1 /* Functions related to invoking methods and overloaded functions. 2 Copyright (C) 1987-2015 Free Software Foundation, Inc. 3 Contributed by Michael Tiemann (tiemann@cygnus.com) and 4 modified by Brendan Kehoe (brendan@cygnus.com). 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3, or (at your option) 11 any later version. 12 13 GCC is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 23 /* High-level class interface. */ 24 25 #include "config.h" 26 #include "system.h" 27 #include "coretypes.h" 28 #include "tm.h" 29 #include "hash-set.h" 30 #include "machmode.h" 31 #include "vec.h" 32 #include "double-int.h" 33 #include "input.h" 34 #include "alias.h" 35 #include "symtab.h" 36 #include "wide-int.h" 37 #include "inchash.h" 38 #include "tree.h" 39 #include "stor-layout.h" 40 #include "trans-mem.h" 41 #include "stringpool.h" 42 #include "cp-tree.h" 43 #include "flags.h" 44 #include "toplev.h" 45 #include "diagnostic-core.h" 46 #include "intl.h" 47 #include "target.h" 48 #include "convert.h" 49 #include "langhooks.h" 50 #include "c-family/c-objc.h" 51 #include "timevar.h" 52 #include "hash-map.h" 53 #include "is-a.h" 54 #include "plugin-api.h" 55 #include "hard-reg-set.h" 56 #include "input.h" 57 #include "function.h" 58 #include "ipa-ref.h" 59 #include "cgraph.h" 60 #include "wide-int.h" 61 #include "internal-fn.h" 62 63 /* The various kinds of conversion. */ 64 65 typedef enum conversion_kind { 66 ck_identity, 67 ck_lvalue, 68 ck_qual, 69 ck_std, 70 ck_ptr, 71 ck_pmem, 72 ck_base, 73 ck_ref_bind, 74 ck_user, 75 ck_ambig, 76 ck_list, 77 ck_aggr, 78 ck_rvalue 79 } conversion_kind; 80 81 /* The rank of the conversion. Order of the enumerals matters; better 82 conversions should come earlier in the list. */ 83 84 typedef enum conversion_rank { 85 cr_identity, 86 cr_exact, 87 cr_promotion, 88 cr_std, 89 cr_pbool, 90 cr_user, 91 cr_ellipsis, 92 cr_bad 93 } conversion_rank; 94 95 /* An implicit conversion sequence, in the sense of [over.best.ics]. 96 The first conversion to be performed is at the end of the chain. 97 That conversion is always a cr_identity conversion. */ 98 99 typedef struct conversion conversion; 100 struct conversion { 101 /* The kind of conversion represented by this step. */ 102 conversion_kind kind; 103 /* The rank of this conversion. */ 104 conversion_rank rank; 105 BOOL_BITFIELD user_conv_p : 1; 106 BOOL_BITFIELD ellipsis_p : 1; 107 BOOL_BITFIELD this_p : 1; 108 /* True if this conversion would be permitted with a bending of 109 language standards, e.g. disregarding pointer qualifiers or 110 converting integers to pointers. */ 111 BOOL_BITFIELD bad_p : 1; 112 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a 113 temporary should be created to hold the result of the 114 conversion. */ 115 BOOL_BITFIELD need_temporary_p : 1; 116 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 117 from a pointer-to-derived to pointer-to-base is being performed. */ 118 BOOL_BITFIELD base_p : 1; 119 /* If KIND is ck_ref_bind, true when either an lvalue reference is 120 being bound to an lvalue expression or an rvalue reference is 121 being bound to an rvalue expression. If KIND is ck_rvalue, 122 true when we should treat an lvalue as an rvalue (12.8p33). If 123 KIND is ck_base, always false. */ 124 BOOL_BITFIELD rvaluedness_matches_p: 1; 125 BOOL_BITFIELD check_narrowing: 1; 126 /* The type of the expression resulting from the conversion. */ 127 tree type; 128 union { 129 /* The next conversion in the chain. Since the conversions are 130 arranged from outermost to innermost, the NEXT conversion will 131 actually be performed before this conversion. This variant is 132 used only when KIND is neither ck_identity, ck_ambig nor 133 ck_list. Please use the next_conversion function instead 134 of using this field directly. */ 135 conversion *next; 136 /* The expression at the beginning of the conversion chain. This 137 variant is used only if KIND is ck_identity or ck_ambig. */ 138 tree expr; 139 /* The array of conversions for an initializer_list, so this 140 variant is used only when KIN D is ck_list. */ 141 conversion **list; 142 } u; 143 /* The function candidate corresponding to this conversion 144 sequence. This field is only used if KIND is ck_user. */ 145 struct z_candidate *cand; 146 }; 147 148 #define CONVERSION_RANK(NODE) \ 149 ((NODE)->bad_p ? cr_bad \ 150 : (NODE)->ellipsis_p ? cr_ellipsis \ 151 : (NODE)->user_conv_p ? cr_user \ 152 : (NODE)->rank) 153 154 #define BAD_CONVERSION_RANK(NODE) \ 155 ((NODE)->ellipsis_p ? cr_ellipsis \ 156 : (NODE)->user_conv_p ? cr_user \ 157 : (NODE)->rank) 158 159 static struct obstack conversion_obstack; 160 static bool conversion_obstack_initialized; 161 struct rejection_reason; 162 163 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t); 164 static int equal_functions (tree, tree); 165 static int joust (struct z_candidate *, struct z_candidate *, bool, 166 tsubst_flags_t); 167 static int compare_ics (conversion *, conversion *); 168 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 169 static tree build_java_interface_fn_ref (tree, tree); 170 #define convert_like(CONV, EXPR, COMPLAIN) \ 171 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \ 172 /*issue_conversion_warnings=*/true, \ 173 /*c_cast_p=*/false, (COMPLAIN)) 174 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 175 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \ 176 /*issue_conversion_warnings=*/true, \ 177 /*c_cast_p=*/false, (COMPLAIN)) 178 static tree convert_like_real (conversion *, tree, tree, int, int, bool, 179 bool, tsubst_flags_t); 180 static void op_error (location_t, enum tree_code, enum tree_code, tree, 181 tree, tree, bool); 182 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int, 183 tsubst_flags_t); 184 static void print_z_candidate (location_t, const char *, struct z_candidate *); 185 static void print_z_candidates (location_t, struct z_candidate *); 186 static tree build_this (tree); 187 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 188 static bool any_strictly_viable (struct z_candidate *); 189 static struct z_candidate *add_template_candidate 190 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 191 tree, tree, tree, int, unification_kind_t, tsubst_flags_t); 192 static struct z_candidate *add_template_candidate_real 193 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 194 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t); 195 static struct z_candidate *add_template_conv_candidate 196 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, 197 tree, tree, tree, tsubst_flags_t); 198 static void add_builtin_candidates 199 (struct z_candidate **, enum tree_code, enum tree_code, 200 tree, tree *, int, tsubst_flags_t); 201 static void add_builtin_candidate 202 (struct z_candidate **, enum tree_code, enum tree_code, 203 tree, tree, tree, tree *, tree *, int, tsubst_flags_t); 204 static bool is_complete (tree); 205 static void build_builtin_candidate 206 (struct z_candidate **, tree, tree, tree, tree *, tree *, 207 int, tsubst_flags_t); 208 static struct z_candidate *add_conv_candidate 209 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree, 210 tree, tsubst_flags_t); 211 static struct z_candidate *add_function_candidate 212 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree, 213 tree, int, tsubst_flags_t); 214 static conversion *implicit_conversion (tree, tree, tree, bool, int, 215 tsubst_flags_t); 216 static conversion *reference_binding (tree, tree, tree, bool, int, 217 tsubst_flags_t); 218 static conversion *build_conv (conversion_kind, tree, conversion *); 219 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t); 220 static conversion *next_conversion (conversion *); 221 static bool is_subseq (conversion *, conversion *); 222 static conversion *maybe_handle_ref_bind (conversion **); 223 static void maybe_handle_implicit_object (conversion **); 224 static struct z_candidate *add_candidate 225 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t, 226 conversion **, tree, tree, int, struct rejection_reason *, int); 227 static tree source_type (conversion *); 228 static void add_warning (struct z_candidate *, struct z_candidate *); 229 static bool reference_compatible_p (tree, tree); 230 static conversion *direct_reference_binding (tree, conversion *); 231 static bool promoted_arithmetic_type_p (tree); 232 static conversion *conditional_conversion (tree, tree, tsubst_flags_t); 233 static char *name_as_c_string (tree, tree, bool *); 234 static tree prep_operand (tree); 235 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree, 236 bool, tree, tree, int, struct z_candidate **, 237 tsubst_flags_t); 238 static conversion *merge_conversion_sequences (conversion *, conversion *); 239 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t); 240 241 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 242 NAME can take many forms... */ 243 244 bool 245 check_dtor_name (tree basetype, tree name) 246 { 247 /* Just accept something we've already complained about. */ 248 if (name == error_mark_node) 249 return true; 250 251 if (TREE_CODE (name) == TYPE_DECL) 252 name = TREE_TYPE (name); 253 else if (TYPE_P (name)) 254 /* OK */; 255 else if (identifier_p (name)) 256 { 257 if ((MAYBE_CLASS_TYPE_P (basetype) 258 && name == constructor_name (basetype)) 259 || (TREE_CODE (basetype) == ENUMERAL_TYPE 260 && name == TYPE_IDENTIFIER (basetype))) 261 return true; 262 else 263 name = get_type_value (name); 264 } 265 else 266 { 267 /* In the case of: 268 269 template <class T> struct S { ~S(); }; 270 int i; 271 i.~S(); 272 273 NAME will be a class template. */ 274 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 275 return false; 276 } 277 278 if (!name || name == error_mark_node) 279 return false; 280 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 281 } 282 283 /* We want the address of a function or method. We avoid creating a 284 pointer-to-member function. */ 285 286 tree 287 build_addr_func (tree function, tsubst_flags_t complain) 288 { 289 tree type = TREE_TYPE (function); 290 291 /* We have to do these by hand to avoid real pointer to member 292 functions. */ 293 if (TREE_CODE (type) == METHOD_TYPE) 294 { 295 if (TREE_CODE (function) == OFFSET_REF) 296 { 297 tree object = build_address (TREE_OPERAND (function, 0)); 298 return get_member_function_from_ptrfunc (&object, 299 TREE_OPERAND (function, 1), 300 complain); 301 } 302 function = build_address (function); 303 } 304 else 305 function = decay_conversion (function, complain); 306 307 return function; 308 } 309 310 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 311 POINTER_TYPE to those. Note, pointer to member function types 312 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 313 two variants. build_call_a is the primitive taking an array of 314 arguments, while build_call_n is a wrapper that handles varargs. */ 315 316 tree 317 build_call_n (tree function, int n, ...) 318 { 319 if (n == 0) 320 return build_call_a (function, 0, NULL); 321 else 322 { 323 tree *argarray = XALLOCAVEC (tree, n); 324 va_list ap; 325 int i; 326 327 va_start (ap, n); 328 for (i = 0; i < n; i++) 329 argarray[i] = va_arg (ap, tree); 330 va_end (ap); 331 return build_call_a (function, n, argarray); 332 } 333 } 334 335 /* Update various flags in cfun and the call itself based on what is being 336 called. Split out of build_call_a so that bot_manip can use it too. */ 337 338 void 339 set_flags_from_callee (tree call) 340 { 341 bool nothrow; 342 tree decl = get_callee_fndecl (call); 343 344 /* We check both the decl and the type; a function may be known not to 345 throw without being declared throw(). */ 346 nothrow = decl && TREE_NOTHROW (decl); 347 if (CALL_EXPR_FN (call)) 348 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call)))); 349 else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW) 350 nothrow = true; 351 352 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain) 353 cp_function_chain->can_throw = 1; 354 355 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 356 current_function_returns_abnormally = 1; 357 358 TREE_NOTHROW (call) = nothrow; 359 } 360 361 tree 362 build_call_a (tree function, int n, tree *argarray) 363 { 364 tree decl; 365 tree result_type; 366 tree fntype; 367 int i; 368 369 function = build_addr_func (function, tf_warning_or_error); 370 371 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 372 fntype = TREE_TYPE (TREE_TYPE (function)); 373 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 374 || TREE_CODE (fntype) == METHOD_TYPE); 375 result_type = TREE_TYPE (fntype); 376 /* An rvalue has no cv-qualifiers. */ 377 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 378 result_type = cv_unqualified (result_type); 379 380 function = build_call_array_loc (input_location, 381 result_type, function, n, argarray); 382 set_flags_from_callee (function); 383 384 decl = get_callee_fndecl (function); 385 386 if (decl && !TREE_USED (decl)) 387 { 388 /* We invoke build_call directly for several library 389 functions. These may have been declared normally if 390 we're building libgcc, so we can't just check 391 DECL_ARTIFICIAL. */ 392 gcc_assert (DECL_ARTIFICIAL (decl) 393 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 394 "__", 2)); 395 mark_used (decl); 396 } 397 398 require_complete_eh_spec_types (fntype, decl); 399 400 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl)); 401 402 /* Don't pass empty class objects by value. This is useful 403 for tags in STL, which are used to control overload resolution. 404 We don't need to handle other cases of copying empty classes. */ 405 if (! decl || ! DECL_BUILT_IN (decl)) 406 for (i = 0; i < n; i++) 407 { 408 tree arg = CALL_EXPR_ARG (function, i); 409 if (is_empty_class (TREE_TYPE (arg)) 410 && ! TREE_ADDRESSABLE (TREE_TYPE (arg))) 411 { 412 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg)); 413 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t); 414 CALL_EXPR_ARG (function, i) = arg; 415 } 416 } 417 418 return function; 419 } 420 421 /* Build something of the form ptr->method (args) 422 or object.method (args). This can also build 423 calls to constructors, and find friends. 424 425 Member functions always take their class variable 426 as a pointer. 427 428 INSTANCE is a class instance. 429 430 NAME is the name of the method desired, usually an IDENTIFIER_NODE. 431 432 PARMS help to figure out what that NAME really refers to. 433 434 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE 435 down to the real instance type to use for access checking. We need this 436 information to get protected accesses correct. 437 438 FLAGS is the logical disjunction of zero or more LOOKUP_ 439 flags. See cp-tree.h for more info. 440 441 If this is all OK, calls build_function_call with the resolved 442 member function. 443 444 This function must also handle being called to perform 445 initialization, promotion/coercion of arguments, and 446 instantiation of default parameters. 447 448 Note that NAME may refer to an instance variable name. If 449 `operator()()' is defined for the type of that field, then we return 450 that result. */ 451 452 /* New overloading code. */ 453 454 typedef struct z_candidate z_candidate; 455 456 typedef struct candidate_warning candidate_warning; 457 struct candidate_warning { 458 z_candidate *loser; 459 candidate_warning *next; 460 }; 461 462 /* Information for providing diagnostics about why overloading failed. */ 463 464 enum rejection_reason_code { 465 rr_none, 466 rr_arity, 467 rr_explicit_conversion, 468 rr_template_conversion, 469 rr_arg_conversion, 470 rr_bad_arg_conversion, 471 rr_template_unification, 472 rr_invalid_copy 473 }; 474 475 struct conversion_info { 476 /* The index of the argument, 0-based. */ 477 int n_arg; 478 /* The actual argument or its type. */ 479 tree from; 480 /* The type of the parameter. */ 481 tree to_type; 482 }; 483 484 struct rejection_reason { 485 enum rejection_reason_code code; 486 union { 487 /* Information about an arity mismatch. */ 488 struct { 489 /* The expected number of arguments. */ 490 int expected; 491 /* The actual number of arguments in the call. */ 492 int actual; 493 /* Whether the call was a varargs call. */ 494 bool call_varargs_p; 495 } arity; 496 /* Information about an argument conversion mismatch. */ 497 struct conversion_info conversion; 498 /* Same, but for bad argument conversions. */ 499 struct conversion_info bad_conversion; 500 /* Information about template unification failures. These are the 501 parameters passed to fn_type_unification. */ 502 struct { 503 tree tmpl; 504 tree explicit_targs; 505 int num_targs; 506 const tree *args; 507 unsigned int nargs; 508 tree return_type; 509 unification_kind_t strict; 510 int flags; 511 } template_unification; 512 /* Information about template instantiation failures. These are the 513 parameters passed to instantiate_template. */ 514 struct { 515 tree tmpl; 516 tree targs; 517 } template_instantiation; 518 } u; 519 }; 520 521 struct z_candidate { 522 /* The FUNCTION_DECL that will be called if this candidate is 523 selected by overload resolution. */ 524 tree fn; 525 /* If not NULL_TREE, the first argument to use when calling this 526 function. */ 527 tree first_arg; 528 /* The rest of the arguments to use when calling this function. If 529 there are no further arguments this may be NULL or it may be an 530 empty vector. */ 531 const vec<tree, va_gc> *args; 532 /* The implicit conversion sequences for each of the arguments to 533 FN. */ 534 conversion **convs; 535 /* The number of implicit conversion sequences. */ 536 size_t num_convs; 537 /* If FN is a user-defined conversion, the standard conversion 538 sequence from the type returned by FN to the desired destination 539 type. */ 540 conversion *second_conv; 541 struct rejection_reason *reason; 542 /* If FN is a member function, the binfo indicating the path used to 543 qualify the name of FN at the call site. This path is used to 544 determine whether or not FN is accessible if it is selected by 545 overload resolution. The DECL_CONTEXT of FN will always be a 546 (possibly improper) base of this binfo. */ 547 tree access_path; 548 /* If FN is a non-static member function, the binfo indicating the 549 subobject to which the `this' pointer should be converted if FN 550 is selected by overload resolution. The type pointed to by 551 the `this' pointer must correspond to the most derived class 552 indicated by the CONVERSION_PATH. */ 553 tree conversion_path; 554 tree template_decl; 555 tree explicit_targs; 556 candidate_warning *warnings; 557 z_candidate *next; 558 int viable; 559 560 /* The flags active in add_candidate. */ 561 int flags; 562 }; 563 564 /* Returns true iff T is a null pointer constant in the sense of 565 [conv.ptr]. */ 566 567 bool 568 null_ptr_cst_p (tree t) 569 { 570 /* [conv.ptr] 571 572 A null pointer constant is an integral constant expression 573 (_expr.const_) rvalue of integer type that evaluates to zero or 574 an rvalue of type std::nullptr_t. */ 575 if (NULLPTR_TYPE_P (TREE_TYPE (t))) 576 return true; 577 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t))) 578 { 579 /* Core issue 903 says only literal 0 is a null pointer constant. */ 580 if (cxx_dialect < cxx11) 581 t = fold_non_dependent_expr (t); 582 STRIP_NOPS (t); 583 if (integer_zerop (t) && !TREE_OVERFLOW (t)) 584 return true; 585 } 586 return false; 587 } 588 589 /* Returns true iff T is a null member pointer value (4.11). */ 590 591 bool 592 null_member_pointer_value_p (tree t) 593 { 594 tree type = TREE_TYPE (t); 595 if (!type) 596 return false; 597 else if (TYPE_PTRMEMFUNC_P (type)) 598 return (TREE_CODE (t) == CONSTRUCTOR 599 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value)); 600 else if (TYPE_PTRDATAMEM_P (type)) 601 return integer_all_onesp (t); 602 else 603 return false; 604 } 605 606 /* Returns nonzero if PARMLIST consists of only default parms, 607 ellipsis, and/or undeduced parameter packs. */ 608 609 bool 610 sufficient_parms_p (const_tree parmlist) 611 { 612 for (; parmlist && parmlist != void_list_node; 613 parmlist = TREE_CHAIN (parmlist)) 614 if (!TREE_PURPOSE (parmlist) 615 && !PACK_EXPANSION_P (TREE_VALUE (parmlist))) 616 return false; 617 return true; 618 } 619 620 /* Allocate N bytes of memory from the conversion obstack. The memory 621 is zeroed before being returned. */ 622 623 static void * 624 conversion_obstack_alloc (size_t n) 625 { 626 void *p; 627 if (!conversion_obstack_initialized) 628 { 629 gcc_obstack_init (&conversion_obstack); 630 conversion_obstack_initialized = true; 631 } 632 p = obstack_alloc (&conversion_obstack, n); 633 memset (p, 0, n); 634 return p; 635 } 636 637 /* Allocate rejection reasons. */ 638 639 static struct rejection_reason * 640 alloc_rejection (enum rejection_reason_code code) 641 { 642 struct rejection_reason *p; 643 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p); 644 p->code = code; 645 return p; 646 } 647 648 static struct rejection_reason * 649 arity_rejection (tree first_arg, int expected, int actual) 650 { 651 struct rejection_reason *r = alloc_rejection (rr_arity); 652 int adjust = first_arg != NULL_TREE; 653 r->u.arity.expected = expected - adjust; 654 r->u.arity.actual = actual - adjust; 655 return r; 656 } 657 658 static struct rejection_reason * 659 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 660 { 661 struct rejection_reason *r = alloc_rejection (rr_arg_conversion); 662 int adjust = first_arg != NULL_TREE; 663 r->u.conversion.n_arg = n_arg - adjust; 664 r->u.conversion.from = from; 665 r->u.conversion.to_type = to; 666 return r; 667 } 668 669 static struct rejection_reason * 670 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 671 { 672 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion); 673 int adjust = first_arg != NULL_TREE; 674 r->u.bad_conversion.n_arg = n_arg - adjust; 675 r->u.bad_conversion.from = from; 676 r->u.bad_conversion.to_type = to; 677 return r; 678 } 679 680 static struct rejection_reason * 681 explicit_conversion_rejection (tree from, tree to) 682 { 683 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion); 684 r->u.conversion.n_arg = 0; 685 r->u.conversion.from = from; 686 r->u.conversion.to_type = to; 687 return r; 688 } 689 690 static struct rejection_reason * 691 template_conversion_rejection (tree from, tree to) 692 { 693 struct rejection_reason *r = alloc_rejection (rr_template_conversion); 694 r->u.conversion.n_arg = 0; 695 r->u.conversion.from = from; 696 r->u.conversion.to_type = to; 697 return r; 698 } 699 700 static struct rejection_reason * 701 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs, 702 const tree *args, unsigned int nargs, 703 tree return_type, unification_kind_t strict, 704 int flags) 705 { 706 size_t args_n_bytes = sizeof (*args) * nargs; 707 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes); 708 struct rejection_reason *r = alloc_rejection (rr_template_unification); 709 r->u.template_unification.tmpl = tmpl; 710 r->u.template_unification.explicit_targs = explicit_targs; 711 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs); 712 /* Copy args to our own storage. */ 713 memcpy (args1, args, args_n_bytes); 714 r->u.template_unification.args = args1; 715 r->u.template_unification.nargs = nargs; 716 r->u.template_unification.return_type = return_type; 717 r->u.template_unification.strict = strict; 718 r->u.template_unification.flags = flags; 719 return r; 720 } 721 722 static struct rejection_reason * 723 template_unification_error_rejection (void) 724 { 725 return alloc_rejection (rr_template_unification); 726 } 727 728 static struct rejection_reason * 729 invalid_copy_with_fn_template_rejection (void) 730 { 731 struct rejection_reason *r = alloc_rejection (rr_invalid_copy); 732 return r; 733 } 734 735 /* Dynamically allocate a conversion. */ 736 737 static conversion * 738 alloc_conversion (conversion_kind kind) 739 { 740 conversion *c; 741 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 742 c->kind = kind; 743 return c; 744 } 745 746 #ifdef ENABLE_CHECKING 747 748 /* Make sure that all memory on the conversion obstack has been 749 freed. */ 750 751 void 752 validate_conversion_obstack (void) 753 { 754 if (conversion_obstack_initialized) 755 gcc_assert ((obstack_next_free (&conversion_obstack) 756 == obstack_base (&conversion_obstack))); 757 } 758 759 #endif /* ENABLE_CHECKING */ 760 761 /* Dynamically allocate an array of N conversions. */ 762 763 static conversion ** 764 alloc_conversions (size_t n) 765 { 766 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 767 } 768 769 static conversion * 770 build_conv (conversion_kind code, tree type, conversion *from) 771 { 772 conversion *t; 773 conversion_rank rank = CONVERSION_RANK (from); 774 775 /* Note that the caller is responsible for filling in t->cand for 776 user-defined conversions. */ 777 t = alloc_conversion (code); 778 t->type = type; 779 t->u.next = from; 780 781 switch (code) 782 { 783 case ck_ptr: 784 case ck_pmem: 785 case ck_base: 786 case ck_std: 787 if (rank < cr_std) 788 rank = cr_std; 789 break; 790 791 case ck_qual: 792 if (rank < cr_exact) 793 rank = cr_exact; 794 break; 795 796 default: 797 break; 798 } 799 t->rank = rank; 800 t->user_conv_p = (code == ck_user || from->user_conv_p); 801 t->bad_p = from->bad_p; 802 t->base_p = false; 803 return t; 804 } 805 806 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 807 specialization of std::initializer_list<T>, if such a conversion is 808 possible. */ 809 810 static conversion * 811 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 812 { 813 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 814 unsigned len = CONSTRUCTOR_NELTS (ctor); 815 conversion **subconvs = alloc_conversions (len); 816 conversion *t; 817 unsigned i; 818 tree val; 819 820 /* Within a list-initialization we can have more user-defined 821 conversions. */ 822 flags &= ~LOOKUP_NO_CONVERSION; 823 /* But no narrowing conversions. */ 824 flags |= LOOKUP_NO_NARROWING; 825 826 /* Can't make an array of these types. */ 827 if (TREE_CODE (elttype) == REFERENCE_TYPE 828 || TREE_CODE (elttype) == FUNCTION_TYPE 829 || VOID_TYPE_P (elttype)) 830 return NULL; 831 832 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 833 { 834 conversion *sub 835 = implicit_conversion (elttype, TREE_TYPE (val), val, 836 false, flags, complain); 837 if (sub == NULL) 838 return NULL; 839 840 subconvs[i] = sub; 841 } 842 843 t = alloc_conversion (ck_list); 844 t->type = type; 845 t->u.list = subconvs; 846 t->rank = cr_exact; 847 848 for (i = 0; i < len; ++i) 849 { 850 conversion *sub = subconvs[i]; 851 if (sub->rank > t->rank) 852 t->rank = sub->rank; 853 if (sub->user_conv_p) 854 t->user_conv_p = true; 855 if (sub->bad_p) 856 t->bad_p = true; 857 } 858 859 return t; 860 } 861 862 /* Return the next conversion of the conversion chain (if applicable), 863 or NULL otherwise. Please use this function instead of directly 864 accessing fields of struct conversion. */ 865 866 static conversion * 867 next_conversion (conversion *conv) 868 { 869 if (conv == NULL 870 || conv->kind == ck_identity 871 || conv->kind == ck_ambig 872 || conv->kind == ck_list) 873 return NULL; 874 return conv->u.next; 875 } 876 877 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list, 878 is a valid aggregate initializer for array type ATYPE. */ 879 880 static bool 881 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain) 882 { 883 unsigned i; 884 tree elttype = TREE_TYPE (atype); 885 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i) 886 { 887 tree val = CONSTRUCTOR_ELT (ctor, i)->value; 888 bool ok; 889 if (TREE_CODE (elttype) == ARRAY_TYPE 890 && TREE_CODE (val) == CONSTRUCTOR) 891 ok = can_convert_array (elttype, val, flags, complain); 892 else 893 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags, 894 complain); 895 if (!ok) 896 return false; 897 } 898 return true; 899 } 900 901 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 902 aggregate class, if such a conversion is possible. */ 903 904 static conversion * 905 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 906 { 907 unsigned HOST_WIDE_INT i = 0; 908 conversion *c; 909 tree field = next_initializable_field (TYPE_FIELDS (type)); 910 tree empty_ctor = NULL_TREE; 911 912 /* We already called reshape_init in implicit_conversion. */ 913 914 /* The conversions within the init-list aren't affected by the enclosing 915 context; they're always simple copy-initialization. */ 916 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 917 918 for (; field; field = next_initializable_field (DECL_CHAIN (field))) 919 { 920 tree ftype = TREE_TYPE (field); 921 tree val; 922 bool ok; 923 924 if (i < CONSTRUCTOR_NELTS (ctor)) 925 val = CONSTRUCTOR_ELT (ctor, i)->value; 926 else if (DECL_INITIAL (field)) 927 val = get_nsdmi (field, /*ctor*/false); 928 else if (TREE_CODE (ftype) == REFERENCE_TYPE) 929 /* Value-initialization of reference is ill-formed. */ 930 return NULL; 931 else 932 { 933 if (empty_ctor == NULL_TREE) 934 empty_ctor = build_constructor (init_list_type_node, NULL); 935 val = empty_ctor; 936 } 937 ++i; 938 939 if (TREE_CODE (ftype) == ARRAY_TYPE 940 && TREE_CODE (val) == CONSTRUCTOR) 941 ok = can_convert_array (ftype, val, flags, complain); 942 else 943 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags, 944 complain); 945 946 if (!ok) 947 return NULL; 948 949 if (TREE_CODE (type) == UNION_TYPE) 950 break; 951 } 952 953 if (i < CONSTRUCTOR_NELTS (ctor)) 954 return NULL; 955 956 c = alloc_conversion (ck_aggr); 957 c->type = type; 958 c->rank = cr_exact; 959 c->user_conv_p = true; 960 c->check_narrowing = true; 961 c->u.next = NULL; 962 return c; 963 } 964 965 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 966 array type, if such a conversion is possible. */ 967 968 static conversion * 969 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 970 { 971 conversion *c; 972 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 973 tree elttype = TREE_TYPE (type); 974 unsigned i; 975 tree val; 976 bool bad = false; 977 bool user = false; 978 enum conversion_rank rank = cr_exact; 979 980 /* We might need to propagate the size from the element to the array. */ 981 complete_type (type); 982 983 if (TYPE_DOMAIN (type) 984 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE)) 985 { 986 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type)); 987 if (alen < len) 988 return NULL; 989 } 990 991 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 992 993 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 994 { 995 conversion *sub 996 = implicit_conversion (elttype, TREE_TYPE (val), val, 997 false, flags, complain); 998 if (sub == NULL) 999 return NULL; 1000 1001 if (sub->rank > rank) 1002 rank = sub->rank; 1003 if (sub->user_conv_p) 1004 user = true; 1005 if (sub->bad_p) 1006 bad = true; 1007 } 1008 1009 c = alloc_conversion (ck_aggr); 1010 c->type = type; 1011 c->rank = rank; 1012 c->user_conv_p = user; 1013 c->bad_p = bad; 1014 c->u.next = NULL; 1015 return c; 1016 } 1017 1018 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 1019 complex type, if such a conversion is possible. */ 1020 1021 static conversion * 1022 build_complex_conv (tree type, tree ctor, int flags, 1023 tsubst_flags_t complain) 1024 { 1025 conversion *c; 1026 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 1027 tree elttype = TREE_TYPE (type); 1028 unsigned i; 1029 tree val; 1030 bool bad = false; 1031 bool user = false; 1032 enum conversion_rank rank = cr_exact; 1033 1034 if (len != 2) 1035 return NULL; 1036 1037 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 1038 1039 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 1040 { 1041 conversion *sub 1042 = implicit_conversion (elttype, TREE_TYPE (val), val, 1043 false, flags, complain); 1044 if (sub == NULL) 1045 return NULL; 1046 1047 if (sub->rank > rank) 1048 rank = sub->rank; 1049 if (sub->user_conv_p) 1050 user = true; 1051 if (sub->bad_p) 1052 bad = true; 1053 } 1054 1055 c = alloc_conversion (ck_aggr); 1056 c->type = type; 1057 c->rank = rank; 1058 c->user_conv_p = user; 1059 c->bad_p = bad; 1060 c->u.next = NULL; 1061 return c; 1062 } 1063 1064 /* Build a representation of the identity conversion from EXPR to 1065 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1066 1067 static conversion * 1068 build_identity_conv (tree type, tree expr) 1069 { 1070 conversion *c; 1071 1072 c = alloc_conversion (ck_identity); 1073 c->type = type; 1074 c->u.expr = expr; 1075 1076 return c; 1077 } 1078 1079 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1080 were multiple user-defined conversions to accomplish the job. 1081 Build a conversion that indicates that ambiguity. */ 1082 1083 static conversion * 1084 build_ambiguous_conv (tree type, tree expr) 1085 { 1086 conversion *c; 1087 1088 c = alloc_conversion (ck_ambig); 1089 c->type = type; 1090 c->u.expr = expr; 1091 1092 return c; 1093 } 1094 1095 tree 1096 strip_top_quals (tree t) 1097 { 1098 if (TREE_CODE (t) == ARRAY_TYPE) 1099 return t; 1100 return cp_build_qualified_type (t, 0); 1101 } 1102 1103 /* Returns the standard conversion path (see [conv]) from type FROM to type 1104 TO, if any. For proper handling of null pointer constants, you must 1105 also pass the expression EXPR to convert from. If C_CAST_P is true, 1106 this conversion is coming from a C-style cast. */ 1107 1108 static conversion * 1109 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1110 int flags, tsubst_flags_t complain) 1111 { 1112 enum tree_code fcode, tcode; 1113 conversion *conv; 1114 bool fromref = false; 1115 tree qualified_to; 1116 1117 to = non_reference (to); 1118 if (TREE_CODE (from) == REFERENCE_TYPE) 1119 { 1120 fromref = true; 1121 from = TREE_TYPE (from); 1122 } 1123 qualified_to = to; 1124 to = strip_top_quals (to); 1125 from = strip_top_quals (from); 1126 1127 if (expr && type_unknown_p (expr)) 1128 { 1129 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1130 { 1131 tsubst_flags_t tflags = tf_conv; 1132 expr = instantiate_type (to, expr, tflags); 1133 if (expr == error_mark_node) 1134 return NULL; 1135 from = TREE_TYPE (expr); 1136 } 1137 else if (TREE_CODE (to) == BOOLEAN_TYPE) 1138 { 1139 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */ 1140 expr = resolve_nondeduced_context (expr, complain); 1141 from = TREE_TYPE (expr); 1142 } 1143 } 1144 1145 fcode = TREE_CODE (from); 1146 tcode = TREE_CODE (to); 1147 1148 conv = build_identity_conv (from, expr); 1149 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1150 { 1151 from = type_decays_to (from); 1152 fcode = TREE_CODE (from); 1153 conv = build_conv (ck_lvalue, from, conv); 1154 } 1155 else if (fromref || (expr && lvalue_p (expr))) 1156 { 1157 if (expr) 1158 { 1159 tree bitfield_type; 1160 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1161 if (bitfield_type) 1162 { 1163 from = strip_top_quals (bitfield_type); 1164 fcode = TREE_CODE (from); 1165 } 1166 } 1167 conv = build_conv (ck_rvalue, from, conv); 1168 if (flags & LOOKUP_PREFER_RVALUE) 1169 conv->rvaluedness_matches_p = true; 1170 } 1171 1172 /* Allow conversion between `__complex__' data types. */ 1173 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1174 { 1175 /* The standard conversion sequence to convert FROM to TO is 1176 the standard conversion sequence to perform componentwise 1177 conversion. */ 1178 conversion *part_conv = standard_conversion 1179 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags, 1180 complain); 1181 1182 if (part_conv) 1183 { 1184 conv = build_conv (part_conv->kind, to, conv); 1185 conv->rank = part_conv->rank; 1186 } 1187 else 1188 conv = NULL; 1189 1190 return conv; 1191 } 1192 1193 if (same_type_p (from, to)) 1194 { 1195 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1196 conv->type = qualified_to; 1197 return conv; 1198 } 1199 1200 /* [conv.ptr] 1201 A null pointer constant can be converted to a pointer type; ... A 1202 null pointer constant of integral type can be converted to an 1203 rvalue of type std::nullptr_t. */ 1204 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to) 1205 || NULLPTR_TYPE_P (to)) 1206 && ((expr && null_ptr_cst_p (expr)) 1207 || NULLPTR_TYPE_P (from))) 1208 conv = build_conv (ck_std, to, conv); 1209 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1210 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1211 { 1212 /* For backwards brain damage compatibility, allow interconversion of 1213 pointers and integers with a pedwarn. */ 1214 conv = build_conv (ck_std, to, conv); 1215 conv->bad_p = true; 1216 } 1217 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1218 { 1219 /* For backwards brain damage compatibility, allow interconversion of 1220 enums and integers with a pedwarn. */ 1221 conv = build_conv (ck_std, to, conv); 1222 conv->bad_p = true; 1223 } 1224 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1225 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from))) 1226 { 1227 tree to_pointee; 1228 tree from_pointee; 1229 1230 if (tcode == POINTER_TYPE 1231 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from), 1232 TREE_TYPE (to))) 1233 ; 1234 else if (VOID_TYPE_P (TREE_TYPE (to)) 1235 && !TYPE_PTRDATAMEM_P (from) 1236 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE) 1237 { 1238 tree nfrom = TREE_TYPE (from); 1239 /* Don't try to apply restrict to void. */ 1240 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT; 1241 from = build_pointer_type 1242 (cp_build_qualified_type (void_type_node, quals)); 1243 conv = build_conv (ck_ptr, from, conv); 1244 } 1245 else if (TYPE_PTRDATAMEM_P (from)) 1246 { 1247 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1248 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1249 1250 if (DERIVED_FROM_P (fbase, tbase) 1251 && (same_type_ignoring_top_level_qualifiers_p 1252 (TYPE_PTRMEM_POINTED_TO_TYPE (from), 1253 TYPE_PTRMEM_POINTED_TO_TYPE (to)))) 1254 { 1255 from = build_ptrmem_type (tbase, 1256 TYPE_PTRMEM_POINTED_TO_TYPE (from)); 1257 conv = build_conv (ck_pmem, from, conv); 1258 } 1259 else if (!same_type_p (fbase, tbase)) 1260 return NULL; 1261 } 1262 else if (CLASS_TYPE_P (TREE_TYPE (from)) 1263 && CLASS_TYPE_P (TREE_TYPE (to)) 1264 /* [conv.ptr] 1265 1266 An rvalue of type "pointer to cv D," where D is a 1267 class type, can be converted to an rvalue of type 1268 "pointer to cv B," where B is a base class (clause 1269 _class.derived_) of D. If B is an inaccessible 1270 (clause _class.access_) or ambiguous 1271 (_class.member.lookup_) base class of D, a program 1272 that necessitates this conversion is ill-formed. 1273 Therefore, we use DERIVED_FROM_P, and do not check 1274 access or uniqueness. */ 1275 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))) 1276 { 1277 from = 1278 cp_build_qualified_type (TREE_TYPE (to), 1279 cp_type_quals (TREE_TYPE (from))); 1280 from = build_pointer_type (from); 1281 conv = build_conv (ck_ptr, from, conv); 1282 conv->base_p = true; 1283 } 1284 1285 if (tcode == POINTER_TYPE) 1286 { 1287 to_pointee = TREE_TYPE (to); 1288 from_pointee = TREE_TYPE (from); 1289 } 1290 else 1291 { 1292 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1293 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1294 } 1295 1296 if (same_type_p (from, to)) 1297 /* OK */; 1298 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1299 /* In a C-style cast, we ignore CV-qualification because we 1300 are allowed to perform a static_cast followed by a 1301 const_cast. */ 1302 conv = build_conv (ck_qual, to, conv); 1303 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1304 conv = build_conv (ck_qual, to, conv); 1305 else if (expr && string_conv_p (to, expr, 0)) 1306 /* converting from string constant to char *. */ 1307 conv = build_conv (ck_qual, to, conv); 1308 /* Allow conversions among compatible ObjC pointer types (base 1309 conversions have been already handled above). */ 1310 else if (c_dialect_objc () 1311 && objc_compare_types (to, from, -4, NULL_TREE)) 1312 conv = build_conv (ck_ptr, to, conv); 1313 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1314 { 1315 conv = build_conv (ck_ptr, to, conv); 1316 conv->bad_p = true; 1317 } 1318 else 1319 return NULL; 1320 1321 from = to; 1322 } 1323 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1324 { 1325 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1326 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1327 tree fbase = class_of_this_parm (fromfn); 1328 tree tbase = class_of_this_parm (tofn); 1329 1330 if (!DERIVED_FROM_P (fbase, tbase) 1331 || !same_type_p (static_fn_type (fromfn), 1332 static_fn_type (tofn))) 1333 return NULL; 1334 1335 from = build_memfn_type (fromfn, 1336 tbase, 1337 cp_type_quals (tbase), 1338 type_memfn_rqual (tofn)); 1339 from = build_ptrmemfunc_type (build_pointer_type (from)); 1340 conv = build_conv (ck_pmem, from, conv); 1341 conv->base_p = true; 1342 } 1343 else if (tcode == BOOLEAN_TYPE) 1344 { 1345 /* [conv.bool] 1346 1347 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer 1348 to member type can be converted to a prvalue of type bool. ... 1349 For direct-initialization (8.5 [dcl.init]), a prvalue of type 1350 std::nullptr_t can be converted to a prvalue of type bool; */ 1351 if (ARITHMETIC_TYPE_P (from) 1352 || UNSCOPED_ENUM_P (from) 1353 || fcode == POINTER_TYPE 1354 || TYPE_PTRMEM_P (from) 1355 || NULLPTR_TYPE_P (from)) 1356 { 1357 conv = build_conv (ck_std, to, conv); 1358 if (fcode == POINTER_TYPE 1359 || TYPE_PTRDATAMEM_P (from) 1360 || (TYPE_PTRMEMFUNC_P (from) 1361 && conv->rank < cr_pbool) 1362 || NULLPTR_TYPE_P (from)) 1363 conv->rank = cr_pbool; 1364 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING)) 1365 conv->bad_p = true; 1366 return conv; 1367 } 1368 1369 return NULL; 1370 } 1371 /* We don't check for ENUMERAL_TYPE here because there are no standard 1372 conversions to enum type. */ 1373 /* As an extension, allow conversion to complex type. */ 1374 else if (ARITHMETIC_TYPE_P (to)) 1375 { 1376 if (! (INTEGRAL_CODE_P (fcode) 1377 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL))) 1378 || SCOPED_ENUM_P (from)) 1379 return NULL; 1380 conv = build_conv (ck_std, to, conv); 1381 1382 /* Give this a better rank if it's a promotion. */ 1383 if (same_type_p (to, type_promotes_to (from)) 1384 && next_conversion (conv)->rank <= cr_promotion) 1385 conv->rank = cr_promotion; 1386 } 1387 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1388 && vector_types_convertible_p (from, to, false)) 1389 return build_conv (ck_std, to, conv); 1390 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1391 && is_properly_derived_from (from, to)) 1392 { 1393 if (conv->kind == ck_rvalue) 1394 conv = next_conversion (conv); 1395 conv = build_conv (ck_base, to, conv); 1396 /* The derived-to-base conversion indicates the initialization 1397 of a parameter with base type from an object of a derived 1398 type. A temporary object is created to hold the result of 1399 the conversion unless we're binding directly to a reference. */ 1400 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1401 } 1402 else 1403 return NULL; 1404 1405 if (flags & LOOKUP_NO_NARROWING) 1406 conv->check_narrowing = true; 1407 1408 return conv; 1409 } 1410 1411 /* Returns nonzero if T1 is reference-related to T2. */ 1412 1413 bool 1414 reference_related_p (tree t1, tree t2) 1415 { 1416 if (t1 == error_mark_node || t2 == error_mark_node) 1417 return false; 1418 1419 t1 = TYPE_MAIN_VARIANT (t1); 1420 t2 = TYPE_MAIN_VARIANT (t2); 1421 1422 /* [dcl.init.ref] 1423 1424 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1425 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1426 of T2. */ 1427 return (same_type_p (t1, t2) 1428 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1429 && DERIVED_FROM_P (t1, t2))); 1430 } 1431 1432 /* Returns nonzero if T1 is reference-compatible with T2. */ 1433 1434 static bool 1435 reference_compatible_p (tree t1, tree t2) 1436 { 1437 /* [dcl.init.ref] 1438 1439 "cv1 T1" is reference compatible with "cv2 T2" if T1 is 1440 reference-related to T2 and cv1 is the same cv-qualification as, 1441 or greater cv-qualification than, cv2. */ 1442 return (reference_related_p (t1, t2) 1443 && at_least_as_qualified_p (t1, t2)); 1444 } 1445 1446 /* A reference of the indicated TYPE is being bound directly to the 1447 expression represented by the implicit conversion sequence CONV. 1448 Return a conversion sequence for this binding. */ 1449 1450 static conversion * 1451 direct_reference_binding (tree type, conversion *conv) 1452 { 1453 tree t; 1454 1455 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1456 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1457 1458 t = TREE_TYPE (type); 1459 1460 /* [over.ics.rank] 1461 1462 When a parameter of reference type binds directly 1463 (_dcl.init.ref_) to an argument expression, the implicit 1464 conversion sequence is the identity conversion, unless the 1465 argument expression has a type that is a derived class of the 1466 parameter type, in which case the implicit conversion sequence is 1467 a derived-to-base Conversion. 1468 1469 If the parameter binds directly to the result of applying a 1470 conversion function to the argument expression, the implicit 1471 conversion sequence is a user-defined conversion sequence 1472 (_over.ics.user_), with the second standard conversion sequence 1473 either an identity conversion or, if the conversion function 1474 returns an entity of a type that is a derived class of the 1475 parameter type, a derived-to-base conversion. */ 1476 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type)) 1477 { 1478 /* Represent the derived-to-base conversion. */ 1479 conv = build_conv (ck_base, t, conv); 1480 /* We will actually be binding to the base-class subobject in 1481 the derived class, so we mark this conversion appropriately. 1482 That way, convert_like knows not to generate a temporary. */ 1483 conv->need_temporary_p = false; 1484 } 1485 return build_conv (ck_ref_bind, type, conv); 1486 } 1487 1488 /* Returns the conversion path from type FROM to reference type TO for 1489 purposes of reference binding. For lvalue binding, either pass a 1490 reference type to FROM or an lvalue expression to EXPR. If the 1491 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1492 the conversion returned. If C_CAST_P is true, this 1493 conversion is coming from a C-style cast. */ 1494 1495 static conversion * 1496 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags, 1497 tsubst_flags_t complain) 1498 { 1499 conversion *conv = NULL; 1500 tree to = TREE_TYPE (rto); 1501 tree from = rfrom; 1502 tree tfrom; 1503 bool related_p; 1504 bool compatible_p; 1505 cp_lvalue_kind gl_kind; 1506 bool is_lvalue; 1507 1508 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1509 { 1510 expr = instantiate_type (to, expr, tf_none); 1511 if (expr == error_mark_node) 1512 return NULL; 1513 from = TREE_TYPE (expr); 1514 } 1515 1516 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1517 { 1518 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1519 /* DR 1288: Otherwise, if the initializer list has a single element 1520 of type E and ... [T's] referenced type is reference-related to E, 1521 the object or reference is initialized from that element... */ 1522 if (CONSTRUCTOR_NELTS (expr) == 1) 1523 { 1524 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1525 if (error_operand_p (elt)) 1526 return NULL; 1527 tree etype = TREE_TYPE (elt); 1528 if (reference_related_p (to, etype)) 1529 { 1530 expr = elt; 1531 from = etype; 1532 goto skip; 1533 } 1534 } 1535 /* Otherwise, if T is a reference type, a prvalue temporary of the 1536 type referenced by T is copy-list-initialized or 1537 direct-list-initialized, depending on the kind of initialization 1538 for the reference, and the reference is bound to that temporary. */ 1539 conv = implicit_conversion (to, from, expr, c_cast_p, 1540 flags|LOOKUP_NO_TEMP_BIND, complain); 1541 skip:; 1542 } 1543 1544 if (TREE_CODE (from) == REFERENCE_TYPE) 1545 { 1546 from = TREE_TYPE (from); 1547 if (!TYPE_REF_IS_RVALUE (rfrom) 1548 || TREE_CODE (from) == FUNCTION_TYPE) 1549 gl_kind = clk_ordinary; 1550 else 1551 gl_kind = clk_rvalueref; 1552 } 1553 else if (expr) 1554 { 1555 gl_kind = lvalue_kind (expr); 1556 if (gl_kind & clk_class) 1557 /* A class prvalue is not a glvalue. */ 1558 gl_kind = clk_none; 1559 } 1560 else 1561 gl_kind = clk_none; 1562 is_lvalue = gl_kind && !(gl_kind & clk_rvalueref); 1563 1564 tfrom = from; 1565 if ((gl_kind & clk_bitfield) != 0) 1566 tfrom = unlowered_expr_type (expr); 1567 1568 /* Figure out whether or not the types are reference-related and 1569 reference compatible. We have do do this after stripping 1570 references from FROM. */ 1571 related_p = reference_related_p (to, tfrom); 1572 /* If this is a C cast, first convert to an appropriately qualified 1573 type, so that we can later do a const_cast to the desired type. */ 1574 if (related_p && c_cast_p 1575 && !at_least_as_qualified_p (to, tfrom)) 1576 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1577 compatible_p = reference_compatible_p (to, tfrom); 1578 1579 /* Directly bind reference when target expression's type is compatible with 1580 the reference and expression is an lvalue. In DR391, the wording in 1581 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1582 const and rvalue references to rvalues of compatible class type. 1583 We should also do direct bindings for non-class xvalues. */ 1584 if (related_p 1585 && (gl_kind 1586 || (!(flags & LOOKUP_NO_TEMP_BIND) 1587 && (CLASS_TYPE_P (from) 1588 || TREE_CODE (from) == ARRAY_TYPE)))) 1589 { 1590 /* [dcl.init.ref] 1591 1592 If the initializer expression 1593 1594 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1595 is reference-compatible with "cv2 T2," 1596 1597 the reference is bound directly to the initializer expression 1598 lvalue. 1599 1600 [...] 1601 If the initializer expression is an rvalue, with T2 a class type, 1602 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1603 is bound to the object represented by the rvalue or to a sub-object 1604 within that object. */ 1605 1606 conv = build_identity_conv (tfrom, expr); 1607 conv = direct_reference_binding (rto, conv); 1608 1609 if (flags & LOOKUP_PREFER_RVALUE) 1610 /* The top-level caller requested that we pretend that the lvalue 1611 be treated as an rvalue. */ 1612 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1613 else if (TREE_CODE (rfrom) == REFERENCE_TYPE) 1614 /* Handle rvalue reference to function properly. */ 1615 conv->rvaluedness_matches_p 1616 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1617 else 1618 conv->rvaluedness_matches_p 1619 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1620 1621 if ((gl_kind & clk_bitfield) != 0 1622 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1623 /* For the purposes of overload resolution, we ignore the fact 1624 this expression is a bitfield or packed field. (In particular, 1625 [over.ics.ref] says specifically that a function with a 1626 non-const reference parameter is viable even if the 1627 argument is a bitfield.) 1628 1629 However, when we actually call the function we must create 1630 a temporary to which to bind the reference. If the 1631 reference is volatile, or isn't const, then we cannot make 1632 a temporary, so we just issue an error when the conversion 1633 actually occurs. */ 1634 conv->need_temporary_p = true; 1635 1636 /* Don't allow binding of lvalues (other than function lvalues) to 1637 rvalue references. */ 1638 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1639 && TREE_CODE (to) != FUNCTION_TYPE 1640 && !(flags & LOOKUP_PREFER_RVALUE)) 1641 conv->bad_p = true; 1642 1643 /* Nor the reverse. */ 1644 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto) 1645 && (!CP_TYPE_CONST_NON_VOLATILE_P (to) 1646 || (flags & LOOKUP_NO_RVAL_BIND)) 1647 && TREE_CODE (to) != FUNCTION_TYPE) 1648 conv->bad_p = true; 1649 1650 if (!compatible_p) 1651 conv->bad_p = true; 1652 1653 return conv; 1654 } 1655 /* [class.conv.fct] A conversion function is never used to convert a 1656 (possibly cv-qualified) object to the (possibly cv-qualified) same 1657 object type (or a reference to it), to a (possibly cv-qualified) base 1658 class of that type (or a reference to it).... */ 1659 else if (CLASS_TYPE_P (from) && !related_p 1660 && !(flags & LOOKUP_NO_CONVERSION)) 1661 { 1662 /* [dcl.init.ref] 1663 1664 If the initializer expression 1665 1666 -- has a class type (i.e., T2 is a class type) can be 1667 implicitly converted to an lvalue of type "cv3 T3," where 1668 "cv1 T1" is reference-compatible with "cv3 T3". (this 1669 conversion is selected by enumerating the applicable 1670 conversion functions (_over.match.ref_) and choosing the 1671 best one through overload resolution. (_over.match_). 1672 1673 the reference is bound to the lvalue result of the conversion 1674 in the second case. */ 1675 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags, 1676 complain); 1677 if (cand) 1678 return cand->second_conv; 1679 } 1680 1681 /* From this point on, we conceptually need temporaries, even if we 1682 elide them. Only the cases above are "direct bindings". */ 1683 if (flags & LOOKUP_NO_TEMP_BIND) 1684 return NULL; 1685 1686 /* [over.ics.rank] 1687 1688 When a parameter of reference type is not bound directly to an 1689 argument expression, the conversion sequence is the one required 1690 to convert the argument expression to the underlying type of the 1691 reference according to _over.best.ics_. Conceptually, this 1692 conversion sequence corresponds to copy-initializing a temporary 1693 of the underlying type with the argument expression. Any 1694 difference in top-level cv-qualification is subsumed by the 1695 initialization itself and does not constitute a conversion. */ 1696 1697 /* [dcl.init.ref] 1698 1699 Otherwise, the reference shall be an lvalue reference to a 1700 non-volatile const type, or the reference shall be an rvalue 1701 reference. 1702 1703 We try below to treat this as a bad conversion to improve diagnostics, 1704 but if TO is an incomplete class, we need to reject this conversion 1705 now to avoid unnecessary instantiation. */ 1706 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto) 1707 && !COMPLETE_TYPE_P (to)) 1708 return NULL; 1709 1710 /* We're generating a temporary now, but don't bind any more in the 1711 conversion (specifically, don't slice the temporary returned by a 1712 conversion operator). */ 1713 flags |= LOOKUP_NO_TEMP_BIND; 1714 1715 /* Core issue 899: When [copy-]initializing a temporary to be bound 1716 to the first parameter of a copy constructor (12.8) called with 1717 a single argument in the context of direct-initialization, 1718 explicit conversion functions are also considered. 1719 1720 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1721 if (!(flags & LOOKUP_COPY_PARM)) 1722 flags |= LOOKUP_ONLYCONVERTING; 1723 1724 if (!conv) 1725 conv = implicit_conversion (to, from, expr, c_cast_p, 1726 flags, complain); 1727 if (!conv) 1728 return NULL; 1729 1730 if (conv->user_conv_p) 1731 { 1732 /* If initializing the temporary used a conversion function, 1733 recalculate the second conversion sequence. */ 1734 for (conversion *t = conv; t; t = next_conversion (t)) 1735 if (t->kind == ck_user 1736 && DECL_CONV_FN_P (t->cand->fn)) 1737 { 1738 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn)); 1739 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND; 1740 conversion *new_second 1741 = reference_binding (rto, ftype, NULL_TREE, c_cast_p, 1742 sflags, complain); 1743 if (!new_second) 1744 return NULL; 1745 return merge_conversion_sequences (t, new_second); 1746 } 1747 } 1748 1749 conv = build_conv (ck_ref_bind, rto, conv); 1750 /* This reference binding, unlike those above, requires the 1751 creation of a temporary. */ 1752 conv->need_temporary_p = true; 1753 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1754 1755 /* [dcl.init.ref] 1756 1757 Otherwise, the reference shall be an lvalue reference to a 1758 non-volatile const type, or the reference shall be an rvalue 1759 reference. */ 1760 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1761 conv->bad_p = true; 1762 1763 /* [dcl.init.ref] 1764 1765 Otherwise, a temporary of type "cv1 T1" is created and 1766 initialized from the initializer expression using the rules for a 1767 non-reference copy initialization. If T1 is reference-related to 1768 T2, cv1 must be the same cv-qualification as, or greater 1769 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1770 if (related_p && !at_least_as_qualified_p (to, from)) 1771 conv->bad_p = true; 1772 1773 return conv; 1774 } 1775 1776 /* Returns the implicit conversion sequence (see [over.ics]) from type 1777 FROM to type TO. The optional expression EXPR may affect the 1778 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1779 true, this conversion is coming from a C-style cast. */ 1780 1781 static conversion * 1782 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1783 int flags, tsubst_flags_t complain) 1784 { 1785 conversion *conv; 1786 1787 if (from == error_mark_node || to == error_mark_node 1788 || expr == error_mark_node) 1789 return NULL; 1790 1791 /* Other flags only apply to the primary function in overload 1792 resolution, or after we've chosen one. */ 1793 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1794 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1795 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL); 1796 1797 /* FIXME: actually we don't want warnings either, but we can't just 1798 have 'complain &= ~(tf_warning|tf_error)' because it would cause 1799 the regression of, eg, g++.old-deja/g++.benjamin/16077.C. 1800 We really ought not to issue that warning until we've committed 1801 to that conversion. */ 1802 complain &= ~tf_error; 1803 1804 /* Call reshape_init early to remove redundant braces. */ 1805 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) 1806 && CLASS_TYPE_P (to) 1807 && COMPLETE_TYPE_P (complete_type (to)) 1808 && !CLASSTYPE_NON_AGGREGATE (to)) 1809 { 1810 expr = reshape_init (to, expr, complain); 1811 if (expr == error_mark_node) 1812 return NULL; 1813 from = TREE_TYPE (expr); 1814 } 1815 1816 if (TREE_CODE (to) == REFERENCE_TYPE) 1817 conv = reference_binding (to, from, expr, c_cast_p, flags, complain); 1818 else 1819 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain); 1820 1821 if (conv) 1822 return conv; 1823 1824 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1825 { 1826 if (is_std_init_list (to)) 1827 return build_list_conv (to, expr, flags, complain); 1828 1829 /* As an extension, allow list-initialization of _Complex. */ 1830 if (TREE_CODE (to) == COMPLEX_TYPE) 1831 { 1832 conv = build_complex_conv (to, expr, flags, complain); 1833 if (conv) 1834 return conv; 1835 } 1836 1837 /* Allow conversion from an initializer-list with one element to a 1838 scalar type. */ 1839 if (SCALAR_TYPE_P (to)) 1840 { 1841 int nelts = CONSTRUCTOR_NELTS (expr); 1842 tree elt; 1843 1844 if (nelts == 0) 1845 elt = build_value_init (to, tf_none); 1846 else if (nelts == 1) 1847 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1848 else 1849 elt = error_mark_node; 1850 1851 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1852 c_cast_p, flags, complain); 1853 if (conv) 1854 { 1855 conv->check_narrowing = true; 1856 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1857 /* Too many levels of braces, i.e. '{{1}}'. */ 1858 conv->bad_p = true; 1859 return conv; 1860 } 1861 } 1862 else if (TREE_CODE (to) == ARRAY_TYPE) 1863 return build_array_conv (to, expr, flags, complain); 1864 } 1865 1866 if (expr != NULL_TREE 1867 && (MAYBE_CLASS_TYPE_P (from) 1868 || MAYBE_CLASS_TYPE_P (to)) 1869 && (flags & LOOKUP_NO_CONVERSION) == 0) 1870 { 1871 struct z_candidate *cand; 1872 1873 if (CLASS_TYPE_P (to) 1874 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1875 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1876 return build_aggr_conv (to, expr, flags, complain); 1877 1878 cand = build_user_type_conversion_1 (to, expr, flags, complain); 1879 if (cand) 1880 conv = cand->second_conv; 1881 1882 /* We used to try to bind a reference to a temporary here, but that 1883 is now handled after the recursive call to this function at the end 1884 of reference_binding. */ 1885 return conv; 1886 } 1887 1888 return NULL; 1889 } 1890 1891 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1892 functions. ARGS will not be changed until a single candidate is 1893 selected. */ 1894 1895 static struct z_candidate * 1896 add_candidate (struct z_candidate **candidates, 1897 tree fn, tree first_arg, const vec<tree, va_gc> *args, 1898 size_t num_convs, conversion **convs, 1899 tree access_path, tree conversion_path, 1900 int viable, struct rejection_reason *reason, 1901 int flags) 1902 { 1903 struct z_candidate *cand = (struct z_candidate *) 1904 conversion_obstack_alloc (sizeof (struct z_candidate)); 1905 1906 cand->fn = fn; 1907 cand->first_arg = first_arg; 1908 cand->args = args; 1909 cand->convs = convs; 1910 cand->num_convs = num_convs; 1911 cand->access_path = access_path; 1912 cand->conversion_path = conversion_path; 1913 cand->viable = viable; 1914 cand->reason = reason; 1915 cand->next = *candidates; 1916 cand->flags = flags; 1917 *candidates = cand; 1918 1919 return cand; 1920 } 1921 1922 /* Return the number of remaining arguments in the parameter list 1923 beginning with ARG. */ 1924 1925 int 1926 remaining_arguments (tree arg) 1927 { 1928 int n; 1929 1930 for (n = 0; arg != NULL_TREE && arg != void_list_node; 1931 arg = TREE_CHAIN (arg)) 1932 n++; 1933 1934 return n; 1935 } 1936 1937 /* Create an overload candidate for the function or method FN called 1938 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1939 FLAGS is passed on to implicit_conversion. 1940 1941 This does not change ARGS. 1942 1943 CTYPE, if non-NULL, is the type we want to pretend this function 1944 comes from for purposes of overload resolution. */ 1945 1946 static struct z_candidate * 1947 add_function_candidate (struct z_candidate **candidates, 1948 tree fn, tree ctype, tree first_arg, 1949 const vec<tree, va_gc> *args, tree access_path, 1950 tree conversion_path, int flags, 1951 tsubst_flags_t complain) 1952 { 1953 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1954 int i, len; 1955 conversion **convs; 1956 tree parmnode; 1957 tree orig_first_arg = first_arg; 1958 int skip; 1959 int viable = 1; 1960 struct rejection_reason *reason = NULL; 1961 1962 /* At this point we should not see any functions which haven't been 1963 explicitly declared, except for friend functions which will have 1964 been found using argument dependent lookup. */ 1965 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 1966 1967 /* The `this', `in_chrg' and VTT arguments to constructors are not 1968 considered in overload resolution. */ 1969 if (DECL_CONSTRUCTOR_P (fn)) 1970 { 1971 parmlist = skip_artificial_parms_for (fn, parmlist); 1972 skip = num_artificial_parms_for (fn); 1973 if (skip > 0 && first_arg != NULL_TREE) 1974 { 1975 --skip; 1976 first_arg = NULL_TREE; 1977 } 1978 } 1979 else 1980 skip = 0; 1981 1982 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0); 1983 convs = alloc_conversions (len); 1984 1985 /* 13.3.2 - Viable functions [over.match.viable] 1986 First, to be a viable function, a candidate function shall have enough 1987 parameters to agree in number with the arguments in the list. 1988 1989 We need to check this first; otherwise, checking the ICSes might cause 1990 us to produce an ill-formed template instantiation. */ 1991 1992 parmnode = parmlist; 1993 for (i = 0; i < len; ++i) 1994 { 1995 if (parmnode == NULL_TREE || parmnode == void_list_node) 1996 break; 1997 parmnode = TREE_CHAIN (parmnode); 1998 } 1999 2000 if ((i < len && parmnode) 2001 || !sufficient_parms_p (parmnode)) 2002 { 2003 int remaining = remaining_arguments (parmnode); 2004 viable = 0; 2005 reason = arity_rejection (first_arg, i + remaining, len); 2006 } 2007 /* When looking for a function from a subobject from an implicit 2008 copy/move constructor/operator=, don't consider anything that takes (a 2009 reference to) an unrelated type. See c++/44909 and core 1092. */ 2010 else if (parmlist && (flags & LOOKUP_DEFAULTED)) 2011 { 2012 if (DECL_CONSTRUCTOR_P (fn)) 2013 i = 1; 2014 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 2015 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR) 2016 i = 2; 2017 else 2018 i = 0; 2019 if (i && len == i) 2020 { 2021 parmnode = chain_index (i-1, parmlist); 2022 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 2023 ctype)) 2024 viable = 0; 2025 } 2026 2027 /* This only applies at the top level. */ 2028 flags &= ~LOOKUP_DEFAULTED; 2029 } 2030 2031 if (! viable) 2032 goto out; 2033 2034 /* Second, for F to be a viable function, there shall exist for each 2035 argument an implicit conversion sequence that converts that argument 2036 to the corresponding parameter of F. */ 2037 2038 parmnode = parmlist; 2039 2040 for (i = 0; i < len; ++i) 2041 { 2042 tree argtype, to_type; 2043 tree arg; 2044 conversion *t; 2045 int is_this; 2046 2047 if (parmnode == void_list_node) 2048 break; 2049 2050 if (i == 0 && first_arg != NULL_TREE) 2051 arg = first_arg; 2052 else 2053 arg = CONST_CAST_TREE ( 2054 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]); 2055 argtype = lvalue_type (arg); 2056 2057 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 2058 && ! DECL_CONSTRUCTOR_P (fn)); 2059 2060 if (parmnode) 2061 { 2062 tree parmtype = TREE_VALUE (parmnode); 2063 int lflags = flags; 2064 2065 parmnode = TREE_CHAIN (parmnode); 2066 2067 /* The type of the implicit object parameter ('this') for 2068 overload resolution is not always the same as for the 2069 function itself; conversion functions are considered to 2070 be members of the class being converted, and functions 2071 introduced by a using-declaration are considered to be 2072 members of the class that uses them. 2073 2074 Since build_over_call ignores the ICS for the `this' 2075 parameter, we can just change the parm type. */ 2076 if (ctype && is_this) 2077 { 2078 parmtype = cp_build_qualified_type 2079 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 2080 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn))) 2081 { 2082 /* If the function has a ref-qualifier, the implicit 2083 object parameter has reference type. */ 2084 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn)); 2085 parmtype = cp_build_reference_type (parmtype, rv); 2086 /* The special handling of 'this' conversions in compare_ics 2087 does not apply if there is a ref-qualifier. */ 2088 is_this = false; 2089 } 2090 else 2091 { 2092 parmtype = build_pointer_type (parmtype); 2093 arg = build_this (arg); 2094 argtype = lvalue_type (arg); 2095 } 2096 } 2097 2098 /* Core issue 899: When [copy-]initializing a temporary to be bound 2099 to the first parameter of a copy constructor (12.8) called with 2100 a single argument in the context of direct-initialization, 2101 explicit conversion functions are also considered. 2102 2103 So set LOOKUP_COPY_PARM to let reference_binding know that 2104 it's being called in that context. We generalize the above 2105 to handle move constructors and template constructors as well; 2106 the standardese should soon be updated similarly. */ 2107 if (ctype && i == 0 && (len-skip == 1) 2108 && DECL_CONSTRUCTOR_P (fn) 2109 && parmtype != error_mark_node 2110 && (same_type_ignoring_top_level_qualifiers_p 2111 (non_reference (parmtype), ctype))) 2112 { 2113 if (!(flags & LOOKUP_ONLYCONVERTING)) 2114 lflags |= LOOKUP_COPY_PARM; 2115 /* We allow user-defined conversions within init-lists, but 2116 don't list-initialize the copy parm, as that would mean 2117 using two levels of braces for the same type. */ 2118 if ((flags & LOOKUP_LIST_INIT_CTOR) 2119 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 2120 lflags |= LOOKUP_NO_CONVERSION; 2121 } 2122 else 2123 lflags |= LOOKUP_ONLYCONVERTING; 2124 2125 t = implicit_conversion (parmtype, argtype, arg, 2126 /*c_cast_p=*/false, lflags, complain); 2127 to_type = parmtype; 2128 } 2129 else 2130 { 2131 t = build_identity_conv (argtype, arg); 2132 t->ellipsis_p = true; 2133 to_type = argtype; 2134 } 2135 2136 if (t && is_this) 2137 t->this_p = true; 2138 2139 convs[i] = t; 2140 if (! t) 2141 { 2142 viable = 0; 2143 reason = arg_conversion_rejection (first_arg, i, argtype, to_type); 2144 break; 2145 } 2146 2147 if (t->bad_p) 2148 { 2149 viable = -1; 2150 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type); 2151 } 2152 } 2153 2154 out: 2155 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2156 access_path, conversion_path, viable, reason, flags); 2157 } 2158 2159 /* Create an overload candidate for the conversion function FN which will 2160 be invoked for expression OBJ, producing a pointer-to-function which 2161 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2162 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2163 passed on to implicit_conversion. 2164 2165 Actually, we don't really care about FN; we care about the type it 2166 converts to. There may be multiple conversion functions that will 2167 convert to that type, and we rely on build_user_type_conversion_1 to 2168 choose the best one; so when we create our candidate, we record the type 2169 instead of the function. */ 2170 2171 static struct z_candidate * 2172 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2173 tree first_arg, const vec<tree, va_gc> *arglist, 2174 tree access_path, tree conversion_path, 2175 tsubst_flags_t complain) 2176 { 2177 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2178 int i, len, viable, flags; 2179 tree parmlist, parmnode; 2180 conversion **convs; 2181 struct rejection_reason *reason; 2182 2183 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2184 parmlist = TREE_TYPE (parmlist); 2185 parmlist = TYPE_ARG_TYPES (parmlist); 2186 2187 len = vec_safe_length (arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1; 2188 convs = alloc_conversions (len); 2189 parmnode = parmlist; 2190 viable = 1; 2191 flags = LOOKUP_IMPLICIT; 2192 reason = NULL; 2193 2194 /* Don't bother looking up the same type twice. */ 2195 if (*candidates && (*candidates)->fn == totype) 2196 return NULL; 2197 2198 for (i = 0; i < len; ++i) 2199 { 2200 tree arg, argtype, convert_type = NULL_TREE; 2201 conversion *t; 2202 2203 if (i == 0) 2204 arg = obj; 2205 else if (i == 1 && first_arg != NULL_TREE) 2206 arg = first_arg; 2207 else 2208 arg = (*arglist)[i - (first_arg != NULL_TREE ? 1 : 0) - 1]; 2209 argtype = lvalue_type (arg); 2210 2211 if (i == 0) 2212 { 2213 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false, 2214 flags, complain); 2215 convert_type = totype; 2216 } 2217 else if (parmnode == void_list_node) 2218 break; 2219 else if (parmnode) 2220 { 2221 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2222 /*c_cast_p=*/false, flags, complain); 2223 convert_type = TREE_VALUE (parmnode); 2224 } 2225 else 2226 { 2227 t = build_identity_conv (argtype, arg); 2228 t->ellipsis_p = true; 2229 convert_type = argtype; 2230 } 2231 2232 convs[i] = t; 2233 if (! t) 2234 break; 2235 2236 if (t->bad_p) 2237 { 2238 viable = -1; 2239 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type); 2240 } 2241 2242 if (i == 0) 2243 continue; 2244 2245 if (parmnode) 2246 parmnode = TREE_CHAIN (parmnode); 2247 } 2248 2249 if (i < len 2250 || ! sufficient_parms_p (parmnode)) 2251 { 2252 int remaining = remaining_arguments (parmnode); 2253 viable = 0; 2254 reason = arity_rejection (NULL_TREE, i + remaining, len); 2255 } 2256 2257 return add_candidate (candidates, totype, first_arg, arglist, len, convs, 2258 access_path, conversion_path, viable, reason, flags); 2259 } 2260 2261 static void 2262 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2263 tree type1, tree type2, tree *args, tree *argtypes, 2264 int flags, tsubst_flags_t complain) 2265 { 2266 conversion *t; 2267 conversion **convs; 2268 size_t num_convs; 2269 int viable = 1, i; 2270 tree types[2]; 2271 struct rejection_reason *reason = NULL; 2272 2273 types[0] = type1; 2274 types[1] = type2; 2275 2276 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2277 convs = alloc_conversions (num_convs); 2278 2279 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2280 conversion ops are allowed. We handle that here by just checking for 2281 boolean_type_node because other operators don't ask for it. COND_EXPR 2282 also does contextual conversion to bool for the first operand, but we 2283 handle that in build_conditional_expr, and type1 here is operand 2. */ 2284 if (type1 != boolean_type_node) 2285 flags |= LOOKUP_ONLYCONVERTING; 2286 2287 for (i = 0; i < 2; ++i) 2288 { 2289 if (! args[i]) 2290 break; 2291 2292 t = implicit_conversion (types[i], argtypes[i], args[i], 2293 /*c_cast_p=*/false, flags, complain); 2294 if (! t) 2295 { 2296 viable = 0; 2297 /* We need something for printing the candidate. */ 2298 t = build_identity_conv (types[i], NULL_TREE); 2299 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], 2300 types[i]); 2301 } 2302 else if (t->bad_p) 2303 { 2304 viable = 0; 2305 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i], 2306 types[i]); 2307 } 2308 convs[i] = t; 2309 } 2310 2311 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2312 if (args[2]) 2313 { 2314 convs[2] = convs[1]; 2315 convs[1] = convs[0]; 2316 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2317 /*c_cast_p=*/false, flags, 2318 complain); 2319 if (t) 2320 convs[0] = t; 2321 else 2322 { 2323 viable = 0; 2324 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2325 boolean_type_node); 2326 } 2327 } 2328 2329 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2330 num_convs, convs, 2331 /*access_path=*/NULL_TREE, 2332 /*conversion_path=*/NULL_TREE, 2333 viable, reason, flags); 2334 } 2335 2336 static bool 2337 is_complete (tree t) 2338 { 2339 return COMPLETE_TYPE_P (complete_type (t)); 2340 } 2341 2342 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2343 2344 static bool 2345 promoted_arithmetic_type_p (tree type) 2346 { 2347 /* [over.built] 2348 2349 In this section, the term promoted integral type is used to refer 2350 to those integral types which are preserved by integral promotion 2351 (including e.g. int and long but excluding e.g. char). 2352 Similarly, the term promoted arithmetic type refers to promoted 2353 integral types plus floating types. */ 2354 return ((CP_INTEGRAL_TYPE_P (type) 2355 && same_type_p (type_promotes_to (type), type)) 2356 || TREE_CODE (type) == REAL_TYPE); 2357 } 2358 2359 /* Create any builtin operator overload candidates for the operator in 2360 question given the converted operand types TYPE1 and TYPE2. The other 2361 args are passed through from add_builtin_candidates to 2362 build_builtin_candidate. 2363 2364 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2365 If CODE is requires candidates operands of the same type of the kind 2366 of which TYPE1 and TYPE2 are, we add both candidates 2367 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2368 2369 static void 2370 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2371 enum tree_code code2, tree fnname, tree type1, 2372 tree type2, tree *args, tree *argtypes, int flags, 2373 tsubst_flags_t complain) 2374 { 2375 switch (code) 2376 { 2377 case POSTINCREMENT_EXPR: 2378 case POSTDECREMENT_EXPR: 2379 args[1] = integer_zero_node; 2380 type2 = integer_type_node; 2381 break; 2382 default: 2383 break; 2384 } 2385 2386 switch (code) 2387 { 2388 2389 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2390 and VQ is either volatile or empty, there exist candidate operator 2391 functions of the form 2392 VQ T& operator++(VQ T&); 2393 T operator++(VQ T&, int); 2394 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2395 type other than bool, and VQ is either volatile or empty, there exist 2396 candidate operator functions of the form 2397 VQ T& operator--(VQ T&); 2398 T operator--(VQ T&, int); 2399 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2400 complete object type, and VQ is either volatile or empty, there exist 2401 candidate operator functions of the form 2402 T*VQ& operator++(T*VQ&); 2403 T*VQ& operator--(T*VQ&); 2404 T* operator++(T*VQ&, int); 2405 T* operator--(T*VQ&, int); */ 2406 2407 case POSTDECREMENT_EXPR: 2408 case PREDECREMENT_EXPR: 2409 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2410 return; 2411 case POSTINCREMENT_EXPR: 2412 case PREINCREMENT_EXPR: 2413 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2414 { 2415 type1 = build_reference_type (type1); 2416 break; 2417 } 2418 return; 2419 2420 /* 7 For every cv-qualified or cv-unqualified object type T, there 2421 exist candidate operator functions of the form 2422 2423 T& operator*(T*); 2424 2425 8 For every function type T, there exist candidate operator functions of 2426 the form 2427 T& operator*(T*); */ 2428 2429 case INDIRECT_REF: 2430 if (TYPE_PTR_P (type1) 2431 && (TYPE_PTROB_P (type1) 2432 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2433 break; 2434 return; 2435 2436 /* 9 For every type T, there exist candidate operator functions of the form 2437 T* operator+(T*); 2438 2439 10For every promoted arithmetic type T, there exist candidate operator 2440 functions of the form 2441 T operator+(T); 2442 T operator-(T); */ 2443 2444 case UNARY_PLUS_EXPR: /* unary + */ 2445 if (TYPE_PTR_P (type1)) 2446 break; 2447 case NEGATE_EXPR: 2448 if (ARITHMETIC_TYPE_P (type1)) 2449 break; 2450 return; 2451 2452 /* 11For every promoted integral type T, there exist candidate operator 2453 functions of the form 2454 T operator~(T); */ 2455 2456 case BIT_NOT_EXPR: 2457 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2458 break; 2459 return; 2460 2461 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2462 is the same type as C2 or is a derived class of C2, T is a complete 2463 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2464 there exist candidate operator functions of the form 2465 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2466 where CV12 is the union of CV1 and CV2. */ 2467 2468 case MEMBER_REF: 2469 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2)) 2470 { 2471 tree c1 = TREE_TYPE (type1); 2472 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2473 2474 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2475 && (TYPE_PTRMEMFUNC_P (type2) 2476 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2477 break; 2478 } 2479 return; 2480 2481 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2482 didate operator functions of the form 2483 LR operator*(L, R); 2484 LR operator/(L, R); 2485 LR operator+(L, R); 2486 LR operator-(L, R); 2487 bool operator<(L, R); 2488 bool operator>(L, R); 2489 bool operator<=(L, R); 2490 bool operator>=(L, R); 2491 bool operator==(L, R); 2492 bool operator!=(L, R); 2493 where LR is the result of the usual arithmetic conversions between 2494 types L and R. 2495 2496 14For every pair of types T and I, where T is a cv-qualified or cv- 2497 unqualified complete object type and I is a promoted integral type, 2498 there exist candidate operator functions of the form 2499 T* operator+(T*, I); 2500 T& operator[](T*, I); 2501 T* operator-(T*, I); 2502 T* operator+(I, T*); 2503 T& operator[](I, T*); 2504 2505 15For every T, where T is a pointer to complete object type, there exist 2506 candidate operator functions of the form112) 2507 ptrdiff_t operator-(T, T); 2508 2509 16For every pointer or enumeration type T, there exist candidate operator 2510 functions of the form 2511 bool operator<(T, T); 2512 bool operator>(T, T); 2513 bool operator<=(T, T); 2514 bool operator>=(T, T); 2515 bool operator==(T, T); 2516 bool operator!=(T, T); 2517 2518 17For every pointer to member type T, there exist candidate operator 2519 functions of the form 2520 bool operator==(T, T); 2521 bool operator!=(T, T); */ 2522 2523 case MINUS_EXPR: 2524 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2525 break; 2526 if (TYPE_PTROB_P (type1) 2527 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2528 { 2529 type2 = ptrdiff_type_node; 2530 break; 2531 } 2532 case MULT_EXPR: 2533 case TRUNC_DIV_EXPR: 2534 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2535 break; 2536 return; 2537 2538 case EQ_EXPR: 2539 case NE_EXPR: 2540 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2541 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))) 2542 break; 2543 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1])) 2544 { 2545 type2 = type1; 2546 break; 2547 } 2548 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0])) 2549 { 2550 type1 = type2; 2551 break; 2552 } 2553 /* Fall through. */ 2554 case LT_EXPR: 2555 case GT_EXPR: 2556 case LE_EXPR: 2557 case GE_EXPR: 2558 case MAX_EXPR: 2559 case MIN_EXPR: 2560 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2561 break; 2562 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2563 break; 2564 if (TREE_CODE (type1) == ENUMERAL_TYPE 2565 && TREE_CODE (type2) == ENUMERAL_TYPE) 2566 break; 2567 if (TYPE_PTR_P (type1) 2568 && null_ptr_cst_p (args[1])) 2569 { 2570 type2 = type1; 2571 break; 2572 } 2573 if (null_ptr_cst_p (args[0]) 2574 && TYPE_PTR_P (type2)) 2575 { 2576 type1 = type2; 2577 break; 2578 } 2579 return; 2580 2581 case PLUS_EXPR: 2582 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2583 break; 2584 case ARRAY_REF: 2585 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2586 { 2587 type1 = ptrdiff_type_node; 2588 break; 2589 } 2590 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2591 { 2592 type2 = ptrdiff_type_node; 2593 break; 2594 } 2595 return; 2596 2597 /* 18For every pair of promoted integral types L and R, there exist candi- 2598 date operator functions of the form 2599 LR operator%(L, R); 2600 LR operator&(L, R); 2601 LR operator^(L, R); 2602 LR operator|(L, R); 2603 L operator<<(L, R); 2604 L operator>>(L, R); 2605 where LR is the result of the usual arithmetic conversions between 2606 types L and R. */ 2607 2608 case TRUNC_MOD_EXPR: 2609 case BIT_AND_EXPR: 2610 case BIT_IOR_EXPR: 2611 case BIT_XOR_EXPR: 2612 case LSHIFT_EXPR: 2613 case RSHIFT_EXPR: 2614 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2615 break; 2616 return; 2617 2618 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2619 type, VQ is either volatile or empty, and R is a promoted arithmetic 2620 type, there exist candidate operator functions of the form 2621 VQ L& operator=(VQ L&, R); 2622 VQ L& operator*=(VQ L&, R); 2623 VQ L& operator/=(VQ L&, R); 2624 VQ L& operator+=(VQ L&, R); 2625 VQ L& operator-=(VQ L&, R); 2626 2627 20For every pair T, VQ), where T is any type and VQ is either volatile 2628 or empty, there exist candidate operator functions of the form 2629 T*VQ& operator=(T*VQ&, T*); 2630 2631 21For every pair T, VQ), where T is a pointer to member type and VQ is 2632 either volatile or empty, there exist candidate operator functions of 2633 the form 2634 VQ T& operator=(VQ T&, T); 2635 2636 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2637 unqualified complete object type, VQ is either volatile or empty, and 2638 I is a promoted integral type, there exist candidate operator func- 2639 tions of the form 2640 T*VQ& operator+=(T*VQ&, I); 2641 T*VQ& operator-=(T*VQ&, I); 2642 2643 23For every triple L, VQ, R), where L is an integral or enumeration 2644 type, VQ is either volatile or empty, and R is a promoted integral 2645 type, there exist candidate operator functions of the form 2646 2647 VQ L& operator%=(VQ L&, R); 2648 VQ L& operator<<=(VQ L&, R); 2649 VQ L& operator>>=(VQ L&, R); 2650 VQ L& operator&=(VQ L&, R); 2651 VQ L& operator^=(VQ L&, R); 2652 VQ L& operator|=(VQ L&, R); */ 2653 2654 case MODIFY_EXPR: 2655 switch (code2) 2656 { 2657 case PLUS_EXPR: 2658 case MINUS_EXPR: 2659 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2660 { 2661 type2 = ptrdiff_type_node; 2662 break; 2663 } 2664 case MULT_EXPR: 2665 case TRUNC_DIV_EXPR: 2666 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2667 break; 2668 return; 2669 2670 case TRUNC_MOD_EXPR: 2671 case BIT_AND_EXPR: 2672 case BIT_IOR_EXPR: 2673 case BIT_XOR_EXPR: 2674 case LSHIFT_EXPR: 2675 case RSHIFT_EXPR: 2676 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2677 break; 2678 return; 2679 2680 case NOP_EXPR: 2681 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2682 break; 2683 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2684 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2685 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2686 || ((TYPE_PTRMEMFUNC_P (type1) 2687 || TYPE_PTR_P (type1)) 2688 && null_ptr_cst_p (args[1]))) 2689 { 2690 type2 = type1; 2691 break; 2692 } 2693 return; 2694 2695 default: 2696 gcc_unreachable (); 2697 } 2698 type1 = build_reference_type (type1); 2699 break; 2700 2701 case COND_EXPR: 2702 /* [over.built] 2703 2704 For every pair of promoted arithmetic types L and R, there 2705 exist candidate operator functions of the form 2706 2707 LR operator?(bool, L, R); 2708 2709 where LR is the result of the usual arithmetic conversions 2710 between types L and R. 2711 2712 For every type T, where T is a pointer or pointer-to-member 2713 type, there exist candidate operator functions of the form T 2714 operator?(bool, T, T); */ 2715 2716 if (promoted_arithmetic_type_p (type1) 2717 && promoted_arithmetic_type_p (type2)) 2718 /* That's OK. */ 2719 break; 2720 2721 /* Otherwise, the types should be pointers. */ 2722 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2)) 2723 return; 2724 2725 /* We don't check that the two types are the same; the logic 2726 below will actually create two candidates; one in which both 2727 parameter types are TYPE1, and one in which both parameter 2728 types are TYPE2. */ 2729 break; 2730 2731 case REALPART_EXPR: 2732 case IMAGPART_EXPR: 2733 if (ARITHMETIC_TYPE_P (type1)) 2734 break; 2735 return; 2736 2737 default: 2738 gcc_unreachable (); 2739 } 2740 2741 /* Make sure we don't create builtin candidates with dependent types. */ 2742 bool u1 = uses_template_parms (type1); 2743 bool u2 = type2 ? uses_template_parms (type2) : false; 2744 if (u1 || u2) 2745 { 2746 /* Try to recover if one of the types is non-dependent. But if 2747 there's only one type, there's nothing we can do. */ 2748 if (!type2) 2749 return; 2750 /* And we lose if both are dependent. */ 2751 if (u1 && u2) 2752 return; 2753 /* Or if they have different forms. */ 2754 if (TREE_CODE (type1) != TREE_CODE (type2)) 2755 return; 2756 2757 if (u1 && !u2) 2758 type1 = type2; 2759 else if (u2 && !u1) 2760 type2 = type1; 2761 } 2762 2763 /* If we're dealing with two pointer types or two enumeral types, 2764 we need candidates for both of them. */ 2765 if (type2 && !same_type_p (type1, type2) 2766 && TREE_CODE (type1) == TREE_CODE (type2) 2767 && (TREE_CODE (type1) == REFERENCE_TYPE 2768 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2769 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2770 || TYPE_PTRMEMFUNC_P (type1) 2771 || MAYBE_CLASS_TYPE_P (type1) 2772 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2773 { 2774 if (TYPE_PTR_OR_PTRMEM_P (type1)) 2775 { 2776 tree cptype = composite_pointer_type (type1, type2, 2777 error_mark_node, 2778 error_mark_node, 2779 CPO_CONVERSION, 2780 tf_none); 2781 if (cptype != error_mark_node) 2782 { 2783 build_builtin_candidate 2784 (candidates, fnname, cptype, cptype, args, argtypes, 2785 flags, complain); 2786 return; 2787 } 2788 } 2789 2790 build_builtin_candidate 2791 (candidates, fnname, type1, type1, args, argtypes, flags, complain); 2792 build_builtin_candidate 2793 (candidates, fnname, type2, type2, args, argtypes, flags, complain); 2794 return; 2795 } 2796 2797 build_builtin_candidate 2798 (candidates, fnname, type1, type2, args, argtypes, flags, complain); 2799 } 2800 2801 tree 2802 type_decays_to (tree type) 2803 { 2804 if (TREE_CODE (type) == ARRAY_TYPE) 2805 return build_pointer_type (TREE_TYPE (type)); 2806 if (TREE_CODE (type) == FUNCTION_TYPE) 2807 return build_pointer_type (type); 2808 return type; 2809 } 2810 2811 /* There are three conditions of builtin candidates: 2812 2813 1) bool-taking candidates. These are the same regardless of the input. 2814 2) pointer-pair taking candidates. These are generated for each type 2815 one of the input types converts to. 2816 3) arithmetic candidates. According to the standard, we should generate 2817 all of these, but I'm trying not to... 2818 2819 Here we generate a superset of the possible candidates for this particular 2820 case. That is a subset of the full set the standard defines, plus some 2821 other cases which the standard disallows. add_builtin_candidate will 2822 filter out the invalid set. */ 2823 2824 static void 2825 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2826 enum tree_code code2, tree fnname, tree *args, 2827 int flags, tsubst_flags_t complain) 2828 { 2829 int ref1, i; 2830 int enum_p = 0; 2831 tree type, argtypes[3], t; 2832 /* TYPES[i] is the set of possible builtin-operator parameter types 2833 we will consider for the Ith argument. */ 2834 vec<tree, va_gc> *types[2]; 2835 unsigned ix; 2836 2837 for (i = 0; i < 3; ++i) 2838 { 2839 if (args[i]) 2840 argtypes[i] = unlowered_expr_type (args[i]); 2841 else 2842 argtypes[i] = NULL_TREE; 2843 } 2844 2845 switch (code) 2846 { 2847 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2848 and VQ is either volatile or empty, there exist candidate operator 2849 functions of the form 2850 VQ T& operator++(VQ T&); */ 2851 2852 case POSTINCREMENT_EXPR: 2853 case PREINCREMENT_EXPR: 2854 case POSTDECREMENT_EXPR: 2855 case PREDECREMENT_EXPR: 2856 case MODIFY_EXPR: 2857 ref1 = 1; 2858 break; 2859 2860 /* 24There also exist candidate operator functions of the form 2861 bool operator!(bool); 2862 bool operator&&(bool, bool); 2863 bool operator||(bool, bool); */ 2864 2865 case TRUTH_NOT_EXPR: 2866 build_builtin_candidate 2867 (candidates, fnname, boolean_type_node, 2868 NULL_TREE, args, argtypes, flags, complain); 2869 return; 2870 2871 case TRUTH_ORIF_EXPR: 2872 case TRUTH_ANDIF_EXPR: 2873 build_builtin_candidate 2874 (candidates, fnname, boolean_type_node, 2875 boolean_type_node, args, argtypes, flags, complain); 2876 return; 2877 2878 case ADDR_EXPR: 2879 case COMPOUND_EXPR: 2880 case COMPONENT_REF: 2881 return; 2882 2883 case COND_EXPR: 2884 case EQ_EXPR: 2885 case NE_EXPR: 2886 case LT_EXPR: 2887 case LE_EXPR: 2888 case GT_EXPR: 2889 case GE_EXPR: 2890 enum_p = 1; 2891 /* Fall through. */ 2892 2893 default: 2894 ref1 = 0; 2895 } 2896 2897 types[0] = make_tree_vector (); 2898 types[1] = make_tree_vector (); 2899 2900 for (i = 0; i < 2; ++i) 2901 { 2902 if (! args[i]) 2903 ; 2904 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2905 { 2906 tree convs; 2907 2908 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2909 return; 2910 2911 convs = lookup_conversions (argtypes[i]); 2912 2913 if (code == COND_EXPR) 2914 { 2915 if (real_lvalue_p (args[i])) 2916 vec_safe_push (types[i], build_reference_type (argtypes[i])); 2917 2918 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i])); 2919 } 2920 2921 else if (! convs) 2922 return; 2923 2924 for (; convs; convs = TREE_CHAIN (convs)) 2925 { 2926 type = TREE_TYPE (convs); 2927 2928 if (i == 0 && ref1 2929 && (TREE_CODE (type) != REFERENCE_TYPE 2930 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 2931 continue; 2932 2933 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 2934 vec_safe_push (types[i], type); 2935 2936 type = non_reference (type); 2937 if (i != 0 || ! ref1) 2938 { 2939 type = cv_unqualified (type_decays_to (type)); 2940 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 2941 vec_safe_push (types[i], type); 2942 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2943 type = type_promotes_to (type); 2944 } 2945 2946 if (! vec_member (type, types[i])) 2947 vec_safe_push (types[i], type); 2948 } 2949 } 2950 else 2951 { 2952 if (code == COND_EXPR && real_lvalue_p (args[i])) 2953 vec_safe_push (types[i], build_reference_type (argtypes[i])); 2954 type = non_reference (argtypes[i]); 2955 if (i != 0 || ! ref1) 2956 { 2957 type = cv_unqualified (type_decays_to (type)); 2958 if (enum_p && UNSCOPED_ENUM_P (type)) 2959 vec_safe_push (types[i], type); 2960 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2961 type = type_promotes_to (type); 2962 } 2963 vec_safe_push (types[i], type); 2964 } 2965 } 2966 2967 /* Run through the possible parameter types of both arguments, 2968 creating candidates with those parameter types. */ 2969 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t) 2970 { 2971 unsigned jx; 2972 tree u; 2973 2974 if (!types[1]->is_empty ()) 2975 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u) 2976 add_builtin_candidate 2977 (candidates, code, code2, fnname, t, 2978 u, args, argtypes, flags, complain); 2979 else 2980 add_builtin_candidate 2981 (candidates, code, code2, fnname, t, 2982 NULL_TREE, args, argtypes, flags, complain); 2983 } 2984 2985 release_tree_vector (types[0]); 2986 release_tree_vector (types[1]); 2987 } 2988 2989 2990 /* If TMPL can be successfully instantiated as indicated by 2991 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 2992 2993 TMPL is the template. EXPLICIT_TARGS are any explicit template 2994 arguments. ARGLIST is the arguments provided at the call-site. 2995 This does not change ARGLIST. The RETURN_TYPE is the desired type 2996 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 2997 as for add_function_candidate. If an OBJ is supplied, FLAGS and 2998 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 2999 3000 static struct z_candidate* 3001 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 3002 tree ctype, tree explicit_targs, tree first_arg, 3003 const vec<tree, va_gc> *arglist, tree return_type, 3004 tree access_path, tree conversion_path, 3005 int flags, tree obj, unification_kind_t strict, 3006 tsubst_flags_t complain) 3007 { 3008 int ntparms = DECL_NTPARMS (tmpl); 3009 tree targs = make_tree_vec (ntparms); 3010 unsigned int len = vec_safe_length (arglist); 3011 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 3012 unsigned int skip_without_in_chrg = 0; 3013 tree first_arg_without_in_chrg = first_arg; 3014 tree *args_without_in_chrg; 3015 unsigned int nargs_without_in_chrg; 3016 unsigned int ia, ix; 3017 tree arg; 3018 struct z_candidate *cand; 3019 tree fn; 3020 struct rejection_reason *reason = NULL; 3021 int errs; 3022 3023 /* We don't do deduction on the in-charge parameter, the VTT 3024 parameter or 'this'. */ 3025 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 3026 { 3027 if (first_arg_without_in_chrg != NULL_TREE) 3028 first_arg_without_in_chrg = NULL_TREE; 3029 else 3030 ++skip_without_in_chrg; 3031 } 3032 3033 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 3034 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 3035 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 3036 { 3037 if (first_arg_without_in_chrg != NULL_TREE) 3038 first_arg_without_in_chrg = NULL_TREE; 3039 else 3040 ++skip_without_in_chrg; 3041 } 3042 3043 if (len < skip_without_in_chrg) 3044 return NULL; 3045 3046 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 3047 + (len - skip_without_in_chrg)); 3048 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 3049 ia = 0; 3050 if (first_arg_without_in_chrg != NULL_TREE) 3051 { 3052 args_without_in_chrg[ia] = first_arg_without_in_chrg; 3053 ++ia; 3054 } 3055 for (ix = skip_without_in_chrg; 3056 vec_safe_iterate (arglist, ix, &arg); 3057 ++ix) 3058 { 3059 args_without_in_chrg[ia] = arg; 3060 ++ia; 3061 } 3062 gcc_assert (ia == nargs_without_in_chrg); 3063 3064 errs = errorcount+sorrycount; 3065 fn = fn_type_unification (tmpl, explicit_targs, targs, 3066 args_without_in_chrg, 3067 nargs_without_in_chrg, 3068 return_type, strict, flags, false, 3069 complain & tf_decltype); 3070 3071 if (fn == error_mark_node) 3072 { 3073 /* Don't repeat unification later if it already resulted in errors. */ 3074 if (errorcount+sorrycount == errs) 3075 reason = template_unification_rejection (tmpl, explicit_targs, 3076 targs, args_without_in_chrg, 3077 nargs_without_in_chrg, 3078 return_type, strict, flags); 3079 else 3080 reason = template_unification_error_rejection (); 3081 goto fail; 3082 } 3083 3084 /* In [class.copy]: 3085 3086 A member function template is never instantiated to perform the 3087 copy of a class object to an object of its class type. 3088 3089 It's a little unclear what this means; the standard explicitly 3090 does allow a template to be used to copy a class. For example, 3091 in: 3092 3093 struct A { 3094 A(A&); 3095 template <class T> A(const T&); 3096 }; 3097 const A f (); 3098 void g () { A a (f ()); } 3099 3100 the member template will be used to make the copy. The section 3101 quoted above appears in the paragraph that forbids constructors 3102 whose only parameter is (a possibly cv-qualified variant of) the 3103 class type, and a logical interpretation is that the intent was 3104 to forbid the instantiation of member templates which would then 3105 have that form. */ 3106 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 3107 { 3108 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 3109 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 3110 ctype)) 3111 { 3112 reason = invalid_copy_with_fn_template_rejection (); 3113 goto fail; 3114 } 3115 } 3116 3117 if (obj != NULL_TREE) 3118 /* Aha, this is a conversion function. */ 3119 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist, 3120 access_path, conversion_path, complain); 3121 else 3122 cand = add_function_candidate (candidates, fn, ctype, 3123 first_arg, arglist, access_path, 3124 conversion_path, flags, complain); 3125 if (DECL_TI_TEMPLATE (fn) != tmpl) 3126 /* This situation can occur if a member template of a template 3127 class is specialized. Then, instantiate_template might return 3128 an instantiation of the specialization, in which case the 3129 DECL_TI_TEMPLATE field will point at the original 3130 specialization. For example: 3131 3132 template <class T> struct S { template <class U> void f(U); 3133 template <> void f(int) {}; }; 3134 S<double> sd; 3135 sd.f(3); 3136 3137 Here, TMPL will be template <class U> S<double>::f(U). 3138 And, instantiate template will give us the specialization 3139 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 3140 for this will point at template <class T> template <> S<T>::f(int), 3141 so that we can find the definition. For the purposes of 3142 overload resolution, however, we want the original TMPL. */ 3143 cand->template_decl = build_template_info (tmpl, targs); 3144 else 3145 cand->template_decl = DECL_TEMPLATE_INFO (fn); 3146 cand->explicit_targs = explicit_targs; 3147 3148 return cand; 3149 fail: 3150 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 3151 access_path, conversion_path, 0, reason, flags); 3152 } 3153 3154 3155 static struct z_candidate * 3156 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 3157 tree explicit_targs, tree first_arg, 3158 const vec<tree, va_gc> *arglist, tree return_type, 3159 tree access_path, tree conversion_path, int flags, 3160 unification_kind_t strict, tsubst_flags_t complain) 3161 { 3162 return 3163 add_template_candidate_real (candidates, tmpl, ctype, 3164 explicit_targs, first_arg, arglist, 3165 return_type, access_path, conversion_path, 3166 flags, NULL_TREE, strict, complain); 3167 } 3168 3169 3170 static struct z_candidate * 3171 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3172 tree obj, tree first_arg, 3173 const vec<tree, va_gc> *arglist, 3174 tree return_type, tree access_path, 3175 tree conversion_path, tsubst_flags_t complain) 3176 { 3177 return 3178 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3179 first_arg, arglist, return_type, access_path, 3180 conversion_path, 0, obj, DEDUCE_CONV, 3181 complain); 3182 } 3183 3184 /* The CANDS are the set of candidates that were considered for 3185 overload resolution. Return the set of viable candidates, or CANDS 3186 if none are viable. If any of the candidates were viable, set 3187 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3188 considered viable only if it is strictly viable. */ 3189 3190 static struct z_candidate* 3191 splice_viable (struct z_candidate *cands, 3192 bool strict_p, 3193 bool *any_viable_p) 3194 { 3195 struct z_candidate *viable; 3196 struct z_candidate **last_viable; 3197 struct z_candidate **cand; 3198 bool found_strictly_viable = false; 3199 3200 /* Be strict inside templates, since build_over_call won't actually 3201 do the conversions to get pedwarns. */ 3202 if (processing_template_decl) 3203 strict_p = true; 3204 3205 viable = NULL; 3206 last_viable = &viable; 3207 *any_viable_p = false; 3208 3209 cand = &cands; 3210 while (*cand) 3211 { 3212 struct z_candidate *c = *cand; 3213 if (!strict_p 3214 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL)) 3215 { 3216 /* Be strict in the presence of a viable candidate. Also if 3217 there are template candidates, so that we get deduction errors 3218 for them instead of silently preferring a bad conversion. */ 3219 strict_p = true; 3220 if (viable && !found_strictly_viable) 3221 { 3222 /* Put any spliced near matches back onto the main list so 3223 that we see them if there is no strict match. */ 3224 *any_viable_p = false; 3225 *last_viable = cands; 3226 cands = viable; 3227 viable = NULL; 3228 last_viable = &viable; 3229 } 3230 } 3231 3232 if (strict_p ? c->viable == 1 : c->viable) 3233 { 3234 *last_viable = c; 3235 *cand = c->next; 3236 c->next = NULL; 3237 last_viable = &c->next; 3238 *any_viable_p = true; 3239 if (c->viable == 1) 3240 found_strictly_viable = true; 3241 } 3242 else 3243 cand = &c->next; 3244 } 3245 3246 return viable ? viable : cands; 3247 } 3248 3249 static bool 3250 any_strictly_viable (struct z_candidate *cands) 3251 { 3252 for (; cands; cands = cands->next) 3253 if (cands->viable == 1) 3254 return true; 3255 return false; 3256 } 3257 3258 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3259 words, it is about to become the "this" pointer for a member 3260 function call. Take the address of the object. */ 3261 3262 static tree 3263 build_this (tree obj) 3264 { 3265 /* In a template, we are only concerned about the type of the 3266 expression, so we can take a shortcut. */ 3267 if (processing_template_decl) 3268 return build_address (obj); 3269 3270 return cp_build_addr_expr (obj, tf_warning_or_error); 3271 } 3272 3273 /* Returns true iff functions are equivalent. Equivalent functions are 3274 not '==' only if one is a function-local extern function or if 3275 both are extern "C". */ 3276 3277 static inline int 3278 equal_functions (tree fn1, tree fn2) 3279 { 3280 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3281 return 0; 3282 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3283 return fn1 == fn2; 3284 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3285 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3286 return decls_match (fn1, fn2); 3287 return fn1 == fn2; 3288 } 3289 3290 /* Print information about a candidate being rejected due to INFO. */ 3291 3292 static void 3293 print_conversion_rejection (location_t loc, struct conversion_info *info) 3294 { 3295 tree from = info->from; 3296 if (!TYPE_P (from)) 3297 from = lvalue_type (from); 3298 if (info->n_arg == -1) 3299 { 3300 /* Conversion of implicit `this' argument failed. */ 3301 if (!TYPE_P (info->from)) 3302 /* A bad conversion for 'this' must be discarding cv-quals. */ 3303 inform (loc, " passing %qT as %<this%> " 3304 "argument discards qualifiers", 3305 from); 3306 else 3307 inform (loc, " no known conversion for implicit " 3308 "%<this%> parameter from %qT to %qT", 3309 from, info->to_type); 3310 } 3311 else if (!TYPE_P (info->from)) 3312 { 3313 if (info->n_arg >= 0) 3314 inform (loc, " conversion of argument %d would be ill-formed:", 3315 info->n_arg + 1); 3316 perform_implicit_conversion (info->to_type, info->from, 3317 tf_warning_or_error); 3318 } 3319 else if (info->n_arg == -2) 3320 /* Conversion of conversion function return value failed. */ 3321 inform (loc, " no known conversion from %qT to %qT", 3322 from, info->to_type); 3323 else 3324 inform (loc, " no known conversion for argument %d from %qT to %qT", 3325 info->n_arg + 1, from, info->to_type); 3326 } 3327 3328 /* Print information about a candidate with WANT parameters and we found 3329 HAVE. */ 3330 3331 static void 3332 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3333 { 3334 inform_n (loc, want, 3335 " candidate expects %d argument, %d provided", 3336 " candidate expects %d arguments, %d provided", 3337 want, have); 3338 } 3339 3340 /* Print information about one overload candidate CANDIDATE. MSGSTR 3341 is the text to print before the candidate itself. 3342 3343 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3344 to have been run through gettext by the caller. This wart makes 3345 life simpler in print_z_candidates and for the translators. */ 3346 3347 static void 3348 print_z_candidate (location_t loc, const char *msgstr, 3349 struct z_candidate *candidate) 3350 { 3351 const char *msg = (msgstr == NULL 3352 ? "" 3353 : ACONCAT ((msgstr, " ", NULL))); 3354 location_t cloc = location_of (candidate->fn); 3355 3356 if (identifier_p (candidate->fn)) 3357 { 3358 cloc = loc; 3359 if (candidate->num_convs == 3) 3360 inform (cloc, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn, 3361 candidate->convs[0]->type, 3362 candidate->convs[1]->type, 3363 candidate->convs[2]->type); 3364 else if (candidate->num_convs == 2) 3365 inform (cloc, "%s%D(%T, %T) <built-in>", msg, candidate->fn, 3366 candidate->convs[0]->type, 3367 candidate->convs[1]->type); 3368 else 3369 inform (cloc, "%s%D(%T) <built-in>", msg, candidate->fn, 3370 candidate->convs[0]->type); 3371 } 3372 else if (TYPE_P (candidate->fn)) 3373 inform (cloc, "%s%T <conversion>", msg, candidate->fn); 3374 else if (candidate->viable == -1) 3375 inform (cloc, "%s%#D <near match>", msg, candidate->fn); 3376 else if (DECL_DELETED_FN (candidate->fn)) 3377 inform (cloc, "%s%#D <deleted>", msg, candidate->fn); 3378 else 3379 inform (cloc, "%s%#D", msg, candidate->fn); 3380 /* Give the user some information about why this candidate failed. */ 3381 if (candidate->reason != NULL) 3382 { 3383 struct rejection_reason *r = candidate->reason; 3384 3385 switch (r->code) 3386 { 3387 case rr_arity: 3388 print_arity_information (cloc, r->u.arity.actual, 3389 r->u.arity.expected); 3390 break; 3391 case rr_arg_conversion: 3392 print_conversion_rejection (cloc, &r->u.conversion); 3393 break; 3394 case rr_bad_arg_conversion: 3395 print_conversion_rejection (cloc, &r->u.bad_conversion); 3396 break; 3397 case rr_explicit_conversion: 3398 inform (cloc, " return type %qT of explicit conversion function " 3399 "cannot be converted to %qT with a qualification " 3400 "conversion", r->u.conversion.from, 3401 r->u.conversion.to_type); 3402 break; 3403 case rr_template_conversion: 3404 inform (cloc, " conversion from return type %qT of template " 3405 "conversion function specialization to %qT is not an " 3406 "exact match", r->u.conversion.from, 3407 r->u.conversion.to_type); 3408 break; 3409 case rr_template_unification: 3410 /* We use template_unification_error_rejection if unification caused 3411 actual non-SFINAE errors, in which case we don't need to repeat 3412 them here. */ 3413 if (r->u.template_unification.tmpl == NULL_TREE) 3414 { 3415 inform (cloc, " substitution of deduced template arguments " 3416 "resulted in errors seen above"); 3417 break; 3418 } 3419 /* Re-run template unification with diagnostics. */ 3420 inform (cloc, " template argument deduction/substitution failed:"); 3421 fn_type_unification (r->u.template_unification.tmpl, 3422 r->u.template_unification.explicit_targs, 3423 (make_tree_vec 3424 (r->u.template_unification.num_targs)), 3425 r->u.template_unification.args, 3426 r->u.template_unification.nargs, 3427 r->u.template_unification.return_type, 3428 r->u.template_unification.strict, 3429 r->u.template_unification.flags, 3430 true, false); 3431 break; 3432 case rr_invalid_copy: 3433 inform (cloc, 3434 " a constructor taking a single argument of its own " 3435 "class type is invalid"); 3436 break; 3437 case rr_none: 3438 default: 3439 /* This candidate didn't have any issues or we failed to 3440 handle a particular code. Either way... */ 3441 gcc_unreachable (); 3442 } 3443 } 3444 } 3445 3446 static void 3447 print_z_candidates (location_t loc, struct z_candidate *candidates) 3448 { 3449 struct z_candidate *cand1; 3450 struct z_candidate **cand2; 3451 int n_candidates; 3452 3453 if (!candidates) 3454 return; 3455 3456 /* Remove non-viable deleted candidates. */ 3457 cand1 = candidates; 3458 for (cand2 = &cand1; *cand2; ) 3459 { 3460 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3461 && !(*cand2)->viable 3462 && DECL_DELETED_FN ((*cand2)->fn)) 3463 *cand2 = (*cand2)->next; 3464 else 3465 cand2 = &(*cand2)->next; 3466 } 3467 /* ...if there are any non-deleted ones. */ 3468 if (cand1) 3469 candidates = cand1; 3470 3471 /* There may be duplicates in the set of candidates. We put off 3472 checking this condition as long as possible, since we have no way 3473 to eliminate duplicates from a set of functions in less than n^2 3474 time. Now we are about to emit an error message, so it is more 3475 permissible to go slowly. */ 3476 for (cand1 = candidates; cand1; cand1 = cand1->next) 3477 { 3478 tree fn = cand1->fn; 3479 /* Skip builtin candidates and conversion functions. */ 3480 if (!DECL_P (fn)) 3481 continue; 3482 cand2 = &cand1->next; 3483 while (*cand2) 3484 { 3485 if (DECL_P ((*cand2)->fn) 3486 && equal_functions (fn, (*cand2)->fn)) 3487 *cand2 = (*cand2)->next; 3488 else 3489 cand2 = &(*cand2)->next; 3490 } 3491 } 3492 3493 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next) 3494 n_candidates++; 3495 3496 for (; candidates; candidates = candidates->next) 3497 print_z_candidate (loc, "candidate:", candidates); 3498 } 3499 3500 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3501 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3502 the result of the conversion function to convert it to the final 3503 desired type. Merge the two sequences into a single sequence, 3504 and return the merged sequence. */ 3505 3506 static conversion * 3507 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3508 { 3509 conversion **t; 3510 bool bad = user_seq->bad_p; 3511 3512 gcc_assert (user_seq->kind == ck_user); 3513 3514 /* Find the end of the second conversion sequence. */ 3515 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3516 { 3517 /* The entire sequence is a user-conversion sequence. */ 3518 (*t)->user_conv_p = true; 3519 if (bad) 3520 (*t)->bad_p = true; 3521 } 3522 3523 /* Replace the identity conversion with the user conversion 3524 sequence. */ 3525 *t = user_seq; 3526 3527 return std_seq; 3528 } 3529 3530 /* Handle overload resolution for initializing an object of class type from 3531 an initializer list. First we look for a suitable constructor that 3532 takes a std::initializer_list; if we don't find one, we then look for a 3533 non-list constructor. 3534 3535 Parameters are as for add_candidates, except that the arguments are in 3536 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and 3537 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3538 3539 static void 3540 add_list_candidates (tree fns, tree first_arg, 3541 tree init_list, tree totype, 3542 tree explicit_targs, bool template_only, 3543 tree conversion_path, tree access_path, 3544 int flags, 3545 struct z_candidate **candidates, 3546 tsubst_flags_t complain) 3547 { 3548 vec<tree, va_gc> *args; 3549 3550 gcc_assert (*candidates == NULL); 3551 3552 /* We're looking for a ctor for list-initialization. */ 3553 flags |= LOOKUP_LIST_INIT_CTOR; 3554 /* And we don't allow narrowing conversions. We also use this flag to 3555 avoid the copy constructor call for copy-list-initialization. */ 3556 flags |= LOOKUP_NO_NARROWING; 3557 3558 /* Always use the default constructor if the list is empty (DR 990). */ 3559 if (CONSTRUCTOR_NELTS (init_list) == 0 3560 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3561 ; 3562 /* If the class has a list ctor, try passing the list as a single 3563 argument first, but only consider list ctors. */ 3564 else if (TYPE_HAS_LIST_CTOR (totype)) 3565 { 3566 flags |= LOOKUP_LIST_ONLY; 3567 args = make_tree_vector_single (init_list); 3568 add_candidates (fns, first_arg, args, NULL_TREE, 3569 explicit_targs, template_only, conversion_path, 3570 access_path, flags, candidates, complain); 3571 if (any_strictly_viable (*candidates)) 3572 return; 3573 } 3574 3575 args = ctor_to_vec (init_list); 3576 3577 /* We aren't looking for list-ctors anymore. */ 3578 flags &= ~LOOKUP_LIST_ONLY; 3579 /* We allow more user-defined conversions within an init-list. */ 3580 flags &= ~LOOKUP_NO_CONVERSION; 3581 3582 add_candidates (fns, first_arg, args, NULL_TREE, 3583 explicit_targs, template_only, conversion_path, 3584 access_path, flags, candidates, complain); 3585 } 3586 3587 /* Returns the best overload candidate to perform the requested 3588 conversion. This function is used for three the overloading situations 3589 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3590 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3591 per [dcl.init.ref], so we ignore temporary bindings. */ 3592 3593 static struct z_candidate * 3594 build_user_type_conversion_1 (tree totype, tree expr, int flags, 3595 tsubst_flags_t complain) 3596 { 3597 struct z_candidate *candidates, *cand; 3598 tree fromtype; 3599 tree ctors = NULL_TREE; 3600 tree conv_fns = NULL_TREE; 3601 conversion *conv = NULL; 3602 tree first_arg = NULL_TREE; 3603 vec<tree, va_gc> *args = NULL; 3604 bool any_viable_p; 3605 int convflags; 3606 3607 if (!expr) 3608 return NULL; 3609 3610 fromtype = TREE_TYPE (expr); 3611 3612 /* We represent conversion within a hierarchy using RVALUE_CONV and 3613 BASE_CONV, as specified by [over.best.ics]; these become plain 3614 constructor calls, as specified in [dcl.init]. */ 3615 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3616 || !DERIVED_FROM_P (totype, fromtype)); 3617 3618 if (MAYBE_CLASS_TYPE_P (totype)) 3619 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3620 creating a garbage BASELINK; constructors can't be inherited. */ 3621 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier); 3622 3623 if (MAYBE_CLASS_TYPE_P (fromtype)) 3624 { 3625 tree to_nonref = non_reference (totype); 3626 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3627 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3628 && DERIVED_FROM_P (to_nonref, fromtype))) 3629 { 3630 /* [class.conv.fct] A conversion function is never used to 3631 convert a (possibly cv-qualified) object to the (possibly 3632 cv-qualified) same object type (or a reference to it), to a 3633 (possibly cv-qualified) base class of that type (or a 3634 reference to it)... */ 3635 } 3636 else 3637 conv_fns = lookup_conversions (fromtype); 3638 } 3639 3640 candidates = 0; 3641 flags |= LOOKUP_NO_CONVERSION; 3642 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3643 flags |= LOOKUP_NO_NARROWING; 3644 3645 /* It's OK to bind a temporary for converting constructor arguments, but 3646 not in converting the return value of a conversion operator. */ 3647 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION 3648 | (flags & LOOKUP_NO_NARROWING)); 3649 flags &= ~LOOKUP_NO_TEMP_BIND; 3650 3651 if (ctors) 3652 { 3653 int ctorflags = flags; 3654 3655 first_arg = build_dummy_object (totype); 3656 3657 /* We should never try to call the abstract or base constructor 3658 from here. */ 3659 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors)) 3660 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors))); 3661 3662 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3663 { 3664 /* List-initialization. */ 3665 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE, 3666 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3667 ctorflags, &candidates, complain); 3668 } 3669 else 3670 { 3671 args = make_tree_vector_single (expr); 3672 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3673 TYPE_BINFO (totype), TYPE_BINFO (totype), 3674 ctorflags, &candidates, complain); 3675 } 3676 3677 for (cand = candidates; cand; cand = cand->next) 3678 { 3679 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3680 3681 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3682 set, then this is copy-initialization. In that case, "The 3683 result of the call is then used to direct-initialize the 3684 object that is the destination of the copy-initialization." 3685 [dcl.init] 3686 3687 We represent this in the conversion sequence with an 3688 rvalue conversion, which means a constructor call. */ 3689 if (TREE_CODE (totype) != REFERENCE_TYPE 3690 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3691 cand->second_conv 3692 = build_conv (ck_rvalue, totype, cand->second_conv); 3693 } 3694 } 3695 3696 if (conv_fns) 3697 first_arg = expr; 3698 3699 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3700 { 3701 tree conversion_path = TREE_PURPOSE (conv_fns); 3702 struct z_candidate *old_candidates; 3703 3704 /* If we are called to convert to a reference type, we are trying to 3705 find a direct binding, so don't even consider temporaries. If 3706 we don't find a direct binding, the caller will try again to 3707 look for a temporary binding. */ 3708 if (TREE_CODE (totype) == REFERENCE_TYPE) 3709 convflags |= LOOKUP_NO_TEMP_BIND; 3710 3711 old_candidates = candidates; 3712 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3713 NULL_TREE, false, 3714 conversion_path, TYPE_BINFO (fromtype), 3715 flags, &candidates, complain); 3716 3717 for (cand = candidates; cand != old_candidates; cand = cand->next) 3718 { 3719 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 3720 conversion *ics 3721 = implicit_conversion (totype, 3722 rettype, 3723 0, 3724 /*c_cast_p=*/false, convflags, 3725 complain); 3726 3727 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 3728 copy-initialization. In that case, "The result of the 3729 call is then used to direct-initialize the object that is 3730 the destination of the copy-initialization." [dcl.init] 3731 3732 We represent this in the conversion sequence with an 3733 rvalue conversion, which means a constructor call. But 3734 don't add a second rvalue conversion if there's already 3735 one there. Which there really shouldn't be, but it's 3736 harmless since we'd add it here anyway. */ 3737 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3738 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3739 ics = build_conv (ck_rvalue, totype, ics); 3740 3741 cand->second_conv = ics; 3742 3743 if (!ics) 3744 { 3745 cand->viable = 0; 3746 cand->reason = arg_conversion_rejection (NULL_TREE, -2, 3747 rettype, totype); 3748 } 3749 else if (DECL_NONCONVERTING_P (cand->fn) 3750 && ics->rank > cr_exact) 3751 { 3752 /* 13.3.1.5: For direct-initialization, those explicit 3753 conversion functions that are not hidden within S and 3754 yield type T or a type that can be converted to type T 3755 with a qualification conversion (4.4) are also candidate 3756 functions. */ 3757 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 3758 I've raised this issue with the committee. --jason 9/2011 */ 3759 cand->viable = -1; 3760 cand->reason = explicit_conversion_rejection (rettype, totype); 3761 } 3762 else if (cand->viable == 1 && ics->bad_p) 3763 { 3764 cand->viable = -1; 3765 cand->reason 3766 = bad_arg_conversion_rejection (NULL_TREE, -2, 3767 rettype, totype); 3768 } 3769 else if (primary_template_instantiation_p (cand->fn) 3770 && ics->rank > cr_exact) 3771 { 3772 /* 13.3.3.1.2: If the user-defined conversion is specified by 3773 a specialization of a conversion function template, the 3774 second standard conversion sequence shall have exact match 3775 rank. */ 3776 cand->viable = -1; 3777 cand->reason = template_conversion_rejection (rettype, totype); 3778 } 3779 } 3780 } 3781 3782 candidates = splice_viable (candidates, false, &any_viable_p); 3783 if (!any_viable_p) 3784 { 3785 if (args) 3786 release_tree_vector (args); 3787 return NULL; 3788 } 3789 3790 cand = tourney (candidates, complain); 3791 if (cand == 0) 3792 { 3793 if (complain & tf_error) 3794 { 3795 error ("conversion from %qT to %qT is ambiguous", 3796 fromtype, totype); 3797 print_z_candidates (location_of (expr), candidates); 3798 } 3799 3800 cand = candidates; /* any one will do */ 3801 cand->second_conv = build_ambiguous_conv (totype, expr); 3802 cand->second_conv->user_conv_p = true; 3803 if (!any_strictly_viable (candidates)) 3804 cand->second_conv->bad_p = true; 3805 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3806 ambiguous conversion is no worse than another user-defined 3807 conversion. */ 3808 3809 return cand; 3810 } 3811 3812 tree convtype; 3813 if (!DECL_CONSTRUCTOR_P (cand->fn)) 3814 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn))); 3815 else if (cand->second_conv->kind == ck_rvalue) 3816 /* DR 5: [in the first step of copy-initialization]...if the function 3817 is a constructor, the call initializes a temporary of the 3818 cv-unqualified version of the destination type. */ 3819 convtype = cv_unqualified (totype); 3820 else 3821 convtype = totype; 3822 /* Build the user conversion sequence. */ 3823 conv = build_conv 3824 (ck_user, 3825 convtype, 3826 build_identity_conv (TREE_TYPE (expr), expr)); 3827 conv->cand = cand; 3828 if (cand->viable == -1) 3829 conv->bad_p = true; 3830 3831 /* Remember that this was a list-initialization. */ 3832 if (flags & LOOKUP_NO_NARROWING) 3833 conv->check_narrowing = true; 3834 3835 /* Combine it with the second conversion sequence. */ 3836 cand->second_conv = merge_conversion_sequences (conv, 3837 cand->second_conv); 3838 3839 return cand; 3840 } 3841 3842 /* Wrapper for above. */ 3843 3844 tree 3845 build_user_type_conversion (tree totype, tree expr, int flags, 3846 tsubst_flags_t complain) 3847 { 3848 struct z_candidate *cand; 3849 tree ret; 3850 3851 bool subtime = timevar_cond_start (TV_OVERLOAD); 3852 cand = build_user_type_conversion_1 (totype, expr, flags, complain); 3853 3854 if (cand) 3855 { 3856 if (cand->second_conv->kind == ck_ambig) 3857 ret = error_mark_node; 3858 else 3859 { 3860 expr = convert_like (cand->second_conv, expr, complain); 3861 ret = convert_from_reference (expr); 3862 } 3863 } 3864 else 3865 ret = NULL_TREE; 3866 3867 timevar_cond_stop (TV_OVERLOAD, subtime); 3868 return ret; 3869 } 3870 3871 /* Subroutine of convert_nontype_argument. 3872 3873 EXPR is an argument for a template non-type parameter of integral or 3874 enumeration type. Do any necessary conversions (that are permitted for 3875 non-type arguments) to convert it to the parameter type. 3876 3877 If conversion is successful, returns the converted expression; 3878 otherwise, returns error_mark_node. */ 3879 3880 tree 3881 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain) 3882 { 3883 conversion *conv; 3884 void *p; 3885 tree t; 3886 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 3887 3888 if (error_operand_p (expr)) 3889 return error_mark_node; 3890 3891 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type)); 3892 3893 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3894 p = conversion_obstack_alloc (0); 3895 3896 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 3897 /*c_cast_p=*/false, 3898 LOOKUP_IMPLICIT, complain); 3899 3900 /* for a non-type template-parameter of integral or 3901 enumeration type, integral promotions (4.5) and integral 3902 conversions (4.7) are applied. */ 3903 /* It should be sufficient to check the outermost conversion step, since 3904 there are no qualification conversions to integer type. */ 3905 if (conv) 3906 switch (conv->kind) 3907 { 3908 /* A conversion function is OK. If it isn't constexpr, we'll 3909 complain later that the argument isn't constant. */ 3910 case ck_user: 3911 /* The lvalue-to-rvalue conversion is OK. */ 3912 case ck_rvalue: 3913 case ck_identity: 3914 break; 3915 3916 case ck_std: 3917 t = next_conversion (conv)->type; 3918 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t)) 3919 break; 3920 3921 if (complain & tf_error) 3922 error_at (loc, "conversion from %qT to %qT not considered for " 3923 "non-type template argument", t, type); 3924 /* and fall through. */ 3925 3926 default: 3927 conv = NULL; 3928 break; 3929 } 3930 3931 if (conv) 3932 expr = convert_like (conv, expr, complain); 3933 else 3934 expr = error_mark_node; 3935 3936 /* Free all the conversions we allocated. */ 3937 obstack_free (&conversion_obstack, p); 3938 3939 return expr; 3940 } 3941 3942 /* Do any initial processing on the arguments to a function call. */ 3943 3944 static vec<tree, va_gc> * 3945 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain) 3946 { 3947 unsigned int ix; 3948 tree arg; 3949 3950 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 3951 { 3952 if (error_operand_p (arg)) 3953 return NULL; 3954 else if (VOID_TYPE_P (TREE_TYPE (arg))) 3955 { 3956 if (complain & tf_error) 3957 error ("invalid use of void expression"); 3958 return NULL; 3959 } 3960 else if (invalid_nonstatic_memfn_p (arg, complain)) 3961 return NULL; 3962 } 3963 return args; 3964 } 3965 3966 /* Perform overload resolution on FN, which is called with the ARGS. 3967 3968 Return the candidate function selected by overload resolution, or 3969 NULL if the event that overload resolution failed. In the case 3970 that overload resolution fails, *CANDIDATES will be the set of 3971 candidates considered, and ANY_VIABLE_P will be set to true or 3972 false to indicate whether or not any of the candidates were 3973 viable. 3974 3975 The ARGS should already have gone through RESOLVE_ARGS before this 3976 function is called. */ 3977 3978 static struct z_candidate * 3979 perform_overload_resolution (tree fn, 3980 const vec<tree, va_gc> *args, 3981 struct z_candidate **candidates, 3982 bool *any_viable_p, tsubst_flags_t complain) 3983 { 3984 struct z_candidate *cand; 3985 tree explicit_targs; 3986 int template_only; 3987 3988 bool subtime = timevar_cond_start (TV_OVERLOAD); 3989 3990 explicit_targs = NULL_TREE; 3991 template_only = 0; 3992 3993 *candidates = NULL; 3994 *any_viable_p = true; 3995 3996 /* Check FN. */ 3997 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 3998 || TREE_CODE (fn) == TEMPLATE_DECL 3999 || TREE_CODE (fn) == OVERLOAD 4000 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 4001 4002 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4003 { 4004 explicit_targs = TREE_OPERAND (fn, 1); 4005 fn = TREE_OPERAND (fn, 0); 4006 template_only = 1; 4007 } 4008 4009 /* Add the various candidate functions. */ 4010 add_candidates (fn, NULL_TREE, args, NULL_TREE, 4011 explicit_targs, template_only, 4012 /*conversion_path=*/NULL_TREE, 4013 /*access_path=*/NULL_TREE, 4014 LOOKUP_NORMAL, 4015 candidates, complain); 4016 4017 *candidates = splice_viable (*candidates, false, any_viable_p); 4018 if (*any_viable_p) 4019 cand = tourney (*candidates, complain); 4020 else 4021 cand = NULL; 4022 4023 timevar_cond_stop (TV_OVERLOAD, subtime); 4024 return cand; 4025 } 4026 4027 /* Print an error message about being unable to build a call to FN with 4028 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 4029 be located; CANDIDATES is a possibly empty list of such 4030 functions. */ 4031 4032 static void 4033 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args, 4034 struct z_candidate *candidates) 4035 { 4036 tree name = DECL_NAME (OVL_CURRENT (fn)); 4037 location_t loc = location_of (name); 4038 4039 if (!any_strictly_viable (candidates)) 4040 error_at (loc, "no matching function for call to %<%D(%A)%>", 4041 name, build_tree_list_vec (args)); 4042 else 4043 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 4044 name, build_tree_list_vec (args)); 4045 if (candidates) 4046 print_z_candidates (loc, candidates); 4047 } 4048 4049 /* Return an expression for a call to FN (a namespace-scope function, 4050 or a static member function) with the ARGS. This may change 4051 ARGS. */ 4052 4053 tree 4054 build_new_function_call (tree fn, vec<tree, va_gc> **args, bool koenig_p, 4055 tsubst_flags_t complain) 4056 { 4057 struct z_candidate *candidates, *cand; 4058 bool any_viable_p; 4059 void *p; 4060 tree result; 4061 4062 if (args != NULL && *args != NULL) 4063 { 4064 *args = resolve_args (*args, complain); 4065 if (*args == NULL) 4066 return error_mark_node; 4067 } 4068 4069 if (flag_tm) 4070 tm_malloc_replacement (fn); 4071 4072 /* If this function was found without using argument dependent 4073 lookup, then we want to ignore any undeclared friend 4074 functions. */ 4075 if (!koenig_p) 4076 { 4077 tree orig_fn = fn; 4078 4079 fn = remove_hidden_names (fn); 4080 if (!fn) 4081 { 4082 if (complain & tf_error) 4083 print_error_for_call_failure (orig_fn, *args, NULL); 4084 return error_mark_node; 4085 } 4086 } 4087 4088 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4089 p = conversion_obstack_alloc (0); 4090 4091 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p, 4092 complain); 4093 4094 if (!cand) 4095 { 4096 if (complain & tf_error) 4097 { 4098 if (!any_viable_p && candidates && ! candidates->next 4099 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 4100 return cp_build_function_call_vec (candidates->fn, args, complain); 4101 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4102 fn = TREE_OPERAND (fn, 0); 4103 print_error_for_call_failure (fn, *args, candidates); 4104 } 4105 result = error_mark_node; 4106 } 4107 else 4108 { 4109 int flags = LOOKUP_NORMAL; 4110 /* If fn is template_id_expr, the call has explicit template arguments 4111 (e.g. func<int>(5)), communicate this info to build_over_call 4112 through flags so that later we can use it to decide whether to warn 4113 about peculiar null pointer conversion. */ 4114 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4115 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 4116 result = build_over_call (cand, flags, complain); 4117 } 4118 4119 /* Free all the conversions we allocated. */ 4120 obstack_free (&conversion_obstack, p); 4121 4122 return result; 4123 } 4124 4125 /* Build a call to a global operator new. FNNAME is the name of the 4126 operator (either "operator new" or "operator new[]") and ARGS are 4127 the arguments provided. This may change ARGS. *SIZE points to the 4128 total number of bytes required by the allocation, and is updated if 4129 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 4130 be used. If this function determines that no cookie should be 4131 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK 4132 is not NULL_TREE, it is evaluated before calculating the final 4133 array size, and if it fails, the array size is replaced with 4134 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN 4135 is non-NULL, it will be set, upon return, to the allocation 4136 function called. */ 4137 4138 tree 4139 build_operator_new_call (tree fnname, vec<tree, va_gc> **args, 4140 tree *size, tree *cookie_size, tree size_check, 4141 tree *fn, tsubst_flags_t complain) 4142 { 4143 tree original_size = *size; 4144 tree fns; 4145 struct z_candidate *candidates; 4146 struct z_candidate *cand; 4147 bool any_viable_p; 4148 4149 if (fn) 4150 *fn = NULL_TREE; 4151 /* Set to (size_t)-1 if the size check fails. */ 4152 if (size_check != NULL_TREE) 4153 { 4154 tree errval = TYPE_MAX_VALUE (sizetype); 4155 if (cxx_dialect >= cxx11 && flag_exceptions) 4156 errval = throw_bad_array_new_length (); 4157 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4158 original_size, errval); 4159 } 4160 vec_safe_insert (*args, 0, *size); 4161 *args = resolve_args (*args, complain); 4162 if (*args == NULL) 4163 return error_mark_node; 4164 4165 /* Based on: 4166 4167 [expr.new] 4168 4169 If this lookup fails to find the name, or if the allocated type 4170 is not a class type, the allocation function's name is looked 4171 up in the global scope. 4172 4173 we disregard block-scope declarations of "operator new". */ 4174 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false); 4175 4176 /* Figure out what function is being called. */ 4177 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p, 4178 complain); 4179 4180 /* If no suitable function could be found, issue an error message 4181 and give up. */ 4182 if (!cand) 4183 { 4184 if (complain & tf_error) 4185 print_error_for_call_failure (fns, *args, candidates); 4186 return error_mark_node; 4187 } 4188 4189 /* If a cookie is required, add some extra space. Whether 4190 or not a cookie is required cannot be determined until 4191 after we know which function was called. */ 4192 if (*cookie_size) 4193 { 4194 bool use_cookie = true; 4195 tree arg_types; 4196 4197 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 4198 /* Skip the size_t parameter. */ 4199 arg_types = TREE_CHAIN (arg_types); 4200 /* Check the remaining parameters (if any). */ 4201 if (arg_types 4202 && TREE_CHAIN (arg_types) == void_list_node 4203 && same_type_p (TREE_VALUE (arg_types), 4204 ptr_type_node)) 4205 use_cookie = false; 4206 /* If we need a cookie, adjust the number of bytes allocated. */ 4207 if (use_cookie) 4208 { 4209 /* Update the total size. */ 4210 *size = size_binop (PLUS_EXPR, original_size, *cookie_size); 4211 /* Set to (size_t)-1 if the size check fails. */ 4212 gcc_assert (size_check != NULL_TREE); 4213 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4214 *size, TYPE_MAX_VALUE (sizetype)); 4215 /* Update the argument list to reflect the adjusted size. */ 4216 (**args)[0] = *size; 4217 } 4218 else 4219 *cookie_size = NULL_TREE; 4220 } 4221 4222 /* Tell our caller which function we decided to call. */ 4223 if (fn) 4224 *fn = cand->fn; 4225 4226 /* Build the CALL_EXPR. */ 4227 return build_over_call (cand, LOOKUP_NORMAL, complain); 4228 } 4229 4230 /* Build a new call to operator(). This may change ARGS. */ 4231 4232 static tree 4233 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4234 { 4235 struct z_candidate *candidates = 0, *cand; 4236 tree fns, convs, first_mem_arg = NULL_TREE; 4237 tree type = TREE_TYPE (obj); 4238 bool any_viable_p; 4239 tree result = NULL_TREE; 4240 void *p; 4241 4242 if (error_operand_p (obj)) 4243 return error_mark_node; 4244 4245 obj = prep_operand (obj); 4246 4247 if (TYPE_PTRMEMFUNC_P (type)) 4248 { 4249 if (complain & tf_error) 4250 /* It's no good looking for an overloaded operator() on a 4251 pointer-to-member-function. */ 4252 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj); 4253 return error_mark_node; 4254 } 4255 4256 if (TYPE_BINFO (type)) 4257 { 4258 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1); 4259 if (fns == error_mark_node) 4260 return error_mark_node; 4261 } 4262 else 4263 fns = NULL_TREE; 4264 4265 if (args != NULL && *args != NULL) 4266 { 4267 *args = resolve_args (*args, complain); 4268 if (*args == NULL) 4269 return error_mark_node; 4270 } 4271 4272 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4273 p = conversion_obstack_alloc (0); 4274 4275 if (fns) 4276 { 4277 first_mem_arg = obj; 4278 4279 add_candidates (BASELINK_FUNCTIONS (fns), 4280 first_mem_arg, *args, NULL_TREE, 4281 NULL_TREE, false, 4282 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4283 LOOKUP_NORMAL, &candidates, complain); 4284 } 4285 4286 convs = lookup_conversions (type); 4287 4288 for (; convs; convs = TREE_CHAIN (convs)) 4289 { 4290 tree fns = TREE_VALUE (convs); 4291 tree totype = TREE_TYPE (convs); 4292 4293 if (TYPE_PTRFN_P (totype) 4294 || TYPE_REFFN_P (totype) 4295 || (TREE_CODE (totype) == REFERENCE_TYPE 4296 && TYPE_PTRFN_P (TREE_TYPE (totype)))) 4297 for (; fns; fns = OVL_NEXT (fns)) 4298 { 4299 tree fn = OVL_CURRENT (fns); 4300 4301 if (DECL_NONCONVERTING_P (fn)) 4302 continue; 4303 4304 if (TREE_CODE (fn) == TEMPLATE_DECL) 4305 add_template_conv_candidate 4306 (&candidates, fn, obj, NULL_TREE, *args, totype, 4307 /*access_path=*/NULL_TREE, 4308 /*conversion_path=*/NULL_TREE, complain); 4309 else 4310 add_conv_candidate (&candidates, fn, obj, NULL_TREE, 4311 *args, /*conversion_path=*/NULL_TREE, 4312 /*access_path=*/NULL_TREE, complain); 4313 } 4314 } 4315 4316 /* Be strict here because if we choose a bad conversion candidate, the 4317 errors we get won't mention the call context. */ 4318 candidates = splice_viable (candidates, true, &any_viable_p); 4319 if (!any_viable_p) 4320 { 4321 if (complain & tf_error) 4322 { 4323 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4324 build_tree_list_vec (*args)); 4325 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4326 } 4327 result = error_mark_node; 4328 } 4329 else 4330 { 4331 cand = tourney (candidates, complain); 4332 if (cand == 0) 4333 { 4334 if (complain & tf_error) 4335 { 4336 error ("call of %<(%T) (%A)%> is ambiguous", 4337 TREE_TYPE (obj), build_tree_list_vec (*args)); 4338 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4339 } 4340 result = error_mark_node; 4341 } 4342 /* Since cand->fn will be a type, not a function, for a conversion 4343 function, we must be careful not to unconditionally look at 4344 DECL_NAME here. */ 4345 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4346 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR) 4347 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4348 else 4349 { 4350 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1, 4351 complain); 4352 obj = convert_from_reference (obj); 4353 result = cp_build_function_call_vec (obj, args, complain); 4354 } 4355 } 4356 4357 /* Free all the conversions we allocated. */ 4358 obstack_free (&conversion_obstack, p); 4359 4360 return result; 4361 } 4362 4363 /* Wrapper for above. */ 4364 4365 tree 4366 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4367 { 4368 tree ret; 4369 bool subtime = timevar_cond_start (TV_OVERLOAD); 4370 ret = build_op_call_1 (obj, args, complain); 4371 timevar_cond_stop (TV_OVERLOAD, subtime); 4372 return ret; 4373 } 4374 4375 /* Called by op_error to prepare format strings suitable for the error 4376 function. It concatenates a prefix (controlled by MATCH), ERRMSG, 4377 and a suffix (controlled by NTYPES). */ 4378 4379 static const char * 4380 op_error_string (const char *errmsg, int ntypes, bool match) 4381 { 4382 const char *msg; 4383 4384 const char *msgp = concat (match ? G_("ambiguous overload for ") 4385 : G_("no match for "), errmsg, NULL); 4386 4387 if (ntypes == 3) 4388 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL); 4389 else if (ntypes == 2) 4390 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL); 4391 else 4392 msg = concat (msgp, G_(" (operand type is %qT)"), NULL); 4393 4394 return msg; 4395 } 4396 4397 static void 4398 op_error (location_t loc, enum tree_code code, enum tree_code code2, 4399 tree arg1, tree arg2, tree arg3, bool match) 4400 { 4401 const char *opname; 4402 4403 if (code == MODIFY_EXPR) 4404 opname = assignment_operator_name_info[code2].name; 4405 else 4406 opname = operator_name_info[code].name; 4407 4408 switch (code) 4409 { 4410 case COND_EXPR: 4411 if (flag_diagnostics_show_caret) 4412 error_at (loc, op_error_string (G_("ternary %<operator?:%>"), 4413 3, match), 4414 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4415 else 4416 error_at (loc, op_error_string (G_("ternary %<operator?:%> " 4417 "in %<%E ? %E : %E%>"), 3, match), 4418 arg1, arg2, arg3, 4419 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4420 break; 4421 4422 case POSTINCREMENT_EXPR: 4423 case POSTDECREMENT_EXPR: 4424 if (flag_diagnostics_show_caret) 4425 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4426 opname, TREE_TYPE (arg1)); 4427 else 4428 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"), 4429 1, match), 4430 opname, arg1, opname, TREE_TYPE (arg1)); 4431 break; 4432 4433 case ARRAY_REF: 4434 if (flag_diagnostics_show_caret) 4435 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match), 4436 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4437 else 4438 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"), 4439 2, match), 4440 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4441 break; 4442 4443 case REALPART_EXPR: 4444 case IMAGPART_EXPR: 4445 if (flag_diagnostics_show_caret) 4446 error_at (loc, op_error_string (G_("%qs"), 1, match), 4447 opname, TREE_TYPE (arg1)); 4448 else 4449 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match), 4450 opname, opname, arg1, TREE_TYPE (arg1)); 4451 break; 4452 4453 default: 4454 if (arg2) 4455 if (flag_diagnostics_show_caret) 4456 error_at (loc, op_error_string (G_("%<operator%s%>"), 2, match), 4457 opname, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4458 else 4459 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"), 4460 2, match), 4461 opname, arg1, opname, arg2, 4462 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4463 else 4464 if (flag_diagnostics_show_caret) 4465 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4466 opname, TREE_TYPE (arg1)); 4467 else 4468 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"), 4469 1, match), 4470 opname, opname, arg1, TREE_TYPE (arg1)); 4471 break; 4472 } 4473 } 4474 4475 /* Return the implicit conversion sequence that could be used to 4476 convert E1 to E2 in [expr.cond]. */ 4477 4478 static conversion * 4479 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain) 4480 { 4481 tree t1 = non_reference (TREE_TYPE (e1)); 4482 tree t2 = non_reference (TREE_TYPE (e2)); 4483 conversion *conv; 4484 bool good_base; 4485 4486 /* [expr.cond] 4487 4488 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4489 implicitly converted (clause _conv_) to the type "lvalue reference to 4490 T2", subject to the constraint that in the conversion the 4491 reference must bind directly (_dcl.init.ref_) to an lvalue. 4492 4493 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be 4494 implicitly converted to the type "rvalue reference to T2", subject to 4495 the constraint that the reference must bind directly. */ 4496 if (lvalue_or_rvalue_with_address_p (e2)) 4497 { 4498 tree rtype = cp_build_reference_type (t2, !real_lvalue_p (e2)); 4499 conv = implicit_conversion (rtype, 4500 t1, 4501 e1, 4502 /*c_cast_p=*/false, 4503 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4504 |LOOKUP_ONLYCONVERTING, 4505 complain); 4506 if (conv && !conv->bad_p) 4507 return conv; 4508 } 4509 4510 /* If E2 is a prvalue or if neither of the conversions above can be done 4511 and at least one of the operands has (possibly cv-qualified) class 4512 type: */ 4513 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2)) 4514 return NULL; 4515 4516 /* [expr.cond] 4517 4518 If E1 and E2 have class type, and the underlying class types are 4519 the same or one is a base class of the other: E1 can be converted 4520 to match E2 if the class of T2 is the same type as, or a base 4521 class of, the class of T1, and the cv-qualification of T2 is the 4522 same cv-qualification as, or a greater cv-qualification than, the 4523 cv-qualification of T1. If the conversion is applied, E1 is 4524 changed to an rvalue of type T2 that still refers to the original 4525 source class object (or the appropriate subobject thereof). */ 4526 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4527 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4528 { 4529 if (good_base && at_least_as_qualified_p (t2, t1)) 4530 { 4531 conv = build_identity_conv (t1, e1); 4532 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4533 TYPE_MAIN_VARIANT (t2))) 4534 conv = build_conv (ck_base, t2, conv); 4535 else 4536 conv = build_conv (ck_rvalue, t2, conv); 4537 return conv; 4538 } 4539 else 4540 return NULL; 4541 } 4542 else 4543 /* [expr.cond] 4544 4545 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4546 converted to the type that expression E2 would have if E2 were 4547 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4548 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4549 LOOKUP_IMPLICIT, complain); 4550 } 4551 4552 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4553 arguments to the conditional expression. */ 4554 4555 static tree 4556 build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3, 4557 tsubst_flags_t complain) 4558 { 4559 tree arg2_type; 4560 tree arg3_type; 4561 tree result = NULL_TREE; 4562 tree result_type = NULL_TREE; 4563 bool lvalue_p = true; 4564 struct z_candidate *candidates = 0; 4565 struct z_candidate *cand; 4566 void *p; 4567 tree orig_arg2, orig_arg3; 4568 4569 /* As a G++ extension, the second argument to the conditional can be 4570 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 4571 c'.) If the second operand is omitted, make sure it is 4572 calculated only once. */ 4573 if (!arg2) 4574 { 4575 if (complain & tf_error) 4576 pedwarn (loc, OPT_Wpedantic, 4577 "ISO C++ forbids omitting the middle term of a ?: expression"); 4578 4579 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 4580 if (real_lvalue_p (arg1)) 4581 arg2 = arg1 = stabilize_reference (arg1); 4582 else 4583 arg2 = arg1 = save_expr (arg1); 4584 } 4585 4586 /* If something has already gone wrong, just pass that fact up the 4587 tree. */ 4588 if (error_operand_p (arg1) 4589 || error_operand_p (arg2) 4590 || error_operand_p (arg3)) 4591 return error_mark_node; 4592 4593 orig_arg2 = arg2; 4594 orig_arg3 = arg3; 4595 4596 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1))) 4597 { 4598 arg1 = force_rvalue (arg1, complain); 4599 arg2 = force_rvalue (arg2, complain); 4600 arg3 = force_rvalue (arg3, complain); 4601 4602 /* force_rvalue can return error_mark on valid arguments. */ 4603 if (error_operand_p (arg1) 4604 || error_operand_p (arg2) 4605 || error_operand_p (arg3)) 4606 return error_mark_node; 4607 4608 tree arg1_type = TREE_TYPE (arg1); 4609 arg2_type = TREE_TYPE (arg2); 4610 arg3_type = TREE_TYPE (arg3); 4611 4612 if (TREE_CODE (arg2_type) != VECTOR_TYPE 4613 && TREE_CODE (arg3_type) != VECTOR_TYPE) 4614 { 4615 /* Rely on the error messages of the scalar version. */ 4616 tree scal = build_conditional_expr_1 (loc, integer_one_node, 4617 orig_arg2, orig_arg3, complain); 4618 if (scal == error_mark_node) 4619 return error_mark_node; 4620 tree stype = TREE_TYPE (scal); 4621 tree ctype = TREE_TYPE (arg1_type); 4622 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype) 4623 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype))) 4624 { 4625 if (complain & tf_error) 4626 error_at (loc, "inferred scalar type %qT is not an integer or " 4627 "floating point type of the same size as %qT", stype, 4628 COMPARISON_CLASS_P (arg1) 4629 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0))) 4630 : ctype); 4631 return error_mark_node; 4632 } 4633 4634 tree vtype = build_opaque_vector_type (stype, 4635 TYPE_VECTOR_SUBPARTS (arg1_type)); 4636 /* We could pass complain & tf_warning to unsafe_conversion_p, 4637 but the warnings (like Wsign-conversion) have already been 4638 given by the scalar build_conditional_expr_1. We still check 4639 unsafe_conversion_p to forbid truncating long long -> float. */ 4640 if (unsafe_conversion_p (loc, stype, arg2, false)) 4641 { 4642 if (complain & tf_error) 4643 error_at (loc, "conversion of scalar %qT to vector %qT " 4644 "involves truncation", arg2_type, vtype); 4645 return error_mark_node; 4646 } 4647 if (unsafe_conversion_p (loc, stype, arg3, false)) 4648 { 4649 if (complain & tf_error) 4650 error_at (loc, "conversion of scalar %qT to vector %qT " 4651 "involves truncation", arg3_type, vtype); 4652 return error_mark_node; 4653 } 4654 4655 arg2 = cp_convert (stype, arg2, complain); 4656 arg2 = save_expr (arg2); 4657 arg2 = build_vector_from_val (vtype, arg2); 4658 arg2_type = vtype; 4659 arg3 = cp_convert (stype, arg3, complain); 4660 arg3 = save_expr (arg3); 4661 arg3 = build_vector_from_val (vtype, arg3); 4662 arg3_type = vtype; 4663 } 4664 4665 if ((TREE_CODE (arg2_type) == VECTOR_TYPE) 4666 != (TREE_CODE (arg3_type) == VECTOR_TYPE)) 4667 { 4668 enum stv_conv convert_flag = 4669 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3, 4670 complain & tf_error); 4671 4672 switch (convert_flag) 4673 { 4674 case stv_error: 4675 return error_mark_node; 4676 case stv_firstarg: 4677 { 4678 arg2 = save_expr (arg2); 4679 arg2 = convert (TREE_TYPE (arg3_type), arg2); 4680 arg2 = build_vector_from_val (arg3_type, arg2); 4681 arg2_type = TREE_TYPE (arg2); 4682 break; 4683 } 4684 case stv_secondarg: 4685 { 4686 arg3 = save_expr (arg3); 4687 arg3 = convert (TREE_TYPE (arg2_type), arg3); 4688 arg3 = build_vector_from_val (arg2_type, arg3); 4689 arg3_type = TREE_TYPE (arg3); 4690 break; 4691 } 4692 default: 4693 break; 4694 } 4695 } 4696 4697 if (!same_type_p (arg2_type, arg3_type) 4698 || TYPE_VECTOR_SUBPARTS (arg1_type) 4699 != TYPE_VECTOR_SUBPARTS (arg2_type) 4700 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type)) 4701 { 4702 if (complain & tf_error) 4703 error_at (loc, 4704 "incompatible vector types in conditional expression: " 4705 "%qT, %qT and %qT", TREE_TYPE (arg1), 4706 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3)); 4707 return error_mark_node; 4708 } 4709 4710 if (!COMPARISON_CLASS_P (arg1)) 4711 arg1 = cp_build_binary_op (loc, NE_EXPR, arg1, 4712 build_zero_cst (arg1_type), complain); 4713 return fold_build3 (VEC_COND_EXPR, arg2_type, arg1, arg2, arg3); 4714 } 4715 4716 /* [expr.cond] 4717 4718 The first expression is implicitly converted to bool (clause 4719 _conv_). */ 4720 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 4721 LOOKUP_NORMAL); 4722 if (error_operand_p (arg1)) 4723 return error_mark_node; 4724 4725 /* [expr.cond] 4726 4727 If either the second or the third operand has type (possibly 4728 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 4729 array-to-pointer (_conv.array_), and function-to-pointer 4730 (_conv.func_) standard conversions are performed on the second 4731 and third operands. */ 4732 arg2_type = unlowered_expr_type (arg2); 4733 arg3_type = unlowered_expr_type (arg3); 4734 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 4735 { 4736 /* Do the conversions. We don't these for `void' type arguments 4737 since it can't have any effect and since decay_conversion 4738 does not handle that case gracefully. */ 4739 if (!VOID_TYPE_P (arg2_type)) 4740 arg2 = decay_conversion (arg2, complain); 4741 if (!VOID_TYPE_P (arg3_type)) 4742 arg3 = decay_conversion (arg3, complain); 4743 arg2_type = TREE_TYPE (arg2); 4744 arg3_type = TREE_TYPE (arg3); 4745 4746 /* [expr.cond] 4747 4748 One of the following shall hold: 4749 4750 --The second or the third operand (but not both) is a 4751 throw-expression (_except.throw_); the result is of the 4752 type of the other and is an rvalue. 4753 4754 --Both the second and the third operands have type void; the 4755 result is of type void and is an rvalue. 4756 4757 We must avoid calling force_rvalue for expressions of type 4758 "void" because it will complain that their value is being 4759 used. */ 4760 if (TREE_CODE (arg2) == THROW_EXPR 4761 && TREE_CODE (arg3) != THROW_EXPR) 4762 { 4763 if (!VOID_TYPE_P (arg3_type)) 4764 { 4765 arg3 = force_rvalue (arg3, complain); 4766 if (arg3 == error_mark_node) 4767 return error_mark_node; 4768 } 4769 arg3_type = TREE_TYPE (arg3); 4770 result_type = arg3_type; 4771 } 4772 else if (TREE_CODE (arg2) != THROW_EXPR 4773 && TREE_CODE (arg3) == THROW_EXPR) 4774 { 4775 if (!VOID_TYPE_P (arg2_type)) 4776 { 4777 arg2 = force_rvalue (arg2, complain); 4778 if (arg2 == error_mark_node) 4779 return error_mark_node; 4780 } 4781 arg2_type = TREE_TYPE (arg2); 4782 result_type = arg2_type; 4783 } 4784 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 4785 result_type = void_type_node; 4786 else 4787 { 4788 if (complain & tf_error) 4789 { 4790 if (VOID_TYPE_P (arg2_type)) 4791 error_at (EXPR_LOC_OR_LOC (arg3, loc), 4792 "second operand to the conditional operator " 4793 "is of type %<void%>, but the third operand is " 4794 "neither a throw-expression nor of type %<void%>"); 4795 else 4796 error_at (EXPR_LOC_OR_LOC (arg2, loc), 4797 "third operand to the conditional operator " 4798 "is of type %<void%>, but the second operand is " 4799 "neither a throw-expression nor of type %<void%>"); 4800 } 4801 return error_mark_node; 4802 } 4803 4804 lvalue_p = false; 4805 goto valid_operands; 4806 } 4807 /* [expr.cond] 4808 4809 Otherwise, if the second and third operand have different types, 4810 and either has (possibly cv-qualified) class type, or if both are 4811 glvalues of the same value category and the same type except for 4812 cv-qualification, an attempt is made to convert each of those operands 4813 to the type of the other. */ 4814 else if (!same_type_p (arg2_type, arg3_type) 4815 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type) 4816 || (same_type_ignoring_top_level_qualifiers_p (arg2_type, 4817 arg3_type) 4818 && lvalue_or_rvalue_with_address_p (arg2) 4819 && lvalue_or_rvalue_with_address_p (arg3) 4820 && real_lvalue_p (arg2) == real_lvalue_p (arg3)))) 4821 { 4822 conversion *conv2; 4823 conversion *conv3; 4824 bool converted = false; 4825 4826 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4827 p = conversion_obstack_alloc (0); 4828 4829 conv2 = conditional_conversion (arg2, arg3, complain); 4830 conv3 = conditional_conversion (arg3, arg2, complain); 4831 4832 /* [expr.cond] 4833 4834 If both can be converted, or one can be converted but the 4835 conversion is ambiguous, the program is ill-formed. If 4836 neither can be converted, the operands are left unchanged and 4837 further checking is performed as described below. If exactly 4838 one conversion is possible, that conversion is applied to the 4839 chosen operand and the converted operand is used in place of 4840 the original operand for the remainder of this section. */ 4841 if ((conv2 && !conv2->bad_p 4842 && conv3 && !conv3->bad_p) 4843 || (conv2 && conv2->kind == ck_ambig) 4844 || (conv3 && conv3->kind == ck_ambig)) 4845 { 4846 if (complain & tf_error) 4847 { 4848 error_at (loc, "operands to ?: have different types %qT and %qT", 4849 arg2_type, arg3_type); 4850 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p) 4851 inform (loc, " and each type can be converted to the other"); 4852 else if (conv2 && conv2->kind == ck_ambig) 4853 convert_like (conv2, arg2, complain); 4854 else 4855 convert_like (conv3, arg3, complain); 4856 } 4857 result = error_mark_node; 4858 } 4859 else if (conv2 && !conv2->bad_p) 4860 { 4861 arg2 = convert_like (conv2, arg2, complain); 4862 arg2 = convert_from_reference (arg2); 4863 arg2_type = TREE_TYPE (arg2); 4864 /* Even if CONV2 is a valid conversion, the result of the 4865 conversion may be invalid. For example, if ARG3 has type 4866 "volatile X", and X does not have a copy constructor 4867 accepting a "volatile X&", then even if ARG2 can be 4868 converted to X, the conversion will fail. */ 4869 if (error_operand_p (arg2)) 4870 result = error_mark_node; 4871 converted = true; 4872 } 4873 else if (conv3 && !conv3->bad_p) 4874 { 4875 arg3 = convert_like (conv3, arg3, complain); 4876 arg3 = convert_from_reference (arg3); 4877 arg3_type = TREE_TYPE (arg3); 4878 if (error_operand_p (arg3)) 4879 result = error_mark_node; 4880 converted = true; 4881 } 4882 4883 /* Free all the conversions we allocated. */ 4884 obstack_free (&conversion_obstack, p); 4885 4886 if (result) 4887 return result; 4888 4889 /* If, after the conversion, both operands have class type, 4890 treat the cv-qualification of both operands as if it were the 4891 union of the cv-qualification of the operands. 4892 4893 The standard is not clear about what to do in this 4894 circumstance. For example, if the first operand has type 4895 "const X" and the second operand has a user-defined 4896 conversion to "volatile X", what is the type of the second 4897 operand after this step? Making it be "const X" (matching 4898 the first operand) seems wrong, as that discards the 4899 qualification without actually performing a copy. Leaving it 4900 as "volatile X" seems wrong as that will result in the 4901 conditional expression failing altogether, even though, 4902 according to this step, the one operand could be converted to 4903 the type of the other. */ 4904 if (converted 4905 && CLASS_TYPE_P (arg2_type) 4906 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 4907 arg2_type = arg3_type = 4908 cp_build_qualified_type (arg2_type, 4909 cp_type_quals (arg2_type) 4910 | cp_type_quals (arg3_type)); 4911 } 4912 4913 /* [expr.cond] 4914 4915 If the second and third operands are glvalues of the same value 4916 category and have the same type, the result is of that type and 4917 value category. */ 4918 if (((real_lvalue_p (arg2) && real_lvalue_p (arg3)) 4919 || (xvalue_p (arg2) && xvalue_p (arg3))) 4920 && same_type_p (arg2_type, arg3_type)) 4921 { 4922 result_type = arg2_type; 4923 arg2 = mark_lvalue_use (arg2); 4924 arg3 = mark_lvalue_use (arg3); 4925 goto valid_operands; 4926 } 4927 4928 /* [expr.cond] 4929 4930 Otherwise, the result is an rvalue. If the second and third 4931 operand do not have the same type, and either has (possibly 4932 cv-qualified) class type, overload resolution is used to 4933 determine the conversions (if any) to be applied to the operands 4934 (_over.match.oper_, _over.built_). */ 4935 lvalue_p = false; 4936 if (!same_type_p (arg2_type, arg3_type) 4937 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 4938 { 4939 tree args[3]; 4940 conversion *conv; 4941 bool any_viable_p; 4942 4943 /* Rearrange the arguments so that add_builtin_candidate only has 4944 to know about two args. In build_builtin_candidate, the 4945 arguments are unscrambled. */ 4946 args[0] = arg2; 4947 args[1] = arg3; 4948 args[2] = arg1; 4949 add_builtin_candidates (&candidates, 4950 COND_EXPR, 4951 NOP_EXPR, 4952 ansi_opname (COND_EXPR), 4953 args, 4954 LOOKUP_NORMAL, complain); 4955 4956 /* [expr.cond] 4957 4958 If the overload resolution fails, the program is 4959 ill-formed. */ 4960 candidates = splice_viable (candidates, false, &any_viable_p); 4961 if (!any_viable_p) 4962 { 4963 if (complain & tf_error) 4964 error_at (loc, "operands to ?: have different types %qT and %qT", 4965 arg2_type, arg3_type); 4966 return error_mark_node; 4967 } 4968 cand = tourney (candidates, complain); 4969 if (!cand) 4970 { 4971 if (complain & tf_error) 4972 { 4973 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 4974 print_z_candidates (loc, candidates); 4975 } 4976 return error_mark_node; 4977 } 4978 4979 /* [expr.cond] 4980 4981 Otherwise, the conversions thus determined are applied, and 4982 the converted operands are used in place of the original 4983 operands for the remainder of this section. */ 4984 conv = cand->convs[0]; 4985 arg1 = convert_like (conv, arg1, complain); 4986 conv = cand->convs[1]; 4987 arg2 = convert_like (conv, arg2, complain); 4988 arg2_type = TREE_TYPE (arg2); 4989 conv = cand->convs[2]; 4990 arg3 = convert_like (conv, arg3, complain); 4991 arg3_type = TREE_TYPE (arg3); 4992 } 4993 4994 /* [expr.cond] 4995 4996 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 4997 and function-to-pointer (_conv.func_) standard conversions are 4998 performed on the second and third operands. 4999 5000 We need to force the lvalue-to-rvalue conversion here for class types, 5001 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 5002 that isn't wrapped with a TARGET_EXPR plays havoc with exception 5003 regions. */ 5004 5005 arg2 = force_rvalue (arg2, complain); 5006 if (!CLASS_TYPE_P (arg2_type)) 5007 arg2_type = TREE_TYPE (arg2); 5008 5009 arg3 = force_rvalue (arg3, complain); 5010 if (!CLASS_TYPE_P (arg3_type)) 5011 arg3_type = TREE_TYPE (arg3); 5012 5013 if (arg2 == error_mark_node || arg3 == error_mark_node) 5014 return error_mark_node; 5015 5016 /* [expr.cond] 5017 5018 After those conversions, one of the following shall hold: 5019 5020 --The second and third operands have the same type; the result is of 5021 that type. */ 5022 if (same_type_p (arg2_type, arg3_type)) 5023 result_type = arg2_type; 5024 /* [expr.cond] 5025 5026 --The second and third operands have arithmetic or enumeration 5027 type; the usual arithmetic conversions are performed to bring 5028 them to a common type, and the result is of that type. */ 5029 else if ((ARITHMETIC_TYPE_P (arg2_type) 5030 || UNSCOPED_ENUM_P (arg2_type)) 5031 && (ARITHMETIC_TYPE_P (arg3_type) 5032 || UNSCOPED_ENUM_P (arg3_type))) 5033 { 5034 /* In this case, there is always a common type. */ 5035 result_type = type_after_usual_arithmetic_conversions (arg2_type, 5036 arg3_type); 5037 if (complain & tf_warning) 5038 do_warn_double_promotion (result_type, arg2_type, arg3_type, 5039 "implicit conversion from %qT to %qT to " 5040 "match other result of conditional", 5041 loc); 5042 5043 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 5044 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 5045 { 5046 if (TREE_CODE (orig_arg2) == CONST_DECL 5047 && TREE_CODE (orig_arg3) == CONST_DECL 5048 && DECL_CONTEXT (orig_arg2) == DECL_CONTEXT (orig_arg3)) 5049 /* Two enumerators from the same enumeration can have different 5050 types when the enumeration is still being defined. */; 5051 else if (complain & tf_warning) 5052 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in " 5053 "conditional expression: %qT vs %qT", 5054 arg2_type, arg3_type); 5055 } 5056 else if (extra_warnings 5057 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 5058 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 5059 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 5060 && !same_type_p (arg2_type, 5061 type_promotes_to (arg3_type))))) 5062 { 5063 if (complain & tf_warning) 5064 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in " 5065 "conditional expression"); 5066 } 5067 5068 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5069 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5070 } 5071 /* [expr.cond] 5072 5073 --The second and third operands have pointer type, or one has 5074 pointer type and the other is a null pointer constant; pointer 5075 conversions (_conv.ptr_) and qualification conversions 5076 (_conv.qual_) are performed to bring them to their composite 5077 pointer type (_expr.rel_). The result is of the composite 5078 pointer type. 5079 5080 --The second and third operands have pointer to member type, or 5081 one has pointer to member type and the other is a null pointer 5082 constant; pointer to member conversions (_conv.mem_) and 5083 qualification conversions (_conv.qual_) are performed to bring 5084 them to a common type, whose cv-qualification shall match the 5085 cv-qualification of either the second or the third operand. 5086 The result is of the common type. */ 5087 else if ((null_ptr_cst_p (arg2) 5088 && TYPE_PTR_OR_PTRMEM_P (arg3_type)) 5089 || (null_ptr_cst_p (arg3) 5090 && TYPE_PTR_OR_PTRMEM_P (arg2_type)) 5091 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 5092 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type)) 5093 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 5094 { 5095 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 5096 arg3, CPO_CONDITIONAL_EXPR, 5097 complain); 5098 if (result_type == error_mark_node) 5099 return error_mark_node; 5100 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5101 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5102 } 5103 5104 if (!result_type) 5105 { 5106 if (complain & tf_error) 5107 error_at (loc, "operands to ?: have different types %qT and %qT", 5108 arg2_type, arg3_type); 5109 return error_mark_node; 5110 } 5111 5112 if (arg2 == error_mark_node || arg3 == error_mark_node) 5113 return error_mark_node; 5114 5115 valid_operands: 5116 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3); 5117 if (!cp_unevaluated_operand) 5118 /* Avoid folding within decltype (c++/42013) and noexcept. */ 5119 result = fold_if_not_in_template (result); 5120 5121 /* We can't use result_type below, as fold might have returned a 5122 throw_expr. */ 5123 5124 if (!lvalue_p) 5125 { 5126 /* Expand both sides into the same slot, hopefully the target of 5127 the ?: expression. We used to check for TARGET_EXPRs here, 5128 but now we sometimes wrap them in NOP_EXPRs so the test would 5129 fail. */ 5130 if (CLASS_TYPE_P (TREE_TYPE (result))) 5131 result = get_target_expr_sfinae (result, complain); 5132 /* If this expression is an rvalue, but might be mistaken for an 5133 lvalue, we must add a NON_LVALUE_EXPR. */ 5134 result = rvalue (result); 5135 } 5136 else 5137 result = force_paren_expr (result); 5138 5139 return result; 5140 } 5141 5142 /* Wrapper for above. */ 5143 5144 tree 5145 build_conditional_expr (location_t loc, tree arg1, tree arg2, tree arg3, 5146 tsubst_flags_t complain) 5147 { 5148 tree ret; 5149 bool subtime = timevar_cond_start (TV_OVERLOAD); 5150 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain); 5151 timevar_cond_stop (TV_OVERLOAD, subtime); 5152 return ret; 5153 } 5154 5155 /* OPERAND is an operand to an expression. Perform necessary steps 5156 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 5157 returned. */ 5158 5159 static tree 5160 prep_operand (tree operand) 5161 { 5162 if (operand) 5163 { 5164 if (CLASS_TYPE_P (TREE_TYPE (operand)) 5165 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 5166 /* Make sure the template type is instantiated now. */ 5167 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 5168 } 5169 5170 return operand; 5171 } 5172 5173 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 5174 OVERLOAD) to the CANDIDATES, returning an updated list of 5175 CANDIDATES. The ARGS are the arguments provided to the call; 5176 if FIRST_ARG is non-null it is the implicit object argument, 5177 otherwise the first element of ARGS is used if needed. The 5178 EXPLICIT_TARGS are explicit template arguments provided. 5179 TEMPLATE_ONLY is true if only template functions should be 5180 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 5181 add_function_candidate. */ 5182 5183 static void 5184 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args, 5185 tree return_type, 5186 tree explicit_targs, bool template_only, 5187 tree conversion_path, tree access_path, 5188 int flags, 5189 struct z_candidate **candidates, 5190 tsubst_flags_t complain) 5191 { 5192 tree ctype; 5193 const vec<tree, va_gc> *non_static_args; 5194 bool check_list_ctor; 5195 bool check_converting; 5196 unification_kind_t strict; 5197 tree fn; 5198 5199 if (!fns) 5200 return; 5201 5202 /* Precalculate special handling of constructors and conversion ops. */ 5203 fn = OVL_CURRENT (fns); 5204 if (DECL_CONV_FN_P (fn)) 5205 { 5206 check_list_ctor = false; 5207 check_converting = !!(flags & LOOKUP_ONLYCONVERTING); 5208 if (flags & LOOKUP_NO_CONVERSION) 5209 /* We're doing return_type(x). */ 5210 strict = DEDUCE_CONV; 5211 else 5212 /* We're doing x.operator return_type(). */ 5213 strict = DEDUCE_EXACT; 5214 /* [over.match.funcs] For conversion functions, the function 5215 is considered to be a member of the class of the implicit 5216 object argument for the purpose of defining the type of 5217 the implicit object parameter. */ 5218 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg)); 5219 } 5220 else 5221 { 5222 if (DECL_CONSTRUCTOR_P (fn)) 5223 { 5224 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY); 5225 /* For list-initialization we consider explicit constructors 5226 and complain if one is chosen. */ 5227 check_converting 5228 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 5229 == LOOKUP_ONLYCONVERTING); 5230 } 5231 else 5232 { 5233 check_list_ctor = false; 5234 check_converting = false; 5235 } 5236 strict = DEDUCE_CALL; 5237 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 5238 } 5239 5240 if (first_arg) 5241 non_static_args = args; 5242 else 5243 /* Delay creating the implicit this parameter until it is needed. */ 5244 non_static_args = NULL; 5245 5246 for (; fns; fns = OVL_NEXT (fns)) 5247 { 5248 tree fn_first_arg; 5249 const vec<tree, va_gc> *fn_args; 5250 5251 fn = OVL_CURRENT (fns); 5252 5253 if (check_converting && DECL_NONCONVERTING_P (fn)) 5254 continue; 5255 if (check_list_ctor && !is_list_ctor (fn)) 5256 continue; 5257 5258 /* Figure out which set of arguments to use. */ 5259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 5260 { 5261 /* If this function is a non-static member and we didn't get an 5262 implicit object argument, move it out of args. */ 5263 if (first_arg == NULL_TREE) 5264 { 5265 unsigned int ix; 5266 tree arg; 5267 vec<tree, va_gc> *tempvec; 5268 vec_alloc (tempvec, args->length () - 1); 5269 for (ix = 1; args->iterate (ix, &arg); ++ix) 5270 tempvec->quick_push (arg); 5271 non_static_args = tempvec; 5272 first_arg = (*args)[0]; 5273 } 5274 5275 fn_first_arg = first_arg; 5276 fn_args = non_static_args; 5277 } 5278 else 5279 { 5280 /* Otherwise, just use the list of arguments provided. */ 5281 fn_first_arg = NULL_TREE; 5282 fn_args = args; 5283 } 5284 5285 if (TREE_CODE (fn) == TEMPLATE_DECL) 5286 add_template_candidate (candidates, 5287 fn, 5288 ctype, 5289 explicit_targs, 5290 fn_first_arg, 5291 fn_args, 5292 return_type, 5293 access_path, 5294 conversion_path, 5295 flags, 5296 strict, 5297 complain); 5298 else if (!template_only) 5299 add_function_candidate (candidates, 5300 fn, 5301 ctype, 5302 fn_first_arg, 5303 fn_args, 5304 access_path, 5305 conversion_path, 5306 flags, 5307 complain); 5308 } 5309 } 5310 5311 static tree 5312 build_new_op_1 (location_t loc, enum tree_code code, int flags, tree arg1, 5313 tree arg2, tree arg3, tree *overload, tsubst_flags_t complain) 5314 { 5315 struct z_candidate *candidates = 0, *cand; 5316 vec<tree, va_gc> *arglist; 5317 tree fnname; 5318 tree args[3]; 5319 tree result = NULL_TREE; 5320 bool result_valid_p = false; 5321 enum tree_code code2 = NOP_EXPR; 5322 enum tree_code code_orig_arg1 = ERROR_MARK; 5323 enum tree_code code_orig_arg2 = ERROR_MARK; 5324 conversion *conv; 5325 void *p; 5326 bool strict_p; 5327 bool any_viable_p; 5328 5329 if (error_operand_p (arg1) 5330 || error_operand_p (arg2) 5331 || error_operand_p (arg3)) 5332 return error_mark_node; 5333 5334 if (code == MODIFY_EXPR) 5335 { 5336 code2 = TREE_CODE (arg3); 5337 arg3 = NULL_TREE; 5338 fnname = ansi_assopname (code2); 5339 } 5340 else 5341 fnname = ansi_opname (code); 5342 5343 arg1 = prep_operand (arg1); 5344 5345 bool memonly = false; 5346 switch (code) 5347 { 5348 case NEW_EXPR: 5349 case VEC_NEW_EXPR: 5350 case VEC_DELETE_EXPR: 5351 case DELETE_EXPR: 5352 /* Use build_op_new_call and build_op_delete_call instead. */ 5353 gcc_unreachable (); 5354 5355 case CALL_EXPR: 5356 /* Use build_op_call instead. */ 5357 gcc_unreachable (); 5358 5359 case TRUTH_ORIF_EXPR: 5360 case TRUTH_ANDIF_EXPR: 5361 case TRUTH_AND_EXPR: 5362 case TRUTH_OR_EXPR: 5363 /* These are saved for the sake of warn_logical_operator. */ 5364 code_orig_arg1 = TREE_CODE (arg1); 5365 code_orig_arg2 = TREE_CODE (arg2); 5366 break; 5367 case GT_EXPR: 5368 case LT_EXPR: 5369 case GE_EXPR: 5370 case LE_EXPR: 5371 case EQ_EXPR: 5372 case NE_EXPR: 5373 /* These are saved for the sake of maybe_warn_bool_compare. */ 5374 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1)); 5375 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2)); 5376 break; 5377 5378 /* =, ->, [], () must be non-static member functions. */ 5379 case MODIFY_EXPR: 5380 if (code2 != NOP_EXPR) 5381 break; 5382 case COMPONENT_REF: 5383 case ARRAY_REF: 5384 memonly = true; 5385 break; 5386 5387 default: 5388 break; 5389 } 5390 5391 arg2 = prep_operand (arg2); 5392 arg3 = prep_operand (arg3); 5393 5394 if (code == COND_EXPR) 5395 /* Use build_conditional_expr instead. */ 5396 gcc_unreachable (); 5397 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1)) 5398 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2)))) 5399 goto builtin; 5400 5401 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 5402 arg2 = integer_zero_node; 5403 5404 vec_alloc (arglist, 3); 5405 arglist->quick_push (arg1); 5406 if (arg2 != NULL_TREE) 5407 arglist->quick_push (arg2); 5408 if (arg3 != NULL_TREE) 5409 arglist->quick_push (arg3); 5410 5411 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5412 p = conversion_obstack_alloc (0); 5413 5414 /* Add namespace-scope operators to the list of functions to 5415 consider. */ 5416 if (!memonly) 5417 add_candidates (lookup_function_nonclass (fnname, arglist, 5418 /*block_p=*/true), 5419 NULL_TREE, arglist, NULL_TREE, 5420 NULL_TREE, false, NULL_TREE, NULL_TREE, 5421 flags, &candidates, complain); 5422 5423 args[0] = arg1; 5424 args[1] = arg2; 5425 args[2] = NULL_TREE; 5426 5427 /* Add class-member operators to the candidate set. */ 5428 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 5429 { 5430 tree fns; 5431 5432 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 5433 if (fns == error_mark_node) 5434 { 5435 result = error_mark_node; 5436 goto user_defined_result_ready; 5437 } 5438 if (fns) 5439 add_candidates (BASELINK_FUNCTIONS (fns), 5440 NULL_TREE, arglist, NULL_TREE, 5441 NULL_TREE, false, 5442 BASELINK_BINFO (fns), 5443 BASELINK_ACCESS_BINFO (fns), 5444 flags, &candidates, complain); 5445 } 5446 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then 5447 only non-member functions that have type T1 or reference to 5448 cv-qualified-opt T1 for the first argument, if the first argument 5449 has an enumeration type, or T2 or reference to cv-qualified-opt 5450 T2 for the second argument, if the the second argument has an 5451 enumeration type. Filter out those that don't match. */ 5452 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2))) 5453 { 5454 struct z_candidate **candp, **next; 5455 5456 for (candp = &candidates; *candp; candp = next) 5457 { 5458 tree parmlist, parmtype; 5459 int i, nargs = (arg2 ? 2 : 1); 5460 5461 cand = *candp; 5462 next = &cand->next; 5463 5464 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 5465 5466 for (i = 0; i < nargs; ++i) 5467 { 5468 parmtype = TREE_VALUE (parmlist); 5469 5470 if (TREE_CODE (parmtype) == REFERENCE_TYPE) 5471 parmtype = TREE_TYPE (parmtype); 5472 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE 5473 && (same_type_ignoring_top_level_qualifiers_p 5474 (TREE_TYPE (args[i]), parmtype))) 5475 break; 5476 5477 parmlist = TREE_CHAIN (parmlist); 5478 } 5479 5480 /* No argument has an appropriate type, so remove this 5481 candidate function from the list. */ 5482 if (i == nargs) 5483 { 5484 *candp = cand->next; 5485 next = candp; 5486 } 5487 } 5488 } 5489 5490 add_builtin_candidates (&candidates, code, code2, fnname, args, 5491 flags, complain); 5492 5493 switch (code) 5494 { 5495 case COMPOUND_EXPR: 5496 case ADDR_EXPR: 5497 /* For these, the built-in candidates set is empty 5498 [over.match.oper]/3. We don't want non-strict matches 5499 because exact matches are always possible with built-in 5500 operators. The built-in candidate set for COMPONENT_REF 5501 would be empty too, but since there are no such built-in 5502 operators, we accept non-strict matches for them. */ 5503 strict_p = true; 5504 break; 5505 5506 default: 5507 strict_p = false; 5508 break; 5509 } 5510 5511 candidates = splice_viable (candidates, strict_p, &any_viable_p); 5512 if (!any_viable_p) 5513 { 5514 switch (code) 5515 { 5516 case POSTINCREMENT_EXPR: 5517 case POSTDECREMENT_EXPR: 5518 /* Don't try anything fancy if we're not allowed to produce 5519 errors. */ 5520 if (!(complain & tf_error)) 5521 return error_mark_node; 5522 5523 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 5524 distinguish between prefix and postfix ++ and 5525 operator++() was used for both, so we allow this with 5526 -fpermissive. */ 5527 else 5528 { 5529 const char *msg = (flag_permissive) 5530 ? G_("no %<%D(int)%> declared for postfix %qs," 5531 " trying prefix operator instead") 5532 : G_("no %<%D(int)%> declared for postfix %qs"); 5533 permerror (loc, msg, fnname, operator_name_info[code].name); 5534 } 5535 5536 if (!flag_permissive) 5537 return error_mark_node; 5538 5539 if (code == POSTINCREMENT_EXPR) 5540 code = PREINCREMENT_EXPR; 5541 else 5542 code = PREDECREMENT_EXPR; 5543 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE, 5544 NULL_TREE, overload, complain); 5545 break; 5546 5547 /* The caller will deal with these. */ 5548 case ADDR_EXPR: 5549 case COMPOUND_EXPR: 5550 case COMPONENT_REF: 5551 result = NULL_TREE; 5552 result_valid_p = true; 5553 break; 5554 5555 default: 5556 if (complain & tf_error) 5557 { 5558 /* If one of the arguments of the operator represents 5559 an invalid use of member function pointer, try to report 5560 a meaningful error ... */ 5561 if (invalid_nonstatic_memfn_p (arg1, tf_error) 5562 || invalid_nonstatic_memfn_p (arg2, tf_error) 5563 || invalid_nonstatic_memfn_p (arg3, tf_error)) 5564 /* We displayed the error message. */; 5565 else 5566 { 5567 /* ... Otherwise, report the more generic 5568 "no matching operator found" error */ 5569 op_error (loc, code, code2, arg1, arg2, arg3, FALSE); 5570 print_z_candidates (loc, candidates); 5571 } 5572 } 5573 result = error_mark_node; 5574 break; 5575 } 5576 } 5577 else 5578 { 5579 cand = tourney (candidates, complain); 5580 if (cand == 0) 5581 { 5582 if (complain & tf_error) 5583 { 5584 op_error (loc, code, code2, arg1, arg2, arg3, TRUE); 5585 print_z_candidates (loc, candidates); 5586 } 5587 result = error_mark_node; 5588 } 5589 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 5590 { 5591 if (overload) 5592 *overload = cand->fn; 5593 5594 if (resolve_args (arglist, complain) == NULL) 5595 result = error_mark_node; 5596 else 5597 result = build_over_call (cand, LOOKUP_NORMAL, complain); 5598 } 5599 else 5600 { 5601 /* Give any warnings we noticed during overload resolution. */ 5602 if (cand->warnings && (complain & tf_warning)) 5603 { 5604 struct candidate_warning *w; 5605 for (w = cand->warnings; w; w = w->next) 5606 joust (cand, w->loser, 1, complain); 5607 } 5608 5609 /* Check for comparison of different enum types. */ 5610 switch (code) 5611 { 5612 case GT_EXPR: 5613 case LT_EXPR: 5614 case GE_EXPR: 5615 case LE_EXPR: 5616 case EQ_EXPR: 5617 case NE_EXPR: 5618 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 5619 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 5620 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 5621 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 5622 && (complain & tf_warning)) 5623 { 5624 warning (OPT_Wenum_compare, 5625 "comparison between %q#T and %q#T", 5626 TREE_TYPE (arg1), TREE_TYPE (arg2)); 5627 } 5628 break; 5629 default: 5630 break; 5631 } 5632 5633 /* We need to strip any leading REF_BIND so that bitfields 5634 don't cause errors. This should not remove any important 5635 conversions, because builtins don't apply to class 5636 objects directly. */ 5637 conv = cand->convs[0]; 5638 if (conv->kind == ck_ref_bind) 5639 conv = next_conversion (conv); 5640 arg1 = convert_like (conv, arg1, complain); 5641 5642 if (arg2) 5643 { 5644 conv = cand->convs[1]; 5645 if (conv->kind == ck_ref_bind) 5646 conv = next_conversion (conv); 5647 else 5648 arg2 = decay_conversion (arg2, complain); 5649 5650 /* We need to call warn_logical_operator before 5651 converting arg2 to a boolean_type, but after 5652 decaying an enumerator to its value. */ 5653 if (complain & tf_warning) 5654 warn_logical_operator (loc, code, boolean_type_node, 5655 code_orig_arg1, arg1, 5656 code_orig_arg2, arg2); 5657 5658 arg2 = convert_like (conv, arg2, complain); 5659 } 5660 if (arg3) 5661 { 5662 conv = cand->convs[2]; 5663 if (conv->kind == ck_ref_bind) 5664 conv = next_conversion (conv); 5665 arg3 = convert_like (conv, arg3, complain); 5666 } 5667 5668 } 5669 } 5670 5671 user_defined_result_ready: 5672 5673 /* Free all the conversions we allocated. */ 5674 obstack_free (&conversion_obstack, p); 5675 5676 if (result || result_valid_p) 5677 return result; 5678 5679 builtin: 5680 switch (code) 5681 { 5682 case MODIFY_EXPR: 5683 return cp_build_modify_expr (arg1, code2, arg2, complain); 5684 5685 case INDIRECT_REF: 5686 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 5687 5688 case TRUTH_ANDIF_EXPR: 5689 case TRUTH_ORIF_EXPR: 5690 case TRUTH_AND_EXPR: 5691 case TRUTH_OR_EXPR: 5692 if (complain & tf_warning) 5693 warn_logical_operator (loc, code, boolean_type_node, 5694 code_orig_arg1, arg1, code_orig_arg2, arg2); 5695 /* Fall through. */ 5696 case GT_EXPR: 5697 case LT_EXPR: 5698 case GE_EXPR: 5699 case LE_EXPR: 5700 case EQ_EXPR: 5701 case NE_EXPR: 5702 if ((complain & tf_warning) 5703 && ((code_orig_arg1 == BOOLEAN_TYPE) 5704 ^ (code_orig_arg2 == BOOLEAN_TYPE))) 5705 maybe_warn_bool_compare (loc, code, arg1, arg2); 5706 /* Fall through. */ 5707 case PLUS_EXPR: 5708 case MINUS_EXPR: 5709 case MULT_EXPR: 5710 case TRUNC_DIV_EXPR: 5711 case MAX_EXPR: 5712 case MIN_EXPR: 5713 case LSHIFT_EXPR: 5714 case RSHIFT_EXPR: 5715 case TRUNC_MOD_EXPR: 5716 case BIT_AND_EXPR: 5717 case BIT_IOR_EXPR: 5718 case BIT_XOR_EXPR: 5719 return cp_build_binary_op (loc, code, arg1, arg2, complain); 5720 5721 case UNARY_PLUS_EXPR: 5722 case NEGATE_EXPR: 5723 case BIT_NOT_EXPR: 5724 case TRUTH_NOT_EXPR: 5725 case PREINCREMENT_EXPR: 5726 case POSTINCREMENT_EXPR: 5727 case PREDECREMENT_EXPR: 5728 case POSTDECREMENT_EXPR: 5729 case REALPART_EXPR: 5730 case IMAGPART_EXPR: 5731 case ABS_EXPR: 5732 return cp_build_unary_op (code, arg1, candidates != 0, complain); 5733 5734 case ARRAY_REF: 5735 return cp_build_array_ref (input_location, arg1, arg2, complain); 5736 5737 case MEMBER_REF: 5738 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR, 5739 complain), 5740 arg2, complain); 5741 5742 /* The caller will deal with these. */ 5743 case ADDR_EXPR: 5744 case COMPONENT_REF: 5745 case COMPOUND_EXPR: 5746 return NULL_TREE; 5747 5748 default: 5749 gcc_unreachable (); 5750 } 5751 return NULL_TREE; 5752 } 5753 5754 /* Wrapper for above. */ 5755 5756 tree 5757 build_new_op (location_t loc, enum tree_code code, int flags, 5758 tree arg1, tree arg2, tree arg3, 5759 tree *overload, tsubst_flags_t complain) 5760 { 5761 tree ret; 5762 bool subtime = timevar_cond_start (TV_OVERLOAD); 5763 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3, 5764 overload, complain); 5765 timevar_cond_stop (TV_OVERLOAD, subtime); 5766 return ret; 5767 } 5768 5769 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 5770 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 5771 5772 bool 5773 non_placement_deallocation_fn_p (tree t) 5774 { 5775 /* A template instance is never a usual deallocation function, 5776 regardless of its signature. */ 5777 if (TREE_CODE (t) == TEMPLATE_DECL 5778 || primary_template_instantiation_p (t)) 5779 return false; 5780 5781 /* If a class T has a member deallocation function named operator delete 5782 with exactly one parameter, then that function is a usual 5783 (non-placement) deallocation function. If class T does not declare 5784 such an operator delete but does declare a member deallocation 5785 function named operator delete with exactly two parameters, the second 5786 of which has type std::size_t (18.2), then this function is a usual 5787 deallocation function. */ 5788 bool global = DECL_NAMESPACE_SCOPE_P (t); 5789 t = FUNCTION_ARG_CHAIN (t); 5790 if (t == void_list_node 5791 || (t && same_type_p (TREE_VALUE (t), size_type_node) 5792 && (!global || flag_sized_deallocation) 5793 && TREE_CHAIN (t) == void_list_node)) 5794 return true; 5795 return false; 5796 } 5797 5798 /* Build a call to operator delete. This has to be handled very specially, 5799 because the restrictions on what signatures match are different from all 5800 other call instances. For a normal delete, only a delete taking (void *) 5801 or (void *, size_t) is accepted. For a placement delete, only an exact 5802 match with the placement new is accepted. 5803 5804 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 5805 ADDR is the pointer to be deleted. 5806 SIZE is the size of the memory block to be deleted. 5807 GLOBAL_P is true if the delete-expression should not consider 5808 class-specific delete operators. 5809 PLACEMENT is the corresponding placement new call, or NULL_TREE. 5810 5811 If this call to "operator delete" is being generated as part to 5812 deallocate memory allocated via a new-expression (as per [expr.new] 5813 which requires that if the initialization throws an exception then 5814 we call a deallocation function), then ALLOC_FN is the allocation 5815 function. */ 5816 5817 tree 5818 build_op_delete_call (enum tree_code code, tree addr, tree size, 5819 bool global_p, tree placement, 5820 tree alloc_fn, tsubst_flags_t complain) 5821 { 5822 tree fn = NULL_TREE; 5823 tree fns, fnname, type, t; 5824 5825 if (addr == error_mark_node) 5826 return error_mark_node; 5827 5828 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 5829 5830 fnname = ansi_opname (code); 5831 5832 if (CLASS_TYPE_P (type) 5833 && COMPLETE_TYPE_P (complete_type (type)) 5834 && !global_p) 5835 /* In [class.free] 5836 5837 If the result of the lookup is ambiguous or inaccessible, or if 5838 the lookup selects a placement deallocation function, the 5839 program is ill-formed. 5840 5841 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 5842 { 5843 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 5844 if (fns == error_mark_node) 5845 return error_mark_node; 5846 } 5847 else 5848 fns = NULL_TREE; 5849 5850 if (fns == NULL_TREE) 5851 fns = lookup_name_nonclass (fnname); 5852 5853 /* Strip const and volatile from addr. */ 5854 addr = cp_convert (ptr_type_node, addr, complain); 5855 5856 if (placement) 5857 { 5858 /* "A declaration of a placement deallocation function matches the 5859 declaration of a placement allocation function if it has the same 5860 number of parameters and, after parameter transformations (8.3.5), 5861 all parameter types except the first are identical." 5862 5863 So we build up the function type we want and ask instantiate_type 5864 to get it for us. */ 5865 t = FUNCTION_ARG_CHAIN (alloc_fn); 5866 t = tree_cons (NULL_TREE, ptr_type_node, t); 5867 t = build_function_type (void_type_node, t); 5868 5869 fn = instantiate_type (t, fns, tf_none); 5870 if (fn == error_mark_node) 5871 return NULL_TREE; 5872 5873 if (BASELINK_P (fn)) 5874 fn = BASELINK_FUNCTIONS (fn); 5875 5876 /* "If the lookup finds the two-parameter form of a usual deallocation 5877 function (3.7.4.2) and that function, considered as a placement 5878 deallocation function, would have been selected as a match for the 5879 allocation function, the program is ill-formed." */ 5880 if (non_placement_deallocation_fn_p (fn)) 5881 { 5882 /* But if the class has an operator delete (void *), then that is 5883 the usual deallocation function, so we shouldn't complain 5884 about using the operator delete (void *, size_t). */ 5885 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5886 t; t = OVL_NEXT (t)) 5887 { 5888 tree elt = OVL_CURRENT (t); 5889 if (non_placement_deallocation_fn_p (elt) 5890 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 5891 goto ok; 5892 } 5893 if (complain & tf_error) 5894 { 5895 permerror (0, "non-placement deallocation function %q+D", fn); 5896 permerror (input_location, "selected for placement delete"); 5897 } 5898 else 5899 return error_mark_node; 5900 ok:; 5901 } 5902 } 5903 else 5904 /* "Any non-placement deallocation function matches a non-placement 5905 allocation function. If the lookup finds a single matching 5906 deallocation function, that function will be called; otherwise, no 5907 deallocation function will be called." */ 5908 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5909 t; t = OVL_NEXT (t)) 5910 { 5911 tree elt = OVL_CURRENT (t); 5912 if (non_placement_deallocation_fn_p (elt)) 5913 { 5914 fn = elt; 5915 /* "If a class T has a member deallocation function named 5916 operator delete with exactly one parameter, then that 5917 function is a usual (non-placement) deallocation 5918 function. If class T does not declare such an operator 5919 delete but does declare a member deallocation function named 5920 operator delete with exactly two parameters, the second of 5921 which has type std::size_t (18.2), then this function is a 5922 usual deallocation function." 5923 5924 So in a class (void*) beats (void*, size_t). */ 5925 if (DECL_CLASS_SCOPE_P (fn)) 5926 { 5927 if (FUNCTION_ARG_CHAIN (fn) == void_list_node) 5928 break; 5929 } 5930 /* At global scope (in C++14 and above) the rules are different: 5931 5932 If deallocation function lookup finds both a usual 5933 deallocation function with only a pointer parameter and a 5934 usual deallocation function with both a pointer parameter 5935 and a size parameter, the function to be called is selected 5936 as follows: 5937 5938 * If the type is complete and if, for the second alternative 5939 (delete array) only, the operand is a pointer to a class 5940 type with a non-trivial destructor or a (possibly 5941 multi-dimensional) array thereof, the function with two 5942 parameters is selected. 5943 5944 * Otherwise, it is unspecified which of the two deallocation 5945 functions is selected. */ 5946 else 5947 { 5948 bool want_size = COMPLETE_TYPE_P (type); 5949 if (code == VEC_DELETE_EXPR 5950 && !TYPE_VEC_NEW_USES_COOKIE (type)) 5951 /* We need a cookie to determine the array size. */ 5952 want_size = false; 5953 bool have_size = (FUNCTION_ARG_CHAIN (fn) != void_list_node); 5954 if (want_size == have_size) 5955 break; 5956 } 5957 } 5958 } 5959 5960 /* If we have a matching function, call it. */ 5961 if (fn) 5962 { 5963 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 5964 5965 /* If the FN is a member function, make sure that it is 5966 accessible. */ 5967 if (BASELINK_P (fns)) 5968 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn, 5969 complain); 5970 5971 /* Core issue 901: It's ok to new a type with deleted delete. */ 5972 if (DECL_DELETED_FN (fn) && alloc_fn) 5973 return NULL_TREE; 5974 5975 if (placement) 5976 { 5977 /* The placement args might not be suitable for overload 5978 resolution at this point, so build the call directly. */ 5979 int nargs = call_expr_nargs (placement); 5980 tree *argarray = XALLOCAVEC (tree, nargs); 5981 int i; 5982 argarray[0] = addr; 5983 for (i = 1; i < nargs; i++) 5984 argarray[i] = CALL_EXPR_ARG (placement, i); 5985 if (!mark_used (fn, complain) && !(complain & tf_error)) 5986 return error_mark_node; 5987 return build_cxx_call (fn, nargs, argarray, complain); 5988 } 5989 else 5990 { 5991 tree ret; 5992 vec<tree, va_gc> *args = make_tree_vector (); 5993 args->quick_push (addr); 5994 if (FUNCTION_ARG_CHAIN (fn) != void_list_node) 5995 args->quick_push (size); 5996 ret = cp_build_function_call_vec (fn, &args, complain); 5997 release_tree_vector (args); 5998 return ret; 5999 } 6000 } 6001 6002 /* [expr.new] 6003 6004 If no unambiguous matching deallocation function can be found, 6005 propagating the exception does not cause the object's memory to 6006 be freed. */ 6007 if (alloc_fn) 6008 { 6009 if ((complain & tf_warning) 6010 && !placement) 6011 warning (0, "no corresponding deallocation function for %qD", 6012 alloc_fn); 6013 return NULL_TREE; 6014 } 6015 6016 if (complain & tf_error) 6017 error ("no suitable %<operator %s%> for %qT", 6018 operator_name_info[(int)code].name, type); 6019 return error_mark_node; 6020 } 6021 6022 /* If the current scope isn't allowed to access DECL along 6023 BASETYPE_PATH, give an error. The most derived class in 6024 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 6025 the declaration to use in the error diagnostic. */ 6026 6027 bool 6028 enforce_access (tree basetype_path, tree decl, tree diag_decl, 6029 tsubst_flags_t complain) 6030 { 6031 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 6032 6033 if (!accessible_p (basetype_path, decl, true)) 6034 { 6035 if (complain & tf_error) 6036 { 6037 if (TREE_PRIVATE (decl)) 6038 error ("%q+#D is private", diag_decl); 6039 else if (TREE_PROTECTED (decl)) 6040 error ("%q+#D is protected", diag_decl); 6041 else 6042 error ("%q+#D is inaccessible", diag_decl); 6043 error ("within this context"); 6044 } 6045 return false; 6046 } 6047 6048 return true; 6049 } 6050 6051 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 6052 bitwise or of LOOKUP_* values. If any errors are warnings are 6053 generated, set *DIAGNOSTIC_FN to "error" or "warning", 6054 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 6055 to NULL. */ 6056 6057 static tree 6058 build_temp (tree expr, tree type, int flags, 6059 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 6060 { 6061 int savew, savee; 6062 vec<tree, va_gc> *args; 6063 6064 savew = warningcount + werrorcount, savee = errorcount; 6065 args = make_tree_vector_single (expr); 6066 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 6067 &args, type, flags, complain); 6068 release_tree_vector (args); 6069 if (warningcount + werrorcount > savew) 6070 *diagnostic_kind = DK_WARNING; 6071 else if (errorcount > savee) 6072 *diagnostic_kind = DK_ERROR; 6073 else 6074 *diagnostic_kind = DK_UNSPECIFIED; 6075 return expr; 6076 } 6077 6078 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 6079 EXPR is implicitly converted to type TOTYPE. 6080 FN and ARGNUM are used for diagnostics. */ 6081 6082 static void 6083 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 6084 { 6085 /* Issue warnings about peculiar, but valid, uses of NULL. */ 6086 if (expr == null_node && TREE_CODE (totype) != BOOLEAN_TYPE 6087 && ARITHMETIC_TYPE_P (totype)) 6088 { 6089 source_location loc = 6090 expansion_point_location_if_in_system_header (input_location); 6091 6092 if (fn) 6093 warning_at (loc, OPT_Wconversion_null, 6094 "passing NULL to non-pointer argument %P of %qD", 6095 argnum, fn); 6096 else 6097 warning_at (loc, OPT_Wconversion_null, 6098 "converting to non-pointer type %qT from NULL", totype); 6099 } 6100 6101 /* Issue warnings if "false" is converted to a NULL pointer */ 6102 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 6103 && TYPE_PTR_P (totype)) 6104 { 6105 if (fn) 6106 warning_at (input_location, OPT_Wconversion_null, 6107 "converting %<false%> to pointer type for argument %P " 6108 "of %qD", argnum, fn); 6109 else 6110 warning_at (input_location, OPT_Wconversion_null, 6111 "converting %<false%> to pointer type %qT", totype); 6112 } 6113 } 6114 6115 /* We gave a diagnostic during a conversion. If this was in the second 6116 standard conversion sequence of a user-defined conversion sequence, say 6117 which user-defined conversion. */ 6118 6119 static void 6120 maybe_print_user_conv_context (conversion *convs) 6121 { 6122 if (convs->user_conv_p) 6123 for (conversion *t = convs; t; t = next_conversion (t)) 6124 if (t->kind == ck_user) 6125 { 6126 print_z_candidate (0, " after user-defined conversion:", 6127 t->cand); 6128 break; 6129 } 6130 } 6131 6132 /* Perform the conversions in CONVS on the expression EXPR. FN and 6133 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 6134 indicates the `this' argument of a method. INNER is nonzero when 6135 being called to continue a conversion chain. It is negative when a 6136 reference binding will be applied, positive otherwise. If 6137 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 6138 conversions will be emitted if appropriate. If C_CAST_P is true, 6139 this conversion is coming from a C-style cast; in that case, 6140 conversions to inaccessible bases are permitted. */ 6141 6142 static tree 6143 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 6144 int inner, bool issue_conversion_warnings, 6145 bool c_cast_p, tsubst_flags_t complain) 6146 { 6147 tree totype = convs->type; 6148 diagnostic_t diag_kind; 6149 int flags; 6150 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 6151 6152 if (convs->bad_p && !(complain & tf_error)) 6153 return error_mark_node; 6154 6155 if (convs->bad_p 6156 && convs->kind != ck_user 6157 && convs->kind != ck_list 6158 && convs->kind != ck_ambig 6159 && (convs->kind != ck_ref_bind 6160 || (convs->user_conv_p && next_conversion (convs)->bad_p)) 6161 && (convs->kind != ck_rvalue 6162 || SCALAR_TYPE_P (totype)) 6163 && convs->kind != ck_base) 6164 { 6165 bool complained = false; 6166 conversion *t = convs; 6167 6168 /* Give a helpful error if this is bad because of excess braces. */ 6169 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6170 && SCALAR_TYPE_P (totype) 6171 && CONSTRUCTOR_NELTS (expr) > 0 6172 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 6173 { 6174 complained = permerror (loc, "too many braces around initializer " 6175 "for %qT", totype); 6176 while (BRACE_ENCLOSED_INITIALIZER_P (expr) 6177 && CONSTRUCTOR_NELTS (expr) == 1) 6178 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6179 } 6180 6181 /* Give a helpful error if this is bad because a conversion to bool 6182 from std::nullptr_t requires direct-initialization. */ 6183 if (NULLPTR_TYPE_P (TREE_TYPE (expr)) 6184 && TREE_CODE (totype) == BOOLEAN_TYPE) 6185 complained = permerror (loc, "converting to %qT from %qT requires " 6186 "direct-initialization", 6187 totype, TREE_TYPE (expr)); 6188 6189 for (; t ; t = next_conversion (t)) 6190 { 6191 if (t->kind == ck_user && t->cand->reason) 6192 { 6193 complained = permerror (loc, "invalid user-defined conversion " 6194 "from %qT to %qT", TREE_TYPE (expr), 6195 totype); 6196 if (complained) 6197 print_z_candidate (loc, "candidate is:", t->cand); 6198 expr = convert_like_real (t, expr, fn, argnum, 1, 6199 /*issue_conversion_warnings=*/false, 6200 /*c_cast_p=*/false, 6201 complain); 6202 if (convs->kind == ck_ref_bind) 6203 expr = convert_to_reference (totype, expr, CONV_IMPLICIT, 6204 LOOKUP_NORMAL, NULL_TREE, 6205 complain); 6206 else 6207 expr = cp_convert (totype, expr, complain); 6208 if (complained && fn) 6209 inform (DECL_SOURCE_LOCATION (fn), 6210 " initializing argument %P of %qD", argnum, fn); 6211 return expr; 6212 } 6213 else if (t->kind == ck_user || !t->bad_p) 6214 { 6215 expr = convert_like_real (t, expr, fn, argnum, 1, 6216 /*issue_conversion_warnings=*/false, 6217 /*c_cast_p=*/false, 6218 complain); 6219 break; 6220 } 6221 else if (t->kind == ck_ambig) 6222 return convert_like_real (t, expr, fn, argnum, 1, 6223 /*issue_conversion_warnings=*/false, 6224 /*c_cast_p=*/false, 6225 complain); 6226 else if (t->kind == ck_identity) 6227 break; 6228 } 6229 if (!complained) 6230 complained = permerror (loc, "invalid conversion from %qT to %qT", 6231 TREE_TYPE (expr), totype); 6232 if (complained && fn) 6233 inform (DECL_SOURCE_LOCATION (fn), 6234 " initializing argument %P of %qD", argnum, fn); 6235 6236 return cp_convert (totype, expr, complain); 6237 } 6238 6239 if (issue_conversion_warnings && (complain & tf_warning)) 6240 conversion_null_warnings (totype, expr, fn, argnum); 6241 6242 switch (convs->kind) 6243 { 6244 case ck_user: 6245 { 6246 struct z_candidate *cand = convs->cand; 6247 tree convfn = cand->fn; 6248 unsigned i; 6249 6250 /* When converting from an init list we consider explicit 6251 constructors, but actually trying to call one is an error. */ 6252 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 6253 && BRACE_ENCLOSED_INITIALIZER_P (expr) 6254 /* Unless this is for direct-list-initialization. */ 6255 && !CONSTRUCTOR_IS_DIRECT_INIT (expr)) 6256 { 6257 if (!(complain & tf_error)) 6258 return error_mark_node; 6259 error ("converting to %qT from initializer list would use " 6260 "explicit constructor %qD", totype, convfn); 6261 } 6262 6263 /* If we're initializing from {}, it's value-initialization. */ 6264 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6265 && CONSTRUCTOR_NELTS (expr) == 0 6266 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 6267 { 6268 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 6269 expr = build_value_init (totype, complain); 6270 expr = get_target_expr_sfinae (expr, complain); 6271 if (expr != error_mark_node) 6272 { 6273 TARGET_EXPR_LIST_INIT_P (expr) = true; 6274 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 6275 } 6276 return expr; 6277 } 6278 6279 expr = mark_rvalue_use (expr); 6280 6281 /* Set user_conv_p on the argument conversions, so rvalue/base 6282 handling knows not to allow any more UDCs. */ 6283 for (i = 0; i < cand->num_convs; ++i) 6284 cand->convs[i]->user_conv_p = true; 6285 6286 expr = build_over_call (cand, LOOKUP_NORMAL, complain); 6287 6288 /* If this is a constructor or a function returning an aggr type, 6289 we need to build up a TARGET_EXPR. */ 6290 if (DECL_CONSTRUCTOR_P (convfn)) 6291 { 6292 expr = build_cplus_new (totype, expr, complain); 6293 6294 /* Remember that this was list-initialization. */ 6295 if (convs->check_narrowing && expr != error_mark_node) 6296 TARGET_EXPR_LIST_INIT_P (expr) = true; 6297 } 6298 6299 return expr; 6300 } 6301 case ck_identity: 6302 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 6303 { 6304 int nelts = CONSTRUCTOR_NELTS (expr); 6305 if (nelts == 0) 6306 expr = build_value_init (totype, complain); 6307 else if (nelts == 1) 6308 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6309 else 6310 gcc_unreachable (); 6311 } 6312 expr = mark_rvalue_use (expr); 6313 6314 if (type_unknown_p (expr)) 6315 expr = instantiate_type (totype, expr, complain); 6316 /* Convert a constant to its underlying value, unless we are 6317 about to bind it to a reference, in which case we need to 6318 leave it as an lvalue. */ 6319 if (inner >= 0) 6320 { 6321 expr = scalar_constant_value (expr); 6322 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 6323 /* If __null has been converted to an integer type, we do not 6324 want to warn about uses of EXPR as an integer, rather than 6325 as a pointer. */ 6326 expr = build_int_cst (totype, 0); 6327 } 6328 return expr; 6329 case ck_ambig: 6330 /* We leave bad_p off ck_ambig because overload resolution considers 6331 it valid, it just fails when we try to perform it. So we need to 6332 check complain here, too. */ 6333 if (complain & tf_error) 6334 { 6335 /* Call build_user_type_conversion again for the error. */ 6336 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL, 6337 complain); 6338 if (fn) 6339 inform (input_location, " initializing argument %P of %q+D", 6340 argnum, fn); 6341 } 6342 return error_mark_node; 6343 6344 case ck_list: 6345 { 6346 /* Conversion to std::initializer_list<T>. */ 6347 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 6348 tree new_ctor = build_constructor (init_list_type_node, NULL); 6349 unsigned len = CONSTRUCTOR_NELTS (expr); 6350 tree array, val, field; 6351 vec<constructor_elt, va_gc> *vec = NULL; 6352 unsigned ix; 6353 6354 /* Convert all the elements. */ 6355 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 6356 { 6357 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 6358 1, false, false, complain); 6359 if (sub == error_mark_node) 6360 return sub; 6361 if (!BRACE_ENCLOSED_INITIALIZER_P (val) 6362 && !check_narrowing (TREE_TYPE (sub), val, complain)) 6363 return error_mark_node; 6364 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 6365 if (!TREE_CONSTANT (sub)) 6366 TREE_CONSTANT (new_ctor) = false; 6367 } 6368 /* Build up the array. */ 6369 elttype = cp_build_qualified_type 6370 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 6371 array = build_array_of_n_type (elttype, len); 6372 array = finish_compound_literal (array, new_ctor, complain); 6373 /* Take the address explicitly rather than via decay_conversion 6374 to avoid the error about taking the address of a temporary. */ 6375 array = cp_build_addr_expr (array, complain); 6376 array = cp_convert (build_pointer_type (elttype), array, complain); 6377 if (array == error_mark_node) 6378 return error_mark_node; 6379 6380 /* Build up the initializer_list object. */ 6381 totype = complete_type (totype); 6382 field = next_initializable_field (TYPE_FIELDS (totype)); 6383 CONSTRUCTOR_APPEND_ELT (vec, field, array); 6384 field = next_initializable_field (DECL_CHAIN (field)); 6385 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 6386 new_ctor = build_constructor (totype, vec); 6387 return get_target_expr_sfinae (new_ctor, complain); 6388 } 6389 6390 case ck_aggr: 6391 if (TREE_CODE (totype) == COMPLEX_TYPE) 6392 { 6393 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 6394 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 6395 real = perform_implicit_conversion (TREE_TYPE (totype), 6396 real, complain); 6397 imag = perform_implicit_conversion (TREE_TYPE (totype), 6398 imag, complain); 6399 expr = build2 (COMPLEX_EXPR, totype, real, imag); 6400 return fold_if_not_in_template (expr); 6401 } 6402 expr = reshape_init (totype, expr, complain); 6403 expr = get_target_expr_sfinae (digest_init (totype, expr, complain), 6404 complain); 6405 if (expr != error_mark_node) 6406 TARGET_EXPR_LIST_INIT_P (expr) = true; 6407 return expr; 6408 6409 default: 6410 break; 6411 }; 6412 6413 expr = convert_like_real (next_conversion (convs), expr, fn, argnum, 6414 convs->kind == ck_ref_bind ? -1 : 1, 6415 convs->kind == ck_ref_bind ? issue_conversion_warnings : false, 6416 c_cast_p, 6417 complain); 6418 if (expr == error_mark_node) 6419 return error_mark_node; 6420 6421 switch (convs->kind) 6422 { 6423 case ck_rvalue: 6424 expr = decay_conversion (expr, complain); 6425 if (expr == error_mark_node) 6426 return error_mark_node; 6427 6428 if (! MAYBE_CLASS_TYPE_P (totype)) 6429 return expr; 6430 /* Else fall through. */ 6431 case ck_base: 6432 if (convs->kind == ck_base && !convs->need_temporary_p) 6433 { 6434 /* We are going to bind a reference directly to a base-class 6435 subobject of EXPR. */ 6436 /* Build an expression for `*((base*) &expr)'. */ 6437 expr = convert_to_base (expr, totype, 6438 !c_cast_p, /*nonnull=*/true, complain); 6439 return expr; 6440 } 6441 6442 /* Copy-initialization where the cv-unqualified version of the source 6443 type is the same class as, or a derived class of, the class of the 6444 destination [is treated as direct-initialization]. [dcl.init] */ 6445 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING; 6446 if (convs->user_conv_p) 6447 /* This conversion is being done in the context of a user-defined 6448 conversion (i.e. the second step of copy-initialization), so 6449 don't allow any more. */ 6450 flags |= LOOKUP_NO_CONVERSION; 6451 if (convs->rvaluedness_matches_p) 6452 flags |= LOOKUP_PREFER_RVALUE; 6453 if (TREE_CODE (expr) == TARGET_EXPR 6454 && TARGET_EXPR_LIST_INIT_P (expr)) 6455 /* Copy-list-initialization doesn't actually involve a copy. */ 6456 return expr; 6457 expr = build_temp (expr, totype, flags, &diag_kind, complain); 6458 if (diag_kind && complain) 6459 { 6460 maybe_print_user_conv_context (convs); 6461 if (fn) 6462 inform (DECL_SOURCE_LOCATION (fn), 6463 " initializing argument %P of %qD", argnum, fn); 6464 } 6465 6466 return build_cplus_new (totype, expr, complain); 6467 6468 case ck_ref_bind: 6469 { 6470 tree ref_type = totype; 6471 6472 if (convs->bad_p && !next_conversion (convs)->bad_p) 6473 { 6474 tree extype = TREE_TYPE (expr); 6475 if (TYPE_REF_IS_RVALUE (ref_type) 6476 && real_lvalue_p (expr)) 6477 error_at (loc, "cannot bind %qT lvalue to %qT", 6478 extype, totype); 6479 else if (!TYPE_REF_IS_RVALUE (ref_type) && !real_lvalue_p (expr) 6480 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))) 6481 error_at (loc, "invalid initialization of non-const reference of " 6482 "type %qT from an rvalue of type %qT", totype, extype); 6483 else if (!reference_compatible_p (TREE_TYPE (totype), extype)) 6484 error_at (loc, "binding %qT to reference of type %qT " 6485 "discards qualifiers", extype, totype); 6486 else 6487 gcc_unreachable (); 6488 maybe_print_user_conv_context (convs); 6489 if (fn) 6490 inform (input_location, 6491 " initializing argument %P of %q+D", argnum, fn); 6492 return error_mark_node; 6493 } 6494 6495 /* If necessary, create a temporary. 6496 6497 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 6498 that need temporaries, even when their types are reference 6499 compatible with the type of reference being bound, so the 6500 upcoming call to cp_build_addr_expr doesn't fail. */ 6501 if (convs->need_temporary_p 6502 || TREE_CODE (expr) == CONSTRUCTOR 6503 || TREE_CODE (expr) == VA_ARG_EXPR) 6504 { 6505 /* Otherwise, a temporary of type "cv1 T1" is created and 6506 initialized from the initializer expression using the rules 6507 for a non-reference copy-initialization (8.5). */ 6508 6509 tree type = TREE_TYPE (ref_type); 6510 cp_lvalue_kind lvalue = real_lvalue_p (expr); 6511 6512 gcc_assert (same_type_ignoring_top_level_qualifiers_p 6513 (type, next_conversion (convs)->type)); 6514 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 6515 && !TYPE_REF_IS_RVALUE (ref_type)) 6516 { 6517 /* If the reference is volatile or non-const, we 6518 cannot create a temporary. */ 6519 if (lvalue & clk_bitfield) 6520 error_at (loc, "cannot bind bitfield %qE to %qT", 6521 expr, ref_type); 6522 else if (lvalue & clk_packed) 6523 error_at (loc, "cannot bind packed field %qE to %qT", 6524 expr, ref_type); 6525 else 6526 error_at (loc, "cannot bind rvalue %qE to %qT", 6527 expr, ref_type); 6528 return error_mark_node; 6529 } 6530 /* If the source is a packed field, and we must use a copy 6531 constructor, then building the target expr will require 6532 binding the field to the reference parameter to the 6533 copy constructor, and we'll end up with an infinite 6534 loop. If we can use a bitwise copy, then we'll be 6535 OK. */ 6536 if ((lvalue & clk_packed) 6537 && CLASS_TYPE_P (type) 6538 && type_has_nontrivial_copy_init (type)) 6539 { 6540 error_at (loc, "cannot bind packed field %qE to %qT", 6541 expr, ref_type); 6542 return error_mark_node; 6543 } 6544 if (lvalue & clk_bitfield) 6545 { 6546 expr = convert_bitfield_to_declared_type (expr); 6547 expr = fold_convert (type, expr); 6548 } 6549 expr = build_target_expr_with_type (expr, type, complain); 6550 } 6551 6552 /* Take the address of the thing to which we will bind the 6553 reference. */ 6554 expr = cp_build_addr_expr (expr, complain); 6555 if (expr == error_mark_node) 6556 return error_mark_node; 6557 6558 /* Convert it to a pointer to the type referred to by the 6559 reference. This will adjust the pointer if a derived to 6560 base conversion is being performed. */ 6561 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 6562 expr, complain); 6563 /* Convert the pointer to the desired reference type. */ 6564 return build_nop (ref_type, expr); 6565 } 6566 6567 case ck_lvalue: 6568 return decay_conversion (expr, complain); 6569 6570 case ck_qual: 6571 /* Warn about deprecated conversion if appropriate. */ 6572 string_conv_p (totype, expr, 1); 6573 break; 6574 6575 case ck_ptr: 6576 if (convs->base_p) 6577 expr = convert_to_base (expr, totype, !c_cast_p, 6578 /*nonnull=*/false, complain); 6579 return build_nop (totype, expr); 6580 6581 case ck_pmem: 6582 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 6583 c_cast_p, complain); 6584 6585 default: 6586 break; 6587 } 6588 6589 if (convs->check_narrowing 6590 && !check_narrowing (totype, expr, complain)) 6591 return error_mark_node; 6592 6593 if (issue_conversion_warnings) 6594 expr = cp_convert_and_check (totype, expr, complain); 6595 else 6596 expr = cp_convert (totype, expr, complain); 6597 6598 return expr; 6599 } 6600 6601 /* ARG is being passed to a varargs function. Perform any conversions 6602 required. Return the converted value. */ 6603 6604 tree 6605 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain) 6606 { 6607 tree arg_type; 6608 location_t loc = EXPR_LOC_OR_LOC (arg, input_location); 6609 6610 /* [expr.call] 6611 6612 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 6613 standard conversions are performed. */ 6614 arg = decay_conversion (arg, complain); 6615 arg_type = TREE_TYPE (arg); 6616 /* [expr.call] 6617 6618 If the argument has integral or enumeration type that is subject 6619 to the integral promotions (_conv.prom_), or a floating point 6620 type that is subject to the floating point promotion 6621 (_conv.fpprom_), the value of the argument is converted to the 6622 promoted type before the call. */ 6623 if (TREE_CODE (arg_type) == REAL_TYPE 6624 && (TYPE_PRECISION (arg_type) 6625 < TYPE_PRECISION (double_type_node)) 6626 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 6627 { 6628 if ((complain & tf_warning) 6629 && warn_double_promotion && !c_inhibit_evaluation_warnings) 6630 warning_at (loc, OPT_Wdouble_promotion, 6631 "implicit conversion from %qT to %qT when passing " 6632 "argument to function", 6633 arg_type, double_type_node); 6634 arg = convert_to_real (double_type_node, arg); 6635 } 6636 else if (NULLPTR_TYPE_P (arg_type)) 6637 arg = null_pointer_node; 6638 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 6639 { 6640 if (SCOPED_ENUM_P (arg_type)) 6641 { 6642 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg, 6643 complain); 6644 prom = cp_perform_integral_promotions (prom, complain); 6645 if (abi_version_crosses (6) 6646 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type) 6647 && (complain & tf_warning)) 6648 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as " 6649 "%qT before -fabi-version=6, %qT after", arg_type, 6650 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type)); 6651 if (!abi_version_at_least (6)) 6652 arg = prom; 6653 } 6654 else 6655 arg = cp_perform_integral_promotions (arg, complain); 6656 } 6657 6658 arg = require_complete_type_sfinae (arg, complain); 6659 arg_type = TREE_TYPE (arg); 6660 6661 if (arg != error_mark_node 6662 /* In a template (or ill-formed code), we can have an incomplete type 6663 even after require_complete_type_sfinae, in which case we don't know 6664 whether it has trivial copy or not. */ 6665 && COMPLETE_TYPE_P (arg_type)) 6666 { 6667 /* Build up a real lvalue-to-rvalue conversion in case the 6668 copy constructor is trivial but not callable. */ 6669 if (!cp_unevaluated_operand && CLASS_TYPE_P (arg_type)) 6670 force_rvalue (arg, complain); 6671 6672 /* [expr.call] 5.2.2/7: 6673 Passing a potentially-evaluated argument of class type (Clause 9) 6674 with a non-trivial copy constructor or a non-trivial destructor 6675 with no corresponding parameter is conditionally-supported, with 6676 implementation-defined semantics. 6677 6678 We support it as pass-by-invisible-reference, just like a normal 6679 value parameter. 6680 6681 If the call appears in the context of a sizeof expression, 6682 it is not potentially-evaluated. */ 6683 if (cp_unevaluated_operand == 0 6684 && (type_has_nontrivial_copy_init (arg_type) 6685 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type))) 6686 { 6687 if (complain & tf_warning) 6688 warning (OPT_Wconditionally_supported, 6689 "passing objects of non-trivially-copyable " 6690 "type %q#T through %<...%> is conditionally supported", 6691 arg_type); 6692 return cp_build_addr_expr (arg, complain); 6693 } 6694 } 6695 6696 return arg; 6697 } 6698 6699 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 6700 6701 tree 6702 build_x_va_arg (source_location loc, tree expr, tree type) 6703 { 6704 if (processing_template_decl) 6705 { 6706 tree r = build_min (VA_ARG_EXPR, type, expr); 6707 SET_EXPR_LOCATION (r, loc); 6708 return r; 6709 } 6710 6711 type = complete_type_or_else (type, NULL_TREE); 6712 6713 if (expr == error_mark_node || !type) 6714 return error_mark_node; 6715 6716 expr = mark_lvalue_use (expr); 6717 6718 if (TREE_CODE (type) == REFERENCE_TYPE) 6719 { 6720 error ("cannot receive reference type %qT through %<...%>", type); 6721 return error_mark_node; 6722 } 6723 6724 if (type_has_nontrivial_copy_init (type) 6725 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 6726 { 6727 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat 6728 it as pass by invisible reference. */ 6729 warning_at (loc, OPT_Wconditionally_supported, 6730 "receiving objects of non-trivially-copyable type %q#T " 6731 "through %<...%> is conditionally-supported", type); 6732 6733 tree ref = cp_build_reference_type (type, false); 6734 expr = build_va_arg (loc, expr, ref); 6735 return convert_from_reference (expr); 6736 } 6737 6738 return build_va_arg (loc, expr, type); 6739 } 6740 6741 /* TYPE has been given to va_arg. Apply the default conversions which 6742 would have happened when passed via ellipsis. Return the promoted 6743 type, or the passed type if there is no change. */ 6744 6745 tree 6746 cxx_type_promotes_to (tree type) 6747 { 6748 tree promote; 6749 6750 /* Perform the array-to-pointer and function-to-pointer 6751 conversions. */ 6752 type = type_decays_to (type); 6753 6754 promote = type_promotes_to (type); 6755 if (same_type_p (type, promote)) 6756 promote = type; 6757 6758 return promote; 6759 } 6760 6761 /* ARG is a default argument expression being passed to a parameter of 6762 the indicated TYPE, which is a parameter to FN. PARMNUM is the 6763 zero-based argument number. Do any required conversions. Return 6764 the converted value. */ 6765 6766 static GTY(()) vec<tree, va_gc> *default_arg_context; 6767 void 6768 push_defarg_context (tree fn) 6769 { vec_safe_push (default_arg_context, fn); } 6770 6771 void 6772 pop_defarg_context (void) 6773 { default_arg_context->pop (); } 6774 6775 tree 6776 convert_default_arg (tree type, tree arg, tree fn, int parmnum, 6777 tsubst_flags_t complain) 6778 { 6779 int i; 6780 tree t; 6781 6782 /* See through clones. */ 6783 fn = DECL_ORIGIN (fn); 6784 6785 /* Detect recursion. */ 6786 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t) 6787 if (t == fn) 6788 { 6789 if (complain & tf_error) 6790 error ("recursive evaluation of default argument for %q#D", fn); 6791 return error_mark_node; 6792 } 6793 6794 /* If the ARG is an unparsed default argument expression, the 6795 conversion cannot be performed. */ 6796 if (TREE_CODE (arg) == DEFAULT_ARG) 6797 { 6798 if (complain & tf_error) 6799 error ("call to %qD uses the default argument for parameter %P, which " 6800 "is not yet defined", fn, parmnum); 6801 return error_mark_node; 6802 } 6803 6804 push_defarg_context (fn); 6805 6806 if (fn && DECL_TEMPLATE_INFO (fn)) 6807 arg = tsubst_default_argument (fn, type, arg, complain); 6808 6809 /* Due to: 6810 6811 [dcl.fct.default] 6812 6813 The names in the expression are bound, and the semantic 6814 constraints are checked, at the point where the default 6815 expressions appears. 6816 6817 we must not perform access checks here. */ 6818 push_deferring_access_checks (dk_no_check); 6819 /* We must make a copy of ARG, in case subsequent processing 6820 alters any part of it. */ 6821 arg = break_out_target_exprs (arg); 6822 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 6823 ICR_DEFAULT_ARGUMENT, fn, parmnum, 6824 complain); 6825 arg = convert_for_arg_passing (type, arg, complain); 6826 pop_deferring_access_checks(); 6827 6828 pop_defarg_context (); 6829 6830 return arg; 6831 } 6832 6833 /* Returns the type which will really be used for passing an argument of 6834 type TYPE. */ 6835 6836 tree 6837 type_passed_as (tree type) 6838 { 6839 /* Pass classes with copy ctors by invisible reference. */ 6840 if (TREE_ADDRESSABLE (type)) 6841 { 6842 type = build_reference_type (type); 6843 /* There are no other pointers to this temporary. */ 6844 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 6845 } 6846 else if (targetm.calls.promote_prototypes (type) 6847 && INTEGRAL_TYPE_P (type) 6848 && COMPLETE_TYPE_P (type) 6849 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 6850 type = integer_type_node; 6851 6852 return type; 6853 } 6854 6855 /* Actually perform the appropriate conversion. */ 6856 6857 tree 6858 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain) 6859 { 6860 tree bitfield_type; 6861 6862 /* If VAL is a bitfield, then -- since it has already been converted 6863 to TYPE -- it cannot have a precision greater than TYPE. 6864 6865 If it has a smaller precision, we must widen it here. For 6866 example, passing "int f:3;" to a function expecting an "int" will 6867 not result in any conversion before this point. 6868 6869 If the precision is the same we must not risk widening. For 6870 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 6871 often have type "int", even though the C++ type for the field is 6872 "long long". If the value is being passed to a function 6873 expecting an "int", then no conversions will be required. But, 6874 if we call convert_bitfield_to_declared_type, the bitfield will 6875 be converted to "long long". */ 6876 bitfield_type = is_bitfield_expr_with_lowered_type (val); 6877 if (bitfield_type 6878 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 6879 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val); 6880 6881 if (val == error_mark_node) 6882 ; 6883 /* Pass classes with copy ctors by invisible reference. */ 6884 else if (TREE_ADDRESSABLE (type)) 6885 val = build1 (ADDR_EXPR, build_reference_type (type), val); 6886 else if (targetm.calls.promote_prototypes (type) 6887 && INTEGRAL_TYPE_P (type) 6888 && COMPLETE_TYPE_P (type) 6889 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 6890 val = cp_perform_integral_promotions (val, complain); 6891 if ((complain & tf_warning) 6892 && warn_suggest_attribute_format) 6893 { 6894 tree rhstype = TREE_TYPE (val); 6895 const enum tree_code coder = TREE_CODE (rhstype); 6896 const enum tree_code codel = TREE_CODE (type); 6897 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 6898 && coder == codel 6899 && check_missing_format_attribute (type, rhstype)) 6900 warning (OPT_Wsuggest_attribute_format, 6901 "argument of function call might be a candidate for a format attribute"); 6902 } 6903 return val; 6904 } 6905 6906 /* Returns true iff FN is a function with magic varargs, i.e. ones for 6907 which no conversions at all should be done. This is true for some 6908 builtins which don't act like normal functions. */ 6909 6910 bool 6911 magic_varargs_p (tree fn) 6912 { 6913 if (flag_cilkplus && is_cilkplus_reduce_builtin (fn) != BUILT_IN_NONE) 6914 return true; 6915 6916 if (DECL_BUILT_IN (fn)) 6917 switch (DECL_FUNCTION_CODE (fn)) 6918 { 6919 case BUILT_IN_CLASSIFY_TYPE: 6920 case BUILT_IN_CONSTANT_P: 6921 case BUILT_IN_NEXT_ARG: 6922 case BUILT_IN_VA_START: 6923 return true; 6924 6925 default:; 6926 return lookup_attribute ("type generic", 6927 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 6928 } 6929 6930 return false; 6931 } 6932 6933 /* Returns the decl of the dispatcher function if FN is a function version. */ 6934 6935 tree 6936 get_function_version_dispatcher (tree fn) 6937 { 6938 tree dispatcher_decl = NULL; 6939 6940 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 6941 && DECL_FUNCTION_VERSIONED (fn)); 6942 6943 gcc_assert (targetm.get_function_versions_dispatcher); 6944 dispatcher_decl = targetm.get_function_versions_dispatcher (fn); 6945 6946 if (dispatcher_decl == NULL) 6947 { 6948 error_at (input_location, "use of multiversioned function " 6949 "without a default"); 6950 return NULL; 6951 } 6952 6953 retrofit_lang_decl (dispatcher_decl); 6954 gcc_assert (dispatcher_decl != NULL); 6955 return dispatcher_decl; 6956 } 6957 6958 /* fn is a function version dispatcher that is marked used. Mark all the 6959 semantically identical function versions it will dispatch as used. */ 6960 6961 void 6962 mark_versions_used (tree fn) 6963 { 6964 struct cgraph_node *node; 6965 struct cgraph_function_version_info *node_v; 6966 struct cgraph_function_version_info *it_v; 6967 6968 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 6969 6970 node = cgraph_node::get (fn); 6971 if (node == NULL) 6972 return; 6973 6974 gcc_assert (node->dispatcher_function); 6975 6976 node_v = node->function_version (); 6977 if (node_v == NULL) 6978 return; 6979 6980 /* All semantically identical versions are chained. Traverse and mark each 6981 one of them as used. */ 6982 it_v = node_v->next; 6983 while (it_v != NULL) 6984 { 6985 mark_used (it_v->this_node->decl); 6986 it_v = it_v->next; 6987 } 6988 } 6989 6990 /* Build a call to "the copy constructor" for the type of A, even if it 6991 wouldn't be selected by normal overload resolution. Used for 6992 diagnostics. */ 6993 6994 static tree 6995 call_copy_ctor (tree a, tsubst_flags_t complain) 6996 { 6997 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a)); 6998 tree binfo = TYPE_BINFO (ctype); 6999 tree copy = get_copy_ctor (ctype, complain); 7000 copy = build_baselink (binfo, binfo, copy, NULL_TREE); 7001 tree ob = build_dummy_object (ctype); 7002 vec<tree, va_gc>* args = make_tree_vector_single (a); 7003 tree r = build_new_method_call (ob, copy, &args, NULL_TREE, 7004 LOOKUP_NORMAL, NULL, complain); 7005 release_tree_vector (args); 7006 return r; 7007 } 7008 7009 /* Return true iff T refers to a base field. */ 7010 7011 static bool 7012 is_base_field_ref (tree t) 7013 { 7014 STRIP_NOPS (t); 7015 if (TREE_CODE (t) == ADDR_EXPR) 7016 t = TREE_OPERAND (t, 0); 7017 if (TREE_CODE (t) == COMPONENT_REF) 7018 t = TREE_OPERAND (t, 1); 7019 if (TREE_CODE (t) == FIELD_DECL) 7020 return DECL_FIELD_IS_BASE (t); 7021 return false; 7022 } 7023 7024 /* We can't elide a copy from a function returning by value to a base 7025 subobject, as the callee might clobber tail padding. Return true iff this 7026 could be that case. */ 7027 7028 static bool 7029 unsafe_copy_elision_p (tree target, tree exp) 7030 { 7031 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 7032 /* It's safe to elide the copy for a class with no tail padding. */ 7033 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type))) 7034 return false; 7035 /* It's safe to elide the copy if we aren't initializing a base object. */ 7036 if (!is_base_field_ref (target)) 7037 return false; 7038 tree init = TARGET_EXPR_INITIAL (exp); 7039 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */ 7040 while (TREE_CODE (init) == COMPOUND_EXPR) 7041 init = TREE_OPERAND (init, 1); 7042 return (TREE_CODE (init) == AGGR_INIT_EXPR 7043 && !AGGR_INIT_VIA_CTOR_P (init)); 7044 } 7045 7046 /* Subroutine of the various build_*_call functions. Overload resolution 7047 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 7048 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 7049 bitmask of various LOOKUP_* flags which apply to the call itself. */ 7050 7051 static tree 7052 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 7053 { 7054 tree fn = cand->fn; 7055 const vec<tree, va_gc> *args = cand->args; 7056 tree first_arg = cand->first_arg; 7057 conversion **convs = cand->convs; 7058 conversion *conv; 7059 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 7060 int parmlen; 7061 tree val; 7062 int i = 0; 7063 int j = 0; 7064 unsigned int arg_index = 0; 7065 int is_method = 0; 7066 int nargs; 7067 tree *argarray; 7068 bool already_used = false; 7069 7070 /* In a template, there is no need to perform all of the work that 7071 is normally done. We are only interested in the type of the call 7072 expression, i.e., the return type of the function. Any semantic 7073 errors will be deferred until the template is instantiated. */ 7074 if (processing_template_decl) 7075 { 7076 tree expr, addr; 7077 tree return_type; 7078 const tree *argarray; 7079 unsigned int nargs; 7080 7081 return_type = TREE_TYPE (TREE_TYPE (fn)); 7082 nargs = vec_safe_length (args); 7083 if (first_arg == NULL_TREE) 7084 argarray = args->address (); 7085 else 7086 { 7087 tree *alcarray; 7088 unsigned int ix; 7089 tree arg; 7090 7091 ++nargs; 7092 alcarray = XALLOCAVEC (tree, nargs); 7093 alcarray[0] = build_this (first_arg); 7094 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 7095 alcarray[ix + 1] = arg; 7096 argarray = alcarray; 7097 } 7098 7099 addr = build_addr_func (fn, complain); 7100 if (addr == error_mark_node) 7101 return error_mark_node; 7102 expr = build_call_array_loc (input_location, return_type, 7103 addr, nargs, argarray); 7104 if (TREE_THIS_VOLATILE (fn) && cfun) 7105 current_function_returns_abnormally = 1; 7106 return convert_from_reference (expr); 7107 } 7108 7109 /* Give any warnings we noticed during overload resolution. */ 7110 if (cand->warnings && (complain & tf_warning)) 7111 { 7112 struct candidate_warning *w; 7113 for (w = cand->warnings; w; w = w->next) 7114 joust (cand, w->loser, 1, complain); 7115 } 7116 7117 /* Make =delete work with SFINAE. */ 7118 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 7119 return error_mark_node; 7120 7121 if (DECL_FUNCTION_MEMBER_P (fn)) 7122 { 7123 tree access_fn; 7124 /* If FN is a template function, two cases must be considered. 7125 For example: 7126 7127 struct A { 7128 protected: 7129 template <class T> void f(); 7130 }; 7131 template <class T> struct B { 7132 protected: 7133 void g(); 7134 }; 7135 struct C : A, B<int> { 7136 using A::f; // #1 7137 using B<int>::g; // #2 7138 }; 7139 7140 In case #1 where `A::f' is a member template, DECL_ACCESS is 7141 recorded in the primary template but not in its specialization. 7142 We check access of FN using its primary template. 7143 7144 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 7145 because it is a member of class template B, DECL_ACCESS is 7146 recorded in the specialization `B<int>::g'. We cannot use its 7147 primary template because `B<T>::g' and `B<int>::g' may have 7148 different access. */ 7149 if (DECL_TEMPLATE_INFO (fn) 7150 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 7151 access_fn = DECL_TI_TEMPLATE (fn); 7152 else 7153 access_fn = fn; 7154 if (!perform_or_defer_access_check (cand->access_path, access_fn, 7155 fn, complain)) 7156 return error_mark_node; 7157 } 7158 7159 /* If we're checking for implicit delete, don't bother with argument 7160 conversions. */ 7161 if (flags & LOOKUP_SPECULATIVE) 7162 { 7163 if (DECL_DELETED_FN (fn)) 7164 { 7165 if (complain & tf_error) 7166 mark_used (fn); 7167 return error_mark_node; 7168 } 7169 if (cand->viable == 1) 7170 return fn; 7171 else if (!(complain & tf_error)) 7172 /* Reject bad conversions now. */ 7173 return error_mark_node; 7174 /* else continue to get conversion error. */ 7175 } 7176 7177 /* N3276 magic doesn't apply to nested calls. */ 7178 int decltype_flag = (complain & tf_decltype); 7179 complain &= ~tf_decltype; 7180 7181 /* Find maximum size of vector to hold converted arguments. */ 7182 parmlen = list_length (parm); 7183 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0); 7184 if (parmlen > nargs) 7185 nargs = parmlen; 7186 argarray = XALLOCAVEC (tree, nargs); 7187 7188 /* The implicit parameters to a constructor are not considered by overload 7189 resolution, and must be of the proper type. */ 7190 if (DECL_CONSTRUCTOR_P (fn)) 7191 { 7192 tree object_arg; 7193 if (first_arg != NULL_TREE) 7194 { 7195 object_arg = first_arg; 7196 first_arg = NULL_TREE; 7197 } 7198 else 7199 { 7200 object_arg = (*args)[arg_index]; 7201 ++arg_index; 7202 } 7203 argarray[j++] = build_this (object_arg); 7204 parm = TREE_CHAIN (parm); 7205 /* We should never try to call the abstract constructor. */ 7206 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 7207 7208 if (DECL_HAS_VTT_PARM_P (fn)) 7209 { 7210 argarray[j++] = (*args)[arg_index]; 7211 ++arg_index; 7212 parm = TREE_CHAIN (parm); 7213 } 7214 } 7215 /* Bypass access control for 'this' parameter. */ 7216 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 7217 { 7218 tree parmtype = TREE_VALUE (parm); 7219 tree arg = build_this (first_arg != NULL_TREE 7220 ? first_arg 7221 : (*args)[arg_index]); 7222 tree argtype = TREE_TYPE (arg); 7223 tree converted_arg; 7224 tree base_binfo; 7225 7226 if (convs[i]->bad_p) 7227 { 7228 if (complain & tf_error) 7229 { 7230 if (permerror (input_location, "passing %qT as %<this%> " 7231 "argument discards qualifiers", 7232 TREE_TYPE (argtype))) 7233 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn); 7234 } 7235 else 7236 return error_mark_node; 7237 } 7238 7239 /* See if the function member or the whole class type is declared 7240 final and the call can be devirtualized. */ 7241 if (DECL_FINAL_P (fn) 7242 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 7243 flags |= LOOKUP_NONVIRTUAL; 7244 7245 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 7246 X is called for an object that is not of type X, or of a type 7247 derived from X, the behavior is undefined. 7248 7249 So we can assume that anything passed as 'this' is non-null, and 7250 optimize accordingly. */ 7251 gcc_assert (TYPE_PTR_P (parmtype)); 7252 /* Convert to the base in which the function was declared. */ 7253 gcc_assert (cand->conversion_path != NULL_TREE); 7254 converted_arg = build_base_path (PLUS_EXPR, 7255 arg, 7256 cand->conversion_path, 7257 1, complain); 7258 /* Check that the base class is accessible. */ 7259 if (!accessible_base_p (TREE_TYPE (argtype), 7260 BINFO_TYPE (cand->conversion_path), true)) 7261 { 7262 if (complain & tf_error) 7263 error ("%qT is not an accessible base of %qT", 7264 BINFO_TYPE (cand->conversion_path), 7265 TREE_TYPE (argtype)); 7266 else 7267 return error_mark_node; 7268 } 7269 /* If fn was found by a using declaration, the conversion path 7270 will be to the derived class, not the base declaring fn. We 7271 must convert from derived to base. */ 7272 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 7273 TREE_TYPE (parmtype), ba_unique, 7274 NULL, complain); 7275 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 7276 base_binfo, 1, complain); 7277 7278 argarray[j++] = converted_arg; 7279 parm = TREE_CHAIN (parm); 7280 if (first_arg != NULL_TREE) 7281 first_arg = NULL_TREE; 7282 else 7283 ++arg_index; 7284 ++i; 7285 is_method = 1; 7286 } 7287 7288 gcc_assert (first_arg == NULL_TREE); 7289 for (; arg_index < vec_safe_length (args) && parm; 7290 parm = TREE_CHAIN (parm), ++arg_index, ++i) 7291 { 7292 tree type = TREE_VALUE (parm); 7293 tree arg = (*args)[arg_index]; 7294 bool conversion_warning = true; 7295 7296 conv = convs[i]; 7297 7298 /* If the argument is NULL and used to (implicitly) instantiate a 7299 template function (and bind one of the template arguments to 7300 the type of 'long int'), we don't want to warn about passing NULL 7301 to non-pointer argument. 7302 For example, if we have this template function: 7303 7304 template<typename T> void func(T x) {} 7305 7306 we want to warn (when -Wconversion is enabled) in this case: 7307 7308 void foo() { 7309 func<int>(NULL); 7310 } 7311 7312 but not in this case: 7313 7314 void foo() { 7315 func(NULL); 7316 } 7317 */ 7318 if (arg == null_node 7319 && DECL_TEMPLATE_INFO (fn) 7320 && cand->template_decl 7321 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 7322 conversion_warning = false; 7323 7324 /* Warn about initializer_list deduction that isn't currently in the 7325 working draft. */ 7326 if (cxx_dialect > cxx98 7327 && flag_deduce_init_list 7328 && cand->template_decl 7329 && is_std_init_list (non_reference (type)) 7330 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 7331 { 7332 tree tmpl = TI_TEMPLATE (cand->template_decl); 7333 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 7334 tree patparm = get_pattern_parm (realparm, tmpl); 7335 tree pattype = TREE_TYPE (patparm); 7336 if (PACK_EXPANSION_P (pattype)) 7337 pattype = PACK_EXPANSION_PATTERN (pattype); 7338 pattype = non_reference (pattype); 7339 7340 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 7341 && (cand->explicit_targs == NULL_TREE 7342 || (TREE_VEC_LENGTH (cand->explicit_targs) 7343 <= TEMPLATE_TYPE_IDX (pattype)))) 7344 { 7345 pedwarn (input_location, 0, "deducing %qT as %qT", 7346 non_reference (TREE_TYPE (patparm)), 7347 non_reference (type)); 7348 pedwarn (input_location, 0, " in call to %q+D", cand->fn); 7349 pedwarn (input_location, 0, 7350 " (you can disable this with -fno-deduce-init-list)"); 7351 } 7352 } 7353 val = convert_like_with_context (conv, arg, fn, i - is_method, 7354 conversion_warning 7355 ? complain 7356 : complain & (~tf_warning)); 7357 7358 val = convert_for_arg_passing (type, val, complain); 7359 7360 if (val == error_mark_node) 7361 return error_mark_node; 7362 else 7363 argarray[j++] = val; 7364 } 7365 7366 /* Default arguments */ 7367 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 7368 { 7369 if (TREE_VALUE (parm) == error_mark_node) 7370 return error_mark_node; 7371 argarray[j++] = convert_default_arg (TREE_VALUE (parm), 7372 TREE_PURPOSE (parm), 7373 fn, i - is_method, 7374 complain); 7375 } 7376 7377 /* Ellipsis */ 7378 for (; arg_index < vec_safe_length (args); ++arg_index) 7379 { 7380 tree a = (*args)[arg_index]; 7381 if (magic_varargs_p (fn)) 7382 /* Do no conversions for magic varargs. */ 7383 a = mark_type_use (a); 7384 else if (DECL_CONSTRUCTOR_P (fn) 7385 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn), 7386 TREE_TYPE (a))) 7387 { 7388 /* Avoid infinite recursion trying to call A(...). */ 7389 if (complain & tf_error) 7390 /* Try to call the actual copy constructor for a good error. */ 7391 call_copy_ctor (a, complain); 7392 return error_mark_node; 7393 } 7394 else 7395 a = convert_arg_to_ellipsis (a, complain); 7396 argarray[j++] = a; 7397 } 7398 7399 gcc_assert (j <= nargs); 7400 nargs = j; 7401 7402 check_function_arguments (TREE_TYPE (fn), nargs, argarray); 7403 7404 /* Avoid actually calling copy constructors and copy assignment operators, 7405 if possible. */ 7406 7407 if (! flag_elide_constructors) 7408 /* Do things the hard way. */; 7409 else if (cand->num_convs == 1 7410 && (DECL_COPY_CONSTRUCTOR_P (fn) 7411 || DECL_MOVE_CONSTRUCTOR_P (fn)) 7412 /* It's unsafe to elide the constructor when handling 7413 a noexcept-expression, it may evaluate to the wrong 7414 value (c++/53025). */ 7415 && cp_noexcept_operand == 0) 7416 { 7417 tree targ; 7418 tree arg = argarray[num_artificial_parms_for (fn)]; 7419 tree fa; 7420 bool trivial = trivial_fn_p (fn); 7421 7422 /* Pull out the real argument, disregarding const-correctness. */ 7423 targ = arg; 7424 while (CONVERT_EXPR_P (targ) 7425 || TREE_CODE (targ) == NON_LVALUE_EXPR) 7426 targ = TREE_OPERAND (targ, 0); 7427 if (TREE_CODE (targ) == ADDR_EXPR) 7428 { 7429 targ = TREE_OPERAND (targ, 0); 7430 if (!same_type_ignoring_top_level_qualifiers_p 7431 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 7432 targ = NULL_TREE; 7433 } 7434 else 7435 targ = NULL_TREE; 7436 7437 if (targ) 7438 arg = targ; 7439 else 7440 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 7441 7442 /* [class.copy]: the copy constructor is implicitly defined even if 7443 the implementation elided its use. */ 7444 if (!trivial || DECL_DELETED_FN (fn)) 7445 { 7446 if (!mark_used (fn, complain) && !(complain & tf_error)) 7447 return error_mark_node; 7448 already_used = true; 7449 } 7450 7451 /* If we're creating a temp and we already have one, don't create a 7452 new one. If we're not creating a temp but we get one, use 7453 INIT_EXPR to collapse the temp into our target. Otherwise, if the 7454 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 7455 temp or an INIT_EXPR otherwise. */ 7456 fa = argarray[0]; 7457 if (is_dummy_object (fa)) 7458 { 7459 if (TREE_CODE (arg) == TARGET_EXPR) 7460 return arg; 7461 else if (trivial) 7462 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 7463 } 7464 else if (trivial 7465 || (TREE_CODE (arg) == TARGET_EXPR 7466 && !unsafe_copy_elision_p (fa, arg))) 7467 { 7468 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL, 7469 complain)); 7470 7471 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 7472 return val; 7473 } 7474 } 7475 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR 7476 && trivial_fn_p (fn) 7477 && !DECL_DELETED_FN (fn)) 7478 { 7479 tree to = stabilize_reference 7480 (cp_build_indirect_ref (argarray[0], RO_NULL, complain)); 7481 tree type = TREE_TYPE (to); 7482 tree as_base = CLASSTYPE_AS_BASE (type); 7483 tree arg = argarray[1]; 7484 7485 if (is_really_empty_class (type)) 7486 { 7487 /* Avoid copying empty classes. */ 7488 val = build2 (COMPOUND_EXPR, void_type_node, to, arg); 7489 TREE_NO_WARNING (val) = 1; 7490 val = build2 (COMPOUND_EXPR, type, val, to); 7491 TREE_NO_WARNING (val) = 1; 7492 } 7493 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 7494 { 7495 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 7496 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 7497 } 7498 else 7499 { 7500 /* We must only copy the non-tail padding parts. */ 7501 tree arg0, arg2, t; 7502 tree array_type, alias_set; 7503 7504 arg2 = TYPE_SIZE_UNIT (as_base); 7505 arg0 = cp_build_addr_expr (to, complain); 7506 7507 array_type = build_array_type (char_type_node, 7508 build_index_type 7509 (size_binop (MINUS_EXPR, 7510 arg2, size_int (1)))); 7511 alias_set = build_int_cst (build_pointer_type (type), 0); 7512 t = build2 (MODIFY_EXPR, void_type_node, 7513 build2 (MEM_REF, array_type, arg0, alias_set), 7514 build2 (MEM_REF, array_type, arg, alias_set)); 7515 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 7516 TREE_NO_WARNING (val) = 1; 7517 } 7518 7519 return val; 7520 } 7521 else if (DECL_DESTRUCTOR_P (fn) 7522 && trivial_fn_p (fn) 7523 && !DECL_DELETED_FN (fn)) 7524 return fold_convert (void_type_node, argarray[0]); 7525 /* FIXME handle trivial default constructor, too. */ 7526 7527 /* For calls to a multi-versioned function, overload resolution 7528 returns the function with the highest target priority, that is, 7529 the version that will checked for dispatching first. If this 7530 version is inlinable, a direct call to this version can be made 7531 otherwise the call should go through the dispatcher. */ 7532 7533 if (DECL_FUNCTION_VERSIONED (fn) 7534 && (current_function_decl == NULL 7535 || !targetm.target_option.can_inline_p (current_function_decl, fn))) 7536 { 7537 fn = get_function_version_dispatcher (fn); 7538 if (fn == NULL) 7539 return NULL; 7540 if (!already_used) 7541 mark_versions_used (fn); 7542 } 7543 7544 if (!already_used 7545 && !mark_used (fn, complain)) 7546 return error_mark_node; 7547 7548 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0 7549 /* Don't mess with virtual lookup in instantiate_non_dependent_expr; 7550 virtual functions can't be constexpr. */ 7551 && !in_template_function ()) 7552 { 7553 tree t; 7554 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 7555 DECL_CONTEXT (fn), 7556 ba_any, NULL, complain); 7557 gcc_assert (binfo && binfo != error_mark_node); 7558 7559 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 7560 complain); 7561 if (TREE_SIDE_EFFECTS (argarray[0])) 7562 argarray[0] = save_expr (argarray[0]); 7563 t = build_pointer_type (TREE_TYPE (fn)); 7564 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn))) 7565 fn = build_java_interface_fn_ref (fn, argarray[0]); 7566 else 7567 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 7568 TREE_TYPE (fn) = t; 7569 } 7570 else 7571 { 7572 fn = build_addr_func (fn, complain); 7573 if (fn == error_mark_node) 7574 return error_mark_node; 7575 } 7576 7577 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag); 7578 if (TREE_CODE (call) == CALL_EXPR 7579 && (cand->flags & LOOKUP_LIST_INIT_CTOR)) 7580 CALL_EXPR_LIST_INIT_P (call) = true; 7581 return call; 7582 } 7583 7584 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 7585 This function performs no overload resolution, conversion, or other 7586 high-level operations. */ 7587 7588 tree 7589 build_cxx_call (tree fn, int nargs, tree *argarray, 7590 tsubst_flags_t complain) 7591 { 7592 tree fndecl; 7593 int optimize_sav; 7594 7595 /* Remember roughly where this call is. */ 7596 location_t loc = EXPR_LOC_OR_LOC (fn, input_location); 7597 fn = build_call_a (fn, nargs, argarray); 7598 SET_EXPR_LOCATION (fn, loc); 7599 7600 fndecl = get_callee_fndecl (fn); 7601 7602 /* Check that arguments to builtin functions match the expectations. */ 7603 if (fndecl 7604 && DECL_BUILT_IN (fndecl) 7605 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 7606 && !check_builtin_function_arguments (fndecl, nargs, argarray)) 7607 return error_mark_node; 7608 7609 /* If it is a built-in array notation function, then the return type of 7610 the function is the element type of the array passed in as array 7611 notation (i.e. the first parameter of the function). */ 7612 if (flag_cilkplus && TREE_CODE (fn) == CALL_EXPR) 7613 { 7614 enum built_in_function bif = 7615 is_cilkplus_reduce_builtin (CALL_EXPR_FN (fn)); 7616 if (bif == BUILT_IN_CILKPLUS_SEC_REDUCE_ADD 7617 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MUL 7618 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MAX 7619 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MIN 7620 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE 7621 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MUTATING) 7622 { 7623 if (call_expr_nargs (fn) == 0) 7624 { 7625 error_at (EXPR_LOCATION (fn), "Invalid builtin arguments"); 7626 return error_mark_node; 7627 } 7628 /* for bif == BUILT_IN_CILKPLUS_SEC_REDUCE_ALL_ZERO or 7629 BUILT_IN_CILKPLUS_SEC_REDUCE_ANY_ZERO or 7630 BUILT_IN_CILKPLUS_SEC_REDUCE_ANY_NONZERO or 7631 BUILT_IN_CILKPLUS_SEC_REDUCE_ALL_NONZERO or 7632 BUILT_IN_CILKPLUS_SEC_REDUCE_MIN_IND or 7633 BUILT_IN_CILKPLUS_SEC_REDUCE_MAX_IND 7634 The pre-defined return-type is the correct one. */ 7635 tree array_ntn = CALL_EXPR_ARG (fn, 0); 7636 TREE_TYPE (fn) = TREE_TYPE (array_ntn); 7637 return fn; 7638 } 7639 } 7640 7641 /* Some built-in function calls will be evaluated at compile-time in 7642 fold (). Set optimize to 1 when folding __builtin_constant_p inside 7643 a constexpr function so that fold_builtin_1 doesn't fold it to 0. */ 7644 optimize_sav = optimize; 7645 if (!optimize && fndecl && DECL_IS_BUILTIN_CONSTANT_P (fndecl) 7646 && current_function_decl 7647 && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) 7648 optimize = 1; 7649 fn = fold_if_not_in_template (fn); 7650 optimize = optimize_sav; 7651 7652 if (VOID_TYPE_P (TREE_TYPE (fn))) 7653 return fn; 7654 7655 /* 5.2.2/11: If a function call is a prvalue of object type: if the 7656 function call is either the operand of a decltype-specifier or the 7657 right operand of a comma operator that is the operand of a 7658 decltype-specifier, a temporary object is not introduced for the 7659 prvalue. The type of the prvalue may be incomplete. */ 7660 if (!(complain & tf_decltype)) 7661 { 7662 fn = require_complete_type_sfinae (fn, complain); 7663 if (fn == error_mark_node) 7664 return error_mark_node; 7665 7666 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 7667 fn = build_cplus_new (TREE_TYPE (fn), fn, complain); 7668 } 7669 return convert_from_reference (fn); 7670 } 7671 7672 static GTY(()) tree java_iface_lookup_fn; 7673 7674 /* Make an expression which yields the address of the Java interface 7675 method FN. This is achieved by generating a call to libjava's 7676 _Jv_LookupInterfaceMethodIdx(). */ 7677 7678 static tree 7679 build_java_interface_fn_ref (tree fn, tree instance) 7680 { 7681 tree lookup_fn, method, idx; 7682 tree klass_ref, iface, iface_ref; 7683 int i; 7684 7685 if (!java_iface_lookup_fn) 7686 { 7687 tree ftype = build_function_type_list (ptr_type_node, 7688 ptr_type_node, ptr_type_node, 7689 java_int_type_node, NULL_TREE); 7690 java_iface_lookup_fn 7691 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype, 7692 0, NOT_BUILT_IN, NULL, NULL_TREE); 7693 } 7694 7695 /* Look up the pointer to the runtime java.lang.Class object for `instance'. 7696 This is the first entry in the vtable. */ 7697 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL, 7698 tf_warning_or_error), 7699 integer_zero_node); 7700 7701 /* Get the java.lang.Class pointer for the interface being called. */ 7702 iface = DECL_CONTEXT (fn); 7703 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false); 7704 if (!iface_ref || !VAR_P (iface_ref) 7705 || DECL_CONTEXT (iface_ref) != iface) 7706 { 7707 error ("could not find class$ field in java interface type %qT", 7708 iface); 7709 return error_mark_node; 7710 } 7711 iface_ref = build_address (iface_ref); 7712 iface_ref = convert (build_pointer_type (iface), iface_ref); 7713 7714 /* Determine the itable index of FN. */ 7715 i = 1; 7716 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method)) 7717 { 7718 if (!DECL_VIRTUAL_P (method)) 7719 continue; 7720 if (fn == method) 7721 break; 7722 i++; 7723 } 7724 idx = build_int_cst (NULL_TREE, i); 7725 7726 lookup_fn = build1 (ADDR_EXPR, 7727 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)), 7728 java_iface_lookup_fn); 7729 return build_call_nary (ptr_type_node, lookup_fn, 7730 3, klass_ref, iface_ref, idx); 7731 } 7732 7733 /* Returns the value to use for the in-charge parameter when making a 7734 call to a function with the indicated NAME. 7735 7736 FIXME:Can't we find a neater way to do this mapping? */ 7737 7738 tree 7739 in_charge_arg_for_name (tree name) 7740 { 7741 if (name == base_ctor_identifier 7742 || name == base_dtor_identifier) 7743 return integer_zero_node; 7744 else if (name == complete_ctor_identifier) 7745 return integer_one_node; 7746 else if (name == complete_dtor_identifier) 7747 return integer_two_node; 7748 else if (name == deleting_dtor_identifier) 7749 return integer_three_node; 7750 7751 /* This function should only be called with one of the names listed 7752 above. */ 7753 gcc_unreachable (); 7754 return NULL_TREE; 7755 } 7756 7757 /* Build a call to a constructor, destructor, or an assignment 7758 operator for INSTANCE, an expression with class type. NAME 7759 indicates the special member function to call; *ARGS are the 7760 arguments. ARGS may be NULL. This may change ARGS. BINFO 7761 indicates the base of INSTANCE that is to be passed as the `this' 7762 parameter to the member function called. 7763 7764 FLAGS are the LOOKUP_* flags to use when processing the call. 7765 7766 If NAME indicates a complete object constructor, INSTANCE may be 7767 NULL_TREE. In this case, the caller will call build_cplus_new to 7768 store the newly constructed object into a VAR_DECL. */ 7769 7770 tree 7771 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args, 7772 tree binfo, int flags, tsubst_flags_t complain) 7773 { 7774 tree fns; 7775 /* The type of the subobject to be constructed or destroyed. */ 7776 tree class_type; 7777 vec<tree, va_gc> *allocated = NULL; 7778 tree ret; 7779 7780 gcc_assert (name == complete_ctor_identifier 7781 || name == base_ctor_identifier 7782 || name == complete_dtor_identifier 7783 || name == base_dtor_identifier 7784 || name == deleting_dtor_identifier 7785 || name == ansi_assopname (NOP_EXPR)); 7786 if (TYPE_P (binfo)) 7787 { 7788 /* Resolve the name. */ 7789 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 7790 return error_mark_node; 7791 7792 binfo = TYPE_BINFO (binfo); 7793 } 7794 7795 gcc_assert (binfo != NULL_TREE); 7796 7797 class_type = BINFO_TYPE (binfo); 7798 7799 /* Handle the special case where INSTANCE is NULL_TREE. */ 7800 if (name == complete_ctor_identifier && !instance) 7801 instance = build_dummy_object (class_type); 7802 else 7803 { 7804 if (name == complete_dtor_identifier 7805 || name == base_dtor_identifier 7806 || name == deleting_dtor_identifier) 7807 gcc_assert (args == NULL || vec_safe_is_empty (*args)); 7808 7809 /* Convert to the base class, if necessary. */ 7810 if (!same_type_ignoring_top_level_qualifiers_p 7811 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 7812 { 7813 if (name != ansi_assopname (NOP_EXPR)) 7814 /* For constructors and destructors, either the base is 7815 non-virtual, or it is virtual but we are doing the 7816 conversion from a constructor or destructor for the 7817 complete object. In either case, we can convert 7818 statically. */ 7819 instance = convert_to_base_statically (instance, binfo); 7820 else 7821 /* However, for assignment operators, we must convert 7822 dynamically if the base is virtual. */ 7823 instance = build_base_path (PLUS_EXPR, instance, 7824 binfo, /*nonnull=*/1, complain); 7825 } 7826 } 7827 7828 gcc_assert (instance != NULL_TREE); 7829 7830 fns = lookup_fnfields (binfo, name, 1); 7831 7832 /* When making a call to a constructor or destructor for a subobject 7833 that uses virtual base classes, pass down a pointer to a VTT for 7834 the subobject. */ 7835 if ((name == base_ctor_identifier 7836 || name == base_dtor_identifier) 7837 && CLASSTYPE_VBASECLASSES (class_type)) 7838 { 7839 tree vtt; 7840 tree sub_vtt; 7841 7842 /* If the current function is a complete object constructor 7843 or destructor, then we fetch the VTT directly. 7844 Otherwise, we look it up using the VTT we were given. */ 7845 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 7846 vtt = decay_conversion (vtt, complain); 7847 if (vtt == error_mark_node) 7848 return error_mark_node; 7849 vtt = build3 (COND_EXPR, TREE_TYPE (vtt), 7850 build2 (EQ_EXPR, boolean_type_node, 7851 current_in_charge_parm, integer_zero_node), 7852 current_vtt_parm, 7853 vtt); 7854 if (BINFO_SUBVTT_INDEX (binfo)) 7855 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 7856 else 7857 sub_vtt = vtt; 7858 7859 if (args == NULL) 7860 { 7861 allocated = make_tree_vector (); 7862 args = &allocated; 7863 } 7864 7865 vec_safe_insert (*args, 0, sub_vtt); 7866 } 7867 7868 ret = build_new_method_call (instance, fns, args, 7869 TYPE_BINFO (BINFO_TYPE (binfo)), 7870 flags, /*fn=*/NULL, 7871 complain); 7872 7873 if (allocated != NULL) 7874 release_tree_vector (allocated); 7875 7876 if ((complain & tf_error) 7877 && (flags & LOOKUP_DELEGATING_CONS) 7878 && name == complete_ctor_identifier 7879 && TREE_CODE (ret) == CALL_EXPR 7880 && (DECL_ABSTRACT_ORIGIN (TREE_OPERAND (CALL_EXPR_FN (ret), 0)) 7881 == current_function_decl)) 7882 error ("constructor delegates to itself"); 7883 7884 return ret; 7885 } 7886 7887 /* Return the NAME, as a C string. The NAME indicates a function that 7888 is a member of TYPE. *FREE_P is set to true if the caller must 7889 free the memory returned. 7890 7891 Rather than go through all of this, we should simply set the names 7892 of constructors and destructors appropriately, and dispense with 7893 ctor_identifier, dtor_identifier, etc. */ 7894 7895 static char * 7896 name_as_c_string (tree name, tree type, bool *free_p) 7897 { 7898 char *pretty_name; 7899 7900 /* Assume that we will not allocate memory. */ 7901 *free_p = false; 7902 /* Constructors and destructors are special. */ 7903 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 7904 { 7905 pretty_name 7906 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)))); 7907 /* For a destructor, add the '~'. */ 7908 if (name == complete_dtor_identifier 7909 || name == base_dtor_identifier 7910 || name == deleting_dtor_identifier) 7911 { 7912 pretty_name = concat ("~", pretty_name, NULL); 7913 /* Remember that we need to free the memory allocated. */ 7914 *free_p = true; 7915 } 7916 } 7917 else if (IDENTIFIER_TYPENAME_P (name)) 7918 { 7919 pretty_name = concat ("operator ", 7920 type_as_string_translate (TREE_TYPE (name), 7921 TFF_PLAIN_IDENTIFIER), 7922 NULL); 7923 /* Remember that we need to free the memory allocated. */ 7924 *free_p = true; 7925 } 7926 else 7927 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name))); 7928 7929 return pretty_name; 7930 } 7931 7932 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 7933 be set, upon return, to the function called. ARGS may be NULL. 7934 This may change ARGS. */ 7935 7936 static tree 7937 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args, 7938 tree conversion_path, int flags, 7939 tree *fn_p, tsubst_flags_t complain) 7940 { 7941 struct z_candidate *candidates = 0, *cand; 7942 tree explicit_targs = NULL_TREE; 7943 tree basetype = NULL_TREE; 7944 tree access_binfo, binfo; 7945 tree optype; 7946 tree first_mem_arg = NULL_TREE; 7947 tree name; 7948 bool skip_first_for_error; 7949 vec<tree, va_gc> *user_args; 7950 tree call; 7951 tree fn; 7952 int template_only = 0; 7953 bool any_viable_p; 7954 tree orig_instance; 7955 tree orig_fns; 7956 vec<tree, va_gc> *orig_args = NULL; 7957 void *p; 7958 7959 gcc_assert (instance != NULL_TREE); 7960 7961 /* We don't know what function we're going to call, yet. */ 7962 if (fn_p) 7963 *fn_p = NULL_TREE; 7964 7965 if (error_operand_p (instance) 7966 || !fns || error_operand_p (fns)) 7967 return error_mark_node; 7968 7969 if (!BASELINK_P (fns)) 7970 { 7971 if (complain & tf_error) 7972 error ("call to non-function %qD", fns); 7973 return error_mark_node; 7974 } 7975 7976 orig_instance = instance; 7977 orig_fns = fns; 7978 7979 /* Dismantle the baselink to collect all the information we need. */ 7980 if (!conversion_path) 7981 conversion_path = BASELINK_BINFO (fns); 7982 access_binfo = BASELINK_ACCESS_BINFO (fns); 7983 binfo = BASELINK_BINFO (fns); 7984 optype = BASELINK_OPTYPE (fns); 7985 fns = BASELINK_FUNCTIONS (fns); 7986 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 7987 { 7988 explicit_targs = TREE_OPERAND (fns, 1); 7989 fns = TREE_OPERAND (fns, 0); 7990 template_only = 1; 7991 } 7992 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 7993 || TREE_CODE (fns) == TEMPLATE_DECL 7994 || TREE_CODE (fns) == OVERLOAD); 7995 fn = get_first_fn (fns); 7996 name = DECL_NAME (fn); 7997 7998 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 7999 gcc_assert (CLASS_TYPE_P (basetype)); 8000 8001 if (processing_template_decl) 8002 { 8003 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 8004 instance = build_non_dependent_expr (instance); 8005 if (args != NULL) 8006 make_args_non_dependent (*args); 8007 } 8008 8009 user_args = args == NULL ? NULL : *args; 8010 /* Under DR 147 A::A() is an invalid constructor call, 8011 not a functional cast. */ 8012 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 8013 { 8014 if (! (complain & tf_error)) 8015 return error_mark_node; 8016 8017 if (permerror (input_location, 8018 "cannot call constructor %<%T::%D%> directly", 8019 basetype, name)) 8020 inform (input_location, "for a function-style cast, remove the " 8021 "redundant %<::%D%>", name); 8022 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 8023 complain); 8024 return call; 8025 } 8026 8027 /* Figure out whether to skip the first argument for the error 8028 message we will display to users if an error occurs. We don't 8029 want to display any compiler-generated arguments. The "this" 8030 pointer hasn't been added yet. However, we must remove the VTT 8031 pointer if this is a call to a base-class constructor or 8032 destructor. */ 8033 skip_first_for_error = false; 8034 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 8035 { 8036 /* Callers should explicitly indicate whether they want to construct 8037 the complete object or just the part without virtual bases. */ 8038 gcc_assert (name != ctor_identifier); 8039 /* Similarly for destructors. */ 8040 gcc_assert (name != dtor_identifier); 8041 /* Remove the VTT pointer, if present. */ 8042 if ((name == base_ctor_identifier || name == base_dtor_identifier) 8043 && CLASSTYPE_VBASECLASSES (basetype)) 8044 skip_first_for_error = true; 8045 } 8046 8047 /* Process the argument list. */ 8048 if (args != NULL && *args != NULL) 8049 { 8050 *args = resolve_args (*args, complain); 8051 if (*args == NULL) 8052 return error_mark_node; 8053 } 8054 8055 /* Consider the object argument to be used even if we end up selecting a 8056 static member function. */ 8057 instance = mark_type_use (instance); 8058 8059 /* It's OK to call destructors and constructors on cv-qualified objects. 8060 Therefore, convert the INSTANCE to the unqualified type, if 8061 necessary. */ 8062 if (DECL_DESTRUCTOR_P (fn) 8063 || DECL_CONSTRUCTOR_P (fn)) 8064 { 8065 if (!same_type_p (basetype, TREE_TYPE (instance))) 8066 { 8067 instance = build_this (instance); 8068 instance = build_nop (build_pointer_type (basetype), instance); 8069 instance = build_fold_indirect_ref (instance); 8070 } 8071 } 8072 if (DECL_DESTRUCTOR_P (fn)) 8073 name = complete_dtor_identifier; 8074 8075 /* For the overload resolution we need to find the actual `this` 8076 that would be captured if the call turns out to be to a 8077 non-static member function. Do not actually capture it at this 8078 point. */ 8079 if (DECL_CONSTRUCTOR_P (fn)) 8080 /* Constructors don't use the enclosing 'this'. */ 8081 first_mem_arg = instance; 8082 else 8083 first_mem_arg = maybe_resolve_dummy (instance, false); 8084 8085 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8086 p = conversion_obstack_alloc (0); 8087 8088 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 8089 initializer, not T({ }). */ 8090 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !vec_safe_is_empty (*args) 8091 && DIRECT_LIST_INIT_P ((**args)[0])) 8092 { 8093 tree init_list = (**args)[0]; 8094 tree init = NULL_TREE; 8095 8096 gcc_assert ((*args)->length () == 1 8097 && !(flags & LOOKUP_ONLYCONVERTING)); 8098 8099 /* If the initializer list has no elements and T is a class type with 8100 a default constructor, the object is value-initialized. Handle 8101 this here so we don't need to handle it wherever we use 8102 build_special_member_call. */ 8103 if (CONSTRUCTOR_NELTS (init_list) == 0 8104 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 8105 /* For a user-provided default constructor, use the normal 8106 mechanisms so that protected access works. */ 8107 && type_has_non_user_provided_default_constructor (basetype) 8108 && !processing_template_decl) 8109 init = build_value_init (basetype, complain); 8110 8111 /* If BASETYPE is an aggregate, we need to do aggregate 8112 initialization. */ 8113 else if (CP_AGGREGATE_TYPE_P (basetype)) 8114 init = digest_init (basetype, init_list, complain); 8115 8116 if (init) 8117 { 8118 if (is_dummy_object (instance)) 8119 return get_target_expr_sfinae (init, complain); 8120 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init); 8121 TREE_SIDE_EFFECTS (init) = true; 8122 return init; 8123 } 8124 8125 /* Otherwise go ahead with overload resolution. */ 8126 add_list_candidates (fns, first_mem_arg, init_list, 8127 basetype, explicit_targs, template_only, 8128 conversion_path, access_binfo, flags, 8129 &candidates, complain); 8130 } 8131 else 8132 { 8133 add_candidates (fns, first_mem_arg, user_args, optype, 8134 explicit_targs, template_only, conversion_path, 8135 access_binfo, flags, &candidates, complain); 8136 } 8137 any_viable_p = false; 8138 candidates = splice_viable (candidates, false, &any_viable_p); 8139 8140 if (!any_viable_p) 8141 { 8142 if (complain & tf_error) 8143 { 8144 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 8145 cxx_incomplete_type_error (instance, basetype); 8146 else if (optype) 8147 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 8148 basetype, optype, build_tree_list_vec (user_args), 8149 TREE_TYPE (instance)); 8150 else 8151 { 8152 char *pretty_name; 8153 bool free_p; 8154 tree arglist; 8155 8156 pretty_name = name_as_c_string (name, basetype, &free_p); 8157 arglist = build_tree_list_vec (user_args); 8158 if (skip_first_for_error) 8159 arglist = TREE_CHAIN (arglist); 8160 error ("no matching function for call to %<%T::%s(%A)%#V%>", 8161 basetype, pretty_name, arglist, 8162 TREE_TYPE (instance)); 8163 if (free_p) 8164 free (pretty_name); 8165 } 8166 print_z_candidates (location_of (name), candidates); 8167 } 8168 call = error_mark_node; 8169 } 8170 else 8171 { 8172 cand = tourney (candidates, complain); 8173 if (cand == 0) 8174 { 8175 char *pretty_name; 8176 bool free_p; 8177 tree arglist; 8178 8179 if (complain & tf_error) 8180 { 8181 pretty_name = name_as_c_string (name, basetype, &free_p); 8182 arglist = build_tree_list_vec (user_args); 8183 if (skip_first_for_error) 8184 arglist = TREE_CHAIN (arglist); 8185 if (!any_strictly_viable (candidates)) 8186 error ("no matching function for call to %<%s(%A)%>", 8187 pretty_name, arglist); 8188 else 8189 error ("call of overloaded %<%s(%A)%> is ambiguous", 8190 pretty_name, arglist); 8191 print_z_candidates (location_of (name), candidates); 8192 if (free_p) 8193 free (pretty_name); 8194 } 8195 call = error_mark_node; 8196 } 8197 else 8198 { 8199 fn = cand->fn; 8200 call = NULL_TREE; 8201 8202 if (!(flags & LOOKUP_NONVIRTUAL) 8203 && DECL_PURE_VIRTUAL_P (fn) 8204 && instance == current_class_ref 8205 && (complain & tf_warning)) 8206 { 8207 /* This is not an error, it is runtime undefined 8208 behavior. */ 8209 if (!current_function_decl) 8210 warning (0, "pure virtual %q#D called from " 8211 "non-static data member initializer", fn); 8212 else if (DECL_CONSTRUCTOR_P (current_function_decl) 8213 || DECL_DESTRUCTOR_P (current_function_decl)) 8214 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) 8215 ? "pure virtual %q#D called from constructor" 8216 : "pure virtual %q#D called from destructor"), 8217 fn); 8218 } 8219 8220 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 8221 && !DECL_CONSTRUCTOR_P (fn) 8222 && is_dummy_object (instance)) 8223 { 8224 instance = maybe_resolve_dummy (instance, true); 8225 if (instance == error_mark_node) 8226 call = error_mark_node; 8227 else if (!is_dummy_object (instance)) 8228 { 8229 /* We captured 'this' in the current lambda now that 8230 we know we really need it. */ 8231 cand->first_arg = instance; 8232 } 8233 else 8234 { 8235 if (complain & tf_error) 8236 error ("cannot call member function %qD without object", 8237 fn); 8238 call = error_mark_node; 8239 } 8240 } 8241 8242 if (call != error_mark_node) 8243 { 8244 /* Optimize away vtable lookup if we know that this 8245 function can't be overridden. We need to check if 8246 the context and the type where we found fn are the same, 8247 actually FN might be defined in a different class 8248 type because of a using-declaration. In this case, we 8249 do not want to perform a non-virtual call. */ 8250 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 8251 && same_type_ignoring_top_level_qualifiers_p 8252 (DECL_CONTEXT (fn), BINFO_TYPE (binfo)) 8253 && resolves_to_fixed_type_p (instance, 0)) 8254 flags |= LOOKUP_NONVIRTUAL; 8255 if (explicit_targs) 8256 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 8257 /* Now we know what function is being called. */ 8258 if (fn_p) 8259 *fn_p = fn; 8260 /* Build the actual CALL_EXPR. */ 8261 call = build_over_call (cand, flags, complain); 8262 /* In an expression of the form `a->f()' where `f' turns 8263 out to be a static member function, `a' is 8264 none-the-less evaluated. */ 8265 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 8266 && !is_dummy_object (instance) 8267 && TREE_SIDE_EFFECTS (instance)) 8268 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), 8269 instance, call); 8270 else if (call != error_mark_node 8271 && DECL_DESTRUCTOR_P (cand->fn) 8272 && !VOID_TYPE_P (TREE_TYPE (call))) 8273 /* An explicit call of the form "x->~X()" has type 8274 "void". However, on platforms where destructors 8275 return "this" (i.e., those where 8276 targetm.cxx.cdtor_returns_this is true), such calls 8277 will appear to have a return value of pointer type 8278 to the low-level call machinery. We do not want to 8279 change the low-level machinery, since we want to be 8280 able to optimize "delete f()" on such platforms as 8281 "operator delete(~X(f()))" (rather than generating 8282 "t = f(), ~X(t), operator delete (t)"). */ 8283 call = build_nop (void_type_node, call); 8284 } 8285 } 8286 } 8287 8288 if (processing_template_decl && call != error_mark_node) 8289 { 8290 bool cast_to_void = false; 8291 8292 if (TREE_CODE (call) == COMPOUND_EXPR) 8293 call = TREE_OPERAND (call, 1); 8294 else if (TREE_CODE (call) == NOP_EXPR) 8295 { 8296 cast_to_void = true; 8297 call = TREE_OPERAND (call, 0); 8298 } 8299 if (INDIRECT_REF_P (call)) 8300 call = TREE_OPERAND (call, 0); 8301 call = (build_min_non_dep_call_vec 8302 (call, 8303 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 8304 orig_instance, orig_fns, NULL_TREE), 8305 orig_args)); 8306 SET_EXPR_LOCATION (call, input_location); 8307 call = convert_from_reference (call); 8308 if (cast_to_void) 8309 call = build_nop (void_type_node, call); 8310 } 8311 8312 /* Free all the conversions we allocated. */ 8313 obstack_free (&conversion_obstack, p); 8314 8315 if (orig_args != NULL) 8316 release_tree_vector (orig_args); 8317 8318 return call; 8319 } 8320 8321 /* Wrapper for above. */ 8322 8323 tree 8324 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args, 8325 tree conversion_path, int flags, 8326 tree *fn_p, tsubst_flags_t complain) 8327 { 8328 tree ret; 8329 bool subtime = timevar_cond_start (TV_OVERLOAD); 8330 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 8331 fn_p, complain); 8332 timevar_cond_stop (TV_OVERLOAD, subtime); 8333 return ret; 8334 } 8335 8336 /* Returns true iff standard conversion sequence ICS1 is a proper 8337 subsequence of ICS2. */ 8338 8339 static bool 8340 is_subseq (conversion *ics1, conversion *ics2) 8341 { 8342 /* We can assume that a conversion of the same code 8343 between the same types indicates a subsequence since we only get 8344 here if the types we are converting from are the same. */ 8345 8346 while (ics1->kind == ck_rvalue 8347 || ics1->kind == ck_lvalue) 8348 ics1 = next_conversion (ics1); 8349 8350 while (1) 8351 { 8352 while (ics2->kind == ck_rvalue 8353 || ics2->kind == ck_lvalue) 8354 ics2 = next_conversion (ics2); 8355 8356 if (ics2->kind == ck_user 8357 || ics2->kind == ck_ambig 8358 || ics2->kind == ck_aggr 8359 || ics2->kind == ck_list 8360 || ics2->kind == ck_identity) 8361 /* At this point, ICS1 cannot be a proper subsequence of 8362 ICS2. We can get a USER_CONV when we are comparing the 8363 second standard conversion sequence of two user conversion 8364 sequences. */ 8365 return false; 8366 8367 ics2 = next_conversion (ics2); 8368 8369 if (ics2->kind == ics1->kind 8370 && same_type_p (ics2->type, ics1->type) 8371 && same_type_p (next_conversion (ics2)->type, 8372 next_conversion (ics1)->type)) 8373 return true; 8374 } 8375 } 8376 8377 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 8378 be any _TYPE nodes. */ 8379 8380 bool 8381 is_properly_derived_from (tree derived, tree base) 8382 { 8383 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 8384 return false; 8385 8386 /* We only allow proper derivation here. The DERIVED_FROM_P macro 8387 considers every class derived from itself. */ 8388 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 8389 && DERIVED_FROM_P (base, derived)); 8390 } 8391 8392 /* We build the ICS for an implicit object parameter as a pointer 8393 conversion sequence. However, such a sequence should be compared 8394 as if it were a reference conversion sequence. If ICS is the 8395 implicit conversion sequence for an implicit object parameter, 8396 modify it accordingly. */ 8397 8398 static void 8399 maybe_handle_implicit_object (conversion **ics) 8400 { 8401 if ((*ics)->this_p) 8402 { 8403 /* [over.match.funcs] 8404 8405 For non-static member functions, the type of the 8406 implicit object parameter is "reference to cv X" 8407 where X is the class of which the function is a 8408 member and cv is the cv-qualification on the member 8409 function declaration. */ 8410 conversion *t = *ics; 8411 tree reference_type; 8412 8413 /* The `this' parameter is a pointer to a class type. Make the 8414 implicit conversion talk about a reference to that same class 8415 type. */ 8416 reference_type = TREE_TYPE (t->type); 8417 reference_type = build_reference_type (reference_type); 8418 8419 if (t->kind == ck_qual) 8420 t = next_conversion (t); 8421 if (t->kind == ck_ptr) 8422 t = next_conversion (t); 8423 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 8424 t = direct_reference_binding (reference_type, t); 8425 t->this_p = 1; 8426 t->rvaluedness_matches_p = 0; 8427 *ics = t; 8428 } 8429 } 8430 8431 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 8432 and return the initial reference binding conversion. Otherwise, 8433 leave *ICS unchanged and return NULL. */ 8434 8435 static conversion * 8436 maybe_handle_ref_bind (conversion **ics) 8437 { 8438 if ((*ics)->kind == ck_ref_bind) 8439 { 8440 conversion *old_ics = *ics; 8441 *ics = next_conversion (old_ics); 8442 (*ics)->user_conv_p = old_ics->user_conv_p; 8443 return old_ics; 8444 } 8445 8446 return NULL; 8447 } 8448 8449 /* Compare two implicit conversion sequences according to the rules set out in 8450 [over.ics.rank]. Return values: 8451 8452 1: ics1 is better than ics2 8453 -1: ics2 is better than ics1 8454 0: ics1 and ics2 are indistinguishable */ 8455 8456 static int 8457 compare_ics (conversion *ics1, conversion *ics2) 8458 { 8459 tree from_type1; 8460 tree from_type2; 8461 tree to_type1; 8462 tree to_type2; 8463 tree deref_from_type1 = NULL_TREE; 8464 tree deref_from_type2 = NULL_TREE; 8465 tree deref_to_type1 = NULL_TREE; 8466 tree deref_to_type2 = NULL_TREE; 8467 conversion_rank rank1, rank2; 8468 8469 /* REF_BINDING is nonzero if the result of the conversion sequence 8470 is a reference type. In that case REF_CONV is the reference 8471 binding conversion. */ 8472 conversion *ref_conv1; 8473 conversion *ref_conv2; 8474 8475 /* Compare badness before stripping the reference conversion. */ 8476 if (ics1->bad_p > ics2->bad_p) 8477 return -1; 8478 else if (ics1->bad_p < ics2->bad_p) 8479 return 1; 8480 8481 /* Handle implicit object parameters. */ 8482 maybe_handle_implicit_object (&ics1); 8483 maybe_handle_implicit_object (&ics2); 8484 8485 /* Handle reference parameters. */ 8486 ref_conv1 = maybe_handle_ref_bind (&ics1); 8487 ref_conv2 = maybe_handle_ref_bind (&ics2); 8488 8489 /* List-initialization sequence L1 is a better conversion sequence than 8490 list-initialization sequence L2 if L1 converts to 8491 std::initializer_list<X> for some X and L2 does not. */ 8492 if (ics1->kind == ck_list && ics2->kind != ck_list) 8493 return 1; 8494 if (ics2->kind == ck_list && ics1->kind != ck_list) 8495 return -1; 8496 8497 /* [over.ics.rank] 8498 8499 When comparing the basic forms of implicit conversion sequences (as 8500 defined in _over.best.ics_) 8501 8502 --a standard conversion sequence (_over.ics.scs_) is a better 8503 conversion sequence than a user-defined conversion sequence 8504 or an ellipsis conversion sequence, and 8505 8506 --a user-defined conversion sequence (_over.ics.user_) is a 8507 better conversion sequence than an ellipsis conversion sequence 8508 (_over.ics.ellipsis_). */ 8509 /* Use BAD_CONVERSION_RANK because we already checked for a badness 8510 mismatch. If both ICS are bad, we try to make a decision based on 8511 what would have happened if they'd been good. This is not an 8512 extension, we'll still give an error when we build up the call; this 8513 just helps us give a more helpful error message. */ 8514 rank1 = BAD_CONVERSION_RANK (ics1); 8515 rank2 = BAD_CONVERSION_RANK (ics2); 8516 8517 if (rank1 > rank2) 8518 return -1; 8519 else if (rank1 < rank2) 8520 return 1; 8521 8522 if (ics1->ellipsis_p) 8523 /* Both conversions are ellipsis conversions. */ 8524 return 0; 8525 8526 /* User-defined conversion sequence U1 is a better conversion sequence 8527 than another user-defined conversion sequence U2 if they contain the 8528 same user-defined conversion operator or constructor and if the sec- 8529 ond standard conversion sequence of U1 is better than the second 8530 standard conversion sequence of U2. */ 8531 8532 /* Handle list-conversion with the same code even though it isn't always 8533 ranked as a user-defined conversion and it doesn't have a second 8534 standard conversion sequence; it will still have the desired effect. 8535 Specifically, we need to do the reference binding comparison at the 8536 end of this function. */ 8537 8538 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr) 8539 { 8540 conversion *t1; 8541 conversion *t2; 8542 8543 for (t1 = ics1; t1->kind != ck_user; t1 = next_conversion (t1)) 8544 if (t1->kind == ck_ambig || t1->kind == ck_aggr 8545 || t1->kind == ck_list) 8546 break; 8547 for (t2 = ics2; t2->kind != ck_user; t2 = next_conversion (t2)) 8548 if (t2->kind == ck_ambig || t2->kind == ck_aggr 8549 || t2->kind == ck_list) 8550 break; 8551 8552 if (t1->kind != t2->kind) 8553 return 0; 8554 else if (t1->kind == ck_user) 8555 { 8556 if (t1->cand->fn != t2->cand->fn) 8557 return 0; 8558 } 8559 else 8560 { 8561 /* For ambiguous or aggregate conversions, use the target type as 8562 a proxy for the conversion function. */ 8563 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 8564 return 0; 8565 } 8566 8567 /* We can just fall through here, after setting up 8568 FROM_TYPE1 and FROM_TYPE2. */ 8569 from_type1 = t1->type; 8570 from_type2 = t2->type; 8571 } 8572 else 8573 { 8574 conversion *t1; 8575 conversion *t2; 8576 8577 /* We're dealing with two standard conversion sequences. 8578 8579 [over.ics.rank] 8580 8581 Standard conversion sequence S1 is a better conversion 8582 sequence than standard conversion sequence S2 if 8583 8584 --S1 is a proper subsequence of S2 (comparing the conversion 8585 sequences in the canonical form defined by _over.ics.scs_, 8586 excluding any Lvalue Transformation; the identity 8587 conversion sequence is considered to be a subsequence of 8588 any non-identity conversion sequence */ 8589 8590 t1 = ics1; 8591 while (t1->kind != ck_identity) 8592 t1 = next_conversion (t1); 8593 from_type1 = t1->type; 8594 8595 t2 = ics2; 8596 while (t2->kind != ck_identity) 8597 t2 = next_conversion (t2); 8598 from_type2 = t2->type; 8599 } 8600 8601 /* One sequence can only be a subsequence of the other if they start with 8602 the same type. They can start with different types when comparing the 8603 second standard conversion sequence in two user-defined conversion 8604 sequences. */ 8605 if (same_type_p (from_type1, from_type2)) 8606 { 8607 if (is_subseq (ics1, ics2)) 8608 return 1; 8609 if (is_subseq (ics2, ics1)) 8610 return -1; 8611 } 8612 8613 /* [over.ics.rank] 8614 8615 Or, if not that, 8616 8617 --the rank of S1 is better than the rank of S2 (by the rules 8618 defined below): 8619 8620 Standard conversion sequences are ordered by their ranks: an Exact 8621 Match is a better conversion than a Promotion, which is a better 8622 conversion than a Conversion. 8623 8624 Two conversion sequences with the same rank are indistinguishable 8625 unless one of the following rules applies: 8626 8627 --A conversion that does not a convert a pointer, pointer to member, 8628 or std::nullptr_t to bool is better than one that does. 8629 8630 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 8631 so that we do not have to check it explicitly. */ 8632 if (ics1->rank < ics2->rank) 8633 return 1; 8634 else if (ics2->rank < ics1->rank) 8635 return -1; 8636 8637 to_type1 = ics1->type; 8638 to_type2 = ics2->type; 8639 8640 /* A conversion from scalar arithmetic type to complex is worse than a 8641 conversion between scalar arithmetic types. */ 8642 if (same_type_p (from_type1, from_type2) 8643 && ARITHMETIC_TYPE_P (from_type1) 8644 && ARITHMETIC_TYPE_P (to_type1) 8645 && ARITHMETIC_TYPE_P (to_type2) 8646 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 8647 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 8648 { 8649 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 8650 return -1; 8651 else 8652 return 1; 8653 } 8654 8655 if (TYPE_PTR_P (from_type1) 8656 && TYPE_PTR_P (from_type2) 8657 && TYPE_PTR_P (to_type1) 8658 && TYPE_PTR_P (to_type2)) 8659 { 8660 deref_from_type1 = TREE_TYPE (from_type1); 8661 deref_from_type2 = TREE_TYPE (from_type2); 8662 deref_to_type1 = TREE_TYPE (to_type1); 8663 deref_to_type2 = TREE_TYPE (to_type2); 8664 } 8665 /* The rules for pointers to members A::* are just like the rules 8666 for pointers A*, except opposite: if B is derived from A then 8667 A::* converts to B::*, not vice versa. For that reason, we 8668 switch the from_ and to_ variables here. */ 8669 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2) 8670 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2)) 8671 || (TYPE_PTRMEMFUNC_P (from_type1) 8672 && TYPE_PTRMEMFUNC_P (from_type2) 8673 && TYPE_PTRMEMFUNC_P (to_type1) 8674 && TYPE_PTRMEMFUNC_P (to_type2))) 8675 { 8676 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 8677 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 8678 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 8679 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 8680 } 8681 8682 if (deref_from_type1 != NULL_TREE 8683 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 8684 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 8685 { 8686 /* This was one of the pointer or pointer-like conversions. 8687 8688 [over.ics.rank] 8689 8690 --If class B is derived directly or indirectly from class A, 8691 conversion of B* to A* is better than conversion of B* to 8692 void*, and conversion of A* to void* is better than 8693 conversion of B* to void*. */ 8694 if (VOID_TYPE_P (deref_to_type1) 8695 && VOID_TYPE_P (deref_to_type2)) 8696 { 8697 if (is_properly_derived_from (deref_from_type1, 8698 deref_from_type2)) 8699 return -1; 8700 else if (is_properly_derived_from (deref_from_type2, 8701 deref_from_type1)) 8702 return 1; 8703 } 8704 else if (VOID_TYPE_P (deref_to_type1) 8705 || VOID_TYPE_P (deref_to_type2)) 8706 { 8707 if (same_type_p (deref_from_type1, deref_from_type2)) 8708 { 8709 if (VOID_TYPE_P (deref_to_type2)) 8710 { 8711 if (is_properly_derived_from (deref_from_type1, 8712 deref_to_type1)) 8713 return 1; 8714 } 8715 /* We know that DEREF_TO_TYPE1 is `void' here. */ 8716 else if (is_properly_derived_from (deref_from_type1, 8717 deref_to_type2)) 8718 return -1; 8719 } 8720 } 8721 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 8722 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 8723 { 8724 /* [over.ics.rank] 8725 8726 --If class B is derived directly or indirectly from class A 8727 and class C is derived directly or indirectly from B, 8728 8729 --conversion of C* to B* is better than conversion of C* to 8730 A*, 8731 8732 --conversion of B* to A* is better than conversion of C* to 8733 A* */ 8734 if (same_type_p (deref_from_type1, deref_from_type2)) 8735 { 8736 if (is_properly_derived_from (deref_to_type1, 8737 deref_to_type2)) 8738 return 1; 8739 else if (is_properly_derived_from (deref_to_type2, 8740 deref_to_type1)) 8741 return -1; 8742 } 8743 else if (same_type_p (deref_to_type1, deref_to_type2)) 8744 { 8745 if (is_properly_derived_from (deref_from_type2, 8746 deref_from_type1)) 8747 return 1; 8748 else if (is_properly_derived_from (deref_from_type1, 8749 deref_from_type2)) 8750 return -1; 8751 } 8752 } 8753 } 8754 else if (CLASS_TYPE_P (non_reference (from_type1)) 8755 && same_type_p (from_type1, from_type2)) 8756 { 8757 tree from = non_reference (from_type1); 8758 8759 /* [over.ics.rank] 8760 8761 --binding of an expression of type C to a reference of type 8762 B& is better than binding an expression of type C to a 8763 reference of type A& 8764 8765 --conversion of C to B is better than conversion of C to A, */ 8766 if (is_properly_derived_from (from, to_type1) 8767 && is_properly_derived_from (from, to_type2)) 8768 { 8769 if (is_properly_derived_from (to_type1, to_type2)) 8770 return 1; 8771 else if (is_properly_derived_from (to_type2, to_type1)) 8772 return -1; 8773 } 8774 } 8775 else if (CLASS_TYPE_P (non_reference (to_type1)) 8776 && same_type_p (to_type1, to_type2)) 8777 { 8778 tree to = non_reference (to_type1); 8779 8780 /* [over.ics.rank] 8781 8782 --binding of an expression of type B to a reference of type 8783 A& is better than binding an expression of type C to a 8784 reference of type A&, 8785 8786 --conversion of B to A is better than conversion of C to A */ 8787 if (is_properly_derived_from (from_type1, to) 8788 && is_properly_derived_from (from_type2, to)) 8789 { 8790 if (is_properly_derived_from (from_type2, from_type1)) 8791 return 1; 8792 else if (is_properly_derived_from (from_type1, from_type2)) 8793 return -1; 8794 } 8795 } 8796 8797 /* [over.ics.rank] 8798 8799 --S1 and S2 differ only in their qualification conversion and yield 8800 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 8801 qualification signature of type T1 is a proper subset of the cv- 8802 qualification signature of type T2 */ 8803 if (ics1->kind == ck_qual 8804 && ics2->kind == ck_qual 8805 && same_type_p (from_type1, from_type2)) 8806 { 8807 int result = comp_cv_qual_signature (to_type1, to_type2); 8808 if (result != 0) 8809 return result; 8810 } 8811 8812 /* [over.ics.rank] 8813 8814 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 8815 to an implicit object parameter of a non-static member function 8816 declared without a ref-qualifier, and either S1 binds an lvalue 8817 reference to an lvalue and S2 binds an rvalue reference or S1 binds an 8818 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x 8819 draft standard, 13.3.3.2) 8820 8821 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 8822 types to which the references refer are the same type except for 8823 top-level cv-qualifiers, and the type to which the reference 8824 initialized by S2 refers is more cv-qualified than the type to 8825 which the reference initialized by S1 refers. 8826 8827 DR 1328 [over.match.best]: the context is an initialization by 8828 conversion function for direct reference binding (13.3.1.6) of a 8829 reference to function type, the return type of F1 is the same kind of 8830 reference (i.e. lvalue or rvalue) as the reference being initialized, 8831 and the return type of F2 is not. */ 8832 8833 if (ref_conv1 && ref_conv2) 8834 { 8835 if (!ref_conv1->this_p && !ref_conv2->this_p 8836 && (ref_conv1->rvaluedness_matches_p 8837 != ref_conv2->rvaluedness_matches_p) 8838 && (same_type_p (ref_conv1->type, ref_conv2->type) 8839 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 8840 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 8841 { 8842 if (ref_conv1->bad_p 8843 && !same_type_p (TREE_TYPE (ref_conv1->type), 8844 TREE_TYPE (ref_conv2->type))) 8845 /* Don't prefer a bad conversion that drops cv-quals to a bad 8846 conversion with the wrong rvalueness. */ 8847 return 0; 8848 return (ref_conv1->rvaluedness_matches_p 8849 - ref_conv2->rvaluedness_matches_p); 8850 } 8851 8852 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 8853 { 8854 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type)); 8855 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type)); 8856 if (ref_conv1->bad_p) 8857 { 8858 /* Prefer the one that drops fewer cv-quals. */ 8859 tree ftype = next_conversion (ref_conv1)->type; 8860 int fquals = cp_type_quals (ftype); 8861 q1 ^= fquals; 8862 q2 ^= fquals; 8863 } 8864 return comp_cv_qualification (q2, q1); 8865 } 8866 } 8867 8868 /* Neither conversion sequence is better than the other. */ 8869 return 0; 8870 } 8871 8872 /* The source type for this standard conversion sequence. */ 8873 8874 static tree 8875 source_type (conversion *t) 8876 { 8877 for (;; t = next_conversion (t)) 8878 { 8879 if (t->kind == ck_user 8880 || t->kind == ck_ambig 8881 || t->kind == ck_identity) 8882 return t->type; 8883 } 8884 gcc_unreachable (); 8885 } 8886 8887 /* Note a warning about preferring WINNER to LOSER. We do this by storing 8888 a pointer to LOSER and re-running joust to produce the warning if WINNER 8889 is actually used. */ 8890 8891 static void 8892 add_warning (struct z_candidate *winner, struct z_candidate *loser) 8893 { 8894 candidate_warning *cw = (candidate_warning *) 8895 conversion_obstack_alloc (sizeof (candidate_warning)); 8896 cw->loser = loser; 8897 cw->next = winner->warnings; 8898 winner->warnings = cw; 8899 } 8900 8901 /* Compare two candidates for overloading as described in 8902 [over.match.best]. Return values: 8903 8904 1: cand1 is better than cand2 8905 -1: cand2 is better than cand1 8906 0: cand1 and cand2 are indistinguishable */ 8907 8908 static int 8909 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn, 8910 tsubst_flags_t complain) 8911 { 8912 int winner = 0; 8913 int off1 = 0, off2 = 0; 8914 size_t i; 8915 size_t len; 8916 8917 /* Candidates that involve bad conversions are always worse than those 8918 that don't. */ 8919 if (cand1->viable > cand2->viable) 8920 return 1; 8921 if (cand1->viable < cand2->viable) 8922 return -1; 8923 8924 /* If we have two pseudo-candidates for conversions to the same type, 8925 or two candidates for the same function, arbitrarily pick one. */ 8926 if (cand1->fn == cand2->fn 8927 && (IS_TYPE_OR_DECL_P (cand1->fn))) 8928 return 1; 8929 8930 /* Prefer a non-deleted function over an implicitly deleted move 8931 constructor or assignment operator. This differs slightly from the 8932 wording for issue 1402 (which says the move op is ignored by overload 8933 resolution), but this way produces better error messages. */ 8934 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 8935 && TREE_CODE (cand2->fn) == FUNCTION_DECL 8936 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn)) 8937 { 8938 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn) 8939 && move_fn_p (cand1->fn)) 8940 return -1; 8941 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn) 8942 && move_fn_p (cand2->fn)) 8943 return 1; 8944 } 8945 8946 /* a viable function F1 8947 is defined to be a better function than another viable function F2 if 8948 for all arguments i, ICSi(F1) is not a worse conversion sequence than 8949 ICSi(F2), and then */ 8950 8951 /* for some argument j, ICSj(F1) is a better conversion sequence than 8952 ICSj(F2) */ 8953 8954 /* For comparing static and non-static member functions, we ignore 8955 the implicit object parameter of the non-static function. The 8956 standard says to pretend that the static function has an object 8957 parm, but that won't work with operator overloading. */ 8958 len = cand1->num_convs; 8959 if (len != cand2->num_convs) 8960 { 8961 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 8962 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 8963 8964 if (DECL_CONSTRUCTOR_P (cand1->fn) 8965 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 8966 /* We're comparing a near-match list constructor and a near-match 8967 non-list constructor. Just treat them as unordered. */ 8968 return 0; 8969 8970 gcc_assert (static_1 != static_2); 8971 8972 if (static_1) 8973 off2 = 1; 8974 else 8975 { 8976 off1 = 1; 8977 --len; 8978 } 8979 } 8980 8981 for (i = 0; i < len; ++i) 8982 { 8983 conversion *t1 = cand1->convs[i + off1]; 8984 conversion *t2 = cand2->convs[i + off2]; 8985 int comp = compare_ics (t1, t2); 8986 8987 if (comp != 0) 8988 { 8989 if ((complain & tf_warning) 8990 && warn_sign_promo 8991 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 8992 == cr_std + cr_promotion) 8993 && t1->kind == ck_std 8994 && t2->kind == ck_std 8995 && TREE_CODE (t1->type) == INTEGER_TYPE 8996 && TREE_CODE (t2->type) == INTEGER_TYPE 8997 && (TYPE_PRECISION (t1->type) 8998 == TYPE_PRECISION (t2->type)) 8999 && (TYPE_UNSIGNED (next_conversion (t1)->type) 9000 || (TREE_CODE (next_conversion (t1)->type) 9001 == ENUMERAL_TYPE))) 9002 { 9003 tree type = next_conversion (t1)->type; 9004 tree type1, type2; 9005 struct z_candidate *w, *l; 9006 if (comp > 0) 9007 type1 = t1->type, type2 = t2->type, 9008 w = cand1, l = cand2; 9009 else 9010 type1 = t2->type, type2 = t1->type, 9011 w = cand2, l = cand1; 9012 9013 if (warn) 9014 { 9015 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 9016 type, type1, type2); 9017 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 9018 } 9019 else 9020 add_warning (w, l); 9021 } 9022 9023 if (winner && comp != winner) 9024 { 9025 winner = 0; 9026 goto tweak; 9027 } 9028 winner = comp; 9029 } 9030 } 9031 9032 /* warn about confusing overload resolution for user-defined conversions, 9033 either between a constructor and a conversion op, or between two 9034 conversion ops. */ 9035 if ((complain & tf_warning) 9036 && winner && warn_conversion && cand1->second_conv 9037 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 9038 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 9039 { 9040 struct z_candidate *w, *l; 9041 bool give_warning = false; 9042 9043 if (winner == 1) 9044 w = cand1, l = cand2; 9045 else 9046 w = cand2, l = cand1; 9047 9048 /* We don't want to complain about `X::operator T1 ()' 9049 beating `X::operator T2 () const', when T2 is a no less 9050 cv-qualified version of T1. */ 9051 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 9052 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 9053 { 9054 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 9055 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 9056 9057 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 9058 { 9059 t = TREE_TYPE (t); 9060 f = TREE_TYPE (f); 9061 } 9062 if (!comp_ptr_ttypes (t, f)) 9063 give_warning = true; 9064 } 9065 else 9066 give_warning = true; 9067 9068 if (!give_warning) 9069 /*NOP*/; 9070 else if (warn) 9071 { 9072 tree source = source_type (w->convs[0]); 9073 if (! DECL_CONSTRUCTOR_P (w->fn)) 9074 source = TREE_TYPE (source); 9075 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 9076 && warning (OPT_Wconversion, " for conversion from %qT to %qT", 9077 source, w->second_conv->type)) 9078 { 9079 inform (input_location, " because conversion sequence for the argument is better"); 9080 } 9081 } 9082 else 9083 add_warning (w, l); 9084 } 9085 9086 if (winner) 9087 return winner; 9088 9089 /* DR 495 moved this tiebreaker above the template ones. */ 9090 /* or, if not that, 9091 the context is an initialization by user-defined conversion (see 9092 _dcl.init_ and _over.match.user_) and the standard conversion 9093 sequence from the return type of F1 to the destination type (i.e., 9094 the type of the entity being initialized) is a better conversion 9095 sequence than the standard conversion sequence from the return type 9096 of F2 to the destination type. */ 9097 9098 if (cand1->second_conv) 9099 { 9100 winner = compare_ics (cand1->second_conv, cand2->second_conv); 9101 if (winner) 9102 return winner; 9103 } 9104 9105 /* or, if not that, 9106 F1 is a non-template function and F2 is a template function 9107 specialization. */ 9108 9109 if (!cand1->template_decl && cand2->template_decl) 9110 return 1; 9111 else if (cand1->template_decl && !cand2->template_decl) 9112 return -1; 9113 9114 /* or, if not that, 9115 F1 and F2 are template functions and the function template for F1 is 9116 more specialized than the template for F2 according to the partial 9117 ordering rules. */ 9118 9119 if (cand1->template_decl && cand2->template_decl) 9120 { 9121 winner = more_specialized_fn 9122 (TI_TEMPLATE (cand1->template_decl), 9123 TI_TEMPLATE (cand2->template_decl), 9124 /* [temp.func.order]: The presence of unused ellipsis and default 9125 arguments has no effect on the partial ordering of function 9126 templates. add_function_candidate() will not have 9127 counted the "this" argument for constructors. */ 9128 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 9129 if (winner) 9130 return winner; 9131 } 9132 9133 /* Check whether we can discard a builtin candidate, either because we 9134 have two identical ones or matching builtin and non-builtin candidates. 9135 9136 (Pedantically in the latter case the builtin which matched the user 9137 function should not be added to the overload set, but we spot it here. 9138 9139 [over.match.oper] 9140 ... the builtin candidates include ... 9141 - do not have the same parameter type list as any non-template 9142 non-member candidate. */ 9143 9144 if (identifier_p (cand1->fn) || identifier_p (cand2->fn)) 9145 { 9146 for (i = 0; i < len; ++i) 9147 if (!same_type_p (cand1->convs[i]->type, 9148 cand2->convs[i]->type)) 9149 break; 9150 if (i == cand1->num_convs) 9151 { 9152 if (cand1->fn == cand2->fn) 9153 /* Two built-in candidates; arbitrarily pick one. */ 9154 return 1; 9155 else if (identifier_p (cand1->fn)) 9156 /* cand1 is built-in; prefer cand2. */ 9157 return -1; 9158 else 9159 /* cand2 is built-in; prefer cand1. */ 9160 return 1; 9161 } 9162 } 9163 9164 /* For candidates of a multi-versioned function, make the version with 9165 the highest priority win. This version will be checked for dispatching 9166 first. If this version can be inlined into the caller, the front-end 9167 will simply make a direct call to this function. */ 9168 9169 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 9170 && DECL_FUNCTION_VERSIONED (cand1->fn) 9171 && TREE_CODE (cand2->fn) == FUNCTION_DECL 9172 && DECL_FUNCTION_VERSIONED (cand2->fn)) 9173 { 9174 tree f1 = TREE_TYPE (cand1->fn); 9175 tree f2 = TREE_TYPE (cand2->fn); 9176 tree p1 = TYPE_ARG_TYPES (f1); 9177 tree p2 = TYPE_ARG_TYPES (f2); 9178 9179 /* Check if cand1->fn and cand2->fn are versions of the same function. It 9180 is possible that cand1->fn and cand2->fn are function versions but of 9181 different functions. Check types to see if they are versions of the same 9182 function. */ 9183 if (compparms (p1, p2) 9184 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2))) 9185 { 9186 /* Always make the version with the higher priority, more 9187 specialized, win. */ 9188 gcc_assert (targetm.compare_version_priority); 9189 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0) 9190 return 1; 9191 else 9192 return -1; 9193 } 9194 } 9195 9196 /* If the two function declarations represent the same function (this can 9197 happen with declarations in multiple scopes and arg-dependent lookup), 9198 arbitrarily choose one. But first make sure the default args we're 9199 using match. */ 9200 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 9201 && equal_functions (cand1->fn, cand2->fn)) 9202 { 9203 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 9204 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 9205 9206 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 9207 9208 for (i = 0; i < len; ++i) 9209 { 9210 /* Don't crash if the fn is variadic. */ 9211 if (!parms1) 9212 break; 9213 parms1 = TREE_CHAIN (parms1); 9214 parms2 = TREE_CHAIN (parms2); 9215 } 9216 9217 if (off1) 9218 parms1 = TREE_CHAIN (parms1); 9219 else if (off2) 9220 parms2 = TREE_CHAIN (parms2); 9221 9222 for (; parms1; ++i) 9223 { 9224 if (!cp_tree_equal (TREE_PURPOSE (parms1), 9225 TREE_PURPOSE (parms2))) 9226 { 9227 if (warn) 9228 { 9229 if (complain & tf_error) 9230 { 9231 if (permerror (input_location, 9232 "default argument mismatch in " 9233 "overload resolution")) 9234 { 9235 inform (input_location, 9236 " candidate 1: %q+#F", cand1->fn); 9237 inform (input_location, 9238 " candidate 2: %q+#F", cand2->fn); 9239 } 9240 } 9241 else 9242 return 0; 9243 } 9244 else 9245 add_warning (cand1, cand2); 9246 break; 9247 } 9248 parms1 = TREE_CHAIN (parms1); 9249 parms2 = TREE_CHAIN (parms2); 9250 } 9251 9252 return 1; 9253 } 9254 9255 tweak: 9256 9257 /* Extension: If the worst conversion for one candidate is worse than the 9258 worst conversion for the other, take the first. */ 9259 if (!pedantic && (complain & tf_warning_or_error)) 9260 { 9261 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 9262 struct z_candidate *w = 0, *l = 0; 9263 9264 for (i = 0; i < len; ++i) 9265 { 9266 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 9267 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 9268 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 9269 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 9270 } 9271 if (rank1 < rank2) 9272 winner = 1, w = cand1, l = cand2; 9273 if (rank1 > rank2) 9274 winner = -1, w = cand2, l = cand1; 9275 if (winner) 9276 { 9277 /* Don't choose a deleted function over ambiguity. */ 9278 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 9279 return 0; 9280 if (warn) 9281 { 9282 pedwarn (input_location, 0, 9283 "ISO C++ says that these are ambiguous, even " 9284 "though the worst conversion for the first is better than " 9285 "the worst conversion for the second:"); 9286 print_z_candidate (input_location, _("candidate 1:"), w); 9287 print_z_candidate (input_location, _("candidate 2:"), l); 9288 } 9289 else 9290 add_warning (w, l); 9291 return winner; 9292 } 9293 } 9294 9295 gcc_assert (!winner); 9296 return 0; 9297 } 9298 9299 /* Given a list of candidates for overloading, find the best one, if any. 9300 This algorithm has a worst case of O(2n) (winner is last), and a best 9301 case of O(n/2) (totally ambiguous); much better than a sorting 9302 algorithm. */ 9303 9304 static struct z_candidate * 9305 tourney (struct z_candidate *candidates, tsubst_flags_t complain) 9306 { 9307 struct z_candidate *champ = candidates, *challenger; 9308 int fate; 9309 int champ_compared_to_predecessor = 0; 9310 9311 /* Walk through the list once, comparing each current champ to the next 9312 candidate, knocking out a candidate or two with each comparison. */ 9313 9314 for (challenger = champ->next; challenger; ) 9315 { 9316 fate = joust (champ, challenger, 0, complain); 9317 if (fate == 1) 9318 challenger = challenger->next; 9319 else 9320 { 9321 if (fate == 0) 9322 { 9323 champ = challenger->next; 9324 if (champ == 0) 9325 return NULL; 9326 champ_compared_to_predecessor = 0; 9327 } 9328 else 9329 { 9330 champ = challenger; 9331 champ_compared_to_predecessor = 1; 9332 } 9333 9334 challenger = champ->next; 9335 } 9336 } 9337 9338 /* Make sure the champ is better than all the candidates it hasn't yet 9339 been compared to. */ 9340 9341 for (challenger = candidates; 9342 challenger != champ 9343 && !(champ_compared_to_predecessor && challenger->next == champ); 9344 challenger = challenger->next) 9345 { 9346 fate = joust (champ, challenger, 0, complain); 9347 if (fate != 1) 9348 return NULL; 9349 } 9350 9351 return champ; 9352 } 9353 9354 /* Returns nonzero if things of type FROM can be converted to TO. */ 9355 9356 bool 9357 can_convert (tree to, tree from, tsubst_flags_t complain) 9358 { 9359 tree arg = NULL_TREE; 9360 /* implicit_conversion only considers user-defined conversions 9361 if it has an expression for the call argument list. */ 9362 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to)) 9363 arg = build1 (CAST_EXPR, from, NULL_TREE); 9364 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain); 9365 } 9366 9367 /* Returns nonzero if things of type FROM can be converted to TO with a 9368 standard conversion. */ 9369 9370 bool 9371 can_convert_standard (tree to, tree from, tsubst_flags_t complain) 9372 { 9373 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain); 9374 } 9375 9376 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 9377 9378 bool 9379 can_convert_arg (tree to, tree from, tree arg, int flags, 9380 tsubst_flags_t complain) 9381 { 9382 conversion *t; 9383 void *p; 9384 bool ok_p; 9385 9386 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9387 p = conversion_obstack_alloc (0); 9388 /* We want to discard any access checks done for this test, 9389 as we might not be in the appropriate access context and 9390 we'll do the check again when we actually perform the 9391 conversion. */ 9392 push_deferring_access_checks (dk_deferred); 9393 9394 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 9395 flags, complain); 9396 ok_p = (t && !t->bad_p); 9397 9398 /* Discard the access checks now. */ 9399 pop_deferring_access_checks (); 9400 /* Free all the conversions we allocated. */ 9401 obstack_free (&conversion_obstack, p); 9402 9403 return ok_p; 9404 } 9405 9406 /* Like can_convert_arg, but allows dubious conversions as well. */ 9407 9408 bool 9409 can_convert_arg_bad (tree to, tree from, tree arg, int flags, 9410 tsubst_flags_t complain) 9411 { 9412 conversion *t; 9413 void *p; 9414 9415 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9416 p = conversion_obstack_alloc (0); 9417 /* Try to perform the conversion. */ 9418 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 9419 flags, complain); 9420 /* Free all the conversions we allocated. */ 9421 obstack_free (&conversion_obstack, p); 9422 9423 return t != NULL; 9424 } 9425 9426 /* Convert EXPR to TYPE. Return the converted expression. 9427 9428 Note that we allow bad conversions here because by the time we get to 9429 this point we are committed to doing the conversion. If we end up 9430 doing a bad conversion, convert_like will complain. */ 9431 9432 tree 9433 perform_implicit_conversion_flags (tree type, tree expr, 9434 tsubst_flags_t complain, int flags) 9435 { 9436 conversion *conv; 9437 void *p; 9438 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 9439 9440 if (error_operand_p (expr)) 9441 return error_mark_node; 9442 9443 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9444 p = conversion_obstack_alloc (0); 9445 9446 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 9447 /*c_cast_p=*/false, 9448 flags, complain); 9449 9450 if (!conv) 9451 { 9452 if (complain & tf_error) 9453 { 9454 /* If expr has unknown type, then it is an overloaded function. 9455 Call instantiate_type to get good error messages. */ 9456 if (TREE_TYPE (expr) == unknown_type_node) 9457 instantiate_type (type, expr, complain); 9458 else if (invalid_nonstatic_memfn_p (expr, complain)) 9459 /* We gave an error. */; 9460 else 9461 error_at (loc, "could not convert %qE from %qT to %qT", expr, 9462 TREE_TYPE (expr), type); 9463 } 9464 expr = error_mark_node; 9465 } 9466 else if (processing_template_decl && conv->kind != ck_identity) 9467 { 9468 /* In a template, we are only concerned about determining the 9469 type of non-dependent expressions, so we do not have to 9470 perform the actual conversion. But for initializers, we 9471 need to be able to perform it at instantiation 9472 (or instantiate_non_dependent_expr) time. */ 9473 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 9474 if (!(flags & LOOKUP_ONLYCONVERTING)) 9475 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 9476 } 9477 else 9478 expr = convert_like (conv, expr, complain); 9479 9480 /* Free all the conversions we allocated. */ 9481 obstack_free (&conversion_obstack, p); 9482 9483 return expr; 9484 } 9485 9486 tree 9487 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 9488 { 9489 return perform_implicit_conversion_flags (type, expr, complain, 9490 LOOKUP_IMPLICIT); 9491 } 9492 9493 /* Convert EXPR to TYPE (as a direct-initialization) if that is 9494 permitted. If the conversion is valid, the converted expression is 9495 returned. Otherwise, NULL_TREE is returned, except in the case 9496 that TYPE is a class type; in that case, an error is issued. If 9497 C_CAST_P is true, then this direct-initialization is taking 9498 place as part of a static_cast being attempted as part of a C-style 9499 cast. */ 9500 9501 tree 9502 perform_direct_initialization_if_possible (tree type, 9503 tree expr, 9504 bool c_cast_p, 9505 tsubst_flags_t complain) 9506 { 9507 conversion *conv; 9508 void *p; 9509 9510 if (type == error_mark_node || error_operand_p (expr)) 9511 return error_mark_node; 9512 /* [dcl.init] 9513 9514 If the destination type is a (possibly cv-qualified) class type: 9515 9516 -- If the initialization is direct-initialization ..., 9517 constructors are considered. ... If no constructor applies, or 9518 the overload resolution is ambiguous, the initialization is 9519 ill-formed. */ 9520 if (CLASS_TYPE_P (type)) 9521 { 9522 vec<tree, va_gc> *args = make_tree_vector_single (expr); 9523 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 9524 &args, type, LOOKUP_NORMAL, complain); 9525 release_tree_vector (args); 9526 return build_cplus_new (type, expr, complain); 9527 } 9528 9529 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9530 p = conversion_obstack_alloc (0); 9531 9532 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 9533 c_cast_p, 9534 LOOKUP_NORMAL, complain); 9535 if (!conv || conv->bad_p) 9536 expr = NULL_TREE; 9537 else 9538 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0, 9539 /*issue_conversion_warnings=*/false, 9540 c_cast_p, 9541 complain); 9542 9543 /* Free all the conversions we allocated. */ 9544 obstack_free (&conversion_obstack, p); 9545 9546 return expr; 9547 } 9548 9549 /* When initializing a reference that lasts longer than a full-expression, 9550 this special rule applies: 9551 9552 [class.temporary] 9553 9554 The temporary to which the reference is bound or the temporary 9555 that is the complete object to which the reference is bound 9556 persists for the lifetime of the reference. 9557 9558 The temporaries created during the evaluation of the expression 9559 initializing the reference, except the temporary to which the 9560 reference is bound, are destroyed at the end of the 9561 full-expression in which they are created. 9562 9563 In that case, we store the converted expression into a new 9564 VAR_DECL in a new scope. 9565 9566 However, we want to be careful not to create temporaries when 9567 they are not required. For example, given: 9568 9569 struct B {}; 9570 struct D : public B {}; 9571 D f(); 9572 const B& b = f(); 9573 9574 there is no need to copy the return value from "f"; we can just 9575 extend its lifetime. Similarly, given: 9576 9577 struct S {}; 9578 struct T { operator S(); }; 9579 T t; 9580 const S& s = t; 9581 9582 we can extend the lifetime of the return value of the conversion 9583 operator. 9584 9585 The next several functions are involved in this lifetime extension. */ 9586 9587 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The 9588 reference is being bound to a temporary. Create and return a new 9589 VAR_DECL with the indicated TYPE; this variable will store the value to 9590 which the reference is bound. */ 9591 9592 tree 9593 make_temporary_var_for_ref_to_temp (tree decl, tree type) 9594 { 9595 tree var; 9596 9597 /* Create the variable. */ 9598 var = create_temporary_var (type); 9599 9600 /* Register the variable. */ 9601 if (VAR_P (decl) 9602 && (TREE_STATIC (decl) || DECL_THREAD_LOCAL_P (decl))) 9603 { 9604 /* Namespace-scope or local static; give it a mangled name. */ 9605 /* FIXME share comdat with decl? */ 9606 tree name; 9607 9608 TREE_STATIC (var) = TREE_STATIC (decl); 9609 set_decl_tls_model (var, DECL_TLS_MODEL (decl)); 9610 name = mangle_ref_init_variable (decl); 9611 DECL_NAME (var) = name; 9612 SET_DECL_ASSEMBLER_NAME (var, name); 9613 var = pushdecl_top_level (var); 9614 } 9615 else 9616 /* Create a new cleanup level if necessary. */ 9617 maybe_push_cleanup_level (type); 9618 9619 return var; 9620 } 9621 9622 /* EXPR is the initializer for a variable DECL of reference or 9623 std::initializer_list type. Create, push and return a new VAR_DECL 9624 for the initializer so that it will live as long as DECL. Any 9625 cleanup for the new variable is returned through CLEANUP, and the 9626 code to initialize the new variable is returned through INITP. */ 9627 9628 static tree 9629 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups, 9630 tree *initp) 9631 { 9632 tree init; 9633 tree type; 9634 tree var; 9635 9636 /* Create the temporary variable. */ 9637 type = TREE_TYPE (expr); 9638 var = make_temporary_var_for_ref_to_temp (decl, type); 9639 layout_decl (var, 0); 9640 /* If the rvalue is the result of a function call it will be 9641 a TARGET_EXPR. If it is some other construct (such as a 9642 member access expression where the underlying object is 9643 itself the result of a function call), turn it into a 9644 TARGET_EXPR here. It is important that EXPR be a 9645 TARGET_EXPR below since otherwise the INIT_EXPR will 9646 attempt to make a bitwise copy of EXPR to initialize 9647 VAR. */ 9648 if (TREE_CODE (expr) != TARGET_EXPR) 9649 expr = get_target_expr (expr); 9650 9651 if (TREE_CODE (decl) == FIELD_DECL 9652 && extra_warnings && !TREE_NO_WARNING (decl)) 9653 { 9654 warning (OPT_Wextra, "a temporary bound to %qD only persists " 9655 "until the constructor exits", decl); 9656 TREE_NO_WARNING (decl) = true; 9657 } 9658 9659 /* Recursively extend temps in this initializer. */ 9660 TARGET_EXPR_INITIAL (expr) 9661 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups); 9662 9663 /* Any reference temp has a non-trivial initializer. */ 9664 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true; 9665 9666 /* If the initializer is constant, put it in DECL_INITIAL so we get 9667 static initialization and use in constant expressions. */ 9668 init = maybe_constant_init (expr); 9669 if (TREE_CONSTANT (init)) 9670 { 9671 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 9672 { 9673 /* 5.19 says that a constant expression can include an 9674 lvalue-rvalue conversion applied to "a glvalue of literal type 9675 that refers to a non-volatile temporary object initialized 9676 with a constant expression". Rather than try to communicate 9677 that this VAR_DECL is a temporary, just mark it constexpr. 9678 9679 Currently this is only useful for initializer_list temporaries, 9680 since reference vars can't appear in constant expressions. */ 9681 DECL_DECLARED_CONSTEXPR_P (var) = true; 9682 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 9683 TREE_CONSTANT (var) = true; 9684 } 9685 DECL_INITIAL (var) = init; 9686 init = NULL_TREE; 9687 } 9688 else 9689 /* Create the INIT_EXPR that will initialize the temporary 9690 variable. */ 9691 init = split_nonconstant_init (var, expr); 9692 if (at_function_scope_p ()) 9693 { 9694 add_decl_expr (var); 9695 9696 if (TREE_STATIC (var)) 9697 init = add_stmt_to_compound (init, register_dtor_fn (var)); 9698 else 9699 { 9700 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 9701 if (cleanup) 9702 vec_safe_push (*cleanups, cleanup); 9703 } 9704 9705 /* We must be careful to destroy the temporary only 9706 after its initialization has taken place. If the 9707 initialization throws an exception, then the 9708 destructor should not be run. We cannot simply 9709 transform INIT into something like: 9710 9711 (INIT, ({ CLEANUP_STMT; })) 9712 9713 because emit_local_var always treats the 9714 initializer as a full-expression. Thus, the 9715 destructor would run too early; it would run at the 9716 end of initializing the reference variable, rather 9717 than at the end of the block enclosing the 9718 reference variable. 9719 9720 The solution is to pass back a cleanup expression 9721 which the caller is responsible for attaching to 9722 the statement tree. */ 9723 } 9724 else 9725 { 9726 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 9727 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 9728 { 9729 if (DECL_THREAD_LOCAL_P (var)) 9730 tls_aggregates = tree_cons (NULL_TREE, var, 9731 tls_aggregates); 9732 else 9733 static_aggregates = tree_cons (NULL_TREE, var, 9734 static_aggregates); 9735 } 9736 else 9737 /* Check whether the dtor is callable. */ 9738 cxx_maybe_build_cleanup (var, tf_warning_or_error); 9739 } 9740 /* Avoid -Wunused-variable warning (c++/38958). */ 9741 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 9742 && TREE_CODE (decl) == VAR_DECL) 9743 TREE_USED (decl) = DECL_READ_P (decl) = true; 9744 9745 *initp = init; 9746 return var; 9747 } 9748 9749 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 9750 initializing a variable of that TYPE. */ 9751 9752 tree 9753 initialize_reference (tree type, tree expr, 9754 int flags, tsubst_flags_t complain) 9755 { 9756 conversion *conv; 9757 void *p; 9758 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 9759 9760 if (type == error_mark_node || error_operand_p (expr)) 9761 return error_mark_node; 9762 9763 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9764 p = conversion_obstack_alloc (0); 9765 9766 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 9767 flags, complain); 9768 if (!conv || conv->bad_p) 9769 { 9770 if (complain & tf_error) 9771 { 9772 if (conv) 9773 convert_like (conv, expr, complain); 9774 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 9775 && !TYPE_REF_IS_RVALUE (type) 9776 && !real_lvalue_p (expr)) 9777 error_at (loc, "invalid initialization of non-const reference of " 9778 "type %qT from an rvalue of type %qT", 9779 type, TREE_TYPE (expr)); 9780 else 9781 error_at (loc, "invalid initialization of reference of type " 9782 "%qT from expression of type %qT", type, 9783 TREE_TYPE (expr)); 9784 } 9785 return error_mark_node; 9786 } 9787 9788 if (conv->kind == ck_ref_bind) 9789 /* Perform the conversion. */ 9790 expr = convert_like (conv, expr, complain); 9791 else if (conv->kind == ck_ambig) 9792 /* We gave an error in build_user_type_conversion_1. */ 9793 expr = error_mark_node; 9794 else 9795 gcc_unreachable (); 9796 9797 /* Free all the conversions we allocated. */ 9798 obstack_free (&conversion_obstack, p); 9799 9800 return expr; 9801 } 9802 9803 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 9804 which is bound either to a reference or a std::initializer_list. */ 9805 9806 static tree 9807 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups) 9808 { 9809 tree sub = init; 9810 tree *p; 9811 STRIP_NOPS (sub); 9812 if (TREE_CODE (sub) == COMPOUND_EXPR) 9813 { 9814 TREE_OPERAND (sub, 1) 9815 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups); 9816 return init; 9817 } 9818 if (TREE_CODE (sub) != ADDR_EXPR) 9819 return init; 9820 /* Deal with binding to a subobject. */ 9821 for (p = &TREE_OPERAND (sub, 0); TREE_CODE (*p) == COMPONENT_REF; ) 9822 p = &TREE_OPERAND (*p, 0); 9823 if (TREE_CODE (*p) == TARGET_EXPR) 9824 { 9825 tree subinit = NULL_TREE; 9826 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit); 9827 recompute_tree_invariant_for_addr_expr (sub); 9828 if (init != sub) 9829 init = fold_convert (TREE_TYPE (init), sub); 9830 if (subinit) 9831 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 9832 } 9833 return init; 9834 } 9835 9836 /* INIT is part of the initializer for DECL. If there are any 9837 reference or initializer lists being initialized, extend their 9838 lifetime to match that of DECL. */ 9839 9840 tree 9841 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups) 9842 { 9843 tree type = TREE_TYPE (init); 9844 if (processing_template_decl) 9845 return init; 9846 if (TREE_CODE (type) == REFERENCE_TYPE) 9847 init = extend_ref_init_temps_1 (decl, init, cleanups); 9848 else if (is_std_init_list (type)) 9849 { 9850 /* The temporary array underlying a std::initializer_list 9851 is handled like a reference temporary. */ 9852 tree ctor = init; 9853 if (TREE_CODE (ctor) == TARGET_EXPR) 9854 ctor = TARGET_EXPR_INITIAL (ctor); 9855 if (TREE_CODE (ctor) == CONSTRUCTOR) 9856 { 9857 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 9858 array = extend_ref_init_temps_1 (decl, array, cleanups); 9859 CONSTRUCTOR_ELT (ctor, 0)->value = array; 9860 } 9861 } 9862 else if (TREE_CODE (init) == CONSTRUCTOR) 9863 { 9864 unsigned i; 9865 constructor_elt *p; 9866 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (init); 9867 FOR_EACH_VEC_SAFE_ELT (elts, i, p) 9868 p->value = extend_ref_init_temps (decl, p->value, cleanups); 9869 } 9870 9871 return init; 9872 } 9873 9874 /* Returns true iff an initializer for TYPE could contain temporaries that 9875 need to be extended because they are bound to references or 9876 std::initializer_list. */ 9877 9878 bool 9879 type_has_extended_temps (tree type) 9880 { 9881 type = strip_array_types (type); 9882 if (TREE_CODE (type) == REFERENCE_TYPE) 9883 return true; 9884 if (CLASS_TYPE_P (type)) 9885 { 9886 if (is_std_init_list (type)) 9887 return true; 9888 for (tree f = next_initializable_field (TYPE_FIELDS (type)); 9889 f; f = next_initializable_field (DECL_CHAIN (f))) 9890 if (type_has_extended_temps (TREE_TYPE (f))) 9891 return true; 9892 } 9893 return false; 9894 } 9895 9896 /* Returns true iff TYPE is some variant of std::initializer_list. */ 9897 9898 bool 9899 is_std_init_list (tree type) 9900 { 9901 /* Look through typedefs. */ 9902 if (!TYPE_P (type)) 9903 return false; 9904 if (cxx_dialect == cxx98) 9905 return false; 9906 type = TYPE_MAIN_VARIANT (type); 9907 return (CLASS_TYPE_P (type) 9908 && CP_TYPE_CONTEXT (type) == std_node 9909 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0); 9910 } 9911 9912 /* Returns true iff DECL is a list constructor: i.e. a constructor which 9913 will accept an argument list of a single std::initializer_list<T>. */ 9914 9915 bool 9916 is_list_ctor (tree decl) 9917 { 9918 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 9919 tree arg; 9920 9921 if (!args || args == void_list_node) 9922 return false; 9923 9924 arg = non_reference (TREE_VALUE (args)); 9925 if (!is_std_init_list (arg)) 9926 return false; 9927 9928 args = TREE_CHAIN (args); 9929 9930 if (args && args != void_list_node && !TREE_PURPOSE (args)) 9931 /* There are more non-defaulted parms. */ 9932 return false; 9933 9934 return true; 9935 } 9936 9937 #include "gt-cp-call.h" 9938