1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions. 2 Copyright (C) 1987-2019 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 "target.h" 29 #include "cp-tree.h" 30 #include "timevar.h" 31 #include "stringpool.h" 32 #include "cgraph.h" 33 #include "stor-layout.h" 34 #include "trans-mem.h" 35 #include "flags.h" 36 #include "toplev.h" 37 #include "intl.h" 38 #include "convert.h" 39 #include "langhooks.h" 40 #include "c-family/c-objc.h" 41 #include "internal-fn.h" 42 #include "stringpool.h" 43 #include "attribs.h" 44 #include "gcc-rich-location.h" 45 46 /* The various kinds of conversion. */ 47 48 enum conversion_kind { 49 ck_identity, 50 ck_lvalue, 51 ck_fnptr, 52 ck_qual, 53 ck_std, 54 ck_ptr, 55 ck_pmem, 56 ck_base, 57 ck_ref_bind, 58 ck_user, 59 ck_ambig, 60 ck_list, 61 ck_aggr, 62 ck_rvalue 63 }; 64 65 /* The rank of the conversion. Order of the enumerals matters; better 66 conversions should come earlier in the list. */ 67 68 enum conversion_rank { 69 cr_identity, 70 cr_exact, 71 cr_promotion, 72 cr_std, 73 cr_pbool, 74 cr_user, 75 cr_ellipsis, 76 cr_bad 77 }; 78 79 /* An implicit conversion sequence, in the sense of [over.best.ics]. 80 The first conversion to be performed is at the end of the chain. 81 That conversion is always a cr_identity conversion. */ 82 83 struct conversion { 84 /* The kind of conversion represented by this step. */ 85 conversion_kind kind; 86 /* The rank of this conversion. */ 87 conversion_rank rank; 88 BOOL_BITFIELD user_conv_p : 1; 89 BOOL_BITFIELD ellipsis_p : 1; 90 BOOL_BITFIELD this_p : 1; 91 /* True if this conversion would be permitted with a bending of 92 language standards, e.g. disregarding pointer qualifiers or 93 converting integers to pointers. */ 94 BOOL_BITFIELD bad_p : 1; 95 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a 96 temporary should be created to hold the result of the 97 conversion. If KIND is ck_ambig or ck_user, true means force 98 copy-initialization. */ 99 BOOL_BITFIELD need_temporary_p : 1; 100 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 101 from a pointer-to-derived to pointer-to-base is being performed. */ 102 BOOL_BITFIELD base_p : 1; 103 /* If KIND is ck_ref_bind, true when either an lvalue reference is 104 being bound to an lvalue expression or an rvalue reference is 105 being bound to an rvalue expression. If KIND is ck_rvalue or ck_base, 106 true when we are treating an lvalue as an rvalue (12.8p33). If 107 ck_identity, we will be binding a reference directly or decaying to 108 a pointer. */ 109 BOOL_BITFIELD rvaluedness_matches_p: 1; 110 BOOL_BITFIELD check_narrowing: 1; 111 /* Whether check_narrowing should only check TREE_CONSTANTs; used 112 in build_converted_constant_expr. */ 113 BOOL_BITFIELD check_narrowing_const_only: 1; 114 /* The type of the expression resulting from the conversion. */ 115 tree type; 116 union { 117 /* The next conversion in the chain. Since the conversions are 118 arranged from outermost to innermost, the NEXT conversion will 119 actually be performed before this conversion. This variant is 120 used only when KIND is neither ck_identity, ck_ambig nor 121 ck_list. Please use the next_conversion function instead 122 of using this field directly. */ 123 conversion *next; 124 /* The expression at the beginning of the conversion chain. This 125 variant is used only if KIND is ck_identity or ck_ambig. */ 126 tree expr; 127 /* The array of conversions for an initializer_list, so this 128 variant is used only when KIN D is ck_list. */ 129 conversion **list; 130 } u; 131 /* The function candidate corresponding to this conversion 132 sequence. This field is only used if KIND is ck_user. */ 133 struct z_candidate *cand; 134 }; 135 136 #define CONVERSION_RANK(NODE) \ 137 ((NODE)->bad_p ? cr_bad \ 138 : (NODE)->ellipsis_p ? cr_ellipsis \ 139 : (NODE)->user_conv_p ? cr_user \ 140 : (NODE)->rank) 141 142 #define BAD_CONVERSION_RANK(NODE) \ 143 ((NODE)->ellipsis_p ? cr_ellipsis \ 144 : (NODE)->user_conv_p ? cr_user \ 145 : (NODE)->rank) 146 147 static struct obstack conversion_obstack; 148 static bool conversion_obstack_initialized; 149 struct rejection_reason; 150 151 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t); 152 static int equal_functions (tree, tree); 153 static int joust (struct z_candidate *, struct z_candidate *, bool, 154 tsubst_flags_t); 155 static int compare_ics (conversion *, conversion *); 156 static void maybe_warn_class_memaccess (location_t, tree, 157 const vec<tree, va_gc> *); 158 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 159 #define convert_like(CONV, EXPR, COMPLAIN) \ 160 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \ 161 /*issue_conversion_warnings=*/true, \ 162 /*c_cast_p=*/false, (COMPLAIN)) 163 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 164 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \ 165 /*issue_conversion_warnings=*/true, \ 166 /*c_cast_p=*/false, (COMPLAIN)) 167 static tree convert_like_real (conversion *, tree, tree, int, bool, 168 bool, tsubst_flags_t); 169 static void op_error (const op_location_t &, enum tree_code, enum tree_code, 170 tree, tree, tree, bool); 171 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int, 172 tsubst_flags_t); 173 static void print_z_candidate (location_t, const char *, struct z_candidate *); 174 static void print_z_candidates (location_t, struct z_candidate *); 175 static tree build_this (tree); 176 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 177 static bool any_strictly_viable (struct z_candidate *); 178 static struct z_candidate *add_template_candidate 179 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 180 tree, tree, tree, int, unification_kind_t, tsubst_flags_t); 181 static struct z_candidate *add_template_candidate_real 182 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 183 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t); 184 static void add_builtin_candidates 185 (struct z_candidate **, enum tree_code, enum tree_code, 186 tree, tree *, int, tsubst_flags_t); 187 static void add_builtin_candidate 188 (struct z_candidate **, enum tree_code, enum tree_code, 189 tree, tree, tree, tree *, tree *, int, tsubst_flags_t); 190 static bool is_complete (tree); 191 static void build_builtin_candidate 192 (struct z_candidate **, tree, tree, tree, tree *, tree *, 193 int, tsubst_flags_t); 194 static struct z_candidate *add_conv_candidate 195 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, tree, 196 tree, tsubst_flags_t); 197 static struct z_candidate *add_function_candidate 198 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree, 199 tree, int, conversion**, tsubst_flags_t); 200 static conversion *implicit_conversion (tree, tree, tree, bool, int, 201 tsubst_flags_t); 202 static conversion *reference_binding (tree, tree, tree, bool, int, 203 tsubst_flags_t); 204 static conversion *build_conv (conversion_kind, tree, conversion *); 205 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t); 206 static conversion *next_conversion (conversion *); 207 static bool is_subseq (conversion *, conversion *); 208 static conversion *maybe_handle_ref_bind (conversion **); 209 static void maybe_handle_implicit_object (conversion **); 210 static struct z_candidate *add_candidate 211 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t, 212 conversion **, tree, tree, int, struct rejection_reason *, int); 213 static tree source_type (conversion *); 214 static void add_warning (struct z_candidate *, struct z_candidate *); 215 static bool reference_compatible_p (tree, tree); 216 static conversion *direct_reference_binding (tree, conversion *); 217 static bool promoted_arithmetic_type_p (tree); 218 static conversion *conditional_conversion (tree, tree, tsubst_flags_t); 219 static char *name_as_c_string (tree, tree, bool *); 220 static tree prep_operand (tree); 221 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree, 222 bool, tree, tree, int, struct z_candidate **, 223 tsubst_flags_t); 224 static conversion *merge_conversion_sequences (conversion *, conversion *); 225 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t); 226 227 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 228 NAME can take many forms... */ 229 230 bool 231 check_dtor_name (tree basetype, tree name) 232 { 233 /* Just accept something we've already complained about. */ 234 if (name == error_mark_node) 235 return true; 236 237 if (TREE_CODE (name) == TYPE_DECL) 238 name = TREE_TYPE (name); 239 else if (TYPE_P (name)) 240 /* OK */; 241 else if (identifier_p (name)) 242 { 243 if ((MAYBE_CLASS_TYPE_P (basetype) 244 || TREE_CODE (basetype) == ENUMERAL_TYPE) 245 && name == constructor_name (basetype)) 246 return true; 247 else 248 name = get_type_value (name); 249 } 250 else 251 { 252 /* In the case of: 253 254 template <class T> struct S { ~S(); }; 255 int i; 256 i.~S(); 257 258 NAME will be a class template. */ 259 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 260 return false; 261 } 262 263 if (!name || name == error_mark_node) 264 return false; 265 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 266 } 267 268 /* We want the address of a function or method. We avoid creating a 269 pointer-to-member function. */ 270 271 tree 272 build_addr_func (tree function, tsubst_flags_t complain) 273 { 274 tree type = TREE_TYPE (function); 275 276 /* We have to do these by hand to avoid real pointer to member 277 functions. */ 278 if (TREE_CODE (type) == METHOD_TYPE) 279 { 280 if (TREE_CODE (function) == OFFSET_REF) 281 { 282 tree object = build_address (TREE_OPERAND (function, 0)); 283 return get_member_function_from_ptrfunc (&object, 284 TREE_OPERAND (function, 1), 285 complain); 286 } 287 function = build_address (function); 288 } 289 else 290 function = decay_conversion (function, complain, /*reject_builtin=*/false); 291 292 return function; 293 } 294 295 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 296 POINTER_TYPE to those. Note, pointer to member function types 297 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 298 two variants. build_call_a is the primitive taking an array of 299 arguments, while build_call_n is a wrapper that handles varargs. */ 300 301 tree 302 build_call_n (tree function, int n, ...) 303 { 304 if (n == 0) 305 return build_call_a (function, 0, NULL); 306 else 307 { 308 tree *argarray = XALLOCAVEC (tree, n); 309 va_list ap; 310 int i; 311 312 va_start (ap, n); 313 for (i = 0; i < n; i++) 314 argarray[i] = va_arg (ap, tree); 315 va_end (ap); 316 return build_call_a (function, n, argarray); 317 } 318 } 319 320 /* Update various flags in cfun and the call itself based on what is being 321 called. Split out of build_call_a so that bot_manip can use it too. */ 322 323 void 324 set_flags_from_callee (tree call) 325 { 326 /* Handle both CALL_EXPRs and AGGR_INIT_EXPRs. */ 327 tree decl = cp_get_callee_fndecl_nofold (call); 328 329 /* We check both the decl and the type; a function may be known not to 330 throw without being declared throw(). */ 331 bool nothrow = decl && TREE_NOTHROW (decl); 332 tree callee = cp_get_callee (call); 333 if (callee) 334 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (callee))); 335 else if (TREE_CODE (call) == CALL_EXPR 336 && internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW) 337 nothrow = true; 338 339 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain) 340 cp_function_chain->can_throw = 1; 341 342 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 343 current_function_returns_abnormally = 1; 344 345 TREE_NOTHROW (call) = nothrow; 346 } 347 348 tree 349 build_call_a (tree function, int n, tree *argarray) 350 { 351 tree decl; 352 tree result_type; 353 tree fntype; 354 int i; 355 356 function = build_addr_func (function, tf_warning_or_error); 357 358 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 359 fntype = TREE_TYPE (TREE_TYPE (function)); 360 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 361 || TREE_CODE (fntype) == METHOD_TYPE); 362 result_type = TREE_TYPE (fntype); 363 /* An rvalue has no cv-qualifiers. */ 364 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 365 result_type = cv_unqualified (result_type); 366 367 function = build_call_array_loc (input_location, 368 result_type, function, n, argarray); 369 set_flags_from_callee (function); 370 371 decl = get_callee_fndecl (function); 372 373 if (decl && !TREE_USED (decl)) 374 { 375 /* We invoke build_call directly for several library 376 functions. These may have been declared normally if 377 we're building libgcc, so we can't just check 378 DECL_ARTIFICIAL. */ 379 gcc_assert (DECL_ARTIFICIAL (decl) 380 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 381 "__", 2)); 382 mark_used (decl); 383 } 384 385 require_complete_eh_spec_types (fntype, decl); 386 387 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl)); 388 389 /* Don't pass empty class objects by value. This is useful 390 for tags in STL, which are used to control overload resolution. 391 We don't need to handle other cases of copying empty classes. */ 392 if (!decl || !fndecl_built_in_p (decl)) 393 for (i = 0; i < n; i++) 394 { 395 tree arg = CALL_EXPR_ARG (function, i); 396 if (is_empty_class (TREE_TYPE (arg)) 397 && ! TREE_ADDRESSABLE (TREE_TYPE (arg))) 398 { 399 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg)); 400 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t); 401 CALL_EXPR_ARG (function, i) = arg; 402 } 403 } 404 405 return function; 406 } 407 408 /* New overloading code. */ 409 410 struct z_candidate; 411 412 struct candidate_warning { 413 z_candidate *loser; 414 candidate_warning *next; 415 }; 416 417 /* Information for providing diagnostics about why overloading failed. */ 418 419 enum rejection_reason_code { 420 rr_none, 421 rr_arity, 422 rr_explicit_conversion, 423 rr_template_conversion, 424 rr_arg_conversion, 425 rr_bad_arg_conversion, 426 rr_template_unification, 427 rr_invalid_copy, 428 rr_inherited_ctor, 429 rr_constraint_failure 430 }; 431 432 struct conversion_info { 433 /* The index of the argument, 0-based. */ 434 int n_arg; 435 /* The actual argument or its type. */ 436 tree from; 437 /* The type of the parameter. */ 438 tree to_type; 439 /* The location of the argument. */ 440 location_t loc; 441 }; 442 443 struct rejection_reason { 444 enum rejection_reason_code code; 445 union { 446 /* Information about an arity mismatch. */ 447 struct { 448 /* The expected number of arguments. */ 449 int expected; 450 /* The actual number of arguments in the call. */ 451 int actual; 452 /* Whether the call was a varargs call. */ 453 bool call_varargs_p; 454 } arity; 455 /* Information about an argument conversion mismatch. */ 456 struct conversion_info conversion; 457 /* Same, but for bad argument conversions. */ 458 struct conversion_info bad_conversion; 459 /* Information about template unification failures. These are the 460 parameters passed to fn_type_unification. */ 461 struct { 462 tree tmpl; 463 tree explicit_targs; 464 int num_targs; 465 const tree *args; 466 unsigned int nargs; 467 tree return_type; 468 unification_kind_t strict; 469 int flags; 470 } template_unification; 471 /* Information about template instantiation failures. These are the 472 parameters passed to instantiate_template. */ 473 struct { 474 tree tmpl; 475 tree targs; 476 } template_instantiation; 477 } u; 478 }; 479 480 struct z_candidate { 481 /* The FUNCTION_DECL that will be called if this candidate is 482 selected by overload resolution. */ 483 tree fn; 484 /* If not NULL_TREE, the first argument to use when calling this 485 function. */ 486 tree first_arg; 487 /* The rest of the arguments to use when calling this function. If 488 there are no further arguments this may be NULL or it may be an 489 empty vector. */ 490 const vec<tree, va_gc> *args; 491 /* The implicit conversion sequences for each of the arguments to 492 FN. */ 493 conversion **convs; 494 /* The number of implicit conversion sequences. */ 495 size_t num_convs; 496 /* If FN is a user-defined conversion, the standard conversion 497 sequence from the type returned by FN to the desired destination 498 type. */ 499 conversion *second_conv; 500 struct rejection_reason *reason; 501 /* If FN is a member function, the binfo indicating the path used to 502 qualify the name of FN at the call site. This path is used to 503 determine whether or not FN is accessible if it is selected by 504 overload resolution. The DECL_CONTEXT of FN will always be a 505 (possibly improper) base of this binfo. */ 506 tree access_path; 507 /* If FN is a non-static member function, the binfo indicating the 508 subobject to which the `this' pointer should be converted if FN 509 is selected by overload resolution. The type pointed to by 510 the `this' pointer must correspond to the most derived class 511 indicated by the CONVERSION_PATH. */ 512 tree conversion_path; 513 tree template_decl; 514 tree explicit_targs; 515 candidate_warning *warnings; 516 z_candidate *next; 517 int viable; 518 519 /* The flags active in add_candidate. */ 520 int flags; 521 }; 522 523 /* Returns true iff T is a null pointer constant in the sense of 524 [conv.ptr]. */ 525 526 bool 527 null_ptr_cst_p (tree t) 528 { 529 tree type = TREE_TYPE (t); 530 531 /* [conv.ptr] 532 533 A null pointer constant is an integer literal ([lex.icon]) with value 534 zero or a prvalue of type std::nullptr_t. */ 535 if (NULLPTR_TYPE_P (type)) 536 return true; 537 538 if (cxx_dialect >= cxx11) 539 { 540 STRIP_ANY_LOCATION_WRAPPER (t); 541 542 /* Core issue 903 says only literal 0 is a null pointer constant. */ 543 if (TREE_CODE (t) == INTEGER_CST 544 && !TREE_OVERFLOW (t) 545 && TREE_CODE (type) == INTEGER_TYPE 546 && integer_zerop (t) 547 && !char_type_p (type)) 548 return true; 549 } 550 else if (CP_INTEGRAL_TYPE_P (type)) 551 { 552 t = fold_non_dependent_expr (t, tf_none); 553 STRIP_NOPS (t); 554 if (integer_zerop (t) && !TREE_OVERFLOW (t)) 555 return true; 556 } 557 558 return false; 559 } 560 561 /* Returns true iff T is a null member pointer value (4.11). */ 562 563 bool 564 null_member_pointer_value_p (tree t) 565 { 566 tree type = TREE_TYPE (t); 567 if (!type) 568 return false; 569 else if (TYPE_PTRMEMFUNC_P (type)) 570 return (TREE_CODE (t) == CONSTRUCTOR 571 && CONSTRUCTOR_NELTS (t) 572 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value)); 573 else if (TYPE_PTRDATAMEM_P (type)) 574 return integer_all_onesp (t); 575 else 576 return false; 577 } 578 579 /* Returns nonzero if PARMLIST consists of only default parms, 580 ellipsis, and/or undeduced parameter packs. */ 581 582 bool 583 sufficient_parms_p (const_tree parmlist) 584 { 585 for (; parmlist && parmlist != void_list_node; 586 parmlist = TREE_CHAIN (parmlist)) 587 if (!TREE_PURPOSE (parmlist) 588 && !PACK_EXPANSION_P (TREE_VALUE (parmlist))) 589 return false; 590 return true; 591 } 592 593 /* Allocate N bytes of memory from the conversion obstack. The memory 594 is zeroed before being returned. */ 595 596 static void * 597 conversion_obstack_alloc (size_t n) 598 { 599 void *p; 600 if (!conversion_obstack_initialized) 601 { 602 gcc_obstack_init (&conversion_obstack); 603 conversion_obstack_initialized = true; 604 } 605 p = obstack_alloc (&conversion_obstack, n); 606 memset (p, 0, n); 607 return p; 608 } 609 610 /* Allocate rejection reasons. */ 611 612 static struct rejection_reason * 613 alloc_rejection (enum rejection_reason_code code) 614 { 615 struct rejection_reason *p; 616 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p); 617 p->code = code; 618 return p; 619 } 620 621 static struct rejection_reason * 622 arity_rejection (tree first_arg, int expected, int actual) 623 { 624 struct rejection_reason *r = alloc_rejection (rr_arity); 625 int adjust = first_arg != NULL_TREE; 626 r->u.arity.expected = expected - adjust; 627 r->u.arity.actual = actual - adjust; 628 return r; 629 } 630 631 static struct rejection_reason * 632 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to, 633 location_t loc) 634 { 635 struct rejection_reason *r = alloc_rejection (rr_arg_conversion); 636 int adjust = first_arg != NULL_TREE; 637 r->u.conversion.n_arg = n_arg - adjust; 638 r->u.conversion.from = from; 639 r->u.conversion.to_type = to; 640 r->u.conversion.loc = loc; 641 return r; 642 } 643 644 static struct rejection_reason * 645 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to, 646 location_t loc) 647 { 648 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion); 649 int adjust = first_arg != NULL_TREE; 650 r->u.bad_conversion.n_arg = n_arg - adjust; 651 r->u.bad_conversion.from = from; 652 r->u.bad_conversion.to_type = to; 653 r->u.bad_conversion.loc = loc; 654 return r; 655 } 656 657 static struct rejection_reason * 658 explicit_conversion_rejection (tree from, tree to) 659 { 660 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion); 661 r->u.conversion.n_arg = 0; 662 r->u.conversion.from = from; 663 r->u.conversion.to_type = to; 664 r->u.conversion.loc = UNKNOWN_LOCATION; 665 return r; 666 } 667 668 static struct rejection_reason * 669 template_conversion_rejection (tree from, tree to) 670 { 671 struct rejection_reason *r = alloc_rejection (rr_template_conversion); 672 r->u.conversion.n_arg = 0; 673 r->u.conversion.from = from; 674 r->u.conversion.to_type = to; 675 r->u.conversion.loc = UNKNOWN_LOCATION; 676 return r; 677 } 678 679 static struct rejection_reason * 680 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs, 681 const tree *args, unsigned int nargs, 682 tree return_type, unification_kind_t strict, 683 int flags) 684 { 685 size_t args_n_bytes = sizeof (*args) * nargs; 686 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes); 687 struct rejection_reason *r = alloc_rejection (rr_template_unification); 688 r->u.template_unification.tmpl = tmpl; 689 r->u.template_unification.explicit_targs = explicit_targs; 690 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs); 691 /* Copy args to our own storage. */ 692 memcpy (args1, args, args_n_bytes); 693 r->u.template_unification.args = args1; 694 r->u.template_unification.nargs = nargs; 695 r->u.template_unification.return_type = return_type; 696 r->u.template_unification.strict = strict; 697 r->u.template_unification.flags = flags; 698 return r; 699 } 700 701 static struct rejection_reason * 702 template_unification_error_rejection (void) 703 { 704 return alloc_rejection (rr_template_unification); 705 } 706 707 static struct rejection_reason * 708 invalid_copy_with_fn_template_rejection (void) 709 { 710 struct rejection_reason *r = alloc_rejection (rr_invalid_copy); 711 return r; 712 } 713 714 static struct rejection_reason * 715 inherited_ctor_rejection (void) 716 { 717 struct rejection_reason *r = alloc_rejection (rr_inherited_ctor); 718 return r; 719 } 720 721 // Build a constraint failure record, saving information into the 722 // template_instantiation field of the rejection. If FN is not a template 723 // declaration, the TMPL member is the FN declaration and TARGS is empty. 724 725 static struct rejection_reason * 726 constraint_failure (tree fn) 727 { 728 struct rejection_reason *r = alloc_rejection (rr_constraint_failure); 729 if (tree ti = DECL_TEMPLATE_INFO (fn)) 730 { 731 r->u.template_instantiation.tmpl = TI_TEMPLATE (ti); 732 r->u.template_instantiation.targs = TI_ARGS (ti); 733 } 734 else 735 { 736 r->u.template_instantiation.tmpl = fn; 737 r->u.template_instantiation.targs = NULL_TREE; 738 } 739 return r; 740 } 741 742 /* Dynamically allocate a conversion. */ 743 744 static conversion * 745 alloc_conversion (conversion_kind kind) 746 { 747 conversion *c; 748 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 749 c->kind = kind; 750 return c; 751 } 752 753 /* Make sure that all memory on the conversion obstack has been 754 freed. */ 755 756 void 757 validate_conversion_obstack (void) 758 { 759 if (conversion_obstack_initialized) 760 gcc_assert ((obstack_next_free (&conversion_obstack) 761 == obstack_base (&conversion_obstack))); 762 } 763 764 /* Dynamically allocate an array of N conversions. */ 765 766 static conversion ** 767 alloc_conversions (size_t n) 768 { 769 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 770 } 771 772 static conversion * 773 build_conv (conversion_kind code, tree type, conversion *from) 774 { 775 conversion *t; 776 conversion_rank rank = CONVERSION_RANK (from); 777 778 /* Note that the caller is responsible for filling in t->cand for 779 user-defined conversions. */ 780 t = alloc_conversion (code); 781 t->type = type; 782 t->u.next = from; 783 784 switch (code) 785 { 786 case ck_ptr: 787 case ck_pmem: 788 case ck_base: 789 case ck_std: 790 if (rank < cr_std) 791 rank = cr_std; 792 break; 793 794 case ck_qual: 795 case ck_fnptr: 796 if (rank < cr_exact) 797 rank = cr_exact; 798 break; 799 800 default: 801 break; 802 } 803 t->rank = rank; 804 t->user_conv_p = (code == ck_user || from->user_conv_p); 805 t->bad_p = from->bad_p; 806 t->base_p = false; 807 return t; 808 } 809 810 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 811 specialization of std::initializer_list<T>, if such a conversion is 812 possible. */ 813 814 static conversion * 815 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 816 { 817 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 818 unsigned len = CONSTRUCTOR_NELTS (ctor); 819 conversion **subconvs = alloc_conversions (len); 820 conversion *t; 821 unsigned i; 822 tree val; 823 824 /* Within a list-initialization we can have more user-defined 825 conversions. */ 826 flags &= ~LOOKUP_NO_CONVERSION; 827 /* But no narrowing conversions. */ 828 flags |= LOOKUP_NO_NARROWING; 829 830 /* Can't make an array of these types. */ 831 if (TYPE_REF_P (elttype) 832 || TREE_CODE (elttype) == FUNCTION_TYPE 833 || VOID_TYPE_P (elttype)) 834 return NULL; 835 836 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 837 { 838 conversion *sub 839 = implicit_conversion (elttype, TREE_TYPE (val), val, 840 false, flags, complain); 841 if (sub == NULL) 842 return NULL; 843 844 subconvs[i] = sub; 845 } 846 847 t = alloc_conversion (ck_list); 848 t->type = type; 849 t->u.list = subconvs; 850 t->rank = cr_exact; 851 852 for (i = 0; i < len; ++i) 853 { 854 conversion *sub = subconvs[i]; 855 if (sub->rank > t->rank) 856 t->rank = sub->rank; 857 if (sub->user_conv_p) 858 t->user_conv_p = true; 859 if (sub->bad_p) 860 t->bad_p = true; 861 } 862 863 return t; 864 } 865 866 /* Return the next conversion of the conversion chain (if applicable), 867 or NULL otherwise. Please use this function instead of directly 868 accessing fields of struct conversion. */ 869 870 static conversion * 871 next_conversion (conversion *conv) 872 { 873 if (conv == NULL 874 || conv->kind == ck_identity 875 || conv->kind == ck_ambig 876 || conv->kind == ck_list) 877 return NULL; 878 return conv->u.next; 879 } 880 881 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list, 882 is a valid aggregate initializer for array type ATYPE. */ 883 884 static bool 885 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain) 886 { 887 unsigned i; 888 tree elttype = TREE_TYPE (atype); 889 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i) 890 { 891 tree val = CONSTRUCTOR_ELT (ctor, i)->value; 892 bool ok; 893 if (TREE_CODE (elttype) == ARRAY_TYPE 894 && TREE_CODE (val) == CONSTRUCTOR) 895 ok = can_convert_array (elttype, val, flags, complain); 896 else 897 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags, 898 complain); 899 if (!ok) 900 return false; 901 } 902 return true; 903 } 904 905 /* Helper for build_aggr_conv. Return true if FIELD is in PSET, or if 906 FIELD has ANON_AGGR_TYPE_P and any initializable field in there recursively 907 is in PSET. */ 908 909 static bool 910 field_in_pset (hash_set<tree, true> &pset, tree field) 911 { 912 if (pset.contains (field)) 913 return true; 914 if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) 915 for (field = TYPE_FIELDS (TREE_TYPE (field)); 916 field; field = DECL_CHAIN (field)) 917 { 918 field = next_initializable_field (field); 919 if (field == NULL_TREE) 920 break; 921 if (field_in_pset (pset, field)) 922 return true; 923 } 924 return false; 925 } 926 927 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 928 aggregate class, if such a conversion is possible. */ 929 930 static conversion * 931 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 932 { 933 unsigned HOST_WIDE_INT i = 0; 934 conversion *c; 935 tree field = next_initializable_field (TYPE_FIELDS (type)); 936 tree empty_ctor = NULL_TREE; 937 hash_set<tree, true> pset; 938 939 /* We already called reshape_init in implicit_conversion. */ 940 941 /* The conversions within the init-list aren't affected by the enclosing 942 context; they're always simple copy-initialization. */ 943 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 944 945 /* For designated initializers, verify that each initializer is convertible 946 to corresponding TREE_TYPE (ce->index) and mark those FIELD_DECLs as 947 visited. In the following loop then ignore already visited 948 FIELD_DECLs. */ 949 if (CONSTRUCTOR_IS_DESIGNATED_INIT (ctor)) 950 { 951 tree idx, val; 952 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, val) 953 { 954 if (idx && TREE_CODE (idx) == FIELD_DECL) 955 { 956 tree ftype = TREE_TYPE (idx); 957 bool ok; 958 959 if (TREE_CODE (ftype) == ARRAY_TYPE 960 && TREE_CODE (val) == CONSTRUCTOR) 961 ok = can_convert_array (ftype, val, flags, complain); 962 else 963 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags, 964 complain); 965 966 if (!ok) 967 return NULL; 968 /* For unions, there should be just one initializer. */ 969 if (TREE_CODE (type) == UNION_TYPE) 970 { 971 field = NULL_TREE; 972 i = 1; 973 break; 974 } 975 pset.add (idx); 976 } 977 else 978 return NULL; 979 } 980 } 981 982 for (; field; field = next_initializable_field (DECL_CHAIN (field))) 983 { 984 tree ftype = TREE_TYPE (field); 985 tree val; 986 bool ok; 987 988 if (pset.elements () && field_in_pset (pset, field)) 989 continue; 990 if (i < CONSTRUCTOR_NELTS (ctor)) 991 { 992 val = CONSTRUCTOR_ELT (ctor, i)->value; 993 ++i; 994 } 995 else if (DECL_INITIAL (field)) 996 val = get_nsdmi (field, /*ctor*/false, complain); 997 else if (TYPE_REF_P (ftype)) 998 /* Value-initialization of reference is ill-formed. */ 999 return NULL; 1000 else 1001 { 1002 if (empty_ctor == NULL_TREE) 1003 empty_ctor = build_constructor (init_list_type_node, NULL); 1004 val = empty_ctor; 1005 } 1006 1007 if (TREE_CODE (ftype) == ARRAY_TYPE 1008 && TREE_CODE (val) == CONSTRUCTOR) 1009 ok = can_convert_array (ftype, val, flags, complain); 1010 else 1011 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags, 1012 complain); 1013 1014 if (!ok) 1015 return NULL; 1016 1017 if (TREE_CODE (type) == UNION_TYPE) 1018 break; 1019 } 1020 1021 if (i < CONSTRUCTOR_NELTS (ctor)) 1022 return NULL; 1023 1024 c = alloc_conversion (ck_aggr); 1025 c->type = type; 1026 c->rank = cr_exact; 1027 c->user_conv_p = true; 1028 c->check_narrowing = true; 1029 c->u.next = NULL; 1030 return c; 1031 } 1032 1033 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 1034 array type, if such a conversion is possible. */ 1035 1036 static conversion * 1037 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 1038 { 1039 conversion *c; 1040 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 1041 tree elttype = TREE_TYPE (type); 1042 unsigned i; 1043 tree val; 1044 bool bad = false; 1045 bool user = false; 1046 enum conversion_rank rank = cr_exact; 1047 1048 /* We might need to propagate the size from the element to the array. */ 1049 complete_type (type); 1050 1051 if (TYPE_DOMAIN (type) 1052 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE)) 1053 { 1054 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type)); 1055 if (alen < len) 1056 return NULL; 1057 } 1058 1059 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 1060 1061 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 1062 { 1063 conversion *sub 1064 = implicit_conversion (elttype, TREE_TYPE (val), val, 1065 false, flags, complain); 1066 if (sub == NULL) 1067 return NULL; 1068 1069 if (sub->rank > rank) 1070 rank = sub->rank; 1071 if (sub->user_conv_p) 1072 user = true; 1073 if (sub->bad_p) 1074 bad = true; 1075 } 1076 1077 c = alloc_conversion (ck_aggr); 1078 c->type = type; 1079 c->rank = rank; 1080 c->user_conv_p = user; 1081 c->bad_p = bad; 1082 c->u.next = NULL; 1083 return c; 1084 } 1085 1086 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 1087 complex type, if such a conversion is possible. */ 1088 1089 static conversion * 1090 build_complex_conv (tree type, tree ctor, int flags, 1091 tsubst_flags_t complain) 1092 { 1093 conversion *c; 1094 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 1095 tree elttype = TREE_TYPE (type); 1096 unsigned i; 1097 tree val; 1098 bool bad = false; 1099 bool user = false; 1100 enum conversion_rank rank = cr_exact; 1101 1102 if (len != 2) 1103 return NULL; 1104 1105 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 1106 1107 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 1108 { 1109 conversion *sub 1110 = implicit_conversion (elttype, TREE_TYPE (val), val, 1111 false, flags, complain); 1112 if (sub == NULL) 1113 return NULL; 1114 1115 if (sub->rank > rank) 1116 rank = sub->rank; 1117 if (sub->user_conv_p) 1118 user = true; 1119 if (sub->bad_p) 1120 bad = true; 1121 } 1122 1123 c = alloc_conversion (ck_aggr); 1124 c->type = type; 1125 c->rank = rank; 1126 c->user_conv_p = user; 1127 c->bad_p = bad; 1128 c->u.next = NULL; 1129 return c; 1130 } 1131 1132 /* Build a representation of the identity conversion from EXPR to 1133 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1134 1135 static conversion * 1136 build_identity_conv (tree type, tree expr) 1137 { 1138 conversion *c; 1139 1140 c = alloc_conversion (ck_identity); 1141 c->type = type; 1142 c->u.expr = expr; 1143 1144 return c; 1145 } 1146 1147 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1148 were multiple user-defined conversions to accomplish the job. 1149 Build a conversion that indicates that ambiguity. */ 1150 1151 static conversion * 1152 build_ambiguous_conv (tree type, tree expr) 1153 { 1154 conversion *c; 1155 1156 c = alloc_conversion (ck_ambig); 1157 c->type = type; 1158 c->u.expr = expr; 1159 1160 return c; 1161 } 1162 1163 tree 1164 strip_top_quals (tree t) 1165 { 1166 if (TREE_CODE (t) == ARRAY_TYPE) 1167 return t; 1168 return cp_build_qualified_type (t, 0); 1169 } 1170 1171 /* Returns the standard conversion path (see [conv]) from type FROM to type 1172 TO, if any. For proper handling of null pointer constants, you must 1173 also pass the expression EXPR to convert from. If C_CAST_P is true, 1174 this conversion is coming from a C-style cast. */ 1175 1176 static conversion * 1177 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1178 int flags, tsubst_flags_t complain) 1179 { 1180 enum tree_code fcode, tcode; 1181 conversion *conv; 1182 bool fromref = false; 1183 tree qualified_to; 1184 1185 to = non_reference (to); 1186 if (TYPE_REF_P (from)) 1187 { 1188 fromref = true; 1189 from = TREE_TYPE (from); 1190 } 1191 qualified_to = to; 1192 to = strip_top_quals (to); 1193 from = strip_top_quals (from); 1194 1195 if (expr && type_unknown_p (expr)) 1196 { 1197 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1198 { 1199 tsubst_flags_t tflags = tf_conv; 1200 expr = instantiate_type (to, expr, tflags); 1201 if (expr == error_mark_node) 1202 return NULL; 1203 from = TREE_TYPE (expr); 1204 } 1205 else if (TREE_CODE (to) == BOOLEAN_TYPE) 1206 { 1207 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */ 1208 expr = resolve_nondeduced_context (expr, complain); 1209 from = TREE_TYPE (expr); 1210 } 1211 } 1212 1213 fcode = TREE_CODE (from); 1214 tcode = TREE_CODE (to); 1215 1216 conv = build_identity_conv (from, expr); 1217 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1218 { 1219 from = type_decays_to (from); 1220 fcode = TREE_CODE (from); 1221 /* Tell convert_like_real that we're using the address. */ 1222 conv->rvaluedness_matches_p = true; 1223 conv = build_conv (ck_lvalue, from, conv); 1224 } 1225 /* Wrapping a ck_rvalue around a class prvalue (as a result of using 1226 obvalue_p) seems odd, since it's already a prvalue, but that's how we 1227 express the copy constructor call required by copy-initialization. */ 1228 else if (fromref || (expr && obvalue_p (expr))) 1229 { 1230 if (expr) 1231 { 1232 tree bitfield_type; 1233 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1234 if (bitfield_type) 1235 { 1236 from = strip_top_quals (bitfield_type); 1237 fcode = TREE_CODE (from); 1238 } 1239 } 1240 conv = build_conv (ck_rvalue, from, conv); 1241 if (flags & LOOKUP_PREFER_RVALUE) 1242 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */ 1243 conv->rvaluedness_matches_p = true; 1244 } 1245 1246 /* Allow conversion between `__complex__' data types. */ 1247 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1248 { 1249 /* The standard conversion sequence to convert FROM to TO is 1250 the standard conversion sequence to perform componentwise 1251 conversion. */ 1252 conversion *part_conv = standard_conversion 1253 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags, 1254 complain); 1255 1256 if (part_conv) 1257 { 1258 conv = build_conv (part_conv->kind, to, conv); 1259 conv->rank = part_conv->rank; 1260 } 1261 else 1262 conv = NULL; 1263 1264 return conv; 1265 } 1266 1267 if (same_type_p (from, to)) 1268 { 1269 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1270 conv->type = qualified_to; 1271 return conv; 1272 } 1273 1274 /* [conv.ptr] 1275 A null pointer constant can be converted to a pointer type; ... A 1276 null pointer constant of integral type can be converted to an 1277 rvalue of type std::nullptr_t. */ 1278 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to) 1279 || NULLPTR_TYPE_P (to)) 1280 && ((expr && null_ptr_cst_p (expr)) 1281 || NULLPTR_TYPE_P (from))) 1282 conv = build_conv (ck_std, to, conv); 1283 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1284 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1285 { 1286 /* For backwards brain damage compatibility, allow interconversion of 1287 pointers and integers with a pedwarn. */ 1288 conv = build_conv (ck_std, to, conv); 1289 conv->bad_p = true; 1290 } 1291 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1292 { 1293 /* For backwards brain damage compatibility, allow interconversion of 1294 enums and integers with a pedwarn. */ 1295 conv = build_conv (ck_std, to, conv); 1296 conv->bad_p = true; 1297 } 1298 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1299 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from))) 1300 { 1301 tree to_pointee; 1302 tree from_pointee; 1303 1304 if (tcode == POINTER_TYPE) 1305 { 1306 to_pointee = TREE_TYPE (to); 1307 from_pointee = TREE_TYPE (from); 1308 1309 /* Since this is the target of a pointer, it can't have function 1310 qualifiers, so any TYPE_QUALS must be for attributes const or 1311 noreturn. Strip them. */ 1312 if (TREE_CODE (to_pointee) == FUNCTION_TYPE 1313 && TYPE_QUALS (to_pointee)) 1314 to_pointee = build_qualified_type (to_pointee, TYPE_UNQUALIFIED); 1315 if (TREE_CODE (from_pointee) == FUNCTION_TYPE 1316 && TYPE_QUALS (from_pointee)) 1317 from_pointee = build_qualified_type (from_pointee, TYPE_UNQUALIFIED); 1318 } 1319 else 1320 { 1321 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1322 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1323 } 1324 1325 if (tcode == POINTER_TYPE 1326 && same_type_ignoring_top_level_qualifiers_p (from_pointee, 1327 to_pointee)) 1328 ; 1329 else if (VOID_TYPE_P (to_pointee) 1330 && !TYPE_PTRDATAMEM_P (from) 1331 && TREE_CODE (from_pointee) != FUNCTION_TYPE) 1332 { 1333 tree nfrom = TREE_TYPE (from); 1334 /* Don't try to apply restrict to void. */ 1335 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT; 1336 from_pointee = cp_build_qualified_type (void_type_node, quals); 1337 from = build_pointer_type (from_pointee); 1338 conv = build_conv (ck_ptr, from, conv); 1339 } 1340 else if (TYPE_PTRDATAMEM_P (from)) 1341 { 1342 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1343 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1344 1345 if (same_type_p (fbase, tbase)) 1346 /* No base conversion needed. */; 1347 else if (DERIVED_FROM_P (fbase, tbase) 1348 && (same_type_ignoring_top_level_qualifiers_p 1349 (from_pointee, to_pointee))) 1350 { 1351 from = build_ptrmem_type (tbase, from_pointee); 1352 conv = build_conv (ck_pmem, from, conv); 1353 } 1354 else 1355 return NULL; 1356 } 1357 else if (CLASS_TYPE_P (from_pointee) 1358 && CLASS_TYPE_P (to_pointee) 1359 /* [conv.ptr] 1360 1361 An rvalue of type "pointer to cv D," where D is a 1362 class type, can be converted to an rvalue of type 1363 "pointer to cv B," where B is a base class (clause 1364 _class.derived_) of D. If B is an inaccessible 1365 (clause _class.access_) or ambiguous 1366 (_class.member.lookup_) base class of D, a program 1367 that necessitates this conversion is ill-formed. 1368 Therefore, we use DERIVED_FROM_P, and do not check 1369 access or uniqueness. */ 1370 && DERIVED_FROM_P (to_pointee, from_pointee)) 1371 { 1372 from_pointee 1373 = cp_build_qualified_type (to_pointee, 1374 cp_type_quals (from_pointee)); 1375 from = build_pointer_type (from_pointee); 1376 conv = build_conv (ck_ptr, from, conv); 1377 conv->base_p = true; 1378 } 1379 1380 if (same_type_p (from, to)) 1381 /* OK */; 1382 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1383 /* In a C-style cast, we ignore CV-qualification because we 1384 are allowed to perform a static_cast followed by a 1385 const_cast. */ 1386 conv = build_conv (ck_qual, to, conv); 1387 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1388 conv = build_conv (ck_qual, to, conv); 1389 else if (expr && string_conv_p (to, expr, 0)) 1390 /* converting from string constant to char *. */ 1391 conv = build_conv (ck_qual, to, conv); 1392 else if (fnptr_conv_p (to, from)) 1393 conv = build_conv (ck_fnptr, to, conv); 1394 /* Allow conversions among compatible ObjC pointer types (base 1395 conversions have been already handled above). */ 1396 else if (c_dialect_objc () 1397 && objc_compare_types (to, from, -4, NULL_TREE)) 1398 conv = build_conv (ck_ptr, to, conv); 1399 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1400 { 1401 conv = build_conv (ck_ptr, to, conv); 1402 conv->bad_p = true; 1403 } 1404 else 1405 return NULL; 1406 1407 from = to; 1408 } 1409 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1410 { 1411 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1412 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1413 tree fbase = class_of_this_parm (fromfn); 1414 tree tbase = class_of_this_parm (tofn); 1415 1416 if (!DERIVED_FROM_P (fbase, tbase)) 1417 return NULL; 1418 1419 tree fstat = static_fn_type (fromfn); 1420 tree tstat = static_fn_type (tofn); 1421 if (same_type_p (tstat, fstat) 1422 || fnptr_conv_p (tstat, fstat)) 1423 /* OK */; 1424 else 1425 return NULL; 1426 1427 if (!same_type_p (fbase, tbase)) 1428 { 1429 from = build_memfn_type (fstat, 1430 tbase, 1431 cp_type_quals (tbase), 1432 type_memfn_rqual (tofn)); 1433 from = build_ptrmemfunc_type (build_pointer_type (from)); 1434 conv = build_conv (ck_pmem, from, conv); 1435 conv->base_p = true; 1436 } 1437 if (fnptr_conv_p (tstat, fstat)) 1438 conv = build_conv (ck_fnptr, to, conv); 1439 } 1440 else if (tcode == BOOLEAN_TYPE) 1441 { 1442 /* [conv.bool] 1443 1444 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer 1445 to member type can be converted to a prvalue of type bool. ... 1446 For direct-initialization (8.5 [dcl.init]), a prvalue of type 1447 std::nullptr_t can be converted to a prvalue of type bool; */ 1448 if (ARITHMETIC_TYPE_P (from) 1449 || UNSCOPED_ENUM_P (from) 1450 || fcode == POINTER_TYPE 1451 || TYPE_PTRMEM_P (from) 1452 || NULLPTR_TYPE_P (from)) 1453 { 1454 conv = build_conv (ck_std, to, conv); 1455 if (fcode == POINTER_TYPE 1456 || TYPE_PTRDATAMEM_P (from) 1457 || (TYPE_PTRMEMFUNC_P (from) 1458 && conv->rank < cr_pbool) 1459 || NULLPTR_TYPE_P (from)) 1460 conv->rank = cr_pbool; 1461 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING)) 1462 conv->bad_p = true; 1463 if (flags & LOOKUP_NO_NARROWING) 1464 conv->check_narrowing = true; 1465 return conv; 1466 } 1467 1468 return NULL; 1469 } 1470 /* We don't check for ENUMERAL_TYPE here because there are no standard 1471 conversions to enum type. */ 1472 /* As an extension, allow conversion to complex type. */ 1473 else if (ARITHMETIC_TYPE_P (to)) 1474 { 1475 if (! (INTEGRAL_CODE_P (fcode) 1476 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL))) 1477 || SCOPED_ENUM_P (from)) 1478 return NULL; 1479 1480 /* If we're parsing an enum with no fixed underlying type, we're 1481 dealing with an incomplete type, which renders the conversion 1482 ill-formed. */ 1483 if (!COMPLETE_TYPE_P (from)) 1484 return NULL; 1485 1486 conv = build_conv (ck_std, to, conv); 1487 1488 /* Give this a better rank if it's a promotion. */ 1489 if (same_type_p (to, type_promotes_to (from)) 1490 && next_conversion (conv)->rank <= cr_promotion) 1491 conv->rank = cr_promotion; 1492 } 1493 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1494 && vector_types_convertible_p (from, to, false)) 1495 return build_conv (ck_std, to, conv); 1496 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1497 && is_properly_derived_from (from, to)) 1498 { 1499 if (conv->kind == ck_rvalue) 1500 conv = next_conversion (conv); 1501 conv = build_conv (ck_base, to, conv); 1502 /* The derived-to-base conversion indicates the initialization 1503 of a parameter with base type from an object of a derived 1504 type. A temporary object is created to hold the result of 1505 the conversion unless we're binding directly to a reference. */ 1506 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1507 if (flags & LOOKUP_PREFER_RVALUE) 1508 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */ 1509 conv->rvaluedness_matches_p = true; 1510 } 1511 else 1512 return NULL; 1513 1514 if (flags & LOOKUP_NO_NARROWING) 1515 conv->check_narrowing = true; 1516 1517 return conv; 1518 } 1519 1520 /* Returns nonzero if T1 is reference-related to T2. */ 1521 1522 bool 1523 reference_related_p (tree t1, tree t2) 1524 { 1525 if (t1 == error_mark_node || t2 == error_mark_node) 1526 return false; 1527 1528 t1 = TYPE_MAIN_VARIANT (t1); 1529 t2 = TYPE_MAIN_VARIANT (t2); 1530 1531 /* [dcl.init.ref] 1532 1533 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1534 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1535 of T2. */ 1536 return (same_type_p (t1, t2) 1537 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1538 && DERIVED_FROM_P (t1, t2))); 1539 } 1540 1541 /* Returns nonzero if T1 is reference-compatible with T2. */ 1542 1543 static bool 1544 reference_compatible_p (tree t1, tree t2) 1545 { 1546 /* [dcl.init.ref] 1547 1548 "cv1 T1" is reference compatible with "cv2 T2" if 1549 * T1 is reference-related to T2 or 1550 * T2 is "noexcept function" and T1 is "function", where the 1551 function types are otherwise the same, 1552 and cv1 is the same cv-qualification as, or greater cv-qualification 1553 than, cv2. */ 1554 return ((reference_related_p (t1, t2) 1555 || fnptr_conv_p (t1, t2)) 1556 && at_least_as_qualified_p (t1, t2)); 1557 } 1558 1559 /* A reference of the indicated TYPE is being bound directly to the 1560 expression represented by the implicit conversion sequence CONV. 1561 Return a conversion sequence for this binding. */ 1562 1563 static conversion * 1564 direct_reference_binding (tree type, conversion *conv) 1565 { 1566 tree t; 1567 1568 gcc_assert (TYPE_REF_P (type)); 1569 gcc_assert (!TYPE_REF_P (conv->type)); 1570 1571 t = TREE_TYPE (type); 1572 1573 if (conv->kind == ck_identity) 1574 /* Mark the identity conv as to not decay to rvalue. */ 1575 conv->rvaluedness_matches_p = true; 1576 1577 /* [over.ics.rank] 1578 1579 When a parameter of reference type binds directly 1580 (_dcl.init.ref_) to an argument expression, the implicit 1581 conversion sequence is the identity conversion, unless the 1582 argument expression has a type that is a derived class of the 1583 parameter type, in which case the implicit conversion sequence is 1584 a derived-to-base Conversion. 1585 1586 If the parameter binds directly to the result of applying a 1587 conversion function to the argument expression, the implicit 1588 conversion sequence is a user-defined conversion sequence 1589 (_over.ics.user_), with the second standard conversion sequence 1590 either an identity conversion or, if the conversion function 1591 returns an entity of a type that is a derived class of the 1592 parameter type, a derived-to-base conversion. */ 1593 if (is_properly_derived_from (conv->type, t)) 1594 { 1595 /* Represent the derived-to-base conversion. */ 1596 conv = build_conv (ck_base, t, conv); 1597 /* We will actually be binding to the base-class subobject in 1598 the derived class, so we mark this conversion appropriately. 1599 That way, convert_like knows not to generate a temporary. */ 1600 conv->need_temporary_p = false; 1601 } 1602 1603 return build_conv (ck_ref_bind, type, conv); 1604 } 1605 1606 /* Returns the conversion path from type FROM to reference type TO for 1607 purposes of reference binding. For lvalue binding, either pass a 1608 reference type to FROM or an lvalue expression to EXPR. If the 1609 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1610 the conversion returned. If C_CAST_P is true, this 1611 conversion is coming from a C-style cast. */ 1612 1613 static conversion * 1614 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags, 1615 tsubst_flags_t complain) 1616 { 1617 conversion *conv = NULL; 1618 tree to = TREE_TYPE (rto); 1619 tree from = rfrom; 1620 tree tfrom; 1621 bool related_p; 1622 bool compatible_p; 1623 cp_lvalue_kind gl_kind; 1624 bool is_lvalue; 1625 1626 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1627 { 1628 expr = instantiate_type (to, expr, tf_none); 1629 if (expr == error_mark_node) 1630 return NULL; 1631 from = TREE_TYPE (expr); 1632 } 1633 1634 bool copy_list_init = false; 1635 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1636 { 1637 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1638 /* DR 1288: Otherwise, if the initializer list has a single element 1639 of type E and ... [T's] referenced type is reference-related to E, 1640 the object or reference is initialized from that element... */ 1641 if (CONSTRUCTOR_NELTS (expr) == 1) 1642 { 1643 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1644 if (error_operand_p (elt)) 1645 return NULL; 1646 tree etype = TREE_TYPE (elt); 1647 if (reference_related_p (to, etype)) 1648 { 1649 expr = elt; 1650 from = etype; 1651 goto skip; 1652 } 1653 } 1654 /* Otherwise, if T is a reference type, a prvalue temporary of the type 1655 referenced by T is copy-list-initialized, and the reference is bound 1656 to that temporary. */ 1657 copy_list_init = true; 1658 skip:; 1659 } 1660 1661 if (TYPE_REF_P (from)) 1662 { 1663 from = TREE_TYPE (from); 1664 if (!TYPE_REF_IS_RVALUE (rfrom) 1665 || TREE_CODE (from) == FUNCTION_TYPE) 1666 gl_kind = clk_ordinary; 1667 else 1668 gl_kind = clk_rvalueref; 1669 } 1670 else if (expr) 1671 gl_kind = lvalue_kind (expr); 1672 else if (CLASS_TYPE_P (from) 1673 || TREE_CODE (from) == ARRAY_TYPE) 1674 gl_kind = clk_class; 1675 else 1676 gl_kind = clk_none; 1677 1678 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */ 1679 if ((flags & LOOKUP_NO_TEMP_BIND) 1680 && (gl_kind & clk_class)) 1681 gl_kind = clk_none; 1682 1683 /* Same mask as real_lvalue_p. */ 1684 is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class)); 1685 1686 tfrom = from; 1687 if ((gl_kind & clk_bitfield) != 0) 1688 tfrom = unlowered_expr_type (expr); 1689 1690 /* Figure out whether or not the types are reference-related and 1691 reference compatible. We have to do this after stripping 1692 references from FROM. */ 1693 related_p = reference_related_p (to, tfrom); 1694 /* If this is a C cast, first convert to an appropriately qualified 1695 type, so that we can later do a const_cast to the desired type. */ 1696 if (related_p && c_cast_p 1697 && !at_least_as_qualified_p (to, tfrom)) 1698 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1699 compatible_p = reference_compatible_p (to, tfrom); 1700 1701 /* Directly bind reference when target expression's type is compatible with 1702 the reference and expression is an lvalue. In DR391, the wording in 1703 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1704 const and rvalue references to rvalues of compatible class type. 1705 We should also do direct bindings for non-class xvalues. */ 1706 if ((related_p || compatible_p) && gl_kind) 1707 { 1708 /* [dcl.init.ref] 1709 1710 If the initializer expression 1711 1712 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1713 is reference-compatible with "cv2 T2," 1714 1715 the reference is bound directly to the initializer expression 1716 lvalue. 1717 1718 [...] 1719 If the initializer expression is an rvalue, with T2 a class type, 1720 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1721 is bound to the object represented by the rvalue or to a sub-object 1722 within that object. */ 1723 1724 conv = build_identity_conv (tfrom, expr); 1725 conv = direct_reference_binding (rto, conv); 1726 1727 if (TYPE_REF_P (rfrom)) 1728 /* Handle rvalue reference to function properly. */ 1729 conv->rvaluedness_matches_p 1730 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1731 else 1732 conv->rvaluedness_matches_p 1733 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1734 1735 if ((gl_kind & clk_bitfield) != 0 1736 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1737 /* For the purposes of overload resolution, we ignore the fact 1738 this expression is a bitfield or packed field. (In particular, 1739 [over.ics.ref] says specifically that a function with a 1740 non-const reference parameter is viable even if the 1741 argument is a bitfield.) 1742 1743 However, when we actually call the function we must create 1744 a temporary to which to bind the reference. If the 1745 reference is volatile, or isn't const, then we cannot make 1746 a temporary, so we just issue an error when the conversion 1747 actually occurs. */ 1748 conv->need_temporary_p = true; 1749 1750 /* Don't allow binding of lvalues (other than function lvalues) to 1751 rvalue references. */ 1752 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1753 && TREE_CODE (to) != FUNCTION_TYPE) 1754 conv->bad_p = true; 1755 1756 /* Nor the reverse. */ 1757 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto) 1758 && (!CP_TYPE_CONST_NON_VOLATILE_P (to) 1759 || (flags & LOOKUP_NO_RVAL_BIND)) 1760 && TREE_CODE (to) != FUNCTION_TYPE) 1761 conv->bad_p = true; 1762 1763 if (!compatible_p) 1764 conv->bad_p = true; 1765 1766 return conv; 1767 } 1768 /* [class.conv.fct] A conversion function is never used to convert a 1769 (possibly cv-qualified) object to the (possibly cv-qualified) same 1770 object type (or a reference to it), to a (possibly cv-qualified) base 1771 class of that type (or a reference to it).... */ 1772 else if (CLASS_TYPE_P (from) && !related_p 1773 && !(flags & LOOKUP_NO_CONVERSION)) 1774 { 1775 /* [dcl.init.ref] 1776 1777 If the initializer expression 1778 1779 -- has a class type (i.e., T2 is a class type) can be 1780 implicitly converted to an lvalue of type "cv3 T3," where 1781 "cv1 T1" is reference-compatible with "cv3 T3". (this 1782 conversion is selected by enumerating the applicable 1783 conversion functions (_over.match.ref_) and choosing the 1784 best one through overload resolution. (_over.match_). 1785 1786 the reference is bound to the lvalue result of the conversion 1787 in the second case. */ 1788 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags, 1789 complain); 1790 if (cand) 1791 return cand->second_conv; 1792 } 1793 1794 /* From this point on, we conceptually need temporaries, even if we 1795 elide them. Only the cases above are "direct bindings". */ 1796 if (flags & LOOKUP_NO_TEMP_BIND) 1797 return NULL; 1798 1799 /* [over.ics.rank] 1800 1801 When a parameter of reference type is not bound directly to an 1802 argument expression, the conversion sequence is the one required 1803 to convert the argument expression to the underlying type of the 1804 reference according to _over.best.ics_. Conceptually, this 1805 conversion sequence corresponds to copy-initializing a temporary 1806 of the underlying type with the argument expression. Any 1807 difference in top-level cv-qualification is subsumed by the 1808 initialization itself and does not constitute a conversion. */ 1809 1810 /* [dcl.init.ref] 1811 1812 Otherwise, the reference shall be an lvalue reference to a 1813 non-volatile const type, or the reference shall be an rvalue 1814 reference. 1815 1816 We try below to treat this as a bad conversion to improve diagnostics, 1817 but if TO is an incomplete class, we need to reject this conversion 1818 now to avoid unnecessary instantiation. */ 1819 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto) 1820 && !COMPLETE_TYPE_P (to)) 1821 return NULL; 1822 1823 /* We're generating a temporary now, but don't bind any more in the 1824 conversion (specifically, don't slice the temporary returned by a 1825 conversion operator). */ 1826 flags |= LOOKUP_NO_TEMP_BIND; 1827 1828 /* Core issue 899: When [copy-]initializing a temporary to be bound 1829 to the first parameter of a copy constructor (12.8) called with 1830 a single argument in the context of direct-initialization, 1831 explicit conversion functions are also considered. 1832 1833 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1834 if (!(flags & LOOKUP_COPY_PARM)) 1835 flags |= LOOKUP_ONLYCONVERTING; 1836 1837 if (!conv) 1838 conv = implicit_conversion (to, from, expr, c_cast_p, 1839 flags, complain); 1840 if (!conv) 1841 return NULL; 1842 1843 if (conv->user_conv_p) 1844 { 1845 if (copy_list_init) 1846 /* Remember this was copy-list-initialization. */ 1847 conv->need_temporary_p = true; 1848 1849 /* If initializing the temporary used a conversion function, 1850 recalculate the second conversion sequence. */ 1851 for (conversion *t = conv; t; t = next_conversion (t)) 1852 if (t->kind == ck_user 1853 && DECL_CONV_FN_P (t->cand->fn)) 1854 { 1855 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn)); 1856 /* A prvalue of non-class type is cv-unqualified. */ 1857 if (!TYPE_REF_P (ftype) && !CLASS_TYPE_P (ftype)) 1858 ftype = cv_unqualified (ftype); 1859 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND; 1860 conversion *new_second 1861 = reference_binding (rto, ftype, NULL_TREE, c_cast_p, 1862 sflags, complain); 1863 if (!new_second) 1864 return NULL; 1865 return merge_conversion_sequences (t, new_second); 1866 } 1867 } 1868 1869 conv = build_conv (ck_ref_bind, rto, conv); 1870 /* This reference binding, unlike those above, requires the 1871 creation of a temporary. */ 1872 conv->need_temporary_p = true; 1873 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1874 1875 /* [dcl.init.ref] 1876 1877 Otherwise, the reference shall be an lvalue reference to a 1878 non-volatile const type, or the reference shall be an rvalue 1879 reference. */ 1880 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1881 conv->bad_p = true; 1882 1883 /* [dcl.init.ref] 1884 1885 Otherwise, a temporary of type "cv1 T1" is created and 1886 initialized from the initializer expression using the rules for a 1887 non-reference copy initialization. If T1 is reference-related to 1888 T2, cv1 must be the same cv-qualification as, or greater 1889 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1890 if (related_p && !at_least_as_qualified_p (to, from)) 1891 conv->bad_p = true; 1892 1893 return conv; 1894 } 1895 1896 /* Returns the implicit conversion sequence (see [over.ics]) from type 1897 FROM to type TO. The optional expression EXPR may affect the 1898 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1899 true, this conversion is coming from a C-style cast. */ 1900 1901 static conversion * 1902 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1903 int flags, tsubst_flags_t complain) 1904 { 1905 conversion *conv; 1906 1907 if (from == error_mark_node || to == error_mark_node 1908 || expr == error_mark_node) 1909 return NULL; 1910 1911 /* Other flags only apply to the primary function in overload 1912 resolution, or after we've chosen one. */ 1913 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1914 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1915 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL); 1916 1917 /* FIXME: actually we don't want warnings either, but we can't just 1918 have 'complain &= ~(tf_warning|tf_error)' because it would cause 1919 the regression of, eg, g++.old-deja/g++.benjamin/16077.C. 1920 We really ought not to issue that warning until we've committed 1921 to that conversion. */ 1922 complain &= ~tf_error; 1923 1924 /* Call reshape_init early to remove redundant braces. */ 1925 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) 1926 && CLASS_TYPE_P (to) 1927 && COMPLETE_TYPE_P (complete_type (to)) 1928 && !CLASSTYPE_NON_AGGREGATE (to)) 1929 { 1930 expr = reshape_init (to, expr, complain); 1931 if (expr == error_mark_node) 1932 return NULL; 1933 from = TREE_TYPE (expr); 1934 } 1935 1936 if (TYPE_REF_P (to)) 1937 conv = reference_binding (to, from, expr, c_cast_p, flags, complain); 1938 else 1939 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain); 1940 1941 if (conv) 1942 return conv; 1943 1944 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1945 { 1946 if (is_std_init_list (to) && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr)) 1947 return build_list_conv (to, expr, flags, complain); 1948 1949 /* As an extension, allow list-initialization of _Complex. */ 1950 if (TREE_CODE (to) == COMPLEX_TYPE 1951 && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr)) 1952 { 1953 conv = build_complex_conv (to, expr, flags, complain); 1954 if (conv) 1955 return conv; 1956 } 1957 1958 /* Allow conversion from an initializer-list with one element to a 1959 scalar type. */ 1960 if (SCALAR_TYPE_P (to)) 1961 { 1962 int nelts = CONSTRUCTOR_NELTS (expr); 1963 tree elt; 1964 1965 if (nelts == 0) 1966 elt = build_value_init (to, tf_none); 1967 else if (nelts == 1 && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr)) 1968 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1969 else 1970 elt = error_mark_node; 1971 1972 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1973 c_cast_p, flags, complain); 1974 if (conv) 1975 { 1976 conv->check_narrowing = true; 1977 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1978 /* Too many levels of braces, i.e. '{{1}}'. */ 1979 conv->bad_p = true; 1980 return conv; 1981 } 1982 } 1983 else if (TREE_CODE (to) == ARRAY_TYPE) 1984 return build_array_conv (to, expr, flags, complain); 1985 } 1986 1987 if (expr != NULL_TREE 1988 && (MAYBE_CLASS_TYPE_P (from) 1989 || MAYBE_CLASS_TYPE_P (to)) 1990 && (flags & LOOKUP_NO_CONVERSION) == 0) 1991 { 1992 struct z_candidate *cand; 1993 1994 if (CLASS_TYPE_P (to) 1995 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1996 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1997 return build_aggr_conv (to, expr, flags, complain); 1998 1999 cand = build_user_type_conversion_1 (to, expr, flags, complain); 2000 if (cand) 2001 { 2002 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 2003 && CONSTRUCTOR_NELTS (expr) == 1 2004 && !is_list_ctor (cand->fn)) 2005 { 2006 /* "If C is not an initializer-list constructor and the 2007 initializer list has a single element of type cv U, where U is 2008 X or a class derived from X, the implicit conversion sequence 2009 has Exact Match rank if U is X, or Conversion rank if U is 2010 derived from X." */ 2011 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 2012 tree elttype = TREE_TYPE (elt); 2013 if (reference_related_p (to, elttype)) 2014 return implicit_conversion (to, elttype, elt, 2015 c_cast_p, flags, complain); 2016 } 2017 conv = cand->second_conv; 2018 } 2019 2020 /* We used to try to bind a reference to a temporary here, but that 2021 is now handled after the recursive call to this function at the end 2022 of reference_binding. */ 2023 return conv; 2024 } 2025 2026 return NULL; 2027 } 2028 2029 /* Like implicit_conversion, but return NULL if the conversion is bad. 2030 2031 This is not static so that check_non_deducible_conversion can call it within 2032 add_template_candidate_real as part of overload resolution; it should not be 2033 called outside of overload resolution. */ 2034 2035 conversion * 2036 good_conversion (tree to, tree from, tree expr, 2037 int flags, tsubst_flags_t complain) 2038 { 2039 conversion *c = implicit_conversion (to, from, expr, /*cast*/false, 2040 flags, complain); 2041 if (c && c->bad_p) 2042 c = NULL; 2043 return c; 2044 } 2045 2046 /* Add a new entry to the list of candidates. Used by the add_*_candidate 2047 functions. ARGS will not be changed until a single candidate is 2048 selected. */ 2049 2050 static struct z_candidate * 2051 add_candidate (struct z_candidate **candidates, 2052 tree fn, tree first_arg, const vec<tree, va_gc> *args, 2053 size_t num_convs, conversion **convs, 2054 tree access_path, tree conversion_path, 2055 int viable, struct rejection_reason *reason, 2056 int flags) 2057 { 2058 struct z_candidate *cand = (struct z_candidate *) 2059 conversion_obstack_alloc (sizeof (struct z_candidate)); 2060 2061 cand->fn = fn; 2062 cand->first_arg = first_arg; 2063 cand->args = args; 2064 cand->convs = convs; 2065 cand->num_convs = num_convs; 2066 cand->access_path = access_path; 2067 cand->conversion_path = conversion_path; 2068 cand->viable = viable; 2069 cand->reason = reason; 2070 cand->next = *candidates; 2071 cand->flags = flags; 2072 *candidates = cand; 2073 2074 return cand; 2075 } 2076 2077 /* Return the number of remaining arguments in the parameter list 2078 beginning with ARG. */ 2079 2080 int 2081 remaining_arguments (tree arg) 2082 { 2083 int n; 2084 2085 for (n = 0; arg != NULL_TREE && arg != void_list_node; 2086 arg = TREE_CHAIN (arg)) 2087 n++; 2088 2089 return n; 2090 } 2091 2092 /* [over.match.copy]: When initializing a temporary object (12.2) to be bound 2093 to the first parameter of a constructor where the parameter is of type 2094 "reference to possibly cv-qualified T" and the constructor is called with a 2095 single argument in the context of direct-initialization of an object of type 2096 "cv2 T", explicit conversion functions are also considered. 2097 2098 So set LOOKUP_COPY_PARM to let reference_binding know that 2099 it's being called in that context. */ 2100 2101 int 2102 conv_flags (int i, int nargs, tree fn, tree arg, int flags) 2103 { 2104 int lflags = flags; 2105 tree t; 2106 if (i == 0 && nargs == 1 && DECL_CONSTRUCTOR_P (fn) 2107 && (t = FUNCTION_FIRST_USER_PARMTYPE (fn)) 2108 && (same_type_ignoring_top_level_qualifiers_p 2109 (non_reference (TREE_VALUE (t)), DECL_CONTEXT (fn)))) 2110 { 2111 if (!(flags & LOOKUP_ONLYCONVERTING)) 2112 lflags |= LOOKUP_COPY_PARM; 2113 if ((flags & LOOKUP_LIST_INIT_CTOR) 2114 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 2115 lflags |= LOOKUP_NO_CONVERSION; 2116 } 2117 else 2118 lflags |= LOOKUP_ONLYCONVERTING; 2119 2120 return lflags; 2121 } 2122 2123 /* Create an overload candidate for the function or method FN called 2124 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 2125 FLAGS is passed on to implicit_conversion. 2126 2127 This does not change ARGS. 2128 2129 CTYPE, if non-NULL, is the type we want to pretend this function 2130 comes from for purposes of overload resolution. */ 2131 2132 static struct z_candidate * 2133 add_function_candidate (struct z_candidate **candidates, 2134 tree fn, tree ctype, tree first_arg, 2135 const vec<tree, va_gc> *args, tree access_path, 2136 tree conversion_path, int flags, 2137 conversion **convs, 2138 tsubst_flags_t complain) 2139 { 2140 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 2141 int i, len; 2142 tree parmnode; 2143 tree orig_first_arg = first_arg; 2144 int skip; 2145 int viable = 1; 2146 struct rejection_reason *reason = NULL; 2147 2148 /* At this point we should not see any functions which haven't been 2149 explicitly declared, except for friend functions which will have 2150 been found using argument dependent lookup. */ 2151 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 2152 2153 /* The `this', `in_chrg' and VTT arguments to constructors are not 2154 considered in overload resolution. */ 2155 if (DECL_CONSTRUCTOR_P (fn)) 2156 { 2157 if (ctor_omit_inherited_parms (fn)) 2158 /* Bring back parameters omitted from an inherited ctor. */ 2159 parmlist = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)); 2160 else 2161 parmlist = skip_artificial_parms_for (fn, parmlist); 2162 skip = num_artificial_parms_for (fn); 2163 if (skip > 0 && first_arg != NULL_TREE) 2164 { 2165 --skip; 2166 first_arg = NULL_TREE; 2167 } 2168 } 2169 else 2170 skip = 0; 2171 2172 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0); 2173 if (!convs) 2174 convs = alloc_conversions (len); 2175 2176 /* 13.3.2 - Viable functions [over.match.viable] 2177 First, to be a viable function, a candidate function shall have enough 2178 parameters to agree in number with the arguments in the list. 2179 2180 We need to check this first; otherwise, checking the ICSes might cause 2181 us to produce an ill-formed template instantiation. */ 2182 2183 parmnode = parmlist; 2184 for (i = 0; i < len; ++i) 2185 { 2186 if (parmnode == NULL_TREE || parmnode == void_list_node) 2187 break; 2188 parmnode = TREE_CHAIN (parmnode); 2189 } 2190 2191 if ((i < len && parmnode) 2192 || !sufficient_parms_p (parmnode)) 2193 { 2194 int remaining = remaining_arguments (parmnode); 2195 viable = 0; 2196 reason = arity_rejection (first_arg, i + remaining, len); 2197 } 2198 2199 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first 2200 parameter of type "reference to cv C" (including such a constructor 2201 instantiated from a template) is excluded from the set of candidate 2202 functions when used to construct an object of type D with an argument list 2203 containing a single argument if C is reference-related to D. */ 2204 if (viable && len == 1 && parmlist && DECL_CONSTRUCTOR_P (fn) 2205 && flag_new_inheriting_ctors 2206 && DECL_INHERITED_CTOR (fn)) 2207 { 2208 tree ptype = non_reference (TREE_VALUE (parmlist)); 2209 tree dtype = DECL_CONTEXT (fn); 2210 tree btype = DECL_INHERITED_CTOR_BASE (fn); 2211 if (reference_related_p (ptype, dtype) 2212 && reference_related_p (btype, ptype)) 2213 { 2214 viable = false; 2215 reason = inherited_ctor_rejection (); 2216 } 2217 } 2218 2219 /* Second, for a function to be viable, its constraints must be 2220 satisfied. */ 2221 if (flag_concepts && viable 2222 && !constraints_satisfied_p (fn)) 2223 { 2224 reason = constraint_failure (fn); 2225 viable = false; 2226 } 2227 2228 /* When looking for a function from a subobject from an implicit 2229 copy/move constructor/operator=, don't consider anything that takes (a 2230 reference to) an unrelated type. See c++/44909 and core 1092. */ 2231 if (viable && parmlist && (flags & LOOKUP_DEFAULTED)) 2232 { 2233 if (DECL_CONSTRUCTOR_P (fn)) 2234 i = 1; 2235 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 2236 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR)) 2237 i = 2; 2238 else 2239 i = 0; 2240 if (i && len == i) 2241 { 2242 parmnode = chain_index (i-1, parmlist); 2243 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 2244 ctype)) 2245 viable = 0; 2246 } 2247 2248 /* This only applies at the top level. */ 2249 flags &= ~LOOKUP_DEFAULTED; 2250 } 2251 2252 if (! viable) 2253 goto out; 2254 2255 /* Third, for F to be a viable function, there shall exist for each 2256 argument an implicit conversion sequence that converts that argument 2257 to the corresponding parameter of F. */ 2258 2259 parmnode = parmlist; 2260 2261 for (i = 0; i < len; ++i) 2262 { 2263 tree argtype, to_type; 2264 tree arg; 2265 conversion *t; 2266 int is_this; 2267 2268 if (parmnode == void_list_node) 2269 break; 2270 2271 if (convs[i]) 2272 { 2273 /* Already set during deduction. */ 2274 parmnode = TREE_CHAIN (parmnode); 2275 continue; 2276 } 2277 2278 if (i == 0 && first_arg != NULL_TREE) 2279 arg = first_arg; 2280 else 2281 arg = CONST_CAST_TREE ( 2282 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]); 2283 argtype = lvalue_type (arg); 2284 2285 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 2286 && ! DECL_CONSTRUCTOR_P (fn)); 2287 2288 if (parmnode) 2289 { 2290 tree parmtype = TREE_VALUE (parmnode); 2291 2292 parmnode = TREE_CHAIN (parmnode); 2293 2294 /* The type of the implicit object parameter ('this') for 2295 overload resolution is not always the same as for the 2296 function itself; conversion functions are considered to 2297 be members of the class being converted, and functions 2298 introduced by a using-declaration are considered to be 2299 members of the class that uses them. 2300 2301 Since build_over_call ignores the ICS for the `this' 2302 parameter, we can just change the parm type. */ 2303 if (ctype && is_this) 2304 { 2305 parmtype = cp_build_qualified_type 2306 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 2307 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn))) 2308 { 2309 /* If the function has a ref-qualifier, the implicit 2310 object parameter has reference type. */ 2311 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn)); 2312 parmtype = cp_build_reference_type (parmtype, rv); 2313 /* The special handling of 'this' conversions in compare_ics 2314 does not apply if there is a ref-qualifier. */ 2315 is_this = false; 2316 } 2317 else 2318 { 2319 parmtype = build_pointer_type (parmtype); 2320 /* We don't use build_this here because we don't want to 2321 capture the object argument until we've chosen a 2322 non-static member function. */ 2323 arg = build_address (arg); 2324 argtype = lvalue_type (arg); 2325 } 2326 } 2327 2328 int lflags = conv_flags (i, len-skip, fn, arg, flags); 2329 2330 t = implicit_conversion (parmtype, argtype, arg, 2331 /*c_cast_p=*/false, lflags, complain); 2332 to_type = parmtype; 2333 } 2334 else 2335 { 2336 t = build_identity_conv (argtype, arg); 2337 t->ellipsis_p = true; 2338 to_type = argtype; 2339 } 2340 2341 if (t && is_this) 2342 t->this_p = true; 2343 2344 convs[i] = t; 2345 if (! t) 2346 { 2347 viable = 0; 2348 reason = arg_conversion_rejection (first_arg, i, argtype, to_type, 2349 EXPR_LOCATION (arg)); 2350 break; 2351 } 2352 2353 if (t->bad_p) 2354 { 2355 viable = -1; 2356 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type, 2357 EXPR_LOCATION (arg)); 2358 2359 } 2360 } 2361 2362 out: 2363 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2364 access_path, conversion_path, viable, reason, flags); 2365 } 2366 2367 /* Create an overload candidate for the conversion function FN which will 2368 be invoked for expression OBJ, producing a pointer-to-function which 2369 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2370 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2371 passed on to implicit_conversion. 2372 2373 Actually, we don't really care about FN; we care about the type it 2374 converts to. There may be multiple conversion functions that will 2375 convert to that type, and we rely on build_user_type_conversion_1 to 2376 choose the best one; so when we create our candidate, we record the type 2377 instead of the function. */ 2378 2379 static struct z_candidate * 2380 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2381 const vec<tree, va_gc> *arglist, 2382 tree access_path, tree conversion_path, 2383 tsubst_flags_t complain) 2384 { 2385 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2386 int i, len, viable, flags; 2387 tree parmlist, parmnode; 2388 conversion **convs; 2389 struct rejection_reason *reason; 2390 2391 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2392 parmlist = TREE_TYPE (parmlist); 2393 parmlist = TYPE_ARG_TYPES (parmlist); 2394 2395 len = vec_safe_length (arglist) + 1; 2396 convs = alloc_conversions (len); 2397 parmnode = parmlist; 2398 viable = 1; 2399 flags = LOOKUP_IMPLICIT; 2400 reason = NULL; 2401 2402 /* Don't bother looking up the same type twice. */ 2403 if (*candidates && (*candidates)->fn == totype) 2404 return NULL; 2405 2406 for (i = 0; i < len; ++i) 2407 { 2408 tree arg, argtype, convert_type = NULL_TREE; 2409 conversion *t; 2410 2411 if (i == 0) 2412 arg = obj; 2413 else 2414 arg = (*arglist)[i - 1]; 2415 argtype = lvalue_type (arg); 2416 2417 if (i == 0) 2418 { 2419 t = build_identity_conv (argtype, NULL_TREE); 2420 t = build_conv (ck_user, totype, t); 2421 /* Leave the 'cand' field null; we'll figure out the conversion in 2422 convert_like_real if this candidate is chosen. */ 2423 convert_type = totype; 2424 } 2425 else if (parmnode == void_list_node) 2426 break; 2427 else if (parmnode) 2428 { 2429 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2430 /*c_cast_p=*/false, flags, complain); 2431 convert_type = TREE_VALUE (parmnode); 2432 } 2433 else 2434 { 2435 t = build_identity_conv (argtype, arg); 2436 t->ellipsis_p = true; 2437 convert_type = argtype; 2438 } 2439 2440 convs[i] = t; 2441 if (! t) 2442 break; 2443 2444 if (t->bad_p) 2445 { 2446 viable = -1; 2447 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type, 2448 EXPR_LOCATION (arg)); 2449 } 2450 2451 if (i == 0) 2452 continue; 2453 2454 if (parmnode) 2455 parmnode = TREE_CHAIN (parmnode); 2456 } 2457 2458 if (i < len 2459 || ! sufficient_parms_p (parmnode)) 2460 { 2461 int remaining = remaining_arguments (parmnode); 2462 viable = 0; 2463 reason = arity_rejection (NULL_TREE, i + remaining, len); 2464 } 2465 2466 return add_candidate (candidates, totype, obj, arglist, len, convs, 2467 access_path, conversion_path, viable, reason, flags); 2468 } 2469 2470 static void 2471 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2472 tree type1, tree type2, tree *args, tree *argtypes, 2473 int flags, tsubst_flags_t complain) 2474 { 2475 conversion *t; 2476 conversion **convs; 2477 size_t num_convs; 2478 int viable = 1, i; 2479 tree types[2]; 2480 struct rejection_reason *reason = NULL; 2481 2482 types[0] = type1; 2483 types[1] = type2; 2484 2485 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2486 convs = alloc_conversions (num_convs); 2487 2488 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2489 conversion ops are allowed. We handle that here by just checking for 2490 boolean_type_node because other operators don't ask for it. COND_EXPR 2491 also does contextual conversion to bool for the first operand, but we 2492 handle that in build_conditional_expr, and type1 here is operand 2. */ 2493 if (type1 != boolean_type_node) 2494 flags |= LOOKUP_ONLYCONVERTING; 2495 2496 for (i = 0; i < 2; ++i) 2497 { 2498 if (! args[i]) 2499 break; 2500 2501 t = implicit_conversion (types[i], argtypes[i], args[i], 2502 /*c_cast_p=*/false, flags, complain); 2503 if (! t) 2504 { 2505 viable = 0; 2506 /* We need something for printing the candidate. */ 2507 t = build_identity_conv (types[i], NULL_TREE); 2508 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], 2509 types[i], EXPR_LOCATION (args[i])); 2510 } 2511 else if (t->bad_p) 2512 { 2513 viable = 0; 2514 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i], 2515 types[i], 2516 EXPR_LOCATION (args[i])); 2517 } 2518 convs[i] = t; 2519 } 2520 2521 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2522 if (args[2]) 2523 { 2524 convs[2] = convs[1]; 2525 convs[1] = convs[0]; 2526 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2527 /*c_cast_p=*/false, flags, 2528 complain); 2529 if (t) 2530 convs[0] = t; 2531 else 2532 { 2533 viable = 0; 2534 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2535 boolean_type_node, 2536 EXPR_LOCATION (args[2])); 2537 } 2538 } 2539 2540 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2541 num_convs, convs, 2542 /*access_path=*/NULL_TREE, 2543 /*conversion_path=*/NULL_TREE, 2544 viable, reason, flags); 2545 } 2546 2547 static bool 2548 is_complete (tree t) 2549 { 2550 return COMPLETE_TYPE_P (complete_type (t)); 2551 } 2552 2553 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2554 2555 static bool 2556 promoted_arithmetic_type_p (tree type) 2557 { 2558 /* [over.built] 2559 2560 In this section, the term promoted integral type is used to refer 2561 to those integral types which are preserved by integral promotion 2562 (including e.g. int and long but excluding e.g. char). 2563 Similarly, the term promoted arithmetic type refers to promoted 2564 integral types plus floating types. */ 2565 return ((CP_INTEGRAL_TYPE_P (type) 2566 && same_type_p (type_promotes_to (type), type)) 2567 || TREE_CODE (type) == REAL_TYPE); 2568 } 2569 2570 /* Create any builtin operator overload candidates for the operator in 2571 question given the converted operand types TYPE1 and TYPE2. The other 2572 args are passed through from add_builtin_candidates to 2573 build_builtin_candidate. 2574 2575 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2576 If CODE is requires candidates operands of the same type of the kind 2577 of which TYPE1 and TYPE2 are, we add both candidates 2578 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2579 2580 static void 2581 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2582 enum tree_code code2, tree fnname, tree type1, 2583 tree type2, tree *args, tree *argtypes, int flags, 2584 tsubst_flags_t complain) 2585 { 2586 switch (code) 2587 { 2588 case POSTINCREMENT_EXPR: 2589 case POSTDECREMENT_EXPR: 2590 args[1] = integer_zero_node; 2591 type2 = integer_type_node; 2592 break; 2593 default: 2594 break; 2595 } 2596 2597 switch (code) 2598 { 2599 2600 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2601 and VQ is either volatile or empty, there exist candidate operator 2602 functions of the form 2603 VQ T& operator++(VQ T&); 2604 T operator++(VQ T&, int); 2605 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2606 type other than bool, and VQ is either volatile or empty, there exist 2607 candidate operator functions of the form 2608 VQ T& operator--(VQ T&); 2609 T operator--(VQ T&, int); 2610 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2611 complete object type, and VQ is either volatile or empty, there exist 2612 candidate operator functions of the form 2613 T*VQ& operator++(T*VQ&); 2614 T*VQ& operator--(T*VQ&); 2615 T* operator++(T*VQ&, int); 2616 T* operator--(T*VQ&, int); */ 2617 2618 case POSTDECREMENT_EXPR: 2619 case PREDECREMENT_EXPR: 2620 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2621 return; 2622 /* FALLTHRU */ 2623 case POSTINCREMENT_EXPR: 2624 case PREINCREMENT_EXPR: 2625 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2626 { 2627 type1 = build_reference_type (type1); 2628 break; 2629 } 2630 return; 2631 2632 /* 7 For every cv-qualified or cv-unqualified object type T, there 2633 exist candidate operator functions of the form 2634 2635 T& operator*(T*); 2636 2637 8 For every function type T, there exist candidate operator functions of 2638 the form 2639 T& operator*(T*); */ 2640 2641 case INDIRECT_REF: 2642 if (TYPE_PTR_P (type1) 2643 && (TYPE_PTROB_P (type1) 2644 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2645 break; 2646 return; 2647 2648 /* 9 For every type T, there exist candidate operator functions of the form 2649 T* operator+(T*); 2650 2651 10For every promoted arithmetic type T, there exist candidate operator 2652 functions of the form 2653 T operator+(T); 2654 T operator-(T); */ 2655 2656 case UNARY_PLUS_EXPR: /* unary + */ 2657 if (TYPE_PTR_P (type1)) 2658 break; 2659 /* FALLTHRU */ 2660 case NEGATE_EXPR: 2661 if (ARITHMETIC_TYPE_P (type1)) 2662 break; 2663 return; 2664 2665 /* 11For every promoted integral type T, there exist candidate operator 2666 functions of the form 2667 T operator~(T); */ 2668 2669 case BIT_NOT_EXPR: 2670 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2671 break; 2672 return; 2673 2674 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2675 is the same type as C2 or is a derived class of C2, T is a complete 2676 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2677 there exist candidate operator functions of the form 2678 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2679 where CV12 is the union of CV1 and CV2. */ 2680 2681 case MEMBER_REF: 2682 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2)) 2683 { 2684 tree c1 = TREE_TYPE (type1); 2685 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2686 2687 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2688 && (TYPE_PTRMEMFUNC_P (type2) 2689 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2690 break; 2691 } 2692 return; 2693 2694 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2695 didate operator functions of the form 2696 LR operator*(L, R); 2697 LR operator/(L, R); 2698 LR operator+(L, R); 2699 LR operator-(L, R); 2700 bool operator<(L, R); 2701 bool operator>(L, R); 2702 bool operator<=(L, R); 2703 bool operator>=(L, R); 2704 bool operator==(L, R); 2705 bool operator!=(L, R); 2706 where LR is the result of the usual arithmetic conversions between 2707 types L and R. 2708 2709 14For every pair of types T and I, where T is a cv-qualified or cv- 2710 unqualified complete object type and I is a promoted integral type, 2711 there exist candidate operator functions of the form 2712 T* operator+(T*, I); 2713 T& operator[](T*, I); 2714 T* operator-(T*, I); 2715 T* operator+(I, T*); 2716 T& operator[](I, T*); 2717 2718 15For every T, where T is a pointer to complete object type, there exist 2719 candidate operator functions of the form112) 2720 ptrdiff_t operator-(T, T); 2721 2722 16For every pointer or enumeration type T, there exist candidate operator 2723 functions of the form 2724 bool operator<(T, T); 2725 bool operator>(T, T); 2726 bool operator<=(T, T); 2727 bool operator>=(T, T); 2728 bool operator==(T, T); 2729 bool operator!=(T, T); 2730 2731 17For every pointer to member type T, there exist candidate operator 2732 functions of the form 2733 bool operator==(T, T); 2734 bool operator!=(T, T); */ 2735 2736 case MINUS_EXPR: 2737 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2738 break; 2739 if (TYPE_PTROB_P (type1) 2740 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2741 { 2742 type2 = ptrdiff_type_node; 2743 break; 2744 } 2745 /* FALLTHRU */ 2746 case MULT_EXPR: 2747 case TRUNC_DIV_EXPR: 2748 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2749 break; 2750 return; 2751 2752 case EQ_EXPR: 2753 case NE_EXPR: 2754 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2755 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))) 2756 break; 2757 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1])) 2758 { 2759 type2 = type1; 2760 break; 2761 } 2762 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0])) 2763 { 2764 type1 = type2; 2765 break; 2766 } 2767 /* Fall through. */ 2768 case LT_EXPR: 2769 case GT_EXPR: 2770 case LE_EXPR: 2771 case GE_EXPR: 2772 case MAX_EXPR: 2773 case MIN_EXPR: 2774 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2775 break; 2776 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2777 break; 2778 if (TREE_CODE (type1) == ENUMERAL_TYPE 2779 && TREE_CODE (type2) == ENUMERAL_TYPE) 2780 break; 2781 if (TYPE_PTR_P (type1) 2782 && null_ptr_cst_p (args[1])) 2783 { 2784 type2 = type1; 2785 break; 2786 } 2787 if (null_ptr_cst_p (args[0]) 2788 && TYPE_PTR_P (type2)) 2789 { 2790 type1 = type2; 2791 break; 2792 } 2793 return; 2794 2795 case PLUS_EXPR: 2796 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2797 break; 2798 /* FALLTHRU */ 2799 case ARRAY_REF: 2800 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2801 { 2802 type1 = ptrdiff_type_node; 2803 break; 2804 } 2805 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2806 { 2807 type2 = ptrdiff_type_node; 2808 break; 2809 } 2810 return; 2811 2812 /* 18For every pair of promoted integral types L and R, there exist candi- 2813 date operator functions of the form 2814 LR operator%(L, R); 2815 LR operator&(L, R); 2816 LR operator^(L, R); 2817 LR operator|(L, R); 2818 L operator<<(L, R); 2819 L operator>>(L, R); 2820 where LR is the result of the usual arithmetic conversions between 2821 types L and R. */ 2822 2823 case TRUNC_MOD_EXPR: 2824 case BIT_AND_EXPR: 2825 case BIT_IOR_EXPR: 2826 case BIT_XOR_EXPR: 2827 case LSHIFT_EXPR: 2828 case RSHIFT_EXPR: 2829 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2830 break; 2831 return; 2832 2833 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2834 type, VQ is either volatile or empty, and R is a promoted arithmetic 2835 type, there exist candidate operator functions of the form 2836 VQ L& operator=(VQ L&, R); 2837 VQ L& operator*=(VQ L&, R); 2838 VQ L& operator/=(VQ L&, R); 2839 VQ L& operator+=(VQ L&, R); 2840 VQ L& operator-=(VQ L&, R); 2841 2842 20For every pair T, VQ), where T is any type and VQ is either volatile 2843 or empty, there exist candidate operator functions of the form 2844 T*VQ& operator=(T*VQ&, T*); 2845 2846 21For every pair T, VQ), where T is a pointer to member type and VQ is 2847 either volatile or empty, there exist candidate operator functions of 2848 the form 2849 VQ T& operator=(VQ T&, T); 2850 2851 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2852 unqualified complete object type, VQ is either volatile or empty, and 2853 I is a promoted integral type, there exist candidate operator func- 2854 tions of the form 2855 T*VQ& operator+=(T*VQ&, I); 2856 T*VQ& operator-=(T*VQ&, I); 2857 2858 23For every triple L, VQ, R), where L is an integral or enumeration 2859 type, VQ is either volatile or empty, and R is a promoted integral 2860 type, there exist candidate operator functions of the form 2861 2862 VQ L& operator%=(VQ L&, R); 2863 VQ L& operator<<=(VQ L&, R); 2864 VQ L& operator>>=(VQ L&, R); 2865 VQ L& operator&=(VQ L&, R); 2866 VQ L& operator^=(VQ L&, R); 2867 VQ L& operator|=(VQ L&, R); */ 2868 2869 case MODIFY_EXPR: 2870 switch (code2) 2871 { 2872 case PLUS_EXPR: 2873 case MINUS_EXPR: 2874 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2875 { 2876 type2 = ptrdiff_type_node; 2877 break; 2878 } 2879 /* FALLTHRU */ 2880 case MULT_EXPR: 2881 case TRUNC_DIV_EXPR: 2882 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2883 break; 2884 return; 2885 2886 case TRUNC_MOD_EXPR: 2887 case BIT_AND_EXPR: 2888 case BIT_IOR_EXPR: 2889 case BIT_XOR_EXPR: 2890 case LSHIFT_EXPR: 2891 case RSHIFT_EXPR: 2892 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2893 break; 2894 return; 2895 2896 case NOP_EXPR: 2897 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2898 break; 2899 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2900 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2901 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2902 || ((TYPE_PTRMEMFUNC_P (type1) 2903 || TYPE_PTR_P (type1)) 2904 && null_ptr_cst_p (args[1]))) 2905 { 2906 type2 = type1; 2907 break; 2908 } 2909 return; 2910 2911 default: 2912 gcc_unreachable (); 2913 } 2914 type1 = build_reference_type (type1); 2915 break; 2916 2917 case COND_EXPR: 2918 /* [over.built] 2919 2920 For every pair of promoted arithmetic types L and R, there 2921 exist candidate operator functions of the form 2922 2923 LR operator?(bool, L, R); 2924 2925 where LR is the result of the usual arithmetic conversions 2926 between types L and R. 2927 2928 For every type T, where T is a pointer or pointer-to-member 2929 type, there exist candidate operator functions of the form T 2930 operator?(bool, T, T); */ 2931 2932 if (promoted_arithmetic_type_p (type1) 2933 && promoted_arithmetic_type_p (type2)) 2934 /* That's OK. */ 2935 break; 2936 2937 /* Otherwise, the types should be pointers. */ 2938 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2)) 2939 return; 2940 2941 /* We don't check that the two types are the same; the logic 2942 below will actually create two candidates; one in which both 2943 parameter types are TYPE1, and one in which both parameter 2944 types are TYPE2. */ 2945 break; 2946 2947 case REALPART_EXPR: 2948 case IMAGPART_EXPR: 2949 if (ARITHMETIC_TYPE_P (type1)) 2950 break; 2951 return; 2952 2953 default: 2954 gcc_unreachable (); 2955 } 2956 2957 /* Make sure we don't create builtin candidates with dependent types. */ 2958 bool u1 = uses_template_parms (type1); 2959 bool u2 = type2 ? uses_template_parms (type2) : false; 2960 if (u1 || u2) 2961 { 2962 /* Try to recover if one of the types is non-dependent. But if 2963 there's only one type, there's nothing we can do. */ 2964 if (!type2) 2965 return; 2966 /* And we lose if both are dependent. */ 2967 if (u1 && u2) 2968 return; 2969 /* Or if they have different forms. */ 2970 if (TREE_CODE (type1) != TREE_CODE (type2)) 2971 return; 2972 2973 if (u1 && !u2) 2974 type1 = type2; 2975 else if (u2 && !u1) 2976 type2 = type1; 2977 } 2978 2979 /* If we're dealing with two pointer types or two enumeral types, 2980 we need candidates for both of them. */ 2981 if (type2 && !same_type_p (type1, type2) 2982 && TREE_CODE (type1) == TREE_CODE (type2) 2983 && (TYPE_REF_P (type1) 2984 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2985 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2986 || TYPE_PTRMEMFUNC_P (type1) 2987 || MAYBE_CLASS_TYPE_P (type1) 2988 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2989 { 2990 if (TYPE_PTR_OR_PTRMEM_P (type1)) 2991 { 2992 tree cptype = composite_pointer_type (type1, type2, 2993 error_mark_node, 2994 error_mark_node, 2995 CPO_CONVERSION, 2996 tf_none); 2997 if (cptype != error_mark_node) 2998 { 2999 build_builtin_candidate 3000 (candidates, fnname, cptype, cptype, args, argtypes, 3001 flags, complain); 3002 return; 3003 } 3004 } 3005 3006 build_builtin_candidate 3007 (candidates, fnname, type1, type1, args, argtypes, flags, complain); 3008 build_builtin_candidate 3009 (candidates, fnname, type2, type2, args, argtypes, flags, complain); 3010 return; 3011 } 3012 3013 build_builtin_candidate 3014 (candidates, fnname, type1, type2, args, argtypes, flags, complain); 3015 } 3016 3017 tree 3018 type_decays_to (tree type) 3019 { 3020 if (TREE_CODE (type) == ARRAY_TYPE) 3021 return build_pointer_type (TREE_TYPE (type)); 3022 if (TREE_CODE (type) == FUNCTION_TYPE) 3023 return build_pointer_type (type); 3024 return type; 3025 } 3026 3027 /* There are three conditions of builtin candidates: 3028 3029 1) bool-taking candidates. These are the same regardless of the input. 3030 2) pointer-pair taking candidates. These are generated for each type 3031 one of the input types converts to. 3032 3) arithmetic candidates. According to the standard, we should generate 3033 all of these, but I'm trying not to... 3034 3035 Here we generate a superset of the possible candidates for this particular 3036 case. That is a subset of the full set the standard defines, plus some 3037 other cases which the standard disallows. add_builtin_candidate will 3038 filter out the invalid set. */ 3039 3040 static void 3041 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 3042 enum tree_code code2, tree fnname, tree *args, 3043 int flags, tsubst_flags_t complain) 3044 { 3045 int ref1, i; 3046 int enum_p = 0; 3047 tree type, argtypes[3], t; 3048 /* TYPES[i] is the set of possible builtin-operator parameter types 3049 we will consider for the Ith argument. */ 3050 vec<tree, va_gc> *types[2]; 3051 unsigned ix; 3052 3053 for (i = 0; i < 3; ++i) 3054 { 3055 if (args[i]) 3056 argtypes[i] = unlowered_expr_type (args[i]); 3057 else 3058 argtypes[i] = NULL_TREE; 3059 } 3060 3061 switch (code) 3062 { 3063 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 3064 and VQ is either volatile or empty, there exist candidate operator 3065 functions of the form 3066 VQ T& operator++(VQ T&); */ 3067 3068 case POSTINCREMENT_EXPR: 3069 case PREINCREMENT_EXPR: 3070 case POSTDECREMENT_EXPR: 3071 case PREDECREMENT_EXPR: 3072 case MODIFY_EXPR: 3073 ref1 = 1; 3074 break; 3075 3076 /* 24There also exist candidate operator functions of the form 3077 bool operator!(bool); 3078 bool operator&&(bool, bool); 3079 bool operator||(bool, bool); */ 3080 3081 case TRUTH_NOT_EXPR: 3082 build_builtin_candidate 3083 (candidates, fnname, boolean_type_node, 3084 NULL_TREE, args, argtypes, flags, complain); 3085 return; 3086 3087 case TRUTH_ORIF_EXPR: 3088 case TRUTH_ANDIF_EXPR: 3089 build_builtin_candidate 3090 (candidates, fnname, boolean_type_node, 3091 boolean_type_node, args, argtypes, flags, complain); 3092 return; 3093 3094 case ADDR_EXPR: 3095 case COMPOUND_EXPR: 3096 case COMPONENT_REF: 3097 return; 3098 3099 case COND_EXPR: 3100 case EQ_EXPR: 3101 case NE_EXPR: 3102 case LT_EXPR: 3103 case LE_EXPR: 3104 case GT_EXPR: 3105 case GE_EXPR: 3106 enum_p = 1; 3107 /* Fall through. */ 3108 3109 default: 3110 ref1 = 0; 3111 } 3112 3113 types[0] = make_tree_vector (); 3114 types[1] = make_tree_vector (); 3115 3116 for (i = 0; i < 2; ++i) 3117 { 3118 if (! args[i]) 3119 ; 3120 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 3121 { 3122 tree convs; 3123 3124 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 3125 return; 3126 3127 convs = lookup_conversions (argtypes[i]); 3128 3129 if (code == COND_EXPR) 3130 { 3131 if (lvalue_p (args[i])) 3132 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3133 3134 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i])); 3135 } 3136 3137 else if (! convs) 3138 return; 3139 3140 for (; convs; convs = TREE_CHAIN (convs)) 3141 { 3142 type = TREE_TYPE (convs); 3143 3144 if (i == 0 && ref1 3145 && (!TYPE_REF_P (type) 3146 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 3147 continue; 3148 3149 if (code == COND_EXPR && TYPE_REF_P (type)) 3150 vec_safe_push (types[i], type); 3151 3152 type = non_reference (type); 3153 if (i != 0 || ! ref1) 3154 { 3155 type = cv_unqualified (type_decays_to (type)); 3156 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 3157 vec_safe_push (types[i], type); 3158 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3159 type = type_promotes_to (type); 3160 } 3161 3162 if (! vec_member (type, types[i])) 3163 vec_safe_push (types[i], type); 3164 } 3165 } 3166 else 3167 { 3168 if (code == COND_EXPR && lvalue_p (args[i])) 3169 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3170 type = non_reference (argtypes[i]); 3171 if (i != 0 || ! ref1) 3172 { 3173 type = cv_unqualified (type_decays_to (type)); 3174 if (enum_p && UNSCOPED_ENUM_P (type)) 3175 vec_safe_push (types[i], type); 3176 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3177 type = type_promotes_to (type); 3178 } 3179 vec_safe_push (types[i], type); 3180 } 3181 } 3182 3183 /* Run through the possible parameter types of both arguments, 3184 creating candidates with those parameter types. */ 3185 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t) 3186 { 3187 unsigned jx; 3188 tree u; 3189 3190 if (!types[1]->is_empty ()) 3191 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u) 3192 add_builtin_candidate 3193 (candidates, code, code2, fnname, t, 3194 u, args, argtypes, flags, complain); 3195 else 3196 add_builtin_candidate 3197 (candidates, code, code2, fnname, t, 3198 NULL_TREE, args, argtypes, flags, complain); 3199 } 3200 3201 release_tree_vector (types[0]); 3202 release_tree_vector (types[1]); 3203 } 3204 3205 3206 /* If TMPL can be successfully instantiated as indicated by 3207 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 3208 3209 TMPL is the template. EXPLICIT_TARGS are any explicit template 3210 arguments. ARGLIST is the arguments provided at the call-site. 3211 This does not change ARGLIST. The RETURN_TYPE is the desired type 3212 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 3213 as for add_function_candidate. If an OBJ is supplied, FLAGS and 3214 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 3215 3216 static struct z_candidate* 3217 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 3218 tree ctype, tree explicit_targs, tree first_arg, 3219 const vec<tree, va_gc> *arglist, tree return_type, 3220 tree access_path, tree conversion_path, 3221 int flags, tree obj, unification_kind_t strict, 3222 tsubst_flags_t complain) 3223 { 3224 int ntparms = DECL_NTPARMS (tmpl); 3225 tree targs = make_tree_vec (ntparms); 3226 unsigned int len = vec_safe_length (arglist); 3227 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 3228 unsigned int skip_without_in_chrg = 0; 3229 tree first_arg_without_in_chrg = first_arg; 3230 tree *args_without_in_chrg; 3231 unsigned int nargs_without_in_chrg; 3232 unsigned int ia, ix; 3233 tree arg; 3234 struct z_candidate *cand; 3235 tree fn; 3236 struct rejection_reason *reason = NULL; 3237 int errs; 3238 conversion **convs = NULL; 3239 3240 /* We don't do deduction on the in-charge parameter, the VTT 3241 parameter or 'this'. */ 3242 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 3243 { 3244 if (first_arg_without_in_chrg != NULL_TREE) 3245 first_arg_without_in_chrg = NULL_TREE; 3246 else if (return_type && strict == DEDUCE_CALL) 3247 /* We're deducing for a call to the result of a template conversion 3248 function, so the args don't contain 'this'; leave them alone. */; 3249 else 3250 ++skip_without_in_chrg; 3251 } 3252 3253 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 3254 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 3255 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 3256 { 3257 if (first_arg_without_in_chrg != NULL_TREE) 3258 first_arg_without_in_chrg = NULL_TREE; 3259 else 3260 ++skip_without_in_chrg; 3261 } 3262 3263 if (len < skip_without_in_chrg) 3264 return NULL; 3265 3266 if (DECL_CONSTRUCTOR_P (tmpl) && nargs == 2 3267 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (first_arg), 3268 TREE_TYPE ((*arglist)[0]))) 3269 { 3270 /* 12.8/6 says, "A declaration of a constructor for a class X is 3271 ill-formed if its first parameter is of type (optionally cv-qualified) 3272 X and either there are no other parameters or else all other 3273 parameters have default arguments. A member function template is never 3274 instantiated to produce such a constructor signature." 3275 3276 So if we're trying to copy an object of the containing class, don't 3277 consider a template constructor that has a first parameter type that 3278 is just a template parameter, as we would deduce a signature that we 3279 would then reject in the code below. */ 3280 if (tree firstparm = FUNCTION_FIRST_USER_PARMTYPE (tmpl)) 3281 { 3282 firstparm = TREE_VALUE (firstparm); 3283 if (PACK_EXPANSION_P (firstparm)) 3284 firstparm = PACK_EXPANSION_PATTERN (firstparm); 3285 if (TREE_CODE (firstparm) == TEMPLATE_TYPE_PARM) 3286 { 3287 gcc_assert (!explicit_targs); 3288 reason = invalid_copy_with_fn_template_rejection (); 3289 goto fail; 3290 } 3291 } 3292 } 3293 3294 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 3295 + (len - skip_without_in_chrg)); 3296 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 3297 ia = 0; 3298 if (first_arg_without_in_chrg != NULL_TREE) 3299 { 3300 args_without_in_chrg[ia] = first_arg_without_in_chrg; 3301 ++ia; 3302 } 3303 for (ix = skip_without_in_chrg; 3304 vec_safe_iterate (arglist, ix, &arg); 3305 ++ix) 3306 { 3307 args_without_in_chrg[ia] = arg; 3308 ++ia; 3309 } 3310 gcc_assert (ia == nargs_without_in_chrg); 3311 3312 errs = errorcount+sorrycount; 3313 if (!obj) 3314 convs = alloc_conversions (nargs); 3315 fn = fn_type_unification (tmpl, explicit_targs, targs, 3316 args_without_in_chrg, 3317 nargs_without_in_chrg, 3318 return_type, strict, flags, convs, 3319 false, complain & tf_decltype); 3320 3321 if (fn == error_mark_node) 3322 { 3323 /* Don't repeat unification later if it already resulted in errors. */ 3324 if (errorcount+sorrycount == errs) 3325 reason = template_unification_rejection (tmpl, explicit_targs, 3326 targs, args_without_in_chrg, 3327 nargs_without_in_chrg, 3328 return_type, strict, flags); 3329 else 3330 reason = template_unification_error_rejection (); 3331 goto fail; 3332 } 3333 3334 /* Now the explicit specifier might have been deduced; check if this 3335 declaration is explicit. If it is and we're ignoring non-converting 3336 constructors, don't add this function to the set of candidates. */ 3337 if ((flags & LOOKUP_ONLYCONVERTING) && DECL_NONCONVERTING_P (fn)) 3338 return NULL; 3339 3340 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 3341 { 3342 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 3343 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 3344 ctype)) 3345 { 3346 /* We're trying to produce a constructor with a prohibited signature, 3347 as discussed above; handle here any cases we didn't catch then, 3348 such as X(X<T>). */ 3349 reason = invalid_copy_with_fn_template_rejection (); 3350 goto fail; 3351 } 3352 } 3353 3354 if (obj != NULL_TREE) 3355 /* Aha, this is a conversion function. */ 3356 cand = add_conv_candidate (candidates, fn, obj, arglist, 3357 access_path, conversion_path, complain); 3358 else 3359 cand = add_function_candidate (candidates, fn, ctype, 3360 first_arg, arglist, access_path, 3361 conversion_path, flags, convs, complain); 3362 if (DECL_TI_TEMPLATE (fn) != tmpl) 3363 /* This situation can occur if a member template of a template 3364 class is specialized. Then, instantiate_template might return 3365 an instantiation of the specialization, in which case the 3366 DECL_TI_TEMPLATE field will point at the original 3367 specialization. For example: 3368 3369 template <class T> struct S { template <class U> void f(U); 3370 template <> void f(int) {}; }; 3371 S<double> sd; 3372 sd.f(3); 3373 3374 Here, TMPL will be template <class U> S<double>::f(U). 3375 And, instantiate template will give us the specialization 3376 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 3377 for this will point at template <class T> template <> S<T>::f(int), 3378 so that we can find the definition. For the purposes of 3379 overload resolution, however, we want the original TMPL. */ 3380 cand->template_decl = build_template_info (tmpl, targs); 3381 else 3382 cand->template_decl = DECL_TEMPLATE_INFO (fn); 3383 cand->explicit_targs = explicit_targs; 3384 3385 return cand; 3386 fail: 3387 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 3388 access_path, conversion_path, 0, reason, flags); 3389 } 3390 3391 3392 static struct z_candidate * 3393 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 3394 tree explicit_targs, tree first_arg, 3395 const vec<tree, va_gc> *arglist, tree return_type, 3396 tree access_path, tree conversion_path, int flags, 3397 unification_kind_t strict, tsubst_flags_t complain) 3398 { 3399 return 3400 add_template_candidate_real (candidates, tmpl, ctype, 3401 explicit_targs, first_arg, arglist, 3402 return_type, access_path, conversion_path, 3403 flags, NULL_TREE, strict, complain); 3404 } 3405 3406 /* Create an overload candidate for the conversion function template TMPL, 3407 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a 3408 pointer-to-function which will in turn be called with the argument list 3409 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 3410 passed on to implicit_conversion. */ 3411 3412 static struct z_candidate * 3413 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3414 tree obj, 3415 const vec<tree, va_gc> *arglist, 3416 tree return_type, tree access_path, 3417 tree conversion_path, tsubst_flags_t complain) 3418 { 3419 /* Making this work broke PR 71117 and 85118, so until the committee resolves 3420 core issue 2189, let's disable this candidate if there are any call 3421 operators. */ 3422 if (*candidates) 3423 return NULL; 3424 3425 return 3426 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3427 NULL_TREE, arglist, return_type, access_path, 3428 conversion_path, 0, obj, DEDUCE_CALL, 3429 complain); 3430 } 3431 3432 /* The CANDS are the set of candidates that were considered for 3433 overload resolution. Return the set of viable candidates, or CANDS 3434 if none are viable. If any of the candidates were viable, set 3435 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3436 considered viable only if it is strictly viable. */ 3437 3438 static struct z_candidate* 3439 splice_viable (struct z_candidate *cands, 3440 bool strict_p, 3441 bool *any_viable_p) 3442 { 3443 struct z_candidate *viable; 3444 struct z_candidate **last_viable; 3445 struct z_candidate **cand; 3446 bool found_strictly_viable = false; 3447 3448 /* Be strict inside templates, since build_over_call won't actually 3449 do the conversions to get pedwarns. */ 3450 if (processing_template_decl) 3451 strict_p = true; 3452 3453 viable = NULL; 3454 last_viable = &viable; 3455 *any_viable_p = false; 3456 3457 cand = &cands; 3458 while (*cand) 3459 { 3460 struct z_candidate *c = *cand; 3461 if (!strict_p 3462 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL)) 3463 { 3464 /* Be strict in the presence of a viable candidate. Also if 3465 there are template candidates, so that we get deduction errors 3466 for them instead of silently preferring a bad conversion. */ 3467 strict_p = true; 3468 if (viable && !found_strictly_viable) 3469 { 3470 /* Put any spliced near matches back onto the main list so 3471 that we see them if there is no strict match. */ 3472 *any_viable_p = false; 3473 *last_viable = cands; 3474 cands = viable; 3475 viable = NULL; 3476 last_viable = &viable; 3477 } 3478 } 3479 3480 if (strict_p ? c->viable == 1 : c->viable) 3481 { 3482 *last_viable = c; 3483 *cand = c->next; 3484 c->next = NULL; 3485 last_viable = &c->next; 3486 *any_viable_p = true; 3487 if (c->viable == 1) 3488 found_strictly_viable = true; 3489 } 3490 else 3491 cand = &c->next; 3492 } 3493 3494 return viable ? viable : cands; 3495 } 3496 3497 static bool 3498 any_strictly_viable (struct z_candidate *cands) 3499 { 3500 for (; cands; cands = cands->next) 3501 if (cands->viable == 1) 3502 return true; 3503 return false; 3504 } 3505 3506 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3507 words, it is about to become the "this" pointer for a member 3508 function call. Take the address of the object. */ 3509 3510 static tree 3511 build_this (tree obj) 3512 { 3513 /* In a template, we are only concerned about the type of the 3514 expression, so we can take a shortcut. */ 3515 if (processing_template_decl) 3516 return build_address (obj); 3517 3518 return cp_build_addr_expr (obj, tf_warning_or_error); 3519 } 3520 3521 /* Returns true iff functions are equivalent. Equivalent functions are 3522 not '==' only if one is a function-local extern function or if 3523 both are extern "C". */ 3524 3525 static inline int 3526 equal_functions (tree fn1, tree fn2) 3527 { 3528 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3529 return 0; 3530 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3531 return fn1 == fn2; 3532 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3533 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3534 return decls_match (fn1, fn2); 3535 return fn1 == fn2; 3536 } 3537 3538 /* Print information about a candidate FN being rejected due to INFO. */ 3539 3540 static void 3541 print_conversion_rejection (location_t loc, struct conversion_info *info, 3542 tree fn) 3543 { 3544 tree from = info->from; 3545 if (!TYPE_P (from)) 3546 from = lvalue_type (from); 3547 if (info->n_arg == -1) 3548 { 3549 /* Conversion of implicit `this' argument failed. */ 3550 if (!TYPE_P (info->from)) 3551 /* A bad conversion for 'this' must be discarding cv-quals. */ 3552 inform (loc, " passing %qT as %<this%> " 3553 "argument discards qualifiers", 3554 from); 3555 else 3556 inform (loc, " no known conversion for implicit " 3557 "%<this%> parameter from %qH to %qI", 3558 from, info->to_type); 3559 } 3560 else if (!TYPE_P (info->from)) 3561 { 3562 if (info->n_arg >= 0) 3563 inform (loc, " conversion of argument %d would be ill-formed:", 3564 info->n_arg + 1); 3565 perform_implicit_conversion (info->to_type, info->from, 3566 tf_warning_or_error); 3567 } 3568 else if (info->n_arg == -2) 3569 /* Conversion of conversion function return value failed. */ 3570 inform (loc, " no known conversion from %qH to %qI", 3571 from, info->to_type); 3572 else 3573 { 3574 if (TREE_CODE (fn) == FUNCTION_DECL) 3575 loc = get_fndecl_argument_location (fn, info->n_arg); 3576 inform (loc, " no known conversion for argument %d from %qH to %qI", 3577 info->n_arg + 1, from, info->to_type); 3578 } 3579 } 3580 3581 /* Print information about a candidate with WANT parameters and we found 3582 HAVE. */ 3583 3584 static void 3585 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3586 { 3587 inform_n (loc, want, 3588 " candidate expects %d argument, %d provided", 3589 " candidate expects %d arguments, %d provided", 3590 want, have); 3591 } 3592 3593 /* Print information about one overload candidate CANDIDATE. MSGSTR 3594 is the text to print before the candidate itself. 3595 3596 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3597 to have been run through gettext by the caller. This wart makes 3598 life simpler in print_z_candidates and for the translators. */ 3599 3600 static void 3601 print_z_candidate (location_t loc, const char *msgstr, 3602 struct z_candidate *candidate) 3603 { 3604 const char *msg = (msgstr == NULL 3605 ? "" 3606 : ACONCAT ((msgstr, " ", NULL))); 3607 tree fn = candidate->fn; 3608 if (flag_new_inheriting_ctors) 3609 fn = strip_inheriting_ctors (fn); 3610 location_t cloc = location_of (fn); 3611 3612 if (identifier_p (fn)) 3613 { 3614 cloc = loc; 3615 if (candidate->num_convs == 3) 3616 inform (cloc, "%s%<%D(%T, %T, %T)%> <built-in>", msg, fn, 3617 candidate->convs[0]->type, 3618 candidate->convs[1]->type, 3619 candidate->convs[2]->type); 3620 else if (candidate->num_convs == 2) 3621 inform (cloc, "%s%<%D(%T, %T)%> <built-in>", msg, fn, 3622 candidate->convs[0]->type, 3623 candidate->convs[1]->type); 3624 else 3625 inform (cloc, "%s%<%D(%T)%> <built-in>", msg, fn, 3626 candidate->convs[0]->type); 3627 } 3628 else if (TYPE_P (fn)) 3629 inform (cloc, "%s%qT <conversion>", msg, fn); 3630 else if (candidate->viable == -1) 3631 inform (cloc, "%s%#qD <near match>", msg, fn); 3632 else if (DECL_DELETED_FN (fn)) 3633 inform (cloc, "%s%#qD <deleted>", msg, fn); 3634 else 3635 inform (cloc, "%s%#qD", msg, fn); 3636 if (fn != candidate->fn) 3637 { 3638 cloc = location_of (candidate->fn); 3639 inform (cloc, " inherited here"); 3640 } 3641 /* Give the user some information about why this candidate failed. */ 3642 if (candidate->reason != NULL) 3643 { 3644 struct rejection_reason *r = candidate->reason; 3645 3646 switch (r->code) 3647 { 3648 case rr_arity: 3649 print_arity_information (cloc, r->u.arity.actual, 3650 r->u.arity.expected); 3651 break; 3652 case rr_arg_conversion: 3653 print_conversion_rejection (cloc, &r->u.conversion, fn); 3654 break; 3655 case rr_bad_arg_conversion: 3656 print_conversion_rejection (cloc, &r->u.bad_conversion, fn); 3657 break; 3658 case rr_explicit_conversion: 3659 inform (cloc, " return type %qT of explicit conversion function " 3660 "cannot be converted to %qT with a qualification " 3661 "conversion", r->u.conversion.from, 3662 r->u.conversion.to_type); 3663 break; 3664 case rr_template_conversion: 3665 inform (cloc, " conversion from return type %qT of template " 3666 "conversion function specialization to %qT is not an " 3667 "exact match", r->u.conversion.from, 3668 r->u.conversion.to_type); 3669 break; 3670 case rr_template_unification: 3671 /* We use template_unification_error_rejection if unification caused 3672 actual non-SFINAE errors, in which case we don't need to repeat 3673 them here. */ 3674 if (r->u.template_unification.tmpl == NULL_TREE) 3675 { 3676 inform (cloc, " substitution of deduced template arguments " 3677 "resulted in errors seen above"); 3678 break; 3679 } 3680 /* Re-run template unification with diagnostics. */ 3681 inform (cloc, " template argument deduction/substitution failed:"); 3682 fn_type_unification (r->u.template_unification.tmpl, 3683 r->u.template_unification.explicit_targs, 3684 (make_tree_vec 3685 (r->u.template_unification.num_targs)), 3686 r->u.template_unification.args, 3687 r->u.template_unification.nargs, 3688 r->u.template_unification.return_type, 3689 r->u.template_unification.strict, 3690 r->u.template_unification.flags, 3691 NULL, true, false); 3692 break; 3693 case rr_invalid_copy: 3694 inform (cloc, 3695 " a constructor taking a single argument of its own " 3696 "class type is invalid"); 3697 break; 3698 case rr_constraint_failure: 3699 { 3700 tree tmpl = r->u.template_instantiation.tmpl; 3701 tree args = r->u.template_instantiation.targs; 3702 diagnose_constraints (cloc, tmpl, args); 3703 } 3704 break; 3705 case rr_inherited_ctor: 3706 inform (cloc, " an inherited constructor is not a candidate for " 3707 "initialization from an expression of the same or derived " 3708 "type"); 3709 break; 3710 case rr_none: 3711 default: 3712 /* This candidate didn't have any issues or we failed to 3713 handle a particular code. Either way... */ 3714 gcc_unreachable (); 3715 } 3716 } 3717 } 3718 3719 static void 3720 print_z_candidates (location_t loc, struct z_candidate *candidates) 3721 { 3722 struct z_candidate *cand1; 3723 struct z_candidate **cand2; 3724 3725 if (!candidates) 3726 return; 3727 3728 /* Remove non-viable deleted candidates. */ 3729 cand1 = candidates; 3730 for (cand2 = &cand1; *cand2; ) 3731 { 3732 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3733 && !(*cand2)->viable 3734 && DECL_DELETED_FN ((*cand2)->fn)) 3735 *cand2 = (*cand2)->next; 3736 else 3737 cand2 = &(*cand2)->next; 3738 } 3739 /* ...if there are any non-deleted ones. */ 3740 if (cand1) 3741 candidates = cand1; 3742 3743 /* There may be duplicates in the set of candidates. We put off 3744 checking this condition as long as possible, since we have no way 3745 to eliminate duplicates from a set of functions in less than n^2 3746 time. Now we are about to emit an error message, so it is more 3747 permissible to go slowly. */ 3748 for (cand1 = candidates; cand1; cand1 = cand1->next) 3749 { 3750 tree fn = cand1->fn; 3751 /* Skip builtin candidates and conversion functions. */ 3752 if (!DECL_P (fn)) 3753 continue; 3754 cand2 = &cand1->next; 3755 while (*cand2) 3756 { 3757 if (DECL_P ((*cand2)->fn) 3758 && equal_functions (fn, (*cand2)->fn)) 3759 *cand2 = (*cand2)->next; 3760 else 3761 cand2 = &(*cand2)->next; 3762 } 3763 } 3764 3765 for (; candidates; candidates = candidates->next) 3766 print_z_candidate (loc, "candidate:", candidates); 3767 } 3768 3769 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3770 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3771 the result of the conversion function to convert it to the final 3772 desired type. Merge the two sequences into a single sequence, 3773 and return the merged sequence. */ 3774 3775 static conversion * 3776 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3777 { 3778 conversion **t; 3779 bool bad = user_seq->bad_p; 3780 3781 gcc_assert (user_seq->kind == ck_user); 3782 3783 /* Find the end of the second conversion sequence. */ 3784 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3785 { 3786 /* The entire sequence is a user-conversion sequence. */ 3787 (*t)->user_conv_p = true; 3788 if (bad) 3789 (*t)->bad_p = true; 3790 } 3791 3792 if ((*t)->rvaluedness_matches_p) 3793 /* We're binding a reference directly to the result of the conversion. 3794 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return 3795 type, but we want it back. */ 3796 user_seq->type = TREE_TYPE (TREE_TYPE (user_seq->cand->fn)); 3797 3798 /* Replace the identity conversion with the user conversion 3799 sequence. */ 3800 *t = user_seq; 3801 3802 return std_seq; 3803 } 3804 3805 /* Handle overload resolution for initializing an object of class type from 3806 an initializer list. First we look for a suitable constructor that 3807 takes a std::initializer_list; if we don't find one, we then look for a 3808 non-list constructor. 3809 3810 Parameters are as for add_candidates, except that the arguments are in 3811 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and 3812 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3813 3814 static void 3815 add_list_candidates (tree fns, tree first_arg, 3816 const vec<tree, va_gc> *args, tree totype, 3817 tree explicit_targs, bool template_only, 3818 tree conversion_path, tree access_path, 3819 int flags, 3820 struct z_candidate **candidates, 3821 tsubst_flags_t complain) 3822 { 3823 gcc_assert (*candidates == NULL); 3824 3825 /* We're looking for a ctor for list-initialization. */ 3826 flags |= LOOKUP_LIST_INIT_CTOR; 3827 /* And we don't allow narrowing conversions. We also use this flag to 3828 avoid the copy constructor call for copy-list-initialization. */ 3829 flags |= LOOKUP_NO_NARROWING; 3830 3831 unsigned nart = num_artificial_parms_for (OVL_FIRST (fns)) - 1; 3832 tree init_list = (*args)[nart]; 3833 3834 /* Always use the default constructor if the list is empty (DR 990). */ 3835 if (CONSTRUCTOR_NELTS (init_list) == 0 3836 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3837 ; 3838 /* If the class has a list ctor, try passing the list as a single 3839 argument first, but only consider list ctors. */ 3840 else if (TYPE_HAS_LIST_CTOR (totype)) 3841 { 3842 flags |= LOOKUP_LIST_ONLY; 3843 add_candidates (fns, first_arg, args, NULL_TREE, 3844 explicit_targs, template_only, conversion_path, 3845 access_path, flags, candidates, complain); 3846 if (any_strictly_viable (*candidates)) 3847 return; 3848 } 3849 3850 /* Expand the CONSTRUCTOR into a new argument vec. */ 3851 vec<tree, va_gc> *new_args; 3852 vec_alloc (new_args, nart + CONSTRUCTOR_NELTS (init_list)); 3853 for (unsigned i = 0; i < nart; ++i) 3854 new_args->quick_push ((*args)[i]); 3855 for (unsigned i = 0; i < CONSTRUCTOR_NELTS (init_list); ++i) 3856 new_args->quick_push (CONSTRUCTOR_ELT (init_list, i)->value); 3857 3858 /* We aren't looking for list-ctors anymore. */ 3859 flags &= ~LOOKUP_LIST_ONLY; 3860 /* We allow more user-defined conversions within an init-list. */ 3861 flags &= ~LOOKUP_NO_CONVERSION; 3862 3863 add_candidates (fns, first_arg, new_args, NULL_TREE, 3864 explicit_targs, template_only, conversion_path, 3865 access_path, flags, candidates, complain); 3866 } 3867 3868 /* Returns the best overload candidate to perform the requested 3869 conversion. This function is used for three the overloading situations 3870 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3871 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3872 per [dcl.init.ref], so we ignore temporary bindings. */ 3873 3874 static struct z_candidate * 3875 build_user_type_conversion_1 (tree totype, tree expr, int flags, 3876 tsubst_flags_t complain) 3877 { 3878 struct z_candidate *candidates, *cand; 3879 tree fromtype; 3880 tree ctors = NULL_TREE; 3881 tree conv_fns = NULL_TREE; 3882 conversion *conv = NULL; 3883 tree first_arg = NULL_TREE; 3884 vec<tree, va_gc> *args = NULL; 3885 bool any_viable_p; 3886 int convflags; 3887 3888 if (!expr) 3889 return NULL; 3890 3891 fromtype = TREE_TYPE (expr); 3892 3893 /* We represent conversion within a hierarchy using RVALUE_CONV and 3894 BASE_CONV, as specified by [over.best.ics]; these become plain 3895 constructor calls, as specified in [dcl.init]. */ 3896 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3897 || !DERIVED_FROM_P (totype, fromtype)); 3898 3899 if (CLASS_TYPE_P (totype)) 3900 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3901 creating a garbage BASELINK; constructors can't be inherited. */ 3902 ctors = get_class_binding (totype, complete_ctor_identifier); 3903 3904 if (MAYBE_CLASS_TYPE_P (fromtype)) 3905 { 3906 tree to_nonref = non_reference (totype); 3907 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3908 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3909 && DERIVED_FROM_P (to_nonref, fromtype))) 3910 { 3911 /* [class.conv.fct] A conversion function is never used to 3912 convert a (possibly cv-qualified) object to the (possibly 3913 cv-qualified) same object type (or a reference to it), to a 3914 (possibly cv-qualified) base class of that type (or a 3915 reference to it)... */ 3916 } 3917 else 3918 conv_fns = lookup_conversions (fromtype); 3919 } 3920 3921 candidates = 0; 3922 flags |= LOOKUP_NO_CONVERSION; 3923 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3924 flags |= LOOKUP_NO_NARROWING; 3925 3926 /* It's OK to bind a temporary for converting constructor arguments, but 3927 not in converting the return value of a conversion operator. */ 3928 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION 3929 | (flags & LOOKUP_NO_NARROWING)); 3930 flags &= ~LOOKUP_NO_TEMP_BIND; 3931 3932 if (ctors) 3933 { 3934 int ctorflags = flags; 3935 3936 first_arg = build_dummy_object (totype); 3937 3938 /* We should never try to call the abstract or base constructor 3939 from here. */ 3940 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_FIRST (ctors)) 3941 && !DECL_HAS_VTT_PARM_P (OVL_FIRST (ctors))); 3942 3943 args = make_tree_vector_single (expr); 3944 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3945 { 3946 /* List-initialization. */ 3947 add_list_candidates (ctors, first_arg, args, totype, NULL_TREE, 3948 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3949 ctorflags, &candidates, complain); 3950 } 3951 else 3952 { 3953 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3954 TYPE_BINFO (totype), TYPE_BINFO (totype), 3955 ctorflags, &candidates, complain); 3956 } 3957 3958 for (cand = candidates; cand; cand = cand->next) 3959 { 3960 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3961 3962 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3963 set, then this is copy-initialization. In that case, "The 3964 result of the call is then used to direct-initialize the 3965 object that is the destination of the copy-initialization." 3966 [dcl.init] 3967 3968 We represent this in the conversion sequence with an 3969 rvalue conversion, which means a constructor call. */ 3970 if (!TYPE_REF_P (totype) 3971 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3972 cand->second_conv 3973 = build_conv (ck_rvalue, totype, cand->second_conv); 3974 } 3975 } 3976 3977 if (conv_fns) 3978 { 3979 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3980 first_arg = CONSTRUCTOR_ELT (expr, 0)->value; 3981 else 3982 first_arg = expr; 3983 } 3984 3985 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3986 { 3987 tree conversion_path = TREE_PURPOSE (conv_fns); 3988 struct z_candidate *old_candidates; 3989 3990 /* If we are called to convert to a reference type, we are trying to 3991 find a direct binding, so don't even consider temporaries. If 3992 we don't find a direct binding, the caller will try again to 3993 look for a temporary binding. */ 3994 if (TYPE_REF_P (totype)) 3995 convflags |= LOOKUP_NO_TEMP_BIND; 3996 3997 old_candidates = candidates; 3998 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3999 NULL_TREE, false, 4000 conversion_path, TYPE_BINFO (fromtype), 4001 flags, &candidates, complain); 4002 4003 for (cand = candidates; cand != old_candidates; cand = cand->next) 4004 { 4005 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 4006 conversion *ics 4007 = implicit_conversion (totype, 4008 rettype, 4009 0, 4010 /*c_cast_p=*/false, convflags, 4011 complain); 4012 4013 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 4014 copy-initialization. In that case, "The result of the 4015 call is then used to direct-initialize the object that is 4016 the destination of the copy-initialization." [dcl.init] 4017 4018 We represent this in the conversion sequence with an 4019 rvalue conversion, which means a constructor call. But 4020 don't add a second rvalue conversion if there's already 4021 one there. Which there really shouldn't be, but it's 4022 harmless since we'd add it here anyway. */ 4023 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 4024 && !(convflags & LOOKUP_NO_TEMP_BIND)) 4025 ics = build_conv (ck_rvalue, totype, ics); 4026 4027 cand->second_conv = ics; 4028 4029 if (!ics) 4030 { 4031 cand->viable = 0; 4032 cand->reason = arg_conversion_rejection (NULL_TREE, -2, 4033 rettype, totype, 4034 EXPR_LOCATION (expr)); 4035 } 4036 else if (TYPE_REF_P (totype) && !ics->rvaluedness_matches_p 4037 /* Limit this to non-templates for now (PR90546). */ 4038 && !cand->template_decl 4039 && TREE_CODE (TREE_TYPE (totype)) != FUNCTION_TYPE) 4040 { 4041 /* If we are called to convert to a reference type, we are trying 4042 to find a direct binding per [over.match.ref], so rvaluedness 4043 must match for non-functions. */ 4044 cand->viable = 0; 4045 } 4046 else if (DECL_NONCONVERTING_P (cand->fn) 4047 && ics->rank > cr_exact) 4048 { 4049 /* 13.3.1.5: For direct-initialization, those explicit 4050 conversion functions that are not hidden within S and 4051 yield type T or a type that can be converted to type T 4052 with a qualification conversion (4.4) are also candidate 4053 functions. */ 4054 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 4055 I've raised this issue with the committee. --jason 9/2011 */ 4056 cand->viable = -1; 4057 cand->reason = explicit_conversion_rejection (rettype, totype); 4058 } 4059 else if (cand->viable == 1 && ics->bad_p) 4060 { 4061 cand->viable = -1; 4062 cand->reason 4063 = bad_arg_conversion_rejection (NULL_TREE, -2, 4064 rettype, totype, 4065 EXPR_LOCATION (expr)); 4066 } 4067 else if (primary_template_specialization_p (cand->fn) 4068 && ics->rank > cr_exact) 4069 { 4070 /* 13.3.3.1.2: If the user-defined conversion is specified by 4071 a specialization of a conversion function template, the 4072 second standard conversion sequence shall have exact match 4073 rank. */ 4074 cand->viable = -1; 4075 cand->reason = template_conversion_rejection (rettype, totype); 4076 } 4077 } 4078 } 4079 4080 candidates = splice_viable (candidates, false, &any_viable_p); 4081 if (!any_viable_p) 4082 { 4083 if (args) 4084 release_tree_vector (args); 4085 return NULL; 4086 } 4087 4088 cand = tourney (candidates, complain); 4089 if (cand == NULL) 4090 { 4091 if (complain & tf_error) 4092 { 4093 auto_diagnostic_group d; 4094 error ("conversion from %qH to %qI is ambiguous", 4095 fromtype, totype); 4096 print_z_candidates (location_of (expr), candidates); 4097 } 4098 4099 cand = candidates; /* any one will do */ 4100 cand->second_conv = build_ambiguous_conv (totype, expr); 4101 cand->second_conv->user_conv_p = true; 4102 if (!any_strictly_viable (candidates)) 4103 cand->second_conv->bad_p = true; 4104 if (flags & LOOKUP_ONLYCONVERTING) 4105 cand->second_conv->need_temporary_p = true; 4106 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 4107 ambiguous conversion is no worse than another user-defined 4108 conversion. */ 4109 4110 return cand; 4111 } 4112 4113 tree convtype; 4114 if (!DECL_CONSTRUCTOR_P (cand->fn)) 4115 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn))); 4116 else if (cand->second_conv->kind == ck_rvalue) 4117 /* DR 5: [in the first step of copy-initialization]...if the function 4118 is a constructor, the call initializes a temporary of the 4119 cv-unqualified version of the destination type. */ 4120 convtype = cv_unqualified (totype); 4121 else 4122 convtype = totype; 4123 /* Build the user conversion sequence. */ 4124 conv = build_conv 4125 (ck_user, 4126 convtype, 4127 build_identity_conv (TREE_TYPE (expr), expr)); 4128 conv->cand = cand; 4129 if (cand->viable == -1) 4130 conv->bad_p = true; 4131 4132 /* We're performing the maybe-rvalue overload resolution and 4133 a conversion function is in play. Reject converting the return 4134 value of the conversion function to a base class. */ 4135 if ((flags & LOOKUP_PREFER_RVALUE) && !DECL_CONSTRUCTOR_P (cand->fn)) 4136 for (conversion *t = cand->second_conv; t; t = next_conversion (t)) 4137 if (t->kind == ck_base) 4138 return NULL; 4139 4140 /* Remember that this was a list-initialization. */ 4141 if (flags & LOOKUP_NO_NARROWING) 4142 conv->check_narrowing = true; 4143 4144 /* Combine it with the second conversion sequence. */ 4145 cand->second_conv = merge_conversion_sequences (conv, 4146 cand->second_conv); 4147 4148 return cand; 4149 } 4150 4151 /* Wrapper for above. */ 4152 4153 tree 4154 build_user_type_conversion (tree totype, tree expr, int flags, 4155 tsubst_flags_t complain) 4156 { 4157 struct z_candidate *cand; 4158 tree ret; 4159 4160 bool subtime = timevar_cond_start (TV_OVERLOAD); 4161 cand = build_user_type_conversion_1 (totype, expr, flags, complain); 4162 4163 if (cand) 4164 { 4165 if (cand->second_conv->kind == ck_ambig) 4166 ret = error_mark_node; 4167 else 4168 { 4169 expr = convert_like (cand->second_conv, expr, complain); 4170 ret = convert_from_reference (expr); 4171 } 4172 } 4173 else 4174 ret = NULL_TREE; 4175 4176 timevar_cond_stop (TV_OVERLOAD, subtime); 4177 return ret; 4178 } 4179 4180 /* Worker for build_converted_constant_expr. */ 4181 4182 static tree 4183 build_converted_constant_expr_internal (tree type, tree expr, 4184 int flags, tsubst_flags_t complain) 4185 { 4186 conversion *conv; 4187 void *p; 4188 tree t; 4189 location_t loc = cp_expr_loc_or_loc (expr, input_location); 4190 4191 if (error_operand_p (expr)) 4192 return error_mark_node; 4193 4194 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4195 p = conversion_obstack_alloc (0); 4196 4197 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 4198 /*c_cast_p=*/false, flags, complain); 4199 4200 /* A converted constant expression of type T is an expression, implicitly 4201 converted to type T, where the converted expression is a constant 4202 expression and the implicit conversion sequence contains only 4203 4204 * user-defined conversions, 4205 * lvalue-to-rvalue conversions (7.1), 4206 * array-to-pointer conversions (7.2), 4207 * function-to-pointer conversions (7.3), 4208 * qualification conversions (7.5), 4209 * integral promotions (7.6), 4210 * integral conversions (7.8) other than narrowing conversions (11.6.4), 4211 * null pointer conversions (7.11) from std::nullptr_t, 4212 * null member pointer conversions (7.12) from std::nullptr_t, and 4213 * function pointer conversions (7.13), 4214 4215 and where the reference binding (if any) binds directly. */ 4216 4217 for (conversion *c = conv; 4218 conv && c->kind != ck_identity; 4219 c = next_conversion (c)) 4220 { 4221 switch (c->kind) 4222 { 4223 /* A conversion function is OK. If it isn't constexpr, we'll 4224 complain later that the argument isn't constant. */ 4225 case ck_user: 4226 /* The lvalue-to-rvalue conversion is OK. */ 4227 case ck_rvalue: 4228 /* Array-to-pointer and function-to-pointer. */ 4229 case ck_lvalue: 4230 /* Function pointer conversions. */ 4231 case ck_fnptr: 4232 /* Qualification conversions. */ 4233 case ck_qual: 4234 break; 4235 4236 case ck_ref_bind: 4237 if (c->need_temporary_p) 4238 { 4239 if (complain & tf_error) 4240 error_at (loc, "initializing %qH with %qI in converted " 4241 "constant expression does not bind directly", 4242 type, next_conversion (c)->type); 4243 conv = NULL; 4244 } 4245 break; 4246 4247 case ck_base: 4248 case ck_pmem: 4249 case ck_ptr: 4250 case ck_std: 4251 t = next_conversion (c)->type; 4252 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t) 4253 && INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 4254 /* Integral promotion or conversion. */ 4255 break; 4256 if (NULLPTR_TYPE_P (t)) 4257 /* Conversion from nullptr to pointer or pointer-to-member. */ 4258 break; 4259 4260 if (complain & tf_error) 4261 error_at (loc, "conversion from %qH to %qI in a " 4262 "converted constant expression", t, type); 4263 /* fall through. */ 4264 4265 default: 4266 conv = NULL; 4267 break; 4268 } 4269 } 4270 4271 /* Avoid confusing convert_nontype_argument by introducing 4272 a redundant conversion to the same reference type. */ 4273 if (conv && conv->kind == ck_ref_bind 4274 && REFERENCE_REF_P (expr)) 4275 { 4276 tree ref = TREE_OPERAND (expr, 0); 4277 if (same_type_p (type, TREE_TYPE (ref))) 4278 return ref; 4279 } 4280 4281 if (conv) 4282 { 4283 /* Don't copy a class non-type template parameter. */ 4284 if (CLASS_TYPE_P (type) && conv->kind == ck_rvalue 4285 && TREE_CODE (expr) == VIEW_CONVERT_EXPR 4286 && TREE_CODE (TREE_OPERAND (expr, 0)) == TEMPLATE_PARM_INDEX) 4287 conv = next_conversion (conv); 4288 4289 conv->check_narrowing = true; 4290 conv->check_narrowing_const_only = true; 4291 expr = convert_like (conv, expr, complain); 4292 } 4293 else 4294 { 4295 if (complain & tf_error) 4296 error_at (loc, "could not convert %qE from %qH to %qI", expr, 4297 TREE_TYPE (expr), type); 4298 expr = error_mark_node; 4299 } 4300 4301 /* Free all the conversions we allocated. */ 4302 obstack_free (&conversion_obstack, p); 4303 4304 return expr; 4305 } 4306 4307 /* Subroutine of convert_nontype_argument. 4308 4309 EXPR is an expression used in a context that requires a converted 4310 constant-expression, such as a template non-type parameter. Do any 4311 necessary conversions (that are permitted for converted 4312 constant-expressions) to convert it to the desired type. 4313 4314 This function doesn't consider explicit conversion functions. If 4315 you mean to use "a contextually converted constant expression of type 4316 bool", use build_converted_constant_bool_expr. 4317 4318 If conversion is successful, returns the converted expression; 4319 otherwise, returns error_mark_node. */ 4320 4321 tree 4322 build_converted_constant_expr (tree type, tree expr, tsubst_flags_t complain) 4323 { 4324 return build_converted_constant_expr_internal (type, expr, LOOKUP_IMPLICIT, 4325 complain); 4326 } 4327 4328 /* Used to create "a contextually converted constant expression of type 4329 bool". This differs from build_converted_constant_expr in that it 4330 also considers explicit conversion functions. */ 4331 4332 tree 4333 build_converted_constant_bool_expr (tree expr, tsubst_flags_t complain) 4334 { 4335 return build_converted_constant_expr_internal (boolean_type_node, expr, 4336 LOOKUP_NORMAL, complain); 4337 } 4338 4339 /* Do any initial processing on the arguments to a function call. */ 4340 4341 static vec<tree, va_gc> * 4342 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain) 4343 { 4344 unsigned int ix; 4345 tree arg; 4346 4347 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 4348 { 4349 if (error_operand_p (arg)) 4350 return NULL; 4351 else if (VOID_TYPE_P (TREE_TYPE (arg))) 4352 { 4353 if (complain & tf_error) 4354 error ("invalid use of void expression"); 4355 return NULL; 4356 } 4357 else if (invalid_nonstatic_memfn_p (EXPR_LOCATION (arg), arg, complain)) 4358 return NULL; 4359 } 4360 return args; 4361 } 4362 4363 /* Perform overload resolution on FN, which is called with the ARGS. 4364 4365 Return the candidate function selected by overload resolution, or 4366 NULL if the event that overload resolution failed. In the case 4367 that overload resolution fails, *CANDIDATES will be the set of 4368 candidates considered, and ANY_VIABLE_P will be set to true or 4369 false to indicate whether or not any of the candidates were 4370 viable. 4371 4372 The ARGS should already have gone through RESOLVE_ARGS before this 4373 function is called. */ 4374 4375 static struct z_candidate * 4376 perform_overload_resolution (tree fn, 4377 const vec<tree, va_gc> *args, 4378 struct z_candidate **candidates, 4379 bool *any_viable_p, tsubst_flags_t complain) 4380 { 4381 struct z_candidate *cand; 4382 tree explicit_targs; 4383 int template_only; 4384 4385 bool subtime = timevar_cond_start (TV_OVERLOAD); 4386 4387 explicit_targs = NULL_TREE; 4388 template_only = 0; 4389 4390 *candidates = NULL; 4391 *any_viable_p = true; 4392 4393 /* Check FN. */ 4394 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 4395 || TREE_CODE (fn) == TEMPLATE_DECL 4396 || TREE_CODE (fn) == OVERLOAD 4397 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 4398 4399 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4400 { 4401 explicit_targs = TREE_OPERAND (fn, 1); 4402 fn = TREE_OPERAND (fn, 0); 4403 template_only = 1; 4404 } 4405 4406 /* Add the various candidate functions. */ 4407 add_candidates (fn, NULL_TREE, args, NULL_TREE, 4408 explicit_targs, template_only, 4409 /*conversion_path=*/NULL_TREE, 4410 /*access_path=*/NULL_TREE, 4411 LOOKUP_NORMAL, 4412 candidates, complain); 4413 4414 *candidates = splice_viable (*candidates, false, any_viable_p); 4415 if (*any_viable_p) 4416 cand = tourney (*candidates, complain); 4417 else 4418 cand = NULL; 4419 4420 timevar_cond_stop (TV_OVERLOAD, subtime); 4421 return cand; 4422 } 4423 4424 /* Print an error message about being unable to build a call to FN with 4425 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 4426 be located; CANDIDATES is a possibly empty list of such 4427 functions. */ 4428 4429 static void 4430 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args, 4431 struct z_candidate *candidates) 4432 { 4433 tree targs = NULL_TREE; 4434 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4435 { 4436 targs = TREE_OPERAND (fn, 1); 4437 fn = TREE_OPERAND (fn, 0); 4438 } 4439 tree name = OVL_NAME (fn); 4440 location_t loc = location_of (name); 4441 if (targs) 4442 name = lookup_template_function (name, targs); 4443 4444 auto_diagnostic_group d; 4445 if (!any_strictly_viable (candidates)) 4446 error_at (loc, "no matching function for call to %<%D(%A)%>", 4447 name, build_tree_list_vec (args)); 4448 else 4449 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 4450 name, build_tree_list_vec (args)); 4451 if (candidates) 4452 print_z_candidates (loc, candidates); 4453 } 4454 4455 /* Return an expression for a call to FN (a namespace-scope function, 4456 or a static member function) with the ARGS. This may change 4457 ARGS. */ 4458 4459 tree 4460 build_new_function_call (tree fn, vec<tree, va_gc> **args, 4461 tsubst_flags_t complain) 4462 { 4463 struct z_candidate *candidates, *cand; 4464 bool any_viable_p; 4465 void *p; 4466 tree result; 4467 4468 if (args != NULL && *args != NULL) 4469 { 4470 *args = resolve_args (*args, complain); 4471 if (*args == NULL) 4472 return error_mark_node; 4473 } 4474 4475 if (flag_tm) 4476 tm_malloc_replacement (fn); 4477 4478 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4479 p = conversion_obstack_alloc (0); 4480 4481 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p, 4482 complain); 4483 4484 if (!cand) 4485 { 4486 if (complain & tf_error) 4487 { 4488 // If there is a single (non-viable) function candidate, 4489 // let the error be diagnosed by cp_build_function_call_vec. 4490 if (!any_viable_p && candidates && ! candidates->next 4491 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 4492 return cp_build_function_call_vec (candidates->fn, args, complain); 4493 4494 // Otherwise, emit notes for non-viable candidates. 4495 print_error_for_call_failure (fn, *args, candidates); 4496 } 4497 result = error_mark_node; 4498 } 4499 else 4500 { 4501 int flags = LOOKUP_NORMAL; 4502 /* If fn is template_id_expr, the call has explicit template arguments 4503 (e.g. func<int>(5)), communicate this info to build_over_call 4504 through flags so that later we can use it to decide whether to warn 4505 about peculiar null pointer conversion. */ 4506 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4507 { 4508 /* If overload resolution selects a specialization of a 4509 function concept for non-dependent template arguments, 4510 the expression is true if the constraints are satisfied 4511 and false otherwise. 4512 4513 NOTE: This is an extension of Concepts Lite TS that 4514 allows constraints to be used in expressions. */ 4515 if (flag_concepts && !processing_template_decl) 4516 { 4517 tree tmpl = DECL_TI_TEMPLATE (cand->fn); 4518 tree targs = DECL_TI_ARGS (cand->fn); 4519 tree decl = DECL_TEMPLATE_RESULT (tmpl); 4520 if (DECL_DECLARED_CONCEPT_P (decl)) 4521 return evaluate_function_concept (decl, targs); 4522 } 4523 4524 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 4525 } 4526 4527 result = build_over_call (cand, flags, complain); 4528 } 4529 4530 /* Free all the conversions we allocated. */ 4531 obstack_free (&conversion_obstack, p); 4532 4533 return result; 4534 } 4535 4536 /* Build a call to a global operator new. FNNAME is the name of the 4537 operator (either "operator new" or "operator new[]") and ARGS are 4538 the arguments provided. This may change ARGS. *SIZE points to the 4539 total number of bytes required by the allocation, and is updated if 4540 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 4541 be used. If this function determines that no cookie should be 4542 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK 4543 is not NULL_TREE, it is evaluated before calculating the final 4544 array size, and if it fails, the array size is replaced with 4545 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN 4546 is non-NULL, it will be set, upon return, to the allocation 4547 function called. */ 4548 4549 tree 4550 build_operator_new_call (tree fnname, vec<tree, va_gc> **args, 4551 tree *size, tree *cookie_size, 4552 tree align_arg, tree size_check, 4553 tree *fn, tsubst_flags_t complain) 4554 { 4555 tree original_size = *size; 4556 tree fns; 4557 struct z_candidate *candidates; 4558 struct z_candidate *cand = NULL; 4559 bool any_viable_p; 4560 4561 if (fn) 4562 *fn = NULL_TREE; 4563 /* Set to (size_t)-1 if the size check fails. */ 4564 if (size_check != NULL_TREE) 4565 { 4566 tree errval = TYPE_MAX_VALUE (sizetype); 4567 if (cxx_dialect >= cxx11 && flag_exceptions) 4568 errval = throw_bad_array_new_length (); 4569 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4570 original_size, errval); 4571 } 4572 vec_safe_insert (*args, 0, *size); 4573 *args = resolve_args (*args, complain); 4574 if (*args == NULL) 4575 return error_mark_node; 4576 4577 /* Based on: 4578 4579 [expr.new] 4580 4581 If this lookup fails to find the name, or if the allocated type 4582 is not a class type, the allocation function's name is looked 4583 up in the global scope. 4584 4585 we disregard block-scope declarations of "operator new". */ 4586 fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0); 4587 fns = lookup_arg_dependent (fnname, fns, *args); 4588 4589 if (align_arg) 4590 { 4591 vec<tree, va_gc>* align_args 4592 = vec_copy_and_insert (*args, align_arg, 1); 4593 cand = perform_overload_resolution (fns, align_args, &candidates, 4594 &any_viable_p, tf_none); 4595 if (cand) 4596 *args = align_args; 4597 /* If no aligned allocation function matches, try again without the 4598 alignment. */ 4599 } 4600 4601 /* Figure out what function is being called. */ 4602 if (!cand) 4603 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p, 4604 complain); 4605 4606 /* If no suitable function could be found, issue an error message 4607 and give up. */ 4608 if (!cand) 4609 { 4610 if (complain & tf_error) 4611 print_error_for_call_failure (fns, *args, candidates); 4612 return error_mark_node; 4613 } 4614 4615 /* If a cookie is required, add some extra space. Whether 4616 or not a cookie is required cannot be determined until 4617 after we know which function was called. */ 4618 if (*cookie_size) 4619 { 4620 bool use_cookie = true; 4621 tree arg_types; 4622 4623 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 4624 /* Skip the size_t parameter. */ 4625 arg_types = TREE_CHAIN (arg_types); 4626 /* Check the remaining parameters (if any). */ 4627 if (arg_types 4628 && TREE_CHAIN (arg_types) == void_list_node 4629 && same_type_p (TREE_VALUE (arg_types), 4630 ptr_type_node)) 4631 use_cookie = false; 4632 /* If we need a cookie, adjust the number of bytes allocated. */ 4633 if (use_cookie) 4634 { 4635 /* Update the total size. */ 4636 *size = size_binop (PLUS_EXPR, original_size, *cookie_size); 4637 if (size_check) 4638 { 4639 /* Set to (size_t)-1 if the size check fails. */ 4640 gcc_assert (size_check != NULL_TREE); 4641 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4642 *size, TYPE_MAX_VALUE (sizetype)); 4643 } 4644 /* Update the argument list to reflect the adjusted size. */ 4645 (**args)[0] = *size; 4646 } 4647 else 4648 *cookie_size = NULL_TREE; 4649 } 4650 4651 /* Tell our caller which function we decided to call. */ 4652 if (fn) 4653 *fn = cand->fn; 4654 4655 /* Build the CALL_EXPR. */ 4656 return build_over_call (cand, LOOKUP_NORMAL, complain); 4657 } 4658 4659 /* Build a new call to operator(). This may change ARGS. */ 4660 4661 static tree 4662 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4663 { 4664 struct z_candidate *candidates = 0, *cand; 4665 tree fns, convs, first_mem_arg = NULL_TREE; 4666 bool any_viable_p; 4667 tree result = NULL_TREE; 4668 void *p; 4669 4670 obj = mark_lvalue_use (obj); 4671 4672 if (error_operand_p (obj)) 4673 return error_mark_node; 4674 4675 tree type = TREE_TYPE (obj); 4676 4677 obj = prep_operand (obj); 4678 4679 if (TYPE_PTRMEMFUNC_P (type)) 4680 { 4681 if (complain & tf_error) 4682 /* It's no good looking for an overloaded operator() on a 4683 pointer-to-member-function. */ 4684 error ("pointer-to-member function %qE cannot be called without " 4685 "an object; consider using %<.*%> or %<->*%>", obj); 4686 return error_mark_node; 4687 } 4688 4689 if (TYPE_BINFO (type)) 4690 { 4691 fns = lookup_fnfields (TYPE_BINFO (type), call_op_identifier, 1); 4692 if (fns == error_mark_node) 4693 return error_mark_node; 4694 } 4695 else 4696 fns = NULL_TREE; 4697 4698 if (args != NULL && *args != NULL) 4699 { 4700 *args = resolve_args (*args, complain); 4701 if (*args == NULL) 4702 return error_mark_node; 4703 } 4704 4705 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4706 p = conversion_obstack_alloc (0); 4707 4708 if (fns) 4709 { 4710 first_mem_arg = obj; 4711 4712 add_candidates (BASELINK_FUNCTIONS (fns), 4713 first_mem_arg, *args, NULL_TREE, 4714 NULL_TREE, false, 4715 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4716 LOOKUP_NORMAL, &candidates, complain); 4717 } 4718 4719 convs = lookup_conversions (type); 4720 4721 for (; convs; convs = TREE_CHAIN (convs)) 4722 { 4723 tree totype = TREE_TYPE (convs); 4724 4725 if (TYPE_PTRFN_P (totype) 4726 || TYPE_REFFN_P (totype) 4727 || (TYPE_REF_P (totype) 4728 && TYPE_PTRFN_P (TREE_TYPE (totype)))) 4729 for (ovl_iterator iter (TREE_VALUE (convs)); iter; ++iter) 4730 { 4731 tree fn = *iter; 4732 4733 if (DECL_NONCONVERTING_P (fn)) 4734 continue; 4735 4736 if (TREE_CODE (fn) == TEMPLATE_DECL) 4737 add_template_conv_candidate 4738 (&candidates, fn, obj, *args, totype, 4739 /*access_path=*/NULL_TREE, 4740 /*conversion_path=*/NULL_TREE, complain); 4741 else 4742 add_conv_candidate (&candidates, fn, obj, 4743 *args, /*conversion_path=*/NULL_TREE, 4744 /*access_path=*/NULL_TREE, complain); 4745 } 4746 } 4747 4748 /* Be strict here because if we choose a bad conversion candidate, the 4749 errors we get won't mention the call context. */ 4750 candidates = splice_viable (candidates, true, &any_viable_p); 4751 if (!any_viable_p) 4752 { 4753 if (complain & tf_error) 4754 { 4755 auto_diagnostic_group d; 4756 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4757 build_tree_list_vec (*args)); 4758 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4759 } 4760 result = error_mark_node; 4761 } 4762 else 4763 { 4764 cand = tourney (candidates, complain); 4765 if (cand == 0) 4766 { 4767 if (complain & tf_error) 4768 { 4769 auto_diagnostic_group d; 4770 error ("call of %<(%T) (%A)%> is ambiguous", 4771 TREE_TYPE (obj), build_tree_list_vec (*args)); 4772 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4773 } 4774 result = error_mark_node; 4775 } 4776 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4777 && DECL_OVERLOADED_OPERATOR_P (cand->fn) 4778 && DECL_OVERLOADED_OPERATOR_IS (cand->fn, CALL_EXPR)) 4779 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4780 else 4781 { 4782 if (TREE_CODE (cand->fn) == FUNCTION_DECL) 4783 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, 4784 -1, complain); 4785 else 4786 { 4787 gcc_checking_assert (TYPE_P (cand->fn)); 4788 obj = convert_like (cand->convs[0], obj, complain); 4789 } 4790 obj = convert_from_reference (obj); 4791 result = cp_build_function_call_vec (obj, args, complain); 4792 } 4793 } 4794 4795 /* Free all the conversions we allocated. */ 4796 obstack_free (&conversion_obstack, p); 4797 4798 return result; 4799 } 4800 4801 /* Wrapper for above. */ 4802 4803 tree 4804 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4805 { 4806 tree ret; 4807 bool subtime = timevar_cond_start (TV_OVERLOAD); 4808 ret = build_op_call_1 (obj, args, complain); 4809 timevar_cond_stop (TV_OVERLOAD, subtime); 4810 return ret; 4811 } 4812 4813 /* Called by op_error to prepare format strings suitable for the error 4814 function. It concatenates a prefix (controlled by MATCH), ERRMSG, 4815 and a suffix (controlled by NTYPES). */ 4816 4817 static const char * 4818 op_error_string (const char *errmsg, int ntypes, bool match) 4819 { 4820 const char *msg; 4821 4822 const char *msgp = concat (match ? G_("ambiguous overload for ") 4823 : G_("no match for "), errmsg, NULL); 4824 4825 if (ntypes == 3) 4826 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL); 4827 else if (ntypes == 2) 4828 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL); 4829 else 4830 msg = concat (msgp, G_(" (operand type is %qT)"), NULL); 4831 4832 return msg; 4833 } 4834 4835 static void 4836 op_error (const op_location_t &loc, 4837 enum tree_code code, enum tree_code code2, 4838 tree arg1, tree arg2, tree arg3, bool match) 4839 { 4840 bool assop = code == MODIFY_EXPR; 4841 const char *opname = OVL_OP_INFO (assop, assop ? code2 : code)->name; 4842 4843 switch (code) 4844 { 4845 case COND_EXPR: 4846 if (flag_diagnostics_show_caret) 4847 error_at (loc, op_error_string (G_("ternary %<operator?:%>"), 4848 3, match), 4849 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4850 else 4851 error_at (loc, op_error_string (G_("ternary %<operator?:%> " 4852 "in %<%E ? %E : %E%>"), 3, match), 4853 arg1, arg2, arg3, 4854 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4855 break; 4856 4857 case POSTINCREMENT_EXPR: 4858 case POSTDECREMENT_EXPR: 4859 if (flag_diagnostics_show_caret) 4860 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4861 opname, TREE_TYPE (arg1)); 4862 else 4863 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"), 4864 1, match), 4865 opname, arg1, opname, TREE_TYPE (arg1)); 4866 break; 4867 4868 case ARRAY_REF: 4869 if (flag_diagnostics_show_caret) 4870 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match), 4871 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4872 else 4873 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"), 4874 2, match), 4875 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4876 break; 4877 4878 case REALPART_EXPR: 4879 case IMAGPART_EXPR: 4880 if (flag_diagnostics_show_caret) 4881 error_at (loc, op_error_string (G_("%qs"), 1, match), 4882 opname, TREE_TYPE (arg1)); 4883 else 4884 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match), 4885 opname, opname, arg1, TREE_TYPE (arg1)); 4886 break; 4887 4888 default: 4889 if (arg2) 4890 if (flag_diagnostics_show_caret) 4891 { 4892 binary_op_rich_location richloc (loc, arg1, arg2, true); 4893 error_at (&richloc, 4894 op_error_string (G_("%<operator%s%>"), 2, match), 4895 opname, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4896 } 4897 else 4898 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"), 4899 2, match), 4900 opname, arg1, opname, arg2, 4901 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4902 else 4903 if (flag_diagnostics_show_caret) 4904 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4905 opname, TREE_TYPE (arg1)); 4906 else 4907 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"), 4908 1, match), 4909 opname, opname, arg1, TREE_TYPE (arg1)); 4910 break; 4911 } 4912 } 4913 4914 /* Return the implicit conversion sequence that could be used to 4915 convert E1 to E2 in [expr.cond]. */ 4916 4917 static conversion * 4918 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain) 4919 { 4920 tree t1 = non_reference (TREE_TYPE (e1)); 4921 tree t2 = non_reference (TREE_TYPE (e2)); 4922 conversion *conv; 4923 bool good_base; 4924 4925 /* [expr.cond] 4926 4927 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4928 implicitly converted (clause _conv_) to the type "lvalue reference to 4929 T2", subject to the constraint that in the conversion the 4930 reference must bind directly (_dcl.init.ref_) to an lvalue. 4931 4932 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be 4933 implicitly converted to the type "rvalue reference to T2", subject to 4934 the constraint that the reference must bind directly. */ 4935 if (glvalue_p (e2)) 4936 { 4937 tree rtype = cp_build_reference_type (t2, !lvalue_p (e2)); 4938 conv = implicit_conversion (rtype, 4939 t1, 4940 e1, 4941 /*c_cast_p=*/false, 4942 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4943 |LOOKUP_ONLYCONVERTING, 4944 complain); 4945 if (conv && !conv->bad_p) 4946 return conv; 4947 } 4948 4949 /* If E2 is a prvalue or if neither of the conversions above can be done 4950 and at least one of the operands has (possibly cv-qualified) class 4951 type: */ 4952 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2)) 4953 return NULL; 4954 4955 /* [expr.cond] 4956 4957 If E1 and E2 have class type, and the underlying class types are 4958 the same or one is a base class of the other: E1 can be converted 4959 to match E2 if the class of T2 is the same type as, or a base 4960 class of, the class of T1, and the cv-qualification of T2 is the 4961 same cv-qualification as, or a greater cv-qualification than, the 4962 cv-qualification of T1. If the conversion is applied, E1 is 4963 changed to an rvalue of type T2 that still refers to the original 4964 source class object (or the appropriate subobject thereof). */ 4965 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4966 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4967 { 4968 if (good_base && at_least_as_qualified_p (t2, t1)) 4969 { 4970 conv = build_identity_conv (t1, e1); 4971 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4972 TYPE_MAIN_VARIANT (t2))) 4973 conv = build_conv (ck_base, t2, conv); 4974 else 4975 conv = build_conv (ck_rvalue, t2, conv); 4976 return conv; 4977 } 4978 else 4979 return NULL; 4980 } 4981 else 4982 /* [expr.cond] 4983 4984 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4985 converted to the type that expression E2 would have if E2 were 4986 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4987 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4988 LOOKUP_IMPLICIT, complain); 4989 } 4990 4991 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4992 arguments to the conditional expression. */ 4993 4994 static tree 4995 build_conditional_expr_1 (const op_location_t &loc, 4996 tree arg1, tree arg2, tree arg3, 4997 tsubst_flags_t complain) 4998 { 4999 tree arg2_type; 5000 tree arg3_type; 5001 tree result = NULL_TREE; 5002 tree result_type = NULL_TREE; 5003 bool is_glvalue = true; 5004 struct z_candidate *candidates = 0; 5005 struct z_candidate *cand; 5006 void *p; 5007 tree orig_arg2, orig_arg3; 5008 5009 /* As a G++ extension, the second argument to the conditional can be 5010 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 5011 c'.) If the second operand is omitted, make sure it is 5012 calculated only once. */ 5013 if (!arg2) 5014 { 5015 if (complain & tf_error) 5016 pedwarn (loc, OPT_Wpedantic, 5017 "ISO C++ forbids omitting the middle term of a ?: expression"); 5018 5019 if ((complain & tf_warning) && !truth_value_p (TREE_CODE (arg1))) 5020 warn_for_omitted_condop (loc, arg1); 5021 5022 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 5023 if (lvalue_p (arg1)) 5024 arg2 = arg1 = cp_stabilize_reference (arg1); 5025 else 5026 arg2 = arg1 = cp_save_expr (arg1); 5027 } 5028 5029 /* If something has already gone wrong, just pass that fact up the 5030 tree. */ 5031 if (error_operand_p (arg1) 5032 || error_operand_p (arg2) 5033 || error_operand_p (arg3)) 5034 return error_mark_node; 5035 5036 orig_arg2 = arg2; 5037 orig_arg3 = arg3; 5038 5039 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1))) 5040 { 5041 tree arg1_type = TREE_TYPE (arg1); 5042 5043 /* If arg1 is another cond_expr choosing between -1 and 0, 5044 then we can use its comparison. It may help to avoid 5045 additional comparison, produce more accurate diagnostics 5046 and enables folding. */ 5047 if (TREE_CODE (arg1) == VEC_COND_EXPR 5048 && integer_minus_onep (TREE_OPERAND (arg1, 1)) 5049 && integer_zerop (TREE_OPERAND (arg1, 2))) 5050 arg1 = TREE_OPERAND (arg1, 0); 5051 5052 arg1 = force_rvalue (arg1, complain); 5053 arg2 = force_rvalue (arg2, complain); 5054 arg3 = force_rvalue (arg3, complain); 5055 5056 /* force_rvalue can return error_mark on valid arguments. */ 5057 if (error_operand_p (arg1) 5058 || error_operand_p (arg2) 5059 || error_operand_p (arg3)) 5060 return error_mark_node; 5061 5062 arg2_type = TREE_TYPE (arg2); 5063 arg3_type = TREE_TYPE (arg3); 5064 5065 if (!VECTOR_TYPE_P (arg2_type) 5066 && !VECTOR_TYPE_P (arg3_type)) 5067 { 5068 /* Rely on the error messages of the scalar version. */ 5069 tree scal = build_conditional_expr_1 (loc, integer_one_node, 5070 orig_arg2, orig_arg3, complain); 5071 if (scal == error_mark_node) 5072 return error_mark_node; 5073 tree stype = TREE_TYPE (scal); 5074 tree ctype = TREE_TYPE (arg1_type); 5075 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype) 5076 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype))) 5077 { 5078 if (complain & tf_error) 5079 error_at (loc, "inferred scalar type %qT is not an integer or " 5080 "floating point type of the same size as %qT", stype, 5081 COMPARISON_CLASS_P (arg1) 5082 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0))) 5083 : ctype); 5084 return error_mark_node; 5085 } 5086 5087 tree vtype = build_opaque_vector_type (stype, 5088 TYPE_VECTOR_SUBPARTS (arg1_type)); 5089 /* We could pass complain & tf_warning to unsafe_conversion_p, 5090 but the warnings (like Wsign-conversion) have already been 5091 given by the scalar build_conditional_expr_1. We still check 5092 unsafe_conversion_p to forbid truncating long long -> float. */ 5093 if (unsafe_conversion_p (loc, stype, arg2, NULL_TREE, false)) 5094 { 5095 if (complain & tf_error) 5096 error_at (loc, "conversion of scalar %qH to vector %qI " 5097 "involves truncation", arg2_type, vtype); 5098 return error_mark_node; 5099 } 5100 if (unsafe_conversion_p (loc, stype, arg3, NULL_TREE, false)) 5101 { 5102 if (complain & tf_error) 5103 error_at (loc, "conversion of scalar %qH to vector %qI " 5104 "involves truncation", arg3_type, vtype); 5105 return error_mark_node; 5106 } 5107 5108 arg2 = cp_convert (stype, arg2, complain); 5109 arg2 = save_expr (arg2); 5110 arg2 = build_vector_from_val (vtype, arg2); 5111 arg2_type = vtype; 5112 arg3 = cp_convert (stype, arg3, complain); 5113 arg3 = save_expr (arg3); 5114 arg3 = build_vector_from_val (vtype, arg3); 5115 arg3_type = vtype; 5116 } 5117 5118 if (VECTOR_TYPE_P (arg2_type) != VECTOR_TYPE_P (arg3_type)) 5119 { 5120 enum stv_conv convert_flag = 5121 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3, 5122 complain & tf_error); 5123 5124 switch (convert_flag) 5125 { 5126 case stv_error: 5127 return error_mark_node; 5128 case stv_firstarg: 5129 { 5130 arg2 = save_expr (arg2); 5131 arg2 = convert (TREE_TYPE (arg3_type), arg2); 5132 arg2 = build_vector_from_val (arg3_type, arg2); 5133 arg2_type = TREE_TYPE (arg2); 5134 break; 5135 } 5136 case stv_secondarg: 5137 { 5138 arg3 = save_expr (arg3); 5139 arg3 = convert (TREE_TYPE (arg2_type), arg3); 5140 arg3 = build_vector_from_val (arg2_type, arg3); 5141 arg3_type = TREE_TYPE (arg3); 5142 break; 5143 } 5144 default: 5145 break; 5146 } 5147 } 5148 5149 if (!same_type_p (arg2_type, arg3_type) 5150 || maybe_ne (TYPE_VECTOR_SUBPARTS (arg1_type), 5151 TYPE_VECTOR_SUBPARTS (arg2_type)) 5152 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type)) 5153 { 5154 if (complain & tf_error) 5155 error_at (loc, 5156 "incompatible vector types in conditional expression: " 5157 "%qT, %qT and %qT", TREE_TYPE (arg1), 5158 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3)); 5159 return error_mark_node; 5160 } 5161 5162 if (!COMPARISON_CLASS_P (arg1)) 5163 { 5164 tree cmp_type = build_same_sized_truth_vector_type (arg1_type); 5165 arg1 = build2 (NE_EXPR, cmp_type, arg1, build_zero_cst (arg1_type)); 5166 } 5167 return build3_loc (loc, VEC_COND_EXPR, arg2_type, arg1, arg2, arg3); 5168 } 5169 5170 /* [expr.cond] 5171 5172 The first expression is implicitly converted to bool (clause 5173 _conv_). */ 5174 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 5175 LOOKUP_NORMAL); 5176 if (error_operand_p (arg1)) 5177 return error_mark_node; 5178 5179 /* [expr.cond] 5180 5181 If either the second or the third operand has type (possibly 5182 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 5183 array-to-pointer (_conv.array_), and function-to-pointer 5184 (_conv.func_) standard conversions are performed on the second 5185 and third operands. */ 5186 arg2_type = unlowered_expr_type (arg2); 5187 arg3_type = unlowered_expr_type (arg3); 5188 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 5189 { 5190 /* Do the conversions. We don't these for `void' type arguments 5191 since it can't have any effect and since decay_conversion 5192 does not handle that case gracefully. */ 5193 if (!VOID_TYPE_P (arg2_type)) 5194 arg2 = decay_conversion (arg2, complain); 5195 if (!VOID_TYPE_P (arg3_type)) 5196 arg3 = decay_conversion (arg3, complain); 5197 arg2_type = TREE_TYPE (arg2); 5198 arg3_type = TREE_TYPE (arg3); 5199 5200 /* [expr.cond] 5201 5202 One of the following shall hold: 5203 5204 --The second or the third operand (but not both) is a 5205 throw-expression (_except.throw_); the result is of the 5206 type of the other and is an rvalue. 5207 5208 --Both the second and the third operands have type void; the 5209 result is of type void and is an rvalue. 5210 5211 We must avoid calling force_rvalue for expressions of type 5212 "void" because it will complain that their value is being 5213 used. */ 5214 if (TREE_CODE (arg2) == THROW_EXPR 5215 && TREE_CODE (arg3) != THROW_EXPR) 5216 { 5217 if (!VOID_TYPE_P (arg3_type)) 5218 { 5219 arg3 = force_rvalue (arg3, complain); 5220 if (arg3 == error_mark_node) 5221 return error_mark_node; 5222 } 5223 arg3_type = TREE_TYPE (arg3); 5224 result_type = arg3_type; 5225 } 5226 else if (TREE_CODE (arg2) != THROW_EXPR 5227 && TREE_CODE (arg3) == THROW_EXPR) 5228 { 5229 if (!VOID_TYPE_P (arg2_type)) 5230 { 5231 arg2 = force_rvalue (arg2, complain); 5232 if (arg2 == error_mark_node) 5233 return error_mark_node; 5234 } 5235 arg2_type = TREE_TYPE (arg2); 5236 result_type = arg2_type; 5237 } 5238 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 5239 result_type = void_type_node; 5240 else 5241 { 5242 if (complain & tf_error) 5243 { 5244 if (VOID_TYPE_P (arg2_type)) 5245 error_at (cp_expr_loc_or_loc (arg3, loc), 5246 "second operand to the conditional operator " 5247 "is of type %<void%>, but the third operand is " 5248 "neither a throw-expression nor of type %<void%>"); 5249 else 5250 error_at (cp_expr_loc_or_loc (arg2, loc), 5251 "third operand to the conditional operator " 5252 "is of type %<void%>, but the second operand is " 5253 "neither a throw-expression nor of type %<void%>"); 5254 } 5255 return error_mark_node; 5256 } 5257 5258 is_glvalue = false; 5259 goto valid_operands; 5260 } 5261 /* [expr.cond] 5262 5263 Otherwise, if the second and third operand have different types, 5264 and either has (possibly cv-qualified) class type, or if both are 5265 glvalues of the same value category and the same type except for 5266 cv-qualification, an attempt is made to convert each of those operands 5267 to the type of the other. */ 5268 else if (!same_type_p (arg2_type, arg3_type) 5269 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type) 5270 || (same_type_ignoring_top_level_qualifiers_p (arg2_type, 5271 arg3_type) 5272 && glvalue_p (arg2) && glvalue_p (arg3) 5273 && lvalue_p (arg2) == lvalue_p (arg3)))) 5274 { 5275 conversion *conv2; 5276 conversion *conv3; 5277 bool converted = false; 5278 5279 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5280 p = conversion_obstack_alloc (0); 5281 5282 conv2 = conditional_conversion (arg2, arg3, complain); 5283 conv3 = conditional_conversion (arg3, arg2, complain); 5284 5285 /* [expr.cond] 5286 5287 If both can be converted, or one can be converted but the 5288 conversion is ambiguous, the program is ill-formed. If 5289 neither can be converted, the operands are left unchanged and 5290 further checking is performed as described below. If exactly 5291 one conversion is possible, that conversion is applied to the 5292 chosen operand and the converted operand is used in place of 5293 the original operand for the remainder of this section. */ 5294 if ((conv2 && !conv2->bad_p 5295 && conv3 && !conv3->bad_p) 5296 || (conv2 && conv2->kind == ck_ambig) 5297 || (conv3 && conv3->kind == ck_ambig)) 5298 { 5299 if (complain & tf_error) 5300 { 5301 error_at (loc, "operands to ?: have different types %qT and %qT", 5302 arg2_type, arg3_type); 5303 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p) 5304 inform (loc, " and each type can be converted to the other"); 5305 else if (conv2 && conv2->kind == ck_ambig) 5306 convert_like (conv2, arg2, complain); 5307 else 5308 convert_like (conv3, arg3, complain); 5309 } 5310 result = error_mark_node; 5311 } 5312 else if (conv2 && !conv2->bad_p) 5313 { 5314 arg2 = convert_like (conv2, arg2, complain); 5315 arg2 = convert_from_reference (arg2); 5316 arg2_type = TREE_TYPE (arg2); 5317 /* Even if CONV2 is a valid conversion, the result of the 5318 conversion may be invalid. For example, if ARG3 has type 5319 "volatile X", and X does not have a copy constructor 5320 accepting a "volatile X&", then even if ARG2 can be 5321 converted to X, the conversion will fail. */ 5322 if (error_operand_p (arg2)) 5323 result = error_mark_node; 5324 converted = true; 5325 } 5326 else if (conv3 && !conv3->bad_p) 5327 { 5328 arg3 = convert_like (conv3, arg3, complain); 5329 arg3 = convert_from_reference (arg3); 5330 arg3_type = TREE_TYPE (arg3); 5331 if (error_operand_p (arg3)) 5332 result = error_mark_node; 5333 converted = true; 5334 } 5335 5336 /* Free all the conversions we allocated. */ 5337 obstack_free (&conversion_obstack, p); 5338 5339 if (result) 5340 return result; 5341 5342 /* If, after the conversion, both operands have class type, 5343 treat the cv-qualification of both operands as if it were the 5344 union of the cv-qualification of the operands. 5345 5346 The standard is not clear about what to do in this 5347 circumstance. For example, if the first operand has type 5348 "const X" and the second operand has a user-defined 5349 conversion to "volatile X", what is the type of the second 5350 operand after this step? Making it be "const X" (matching 5351 the first operand) seems wrong, as that discards the 5352 qualification without actually performing a copy. Leaving it 5353 as "volatile X" seems wrong as that will result in the 5354 conditional expression failing altogether, even though, 5355 according to this step, the one operand could be converted to 5356 the type of the other. */ 5357 if (converted 5358 && CLASS_TYPE_P (arg2_type) 5359 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 5360 arg2_type = arg3_type = 5361 cp_build_qualified_type (arg2_type, 5362 cp_type_quals (arg2_type) 5363 | cp_type_quals (arg3_type)); 5364 } 5365 5366 /* [expr.cond] 5367 5368 If the second and third operands are glvalues of the same value 5369 category and have the same type, the result is of that type and 5370 value category. */ 5371 if (((lvalue_p (arg2) && lvalue_p (arg3)) 5372 || (xvalue_p (arg2) && xvalue_p (arg3))) 5373 && same_type_p (arg2_type, arg3_type)) 5374 { 5375 result_type = arg2_type; 5376 if (processing_template_decl) 5377 /* Let lvalue_kind know this was a glvalue. */ 5378 result_type = cp_build_reference_type (result_type, xvalue_p (arg2)); 5379 5380 arg2 = mark_lvalue_use (arg2); 5381 arg3 = mark_lvalue_use (arg3); 5382 goto valid_operands; 5383 } 5384 5385 /* [expr.cond] 5386 5387 Otherwise, the result is an rvalue. If the second and third 5388 operand do not have the same type, and either has (possibly 5389 cv-qualified) class type, overload resolution is used to 5390 determine the conversions (if any) to be applied to the operands 5391 (_over.match.oper_, _over.built_). */ 5392 is_glvalue = false; 5393 if (!same_type_p (arg2_type, arg3_type) 5394 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 5395 { 5396 tree args[3]; 5397 conversion *conv; 5398 bool any_viable_p; 5399 5400 /* Rearrange the arguments so that add_builtin_candidate only has 5401 to know about two args. In build_builtin_candidate, the 5402 arguments are unscrambled. */ 5403 args[0] = arg2; 5404 args[1] = arg3; 5405 args[2] = arg1; 5406 add_builtin_candidates (&candidates, 5407 COND_EXPR, 5408 NOP_EXPR, 5409 ovl_op_identifier (false, COND_EXPR), 5410 args, 5411 LOOKUP_NORMAL, complain); 5412 5413 /* [expr.cond] 5414 5415 If the overload resolution fails, the program is 5416 ill-formed. */ 5417 candidates = splice_viable (candidates, false, &any_viable_p); 5418 if (!any_viable_p) 5419 { 5420 if (complain & tf_error) 5421 error_at (loc, "operands to ?: have different types %qT and %qT", 5422 arg2_type, arg3_type); 5423 return error_mark_node; 5424 } 5425 cand = tourney (candidates, complain); 5426 if (!cand) 5427 { 5428 if (complain & tf_error) 5429 { 5430 auto_diagnostic_group d; 5431 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 5432 print_z_candidates (loc, candidates); 5433 } 5434 return error_mark_node; 5435 } 5436 5437 /* [expr.cond] 5438 5439 Otherwise, the conversions thus determined are applied, and 5440 the converted operands are used in place of the original 5441 operands for the remainder of this section. */ 5442 conv = cand->convs[0]; 5443 arg1 = convert_like (conv, arg1, complain); 5444 conv = cand->convs[1]; 5445 arg2 = convert_like (conv, arg2, complain); 5446 arg2_type = TREE_TYPE (arg2); 5447 conv = cand->convs[2]; 5448 arg3 = convert_like (conv, arg3, complain); 5449 arg3_type = TREE_TYPE (arg3); 5450 } 5451 5452 /* [expr.cond] 5453 5454 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 5455 and function-to-pointer (_conv.func_) standard conversions are 5456 performed on the second and third operands. 5457 5458 We need to force the lvalue-to-rvalue conversion here for class types, 5459 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 5460 that isn't wrapped with a TARGET_EXPR plays havoc with exception 5461 regions. */ 5462 5463 arg2 = force_rvalue (arg2, complain); 5464 if (!CLASS_TYPE_P (arg2_type)) 5465 arg2_type = TREE_TYPE (arg2); 5466 5467 arg3 = force_rvalue (arg3, complain); 5468 if (!CLASS_TYPE_P (arg3_type)) 5469 arg3_type = TREE_TYPE (arg3); 5470 5471 if (arg2 == error_mark_node || arg3 == error_mark_node) 5472 return error_mark_node; 5473 5474 /* [expr.cond] 5475 5476 After those conversions, one of the following shall hold: 5477 5478 --The second and third operands have the same type; the result is of 5479 that type. */ 5480 if (same_type_p (arg2_type, arg3_type)) 5481 result_type = arg2_type; 5482 /* [expr.cond] 5483 5484 --The second and third operands have arithmetic or enumeration 5485 type; the usual arithmetic conversions are performed to bring 5486 them to a common type, and the result is of that type. */ 5487 else if ((ARITHMETIC_TYPE_P (arg2_type) 5488 || UNSCOPED_ENUM_P (arg2_type)) 5489 && (ARITHMETIC_TYPE_P (arg3_type) 5490 || UNSCOPED_ENUM_P (arg3_type))) 5491 { 5492 /* In this case, there is always a common type. */ 5493 result_type = type_after_usual_arithmetic_conversions (arg2_type, 5494 arg3_type); 5495 if (complain & tf_warning) 5496 do_warn_double_promotion (result_type, arg2_type, arg3_type, 5497 "implicit conversion from %qH to %qI to " 5498 "match other result of conditional", 5499 loc); 5500 5501 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 5502 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 5503 { 5504 tree stripped_orig_arg2 = tree_strip_any_location_wrapper (orig_arg2); 5505 tree stripped_orig_arg3 = tree_strip_any_location_wrapper (orig_arg3); 5506 if (TREE_CODE (stripped_orig_arg2) == CONST_DECL 5507 && TREE_CODE (stripped_orig_arg3) == CONST_DECL 5508 && (DECL_CONTEXT (stripped_orig_arg2) 5509 == DECL_CONTEXT (stripped_orig_arg3))) 5510 /* Two enumerators from the same enumeration can have different 5511 types when the enumeration is still being defined. */; 5512 else if (complain & tf_warning) 5513 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in " 5514 "conditional expression: %qT vs %qT", 5515 arg2_type, arg3_type); 5516 } 5517 else if (extra_warnings 5518 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 5519 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 5520 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 5521 && !same_type_p (arg2_type, 5522 type_promotes_to (arg3_type))))) 5523 { 5524 if (complain & tf_warning) 5525 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in " 5526 "conditional expression"); 5527 } 5528 5529 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5530 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5531 } 5532 /* [expr.cond] 5533 5534 --The second and third operands have pointer type, or one has 5535 pointer type and the other is a null pointer constant; pointer 5536 conversions (_conv.ptr_) and qualification conversions 5537 (_conv.qual_) are performed to bring them to their composite 5538 pointer type (_expr.rel_). The result is of the composite 5539 pointer type. 5540 5541 --The second and third operands have pointer to member type, or 5542 one has pointer to member type and the other is a null pointer 5543 constant; pointer to member conversions (_conv.mem_) and 5544 qualification conversions (_conv.qual_) are performed to bring 5545 them to a common type, whose cv-qualification shall match the 5546 cv-qualification of either the second or the third operand. 5547 The result is of the common type. */ 5548 else if ((null_ptr_cst_p (arg2) 5549 && TYPE_PTR_OR_PTRMEM_P (arg3_type)) 5550 || (null_ptr_cst_p (arg3) 5551 && TYPE_PTR_OR_PTRMEM_P (arg2_type)) 5552 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 5553 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type)) 5554 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 5555 { 5556 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 5557 arg3, CPO_CONDITIONAL_EXPR, 5558 complain); 5559 if (result_type == error_mark_node) 5560 return error_mark_node; 5561 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5562 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5563 } 5564 5565 if (!result_type) 5566 { 5567 if (complain & tf_error) 5568 error_at (loc, "operands to ?: have different types %qT and %qT", 5569 arg2_type, arg3_type); 5570 return error_mark_node; 5571 } 5572 5573 if (arg2 == error_mark_node || arg3 == error_mark_node) 5574 return error_mark_node; 5575 5576 valid_operands: 5577 result = build3_loc (loc, COND_EXPR, result_type, arg1, arg2, arg3); 5578 5579 /* If the ARG2 and ARG3 are the same and don't have side-effects, 5580 warn here, because the COND_EXPR will be turned into ARG2. */ 5581 if (warn_duplicated_branches 5582 && (complain & tf_warning) 5583 && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0))) 5584 warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches, 5585 "this condition has identical branches"); 5586 5587 /* We can't use result_type below, as fold might have returned a 5588 throw_expr. */ 5589 5590 if (!is_glvalue) 5591 { 5592 /* Expand both sides into the same slot, hopefully the target of 5593 the ?: expression. We used to check for TARGET_EXPRs here, 5594 but now we sometimes wrap them in NOP_EXPRs so the test would 5595 fail. */ 5596 if (CLASS_TYPE_P (TREE_TYPE (result))) 5597 result = get_target_expr_sfinae (result, complain); 5598 /* If this expression is an rvalue, but might be mistaken for an 5599 lvalue, we must add a NON_LVALUE_EXPR. */ 5600 result = rvalue (result); 5601 } 5602 else 5603 result = force_paren_expr (result); 5604 5605 return result; 5606 } 5607 5608 /* Wrapper for above. */ 5609 5610 tree 5611 build_conditional_expr (const op_location_t &loc, 5612 tree arg1, tree arg2, tree arg3, 5613 tsubst_flags_t complain) 5614 { 5615 tree ret; 5616 bool subtime = timevar_cond_start (TV_OVERLOAD); 5617 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain); 5618 timevar_cond_stop (TV_OVERLOAD, subtime); 5619 return ret; 5620 } 5621 5622 /* OPERAND is an operand to an expression. Perform necessary steps 5623 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 5624 returned. */ 5625 5626 static tree 5627 prep_operand (tree operand) 5628 { 5629 if (operand) 5630 { 5631 if (CLASS_TYPE_P (TREE_TYPE (operand)) 5632 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 5633 /* Make sure the template type is instantiated now. */ 5634 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 5635 } 5636 5637 return operand; 5638 } 5639 5640 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 5641 OVERLOAD) to the CANDIDATES, returning an updated list of 5642 CANDIDATES. The ARGS are the arguments provided to the call; 5643 if FIRST_ARG is non-null it is the implicit object argument, 5644 otherwise the first element of ARGS is used if needed. The 5645 EXPLICIT_TARGS are explicit template arguments provided. 5646 TEMPLATE_ONLY is true if only template functions should be 5647 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 5648 add_function_candidate. */ 5649 5650 static void 5651 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args, 5652 tree return_type, 5653 tree explicit_targs, bool template_only, 5654 tree conversion_path, tree access_path, 5655 int flags, 5656 struct z_candidate **candidates, 5657 tsubst_flags_t complain) 5658 { 5659 tree ctype; 5660 const vec<tree, va_gc> *non_static_args; 5661 bool check_list_ctor = false; 5662 bool check_converting = false; 5663 unification_kind_t strict; 5664 5665 if (!fns) 5666 return; 5667 5668 /* Precalculate special handling of constructors and conversion ops. */ 5669 tree fn = OVL_FIRST (fns); 5670 if (DECL_CONV_FN_P (fn)) 5671 { 5672 check_list_ctor = false; 5673 check_converting = (flags & LOOKUP_ONLYCONVERTING) != 0; 5674 if (flags & LOOKUP_NO_CONVERSION) 5675 /* We're doing return_type(x). */ 5676 strict = DEDUCE_CONV; 5677 else 5678 /* We're doing x.operator return_type(). */ 5679 strict = DEDUCE_EXACT; 5680 /* [over.match.funcs] For conversion functions, the function 5681 is considered to be a member of the class of the implicit 5682 object argument for the purpose of defining the type of 5683 the implicit object parameter. */ 5684 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg)); 5685 } 5686 else 5687 { 5688 if (DECL_CONSTRUCTOR_P (fn)) 5689 { 5690 check_list_ctor = (flags & LOOKUP_LIST_ONLY) != 0; 5691 /* For list-initialization we consider explicit constructors 5692 and complain if one is chosen. */ 5693 check_converting 5694 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 5695 == LOOKUP_ONLYCONVERTING); 5696 } 5697 strict = DEDUCE_CALL; 5698 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 5699 } 5700 5701 if (first_arg) 5702 non_static_args = args; 5703 else 5704 /* Delay creating the implicit this parameter until it is needed. */ 5705 non_static_args = NULL; 5706 5707 for (lkp_iterator iter (fns); iter; ++iter) 5708 { 5709 fn = *iter; 5710 5711 if (check_converting && DECL_NONCONVERTING_P (fn)) 5712 continue; 5713 if (check_list_ctor && !is_list_ctor (fn)) 5714 continue; 5715 5716 tree fn_first_arg = NULL_TREE; 5717 const vec<tree, va_gc> *fn_args = args; 5718 5719 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 5720 { 5721 /* Figure out where the object arg comes from. If this 5722 function is a non-static member and we didn't get an 5723 implicit object argument, move it out of args. */ 5724 if (first_arg == NULL_TREE) 5725 { 5726 unsigned int ix; 5727 tree arg; 5728 vec<tree, va_gc> *tempvec; 5729 vec_alloc (tempvec, args->length () - 1); 5730 for (ix = 1; args->iterate (ix, &arg); ++ix) 5731 tempvec->quick_push (arg); 5732 non_static_args = tempvec; 5733 first_arg = (*args)[0]; 5734 } 5735 5736 fn_first_arg = first_arg; 5737 fn_args = non_static_args; 5738 } 5739 5740 if (TREE_CODE (fn) == TEMPLATE_DECL) 5741 add_template_candidate (candidates, 5742 fn, 5743 ctype, 5744 explicit_targs, 5745 fn_first_arg, 5746 fn_args, 5747 return_type, 5748 access_path, 5749 conversion_path, 5750 flags, 5751 strict, 5752 complain); 5753 else if (!template_only) 5754 add_function_candidate (candidates, 5755 fn, 5756 ctype, 5757 fn_first_arg, 5758 fn_args, 5759 access_path, 5760 conversion_path, 5761 flags, 5762 NULL, 5763 complain); 5764 } 5765 } 5766 5767 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first, 5768 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */ 5769 5770 static int 5771 op_is_ordered (tree_code code) 5772 { 5773 switch (code) 5774 { 5775 // 5. b @= a 5776 case MODIFY_EXPR: 5777 return (flag_strong_eval_order > 1 ? -1 : 0); 5778 5779 // 6. a[b] 5780 case ARRAY_REF: 5781 return (flag_strong_eval_order > 1 ? 1 : 0); 5782 5783 // 1. a.b 5784 // Not overloadable (yet). 5785 // 2. a->b 5786 // Only one argument. 5787 // 3. a->*b 5788 case MEMBER_REF: 5789 // 7. a << b 5790 case LSHIFT_EXPR: 5791 // 8. a >> b 5792 case RSHIFT_EXPR: 5793 return (flag_strong_eval_order ? 1 : 0); 5794 5795 default: 5796 return 0; 5797 } 5798 } 5799 5800 static tree 5801 build_new_op_1 (const op_location_t &loc, enum tree_code code, int flags, 5802 tree arg1, tree arg2, tree arg3, tree *overload, 5803 tsubst_flags_t complain) 5804 { 5805 struct z_candidate *candidates = 0, *cand; 5806 vec<tree, va_gc> *arglist; 5807 tree args[3]; 5808 tree result = NULL_TREE; 5809 bool result_valid_p = false; 5810 enum tree_code code2 = NOP_EXPR; 5811 enum tree_code code_orig_arg1 = ERROR_MARK; 5812 enum tree_code code_orig_arg2 = ERROR_MARK; 5813 conversion *conv; 5814 void *p; 5815 bool strict_p; 5816 bool any_viable_p; 5817 5818 if (error_operand_p (arg1) 5819 || error_operand_p (arg2) 5820 || error_operand_p (arg3)) 5821 return error_mark_node; 5822 5823 bool ismodop = code == MODIFY_EXPR; 5824 if (ismodop) 5825 { 5826 code2 = TREE_CODE (arg3); 5827 arg3 = NULL_TREE; 5828 } 5829 tree fnname = ovl_op_identifier (ismodop, ismodop ? code2 : code); 5830 5831 arg1 = prep_operand (arg1); 5832 5833 bool memonly = false; 5834 switch (code) 5835 { 5836 case NEW_EXPR: 5837 case VEC_NEW_EXPR: 5838 case VEC_DELETE_EXPR: 5839 case DELETE_EXPR: 5840 /* Use build_op_new_call and build_op_delete_call instead. */ 5841 gcc_unreachable (); 5842 5843 case CALL_EXPR: 5844 /* Use build_op_call instead. */ 5845 gcc_unreachable (); 5846 5847 case TRUTH_ORIF_EXPR: 5848 case TRUTH_ANDIF_EXPR: 5849 case TRUTH_AND_EXPR: 5850 case TRUTH_OR_EXPR: 5851 /* These are saved for the sake of warn_logical_operator. */ 5852 code_orig_arg1 = TREE_CODE (arg1); 5853 code_orig_arg2 = TREE_CODE (arg2); 5854 break; 5855 case GT_EXPR: 5856 case LT_EXPR: 5857 case GE_EXPR: 5858 case LE_EXPR: 5859 case EQ_EXPR: 5860 case NE_EXPR: 5861 /* These are saved for the sake of maybe_warn_bool_compare. */ 5862 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1)); 5863 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2)); 5864 break; 5865 5866 /* =, ->, [], () must be non-static member functions. */ 5867 case MODIFY_EXPR: 5868 if (code2 != NOP_EXPR) 5869 break; 5870 /* FALLTHRU */ 5871 case COMPONENT_REF: 5872 case ARRAY_REF: 5873 memonly = true; 5874 break; 5875 5876 default: 5877 break; 5878 } 5879 5880 arg2 = prep_operand (arg2); 5881 arg3 = prep_operand (arg3); 5882 5883 if (code == COND_EXPR) 5884 /* Use build_conditional_expr instead. */ 5885 gcc_unreachable (); 5886 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1)) 5887 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2)))) 5888 goto builtin; 5889 5890 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 5891 arg2 = integer_zero_node; 5892 5893 vec_alloc (arglist, 3); 5894 arglist->quick_push (arg1); 5895 if (arg2 != NULL_TREE) 5896 arglist->quick_push (arg2); 5897 if (arg3 != NULL_TREE) 5898 arglist->quick_push (arg3); 5899 5900 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5901 p = conversion_obstack_alloc (0); 5902 5903 /* Add namespace-scope operators to the list of functions to 5904 consider. */ 5905 if (!memonly) 5906 { 5907 tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0); 5908 fns = lookup_arg_dependent (fnname, fns, arglist); 5909 add_candidates (fns, NULL_TREE, arglist, NULL_TREE, 5910 NULL_TREE, false, NULL_TREE, NULL_TREE, 5911 flags, &candidates, complain); 5912 } 5913 5914 args[0] = arg1; 5915 args[1] = arg2; 5916 args[2] = NULL_TREE; 5917 5918 /* Add class-member operators to the candidate set. */ 5919 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 5920 { 5921 tree fns; 5922 5923 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 5924 if (fns == error_mark_node) 5925 { 5926 result = error_mark_node; 5927 goto user_defined_result_ready; 5928 } 5929 if (fns) 5930 add_candidates (BASELINK_FUNCTIONS (fns), 5931 NULL_TREE, arglist, NULL_TREE, 5932 NULL_TREE, false, 5933 BASELINK_BINFO (fns), 5934 BASELINK_ACCESS_BINFO (fns), 5935 flags, &candidates, complain); 5936 } 5937 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then 5938 only non-member functions that have type T1 or reference to 5939 cv-qualified-opt T1 for the first argument, if the first argument 5940 has an enumeration type, or T2 or reference to cv-qualified-opt 5941 T2 for the second argument, if the second argument has an 5942 enumeration type. Filter out those that don't match. */ 5943 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2))) 5944 { 5945 struct z_candidate **candp, **next; 5946 5947 for (candp = &candidates; *candp; candp = next) 5948 { 5949 tree parmlist, parmtype; 5950 int i, nargs = (arg2 ? 2 : 1); 5951 5952 cand = *candp; 5953 next = &cand->next; 5954 5955 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 5956 5957 for (i = 0; i < nargs; ++i) 5958 { 5959 parmtype = TREE_VALUE (parmlist); 5960 5961 if (TYPE_REF_P (parmtype)) 5962 parmtype = TREE_TYPE (parmtype); 5963 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE 5964 && (same_type_ignoring_top_level_qualifiers_p 5965 (TREE_TYPE (args[i]), parmtype))) 5966 break; 5967 5968 parmlist = TREE_CHAIN (parmlist); 5969 } 5970 5971 /* No argument has an appropriate type, so remove this 5972 candidate function from the list. */ 5973 if (i == nargs) 5974 { 5975 *candp = cand->next; 5976 next = candp; 5977 } 5978 } 5979 } 5980 5981 add_builtin_candidates (&candidates, code, code2, fnname, args, 5982 flags, complain); 5983 5984 switch (code) 5985 { 5986 case COMPOUND_EXPR: 5987 case ADDR_EXPR: 5988 /* For these, the built-in candidates set is empty 5989 [over.match.oper]/3. We don't want non-strict matches 5990 because exact matches are always possible with built-in 5991 operators. The built-in candidate set for COMPONENT_REF 5992 would be empty too, but since there are no such built-in 5993 operators, we accept non-strict matches for them. */ 5994 strict_p = true; 5995 break; 5996 5997 default: 5998 strict_p = false; 5999 break; 6000 } 6001 6002 candidates = splice_viable (candidates, strict_p, &any_viable_p); 6003 if (!any_viable_p) 6004 { 6005 switch (code) 6006 { 6007 case POSTINCREMENT_EXPR: 6008 case POSTDECREMENT_EXPR: 6009 /* Don't try anything fancy if we're not allowed to produce 6010 errors. */ 6011 if (!(complain & tf_error)) 6012 return error_mark_node; 6013 6014 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 6015 distinguish between prefix and postfix ++ and 6016 operator++() was used for both, so we allow this with 6017 -fpermissive. */ 6018 else 6019 { 6020 const char *msg = (flag_permissive) 6021 ? G_("no %<%D(int)%> declared for postfix %qs," 6022 " trying prefix operator instead") 6023 : G_("no %<%D(int)%> declared for postfix %qs"); 6024 permerror (loc, msg, fnname, OVL_OP_INFO (false, code)->name); 6025 } 6026 6027 if (!flag_permissive) 6028 return error_mark_node; 6029 6030 if (code == POSTINCREMENT_EXPR) 6031 code = PREINCREMENT_EXPR; 6032 else 6033 code = PREDECREMENT_EXPR; 6034 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE, 6035 NULL_TREE, overload, complain); 6036 break; 6037 6038 /* The caller will deal with these. */ 6039 case ADDR_EXPR: 6040 case COMPOUND_EXPR: 6041 case COMPONENT_REF: 6042 result = NULL_TREE; 6043 result_valid_p = true; 6044 break; 6045 6046 default: 6047 if (complain & tf_error) 6048 { 6049 /* If one of the arguments of the operator represents 6050 an invalid use of member function pointer, try to report 6051 a meaningful error ... */ 6052 if (invalid_nonstatic_memfn_p (loc, arg1, tf_error) 6053 || invalid_nonstatic_memfn_p (loc, arg2, tf_error) 6054 || invalid_nonstatic_memfn_p (loc, arg3, tf_error)) 6055 /* We displayed the error message. */; 6056 else 6057 { 6058 /* ... Otherwise, report the more generic 6059 "no matching operator found" error */ 6060 auto_diagnostic_group d; 6061 op_error (loc, code, code2, arg1, arg2, arg3, FALSE); 6062 print_z_candidates (loc, candidates); 6063 } 6064 } 6065 result = error_mark_node; 6066 break; 6067 } 6068 } 6069 else 6070 { 6071 cand = tourney (candidates, complain); 6072 if (cand == 0) 6073 { 6074 if (complain & tf_error) 6075 { 6076 auto_diagnostic_group d; 6077 op_error (loc, code, code2, arg1, arg2, arg3, TRUE); 6078 print_z_candidates (loc, candidates); 6079 } 6080 result = error_mark_node; 6081 } 6082 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 6083 { 6084 if (overload) 6085 *overload = cand->fn; 6086 6087 if (resolve_args (arglist, complain) == NULL) 6088 result = error_mark_node; 6089 else 6090 result = build_over_call (cand, LOOKUP_NORMAL, complain); 6091 6092 if (trivial_fn_p (cand->fn)) 6093 /* There won't be a CALL_EXPR. */; 6094 else if (result && result != error_mark_node) 6095 { 6096 tree call = extract_call_expr (result); 6097 CALL_EXPR_OPERATOR_SYNTAX (call) = true; 6098 6099 if (processing_template_decl && DECL_HIDDEN_FRIEND_P (cand->fn)) 6100 /* This prevents build_new_function_call from discarding this 6101 function during instantiation of the enclosing template. */ 6102 KOENIG_LOOKUP_P (call) = 1; 6103 6104 /* Specify evaluation order as per P0145R2. */ 6105 CALL_EXPR_ORDERED_ARGS (call) = false; 6106 switch (op_is_ordered (code)) 6107 { 6108 case -1: 6109 CALL_EXPR_REVERSE_ARGS (call) = true; 6110 break; 6111 6112 case 1: 6113 CALL_EXPR_ORDERED_ARGS (call) = true; 6114 break; 6115 6116 default: 6117 break; 6118 } 6119 } 6120 } 6121 else 6122 { 6123 /* Give any warnings we noticed during overload resolution. */ 6124 if (cand->warnings && (complain & tf_warning)) 6125 { 6126 struct candidate_warning *w; 6127 for (w = cand->warnings; w; w = w->next) 6128 joust (cand, w->loser, 1, complain); 6129 } 6130 6131 /* Check for comparison of different enum types. */ 6132 switch (code) 6133 { 6134 case GT_EXPR: 6135 case LT_EXPR: 6136 case GE_EXPR: 6137 case LE_EXPR: 6138 case EQ_EXPR: 6139 case NE_EXPR: 6140 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 6141 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 6142 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 6143 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 6144 && (complain & tf_warning)) 6145 { 6146 warning (OPT_Wenum_compare, 6147 "comparison between %q#T and %q#T", 6148 TREE_TYPE (arg1), TREE_TYPE (arg2)); 6149 } 6150 break; 6151 default: 6152 break; 6153 } 6154 6155 /* We need to strip any leading REF_BIND so that bitfields 6156 don't cause errors. This should not remove any important 6157 conversions, because builtins don't apply to class 6158 objects directly. */ 6159 conv = cand->convs[0]; 6160 if (conv->kind == ck_ref_bind) 6161 conv = next_conversion (conv); 6162 arg1 = convert_like (conv, arg1, complain); 6163 6164 if (arg2) 6165 { 6166 conv = cand->convs[1]; 6167 if (conv->kind == ck_ref_bind) 6168 conv = next_conversion (conv); 6169 else 6170 arg2 = decay_conversion (arg2, complain); 6171 6172 /* We need to call warn_logical_operator before 6173 converting arg2 to a boolean_type, but after 6174 decaying an enumerator to its value. */ 6175 if (complain & tf_warning) 6176 warn_logical_operator (loc, code, boolean_type_node, 6177 code_orig_arg1, arg1, 6178 code_orig_arg2, arg2); 6179 6180 arg2 = convert_like (conv, arg2, complain); 6181 } 6182 if (arg3) 6183 { 6184 conv = cand->convs[2]; 6185 if (conv->kind == ck_ref_bind) 6186 conv = next_conversion (conv); 6187 arg3 = convert_like (conv, arg3, complain); 6188 } 6189 6190 } 6191 } 6192 6193 user_defined_result_ready: 6194 6195 /* Free all the conversions we allocated. */ 6196 obstack_free (&conversion_obstack, p); 6197 6198 if (result || result_valid_p) 6199 return result; 6200 6201 builtin: 6202 switch (code) 6203 { 6204 case MODIFY_EXPR: 6205 return cp_build_modify_expr (loc, arg1, code2, arg2, complain); 6206 6207 case INDIRECT_REF: 6208 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 6209 6210 case TRUTH_ANDIF_EXPR: 6211 case TRUTH_ORIF_EXPR: 6212 case TRUTH_AND_EXPR: 6213 case TRUTH_OR_EXPR: 6214 if (complain & tf_warning) 6215 warn_logical_operator (loc, code, boolean_type_node, 6216 code_orig_arg1, arg1, 6217 code_orig_arg2, arg2); 6218 /* Fall through. */ 6219 case GT_EXPR: 6220 case LT_EXPR: 6221 case GE_EXPR: 6222 case LE_EXPR: 6223 case EQ_EXPR: 6224 case NE_EXPR: 6225 if ((complain & tf_warning) 6226 && ((code_orig_arg1 == BOOLEAN_TYPE) 6227 ^ (code_orig_arg2 == BOOLEAN_TYPE))) 6228 maybe_warn_bool_compare (loc, code, arg1, arg2); 6229 if (complain & tf_warning && warn_tautological_compare) 6230 warn_tautological_cmp (loc, code, arg1, arg2); 6231 /* Fall through. */ 6232 case PLUS_EXPR: 6233 case MINUS_EXPR: 6234 case MULT_EXPR: 6235 case TRUNC_DIV_EXPR: 6236 case MAX_EXPR: 6237 case MIN_EXPR: 6238 case LSHIFT_EXPR: 6239 case RSHIFT_EXPR: 6240 case TRUNC_MOD_EXPR: 6241 case BIT_AND_EXPR: 6242 case BIT_IOR_EXPR: 6243 case BIT_XOR_EXPR: 6244 return cp_build_binary_op (loc, code, arg1, arg2, complain); 6245 6246 case UNARY_PLUS_EXPR: 6247 case NEGATE_EXPR: 6248 case BIT_NOT_EXPR: 6249 case TRUTH_NOT_EXPR: 6250 case PREINCREMENT_EXPR: 6251 case POSTINCREMENT_EXPR: 6252 case PREDECREMENT_EXPR: 6253 case POSTDECREMENT_EXPR: 6254 case REALPART_EXPR: 6255 case IMAGPART_EXPR: 6256 case ABS_EXPR: 6257 return cp_build_unary_op (code, arg1, candidates != 0, complain); 6258 6259 case ARRAY_REF: 6260 return cp_build_array_ref (input_location, arg1, arg2, complain); 6261 6262 case MEMBER_REF: 6263 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR, 6264 complain), 6265 arg2, complain); 6266 6267 /* The caller will deal with these. */ 6268 case ADDR_EXPR: 6269 case COMPONENT_REF: 6270 case COMPOUND_EXPR: 6271 return NULL_TREE; 6272 6273 default: 6274 gcc_unreachable (); 6275 } 6276 return NULL_TREE; 6277 } 6278 6279 /* Wrapper for above. */ 6280 6281 tree 6282 build_new_op (const op_location_t &loc, enum tree_code code, int flags, 6283 tree arg1, tree arg2, tree arg3, 6284 tree *overload, tsubst_flags_t complain) 6285 { 6286 tree ret; 6287 bool subtime = timevar_cond_start (TV_OVERLOAD); 6288 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3, 6289 overload, complain); 6290 timevar_cond_stop (TV_OVERLOAD, subtime); 6291 return ret; 6292 } 6293 6294 /* CALL was returned by some call-building function; extract the actual 6295 CALL_EXPR from any bits that have been tacked on, e.g. by 6296 convert_from_reference. */ 6297 6298 tree 6299 extract_call_expr (tree call) 6300 { 6301 while (TREE_CODE (call) == COMPOUND_EXPR) 6302 call = TREE_OPERAND (call, 1); 6303 if (REFERENCE_REF_P (call)) 6304 call = TREE_OPERAND (call, 0); 6305 if (TREE_CODE (call) == TARGET_EXPR) 6306 call = TARGET_EXPR_INITIAL (call); 6307 gcc_assert (TREE_CODE (call) == CALL_EXPR 6308 || TREE_CODE (call) == AGGR_INIT_EXPR 6309 || call == error_mark_node); 6310 return call; 6311 } 6312 6313 /* Returns true if FN has two parameters, of which the second has type 6314 size_t. */ 6315 6316 static bool 6317 second_parm_is_size_t (tree fn) 6318 { 6319 tree t = FUNCTION_ARG_CHAIN (fn); 6320 if (!t || !same_type_p (TREE_VALUE (t), size_type_node)) 6321 return false; 6322 t = TREE_CHAIN (t); 6323 if (t == void_list_node) 6324 return true; 6325 return false; 6326 } 6327 6328 /* True if T, an allocation function, has std::align_val_t as its second 6329 argument. */ 6330 6331 bool 6332 aligned_allocation_fn_p (tree t) 6333 { 6334 if (!aligned_new_threshold) 6335 return false; 6336 6337 tree a = FUNCTION_ARG_CHAIN (t); 6338 return (a && same_type_p (TREE_VALUE (a), align_type_node)); 6339 } 6340 6341 /* True if T is std::destroying_delete_t. */ 6342 6343 static bool 6344 std_destroying_delete_t_p (tree t) 6345 { 6346 return (TYPE_CONTEXT (t) == std_node 6347 && id_equal (TYPE_IDENTIFIER (t), "destroying_delete_t")); 6348 } 6349 6350 /* A deallocation function with at least two parameters whose second parameter 6351 type is of type std::destroying_delete_t is a destroying operator delete. A 6352 destroying operator delete shall be a class member function named operator 6353 delete. [ Note: Array deletion cannot use a destroying operator 6354 delete. --end note ] */ 6355 6356 tree 6357 destroying_delete_p (tree t) 6358 { 6359 tree a = TYPE_ARG_TYPES (TREE_TYPE (t)); 6360 if (!a || !TREE_CHAIN (a)) 6361 return NULL_TREE; 6362 tree type = TREE_VALUE (TREE_CHAIN (a)); 6363 return std_destroying_delete_t_p (type) ? type : NULL_TREE; 6364 } 6365 6366 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation 6367 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of 6368 std::align_val_t. */ 6369 6370 static bool 6371 aligned_deallocation_fn_p (tree t) 6372 { 6373 if (!aligned_new_threshold) 6374 return false; 6375 6376 /* A template instance is never a usual deallocation function, 6377 regardless of its signature. */ 6378 if (TREE_CODE (t) == TEMPLATE_DECL 6379 || primary_template_specialization_p (t)) 6380 return false; 6381 6382 tree a = FUNCTION_ARG_CHAIN (t); 6383 if (destroying_delete_p (t)) 6384 a = TREE_CHAIN (a); 6385 if (same_type_p (TREE_VALUE (a), align_type_node) 6386 && TREE_CHAIN (a) == void_list_node) 6387 return true; 6388 if (!same_type_p (TREE_VALUE (a), size_type_node)) 6389 return false; 6390 a = TREE_CHAIN (a); 6391 if (a && same_type_p (TREE_VALUE (a), align_type_node) 6392 && TREE_CHAIN (a) == void_list_node) 6393 return true; 6394 return false; 6395 } 6396 6397 /* Returns true if FN is a usual deallocation fn with a size_t parameter. */ 6398 6399 static bool 6400 sized_deallocation_fn_p (tree fn) 6401 { 6402 tree t = FUNCTION_ARG_CHAIN (fn); 6403 if (destroying_delete_p (fn)) 6404 t = TREE_CHAIN (t); 6405 if (!t || !same_type_p (TREE_VALUE (t), size_type_node)) 6406 return false; 6407 t = TREE_CHAIN (t); 6408 if (t == void_list_node) 6409 return true; 6410 if (aligned_new_threshold && t 6411 && same_type_p (TREE_VALUE (t), align_type_node) 6412 && TREE_CHAIN (t) == void_list_node) 6413 return true; 6414 return false; 6415 } 6416 6417 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 6418 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 6419 6420 bool 6421 usual_deallocation_fn_p (tree t) 6422 { 6423 /* A template instance is never a usual deallocation function, 6424 regardless of its signature. */ 6425 if (TREE_CODE (t) == TEMPLATE_DECL 6426 || primary_template_specialization_p (t)) 6427 return false; 6428 6429 /* A usual deallocation function is a deallocation function whose parameters 6430 after the first are 6431 - optionally, a parameter of type std::destroying_delete_t, then 6432 - optionally, a parameter of type std::size_t, then 6433 - optionally, a parameter of type std::align_val_t. */ 6434 bool global = DECL_NAMESPACE_SCOPE_P (t); 6435 tree chain = FUNCTION_ARG_CHAIN (t); 6436 if (!chain) 6437 return false; 6438 if (destroying_delete_p (t)) 6439 chain = TREE_CHAIN (chain); 6440 if (chain == void_list_node 6441 || ((!global || flag_sized_deallocation) 6442 && sized_deallocation_fn_p (t))) 6443 return true; 6444 if (aligned_deallocation_fn_p (t)) 6445 return true; 6446 return false; 6447 } 6448 6449 /* Build a call to operator delete. This has to be handled very specially, 6450 because the restrictions on what signatures match are different from all 6451 other call instances. For a normal delete, only a delete taking (void *) 6452 or (void *, size_t) is accepted. For a placement delete, only an exact 6453 match with the placement new is accepted. 6454 6455 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 6456 ADDR is the pointer to be deleted. 6457 SIZE is the size of the memory block to be deleted. 6458 GLOBAL_P is true if the delete-expression should not consider 6459 class-specific delete operators. 6460 PLACEMENT is the corresponding placement new call, or NULL_TREE. 6461 6462 If this call to "operator delete" is being generated as part to 6463 deallocate memory allocated via a new-expression (as per [expr.new] 6464 which requires that if the initialization throws an exception then 6465 we call a deallocation function), then ALLOC_FN is the allocation 6466 function. */ 6467 6468 tree 6469 build_op_delete_call (enum tree_code code, tree addr, tree size, 6470 bool global_p, tree placement, 6471 tree alloc_fn, tsubst_flags_t complain) 6472 { 6473 tree fn = NULL_TREE; 6474 tree fns, fnname, type, t; 6475 6476 if (addr == error_mark_node) 6477 return error_mark_node; 6478 6479 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 6480 6481 fnname = ovl_op_identifier (false, code); 6482 6483 if (CLASS_TYPE_P (type) 6484 && COMPLETE_TYPE_P (complete_type (type)) 6485 && !global_p) 6486 /* In [class.free] 6487 6488 If the result of the lookup is ambiguous or inaccessible, or if 6489 the lookup selects a placement deallocation function, the 6490 program is ill-formed. 6491 6492 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 6493 { 6494 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 6495 if (fns == error_mark_node) 6496 return error_mark_node; 6497 } 6498 else 6499 fns = NULL_TREE; 6500 6501 if (fns == NULL_TREE) 6502 fns = lookup_name_nonclass (fnname); 6503 6504 /* Strip const and volatile from addr. */ 6505 tree oaddr = addr; 6506 addr = cp_convert (ptr_type_node, addr, complain); 6507 6508 if (placement) 6509 { 6510 /* "A declaration of a placement deallocation function matches the 6511 declaration of a placement allocation function if it has the same 6512 number of parameters and, after parameter transformations (8.3.5), 6513 all parameter types except the first are identical." 6514 6515 So we build up the function type we want and ask instantiate_type 6516 to get it for us. */ 6517 t = FUNCTION_ARG_CHAIN (alloc_fn); 6518 t = tree_cons (NULL_TREE, ptr_type_node, t); 6519 t = build_function_type (void_type_node, t); 6520 6521 fn = instantiate_type (t, fns, tf_none); 6522 if (fn == error_mark_node) 6523 return NULL_TREE; 6524 6525 fn = MAYBE_BASELINK_FUNCTIONS (fn); 6526 6527 /* "If the lookup finds the two-parameter form of a usual deallocation 6528 function (3.7.4.2) and that function, considered as a placement 6529 deallocation function, would have been selected as a match for the 6530 allocation function, the program is ill-formed." */ 6531 if (second_parm_is_size_t (fn)) 6532 { 6533 const char *const msg1 6534 = G_("exception cleanup for this placement new selects " 6535 "non-placement operator delete"); 6536 const char *const msg2 6537 = G_("%qD is a usual (non-placement) deallocation " 6538 "function in C++14 (or with -fsized-deallocation)"); 6539 6540 /* But if the class has an operator delete (void *), then that is 6541 the usual deallocation function, so we shouldn't complain 6542 about using the operator delete (void *, size_t). */ 6543 if (DECL_CLASS_SCOPE_P (fn)) 6544 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); 6545 iter; ++iter) 6546 { 6547 tree elt = *iter; 6548 if (usual_deallocation_fn_p (elt) 6549 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 6550 goto ok; 6551 } 6552 /* Before C++14 a two-parameter global deallocation function is 6553 always a placement deallocation function, but warn if 6554 -Wc++14-compat. */ 6555 else if (!flag_sized_deallocation) 6556 { 6557 if (complain & tf_warning) 6558 { 6559 auto_diagnostic_group d; 6560 if (warning (OPT_Wc__14_compat, msg1)) 6561 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6562 } 6563 goto ok; 6564 } 6565 6566 if (complain & tf_warning_or_error) 6567 { 6568 auto_diagnostic_group d; 6569 if (permerror (input_location, msg1)) 6570 { 6571 /* Only mention C++14 for namespace-scope delete. */ 6572 if (DECL_NAMESPACE_SCOPE_P (fn)) 6573 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6574 else 6575 inform (DECL_SOURCE_LOCATION (fn), 6576 "%qD is a usual (non-placement) deallocation " 6577 "function", fn); 6578 } 6579 } 6580 else 6581 return error_mark_node; 6582 ok:; 6583 } 6584 } 6585 else 6586 /* "Any non-placement deallocation function matches a non-placement 6587 allocation function. If the lookup finds a single matching 6588 deallocation function, that function will be called; otherwise, no 6589 deallocation function will be called." */ 6590 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter) 6591 { 6592 tree elt = *iter; 6593 if (usual_deallocation_fn_p (elt)) 6594 { 6595 if (!fn) 6596 { 6597 fn = elt; 6598 continue; 6599 } 6600 6601 /* -- If any of the deallocation functions is a destroying 6602 operator delete, all deallocation functions that are not 6603 destroying operator deletes are eliminated from further 6604 consideration. */ 6605 bool fn_destroying = destroying_delete_p (fn); 6606 bool elt_destroying = destroying_delete_p (elt); 6607 if (elt_destroying != fn_destroying) 6608 { 6609 if (elt_destroying) 6610 fn = elt; 6611 continue; 6612 } 6613 6614 /* -- If the type has new-extended alignment, a function with a 6615 parameter of type std::align_val_t is preferred; otherwise a 6616 function without such a parameter is preferred. If exactly one 6617 preferred function is found, that function is selected and the 6618 selection process terminates. If more than one preferred 6619 function is found, all non-preferred functions are eliminated 6620 from further consideration. */ 6621 if (aligned_new_threshold) 6622 { 6623 bool want_align = type_has_new_extended_alignment (type); 6624 bool fn_align = aligned_deallocation_fn_p (fn); 6625 bool elt_align = aligned_deallocation_fn_p (elt); 6626 6627 if (elt_align != fn_align) 6628 { 6629 if (want_align == elt_align) 6630 fn = elt; 6631 continue; 6632 } 6633 } 6634 6635 /* -- If the deallocation functions have class scope, the one 6636 without a parameter of type std::size_t is selected. */ 6637 bool want_size; 6638 if (DECL_CLASS_SCOPE_P (fn)) 6639 want_size = false; 6640 6641 /* -- If the type is complete and if, for the second alternative 6642 (delete array) only, the operand is a pointer to a class type 6643 with a non-trivial destructor or a (possibly multi-dimensional) 6644 array thereof, the function with a parameter of type std::size_t 6645 is selected. 6646 6647 -- Otherwise, it is unspecified whether a deallocation function 6648 with a parameter of type std::size_t is selected. */ 6649 else 6650 { 6651 want_size = COMPLETE_TYPE_P (type); 6652 if (code == VEC_DELETE_EXPR 6653 && !TYPE_VEC_NEW_USES_COOKIE (type)) 6654 /* We need a cookie to determine the array size. */ 6655 want_size = false; 6656 } 6657 bool fn_size = sized_deallocation_fn_p (fn); 6658 bool elt_size = sized_deallocation_fn_p (elt); 6659 gcc_assert (fn_size != elt_size); 6660 if (want_size == elt_size) 6661 fn = elt; 6662 } 6663 } 6664 6665 /* If we have a matching function, call it. */ 6666 if (fn) 6667 { 6668 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 6669 6670 /* If the FN is a member function, make sure that it is 6671 accessible. */ 6672 if (BASELINK_P (fns)) 6673 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn, 6674 complain); 6675 6676 /* Core issue 901: It's ok to new a type with deleted delete. */ 6677 if (DECL_DELETED_FN (fn) && alloc_fn) 6678 return NULL_TREE; 6679 6680 if (placement) 6681 { 6682 /* The placement args might not be suitable for overload 6683 resolution at this point, so build the call directly. */ 6684 int nargs = call_expr_nargs (placement); 6685 tree *argarray = XALLOCAVEC (tree, nargs); 6686 int i; 6687 argarray[0] = addr; 6688 for (i = 1; i < nargs; i++) 6689 argarray[i] = CALL_EXPR_ARG (placement, i); 6690 if (!mark_used (fn, complain) && !(complain & tf_error)) 6691 return error_mark_node; 6692 return build_cxx_call (fn, nargs, argarray, complain); 6693 } 6694 else 6695 { 6696 tree destroying = destroying_delete_p (fn); 6697 if (destroying) 6698 { 6699 /* Strip const and volatile from addr but retain the type of the 6700 object. */ 6701 tree rtype = TREE_TYPE (TREE_TYPE (oaddr)); 6702 rtype = cv_unqualified (rtype); 6703 rtype = TYPE_POINTER_TO (rtype); 6704 addr = cp_convert (rtype, oaddr, complain); 6705 destroying = build_functional_cast (destroying, NULL_TREE, 6706 complain); 6707 } 6708 6709 tree ret; 6710 vec<tree, va_gc> *args = make_tree_vector (); 6711 args->quick_push (addr); 6712 if (destroying) 6713 args->quick_push (destroying); 6714 if (sized_deallocation_fn_p (fn)) 6715 args->quick_push (size); 6716 if (aligned_deallocation_fn_p (fn)) 6717 { 6718 tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type)); 6719 args->quick_push (al); 6720 } 6721 ret = cp_build_function_call_vec (fn, &args, complain); 6722 release_tree_vector (args); 6723 return ret; 6724 } 6725 } 6726 6727 /* [expr.new] 6728 6729 If no unambiguous matching deallocation function can be found, 6730 propagating the exception does not cause the object's memory to 6731 be freed. */ 6732 if (alloc_fn) 6733 { 6734 if ((complain & tf_warning) 6735 && !placement) 6736 warning (0, "no corresponding deallocation function for %qD", 6737 alloc_fn); 6738 return NULL_TREE; 6739 } 6740 6741 if (complain & tf_error) 6742 error ("no suitable %<operator %s%> for %qT", 6743 OVL_OP_INFO (false, code)->name, type); 6744 return error_mark_node; 6745 } 6746 6747 /* Issue diagnostics about a disallowed access of DECL, using DIAG_DECL 6748 in the diagnostics. 6749 6750 If ISSUE_ERROR is true, then issue an error about the 6751 access, followed by a note showing the declaration. 6752 Otherwise, just show the note. */ 6753 6754 void 6755 complain_about_access (tree decl, tree diag_decl, bool issue_error) 6756 { 6757 if (TREE_PRIVATE (decl)) 6758 { 6759 if (issue_error) 6760 error ("%q#D is private within this context", diag_decl); 6761 inform (DECL_SOURCE_LOCATION (diag_decl), 6762 "declared private here"); 6763 } 6764 else if (TREE_PROTECTED (decl)) 6765 { 6766 if (issue_error) 6767 error ("%q#D is protected within this context", diag_decl); 6768 inform (DECL_SOURCE_LOCATION (diag_decl), 6769 "declared protected here"); 6770 } 6771 else 6772 { 6773 if (issue_error) 6774 error ("%q#D is inaccessible within this context", diag_decl); 6775 inform (DECL_SOURCE_LOCATION (diag_decl), "declared here"); 6776 } 6777 } 6778 6779 /* If the current scope isn't allowed to access DECL along 6780 BASETYPE_PATH, give an error. The most derived class in 6781 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 6782 the declaration to use in the error diagnostic. */ 6783 6784 bool 6785 enforce_access (tree basetype_path, tree decl, tree diag_decl, 6786 tsubst_flags_t complain, access_failure_info *afi) 6787 { 6788 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 6789 6790 if (flag_new_inheriting_ctors 6791 && DECL_INHERITED_CTOR (decl)) 6792 { 6793 /* 7.3.3/18: The additional constructors are accessible if they would be 6794 accessible when used to construct an object of the corresponding base 6795 class. */ 6796 decl = strip_inheriting_ctors (decl); 6797 basetype_path = lookup_base (basetype_path, DECL_CONTEXT (decl), 6798 ba_any, NULL, complain); 6799 } 6800 6801 if (!accessible_p (basetype_path, decl, true)) 6802 { 6803 if (flag_new_inheriting_ctors) 6804 diag_decl = strip_inheriting_ctors (diag_decl); 6805 if (complain & tf_error) 6806 complain_about_access (decl, diag_decl, true); 6807 if (afi) 6808 afi->record_access_failure (basetype_path, decl, diag_decl); 6809 return false; 6810 } 6811 6812 return true; 6813 } 6814 6815 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 6816 bitwise or of LOOKUP_* values. If any errors are warnings are 6817 generated, set *DIAGNOSTIC_FN to "error" or "warning", 6818 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 6819 to NULL. */ 6820 6821 static tree 6822 build_temp (tree expr, tree type, int flags, 6823 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 6824 { 6825 int savew, savee; 6826 vec<tree, va_gc> *args; 6827 6828 *diagnostic_kind = DK_UNSPECIFIED; 6829 6830 /* If the source is a packed field, calling the copy constructor will require 6831 binding the field to the reference parameter to the copy constructor, and 6832 we'll end up with an infinite loop. If we can use a bitwise copy, then 6833 do that now. */ 6834 if ((lvalue_kind (expr) & clk_packed) 6835 && CLASS_TYPE_P (TREE_TYPE (expr)) 6836 && !type_has_nontrivial_copy_init (TREE_TYPE (expr))) 6837 return get_target_expr_sfinae (expr, complain); 6838 6839 savew = warningcount + werrorcount, savee = errorcount; 6840 args = make_tree_vector_single (expr); 6841 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 6842 &args, type, flags, complain); 6843 release_tree_vector (args); 6844 if (warningcount + werrorcount > savew) 6845 *diagnostic_kind = DK_WARNING; 6846 else if (errorcount > savee) 6847 *diagnostic_kind = DK_ERROR; 6848 return expr; 6849 } 6850 6851 /* Get any location for EXPR, falling back to input_location. 6852 6853 If the result is in a system header and is the virtual location for 6854 a token coming from the expansion of a macro, unwind it to the 6855 location of the expansion point of the macro (e.g. to avoid the 6856 diagnostic being suppressed for expansions of NULL where "NULL" is 6857 in a system header). */ 6858 6859 static location_t 6860 get_location_for_expr_unwinding_for_system_header (tree expr) 6861 { 6862 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 6863 loc = expansion_point_location_if_in_system_header (loc); 6864 return loc; 6865 } 6866 6867 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 6868 Also handle a subset of zero as null warnings. 6869 EXPR is implicitly converted to type TOTYPE. 6870 FN and ARGNUM are used for diagnostics. */ 6871 6872 static void 6873 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 6874 { 6875 /* Issue warnings about peculiar, but valid, uses of NULL. */ 6876 if (TREE_CODE (totype) != BOOLEAN_TYPE 6877 && ARITHMETIC_TYPE_P (totype) 6878 && null_node_p (expr)) 6879 { 6880 location_t loc = get_location_for_expr_unwinding_for_system_header (expr); 6881 if (fn) 6882 { 6883 auto_diagnostic_group d; 6884 if (warning_at (loc, OPT_Wconversion_null, 6885 "passing NULL to non-pointer argument %P of %qD", 6886 argnum, fn)) 6887 inform (get_fndecl_argument_location (fn, argnum), 6888 " declared here"); 6889 } 6890 else 6891 warning_at (loc, OPT_Wconversion_null, 6892 "converting to non-pointer type %qT from NULL", totype); 6893 } 6894 6895 /* Issue warnings if "false" is converted to a NULL pointer */ 6896 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 6897 && TYPE_PTR_P (totype)) 6898 { 6899 location_t loc = get_location_for_expr_unwinding_for_system_header (expr); 6900 if (fn) 6901 { 6902 auto_diagnostic_group d; 6903 if (warning_at (loc, OPT_Wconversion_null, 6904 "converting %<false%> to pointer type for argument " 6905 "%P of %qD", argnum, fn)) 6906 inform (get_fndecl_argument_location (fn, argnum), 6907 " declared here"); 6908 } 6909 else 6910 warning_at (loc, OPT_Wconversion_null, 6911 "converting %<false%> to pointer type %qT", totype); 6912 } 6913 /* Handle zero as null pointer warnings for cases other 6914 than EQ_EXPR and NE_EXPR */ 6915 else if ((TYPE_PTR_OR_PTRMEM_P (totype) || NULLPTR_TYPE_P (totype)) 6916 && null_ptr_cst_p (expr)) 6917 { 6918 location_t loc = get_location_for_expr_unwinding_for_system_header (expr); 6919 maybe_warn_zero_as_null_pointer_constant (expr, loc); 6920 } 6921 } 6922 6923 /* We gave a diagnostic during a conversion. If this was in the second 6924 standard conversion sequence of a user-defined conversion sequence, say 6925 which user-defined conversion. */ 6926 6927 static void 6928 maybe_print_user_conv_context (conversion *convs) 6929 { 6930 if (convs->user_conv_p) 6931 for (conversion *t = convs; t; t = next_conversion (t)) 6932 if (t->kind == ck_user) 6933 { 6934 print_z_candidate (0, " after user-defined conversion:", 6935 t->cand); 6936 break; 6937 } 6938 } 6939 6940 /* Locate the parameter with the given index within FNDECL. 6941 ARGNUM is zero based, -1 indicates the `this' argument of a method. 6942 Return the location of the FNDECL itself if there are problems. */ 6943 6944 location_t 6945 get_fndecl_argument_location (tree fndecl, int argnum) 6946 { 6947 /* The locations of implicitly-declared functions are likely to be 6948 more meaningful than those of their parameters. */ 6949 if (DECL_ARTIFICIAL (fndecl)) 6950 return DECL_SOURCE_LOCATION (fndecl); 6951 6952 int i; 6953 tree param; 6954 6955 /* Locate param by index within DECL_ARGUMENTS (fndecl). */ 6956 for (i = 0, param = FUNCTION_FIRST_USER_PARM (fndecl); 6957 i < argnum && param; 6958 i++, param = TREE_CHAIN (param)) 6959 ; 6960 6961 /* If something went wrong (e.g. if we have a builtin and thus no arguments), 6962 return the location of FNDECL. */ 6963 if (param == NULL) 6964 return DECL_SOURCE_LOCATION (fndecl); 6965 6966 return DECL_SOURCE_LOCATION (param); 6967 } 6968 6969 /* If FNDECL is non-NULL, issue a note highlighting ARGNUM 6970 within its declaration (or the fndecl itself if something went 6971 wrong). */ 6972 6973 void 6974 maybe_inform_about_fndecl_for_bogus_argument_init (tree fn, int argnum) 6975 { 6976 if (fn) 6977 inform (get_fndecl_argument_location (fn, argnum), 6978 " initializing argument %P of %qD", argnum, fn); 6979 } 6980 6981 /* Perform the conversions in CONVS on the expression EXPR. FN and 6982 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 6983 indicates the `this' argument of a method. INNER is nonzero when 6984 being called to continue a conversion chain. It is negative when a 6985 reference binding will be applied, positive otherwise. If 6986 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 6987 conversions will be emitted if appropriate. If C_CAST_P is true, 6988 this conversion is coming from a C-style cast; in that case, 6989 conversions to inaccessible bases are permitted. */ 6990 6991 static tree 6992 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 6993 bool issue_conversion_warnings, 6994 bool c_cast_p, tsubst_flags_t complain) 6995 { 6996 tree totype = convs->type; 6997 diagnostic_t diag_kind; 6998 int flags; 6999 location_t loc = cp_expr_loc_or_loc (expr, input_location); 7000 7001 if (convs->bad_p && !(complain & tf_error)) 7002 return error_mark_node; 7003 7004 if (convs->bad_p 7005 && convs->kind != ck_user 7006 && convs->kind != ck_list 7007 && convs->kind != ck_ambig 7008 && (convs->kind != ck_ref_bind 7009 || (convs->user_conv_p && next_conversion (convs)->bad_p)) 7010 && (convs->kind != ck_rvalue 7011 || SCALAR_TYPE_P (totype)) 7012 && convs->kind != ck_base) 7013 { 7014 bool complained = false; 7015 conversion *t = convs; 7016 7017 /* Give a helpful error if this is bad because of excess braces. */ 7018 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 7019 && SCALAR_TYPE_P (totype) 7020 && CONSTRUCTOR_NELTS (expr) > 0 7021 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 7022 { 7023 complained = permerror (loc, "too many braces around initializer " 7024 "for %qT", totype); 7025 while (BRACE_ENCLOSED_INITIALIZER_P (expr) 7026 && CONSTRUCTOR_NELTS (expr) == 1) 7027 expr = CONSTRUCTOR_ELT (expr, 0)->value; 7028 } 7029 7030 /* Give a helpful error if this is bad because a conversion to bool 7031 from std::nullptr_t requires direct-initialization. */ 7032 if (NULLPTR_TYPE_P (TREE_TYPE (expr)) 7033 && TREE_CODE (totype) == BOOLEAN_TYPE) 7034 complained = permerror (loc, "converting to %qH from %qI requires " 7035 "direct-initialization", 7036 totype, TREE_TYPE (expr)); 7037 7038 for (; t ; t = next_conversion (t)) 7039 { 7040 if (t->kind == ck_user && t->cand->reason) 7041 { 7042 auto_diagnostic_group d; 7043 complained = permerror (loc, "invalid user-defined conversion " 7044 "from %qH to %qI", TREE_TYPE (expr), 7045 totype); 7046 if (complained) 7047 print_z_candidate (loc, "candidate is:", t->cand); 7048 expr = convert_like_real (t, expr, fn, argnum, 7049 /*issue_conversion_warnings=*/false, 7050 /*c_cast_p=*/false, 7051 complain); 7052 if (convs->kind == ck_ref_bind) 7053 expr = convert_to_reference (totype, expr, CONV_IMPLICIT, 7054 LOOKUP_NORMAL, NULL_TREE, 7055 complain); 7056 else 7057 expr = cp_convert (totype, expr, complain); 7058 if (complained) 7059 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7060 return expr; 7061 } 7062 else if (t->kind == ck_user || !t->bad_p) 7063 { 7064 expr = convert_like_real (t, expr, fn, argnum, 7065 /*issue_conversion_warnings=*/false, 7066 /*c_cast_p=*/false, 7067 complain); 7068 break; 7069 } 7070 else if (t->kind == ck_ambig) 7071 return convert_like_real (t, expr, fn, argnum, 7072 /*issue_conversion_warnings=*/false, 7073 /*c_cast_p=*/false, 7074 complain); 7075 else if (t->kind == ck_identity) 7076 break; 7077 } 7078 if (!complained) 7079 { 7080 range_label_for_type_mismatch label (TREE_TYPE (expr), totype); 7081 gcc_rich_location richloc (loc, &label); 7082 complained = permerror (&richloc, 7083 "invalid conversion from %qH to %qI", 7084 TREE_TYPE (expr), totype); 7085 } 7086 if (complained) 7087 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7088 7089 return cp_convert (totype, expr, complain); 7090 } 7091 7092 if (issue_conversion_warnings && (complain & tf_warning)) 7093 conversion_null_warnings (totype, expr, fn, argnum); 7094 7095 switch (convs->kind) 7096 { 7097 case ck_user: 7098 { 7099 struct z_candidate *cand = convs->cand; 7100 7101 if (cand == NULL) 7102 /* We chose the surrogate function from add_conv_candidate, now we 7103 actually need to build the conversion. */ 7104 cand = build_user_type_conversion_1 (totype, expr, 7105 LOOKUP_NO_CONVERSION, complain); 7106 7107 tree convfn = cand->fn; 7108 7109 /* When converting from an init list we consider explicit 7110 constructors, but actually trying to call one is an error. */ 7111 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 7112 && BRACE_ENCLOSED_INITIALIZER_P (expr) 7113 /* Unless this is for direct-list-initialization. */ 7114 && (!CONSTRUCTOR_IS_DIRECT_INIT (expr) || convs->need_temporary_p) 7115 /* And in C++98 a default constructor can't be explicit. */ 7116 && cxx_dialect >= cxx11) 7117 { 7118 if (!(complain & tf_error)) 7119 return error_mark_node; 7120 location_t loc = location_of (expr); 7121 if (CONSTRUCTOR_NELTS (expr) == 0 7122 && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node) 7123 { 7124 auto_diagnostic_group d; 7125 if (pedwarn (loc, 0, "converting to %qT from initializer list " 7126 "would use explicit constructor %qD", 7127 totype, convfn)) 7128 inform (loc, "in C++11 and above a default constructor " 7129 "can be explicit"); 7130 } 7131 else 7132 error ("converting to %qT from initializer list would use " 7133 "explicit constructor %qD", totype, convfn); 7134 } 7135 7136 /* If we're initializing from {}, it's value-initialization. */ 7137 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 7138 && CONSTRUCTOR_NELTS (expr) == 0 7139 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype) 7140 && !processing_template_decl) 7141 { 7142 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 7143 if (abstract_virtuals_error_sfinae (NULL_TREE, totype, complain)) 7144 return error_mark_node; 7145 expr = build_value_init (totype, complain); 7146 expr = get_target_expr_sfinae (expr, complain); 7147 if (expr != error_mark_node) 7148 { 7149 TARGET_EXPR_LIST_INIT_P (expr) = true; 7150 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 7151 } 7152 return expr; 7153 } 7154 7155 /* We don't know here whether EXPR is being used as an lvalue or 7156 rvalue, but we know it's read. */ 7157 mark_exp_read (expr); 7158 7159 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow 7160 any more UDCs. */ 7161 expr = build_over_call (cand, LOOKUP_NORMAL|LOOKUP_NO_CONVERSION, 7162 complain); 7163 7164 /* If this is a constructor or a function returning an aggr type, 7165 we need to build up a TARGET_EXPR. */ 7166 if (DECL_CONSTRUCTOR_P (convfn)) 7167 { 7168 expr = build_cplus_new (totype, expr, complain); 7169 7170 /* Remember that this was list-initialization. */ 7171 if (convs->check_narrowing && expr != error_mark_node) 7172 TARGET_EXPR_LIST_INIT_P (expr) = true; 7173 } 7174 7175 return expr; 7176 } 7177 case ck_identity: 7178 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 7179 { 7180 int nelts = CONSTRUCTOR_NELTS (expr); 7181 if (nelts == 0) 7182 expr = build_value_init (totype, complain); 7183 else if (nelts == 1) 7184 expr = CONSTRUCTOR_ELT (expr, 0)->value; 7185 else 7186 gcc_unreachable (); 7187 } 7188 expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p, 7189 /*read_p=*/true, UNKNOWN_LOCATION, 7190 /*reject_builtin=*/true); 7191 7192 if (type_unknown_p (expr)) 7193 expr = instantiate_type (totype, expr, complain); 7194 if (expr == null_node 7195 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 7196 /* If __null has been converted to an integer type, we do not want to 7197 continue to warn about uses of EXPR as an integer, rather than as a 7198 pointer. */ 7199 expr = build_int_cst (totype, 0); 7200 return expr; 7201 case ck_ambig: 7202 /* We leave bad_p off ck_ambig because overload resolution considers 7203 it valid, it just fails when we try to perform it. So we need to 7204 check complain here, too. */ 7205 if (complain & tf_error) 7206 { 7207 /* Call build_user_type_conversion again for the error. */ 7208 int flags = (convs->need_temporary_p 7209 ? LOOKUP_IMPLICIT : LOOKUP_NORMAL); 7210 build_user_type_conversion (totype, convs->u.expr, flags, complain); 7211 gcc_assert (seen_error ()); 7212 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7213 } 7214 return error_mark_node; 7215 7216 case ck_list: 7217 { 7218 /* Conversion to std::initializer_list<T>. */ 7219 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 7220 unsigned len = CONSTRUCTOR_NELTS (expr); 7221 tree array; 7222 7223 if (len) 7224 { 7225 tree val; unsigned ix; 7226 7227 tree new_ctor = build_constructor (init_list_type_node, NULL); 7228 7229 /* Convert all the elements. */ 7230 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 7231 { 7232 tree sub = convert_like_real (convs->u.list[ix], val, fn, 7233 argnum, false, false, complain); 7234 if (sub == error_mark_node) 7235 return sub; 7236 if (!BRACE_ENCLOSED_INITIALIZER_P (val) 7237 && !check_narrowing (TREE_TYPE (sub), val, complain)) 7238 return error_mark_node; 7239 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), 7240 NULL_TREE, sub); 7241 if (!TREE_CONSTANT (sub)) 7242 TREE_CONSTANT (new_ctor) = false; 7243 } 7244 /* Build up the array. */ 7245 elttype = cp_build_qualified_type 7246 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 7247 array = build_array_of_n_type (elttype, len); 7248 array = finish_compound_literal (array, new_ctor, complain); 7249 /* Take the address explicitly rather than via decay_conversion 7250 to avoid the error about taking the address of a temporary. */ 7251 array = cp_build_addr_expr (array, complain); 7252 } 7253 else 7254 array = nullptr_node; 7255 7256 array = cp_convert (build_pointer_type (elttype), array, complain); 7257 if (array == error_mark_node) 7258 return error_mark_node; 7259 7260 /* Build up the initializer_list object. Note: fail gracefully 7261 if the object cannot be completed because, for example, no 7262 definition is provided (c++/80956). */ 7263 totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain); 7264 if (!totype) 7265 return error_mark_node; 7266 tree field = next_initializable_field (TYPE_FIELDS (totype)); 7267 vec<constructor_elt, va_gc> *vec = NULL; 7268 CONSTRUCTOR_APPEND_ELT (vec, field, array); 7269 field = next_initializable_field (DECL_CHAIN (field)); 7270 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 7271 tree new_ctor = build_constructor (totype, vec); 7272 return get_target_expr_sfinae (new_ctor, complain); 7273 } 7274 7275 case ck_aggr: 7276 if (TREE_CODE (totype) == COMPLEX_TYPE) 7277 { 7278 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 7279 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 7280 real = perform_implicit_conversion (TREE_TYPE (totype), 7281 real, complain); 7282 imag = perform_implicit_conversion (TREE_TYPE (totype), 7283 imag, complain); 7284 expr = build2 (COMPLEX_EXPR, totype, real, imag); 7285 return expr; 7286 } 7287 expr = reshape_init (totype, expr, complain); 7288 expr = get_target_expr_sfinae (digest_init (totype, expr, complain), 7289 complain); 7290 if (expr != error_mark_node) 7291 TARGET_EXPR_LIST_INIT_P (expr) = true; 7292 return expr; 7293 7294 default: 7295 break; 7296 }; 7297 7298 expr = convert_like_real (next_conversion (convs), expr, fn, argnum, 7299 convs->kind == ck_ref_bind 7300 ? issue_conversion_warnings : false, 7301 c_cast_p, complain); 7302 if (expr == error_mark_node) 7303 return error_mark_node; 7304 7305 switch (convs->kind) 7306 { 7307 case ck_rvalue: 7308 expr = decay_conversion (expr, complain); 7309 if (expr == error_mark_node) 7310 { 7311 if (complain & tf_error) 7312 { 7313 auto_diagnostic_group d; 7314 maybe_print_user_conv_context (convs); 7315 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7316 } 7317 return error_mark_node; 7318 } 7319 7320 if (! MAYBE_CLASS_TYPE_P (totype)) 7321 return expr; 7322 7323 /* Don't introduce copies when passing arguments along to the inherited 7324 constructor. */ 7325 if (current_function_decl 7326 && flag_new_inheriting_ctors 7327 && DECL_INHERITED_CTOR (current_function_decl)) 7328 return expr; 7329 7330 if (TREE_CODE (expr) == TARGET_EXPR 7331 && TARGET_EXPR_LIST_INIT_P (expr)) 7332 /* Copy-list-initialization doesn't actually involve a copy. */ 7333 return expr; 7334 7335 /* Fall through. */ 7336 case ck_base: 7337 if (convs->kind == ck_base && !convs->need_temporary_p) 7338 { 7339 /* We are going to bind a reference directly to a base-class 7340 subobject of EXPR. */ 7341 /* Build an expression for `*((base*) &expr)'. */ 7342 expr = convert_to_base (expr, totype, 7343 !c_cast_p, /*nonnull=*/true, complain); 7344 return expr; 7345 } 7346 7347 /* Copy-initialization where the cv-unqualified version of the source 7348 type is the same class as, or a derived class of, the class of the 7349 destination [is treated as direct-initialization]. [dcl.init] */ 7350 flags = LOOKUP_NORMAL; 7351 if (convs->user_conv_p) 7352 /* This conversion is being done in the context of a user-defined 7353 conversion (i.e. the second step of copy-initialization), so 7354 don't allow any more. */ 7355 flags |= LOOKUP_NO_CONVERSION; 7356 else 7357 flags |= LOOKUP_ONLYCONVERTING; 7358 if (convs->rvaluedness_matches_p) 7359 /* standard_conversion got LOOKUP_PREFER_RVALUE. */ 7360 flags |= LOOKUP_PREFER_RVALUE; 7361 expr = build_temp (expr, totype, flags, &diag_kind, complain); 7362 if (diag_kind && complain) 7363 { 7364 auto_diagnostic_group d; 7365 maybe_print_user_conv_context (convs); 7366 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7367 } 7368 7369 return build_cplus_new (totype, expr, complain); 7370 7371 case ck_ref_bind: 7372 { 7373 tree ref_type = totype; 7374 7375 if (convs->bad_p && !next_conversion (convs)->bad_p) 7376 { 7377 tree extype = TREE_TYPE (expr); 7378 auto_diagnostic_group d; 7379 if (TYPE_REF_IS_RVALUE (ref_type) 7380 && lvalue_p (expr)) 7381 error_at (loc, "cannot bind rvalue reference of type %qH to " 7382 "lvalue of type %qI", totype, extype); 7383 else if (!TYPE_REF_IS_RVALUE (ref_type) && !lvalue_p (expr) 7384 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))) 7385 error_at (loc, "cannot bind non-const lvalue reference of " 7386 "type %qH to an rvalue of type %qI", totype, extype); 7387 else if (!reference_compatible_p (TREE_TYPE (totype), extype)) 7388 error_at (loc, "binding reference of type %qH to %qI " 7389 "discards qualifiers", totype, extype); 7390 else 7391 gcc_unreachable (); 7392 maybe_print_user_conv_context (convs); 7393 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum); 7394 7395 return error_mark_node; 7396 } 7397 7398 /* If necessary, create a temporary. 7399 7400 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 7401 that need temporaries, even when their types are reference 7402 compatible with the type of reference being bound, so the 7403 upcoming call to cp_build_addr_expr doesn't fail. */ 7404 if (convs->need_temporary_p 7405 || TREE_CODE (expr) == CONSTRUCTOR 7406 || TREE_CODE (expr) == VA_ARG_EXPR) 7407 { 7408 /* Otherwise, a temporary of type "cv1 T1" is created and 7409 initialized from the initializer expression using the rules 7410 for a non-reference copy-initialization (8.5). */ 7411 7412 tree type = TREE_TYPE (ref_type); 7413 cp_lvalue_kind lvalue = lvalue_kind (expr); 7414 7415 gcc_assert (same_type_ignoring_top_level_qualifiers_p 7416 (type, next_conversion (convs)->type)); 7417 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 7418 && !TYPE_REF_IS_RVALUE (ref_type)) 7419 { 7420 /* If the reference is volatile or non-const, we 7421 cannot create a temporary. */ 7422 if (lvalue & clk_bitfield) 7423 error_at (loc, "cannot bind bitfield %qE to %qT", 7424 expr, ref_type); 7425 else if (lvalue & clk_packed) 7426 error_at (loc, "cannot bind packed field %qE to %qT", 7427 expr, ref_type); 7428 else 7429 error_at (loc, "cannot bind rvalue %qE to %qT", 7430 expr, ref_type); 7431 return error_mark_node; 7432 } 7433 /* If the source is a packed field, and we must use a copy 7434 constructor, then building the target expr will require 7435 binding the field to the reference parameter to the 7436 copy constructor, and we'll end up with an infinite 7437 loop. If we can use a bitwise copy, then we'll be 7438 OK. */ 7439 if ((lvalue & clk_packed) 7440 && CLASS_TYPE_P (type) 7441 && type_has_nontrivial_copy_init (type)) 7442 { 7443 error_at (loc, "cannot bind packed field %qE to %qT", 7444 expr, ref_type); 7445 return error_mark_node; 7446 } 7447 if (lvalue & clk_bitfield) 7448 { 7449 expr = convert_bitfield_to_declared_type (expr); 7450 expr = fold_convert (type, expr); 7451 } 7452 expr = build_target_expr_with_type (expr, type, complain); 7453 } 7454 7455 /* Take the address of the thing to which we will bind the 7456 reference. */ 7457 expr = cp_build_addr_expr (expr, complain); 7458 if (expr == error_mark_node) 7459 return error_mark_node; 7460 7461 /* Convert it to a pointer to the type referred to by the 7462 reference. This will adjust the pointer if a derived to 7463 base conversion is being performed. */ 7464 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 7465 expr, complain); 7466 /* Convert the pointer to the desired reference type. */ 7467 return build_nop (ref_type, expr); 7468 } 7469 7470 case ck_lvalue: 7471 return decay_conversion (expr, complain); 7472 7473 case ck_fnptr: 7474 /* ??? Should the address of a transaction-safe pointer point to the TM 7475 clone, and this conversion look up the primary function? */ 7476 return build_nop (totype, expr); 7477 7478 case ck_qual: 7479 /* Warn about deprecated conversion if appropriate. */ 7480 if (complain & tf_warning) 7481 string_conv_p (totype, expr, 1); 7482 break; 7483 7484 case ck_ptr: 7485 if (convs->base_p) 7486 expr = convert_to_base (expr, totype, !c_cast_p, 7487 /*nonnull=*/false, complain); 7488 return build_nop (totype, expr); 7489 7490 case ck_pmem: 7491 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 7492 c_cast_p, complain); 7493 7494 default: 7495 break; 7496 } 7497 7498 if (convs->check_narrowing 7499 && !check_narrowing (totype, expr, complain, 7500 convs->check_narrowing_const_only)) 7501 return error_mark_node; 7502 7503 warning_sentinel w (warn_zero_as_null_pointer_constant); 7504 if (issue_conversion_warnings) 7505 expr = cp_convert_and_check (totype, expr, complain); 7506 else 7507 expr = cp_convert (totype, expr, complain); 7508 7509 return expr; 7510 } 7511 7512 /* ARG is being passed to a varargs function. Perform any conversions 7513 required. Return the converted value. */ 7514 7515 tree 7516 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain) 7517 { 7518 tree arg_type; 7519 location_t loc = cp_expr_loc_or_loc (arg, input_location); 7520 7521 /* [expr.call] 7522 7523 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 7524 standard conversions are performed. */ 7525 arg = decay_conversion (arg, complain); 7526 arg_type = TREE_TYPE (arg); 7527 /* [expr.call] 7528 7529 If the argument has integral or enumeration type that is subject 7530 to the integral promotions (_conv.prom_), or a floating point 7531 type that is subject to the floating point promotion 7532 (_conv.fpprom_), the value of the argument is converted to the 7533 promoted type before the call. */ 7534 if (TREE_CODE (arg_type) == REAL_TYPE 7535 && (TYPE_PRECISION (arg_type) 7536 < TYPE_PRECISION (double_type_node)) 7537 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 7538 { 7539 if ((complain & tf_warning) 7540 && warn_double_promotion && !c_inhibit_evaluation_warnings) 7541 warning_at (loc, OPT_Wdouble_promotion, 7542 "implicit conversion from %qH to %qI when passing " 7543 "argument to function", 7544 arg_type, double_type_node); 7545 arg = convert_to_real_nofold (double_type_node, arg); 7546 } 7547 else if (NULLPTR_TYPE_P (arg_type)) 7548 { 7549 if (TREE_SIDE_EFFECTS (arg)) 7550 arg = cp_build_compound_expr (arg, null_pointer_node, complain); 7551 else 7552 arg = null_pointer_node; 7553 } 7554 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 7555 { 7556 if (SCOPED_ENUM_P (arg_type)) 7557 { 7558 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg, 7559 complain); 7560 prom = cp_perform_integral_promotions (prom, complain); 7561 if (abi_version_crosses (6) 7562 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type) 7563 && (complain & tf_warning)) 7564 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as " 7565 "%qT before %<-fabi-version=6%>, %qT after", arg_type, 7566 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type)); 7567 if (!abi_version_at_least (6)) 7568 arg = prom; 7569 } 7570 else 7571 arg = cp_perform_integral_promotions (arg, complain); 7572 } 7573 7574 arg = require_complete_type_sfinae (arg, complain); 7575 arg_type = TREE_TYPE (arg); 7576 7577 if (arg != error_mark_node 7578 /* In a template (or ill-formed code), we can have an incomplete type 7579 even after require_complete_type_sfinae, in which case we don't know 7580 whether it has trivial copy or not. */ 7581 && COMPLETE_TYPE_P (arg_type) 7582 && !cp_unevaluated_operand) 7583 { 7584 /* [expr.call] 5.2.2/7: 7585 Passing a potentially-evaluated argument of class type (Clause 9) 7586 with a non-trivial copy constructor or a non-trivial destructor 7587 with no corresponding parameter is conditionally-supported, with 7588 implementation-defined semantics. 7589 7590 We support it as pass-by-invisible-reference, just like a normal 7591 value parameter. 7592 7593 If the call appears in the context of a sizeof expression, 7594 it is not potentially-evaluated. */ 7595 if (type_has_nontrivial_copy_init (arg_type) 7596 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)) 7597 { 7598 arg = force_rvalue (arg, complain); 7599 if (complain & tf_warning) 7600 warning (OPT_Wconditionally_supported, 7601 "passing objects of non-trivially-copyable " 7602 "type %q#T through %<...%> is conditionally supported", 7603 arg_type); 7604 return build1 (ADDR_EXPR, build_reference_type (arg_type), arg); 7605 } 7606 /* Build up a real lvalue-to-rvalue conversion in case the 7607 copy constructor is trivial but not callable. */ 7608 else if (CLASS_TYPE_P (arg_type)) 7609 force_rvalue (arg, complain); 7610 7611 } 7612 7613 return arg; 7614 } 7615 7616 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 7617 7618 tree 7619 build_x_va_arg (location_t loc, tree expr, tree type) 7620 { 7621 if (processing_template_decl) 7622 { 7623 tree r = build_min (VA_ARG_EXPR, type, expr); 7624 SET_EXPR_LOCATION (r, loc); 7625 return r; 7626 } 7627 7628 type = complete_type_or_else (type, NULL_TREE); 7629 7630 if (expr == error_mark_node || !type) 7631 return error_mark_node; 7632 7633 expr = mark_lvalue_use (expr); 7634 7635 if (TYPE_REF_P (type)) 7636 { 7637 error ("cannot receive reference type %qT through %<...%>", type); 7638 return error_mark_node; 7639 } 7640 7641 if (type_has_nontrivial_copy_init (type) 7642 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 7643 { 7644 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat 7645 it as pass by invisible reference. */ 7646 warning_at (loc, OPT_Wconditionally_supported, 7647 "receiving objects of non-trivially-copyable type %q#T " 7648 "through %<...%> is conditionally-supported", type); 7649 7650 tree ref = cp_build_reference_type (type, false); 7651 expr = build_va_arg (loc, expr, ref); 7652 return convert_from_reference (expr); 7653 } 7654 7655 tree ret = build_va_arg (loc, expr, type); 7656 if (CLASS_TYPE_P (type)) 7657 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to 7658 know how to handle it. */ 7659 ret = get_target_expr (ret); 7660 return ret; 7661 } 7662 7663 /* TYPE has been given to va_arg. Apply the default conversions which 7664 would have happened when passed via ellipsis. Return the promoted 7665 type, or the passed type if there is no change. */ 7666 7667 tree 7668 cxx_type_promotes_to (tree type) 7669 { 7670 tree promote; 7671 7672 /* Perform the array-to-pointer and function-to-pointer 7673 conversions. */ 7674 type = type_decays_to (type); 7675 7676 promote = type_promotes_to (type); 7677 if (same_type_p (type, promote)) 7678 promote = type; 7679 7680 return promote; 7681 } 7682 7683 /* ARG is a default argument expression being passed to a parameter of 7684 the indicated TYPE, which is a parameter to FN. PARMNUM is the 7685 zero-based argument number. Do any required conversions. Return 7686 the converted value. */ 7687 7688 static GTY(()) vec<tree, va_gc> *default_arg_context; 7689 void 7690 push_defarg_context (tree fn) 7691 { vec_safe_push (default_arg_context, fn); } 7692 7693 void 7694 pop_defarg_context (void) 7695 { default_arg_context->pop (); } 7696 7697 tree 7698 convert_default_arg (tree type, tree arg, tree fn, int parmnum, 7699 tsubst_flags_t complain) 7700 { 7701 int i; 7702 tree t; 7703 7704 /* See through clones. */ 7705 fn = DECL_ORIGIN (fn); 7706 /* And inheriting ctors. */ 7707 if (flag_new_inheriting_ctors) 7708 fn = strip_inheriting_ctors (fn); 7709 7710 /* Detect recursion. */ 7711 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t) 7712 if (t == fn) 7713 { 7714 if (complain & tf_error) 7715 error ("recursive evaluation of default argument for %q#D", fn); 7716 return error_mark_node; 7717 } 7718 7719 /* If the ARG is an unparsed default argument expression, the 7720 conversion cannot be performed. */ 7721 if (TREE_CODE (arg) == DEFAULT_ARG) 7722 { 7723 if (complain & tf_error) 7724 error ("call to %qD uses the default argument for parameter %P, which " 7725 "is not yet defined", fn, parmnum); 7726 return error_mark_node; 7727 } 7728 7729 push_defarg_context (fn); 7730 7731 if (fn && DECL_TEMPLATE_INFO (fn)) 7732 arg = tsubst_default_argument (fn, parmnum, type, arg, complain); 7733 7734 /* Due to: 7735 7736 [dcl.fct.default] 7737 7738 The names in the expression are bound, and the semantic 7739 constraints are checked, at the point where the default 7740 expressions appears. 7741 7742 we must not perform access checks here. */ 7743 push_deferring_access_checks (dk_no_check); 7744 /* We must make a copy of ARG, in case subsequent processing 7745 alters any part of it. */ 7746 arg = break_out_target_exprs (arg, /*clear location*/true); 7747 7748 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 7749 ICR_DEFAULT_ARGUMENT, fn, parmnum, 7750 complain); 7751 arg = convert_for_arg_passing (type, arg, complain); 7752 pop_deferring_access_checks(); 7753 7754 pop_defarg_context (); 7755 7756 return arg; 7757 } 7758 7759 /* Returns the type which will really be used for passing an argument of 7760 type TYPE. */ 7761 7762 tree 7763 type_passed_as (tree type) 7764 { 7765 /* Pass classes with copy ctors by invisible reference. */ 7766 if (TREE_ADDRESSABLE (type)) 7767 { 7768 type = build_reference_type (type); 7769 /* There are no other pointers to this temporary. */ 7770 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 7771 } 7772 else if (targetm.calls.promote_prototypes (NULL_TREE) 7773 && INTEGRAL_TYPE_P (type) 7774 && COMPLETE_TYPE_P (type) 7775 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7776 type = integer_type_node; 7777 7778 return type; 7779 } 7780 7781 /* Actually perform the appropriate conversion. */ 7782 7783 tree 7784 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain) 7785 { 7786 tree bitfield_type; 7787 7788 /* If VAL is a bitfield, then -- since it has already been converted 7789 to TYPE -- it cannot have a precision greater than TYPE. 7790 7791 If it has a smaller precision, we must widen it here. For 7792 example, passing "int f:3;" to a function expecting an "int" will 7793 not result in any conversion before this point. 7794 7795 If the precision is the same we must not risk widening. For 7796 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 7797 often have type "int", even though the C++ type for the field is 7798 "long long". If the value is being passed to a function 7799 expecting an "int", then no conversions will be required. But, 7800 if we call convert_bitfield_to_declared_type, the bitfield will 7801 be converted to "long long". */ 7802 bitfield_type = is_bitfield_expr_with_lowered_type (val); 7803 if (bitfield_type 7804 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 7805 val = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type), val); 7806 7807 if (val == error_mark_node) 7808 ; 7809 /* Pass classes with copy ctors by invisible reference. */ 7810 else if (TREE_ADDRESSABLE (type)) 7811 val = build1 (ADDR_EXPR, build_reference_type (type), val); 7812 else if (targetm.calls.promote_prototypes (NULL_TREE) 7813 && INTEGRAL_TYPE_P (type) 7814 && COMPLETE_TYPE_P (type) 7815 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7816 val = cp_perform_integral_promotions (val, complain); 7817 if (complain & tf_warning) 7818 { 7819 if (warn_suggest_attribute_format) 7820 { 7821 tree rhstype = TREE_TYPE (val); 7822 const enum tree_code coder = TREE_CODE (rhstype); 7823 const enum tree_code codel = TREE_CODE (type); 7824 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 7825 && coder == codel 7826 && check_missing_format_attribute (type, rhstype)) 7827 warning (OPT_Wsuggest_attribute_format, 7828 "argument of function call might be a candidate " 7829 "for a format attribute"); 7830 } 7831 maybe_warn_parm_abi (type, cp_expr_loc_or_loc (val, input_location)); 7832 } 7833 7834 if (complain & tf_warning) 7835 warn_for_address_or_pointer_of_packed_member (type, val); 7836 7837 return val; 7838 } 7839 7840 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for 7841 which just decay_conversion or no conversions at all should be done. 7842 This is true for some builtins which don't act like normal functions. 7843 Return 2 if no conversions at all should be done, 1 if just 7844 decay_conversion. Return 3 for special treatment of the 3rd argument 7845 for __builtin_*_overflow_p. */ 7846 7847 int 7848 magic_varargs_p (tree fn) 7849 { 7850 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 7851 switch (DECL_FUNCTION_CODE (fn)) 7852 { 7853 case BUILT_IN_CLASSIFY_TYPE: 7854 case BUILT_IN_CONSTANT_P: 7855 case BUILT_IN_NEXT_ARG: 7856 case BUILT_IN_VA_START: 7857 return 1; 7858 7859 case BUILT_IN_ADD_OVERFLOW_P: 7860 case BUILT_IN_SUB_OVERFLOW_P: 7861 case BUILT_IN_MUL_OVERFLOW_P: 7862 return 3; 7863 7864 default:; 7865 return lookup_attribute ("type generic", 7866 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 7867 } 7868 7869 return 0; 7870 } 7871 7872 /* Returns the decl of the dispatcher function if FN is a function version. */ 7873 7874 tree 7875 get_function_version_dispatcher (tree fn) 7876 { 7877 tree dispatcher_decl = NULL; 7878 7879 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 7880 && DECL_FUNCTION_VERSIONED (fn)); 7881 7882 gcc_assert (targetm.get_function_versions_dispatcher); 7883 dispatcher_decl = targetm.get_function_versions_dispatcher (fn); 7884 7885 if (dispatcher_decl == NULL) 7886 { 7887 error_at (input_location, "use of multiversioned function " 7888 "without a default"); 7889 return NULL; 7890 } 7891 7892 retrofit_lang_decl (dispatcher_decl); 7893 gcc_assert (dispatcher_decl != NULL); 7894 return dispatcher_decl; 7895 } 7896 7897 /* fn is a function version dispatcher that is marked used. Mark all the 7898 semantically identical function versions it will dispatch as used. */ 7899 7900 void 7901 mark_versions_used (tree fn) 7902 { 7903 struct cgraph_node *node; 7904 struct cgraph_function_version_info *node_v; 7905 struct cgraph_function_version_info *it_v; 7906 7907 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7908 7909 node = cgraph_node::get (fn); 7910 if (node == NULL) 7911 return; 7912 7913 gcc_assert (node->dispatcher_function); 7914 7915 node_v = node->function_version (); 7916 if (node_v == NULL) 7917 return; 7918 7919 /* All semantically identical versions are chained. Traverse and mark each 7920 one of them as used. */ 7921 it_v = node_v->next; 7922 while (it_v != NULL) 7923 { 7924 mark_used (it_v->this_node->decl); 7925 it_v = it_v->next; 7926 } 7927 } 7928 7929 /* Build a call to "the copy constructor" for the type of A, even if it 7930 wouldn't be selected by normal overload resolution. Used for 7931 diagnostics. */ 7932 7933 static tree 7934 call_copy_ctor (tree a, tsubst_flags_t complain) 7935 { 7936 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a)); 7937 tree binfo = TYPE_BINFO (ctype); 7938 tree copy = get_copy_ctor (ctype, complain); 7939 copy = build_baselink (binfo, binfo, copy, NULL_TREE); 7940 tree ob = build_dummy_object (ctype); 7941 vec<tree, va_gc>* args = make_tree_vector_single (a); 7942 tree r = build_new_method_call (ob, copy, &args, NULL_TREE, 7943 LOOKUP_NORMAL, NULL, complain); 7944 release_tree_vector (args); 7945 return r; 7946 } 7947 7948 /* Return true iff T refers to a base field. */ 7949 7950 static bool 7951 is_base_field_ref (tree t) 7952 { 7953 STRIP_NOPS (t); 7954 if (TREE_CODE (t) == ADDR_EXPR) 7955 t = TREE_OPERAND (t, 0); 7956 if (TREE_CODE (t) == COMPONENT_REF) 7957 t = TREE_OPERAND (t, 1); 7958 if (TREE_CODE (t) == FIELD_DECL) 7959 return DECL_FIELD_IS_BASE (t); 7960 return false; 7961 } 7962 7963 /* We can't elide a copy from a function returning by value to a base 7964 subobject, as the callee might clobber tail padding. Return true iff this 7965 could be that case. */ 7966 7967 static bool 7968 unsafe_copy_elision_p (tree target, tree exp) 7969 { 7970 /* Copy elision only happens with a TARGET_EXPR. */ 7971 if (TREE_CODE (exp) != TARGET_EXPR) 7972 return false; 7973 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 7974 /* It's safe to elide the copy for a class with no tail padding. */ 7975 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type))) 7976 return false; 7977 /* It's safe to elide the copy if we aren't initializing a base object. */ 7978 if (!is_base_field_ref (target)) 7979 return false; 7980 tree init = TARGET_EXPR_INITIAL (exp); 7981 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */ 7982 while (TREE_CODE (init) == COMPOUND_EXPR) 7983 init = TREE_OPERAND (init, 1); 7984 if (TREE_CODE (init) == COND_EXPR) 7985 { 7986 /* We'll end up copying from each of the arms of the COND_EXPR directly 7987 into the target, so look at them. */ 7988 if (tree op = TREE_OPERAND (init, 1)) 7989 if (unsafe_copy_elision_p (target, op)) 7990 return true; 7991 return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2)); 7992 } 7993 return (TREE_CODE (init) == AGGR_INIT_EXPR 7994 && !AGGR_INIT_VIA_CTOR_P (init)); 7995 } 7996 7997 /* True iff C is a conversion that binds a reference to a prvalue. */ 7998 7999 static bool 8000 conv_binds_ref_to_prvalue (conversion *c) 8001 { 8002 if (c->kind != ck_ref_bind) 8003 return false; 8004 if (c->need_temporary_p) 8005 return true; 8006 8007 c = next_conversion (c); 8008 8009 if (c->kind == ck_rvalue) 8010 return true; 8011 if (c->kind == ck_user && !TYPE_REF_P (c->type)) 8012 return true; 8013 if (c->kind == ck_identity && c->u.expr 8014 && TREE_CODE (c->u.expr) == TARGET_EXPR) 8015 return true; 8016 8017 return false; 8018 } 8019 8020 /* Call the trivial destructor for INSTANCE, which can be either an lvalue of 8021 class type or a pointer to class type. */ 8022 8023 tree 8024 build_trivial_dtor_call (tree instance) 8025 { 8026 gcc_assert (!is_dummy_object (instance)); 8027 8028 if (!flag_lifetime_dse) 8029 { 8030 no_clobber: 8031 return fold_convert (void_type_node, instance); 8032 } 8033 8034 if (INDIRECT_TYPE_P (TREE_TYPE (instance))) 8035 { 8036 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (instance)))) 8037 goto no_clobber; 8038 instance = cp_build_fold_indirect_ref (instance); 8039 } 8040 8041 /* A trivial destructor should still clobber the object. */ 8042 tree clobber = build_clobber (TREE_TYPE (instance)); 8043 return build2 (MODIFY_EXPR, void_type_node, 8044 instance, clobber); 8045 } 8046 8047 /* Subroutine of the various build_*_call functions. Overload resolution 8048 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 8049 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 8050 bitmask of various LOOKUP_* flags which apply to the call itself. */ 8051 8052 static tree 8053 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 8054 { 8055 tree fn = cand->fn; 8056 const vec<tree, va_gc> *args = cand->args; 8057 tree first_arg = cand->first_arg; 8058 conversion **convs = cand->convs; 8059 conversion *conv; 8060 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 8061 int parmlen; 8062 tree val; 8063 int i = 0; 8064 int j = 0; 8065 unsigned int arg_index = 0; 8066 int is_method = 0; 8067 int nargs; 8068 tree *argarray; 8069 bool already_used = false; 8070 8071 /* In a template, there is no need to perform all of the work that 8072 is normally done. We are only interested in the type of the call 8073 expression, i.e., the return type of the function. Any semantic 8074 errors will be deferred until the template is instantiated. */ 8075 if (processing_template_decl) 8076 { 8077 tree expr, addr; 8078 tree return_type; 8079 const tree *argarray; 8080 unsigned int nargs; 8081 8082 if (undeduced_auto_decl (fn)) 8083 mark_used (fn, complain); 8084 else 8085 /* Otherwise set TREE_USED for the benefit of -Wunused-function. 8086 See PR80598. */ 8087 TREE_USED (fn) = 1; 8088 8089 return_type = TREE_TYPE (TREE_TYPE (fn)); 8090 nargs = vec_safe_length (args); 8091 if (first_arg == NULL_TREE) 8092 argarray = args->address (); 8093 else 8094 { 8095 tree *alcarray; 8096 unsigned int ix; 8097 tree arg; 8098 8099 ++nargs; 8100 alcarray = XALLOCAVEC (tree, nargs); 8101 alcarray[0] = build_this (first_arg); 8102 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 8103 alcarray[ix + 1] = arg; 8104 argarray = alcarray; 8105 } 8106 8107 addr = build_addr_func (fn, complain); 8108 if (addr == error_mark_node) 8109 return error_mark_node; 8110 expr = build_call_array_loc (input_location, return_type, 8111 addr, nargs, argarray); 8112 if (TREE_THIS_VOLATILE (fn) && cfun) 8113 current_function_returns_abnormally = 1; 8114 return convert_from_reference (expr); 8115 } 8116 8117 /* Give any warnings we noticed during overload resolution. */ 8118 if (cand->warnings && (complain & tf_warning)) 8119 { 8120 struct candidate_warning *w; 8121 for (w = cand->warnings; w; w = w->next) 8122 joust (cand, w->loser, 1, complain); 8123 } 8124 8125 /* Core issue 2327: P0135 doesn't say how to handle the case where the 8126 argument to the copy constructor ends up being a prvalue after 8127 conversion. Let's do the normal processing, but pretend we aren't 8128 actually using the copy constructor. */ 8129 bool force_elide = false; 8130 if (cxx_dialect >= cxx17 8131 && cand->num_convs == 1 8132 && DECL_COMPLETE_CONSTRUCTOR_P (fn) 8133 && (DECL_COPY_CONSTRUCTOR_P (fn) 8134 || DECL_MOVE_CONSTRUCTOR_P (fn)) 8135 && conv_binds_ref_to_prvalue (convs[0])) 8136 { 8137 force_elide = true; 8138 goto not_really_used; 8139 } 8140 8141 /* OK, we're actually calling this inherited constructor; set its deletedness 8142 appropriately. We can get away with doing this here because calling is 8143 the only way to refer to a constructor. */ 8144 if (DECL_INHERITED_CTOR (fn)) 8145 deduce_inheriting_ctor (fn); 8146 8147 /* Make =delete work with SFINAE. */ 8148 if (DECL_DELETED_FN (fn)) 8149 { 8150 if (complain & tf_error) 8151 mark_used (fn); 8152 return error_mark_node; 8153 } 8154 8155 if (DECL_FUNCTION_MEMBER_P (fn)) 8156 { 8157 tree access_fn; 8158 /* If FN is a template function, two cases must be considered. 8159 For example: 8160 8161 struct A { 8162 protected: 8163 template <class T> void f(); 8164 }; 8165 template <class T> struct B { 8166 protected: 8167 void g(); 8168 }; 8169 struct C : A, B<int> { 8170 using A::f; // #1 8171 using B<int>::g; // #2 8172 }; 8173 8174 In case #1 where `A::f' is a member template, DECL_ACCESS is 8175 recorded in the primary template but not in its specialization. 8176 We check access of FN using its primary template. 8177 8178 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 8179 because it is a member of class template B, DECL_ACCESS is 8180 recorded in the specialization `B<int>::g'. We cannot use its 8181 primary template because `B<T>::g' and `B<int>::g' may have 8182 different access. */ 8183 if (DECL_TEMPLATE_INFO (fn) 8184 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 8185 access_fn = DECL_TI_TEMPLATE (fn); 8186 else 8187 access_fn = fn; 8188 if (!perform_or_defer_access_check (cand->access_path, access_fn, 8189 fn, complain)) 8190 return error_mark_node; 8191 } 8192 8193 /* If we're checking for implicit delete, don't bother with argument 8194 conversions. */ 8195 if (flags & LOOKUP_SPECULATIVE) 8196 { 8197 if (cand->viable == 1) 8198 return fn; 8199 else if (!(complain & tf_error)) 8200 /* Reject bad conversions now. */ 8201 return error_mark_node; 8202 /* else continue to get conversion error. */ 8203 } 8204 8205 not_really_used: 8206 8207 /* N3276 magic doesn't apply to nested calls. */ 8208 tsubst_flags_t decltype_flag = (complain & tf_decltype); 8209 complain &= ~tf_decltype; 8210 /* No-Cleanup doesn't apply to nested calls either. */ 8211 tsubst_flags_t no_cleanup_complain = complain; 8212 complain &= ~tf_no_cleanup; 8213 8214 /* Find maximum size of vector to hold converted arguments. */ 8215 parmlen = list_length (parm); 8216 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0); 8217 if (parmlen > nargs) 8218 nargs = parmlen; 8219 argarray = XALLOCAVEC (tree, nargs); 8220 8221 /* The implicit parameters to a constructor are not considered by overload 8222 resolution, and must be of the proper type. */ 8223 if (DECL_CONSTRUCTOR_P (fn)) 8224 { 8225 tree object_arg; 8226 if (first_arg != NULL_TREE) 8227 { 8228 object_arg = first_arg; 8229 first_arg = NULL_TREE; 8230 } 8231 else 8232 { 8233 object_arg = (*args)[arg_index]; 8234 ++arg_index; 8235 } 8236 argarray[j++] = build_this (object_arg); 8237 parm = TREE_CHAIN (parm); 8238 /* We should never try to call the abstract constructor. */ 8239 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 8240 8241 if (DECL_HAS_VTT_PARM_P (fn)) 8242 { 8243 argarray[j++] = (*args)[arg_index]; 8244 ++arg_index; 8245 parm = TREE_CHAIN (parm); 8246 } 8247 8248 if (flags & LOOKUP_PREFER_RVALUE) 8249 { 8250 /* The implicit move specified in 15.8.3/3 fails "...if the type of 8251 the first parameter of the selected constructor is not an rvalue 8252 reference to the object's type (possibly cv-qualified)...." */ 8253 gcc_assert (!(complain & tf_error)); 8254 tree ptype = convs[0]->type; 8255 if (!TYPE_REF_P (ptype) 8256 || !TYPE_REF_IS_RVALUE (ptype) 8257 || CONVERSION_RANK (convs[0]) > cr_exact) 8258 return error_mark_node; 8259 } 8260 } 8261 /* Bypass access control for 'this' parameter. */ 8262 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 8263 { 8264 tree parmtype = TREE_VALUE (parm); 8265 tree arg = build_this (first_arg != NULL_TREE 8266 ? first_arg 8267 : (*args)[arg_index]); 8268 tree argtype = TREE_TYPE (arg); 8269 tree converted_arg; 8270 tree base_binfo; 8271 8272 if (arg == error_mark_node) 8273 return error_mark_node; 8274 8275 if (convs[i]->bad_p) 8276 { 8277 if (complain & tf_error) 8278 { 8279 auto_diagnostic_group d; 8280 if (permerror (input_location, "passing %qT as %<this%> " 8281 "argument discards qualifiers", 8282 TREE_TYPE (argtype))) 8283 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn); 8284 } 8285 else 8286 return error_mark_node; 8287 } 8288 8289 /* See if the function member or the whole class type is declared 8290 final and the call can be devirtualized. */ 8291 if (DECL_FINAL_P (fn) 8292 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 8293 flags |= LOOKUP_NONVIRTUAL; 8294 8295 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 8296 X is called for an object that is not of type X, or of a type 8297 derived from X, the behavior is undefined. 8298 8299 So we can assume that anything passed as 'this' is non-null, and 8300 optimize accordingly. */ 8301 gcc_assert (TYPE_PTR_P (parmtype)); 8302 /* Convert to the base in which the function was declared. */ 8303 gcc_assert (cand->conversion_path != NULL_TREE); 8304 converted_arg = build_base_path (PLUS_EXPR, 8305 arg, 8306 cand->conversion_path, 8307 1, complain); 8308 /* Check that the base class is accessible. */ 8309 if (!accessible_base_p (TREE_TYPE (argtype), 8310 BINFO_TYPE (cand->conversion_path), true)) 8311 { 8312 if (complain & tf_error) 8313 error ("%qT is not an accessible base of %qT", 8314 BINFO_TYPE (cand->conversion_path), 8315 TREE_TYPE (argtype)); 8316 else 8317 return error_mark_node; 8318 } 8319 /* If fn was found by a using declaration, the conversion path 8320 will be to the derived class, not the base declaring fn. We 8321 must convert from derived to base. */ 8322 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 8323 TREE_TYPE (parmtype), ba_unique, 8324 NULL, complain); 8325 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 8326 base_binfo, 1, complain); 8327 8328 argarray[j++] = converted_arg; 8329 parm = TREE_CHAIN (parm); 8330 if (first_arg != NULL_TREE) 8331 first_arg = NULL_TREE; 8332 else 8333 ++arg_index; 8334 ++i; 8335 is_method = 1; 8336 } 8337 8338 gcc_assert (first_arg == NULL_TREE); 8339 for (; arg_index < vec_safe_length (args) && parm; 8340 parm = TREE_CHAIN (parm), ++arg_index, ++i) 8341 { 8342 tree type = TREE_VALUE (parm); 8343 tree arg = (*args)[arg_index]; 8344 bool conversion_warning = true; 8345 8346 conv = convs[i]; 8347 8348 /* If the argument is NULL and used to (implicitly) instantiate a 8349 template function (and bind one of the template arguments to 8350 the type of 'long int'), we don't want to warn about passing NULL 8351 to non-pointer argument. 8352 For example, if we have this template function: 8353 8354 template<typename T> void func(T x) {} 8355 8356 we want to warn (when -Wconversion is enabled) in this case: 8357 8358 void foo() { 8359 func<int>(NULL); 8360 } 8361 8362 but not in this case: 8363 8364 void foo() { 8365 func(NULL); 8366 } 8367 */ 8368 if (null_node_p (arg) 8369 && DECL_TEMPLATE_INFO (fn) 8370 && cand->template_decl 8371 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 8372 conversion_warning = false; 8373 8374 /* Warn about initializer_list deduction that isn't currently in the 8375 working draft. */ 8376 if (cxx_dialect > cxx98 8377 && flag_deduce_init_list 8378 && cand->template_decl 8379 && is_std_init_list (non_reference (type)) 8380 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 8381 { 8382 tree tmpl = TI_TEMPLATE (cand->template_decl); 8383 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 8384 tree patparm = get_pattern_parm (realparm, tmpl); 8385 tree pattype = TREE_TYPE (patparm); 8386 if (PACK_EXPANSION_P (pattype)) 8387 pattype = PACK_EXPANSION_PATTERN (pattype); 8388 pattype = non_reference (pattype); 8389 8390 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 8391 && (cand->explicit_targs == NULL_TREE 8392 || (TREE_VEC_LENGTH (cand->explicit_targs) 8393 <= TEMPLATE_TYPE_IDX (pattype)))) 8394 { 8395 pedwarn (input_location, 0, "deducing %qT as %qT", 8396 non_reference (TREE_TYPE (patparm)), 8397 non_reference (type)); 8398 pedwarn (DECL_SOURCE_LOCATION (cand->fn), 0, 8399 " in call to %qD", cand->fn); 8400 pedwarn (input_location, 0, 8401 " (you can disable this with " 8402 "%<-fno-deduce-init-list%>)"); 8403 } 8404 } 8405 8406 /* Set user_conv_p on the argument conversions, so rvalue/base handling 8407 knows not to allow any more UDCs. This needs to happen after we 8408 process cand->warnings. */ 8409 if (flags & LOOKUP_NO_CONVERSION) 8410 conv->user_conv_p = true; 8411 8412 tsubst_flags_t arg_complain = complain; 8413 if (!conversion_warning) 8414 arg_complain &= ~tf_warning; 8415 8416 val = convert_like_with_context (conv, arg, fn, i - is_method, 8417 arg_complain); 8418 val = convert_for_arg_passing (type, val, arg_complain); 8419 8420 if (val == error_mark_node) 8421 return error_mark_node; 8422 else 8423 argarray[j++] = val; 8424 } 8425 8426 /* Default arguments */ 8427 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 8428 { 8429 if (TREE_VALUE (parm) == error_mark_node) 8430 return error_mark_node; 8431 val = convert_default_arg (TREE_VALUE (parm), 8432 TREE_PURPOSE (parm), 8433 fn, i - is_method, 8434 complain); 8435 if (val == error_mark_node) 8436 return error_mark_node; 8437 argarray[j++] = val; 8438 } 8439 8440 /* Ellipsis */ 8441 int magic = magic_varargs_p (fn); 8442 for (; arg_index < vec_safe_length (args); ++arg_index) 8443 { 8444 tree a = (*args)[arg_index]; 8445 if ((magic == 3 && arg_index == 2) || magic == 2) 8446 { 8447 /* Do no conversions for certain magic varargs. */ 8448 a = mark_type_use (a); 8449 if (TREE_CODE (a) == FUNCTION_DECL && reject_gcc_builtin (a)) 8450 return error_mark_node; 8451 } 8452 else if (magic != 0) 8453 /* For other magic varargs only do decay_conversion. */ 8454 a = decay_conversion (a, complain); 8455 else if (DECL_CONSTRUCTOR_P (fn) 8456 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn), 8457 TREE_TYPE (a))) 8458 { 8459 /* Avoid infinite recursion trying to call A(...). */ 8460 if (complain & tf_error) 8461 /* Try to call the actual copy constructor for a good error. */ 8462 call_copy_ctor (a, complain); 8463 return error_mark_node; 8464 } 8465 else 8466 a = convert_arg_to_ellipsis (a, complain); 8467 if (a == error_mark_node) 8468 return error_mark_node; 8469 argarray[j++] = a; 8470 } 8471 8472 gcc_assert (j <= nargs); 8473 nargs = j; 8474 8475 /* Avoid to do argument-transformation, if warnings for format, and for 8476 nonnull are disabled. Just in case that at least one of them is active 8477 the check_function_arguments function might warn about something. */ 8478 8479 bool warned_p = false; 8480 if (warn_nonnull 8481 || warn_format 8482 || warn_suggest_attribute_format 8483 || warn_restrict) 8484 { 8485 tree *fargs = (!nargs ? argarray 8486 : (tree *) alloca (nargs * sizeof (tree))); 8487 for (j = 0; j < nargs; j++) 8488 { 8489 /* For -Wformat undo the implicit passing by hidden reference 8490 done by convert_arg_to_ellipsis. */ 8491 if (TREE_CODE (argarray[j]) == ADDR_EXPR 8492 && TYPE_REF_P (TREE_TYPE (argarray[j]))) 8493 fargs[j] = TREE_OPERAND (argarray[j], 0); 8494 else 8495 fargs[j] = argarray[j]; 8496 } 8497 8498 warned_p = check_function_arguments (input_location, fn, TREE_TYPE (fn), 8499 nargs, fargs, NULL); 8500 } 8501 8502 if (DECL_INHERITED_CTOR (fn)) 8503 { 8504 /* Check for passing ellipsis arguments to an inherited constructor. We 8505 could handle this by open-coding the inherited constructor rather than 8506 defining it, but let's not bother now. */ 8507 if (!cp_unevaluated_operand 8508 && cand->num_convs 8509 && cand->convs[cand->num_convs-1]->ellipsis_p) 8510 { 8511 if (complain & tf_error) 8512 { 8513 sorry ("passing arguments to ellipsis of inherited constructor " 8514 "%qD", cand->fn); 8515 inform (DECL_SOURCE_LOCATION (cand->fn), "declared here"); 8516 } 8517 return error_mark_node; 8518 } 8519 8520 /* A base constructor inheriting from a virtual base doesn't get the 8521 inherited arguments, just this and __vtt. */ 8522 if (ctor_omit_inherited_parms (fn)) 8523 nargs = 2; 8524 } 8525 8526 /* Avoid actually calling copy constructors and copy assignment operators, 8527 if possible. */ 8528 8529 if (! flag_elide_constructors && !force_elide) 8530 /* Do things the hard way. */; 8531 else if (cand->num_convs == 1 8532 && (DECL_COPY_CONSTRUCTOR_P (fn) 8533 || DECL_MOVE_CONSTRUCTOR_P (fn)) 8534 /* It's unsafe to elide the constructor when handling 8535 a noexcept-expression, it may evaluate to the wrong 8536 value (c++/53025). */ 8537 && (force_elide || cp_noexcept_operand == 0)) 8538 { 8539 tree targ; 8540 tree arg = argarray[num_artificial_parms_for (fn)]; 8541 tree fa; 8542 bool trivial = trivial_fn_p (fn); 8543 8544 /* Pull out the real argument, disregarding const-correctness. */ 8545 targ = arg; 8546 /* Strip the reference binding for the constructor parameter. */ 8547 if (CONVERT_EXPR_P (targ) 8548 && TYPE_REF_P (TREE_TYPE (targ))) 8549 targ = TREE_OPERAND (targ, 0); 8550 /* But don't strip any other reference bindings; binding a temporary to a 8551 reference prevents copy elision. */ 8552 while ((CONVERT_EXPR_P (targ) 8553 && !TYPE_REF_P (TREE_TYPE (targ))) 8554 || TREE_CODE (targ) == NON_LVALUE_EXPR) 8555 targ = TREE_OPERAND (targ, 0); 8556 if (TREE_CODE (targ) == ADDR_EXPR) 8557 { 8558 targ = TREE_OPERAND (targ, 0); 8559 if (!same_type_ignoring_top_level_qualifiers_p 8560 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 8561 targ = NULL_TREE; 8562 } 8563 else 8564 targ = NULL_TREE; 8565 8566 if (targ) 8567 arg = targ; 8568 else 8569 arg = cp_build_fold_indirect_ref (arg); 8570 8571 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base 8572 subobject. */ 8573 if (CHECKING_P && cxx_dialect >= cxx17) 8574 gcc_assert (TREE_CODE (arg) != TARGET_EXPR 8575 || force_elide 8576 /* It's from binding the ref parm to a packed field. */ 8577 || convs[0]->need_temporary_p 8578 || seen_error () 8579 /* See unsafe_copy_elision_p. */ 8580 || DECL_BASE_CONSTRUCTOR_P (fn)); 8581 8582 fa = argarray[0]; 8583 bool unsafe = unsafe_copy_elision_p (fa, arg); 8584 bool eliding_temp = (TREE_CODE (arg) == TARGET_EXPR && !unsafe); 8585 8586 /* [class.copy]: the copy constructor is implicitly defined even if the 8587 implementation elided its use. But don't warn about deprecation when 8588 eliding a temporary, as then no copy is actually performed. */ 8589 warning_sentinel s (warn_deprecated_copy, eliding_temp); 8590 if (force_elide) 8591 /* The language says this isn't called. */; 8592 else if (!trivial) 8593 { 8594 if (!mark_used (fn, complain) && !(complain & tf_error)) 8595 return error_mark_node; 8596 already_used = true; 8597 } 8598 else 8599 cp_warn_deprecated_use (fn, complain); 8600 8601 /* If we're creating a temp and we already have one, don't create a 8602 new one. If we're not creating a temp but we get one, use 8603 INIT_EXPR to collapse the temp into our target. Otherwise, if the 8604 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 8605 temp or an INIT_EXPR otherwise. */ 8606 if (is_dummy_object (fa)) 8607 { 8608 if (TREE_CODE (arg) == TARGET_EXPR) 8609 return arg; 8610 else if (trivial) 8611 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 8612 } 8613 else if ((trivial || TREE_CODE (arg) == TARGET_EXPR) 8614 && !unsafe) 8615 { 8616 tree to = cp_stabilize_reference (cp_build_fold_indirect_ref (fa)); 8617 8618 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 8619 return val; 8620 } 8621 } 8622 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 8623 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR) 8624 && trivial_fn_p (fn)) 8625 { 8626 tree to = cp_stabilize_reference 8627 (cp_build_fold_indirect_ref (argarray[0])); 8628 tree type = TREE_TYPE (to); 8629 tree as_base = CLASSTYPE_AS_BASE (type); 8630 tree arg = argarray[1]; 8631 location_t loc = cp_expr_loc_or_loc (arg, input_location); 8632 8633 if (is_really_empty_class (type, /*ignore_vptr*/true)) 8634 { 8635 /* Avoid copying empty classes. */ 8636 val = build2 (COMPOUND_EXPR, type, arg, to); 8637 TREE_NO_WARNING (val) = 1; 8638 } 8639 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 8640 { 8641 if (is_std_init_list (type) 8642 && conv_binds_ref_to_prvalue (convs[1])) 8643 warning_at (loc, OPT_Winit_list_lifetime, 8644 "assignment from temporary initializer_list does not " 8645 "extend the lifetime of the underlying array"); 8646 arg = cp_build_fold_indirect_ref (arg); 8647 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 8648 } 8649 else 8650 { 8651 /* We must only copy the non-tail padding parts. */ 8652 tree arg0, arg2, t; 8653 tree array_type, alias_set; 8654 8655 arg2 = TYPE_SIZE_UNIT (as_base); 8656 arg0 = cp_build_addr_expr (to, complain); 8657 8658 array_type = build_array_type (unsigned_char_type_node, 8659 build_index_type 8660 (size_binop (MINUS_EXPR, 8661 arg2, size_int (1)))); 8662 alias_set = build_int_cst (build_pointer_type (type), 0); 8663 t = build2 (MODIFY_EXPR, void_type_node, 8664 build2 (MEM_REF, array_type, arg0, alias_set), 8665 build2 (MEM_REF, array_type, arg, alias_set)); 8666 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 8667 TREE_NO_WARNING (val) = 1; 8668 } 8669 8670 cp_warn_deprecated_use (fn, complain); 8671 8672 return val; 8673 } 8674 else if (trivial_fn_p (fn)) 8675 { 8676 if (DECL_DESTRUCTOR_P (fn)) 8677 return build_trivial_dtor_call (argarray[0]); 8678 else if (default_ctor_p (fn)) 8679 { 8680 if (is_dummy_object (argarray[0])) 8681 return force_target_expr (DECL_CONTEXT (fn), void_node, 8682 no_cleanup_complain); 8683 else 8684 return cp_build_fold_indirect_ref (argarray[0]); 8685 } 8686 } 8687 8688 gcc_assert (!force_elide); 8689 8690 if (!already_used 8691 && !mark_used (fn, complain)) 8692 return error_mark_node; 8693 8694 /* Warn if the built-in writes to an object of a non-trivial type. */ 8695 if (warn_class_memaccess 8696 && vec_safe_length (args) >= 2 8697 && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 8698 maybe_warn_class_memaccess (input_location, fn, args); 8699 8700 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0) 8701 { 8702 tree t; 8703 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 8704 DECL_CONTEXT (fn), 8705 ba_any, NULL, complain); 8706 gcc_assert (binfo && binfo != error_mark_node); 8707 8708 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 8709 complain); 8710 if (TREE_SIDE_EFFECTS (argarray[0])) 8711 argarray[0] = save_expr (argarray[0]); 8712 t = build_pointer_type (TREE_TYPE (fn)); 8713 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 8714 TREE_TYPE (fn) = t; 8715 } 8716 else 8717 { 8718 fn = build_addr_func (fn, complain); 8719 if (fn == error_mark_node) 8720 return error_mark_node; 8721 } 8722 8723 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag); 8724 if (call == error_mark_node) 8725 return call; 8726 if (cand->flags & LOOKUP_LIST_INIT_CTOR) 8727 { 8728 tree c = extract_call_expr (call); 8729 /* build_new_op_1 will clear this when appropriate. */ 8730 CALL_EXPR_ORDERED_ARGS (c) = true; 8731 } 8732 if (warned_p) 8733 { 8734 tree c = extract_call_expr (call); 8735 if (TREE_CODE (c) == CALL_EXPR) 8736 TREE_NO_WARNING (c) = 1; 8737 } 8738 return call; 8739 } 8740 8741 namespace 8742 { 8743 8744 /* Return the DECL of the first non-static subobject of class TYPE 8745 that satisfies the predicate PRED or null if none can be found. */ 8746 8747 template <class Predicate> 8748 tree 8749 first_non_static_field (tree type, Predicate pred) 8750 { 8751 if (!type || !CLASS_TYPE_P (type)) 8752 return NULL_TREE; 8753 8754 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8755 { 8756 if (TREE_CODE (field) != FIELD_DECL) 8757 continue; 8758 if (TREE_STATIC (field)) 8759 continue; 8760 if (pred (field)) 8761 return field; 8762 } 8763 8764 int i = 0; 8765 8766 for (tree base_binfo, binfo = TYPE_BINFO (type); 8767 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8768 { 8769 tree base = TREE_TYPE (base_binfo); 8770 if (pred (base)) 8771 return base; 8772 if (tree field = first_non_static_field (base, pred)) 8773 return field; 8774 } 8775 8776 return NULL_TREE; 8777 } 8778 8779 struct NonPublicField 8780 { 8781 bool operator() (const_tree t) 8782 { 8783 return DECL_P (t) && (TREE_PRIVATE (t) || TREE_PROTECTED (t)); 8784 } 8785 }; 8786 8787 /* Return the DECL of the first non-public subobject of class TYPE 8788 or null if none can be found. */ 8789 8790 static inline tree 8791 first_non_public_field (tree type) 8792 { 8793 return first_non_static_field (type, NonPublicField ()); 8794 } 8795 8796 struct NonTrivialField 8797 { 8798 bool operator() (const_tree t) 8799 { 8800 return !trivial_type_p (DECL_P (t) ? TREE_TYPE (t) : t); 8801 } 8802 }; 8803 8804 /* Return the DECL of the first non-trivial subobject of class TYPE 8805 or null if none can be found. */ 8806 8807 static inline tree 8808 first_non_trivial_field (tree type) 8809 { 8810 return first_non_static_field (type, NonTrivialField ()); 8811 } 8812 8813 } /* unnamed namespace */ 8814 8815 /* Return true if all copy and move assignment operator overloads for 8816 class TYPE are trivial and at least one of them is not deleted and, 8817 when ACCESS is set, accessible. Return false otherwise. Set 8818 HASASSIGN to true when the TYPE has a (not necessarily trivial) 8819 copy or move assignment. */ 8820 8821 static bool 8822 has_trivial_copy_assign_p (tree type, bool access, bool *hasassign) 8823 { 8824 tree fns = get_class_binding (type, assign_op_identifier); 8825 bool all_trivial = true; 8826 8827 /* Iterate over overloads of the assignment operator, checking 8828 accessible copy assignments for triviality. */ 8829 8830 for (ovl_iterator oi (fns); oi; ++oi) 8831 { 8832 tree f = *oi; 8833 8834 /* Skip operators that aren't copy assignments. */ 8835 if (!copy_fn_p (f)) 8836 continue; 8837 8838 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8839 || accessible_p (TYPE_BINFO (type), f, true)); 8840 8841 /* Skip template assignment operators and deleted functions. */ 8842 if (TREE_CODE (f) != FUNCTION_DECL || DECL_DELETED_FN (f)) 8843 continue; 8844 8845 if (accessible) 8846 *hasassign = true; 8847 8848 if (!accessible || !trivial_fn_p (f)) 8849 all_trivial = false; 8850 8851 /* Break early when both properties have been determined. */ 8852 if (*hasassign && !all_trivial) 8853 break; 8854 } 8855 8856 /* Return true if they're all trivial and one of the expressions 8857 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */ 8858 tree ref = cp_build_reference_type (type, false); 8859 return (all_trivial 8860 && (is_trivially_xible (MODIFY_EXPR, type, type) 8861 || is_trivially_xible (MODIFY_EXPR, type, ref))); 8862 } 8863 8864 /* Return true if all copy and move ctor overloads for class TYPE are 8865 trivial and at least one of them is not deleted and, when ACCESS is 8866 set, accessible. Return false otherwise. Set each element of HASCTOR[] 8867 to true when the TYPE has a (not necessarily trivial) default and copy 8868 (or move) ctor, respectively. */ 8869 8870 static bool 8871 has_trivial_copy_p (tree type, bool access, bool hasctor[2]) 8872 { 8873 tree fns = get_class_binding (type, complete_ctor_identifier); 8874 bool all_trivial = true; 8875 8876 for (ovl_iterator oi (fns); oi; ++oi) 8877 { 8878 tree f = *oi; 8879 8880 /* Skip template constructors. */ 8881 if (TREE_CODE (f) != FUNCTION_DECL) 8882 continue; 8883 8884 bool cpy_or_move_ctor_p = copy_fn_p (f); 8885 8886 /* Skip ctors other than default, copy, and move. */ 8887 if (!cpy_or_move_ctor_p && !default_ctor_p (f)) 8888 continue; 8889 8890 if (DECL_DELETED_FN (f)) 8891 continue; 8892 8893 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8894 || accessible_p (TYPE_BINFO (type), f, true)); 8895 8896 if (accessible) 8897 hasctor[cpy_or_move_ctor_p] = true; 8898 8899 if (cpy_or_move_ctor_p && (!accessible || !trivial_fn_p (f))) 8900 all_trivial = false; 8901 8902 /* Break early when both properties have been determined. */ 8903 if (hasctor[0] && hasctor[1] && !all_trivial) 8904 break; 8905 } 8906 8907 return all_trivial; 8908 } 8909 8910 /* Issue a warning on a call to the built-in function FNDECL if it is 8911 a raw memory write whose destination is not an object of (something 8912 like) trivial or standard layout type with a non-deleted assignment 8913 and copy ctor. Detects const correctness violations, corrupting 8914 references, virtual table pointers, and bypassing non-trivial 8915 assignments. */ 8916 8917 static void 8918 maybe_warn_class_memaccess (location_t loc, tree fndecl, 8919 const vec<tree, va_gc> *args) 8920 { 8921 /* Except for bcopy where it's second, the destination pointer is 8922 the first argument for all functions handled here. Compute 8923 the index of the destination and source arguments. */ 8924 unsigned dstidx = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_BCOPY; 8925 unsigned srcidx = !dstidx; 8926 8927 tree dest = (*args)[dstidx]; 8928 if (!TREE_TYPE (dest) || !INDIRECT_TYPE_P (TREE_TYPE (dest))) 8929 return; 8930 8931 tree srctype = NULL_TREE; 8932 8933 /* Determine the type of the pointed-to object and whether it's 8934 a complete class type. */ 8935 tree desttype = TREE_TYPE (TREE_TYPE (dest)); 8936 8937 if (!desttype || !COMPLETE_TYPE_P (desttype) || !CLASS_TYPE_P (desttype)) 8938 return; 8939 8940 /* Check to see if the raw memory call is made by a non-static member 8941 function with THIS as the destination argument for the destination 8942 type. If so, and if the class has no non-trivial bases or members, 8943 be more permissive. */ 8944 if (current_function_decl 8945 && DECL_NONSTATIC_MEMBER_FUNCTION_P (current_function_decl) 8946 && is_this_parameter (tree_strip_nop_conversions (dest))) 8947 { 8948 tree ctx = DECL_CONTEXT (current_function_decl); 8949 bool special = same_type_ignoring_top_level_qualifiers_p (ctx, desttype); 8950 tree binfo = TYPE_BINFO (ctx); 8951 8952 if (special 8953 && !BINFO_VTABLE (binfo) 8954 && !first_non_trivial_field (desttype)) 8955 return; 8956 } 8957 8958 /* True if the class is trivial. */ 8959 bool trivial = trivial_type_p (desttype); 8960 8961 /* Set to true if DESTYPE has an accessible copy assignment. */ 8962 bool hasassign = false; 8963 /* True if all of the class' overloaded copy assignment operators 8964 are all trivial (and not deleted) and at least one of them is 8965 accessible. */ 8966 bool trivassign = has_trivial_copy_assign_p (desttype, true, &hasassign); 8967 8968 /* Set to true if DESTTYPE has an accessible default and copy ctor, 8969 respectively. */ 8970 bool hasctors[2] = { false, false }; 8971 8972 /* True if all of the class' overloaded copy constructors are all 8973 trivial (and not deleted) and at least one of them is accessible. */ 8974 bool trivcopy = has_trivial_copy_p (desttype, true, hasctors); 8975 8976 /* Set FLD to the first private/protected member of the class. */ 8977 tree fld = trivial ? first_non_public_field (desttype) : NULL_TREE; 8978 8979 /* The warning format string. */ 8980 const char *warnfmt = NULL; 8981 /* A suggested alternative to offer instead of the raw memory call. 8982 Empty string when none can be come up with. */ 8983 const char *suggest = ""; 8984 bool warned = false; 8985 8986 switch (DECL_FUNCTION_CODE (fndecl)) 8987 { 8988 case BUILT_IN_MEMSET: 8989 if (!integer_zerop (maybe_constant_value ((*args)[1]))) 8990 { 8991 /* Diagnose setting non-copy-assignable or non-trivial types, 8992 or types with a private member, to (potentially) non-zero 8993 bytes. Since the value of the bytes being written is unknown, 8994 suggest using assignment instead (if one exists). Also warn 8995 for writes into objects for which zero-initialization doesn't 8996 mean all bits clear (pointer-to-member data, where null is all 8997 bits set). Since the value being written is (most likely) 8998 non-zero, simply suggest assignment (but not copy assignment). */ 8999 suggest = "; use assignment instead"; 9000 if (!trivassign) 9001 warnfmt = G_("%qD writing to an object of type %#qT with " 9002 "no trivial copy-assignment"); 9003 else if (!trivial) 9004 warnfmt = G_("%qD writing to an object of non-trivial type %#qT%s"); 9005 else if (fld) 9006 { 9007 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 9008 warned = warning_at (loc, OPT_Wclass_memaccess, 9009 "%qD writing to an object of type %#qT with " 9010 "%qs member %qD", 9011 fndecl, desttype, access, fld); 9012 } 9013 else if (!zero_init_p (desttype)) 9014 warnfmt = G_("%qD writing to an object of type %#qT containing " 9015 "a pointer to data member%s"); 9016 9017 break; 9018 } 9019 /* Fall through. */ 9020 9021 case BUILT_IN_BZERO: 9022 /* Similarly to the above, diagnose clearing non-trivial or non- 9023 standard layout objects, or objects of types with no assignmenmt. 9024 Since the value being written is known to be zero, suggest either 9025 copy assignment, copy ctor, or default ctor as an alternative, 9026 depending on what's available. */ 9027 9028 if (hasassign && hasctors[0]) 9029 suggest = G_("; use assignment or value-initialization instead"); 9030 else if (hasassign) 9031 suggest = G_("; use assignment instead"); 9032 else if (hasctors[0]) 9033 suggest = G_("; use value-initialization instead"); 9034 9035 if (!trivassign) 9036 warnfmt = G_("%qD clearing an object of type %#qT with " 9037 "no trivial copy-assignment%s"); 9038 else if (!trivial) 9039 warnfmt = G_("%qD clearing an object of non-trivial type %#qT%s"); 9040 else if (!zero_init_p (desttype)) 9041 warnfmt = G_("%qD clearing an object of type %#qT containing " 9042 "a pointer-to-member%s"); 9043 break; 9044 9045 case BUILT_IN_BCOPY: 9046 case BUILT_IN_MEMCPY: 9047 case BUILT_IN_MEMMOVE: 9048 case BUILT_IN_MEMPCPY: 9049 /* Determine the type of the source object. */ 9050 srctype = TREE_TYPE ((*args)[srcidx]); 9051 if (!srctype || !INDIRECT_TYPE_P (srctype)) 9052 srctype = void_type_node; 9053 else 9054 srctype = TREE_TYPE (srctype); 9055 9056 /* Since it's impossible to determine wheter the byte copy is 9057 being used in place of assignment to an existing object or 9058 as a substitute for initialization, assume it's the former. 9059 Determine the best alternative to use instead depending on 9060 what's not deleted. */ 9061 if (hasassign && hasctors[1]) 9062 suggest = G_("; use copy-assignment or copy-initialization instead"); 9063 else if (hasassign) 9064 suggest = G_("; use copy-assignment instead"); 9065 else if (hasctors[1]) 9066 suggest = G_("; use copy-initialization instead"); 9067 9068 if (!trivassign) 9069 warnfmt = G_("%qD writing to an object of type %#qT with no trivial " 9070 "copy-assignment%s"); 9071 else if (!trivially_copyable_p (desttype)) 9072 warnfmt = G_("%qD writing to an object of non-trivially copyable " 9073 "type %#qT%s"); 9074 else if (!trivcopy) 9075 warnfmt = G_("%qD writing to an object with a deleted copy constructor"); 9076 9077 else if (!trivial 9078 && !VOID_TYPE_P (srctype) 9079 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 9080 && !same_type_ignoring_top_level_qualifiers_p (desttype, 9081 srctype)) 9082 { 9083 /* Warn when copying into a non-trivial object from an object 9084 of a different type other than void or char. */ 9085 warned = warning_at (loc, OPT_Wclass_memaccess, 9086 "%qD copying an object of non-trivial type " 9087 "%#qT from an array of %#qT", 9088 fndecl, desttype, srctype); 9089 } 9090 else if (fld 9091 && !VOID_TYPE_P (srctype) 9092 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 9093 && !same_type_ignoring_top_level_qualifiers_p (desttype, 9094 srctype)) 9095 { 9096 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 9097 warned = warning_at (loc, OPT_Wclass_memaccess, 9098 "%qD copying an object of type %#qT with " 9099 "%qs member %qD from an array of %#qT; use " 9100 "assignment or copy-initialization instead", 9101 fndecl, desttype, access, fld, srctype); 9102 } 9103 else if (!trivial && vec_safe_length (args) > 2) 9104 { 9105 tree sz = maybe_constant_value ((*args)[2]); 9106 if (!tree_fits_uhwi_p (sz)) 9107 break; 9108 9109 /* Finally, warn on partial copies. */ 9110 unsigned HOST_WIDE_INT typesize 9111 = tree_to_uhwi (TYPE_SIZE_UNIT (desttype)); 9112 if (unsigned HOST_WIDE_INT partial = tree_to_uhwi (sz) % typesize) 9113 warned = warning_at (loc, OPT_Wclass_memaccess, 9114 (typesize - partial > 1 9115 ? G_("%qD writing to an object of " 9116 "a non-trivial type %#qT leaves %wu " 9117 "bytes unchanged") 9118 : G_("%qD writing to an object of " 9119 "a non-trivial type %#qT leaves %wu " 9120 "byte unchanged")), 9121 fndecl, desttype, typesize - partial); 9122 } 9123 break; 9124 9125 case BUILT_IN_REALLOC: 9126 9127 if (!trivially_copyable_p (desttype)) 9128 warnfmt = G_("%qD moving an object of non-trivially copyable type " 9129 "%#qT; use %<new%> and %<delete%> instead"); 9130 else if (!trivcopy) 9131 warnfmt = G_("%qD moving an object of type %#qT with deleted copy " 9132 "constructor; use %<new%> and %<delete%> instead"); 9133 else if (!get_dtor (desttype, tf_none)) 9134 warnfmt = G_("%qD moving an object of type %#qT with deleted " 9135 "destructor"); 9136 else if (!trivial) 9137 { 9138 tree sz = maybe_constant_value ((*args)[1]); 9139 if (TREE_CODE (sz) == INTEGER_CST 9140 && tree_int_cst_lt (sz, TYPE_SIZE_UNIT (desttype))) 9141 /* Finally, warn on reallocation into insufficient space. */ 9142 warned = warning_at (loc, OPT_Wclass_memaccess, 9143 "%qD moving an object of non-trivial type " 9144 "%#qT and size %E into a region of size %E", 9145 fndecl, desttype, TYPE_SIZE_UNIT (desttype), 9146 sz); 9147 } 9148 break; 9149 9150 default: 9151 return; 9152 } 9153 9154 if (warnfmt) 9155 { 9156 if (suggest) 9157 warned = warning_at (loc, OPT_Wclass_memaccess, 9158 warnfmt, fndecl, desttype, suggest); 9159 else 9160 warned = warning_at (loc, OPT_Wclass_memaccess, 9161 warnfmt, fndecl, desttype); 9162 } 9163 9164 if (warned) 9165 inform (location_of (desttype), "%#qT declared here", desttype); 9166 } 9167 9168 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 9169 This function performs no overload resolution, conversion, or other 9170 high-level operations. */ 9171 9172 tree 9173 build_cxx_call (tree fn, int nargs, tree *argarray, 9174 tsubst_flags_t complain) 9175 { 9176 tree fndecl; 9177 9178 /* Remember roughly where this call is. */ 9179 location_t loc = cp_expr_loc_or_loc (fn, input_location); 9180 fn = build_call_a (fn, nargs, argarray); 9181 SET_EXPR_LOCATION (fn, loc); 9182 9183 fndecl = get_callee_fndecl (fn); 9184 9185 /* Check that arguments to builtin functions match the expectations. */ 9186 if (fndecl 9187 && !processing_template_decl 9188 && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) 9189 { 9190 int i; 9191 9192 /* We need to take care that values to BUILT_IN_NORMAL 9193 are reduced. */ 9194 for (i = 0; i < nargs; i++) 9195 argarray[i] = maybe_constant_value (argarray[i]); 9196 9197 if (!check_builtin_function_arguments (EXPR_LOCATION (fn), vNULL, fndecl, 9198 nargs, argarray)) 9199 return error_mark_node; 9200 } 9201 9202 if (VOID_TYPE_P (TREE_TYPE (fn))) 9203 return fn; 9204 9205 /* 5.2.2/11: If a function call is a prvalue of object type: if the 9206 function call is either the operand of a decltype-specifier or the 9207 right operand of a comma operator that is the operand of a 9208 decltype-specifier, a temporary object is not introduced for the 9209 prvalue. The type of the prvalue may be incomplete. */ 9210 if (!(complain & tf_decltype)) 9211 { 9212 fn = require_complete_type_sfinae (fn, complain); 9213 if (fn == error_mark_node) 9214 return error_mark_node; 9215 9216 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 9217 { 9218 fn = build_cplus_new (TREE_TYPE (fn), fn, complain); 9219 maybe_warn_parm_abi (TREE_TYPE (fn), loc); 9220 } 9221 } 9222 return convert_from_reference (fn); 9223 } 9224 9225 /* Returns the value to use for the in-charge parameter when making a 9226 call to a function with the indicated NAME. 9227 9228 FIXME:Can't we find a neater way to do this mapping? */ 9229 9230 tree 9231 in_charge_arg_for_name (tree name) 9232 { 9233 if (IDENTIFIER_CTOR_P (name)) 9234 { 9235 if (name == complete_ctor_identifier) 9236 return integer_one_node; 9237 gcc_checking_assert (name == base_ctor_identifier); 9238 } 9239 else 9240 { 9241 if (name == complete_dtor_identifier) 9242 return integer_two_node; 9243 else if (name == deleting_dtor_identifier) 9244 return integer_three_node; 9245 gcc_checking_assert (name == base_dtor_identifier); 9246 } 9247 9248 return integer_zero_node; 9249 } 9250 9251 /* We've built up a constructor call RET. Complain if it delegates to the 9252 constructor we're currently compiling. */ 9253 9254 static void 9255 check_self_delegation (tree ret) 9256 { 9257 if (TREE_CODE (ret) == TARGET_EXPR) 9258 ret = TARGET_EXPR_INITIAL (ret); 9259 tree fn = cp_get_callee_fndecl_nofold (ret); 9260 if (fn && DECL_ABSTRACT_ORIGIN (fn) == current_function_decl) 9261 error ("constructor delegates to itself"); 9262 } 9263 9264 /* Build a call to a constructor, destructor, or an assignment 9265 operator for INSTANCE, an expression with class type. NAME 9266 indicates the special member function to call; *ARGS are the 9267 arguments. ARGS may be NULL. This may change ARGS. BINFO 9268 indicates the base of INSTANCE that is to be passed as the `this' 9269 parameter to the member function called. 9270 9271 FLAGS are the LOOKUP_* flags to use when processing the call. 9272 9273 If NAME indicates a complete object constructor, INSTANCE may be 9274 NULL_TREE. In this case, the caller will call build_cplus_new to 9275 store the newly constructed object into a VAR_DECL. */ 9276 9277 tree 9278 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args, 9279 tree binfo, int flags, tsubst_flags_t complain) 9280 { 9281 tree fns; 9282 /* The type of the subobject to be constructed or destroyed. */ 9283 tree class_type; 9284 vec<tree, va_gc> *allocated = NULL; 9285 tree ret; 9286 9287 gcc_assert (IDENTIFIER_CDTOR_P (name) || name == assign_op_identifier); 9288 9289 if (error_operand_p (instance)) 9290 return error_mark_node; 9291 9292 if (IDENTIFIER_DTOR_P (name)) 9293 { 9294 gcc_assert (args == NULL || vec_safe_is_empty (*args)); 9295 if (!type_build_dtor_call (TREE_TYPE (instance))) 9296 /* Shortcut to avoid lazy destructor declaration. */ 9297 return build_trivial_dtor_call (instance); 9298 } 9299 9300 if (TYPE_P (binfo)) 9301 { 9302 /* Resolve the name. */ 9303 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 9304 return error_mark_node; 9305 9306 binfo = TYPE_BINFO (binfo); 9307 } 9308 9309 gcc_assert (binfo != NULL_TREE); 9310 9311 class_type = BINFO_TYPE (binfo); 9312 9313 /* Handle the special case where INSTANCE is NULL_TREE. */ 9314 if (name == complete_ctor_identifier && !instance) 9315 instance = build_dummy_object (class_type); 9316 else 9317 { 9318 /* Convert to the base class, if necessary. */ 9319 if (!same_type_ignoring_top_level_qualifiers_p 9320 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 9321 { 9322 if (IDENTIFIER_CDTOR_P (name)) 9323 /* For constructors and destructors, either the base is 9324 non-virtual, or it is virtual but we are doing the 9325 conversion from a constructor or destructor for the 9326 complete object. In either case, we can convert 9327 statically. */ 9328 instance = convert_to_base_statically (instance, binfo); 9329 else 9330 { 9331 /* However, for assignment operators, we must convert 9332 dynamically if the base is virtual. */ 9333 gcc_checking_assert (name == assign_op_identifier); 9334 instance = build_base_path (PLUS_EXPR, instance, 9335 binfo, /*nonnull=*/1, complain); 9336 } 9337 } 9338 } 9339 9340 gcc_assert (instance != NULL_TREE); 9341 9342 /* In C++17, "If the initializer expression is a prvalue and the 9343 cv-unqualified version of the source type is the same class as the class 9344 of the destination, the initializer expression is used to initialize the 9345 destination object." Handle that here to avoid doing overload 9346 resolution. */ 9347 if (cxx_dialect >= cxx17 9348 && args && vec_safe_length (*args) == 1 9349 && name == complete_ctor_identifier) 9350 { 9351 tree arg = (**args)[0]; 9352 9353 if (BRACE_ENCLOSED_INITIALIZER_P (arg) 9354 && !TYPE_HAS_LIST_CTOR (class_type) 9355 && CONSTRUCTOR_NELTS (arg) == 1) 9356 arg = CONSTRUCTOR_ELT (arg, 0)->value; 9357 9358 if ((TREE_CODE (arg) == TARGET_EXPR 9359 || TREE_CODE (arg) == CONSTRUCTOR) 9360 && (same_type_ignoring_top_level_qualifiers_p 9361 (class_type, TREE_TYPE (arg)))) 9362 { 9363 if (is_dummy_object (instance)) 9364 return arg; 9365 else if (TREE_CODE (arg) == TARGET_EXPR) 9366 TARGET_EXPR_DIRECT_INIT_P (arg) = true; 9367 9368 if ((complain & tf_error) 9369 && (flags & LOOKUP_DELEGATING_CONS)) 9370 check_self_delegation (arg); 9371 /* Avoid change of behavior on Wunused-var-2.C. */ 9372 instance = mark_lvalue_use (instance); 9373 return build2 (INIT_EXPR, class_type, instance, arg); 9374 } 9375 } 9376 9377 fns = lookup_fnfields (binfo, name, 1); 9378 9379 /* When making a call to a constructor or destructor for a subobject 9380 that uses virtual base classes, pass down a pointer to a VTT for 9381 the subobject. */ 9382 if ((name == base_ctor_identifier 9383 || name == base_dtor_identifier) 9384 && CLASSTYPE_VBASECLASSES (class_type)) 9385 { 9386 tree vtt; 9387 tree sub_vtt; 9388 9389 /* If the current function is a complete object constructor 9390 or destructor, then we fetch the VTT directly. 9391 Otherwise, we look it up using the VTT we were given. */ 9392 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 9393 vtt = decay_conversion (vtt, complain); 9394 if (vtt == error_mark_node) 9395 return error_mark_node; 9396 vtt = build_if_in_charge (vtt, current_vtt_parm); 9397 if (BINFO_SUBVTT_INDEX (binfo)) 9398 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 9399 else 9400 sub_vtt = vtt; 9401 9402 if (args == NULL) 9403 { 9404 allocated = make_tree_vector (); 9405 args = &allocated; 9406 } 9407 9408 vec_safe_insert (*args, 0, sub_vtt); 9409 } 9410 9411 ret = build_new_method_call (instance, fns, args, 9412 TYPE_BINFO (BINFO_TYPE (binfo)), 9413 flags, /*fn=*/NULL, 9414 complain); 9415 9416 if (allocated != NULL) 9417 release_tree_vector (allocated); 9418 9419 if ((complain & tf_error) 9420 && (flags & LOOKUP_DELEGATING_CONS) 9421 && name == complete_ctor_identifier) 9422 check_self_delegation (ret); 9423 9424 return ret; 9425 } 9426 9427 /* Return the NAME, as a C string. The NAME indicates a function that 9428 is a member of TYPE. *FREE_P is set to true if the caller must 9429 free the memory returned. 9430 9431 Rather than go through all of this, we should simply set the names 9432 of constructors and destructors appropriately, and dispense with 9433 ctor_identifier, dtor_identifier, etc. */ 9434 9435 static char * 9436 name_as_c_string (tree name, tree type, bool *free_p) 9437 { 9438 const char *pretty_name; 9439 9440 /* Assume that we will not allocate memory. */ 9441 *free_p = false; 9442 /* Constructors and destructors are special. */ 9443 if (IDENTIFIER_CDTOR_P (name)) 9444 { 9445 pretty_name 9446 = identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))); 9447 /* For a destructor, add the '~'. */ 9448 if (IDENTIFIER_DTOR_P (name)) 9449 { 9450 pretty_name = concat ("~", pretty_name, NULL); 9451 /* Remember that we need to free the memory allocated. */ 9452 *free_p = true; 9453 } 9454 } 9455 else if (IDENTIFIER_CONV_OP_P (name)) 9456 { 9457 pretty_name = concat ("operator ", 9458 type_as_string_translate (TREE_TYPE (name), 9459 TFF_PLAIN_IDENTIFIER), 9460 NULL); 9461 /* Remember that we need to free the memory allocated. */ 9462 *free_p = true; 9463 } 9464 else 9465 pretty_name = identifier_to_locale (IDENTIFIER_POINTER (name)); 9466 9467 return CONST_CAST (char *, pretty_name); 9468 } 9469 9470 /* If CANDIDATES contains exactly one candidate, return it, otherwise 9471 return NULL. */ 9472 9473 static z_candidate * 9474 single_z_candidate (z_candidate *candidates) 9475 { 9476 if (candidates == NULL) 9477 return NULL; 9478 9479 if (candidates->next) 9480 return NULL; 9481 9482 return candidates; 9483 } 9484 9485 /* If CANDIDATE is invalid due to a bad argument type, return the 9486 pertinent conversion_info. 9487 9488 Otherwise, return NULL. */ 9489 9490 static const conversion_info * 9491 maybe_get_bad_conversion_for_unmatched_call (const z_candidate *candidate) 9492 { 9493 /* Must be an rr_arg_conversion or rr_bad_arg_conversion. */ 9494 rejection_reason *r = candidate->reason; 9495 9496 if (r == NULL) 9497 return NULL; 9498 9499 switch (r->code) 9500 { 9501 default: 9502 return NULL; 9503 9504 case rr_arg_conversion: 9505 return &r->u.conversion; 9506 9507 case rr_bad_arg_conversion: 9508 return &r->u.bad_conversion; 9509 } 9510 } 9511 9512 /* Issue an error and note complaining about a bad argument type at a 9513 callsite with a single candidate FNDECL. 9514 9515 ARG_LOC is the location of the argument (or UNKNOWN_LOCATION, in which 9516 case input_location is used). 9517 FROM_TYPE is the type of the actual argument; TO_TYPE is the type of 9518 the formal parameter. */ 9519 9520 void 9521 complain_about_bad_argument (location_t arg_loc, 9522 tree from_type, tree to_type, 9523 tree fndecl, int parmnum) 9524 { 9525 auto_diagnostic_group d; 9526 range_label_for_type_mismatch rhs_label (from_type, to_type); 9527 range_label *label = &rhs_label; 9528 if (arg_loc == UNKNOWN_LOCATION) 9529 { 9530 arg_loc = input_location; 9531 label = NULL; 9532 } 9533 gcc_rich_location richloc (arg_loc, label); 9534 error_at (&richloc, 9535 "cannot convert %qH to %qI", 9536 from_type, to_type); 9537 maybe_inform_about_fndecl_for_bogus_argument_init (fndecl, 9538 parmnum); 9539 } 9540 9541 /* Subroutine of build_new_method_call_1, for where there are no viable 9542 candidates for the call. */ 9543 9544 static void 9545 complain_about_no_candidates_for_method_call (tree instance, 9546 z_candidate *candidates, 9547 tree explicit_targs, 9548 tree basetype, 9549 tree optype, tree name, 9550 bool skip_first_for_error, 9551 vec<tree, va_gc> *user_args) 9552 { 9553 auto_diagnostic_group d; 9554 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 9555 cxx_incomplete_type_error (instance, basetype); 9556 else if (optype) 9557 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 9558 basetype, optype, build_tree_list_vec (user_args), 9559 TREE_TYPE (instance)); 9560 else 9561 { 9562 /* Special-case for when there's a single candidate that's failing 9563 due to a bad argument type. */ 9564 if (z_candidate *candidate = single_z_candidate (candidates)) 9565 if (const conversion_info *conv 9566 = maybe_get_bad_conversion_for_unmatched_call (candidate)) 9567 { 9568 tree from_type = conv->from; 9569 if (!TYPE_P (conv->from)) 9570 from_type = lvalue_type (conv->from); 9571 complain_about_bad_argument (conv->loc, 9572 from_type, conv->to_type, 9573 candidate->fn, conv->n_arg); 9574 return; 9575 } 9576 9577 tree arglist = build_tree_list_vec (user_args); 9578 tree errname = name; 9579 bool twiddle = false; 9580 if (IDENTIFIER_CDTOR_P (errname)) 9581 { 9582 twiddle = IDENTIFIER_DTOR_P (errname); 9583 errname = constructor_name (basetype); 9584 } 9585 if (explicit_targs) 9586 errname = lookup_template_function (errname, explicit_targs); 9587 if (skip_first_for_error) 9588 arglist = TREE_CHAIN (arglist); 9589 error ("no matching function for call to %<%T::%s%E(%A)%#V%>", 9590 basetype, &"~"[!twiddle], errname, arglist, 9591 TREE_TYPE (instance)); 9592 } 9593 print_z_candidates (location_of (name), candidates); 9594 } 9595 9596 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 9597 be set, upon return, to the function called. ARGS may be NULL. 9598 This may change ARGS. */ 9599 9600 static tree 9601 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args, 9602 tree conversion_path, int flags, 9603 tree *fn_p, tsubst_flags_t complain) 9604 { 9605 struct z_candidate *candidates = 0, *cand; 9606 tree explicit_targs = NULL_TREE; 9607 tree basetype = NULL_TREE; 9608 tree access_binfo, binfo; 9609 tree optype; 9610 tree first_mem_arg = NULL_TREE; 9611 tree name; 9612 bool skip_first_for_error; 9613 vec<tree, va_gc> *user_args; 9614 tree call; 9615 tree fn; 9616 int template_only = 0; 9617 bool any_viable_p; 9618 tree orig_instance; 9619 tree orig_fns; 9620 vec<tree, va_gc> *orig_args = NULL; 9621 void *p; 9622 9623 gcc_assert (instance != NULL_TREE); 9624 9625 /* We don't know what function we're going to call, yet. */ 9626 if (fn_p) 9627 *fn_p = NULL_TREE; 9628 9629 if (error_operand_p (instance) 9630 || !fns || error_operand_p (fns)) 9631 return error_mark_node; 9632 9633 if (!BASELINK_P (fns)) 9634 { 9635 if (complain & tf_error) 9636 error ("call to non-function %qD", fns); 9637 return error_mark_node; 9638 } 9639 9640 orig_instance = instance; 9641 orig_fns = fns; 9642 9643 /* Dismantle the baselink to collect all the information we need. */ 9644 if (!conversion_path) 9645 conversion_path = BASELINK_BINFO (fns); 9646 access_binfo = BASELINK_ACCESS_BINFO (fns); 9647 binfo = BASELINK_BINFO (fns); 9648 optype = BASELINK_OPTYPE (fns); 9649 fns = BASELINK_FUNCTIONS (fns); 9650 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 9651 { 9652 explicit_targs = TREE_OPERAND (fns, 1); 9653 fns = TREE_OPERAND (fns, 0); 9654 template_only = 1; 9655 } 9656 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 9657 || TREE_CODE (fns) == TEMPLATE_DECL 9658 || TREE_CODE (fns) == OVERLOAD); 9659 fn = OVL_FIRST (fns); 9660 name = DECL_NAME (fn); 9661 9662 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 9663 gcc_assert (CLASS_TYPE_P (basetype)); 9664 9665 user_args = args == NULL ? NULL : *args; 9666 /* Under DR 147 A::A() is an invalid constructor call, 9667 not a functional cast. */ 9668 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 9669 { 9670 if (! (complain & tf_error)) 9671 return error_mark_node; 9672 9673 basetype = DECL_CONTEXT (fn); 9674 name = constructor_name (basetype); 9675 auto_diagnostic_group d; 9676 if (permerror (input_location, 9677 "cannot call constructor %<%T::%D%> directly", 9678 basetype, name)) 9679 inform (input_location, "for a function-style cast, remove the " 9680 "redundant %<::%D%>", name); 9681 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 9682 complain); 9683 return call; 9684 } 9685 9686 if (processing_template_decl) 9687 { 9688 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 9689 instance = build_non_dependent_expr (instance); 9690 if (args != NULL) 9691 make_args_non_dependent (*args); 9692 } 9693 9694 /* Process the argument list. */ 9695 if (args != NULL && *args != NULL) 9696 { 9697 *args = resolve_args (*args, complain); 9698 if (*args == NULL) 9699 return error_mark_node; 9700 user_args = *args; 9701 } 9702 9703 /* Consider the object argument to be used even if we end up selecting a 9704 static member function. */ 9705 instance = mark_type_use (instance); 9706 9707 /* Figure out whether to skip the first argument for the error 9708 message we will display to users if an error occurs. We don't 9709 want to display any compiler-generated arguments. The "this" 9710 pointer hasn't been added yet. However, we must remove the VTT 9711 pointer if this is a call to a base-class constructor or 9712 destructor. */ 9713 skip_first_for_error = false; 9714 if (IDENTIFIER_CDTOR_P (name)) 9715 { 9716 /* Callers should explicitly indicate whether they want to ctor 9717 the complete object or just the part without virtual bases. */ 9718 gcc_assert (name != ctor_identifier); 9719 9720 /* Remove the VTT pointer, if present. */ 9721 if ((name == base_ctor_identifier || name == base_dtor_identifier) 9722 && CLASSTYPE_VBASECLASSES (basetype)) 9723 skip_first_for_error = true; 9724 9725 /* It's OK to call destructors and constructors on cv-qualified 9726 objects. Therefore, convert the INSTANCE to the unqualified 9727 type, if necessary. */ 9728 if (!same_type_p (basetype, TREE_TYPE (instance))) 9729 { 9730 instance = build_this (instance); 9731 instance = build_nop (build_pointer_type (basetype), instance); 9732 instance = build_fold_indirect_ref (instance); 9733 } 9734 } 9735 else 9736 gcc_assert (!DECL_DESTRUCTOR_P (fn) && !DECL_CONSTRUCTOR_P (fn)); 9737 9738 /* For the overload resolution we need to find the actual `this` 9739 that would be captured if the call turns out to be to a 9740 non-static member function. Do not actually capture it at this 9741 point. */ 9742 if (DECL_CONSTRUCTOR_P (fn)) 9743 /* Constructors don't use the enclosing 'this'. */ 9744 first_mem_arg = instance; 9745 else 9746 first_mem_arg = maybe_resolve_dummy (instance, false); 9747 9748 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9749 p = conversion_obstack_alloc (0); 9750 9751 /* The number of arguments artificial parms in ARGS; we subtract one because 9752 there's no 'this' in ARGS. */ 9753 unsigned skip = num_artificial_parms_for (fn) - 1; 9754 9755 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 9756 initializer, not T({ }). */ 9757 if (DECL_CONSTRUCTOR_P (fn) 9758 && vec_safe_length (user_args) > skip 9759 && DIRECT_LIST_INIT_P ((*user_args)[skip])) 9760 { 9761 tree init_list = (*user_args)[skip]; 9762 tree init = NULL_TREE; 9763 9764 gcc_assert (user_args->length () == skip + 1 9765 && !(flags & LOOKUP_ONLYCONVERTING)); 9766 9767 /* If the initializer list has no elements and T is a class type with 9768 a default constructor, the object is value-initialized. Handle 9769 this here so we don't need to handle it wherever we use 9770 build_special_member_call. */ 9771 if (CONSTRUCTOR_NELTS (init_list) == 0 9772 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 9773 /* For a user-provided default constructor, use the normal 9774 mechanisms so that protected access works. */ 9775 && type_has_non_user_provided_default_constructor (basetype) 9776 && !processing_template_decl) 9777 init = build_value_init (basetype, complain); 9778 9779 /* If BASETYPE is an aggregate, we need to do aggregate 9780 initialization. */ 9781 else if (CP_AGGREGATE_TYPE_P (basetype)) 9782 { 9783 init = reshape_init (basetype, init_list, complain); 9784 init = digest_init (basetype, init, complain); 9785 } 9786 9787 if (init) 9788 { 9789 if (is_dummy_object (instance)) 9790 return get_target_expr_sfinae (init, complain); 9791 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init); 9792 TREE_SIDE_EFFECTS (init) = true; 9793 return init; 9794 } 9795 9796 /* Otherwise go ahead with overload resolution. */ 9797 add_list_candidates (fns, first_mem_arg, user_args, 9798 basetype, explicit_targs, template_only, 9799 conversion_path, access_binfo, flags, 9800 &candidates, complain); 9801 } 9802 else 9803 add_candidates (fns, first_mem_arg, user_args, optype, 9804 explicit_targs, template_only, conversion_path, 9805 access_binfo, flags, &candidates, complain); 9806 9807 any_viable_p = false; 9808 candidates = splice_viable (candidates, false, &any_viable_p); 9809 9810 if (!any_viable_p) 9811 { 9812 if (complain & tf_error) 9813 complain_about_no_candidates_for_method_call (instance, candidates, 9814 explicit_targs, basetype, 9815 optype, name, 9816 skip_first_for_error, 9817 user_args); 9818 call = error_mark_node; 9819 } 9820 else 9821 { 9822 cand = tourney (candidates, complain); 9823 if (cand == 0) 9824 { 9825 char *pretty_name; 9826 bool free_p; 9827 tree arglist; 9828 9829 if (complain & tf_error) 9830 { 9831 pretty_name = name_as_c_string (name, basetype, &free_p); 9832 arglist = build_tree_list_vec (user_args); 9833 if (skip_first_for_error) 9834 arglist = TREE_CHAIN (arglist); 9835 auto_diagnostic_group d; 9836 if (!any_strictly_viable (candidates)) 9837 error ("no matching function for call to %<%s(%A)%>", 9838 pretty_name, arglist); 9839 else 9840 error ("call of overloaded %<%s(%A)%> is ambiguous", 9841 pretty_name, arglist); 9842 print_z_candidates (location_of (name), candidates); 9843 if (free_p) 9844 free (pretty_name); 9845 } 9846 call = error_mark_node; 9847 } 9848 else 9849 { 9850 fn = cand->fn; 9851 call = NULL_TREE; 9852 9853 if (!(flags & LOOKUP_NONVIRTUAL) 9854 && DECL_PURE_VIRTUAL_P (fn) 9855 && instance == current_class_ref 9856 && (complain & tf_warning)) 9857 { 9858 /* This is not an error, it is runtime undefined 9859 behavior. */ 9860 if (!current_function_decl) 9861 warning (0, "pure virtual %q#D called from " 9862 "non-static data member initializer", fn); 9863 else if (DECL_CONSTRUCTOR_P (current_function_decl) 9864 || DECL_DESTRUCTOR_P (current_function_decl)) 9865 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) 9866 ? G_("pure virtual %q#D called from constructor") 9867 : G_("pure virtual %q#D called from destructor")), 9868 fn); 9869 } 9870 9871 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 9872 && !DECL_CONSTRUCTOR_P (fn) 9873 && is_dummy_object (instance)) 9874 { 9875 instance = maybe_resolve_dummy (instance, true); 9876 if (instance == error_mark_node) 9877 call = error_mark_node; 9878 else if (!is_dummy_object (instance)) 9879 { 9880 /* We captured 'this' in the current lambda now that 9881 we know we really need it. */ 9882 cand->first_arg = instance; 9883 } 9884 else if (any_dependent_bases_p ()) 9885 /* We can't tell until instantiation time whether we can use 9886 *this as the implicit object argument. */; 9887 else 9888 { 9889 if (complain & tf_error) 9890 error ("cannot call member function %qD without object", 9891 fn); 9892 call = error_mark_node; 9893 } 9894 } 9895 9896 if (call != error_mark_node) 9897 { 9898 /* Optimize away vtable lookup if we know that this 9899 function can't be overridden. We need to check if 9900 the context and the type where we found fn are the same, 9901 actually FN might be defined in a different class 9902 type because of a using-declaration. In this case, we 9903 do not want to perform a non-virtual call. */ 9904 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 9905 && same_type_ignoring_top_level_qualifiers_p 9906 (DECL_CONTEXT (fn), BINFO_TYPE (binfo)) 9907 && resolves_to_fixed_type_p (instance, 0)) 9908 flags |= LOOKUP_NONVIRTUAL; 9909 if (explicit_targs) 9910 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 9911 /* Now we know what function is being called. */ 9912 if (fn_p) 9913 *fn_p = fn; 9914 /* Build the actual CALL_EXPR. */ 9915 call = build_over_call (cand, flags, complain); 9916 /* In an expression of the form `a->f()' where `f' turns 9917 out to be a static member function, `a' is 9918 none-the-less evaluated. */ 9919 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 9920 && !is_dummy_object (instance) 9921 && TREE_SIDE_EFFECTS (instance)) 9922 { 9923 /* But avoid the implicit lvalue-rvalue conversion when 'a' 9924 is volatile. */ 9925 tree a = instance; 9926 if (TREE_THIS_VOLATILE (a)) 9927 a = build_this (a); 9928 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), a, call); 9929 } 9930 else if (call != error_mark_node 9931 && DECL_DESTRUCTOR_P (cand->fn) 9932 && !VOID_TYPE_P (TREE_TYPE (call))) 9933 /* An explicit call of the form "x->~X()" has type 9934 "void". However, on platforms where destructors 9935 return "this" (i.e., those where 9936 targetm.cxx.cdtor_returns_this is true), such calls 9937 will appear to have a return value of pointer type 9938 to the low-level call machinery. We do not want to 9939 change the low-level machinery, since we want to be 9940 able to optimize "delete f()" on such platforms as 9941 "operator delete(~X(f()))" (rather than generating 9942 "t = f(), ~X(t), operator delete (t)"). */ 9943 call = build_nop (void_type_node, call); 9944 } 9945 } 9946 } 9947 9948 if (processing_template_decl && call != error_mark_node) 9949 { 9950 bool cast_to_void = false; 9951 9952 if (TREE_CODE (call) == COMPOUND_EXPR) 9953 call = TREE_OPERAND (call, 1); 9954 else if (TREE_CODE (call) == NOP_EXPR) 9955 { 9956 cast_to_void = true; 9957 call = TREE_OPERAND (call, 0); 9958 } 9959 if (INDIRECT_REF_P (call)) 9960 call = TREE_OPERAND (call, 0); 9961 call = (build_min_non_dep_call_vec 9962 (call, 9963 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 9964 orig_instance, orig_fns, NULL_TREE), 9965 orig_args)); 9966 SET_EXPR_LOCATION (call, input_location); 9967 call = convert_from_reference (call); 9968 if (cast_to_void) 9969 call = build_nop (void_type_node, call); 9970 } 9971 9972 /* Free all the conversions we allocated. */ 9973 obstack_free (&conversion_obstack, p); 9974 9975 if (orig_args != NULL) 9976 release_tree_vector (orig_args); 9977 9978 return call; 9979 } 9980 9981 /* Wrapper for above. */ 9982 9983 tree 9984 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args, 9985 tree conversion_path, int flags, 9986 tree *fn_p, tsubst_flags_t complain) 9987 { 9988 tree ret; 9989 bool subtime = timevar_cond_start (TV_OVERLOAD); 9990 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 9991 fn_p, complain); 9992 timevar_cond_stop (TV_OVERLOAD, subtime); 9993 return ret; 9994 } 9995 9996 /* Returns true iff standard conversion sequence ICS1 is a proper 9997 subsequence of ICS2. */ 9998 9999 static bool 10000 is_subseq (conversion *ics1, conversion *ics2) 10001 { 10002 /* We can assume that a conversion of the same code 10003 between the same types indicates a subsequence since we only get 10004 here if the types we are converting from are the same. */ 10005 10006 while (ics1->kind == ck_rvalue 10007 || ics1->kind == ck_lvalue) 10008 ics1 = next_conversion (ics1); 10009 10010 while (1) 10011 { 10012 while (ics2->kind == ck_rvalue 10013 || ics2->kind == ck_lvalue) 10014 ics2 = next_conversion (ics2); 10015 10016 if (ics2->kind == ck_user 10017 || ics2->kind == ck_ambig 10018 || ics2->kind == ck_aggr 10019 || ics2->kind == ck_list 10020 || ics2->kind == ck_identity) 10021 /* At this point, ICS1 cannot be a proper subsequence of 10022 ICS2. We can get a USER_CONV when we are comparing the 10023 second standard conversion sequence of two user conversion 10024 sequences. */ 10025 return false; 10026 10027 ics2 = next_conversion (ics2); 10028 10029 while (ics2->kind == ck_rvalue 10030 || ics2->kind == ck_lvalue) 10031 ics2 = next_conversion (ics2); 10032 10033 if (ics2->kind == ics1->kind 10034 && same_type_p (ics2->type, ics1->type) 10035 && (ics1->kind == ck_identity 10036 || same_type_p (next_conversion (ics2)->type, 10037 next_conversion (ics1)->type))) 10038 return true; 10039 } 10040 } 10041 10042 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 10043 be any _TYPE nodes. */ 10044 10045 bool 10046 is_properly_derived_from (tree derived, tree base) 10047 { 10048 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 10049 return false; 10050 10051 /* We only allow proper derivation here. The DERIVED_FROM_P macro 10052 considers every class derived from itself. */ 10053 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 10054 && DERIVED_FROM_P (base, derived)); 10055 } 10056 10057 /* We build the ICS for an implicit object parameter as a pointer 10058 conversion sequence. However, such a sequence should be compared 10059 as if it were a reference conversion sequence. If ICS is the 10060 implicit conversion sequence for an implicit object parameter, 10061 modify it accordingly. */ 10062 10063 static void 10064 maybe_handle_implicit_object (conversion **ics) 10065 { 10066 if ((*ics)->this_p) 10067 { 10068 /* [over.match.funcs] 10069 10070 For non-static member functions, the type of the 10071 implicit object parameter is "reference to cv X" 10072 where X is the class of which the function is a 10073 member and cv is the cv-qualification on the member 10074 function declaration. */ 10075 conversion *t = *ics; 10076 tree reference_type; 10077 10078 /* The `this' parameter is a pointer to a class type. Make the 10079 implicit conversion talk about a reference to that same class 10080 type. */ 10081 reference_type = TREE_TYPE (t->type); 10082 reference_type = build_reference_type (reference_type); 10083 10084 if (t->kind == ck_qual) 10085 t = next_conversion (t); 10086 if (t->kind == ck_ptr) 10087 t = next_conversion (t); 10088 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 10089 t = direct_reference_binding (reference_type, t); 10090 t->this_p = 1; 10091 t->rvaluedness_matches_p = 0; 10092 *ics = t; 10093 } 10094 } 10095 10096 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 10097 and return the initial reference binding conversion. Otherwise, 10098 leave *ICS unchanged and return NULL. */ 10099 10100 static conversion * 10101 maybe_handle_ref_bind (conversion **ics) 10102 { 10103 if ((*ics)->kind == ck_ref_bind) 10104 { 10105 conversion *old_ics = *ics; 10106 *ics = next_conversion (old_ics); 10107 (*ics)->user_conv_p = old_ics->user_conv_p; 10108 return old_ics; 10109 } 10110 10111 return NULL; 10112 } 10113 10114 /* Compare two implicit conversion sequences according to the rules set out in 10115 [over.ics.rank]. Return values: 10116 10117 1: ics1 is better than ics2 10118 -1: ics2 is better than ics1 10119 0: ics1 and ics2 are indistinguishable */ 10120 10121 static int 10122 compare_ics (conversion *ics1, conversion *ics2) 10123 { 10124 tree from_type1; 10125 tree from_type2; 10126 tree to_type1; 10127 tree to_type2; 10128 tree deref_from_type1 = NULL_TREE; 10129 tree deref_from_type2 = NULL_TREE; 10130 tree deref_to_type1 = NULL_TREE; 10131 tree deref_to_type2 = NULL_TREE; 10132 conversion_rank rank1, rank2; 10133 10134 /* REF_BINDING is nonzero if the result of the conversion sequence 10135 is a reference type. In that case REF_CONV is the reference 10136 binding conversion. */ 10137 conversion *ref_conv1; 10138 conversion *ref_conv2; 10139 10140 /* Compare badness before stripping the reference conversion. */ 10141 if (ics1->bad_p > ics2->bad_p) 10142 return -1; 10143 else if (ics1->bad_p < ics2->bad_p) 10144 return 1; 10145 10146 /* Handle implicit object parameters. */ 10147 maybe_handle_implicit_object (&ics1); 10148 maybe_handle_implicit_object (&ics2); 10149 10150 /* Handle reference parameters. */ 10151 ref_conv1 = maybe_handle_ref_bind (&ics1); 10152 ref_conv2 = maybe_handle_ref_bind (&ics2); 10153 10154 /* List-initialization sequence L1 is a better conversion sequence than 10155 list-initialization sequence L2 if L1 converts to 10156 std::initializer_list<X> for some X and L2 does not. */ 10157 if (ics1->kind == ck_list && ics2->kind != ck_list) 10158 return 1; 10159 if (ics2->kind == ck_list && ics1->kind != ck_list) 10160 return -1; 10161 10162 /* [over.ics.rank] 10163 10164 When comparing the basic forms of implicit conversion sequences (as 10165 defined in _over.best.ics_) 10166 10167 --a standard conversion sequence (_over.ics.scs_) is a better 10168 conversion sequence than a user-defined conversion sequence 10169 or an ellipsis conversion sequence, and 10170 10171 --a user-defined conversion sequence (_over.ics.user_) is a 10172 better conversion sequence than an ellipsis conversion sequence 10173 (_over.ics.ellipsis_). */ 10174 /* Use BAD_CONVERSION_RANK because we already checked for a badness 10175 mismatch. If both ICS are bad, we try to make a decision based on 10176 what would have happened if they'd been good. This is not an 10177 extension, we'll still give an error when we build up the call; this 10178 just helps us give a more helpful error message. */ 10179 rank1 = BAD_CONVERSION_RANK (ics1); 10180 rank2 = BAD_CONVERSION_RANK (ics2); 10181 10182 if (rank1 > rank2) 10183 return -1; 10184 else if (rank1 < rank2) 10185 return 1; 10186 10187 if (ics1->ellipsis_p) 10188 /* Both conversions are ellipsis conversions. */ 10189 return 0; 10190 10191 /* User-defined conversion sequence U1 is a better conversion sequence 10192 than another user-defined conversion sequence U2 if they contain the 10193 same user-defined conversion operator or constructor and if the sec- 10194 ond standard conversion sequence of U1 is better than the second 10195 standard conversion sequence of U2. */ 10196 10197 /* Handle list-conversion with the same code even though it isn't always 10198 ranked as a user-defined conversion and it doesn't have a second 10199 standard conversion sequence; it will still have the desired effect. 10200 Specifically, we need to do the reference binding comparison at the 10201 end of this function. */ 10202 10203 if (ics1->user_conv_p || ics1->kind == ck_list 10204 || ics1->kind == ck_aggr || ics2->kind == ck_aggr) 10205 { 10206 conversion *t1; 10207 conversion *t2; 10208 10209 for (t1 = ics1; t1 && t1->kind != ck_user; t1 = next_conversion (t1)) 10210 if (t1->kind == ck_ambig || t1->kind == ck_aggr 10211 || t1->kind == ck_list) 10212 break; 10213 for (t2 = ics2; t2 && t2->kind != ck_user; t2 = next_conversion (t2)) 10214 if (t2->kind == ck_ambig || t2->kind == ck_aggr 10215 || t2->kind == ck_list) 10216 break; 10217 10218 if (!t1 || !t2 || t1->kind != t2->kind) 10219 return 0; 10220 else if (t1->kind == ck_user) 10221 { 10222 tree f1 = t1->cand ? t1->cand->fn : t1->type; 10223 tree f2 = t2->cand ? t2->cand->fn : t2->type; 10224 if (f1 != f2) 10225 return 0; 10226 } 10227 else 10228 { 10229 /* For ambiguous or aggregate conversions, use the target type as 10230 a proxy for the conversion function. */ 10231 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 10232 return 0; 10233 } 10234 10235 /* We can just fall through here, after setting up 10236 FROM_TYPE1 and FROM_TYPE2. */ 10237 from_type1 = t1->type; 10238 from_type2 = t2->type; 10239 } 10240 else 10241 { 10242 conversion *t1; 10243 conversion *t2; 10244 10245 /* We're dealing with two standard conversion sequences. 10246 10247 [over.ics.rank] 10248 10249 Standard conversion sequence S1 is a better conversion 10250 sequence than standard conversion sequence S2 if 10251 10252 --S1 is a proper subsequence of S2 (comparing the conversion 10253 sequences in the canonical form defined by _over.ics.scs_, 10254 excluding any Lvalue Transformation; the identity 10255 conversion sequence is considered to be a subsequence of 10256 any non-identity conversion sequence */ 10257 10258 t1 = ics1; 10259 while (t1->kind != ck_identity) 10260 t1 = next_conversion (t1); 10261 from_type1 = t1->type; 10262 10263 t2 = ics2; 10264 while (t2->kind != ck_identity) 10265 t2 = next_conversion (t2); 10266 from_type2 = t2->type; 10267 } 10268 10269 /* One sequence can only be a subsequence of the other if they start with 10270 the same type. They can start with different types when comparing the 10271 second standard conversion sequence in two user-defined conversion 10272 sequences. */ 10273 if (same_type_p (from_type1, from_type2)) 10274 { 10275 if (is_subseq (ics1, ics2)) 10276 return 1; 10277 if (is_subseq (ics2, ics1)) 10278 return -1; 10279 } 10280 10281 /* [over.ics.rank] 10282 10283 Or, if not that, 10284 10285 --the rank of S1 is better than the rank of S2 (by the rules 10286 defined below): 10287 10288 Standard conversion sequences are ordered by their ranks: an Exact 10289 Match is a better conversion than a Promotion, which is a better 10290 conversion than a Conversion. 10291 10292 Two conversion sequences with the same rank are indistinguishable 10293 unless one of the following rules applies: 10294 10295 --A conversion that does not a convert a pointer, pointer to member, 10296 or std::nullptr_t to bool is better than one that does. 10297 10298 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 10299 so that we do not have to check it explicitly. */ 10300 if (ics1->rank < ics2->rank) 10301 return 1; 10302 else if (ics2->rank < ics1->rank) 10303 return -1; 10304 10305 to_type1 = ics1->type; 10306 to_type2 = ics2->type; 10307 10308 /* A conversion from scalar arithmetic type to complex is worse than a 10309 conversion between scalar arithmetic types. */ 10310 if (same_type_p (from_type1, from_type2) 10311 && ARITHMETIC_TYPE_P (from_type1) 10312 && ARITHMETIC_TYPE_P (to_type1) 10313 && ARITHMETIC_TYPE_P (to_type2) 10314 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 10315 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 10316 { 10317 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 10318 return -1; 10319 else 10320 return 1; 10321 } 10322 10323 if (TYPE_PTR_P (from_type1) 10324 && TYPE_PTR_P (from_type2) 10325 && TYPE_PTR_P (to_type1) 10326 && TYPE_PTR_P (to_type2)) 10327 { 10328 deref_from_type1 = TREE_TYPE (from_type1); 10329 deref_from_type2 = TREE_TYPE (from_type2); 10330 deref_to_type1 = TREE_TYPE (to_type1); 10331 deref_to_type2 = TREE_TYPE (to_type2); 10332 } 10333 /* The rules for pointers to members A::* are just like the rules 10334 for pointers A*, except opposite: if B is derived from A then 10335 A::* converts to B::*, not vice versa. For that reason, we 10336 switch the from_ and to_ variables here. */ 10337 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2) 10338 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2)) 10339 || (TYPE_PTRMEMFUNC_P (from_type1) 10340 && TYPE_PTRMEMFUNC_P (from_type2) 10341 && TYPE_PTRMEMFUNC_P (to_type1) 10342 && TYPE_PTRMEMFUNC_P (to_type2))) 10343 { 10344 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 10345 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 10346 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 10347 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 10348 } 10349 10350 if (deref_from_type1 != NULL_TREE 10351 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 10352 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 10353 { 10354 /* This was one of the pointer or pointer-like conversions. 10355 10356 [over.ics.rank] 10357 10358 --If class B is derived directly or indirectly from class A, 10359 conversion of B* to A* is better than conversion of B* to 10360 void*, and conversion of A* to void* is better than 10361 conversion of B* to void*. */ 10362 if (VOID_TYPE_P (deref_to_type1) 10363 && VOID_TYPE_P (deref_to_type2)) 10364 { 10365 if (is_properly_derived_from (deref_from_type1, 10366 deref_from_type2)) 10367 return -1; 10368 else if (is_properly_derived_from (deref_from_type2, 10369 deref_from_type1)) 10370 return 1; 10371 } 10372 else if (VOID_TYPE_P (deref_to_type1) 10373 || VOID_TYPE_P (deref_to_type2)) 10374 { 10375 if (same_type_p (deref_from_type1, deref_from_type2)) 10376 { 10377 if (VOID_TYPE_P (deref_to_type2)) 10378 { 10379 if (is_properly_derived_from (deref_from_type1, 10380 deref_to_type1)) 10381 return 1; 10382 } 10383 /* We know that DEREF_TO_TYPE1 is `void' here. */ 10384 else if (is_properly_derived_from (deref_from_type1, 10385 deref_to_type2)) 10386 return -1; 10387 } 10388 } 10389 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 10390 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 10391 { 10392 /* [over.ics.rank] 10393 10394 --If class B is derived directly or indirectly from class A 10395 and class C is derived directly or indirectly from B, 10396 10397 --conversion of C* to B* is better than conversion of C* to 10398 A*, 10399 10400 --conversion of B* to A* is better than conversion of C* to 10401 A* */ 10402 if (same_type_p (deref_from_type1, deref_from_type2)) 10403 { 10404 if (is_properly_derived_from (deref_to_type1, 10405 deref_to_type2)) 10406 return 1; 10407 else if (is_properly_derived_from (deref_to_type2, 10408 deref_to_type1)) 10409 return -1; 10410 } 10411 else if (same_type_p (deref_to_type1, deref_to_type2)) 10412 { 10413 if (is_properly_derived_from (deref_from_type2, 10414 deref_from_type1)) 10415 return 1; 10416 else if (is_properly_derived_from (deref_from_type1, 10417 deref_from_type2)) 10418 return -1; 10419 } 10420 } 10421 } 10422 else if (CLASS_TYPE_P (non_reference (from_type1)) 10423 && same_type_p (from_type1, from_type2)) 10424 { 10425 tree from = non_reference (from_type1); 10426 10427 /* [over.ics.rank] 10428 10429 --binding of an expression of type C to a reference of type 10430 B& is better than binding an expression of type C to a 10431 reference of type A& 10432 10433 --conversion of C to B is better than conversion of C to A, */ 10434 if (is_properly_derived_from (from, to_type1) 10435 && is_properly_derived_from (from, to_type2)) 10436 { 10437 if (is_properly_derived_from (to_type1, to_type2)) 10438 return 1; 10439 else if (is_properly_derived_from (to_type2, to_type1)) 10440 return -1; 10441 } 10442 } 10443 else if (CLASS_TYPE_P (non_reference (to_type1)) 10444 && same_type_p (to_type1, to_type2)) 10445 { 10446 tree to = non_reference (to_type1); 10447 10448 /* [over.ics.rank] 10449 10450 --binding of an expression of type B to a reference of type 10451 A& is better than binding an expression of type C to a 10452 reference of type A&, 10453 10454 --conversion of B to A is better than conversion of C to A */ 10455 if (is_properly_derived_from (from_type1, to) 10456 && is_properly_derived_from (from_type2, to)) 10457 { 10458 if (is_properly_derived_from (from_type2, from_type1)) 10459 return 1; 10460 else if (is_properly_derived_from (from_type1, from_type2)) 10461 return -1; 10462 } 10463 } 10464 10465 /* [over.ics.rank] 10466 10467 --S1 and S2 differ only in their qualification conversion and yield 10468 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 10469 qualification signature of type T1 is a proper subset of the cv- 10470 qualification signature of type T2 */ 10471 if (ics1->kind == ck_qual 10472 && ics2->kind == ck_qual 10473 && same_type_p (from_type1, from_type2)) 10474 { 10475 int result = comp_cv_qual_signature (to_type1, to_type2); 10476 if (result != 0) 10477 return result; 10478 } 10479 10480 /* [over.ics.rank] 10481 10482 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 10483 to an implicit object parameter of a non-static member function 10484 declared without a ref-qualifier, and either S1 binds an lvalue 10485 reference to an lvalue and S2 binds an rvalue reference or S1 binds an 10486 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x 10487 draft standard, 13.3.3.2) 10488 10489 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 10490 types to which the references refer are the same type except for 10491 top-level cv-qualifiers, and the type to which the reference 10492 initialized by S2 refers is more cv-qualified than the type to 10493 which the reference initialized by S1 refers. 10494 10495 DR 1328 [over.match.best]: the context is an initialization by 10496 conversion function for direct reference binding (13.3.1.6) of a 10497 reference to function type, the return type of F1 is the same kind of 10498 reference (i.e. lvalue or rvalue) as the reference being initialized, 10499 and the return type of F2 is not. */ 10500 10501 if (ref_conv1 && ref_conv2) 10502 { 10503 if (!ref_conv1->this_p && !ref_conv2->this_p 10504 && (ref_conv1->rvaluedness_matches_p 10505 != ref_conv2->rvaluedness_matches_p) 10506 && (same_type_p (ref_conv1->type, ref_conv2->type) 10507 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 10508 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 10509 { 10510 if (ref_conv1->bad_p 10511 && !same_type_p (TREE_TYPE (ref_conv1->type), 10512 TREE_TYPE (ref_conv2->type))) 10513 /* Don't prefer a bad conversion that drops cv-quals to a bad 10514 conversion with the wrong rvalueness. */ 10515 return 0; 10516 return (ref_conv1->rvaluedness_matches_p 10517 - ref_conv2->rvaluedness_matches_p); 10518 } 10519 10520 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 10521 { 10522 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type)); 10523 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type)); 10524 if (ref_conv1->bad_p) 10525 { 10526 /* Prefer the one that drops fewer cv-quals. */ 10527 tree ftype = next_conversion (ref_conv1)->type; 10528 int fquals = cp_type_quals (ftype); 10529 q1 ^= fquals; 10530 q2 ^= fquals; 10531 } 10532 return comp_cv_qualification (q2, q1); 10533 } 10534 } 10535 10536 /* Neither conversion sequence is better than the other. */ 10537 return 0; 10538 } 10539 10540 /* The source type for this standard conversion sequence. */ 10541 10542 static tree 10543 source_type (conversion *t) 10544 { 10545 for (;; t = next_conversion (t)) 10546 { 10547 if (t->kind == ck_user 10548 || t->kind == ck_ambig 10549 || t->kind == ck_identity) 10550 return t->type; 10551 } 10552 gcc_unreachable (); 10553 } 10554 10555 /* Note a warning about preferring WINNER to LOSER. We do this by storing 10556 a pointer to LOSER and re-running joust to produce the warning if WINNER 10557 is actually used. */ 10558 10559 static void 10560 add_warning (struct z_candidate *winner, struct z_candidate *loser) 10561 { 10562 candidate_warning *cw = (candidate_warning *) 10563 conversion_obstack_alloc (sizeof (candidate_warning)); 10564 cw->loser = loser; 10565 cw->next = winner->warnings; 10566 winner->warnings = cw; 10567 } 10568 10569 /* CAND is a constructor candidate in joust in C++17 and up. If it copies a 10570 prvalue returned from a conversion function, replace CAND with the candidate 10571 for the conversion and return true. Otherwise, return false. */ 10572 10573 static bool 10574 joust_maybe_elide_copy (z_candidate *&cand) 10575 { 10576 tree fn = cand->fn; 10577 if (!DECL_COPY_CONSTRUCTOR_P (fn) && !DECL_MOVE_CONSTRUCTOR_P (fn)) 10578 return false; 10579 conversion *conv = cand->convs[0]; 10580 gcc_checking_assert (conv->kind == ck_ref_bind); 10581 conv = next_conversion (conv); 10582 if (conv->kind == ck_user && !TYPE_REF_P (conv->type)) 10583 { 10584 gcc_checking_assert (same_type_ignoring_top_level_qualifiers_p 10585 (conv->type, DECL_CONTEXT (fn))); 10586 z_candidate *uc = conv->cand; 10587 if (DECL_CONV_FN_P (uc->fn)) 10588 { 10589 cand = uc; 10590 return true; 10591 } 10592 } 10593 return false; 10594 } 10595 10596 /* Compare two candidates for overloading as described in 10597 [over.match.best]. Return values: 10598 10599 1: cand1 is better than cand2 10600 -1: cand2 is better than cand1 10601 0: cand1 and cand2 are indistinguishable */ 10602 10603 static int 10604 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn, 10605 tsubst_flags_t complain) 10606 { 10607 int winner = 0; 10608 int off1 = 0, off2 = 0; 10609 size_t i; 10610 size_t len; 10611 10612 /* Candidates that involve bad conversions are always worse than those 10613 that don't. */ 10614 if (cand1->viable > cand2->viable) 10615 return 1; 10616 if (cand1->viable < cand2->viable) 10617 return -1; 10618 10619 /* If we have two pseudo-candidates for conversions to the same type, 10620 or two candidates for the same function, arbitrarily pick one. */ 10621 if (cand1->fn == cand2->fn 10622 && (IS_TYPE_OR_DECL_P (cand1->fn))) 10623 return 1; 10624 10625 /* Prefer a non-deleted function over an implicitly deleted move 10626 constructor or assignment operator. This differs slightly from the 10627 wording for issue 1402 (which says the move op is ignored by overload 10628 resolution), but this way produces better error messages. */ 10629 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10630 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10631 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn)) 10632 { 10633 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn) 10634 && move_fn_p (cand1->fn)) 10635 return -1; 10636 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn) 10637 && move_fn_p (cand2->fn)) 10638 return 1; 10639 } 10640 10641 /* a viable function F1 10642 is defined to be a better function than another viable function F2 if 10643 for all arguments i, ICSi(F1) is not a worse conversion sequence than 10644 ICSi(F2), and then */ 10645 10646 /* for some argument j, ICSj(F1) is a better conversion sequence than 10647 ICSj(F2) */ 10648 10649 /* For comparing static and non-static member functions, we ignore 10650 the implicit object parameter of the non-static function. The 10651 standard says to pretend that the static function has an object 10652 parm, but that won't work with operator overloading. */ 10653 len = cand1->num_convs; 10654 if (len != cand2->num_convs) 10655 { 10656 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 10657 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 10658 10659 if (DECL_CONSTRUCTOR_P (cand1->fn) 10660 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 10661 /* We're comparing a near-match list constructor and a near-match 10662 non-list constructor. Just treat them as unordered. */ 10663 return 0; 10664 10665 gcc_assert (static_1 != static_2); 10666 10667 if (static_1) 10668 off2 = 1; 10669 else 10670 { 10671 off1 = 1; 10672 --len; 10673 } 10674 } 10675 10676 /* Handle C++17 copy elision in [over.match.ctor] (direct-init) context. The 10677 standard currently says that only constructors are candidates, but if one 10678 copies a prvalue returned by a conversion function we want to treat the 10679 conversion as the candidate instead. 10680 10681 Clang does something similar, as discussed at 10682 http://lists.isocpp.org/core/2017/10/3166.php 10683 http://lists.isocpp.org/core/2019/03/5721.php */ 10684 int elided_tiebreaker = 0; 10685 if (len == 1 && cxx_dialect >= cxx17 10686 && DECL_P (cand1->fn) 10687 && DECL_COMPLETE_CONSTRUCTOR_P (cand1->fn) 10688 && !(cand1->flags & LOOKUP_ONLYCONVERTING)) 10689 { 10690 bool elided1 = joust_maybe_elide_copy (cand1); 10691 bool elided2 = joust_maybe_elide_copy (cand2); 10692 /* As a tiebreaker below we will prefer a constructor to a conversion 10693 operator exposed this way. */ 10694 elided_tiebreaker = elided2 - elided1; 10695 } 10696 10697 for (i = 0; i < len; ++i) 10698 { 10699 conversion *t1 = cand1->convs[i + off1]; 10700 conversion *t2 = cand2->convs[i + off2]; 10701 int comp = compare_ics (t1, t2); 10702 10703 if (comp != 0) 10704 { 10705 if ((complain & tf_warning) 10706 && warn_sign_promo 10707 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 10708 == cr_std + cr_promotion) 10709 && t1->kind == ck_std 10710 && t2->kind == ck_std 10711 && TREE_CODE (t1->type) == INTEGER_TYPE 10712 && TREE_CODE (t2->type) == INTEGER_TYPE 10713 && (TYPE_PRECISION (t1->type) 10714 == TYPE_PRECISION (t2->type)) 10715 && (TYPE_UNSIGNED (next_conversion (t1)->type) 10716 || (TREE_CODE (next_conversion (t1)->type) 10717 == ENUMERAL_TYPE))) 10718 { 10719 tree type = next_conversion (t1)->type; 10720 tree type1, type2; 10721 struct z_candidate *w, *l; 10722 if (comp > 0) 10723 type1 = t1->type, type2 = t2->type, 10724 w = cand1, l = cand2; 10725 else 10726 type1 = t2->type, type2 = t1->type, 10727 w = cand2, l = cand1; 10728 10729 if (warn) 10730 { 10731 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 10732 type, type1, type2); 10733 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 10734 } 10735 else 10736 add_warning (w, l); 10737 } 10738 10739 if (winner && comp != winner) 10740 { 10741 winner = 0; 10742 goto tweak; 10743 } 10744 winner = comp; 10745 } 10746 } 10747 10748 /* warn about confusing overload resolution for user-defined conversions, 10749 either between a constructor and a conversion op, or between two 10750 conversion ops. */ 10751 if ((complain & tf_warning) 10752 /* In C++17, the constructor might have been elided, which means that 10753 an originally null ->second_conv could become non-null. */ 10754 && winner && warn_conversion && cand1->second_conv && cand2->second_conv 10755 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 10756 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 10757 { 10758 struct z_candidate *w, *l; 10759 bool give_warning = false; 10760 10761 if (winner == 1) 10762 w = cand1, l = cand2; 10763 else 10764 w = cand2, l = cand1; 10765 10766 /* We don't want to complain about `X::operator T1 ()' 10767 beating `X::operator T2 () const', when T2 is a no less 10768 cv-qualified version of T1. */ 10769 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 10770 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 10771 { 10772 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 10773 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 10774 10775 if (TREE_CODE (t) == TREE_CODE (f) && INDIRECT_TYPE_P (t)) 10776 { 10777 t = TREE_TYPE (t); 10778 f = TREE_TYPE (f); 10779 } 10780 if (!comp_ptr_ttypes (t, f)) 10781 give_warning = true; 10782 } 10783 else 10784 give_warning = true; 10785 10786 if (!give_warning) 10787 /*NOP*/; 10788 else if (warn) 10789 { 10790 tree source = source_type (w->convs[0]); 10791 if (INDIRECT_TYPE_P (source)) 10792 source = TREE_TYPE (source); 10793 auto_diagnostic_group d; 10794 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 10795 && warning (OPT_Wconversion, " for conversion from %qH to %qI", 10796 source, w->second_conv->type)) 10797 { 10798 inform (input_location, " because conversion sequence for the argument is better"); 10799 } 10800 } 10801 else 10802 add_warning (w, l); 10803 } 10804 10805 if (winner) 10806 return winner; 10807 10808 /* Put this tiebreaker first, so that we don't try to look at second_conv of 10809 a constructor candidate that doesn't have one. */ 10810 if (elided_tiebreaker) 10811 return elided_tiebreaker; 10812 10813 /* DR 495 moved this tiebreaker above the template ones. */ 10814 /* or, if not that, 10815 the context is an initialization by user-defined conversion (see 10816 _dcl.init_ and _over.match.user_) and the standard conversion 10817 sequence from the return type of F1 to the destination type (i.e., 10818 the type of the entity being initialized) is a better conversion 10819 sequence than the standard conversion sequence from the return type 10820 of F2 to the destination type. */ 10821 10822 if (cand1->second_conv) 10823 { 10824 winner = compare_ics (cand1->second_conv, cand2->second_conv); 10825 if (winner) 10826 return winner; 10827 } 10828 10829 /* or, if not that, 10830 F1 is a non-template function and F2 is a template function 10831 specialization. */ 10832 10833 if (!cand1->template_decl && cand2->template_decl) 10834 return 1; 10835 else if (cand1->template_decl && !cand2->template_decl) 10836 return -1; 10837 10838 /* or, if not that, 10839 F1 and F2 are template functions and the function template for F1 is 10840 more specialized than the template for F2 according to the partial 10841 ordering rules. */ 10842 10843 if (cand1->template_decl && cand2->template_decl) 10844 { 10845 winner = more_specialized_fn 10846 (TI_TEMPLATE (cand1->template_decl), 10847 TI_TEMPLATE (cand2->template_decl), 10848 /* [temp.func.order]: The presence of unused ellipsis and default 10849 arguments has no effect on the partial ordering of function 10850 templates. add_function_candidate() will not have 10851 counted the "this" argument for constructors. */ 10852 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 10853 if (winner) 10854 return winner; 10855 } 10856 10857 // C++ Concepts 10858 // or, if not that, F1 is more constrained than F2. 10859 if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn)) 10860 { 10861 winner = more_constrained (cand1->fn, cand2->fn); 10862 if (winner) 10863 return winner; 10864 } 10865 10866 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */ 10867 if (deduction_guide_p (cand1->fn)) 10868 { 10869 gcc_assert (deduction_guide_p (cand2->fn)); 10870 /* We distinguish between candidates from an explicit deduction guide and 10871 candidates built from a constructor based on DECL_ARTIFICIAL. */ 10872 int art1 = DECL_ARTIFICIAL (cand1->fn); 10873 int art2 = DECL_ARTIFICIAL (cand2->fn); 10874 if (art1 != art2) 10875 return art2 - art1; 10876 10877 if (art1) 10878 { 10879 /* Prefer the special copy guide over a declared copy/move 10880 constructor. */ 10881 if (copy_guide_p (cand1->fn)) 10882 return 1; 10883 if (copy_guide_p (cand2->fn)) 10884 return -1; 10885 10886 /* Prefer a candidate generated from a non-template constructor. */ 10887 int tg1 = template_guide_p (cand1->fn); 10888 int tg2 = template_guide_p (cand2->fn); 10889 if (tg1 != tg2) 10890 return tg2 - tg1; 10891 } 10892 } 10893 10894 /* F1 is a member of a class D, F2 is a member of a base class B of D, and 10895 for all arguments the corresponding parameters of F1 and F2 have the same 10896 type (CWG 2273/2277). */ 10897 if (DECL_P (cand1->fn) && DECL_CLASS_SCOPE_P (cand1->fn) 10898 && !DECL_CONV_FN_P (cand1->fn) 10899 && DECL_P (cand2->fn) && DECL_CLASS_SCOPE_P (cand2->fn) 10900 && !DECL_CONV_FN_P (cand2->fn)) 10901 { 10902 tree base1 = DECL_CONTEXT (strip_inheriting_ctors (cand1->fn)); 10903 tree base2 = DECL_CONTEXT (strip_inheriting_ctors (cand2->fn)); 10904 10905 bool used1 = false; 10906 bool used2 = false; 10907 if (base1 == base2) 10908 /* No difference. */; 10909 else if (DERIVED_FROM_P (base1, base2)) 10910 used1 = true; 10911 else if (DERIVED_FROM_P (base2, base1)) 10912 used2 = true; 10913 10914 if (int diff = used2 - used1) 10915 { 10916 for (i = 0; i < len; ++i) 10917 { 10918 conversion *t1 = cand1->convs[i + off1]; 10919 conversion *t2 = cand2->convs[i + off2]; 10920 if (!same_type_p (t1->type, t2->type)) 10921 break; 10922 } 10923 if (i == len) 10924 return diff; 10925 } 10926 } 10927 10928 /* Check whether we can discard a builtin candidate, either because we 10929 have two identical ones or matching builtin and non-builtin candidates. 10930 10931 (Pedantically in the latter case the builtin which matched the user 10932 function should not be added to the overload set, but we spot it here. 10933 10934 [over.match.oper] 10935 ... the builtin candidates include ... 10936 - do not have the same parameter type list as any non-template 10937 non-member candidate. */ 10938 10939 if (identifier_p (cand1->fn) || identifier_p (cand2->fn)) 10940 { 10941 for (i = 0; i < len; ++i) 10942 if (!same_type_p (cand1->convs[i]->type, 10943 cand2->convs[i]->type)) 10944 break; 10945 if (i == cand1->num_convs) 10946 { 10947 if (cand1->fn == cand2->fn) 10948 /* Two built-in candidates; arbitrarily pick one. */ 10949 return 1; 10950 else if (identifier_p (cand1->fn)) 10951 /* cand1 is built-in; prefer cand2. */ 10952 return -1; 10953 else 10954 /* cand2 is built-in; prefer cand1. */ 10955 return 1; 10956 } 10957 } 10958 10959 /* For candidates of a multi-versioned function, make the version with 10960 the highest priority win. This version will be checked for dispatching 10961 first. If this version can be inlined into the caller, the front-end 10962 will simply make a direct call to this function. */ 10963 10964 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10965 && DECL_FUNCTION_VERSIONED (cand1->fn) 10966 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10967 && DECL_FUNCTION_VERSIONED (cand2->fn)) 10968 { 10969 tree f1 = TREE_TYPE (cand1->fn); 10970 tree f2 = TREE_TYPE (cand2->fn); 10971 tree p1 = TYPE_ARG_TYPES (f1); 10972 tree p2 = TYPE_ARG_TYPES (f2); 10973 10974 /* Check if cand1->fn and cand2->fn are versions of the same function. It 10975 is possible that cand1->fn and cand2->fn are function versions but of 10976 different functions. Check types to see if they are versions of the same 10977 function. */ 10978 if (compparms (p1, p2) 10979 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2))) 10980 { 10981 /* Always make the version with the higher priority, more 10982 specialized, win. */ 10983 gcc_assert (targetm.compare_version_priority); 10984 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0) 10985 return 1; 10986 else 10987 return -1; 10988 } 10989 } 10990 10991 /* If the two function declarations represent the same function (this can 10992 happen with declarations in multiple scopes and arg-dependent lookup), 10993 arbitrarily choose one. But first make sure the default args we're 10994 using match. */ 10995 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 10996 && equal_functions (cand1->fn, cand2->fn)) 10997 { 10998 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 10999 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 11000 11001 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 11002 11003 for (i = 0; i < len; ++i) 11004 { 11005 /* Don't crash if the fn is variadic. */ 11006 if (!parms1) 11007 break; 11008 parms1 = TREE_CHAIN (parms1); 11009 parms2 = TREE_CHAIN (parms2); 11010 } 11011 11012 if (off1) 11013 parms1 = TREE_CHAIN (parms1); 11014 else if (off2) 11015 parms2 = TREE_CHAIN (parms2); 11016 11017 for (; parms1; ++i) 11018 { 11019 if (!cp_tree_equal (TREE_PURPOSE (parms1), 11020 TREE_PURPOSE (parms2))) 11021 { 11022 if (warn) 11023 { 11024 if (complain & tf_error) 11025 { 11026 auto_diagnostic_group d; 11027 if (permerror (input_location, 11028 "default argument mismatch in " 11029 "overload resolution")) 11030 { 11031 inform (DECL_SOURCE_LOCATION (cand1->fn), 11032 " candidate 1: %q#F", cand1->fn); 11033 inform (DECL_SOURCE_LOCATION (cand2->fn), 11034 " candidate 2: %q#F", cand2->fn); 11035 } 11036 } 11037 else 11038 return 0; 11039 } 11040 else 11041 add_warning (cand1, cand2); 11042 break; 11043 } 11044 parms1 = TREE_CHAIN (parms1); 11045 parms2 = TREE_CHAIN (parms2); 11046 } 11047 11048 return 1; 11049 } 11050 11051 tweak: 11052 11053 /* Extension: If the worst conversion for one candidate is better than the 11054 worst conversion for the other, take the first. */ 11055 if (!pedantic && (complain & tf_warning_or_error)) 11056 { 11057 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 11058 struct z_candidate *w = 0, *l = 0; 11059 11060 for (i = 0; i < len; ++i) 11061 { 11062 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 11063 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 11064 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 11065 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 11066 } 11067 if (rank1 < rank2) 11068 winner = 1, w = cand1, l = cand2; 11069 if (rank1 > rank2) 11070 winner = -1, w = cand2, l = cand1; 11071 if (winner) 11072 { 11073 /* Don't choose a deleted function over ambiguity. */ 11074 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 11075 return 0; 11076 if (warn) 11077 { 11078 auto_diagnostic_group d; 11079 if (pedwarn (input_location, 0, 11080 "ISO C++ says that these are ambiguous, even " 11081 "though the worst conversion for the first is " 11082 "better than the worst conversion for the second:")) 11083 { 11084 print_z_candidate (input_location, _("candidate 1:"), w); 11085 print_z_candidate (input_location, _("candidate 2:"), l); 11086 } 11087 } 11088 else 11089 add_warning (w, l); 11090 return winner; 11091 } 11092 } 11093 11094 gcc_assert (!winner); 11095 return 0; 11096 } 11097 11098 /* Given a list of candidates for overloading, find the best one, if any. 11099 This algorithm has a worst case of O(2n) (winner is last), and a best 11100 case of O(n/2) (totally ambiguous); much better than a sorting 11101 algorithm. */ 11102 11103 static struct z_candidate * 11104 tourney (struct z_candidate *candidates, tsubst_flags_t complain) 11105 { 11106 struct z_candidate *champ = candidates, *challenger; 11107 int fate; 11108 int champ_compared_to_predecessor = 0; 11109 11110 /* Walk through the list once, comparing each current champ to the next 11111 candidate, knocking out a candidate or two with each comparison. */ 11112 11113 for (challenger = champ->next; challenger; ) 11114 { 11115 fate = joust (champ, challenger, 0, complain); 11116 if (fate == 1) 11117 challenger = challenger->next; 11118 else 11119 { 11120 if (fate == 0) 11121 { 11122 champ = challenger->next; 11123 if (champ == 0) 11124 return NULL; 11125 champ_compared_to_predecessor = 0; 11126 } 11127 else 11128 { 11129 champ = challenger; 11130 champ_compared_to_predecessor = 1; 11131 } 11132 11133 challenger = champ->next; 11134 } 11135 } 11136 11137 /* Make sure the champ is better than all the candidates it hasn't yet 11138 been compared to. */ 11139 11140 for (challenger = candidates; 11141 challenger != champ 11142 && !(champ_compared_to_predecessor && challenger->next == champ); 11143 challenger = challenger->next) 11144 { 11145 fate = joust (champ, challenger, 0, complain); 11146 if (fate != 1) 11147 return NULL; 11148 } 11149 11150 return champ; 11151 } 11152 11153 /* Returns nonzero if things of type FROM can be converted to TO. */ 11154 11155 bool 11156 can_convert (tree to, tree from, tsubst_flags_t complain) 11157 { 11158 tree arg = NULL_TREE; 11159 /* implicit_conversion only considers user-defined conversions 11160 if it has an expression for the call argument list. */ 11161 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to)) 11162 arg = build1 (CAST_EXPR, from, NULL_TREE); 11163 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain); 11164 } 11165 11166 /* Returns nonzero if things of type FROM can be converted to TO with a 11167 standard conversion. */ 11168 11169 bool 11170 can_convert_standard (tree to, tree from, tsubst_flags_t complain) 11171 { 11172 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain); 11173 } 11174 11175 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 11176 11177 bool 11178 can_convert_arg (tree to, tree from, tree arg, int flags, 11179 tsubst_flags_t complain) 11180 { 11181 conversion *t; 11182 void *p; 11183 bool ok_p; 11184 11185 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 11186 p = conversion_obstack_alloc (0); 11187 /* We want to discard any access checks done for this test, 11188 as we might not be in the appropriate access context and 11189 we'll do the check again when we actually perform the 11190 conversion. */ 11191 push_deferring_access_checks (dk_deferred); 11192 11193 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 11194 flags, complain); 11195 ok_p = (t && !t->bad_p); 11196 11197 /* Discard the access checks now. */ 11198 pop_deferring_access_checks (); 11199 /* Free all the conversions we allocated. */ 11200 obstack_free (&conversion_obstack, p); 11201 11202 return ok_p; 11203 } 11204 11205 /* Like can_convert_arg, but allows dubious conversions as well. */ 11206 11207 bool 11208 can_convert_arg_bad (tree to, tree from, tree arg, int flags, 11209 tsubst_flags_t complain) 11210 { 11211 conversion *t; 11212 void *p; 11213 11214 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 11215 p = conversion_obstack_alloc (0); 11216 /* Try to perform the conversion. */ 11217 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 11218 flags, complain); 11219 /* Free all the conversions we allocated. */ 11220 obstack_free (&conversion_obstack, p); 11221 11222 return t != NULL; 11223 } 11224 11225 /* Convert EXPR to TYPE. Return the converted expression. 11226 11227 Note that we allow bad conversions here because by the time we get to 11228 this point we are committed to doing the conversion. If we end up 11229 doing a bad conversion, convert_like will complain. */ 11230 11231 tree 11232 perform_implicit_conversion_flags (tree type, tree expr, 11233 tsubst_flags_t complain, int flags) 11234 { 11235 conversion *conv; 11236 void *p; 11237 location_t loc = cp_expr_loc_or_loc (expr, input_location); 11238 11239 if (TYPE_REF_P (type)) 11240 expr = mark_lvalue_use (expr); 11241 else 11242 expr = mark_rvalue_use (expr); 11243 11244 if (error_operand_p (expr)) 11245 return error_mark_node; 11246 11247 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 11248 p = conversion_obstack_alloc (0); 11249 11250 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 11251 /*c_cast_p=*/false, 11252 flags, complain); 11253 11254 if (!conv) 11255 { 11256 if (complain & tf_error) 11257 { 11258 /* If expr has unknown type, then it is an overloaded function. 11259 Call instantiate_type to get good error messages. */ 11260 if (TREE_TYPE (expr) == unknown_type_node) 11261 instantiate_type (type, expr, complain); 11262 else if (invalid_nonstatic_memfn_p (loc, expr, complain)) 11263 /* We gave an error. */; 11264 else 11265 { 11266 range_label_for_type_mismatch label (TREE_TYPE (expr), type); 11267 gcc_rich_location rich_loc (loc, &label); 11268 error_at (&rich_loc, "could not convert %qE from %qH to %qI", 11269 expr, TREE_TYPE (expr), type); 11270 } 11271 } 11272 expr = error_mark_node; 11273 } 11274 else if (processing_template_decl && conv->kind != ck_identity) 11275 { 11276 /* In a template, we are only concerned about determining the 11277 type of non-dependent expressions, so we do not have to 11278 perform the actual conversion. But for initializers, we 11279 need to be able to perform it at instantiation 11280 (or instantiate_non_dependent_expr) time. */ 11281 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 11282 if (!(flags & LOOKUP_ONLYCONVERTING)) 11283 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 11284 if (flags & LOOKUP_NO_NARROWING) 11285 IMPLICIT_CONV_EXPR_BRACED_INIT (expr) = true; 11286 } 11287 else 11288 expr = convert_like (conv, expr, complain); 11289 11290 /* Free all the conversions we allocated. */ 11291 obstack_free (&conversion_obstack, p); 11292 11293 return expr; 11294 } 11295 11296 tree 11297 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 11298 { 11299 return perform_implicit_conversion_flags (type, expr, complain, 11300 LOOKUP_IMPLICIT); 11301 } 11302 11303 /* Convert EXPR to TYPE (as a direct-initialization) if that is 11304 permitted. If the conversion is valid, the converted expression is 11305 returned. Otherwise, NULL_TREE is returned, except in the case 11306 that TYPE is a class type; in that case, an error is issued. If 11307 C_CAST_P is true, then this direct-initialization is taking 11308 place as part of a static_cast being attempted as part of a C-style 11309 cast. */ 11310 11311 tree 11312 perform_direct_initialization_if_possible (tree type, 11313 tree expr, 11314 bool c_cast_p, 11315 tsubst_flags_t complain) 11316 { 11317 conversion *conv; 11318 void *p; 11319 11320 if (type == error_mark_node || error_operand_p (expr)) 11321 return error_mark_node; 11322 /* [dcl.init] 11323 11324 If the destination type is a (possibly cv-qualified) class type: 11325 11326 -- If the initialization is direct-initialization ..., 11327 constructors are considered. ... If no constructor applies, or 11328 the overload resolution is ambiguous, the initialization is 11329 ill-formed. */ 11330 if (CLASS_TYPE_P (type)) 11331 { 11332 vec<tree, va_gc> *args = make_tree_vector_single (expr); 11333 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 11334 &args, type, LOOKUP_NORMAL, complain); 11335 release_tree_vector (args); 11336 return build_cplus_new (type, expr, complain); 11337 } 11338 11339 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 11340 p = conversion_obstack_alloc (0); 11341 11342 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 11343 c_cast_p, 11344 LOOKUP_NORMAL, complain); 11345 if (!conv || conv->bad_p) 11346 expr = NULL_TREE; 11347 else if (processing_template_decl && conv->kind != ck_identity) 11348 { 11349 /* In a template, we are only concerned about determining the 11350 type of non-dependent expressions, so we do not have to 11351 perform the actual conversion. But for initializers, we 11352 need to be able to perform it at instantiation 11353 (or instantiate_non_dependent_expr) time. */ 11354 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 11355 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 11356 } 11357 else 11358 expr = convert_like_real (conv, expr, NULL_TREE, 0, 11359 /*issue_conversion_warnings=*/false, 11360 c_cast_p, 11361 complain); 11362 11363 /* Free all the conversions we allocated. */ 11364 obstack_free (&conversion_obstack, p); 11365 11366 return expr; 11367 } 11368 11369 /* When initializing a reference that lasts longer than a full-expression, 11370 this special rule applies: 11371 11372 [class.temporary] 11373 11374 The temporary to which the reference is bound or the temporary 11375 that is the complete object to which the reference is bound 11376 persists for the lifetime of the reference. 11377 11378 The temporaries created during the evaluation of the expression 11379 initializing the reference, except the temporary to which the 11380 reference is bound, are destroyed at the end of the 11381 full-expression in which they are created. 11382 11383 In that case, we store the converted expression into a new 11384 VAR_DECL in a new scope. 11385 11386 However, we want to be careful not to create temporaries when 11387 they are not required. For example, given: 11388 11389 struct B {}; 11390 struct D : public B {}; 11391 D f(); 11392 const B& b = f(); 11393 11394 there is no need to copy the return value from "f"; we can just 11395 extend its lifetime. Similarly, given: 11396 11397 struct S {}; 11398 struct T { operator S(); }; 11399 T t; 11400 const S& s = t; 11401 11402 we can extend the lifetime of the return value of the conversion 11403 operator. 11404 11405 The next several functions are involved in this lifetime extension. */ 11406 11407 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The 11408 reference is being bound to a temporary. Create and return a new 11409 VAR_DECL with the indicated TYPE; this variable will store the value to 11410 which the reference is bound. */ 11411 11412 tree 11413 make_temporary_var_for_ref_to_temp (tree decl, tree type) 11414 { 11415 tree var = create_temporary_var (type); 11416 11417 /* Register the variable. */ 11418 if (VAR_P (decl) 11419 && (TREE_STATIC (decl) || CP_DECL_THREAD_LOCAL_P (decl))) 11420 { 11421 /* Namespace-scope or local static; give it a mangled name. */ 11422 11423 /* If an initializer is visible to multiple translation units, those 11424 translation units must agree on the addresses of the 11425 temporaries. Therefore the temporaries must be given a consistent name 11426 and vague linkage. The mangled name of a temporary is the name of the 11427 non-temporary object in whose initializer they appear, prefixed with 11428 GR and suffixed with a sequence number mangled using the usual rules 11429 for a seq-id. Temporaries are numbered with a pre-order, depth-first, 11430 left-to-right walk of the complete initializer. */ 11431 11432 TREE_STATIC (var) = TREE_STATIC (decl); 11433 TREE_PUBLIC (var) = TREE_PUBLIC (decl); 11434 if (decl_anon_ns_mem_p (decl)) 11435 TREE_PUBLIC (var) = 0; 11436 if (vague_linkage_p (decl)) 11437 comdat_linkage (var); 11438 11439 CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl); 11440 set_decl_tls_model (var, DECL_TLS_MODEL (decl)); 11441 11442 tree name = mangle_ref_init_variable (decl); 11443 DECL_NAME (var) = name; 11444 SET_DECL_ASSEMBLER_NAME (var, name); 11445 } 11446 else 11447 /* Create a new cleanup level if necessary. */ 11448 maybe_push_cleanup_level (type); 11449 11450 return pushdecl (var); 11451 } 11452 11453 /* EXPR is the initializer for a variable DECL of reference or 11454 std::initializer_list type. Create, push and return a new VAR_DECL 11455 for the initializer so that it will live as long as DECL. Any 11456 cleanup for the new variable is returned through CLEANUP, and the 11457 code to initialize the new variable is returned through INITP. */ 11458 11459 static tree 11460 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups, 11461 tree *initp, tree *cond_guard) 11462 { 11463 tree init; 11464 tree type; 11465 tree var; 11466 11467 /* Create the temporary variable. */ 11468 type = TREE_TYPE (expr); 11469 var = make_temporary_var_for_ref_to_temp (decl, type); 11470 layout_decl (var, 0); 11471 /* If the rvalue is the result of a function call it will be 11472 a TARGET_EXPR. If it is some other construct (such as a 11473 member access expression where the underlying object is 11474 itself the result of a function call), turn it into a 11475 TARGET_EXPR here. It is important that EXPR be a 11476 TARGET_EXPR below since otherwise the INIT_EXPR will 11477 attempt to make a bitwise copy of EXPR to initialize 11478 VAR. */ 11479 if (TREE_CODE (expr) != TARGET_EXPR) 11480 expr = get_target_expr (expr); 11481 11482 if (TREE_CODE (decl) == FIELD_DECL 11483 && extra_warnings && !TREE_NO_WARNING (decl)) 11484 { 11485 warning (OPT_Wextra, "a temporary bound to %qD only persists " 11486 "until the constructor exits", decl); 11487 TREE_NO_WARNING (decl) = true; 11488 } 11489 11490 /* Recursively extend temps in this initializer. */ 11491 TARGET_EXPR_INITIAL (expr) 11492 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups, 11493 cond_guard); 11494 11495 /* Any reference temp has a non-trivial initializer. */ 11496 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true; 11497 11498 /* If the initializer is constant, put it in DECL_INITIAL so we get 11499 static initialization and use in constant expressions. */ 11500 init = maybe_constant_init (expr); 11501 /* As in store_init_value. */ 11502 init = cp_fully_fold (init); 11503 if (TREE_CONSTANT (init)) 11504 { 11505 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 11506 { 11507 /* 5.19 says that a constant expression can include an 11508 lvalue-rvalue conversion applied to "a glvalue of literal type 11509 that refers to a non-volatile temporary object initialized 11510 with a constant expression". Rather than try to communicate 11511 that this VAR_DECL is a temporary, just mark it constexpr. */ 11512 DECL_DECLARED_CONSTEXPR_P (var) = true; 11513 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 11514 TREE_CONSTANT (var) = true; 11515 TREE_READONLY (var) = true; 11516 } 11517 DECL_INITIAL (var) = init; 11518 init = NULL_TREE; 11519 } 11520 else 11521 /* Create the INIT_EXPR that will initialize the temporary 11522 variable. */ 11523 init = split_nonconstant_init (var, expr); 11524 if (at_function_scope_p ()) 11525 { 11526 add_decl_expr (var); 11527 11528 if (TREE_STATIC (var)) 11529 init = add_stmt_to_compound (init, register_dtor_fn (var)); 11530 else 11531 { 11532 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 11533 if (cleanup) 11534 { 11535 if (cond_guard && cleanup != error_mark_node) 11536 { 11537 if (*cond_guard == NULL_TREE) 11538 { 11539 *cond_guard = build_decl (input_location, VAR_DECL, 11540 NULL_TREE, boolean_type_node); 11541 DECL_ARTIFICIAL (*cond_guard) = 1; 11542 DECL_IGNORED_P (*cond_guard) = 1; 11543 DECL_CONTEXT (*cond_guard) = current_function_decl; 11544 layout_decl (*cond_guard, 0); 11545 add_decl_expr (*cond_guard); 11546 tree set = cp_build_modify_expr (UNKNOWN_LOCATION, 11547 *cond_guard, NOP_EXPR, 11548 boolean_false_node, 11549 tf_warning_or_error); 11550 finish_expr_stmt (set); 11551 } 11552 cleanup = build3 (COND_EXPR, void_type_node, 11553 *cond_guard, cleanup, NULL_TREE); 11554 } 11555 vec_safe_push (*cleanups, cleanup); 11556 } 11557 } 11558 11559 /* We must be careful to destroy the temporary only 11560 after its initialization has taken place. If the 11561 initialization throws an exception, then the 11562 destructor should not be run. We cannot simply 11563 transform INIT into something like: 11564 11565 (INIT, ({ CLEANUP_STMT; })) 11566 11567 because emit_local_var always treats the 11568 initializer as a full-expression. Thus, the 11569 destructor would run too early; it would run at the 11570 end of initializing the reference variable, rather 11571 than at the end of the block enclosing the 11572 reference variable. 11573 11574 The solution is to pass back a cleanup expression 11575 which the caller is responsible for attaching to 11576 the statement tree. */ 11577 } 11578 else 11579 { 11580 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 11581 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 11582 { 11583 if (CP_DECL_THREAD_LOCAL_P (var)) 11584 tls_aggregates = tree_cons (NULL_TREE, var, 11585 tls_aggregates); 11586 else 11587 static_aggregates = tree_cons (NULL_TREE, var, 11588 static_aggregates); 11589 } 11590 else 11591 /* Check whether the dtor is callable. */ 11592 cxx_maybe_build_cleanup (var, tf_warning_or_error); 11593 } 11594 /* Avoid -Wunused-variable warning (c++/38958). */ 11595 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 11596 && VAR_P (decl)) 11597 TREE_USED (decl) = DECL_READ_P (decl) = true; 11598 11599 *initp = init; 11600 return var; 11601 } 11602 11603 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 11604 initializing a variable of that TYPE. */ 11605 11606 tree 11607 initialize_reference (tree type, tree expr, 11608 int flags, tsubst_flags_t complain) 11609 { 11610 conversion *conv; 11611 void *p; 11612 location_t loc = cp_expr_loc_or_loc (expr, input_location); 11613 11614 if (type == error_mark_node || error_operand_p (expr)) 11615 return error_mark_node; 11616 11617 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 11618 p = conversion_obstack_alloc (0); 11619 11620 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 11621 flags, complain); 11622 if (!conv || conv->bad_p) 11623 { 11624 if (complain & tf_error) 11625 { 11626 if (conv) 11627 convert_like (conv, expr, complain); 11628 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 11629 && !TYPE_REF_IS_RVALUE (type) 11630 && !lvalue_p (expr)) 11631 error_at (loc, "invalid initialization of non-const reference of " 11632 "type %qH from an rvalue of type %qI", 11633 type, TREE_TYPE (expr)); 11634 else 11635 error_at (loc, "invalid initialization of reference of type " 11636 "%qH from expression of type %qI", type, 11637 TREE_TYPE (expr)); 11638 } 11639 return error_mark_node; 11640 } 11641 11642 if (conv->kind == ck_ref_bind) 11643 /* Perform the conversion. */ 11644 expr = convert_like (conv, expr, complain); 11645 else if (conv->kind == ck_ambig) 11646 /* We gave an error in build_user_type_conversion_1. */ 11647 expr = error_mark_node; 11648 else 11649 gcc_unreachable (); 11650 11651 /* Free all the conversions we allocated. */ 11652 obstack_free (&conversion_obstack, p); 11653 11654 return expr; 11655 } 11656 11657 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 11658 which is bound either to a reference or a std::initializer_list. */ 11659 11660 static tree 11661 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups, 11662 tree *cond_guard) 11663 { 11664 tree sub = init; 11665 tree *p; 11666 STRIP_NOPS (sub); 11667 if (TREE_CODE (sub) == COMPOUND_EXPR) 11668 { 11669 TREE_OPERAND (sub, 1) 11670 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups, 11671 cond_guard); 11672 return init; 11673 } 11674 if (TREE_CODE (sub) == COND_EXPR) 11675 { 11676 tree cur_cond_guard = NULL_TREE; 11677 if (TREE_OPERAND (sub, 1)) 11678 TREE_OPERAND (sub, 1) 11679 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups, 11680 &cur_cond_guard); 11681 if (cur_cond_guard) 11682 { 11683 tree set = cp_build_modify_expr (UNKNOWN_LOCATION, cur_cond_guard, 11684 NOP_EXPR, boolean_true_node, 11685 tf_warning_or_error); 11686 TREE_OPERAND (sub, 1) 11687 = cp_build_compound_expr (set, TREE_OPERAND (sub, 1), 11688 tf_warning_or_error); 11689 } 11690 cur_cond_guard = NULL_TREE; 11691 if (TREE_OPERAND (sub, 2)) 11692 TREE_OPERAND (sub, 2) 11693 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 2), cleanups, 11694 &cur_cond_guard); 11695 if (cur_cond_guard) 11696 { 11697 tree set = cp_build_modify_expr (UNKNOWN_LOCATION, cur_cond_guard, 11698 NOP_EXPR, boolean_true_node, 11699 tf_warning_or_error); 11700 TREE_OPERAND (sub, 2) 11701 = cp_build_compound_expr (set, TREE_OPERAND (sub, 2), 11702 tf_warning_or_error); 11703 } 11704 return init; 11705 } 11706 if (TREE_CODE (sub) != ADDR_EXPR) 11707 return init; 11708 /* Deal with binding to a subobject. */ 11709 for (p = &TREE_OPERAND (sub, 0); 11710 TREE_CODE (*p) == COMPONENT_REF || TREE_CODE (*p) == ARRAY_REF; ) 11711 p = &TREE_OPERAND (*p, 0); 11712 if (TREE_CODE (*p) == TARGET_EXPR) 11713 { 11714 tree subinit = NULL_TREE; 11715 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit, cond_guard); 11716 recompute_tree_invariant_for_addr_expr (sub); 11717 if (init != sub) 11718 init = fold_convert (TREE_TYPE (init), sub); 11719 if (subinit) 11720 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 11721 } 11722 return init; 11723 } 11724 11725 /* INIT is part of the initializer for DECL. If there are any 11726 reference or initializer lists being initialized, extend their 11727 lifetime to match that of DECL. */ 11728 11729 tree 11730 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups, 11731 tree *cond_guard) 11732 { 11733 tree type = TREE_TYPE (init); 11734 if (processing_template_decl) 11735 return init; 11736 if (TYPE_REF_P (type)) 11737 init = extend_ref_init_temps_1 (decl, init, cleanups, cond_guard); 11738 else 11739 { 11740 tree ctor = init; 11741 if (TREE_CODE (ctor) == TARGET_EXPR) 11742 ctor = TARGET_EXPR_INITIAL (ctor); 11743 if (TREE_CODE (ctor) == CONSTRUCTOR) 11744 { 11745 if (is_std_init_list (type)) 11746 { 11747 /* The temporary array underlying a std::initializer_list 11748 is handled like a reference temporary. */ 11749 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 11750 array = extend_ref_init_temps_1 (decl, array, cleanups, 11751 cond_guard); 11752 CONSTRUCTOR_ELT (ctor, 0)->value = array; 11753 } 11754 else 11755 { 11756 unsigned i; 11757 constructor_elt *p; 11758 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor); 11759 FOR_EACH_VEC_SAFE_ELT (elts, i, p) 11760 p->value = extend_ref_init_temps (decl, p->value, cleanups, 11761 cond_guard); 11762 } 11763 recompute_constructor_flags (ctor); 11764 if (decl_maybe_constant_var_p (decl) && TREE_CONSTANT (ctor)) 11765 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true; 11766 } 11767 } 11768 11769 return init; 11770 } 11771 11772 /* Returns true iff an initializer for TYPE could contain temporaries that 11773 need to be extended because they are bound to references or 11774 std::initializer_list. */ 11775 11776 bool 11777 type_has_extended_temps (tree type) 11778 { 11779 type = strip_array_types (type); 11780 if (TYPE_REF_P (type)) 11781 return true; 11782 if (CLASS_TYPE_P (type)) 11783 { 11784 if (is_std_init_list (type)) 11785 return true; 11786 for (tree f = next_initializable_field (TYPE_FIELDS (type)); 11787 f; f = next_initializable_field (DECL_CHAIN (f))) 11788 if (type_has_extended_temps (TREE_TYPE (f))) 11789 return true; 11790 } 11791 return false; 11792 } 11793 11794 /* Returns true iff TYPE is some variant of std::initializer_list. */ 11795 11796 bool 11797 is_std_init_list (tree type) 11798 { 11799 if (!TYPE_P (type)) 11800 return false; 11801 if (cxx_dialect == cxx98) 11802 return false; 11803 /* Look through typedefs. */ 11804 type = TYPE_MAIN_VARIANT (type); 11805 return (CLASS_TYPE_P (type) 11806 && CP_TYPE_CONTEXT (type) == std_node 11807 && init_list_identifier == DECL_NAME (TYPE_NAME (type))); 11808 } 11809 11810 /* Returns true iff DECL is a list constructor: i.e. a constructor which 11811 will accept an argument list of a single std::initializer_list<T>. */ 11812 11813 bool 11814 is_list_ctor (tree decl) 11815 { 11816 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 11817 tree arg; 11818 11819 if (!args || args == void_list_node) 11820 return false; 11821 11822 arg = non_reference (TREE_VALUE (args)); 11823 if (!is_std_init_list (arg)) 11824 return false; 11825 11826 args = TREE_CHAIN (args); 11827 11828 if (args && args != void_list_node && !TREE_PURPOSE (args)) 11829 /* There are more non-defaulted parms. */ 11830 return false; 11831 11832 return true; 11833 } 11834 11835 #include "gt-cp-call.h" 11836