion **); 188 static struct z_candidate *add_candidate 189 (struct z_candidate **, tree, tree, const VEC(tree,gc) *, size_t, 190 conversion **, tree, tree, int); 191 static tree source_type (conversion *); 192 static void add_warning (struct z_candidate *, struct z_candidate *); 193 static bool reference_compatible_p (tree, tree); 194 static conversion *convert_class_to_reference (tree, tree, tree, int); 195 static conversion *direct_reference_binding (tree, conversion *); 196 static bool promoted_arithmetic_type_p (tree); 197 static conversion *conditional_conversion (tree, tree); 198 static char *name_as_c_string (tree, tree, bool *); 199 static tree prep_operand (tree); 200 static void add_candidates (tree, const VEC(tree,gc) *, tree, bool, tree, tree, 201 int, struct z_candidate **); 202 static conversion *merge_conversion_sequences (conversion *, conversion *); 203 static bool magic_varargs_p (tree); 204 static tree build_temp (tree, tree, int, diagnostic_t *); 205 206 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 207 NAME can take many forms... */ 208 209 bool 210 check_dtor_name (tree basetype, tree name) 211 { 212 /* Just accept something we've already complained about. */ 213 if (name == error_mark_node) 214 return true; 215 216 if (TREE_CODE (name) == TYPE_DECL) 217 name = TREE_TYPE (name); 218 else if (TYPE_P (name)) 219 /* OK */; 220 else if (TREE_CODE (name) == IDENTIFIER_NODE) 221 { 222 if ((MAYBE_CLASS_TYPE_P (basetype) 223 && name == constructor_name (basetype)) 224 || (TREE_CODE (basetype) == ENUMERAL_TYPE 225 && name == TYPE_IDENTIFIER (basetype))) 226 return true; 227 else 228 name = get_type_value (name); 229 } 230 else 231 { 232 /* In the case of: 233 234 template <class T> struct S { ~S(); }; 235 int i; 236 i.~S(); 237 238 NAME will be a class template. */ 239 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 240 return false; 241 } 242 243 if (!name || name == error_mark_node) 244 return false; 245 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 246 } 247 248 /* We want the address of a function or method. We avoid creating a 249 pointer-to-member function. */ 250 251 tree 252 build_addr_func (tree function) 253 { 254 tree type = TREE_TYPE (function); 255 256 /* We have to do these by hand to avoid real pointer to member 257 functions. */ 258 if (TREE_CODE (type) == METHOD_TYPE) 259 { 260 if (TREE_CODE (function) == OFFSET_REF) 261 { 262 tree object = build_address (TREE_OPERAND (function, 0)); 263 return get_member_function_from_ptrfunc (&object, 264 TREE_OPERAND (function, 1)); 265 } 266 function = build_address (function); 267 } 268 else 269 function = decay_conversion (function); 270 271 return function; 272 } 273 274 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 275 POINTER_TYPE to those. Note, pointer to member function types 276 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 277 two variants. build_call_a is the primitive taking an array of 278 arguments, while build_call_n is a wrapper that handles varargs. */ 279 280 tree 281 build_call_n (tree function, int n, ...) 282 { 283 if (n == 0) 284 return build_call_a (function, 0, NULL); 285 else 286 { 287 tree *argarray = (tree *) alloca (n * sizeof (tree)); 288 va_list ap; 289 int i; 290 291 va_start (ap, n); 292 for (i = 0; i < n; i++) 293 argarray[i] = va_arg (ap, tree); 294 va_end (ap); 295 return build_call_a (function, n, argarray); 296 } 297 } 298 299 tree 300 build_call_a (tree function, int n, tree *argarray) 301 { 302 int is_constructor = 0; 303 int nothrow; 304 tree decl; 305 tree result_type; 306 tree fntype; 307 int i; 308 309 function = build_addr_func (function); 310 311 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 312 fntype = TREE_TYPE (TREE_TYPE (function)); 313 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 314 || TREE_CODE (fntype) == METHOD_TYPE); 315 result_type = TREE_TYPE (fntype); 316 /* An rvalue has no cv-qualifiers. */ 317 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 318 result_type = cv_unqualified (result_type); 319 320 if (TREE_CODE (function) == ADDR_EXPR 321 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) 322 { 323 decl = TREE_OPERAND (function, 0); 324 if (!TREE_USED (decl)) 325 { 326 /* We invoke build_call directly for several library 327 functions. These may have been declared normally if 328 we're building libgcc, so we can't just check 329 DECL_ARTIFICIAL. */ 330 gcc_assert (DECL_ARTIFICIAL (decl) 331 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 332 "__", 2)); 333 mark_used (decl); 334 } 335 } 336 else 337 decl = NULL_TREE; 338 339 /* We check both the decl and the type; a function may be known not to 340 throw without being declared throw(). */ 341 nothrow = ((decl && TREE_NOTHROW (decl)) 342 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function)))); 343 344 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 345 current_function_returns_abnormally = 1; 346 347 if (decl && TREE_DEPRECATED (decl)) 348 warn_deprecated_use (decl, NULL_TREE); 349 require_complete_eh_spec_types (fntype, decl); 350 351 if (decl && DECL_CONSTRUCTOR_P (decl)) 352 is_constructor = 1; 353 354 /* Don't pass empty class objects by value. This is useful 355 for tags in STL, which are used to control overload resolution. 356 We don't need to handle other cases of copying empty classes. */ 357 if (! decl || ! DECL_BUILT_IN (decl)) 358 for (i = 0; i < n; i++) 359 if (is_empty_class (TREE_TYPE (argarray[i])) 360 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i]))) 361 { 362 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i])); 363 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t), 364 argarray[i], t); 365 } 366 367 function = build_call_array_loc (input_location, 368 result_type, function, n, argarray); 369 TREE_HAS_CONSTRUCTOR (function) = is_constructor; 370 TREE_NOTHROW (function) = nothrow; 371 372 return function; 373 } 374 375 /* Build something of the form ptr->method (args) 376 or object.method (args). This can also build 377 calls to constructors, and find friends. 378 379 Member functions always take their class variable 380 as a pointer. 381 382 INSTANCE is a class instance. 383 384 NAME is the name of the method desired, usually an IDENTIFIER_NODE. 385 386 PARMS help to figure out what that NAME really refers to. 387 388 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE 389 down to the real instance type to use for access checking. We need this 390 information to get protected accesses correct. 391 392 FLAGS is the logical disjunction of zero or more LOOKUP_ 393 flags. See cp-tree.h for more info. 394 395 If this is all OK, calls build_function_call with the resolved 396 member function. 397 398 This function must also handle being called to perform 399 initialization, promotion/coercion of arguments, and 400 instantiation of default parameters. 401 402 Note that NAME may refer to an instance variable name. If 403 `operator()()' is defined for the type of that field, then we return 404 that result. */ 405 406 /* New overloading code. */ 407 408 typedef struct z_candidate z_candidate; 409 410 typedef struct candidate_warning candidate_warning; 411 struct candidate_warning { 412 z_candidate *loser; 413 candidate_warning *next; 414 }; 415 416 struct z_candidate { 417 /* The FUNCTION_DECL that will be called if this candidate is 418 selected by overload resolution. */ 419 tree fn; 420 /* If not NULL_TREE, the first argument to use when calling this 421 function. */ 422 tree first_arg; 423 /* The rest of the arguments to use when calling this function. If 424 there are no further arguments this may be NULL or it may be an 425 empty vector. */ 426 const VEC(tree,gc) *args; 427 /* The implicit conversion sequences for each of the arguments to 428 FN. */ 429 conversion **convs; 430 /* The number of implicit conversion sequences. */ 431 size_t num_convs; 432 /* If FN is a user-defined conversion, the standard conversion 433 sequence from the type returned by FN to the desired destination 434 type. */ 435 conversion *second_conv; 436 int viable; 437 /* If FN is a member function, the binfo indicating the path used to 438 qualify the name of FN at the call site. This path is used to 439 determine whether or not FN is accessible if it is selected by 440 overload resolution. The DECL_CONTEXT of FN will always be a 441 (possibly improper) base of this binfo. */ 442 tree access_path; 443 /* If FN is a non-static member function, the binfo indicating the 444 subobject to which the `this' pointer should be converted if FN 445 is selected by overload resolution. The type pointed to the by 446 the `this' pointer must correspond to the most derived class 447 indicated by the CONVERSION_PATH. */ 448 tree conversion_path; 449 tree template_decl; 450 tree explicit_targs; 451 candidate_warning *warnings; 452 z_candidate *next; 453 }; 454 455 /* Returns true iff T is a null pointer constant in the sense of 456 [conv.ptr]. */ 457 458 bool 459 null_ptr_cst_p (tree t) 460 { 461 /* [conv.ptr] 462 463 A null pointer constant is an integral constant expression 464 (_expr.const_) rvalue of integer type that evaluates to zero. */ 465 t = integral_constant_value (t); 466 if (t == null_node) 467 return true; 468 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t)) 469 { 470 STRIP_NOPS (t); 471 if (!TREE_OVERFLOW (t)) 472 return true; 473 } 474 return false; 475 } 476 477 /* Returns nonzero if PARMLIST consists of only default parms and/or 478 ellipsis. */ 479 480 bool 481 sufficient_parms_p (const_tree parmlist) 482 { 483 for (; parmlist && parmlist != void_list_node; 484 parmlist = TREE_CHAIN (parmlist)) 485 if (!TREE_PURPOSE (parmlist)) 486 return false; 487 return true; 488 } 489 490 /* Allocate N bytes of memory from the conversion obstack. The memory 491 is zeroed before being returned. */ 492 493 static void * 494 conversion_obstack_alloc (size_t n) 495 { 496 void *p; 497 if (!conversion_obstack_initialized) 498 { 499 gcc_obstack_init (&conversion_obstack); 500 conversion_obstack_initialized = true; 501 } 502 p = obstack_alloc (&conversion_obstack, n); 503 memset (p, 0, n); 504 return p; 505 } 506 507 /* Dynamically allocate a conversion. */ 508 509 static conversion * 510 alloc_conversion (conversion_kind kind) 511 { 512 conversion *c; 513 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 514 c->kind = kind; 515 return c; 516 } 517 518 #ifdef ENABLE_CHECKING 519 520 /* Make sure that all memory on the conversion obstack has been 521 freed. */ 522 523 void 524 validate_conversion_obstack (void) 525 { 526 if (conversion_obstack_initialized) 527 gcc_assert ((obstack_next_free (&conversion_obstack) 528 == obstack_base (&conversion_obstack))); 529 } 530 531 #endif /* ENABLE_CHECKING */ 532 533 /* Dynamically allocate an array of N conversions. */ 534 535 static conversion ** 536 alloc_conversions (size_t n) 537 { 538 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 539 } 540 541 static conversion * 542 build_conv (conversion_kind code, tree type, conversion *from) 543 { 544 conversion *t; 545 conversion_rank rank = CONVERSION_RANK (from); 546 547 /* Note that the caller is responsible for filling in t->cand for 548 user-defined conversions. */ 549 t = alloc_conversion (code); 550 t->type = type; 551 t->u.next = from; 552 553 switch (code) 554 { 555 case ck_ptr: 556 case ck_pmem: 557 case ck_base: 558 case ck_std: 559 if (rank < cr_std) 560 rank = cr_std; 561 break; 562 563 case ck_qual: 564 if (rank < cr_exact) 565 rank = cr_exact; 566 break; 567 568 default: 569 break; 570 } 571 t->rank = rank; 572 t->user_conv_p = (code == ck_user || from->user_conv_p); 573 t->bad_p = from->bad_p; 574 t->base_p = false; 575 return t; 576 } 577 578 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 579 specialization of std::initializer_list<T>, if such a conversion is 580 possible. */ 581 582 static conversion * 583 build_list_conv (tree type, tree ctor, int flags) 584 { 585 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 586 unsigned len = CONSTRUCTOR_NELTS (ctor); 587 conversion **subconvs = alloc_conversions (len); 588 conversion *t; 589 unsigned i; 590 tree val; 591 592 /* Within a list-initialization we can have more user-defined 593 conversions. */ 594 flags &= ~LOOKUP_NO_CONVERSION; 595 /* But no narrowing conversions. */ 596 flags |= LOOKUP_NO_NARROWING; 597 598 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 599 { 600 conversion *sub 601 = implicit_conversion (elttype, TREE_TYPE (val), val, 602 false, flags); 603 if (sub == NULL) 604 return NULL; 605 606 subconvs[i] = sub; 607 } 608 609 t = alloc_conversion (ck_list); 610 t->type = type; 611 t->u.list = subconvs; 612 t->rank = cr_exact; 613 614 for (i = 0; i < len; ++i) 615 { 616 conversion *sub = subconvs[i]; 617 if (sub->rank > t->rank) 618 t->rank = sub->rank; 619 if (sub->user_conv_p) 620 t->user_conv_p = true; 621 if (sub->bad_p) 622 t->bad_p = true; 623 } 624 625 return t; 626 } 627 628 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 629 aggregate class, if such a conversion is possible. */ 630 631 static conversion * 632 build_aggr_conv (tree type, tree ctor, int flags) 633 { 634 unsigned HOST_WIDE_INT i = 0; 635 conversion *c; 636 tree field = next_initializable_field (TYPE_FIELDS (type)); 637 638 for (; field; field = next_initializable_field (TREE_CHAIN (field))) 639 { 640 if (i < CONSTRUCTOR_NELTS (ctor)) 641 { 642 constructor_elt *ce = CONSTRUCTOR_ELT (ctor, i); 643 if (!can_convert_arg (TREE_TYPE (field), TREE_TYPE (ce->value), 644 ce->value, flags)) 645 return NULL; 646 ++i; 647 if (TREE_CODE (type) == UNION_TYPE) 648 break; 649 } 650 else if (build_value_init (TREE_TYPE (field)) == error_mark_node) 651 return NULL; 652 } 653 654 if (i < CONSTRUCTOR_NELTS (ctor)) 655 return NULL; 656 657 c = alloc_conversion (ck_aggr); 658 c->type = type; 659 c->rank = cr_exact; 660 c->user_conv_p = true; 661 c->u.next = NULL; 662 return c; 663 } 664 665 /* Build a representation of the identity conversion from EXPR to 666 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 667 668 static conversion * 669 build_identity_conv (tree type, tree expr) 670 { 671 conversion *c; 672 673 c = alloc_conversion (ck_identity); 674 c->type = type; 675 c->u.expr = expr; 676 677 return c; 678 } 679 680 /* Converting from EXPR to TYPE was ambiguous in the sense that there 681 were multiple user-defined conversions to accomplish the job. 682 Build a conversion that indicates that ambiguity. */ 683 684 static conversion * 685 build_ambiguous_conv (tree type, tree expr) 686 { 687 conversion *c; 688 689 c = alloc_conversion (ck_ambig); 690 c->type = type; 691 c->u.expr = expr; 692 693 return c; 694 } 695 696 tree 697 strip_top_quals (tree t) 698 { 699 if (TREE_CODE (t) == ARRAY_TYPE) 700 return t; 701 return cp_build_qualified_type (t, 0); 702 } 703 704 /* Returns the standard conversion path (see [conv]) from type FROM to type 705 TO, if any. For proper handling of null pointer constants, you must 706 also pass the expression EXPR to convert from. If C_CAST_P is true, 707 this conversion is coming from a C-style cast. */ 708 709 static conversion * 710 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 711 int flags) 712 { 713 enum tree_code fcode, tcode; 714 conversion *conv; 715 bool fromref = false; 716 717 to = non_reference (to); 718 if (TREE_CODE (from) == REFERENCE_TYPE) 719 { 720 fromref = true; 721 from = TREE_TYPE (from); 722 } 723 to = strip_top_quals (to); 724 from = strip_top_quals (from); 725 726 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 727 && expr && type_unknown_p (expr)) 728 { 729 tsubst_flags_t tflags = tf_conv; 730 if (!(flags & LOOKUP_PROTECT)) 731 tflags |= tf_no_access_control; 732 expr = instantiate_type (to, expr, tflags); 733 if (expr == error_mark_node) 734 return NULL; 735 from = TREE_TYPE (expr); 736 } 737 738 fcode = TREE_CODE (from); 739 tcode = TREE_CODE (to); 740 741 conv = build_identity_conv (from, expr); 742 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 743 { 744 from = type_decays_to (from); 745 fcode = TREE_CODE (from); 746 conv = build_conv (ck_lvalue, from, conv); 747 } 748 else if (fromref || (expr && lvalue_p (expr))) 749 { 750 if (expr) 751 { 752 tree bitfield_type; 753 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 754 if (bitfield_type) 755 { 756 from = strip_top_quals (bitfield_type); 757 fcode = TREE_CODE (from); 758 } 759 } 760 conv = build_conv (ck_rvalue, from, conv); 761 } 762 763 /* Allow conversion between `__complex__' data types. */ 764 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 765 { 766 /* The standard conversion sequence to convert FROM to TO is 767 the standard conversion sequence to perform componentwise 768 conversion. */ 769 conversion *part_conv = standard_conversion 770 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags); 771 772 if (part_conv) 773 { 774 conv = build_conv (part_conv->kind, to, conv); 775 conv->rank = part_conv->rank; 776 } 777 else 778 conv = NULL; 779 780 return conv; 781 } 782 783 if (same_type_p (from, to)) 784 return conv; 785 786 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to)) 787 && expr && null_ptr_cst_p (expr)) 788 conv = build_conv (ck_std, to, conv); 789 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 790 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 791 { 792 /* For backwards brain damage compatibility, allow interconversion of 793 pointers and integers with a pedwarn. */ 794 conv = build_conv (ck_std, to, conv); 795 conv->bad_p = true; 796 } 797 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 798 { 799 /* For backwards brain damage compatibility, allow interconversion of 800 enums and integers with a pedwarn. */ 801 conv = build_conv (ck_std, to, conv); 802 conv->bad_p = true; 803 } 804 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 805 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from))) 806 { 807 tree to_pointee; 808 tree from_pointee; 809 810 if (tcode == POINTER_TYPE 811 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from), 812 TREE_TYPE (to))) 813 ; 814 else if (VOID_TYPE_P (TREE_TYPE (to)) 815 && !TYPE_PTRMEM_P (from) 816 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE) 817 { 818 from = build_pointer_type 819 (cp_build_qualified_type (void_type_node, 820 cp_type_quals (TREE_TYPE (from)))); 821 conv = build_conv (ck_ptr, from, conv); 822 } 823 else if (TYPE_PTRMEM_P (from)) 824 { 825 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 826 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 827 828 if (DERIVED_FROM_P (fbase, tbase) 829 && (same_type_ignoring_top_level_qualifiers_p 830 (TYPE_PTRMEM_POINTED_TO_TYPE (from), 831 TYPE_PTRMEM_POINTED_TO_TYPE (to)))) 832 { 833 from = build_ptrmem_type (tbase, 834 TYPE_PTRMEM_POINTED_TO_TYPE (from)); 835 conv = build_conv (ck_pmem, from, conv); 836 } 837 else if (!same_type_p (fbase, tbase)) 838 return NULL; 839 } 840 else if (CLASS_TYPE_P (TREE_TYPE (from)) 841 && CLASS_TYPE_P (TREE_TYPE (to)) 842 /* [conv.ptr] 843 844 An rvalue of type "pointer to cv D," where D is a 845 class type, can be converted to an rvalue of type 846 "pointer to cv B," where B is a base class (clause 847 _class.derived_) of D. If B is an inaccessible 848 (clause _class.access_) or ambiguous 849 (_class.member.lookup_) base class of D, a program 850 that necessitates this conversion is ill-formed. 851 Therefore, we use DERIVED_FROM_P, and do not check 852 access or uniqueness. */ 853 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))) 854 { 855 from = 856 cp_build_qualified_type (TREE_TYPE (to), 857 cp_type_quals (TREE_TYPE (from))); 858 from = build_pointer_type (from); 859 conv = build_conv (ck_ptr, from, conv); 860 conv->base_p = true; 861 } 862 863 if (tcode == POINTER_TYPE) 864 { 865 to_pointee = TREE_TYPE (to); 866 from_pointee = TREE_TYPE (from); 867 } 868 else 869 { 870 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 871 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 872 } 873 874 if (same_type_p (from, to)) 875 /* OK */; 876 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 877 /* In a C-style cast, we ignore CV-qualification because we 878 are allowed to perform a static_cast followed by a 879 const_cast. */ 880 conv = build_conv (ck_qual, to, conv); 881 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 882 conv = build_conv (ck_qual, to, conv); 883 else if (expr && string_conv_p (to, expr, 0)) 884 /* converting from string constant to char *. */ 885 conv = build_conv (ck_qual, to, conv); 886 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 887 { 888 conv = build_conv (ck_ptr, to, conv); 889 conv->bad_p = true; 890 } 891 else 892 return NULL; 893 894 from = to; 895 } 896 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 897 { 898 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 899 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 900 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn))); 901 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn))); 902 903 if (!DERIVED_FROM_P (fbase, tbase) 904 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn)) 905 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)), 906 TREE_CHAIN (TYPE_ARG_TYPES (tofn))) 907 || cp_type_quals (fbase) != cp_type_quals (tbase)) 908 return NULL; 909 910 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase)); 911 from = build_ptrmemfunc_type (build_pointer_type (from)); 912 conv = build_conv (ck_pmem, from, conv); 913 conv->base_p = true; 914 } 915 else if (tcode == BOOLEAN_TYPE) 916 { 917 /* [conv.bool] 918 919 An rvalue of arithmetic, unscoped enumeration, pointer, or 920 pointer to member type can be converted to an rvalue of type 921 bool. */ 922 if (ARITHMETIC_TYPE_P (from) 923 || UNSCOPED_ENUM_P (from) 924 || fcode == POINTER_TYPE 925 || TYPE_PTR_TO_MEMBER_P (from)) 926 { 927 conv = build_conv (ck_std, to, conv); 928 if (fcode == POINTER_TYPE 929 || TYPE_PTRMEM_P (from) 930 || (TYPE_PTRMEMFUNC_P (from) 931 && conv->rank < cr_pbool)) 932 conv->rank = cr_pbool; 933 return conv; 934 } 935 936 return NULL; 937 } 938 /* We don't check for ENUMERAL_TYPE here because there are no standard 939 conversions to enum type. */ 940 /* As an extension, allow conversion to complex type. */ 941 else if (ARITHMETIC_TYPE_P (to)) 942 { 943 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE) 944 || SCOPED_ENUM_P (from)) 945 return NULL; 946 conv = build_conv (ck_std, to, conv); 947 948 /* Give this a better rank if it's a promotion. */ 949 if (same_type_p (to, type_promotes_to (from)) 950 && conv->u.next->rank <= cr_promotion) 951 conv->rank = cr_promotion; 952 } 953 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 954 && vector_types_convertible_p (from, to, false)) 955 return build_conv (ck_std, to, conv); 956 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 957 && is_properly_derived_from (from, to)) 958 { 959 if (conv->kind == ck_rvalue) 960 conv = conv->u.next; 961 conv = build_conv (ck_base, to, conv); 962 /* The derived-to-base conversion indicates the initialization 963 of a parameter with base type from an object of a derived 964 type. A temporary object is created to hold the result of 965 the conversion unless we're binding directly to a reference. */ 966 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 967 } 968 else 969 return NULL; 970 971 if (flags & LOOKUP_NO_NARROWING) 972 conv->check_narrowing = true; 973 974 return conv; 975 } 976 977 /* Returns nonzero if T1 is reference-related to T2. */ 978 979 bool 980 reference_related_p (tree t1, tree t2) 981 { 982 t1 = TYPE_MAIN_VARIANT (t1); 983 t2 = TYPE_MAIN_VARIANT (t2); 984 985 /* [dcl.init.ref] 986 987 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 988 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 989 of T2. */ 990 return (same_type_p (t1, t2) 991 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 992 && DERIVED_FROM_P (t1, t2))); 993 } 994 995 /* Returns nonzero if T1 is reference-compatible with T2. */ 996 997 static bool 998 reference_compatible_p (tree t1, tree t2) 999 { 1000 /* [dcl.init.ref] 1001 1002 "cv1 T1" is reference compatible with "cv2 T2" if T1 is 1003 reference-related to T2 and cv1 is the same cv-qualification as, 1004 or greater cv-qualification than, cv2. */ 1005 return (reference_related_p (t1, t2) 1006 && at_least_as_qualified_p (t1, t2)); 1007 } 1008 1009 /* Determine whether or not the EXPR (of class type S) can be 1010 converted to T as in [over.match.ref]. */ 1011 1012 static conversion * 1013 convert_class_to_reference (tree reference_type, tree s, tree expr, int flags) 1014 { 1015 tree conversions; 1016 tree first_arg; 1017 conversion *conv; 1018 tree t; 1019 struct z_candidate *candidates; 1020 struct z_candidate *cand; 1021 bool any_viable_p; 1022 1023 if (!expr) 1024 return NULL; 1025 1026 conversions = lookup_conversions (s); 1027 if (!conversions) 1028 return NULL; 1029 1030 /* [over.match.ref] 1031 1032 Assuming that "cv1 T" is the underlying type of the reference 1033 being initialized, and "cv S" is the type of the initializer 1034 expression, with S a class type, the candidate functions are 1035 selected as follows: 1036 1037 --The conversion functions of S and its base classes are 1038 considered. Those that are not hidden within S and yield type 1039 "reference to cv2 T2", where "cv1 T" is reference-compatible 1040 (_dcl.init.ref_) with "cv2 T2", are candidate functions. 1041 1042 The argument list has one argument, which is the initializer 1043 expression. */ 1044 1045 candidates = 0; 1046 1047 /* Conceptually, we should take the address of EXPR and put it in 1048 the argument list. Unfortunately, however, that can result in 1049 error messages, which we should not issue now because we are just 1050 trying to find a conversion operator. Therefore, we use NULL, 1051 cast to the appropriate type. */ 1052 first_arg = build_int_cst (build_pointer_type (s), 0); 1053 1054 t = TREE_TYPE (reference_type); 1055 1056 for (; conversions; conversions = TREE_CHAIN (conversions)) 1057 { 1058 tree fns = TREE_VALUE (conversions); 1059 1060 for (; fns; fns = OVL_NEXT (fns)) 1061 { 1062 tree f = OVL_CURRENT (fns); 1063 tree t2 = TREE_TYPE (TREE_TYPE (f)); 1064 1065 if (DECL_NONCONVERTING_P (f) 1066 && (flags & LOOKUP_ONLYCONVERTING)) 1067 continue; 1068 1069 cand = NULL; 1070 1071 /* If this is a template function, try to get an exact 1072 match. */ 1073 if (TREE_CODE (f) == TEMPLATE_DECL) 1074 { 1075 cand = add_template_candidate (&candidates, 1076 f, s, 1077 NULL_TREE, 1078 first_arg, 1079 NULL, 1080 reference_type, 1081 TYPE_BINFO (s), 1082 TREE_PURPOSE (conversions), 1083 LOOKUP_NORMAL, 1084 DEDUCE_CONV); 1085 1086 if (cand) 1087 { 1088 /* Now, see if the conversion function really returns 1089 an lvalue of the appropriate type. From the 1090 point of view of unification, simply returning an 1091 rvalue of the right type is good enough. */ 1092 f = cand->fn; 1093 t2 = TREE_TYPE (TREE_TYPE (f)); 1094 if (TREE_CODE (t2) != REFERENCE_TYPE 1095 || !reference_compatible_p (t, TREE_TYPE (t2))) 1096 { 1097 candidates = candidates->next; 1098 cand = NULL; 1099 } 1100 } 1101 } 1102 else if (TREE_CODE (t2) == REFERENCE_TYPE 1103 && reference_compatible_p (t, TREE_TYPE (t2))) 1104 cand = add_function_candidate (&candidates, f, s, first_arg, 1105 NULL, TYPE_BINFO (s), 1106 TREE_PURPOSE (conversions), 1107 LOOKUP_NORMAL); 1108 1109 if (cand) 1110 { 1111 conversion *identity_conv; 1112 /* Build a standard conversion sequence indicating the 1113 binding from the reference type returned by the 1114 function to the desired REFERENCE_TYPE. */ 1115 identity_conv 1116 = build_identity_conv (TREE_TYPE (TREE_TYPE 1117 (TREE_TYPE (cand->fn))), 1118 NULL_TREE); 1119 cand->second_conv 1120 = (direct_reference_binding 1121 (reference_type, identity_conv)); 1122 cand->second_conv->rvaluedness_matches_p 1123 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn))) 1124 == TYPE_REF_IS_RVALUE (reference_type); 1125 cand->second_conv->bad_p |= cand->convs[0]->bad_p; 1126 1127 /* Don't allow binding of lvalues to rvalue references. */ 1128 if (TYPE_REF_IS_RVALUE (reference_type) 1129 && !TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))) 1130 cand->second_conv->bad_p = true; 1131 } 1132 } 1133 } 1134 1135 candidates = splice_viable (candidates, pedantic, &any_viable_p); 1136 /* If none of the conversion functions worked out, let our caller 1137 know. */ 1138 if (!any_viable_p) 1139 return NULL; 1140 1141 cand = tourney (candidates); 1142 if (!cand) 1143 return NULL; 1144 1145 /* Now that we know that this is the function we're going to use fix 1146 the dummy first argument. */ 1147 gcc_assert (cand->first_arg == NULL_TREE 1148 || integer_zerop (cand->first_arg)); 1149 cand->first_arg = build_this (expr); 1150 1151 /* Build a user-defined conversion sequence representing the 1152 conversion. */ 1153 conv = build_conv (ck_user, 1154 TREE_TYPE (TREE_TYPE (cand->fn)), 1155 build_identity_conv (TREE_TYPE (expr), expr)); 1156 conv->cand = cand; 1157 1158 if (cand->viable == -1) 1159 conv->bad_p = true; 1160 1161 /* Merge it with the standard conversion sequence from the 1162 conversion function's return type to the desired type. */ 1163 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv); 1164 1165 return cand->second_conv; 1166 } 1167 1168 /* A reference of the indicated TYPE is being bound directly to the 1169 expression represented by the implicit conversion sequence CONV. 1170 Return a conversion sequence for this binding. */ 1171 1172 static conversion * 1173 direct_reference_binding (tree type, conversion *conv) 1174 { 1175 tree t; 1176 1177 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1178 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1179 1180 t = TREE_TYPE (type); 1181 1182 /* [over.ics.rank] 1183 1184 When a parameter of reference type binds directly 1185 (_dcl.init.ref_) to an argument expression, the implicit 1186 conversion sequence is the identity conversion, unless the 1187 argument expression has a type that is a derived class of the 1188 parameter type, in which case the implicit conversion sequence is 1189 a derived-to-base Conversion. 1190 1191 If the parameter binds directly to the result of applying a 1192 conversion function to the argument expression, the implicit 1193 conversion sequence is a user-defined conversion sequence 1194 (_over.ics.user_), with the second standard conversion sequence 1195 either an identity conversion or, if the conversion function 1196 returns an entity of a type that is a derived class of the 1197 parameter type, a derived-to-base conversion. */ 1198 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type)) 1199 { 1200 /* Represent the derived-to-base conversion. */ 1201 conv = build_conv (ck_base, t, conv); 1202 /* We will actually be binding to the base-class subobject in 1203 the derived class, so we mark this conversion appropriately. 1204 That way, convert_like knows not to generate a temporary. */ 1205 conv->need_temporary_p = false; 1206 } 1207 return build_conv (ck_ref_bind, type, conv); 1208 } 1209 1210 /* Returns the conversion path from type FROM to reference type TO for 1211 purposes of reference binding. For lvalue binding, either pass a 1212 reference type to FROM or an lvalue expression to EXPR. If the 1213 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1214 the conversion returned. If C_CAST_P is true, this 1215 conversion is coming from a C-style cast. */ 1216 1217 static conversion * 1218 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags) 1219 { 1220 conversion *conv = NULL; 1221 tree to = TREE_TYPE (rto); 1222 tree from = rfrom; 1223 tree tfrom; 1224 bool related_p; 1225 bool compatible_p; 1226 cp_lvalue_kind is_lvalue = clk_none; 1227 1228 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1229 { 1230 expr = instantiate_type (to, expr, tf_none); 1231 if (expr == error_mark_node) 1232 return NULL; 1233 from = TREE_TYPE (expr); 1234 } 1235 1236 if (TREE_CODE (from) == REFERENCE_TYPE) 1237 { 1238 /* Anything with reference type is an lvalue. */ 1239 is_lvalue = clk_ordinary; 1240 from = TREE_TYPE (from); 1241 } 1242 1243 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1244 { 1245 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1246 conv = implicit_conversion (to, from, expr, c_cast_p, 1247 flags); 1248 if (!CLASS_TYPE_P (to) 1249 && CONSTRUCTOR_NELTS (expr) == 1) 1250 { 1251 expr = CONSTRUCTOR_ELT (expr, 0)->value; 1252 if (error_operand_p (expr)) 1253 return NULL; 1254 from = TREE_TYPE (expr); 1255 } 1256 } 1257 1258 if (is_lvalue == clk_none && expr) 1259 is_lvalue = real_lvalue_p (expr); 1260 1261 tfrom = from; 1262 if ((is_lvalue & clk_bitfield) != 0) 1263 tfrom = unlowered_expr_type (expr); 1264 1265 /* Figure out whether or not the types are reference-related and 1266 reference compatible. We have do do this after stripping 1267 references from FROM. */ 1268 related_p = reference_related_p (to, tfrom); 1269 /* If this is a C cast, first convert to an appropriately qualified 1270 type, so that we can later do a const_cast to the desired type. */ 1271 if (related_p && c_cast_p 1272 && !at_least_as_qualified_p (to, tfrom)) 1273 to = build_qualified_type (to, cp_type_quals (tfrom)); 1274 compatible_p = reference_compatible_p (to, tfrom); 1275 1276 /* Directly bind reference when target expression's type is compatible with 1277 the reference and expression is an lvalue. In DR391, the wording in 1278 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1279 const and rvalue references to rvalues of compatible class type. 1280 We should also do direct bindings for non-class "rvalues" derived from 1281 rvalue references. */ 1282 if (compatible_p 1283 && (is_lvalue 1284 || (((CP_TYPE_CONST_NON_VOLATILE_P (to) 1285 && !(flags & LOOKUP_NO_TEMP_BIND)) 1286 || TYPE_REF_IS_RVALUE (rto)) 1287 && (CLASS_TYPE_P (from) || (expr && lvalue_p (expr)))))) 1288 { 1289 /* [dcl.init.ref] 1290 1291 If the initializer expression 1292 1293 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1294 is reference-compatible with "cv2 T2," 1295 1296 the reference is bound directly to the initializer expression 1297 lvalue. 1298 1299 [...] 1300 If the initializer expression is an rvalue, with T2 a class type, 1301 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1302 is bound to the object represented by the rvalue or to a sub-object 1303 within that object. */ 1304 1305 conv = build_identity_conv (tfrom, expr); 1306 conv = direct_reference_binding (rto, conv); 1307 1308 if (flags & LOOKUP_PREFER_RVALUE) 1309 /* The top-level caller requested that we pretend that the lvalue 1310 be treated as an rvalue. */ 1311 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1312 else 1313 conv->rvaluedness_matches_p 1314 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1315 1316 if ((is_lvalue & clk_bitfield) != 0 1317 || ((is_lvalue & clk_packed) != 0 && !TYPE_PACKED (to))) 1318 /* For the purposes of overload resolution, we ignore the fact 1319 this expression is a bitfield or packed field. (In particular, 1320 [over.ics.ref] says specifically that a function with a 1321 non-const reference parameter is viable even if the 1322 argument is a bitfield.) 1323 1324 However, when we actually call the function we must create 1325 a temporary to which to bind the reference. If the 1326 reference is volatile, or isn't const, then we cannot make 1327 a temporary, so we just issue an error when the conversion 1328 actually occurs. */ 1329 conv->need_temporary_p = true; 1330 1331 /* Don't allow binding of lvalues to rvalue references. */ 1332 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1333 && !(flags & LOOKUP_PREFER_RVALUE)) 1334 conv->bad_p = true; 1335 1336 return conv; 1337 } 1338 /* [class.conv.fct] A conversion function is never used to convert a 1339 (possibly cv-qualified) object to the (possibly cv-qualified) same 1340 object type (or a reference to it), to a (possibly cv-qualified) base 1341 class of that type (or a reference to it).... */ 1342 else if (CLASS_TYPE_P (from) && !related_p 1343 && !(flags & LOOKUP_NO_CONVERSION)) 1344 { 1345 /* [dcl.init.ref] 1346 1347 If the initializer expression 1348 1349 -- has a class type (i.e., T2 is a class type) can be 1350 implicitly converted to an lvalue of type "cv3 T3," where 1351 "cv1 T1" is reference-compatible with "cv3 T3". (this 1352 conversion is selected by enumerating the applicable 1353 conversion functions (_over.match.ref_) and choosing the 1354 best one through overload resolution. (_over.match_). 1355 1356 the reference is bound to the lvalue result of the conversion 1357 in the second case. */ 1358 conv = convert_class_to_reference (rto, from, expr, flags); 1359 if (conv) 1360 return conv; 1361 } 1362 1363 /* From this point on, we conceptually need temporaries, even if we 1364 elide them. Only the cases above are "direct bindings". */ 1365 if (flags & LOOKUP_NO_TEMP_BIND) 1366 return NULL; 1367 1368 /* [over.ics.rank] 1369 1370 When a parameter of reference type is not bound directly to an 1371 argument expression, the conversion sequence is the one required 1372 to convert the argument expression to the underlying type of the 1373 reference according to _over.best.ics_. Conceptually, this 1374 conversion sequence corresponds to copy-initializing a temporary 1375 of the underlying type with the argument expression. Any 1376 difference in top-level cv-qualification is subsumed by the 1377 initialization itself and does not constitute a conversion. */ 1378 1379 /* [dcl.init.ref] 1380 1381 Otherwise, the reference shall be to a non-volatile const type. 1382 1383 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */ 1384 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1385 return NULL; 1386 1387 /* [dcl.init.ref] 1388 1389 Otherwise, a temporary of type "cv1 T1" is created and 1390 initialized from the initializer expression using the rules for a 1391 non-reference copy initialization. If T1 is reference-related to 1392 T2, cv1 must be the same cv-qualification as, or greater 1393 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1394 if (related_p && !at_least_as_qualified_p (to, from)) 1395 return NULL; 1396 1397 /* We're generating a temporary now, but don't bind any more in the 1398 conversion (specifically, don't slice the temporary returned by a 1399 conversion operator). */ 1400 flags |= LOOKUP_NO_TEMP_BIND; 1401 1402 /* Temporaries are copy-initialized, except for this hack to allow 1403 explicit conversion ops to the copy ctor. See also 1404 add_function_candidate. */ 1405 if (!(flags & LOOKUP_COPY_PARM)) 1406 flags |= LOOKUP_ONLYCONVERTING; 1407 1408 if (!conv) 1409 conv = implicit_conversion (to, from, expr, c_cast_p, 1410 flags); 1411 if (!conv) 1412 return NULL; 1413 1414 conv = build_conv (ck_ref_bind, rto, conv); 1415 /* This reference binding, unlike those above, requires the 1416 creation of a temporary. */ 1417 conv->need_temporary_p = true; 1418 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1419 1420 return conv; 1421 } 1422 1423 /* Returns the implicit conversion sequence (see [over.ics]) from type 1424 FROM to type TO. The optional expression EXPR may affect the 1425 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1426 true, this conversion is coming from a C-style cast. */ 1427 1428 static conversion * 1429 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1430 int flags) 1431 { 1432 conversion *conv; 1433 1434 if (from == error_mark_node || to == error_mark_node 1435 || expr == error_mark_node) 1436 return NULL; 1437 1438 if (TREE_CODE (to) == REFERENCE_TYPE) 1439 conv = reference_binding (to, from, expr, c_cast_p, flags); 1440 else 1441 conv = standard_conversion (to, from, expr, c_cast_p, flags); 1442 1443 if (conv) 1444 return conv; 1445 1446 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1447 { 1448 if (is_std_init_list (to)) 1449 return build_list_conv (to, expr, flags); 1450 1451 /* Allow conversion from an initializer-list with one element to a 1452 scalar type. */ 1453 if (SCALAR_TYPE_P (to)) 1454 { 1455 int nelts = CONSTRUCTOR_NELTS (expr); 1456 tree elt; 1457 1458 if (nelts == 0) 1459 elt = integer_zero_node; 1460 else if (nelts == 1) 1461 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1462 else 1463 elt = error_mark_node; 1464 1465 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1466 c_cast_p, flags); 1467 if (conv) 1468 { 1469 conv->check_narrowing = true; 1470 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1471 /* Too many levels of braces, i.e. '{{1}}'. */ 1472 conv->bad_p = true; 1473 return conv; 1474 } 1475 } 1476 } 1477 1478 if (expr != NULL_TREE 1479 && (MAYBE_CLASS_TYPE_P (from) 1480 || MAYBE_CLASS_TYPE_P (to)) 1481 && (flags & LOOKUP_NO_CONVERSION) == 0) 1482 { 1483 struct z_candidate *cand; 1484 int convflags = (flags & (LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING)); 1485 1486 if (CLASS_TYPE_P (to) 1487 && !CLASSTYPE_NON_AGGREGATE (complete_type (to)) 1488 && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1489 return build_aggr_conv (to, expr, flags); 1490 1491 cand = build_user_type_conversion_1 (to, expr, convflags); 1492 if (cand) 1493 conv = cand->second_conv; 1494 1495 /* We used to try to bind a reference to a temporary here, but that 1496 is now handled after the recursive call to this function at the end 1497 of reference_binding. */ 1498 return conv; 1499 } 1500 1501 return NULL; 1502 } 1503 1504 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1505 functions. ARGS will not be changed until a single candidate is 1506 selected. */ 1507 1508 static struct z_candidate * 1509 add_candidate (struct z_candidate **candidates, 1510 tree fn, tree first_arg, const VEC(tree,gc) *args, 1511 size_t num_convs, conversion **convs, 1512 tree access_path, tree conversion_path, 1513 int viable) 1514 { 1515 struct z_candidate *cand = (struct z_candidate *) 1516 conversion_obstack_alloc (sizeof (struct z_candidate)); 1517 1518 cand->fn = fn; 1519 cand->first_arg = first_arg; 1520 cand->args = args; 1521 cand->convs = convs; 1522 cand->num_convs = num_convs; 1523 cand->access_path = access_path; 1524 cand->conversion_path = conversion_path; 1525 cand->viable = viable; 1526 cand->next = *candidates; 1527 *candidates = cand; 1528 1529 return cand; 1530 } 1531 1532 /* Create an overload candidate for the function or method FN called 1533 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1534 FLAGS is passed on to implicit_conversion. 1535 1536 This does not change ARGS. 1537 1538 CTYPE, if non-NULL, is the type we want to pretend this function 1539 comes from for purposes of overload resolution. */ 1540 1541 static struct z_candidate * 1542 add_function_candidate (struct z_candidate **candidates, 1543 tree fn, tree ctype, tree first_arg, 1544 const VEC(tree,gc) *args, tree access_path, 1545 tree conversion_path, int flags) 1546 { 1547 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1548 int i, len; 1549 conversion **convs; 1550 tree parmnode; 1551 tree orig_first_arg = first_arg; 1552 int skip; 1553 int viable = 1; 1554 1555 /* At this point we should not see any functions which haven't been 1556 explicitly declared, except for friend functions which will have 1557 been found using argument dependent lookup. */ 1558 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 1559 1560 /* The `this', `in_chrg' and VTT arguments to constructors are not 1561 considered in overload resolution. */ 1562 if (DECL_CONSTRUCTOR_P (fn)) 1563 { 1564 parmlist = skip_artificial_parms_for (fn, parmlist); 1565 skip = num_artificial_parms_for (fn); 1566 if (skip > 0 && first_arg != NULL_TREE) 1567 { 1568 --skip; 1569 first_arg = NULL_TREE; 1570 } 1571 } 1572 else 1573 skip = 0; 1574 1575 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0); 1576 convs = alloc_conversions (len); 1577 1578 /* 13.3.2 - Viable functions [over.match.viable] 1579 First, to be a viable function, a candidate function shall have enough 1580 parameters to agree in number with the arguments in the list. 1581 1582 We need to check this first; otherwise, checking the ICSes might cause 1583 us to produce an ill-formed template instantiation. */ 1584 1585 parmnode = parmlist; 1586 for (i = 0; i < len; ++i) 1587 { 1588 if (parmnode == NULL_TREE || parmnode == void_list_node) 1589 break; 1590 parmnode = TREE_CHAIN (parmnode); 1591 } 1592 1593 if (i < len && parmnode) 1594 viable = 0; 1595 1596 /* Make sure there are default args for the rest of the parms. */ 1597 else if (!sufficient_parms_p (parmnode)) 1598 viable = 0; 1599 1600 if (! viable) 1601 goto out; 1602 1603 /* Second, for F to be a viable function, there shall exist for each 1604 argument an implicit conversion sequence that converts that argument 1605 to the corresponding parameter of F. */ 1606 1607 parmnode = parmlist; 1608 1609 for (i = 0; i < len; ++i) 1610 { 1611 tree arg, argtype; 1612 conversion *t; 1613 int is_this; 1614 1615 if (parmnode == void_list_node) 1616 break; 1617 1618 if (i == 0 && first_arg != NULL_TREE) 1619 arg = first_arg; 1620 else 1621 arg = VEC_index (tree, args, 1622 i + skip - (first_arg != NULL_TREE ? 1 : 0)); 1623 argtype = lvalue_type (arg); 1624 1625 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 1626 && ! DECL_CONSTRUCTOR_P (fn)); 1627 1628 if (parmnode) 1629 { 1630 tree parmtype = TREE_VALUE (parmnode); 1631 int lflags = flags; 1632 1633 /* The type of the implicit object parameter ('this') for 1634 overload resolution is not always the same as for the 1635 function itself; conversion functions are considered to 1636 be members of the class being converted, and functions 1637 introduced by a using-declaration are considered to be 1638 members of the class that uses them. 1639 1640 Since build_over_call ignores the ICS for the `this' 1641 parameter, we can just change the parm type. */ 1642 if (ctype && is_this) 1643 { 1644 parmtype 1645 = build_qualified_type (ctype, 1646 TYPE_QUALS (TREE_TYPE (parmtype))); 1647 parmtype = build_pointer_type (parmtype); 1648 } 1649 1650 if (ctype && i == 0 && DECL_COPY_CONSTRUCTOR_P (fn) 1651 && (len-skip == 1)) 1652 { 1653 /* Hack: Direct-initialize copy parm (i.e. suppress 1654 LOOKUP_ONLYCONVERTING) to make explicit conversion ops 1655 work. See also reference_binding. */ 1656 lflags |= LOOKUP_COPY_PARM; 1657 if (flags & LOOKUP_NO_COPY_CTOR_CONVERSION) 1658 lflags |= LOOKUP_NO_CONVERSION; 1659 } 1660 else 1661 lflags |= LOOKUP_ONLYCONVERTING; 1662 1663 t = implicit_conversion (parmtype, argtype, arg, 1664 /*c_cast_p=*/false, lflags); 1665 } 1666 else 1667 { 1668 t = build_identity_conv (argtype, arg); 1669 t->ellipsis_p = true; 1670 } 1671 1672 if (t && is_this) 1673 t->this_p = true; 1674 1675 convs[i] = t; 1676 if (! t) 1677 { 1678 viable = 0; 1679 break; 1680 } 1681 1682 if (t->bad_p) 1683 viable = -1; 1684 1685 if (parmnode) 1686 parmnode = TREE_CHAIN (parmnode); 1687 } 1688 1689 out: 1690 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 1691 access_path, conversion_path, viable); 1692 } 1693 1694 /* Create an overload candidate for the conversion function FN which will 1695 be invoked for expression OBJ, producing a pointer-to-function which 1696 will in turn be called with the argument list FIRST_ARG/ARGLIST, 1697 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 1698 passed on to implicit_conversion. 1699 1700 Actually, we don't really care about FN; we care about the type it 1701 converts to. There may be multiple conversion functions that will 1702 convert to that type, and we rely on build_user_type_conversion_1 to 1703 choose the best one; so when we create our candidate, we record the type 1704 instead of the function. */ 1705 1706 static struct z_candidate * 1707 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 1708 tree first_arg, const VEC(tree,gc) *arglist, 1709 tree access_path, tree conversion_path) 1710 { 1711 tree totype = TREE_TYPE (TREE_TYPE (fn)); 1712 int i, len, viable, flags; 1713 tree parmlist, parmnode; 1714 conversion **convs; 1715 1716 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 1717 parmlist = TREE_TYPE (parmlist); 1718 parmlist = TYPE_ARG_TYPES (parmlist); 1719 1720 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1; 1721 convs = alloc_conversions (len); 1722 parmnode = parmlist; 1723 viable = 1; 1724 flags = LOOKUP_IMPLICIT; 1725 1726 /* Don't bother looking up the same type twice. */ 1727 if (*candidates && (*candidates)->fn == totype) 1728 return NULL; 1729 1730 for (i = 0; i < len; ++i) 1731 { 1732 tree arg, argtype; 1733 conversion *t; 1734 1735 if (i == 0) 1736 arg = obj; 1737 else if (i == 1 && first_arg != NULL_TREE) 1738 arg = first_arg; 1739 else 1740 arg = VEC_index (tree, arglist, 1741 i - (first_arg != NULL_TREE ? 1 : 0) - 1); 1742 argtype = lvalue_type (arg); 1743 1744 if (i == 0) 1745 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false, 1746 flags); 1747 else if (parmnode == void_list_node) 1748 break; 1749 else if (parmnode) 1750 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 1751 /*c_cast_p=*/false, flags); 1752 else 1753 { 1754 t = build_identity_conv (argtype, arg); 1755 t->ellipsis_p = true; 1756 } 1757 1758 convs[i] = t; 1759 if (! t) 1760 break; 1761 1762 if (t->bad_p) 1763 viable = -1; 1764 1765 if (i == 0) 1766 continue; 1767 1768 if (parmnode) 1769 parmnode = TREE_CHAIN (parmnode); 1770 } 1771 1772 if (i < len) 1773 viable = 0; 1774 1775 if (!sufficient_parms_p (parmnode)) 1776 viable = 0; 1777 1778 return add_candidate (candidates, totype, first_arg, arglist, len, convs, 1779 access_path, conversion_path, viable); 1780 } 1781 1782 static void 1783 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 1784 tree type1, tree type2, tree *args, tree *argtypes, 1785 int flags) 1786 { 1787 conversion *t; 1788 conversion **convs; 1789 size_t num_convs; 1790 int viable = 1, i; 1791 tree types[2]; 1792 1793 types[0] = type1; 1794 types[1] = type2; 1795 1796 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 1797 convs = alloc_conversions (num_convs); 1798 1799 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 1800 conversion ops are allowed. We handle that here by just checking for 1801 boolean_type_node because other operators don't ask for it. COND_EXPR 1802 also does contextual conversion to bool for the first operand, but we 1803 handle that in build_conditional_expr, and type1 here is operand 2. */ 1804 if (type1 != boolean_type_node) 1805 flags |= LOOKUP_ONLYCONVERTING; 1806 1807 for (i = 0; i < 2; ++i) 1808 { 1809 if (! args[i]) 1810 break; 1811 1812 t = implicit_conversion (types[i], argtypes[i], args[i], 1813 /*c_cast_p=*/false, flags); 1814 if (! t) 1815 { 1816 viable = 0; 1817 /* We need something for printing the candidate. */ 1818 t = build_identity_conv (types[i], NULL_TREE); 1819 } 1820 else if (t->bad_p) 1821 viable = 0; 1822 convs[i] = t; 1823 } 1824 1825 /* For COND_EXPR we rearranged the arguments; undo that now. */ 1826 if (args[2]) 1827 { 1828 convs[2] = convs[1]; 1829 convs[1] = convs[0]; 1830 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 1831 /*c_cast_p=*/false, flags); 1832 if (t) 1833 convs[0] = t; 1834 else 1835 viable = 0; 1836 } 1837 1838 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 1839 num_convs, convs, 1840 /*access_path=*/NULL_TREE, 1841 /*conversion_path=*/NULL_TREE, 1842 viable); 1843 } 1844 1845 static bool 1846 is_complete (tree t) 1847 { 1848 return COMPLETE_TYPE_P (complete_type (t)); 1849 } 1850 1851 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 1852 1853 static bool 1854 promoted_arithmetic_type_p (tree type) 1855 { 1856 /* [over.built] 1857 1858 In this section, the term promoted integral type is used to refer 1859 to those integral types which are preserved by integral promotion 1860 (including e.g. int and long but excluding e.g. char). 1861 Similarly, the term promoted arithmetic type refers to promoted 1862 integral types plus floating types. */ 1863 return ((CP_INTEGRAL_TYPE_P (type) 1864 && same_type_p (type_promotes_to (type), type)) 1865 || TREE_CODE (type) == REAL_TYPE); 1866 } 1867 1868 /* Create any builtin operator overload candidates for the operator in 1869 question given the converted operand types TYPE1 and TYPE2. The other 1870 args are passed through from add_builtin_candidates to 1871 build_builtin_candidate. 1872 1873 TYPE1 and TYPE2 may not be permissible, and we must filter them. 1874 If CODE is requires candidates operands of the same type of the kind 1875 of which TYPE1 and TYPE2 are, we add both candidates 1876 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 1877 1878 static void 1879 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 1880 enum tree_code code2, tree fnname, tree type1, 1881 tree type2, tree *args, tree *argtypes, int flags) 1882 { 1883 switch (code) 1884 { 1885 case POSTINCREMENT_EXPR: 1886 case POSTDECREMENT_EXPR: 1887 args[1] = integer_zero_node; 1888 type2 = integer_type_node; 1889 break; 1890 default: 1891 break; 1892 } 1893 1894 switch (code) 1895 { 1896 1897 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 1898 and VQ is either volatile or empty, there exist candidate operator 1899 functions of the form 1900 VQ T& operator++(VQ T&); 1901 T operator++(VQ T&, int); 1902 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 1903 type other than bool, and VQ is either volatile or empty, there exist 1904 candidate operator functions of the form 1905 VQ T& operator--(VQ T&); 1906 T operator--(VQ T&, int); 1907 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 1908 complete object type, and VQ is either volatile or empty, there exist 1909 candidate operator functions of the form 1910 T*VQ& operator++(T*VQ&); 1911 T*VQ& operator--(T*VQ&); 1912 T* operator++(T*VQ&, int); 1913 T* operator--(T*VQ&, int); */ 1914 1915 case POSTDECREMENT_EXPR: 1916 case PREDECREMENT_EXPR: 1917 if (TREE_CODE (type1) == BOOLEAN_TYPE) 1918 return; 1919 case POSTINCREMENT_EXPR: 1920 case PREINCREMENT_EXPR: 1921 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 1922 { 1923 type1 = build_reference_type (type1); 1924 break; 1925 } 1926 return; 1927 1928 /* 7 For every cv-qualified or cv-unqualified object type T, there 1929 exist candidate operator functions of the form 1930 1931 T& operator*(T*); 1932 1933 8 For every function type T, there exist candidate operator functions of 1934 the form 1935 T& operator*(T*); */ 1936 1937 case INDIRECT_REF: 1938 if (TREE_CODE (type1) == POINTER_TYPE 1939 && !uses_template_parms (TREE_TYPE (type1)) 1940 && (TYPE_PTROB_P (type1) 1941 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 1942 break; 1943 return; 1944 1945 /* 9 For every type T, there exist candidate operator functions of the form 1946 T* operator+(T*); 1947 1948 10For every promoted arithmetic type T, there exist candidate operator 1949 functions of the form 1950 T operator+(T); 1951 T operator-(T); */ 1952 1953 case UNARY_PLUS_EXPR: /* unary + */ 1954 if (TREE_CODE (type1) == POINTER_TYPE) 1955 break; 1956 case NEGATE_EXPR: 1957 if (ARITHMETIC_TYPE_P (type1)) 1958 break; 1959 return; 1960 1961 /* 11For every promoted integral type T, there exist candidate operator 1962 functions of the form 1963 T operator~(T); */ 1964 1965 case BIT_NOT_EXPR: 1966 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 1967 break; 1968 return; 1969 1970 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 1971 is the same type as C2 or is a derived class of C2, T is a complete 1972 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 1973 there exist candidate operator functions of the form 1974 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 1975 where CV12 is the union of CV1 and CV2. */ 1976 1977 case MEMBER_REF: 1978 if (TREE_CODE (type1) == POINTER_TYPE 1979 && TYPE_PTR_TO_MEMBER_P (type2)) 1980 { 1981 tree c1 = TREE_TYPE (type1); 1982 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 1983 1984 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 1985 && (TYPE_PTRMEMFUNC_P (type2) 1986 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 1987 break; 1988 } 1989 return; 1990 1991 /* 13For every pair of promoted arithmetic types L and R, there exist can- 1992 didate operator functions of the form 1993 LR operator*(L, R); 1994 LR operator/(L, R); 1995 LR operator+(L, R); 1996 LR operator-(L, R); 1997 bool operator<(L, R); 1998 bool operator>(L, R); 1999 bool operator<=(L, R); 2000 bool operator>=(L, R); 2001 bool operator==(L, R); 2002 bool operator!=(L, R); 2003 where LR is the result of the usual arithmetic conversions between 2004 types L and R. 2005 2006 14For every pair of types T and I, where T is a cv-qualified or cv- 2007 unqualified complete object type and I is a promoted integral type, 2008 there exist candidate operator functions of the form 2009 T* operator+(T*, I); 2010 T& operator[](T*, I); 2011 T* operator-(T*, I); 2012 T* operator+(I, T*); 2013 T& operator[](I, T*); 2014 2015 15For every T, where T is a pointer to complete object type, there exist 2016 candidate operator functions of the form112) 2017 ptrdiff_t operator-(T, T); 2018 2019 16For every pointer or enumeration type T, there exist candidate operator 2020 functions of the form 2021 bool operator<(T, T); 2022 bool operator>(T, T); 2023 bool operator<=(T, T); 2024 bool operator>=(T, T); 2025 bool operator==(T, T); 2026 bool operator!=(T, T); 2027 2028 17For every pointer to member type T, there exist candidate operator 2029 functions of the form 2030 bool operator==(T, T); 2031 bool operator!=(T, T); */ 2032 2033 case MINUS_EXPR: 2034 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2035 break; 2036 if (TYPE_PTROB_P (type1) 2037 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2038 { 2039 type2 = ptrdiff_type_node; 2040 break; 2041 } 2042 case MULT_EXPR: 2043 case TRUNC_DIV_EXPR: 2044 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2045 break; 2046 return; 2047 2048 case EQ_EXPR: 2049 case NE_EXPR: 2050 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2051 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))) 2052 break; 2053 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1])) 2054 { 2055 type2 = type1; 2056 break; 2057 } 2058 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0])) 2059 { 2060 type1 = type2; 2061 break; 2062 } 2063 /* Fall through. */ 2064 case LT_EXPR: 2065 case GT_EXPR: 2066 case LE_EXPR: 2067 case GE_EXPR: 2068 case MAX_EXPR: 2069 case MIN_EXPR: 2070 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2071 break; 2072 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2073 break; 2074 if (TREE_CODE (type1) == ENUMERAL_TYPE 2075 && TREE_CODE (type2) == ENUMERAL_TYPE) 2076 break; 2077 if (TYPE_PTR_P (type1) 2078 && null_ptr_cst_p (args[1]) 2079 && !uses_template_parms (type1)) 2080 { 2081 type2 = type1; 2082 break; 2083 } 2084 if (null_ptr_cst_p (args[0]) 2085 && TYPE_PTR_P (type2) 2086 && !uses_template_parms (type2)) 2087 { 2088 type1 = type2; 2089 break; 2090 } 2091 return; 2092 2093 case PLUS_EXPR: 2094 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2095 break; 2096 case ARRAY_REF: 2097 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2098 { 2099 type1 = ptrdiff_type_node; 2100 break; 2101 } 2102 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2103 { 2104 type2 = ptrdiff_type_node; 2105 break; 2106 } 2107 return; 2108 2109 /* 18For every pair of promoted integral types L and R, there exist candi- 2110 date operator functions of the form 2111 LR operator%(L, R); 2112 LR operator&(L, R); 2113 LR operator^(L, R); 2114 LR operator|(L, R); 2115 L operator<<(L, R); 2116 L operator>>(L, R); 2117 where LR is the result of the usual arithmetic conversions between 2118 types L and R. */ 2119 2120 case TRUNC_MOD_EXPR: 2121 case BIT_AND_EXPR: 2122 case BIT_IOR_EXPR: 2123 case BIT_XOR_EXPR: 2124 case LSHIFT_EXPR: 2125 case RSHIFT_EXPR: 2126 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2127 break; 2128 return; 2129 2130 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2131 type, VQ is either volatile or empty, and R is a promoted arithmetic 2132 type, there exist candidate operator functions of the form 2133 VQ L& operator=(VQ L&, R); 2134 VQ L& operator*=(VQ L&, R); 2135 VQ L& operator/=(VQ L&, R); 2136 VQ L& operator+=(VQ L&, R); 2137 VQ L& operator-=(VQ L&, R); 2138 2139 20For every pair T, VQ), where T is any type and VQ is either volatile 2140 or empty, there exist candidate operator functions of the form 2141 T*VQ& operator=(T*VQ&, T*); 2142 2143 21For every pair T, VQ), where T is a pointer to member type and VQ is 2144 either volatile or empty, there exist candidate operator functions of 2145 the form 2146 VQ T& operator=(VQ T&, T); 2147 2148 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2149 unqualified complete object type, VQ is either volatile or empty, and 2150 I is a promoted integral type, there exist candidate operator func- 2151 tions of the form 2152 T*VQ& operator+=(T*VQ&, I); 2153 T*VQ& operator-=(T*VQ&, I); 2154 2155 23For every triple L, VQ, R), where L is an integral or enumeration 2156 type, VQ is either volatile or empty, and R is a promoted integral 2157 type, there exist candidate operator functions of the form 2158 2159 VQ L& operator%=(VQ L&, R); 2160 VQ L& operator<<=(VQ L&, R); 2161 VQ L& operator>>=(VQ L&, R); 2162 VQ L& operator&=(VQ L&, R); 2163 VQ L& operator^=(VQ L&, R); 2164 VQ L& operator|=(VQ L&, R); */ 2165 2166 case MODIFY_EXPR: 2167 switch (code2) 2168 { 2169 case PLUS_EXPR: 2170 case MINUS_EXPR: 2171 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2172 { 2173 type2 = ptrdiff_type_node; 2174 break; 2175 } 2176 case MULT_EXPR: 2177 case TRUNC_DIV_EXPR: 2178 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2179 break; 2180 return; 2181 2182 case TRUNC_MOD_EXPR: 2183 case BIT_AND_EXPR: 2184 case BIT_IOR_EXPR: 2185 case BIT_XOR_EXPR: 2186 case LSHIFT_EXPR: 2187 case RSHIFT_EXPR: 2188 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2189 break; 2190 return; 2191 2192 case NOP_EXPR: 2193 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2194 break; 2195 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2196 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2197 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2198 || ((TYPE_PTRMEMFUNC_P (type1) 2199 || TREE_CODE (type1) == POINTER_TYPE) 2200 && null_ptr_cst_p (args[1]))) 2201 { 2202 type2 = type1; 2203 break; 2204 } 2205 return; 2206 2207 default: 2208 gcc_unreachable (); 2209 } 2210 type1 = build_reference_type (type1); 2211 break; 2212 2213 case COND_EXPR: 2214 /* [over.built] 2215 2216 For every pair of promoted arithmetic types L and R, there 2217 exist candidate operator functions of the form 2218 2219 LR operator?(bool, L, R); 2220 2221 where LR is the result of the usual arithmetic conversions 2222 between types L and R. 2223 2224 For every type T, where T is a pointer or pointer-to-member 2225 type, there exist candidate operator functions of the form T 2226 operator?(bool, T, T); */ 2227 2228 if (promoted_arithmetic_type_p (type1) 2229 && promoted_arithmetic_type_p (type2)) 2230 /* That's OK. */ 2231 break; 2232 2233 /* Otherwise, the types should be pointers. */ 2234 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1)) 2235 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2))) 2236 return; 2237 2238 /* We don't check that the two types are the same; the logic 2239 below will actually create two candidates; one in which both 2240 parameter types are TYPE1, and one in which both parameter 2241 types are TYPE2. */ 2242 break; 2243 2244 default: 2245 gcc_unreachable (); 2246 } 2247 2248 /* If we're dealing with two pointer types or two enumeral types, 2249 we need candidates for both of them. */ 2250 if (type2 && !same_type_p (type1, type2) 2251 && TREE_CODE (type1) == TREE_CODE (type2) 2252 && (TREE_CODE (type1) == REFERENCE_TYPE 2253 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2254 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2255 || TYPE_PTRMEMFUNC_P (type1) 2256 || MAYBE_CLASS_TYPE_P (type1) 2257 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2258 { 2259 build_builtin_candidate 2260 (candidates, fnname, type1, type1, args, argtypes, flags); 2261 build_builtin_candidate 2262 (candidates, fnname, type2, type2, args, argtypes, flags); 2263 return; 2264 } 2265 2266 build_builtin_candidate 2267 (candidates, fnname, type1, type2, args, argtypes, flags); 2268 } 2269 2270 tree 2271 type_decays_to (tree type) 2272 { 2273 if (TREE_CODE (type) == ARRAY_TYPE) 2274 return build_pointer_type (TREE_TYPE (type)); 2275 if (TREE_CODE (type) == FUNCTION_TYPE) 2276 return build_pointer_type (type); 2277 return type; 2278 } 2279 2280 /* There are three conditions of builtin candidates: 2281 2282 1) bool-taking candidates. These are the same regardless of the input. 2283 2) pointer-pair taking candidates. These are generated for each type 2284 one of the input types converts to. 2285 3) arithmetic candidates. According to the standard, we should generate 2286 all of these, but I'm trying not to... 2287 2288 Here we generate a superset of the possible candidates for this particular 2289 case. That is a subset of the full set the standard defines, plus some 2290 other cases which the standard disallows. add_builtin_candidate will 2291 filter out the invalid set. */ 2292 2293 static void 2294 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2295 enum tree_code code2, tree fnname, tree *args, 2296 int flags) 2297 { 2298 int ref1, i; 2299 int enum_p = 0; 2300 tree type, argtypes[3]; 2301 /* TYPES[i] is the set of possible builtin-operator parameter types 2302 we will consider for the Ith argument. These are represented as 2303 a TREE_LIST; the TREE_VALUE of each node is the potential 2304 parameter type. */ 2305 tree types[2]; 2306 2307 for (i = 0; i < 3; ++i) 2308 { 2309 if (args[i]) 2310 argtypes[i] = unlowered_expr_type (args[i]); 2311 else 2312 argtypes[i] = NULL_TREE; 2313 } 2314 2315 switch (code) 2316 { 2317 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2318 and VQ is either volatile or empty, there exist candidate operator 2319 functions of the form 2320 VQ T& operator++(VQ T&); */ 2321 2322 case POSTINCREMENT_EXPR: 2323 case PREINCREMENT_EXPR: 2324 case POSTDECREMENT_EXPR: 2325 case PREDECREMENT_EXPR: 2326 case MODIFY_EXPR: 2327 ref1 = 1; 2328 break; 2329 2330 /* 24There also exist candidate operator functions of the form 2331 bool operator!(bool); 2332 bool operator&&(bool, bool); 2333 bool operator||(bool, bool); */ 2334 2335 case TRUTH_NOT_EXPR: 2336 build_builtin_candidate 2337 (candidates, fnname, boolean_type_node, 2338 NULL_TREE, args, argtypes, flags); 2339 return; 2340 2341 case TRUTH_ORIF_EXPR: 2342 case TRUTH_ANDIF_EXPR: 2343 build_builtin_candidate 2344 (candidates, fnname, boolean_type_node, 2345 boolean_type_node, args, argtypes, flags); 2346 return; 2347 2348 case ADDR_EXPR: 2349 case COMPOUND_EXPR: 2350 case COMPONENT_REF: 2351 return; 2352 2353 case COND_EXPR: 2354 case EQ_EXPR: 2355 case NE_EXPR: 2356 case LT_EXPR: 2357 case LE_EXPR: 2358 case GT_EXPR: 2359 case GE_EXPR: 2360 enum_p = 1; 2361 /* Fall through. */ 2362 2363 default: 2364 ref1 = 0; 2365 } 2366 2367 types[0] = types[1] = NULL_TREE; 2368 2369 for (i = 0; i < 2; ++i) 2370 { 2371 if (! args[i]) 2372 ; 2373 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2374 { 2375 tree convs; 2376 2377 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2378 return; 2379 2380 convs = lookup_conversions (argtypes[i]); 2381 2382 if (code == COND_EXPR) 2383 { 2384 if (real_lvalue_p (args[i])) 2385 types[i] = tree_cons 2386 (NULL_TREE, build_reference_type (argtypes[i]), types[i]); 2387 2388 types[i] = tree_cons 2389 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]); 2390 } 2391 2392 else if (! convs) 2393 return; 2394 2395 for (; convs; convs = TREE_CHAIN (convs)) 2396 { 2397 type = TREE_TYPE (convs); 2398 2399 if (i == 0 && ref1 2400 && (TREE_CODE (type) != REFERENCE_TYPE 2401 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 2402 continue; 2403 2404 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 2405 types[i] = tree_cons (NULL_TREE, type, types[i]); 2406 2407 type = non_reference (type); 2408 if (i != 0 || ! ref1) 2409 { 2410 type = TYPE_MAIN_VARIANT (type_decays_to (type)); 2411 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 2412 types[i] = tree_cons (NULL_TREE, type, types[i]); 2413 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2414 type = type_promotes_to (type); 2415 } 2416 2417 if (! value_member (type, types[i])) 2418 types[i] = tree_cons (NULL_TREE, type, types[i]); 2419 } 2420 } 2421 else 2422 { 2423 if (code == COND_EXPR && real_lvalue_p (args[i])) 2424 types[i] = tree_cons 2425 (NULL_TREE, build_reference_type (argtypes[i]), types[i]); 2426 type = non_reference (argtypes[i]); 2427 if (i != 0 || ! ref1) 2428 { 2429 type = TYPE_MAIN_VARIANT (type_decays_to (type)); 2430 if (enum_p && UNSCOPED_ENUM_P (type)) 2431 types[i] = tree_cons (NULL_TREE, type, types[i]); 2432 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2433 type = type_promotes_to (type); 2434 } 2435 types[i] = tree_cons (NULL_TREE, type, types[i]); 2436 } 2437 } 2438 2439 /* Run through the possible parameter types of both arguments, 2440 creating candidates with those parameter types. */ 2441 for (; types[0]; types[0] = TREE_CHAIN (types[0])) 2442 { 2443 if (types[1]) 2444 for (type = types[1]; type; type = TREE_CHAIN (type)) 2445 add_builtin_candidate 2446 (candidates, code, code2, fnname, TREE_VALUE (types[0]), 2447 TREE_VALUE (type), args, argtypes, flags); 2448 else 2449 add_builtin_candidate 2450 (candidates, code, code2, fnname, TREE_VALUE (types[0]), 2451 NULL_TREE, args, argtypes, flags); 2452 } 2453 } 2454 2455 2456 /* If TMPL can be successfully instantiated as indicated by 2457 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 2458 2459 TMPL is the template. EXPLICIT_TARGS are any explicit template 2460 arguments. ARGLIST is the arguments provided at the call-site. 2461 This does not change ARGLIST. The RETURN_TYPE is the desired type 2462 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 2463 as for add_function_candidate. If an OBJ is supplied, FLAGS and 2464 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 2465 2466 static struct z_candidate* 2467 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 2468 tree ctype, tree explicit_targs, tree first_arg, 2469 const VEC(tree,gc) *arglist, tree return_type, 2470 tree access_path, tree conversion_path, 2471 int flags, tree obj, unification_kind_t strict) 2472 { 2473 int ntparms = DECL_NTPARMS (tmpl); 2474 tree targs = make_tree_vec (ntparms); 2475 unsigned int len = VEC_length (tree, arglist); 2476 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 2477 unsigned int skip_without_in_chrg = 0; 2478 tree first_arg_without_in_chrg = first_arg; 2479 tree *args_without_in_chrg; 2480 unsigned int nargs_without_in_chrg; 2481 unsigned int ia, ix; 2482 tree arg; 2483 struct z_candidate *cand; 2484 int i; 2485 tree fn; 2486 2487 /* We don't do deduction on the in-charge parameter, the VTT 2488 parameter or 'this'. */ 2489 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 2490 { 2491 if (first_arg_without_in_chrg != NULL_TREE) 2492 first_arg_without_in_chrg = NULL_TREE; 2493 else 2494 ++skip_without_in_chrg; 2495 } 2496 2497 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 2498 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 2499 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 2500 { 2501 if (first_arg_without_in_chrg != NULL_TREE) 2502 first_arg_without_in_chrg = NULL_TREE; 2503 else 2504 ++skip_without_in_chrg; 2505 } 2506 2507 if (len < skip_without_in_chrg) 2508 return NULL; 2509 2510 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 2511 + (len - skip_without_in_chrg)); 2512 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 2513 ia = 0; 2514 if (first_arg_without_in_chrg != NULL_TREE) 2515 { 2516 args_without_in_chrg[ia] = first_arg_without_in_chrg; 2517 ++ia; 2518 } 2519 for (ix = skip_without_in_chrg; 2520 VEC_iterate (tree, arglist, ix, arg); 2521 ++ix) 2522 { 2523 args_without_in_chrg[ia] = arg; 2524 ++ia; 2525 } 2526 gcc_assert (ia == nargs_without_in_chrg); 2527 2528 i = fn_type_unification (tmpl, explicit_targs, targs, 2529 args_without_in_chrg, 2530 nargs_without_in_chrg, 2531 return_type, strict, flags); 2532 2533 if (i != 0) 2534 return NULL; 2535 2536 fn = instantiate_template (tmpl, targs, tf_none); 2537 if (fn == error_mark_node) 2538 return NULL; 2539 2540 /* In [class.copy]: 2541 2542 A member function template is never instantiated to perform the 2543 copy of a class object to an object of its class type. 2544 2545 It's a little unclear what this means; the standard explicitly 2546 does allow a template to be used to copy a class. For example, 2547 in: 2548 2549 struct A { 2550 A(A&); 2551 template <class T> A(const T&); 2552 }; 2553 const A f (); 2554 void g () { A a (f ()); } 2555 2556 the member template will be used to make the copy. The section 2557 quoted above appears in the paragraph that forbids constructors 2558 whose only parameter is (a possibly cv-qualified variant of) the 2559 class type, and a logical interpretation is that the intent was 2560 to forbid the instantiation of member templates which would then 2561 have that form. */ 2562 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 2563 { 2564 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 2565 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 2566 ctype)) 2567 return NULL; 2568 } 2569 2570 if (obj != NULL_TREE) 2571 /* Aha, this is a conversion function. */ 2572 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist, 2573 access_path, conversion_path); 2574 else 2575 cand = add_function_candidate (candidates, fn, ctype, 2576 first_arg, arglist, access_path, 2577 conversion_path, flags); 2578 if (DECL_TI_TEMPLATE (fn) != tmpl) 2579 /* This situation can occur if a member template of a template 2580 class is specialized. Then, instantiate_template might return 2581 an instantiation of the specialization, in which case the 2582 DECL_TI_TEMPLATE field will point at the original 2583 specialization. For example: 2584 2585 template <class T> struct S { template <class U> void f(U); 2586 template <> void f(int) {}; }; 2587 S<double> sd; 2588 sd.f(3); 2589 2590 Here, TMPL will be template <class U> S<double>::f(U). 2591 And, instantiate template will give us the specialization 2592 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 2593 for this will point at template <class T> template <> S<T>::f(int), 2594 so that we can find the definition. For the purposes of 2595 overload resolution, however, we want the original TMPL. */ 2596 cand->template_decl = build_template_info (tmpl, targs); 2597 else 2598 cand->template_decl = DECL_TEMPLATE_INFO (fn); 2599 cand->explicit_targs = explicit_targs; 2600 2601 return cand; 2602 } 2603 2604 2605 static struct z_candidate * 2606 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 2607 tree explicit_targs, tree first_arg, 2608 const VEC(tree,gc) *arglist, tree return_type, 2609 tree access_path, tree conversion_path, int flags, 2610 unification_kind_t strict) 2611 { 2612 return 2613 add_template_candidate_real (candidates, tmpl, ctype, 2614 explicit_targs, first_arg, arglist, 2615 return_type, access_path, conversion_path, 2616 flags, NULL_TREE, strict); 2617 } 2618 2619 2620 static struct z_candidate * 2621 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 2622 tree obj, tree first_arg, 2623 const VEC(tree,gc) *arglist, 2624 tree return_type, tree access_path, 2625 tree conversion_path) 2626 { 2627 return 2628 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 2629 first_arg, arglist, return_type, access_path, 2630 conversion_path, 0, obj, DEDUCE_CONV); 2631 } 2632 2633 /* The CANDS are the set of candidates that were considered for 2634 overload resolution. Return the set of viable candidates. If none 2635 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P 2636 is true if a candidate should be considered viable only if it is 2637 strictly viable. */ 2638 2639 static struct z_candidate* 2640 splice_viable (struct z_candidate *cands, 2641 bool strict_p, 2642 bool *any_viable_p) 2643 { 2644 struct z_candidate *viable; 2645 struct z_candidate **last_viable; 2646 struct z_candidate **cand; 2647 2648 viable = NULL; 2649 last_viable = &viable; 2650 *any_viable_p = false; 2651 2652 cand = &cands; 2653 while (*cand) 2654 { 2655 struct z_candidate *c = *cand; 2656 if (strict_p ? c->viable == 1 : c->viable) 2657 { 2658 *last_viable = c; 2659 *cand = c->next; 2660 c->next = NULL; 2661 last_viable = &c->next; 2662 *any_viable_p = true; 2663 } 2664 else 2665 cand = &c->next; 2666 } 2667 2668 return viable ? viable : cands; 2669 } 2670 2671 static bool 2672 any_strictly_viable (struct z_candidate *cands) 2673 { 2674 for (; cands; cands = cands->next) 2675 if (cands->viable == 1) 2676 return true; 2677 return false; 2678 } 2679 2680 /* OBJ is being used in an expression like "OBJ.f (...)". In other 2681 words, it is about to become the "this" pointer for a member 2682 function call. Take the address of the object. */ 2683 2684 static tree 2685 build_this (tree obj) 2686 { 2687 /* In a template, we are only concerned about the type of the 2688 expression, so we can take a shortcut. */ 2689 if (processing_template_decl) 2690 return build_address (obj); 2691 2692 return cp_build_unary_op (ADDR_EXPR, obj, 0, tf_warning_or_error); 2693 } 2694 2695 /* Returns true iff functions are equivalent. Equivalent functions are 2696 not '==' only if one is a function-local extern function or if 2697 both are extern "C". */ 2698 2699 static inline int 2700 equal_functions (tree fn1, tree fn2) 2701 { 2702 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 2703 || DECL_EXTERN_C_FUNCTION_P (fn1)) 2704 return decls_match (fn1, fn2); 2705 return fn1 == fn2; 2706 } 2707 2708 /* Print information about one overload candidate CANDIDATE. MSGSTR 2709 is the text to print before the candidate itself. 2710 2711 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 2712 to have been run through gettext by the caller. This wart makes 2713 life simpler in print_z_candidates and for the translators. */ 2714 2715 static void 2716 print_z_candidate (const char *msgstr, struct z_candidate *candidate) 2717 { 2718 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE) 2719 { 2720 if (candidate->num_convs == 3) 2721 inform (input_location, "%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn, 2722 candidate->convs[0]->type, 2723 candidate->convs[1]->type, 2724 candidate->convs[2]->type); 2725 else if (candidate->num_convs == 2) 2726 inform (input_location, "%s %D(%T, %T) <built-in>", msgstr, candidate->fn, 2727 candidate->convs[0]->type, 2728 candidate->convs[1]->type); 2729 else 2730 inform (input_location, "%s %D(%T) <built-in>", msgstr, candidate->fn, 2731 candidate->convs[0]->type); 2732 } 2733 else if (TYPE_P (candidate->fn)) 2734 inform (input_location, "%s %T <conversion>", msgstr, candidate->fn); 2735 else if (candidate->viable == -1) 2736 inform (input_location, "%s %+#D <near match>", msgstr, candidate->fn); 2737 else if (DECL_DELETED_FN (candidate->fn)) 2738 inform (input_location, "%s %+#D <deleted>", msgstr, candidate->fn); 2739 else 2740 inform (input_location, "%s %+#D", msgstr, candidate->fn); 2741 } 2742 2743 static void 2744 print_z_candidates (struct z_candidate *candidates) 2745 { 2746 const char *str; 2747 struct z_candidate *cand1; 2748 struct z_candidate **cand2; 2749 char *spaces; 2750 2751 if (!candidates) 2752 return; 2753 2754 /* Remove deleted candidates. */ 2755 cand1 = candidates; 2756 for (cand2 = &cand1; *cand2; ) 2757 { 2758 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 2759 && DECL_DELETED_FN ((*cand2)->fn)) 2760 *cand2 = (*cand2)->next; 2761 else 2762 cand2 = &(*cand2)->next; 2763 } 2764 /* ...if there are any non-deleted ones. */ 2765 if (cand1) 2766 candidates = cand1; 2767 2768 /* There may be duplicates in the set of candidates. We put off 2769 checking this condition as long as possible, since we have no way 2770 to eliminate duplicates from a set of functions in less than n^2 2771 time. Now we are about to emit an error message, so it is more 2772 permissible to go slowly. */ 2773 for (cand1 = candidates; cand1; cand1 = cand1->next) 2774 { 2775 tree fn = cand1->fn; 2776 /* Skip builtin candidates and conversion functions. */ 2777 if (TREE_CODE (fn) != FUNCTION_DECL) 2778 continue; 2779 cand2 = &cand1->next; 2780 while (*cand2) 2781 { 2782 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 2783 && equal_functions (fn, (*cand2)->fn)) 2784 *cand2 = (*cand2)->next; 2785 else 2786 cand2 = &(*cand2)->next; 2787 } 2788 } 2789 2790 str = candidates->next ? _("candidates are:") : _("candidate is:"); 2791 spaces = NULL; 2792 for (; candidates; candidates = candidates->next) 2793 { 2794 print_z_candidate (spaces ? spaces : str, candidates); 2795 spaces = spaces ? spaces : get_spaces (str); 2796 } 2797 free (spaces); 2798 } 2799 2800 /* USER_SEQ is a user-defined conversion sequence, beginning with a 2801 USER_CONV. STD_SEQ is the standard conversion sequence applied to 2802 the result of the conversion function to convert it to the final 2803 desired type. Merge the two sequences into a single sequence, 2804 and return the merged sequence. */ 2805 2806 static conversion * 2807 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 2808 { 2809 conversion **t; 2810 2811 gcc_assert (user_seq->kind == ck_user); 2812 2813 /* Find the end of the second conversion sequence. */ 2814 t = &(std_seq); 2815 while ((*t)->kind != ck_identity) 2816 t = &((*t)->u.next); 2817 2818 /* Replace the identity conversion with the user conversion 2819 sequence. */ 2820 *t = user_seq; 2821 2822 /* The entire sequence is a user-conversion sequence. */ 2823 std_seq->user_conv_p = true; 2824 2825 return std_seq; 2826 } 2827 2828 /* Returns the best overload candidate to perform the requested 2829 conversion. This function is used for three the overloading situations 2830 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 2831 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as 2832 per [dcl.init.ref], so we ignore temporary bindings. */ 2833 2834 static struct z_candidate * 2835 build_user_type_conversion_1 (tree totype, tree expr, int flags) 2836 { 2837 struct z_candidate *candidates, *cand; 2838 tree fromtype = TREE_TYPE (expr); 2839 tree ctors = NULL_TREE; 2840 tree conv_fns = NULL_TREE; 2841 conversion *conv = NULL; 2842 tree first_arg = NULL_TREE; 2843 VEC(tree,gc) *args = NULL; 2844 bool any_viable_p; 2845 int convflags; 2846 2847 /* We represent conversion within a hierarchy using RVALUE_CONV and 2848 BASE_CONV, as specified by [over.best.ics]; these become plain 2849 constructor calls, as specified in [dcl.init]. */ 2850 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 2851 || !DERIVED_FROM_P (totype, fromtype)); 2852 2853 if (MAYBE_CLASS_TYPE_P (totype)) 2854 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0); 2855 2856 if (MAYBE_CLASS_TYPE_P (fromtype)) 2857 { 2858 tree to_nonref = non_reference (totype); 2859 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 2860 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 2861 && DERIVED_FROM_P (to_nonref, fromtype))) 2862 { 2863 /* [class.conv.fct] A conversion function is never used to 2864 convert a (possibly cv-qualified) object to the (possibly 2865 cv-qualified) same object type (or a reference to it), to a 2866 (possibly cv-qualified) base class of that type (or a 2867 reference to it)... */ 2868 } 2869 else 2870 conv_fns = lookup_conversions (fromtype); 2871 } 2872 2873 candidates = 0; 2874 flags |= LOOKUP_NO_CONVERSION; 2875 2876 /* It's OK to bind a temporary for converting constructor arguments, but 2877 not in converting the return value of a conversion operator. */ 2878 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION); 2879 flags &= ~LOOKUP_NO_TEMP_BIND; 2880 2881 if (ctors) 2882 { 2883 ctors = BASELINK_FUNCTIONS (ctors); 2884 2885 first_arg = build_int_cst (build_pointer_type (totype), 0); 2886 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 2887 && !TYPE_HAS_LIST_CTOR (totype)) 2888 { 2889 args = ctor_to_vec (expr); 2890 /* We still allow more conversions within an init-list. */ 2891 flags = ((flags & ~LOOKUP_NO_CONVERSION) 2892 /* But not for the copy ctor. */ 2893 |LOOKUP_NO_COPY_CTOR_CONVERSION 2894 |LOOKUP_NO_NARROWING); 2895 } 2896 else 2897 args = make_tree_vector_single (expr); 2898 2899 /* We should never try to call the abstract or base constructor 2900 from here. */ 2901 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors)) 2902 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors))); 2903 } 2904 for (; ctors; ctors = OVL_NEXT (ctors)) 2905 { 2906 tree ctor = OVL_CURRENT (ctors); 2907 if (DECL_NONCONVERTING_P (ctor) 2908 && !BRACE_ENCLOSED_INITIALIZER_P (expr)) 2909 continue; 2910 2911 if (TREE_CODE (ctor) == TEMPLATE_DECL) 2912 cand = add_template_candidate (&candidates, ctor, totype, 2913 NULL_TREE, first_arg, args, NULL_TREE, 2914 TYPE_BINFO (totype), 2915 TYPE_BINFO (totype), 2916 flags, 2917 DEDUCE_CALL); 2918 else 2919 cand = add_function_candidate (&candidates, ctor, totype, 2920 first_arg, args, TYPE_BINFO (totype), 2921 TYPE_BINFO (totype), 2922 flags); 2923 2924 if (cand) 2925 { 2926 cand->second_conv = build_identity_conv (totype, NULL_TREE); 2927 2928 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 2929 set, then this is copy-initialization. In that case, "The 2930 result of the call is then used to direct-initialize the 2931 object that is the destination of the copy-initialization." 2932 [dcl.init] 2933 2934 We represent this in the conversion sequence with an 2935 rvalue conversion, which means a constructor call. */ 2936 if (TREE_CODE (totype) != REFERENCE_TYPE 2937 && !(convflags & LOOKUP_NO_TEMP_BIND)) 2938 cand->second_conv 2939 = build_conv (ck_rvalue, totype, cand->second_conv); 2940 } 2941 } 2942 2943 if (conv_fns) 2944 first_arg = build_this (expr); 2945 2946 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 2947 { 2948 tree fns; 2949 tree conversion_path = TREE_PURPOSE (conv_fns); 2950 2951 /* If we are called to convert to a reference type, we are trying to 2952 find an lvalue binding, so don't even consider temporaries. If 2953 we don't find an lvalue binding, the caller will try again to 2954 look for a temporary binding. */ 2955 if (TREE_CODE (totype) == REFERENCE_TYPE) 2956 convflags |= LOOKUP_NO_TEMP_BIND; 2957 2958 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns)) 2959 { 2960 tree fn = OVL_CURRENT (fns); 2961 2962 if (DECL_NONCONVERTING_P (fn) 2963 && (flags & LOOKUP_ONLYCONVERTING)) 2964 continue; 2965 2966 /* [over.match.funcs] For conversion functions, the function 2967 is considered to be a member of the class of the implicit 2968 object argument for the purpose of defining the type of 2969 the implicit object parameter. 2970 2971 So we pass fromtype as CTYPE to add_*_candidate. */ 2972 2973 if (TREE_CODE (fn) == TEMPLATE_DECL) 2974 cand = add_template_candidate (&candidates, fn, fromtype, 2975 NULL_TREE, 2976 first_arg, NULL, totype, 2977 TYPE_BINFO (fromtype), 2978 conversion_path, 2979 flags, 2980 DEDUCE_CONV); 2981 else 2982 cand = add_function_candidate (&candidates, fn, fromtype, 2983 first_arg, NULL, 2984 TYPE_BINFO (fromtype), 2985 conversion_path, 2986 flags); 2987 2988 if (cand) 2989 { 2990 conversion *ics 2991 = implicit_conversion (totype, 2992 TREE_TYPE (TREE_TYPE (cand->fn)), 2993 0, 2994 /*c_cast_p=*/false, convflags); 2995 2996 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 2997 copy-initialization. In that case, "The result of the 2998 call is then used to direct-initialize the object that is 2999 the destination of the copy-initialization." [dcl.init] 3000 3001 We represent this in the conversion sequence with an 3002 rvalue conversion, which means a constructor call. But 3003 don't add a second rvalue conversion if there's already 3004 one there. Which there really shouldn't be, but it's 3005 harmless since we'd add it here anyway. */ 3006 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3007 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3008 ics = build_conv (ck_rvalue, totype, ics); 3009 3010 cand->second_conv = ics; 3011 3012 if (!ics) 3013 cand->viable = 0; 3014 else if (candidates->viable == 1 && ics->bad_p) 3015 cand->viable = -1; 3016 } 3017 } 3018 } 3019 3020 candidates = splice_viable (candidates, pedantic, &any_viable_p); 3021 if (!any_viable_p) 3022 return NULL; 3023 3024 cand = tourney (candidates); 3025 if (cand == 0) 3026 { 3027 if (flags & LOOKUP_COMPLAIN) 3028 { 3029 error ("conversion from %qT to %qT is ambiguous", 3030 fromtype, totype); 3031 print_z_candidates (candidates); 3032 } 3033 3034 cand = candidates; /* any one will do */ 3035 cand->second_conv = build_ambiguous_conv (totype, expr); 3036 cand->second_conv->user_conv_p = true; 3037 if (!any_strictly_viable (candidates)) 3038 cand->second_conv->bad_p = true; 3039 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3040 ambiguous conversion is no worse than another user-defined 3041 conversion. */ 3042 3043 return cand; 3044 } 3045 3046 /* Build the user conversion sequence. */ 3047 conv = build_conv 3048 (ck_user, 3049 (DECL_CONSTRUCTOR_P (cand->fn) 3050 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))), 3051 build_identity_conv (TREE_TYPE (expr), expr)); 3052 conv->cand = cand; 3053 3054 /* Remember that this was a list-initialization. */ 3055 if (flags & LOOKUP_NO_NARROWING) 3056 conv->check_narrowing = true; 3057 3058 /* Combine it with the second conversion sequence. */ 3059 cand->second_conv = merge_conversion_sequences (conv, 3060 cand->second_conv); 3061 3062 if (cand->viable == -1) 3063 cand->second_conv->bad_p = true; 3064 3065 return cand; 3066 } 3067 3068 tree 3069 build_user_type_conversion (tree totype, tree expr, int flags) 3070 { 3071 struct z_candidate *cand 3072 = build_user_type_conversion_1 (totype, expr, flags); 3073 3074 if (cand) 3075 { 3076 if (cand->second_conv->kind == ck_ambig) 3077 return error_mark_node; 3078 expr = convert_like (cand->second_conv, expr, tf_warning_or_error); 3079 return convert_from_reference (expr); 3080 } 3081 return NULL_TREE; 3082 } 3083 3084 /* Do any initial processing on the arguments to a function call. */ 3085 3086 static VEC(tree,gc) * 3087 resolve_args (VEC(tree,gc) *args) 3088 { 3089 unsigned int ix; 3090 tree arg; 3091 3092 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix) 3093 { 3094 if (error_operand_p (arg)) 3095 return NULL; 3096 else if (VOID_TYPE_P (TREE_TYPE (arg))) 3097 { 3098 error ("invalid use of void expression"); 3099 return NULL; 3100 } 3101 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error)) 3102 return NULL; 3103 } 3104 return args; 3105 } 3106 3107 /* Perform overload resolution on FN, which is called with the ARGS. 3108 3109 Return the candidate function selected by overload resolution, or 3110 NULL if the event that overload resolution failed. In the case 3111 that overload resolution fails, *CANDIDATES will be the set of 3112 candidates considered, and ANY_VIABLE_P will be set to true or 3113 false to indicate whether or not any of the candidates were 3114 viable. 3115 3116 The ARGS should already have gone through RESOLVE_ARGS before this 3117 function is called. */ 3118 3119 static struct z_candidate * 3120 perform_overload_resolution (tree fn, 3121 const VEC(tree,gc) *args, 3122 struct z_candidate **candidates, 3123 bool *any_viable_p) 3124 { 3125 struct z_candidate *cand; 3126 tree explicit_targs = NULL_TREE; 3127 int template_only = 0; 3128 3129 *candidates = NULL; 3130 *any_viable_p = true; 3131 3132 /* Check FN. */ 3133 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 3134 || TREE_CODE (fn) == TEMPLATE_DECL 3135 || TREE_CODE (fn) == OVERLOAD 3136 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 3137 3138 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3139 { 3140 explicit_targs = TREE_OPERAND (fn, 1); 3141 fn = TREE_OPERAND (fn, 0); 3142 template_only = 1; 3143 } 3144 3145 /* Add the various candidate functions. */ 3146 add_candidates (fn, args, explicit_targs, template_only, 3147 /*conversion_path=*/NULL_TREE, 3148 /*access_path=*/NULL_TREE, 3149 LOOKUP_NORMAL, 3150 candidates); 3151 3152 *candidates = splice_viable (*candidates, pedantic, any_viable_p); 3153 if (!*any_viable_p) 3154 return NULL; 3155 3156 cand = tourney (*candidates); 3157 return cand; 3158 } 3159 3160 /* Return an expression for a call to FN (a namespace-scope function, 3161 or a static member function) with the ARGS. This may change 3162 ARGS. */ 3163 3164 tree 3165 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p, 3166 tsubst_flags_t complain) 3167 { 3168 struct z_candidate *candidates, *cand; 3169 bool any_viable_p; 3170 void *p; 3171 tree result; 3172 3173 if (args != NULL && *args != NULL) 3174 { 3175 *args = resolve_args (*args); 3176 if (*args == NULL) 3177 return error_mark_node; 3178 } 3179 3180 /* If this function was found without using argument dependent 3181 lookup, then we want to ignore any undeclared friend 3182 functions. */ 3183 if (!koenig_p) 3184 { 3185 tree orig_fn = fn; 3186 3187 fn = remove_hidden_names (fn); 3188 if (!fn) 3189 { 3190 if (complain & tf_error) 3191 error ("no matching function for call to %<%D(%A)%>", 3192 DECL_NAME (OVL_CURRENT (orig_fn)), 3193 build_tree_list_vec (*args)); 3194 return error_mark_node; 3195 } 3196 } 3197 3198 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3199 p = conversion_obstack_alloc (0); 3200 3201 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p); 3202 3203 if (!cand) 3204 { 3205 if (complain & tf_error) 3206 { 3207 if (!any_viable_p && candidates && ! candidates->next) 3208 return cp_build_function_call_vec (candidates->fn, args, complain); 3209 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3210 fn = TREE_OPERAND (fn, 0); 3211 if (!any_viable_p) 3212 error ("no matching function for call to %<%D(%A)%>", 3213 DECL_NAME (OVL_CURRENT (fn)), build_tree_list_vec (*args)); 3214 else 3215 error ("call of overloaded %<%D(%A)%> is ambiguous", 3216 DECL_NAME (OVL_CURRENT (fn)), build_tree_list_vec (*args)); 3217 if (candidates) 3218 print_z_candidates (candidates); 3219 } 3220 result = error_mark_node; 3221 } 3222 else 3223 result = build_over_call (cand, LOOKUP_NORMAL, complain); 3224 3225 /* Free all the conversions we allocated. */ 3226 obstack_free (&conversion_obstack, p); 3227 3228 return result; 3229 } 3230 3231 /* Build a call to a global operator new. FNNAME is the name of the 3232 operator (either "operator new" or "operator new[]") and ARGS are 3233 the arguments provided. This may change ARGS. *SIZE points to the 3234 total number of bytes required by the allocation, and is updated if 3235 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 3236 be used. If this function determines that no cookie should be 3237 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is 3238 non-NULL, it will be set, upon return, to the allocation function 3239 called. */ 3240 3241 tree 3242 build_operator_new_call (tree fnname, VEC(tree,gc) **args, 3243 tree *size, tree *cookie_size, 3244 tree *fn) 3245 { 3246 tree fns; 3247 struct z_candidate *candidates; 3248 struct z_candidate *cand; 3249 bool any_viable_p; 3250 3251 if (fn) 3252 *fn = NULL_TREE; 3253 VEC_safe_insert (tree, gc, *args, 0, *size); 3254 *args = resolve_args (*args); 3255 if (*args == NULL) 3256 return error_mark_node; 3257 3258 /* Based on: 3259 3260 [expr.new] 3261 3262 If this lookup fails to find the name, or if the allocated type 3263 is not a class type, the allocation function's name is looked 3264 up in the global scope. 3265 3266 we disregard block-scope declarations of "operator new". */ 3267 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false); 3268 3269 /* Figure out what function is being called. */ 3270 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p); 3271 3272 /* If no suitable function could be found, issue an error message 3273 and give up. */ 3274 if (!cand) 3275 { 3276 if (!any_viable_p) 3277 error ("no matching function for call to %<%D(%A)%>", 3278 DECL_NAME (OVL_CURRENT (fns)), build_tree_list_vec (*args)); 3279 else 3280 error ("call of overloaded %<%D(%A)%> is ambiguous", 3281 DECL_NAME (OVL_CURRENT (fns)), build_tree_list_vec (*args)); 3282 if (candidates) 3283 print_z_candidates (candidates); 3284 return error_mark_node; 3285 } 3286 3287 /* If a cookie is required, add some extra space. Whether 3288 or not a cookie is required cannot be determined until 3289 after we know which function was called. */ 3290 if (*cookie_size) 3291 { 3292 bool use_cookie = true; 3293 if (!abi_version_at_least (2)) 3294 { 3295 /* In G++ 3.2, the check was implemented incorrectly; it 3296 looked at the placement expression, rather than the 3297 type of the function. */ 3298 if (VEC_length (tree, *args) == 2 3299 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)), 3300 ptr_type_node)) 3301 use_cookie = false; 3302 } 3303 else 3304 { 3305 tree arg_types; 3306 3307 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 3308 /* Skip the size_t parameter. */ 3309 arg_types = TREE_CHAIN (arg_types); 3310 /* Check the remaining parameters (if any). */ 3311 if (arg_types 3312 && TREE_CHAIN (arg_types) == void_list_node 3313 && same_type_p (TREE_VALUE (arg_types), 3314 ptr_type_node)) 3315 use_cookie = false; 3316 } 3317 /* If we need a cookie, adjust the number of bytes allocated. */ 3318 if (use_cookie) 3319 { 3320 /* Update the total size. */ 3321 *size = size_binop (PLUS_EXPR, *size, *cookie_size); 3322 /* Update the argument list to reflect the adjusted size. */ 3323 VEC_replace (tree, *args, 0, *size); 3324 } 3325 else 3326 *cookie_size = NULL_TREE; 3327 } 3328 3329 /* Tell our caller which function we decided to call. */ 3330 if (fn) 3331 *fn = cand->fn; 3332 3333 /* Build the CALL_EXPR. */ 3334 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error); 3335 } 3336 3337 /* Build a new call to operator(). This may change ARGS. */ 3338 3339 tree 3340 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain) 3341 { 3342 struct z_candidate *candidates = 0, *cand; 3343 tree fns, convs, first_mem_arg = NULL_TREE; 3344 tree type = TREE_TYPE (obj); 3345 bool any_viable_p; 3346 tree result = NULL_TREE; 3347 void *p; 3348 3349 if (error_operand_p (obj)) 3350 return error_mark_node; 3351 3352 obj = prep_operand (obj); 3353 3354 if (TYPE_PTRMEMFUNC_P (type)) 3355 { 3356 if (complain & tf_error) 3357 /* It's no good looking for an overloaded operator() on a 3358 pointer-to-member-function. */ 3359 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj); 3360 return error_mark_node; 3361 } 3362 3363 if (TYPE_BINFO (type)) 3364 { 3365 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1); 3366 if (fns == error_mark_node) 3367 return error_mark_node; 3368 } 3369 else 3370 fns = NULL_TREE; 3371 3372 if (args != NULL && *args != NULL) 3373 { 3374 *args = resolve_args (*args); 3375 if (*args == NULL) 3376 return error_mark_node; 3377 } 3378 3379 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3380 p = conversion_obstack_alloc (0); 3381 3382 if (fns) 3383 { 3384 tree base = BINFO_TYPE (BASELINK_BINFO (fns)); 3385 first_mem_arg = build_this (obj); 3386 3387 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns)) 3388 { 3389 tree fn = OVL_CURRENT (fns); 3390 3391 if (TREE_CODE (fn) == TEMPLATE_DECL) 3392 add_template_candidate (&candidates, fn, base, NULL_TREE, 3393 first_mem_arg, *args, NULL_TREE, 3394 TYPE_BINFO (type), 3395 TYPE_BINFO (type), 3396 LOOKUP_NORMAL, DEDUCE_CALL); 3397 else 3398 add_function_candidate 3399 (&candidates, fn, base, first_mem_arg, *args, TYPE_BINFO (type), 3400 TYPE_BINFO (type), LOOKUP_NORMAL); 3401 } 3402 } 3403 3404 convs = lookup_conversions (type); 3405 3406 for (; convs; convs = TREE_CHAIN (convs)) 3407 { 3408 tree fns = TREE_VALUE (convs); 3409 tree totype = TREE_TYPE (convs); 3410 3411 if ((TREE_CODE (totype) == POINTER_TYPE 3412 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 3413 || (TREE_CODE (totype) == REFERENCE_TYPE 3414 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 3415 || (TREE_CODE (totype) == REFERENCE_TYPE 3416 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE 3417 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE)) 3418 for (; fns; fns = OVL_NEXT (fns)) 3419 { 3420 tree fn = OVL_CURRENT (fns); 3421 3422 if (DECL_NONCONVERTING_P (fn)) 3423 continue; 3424 3425 if (TREE_CODE (fn) == TEMPLATE_DECL) 3426 add_template_conv_candidate 3427 (&candidates, fn, obj, NULL_TREE, *args, totype, 3428 /*access_path=*/NULL_TREE, 3429 /*conversion_path=*/NULL_TREE); 3430 else 3431 add_conv_candidate (&candidates, fn, obj, NULL_TREE, 3432 *args, /*conversion_path=*/NULL_TREE, 3433 /*access_path=*/NULL_TREE); 3434 } 3435 } 3436 3437 candidates = splice_viable (candidates, pedantic, &any_viable_p); 3438 if (!any_viable_p) 3439 { 3440 if (complain & tf_error) 3441 { 3442 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 3443 build_tree_list_vec (*args)); 3444 print_z_candidates (candidates); 3445 } 3446 result = error_mark_node; 3447 } 3448 else 3449 { 3450 cand = tourney (candidates); 3451 if (cand == 0) 3452 { 3453 if (complain & tf_error) 3454 { 3455 error ("call of %<(%T) (%A)%> is ambiguous", 3456 TREE_TYPE (obj), build_tree_list_vec (*args)); 3457 print_z_candidates (candidates); 3458 } 3459 result = error_mark_node; 3460 } 3461 /* Since cand->fn will be a type, not a function, for a conversion 3462 function, we must be careful not to unconditionally look at 3463 DECL_NAME here. */ 3464 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 3465 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR) 3466 result = build_over_call (cand, LOOKUP_NORMAL, complain); 3467 else 3468 { 3469 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1, 3470 complain); 3471 obj = convert_from_reference (obj); 3472 result = cp_build_function_call_vec (obj, args, complain); 3473 } 3474 } 3475 3476 /* Free all the conversions we allocated. */ 3477 obstack_free (&conversion_obstack, p); 3478 3479 return result; 3480 } 3481 3482 static void 3483 op_error (enum tree_code code, enum tree_code code2, 3484 tree arg1, tree arg2, tree arg3, bool match) 3485 { 3486 const char *opname; 3487 3488 if (code == MODIFY_EXPR) 3489 opname = assignment_operator_name_info[code2].name; 3490 else 3491 opname = operator_name_info[code].name; 3492 3493 switch (code) 3494 { 3495 case COND_EXPR: 3496 if (match) 3497 error ("ambiguous overload for ternary %<operator?:%> " 3498 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 3499 else 3500 error ("no match for ternary %<operator?:%> " 3501 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 3502 break; 3503 3504 case POSTINCREMENT_EXPR: 3505 case POSTDECREMENT_EXPR: 3506 if (match) 3507 error ("ambiguous overload for %<operator%s%> in %<%E%s%>", 3508 opname, arg1, opname); 3509 else 3510 error ("no match for %<operator%s%> in %<%E%s%>", 3511 opname, arg1, opname); 3512 break; 3513 3514 case ARRAY_REF: 3515 if (match) 3516 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>", 3517 arg1, arg2); 3518 else 3519 error ("no match for %<operator[]%> in %<%E[%E]%>", 3520 arg1, arg2); 3521 break; 3522 3523 case REALPART_EXPR: 3524 case IMAGPART_EXPR: 3525 if (match) 3526 error ("ambiguous overload for %qs in %<%s %E%>", 3527 opname, opname, arg1); 3528 else 3529 error ("no match for %qs in %<%s %E%>", 3530 opname, opname, arg1); 3531 break; 3532 3533 default: 3534 if (arg2) 3535 if (match) 3536 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>", 3537 opname, arg1, opname, arg2); 3538 else 3539 error ("no match for %<operator%s%> in %<%E %s %E%>", 3540 opname, arg1, opname, arg2); 3541 else 3542 if (match) 3543 error ("ambiguous overload for %<operator%s%> in %<%s%E%>", 3544 opname, opname, arg1); 3545 else 3546 error ("no match for %<operator%s%> in %<%s%E%>", 3547 opname, opname, arg1); 3548 break; 3549 } 3550 } 3551 3552 /* Return the implicit conversion sequence that could be used to 3553 convert E1 to E2 in [expr.cond]. */ 3554 3555 static conversion * 3556 conditional_conversion (tree e1, tree e2) 3557 { 3558 tree t1 = non_reference (TREE_TYPE (e1)); 3559 tree t2 = non_reference (TREE_TYPE (e2)); 3560 conversion *conv; 3561 bool good_base; 3562 3563 /* [expr.cond] 3564 3565 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 3566 implicitly converted (clause _conv_) to the type "reference to 3567 T2", subject to the constraint that in the conversion the 3568 reference must bind directly (_dcl.init.ref_) to E1. */ 3569 if (real_lvalue_p (e2)) 3570 { 3571 conv = implicit_conversion (build_reference_type (t2), 3572 t1, 3573 e1, 3574 /*c_cast_p=*/false, 3575 LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING); 3576 if (conv) 3577 return conv; 3578 } 3579 3580 /* [expr.cond] 3581 3582 If E1 and E2 have class type, and the underlying class types are 3583 the same or one is a base class of the other: E1 can be converted 3584 to match E2 if the class of T2 is the same type as, or a base 3585 class of, the class of T1, and the cv-qualification of T2 is the 3586 same cv-qualification as, or a greater cv-qualification than, the 3587 cv-qualification of T1. If the conversion is applied, E1 is 3588 changed to an rvalue of type T2 that still refers to the original 3589 source class object (or the appropriate subobject thereof). */ 3590 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 3591 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 3592 { 3593 if (good_base && at_least_as_qualified_p (t2, t1)) 3594 { 3595 conv = build_identity_conv (t1, e1); 3596 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 3597 TYPE_MAIN_VARIANT (t2))) 3598 conv = build_conv (ck_base, t2, conv); 3599 else 3600 conv = build_conv (ck_rvalue, t2, conv); 3601 return conv; 3602 } 3603 else 3604 return NULL; 3605 } 3606 else 3607 /* [expr.cond] 3608 3609 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 3610 converted to the type that expression E2 would have if E2 were 3611 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 3612 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 3613 LOOKUP_IMPLICIT); 3614 } 3615 3616 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 3617 arguments to the conditional expression. */ 3618 3619 tree 3620 build_conditional_expr (tree arg1, tree arg2, tree arg3, 3621 tsubst_flags_t complain) 3622 { 3623 tree arg2_type; 3624 tree arg3_type; 3625 tree result = NULL_TREE; 3626 tree result_save; 3627 tree result_type = NULL_TREE; 3628 bool lvalue_p = true; 3629 struct z_candidate *candidates = 0; 3630 struct z_candidate *cand; 3631 void *p; 3632 3633 /* As a G++ extension, the second argument to the conditional can be 3634 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 3635 c'.) If the second operand is omitted, make sure it is 3636 calculated only once. */ 3637 if (!arg2) 3638 { 3639 if (complain & tf_error) 3640 pedwarn (input_location, OPT_pedantic, 3641 "ISO C++ forbids omitting the middle term of a ?: expression"); 3642 3643 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 3644 if (real_lvalue_p (arg1)) 3645 arg2 = arg1 = stabilize_reference (arg1); 3646 else 3647 arg2 = arg1 = save_expr (arg1); 3648 } 3649 3650 /* [expr.cond] 3651 3652 The first expression is implicitly converted to bool (clause 3653 _conv_). */ 3654 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 3655 LOOKUP_NORMAL); 3656 3657 /* If something has already gone wrong, just pass that fact up the 3658 tree. */ 3659 if (error_operand_p (arg1) 3660 || error_operand_p (arg2) 3661 || error_operand_p (arg3)) 3662 return error_mark_node; 3663 3664 /* [expr.cond] 3665 3666 If either the second or the third operand has type (possibly 3667 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 3668 array-to-pointer (_conv.array_), and function-to-pointer 3669 (_conv.func_) standard conversions are performed on the second 3670 and third operands. */ 3671 arg2_type = unlowered_expr_type (arg2); 3672 arg3_type = unlowered_expr_type (arg3); 3673 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 3674 { 3675 /* Do the conversions. We don't these for `void' type arguments 3676 since it can't have any effect and since decay_conversion 3677 does not handle that case gracefully. */ 3678 if (!VOID_TYPE_P (arg2_type)) 3679 arg2 = decay_conversion (arg2); 3680 if (!VOID_TYPE_P (arg3_type)) 3681 arg3 = decay_conversion (arg3); 3682 arg2_type = TREE_TYPE (arg2); 3683 arg3_type = TREE_TYPE (arg3); 3684 3685 /* [expr.cond] 3686 3687 One of the following shall hold: 3688 3689 --The second or the third operand (but not both) is a 3690 throw-expression (_except.throw_); the result is of the 3691 type of the other and is an rvalue. 3692 3693 --Both the second and the third operands have type void; the 3694 result is of type void and is an rvalue. 3695 3696 We must avoid calling force_rvalue for expressions of type 3697 "void" because it will complain that their value is being 3698 used. */ 3699 if (TREE_CODE (arg2) == THROW_EXPR 3700 && TREE_CODE (arg3) != THROW_EXPR) 3701 { 3702 if (!VOID_TYPE_P (arg3_type)) 3703 arg3 = force_rvalue (arg3); 3704 arg3_type = TREE_TYPE (arg3); 3705 result_type = arg3_type; 3706 } 3707 else if (TREE_CODE (arg2) != THROW_EXPR 3708 && TREE_CODE (arg3) == THROW_EXPR) 3709 { 3710 if (!VOID_TYPE_P (arg2_type)) 3711 arg2 = force_rvalue (arg2); 3712 arg2_type = TREE_TYPE (arg2); 3713 result_type = arg2_type; 3714 } 3715 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 3716 result_type = void_type_node; 3717 else 3718 { 3719 if (complain & tf_error) 3720 { 3721 if (VOID_TYPE_P (arg2_type)) 3722 error ("second operand to the conditional operator " 3723 "is of type %<void%>, " 3724 "but the third operand is neither a throw-expression " 3725 "nor of type %<void%>"); 3726 else 3727 error ("third operand to the conditional operator " 3728 "is of type %<void%>, " 3729 "but the second operand is neither a throw-expression " 3730 "nor of type %<void%>"); 3731 } 3732 return error_mark_node; 3733 } 3734 3735 lvalue_p = false; 3736 goto valid_operands; 3737 } 3738 /* [expr.cond] 3739 3740 Otherwise, if the second and third operand have different types, 3741 and either has (possibly cv-qualified) class type, an attempt is 3742 made to convert each of those operands to the type of the other. */ 3743 else if (!same_type_p (arg2_type, arg3_type) 3744 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 3745 { 3746 conversion *conv2; 3747 conversion *conv3; 3748 3749 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3750 p = conversion_obstack_alloc (0); 3751 3752 conv2 = conditional_conversion (arg2, arg3); 3753 conv3 = conditional_conversion (arg3, arg2); 3754 3755 /* [expr.cond] 3756 3757 If both can be converted, or one can be converted but the 3758 conversion is ambiguous, the program is ill-formed. If 3759 neither can be converted, the operands are left unchanged and 3760 further checking is performed as described below. If exactly 3761 one conversion is possible, that conversion is applied to the 3762 chosen operand and the converted operand is used in place of 3763 the original operand for the remainder of this section. */ 3764 if ((conv2 && !conv2->bad_p 3765 && conv3 && !conv3->bad_p) 3766 || (conv2 && conv2->kind == ck_ambig) 3767 || (conv3 && conv3->kind == ck_ambig)) 3768 { 3769 error ("operands to ?: have different types %qT and %qT", 3770 arg2_type, arg3_type); 3771 result = error_mark_node; 3772 } 3773 else if (conv2 && (!conv2->bad_p || !conv3)) 3774 { 3775 arg2 = convert_like (conv2, arg2, complain); 3776 arg2 = convert_from_reference (arg2); 3777 arg2_type = TREE_TYPE (arg2); 3778 /* Even if CONV2 is a valid conversion, the result of the 3779 conversion may be invalid. For example, if ARG3 has type 3780 "volatile X", and X does not have a copy constructor 3781 accepting a "volatile X&", then even if ARG2 can be 3782 converted to X, the conversion will fail. */ 3783 if (error_operand_p (arg2)) 3784 result = error_mark_node; 3785 } 3786 else if (conv3 && (!conv3->bad_p || !conv2)) 3787 { 3788 arg3 = convert_like (conv3, arg3, complain); 3789 arg3 = convert_from_reference (arg3); 3790 arg3_type = TREE_TYPE (arg3); 3791 if (error_operand_p (arg3)) 3792 result = error_mark_node; 3793 } 3794 3795 /* Free all the conversions we allocated. */ 3796 obstack_free (&conversion_obstack, p); 3797 3798 if (result) 3799 return result; 3800 3801 /* If, after the conversion, both operands have class type, 3802 treat the cv-qualification of both operands as if it were the 3803 union of the cv-qualification of the operands. 3804 3805 The standard is not clear about what to do in this 3806 circumstance. For example, if the first operand has type 3807 "const X" and the second operand has a user-defined 3808 conversion to "volatile X", what is the type of the second 3809 operand after this step? Making it be "const X" (matching 3810 the first operand) seems wrong, as that discards the 3811 qualification without actually performing a copy. Leaving it 3812 as "volatile X" seems wrong as that will result in the 3813 conditional expression failing altogether, even though, 3814 according to this step, the one operand could be converted to 3815 the type of the other. */ 3816 if ((conv2 || conv3) 3817 && CLASS_TYPE_P (arg2_type) 3818 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type)) 3819 arg2_type = arg3_type = 3820 cp_build_qualified_type (arg2_type, 3821 TYPE_QUALS (arg2_type) 3822 | TYPE_QUALS (arg3_type)); 3823 } 3824 3825 /* [expr.cond] 3826 3827 If the second and third operands are lvalues and have the same 3828 type, the result is of that type and is an lvalue. */ 3829 if (real_lvalue_p (arg2) 3830 && real_lvalue_p (arg3) 3831 && same_type_p (arg2_type, arg3_type)) 3832 { 3833 result_type = arg2_type; 3834 goto valid_operands; 3835 } 3836 3837 /* [expr.cond] 3838 3839 Otherwise, the result is an rvalue. If the second and third 3840 operand do not have the same type, and either has (possibly 3841 cv-qualified) class type, overload resolution is used to 3842 determine the conversions (if any) to be applied to the operands 3843 (_over.match.oper_, _over.built_). */ 3844 lvalue_p = false; 3845 if (!same_type_p (arg2_type, arg3_type) 3846 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 3847 { 3848 tree args[3]; 3849 conversion *conv; 3850 bool any_viable_p; 3851 3852 /* Rearrange the arguments so that add_builtin_candidate only has 3853 to know about two args. In build_builtin_candidate, the 3854 arguments are unscrambled. */ 3855 args[0] = arg2; 3856 args[1] = arg3; 3857 args[2] = arg1; 3858 add_builtin_candidates (&candidates, 3859 COND_EXPR, 3860 NOP_EXPR, 3861 ansi_opname (COND_EXPR), 3862 args, 3863 LOOKUP_NORMAL); 3864 3865 /* [expr.cond] 3866 3867 If the overload resolution fails, the program is 3868 ill-formed. */ 3869 candidates = splice_viable (candidates, pedantic, &any_viable_p); 3870 if (!any_viable_p) 3871 { 3872 if (complain & tf_error) 3873 { 3874 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 3875 print_z_candidates (candidates); 3876 } 3877 return error_mark_node; 3878 } 3879 cand = tourney (candidates); 3880 if (!cand) 3881 { 3882 if (complain & tf_error) 3883 { 3884 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 3885 print_z_candidates (candidates); 3886 } 3887 return error_mark_node; 3888 } 3889 3890 /* [expr.cond] 3891 3892 Otherwise, the conversions thus determined are applied, and 3893 the converted operands are used in place of the original 3894 operands for the remainder of this section. */ 3895 conv = cand->convs[0]; 3896 arg1 = convert_like (conv, arg1, complain); 3897 conv = cand->convs[1]; 3898 arg2 = convert_like (conv, arg2, complain); 3899 arg2_type = TREE_TYPE (arg2); 3900 conv = cand->convs[2]; 3901 arg3 = convert_like (conv, arg3, complain); 3902 arg3_type = TREE_TYPE (arg3); 3903 } 3904 3905 /* [expr.cond] 3906 3907 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 3908 and function-to-pointer (_conv.func_) standard conversions are 3909 performed on the second and third operands. 3910 3911 We need to force the lvalue-to-rvalue conversion here for class types, 3912 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 3913 that isn't wrapped with a TARGET_EXPR plays havoc with exception 3914 regions. */ 3915 3916 arg2 = force_rvalue (arg2); 3917 if (!CLASS_TYPE_P (arg2_type)) 3918 arg2_type = TREE_TYPE (arg2); 3919 3920 arg3 = force_rvalue (arg3); 3921 if (!CLASS_TYPE_P (arg3_type)) 3922 arg3_type = TREE_TYPE (arg3); 3923 3924 if (arg2 == error_mark_node || arg3 == error_mark_node) 3925 return error_mark_node; 3926 3927 /* [expr.cond] 3928 3929 After those conversions, one of the following shall hold: 3930 3931 --The second and third operands have the same type; the result is of 3932 that type. */ 3933 if (same_type_p (arg2_type, arg3_type)) 3934 result_type = arg2_type; 3935 /* [expr.cond] 3936 3937 --The second and third operands have arithmetic or enumeration 3938 type; the usual arithmetic conversions are performed to bring 3939 them to a common type, and the result is of that type. */ 3940 else if ((ARITHMETIC_TYPE_P (arg2_type) 3941 || UNSCOPED_ENUM_P (arg2_type)) 3942 && (ARITHMETIC_TYPE_P (arg3_type) 3943 || UNSCOPED_ENUM_P (arg3_type))) 3944 { 3945 /* In this case, there is always a common type. */ 3946 result_type = type_after_usual_arithmetic_conversions (arg2_type, 3947 arg3_type); 3948 3949 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 3950 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 3951 { 3952 if (complain & tf_warning) 3953 warning (0, 3954 "enumeral mismatch in conditional expression: %qT vs %qT", 3955 arg2_type, arg3_type); 3956 } 3957 else if (extra_warnings 3958 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 3959 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 3960 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 3961 && !same_type_p (arg2_type, type_promotes_to (arg3_type))))) 3962 { 3963 if (complain & tf_warning) 3964 warning (0, 3965 "enumeral and non-enumeral type in conditional expression"); 3966 } 3967 3968 arg2 = perform_implicit_conversion (result_type, arg2, complain); 3969 arg3 = perform_implicit_conversion (result_type, arg3, complain); 3970 } 3971 /* [expr.cond] 3972 3973 --The second and third operands have pointer type, or one has 3974 pointer type and the other is a null pointer constant; pointer 3975 conversions (_conv.ptr_) and qualification conversions 3976 (_conv.qual_) are performed to bring them to their composite 3977 pointer type (_expr.rel_). The result is of the composite 3978 pointer type. 3979 3980 --The second and third operands have pointer to member type, or 3981 one has pointer to member type and the other is a null pointer 3982 constant; pointer to member conversions (_conv.mem_) and 3983 qualification conversions (_conv.qual_) are performed to bring 3984 them to a common type, whose cv-qualification shall match the 3985 cv-qualification of either the second or the third operand. 3986 The result is of the common type. */ 3987 else if ((null_ptr_cst_p (arg2) 3988 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type))) 3989 || (null_ptr_cst_p (arg3) 3990 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type))) 3991 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 3992 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type)) 3993 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 3994 { 3995 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 3996 arg3, CPO_CONDITIONAL_EXPR, 3997 complain); 3998 if (result_type == error_mark_node) 3999 return error_mark_node; 4000 arg2 = perform_implicit_conversion (result_type, arg2, complain); 4001 arg3 = perform_implicit_conversion (result_type, arg3, complain); 4002 } 4003 4004 if (!result_type) 4005 { 4006 if (complain & tf_error) 4007 error ("operands to ?: have different types %qT and %qT", 4008 arg2_type, arg3_type); 4009 return error_mark_node; 4010 } 4011 4012 valid_operands: 4013 result_save = build3 (COND_EXPR, result_type, arg1, arg2, arg3); 4014 result = fold_if_not_in_template (result_save); 4015 4016 if (cp_unevaluated_operand && TREE_CODE (result) == CALL_EXPR) 4017 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */ 4018 result = result_save; 4019 4020 /* We can't use result_type below, as fold might have returned a 4021 throw_expr. */ 4022 4023 if (!lvalue_p) 4024 { 4025 /* Expand both sides into the same slot, hopefully the target of 4026 the ?: expression. We used to check for TARGET_EXPRs here, 4027 but now we sometimes wrap them in NOP_EXPRs so the test would 4028 fail. */ 4029 if (CLASS_TYPE_P (TREE_TYPE (result))) 4030 result = get_target_expr (result); 4031 /* If this expression is an rvalue, but might be mistaken for an 4032 lvalue, we must add a NON_LVALUE_EXPR. */ 4033 result = rvalue (result); 4034 } 4035 4036 return result; 4037 } 4038 4039 /* OPERAND is an operand to an expression. Perform necessary steps 4040 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 4041 returned. */ 4042 4043 static tree 4044 prep_operand (tree operand) 4045 { 4046 if (operand) 4047 { 4048 if (CLASS_TYPE_P (TREE_TYPE (operand)) 4049 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 4050 /* Make sure the template type is instantiated now. */ 4051 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 4052 } 4053 4054 return operand; 4055 } 4056 4057 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 4058 OVERLOAD) to the CANDIDATES, returning an updated list of 4059 CANDIDATES. The ARGS are the arguments provided to the call, 4060 without any implicit object parameter. This may change ARGS. The 4061 EXPLICIT_TARGS are explicit template arguments provided. 4062 TEMPLATE_ONLY is true if only template functions should be 4063 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 4064 add_function_candidate. */ 4065 4066 static void 4067 add_candidates (tree fns, const VEC(tree,gc) *args, 4068 tree explicit_targs, bool template_only, 4069 tree conversion_path, tree access_path, 4070 int flags, 4071 struct z_candidate **candidates) 4072 { 4073 tree ctype; 4074 VEC(tree,gc) *non_static_args; 4075 tree first_arg; 4076 4077 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 4078 /* Delay creating the implicit this parameter until it is needed. */ 4079 non_static_args = NULL; 4080 first_arg = NULL_TREE; 4081 4082 while (fns) 4083 { 4084 tree fn; 4085 tree fn_first_arg; 4086 const VEC(tree,gc) *fn_args; 4087 4088 fn = OVL_CURRENT (fns); 4089 /* Figure out which set of arguments to use. */ 4090 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 4091 { 4092 /* If this function is a non-static member, prepend the implicit 4093 object parameter. */ 4094 if (non_static_args == NULL) 4095 { 4096 unsigned int ix; 4097 tree arg; 4098 4099 non_static_args = VEC_alloc (tree, gc, 4100 VEC_length (tree, args) - 1); 4101 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix) 4102 VEC_quick_push (tree, non_static_args, arg); 4103 } 4104 if (first_arg == NULL_TREE) 4105 first_arg = build_this (VEC_index (tree, args, 0)); 4106 fn_first_arg = first_arg; 4107 fn_args = non_static_args; 4108 } 4109 else 4110 { 4111 /* Otherwise, just use the list of arguments provided. */ 4112 fn_first_arg = NULL_TREE; 4113 fn_args = args; 4114 } 4115 4116 if (TREE_CODE (fn) == TEMPLATE_DECL) 4117 add_template_candidate (candidates, 4118 fn, 4119 ctype, 4120 explicit_targs, 4121 fn_first_arg, 4122 fn_args, 4123 NULL_TREE, 4124 access_path, 4125 conversion_path, 4126 flags, 4127 DEDUCE_CALL); 4128 else if (!template_only) 4129 add_function_candidate (candidates, 4130 fn, 4131 ctype, 4132 fn_first_arg, 4133 fn_args, 4134 access_path, 4135 conversion_path, 4136 flags); 4137 fns = OVL_NEXT (fns); 4138 } 4139 } 4140 4141 /* Even unsigned enum types promote to signed int. We don't want to 4142 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the 4143 original argument and ARG is the argument after any conversions 4144 have been applied. We set TREE_NO_WARNING if we have added a cast 4145 from an unsigned enum type to a signed integer type. */ 4146 4147 static void 4148 avoid_sign_compare_warnings (tree orig_arg, tree arg) 4149 { 4150 if (orig_arg != NULL_TREE 4151 && arg != NULL_TREE 4152 && orig_arg != arg 4153 && TREE_CODE (TREE_TYPE (orig_arg)) == ENUMERAL_TYPE 4154 && TYPE_UNSIGNED (TREE_TYPE (orig_arg)) 4155 && INTEGRAL_TYPE_P (TREE_TYPE (arg)) 4156 && !TYPE_UNSIGNED (TREE_TYPE (arg))) 4157 TREE_NO_WARNING (arg) = 1; 4158 } 4159 4160 tree 4161 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3, 4162 bool *overloaded_p, tsubst_flags_t complain) 4163 { 4164 tree orig_arg1 = arg1; 4165 tree orig_arg2 = arg2; 4166 tree orig_arg3 = arg3; 4167 struct z_candidate *candidates = 0, *cand; 4168 VEC(tree,gc) *arglist; 4169 tree fnname; 4170 tree args[3]; 4171 tree result = NULL_TREE; 4172 bool result_valid_p = false; 4173 enum tree_code code2 = NOP_EXPR; 4174 enum tree_code code_orig_arg1 = ERROR_MARK; 4175 enum tree_code code_orig_arg2 = ERROR_MARK; 4176 conversion *conv; 4177 void *p; 4178 bool strict_p; 4179 bool any_viable_p; 4180 4181 if (error_operand_p (arg1) 4182 || error_operand_p (arg2) 4183 || error_operand_p (arg3)) 4184 return error_mark_node; 4185 4186 if (code == MODIFY_EXPR) 4187 { 4188 code2 = TREE_CODE (arg3); 4189 arg3 = NULL_TREE; 4190 fnname = ansi_assopname (code2); 4191 } 4192 else 4193 fnname = ansi_opname (code); 4194 4195 arg1 = prep_operand (arg1); 4196 4197 switch (code) 4198 { 4199 case NEW_EXPR: 4200 case VEC_NEW_EXPR: 4201 case VEC_DELETE_EXPR: 4202 case DELETE_EXPR: 4203 /* Use build_op_new_call and build_op_delete_call instead. */ 4204 gcc_unreachable (); 4205 4206 case CALL_EXPR: 4207 /* Use build_op_call instead. */ 4208 gcc_unreachable (); 4209 4210 case TRUTH_ORIF_EXPR: 4211 case TRUTH_ANDIF_EXPR: 4212 case TRUTH_AND_EXPR: 4213 case TRUTH_OR_EXPR: 4214 /* These are saved for the sake of warn_logical_operator. */ 4215 code_orig_arg1 = TREE_CODE (arg1); 4216 code_orig_arg2 = TREE_CODE (arg2); 4217 4218 default: 4219 break; 4220 } 4221 4222 arg2 = prep_operand (arg2); 4223 arg3 = prep_operand (arg3); 4224 4225 if (code == COND_EXPR) 4226 /* Use build_conditional_expr instead. */ 4227 gcc_unreachable (); 4228 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1)) 4229 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2)))) 4230 goto builtin; 4231 4232 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 4233 arg2 = integer_zero_node; 4234 4235 arglist = VEC_alloc (tree, gc, 3); 4236 VEC_quick_push (tree, arglist, arg1); 4237 if (arg2 != NULL_TREE) 4238 VEC_quick_push (tree, arglist, arg2); 4239 if (arg3 != NULL_TREE) 4240 VEC_quick_push (tree, arglist, arg3); 4241 4242 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4243 p = conversion_obstack_alloc (0); 4244 4245 /* Add namespace-scope operators to the list of functions to 4246 consider. */ 4247 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true), 4248 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE, 4249 flags, &candidates); 4250 /* Add class-member operators to the candidate set. */ 4251 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 4252 { 4253 tree fns; 4254 4255 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 4256 if (fns == error_mark_node) 4257 { 4258 result = error_mark_node; 4259 goto user_defined_result_ready; 4260 } 4261 if (fns) 4262 add_candidates (BASELINK_FUNCTIONS (fns), arglist, 4263 NULL_TREE, false, 4264 BASELINK_BINFO (fns), 4265 TYPE_BINFO (TREE_TYPE (arg1)), 4266 flags, &candidates); 4267 } 4268 4269 args[0] = arg1; 4270 args[1] = arg2; 4271 args[2] = NULL_TREE; 4272 4273 add_builtin_candidates (&candidates, code, code2, fnname, args, flags); 4274 4275 switch (code) 4276 { 4277 case COMPOUND_EXPR: 4278 case ADDR_EXPR: 4279 /* For these, the built-in candidates set is empty 4280 [over.match.oper]/3. We don't want non-strict matches 4281 because exact matches are always possible with built-in 4282 operators. The built-in candidate set for COMPONENT_REF 4283 would be empty too, but since there are no such built-in 4284 operators, we accept non-strict matches for them. */ 4285 strict_p = true; 4286 break; 4287 4288 default: 4289 strict_p = pedantic; 4290 break; 4291 } 4292 4293 candidates = splice_viable (candidates, strict_p, &any_viable_p); 4294 if (!any_viable_p) 4295 { 4296 switch (code) 4297 { 4298 case POSTINCREMENT_EXPR: 4299 case POSTDECREMENT_EXPR: 4300 /* Don't try anything fancy if we're not allowed to produce 4301 errors. */ 4302 if (!(complain & tf_error)) 4303 return error_mark_node; 4304 4305 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 4306 distinguish between prefix and postfix ++ and 4307 operator++() was used for both, so we allow this with 4308 -fpermissive. */ 4309 if (flags & LOOKUP_COMPLAIN) 4310 { 4311 const char *msg = (flag_permissive) 4312 ? G_("no %<%D(int)%> declared for postfix %qs," 4313 " trying prefix operator instead") 4314 : G_("no %<%D(int)%> declared for postfix %qs"); 4315 permerror (input_location, msg, fnname, 4316 operator_name_info[code].name); 4317 } 4318 4319 if (!flag_permissive) 4320 return error_mark_node; 4321 4322 if (code == POSTINCREMENT_EXPR) 4323 code = PREINCREMENT_EXPR; 4324 else 4325 code = PREDECREMENT_EXPR; 4326 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE, 4327 overloaded_p, complain); 4328 break; 4329 4330 /* The caller will deal with these. */ 4331 case ADDR_EXPR: 4332 case COMPOUND_EXPR: 4333 case COMPONENT_REF: 4334 result = NULL_TREE; 4335 result_valid_p = true; 4336 break; 4337 4338 default: 4339 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 4340 { 4341 /* If one of the arguments of the operator represents 4342 an invalid use of member function pointer, try to report 4343 a meaningful error ... */ 4344 if (invalid_nonstatic_memfn_p (arg1, tf_error) 4345 || invalid_nonstatic_memfn_p (arg2, tf_error) 4346 || invalid_nonstatic_memfn_p (arg3, tf_error)) 4347 /* We displayed the error message. */; 4348 else 4349 { 4350 /* ... Otherwise, report the more generic 4351 "no matching operator found" error */ 4352 op_error (code, code2, arg1, arg2, arg3, FALSE); 4353 print_z_candidates (candidates); 4354 } 4355 } 4356 result = error_mark_node; 4357 break; 4358 } 4359 } 4360 else 4361 { 4362 cand = tourney (candidates); 4363 if (cand == 0) 4364 { 4365 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 4366 { 4367 op_error (code, code2, arg1, arg2, arg3, TRUE); 4368 print_z_candidates (candidates); 4369 } 4370 result = error_mark_node; 4371 } 4372 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 4373 { 4374 if (overloaded_p) 4375 *overloaded_p = true; 4376 4377 if (resolve_args (arglist) == NULL) 4378 result = error_mark_node; 4379 else 4380 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4381 } 4382 else 4383 { 4384 /* Give any warnings we noticed during overload resolution. */ 4385 if (cand->warnings && (complain & tf_warning)) 4386 { 4387 struct candidate_warning *w; 4388 for (w = cand->warnings; w; w = w->next) 4389 joust (cand, w->loser, 1); 4390 } 4391 4392 /* Check for comparison of different enum types. */ 4393 switch (code) 4394 { 4395 case GT_EXPR: 4396 case LT_EXPR: 4397 case GE_EXPR: 4398 case LE_EXPR: 4399 case EQ_EXPR: 4400 case NE_EXPR: 4401 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 4402 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 4403 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 4404 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 4405 && (complain & tf_warning)) 4406 { 4407 warning (OPT_Wenum_compare, 4408 "comparison between %q#T and %q#T", 4409 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4410 } 4411 break; 4412 default: 4413 break; 4414 } 4415 4416 /* We need to strip any leading REF_BIND so that bitfields 4417 don't cause errors. This should not remove any important 4418 conversions, because builtins don't apply to class 4419 objects directly. */ 4420 conv = cand->convs[0]; 4421 if (conv->kind == ck_ref_bind) 4422 conv = conv->u.next; 4423 arg1 = convert_like (conv, arg1, complain); 4424 4425 if (arg2) 4426 { 4427 /* We need to call warn_logical_operator before 4428 converting arg2 to a boolean_type. */ 4429 if (complain & tf_warning) 4430 warn_logical_operator (input_location, code, boolean_type_node, 4431 code_orig_arg1, arg1, 4432 code_orig_arg2, arg2); 4433 4434 conv = cand->convs[1]; 4435 if (conv->kind == ck_ref_bind) 4436 conv = conv->u.next; 4437 arg2 = convert_like (conv, arg2, complain); 4438 } 4439 if (arg3) 4440 { 4441 conv = cand->convs[2]; 4442 if (conv->kind == ck_ref_bind) 4443 conv = conv->u.next; 4444 arg3 = convert_like (conv, arg3, complain); 4445 } 4446 4447 } 4448 } 4449 4450 user_defined_result_ready: 4451 4452 /* Free all the conversions we allocated. */ 4453 obstack_free (&conversion_obstack, p); 4454 4455 if (result || result_valid_p) 4456 return result; 4457 4458 builtin: 4459 avoid_sign_compare_warnings (orig_arg1, arg1); 4460 avoid_sign_compare_warnings (orig_arg2, arg2); 4461 avoid_sign_compare_warnings (orig_arg3, arg3); 4462 4463 switch (code) 4464 { 4465 case MODIFY_EXPR: 4466 return cp_build_modify_expr (arg1, code2, arg2, complain); 4467 4468 case INDIRECT_REF: 4469 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 4470 4471 case TRUTH_ANDIF_EXPR: 4472 case TRUTH_ORIF_EXPR: 4473 case TRUTH_AND_EXPR: 4474 case TRUTH_OR_EXPR: 4475 warn_logical_operator (input_location, code, boolean_type_node, 4476 code_orig_arg1, arg1, code_orig_arg2, arg2); 4477 /* Fall through. */ 4478 case PLUS_EXPR: 4479 case MINUS_EXPR: 4480 case MULT_EXPR: 4481 case TRUNC_DIV_EXPR: 4482 case GT_EXPR: 4483 case LT_EXPR: 4484 case GE_EXPR: 4485 case LE_EXPR: 4486 case EQ_EXPR: 4487 case NE_EXPR: 4488 case MAX_EXPR: 4489 case MIN_EXPR: 4490 case LSHIFT_EXPR: 4491 case RSHIFT_EXPR: 4492 case TRUNC_MOD_EXPR: 4493 case BIT_AND_EXPR: 4494 case BIT_IOR_EXPR: 4495 case BIT_XOR_EXPR: 4496 return cp_build_binary_op (input_location, code, arg1, arg2, complain); 4497 4498 case UNARY_PLUS_EXPR: 4499 case NEGATE_EXPR: 4500 case BIT_NOT_EXPR: 4501 case TRUTH_NOT_EXPR: 4502 case PREINCREMENT_EXPR: 4503 case POSTINCREMENT_EXPR: 4504 case PREDECREMENT_EXPR: 4505 case POSTDECREMENT_EXPR: 4506 case REALPART_EXPR: 4507 case IMAGPART_EXPR: 4508 return cp_build_unary_op (code, arg1, candidates != 0, complain); 4509 4510 case ARRAY_REF: 4511 return build_array_ref (input_location, arg1, arg2); 4512 4513 case MEMBER_REF: 4514 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL, 4515 complain), 4516 arg2); 4517 4518 /* The caller will deal with these. */ 4519 case ADDR_EXPR: 4520 case COMPONENT_REF: 4521 case COMPOUND_EXPR: 4522 return NULL_TREE; 4523 4524 default: 4525 gcc_unreachable (); 4526 } 4527 return NULL_TREE; 4528 } 4529 4530 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 4531 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 4532 4533 static bool 4534 non_placement_deallocation_fn_p (tree t) 4535 { 4536 /* A template instance is never a usual deallocation function, 4537 regardless of its signature. */ 4538 if (TREE_CODE (t) == TEMPLATE_DECL 4539 || primary_template_instantiation_p (t)) 4540 return false; 4541 4542 /* If a class T has a member deallocation function named operator delete 4543 with exactly one parameter, then that function is a usual 4544 (non-placement) deallocation function. If class T does not declare 4545 such an operator delete but does declare a member deallocation 4546 function named operator delete with exactly two parameters, the second 4547 of which has type std::size_t (18.2), then this function is a usual 4548 deallocation function. */ 4549 t = FUNCTION_ARG_CHAIN (t); 4550 if (t == void_list_node 4551 || (t && same_type_p (TREE_VALUE (t), size_type_node) 4552 && TREE_CHAIN (t) == void_list_node)) 4553 return true; 4554 return false; 4555 } 4556 4557 /* Build a call to operator delete. This has to be handled very specially, 4558 because the restrictions on what signatures match are different from all 4559 other call instances. For a normal delete, only a delete taking (void *) 4560 or (void *, size_t) is accepted. For a placement delete, only an exact 4561 match with the placement new is accepted. 4562 4563 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 4564 ADDR is the pointer to be deleted. 4565 SIZE is the size of the memory block to be deleted. 4566 GLOBAL_P is true if the delete-expression should not consider 4567 class-specific delete operators. 4568 PLACEMENT is the corresponding placement new call, or NULL_TREE. 4569 4570 If this call to "operator delete" is being generated as part to 4571 deallocate memory allocated via a new-expression (as per [expr.new] 4572 which requires that if the initialization throws an exception then 4573 we call a deallocation function), then ALLOC_FN is the allocation 4574 function. */ 4575 4576 tree 4577 build_op_delete_call (enum tree_code code, tree addr, tree size, 4578 bool global_p, tree placement, 4579 tree alloc_fn) 4580 { 4581 tree fn = NULL_TREE; 4582 tree fns, fnname, type, t; 4583 4584 if (addr == error_mark_node) 4585 return error_mark_node; 4586 4587 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 4588 4589 fnname = ansi_opname (code); 4590 4591 if (CLASS_TYPE_P (type) 4592 && COMPLETE_TYPE_P (complete_type (type)) 4593 && !global_p) 4594 /* In [class.free] 4595 4596 If the result of the lookup is ambiguous or inaccessible, or if 4597 the lookup selects a placement deallocation function, the 4598 program is ill-formed. 4599 4600 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 4601 { 4602 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 4603 if (fns == error_mark_node) 4604 return error_mark_node; 4605 } 4606 else 4607 fns = NULL_TREE; 4608 4609 if (fns == NULL_TREE) 4610 fns = lookup_name_nonclass (fnname); 4611 4612 /* Strip const and volatile from addr. */ 4613 addr = cp_convert (ptr_type_node, addr); 4614 4615 if (placement) 4616 { 4617 /* "A declaration of a placement deallocation function matches the 4618 declaration of a placement allocation function if it has the same 4619 number of parameters and, after parameter transformations (8.3.5), 4620 all parameter types except the first are identical." 4621 4622 So we build up the function type we want and ask instantiate_type 4623 to get it for us. */ 4624 t = FUNCTION_ARG_CHAIN (alloc_fn); 4625 t = tree_cons (NULL_TREE, ptr_type_node, t); 4626 t = build_function_type (void_type_node, t); 4627 4628 fn = instantiate_type (t, fns, tf_none); 4629 if (fn == error_mark_node) 4630 return NULL_TREE; 4631 4632 if (BASELINK_P (fn)) 4633 fn = BASELINK_FUNCTIONS (fn); 4634 4635 /* "If the lookup finds the two-parameter form of a usual deallocation 4636 function (3.7.4.2) and that function, considered as a placement 4637 deallocation function, would have been selected as a match for the 4638 allocation function, the program is ill-formed." */ 4639 if (non_placement_deallocation_fn_p (fn)) 4640 { 4641 /* But if the class has an operator delete (void *), then that is 4642 the usual deallocation function, so we shouldn't complain 4643 about using the operator delete (void *, size_t). */ 4644 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 4645 t; t = OVL_NEXT (t)) 4646 { 4647 tree elt = OVL_CURRENT (t); 4648 if (non_placement_deallocation_fn_p (elt) 4649 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 4650 goto ok; 4651 } 4652 permerror (0, "non-placement deallocation function %q+D", fn); 4653 permerror (input_location, "selected for placement delete"); 4654 ok:; 4655 } 4656 } 4657 else 4658 /* "Any non-placement deallocation function matches a non-placement 4659 allocation function. If the lookup finds a single matching 4660 deallocation function, that function will be called; otherwise, no 4661 deallocation function will be called." */ 4662 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 4663 t; t = OVL_NEXT (t)) 4664 { 4665 tree elt = OVL_CURRENT (t); 4666 if (non_placement_deallocation_fn_p (elt)) 4667 { 4668 fn = elt; 4669 /* "If a class T has a member deallocation function named 4670 operator delete with exactly one parameter, then that 4671 function is a usual (non-placement) deallocation 4672 function. If class T does not declare such an operator 4673 delete but does declare a member deallocation function named 4674 operator delete with exactly two parameters, the second of 4675 which has type std::size_t (18.2), then this function is a 4676 usual deallocation function." 4677 4678 So (void*) beats (void*, size_t). */ 4679 if (FUNCTION_ARG_CHAIN (fn) == void_list_node) 4680 break; 4681 } 4682 } 4683 4684 /* If we have a matching function, call it. */ 4685 if (fn) 4686 { 4687 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 4688 4689 /* If the FN is a member function, make sure that it is 4690 accessible. */ 4691 if (BASELINK_P (fns)) 4692 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn); 4693 4694 /* Core issue 901: It's ok to new a type with deleted delete. */ 4695 if (DECL_DELETED_FN (fn) && alloc_fn) 4696 return NULL_TREE; 4697 4698 if (placement) 4699 { 4700 /* The placement args might not be suitable for overload 4701 resolution at this point, so build the call directly. */ 4702 int nargs = call_expr_nargs (placement); 4703 tree *argarray = (tree *) alloca (nargs * sizeof (tree)); 4704 int i; 4705 argarray[0] = addr; 4706 for (i = 1; i < nargs; i++) 4707 argarray[i] = CALL_EXPR_ARG (placement, i); 4708 mark_used (fn); 4709 return build_cxx_call (fn, nargs, argarray); 4710 } 4711 else 4712 { 4713 tree ret; 4714 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2); 4715 VEC_quick_push (tree, args, addr); 4716 if (FUNCTION_ARG_CHAIN (fn) != void_list_node) 4717 VEC_quick_push (tree, args, size); 4718 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error); 4719 VEC_free (tree, gc, args); 4720 return ret; 4721 } 4722 } 4723 4724 /* [expr.new] 4725 4726 If no unambiguous matching deallocation function can be found, 4727 propagating the exception does not cause the object's memory to 4728 be freed. */ 4729 if (alloc_fn) 4730 { 4731 if (!placement) 4732 warning (0, "no corresponding deallocation function for %qD", 4733 alloc_fn); 4734 return NULL_TREE; 4735 } 4736 4737 error ("no suitable %<operator %s%> for %qT", 4738 operator_name_info[(int)code].name, type); 4739 return error_mark_node; 4740 } 4741 4742 /* If the current scope isn't allowed to access DECL along 4743 BASETYPE_PATH, give an error. The most derived class in 4744 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 4745 the declaration to use in the error diagnostic. */ 4746 4747 bool 4748 enforce_access (tree basetype_path, tree decl, tree diag_decl) 4749 { 4750 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 4751 4752 if (!accessible_p (basetype_path, decl, true)) 4753 { 4754 if (TREE_PRIVATE (decl)) 4755 error ("%q+#D is private", diag_decl); 4756 else if (TREE_PROTECTED (decl)) 4757 error ("%q+#D is protected", diag_decl); 4758 else 4759 error ("%q+#D is inaccessible", diag_decl); 4760 error ("within this context"); 4761 return false; 4762 } 4763 4764 return true; 4765 } 4766 4767 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 4768 bitwise or of LOOKUP_* values. If any errors are warnings are 4769 generated, set *DIAGNOSTIC_FN to "error" or "warning", 4770 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 4771 to NULL. */ 4772 4773 static tree 4774 build_temp (tree expr, tree type, int flags, 4775 diagnostic_t *diagnostic_kind) 4776 { 4777 int savew, savee; 4778 VEC(tree,gc) *args; 4779 4780 savew = warningcount, savee = errorcount; 4781 args = make_tree_vector_single (expr); 4782 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 4783 &args, type, flags, tf_warning_or_error); 4784 release_tree_vector (args); 4785 if (warningcount > savew) 4786 *diagnostic_kind = DK_WARNING; 4787 else if (errorcount > savee) 4788 *diagnostic_kind = DK_ERROR; 4789 else 4790 *diagnostic_kind = DK_UNSPECIFIED; 4791 return expr; 4792 } 4793 4794 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 4795 EXPR is implicitly converted to type TOTYPE. 4796 FN and ARGNUM are used for diagnostics. */ 4797 4798 static void 4799 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 4800 { 4801 tree t = non_reference (totype); 4802 4803 /* Issue warnings about peculiar, but valid, uses of NULL. */ 4804 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t)) 4805 { 4806 if (fn) 4807 warning_at (input_location, OPT_Wconversion_null, 4808 "passing NULL to non-pointer argument %P of %qD", 4809 argnum, fn); 4810 else 4811 warning_at (input_location, OPT_Wconversion_null, 4812 "converting to non-pointer type %qT from NULL", t); 4813 } 4814 4815 /* Issue warnings if "false" is converted to a NULL pointer */ 4816 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t)) 4817 warning_at (input_location, OPT_Wconversion_null, 4818 "converting %<false%> to pointer type for argument %P of %qD", 4819 argnum, fn); 4820 } 4821 4822 /* Perform the conversions in CONVS on the expression EXPR. FN and 4823 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 4824 indicates the `this' argument of a method. INNER is nonzero when 4825 being called to continue a conversion chain. It is negative when a 4826 reference binding will be applied, positive otherwise. If 4827 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 4828 conversions will be emitted if appropriate. If C_CAST_P is true, 4829 this conversion is coming from a C-style cast; in that case, 4830 conversions to inaccessible bases are permitted. */ 4831 4832 static tree 4833 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 4834 int inner, bool issue_conversion_warnings, 4835 bool c_cast_p, tsubst_flags_t complain) 4836 { 4837 tree totype = convs->type; 4838 diagnostic_t diag_kind; 4839 int flags; 4840 4841 if (convs->bad_p 4842 && convs->kind != ck_user 4843 && convs->kind != ck_list 4844 && convs->kind != ck_ambig 4845 && convs->kind != ck_ref_bind 4846 && convs->kind != ck_rvalue 4847 && convs->kind != ck_base) 4848 { 4849 conversion *t = convs; 4850 4851 /* Give a helpful error if this is bad because of excess braces. */ 4852 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 4853 && SCALAR_TYPE_P (totype) 4854 && CONSTRUCTOR_NELTS (expr) > 0 4855 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 4856 permerror (input_location, "too many braces around initializer for %qT", totype); 4857 4858 for (; t; t = convs->u.next) 4859 { 4860 if (t->kind == ck_user || !t->bad_p) 4861 { 4862 expr = convert_like_real (t, expr, fn, argnum, 1, 4863 /*issue_conversion_warnings=*/false, 4864 /*c_cast_p=*/false, 4865 complain); 4866 break; 4867 } 4868 else if (t->kind == ck_ambig) 4869 return convert_like_real (t, expr, fn, argnum, 1, 4870 /*issue_conversion_warnings=*/false, 4871 /*c_cast_p=*/false, 4872 complain); 4873 else if (t->kind == ck_identity) 4874 break; 4875 } 4876 if (complain & tf_error) 4877 { 4878 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype); 4879 if (fn) 4880 permerror (input_location, " initializing argument %P of %qD", argnum, fn); 4881 } 4882 else 4883 return error_mark_node; 4884 4885 return cp_convert (totype, expr); 4886 } 4887 4888 if (issue_conversion_warnings && (complain & tf_warning)) 4889 conversion_null_warnings (totype, expr, fn, argnum); 4890 4891 switch (convs->kind) 4892 { 4893 case ck_user: 4894 { 4895 struct z_candidate *cand = convs->cand; 4896 tree convfn = cand->fn; 4897 unsigned i; 4898 4899 /* When converting from an init list we consider explicit 4900 constructors, but actually trying to call one is an error. */ 4901 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)) 4902 { 4903 if (complain & tf_error) 4904 error ("converting to %qT from initializer list would use " 4905 "explicit constructor %qD", totype, convfn); 4906 else 4907 return error_mark_node; 4908 } 4909 4910 /* Set user_conv_p on the argument conversions, so rvalue/base 4911 handling knows not to allow any more UDCs. */ 4912 for (i = 0; i < cand->num_convs; ++i) 4913 cand->convs[i]->user_conv_p = true; 4914 4915 expr = build_over_call (cand, LOOKUP_NORMAL, complain); 4916 4917 /* If this is a constructor or a function returning an aggr type, 4918 we need to build up a TARGET_EXPR. */ 4919 if (DECL_CONSTRUCTOR_P (convfn)) 4920 { 4921 expr = build_cplus_new (totype, expr); 4922 4923 /* Remember that this was list-initialization. */ 4924 if (convs->check_narrowing) 4925 TARGET_EXPR_LIST_INIT_P (expr) = true; 4926 } 4927 4928 return expr; 4929 } 4930 case ck_identity: 4931 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 4932 { 4933 int nelts = CONSTRUCTOR_NELTS (expr); 4934 if (nelts == 0) 4935 expr = integer_zero_node; 4936 else if (nelts == 1) 4937 expr = CONSTRUCTOR_ELT (expr, 0)->value; 4938 else 4939 gcc_unreachable (); 4940 } 4941 4942 if (type_unknown_p (expr)) 4943 expr = instantiate_type (totype, expr, complain); 4944 /* Convert a constant to its underlying value, unless we are 4945 about to bind it to a reference, in which case we need to 4946 leave it as an lvalue. */ 4947 if (inner >= 0) 4948 { 4949 expr = decl_constant_value (expr); 4950 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 4951 /* If __null has been converted to an integer type, we do not 4952 want to warn about uses of EXPR as an integer, rather than 4953 as a pointer. */ 4954 expr = build_int_cst (totype, 0); 4955 } 4956 return expr; 4957 case ck_ambig: 4958 /* Call build_user_type_conversion again for the error. */ 4959 return build_user_type_conversion 4960 (totype, convs->u.expr, LOOKUP_NORMAL); 4961 4962 case ck_list: 4963 { 4964 /* Conversion to std::initializer_list<T>. */ 4965 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 4966 tree new_ctor = build_constructor (init_list_type_node, NULL); 4967 unsigned len = CONSTRUCTOR_NELTS (expr); 4968 tree array, val; 4969 VEC(tree,gc) *parms; 4970 unsigned ix; 4971 4972 /* Convert all the elements. */ 4973 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 4974 { 4975 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 4976 1, false, false, complain); 4977 if (sub == error_mark_node) 4978 return sub; 4979 check_narrowing (TREE_TYPE (sub), val); 4980 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 4981 } 4982 /* Build up the array. */ 4983 elttype = cp_build_qualified_type 4984 (elttype, TYPE_QUALS (elttype) | TYPE_QUAL_CONST); 4985 array = build_array_of_n_type (elttype, len); 4986 array = finish_compound_literal (array, new_ctor); 4987 4988 parms = make_tree_vector (); 4989 VEC_safe_push (tree, gc, parms, decay_conversion (array)); 4990 VEC_safe_push (tree, gc, parms, size_int (len)); 4991 /* Call the private constructor. */ 4992 push_deferring_access_checks (dk_no_check); 4993 new_ctor = build_special_member_call 4994 (NULL_TREE, complete_ctor_identifier, &parms, totype, 0, complain); 4995 release_tree_vector (parms); 4996 pop_deferring_access_checks (); 4997 return build_cplus_new (totype, new_ctor); 4998 } 4999 5000 case ck_aggr: 5001 return get_target_expr (digest_init (totype, expr)); 5002 5003 default: 5004 break; 5005 }; 5006 5007 expr = convert_like_real (convs->u.next, expr, fn, argnum, 5008 convs->kind == ck_ref_bind ? -1 : 1, 5009 convs->kind == ck_ref_bind ? issue_conversion_warnings : false, 5010 c_cast_p, 5011 complain); 5012 if (expr == error_mark_node) 5013 return error_mark_node; 5014 5015 switch (convs->kind) 5016 { 5017 case ck_rvalue: 5018 expr = decay_conversion (expr); 5019 if (! MAYBE_CLASS_TYPE_P (totype)) 5020 return expr; 5021 /* Else fall through. */ 5022 case ck_base: 5023 if (convs->kind == ck_base && !convs->need_temporary_p) 5024 { 5025 /* We are going to bind a reference directly to a base-class 5026 subobject of EXPR. */ 5027 /* Build an expression for `*((base*) &expr)'. */ 5028 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain); 5029 expr = convert_to_base (expr, build_pointer_type (totype), 5030 !c_cast_p, /*nonnull=*/true); 5031 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain); 5032 return expr; 5033 } 5034 5035 /* Copy-initialization where the cv-unqualified version of the source 5036 type is the same class as, or a derived class of, the class of the 5037 destination [is treated as direct-initialization]. [dcl.init] */ 5038 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING; 5039 if (convs->user_conv_p) 5040 /* This conversion is being done in the context of a user-defined 5041 conversion (i.e. the second step of copy-initialization), so 5042 don't allow any more. */ 5043 flags |= LOOKUP_NO_CONVERSION; 5044 expr = build_temp (expr, totype, flags, &diag_kind); 5045 if (diag_kind && fn) 5046 { 5047 if ((complain & tf_error)) 5048 emit_diagnostic (diag_kind, input_location, 0, 5049 " initializing argument %P of %qD", argnum, fn); 5050 else if (diag_kind == DK_ERROR) 5051 return error_mark_node; 5052 } 5053 return build_cplus_new (totype, expr); 5054 5055 case ck_ref_bind: 5056 { 5057 tree ref_type = totype; 5058 5059 if (convs->bad_p && TYPE_REF_IS_RVALUE (ref_type) 5060 && real_lvalue_p (expr)) 5061 { 5062 if (complain & tf_error) 5063 { 5064 error ("cannot bind %qT lvalue to %qT", 5065 TREE_TYPE (expr), totype); 5066 if (fn) 5067 error (" initializing argument %P of %q+D", argnum, fn); 5068 } 5069 return error_mark_node; 5070 } 5071 5072 /* If necessary, create a temporary. 5073 5074 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 5075 that need temporaries, even when their types are reference 5076 compatible with the type of reference being bound, so the 5077 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...) 5078 doesn't fail. */ 5079 if (convs->need_temporary_p 5080 || TREE_CODE (expr) == CONSTRUCTOR 5081 || TREE_CODE (expr) == VA_ARG_EXPR) 5082 { 5083 tree type = convs->u.next->type; 5084 cp_lvalue_kind lvalue = real_lvalue_p (expr); 5085 5086 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)) 5087 && !TYPE_REF_IS_RVALUE (ref_type)) 5088 { 5089 if (complain & tf_error) 5090 { 5091 /* If the reference is volatile or non-const, we 5092 cannot create a temporary. */ 5093 if (lvalue & clk_bitfield) 5094 error ("cannot bind bitfield %qE to %qT", 5095 expr, ref_type); 5096 else if (lvalue & clk_packed) 5097 error ("cannot bind packed field %qE to %qT", 5098 expr, ref_type); 5099 else 5100 error ("cannot bind rvalue %qE to %qT", expr, ref_type); 5101 } 5102 return error_mark_node; 5103 } 5104 /* If the source is a packed field, and we must use a copy 5105 constructor, then building the target expr will require 5106 binding the field to the reference parameter to the 5107 copy constructor, and we'll end up with an infinite 5108 loop. If we can use a bitwise copy, then we'll be 5109 OK. */ 5110 if ((lvalue & clk_packed) 5111 && CLASS_TYPE_P (type) 5112 && !TYPE_HAS_TRIVIAL_INIT_REF (type)) 5113 { 5114 if (complain & tf_error) 5115 error ("cannot bind packed field %qE to %qT", 5116 expr, ref_type); 5117 return error_mark_node; 5118 } 5119 if (lvalue & clk_bitfield) 5120 { 5121 expr = convert_bitfield_to_declared_type (expr); 5122 expr = fold_convert (type, expr); 5123 } 5124 expr = build_target_expr_with_type (expr, type); 5125 } 5126 5127 /* Take the address of the thing to which we will bind the 5128 reference. */ 5129 expr = cp_build_unary_op (ADDR_EXPR, expr, 1, complain); 5130 if (expr == error_mark_node) 5131 return error_mark_node; 5132 5133 /* Convert it to a pointer to the type referred to by the 5134 reference. This will adjust the pointer if a derived to 5135 base conversion is being performed. */ 5136 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 5137 expr); 5138 /* Convert the pointer to the desired reference type. */ 5139 return build_nop (ref_type, expr); 5140 } 5141 5142 case ck_lvalue: 5143 return decay_conversion (expr); 5144 5145 case ck_qual: 5146 /* Warn about deprecated conversion if appropriate. */ 5147 string_conv_p (totype, expr, 1); 5148 break; 5149 5150 case ck_ptr: 5151 if (convs->base_p) 5152 expr = convert_to_base (expr, totype, !c_cast_p, 5153 /*nonnull=*/false); 5154 return build_nop (totype, expr); 5155 5156 case ck_pmem: 5157 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 5158 c_cast_p); 5159 5160 default: 5161 break; 5162 } 5163 5164 if (convs->check_narrowing) 5165 check_narrowing (totype, expr); 5166 5167 if (issue_conversion_warnings && (complain & tf_warning)) 5168 expr = convert_and_check (totype, expr); 5169 else 5170 expr = convert (totype, expr); 5171 5172 return expr; 5173 } 5174 5175 /* ARG is being passed to a varargs function. Perform any conversions 5176 required. Return the converted value. */ 5177 5178 tree 5179 convert_arg_to_ellipsis (tree arg) 5180 { 5181 /* [expr.call] 5182 5183 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 5184 standard conversions are performed. */ 5185 arg = decay_conversion (arg); 5186 /* [expr.call] 5187 5188 If the argument has integral or enumeration type that is subject 5189 to the integral promotions (_conv.prom_), or a floating point 5190 type that is subject to the floating point promotion 5191 (_conv.fpprom_), the value of the argument is converted to the 5192 promoted type before the call. */ 5193 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE 5194 && (TYPE_PRECISION (TREE_TYPE (arg)) 5195 < TYPE_PRECISION (double_type_node)) 5196 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (arg)))) 5197 arg = convert_to_real (double_type_node, arg); 5198 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg))) 5199 arg = perform_integral_promotions (arg); 5200 5201 arg = require_complete_type (arg); 5202 5203 if (arg != error_mark_node 5204 && (type_has_nontrivial_copy_init (TREE_TYPE (arg)) 5205 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (arg)))) 5206 { 5207 /* [expr.call] 5.2.2/7: 5208 Passing a potentially-evaluated argument of class type (Clause 9) 5209 with a non-trivial copy constructor or a non-trivial destructor 5210 with no corresponding parameter is conditionally-supported, with 5211 implementation-defined semantics. 5212 5213 We used to just warn here and do a bitwise copy, but now 5214 cp_expr_size will abort if we try to do that. 5215 5216 If the call appears in the context of a sizeof expression, 5217 it is not potentially-evaluated. */ 5218 if (cp_unevaluated_operand == 0) 5219 error ("cannot pass objects of non-trivially-copyable " 5220 "type %q#T through %<...%>", TREE_TYPE (arg)); 5221 } 5222 5223 return arg; 5224 } 5225 5226 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 5227 5228 tree 5229 build_x_va_arg (tree expr, tree type) 5230 { 5231 if (processing_template_decl) 5232 return build_min (VA_ARG_EXPR, type, expr); 5233 5234 type = complete_type_or_else (type, NULL_TREE); 5235 5236 if (expr == error_mark_node || !type) 5237 return error_mark_node; 5238 5239 if (type_has_nontrivial_copy_init (type) 5240 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 5241 || TREE_CODE (type) == REFERENCE_TYPE) 5242 { 5243 /* Remove reference types so we don't ICE later on. */ 5244 tree type1 = non_reference (type); 5245 /* conditionally-supported behavior [expr.call] 5.2.2/7. */ 5246 error ("cannot receive objects of non-trivially-copyable type %q#T " 5247 "through %<...%>; ", type); 5248 expr = convert (build_pointer_type (type1), null_node); 5249 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error); 5250 return expr; 5251 } 5252 5253 return build_va_arg (input_location, expr, type); 5254 } 5255 5256 /* TYPE has been given to va_arg. Apply the default conversions which 5257 would have happened when passed via ellipsis. Return the promoted 5258 type, or the passed type if there is no change. */ 5259 5260 tree 5261 cxx_type_promotes_to (tree type) 5262 { 5263 tree promote; 5264 5265 /* Perform the array-to-pointer and function-to-pointer 5266 conversions. */ 5267 type = type_decays_to (type); 5268 5269 promote = type_promotes_to (type); 5270 if (same_type_p (type, promote)) 5271 promote = type; 5272 5273 return promote; 5274 } 5275 5276 /* ARG is a default argument expression being passed to a parameter of 5277 the indicated TYPE, which is a parameter to FN. Do any required 5278 conversions. Return the converted value. */ 5279 5280 static GTY(()) VEC(tree,gc) *default_arg_context; 5281 5282 tree 5283 convert_default_arg (tree type, tree arg, tree fn, int parmnum) 5284 { 5285 int i; 5286 tree t; 5287 5288 /* If the ARG is an unparsed default argument expression, the 5289 conversion cannot be performed. */ 5290 if (TREE_CODE (arg) == DEFAULT_ARG) 5291 { 5292 error ("the default argument for parameter %d of %qD has " 5293 "not yet been parsed", 5294 parmnum, fn); 5295 return error_mark_node; 5296 } 5297 5298 /* Detect recursion. */ 5299 for (i = 0; VEC_iterate (tree, default_arg_context, i, t); ++i) 5300 if (t == fn) 5301 { 5302 error ("recursive evaluation of default argument for %q#D", fn); 5303 return error_mark_node; 5304 } 5305 VEC_safe_push (tree, gc, default_arg_context, fn); 5306 5307 if (fn && DECL_TEMPLATE_INFO (fn)) 5308 arg = tsubst_default_argument (fn, type, arg); 5309 5310 /* Due to: 5311 5312 [dcl.fct.default] 5313 5314 The names in the expression are bound, and the semantic 5315 constraints are checked, at the point where the default 5316 expressions appears. 5317 5318 we must not perform access checks here. */ 5319 push_deferring_access_checks (dk_no_check); 5320 arg = break_out_target_exprs (arg); 5321 if (TREE_CODE (arg) == CONSTRUCTOR) 5322 { 5323 arg = digest_init (type, arg); 5324 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL, 5325 "default argument", fn, parmnum, 5326 tf_warning_or_error); 5327 } 5328 else 5329 { 5330 /* We must make a copy of ARG, in case subsequent processing 5331 alters any part of it. For example, during gimplification a 5332 cast of the form (T) &X::f (where "f" is a member function) 5333 will lead to replacing the PTRMEM_CST for &X::f with a 5334 VAR_DECL. We can avoid the copy for constants, since they 5335 are never modified in place. */ 5336 if (!CONSTANT_CLASS_P (arg)) 5337 arg = unshare_expr (arg); 5338 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL, 5339 "default argument", fn, parmnum, 5340 tf_warning_or_error); 5341 arg = convert_for_arg_passing (type, arg); 5342 } 5343 pop_deferring_access_checks(); 5344 5345 VEC_pop (tree, default_arg_context); 5346 5347 return arg; 5348 } 5349 5350 /* Returns the type which will really be used for passing an argument of 5351 type TYPE. */ 5352 5353 tree 5354 type_passed_as (tree type) 5355 { 5356 /* Pass classes with copy ctors by invisible reference. */ 5357 if (TREE_ADDRESSABLE (type)) 5358 { 5359 type = build_reference_type (type); 5360 /* There are no other pointers to this temporary. */ 5361 type = build_qualified_type (type, TYPE_QUAL_RESTRICT); 5362 } 5363 else if (targetm.calls.promote_prototypes (type) 5364 && INTEGRAL_TYPE_P (type) 5365 && COMPLETE_TYPE_P (type) 5366 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 5367 TYPE_SIZE (integer_type_node))) 5368 type = integer_type_node; 5369 5370 return type; 5371 } 5372 5373 /* Actually perform the appropriate conversion. */ 5374 5375 tree 5376 convert_for_arg_passing (tree type, tree val) 5377 { 5378 tree bitfield_type; 5379 5380 /* If VAL is a bitfield, then -- since it has already been converted 5381 to TYPE -- it cannot have a precision greater than TYPE. 5382 5383 If it has a smaller precision, we must widen it here. For 5384 example, passing "int f:3;" to a function expecting an "int" will 5385 not result in any conversion before this point. 5386 5387 If the precision is the same we must not risk widening. For 5388 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 5389 often have type "int", even though the C++ type for the field is 5390 "long long". If the value is being passed to a function 5391 expecting an "int", then no conversions will be required. But, 5392 if we call convert_bitfield_to_declared_type, the bitfield will 5393 be converted to "long long". */ 5394 bitfield_type = is_bitfield_expr_with_lowered_type (val); 5395 if (bitfield_type 5396 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 5397 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val); 5398 5399 if (val == error_mark_node) 5400 ; 5401 /* Pass classes with copy ctors by invisible reference. */ 5402 else if (TREE_ADDRESSABLE (type)) 5403 val = build1 (ADDR_EXPR, build_reference_type (type), val); 5404 else if (targetm.calls.promote_prototypes (type) 5405 && INTEGRAL_TYPE_P (type) 5406 && COMPLETE_TYPE_P (type) 5407 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 5408 TYPE_SIZE (integer_type_node))) 5409 val = perform_integral_promotions (val); 5410 if (warn_missing_format_attribute) 5411 { 5412 tree rhstype = TREE_TYPE (val); 5413 const enum tree_code coder = TREE_CODE (rhstype); 5414 const enum tree_code codel = TREE_CODE (type); 5415 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 5416 && coder == codel 5417 && check_missing_format_attribute (type, rhstype)) 5418 warning (OPT_Wmissing_format_attribute, 5419 "argument of function call might be a candidate for a format attribute"); 5420 } 5421 return val; 5422 } 5423 5424 /* Returns true iff FN is a function with magic varargs, i.e. ones for 5425 which no conversions at all should be done. This is true for some 5426 builtins which don't act like normal functions. */ 5427 5428 static bool 5429 magic_varargs_p (tree fn) 5430 { 5431 if (DECL_BUILT_IN (fn)) 5432 switch (DECL_FUNCTION_CODE (fn)) 5433 { 5434 case BUILT_IN_CLASSIFY_TYPE: 5435 case BUILT_IN_CONSTANT_P: 5436 case BUILT_IN_NEXT_ARG: 5437 case BUILT_IN_VA_START: 5438 return true; 5439 5440 default:; 5441 return lookup_attribute ("type generic", 5442 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 5443 } 5444 5445 return false; 5446 } 5447 5448 /* Subroutine of the various build_*_call functions. Overload resolution 5449 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 5450 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 5451 bitmask of various LOOKUP_* flags which apply to the call itself. */ 5452 5453 static tree 5454 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 5455 { 5456 tree fn = cand->fn; 5457 const VEC(tree,gc) *args = cand->args; 5458 tree first_arg = cand->first_arg; 5459 conversion **convs = cand->convs; 5460 conversion *conv; 5461 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 5462 int parmlen; 5463 tree val; 5464 int i = 0; 5465 int j = 0; 5466 unsigned int arg_index = 0; 5467 int is_method = 0; 5468 int nargs; 5469 tree *argarray; 5470 bool already_used = false; 5471 5472 /* In a template, there is no need to perform all of the work that 5473 is normally done. We are only interested in the type of the call 5474 expression, i.e., the return type of the function. Any semantic 5475 errors will be deferred until the template is instantiated. */ 5476 if (processing_template_decl) 5477 { 5478 tree expr; 5479 tree return_type; 5480 const tree *argarray; 5481 unsigned int nargs; 5482 5483 return_type = TREE_TYPE (TREE_TYPE (fn)); 5484 nargs = VEC_length (tree, args); 5485 if (first_arg == NULL_TREE) 5486 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args)); 5487 else 5488 { 5489 tree *alcarray; 5490 unsigned int ix; 5491 tree arg; 5492 5493 ++nargs; 5494 alcarray = XALLOCAVEC (tree, nargs); 5495 alcarray[0] = first_arg; 5496 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix) 5497 alcarray[ix + 1] = arg; 5498 argarray = alcarray; 5499 } 5500 expr = build_call_array_loc (input_location, 5501 return_type, build_addr_func (fn), nargs, 5502 argarray); 5503 if (TREE_THIS_VOLATILE (fn) && cfun) 5504 current_function_returns_abnormally = 1; 5505 if (!VOID_TYPE_P (return_type)) 5506 require_complete_type (return_type); 5507 return convert_from_reference (expr); 5508 } 5509 5510 /* Give any warnings we noticed during overload resolution. */ 5511 if (cand->warnings) 5512 { 5513 struct candidate_warning *w; 5514 for (w = cand->warnings; w; w = w->next) 5515 joust (cand, w->loser, 1); 5516 } 5517 5518 /* Make =delete work with SFINAE. */ 5519 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 5520 return error_mark_node; 5521 5522 if (DECL_FUNCTION_MEMBER_P (fn)) 5523 { 5524 /* If FN is a template function, two cases must be considered. 5525 For example: 5526 5527 struct A { 5528 protected: 5529 template <class T> void f(); 5530 }; 5531 template <class T> struct B { 5532 protected: 5533 void g(); 5534 }; 5535 struct C : A, B<int> { 5536 using A::f; // #1 5537 using B<int>::g; // #2 5538 }; 5539 5540 In case #1 where `A::f' is a member template, DECL_ACCESS is 5541 recorded in the primary template but not in its specialization. 5542 We check access of FN using its primary template. 5543 5544 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 5545 because it is a member of class template B, DECL_ACCESS is 5546 recorded in the specialization `B<int>::g'. We cannot use its 5547 primary template because `B<T>::g' and `B<int>::g' may have 5548 different access. */ 5549 if (DECL_TEMPLATE_INFO (fn) 5550 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 5551 perform_or_defer_access_check (cand->access_path, 5552 DECL_TI_TEMPLATE (fn), fn); 5553 else 5554 perform_or_defer_access_check (cand->access_path, fn, fn); 5555 } 5556 5557 /* Find maximum size of vector to hold converted arguments. */ 5558 parmlen = list_length (parm); 5559 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0); 5560 if (parmlen > nargs) 5561 nargs = parmlen; 5562 argarray = (tree *) alloca (nargs * sizeof (tree)); 5563 5564 /* The implicit parameters to a constructor are not considered by overload 5565 resolution, and must be of the proper type. */ 5566 if (DECL_CONSTRUCTOR_P (fn)) 5567 { 5568 if (first_arg != NULL_TREE) 5569 { 5570 argarray[j++] = first_arg; 5571 first_arg = NULL_TREE; 5572 } 5573 else 5574 { 5575 argarray[j++] = VEC_index (tree, args, arg_index); 5576 ++arg_index; 5577 } 5578 parm = TREE_CHAIN (parm); 5579 /* We should never try to call the abstract constructor. */ 5580 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 5581 5582 if (DECL_HAS_VTT_PARM_P (fn)) 5583 { 5584 argarray[j++] = VEC_index (tree, args, arg_index); 5585 ++arg_index; 5586 parm = TREE_CHAIN (parm); 5587 } 5588 } 5589 /* Bypass access control for 'this' parameter. */ 5590 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 5591 { 5592 tree parmtype = TREE_VALUE (parm); 5593 tree arg = (first_arg != NULL_TREE 5594 ? first_arg 5595 : VEC_index (tree, args, arg_index)); 5596 tree argtype = TREE_TYPE (arg); 5597 tree converted_arg; 5598 tree base_binfo; 5599 5600 if (convs[i]->bad_p) 5601 { 5602 if (complain & tf_error) 5603 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers", 5604 TREE_TYPE (argtype), fn); 5605 else 5606 return error_mark_node; 5607 } 5608 5609 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 5610 X is called for an object that is not of type X, or of a type 5611 derived from X, the behavior is undefined. 5612 5613 So we can assume that anything passed as 'this' is non-null, and 5614 optimize accordingly. */ 5615 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE); 5616 /* Convert to the base in which the function was declared. */ 5617 gcc_assert (cand->conversion_path != NULL_TREE); 5618 converted_arg = build_base_path (PLUS_EXPR, 5619 arg, 5620 cand->conversion_path, 5621 1); 5622 /* Check that the base class is accessible. */ 5623 if (!accessible_base_p (TREE_TYPE (argtype), 5624 BINFO_TYPE (cand->conversion_path), true)) 5625 error ("%qT is not an accessible base of %qT", 5626 BINFO_TYPE (cand->conversion_path), 5627 TREE_TYPE (argtype)); 5628 /* If fn was found by a using declaration, the conversion path 5629 will be to the derived class, not the base declaring fn. We 5630 must convert from derived to base. */ 5631 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 5632 TREE_TYPE (parmtype), ba_unique, NULL); 5633 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 5634 base_binfo, 1); 5635 5636 argarray[j++] = converted_arg; 5637 parm = TREE_CHAIN (parm); 5638 if (first_arg != NULL_TREE) 5639 first_arg = NULL_TREE; 5640 else 5641 ++arg_index; 5642 ++i; 5643 is_method = 1; 5644 } 5645 5646 gcc_assert (first_arg == NULL_TREE); 5647 for (; arg_index < VEC_length (tree, args) && parm; 5648 parm = TREE_CHAIN (parm), ++arg_index, ++i) 5649 { 5650 tree type = TREE_VALUE (parm); 5651 tree arg = VEC_index (tree, args, arg_index); 5652 5653 conv = convs[i]; 5654 5655 /* Don't make a copy here if build_call is going to. */ 5656 if (conv->kind == ck_rvalue 5657 && COMPLETE_TYPE_P (complete_type (type)) 5658 && !TREE_ADDRESSABLE (type)) 5659 conv = conv->u.next; 5660 5661 /* Warn about initializer_list deduction that isn't currently in the 5662 working draft. */ 5663 if (cxx_dialect > cxx98 5664 && flag_deduce_init_list 5665 && cand->template_decl 5666 && is_std_init_list (non_reference (type)) 5667 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 5668 { 5669 tree tmpl = TI_TEMPLATE (cand->template_decl); 5670 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 5671 tree patparm = get_pattern_parm (realparm, tmpl); 5672 tree pattype = TREE_TYPE (patparm); 5673 if (PACK_EXPANSION_P (pattype)) 5674 pattype = PACK_EXPANSION_PATTERN (pattype); 5675 pattype = non_reference (pattype); 5676 5677 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 5678 && (cand->explicit_targs == NULL_TREE 5679 || (TREE_VEC_LENGTH (cand->explicit_targs) 5680 <= TEMPLATE_TYPE_IDX (pattype)))) 5681 { 5682 pedwarn (input_location, 0, "deducing %qT as %qT", 5683 non_reference (TREE_TYPE (patparm)), 5684 non_reference (type)); 5685 pedwarn (input_location, 0, " in call to %q+D", cand->fn); 5686 pedwarn (input_location, 0, 5687 " (you can disable this with -fno-deduce-init-list)"); 5688 } 5689 } 5690 5691 val = convert_like_with_context (conv, arg, fn, i-is_method, complain); 5692 5693 val = convert_for_arg_passing (type, val); 5694 if (val == error_mark_node) 5695 return error_mark_node; 5696 else 5697 argarray[j++] = val; 5698 } 5699 5700 /* Default arguments */ 5701 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 5702 argarray[j++] = convert_default_arg (TREE_VALUE (parm), 5703 TREE_PURPOSE (parm), 5704 fn, i - is_method); 5705 /* Ellipsis */ 5706 for (; arg_index < VEC_length (tree, args); ++arg_index) 5707 { 5708 tree a = VEC_index (tree, args, arg_index); 5709 if (magic_varargs_p (fn)) 5710 /* Do no conversions for magic varargs. */; 5711 else 5712 a = convert_arg_to_ellipsis (a); 5713 argarray[j++] = a; 5714 } 5715 5716 gcc_assert (j <= nargs); 5717 nargs = j; 5718 5719 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)), 5720 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn))); 5721 5722 /* Avoid actually calling copy constructors and copy assignment operators, 5723 if possible. */ 5724 5725 if (! flag_elide_constructors) 5726 /* Do things the hard way. */; 5727 else if (cand->num_convs == 1 5728 && (DECL_COPY_CONSTRUCTOR_P (fn) 5729 || DECL_MOVE_CONSTRUCTOR_P (fn))) 5730 { 5731 tree targ; 5732 tree arg = argarray[num_artificial_parms_for (fn)]; 5733 tree fa; 5734 5735 /* Pull out the real argument, disregarding const-correctness. */ 5736 targ = arg; 5737 while (CONVERT_EXPR_P (targ) 5738 || TREE_CODE (targ) == NON_LVALUE_EXPR) 5739 targ = TREE_OPERAND (targ, 0); 5740 if (TREE_CODE (targ) == ADDR_EXPR) 5741 { 5742 targ = TREE_OPERAND (targ, 0); 5743 if (!same_type_ignoring_top_level_qualifiers_p 5744 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 5745 targ = NULL_TREE; 5746 } 5747 else 5748 targ = NULL_TREE; 5749 5750 if (targ) 5751 arg = targ; 5752 else 5753 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 5754 5755 if (TREE_CODE (arg) == TARGET_EXPR 5756 && TARGET_EXPR_LIST_INIT_P (arg)) 5757 { 5758 /* Copy-list-initialization doesn't require the copy constructor 5759 to be defined. */ 5760 } 5761 /* [class.copy]: the copy constructor is implicitly defined even if 5762 the implementation elided its use. */ 5763 else if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)) 5764 || move_fn_p (fn)) 5765 { 5766 mark_used (fn); 5767 already_used = true; 5768 } 5769 5770 /* If we're creating a temp and we already have one, don't create a 5771 new one. If we're not creating a temp but we get one, use 5772 INIT_EXPR to collapse the temp into our target. Otherwise, if the 5773 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 5774 temp or an INIT_EXPR otherwise. */ 5775 fa = (cand->first_arg != NULL_TREE 5776 ? cand->first_arg 5777 : VEC_index (tree, args, 0)); 5778 if (integer_zerop (fa)) 5779 { 5780 if (TREE_CODE (arg) == TARGET_EXPR) 5781 return arg; 5782 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)) 5783 && !move_fn_p (fn)) 5784 return build_target_expr_with_type (arg, DECL_CONTEXT (fn)); 5785 } 5786 else if (TREE_CODE (arg) == TARGET_EXPR 5787 || (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)) 5788 && !move_fn_p (fn))) 5789 { 5790 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL, 5791 complain)); 5792 5793 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 5794 return val; 5795 } 5796 } 5797 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR 5798 && copy_fn_p (fn) 5799 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn))) 5800 { 5801 tree to = stabilize_reference 5802 (cp_build_indirect_ref (argarray[0], RO_NULL, complain)); 5803 tree type = TREE_TYPE (to); 5804 tree as_base = CLASSTYPE_AS_BASE (type); 5805 tree arg = argarray[1]; 5806 5807 if (is_really_empty_class (type)) 5808 { 5809 /* Avoid copying empty classes. */ 5810 val = build2 (COMPOUND_EXPR, void_type_node, to, arg); 5811 TREE_NO_WARNING (val) = 1; 5812 val = build2 (COMPOUND_EXPR, type, val, to); 5813 TREE_NO_WARNING (val) = 1; 5814 } 5815 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 5816 { 5817 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 5818 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 5819 } 5820 else 5821 { 5822 /* We must only copy the non-tail padding parts. 5823 Use __builtin_memcpy for the bitwise copy. 5824 FIXME fix 22488 so we can go back to using MODIFY_EXPR 5825 instead of an explicit call to memcpy. */ 5826 5827 tree arg0, arg1, arg2, t; 5828 tree test = NULL_TREE; 5829 5830 arg2 = TYPE_SIZE_UNIT (as_base); 5831 arg1 = arg; 5832 arg0 = cp_build_unary_op (ADDR_EXPR, to, 0, complain); 5833 5834 if (!can_trust_pointer_alignment ()) 5835 { 5836 /* If we can't be sure about pointer alignment, a call 5837 to __builtin_memcpy is expanded as a call to memcpy, which 5838 is invalid with identical args. Otherwise it is 5839 expanded as a block move, which should be safe. */ 5840 arg0 = save_expr (arg0); 5841 arg1 = save_expr (arg1); 5842 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1); 5843 } 5844 t = implicit_built_in_decls[BUILT_IN_MEMCPY]; 5845 t = build_call_n (t, 3, arg0, arg1, arg2); 5846 5847 t = convert (TREE_TYPE (arg0), t); 5848 if (test) 5849 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t); 5850 val = cp_build_indirect_ref (t, RO_NULL, complain); 5851 TREE_NO_WARNING (val) = 1; 5852 } 5853 5854 return val; 5855 } 5856 5857 if (!already_used) 5858 mark_used (fn); 5859 5860 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0) 5861 { 5862 tree t; 5863 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 5864 DECL_CONTEXT (fn), 5865 ba_any, NULL); 5866 gcc_assert (binfo && binfo != error_mark_node); 5867 5868 /* Warn about deprecated virtual functions now, since we're about 5869 to throw away the decl. */ 5870 if (TREE_DEPRECATED (fn)) 5871 warn_deprecated_use (fn, NULL_TREE); 5872 5873 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1); 5874 if (TREE_SIDE_EFFECTS (argarray[0])) 5875 argarray[0] = save_expr (argarray[0]); 5876 t = build_pointer_type (TREE_TYPE (fn)); 5877 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn))) 5878 fn = build_java_interface_fn_ref (fn, argarray[0]); 5879 else 5880 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 5881 TREE_TYPE (fn) = t; 5882 } 5883 else 5884 fn = build_addr_func (fn); 5885 5886 return build_cxx_call (fn, nargs, argarray); 5887 } 5888 5889 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 5890 This function performs no overload resolution, conversion, or other 5891 high-level operations. */ 5892 5893 tree 5894 build_cxx_call (tree fn, int nargs, tree *argarray) 5895 { 5896 tree fndecl; 5897 5898 fn = build_call_a (fn, nargs, argarray); 5899 5900 /* If this call might throw an exception, note that fact. */ 5901 fndecl = get_callee_fndecl (fn); 5902 if ((!fndecl || !TREE_NOTHROW (fndecl)) 5903 && at_function_scope_p () 5904 && cfun) 5905 cp_function_chain->can_throw = 1; 5906 5907 /* Check that arguments to builtin functions match the expectations. */ 5908 if (fndecl 5909 && DECL_BUILT_IN (fndecl) 5910 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 5911 && !check_builtin_function_arguments (fndecl, nargs, argarray)) 5912 return error_mark_node; 5913 5914 /* Some built-in function calls will be evaluated at compile-time in 5915 fold (). */ 5916 fn = fold_if_not_in_template (fn); 5917 5918 if (VOID_TYPE_P (TREE_TYPE (fn))) 5919 return fn; 5920 5921 fn = require_complete_type (fn); 5922 if (fn == error_mark_node) 5923 return error_mark_node; 5924 5925 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 5926 fn = build_cplus_new (TREE_TYPE (fn), fn); 5927 return convert_from_reference (fn); 5928 } 5929 5930 static GTY(()) tree java_iface_lookup_fn; 5931 5932 /* Make an expression which yields the address of the Java interface 5933 method FN. This is achieved by generating a call to libjava's 5934 _Jv_LookupInterfaceMethodIdx(). */ 5935 5936 static tree 5937 build_java_interface_fn_ref (tree fn, tree instance) 5938 { 5939 tree lookup_fn, method, idx; 5940 tree klass_ref, iface, iface_ref; 5941 int i; 5942 5943 if (!java_iface_lookup_fn) 5944 { 5945 tree endlink = build_void_list_node (); 5946 tree t = tree_cons (NULL_TREE, ptr_type_node, 5947 tree_cons (NULL_TREE, ptr_type_node, 5948 tree_cons (NULL_TREE, java_int_type_node, 5949 endlink))); 5950 java_iface_lookup_fn 5951 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", 5952 build_function_type (ptr_type_node, t), 5953 0, NOT_BUILT_IN, NULL, NULL_TREE); 5954 } 5955 5956 /* Look up the pointer to the runtime java.lang.Class object for `instance'. 5957 This is the first entry in the vtable. */ 5958 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL, 5959 tf_warning_or_error), 5960 integer_zero_node); 5961 5962 /* Get the java.lang.Class pointer for the interface being called. */ 5963 iface = DECL_CONTEXT (fn); 5964 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false); 5965 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL 5966 || DECL_CONTEXT (iface_ref) != iface) 5967 { 5968 error ("could not find class$ field in java interface type %qT", 5969 iface); 5970 return error_mark_node; 5971 } 5972 iface_ref = build_address (iface_ref); 5973 iface_ref = convert (build_pointer_type (iface), iface_ref); 5974 5975 /* Determine the itable index of FN. */ 5976 i = 1; 5977 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method)) 5978 { 5979 if (!DECL_VIRTUAL_P (method)) 5980 continue; 5981 if (fn == method) 5982 break; 5983 i++; 5984 } 5985 idx = build_int_cst (NULL_TREE, i); 5986 5987 lookup_fn = build1 (ADDR_EXPR, 5988 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)), 5989 java_iface_lookup_fn); 5990 return build_call_nary (ptr_type_node, lookup_fn, 5991 3, klass_ref, iface_ref, idx); 5992 } 5993 5994 /* Returns the value to use for the in-charge parameter when making a 5995 call to a function with the indicated NAME. 5996 5997 FIXME:Can't we find a neater way to do this mapping? */ 5998 5999 tree 6000 in_charge_arg_for_name (tree name) 6001 { 6002 if (name == base_ctor_identifier 6003 || name == base_dtor_identifier) 6004 return integer_zero_node; 6005 else if (name == complete_ctor_identifier) 6006 return integer_one_node; 6007 else if (name == complete_dtor_identifier) 6008 return integer_two_node; 6009 else if (name == deleting_dtor_identifier) 6010 return integer_three_node; 6011 6012 /* This function should only be called with one of the names listed 6013 above. */ 6014 gcc_unreachable (); 6015 return NULL_TREE; 6016 } 6017 6018 /* Build a call to a constructor, destructor, or an assignment 6019 operator for INSTANCE, an expression with class type. NAME 6020 indicates the special member function to call; *ARGS are the 6021 arguments. ARGS may be NULL. This may change ARGS. BINFO 6022 indicates the base of INSTANCE that is to be passed as the `this' 6023 parameter to the member function called. 6024 6025 FLAGS are the LOOKUP_* flags to use when processing the call. 6026 6027 If NAME indicates a complete object constructor, INSTANCE may be 6028 NULL_TREE. In this case, the caller will call build_cplus_new to 6029 store the newly constructed object into a VAR_DECL. */ 6030 6031 tree 6032 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args, 6033 tree binfo, int flags, tsubst_flags_t complain) 6034 { 6035 tree fns; 6036 /* The type of the subobject to be constructed or destroyed. */ 6037 tree class_type; 6038 VEC(tree,gc) *allocated = NULL; 6039 tree ret; 6040 6041 gcc_assert (name == complete_ctor_identifier 6042 || name == base_ctor_identifier 6043 || name == complete_dtor_identifier 6044 || name == base_dtor_identifier 6045 || name == deleting_dtor_identifier 6046 || name == ansi_assopname (NOP_EXPR)); 6047 if (TYPE_P (binfo)) 6048 { 6049 /* Resolve the name. */ 6050 if (!complete_type_or_else (binfo, NULL_TREE)) 6051 return error_mark_node; 6052 6053 binfo = TYPE_BINFO (binfo); 6054 } 6055 6056 gcc_assert (binfo != NULL_TREE); 6057 6058 class_type = BINFO_TYPE (binfo); 6059 6060 /* Handle the special case where INSTANCE is NULL_TREE. */ 6061 if (name == complete_ctor_identifier && !instance) 6062 { 6063 instance = build_int_cst (build_pointer_type (class_type), 0); 6064 instance = build1 (INDIRECT_REF, class_type, instance); 6065 } 6066 else 6067 { 6068 if (name == complete_dtor_identifier 6069 || name == base_dtor_identifier 6070 || name == deleting_dtor_identifier) 6071 gcc_assert (args == NULL || VEC_empty (tree, *args)); 6072 6073 /* Convert to the base class, if necessary. */ 6074 if (!same_type_ignoring_top_level_qualifiers_p 6075 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 6076 { 6077 if (name != ansi_assopname (NOP_EXPR)) 6078 /* For constructors and destructors, either the base is 6079 non-virtual, or it is virtual but we are doing the 6080 conversion from a constructor or destructor for the 6081 complete object. In either case, we can convert 6082 statically. */ 6083 instance = convert_to_base_statically (instance, binfo); 6084 else 6085 /* However, for assignment operators, we must convert 6086 dynamically if the base is virtual. */ 6087 instance = build_base_path (PLUS_EXPR, instance, 6088 binfo, /*nonnull=*/1); 6089 } 6090 } 6091 6092 gcc_assert (instance != NULL_TREE); 6093 6094 fns = lookup_fnfields (binfo, name, 1); 6095 6096 /* When making a call to a constructor or destructor for a subobject 6097 that uses virtual base classes, pass down a pointer to a VTT for 6098 the subobject. */ 6099 if ((name == base_ctor_identifier 6100 || name == base_dtor_identifier) 6101 && CLASSTYPE_VBASECLASSES (class_type)) 6102 { 6103 tree vtt; 6104 tree sub_vtt; 6105 6106 /* If the current function is a complete object constructor 6107 or destructor, then we fetch the VTT directly. 6108 Otherwise, we look it up using the VTT we were given. */ 6109 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 6110 vtt = decay_conversion (vtt); 6111 vtt = build3 (COND_EXPR, TREE_TYPE (vtt), 6112 build2 (EQ_EXPR, boolean_type_node, 6113 current_in_charge_parm, integer_zero_node), 6114 current_vtt_parm, 6115 vtt); 6116 gcc_assert (BINFO_SUBVTT_INDEX (binfo)); 6117 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt, 6118 BINFO_SUBVTT_INDEX (binfo)); 6119 6120 if (args == NULL) 6121 { 6122 allocated = make_tree_vector (); 6123 args = &allocated; 6124 } 6125 6126 VEC_safe_insert (tree, gc, *args, 0, sub_vtt); 6127 } 6128 6129 ret = build_new_method_call (instance, fns, args, 6130 TYPE_BINFO (BINFO_TYPE (binfo)), 6131 flags, /*fn=*/NULL, 6132 complain); 6133 6134 if (allocated != NULL) 6135 release_tree_vector (allocated); 6136 6137 return ret; 6138 } 6139 6140 /* Return the NAME, as a C string. The NAME indicates a function that 6141 is a member of TYPE. *FREE_P is set to true if the caller must 6142 free the memory returned. 6143 6144 Rather than go through all of this, we should simply set the names 6145 of constructors and destructors appropriately, and dispense with 6146 ctor_identifier, dtor_identifier, etc. */ 6147 6148 static char * 6149 name_as_c_string (tree name, tree type, bool *free_p) 6150 { 6151 char *pretty_name; 6152 6153 /* Assume that we will not allocate memory. */ 6154 *free_p = false; 6155 /* Constructors and destructors are special. */ 6156 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 6157 { 6158 pretty_name 6159 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)))); 6160 /* For a destructor, add the '~'. */ 6161 if (name == complete_dtor_identifier 6162 || name == base_dtor_identifier 6163 || name == deleting_dtor_identifier) 6164 { 6165 pretty_name = concat ("~", pretty_name, NULL); 6166 /* Remember that we need to free the memory allocated. */ 6167 *free_p = true; 6168 } 6169 } 6170 else if (IDENTIFIER_TYPENAME_P (name)) 6171 { 6172 pretty_name = concat ("operator ", 6173 type_as_string_translate (TREE_TYPE (name), 6174 TFF_PLAIN_IDENTIFIER), 6175 NULL); 6176 /* Remember that we need to free the memory allocated. */ 6177 *free_p = true; 6178 } 6179 else 6180 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name))); 6181 6182 return pretty_name; 6183 } 6184 6185 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 6186 be set, upon return, to the function called. ARGS may be NULL. 6187 This may change ARGS. */ 6188 6189 tree 6190 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args, 6191 tree conversion_path, int flags, 6192 tree *fn_p, tsubst_flags_t complain) 6193 { 6194 struct z_candidate *candidates = 0, *cand; 6195 tree explicit_targs = NULL_TREE; 6196 tree basetype = NULL_TREE; 6197 tree access_binfo; 6198 tree optype; 6199 tree first_mem_arg = NULL_TREE; 6200 tree instance_ptr; 6201 tree name; 6202 bool skip_first_for_error; 6203 VEC(tree,gc) *user_args; 6204 tree call; 6205 tree fn; 6206 tree class_type; 6207 int template_only = 0; 6208 bool any_viable_p; 6209 tree orig_instance; 6210 tree orig_fns; 6211 VEC(tree,gc) *orig_args = NULL; 6212 void *p; 6213 6214 gcc_assert (instance != NULL_TREE); 6215 6216 /* We don't know what function we're going to call, yet. */ 6217 if (fn_p) 6218 *fn_p = NULL_TREE; 6219 6220 if (error_operand_p (instance) 6221 || error_operand_p (fns)) 6222 return error_mark_node; 6223 6224 if (!BASELINK_P (fns)) 6225 { 6226 if (complain & tf_error) 6227 error ("call to non-function %qD", fns); 6228 return error_mark_node; 6229 } 6230 6231 orig_instance = instance; 6232 orig_fns = fns; 6233 6234 /* Dismantle the baselink to collect all the information we need. */ 6235 if (!conversion_path) 6236 conversion_path = BASELINK_BINFO (fns); 6237 access_binfo = BASELINK_ACCESS_BINFO (fns); 6238 optype = BASELINK_OPTYPE (fns); 6239 fns = BASELINK_FUNCTIONS (fns); 6240 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 6241 { 6242 explicit_targs = TREE_OPERAND (fns, 1); 6243 fns = TREE_OPERAND (fns, 0); 6244 template_only = 1; 6245 } 6246 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 6247 || TREE_CODE (fns) == TEMPLATE_DECL 6248 || TREE_CODE (fns) == OVERLOAD); 6249 fn = get_first_fn (fns); 6250 name = DECL_NAME (fn); 6251 6252 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 6253 gcc_assert (CLASS_TYPE_P (basetype)); 6254 6255 if (processing_template_decl) 6256 { 6257 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 6258 instance = build_non_dependent_expr (instance); 6259 if (args != NULL) 6260 make_args_non_dependent (*args); 6261 } 6262 6263 user_args = args == NULL ? NULL : *args; 6264 /* Under DR 147 A::A() is an invalid constructor call, 6265 not a functional cast. */ 6266 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 6267 { 6268 if (! (complain & tf_error)) 6269 return error_mark_node; 6270 6271 permerror (input_location, 6272 "cannot call constructor %<%T::%D%> directly", 6273 basetype, name); 6274 permerror (input_location, " for a function-style cast, remove the " 6275 "redundant %<::%D%>", name); 6276 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 6277 complain); 6278 return call; 6279 } 6280 6281 /* Figure out whether to skip the first argument for the error 6282 message we will display to users if an error occurs. We don't 6283 want to display any compiler-generated arguments. The "this" 6284 pointer hasn't been added yet. However, we must remove the VTT 6285 pointer if this is a call to a base-class constructor or 6286 destructor. */ 6287 skip_first_for_error = false; 6288 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 6289 { 6290 /* Callers should explicitly indicate whether they want to construct 6291 the complete object or just the part without virtual bases. */ 6292 gcc_assert (name != ctor_identifier); 6293 /* Similarly for destructors. */ 6294 gcc_assert (name != dtor_identifier); 6295 /* Remove the VTT pointer, if present. */ 6296 if ((name == base_ctor_identifier || name == base_dtor_identifier) 6297 && CLASSTYPE_VBASECLASSES (basetype)) 6298 skip_first_for_error = true; 6299 } 6300 6301 /* Process the argument list. */ 6302 if (args != NULL && *args != NULL) 6303 { 6304 *args = resolve_args (*args); 6305 if (*args == NULL) 6306 return error_mark_node; 6307 } 6308 6309 instance_ptr = build_this (instance); 6310 6311 /* It's OK to call destructors and constructors on cv-qualified objects. 6312 Therefore, convert the INSTANCE_PTR to the unqualified type, if 6313 necessary. */ 6314 if (DECL_DESTRUCTOR_P (fn) 6315 || DECL_CONSTRUCTOR_P (fn)) 6316 { 6317 tree type = build_pointer_type (basetype); 6318 if (!same_type_p (type, TREE_TYPE (instance_ptr))) 6319 instance_ptr = build_nop (type, instance_ptr); 6320 } 6321 if (DECL_DESTRUCTOR_P (fn)) 6322 name = complete_dtor_identifier; 6323 6324 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 6325 initializer, not T({ }). If the type doesn't have a list ctor, 6326 break apart the list into separate ctor args. */ 6327 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args) 6328 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0)) 6329 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0)) 6330 && !TYPE_HAS_LIST_CTOR (basetype)) 6331 { 6332 gcc_assert (VEC_length (tree, *args) == 1 6333 && !(flags & LOOKUP_ONLYCONVERTING)); 6334 *args = ctor_to_vec (VEC_index (tree, *args, 0)); 6335 } 6336 6337 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE); 6338 first_mem_arg = instance_ptr; 6339 6340 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 6341 p = conversion_obstack_alloc (0); 6342 6343 for (fn = fns; fn; fn = OVL_NEXT (fn)) 6344 { 6345 tree t = OVL_CURRENT (fn); 6346 tree this_first_arg; 6347 6348 /* We can end up here for copy-init of same or base class. */ 6349 if ((flags & LOOKUP_ONLYCONVERTING) 6350 && DECL_NONCONVERTING_P (t)) 6351 continue; 6352 6353 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t)) 6354 this_first_arg = first_mem_arg; 6355 else 6356 this_first_arg = NULL_TREE; 6357 6358 if (TREE_CODE (t) == TEMPLATE_DECL) 6359 /* A member template. */ 6360 add_template_candidate (&candidates, t, 6361 class_type, 6362 explicit_targs, 6363 this_first_arg, 6364 args == NULL ? NULL : *args, 6365 optype, 6366 access_binfo, 6367 conversion_path, 6368 flags, 6369 DEDUCE_CALL); 6370 else if (! template_only) 6371 add_function_candidate (&candidates, t, 6372 class_type, 6373 this_first_arg, 6374 args == NULL ? NULL : *args, 6375 access_binfo, 6376 conversion_path, 6377 flags); 6378 } 6379 6380 candidates = splice_viable (candidates, pedantic, &any_viable_p); 6381 if (!any_viable_p) 6382 { 6383 if (complain & tf_error) 6384 { 6385 if (!COMPLETE_TYPE_P (basetype)) 6386 cxx_incomplete_type_error (instance_ptr, basetype); 6387 else 6388 { 6389 char *pretty_name; 6390 bool free_p; 6391 tree arglist; 6392 6393 pretty_name = name_as_c_string (name, basetype, &free_p); 6394 arglist = build_tree_list_vec (user_args); 6395 if (skip_first_for_error) 6396 arglist = TREE_CHAIN (arglist); 6397 error ("no matching function for call to %<%T::%s(%A)%#V%>", 6398 basetype, pretty_name, arglist, 6399 TREE_TYPE (TREE_TYPE (instance_ptr))); 6400 if (free_p) 6401 free (pretty_name); 6402 } 6403 print_z_candidates (candidates); 6404 } 6405 call = error_mark_node; 6406 } 6407 else 6408 { 6409 cand = tourney (candidates); 6410 if (cand == 0) 6411 { 6412 char *pretty_name; 6413 bool free_p; 6414 tree arglist; 6415 6416 if (complain & tf_error) 6417 { 6418 pretty_name = name_as_c_string (name, basetype, &free_p); 6419 arglist = build_tree_list_vec (user_args); 6420 if (skip_first_for_error) 6421 arglist = TREE_CHAIN (arglist); 6422 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name, 6423 arglist); 6424 print_z_candidates (candidates); 6425 if (free_p) 6426 free (pretty_name); 6427 } 6428 call = error_mark_node; 6429 } 6430 else 6431 { 6432 fn = cand->fn; 6433 6434 if (!(flags & LOOKUP_NONVIRTUAL) 6435 && DECL_PURE_VIRTUAL_P (fn) 6436 && instance == current_class_ref 6437 && (DECL_CONSTRUCTOR_P (current_function_decl) 6438 || DECL_DESTRUCTOR_P (current_function_decl)) 6439 && (complain & tf_warning)) 6440 /* This is not an error, it is runtime undefined 6441 behavior. */ 6442 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ? 6443 "abstract virtual %q#D called from constructor" 6444 : "abstract virtual %q#D called from destructor"), 6445 fn); 6446 6447 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 6448 && is_dummy_object (instance_ptr)) 6449 { 6450 if (complain & tf_error) 6451 error ("cannot call member function %qD without object", 6452 fn); 6453 call = error_mark_node; 6454 } 6455 else 6456 { 6457 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 6458 && resolves_to_fixed_type_p (instance, 0)) 6459 flags |= LOOKUP_NONVIRTUAL; 6460 /* Now we know what function is being called. */ 6461 if (fn_p) 6462 *fn_p = fn; 6463 /* Build the actual CALL_EXPR. */ 6464 call = build_over_call (cand, flags, complain); 6465 /* In an expression of the form `a->f()' where `f' turns 6466 out to be a static member function, `a' is 6467 none-the-less evaluated. */ 6468 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 6469 && !is_dummy_object (instance_ptr) 6470 && TREE_SIDE_EFFECTS (instance_ptr)) 6471 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), 6472 instance_ptr, call); 6473 else if (call != error_mark_node 6474 && DECL_DESTRUCTOR_P (cand->fn) 6475 && !VOID_TYPE_P (TREE_TYPE (call))) 6476 /* An explicit call of the form "x->~X()" has type 6477 "void". However, on platforms where destructors 6478 return "this" (i.e., those where 6479 targetm.cxx.cdtor_returns_this is true), such calls 6480 will appear to have a return value of pointer type 6481 to the low-level call machinery. We do not want to 6482 change the low-level machinery, since we want to be 6483 able to optimize "delete f()" on such platforms as 6484 "operator delete(~X(f()))" (rather than generating 6485 "t = f(), ~X(t), operator delete (t)"). */ 6486 call = build_nop (void_type_node, call); 6487 } 6488 } 6489 } 6490 6491 if (processing_template_decl && call != error_mark_node) 6492 { 6493 bool cast_to_void = false; 6494 6495 if (TREE_CODE (call) == COMPOUND_EXPR) 6496 call = TREE_OPERAND (call, 1); 6497 else if (TREE_CODE (call) == NOP_EXPR) 6498 { 6499 cast_to_void = true; 6500 call = TREE_OPERAND (call, 0); 6501 } 6502 if (TREE_CODE (call) == INDIRECT_REF) 6503 call = TREE_OPERAND (call, 0); 6504 call = (build_min_non_dep_call_vec 6505 (call, 6506 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 6507 orig_instance, orig_fns, NULL_TREE), 6508 orig_args)); 6509 call = convert_from_reference (call); 6510 if (cast_to_void) 6511 call = build_nop (void_type_node, call); 6512 } 6513 6514 /* Free all the conversions we allocated. */ 6515 obstack_free (&conversion_obstack, p); 6516 6517 if (orig_args != NULL) 6518 release_tree_vector (orig_args); 6519 6520 return call; 6521 } 6522 6523 /* Returns true iff standard conversion sequence ICS1 is a proper 6524 subsequence of ICS2. */ 6525 6526 static bool 6527 is_subseq (conversion *ics1, conversion *ics2) 6528 { 6529 /* We can assume that a conversion of the same code 6530 between the same types indicates a subsequence since we only get 6531 here if the types we are converting from are the same. */ 6532 6533 while (ics1->kind == ck_rvalue 6534 || ics1->kind == ck_lvalue) 6535 ics1 = ics1->u.next; 6536 6537 while (1) 6538 { 6539 while (ics2->kind == ck_rvalue 6540 || ics2->kind == ck_lvalue) 6541 ics2 = ics2->u.next; 6542 6543 if (ics2->kind == ck_user 6544 || ics2->kind == ck_ambig 6545 || ics2->kind == ck_identity) 6546 /* At this point, ICS1 cannot be a proper subsequence of 6547 ICS2. We can get a USER_CONV when we are comparing the 6548 second standard conversion sequence of two user conversion 6549 sequences. */ 6550 return false; 6551 6552 ics2 = ics2->u.next; 6553 6554 if (ics2->kind == ics1->kind 6555 && same_type_p (ics2->type, ics1->type) 6556 && same_type_p (ics2->u.next->type, 6557 ics1->u.next->type)) 6558 return true; 6559 } 6560 } 6561 6562 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 6563 be any _TYPE nodes. */ 6564 6565 bool 6566 is_properly_derived_from (tree derived, tree base) 6567 { 6568 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 6569 return false; 6570 6571 /* We only allow proper derivation here. The DERIVED_FROM_P macro 6572 considers every class derived from itself. */ 6573 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 6574 && DERIVED_FROM_P (base, derived)); 6575 } 6576 6577 /* We build the ICS for an implicit object parameter as a pointer 6578 conversion sequence. However, such a sequence should be compared 6579 as if it were a reference conversion sequence. If ICS is the 6580 implicit conversion sequence for an implicit object parameter, 6581 modify it accordingly. */ 6582 6583 static void 6584 maybe_handle_implicit_object (conversion **ics) 6585 { 6586 if ((*ics)->this_p) 6587 { 6588 /* [over.match.funcs] 6589 6590 For non-static member functions, the type of the 6591 implicit object parameter is "reference to cv X" 6592 where X is the class of which the function is a 6593 member and cv is the cv-qualification on the member 6594 function declaration. */ 6595 conversion *t = *ics; 6596 tree reference_type; 6597 6598 /* The `this' parameter is a pointer to a class type. Make the 6599 implicit conversion talk about a reference to that same class 6600 type. */ 6601 reference_type = TREE_TYPE (t->type); 6602 reference_type = build_reference_type (reference_type); 6603 6604 if (t->kind == ck_qual) 6605 t = t->u.next; 6606 if (t->kind == ck_ptr) 6607 t = t->u.next; 6608 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 6609 t = direct_reference_binding (reference_type, t); 6610 t->this_p = 1; 6611 t->rvaluedness_matches_p = 0; 6612 *ics = t; 6613 } 6614 } 6615 6616 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 6617 and return the initial reference binding conversion. Otherwise, 6618 leave *ICS unchanged and return NULL. */ 6619 6620 static conversion * 6621 maybe_handle_ref_bind (conversion **ics) 6622 { 6623 if ((*ics)->kind == ck_ref_bind) 6624 { 6625 conversion *old_ics = *ics; 6626 *ics = old_ics->u.next; 6627 (*ics)->user_conv_p = old_ics->user_conv_p; 6628 return old_ics; 6629 } 6630 6631 return NULL; 6632 } 6633 6634 /* Compare two implicit conversion sequences according to the rules set out in 6635 [over.ics.rank]. Return values: 6636 6637 1: ics1 is better than ics2 6638 -1: ics2 is better than ics1 6639 0: ics1 and ics2 are indistinguishable */ 6640 6641 static int 6642 compare_ics (conversion *ics1, conversion *ics2) 6643 { 6644 tree from_type1; 6645 tree from_type2; 6646 tree to_type1; 6647 tree to_type2; 6648 tree deref_from_type1 = NULL_TREE; 6649 tree deref_from_type2 = NULL_TREE; 6650 tree deref_to_type1 = NULL_TREE; 6651 tree deref_to_type2 = NULL_TREE; 6652 conversion_rank rank1, rank2; 6653 6654 /* REF_BINDING is nonzero if the result of the conversion sequence 6655 is a reference type. In that case REF_CONV is the reference 6656 binding conversion. */ 6657 conversion *ref_conv1; 6658 conversion *ref_conv2; 6659 6660 /* Handle implicit object parameters. */ 6661 maybe_handle_implicit_object (&ics1); 6662 maybe_handle_implicit_object (&ics2); 6663 6664 /* Handle reference parameters. */ 6665 ref_conv1 = maybe_handle_ref_bind (&ics1); 6666 ref_conv2 = maybe_handle_ref_bind (&ics2); 6667 6668 /* List-initialization sequence L1 is a better conversion sequence than 6669 list-initialization sequence L2 if L1 converts to 6670 std::initializer_list<X> for some X and L2 does not. */ 6671 if (ics1->kind == ck_list && ics2->kind != ck_list) 6672 return 1; 6673 if (ics2->kind == ck_list && ics1->kind != ck_list) 6674 return -1; 6675 6676 /* [over.ics.rank] 6677 6678 When comparing the basic forms of implicit conversion sequences (as 6679 defined in _over.best.ics_) 6680 6681 --a standard conversion sequence (_over.ics.scs_) is a better 6682 conversion sequence than a user-defined conversion sequence 6683 or an ellipsis conversion sequence, and 6684 6685 --a user-defined conversion sequence (_over.ics.user_) is a 6686 better conversion sequence than an ellipsis conversion sequence 6687 (_over.ics.ellipsis_). */ 6688 rank1 = CONVERSION_RANK (ics1); 6689 rank2 = CONVERSION_RANK (ics2); 6690 6691 if (rank1 > rank2) 6692 return -1; 6693 else if (rank1 < rank2) 6694 return 1; 6695 6696 if (rank1 == cr_bad) 6697 { 6698 /* XXX Isn't this an extension? */ 6699 /* Both ICS are bad. We try to make a decision based on what 6700 would have happened if they'd been good. */ 6701 if (ics1->user_conv_p > ics2->user_conv_p 6702 || ics1->rank > ics2->rank) 6703 return -1; 6704 else if (ics1->user_conv_p < ics2->user_conv_p 6705 || ics1->rank < ics2->rank) 6706 return 1; 6707 6708 /* We couldn't make up our minds; try to figure it out below. */ 6709 } 6710 6711 if (ics1->ellipsis_p || ics1->kind == ck_list) 6712 /* Both conversions are ellipsis conversions or both are building a 6713 std::initializer_list. */ 6714 return 0; 6715 6716 /* User-defined conversion sequence U1 is a better conversion sequence 6717 than another user-defined conversion sequence U2 if they contain the 6718 same user-defined conversion operator or constructor and if the sec- 6719 ond standard conversion sequence of U1 is better than the second 6720 standard conversion sequence of U2. */ 6721 6722 if (ics1->user_conv_p) 6723 { 6724 conversion *t1; 6725 conversion *t2; 6726 6727 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next) 6728 if (t1->kind == ck_ambig || t1->kind == ck_aggr) 6729 return 0; 6730 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next) 6731 if (t2->kind == ck_ambig || t2->kind == ck_aggr) 6732 return 0; 6733 6734 if (t1->cand->fn != t2->cand->fn) 6735 return 0; 6736 6737 /* We can just fall through here, after setting up 6738 FROM_TYPE1 and FROM_TYPE2. */ 6739 from_type1 = t1->type; 6740 from_type2 = t2->type; 6741 } 6742 else 6743 { 6744 conversion *t1; 6745 conversion *t2; 6746 6747 /* We're dealing with two standard conversion sequences. 6748 6749 [over.ics.rank] 6750 6751 Standard conversion sequence S1 is a better conversion 6752 sequence than standard conversion sequence S2 if 6753 6754 --S1 is a proper subsequence of S2 (comparing the conversion 6755 sequences in the canonical form defined by _over.ics.scs_, 6756 excluding any Lvalue Transformation; the identity 6757 conversion sequence is considered to be a subsequence of 6758 any non-identity conversion sequence */ 6759 6760 t1 = ics1; 6761 while (t1->kind != ck_identity) 6762 t1 = t1->u.next; 6763 from_type1 = t1->type; 6764 6765 t2 = ics2; 6766 while (t2->kind != ck_identity) 6767 t2 = t2->u.next; 6768 from_type2 = t2->type; 6769 } 6770 6771 /* One sequence can only be a subsequence of the other if they start with 6772 the same type. They can start with different types when comparing the 6773 second standard conversion sequence in two user-defined conversion 6774 sequences. */ 6775 if (same_type_p (from_type1, from_type2)) 6776 { 6777 if (is_subseq (ics1, ics2)) 6778 return 1; 6779 if (is_subseq (ics2, ics1)) 6780 return -1; 6781 } 6782 6783 /* [over.ics.rank] 6784 6785 Or, if not that, 6786 6787 --the rank of S1 is better than the rank of S2 (by the rules 6788 defined below): 6789 6790 Standard conversion sequences are ordered by their ranks: an Exact 6791 Match is a better conversion than a Promotion, which is a better 6792 conversion than a Conversion. 6793 6794 Two conversion sequences with the same rank are indistinguishable 6795 unless one of the following rules applies: 6796 6797 --A conversion that is not a conversion of a pointer, or pointer 6798 to member, to bool is better than another conversion that is such 6799 a conversion. 6800 6801 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 6802 so that we do not have to check it explicitly. */ 6803 if (ics1->rank < ics2->rank) 6804 return 1; 6805 else if (ics2->rank < ics1->rank) 6806 return -1; 6807 6808 to_type1 = ics1->type; 6809 to_type2 = ics2->type; 6810 6811 /* A conversion from scalar arithmetic type to complex is worse than a 6812 conversion between scalar arithmetic types. */ 6813 if (same_type_p (from_type1, from_type2) 6814 && ARITHMETIC_TYPE_P (from_type1) 6815 && ARITHMETIC_TYPE_P (to_type1) 6816 && ARITHMETIC_TYPE_P (to_type2) 6817 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 6818 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 6819 { 6820 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 6821 return -1; 6822 else 6823 return 1; 6824 } 6825 6826 if (TYPE_PTR_P (from_type1) 6827 && TYPE_PTR_P (from_type2) 6828 && TYPE_PTR_P (to_type1) 6829 && TYPE_PTR_P (to_type2)) 6830 { 6831 deref_from_type1 = TREE_TYPE (from_type1); 6832 deref_from_type2 = TREE_TYPE (from_type2); 6833 deref_to_type1 = TREE_TYPE (to_type1); 6834 deref_to_type2 = TREE_TYPE (to_type2); 6835 } 6836 /* The rules for pointers to members A::* are just like the rules 6837 for pointers A*, except opposite: if B is derived from A then 6838 A::* converts to B::*, not vice versa. For that reason, we 6839 switch the from_ and to_ variables here. */ 6840 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2) 6841 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2)) 6842 || (TYPE_PTRMEMFUNC_P (from_type1) 6843 && TYPE_PTRMEMFUNC_P (from_type2) 6844 && TYPE_PTRMEMFUNC_P (to_type1) 6845 && TYPE_PTRMEMFUNC_P (to_type2))) 6846 { 6847 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 6848 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 6849 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 6850 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 6851 } 6852 6853 if (deref_from_type1 != NULL_TREE 6854 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 6855 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 6856 { 6857 /* This was one of the pointer or pointer-like conversions. 6858 6859 [over.ics.rank] 6860 6861 --If class B is derived directly or indirectly from class A, 6862 conversion of B* to A* is better than conversion of B* to 6863 void*, and conversion of A* to void* is better than 6864 conversion of B* to void*. */ 6865 if (TREE_CODE (deref_to_type1) == VOID_TYPE 6866 && TREE_CODE (deref_to_type2) == VOID_TYPE) 6867 { 6868 if (is_properly_derived_from (deref_from_type1, 6869 deref_from_type2)) 6870 return -1; 6871 else if (is_properly_derived_from (deref_from_type2, 6872 deref_from_type1)) 6873 return 1; 6874 } 6875 else if (TREE_CODE (deref_to_type1) == VOID_TYPE 6876 || TREE_CODE (deref_to_type2) == VOID_TYPE) 6877 { 6878 if (same_type_p (deref_from_type1, deref_from_type2)) 6879 { 6880 if (TREE_CODE (deref_to_type2) == VOID_TYPE) 6881 { 6882 if (is_properly_derived_from (deref_from_type1, 6883 deref_to_type1)) 6884 return 1; 6885 } 6886 /* We know that DEREF_TO_TYPE1 is `void' here. */ 6887 else if (is_properly_derived_from (deref_from_type1, 6888 deref_to_type2)) 6889 return -1; 6890 } 6891 } 6892 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 6893 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 6894 { 6895 /* [over.ics.rank] 6896 6897 --If class B is derived directly or indirectly from class A 6898 and class C is derived directly or indirectly from B, 6899 6900 --conversion of C* to B* is better than conversion of C* to 6901 A*, 6902 6903 --conversion of B* to A* is better than conversion of C* to 6904 A* */ 6905 if (same_type_p (deref_from_type1, deref_from_type2)) 6906 { 6907 if (is_properly_derived_from (deref_to_type1, 6908 deref_to_type2)) 6909 return 1; 6910 else if (is_properly_derived_from (deref_to_type2, 6911 deref_to_type1)) 6912 return -1; 6913 } 6914 else if (same_type_p (deref_to_type1, deref_to_type2)) 6915 { 6916 if (is_properly_derived_from (deref_from_type2, 6917 deref_from_type1)) 6918 return 1; 6919 else if (is_properly_derived_from (deref_from_type1, 6920 deref_from_type2)) 6921 return -1; 6922 } 6923 } 6924 } 6925 else if (CLASS_TYPE_P (non_reference (from_type1)) 6926 && same_type_p (from_type1, from_type2)) 6927 { 6928 tree from = non_reference (from_type1); 6929 6930 /* [over.ics.rank] 6931 6932 --binding of an expression of type C to a reference of type 6933 B& is better than binding an expression of type C to a 6934 reference of type A& 6935 6936 --conversion of C to B is better than conversion of C to A, */ 6937 if (is_properly_derived_from (from, to_type1) 6938 && is_properly_derived_from (from, to_type2)) 6939 { 6940 if (is_properly_derived_from (to_type1, to_type2)) 6941 return 1; 6942 else if (is_properly_derived_from (to_type2, to_type1)) 6943 return -1; 6944 } 6945 } 6946 else if (CLASS_TYPE_P (non_reference (to_type1)) 6947 && same_type_p (to_type1, to_type2)) 6948 { 6949 tree to = non_reference (to_type1); 6950 6951 /* [over.ics.rank] 6952 6953 --binding of an expression of type B to a reference of type 6954 A& is better than binding an expression of type C to a 6955 reference of type A&, 6956 6957 --conversion of B to A is better than conversion of C to A */ 6958 if (is_properly_derived_from (from_type1, to) 6959 && is_properly_derived_from (from_type2, to)) 6960 { 6961 if (is_properly_derived_from (from_type2, from_type1)) 6962 return 1; 6963 else if (is_properly_derived_from (from_type1, from_type2)) 6964 return -1; 6965 } 6966 } 6967 6968 /* [over.ics.rank] 6969 6970 --S1 and S2 differ only in their qualification conversion and yield 6971 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 6972 qualification signature of type T1 is a proper subset of the cv- 6973 qualification signature of type T2 */ 6974 if (ics1->kind == ck_qual 6975 && ics2->kind == ck_qual 6976 && same_type_p (from_type1, from_type2)) 6977 { 6978 int result = comp_cv_qual_signature (to_type1, to_type2); 6979 if (result != 0) 6980 return result; 6981 } 6982 6983 /* [over.ics.rank] 6984 6985 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 6986 to an implicit object parameter, and either S1 binds an lvalue reference 6987 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue 6988 reference to an rvalue and S2 binds an lvalue reference 6989 (C++0x draft standard, 13.3.3.2) 6990 6991 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 6992 types to which the references refer are the same type except for 6993 top-level cv-qualifiers, and the type to which the reference 6994 initialized by S2 refers is more cv-qualified than the type to 6995 which the reference initialized by S1 refers */ 6996 6997 if (ref_conv1 && ref_conv2) 6998 { 6999 if (!ref_conv1->this_p && !ref_conv2->this_p 7000 && (TYPE_REF_IS_RVALUE (ref_conv1->type) 7001 != TYPE_REF_IS_RVALUE (ref_conv2->type))) 7002 { 7003 if (ref_conv1->rvaluedness_matches_p) 7004 return 1; 7005 if (ref_conv2->rvaluedness_matches_p) 7006 return -1; 7007 } 7008 7009 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 7010 return comp_cv_qualification (TREE_TYPE (ref_conv2->type), 7011 TREE_TYPE (ref_conv1->type)); 7012 } 7013 7014 /* Neither conversion sequence is better than the other. */ 7015 return 0; 7016 } 7017 7018 /* The source type for this standard conversion sequence. */ 7019 7020 static tree 7021 source_type (conversion *t) 7022 { 7023 for (;; t = t->u.next) 7024 { 7025 if (t->kind == ck_user 7026 || t->kind == ck_ambig 7027 || t->kind == ck_identity) 7028 return t->type; 7029 } 7030 gcc_unreachable (); 7031 } 7032 7033 /* Note a warning about preferring WINNER to LOSER. We do this by storing 7034 a pointer to LOSER and re-running joust to produce the warning if WINNER 7035 is actually used. */ 7036 7037 static void 7038 add_warning (struct z_candidate *winner, struct z_candidate *loser) 7039 { 7040 candidate_warning *cw = (candidate_warning *) 7041 conversion_obstack_alloc (sizeof (candidate_warning)); 7042 cw->loser = loser; 7043 cw->next = winner->warnings; 7044 winner->warnings = cw; 7045 } 7046 7047 /* Compare two candidates for overloading as described in 7048 [over.match.best]. Return values: 7049 7050 1: cand1 is better than cand2 7051 -1: cand2 is better than cand1 7052 0: cand1 and cand2 are indistinguishable */ 7053 7054 static int 7055 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn) 7056 { 7057 int winner = 0; 7058 int off1 = 0, off2 = 0; 7059 size_t i; 7060 size_t len; 7061 7062 /* Candidates that involve bad conversions are always worse than those 7063 that don't. */ 7064 if (cand1->viable > cand2->viable) 7065 return 1; 7066 if (cand1->viable < cand2->viable) 7067 return -1; 7068 7069 /* If we have two pseudo-candidates for conversions to the same type, 7070 or two candidates for the same function, arbitrarily pick one. */ 7071 if (cand1->fn == cand2->fn 7072 && (IS_TYPE_OR_DECL_P (cand1->fn))) 7073 return 1; 7074 7075 /* a viable function F1 7076 is defined to be a better function than another viable function F2 if 7077 for all arguments i, ICSi(F1) is not a worse conversion sequence than 7078 ICSi(F2), and then */ 7079 7080 /* for some argument j, ICSj(F1) is a better conversion sequence than 7081 ICSj(F2) */ 7082 7083 /* For comparing static and non-static member functions, we ignore 7084 the implicit object parameter of the non-static function. The 7085 standard says to pretend that the static function has an object 7086 parm, but that won't work with operator overloading. */ 7087 len = cand1->num_convs; 7088 if (len != cand2->num_convs) 7089 { 7090 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 7091 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 7092 7093 gcc_assert (static_1 != static_2); 7094 7095 if (static_1) 7096 off2 = 1; 7097 else 7098 { 7099 off1 = 1; 7100 --len; 7101 } 7102 } 7103 7104 for (i = 0; i < len; ++i) 7105 { 7106 conversion *t1 = cand1->convs[i + off1]; 7107 conversion *t2 = cand2->convs[i + off2]; 7108 int comp = compare_ics (t1, t2); 7109 7110 if (comp != 0) 7111 { 7112 if (warn_sign_promo 7113 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 7114 == cr_std + cr_promotion) 7115 && t1->kind == ck_std 7116 && t2->kind == ck_std 7117 && TREE_CODE (t1->type) == INTEGER_TYPE 7118 && TREE_CODE (t2->type) == INTEGER_TYPE 7119 && (TYPE_PRECISION (t1->type) 7120 == TYPE_PRECISION (t2->type)) 7121 && (TYPE_UNSIGNED (t1->u.next->type) 7122 || (TREE_CODE (t1->u.next->type) 7123 == ENUMERAL_TYPE))) 7124 { 7125 tree type = t1->u.next->type; 7126 tree type1, type2; 7127 struct z_candidate *w, *l; 7128 if (comp > 0) 7129 type1 = t1->type, type2 = t2->type, 7130 w = cand1, l = cand2; 7131 else 7132 type1 = t2->type, type2 = t1->type, 7133 w = cand2, l = cand1; 7134 7135 if (warn) 7136 { 7137 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 7138 type, type1, type2); 7139 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 7140 } 7141 else 7142 add_warning (w, l); 7143 } 7144 7145 if (winner && comp != winner) 7146 { 7147 winner = 0; 7148 goto tweak; 7149 } 7150 winner = comp; 7151 } 7152 } 7153 7154 /* warn about confusing overload resolution for user-defined conversions, 7155 either between a constructor and a conversion op, or between two 7156 conversion ops. */ 7157 if (winner && warn_conversion && cand1->second_conv 7158 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 7159 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 7160 { 7161 struct z_candidate *w, *l; 7162 bool give_warning = false; 7163 7164 if (winner == 1) 7165 w = cand1, l = cand2; 7166 else 7167 w = cand2, l = cand1; 7168 7169 /* We don't want to complain about `X::operator T1 ()' 7170 beating `X::operator T2 () const', when T2 is a no less 7171 cv-qualified version of T1. */ 7172 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 7173 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 7174 { 7175 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 7176 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 7177 7178 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 7179 { 7180 t = TREE_TYPE (t); 7181 f = TREE_TYPE (f); 7182 } 7183 if (!comp_ptr_ttypes (t, f)) 7184 give_warning = true; 7185 } 7186 else 7187 give_warning = true; 7188 7189 if (!give_warning) 7190 /*NOP*/; 7191 else if (warn) 7192 { 7193 tree source = source_type (w->convs[0]); 7194 if (! DECL_CONSTRUCTOR_P (w->fn)) 7195 source = TREE_TYPE (source); 7196 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 7197 && warning (OPT_Wconversion, " for conversion from %qT to %qT", 7198 source, w->second_conv->type)) 7199 { 7200 inform (input_location, " because conversion sequence for the argument is better"); 7201 } 7202 } 7203 else 7204 add_warning (w, l); 7205 } 7206 7207 if (winner) 7208 return winner; 7209 7210 /* or, if not that, 7211 F1 is a non-template function and F2 is a template function 7212 specialization. */ 7213 7214 if (!cand1->template_decl && cand2->template_decl) 7215 return 1; 7216 else if (cand1->template_decl && !cand2->template_decl) 7217 return -1; 7218 7219 /* or, if not that, 7220 F1 and F2 are template functions and the function template for F1 is 7221 more specialized than the template for F2 according to the partial 7222 ordering rules. */ 7223 7224 if (cand1->template_decl && cand2->template_decl) 7225 { 7226 winner = more_specialized_fn 7227 (TI_TEMPLATE (cand1->template_decl), 7228 TI_TEMPLATE (cand2->template_decl), 7229 /* [temp.func.order]: The presence of unused ellipsis and default 7230 arguments has no effect on the partial ordering of function 7231 templates. add_function_candidate() will not have 7232 counted the "this" argument for constructors. */ 7233 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 7234 if (winner) 7235 return winner; 7236 } 7237 7238 /* or, if not that, 7239 the context is an initialization by user-defined conversion (see 7240 _dcl.init_ and _over.match.user_) and the standard conversion 7241 sequence from the return type of F1 to the destination type (i.e., 7242 the type of the entity being initialized) is a better conversion 7243 sequence than the standard conversion sequence from the return type 7244 of F2 to the destination type. */ 7245 7246 if (cand1->second_conv) 7247 { 7248 winner = compare_ics (cand1->second_conv, cand2->second_conv); 7249 if (winner) 7250 return winner; 7251 } 7252 7253 /* Check whether we can discard a builtin candidate, either because we 7254 have two identical ones or matching builtin and non-builtin candidates. 7255 7256 (Pedantically in the latter case the builtin which matched the user 7257 function should not be added to the overload set, but we spot it here. 7258 7259 [over.match.oper] 7260 ... the builtin candidates include ... 7261 - do not have the same parameter type list as any non-template 7262 non-member candidate. */ 7263 7264 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE 7265 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE) 7266 { 7267 for (i = 0; i < len; ++i) 7268 if (!same_type_p (cand1->convs[i]->type, 7269 cand2->convs[i]->type)) 7270 break; 7271 if (i == cand1->num_convs) 7272 { 7273 if (cand1->fn == cand2->fn) 7274 /* Two built-in candidates; arbitrarily pick one. */ 7275 return 1; 7276 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE) 7277 /* cand1 is built-in; prefer cand2. */ 7278 return -1; 7279 else 7280 /* cand2 is built-in; prefer cand1. */ 7281 return 1; 7282 } 7283 } 7284 7285 /* If the two function declarations represent the same function (this can 7286 happen with declarations in multiple scopes and arg-dependent lookup), 7287 arbitrarily choose one. But first make sure the default args we're 7288 using match. */ 7289 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 7290 && equal_functions (cand1->fn, cand2->fn)) 7291 { 7292 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 7293 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 7294 7295 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 7296 7297 for (i = 0; i < len; ++i) 7298 { 7299 /* Don't crash if the fn is variadic. */ 7300 if (!parms1) 7301 break; 7302 parms1 = TREE_CHAIN (parms1); 7303 parms2 = TREE_CHAIN (parms2); 7304 } 7305 7306 if (off1) 7307 parms1 = TREE_CHAIN (parms1); 7308 else if (off2) 7309 parms2 = TREE_CHAIN (parms2); 7310 7311 for (; parms1; ++i) 7312 { 7313 if (!cp_tree_equal (TREE_PURPOSE (parms1), 7314 TREE_PURPOSE (parms2))) 7315 { 7316 if (warn) 7317 { 7318 permerror (input_location, "default argument mismatch in " 7319 "overload resolution"); 7320 inform (input_location, 7321 " candidate 1: %q+#F", cand1->fn); 7322 inform (input_location, 7323 " candidate 2: %q+#F", cand2->fn); 7324 } 7325 else 7326 add_warning (cand1, cand2); 7327 break; 7328 } 7329 parms1 = TREE_CHAIN (parms1); 7330 parms2 = TREE_CHAIN (parms2); 7331 } 7332 7333 return 1; 7334 } 7335 7336 tweak: 7337 7338 /* Extension: If the worst conversion for one candidate is worse than the 7339 worst conversion for the other, take the first. */ 7340 if (!pedantic) 7341 { 7342 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 7343 struct z_candidate *w = 0, *l = 0; 7344 7345 for (i = 0; i < len; ++i) 7346 { 7347 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 7348 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 7349 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 7350 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 7351 } 7352 if (rank1 < rank2) 7353 winner = 1, w = cand1, l = cand2; 7354 if (rank1 > rank2) 7355 winner = -1, w = cand2, l = cand1; 7356 if (winner) 7357 { 7358 if (warn) 7359 { 7360 pedwarn (input_location, 0, 7361 "ISO C++ says that these are ambiguous, even " 7362 "though the worst conversion for the first is better than " 7363 "the worst conversion for the second:"); 7364 print_z_candidate (_("candidate 1:"), w); 7365 print_z_candidate (_("candidate 2:"), l); 7366 } 7367 else 7368 add_warning (w, l); 7369 return winner; 7370 } 7371 } 7372 7373 gcc_assert (!winner); 7374 return 0; 7375 } 7376 7377 /* Given a list of candidates for overloading, find the best one, if any. 7378 This algorithm has a worst case of O(2n) (winner is last), and a best 7379 case of O(n/2) (totally ambiguous); much better than a sorting 7380 algorithm. */ 7381 7382 static struct z_candidate * 7383 tourney (struct z_candidate *candidates) 7384 { 7385 struct z_candidate *champ = candidates, *challenger; 7386 int fate; 7387 int champ_compared_to_predecessor = 0; 7388 7389 /* Walk through the list once, comparing each current champ to the next 7390 candidate, knocking out a candidate or two with each comparison. */ 7391 7392 for (challenger = champ->next; challenger; ) 7393 { 7394 fate = joust (champ, challenger, 0); 7395 if (fate == 1) 7396 challenger = challenger->next; 7397 else 7398 { 7399 if (fate == 0) 7400 { 7401 champ = challenger->next; 7402 if (champ == 0) 7403 return NULL; 7404 champ_compared_to_predecessor = 0; 7405 } 7406 else 7407 { 7408 champ = challenger; 7409 champ_compared_to_predecessor = 1; 7410 } 7411 7412 challenger = champ->next; 7413 } 7414 } 7415 7416 /* Make sure the champ is better than all the candidates it hasn't yet 7417 been compared to. */ 7418 7419 for (challenger = candidates; 7420 challenger != champ 7421 && !(champ_compared_to_predecessor && challenger->next == champ); 7422 challenger = challenger->next) 7423 { 7424 fate = joust (champ, challenger, 0); 7425 if (fate != 1) 7426 return NULL; 7427 } 7428 7429 return champ; 7430 } 7431 7432 /* Returns nonzero if things of type FROM can be converted to TO. */ 7433 7434 bool 7435 can_convert (tree to, tree from) 7436 { 7437 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT); 7438 } 7439 7440 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 7441 7442 bool 7443 can_convert_arg (tree to, tree from, tree arg, int flags) 7444 { 7445 conversion *t; 7446 void *p; 7447 bool ok_p; 7448 7449 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7450 p = conversion_obstack_alloc (0); 7451 7452 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 7453 flags); 7454 ok_p = (t && !t->bad_p); 7455 7456 /* Free all the conversions we allocated. */ 7457 obstack_free (&conversion_obstack, p); 7458 7459 return ok_p; 7460 } 7461 7462 /* Like can_convert_arg, but allows dubious conversions as well. */ 7463 7464 bool 7465 can_convert_arg_bad (tree to, tree from, tree arg, int flags) 7466 { 7467 conversion *t; 7468 void *p; 7469 7470 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7471 p = conversion_obstack_alloc (0); 7472 /* Try to perform the conversion. */ 7473 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 7474 flags); 7475 /* Free all the conversions we allocated. */ 7476 obstack_free (&conversion_obstack, p); 7477 7478 return t != NULL; 7479 } 7480 7481 /* Convert EXPR to TYPE. Return the converted expression. 7482 7483 Note that we allow bad conversions here because by the time we get to 7484 this point we are committed to doing the conversion. If we end up 7485 doing a bad conversion, convert_like will complain. */ 7486 7487 tree 7488 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags) 7489 { 7490 conversion *conv; 7491 void *p; 7492 7493 if (error_operand_p (expr)) 7494 return error_mark_node; 7495 7496 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7497 p = conversion_obstack_alloc (0); 7498 7499 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 7500 /*c_cast_p=*/false, 7501 flags); 7502 7503 if (!conv) 7504 { 7505 if (complain & tf_error) 7506 { 7507 /* If expr has unknown type, then it is an overloaded function. 7508 Call instantiate_type to get good error messages. */ 7509 if (TREE_TYPE (expr) == unknown_type_node) 7510 instantiate_type (type, expr, complain); 7511 else if (invalid_nonstatic_memfn_p (expr, complain)) 7512 /* We gave an error. */; 7513 else 7514 error ("could not convert %qE to %qT", expr, type); 7515 } 7516 expr = error_mark_node; 7517 } 7518 else if (processing_template_decl) 7519 { 7520 /* In a template, we are only concerned about determining the 7521 type of non-dependent expressions, so we do not have to 7522 perform the actual conversion. */ 7523 if (TREE_TYPE (expr) != type) 7524 expr = build_nop (type, expr); 7525 } 7526 else 7527 expr = convert_like (conv, expr, complain); 7528 7529 /* Free all the conversions we allocated. */ 7530 obstack_free (&conversion_obstack, p); 7531 7532 return expr; 7533 } 7534 7535 tree 7536 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 7537 { 7538 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT); 7539 } 7540 7541 /* Convert EXPR to TYPE (as a direct-initialization) if that is 7542 permitted. If the conversion is valid, the converted expression is 7543 returned. Otherwise, NULL_TREE is returned, except in the case 7544 that TYPE is a class type; in that case, an error is issued. If 7545 C_CAST_P is true, then this direction initialization is taking 7546 place as part of a static_cast being attempted as part of a C-style 7547 cast. */ 7548 7549 tree 7550 perform_direct_initialization_if_possible (tree type, 7551 tree expr, 7552 bool c_cast_p, 7553 tsubst_flags_t complain) 7554 { 7555 conversion *conv; 7556 void *p; 7557 7558 if (type == error_mark_node || error_operand_p (expr)) 7559 return error_mark_node; 7560 /* [dcl.init] 7561 7562 If the destination type is a (possibly cv-qualified) class type: 7563 7564 -- If the initialization is direct-initialization ..., 7565 constructors are considered. ... If no constructor applies, or 7566 the overload resolution is ambiguous, the initialization is 7567 ill-formed. */ 7568 if (CLASS_TYPE_P (type)) 7569 { 7570 VEC(tree,gc) *args = make_tree_vector_single (expr); 7571 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 7572 &args, type, LOOKUP_NORMAL, complain); 7573 release_tree_vector (args); 7574 return build_cplus_new (type, expr); 7575 } 7576 7577 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7578 p = conversion_obstack_alloc (0); 7579 7580 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 7581 c_cast_p, 7582 LOOKUP_NORMAL); 7583 if (!conv || conv->bad_p) 7584 expr = NULL_TREE; 7585 else 7586 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0, 7587 /*issue_conversion_warnings=*/false, 7588 c_cast_p, 7589 tf_warning_or_error); 7590 7591 /* Free all the conversions we allocated. */ 7592 obstack_free (&conversion_obstack, p); 7593 7594 return expr; 7595 } 7596 7597 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference 7598 is being bound to a temporary. Create and return a new VAR_DECL 7599 with the indicated TYPE; this variable will store the value to 7600 which the reference is bound. */ 7601 7602 tree 7603 make_temporary_var_for_ref_to_temp (tree decl, tree type) 7604 { 7605 tree var; 7606 7607 /* Create the variable. */ 7608 var = create_temporary_var (type); 7609 7610 /* Register the variable. */ 7611 if (TREE_STATIC (decl)) 7612 { 7613 /* Namespace-scope or local static; give it a mangled name. */ 7614 tree name; 7615 7616 TREE_STATIC (var) = 1; 7617 name = mangle_ref_init_variable (decl); 7618 DECL_NAME (var) = name; 7619 SET_DECL_ASSEMBLER_NAME (var, name); 7620 var = pushdecl_top_level (var); 7621 } 7622 else 7623 /* Create a new cleanup level if necessary. */ 7624 maybe_push_cleanup_level (type); 7625 7626 return var; 7627 } 7628 7629 /* EXPR is the initializer for a variable DECL of reference or 7630 std::initializer_list type. Create, push and return a new VAR_DECL 7631 for the initializer so that it will live as long as DECL. Any 7632 cleanup for the new variable is returned through CLEANUP, and the 7633 code to initialize the new variable is returned through INITP. */ 7634 7635 tree 7636 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp) 7637 { 7638 tree init; 7639 tree type; 7640 tree var; 7641 7642 /* Create the temporary variable. */ 7643 type = TREE_TYPE (expr); 7644 var = make_temporary_var_for_ref_to_temp (decl, type); 7645 layout_decl (var, 0); 7646 /* If the rvalue is the result of a function call it will be 7647 a TARGET_EXPR. If it is some other construct (such as a 7648 member access expression where the underlying object is 7649 itself the result of a function call), turn it into a 7650 TARGET_EXPR here. It is important that EXPR be a 7651 TARGET_EXPR below since otherwise the INIT_EXPR will 7652 attempt to make a bitwise copy of EXPR to initialize 7653 VAR. */ 7654 if (TREE_CODE (expr) != TARGET_EXPR) 7655 expr = get_target_expr (expr); 7656 /* Create the INIT_EXPR that will initialize the temporary 7657 variable. */ 7658 init = build2 (INIT_EXPR, type, var, expr); 7659 if (at_function_scope_p ()) 7660 { 7661 add_decl_expr (var); 7662 7663 if (TREE_STATIC (var)) 7664 init = add_stmt_to_compound (init, register_dtor_fn (var)); 7665 else 7666 *cleanup = cxx_maybe_build_cleanup (var); 7667 7668 /* We must be careful to destroy the temporary only 7669 after its initialization has taken place. If the 7670 initialization throws an exception, then the 7671 destructor should not be run. We cannot simply 7672 transform INIT into something like: 7673 7674 (INIT, ({ CLEANUP_STMT; })) 7675 7676 because emit_local_var always treats the 7677 initializer as a full-expression. Thus, the 7678 destructor would run too early; it would run at the 7679 end of initializing the reference variable, rather 7680 than at the end of the block enclosing the 7681 reference variable. 7682 7683 The solution is to pass back a cleanup expression 7684 which the caller is responsible for attaching to 7685 the statement tree. */ 7686 } 7687 else 7688 { 7689 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 7690 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 7691 static_aggregates = tree_cons (NULL_TREE, var, 7692 static_aggregates); 7693 } 7694 7695 *initp = init; 7696 return var; 7697 } 7698 7699 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 7700 initializing a variable of that TYPE. If DECL is non-NULL, it is 7701 the VAR_DECL being initialized with the EXPR. (In that case, the 7702 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must 7703 also be non-NULL, and with *CLEANUP initialized to NULL. Upon 7704 return, if *CLEANUP is no longer NULL, it will be an expression 7705 that should be pushed as a cleanup after the returned expression 7706 is used to initialize DECL. 7707 7708 Return the converted expression. */ 7709 7710 tree 7711 initialize_reference (tree type, tree expr, tree decl, tree *cleanup, 7712 tsubst_flags_t complain) 7713 { 7714 conversion *conv; 7715 void *p; 7716 7717 if (type == error_mark_node || error_operand_p (expr)) 7718 return error_mark_node; 7719 7720 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7721 p = conversion_obstack_alloc (0); 7722 7723 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 7724 LOOKUP_NORMAL); 7725 if (!conv || conv->bad_p) 7726 { 7727 if (complain & tf_error) 7728 { 7729 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST) 7730 && !TYPE_REF_IS_RVALUE (type) 7731 && !real_lvalue_p (expr)) 7732 error ("invalid initialization of non-const reference of " 7733 "type %qT from an rvalue of type %qT", 7734 type, TREE_TYPE (expr)); 7735 else 7736 error ("invalid initialization of reference of type " 7737 "%qT from expression of type %qT", type, 7738 TREE_TYPE (expr)); 7739 } 7740 return error_mark_node; 7741 } 7742 7743 /* If DECL is non-NULL, then this special rule applies: 7744 7745 [class.temporary] 7746 7747 The temporary to which the reference is bound or the temporary 7748 that is the complete object to which the reference is bound 7749 persists for the lifetime of the reference. 7750 7751 The temporaries created during the evaluation of the expression 7752 initializing the reference, except the temporary to which the 7753 reference is bound, are destroyed at the end of the 7754 full-expression in which they are created. 7755 7756 In that case, we store the converted expression into a new 7757 VAR_DECL in a new scope. 7758 7759 However, we want to be careful not to create temporaries when 7760 they are not required. For example, given: 7761 7762 struct B {}; 7763 struct D : public B {}; 7764 D f(); 7765 const B& b = f(); 7766 7767 there is no need to copy the return value from "f"; we can just 7768 extend its lifetime. Similarly, given: 7769 7770 struct S {}; 7771 struct T { operator S(); }; 7772 T t; 7773 const S& s = t; 7774 7775 we can extend the lifetime of the return value of the conversion 7776 operator. */ 7777 gcc_assert (conv->kind == ck_ref_bind); 7778 if (decl) 7779 { 7780 tree var; 7781 tree base_conv_type; 7782 7783 /* Skip over the REF_BIND. */ 7784 conv = conv->u.next; 7785 /* If the next conversion is a BASE_CONV, skip that too -- but 7786 remember that the conversion was required. */ 7787 if (conv->kind == ck_base) 7788 { 7789 base_conv_type = conv->type; 7790 conv = conv->u.next; 7791 } 7792 else 7793 base_conv_type = NULL_TREE; 7794 /* Perform the remainder of the conversion. */ 7795 expr = convert_like_real (conv, expr, 7796 /*fn=*/NULL_TREE, /*argnum=*/0, 7797 /*inner=*/-1, 7798 /*issue_conversion_warnings=*/true, 7799 /*c_cast_p=*/false, 7800 tf_warning_or_error); 7801 if (error_operand_p (expr)) 7802 expr = error_mark_node; 7803 else 7804 { 7805 if (!lvalue_or_rvalue_with_address_p (expr)) 7806 { 7807 tree init; 7808 var = set_up_extended_ref_temp (decl, expr, cleanup, &init); 7809 /* Use its address to initialize the reference variable. */ 7810 expr = build_address (var); 7811 if (base_conv_type) 7812 expr = convert_to_base (expr, 7813 build_pointer_type (base_conv_type), 7814 /*check_access=*/true, 7815 /*nonnull=*/true); 7816 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr); 7817 } 7818 else 7819 /* Take the address of EXPR. */ 7820 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error); 7821 /* If a BASE_CONV was required, perform it now. */ 7822 if (base_conv_type) 7823 expr = (perform_implicit_conversion 7824 (build_pointer_type (base_conv_type), expr, 7825 tf_warning_or_error)); 7826 expr = build_nop (type, expr); 7827 } 7828 } 7829 else 7830 /* Perform the conversion. */ 7831 expr = convert_like (conv, expr, tf_warning_or_error); 7832 7833 /* Free all the conversions we allocated. */ 7834 obstack_free (&conversion_obstack, p); 7835 7836 return expr; 7837 } 7838 7839 /* Returns true iff TYPE is some variant of std::initializer_list. */ 7840 7841 bool 7842 is_std_init_list (tree type) 7843 { 7844 /* Look through typedefs. */ 7845 if (!TYPE_P (type)) 7846 return false; 7847 type = TYPE_MAIN_VARIANT (type); 7848 return (CLASS_TYPE_P (type) 7849 && CP_TYPE_CONTEXT (type) == std_node 7850 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0); 7851 } 7852 7853 /* Returns true iff DECL is a list constructor: i.e. a constructor which 7854 will accept an argument list of a single std::initializer_list<T>. */ 7855 7856 bool 7857 is_list_ctor (tree decl) 7858 { 7859 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 7860 tree arg; 7861 7862 if (!args || args == void_list_node) 7863 return false; 7864 7865 arg = non_reference (TREE_VALUE (args)); 7866 if (!is_std_init_list (arg)) 7867 return false; 7868 7869 args = TREE_CHAIN (args); 7870 7871 if (args && args != void_list_node && !TREE_PURPOSE (args)) 7872 /* There are more non-defaulted parms. */ 7873 return false; 7874 7875 return true; 7876 } 7877 7878 #include "gt-cp-call.h" 7879