1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions. 2 Copyright (C) 1987-2018 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 45 /* The various kinds of conversion. */ 46 47 enum conversion_kind { 48 ck_identity, 49 ck_lvalue, 50 ck_fnptr, 51 ck_qual, 52 ck_std, 53 ck_ptr, 54 ck_pmem, 55 ck_base, 56 ck_ref_bind, 57 ck_user, 58 ck_ambig, 59 ck_list, 60 ck_aggr, 61 ck_rvalue 62 }; 63 64 /* The rank of the conversion. Order of the enumerals matters; better 65 conversions should come earlier in the list. */ 66 67 enum conversion_rank { 68 cr_identity, 69 cr_exact, 70 cr_promotion, 71 cr_std, 72 cr_pbool, 73 cr_user, 74 cr_ellipsis, 75 cr_bad 76 }; 77 78 /* An implicit conversion sequence, in the sense of [over.best.ics]. 79 The first conversion to be performed is at the end of the chain. 80 That conversion is always a cr_identity conversion. */ 81 82 struct conversion { 83 /* The kind of conversion represented by this step. */ 84 conversion_kind kind; 85 /* The rank of this conversion. */ 86 conversion_rank rank; 87 BOOL_BITFIELD user_conv_p : 1; 88 BOOL_BITFIELD ellipsis_p : 1; 89 BOOL_BITFIELD this_p : 1; 90 /* True if this conversion would be permitted with a bending of 91 language standards, e.g. disregarding pointer qualifiers or 92 converting integers to pointers. */ 93 BOOL_BITFIELD bad_p : 1; 94 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a 95 temporary should be created to hold the result of the 96 conversion. If KIND is ck_ambig, true if the context is 97 copy-initialization. */ 98 BOOL_BITFIELD need_temporary_p : 1; 99 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 100 from a pointer-to-derived to pointer-to-base is being performed. */ 101 BOOL_BITFIELD base_p : 1; 102 /* If KIND is ck_ref_bind, true when either an lvalue reference is 103 being bound to an lvalue expression or an rvalue reference is 104 being bound to an rvalue expression. If KIND is ck_rvalue, 105 true when we are treating an lvalue as an rvalue (12.8p33). If 106 KIND is ck_base, always false. If ck_identity, we will be 107 binding a reference directly or decaying to a pointer. */ 108 BOOL_BITFIELD rvaluedness_matches_p: 1; 109 BOOL_BITFIELD check_narrowing: 1; 110 /* The type of the expression resulting from the conversion. */ 111 tree type; 112 union { 113 /* The next conversion in the chain. Since the conversions are 114 arranged from outermost to innermost, the NEXT conversion will 115 actually be performed before this conversion. This variant is 116 used only when KIND is neither ck_identity, ck_ambig nor 117 ck_list. Please use the next_conversion function instead 118 of using this field directly. */ 119 conversion *next; 120 /* The expression at the beginning of the conversion chain. This 121 variant is used only if KIND is ck_identity or ck_ambig. */ 122 tree expr; 123 /* The array of conversions for an initializer_list, so this 124 variant is used only when KIN D is ck_list. */ 125 conversion **list; 126 } u; 127 /* The function candidate corresponding to this conversion 128 sequence. This field is only used if KIND is ck_user. */ 129 struct z_candidate *cand; 130 }; 131 132 #define CONVERSION_RANK(NODE) \ 133 ((NODE)->bad_p ? cr_bad \ 134 : (NODE)->ellipsis_p ? cr_ellipsis \ 135 : (NODE)->user_conv_p ? cr_user \ 136 : (NODE)->rank) 137 138 #define BAD_CONVERSION_RANK(NODE) \ 139 ((NODE)->ellipsis_p ? cr_ellipsis \ 140 : (NODE)->user_conv_p ? cr_user \ 141 : (NODE)->rank) 142 143 static struct obstack conversion_obstack; 144 static bool conversion_obstack_initialized; 145 struct rejection_reason; 146 147 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t); 148 static int equal_functions (tree, tree); 149 static int joust (struct z_candidate *, struct z_candidate *, bool, 150 tsubst_flags_t); 151 static int compare_ics (conversion *, conversion *); 152 static void maybe_warn_class_memaccess (location_t, tree, 153 const vec<tree, va_gc> *); 154 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 155 #define convert_like(CONV, EXPR, COMPLAIN) \ 156 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \ 157 /*issue_conversion_warnings=*/true, \ 158 /*c_cast_p=*/false, (COMPLAIN)) 159 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 160 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \ 161 /*issue_conversion_warnings=*/true, \ 162 /*c_cast_p=*/false, (COMPLAIN)) 163 static tree convert_like_real (conversion *, tree, tree, int, bool, 164 bool, tsubst_flags_t); 165 static void op_error (location_t, enum tree_code, enum tree_code, tree, 166 tree, tree, bool); 167 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int, 168 tsubst_flags_t); 169 static void print_z_candidate (location_t, const char *, struct z_candidate *); 170 static void print_z_candidates (location_t, struct z_candidate *); 171 static tree build_this (tree); 172 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 173 static bool any_strictly_viable (struct z_candidate *); 174 static struct z_candidate *add_template_candidate 175 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 176 tree, tree, tree, int, unification_kind_t, tsubst_flags_t); 177 static struct z_candidate *add_template_candidate_real 178 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 179 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t); 180 static void add_builtin_candidates 181 (struct z_candidate **, enum tree_code, enum tree_code, 182 tree, tree *, int, tsubst_flags_t); 183 static void add_builtin_candidate 184 (struct z_candidate **, enum tree_code, enum tree_code, 185 tree, tree, tree, tree *, tree *, int, tsubst_flags_t); 186 static bool is_complete (tree); 187 static void build_builtin_candidate 188 (struct z_candidate **, tree, tree, tree, tree *, tree *, 189 int, tsubst_flags_t); 190 static struct z_candidate *add_conv_candidate 191 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, tree, 192 tree, tsubst_flags_t); 193 static struct z_candidate *add_function_candidate 194 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree, 195 tree, int, tsubst_flags_t); 196 static conversion *implicit_conversion (tree, tree, tree, bool, int, 197 tsubst_flags_t); 198 static conversion *reference_binding (tree, tree, tree, bool, int, 199 tsubst_flags_t); 200 static conversion *build_conv (conversion_kind, tree, conversion *); 201 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t); 202 static conversion *next_conversion (conversion *); 203 static bool is_subseq (conversion *, conversion *); 204 static conversion *maybe_handle_ref_bind (conversion **); 205 static void maybe_handle_implicit_object (conversion **); 206 static struct z_candidate *add_candidate 207 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t, 208 conversion **, tree, tree, int, struct rejection_reason *, int); 209 static tree source_type (conversion *); 210 static void add_warning (struct z_candidate *, struct z_candidate *); 211 static bool reference_compatible_p (tree, tree); 212 static conversion *direct_reference_binding (tree, conversion *); 213 static bool promoted_arithmetic_type_p (tree); 214 static conversion *conditional_conversion (tree, tree, tsubst_flags_t); 215 static char *name_as_c_string (tree, tree, bool *); 216 static tree prep_operand (tree); 217 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree, 218 bool, tree, tree, int, struct z_candidate **, 219 tsubst_flags_t); 220 static conversion *merge_conversion_sequences (conversion *, conversion *); 221 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t); 222 223 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 224 NAME can take many forms... */ 225 226 bool 227 check_dtor_name (tree basetype, tree name) 228 { 229 /* Just accept something we've already complained about. */ 230 if (name == error_mark_node) 231 return true; 232 233 if (TREE_CODE (name) == TYPE_DECL) 234 name = TREE_TYPE (name); 235 else if (TYPE_P (name)) 236 /* OK */; 237 else if (identifier_p (name)) 238 { 239 if ((MAYBE_CLASS_TYPE_P (basetype) 240 || TREE_CODE (basetype) == ENUMERAL_TYPE) 241 && name == constructor_name (basetype)) 242 return true; 243 else 244 name = get_type_value (name); 245 } 246 else 247 { 248 /* In the case of: 249 250 template <class T> struct S { ~S(); }; 251 int i; 252 i.~S(); 253 254 NAME will be a class template. */ 255 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 256 return false; 257 } 258 259 if (!name || name == error_mark_node) 260 return false; 261 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 262 } 263 264 /* We want the address of a function or method. We avoid creating a 265 pointer-to-member function. */ 266 267 tree 268 build_addr_func (tree function, tsubst_flags_t complain) 269 { 270 tree type = TREE_TYPE (function); 271 272 /* We have to do these by hand to avoid real pointer to member 273 functions. */ 274 if (TREE_CODE (type) == METHOD_TYPE) 275 { 276 if (TREE_CODE (function) == OFFSET_REF) 277 { 278 tree object = build_address (TREE_OPERAND (function, 0)); 279 return get_member_function_from_ptrfunc (&object, 280 TREE_OPERAND (function, 1), 281 complain); 282 } 283 function = build_address (function); 284 } 285 else 286 function = decay_conversion (function, complain, /*reject_builtin=*/false); 287 288 return function; 289 } 290 291 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 292 POINTER_TYPE to those. Note, pointer to member function types 293 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 294 two variants. build_call_a is the primitive taking an array of 295 arguments, while build_call_n is a wrapper that handles varargs. */ 296 297 tree 298 build_call_n (tree function, int n, ...) 299 { 300 if (n == 0) 301 return build_call_a (function, 0, NULL); 302 else 303 { 304 tree *argarray = XALLOCAVEC (tree, n); 305 va_list ap; 306 int i; 307 308 va_start (ap, n); 309 for (i = 0; i < n; i++) 310 argarray[i] = va_arg (ap, tree); 311 va_end (ap); 312 return build_call_a (function, n, argarray); 313 } 314 } 315 316 /* Update various flags in cfun and the call itself based on what is being 317 called. Split out of build_call_a so that bot_manip can use it too. */ 318 319 void 320 set_flags_from_callee (tree call) 321 { 322 bool nothrow; 323 tree decl = get_callee_fndecl (call); 324 325 /* We check both the decl and the type; a function may be known not to 326 throw without being declared throw(). */ 327 nothrow = decl && TREE_NOTHROW (decl); 328 if (CALL_EXPR_FN (call)) 329 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call)))); 330 else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW) 331 nothrow = true; 332 333 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain) 334 cp_function_chain->can_throw = 1; 335 336 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 337 current_function_returns_abnormally = 1; 338 339 TREE_NOTHROW (call) = nothrow; 340 } 341 342 tree 343 build_call_a (tree function, int n, tree *argarray) 344 { 345 tree decl; 346 tree result_type; 347 tree fntype; 348 int i; 349 350 function = build_addr_func (function, tf_warning_or_error); 351 352 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 353 fntype = TREE_TYPE (TREE_TYPE (function)); 354 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 355 || TREE_CODE (fntype) == METHOD_TYPE); 356 result_type = TREE_TYPE (fntype); 357 /* An rvalue has no cv-qualifiers. */ 358 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 359 result_type = cv_unqualified (result_type); 360 361 function = build_call_array_loc (input_location, 362 result_type, function, n, argarray); 363 set_flags_from_callee (function); 364 365 decl = get_callee_fndecl (function); 366 367 if (decl && !TREE_USED (decl)) 368 { 369 /* We invoke build_call directly for several library 370 functions. These may have been declared normally if 371 we're building libgcc, so we can't just check 372 DECL_ARTIFICIAL. */ 373 gcc_assert (DECL_ARTIFICIAL (decl) 374 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 375 "__", 2)); 376 mark_used (decl); 377 } 378 379 require_complete_eh_spec_types (fntype, decl); 380 381 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl)); 382 383 /* Don't pass empty class objects by value. This is useful 384 for tags in STL, which are used to control overload resolution. 385 We don't need to handle other cases of copying empty classes. */ 386 if (! decl || ! DECL_BUILT_IN (decl)) 387 for (i = 0; i < n; i++) 388 { 389 tree arg = CALL_EXPR_ARG (function, i); 390 if (is_empty_class (TREE_TYPE (arg)) 391 && ! TREE_ADDRESSABLE (TREE_TYPE (arg))) 392 { 393 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg)); 394 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t); 395 CALL_EXPR_ARG (function, i) = arg; 396 } 397 } 398 399 return function; 400 } 401 402 /* New overloading code. */ 403 404 struct z_candidate; 405 406 struct candidate_warning { 407 z_candidate *loser; 408 candidate_warning *next; 409 }; 410 411 /* Information for providing diagnostics about why overloading failed. */ 412 413 enum rejection_reason_code { 414 rr_none, 415 rr_arity, 416 rr_explicit_conversion, 417 rr_template_conversion, 418 rr_arg_conversion, 419 rr_bad_arg_conversion, 420 rr_template_unification, 421 rr_invalid_copy, 422 rr_inherited_ctor, 423 rr_constraint_failure 424 }; 425 426 struct conversion_info { 427 /* The index of the argument, 0-based. */ 428 int n_arg; 429 /* The actual argument or its type. */ 430 tree from; 431 /* The type of the parameter. */ 432 tree to_type; 433 }; 434 435 struct rejection_reason { 436 enum rejection_reason_code code; 437 union { 438 /* Information about an arity mismatch. */ 439 struct { 440 /* The expected number of arguments. */ 441 int expected; 442 /* The actual number of arguments in the call. */ 443 int actual; 444 /* Whether the call was a varargs call. */ 445 bool call_varargs_p; 446 } arity; 447 /* Information about an argument conversion mismatch. */ 448 struct conversion_info conversion; 449 /* Same, but for bad argument conversions. */ 450 struct conversion_info bad_conversion; 451 /* Information about template unification failures. These are the 452 parameters passed to fn_type_unification. */ 453 struct { 454 tree tmpl; 455 tree explicit_targs; 456 int num_targs; 457 const tree *args; 458 unsigned int nargs; 459 tree return_type; 460 unification_kind_t strict; 461 int flags; 462 } template_unification; 463 /* Information about template instantiation failures. These are the 464 parameters passed to instantiate_template. */ 465 struct { 466 tree tmpl; 467 tree targs; 468 } template_instantiation; 469 } u; 470 }; 471 472 struct z_candidate { 473 /* The FUNCTION_DECL that will be called if this candidate is 474 selected by overload resolution. */ 475 tree fn; 476 /* If not NULL_TREE, the first argument to use when calling this 477 function. */ 478 tree first_arg; 479 /* The rest of the arguments to use when calling this function. If 480 there are no further arguments this may be NULL or it may be an 481 empty vector. */ 482 const vec<tree, va_gc> *args; 483 /* The implicit conversion sequences for each of the arguments to 484 FN. */ 485 conversion **convs; 486 /* The number of implicit conversion sequences. */ 487 size_t num_convs; 488 /* If FN is a user-defined conversion, the standard conversion 489 sequence from the type returned by FN to the desired destination 490 type. */ 491 conversion *second_conv; 492 struct rejection_reason *reason; 493 /* If FN is a member function, the binfo indicating the path used to 494 qualify the name of FN at the call site. This path is used to 495 determine whether or not FN is accessible if it is selected by 496 overload resolution. The DECL_CONTEXT of FN will always be a 497 (possibly improper) base of this binfo. */ 498 tree access_path; 499 /* If FN is a non-static member function, the binfo indicating the 500 subobject to which the `this' pointer should be converted if FN 501 is selected by overload resolution. The type pointed to by 502 the `this' pointer must correspond to the most derived class 503 indicated by the CONVERSION_PATH. */ 504 tree conversion_path; 505 tree template_decl; 506 tree explicit_targs; 507 candidate_warning *warnings; 508 z_candidate *next; 509 int viable; 510 511 /* The flags active in add_candidate. */ 512 int flags; 513 }; 514 515 /* Returns true iff T is a null pointer constant in the sense of 516 [conv.ptr]. */ 517 518 bool 519 null_ptr_cst_p (tree t) 520 { 521 tree type = TREE_TYPE (t); 522 523 /* [conv.ptr] 524 525 A null pointer constant is an integral constant expression 526 (_expr.const_) rvalue of integer type that evaluates to zero or 527 an rvalue of type std::nullptr_t. */ 528 if (NULLPTR_TYPE_P (type)) 529 return true; 530 531 if (cxx_dialect >= cxx11) 532 { 533 STRIP_ANY_LOCATION_WRAPPER (t); 534 535 /* Core issue 903 says only literal 0 is a null pointer constant. */ 536 if (TREE_CODE (type) == INTEGER_TYPE 537 && !char_type_p (type) 538 && TREE_CODE (t) == INTEGER_CST 539 && integer_zerop (t) 540 && !TREE_OVERFLOW (t)) 541 return true; 542 } 543 else if (CP_INTEGRAL_TYPE_P (type)) 544 { 545 t = fold_non_dependent_expr (t); 546 STRIP_NOPS (t); 547 if (integer_zerop (t) && !TREE_OVERFLOW (t)) 548 return true; 549 } 550 551 return false; 552 } 553 554 /* Returns true iff T is a null member pointer value (4.11). */ 555 556 bool 557 null_member_pointer_value_p (tree t) 558 { 559 tree type = TREE_TYPE (t); 560 if (!type) 561 return false; 562 else if (TYPE_PTRMEMFUNC_P (type)) 563 return (TREE_CODE (t) == CONSTRUCTOR 564 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value)); 565 else if (TYPE_PTRDATAMEM_P (type)) 566 return integer_all_onesp (t); 567 else 568 return false; 569 } 570 571 /* Returns nonzero if PARMLIST consists of only default parms, 572 ellipsis, and/or undeduced parameter packs. */ 573 574 bool 575 sufficient_parms_p (const_tree parmlist) 576 { 577 for (; parmlist && parmlist != void_list_node; 578 parmlist = TREE_CHAIN (parmlist)) 579 if (!TREE_PURPOSE (parmlist) 580 && !PACK_EXPANSION_P (TREE_VALUE (parmlist))) 581 return false; 582 return true; 583 } 584 585 /* Allocate N bytes of memory from the conversion obstack. The memory 586 is zeroed before being returned. */ 587 588 static void * 589 conversion_obstack_alloc (size_t n) 590 { 591 void *p; 592 if (!conversion_obstack_initialized) 593 { 594 gcc_obstack_init (&conversion_obstack); 595 conversion_obstack_initialized = true; 596 } 597 p = obstack_alloc (&conversion_obstack, n); 598 memset (p, 0, n); 599 return p; 600 } 601 602 /* Allocate rejection reasons. */ 603 604 static struct rejection_reason * 605 alloc_rejection (enum rejection_reason_code code) 606 { 607 struct rejection_reason *p; 608 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p); 609 p->code = code; 610 return p; 611 } 612 613 static struct rejection_reason * 614 arity_rejection (tree first_arg, int expected, int actual) 615 { 616 struct rejection_reason *r = alloc_rejection (rr_arity); 617 int adjust = first_arg != NULL_TREE; 618 r->u.arity.expected = expected - adjust; 619 r->u.arity.actual = actual - adjust; 620 return r; 621 } 622 623 static struct rejection_reason * 624 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 625 { 626 struct rejection_reason *r = alloc_rejection (rr_arg_conversion); 627 int adjust = first_arg != NULL_TREE; 628 r->u.conversion.n_arg = n_arg - adjust; 629 r->u.conversion.from = from; 630 r->u.conversion.to_type = to; 631 return r; 632 } 633 634 static struct rejection_reason * 635 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 636 { 637 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion); 638 int adjust = first_arg != NULL_TREE; 639 r->u.bad_conversion.n_arg = n_arg - adjust; 640 r->u.bad_conversion.from = from; 641 r->u.bad_conversion.to_type = to; 642 return r; 643 } 644 645 static struct rejection_reason * 646 explicit_conversion_rejection (tree from, tree to) 647 { 648 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion); 649 r->u.conversion.n_arg = 0; 650 r->u.conversion.from = from; 651 r->u.conversion.to_type = to; 652 return r; 653 } 654 655 static struct rejection_reason * 656 template_conversion_rejection (tree from, tree to) 657 { 658 struct rejection_reason *r = alloc_rejection (rr_template_conversion); 659 r->u.conversion.n_arg = 0; 660 r->u.conversion.from = from; 661 r->u.conversion.to_type = to; 662 return r; 663 } 664 665 static struct rejection_reason * 666 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs, 667 const tree *args, unsigned int nargs, 668 tree return_type, unification_kind_t strict, 669 int flags) 670 { 671 size_t args_n_bytes = sizeof (*args) * nargs; 672 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes); 673 struct rejection_reason *r = alloc_rejection (rr_template_unification); 674 r->u.template_unification.tmpl = tmpl; 675 r->u.template_unification.explicit_targs = explicit_targs; 676 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs); 677 /* Copy args to our own storage. */ 678 memcpy (args1, args, args_n_bytes); 679 r->u.template_unification.args = args1; 680 r->u.template_unification.nargs = nargs; 681 r->u.template_unification.return_type = return_type; 682 r->u.template_unification.strict = strict; 683 r->u.template_unification.flags = flags; 684 return r; 685 } 686 687 static struct rejection_reason * 688 template_unification_error_rejection (void) 689 { 690 return alloc_rejection (rr_template_unification); 691 } 692 693 static struct rejection_reason * 694 invalid_copy_with_fn_template_rejection (void) 695 { 696 struct rejection_reason *r = alloc_rejection (rr_invalid_copy); 697 return r; 698 } 699 700 static struct rejection_reason * 701 inherited_ctor_rejection (void) 702 { 703 struct rejection_reason *r = alloc_rejection (rr_inherited_ctor); 704 return r; 705 } 706 707 // Build a constraint failure record, saving information into the 708 // template_instantiation field of the rejection. If FN is not a template 709 // declaration, the TMPL member is the FN declaration and TARGS is empty. 710 711 static struct rejection_reason * 712 constraint_failure (tree fn) 713 { 714 struct rejection_reason *r = alloc_rejection (rr_constraint_failure); 715 if (tree ti = DECL_TEMPLATE_INFO (fn)) 716 { 717 r->u.template_instantiation.tmpl = TI_TEMPLATE (ti); 718 r->u.template_instantiation.targs = TI_ARGS (ti); 719 } 720 else 721 { 722 r->u.template_instantiation.tmpl = fn; 723 r->u.template_instantiation.targs = NULL_TREE; 724 } 725 return r; 726 } 727 728 /* Dynamically allocate a conversion. */ 729 730 static conversion * 731 alloc_conversion (conversion_kind kind) 732 { 733 conversion *c; 734 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 735 c->kind = kind; 736 return c; 737 } 738 739 /* Make sure that all memory on the conversion obstack has been 740 freed. */ 741 742 void 743 validate_conversion_obstack (void) 744 { 745 if (conversion_obstack_initialized) 746 gcc_assert ((obstack_next_free (&conversion_obstack) 747 == obstack_base (&conversion_obstack))); 748 } 749 750 /* Dynamically allocate an array of N conversions. */ 751 752 static conversion ** 753 alloc_conversions (size_t n) 754 { 755 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 756 } 757 758 static conversion * 759 build_conv (conversion_kind code, tree type, conversion *from) 760 { 761 conversion *t; 762 conversion_rank rank = CONVERSION_RANK (from); 763 764 /* Note that the caller is responsible for filling in t->cand for 765 user-defined conversions. */ 766 t = alloc_conversion (code); 767 t->type = type; 768 t->u.next = from; 769 770 switch (code) 771 { 772 case ck_ptr: 773 case ck_pmem: 774 case ck_base: 775 case ck_std: 776 if (rank < cr_std) 777 rank = cr_std; 778 break; 779 780 case ck_qual: 781 case ck_fnptr: 782 if (rank < cr_exact) 783 rank = cr_exact; 784 break; 785 786 default: 787 break; 788 } 789 t->rank = rank; 790 t->user_conv_p = (code == ck_user || from->user_conv_p); 791 t->bad_p = from->bad_p; 792 t->base_p = false; 793 return t; 794 } 795 796 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 797 specialization of std::initializer_list<T>, if such a conversion is 798 possible. */ 799 800 static conversion * 801 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 802 { 803 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 804 unsigned len = CONSTRUCTOR_NELTS (ctor); 805 conversion **subconvs = alloc_conversions (len); 806 conversion *t; 807 unsigned i; 808 tree val; 809 810 /* Within a list-initialization we can have more user-defined 811 conversions. */ 812 flags &= ~LOOKUP_NO_CONVERSION; 813 /* But no narrowing conversions. */ 814 flags |= LOOKUP_NO_NARROWING; 815 816 /* Can't make an array of these types. */ 817 if (TREE_CODE (elttype) == REFERENCE_TYPE 818 || TREE_CODE (elttype) == FUNCTION_TYPE 819 || VOID_TYPE_P (elttype)) 820 return NULL; 821 822 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 823 { 824 conversion *sub 825 = implicit_conversion (elttype, TREE_TYPE (val), val, 826 false, flags, complain); 827 if (sub == NULL) 828 return NULL; 829 830 subconvs[i] = sub; 831 } 832 833 t = alloc_conversion (ck_list); 834 t->type = type; 835 t->u.list = subconvs; 836 t->rank = cr_exact; 837 838 for (i = 0; i < len; ++i) 839 { 840 conversion *sub = subconvs[i]; 841 if (sub->rank > t->rank) 842 t->rank = sub->rank; 843 if (sub->user_conv_p) 844 t->user_conv_p = true; 845 if (sub->bad_p) 846 t->bad_p = true; 847 } 848 849 return t; 850 } 851 852 /* Return the next conversion of the conversion chain (if applicable), 853 or NULL otherwise. Please use this function instead of directly 854 accessing fields of struct conversion. */ 855 856 static conversion * 857 next_conversion (conversion *conv) 858 { 859 if (conv == NULL 860 || conv->kind == ck_identity 861 || conv->kind == ck_ambig 862 || conv->kind == ck_list) 863 return NULL; 864 return conv->u.next; 865 } 866 867 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list, 868 is a valid aggregate initializer for array type ATYPE. */ 869 870 static bool 871 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain) 872 { 873 unsigned i; 874 tree elttype = TREE_TYPE (atype); 875 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i) 876 { 877 tree val = CONSTRUCTOR_ELT (ctor, i)->value; 878 bool ok; 879 if (TREE_CODE (elttype) == ARRAY_TYPE 880 && TREE_CODE (val) == CONSTRUCTOR) 881 ok = can_convert_array (elttype, val, flags, complain); 882 else 883 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags, 884 complain); 885 if (!ok) 886 return false; 887 } 888 return true; 889 } 890 891 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 892 aggregate class, if such a conversion is possible. */ 893 894 static conversion * 895 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 896 { 897 unsigned HOST_WIDE_INT i = 0; 898 conversion *c; 899 tree field = next_initializable_field (TYPE_FIELDS (type)); 900 tree empty_ctor = NULL_TREE; 901 902 /* We already called reshape_init in implicit_conversion. */ 903 904 /* The conversions within the init-list aren't affected by the enclosing 905 context; they're always simple copy-initialization. */ 906 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 907 908 for (; field; field = next_initializable_field (DECL_CHAIN (field))) 909 { 910 tree ftype = TREE_TYPE (field); 911 tree val; 912 bool ok; 913 914 if (i < CONSTRUCTOR_NELTS (ctor)) 915 val = CONSTRUCTOR_ELT (ctor, i)->value; 916 else if (DECL_INITIAL (field)) 917 val = get_nsdmi (field, /*ctor*/false, complain); 918 else if (TREE_CODE (ftype) == REFERENCE_TYPE) 919 /* Value-initialization of reference is ill-formed. */ 920 return NULL; 921 else 922 { 923 if (empty_ctor == NULL_TREE) 924 empty_ctor = build_constructor (init_list_type_node, NULL); 925 val = empty_ctor; 926 } 927 ++i; 928 929 if (TREE_CODE (ftype) == ARRAY_TYPE 930 && TREE_CODE (val) == CONSTRUCTOR) 931 ok = can_convert_array (ftype, val, flags, complain); 932 else 933 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags, 934 complain); 935 936 if (!ok) 937 return NULL; 938 939 if (TREE_CODE (type) == UNION_TYPE) 940 break; 941 } 942 943 if (i < CONSTRUCTOR_NELTS (ctor)) 944 return NULL; 945 946 c = alloc_conversion (ck_aggr); 947 c->type = type; 948 c->rank = cr_exact; 949 c->user_conv_p = true; 950 c->check_narrowing = true; 951 c->u.next = NULL; 952 return c; 953 } 954 955 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 956 array type, if such a conversion is possible. */ 957 958 static conversion * 959 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 960 { 961 conversion *c; 962 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 963 tree elttype = TREE_TYPE (type); 964 unsigned i; 965 tree val; 966 bool bad = false; 967 bool user = false; 968 enum conversion_rank rank = cr_exact; 969 970 /* We might need to propagate the size from the element to the array. */ 971 complete_type (type); 972 973 if (TYPE_DOMAIN (type) 974 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE)) 975 { 976 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type)); 977 if (alen < len) 978 return NULL; 979 } 980 981 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 982 983 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 984 { 985 conversion *sub 986 = implicit_conversion (elttype, TREE_TYPE (val), val, 987 false, flags, complain); 988 if (sub == NULL) 989 return NULL; 990 991 if (sub->rank > rank) 992 rank = sub->rank; 993 if (sub->user_conv_p) 994 user = true; 995 if (sub->bad_p) 996 bad = true; 997 } 998 999 c = alloc_conversion (ck_aggr); 1000 c->type = type; 1001 c->rank = rank; 1002 c->user_conv_p = user; 1003 c->bad_p = bad; 1004 c->u.next = NULL; 1005 return c; 1006 } 1007 1008 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 1009 complex type, if such a conversion is possible. */ 1010 1011 static conversion * 1012 build_complex_conv (tree type, tree ctor, int flags, 1013 tsubst_flags_t complain) 1014 { 1015 conversion *c; 1016 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 1017 tree elttype = TREE_TYPE (type); 1018 unsigned i; 1019 tree val; 1020 bool bad = false; 1021 bool user = false; 1022 enum conversion_rank rank = cr_exact; 1023 1024 if (len != 2) 1025 return NULL; 1026 1027 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 1028 1029 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 1030 { 1031 conversion *sub 1032 = implicit_conversion (elttype, TREE_TYPE (val), val, 1033 false, flags, complain); 1034 if (sub == NULL) 1035 return NULL; 1036 1037 if (sub->rank > rank) 1038 rank = sub->rank; 1039 if (sub->user_conv_p) 1040 user = true; 1041 if (sub->bad_p) 1042 bad = true; 1043 } 1044 1045 c = alloc_conversion (ck_aggr); 1046 c->type = type; 1047 c->rank = rank; 1048 c->user_conv_p = user; 1049 c->bad_p = bad; 1050 c->u.next = NULL; 1051 return c; 1052 } 1053 1054 /* Build a representation of the identity conversion from EXPR to 1055 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1056 1057 static conversion * 1058 build_identity_conv (tree type, tree expr) 1059 { 1060 conversion *c; 1061 1062 c = alloc_conversion (ck_identity); 1063 c->type = type; 1064 c->u.expr = expr; 1065 1066 return c; 1067 } 1068 1069 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1070 were multiple user-defined conversions to accomplish the job. 1071 Build a conversion that indicates that ambiguity. */ 1072 1073 static conversion * 1074 build_ambiguous_conv (tree type, tree expr) 1075 { 1076 conversion *c; 1077 1078 c = alloc_conversion (ck_ambig); 1079 c->type = type; 1080 c->u.expr = expr; 1081 1082 return c; 1083 } 1084 1085 tree 1086 strip_top_quals (tree t) 1087 { 1088 if (TREE_CODE (t) == ARRAY_TYPE) 1089 return t; 1090 return cp_build_qualified_type (t, 0); 1091 } 1092 1093 /* Returns the standard conversion path (see [conv]) from type FROM to type 1094 TO, if any. For proper handling of null pointer constants, you must 1095 also pass the expression EXPR to convert from. If C_CAST_P is true, 1096 this conversion is coming from a C-style cast. */ 1097 1098 static conversion * 1099 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1100 int flags, tsubst_flags_t complain) 1101 { 1102 enum tree_code fcode, tcode; 1103 conversion *conv; 1104 bool fromref = false; 1105 tree qualified_to; 1106 1107 to = non_reference (to); 1108 if (TREE_CODE (from) == REFERENCE_TYPE) 1109 { 1110 fromref = true; 1111 from = TREE_TYPE (from); 1112 } 1113 qualified_to = to; 1114 to = strip_top_quals (to); 1115 from = strip_top_quals (from); 1116 1117 if (expr && type_unknown_p (expr)) 1118 { 1119 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1120 { 1121 tsubst_flags_t tflags = tf_conv; 1122 expr = instantiate_type (to, expr, tflags); 1123 if (expr == error_mark_node) 1124 return NULL; 1125 from = TREE_TYPE (expr); 1126 } 1127 else if (TREE_CODE (to) == BOOLEAN_TYPE) 1128 { 1129 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */ 1130 expr = resolve_nondeduced_context (expr, complain); 1131 from = TREE_TYPE (expr); 1132 } 1133 } 1134 1135 fcode = TREE_CODE (from); 1136 tcode = TREE_CODE (to); 1137 1138 conv = build_identity_conv (from, expr); 1139 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1140 { 1141 from = type_decays_to (from); 1142 fcode = TREE_CODE (from); 1143 /* Tell convert_like_real that we're using the address. */ 1144 conv->rvaluedness_matches_p = true; 1145 conv = build_conv (ck_lvalue, from, conv); 1146 } 1147 /* Wrapping a ck_rvalue around a class prvalue (as a result of using 1148 obvalue_p) seems odd, since it's already a prvalue, but that's how we 1149 express the copy constructor call required by copy-initialization. */ 1150 else if (fromref || (expr && obvalue_p (expr))) 1151 { 1152 if (expr) 1153 { 1154 tree bitfield_type; 1155 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1156 if (bitfield_type) 1157 { 1158 from = strip_top_quals (bitfield_type); 1159 fcode = TREE_CODE (from); 1160 } 1161 } 1162 conv = build_conv (ck_rvalue, from, conv); 1163 if (flags & LOOKUP_PREFER_RVALUE) 1164 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */ 1165 conv->rvaluedness_matches_p = true; 1166 } 1167 1168 /* Allow conversion between `__complex__' data types. */ 1169 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1170 { 1171 /* The standard conversion sequence to convert FROM to TO is 1172 the standard conversion sequence to perform componentwise 1173 conversion. */ 1174 conversion *part_conv = standard_conversion 1175 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags, 1176 complain); 1177 1178 if (part_conv) 1179 { 1180 conv = build_conv (part_conv->kind, to, conv); 1181 conv->rank = part_conv->rank; 1182 } 1183 else 1184 conv = NULL; 1185 1186 return conv; 1187 } 1188 1189 if (same_type_p (from, to)) 1190 { 1191 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1192 conv->type = qualified_to; 1193 return conv; 1194 } 1195 1196 /* [conv.ptr] 1197 A null pointer constant can be converted to a pointer type; ... A 1198 null pointer constant of integral type can be converted to an 1199 rvalue of type std::nullptr_t. */ 1200 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to) 1201 || NULLPTR_TYPE_P (to)) 1202 && ((expr && null_ptr_cst_p (expr)) 1203 || NULLPTR_TYPE_P (from))) 1204 conv = build_conv (ck_std, to, conv); 1205 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1206 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1207 { 1208 /* For backwards brain damage compatibility, allow interconversion of 1209 pointers and integers with a pedwarn. */ 1210 conv = build_conv (ck_std, to, conv); 1211 conv->bad_p = true; 1212 } 1213 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1214 { 1215 /* For backwards brain damage compatibility, allow interconversion of 1216 enums and integers with a pedwarn. */ 1217 conv = build_conv (ck_std, to, conv); 1218 conv->bad_p = true; 1219 } 1220 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1221 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from))) 1222 { 1223 tree to_pointee; 1224 tree from_pointee; 1225 1226 if (tcode == POINTER_TYPE) 1227 { 1228 to_pointee = TREE_TYPE (to); 1229 from_pointee = TREE_TYPE (from); 1230 1231 /* Since this is the target of a pointer, it can't have function 1232 qualifiers, so any TYPE_QUALS must be for attributes const or 1233 noreturn. Strip them. */ 1234 if (TREE_CODE (to_pointee) == FUNCTION_TYPE 1235 && TYPE_QUALS (to_pointee)) 1236 to_pointee = build_qualified_type (to_pointee, TYPE_UNQUALIFIED); 1237 if (TREE_CODE (from_pointee) == FUNCTION_TYPE 1238 && TYPE_QUALS (from_pointee)) 1239 from_pointee = build_qualified_type (from_pointee, TYPE_UNQUALIFIED); 1240 } 1241 else 1242 { 1243 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1244 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1245 } 1246 1247 if (tcode == POINTER_TYPE 1248 && same_type_ignoring_top_level_qualifiers_p (from_pointee, 1249 to_pointee)) 1250 ; 1251 else if (VOID_TYPE_P (to_pointee) 1252 && !TYPE_PTRDATAMEM_P (from) 1253 && TREE_CODE (from_pointee) != FUNCTION_TYPE) 1254 { 1255 tree nfrom = TREE_TYPE (from); 1256 /* Don't try to apply restrict to void. */ 1257 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT; 1258 from_pointee = cp_build_qualified_type (void_type_node, quals); 1259 from = build_pointer_type (from_pointee); 1260 conv = build_conv (ck_ptr, from, conv); 1261 } 1262 else if (TYPE_PTRDATAMEM_P (from)) 1263 { 1264 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1265 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1266 1267 if (same_type_p (fbase, tbase)) 1268 /* No base conversion needed. */; 1269 else if (DERIVED_FROM_P (fbase, tbase) 1270 && (same_type_ignoring_top_level_qualifiers_p 1271 (from_pointee, to_pointee))) 1272 { 1273 from = build_ptrmem_type (tbase, from_pointee); 1274 conv = build_conv (ck_pmem, from, conv); 1275 } 1276 else 1277 return NULL; 1278 } 1279 else if (CLASS_TYPE_P (from_pointee) 1280 && CLASS_TYPE_P (to_pointee) 1281 /* [conv.ptr] 1282 1283 An rvalue of type "pointer to cv D," where D is a 1284 class type, can be converted to an rvalue of type 1285 "pointer to cv B," where B is a base class (clause 1286 _class.derived_) of D. If B is an inaccessible 1287 (clause _class.access_) or ambiguous 1288 (_class.member.lookup_) base class of D, a program 1289 that necessitates this conversion is ill-formed. 1290 Therefore, we use DERIVED_FROM_P, and do not check 1291 access or uniqueness. */ 1292 && DERIVED_FROM_P (to_pointee, from_pointee)) 1293 { 1294 from_pointee 1295 = cp_build_qualified_type (to_pointee, 1296 cp_type_quals (from_pointee)); 1297 from = build_pointer_type (from_pointee); 1298 conv = build_conv (ck_ptr, from, conv); 1299 conv->base_p = true; 1300 } 1301 1302 if (same_type_p (from, to)) 1303 /* OK */; 1304 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1305 /* In a C-style cast, we ignore CV-qualification because we 1306 are allowed to perform a static_cast followed by a 1307 const_cast. */ 1308 conv = build_conv (ck_qual, to, conv); 1309 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1310 conv = build_conv (ck_qual, to, conv); 1311 else if (expr && string_conv_p (to, expr, 0)) 1312 /* converting from string constant to char *. */ 1313 conv = build_conv (ck_qual, to, conv); 1314 else if (fnptr_conv_p (to, from)) 1315 conv = build_conv (ck_fnptr, to, conv); 1316 /* Allow conversions among compatible ObjC pointer types (base 1317 conversions have been already handled above). */ 1318 else if (c_dialect_objc () 1319 && objc_compare_types (to, from, -4, NULL_TREE)) 1320 conv = build_conv (ck_ptr, to, conv); 1321 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1322 { 1323 conv = build_conv (ck_ptr, to, conv); 1324 conv->bad_p = true; 1325 } 1326 else 1327 return NULL; 1328 1329 from = to; 1330 } 1331 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1332 { 1333 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1334 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1335 tree fbase = class_of_this_parm (fromfn); 1336 tree tbase = class_of_this_parm (tofn); 1337 1338 if (!DERIVED_FROM_P (fbase, tbase)) 1339 return NULL; 1340 1341 tree fstat = static_fn_type (fromfn); 1342 tree tstat = static_fn_type (tofn); 1343 if (same_type_p (tstat, fstat) 1344 || fnptr_conv_p (tstat, fstat)) 1345 /* OK */; 1346 else 1347 return NULL; 1348 1349 if (!same_type_p (fbase, tbase)) 1350 { 1351 from = build_memfn_type (fstat, 1352 tbase, 1353 cp_type_quals (tbase), 1354 type_memfn_rqual (tofn)); 1355 from = build_ptrmemfunc_type (build_pointer_type (from)); 1356 conv = build_conv (ck_pmem, from, conv); 1357 conv->base_p = true; 1358 } 1359 if (fnptr_conv_p (tstat, fstat)) 1360 conv = build_conv (ck_fnptr, to, conv); 1361 } 1362 else if (tcode == BOOLEAN_TYPE) 1363 { 1364 /* [conv.bool] 1365 1366 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer 1367 to member type can be converted to a prvalue of type bool. ... 1368 For direct-initialization (8.5 [dcl.init]), a prvalue of type 1369 std::nullptr_t can be converted to a prvalue of type bool; */ 1370 if (ARITHMETIC_TYPE_P (from) 1371 || UNSCOPED_ENUM_P (from) 1372 || fcode == POINTER_TYPE 1373 || TYPE_PTRMEM_P (from) 1374 || NULLPTR_TYPE_P (from)) 1375 { 1376 conv = build_conv (ck_std, to, conv); 1377 if (fcode == POINTER_TYPE 1378 || TYPE_PTRDATAMEM_P (from) 1379 || (TYPE_PTRMEMFUNC_P (from) 1380 && conv->rank < cr_pbool) 1381 || NULLPTR_TYPE_P (from)) 1382 conv->rank = cr_pbool; 1383 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING)) 1384 conv->bad_p = true; 1385 return conv; 1386 } 1387 1388 return NULL; 1389 } 1390 /* We don't check for ENUMERAL_TYPE here because there are no standard 1391 conversions to enum type. */ 1392 /* As an extension, allow conversion to complex type. */ 1393 else if (ARITHMETIC_TYPE_P (to)) 1394 { 1395 if (! (INTEGRAL_CODE_P (fcode) 1396 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL))) 1397 || SCOPED_ENUM_P (from)) 1398 return NULL; 1399 1400 /* If we're parsing an enum with no fixed underlying type, we're 1401 dealing with an incomplete type, which renders the conversion 1402 ill-formed. */ 1403 if (!COMPLETE_TYPE_P (from)) 1404 return NULL; 1405 1406 conv = build_conv (ck_std, to, conv); 1407 1408 /* Give this a better rank if it's a promotion. */ 1409 if (same_type_p (to, type_promotes_to (from)) 1410 && next_conversion (conv)->rank <= cr_promotion) 1411 conv->rank = cr_promotion; 1412 } 1413 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1414 && vector_types_convertible_p (from, to, false)) 1415 return build_conv (ck_std, to, conv); 1416 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1417 && is_properly_derived_from (from, to)) 1418 { 1419 if (conv->kind == ck_rvalue) 1420 conv = next_conversion (conv); 1421 conv = build_conv (ck_base, to, conv); 1422 /* The derived-to-base conversion indicates the initialization 1423 of a parameter with base type from an object of a derived 1424 type. A temporary object is created to hold the result of 1425 the conversion unless we're binding directly to a reference. */ 1426 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1427 } 1428 else 1429 return NULL; 1430 1431 if (flags & LOOKUP_NO_NARROWING) 1432 conv->check_narrowing = true; 1433 1434 return conv; 1435 } 1436 1437 /* Returns nonzero if T1 is reference-related to T2. */ 1438 1439 bool 1440 reference_related_p (tree t1, tree t2) 1441 { 1442 if (t1 == error_mark_node || t2 == error_mark_node) 1443 return false; 1444 1445 t1 = TYPE_MAIN_VARIANT (t1); 1446 t2 = TYPE_MAIN_VARIANT (t2); 1447 1448 /* [dcl.init.ref] 1449 1450 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1451 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1452 of T2. */ 1453 return (same_type_p (t1, t2) 1454 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1455 && DERIVED_FROM_P (t1, t2))); 1456 } 1457 1458 /* Returns nonzero if T1 is reference-compatible with T2. */ 1459 1460 static bool 1461 reference_compatible_p (tree t1, tree t2) 1462 { 1463 /* [dcl.init.ref] 1464 1465 "cv1 T1" is reference compatible with "cv2 T2" if 1466 * T1 is reference-related to T2 or 1467 * T2 is "noexcept function" and T1 is "function", where the 1468 function types are otherwise the same, 1469 and cv1 is the same cv-qualification as, or greater cv-qualification 1470 than, cv2. */ 1471 return ((reference_related_p (t1, t2) 1472 || fnptr_conv_p (t1, t2)) 1473 && at_least_as_qualified_p (t1, t2)); 1474 } 1475 1476 /* A reference of the indicated TYPE is being bound directly to the 1477 expression represented by the implicit conversion sequence CONV. 1478 Return a conversion sequence for this binding. */ 1479 1480 static conversion * 1481 direct_reference_binding (tree type, conversion *conv) 1482 { 1483 tree t; 1484 1485 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1486 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1487 1488 t = TREE_TYPE (type); 1489 1490 if (conv->kind == ck_identity) 1491 /* Mark the identity conv as to not decay to rvalue. */ 1492 conv->rvaluedness_matches_p = true; 1493 1494 /* [over.ics.rank] 1495 1496 When a parameter of reference type binds directly 1497 (_dcl.init.ref_) to an argument expression, the implicit 1498 conversion sequence is the identity conversion, unless the 1499 argument expression has a type that is a derived class of the 1500 parameter type, in which case the implicit conversion sequence is 1501 a derived-to-base Conversion. 1502 1503 If the parameter binds directly to the result of applying a 1504 conversion function to the argument expression, the implicit 1505 conversion sequence is a user-defined conversion sequence 1506 (_over.ics.user_), with the second standard conversion sequence 1507 either an identity conversion or, if the conversion function 1508 returns an entity of a type that is a derived class of the 1509 parameter type, a derived-to-base conversion. */ 1510 if (is_properly_derived_from (conv->type, t)) 1511 { 1512 /* Represent the derived-to-base conversion. */ 1513 conv = build_conv (ck_base, t, conv); 1514 /* We will actually be binding to the base-class subobject in 1515 the derived class, so we mark this conversion appropriately. 1516 That way, convert_like knows not to generate a temporary. */ 1517 conv->need_temporary_p = false; 1518 } 1519 1520 return build_conv (ck_ref_bind, type, conv); 1521 } 1522 1523 /* Returns the conversion path from type FROM to reference type TO for 1524 purposes of reference binding. For lvalue binding, either pass a 1525 reference type to FROM or an lvalue expression to EXPR. If the 1526 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1527 the conversion returned. If C_CAST_P is true, this 1528 conversion is coming from a C-style cast. */ 1529 1530 static conversion * 1531 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags, 1532 tsubst_flags_t complain) 1533 { 1534 conversion *conv = NULL; 1535 tree to = TREE_TYPE (rto); 1536 tree from = rfrom; 1537 tree tfrom; 1538 bool related_p; 1539 bool compatible_p; 1540 cp_lvalue_kind gl_kind; 1541 bool is_lvalue; 1542 1543 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1544 { 1545 expr = instantiate_type (to, expr, tf_none); 1546 if (expr == error_mark_node) 1547 return NULL; 1548 from = TREE_TYPE (expr); 1549 } 1550 1551 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1552 { 1553 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1554 /* DR 1288: Otherwise, if the initializer list has a single element 1555 of type E and ... [T's] referenced type is reference-related to E, 1556 the object or reference is initialized from that element... */ 1557 if (CONSTRUCTOR_NELTS (expr) == 1) 1558 { 1559 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1560 if (error_operand_p (elt)) 1561 return NULL; 1562 tree etype = TREE_TYPE (elt); 1563 if (reference_related_p (to, etype)) 1564 { 1565 expr = elt; 1566 from = etype; 1567 goto skip; 1568 } 1569 } 1570 /* Otherwise, if T is a reference type, a prvalue temporary of the 1571 type referenced by T is copy-list-initialized or 1572 direct-list-initialized, depending on the kind of initialization 1573 for the reference, and the reference is bound to that temporary. */ 1574 conv = implicit_conversion (to, from, expr, c_cast_p, 1575 flags|LOOKUP_NO_TEMP_BIND, complain); 1576 skip:; 1577 } 1578 1579 if (TREE_CODE (from) == REFERENCE_TYPE) 1580 { 1581 from = TREE_TYPE (from); 1582 if (!TYPE_REF_IS_RVALUE (rfrom) 1583 || TREE_CODE (from) == FUNCTION_TYPE) 1584 gl_kind = clk_ordinary; 1585 else 1586 gl_kind = clk_rvalueref; 1587 } 1588 else if (expr) 1589 gl_kind = lvalue_kind (expr); 1590 else if (CLASS_TYPE_P (from) 1591 || TREE_CODE (from) == ARRAY_TYPE) 1592 gl_kind = clk_class; 1593 else 1594 gl_kind = clk_none; 1595 1596 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */ 1597 if ((flags & LOOKUP_NO_TEMP_BIND) 1598 && (gl_kind & clk_class)) 1599 gl_kind = clk_none; 1600 1601 /* Same mask as real_lvalue_p. */ 1602 is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class)); 1603 1604 tfrom = from; 1605 if ((gl_kind & clk_bitfield) != 0) 1606 tfrom = unlowered_expr_type (expr); 1607 1608 /* Figure out whether or not the types are reference-related and 1609 reference compatible. We have to do this after stripping 1610 references from FROM. */ 1611 related_p = reference_related_p (to, tfrom); 1612 /* If this is a C cast, first convert to an appropriately qualified 1613 type, so that we can later do a const_cast to the desired type. */ 1614 if (related_p && c_cast_p 1615 && !at_least_as_qualified_p (to, tfrom)) 1616 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1617 compatible_p = reference_compatible_p (to, tfrom); 1618 1619 /* Directly bind reference when target expression's type is compatible with 1620 the reference and expression is an lvalue. In DR391, the wording in 1621 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1622 const and rvalue references to rvalues of compatible class type. 1623 We should also do direct bindings for non-class xvalues. */ 1624 if ((related_p || compatible_p) && gl_kind) 1625 { 1626 /* [dcl.init.ref] 1627 1628 If the initializer expression 1629 1630 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1631 is reference-compatible with "cv2 T2," 1632 1633 the reference is bound directly to the initializer expression 1634 lvalue. 1635 1636 [...] 1637 If the initializer expression is an rvalue, with T2 a class type, 1638 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1639 is bound to the object represented by the rvalue or to a sub-object 1640 within that object. */ 1641 1642 conv = build_identity_conv (tfrom, expr); 1643 conv = direct_reference_binding (rto, conv); 1644 1645 if (TREE_CODE (rfrom) == REFERENCE_TYPE) 1646 /* Handle rvalue reference to function properly. */ 1647 conv->rvaluedness_matches_p 1648 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1649 else 1650 conv->rvaluedness_matches_p 1651 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1652 1653 if ((gl_kind & clk_bitfield) != 0 1654 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1655 /* For the purposes of overload resolution, we ignore the fact 1656 this expression is a bitfield or packed field. (In particular, 1657 [over.ics.ref] says specifically that a function with a 1658 non-const reference parameter is viable even if the 1659 argument is a bitfield.) 1660 1661 However, when we actually call the function we must create 1662 a temporary to which to bind the reference. If the 1663 reference is volatile, or isn't const, then we cannot make 1664 a temporary, so we just issue an error when the conversion 1665 actually occurs. */ 1666 conv->need_temporary_p = true; 1667 1668 /* Don't allow binding of lvalues (other than function lvalues) to 1669 rvalue references. */ 1670 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1671 && TREE_CODE (to) != FUNCTION_TYPE) 1672 conv->bad_p = true; 1673 1674 /* Nor the reverse. */ 1675 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto) 1676 && (!CP_TYPE_CONST_NON_VOLATILE_P (to) 1677 || (flags & LOOKUP_NO_RVAL_BIND)) 1678 && TREE_CODE (to) != FUNCTION_TYPE) 1679 conv->bad_p = true; 1680 1681 if (!compatible_p) 1682 conv->bad_p = true; 1683 1684 return conv; 1685 } 1686 /* [class.conv.fct] A conversion function is never used to convert a 1687 (possibly cv-qualified) object to the (possibly cv-qualified) same 1688 object type (or a reference to it), to a (possibly cv-qualified) base 1689 class of that type (or a reference to it).... */ 1690 else if (CLASS_TYPE_P (from) && !related_p 1691 && !(flags & LOOKUP_NO_CONVERSION)) 1692 { 1693 /* [dcl.init.ref] 1694 1695 If the initializer expression 1696 1697 -- has a class type (i.e., T2 is a class type) can be 1698 implicitly converted to an lvalue of type "cv3 T3," where 1699 "cv1 T1" is reference-compatible with "cv3 T3". (this 1700 conversion is selected by enumerating the applicable 1701 conversion functions (_over.match.ref_) and choosing the 1702 best one through overload resolution. (_over.match_). 1703 1704 the reference is bound to the lvalue result of the conversion 1705 in the second case. */ 1706 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags, 1707 complain); 1708 if (cand) 1709 return cand->second_conv; 1710 } 1711 1712 /* From this point on, we conceptually need temporaries, even if we 1713 elide them. Only the cases above are "direct bindings". */ 1714 if (flags & LOOKUP_NO_TEMP_BIND) 1715 return NULL; 1716 1717 /* [over.ics.rank] 1718 1719 When a parameter of reference type is not bound directly to an 1720 argument expression, the conversion sequence is the one required 1721 to convert the argument expression to the underlying type of the 1722 reference according to _over.best.ics_. Conceptually, this 1723 conversion sequence corresponds to copy-initializing a temporary 1724 of the underlying type with the argument expression. Any 1725 difference in top-level cv-qualification is subsumed by the 1726 initialization itself and does not constitute a conversion. */ 1727 1728 /* [dcl.init.ref] 1729 1730 Otherwise, the reference shall be an lvalue reference to a 1731 non-volatile const type, or the reference shall be an rvalue 1732 reference. 1733 1734 We try below to treat this as a bad conversion to improve diagnostics, 1735 but if TO is an incomplete class, we need to reject this conversion 1736 now to avoid unnecessary instantiation. */ 1737 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto) 1738 && !COMPLETE_TYPE_P (to)) 1739 return NULL; 1740 1741 /* We're generating a temporary now, but don't bind any more in the 1742 conversion (specifically, don't slice the temporary returned by a 1743 conversion operator). */ 1744 flags |= LOOKUP_NO_TEMP_BIND; 1745 1746 /* Core issue 899: When [copy-]initializing a temporary to be bound 1747 to the first parameter of a copy constructor (12.8) called with 1748 a single argument in the context of direct-initialization, 1749 explicit conversion functions are also considered. 1750 1751 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1752 if (!(flags & LOOKUP_COPY_PARM)) 1753 flags |= LOOKUP_ONLYCONVERTING; 1754 1755 if (!conv) 1756 conv = implicit_conversion (to, from, expr, c_cast_p, 1757 flags, complain); 1758 if (!conv) 1759 return NULL; 1760 1761 if (conv->user_conv_p) 1762 { 1763 /* If initializing the temporary used a conversion function, 1764 recalculate the second conversion sequence. */ 1765 for (conversion *t = conv; t; t = next_conversion (t)) 1766 if (t->kind == ck_user 1767 && DECL_CONV_FN_P (t->cand->fn)) 1768 { 1769 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn)); 1770 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND; 1771 conversion *new_second 1772 = reference_binding (rto, ftype, NULL_TREE, c_cast_p, 1773 sflags, complain); 1774 if (!new_second) 1775 return NULL; 1776 return merge_conversion_sequences (t, new_second); 1777 } 1778 } 1779 1780 conv = build_conv (ck_ref_bind, rto, conv); 1781 /* This reference binding, unlike those above, requires the 1782 creation of a temporary. */ 1783 conv->need_temporary_p = true; 1784 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1785 1786 /* [dcl.init.ref] 1787 1788 Otherwise, the reference shall be an lvalue reference to a 1789 non-volatile const type, or the reference shall be an rvalue 1790 reference. */ 1791 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1792 conv->bad_p = true; 1793 1794 /* [dcl.init.ref] 1795 1796 Otherwise, a temporary of type "cv1 T1" is created and 1797 initialized from the initializer expression using the rules for a 1798 non-reference copy initialization. If T1 is reference-related to 1799 T2, cv1 must be the same cv-qualification as, or greater 1800 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1801 if (related_p && !at_least_as_qualified_p (to, from)) 1802 conv->bad_p = true; 1803 1804 return conv; 1805 } 1806 1807 /* Returns the implicit conversion sequence (see [over.ics]) from type 1808 FROM to type TO. The optional expression EXPR may affect the 1809 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1810 true, this conversion is coming from a C-style cast. */ 1811 1812 static conversion * 1813 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1814 int flags, tsubst_flags_t complain) 1815 { 1816 conversion *conv; 1817 1818 if (from == error_mark_node || to == error_mark_node 1819 || expr == error_mark_node) 1820 return NULL; 1821 1822 /* Other flags only apply to the primary function in overload 1823 resolution, or after we've chosen one. */ 1824 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1825 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1826 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL); 1827 1828 /* FIXME: actually we don't want warnings either, but we can't just 1829 have 'complain &= ~(tf_warning|tf_error)' because it would cause 1830 the regression of, eg, g++.old-deja/g++.benjamin/16077.C. 1831 We really ought not to issue that warning until we've committed 1832 to that conversion. */ 1833 complain &= ~tf_error; 1834 1835 /* Call reshape_init early to remove redundant braces. */ 1836 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) 1837 && CLASS_TYPE_P (to) 1838 && COMPLETE_TYPE_P (complete_type (to)) 1839 && !CLASSTYPE_NON_AGGREGATE (to)) 1840 { 1841 expr = reshape_init (to, expr, complain); 1842 if (expr == error_mark_node) 1843 return NULL; 1844 from = TREE_TYPE (expr); 1845 } 1846 1847 if (TREE_CODE (to) == REFERENCE_TYPE) 1848 conv = reference_binding (to, from, expr, c_cast_p, flags, complain); 1849 else 1850 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain); 1851 1852 if (conv) 1853 return conv; 1854 1855 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1856 { 1857 if (is_std_init_list (to)) 1858 return build_list_conv (to, expr, flags, complain); 1859 1860 /* As an extension, allow list-initialization of _Complex. */ 1861 if (TREE_CODE (to) == COMPLEX_TYPE) 1862 { 1863 conv = build_complex_conv (to, expr, flags, complain); 1864 if (conv) 1865 return conv; 1866 } 1867 1868 /* Allow conversion from an initializer-list with one element to a 1869 scalar type. */ 1870 if (SCALAR_TYPE_P (to)) 1871 { 1872 int nelts = CONSTRUCTOR_NELTS (expr); 1873 tree elt; 1874 1875 if (nelts == 0) 1876 elt = build_value_init (to, tf_none); 1877 else if (nelts == 1) 1878 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1879 else 1880 elt = error_mark_node; 1881 1882 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1883 c_cast_p, flags, complain); 1884 if (conv) 1885 { 1886 conv->check_narrowing = true; 1887 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1888 /* Too many levels of braces, i.e. '{{1}}'. */ 1889 conv->bad_p = true; 1890 return conv; 1891 } 1892 } 1893 else if (TREE_CODE (to) == ARRAY_TYPE) 1894 return build_array_conv (to, expr, flags, complain); 1895 } 1896 1897 if (expr != NULL_TREE 1898 && (MAYBE_CLASS_TYPE_P (from) 1899 || MAYBE_CLASS_TYPE_P (to)) 1900 && (flags & LOOKUP_NO_CONVERSION) == 0) 1901 { 1902 struct z_candidate *cand; 1903 1904 if (CLASS_TYPE_P (to) 1905 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1906 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1907 return build_aggr_conv (to, expr, flags, complain); 1908 1909 cand = build_user_type_conversion_1 (to, expr, flags, complain); 1910 if (cand) 1911 { 1912 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 1913 && CONSTRUCTOR_NELTS (expr) == 1 1914 && !is_list_ctor (cand->fn)) 1915 { 1916 /* "If C is not an initializer-list constructor and the 1917 initializer list has a single element of type cv U, where U is 1918 X or a class derived from X, the implicit conversion sequence 1919 has Exact Match rank if U is X, or Conversion rank if U is 1920 derived from X." */ 1921 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1922 tree elttype = TREE_TYPE (elt); 1923 if (reference_related_p (to, elttype)) 1924 return implicit_conversion (to, elttype, elt, 1925 c_cast_p, flags, complain); 1926 } 1927 conv = cand->second_conv; 1928 } 1929 1930 /* We used to try to bind a reference to a temporary here, but that 1931 is now handled after the recursive call to this function at the end 1932 of reference_binding. */ 1933 return conv; 1934 } 1935 1936 return NULL; 1937 } 1938 1939 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1940 functions. ARGS will not be changed until a single candidate is 1941 selected. */ 1942 1943 static struct z_candidate * 1944 add_candidate (struct z_candidate **candidates, 1945 tree fn, tree first_arg, const vec<tree, va_gc> *args, 1946 size_t num_convs, conversion **convs, 1947 tree access_path, tree conversion_path, 1948 int viable, struct rejection_reason *reason, 1949 int flags) 1950 { 1951 struct z_candidate *cand = (struct z_candidate *) 1952 conversion_obstack_alloc (sizeof (struct z_candidate)); 1953 1954 cand->fn = fn; 1955 cand->first_arg = first_arg; 1956 cand->args = args; 1957 cand->convs = convs; 1958 cand->num_convs = num_convs; 1959 cand->access_path = access_path; 1960 cand->conversion_path = conversion_path; 1961 cand->viable = viable; 1962 cand->reason = reason; 1963 cand->next = *candidates; 1964 cand->flags = flags; 1965 *candidates = cand; 1966 1967 return cand; 1968 } 1969 1970 /* Return the number of remaining arguments in the parameter list 1971 beginning with ARG. */ 1972 1973 int 1974 remaining_arguments (tree arg) 1975 { 1976 int n; 1977 1978 for (n = 0; arg != NULL_TREE && arg != void_list_node; 1979 arg = TREE_CHAIN (arg)) 1980 n++; 1981 1982 return n; 1983 } 1984 1985 /* Create an overload candidate for the function or method FN called 1986 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1987 FLAGS is passed on to implicit_conversion. 1988 1989 This does not change ARGS. 1990 1991 CTYPE, if non-NULL, is the type we want to pretend this function 1992 comes from for purposes of overload resolution. */ 1993 1994 static struct z_candidate * 1995 add_function_candidate (struct z_candidate **candidates, 1996 tree fn, tree ctype, tree first_arg, 1997 const vec<tree, va_gc> *args, tree access_path, 1998 tree conversion_path, int flags, 1999 tsubst_flags_t complain) 2000 { 2001 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 2002 int i, len; 2003 conversion **convs; 2004 tree parmnode; 2005 tree orig_first_arg = first_arg; 2006 int skip; 2007 int viable = 1; 2008 struct rejection_reason *reason = NULL; 2009 2010 /* At this point we should not see any functions which haven't been 2011 explicitly declared, except for friend functions which will have 2012 been found using argument dependent lookup. */ 2013 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 2014 2015 /* The `this', `in_chrg' and VTT arguments to constructors are not 2016 considered in overload resolution. */ 2017 if (DECL_CONSTRUCTOR_P (fn)) 2018 { 2019 if (ctor_omit_inherited_parms (fn)) 2020 /* Bring back parameters omitted from an inherited ctor. */ 2021 parmlist = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)); 2022 else 2023 parmlist = skip_artificial_parms_for (fn, parmlist); 2024 skip = num_artificial_parms_for (fn); 2025 if (skip > 0 && first_arg != NULL_TREE) 2026 { 2027 --skip; 2028 first_arg = NULL_TREE; 2029 } 2030 } 2031 else 2032 skip = 0; 2033 2034 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0); 2035 convs = alloc_conversions (len); 2036 2037 /* 13.3.2 - Viable functions [over.match.viable] 2038 First, to be a viable function, a candidate function shall have enough 2039 parameters to agree in number with the arguments in the list. 2040 2041 We need to check this first; otherwise, checking the ICSes might cause 2042 us to produce an ill-formed template instantiation. */ 2043 2044 parmnode = parmlist; 2045 for (i = 0; i < len; ++i) 2046 { 2047 if (parmnode == NULL_TREE || parmnode == void_list_node) 2048 break; 2049 parmnode = TREE_CHAIN (parmnode); 2050 } 2051 2052 if ((i < len && parmnode) 2053 || !sufficient_parms_p (parmnode)) 2054 { 2055 int remaining = remaining_arguments (parmnode); 2056 viable = 0; 2057 reason = arity_rejection (first_arg, i + remaining, len); 2058 } 2059 2060 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first 2061 parameter of type "reference to cv C" (including such a constructor 2062 instantiated from a template) is excluded from the set of candidate 2063 functions when used to construct an object of type D with an argument list 2064 containing a single argument if C is reference-related to D. */ 2065 if (viable && len == 1 && parmlist && DECL_CONSTRUCTOR_P (fn) 2066 && flag_new_inheriting_ctors 2067 && DECL_INHERITED_CTOR (fn)) 2068 { 2069 tree ptype = non_reference (TREE_VALUE (parmlist)); 2070 tree dtype = DECL_CONTEXT (fn); 2071 tree btype = DECL_INHERITED_CTOR_BASE (fn); 2072 if (reference_related_p (ptype, dtype) 2073 && reference_related_p (btype, ptype)) 2074 { 2075 viable = false; 2076 reason = inherited_ctor_rejection (); 2077 } 2078 } 2079 2080 /* Second, for a function to be viable, its constraints must be 2081 satisfied. */ 2082 if (flag_concepts && viable 2083 && !constraints_satisfied_p (fn)) 2084 { 2085 reason = constraint_failure (fn); 2086 viable = false; 2087 } 2088 2089 /* When looking for a function from a subobject from an implicit 2090 copy/move constructor/operator=, don't consider anything that takes (a 2091 reference to) an unrelated type. See c++/44909 and core 1092. */ 2092 if (viable && parmlist && (flags & LOOKUP_DEFAULTED)) 2093 { 2094 if (DECL_CONSTRUCTOR_P (fn)) 2095 i = 1; 2096 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 2097 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR)) 2098 i = 2; 2099 else 2100 i = 0; 2101 if (i && len == i) 2102 { 2103 parmnode = chain_index (i-1, parmlist); 2104 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 2105 ctype)) 2106 viable = 0; 2107 } 2108 2109 /* This only applies at the top level. */ 2110 flags &= ~LOOKUP_DEFAULTED; 2111 } 2112 2113 if (! viable) 2114 goto out; 2115 2116 /* Third, for F to be a viable function, there shall exist for each 2117 argument an implicit conversion sequence that converts that argument 2118 to the corresponding parameter of F. */ 2119 2120 parmnode = parmlist; 2121 2122 for (i = 0; i < len; ++i) 2123 { 2124 tree argtype, to_type; 2125 tree arg; 2126 conversion *t; 2127 int is_this; 2128 2129 if (parmnode == void_list_node) 2130 break; 2131 2132 if (i == 0 && first_arg != NULL_TREE) 2133 arg = first_arg; 2134 else 2135 arg = CONST_CAST_TREE ( 2136 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]); 2137 argtype = lvalue_type (arg); 2138 2139 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 2140 && ! DECL_CONSTRUCTOR_P (fn)); 2141 2142 if (parmnode) 2143 { 2144 tree parmtype = TREE_VALUE (parmnode); 2145 int lflags = flags; 2146 2147 parmnode = TREE_CHAIN (parmnode); 2148 2149 /* The type of the implicit object parameter ('this') for 2150 overload resolution is not always the same as for the 2151 function itself; conversion functions are considered to 2152 be members of the class being converted, and functions 2153 introduced by a using-declaration are considered to be 2154 members of the class that uses them. 2155 2156 Since build_over_call ignores the ICS for the `this' 2157 parameter, we can just change the parm type. */ 2158 if (ctype && is_this) 2159 { 2160 parmtype = cp_build_qualified_type 2161 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 2162 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn))) 2163 { 2164 /* If the function has a ref-qualifier, the implicit 2165 object parameter has reference type. */ 2166 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn)); 2167 parmtype = cp_build_reference_type (parmtype, rv); 2168 /* The special handling of 'this' conversions in compare_ics 2169 does not apply if there is a ref-qualifier. */ 2170 is_this = false; 2171 } 2172 else 2173 { 2174 parmtype = build_pointer_type (parmtype); 2175 /* We don't use build_this here because we don't want to 2176 capture the object argument until we've chosen a 2177 non-static member function. */ 2178 arg = build_address (arg); 2179 argtype = lvalue_type (arg); 2180 } 2181 } 2182 2183 /* Core issue 899: When [copy-]initializing a temporary to be bound 2184 to the first parameter of a copy constructor (12.8) called with 2185 a single argument in the context of direct-initialization, 2186 explicit conversion functions are also considered. 2187 2188 So set LOOKUP_COPY_PARM to let reference_binding know that 2189 it's being called in that context. We generalize the above 2190 to handle move constructors and template constructors as well; 2191 the standardese should soon be updated similarly. */ 2192 if (ctype && i == 0 && (len-skip == 1) 2193 && DECL_CONSTRUCTOR_P (fn) 2194 && parmtype != error_mark_node 2195 && (same_type_ignoring_top_level_qualifiers_p 2196 (non_reference (parmtype), ctype))) 2197 { 2198 if (!(flags & LOOKUP_ONLYCONVERTING)) 2199 lflags |= LOOKUP_COPY_PARM; 2200 /* We allow user-defined conversions within init-lists, but 2201 don't list-initialize the copy parm, as that would mean 2202 using two levels of braces for the same type. */ 2203 if ((flags & LOOKUP_LIST_INIT_CTOR) 2204 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 2205 lflags |= LOOKUP_NO_CONVERSION; 2206 } 2207 else 2208 lflags |= LOOKUP_ONLYCONVERTING; 2209 2210 t = implicit_conversion (parmtype, argtype, arg, 2211 /*c_cast_p=*/false, lflags, complain); 2212 to_type = parmtype; 2213 } 2214 else 2215 { 2216 t = build_identity_conv (argtype, arg); 2217 t->ellipsis_p = true; 2218 to_type = argtype; 2219 } 2220 2221 if (t && is_this) 2222 t->this_p = true; 2223 2224 convs[i] = t; 2225 if (! t) 2226 { 2227 viable = 0; 2228 reason = arg_conversion_rejection (first_arg, i, argtype, to_type); 2229 break; 2230 } 2231 2232 if (t->bad_p) 2233 { 2234 viable = -1; 2235 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type); 2236 } 2237 } 2238 2239 out: 2240 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2241 access_path, conversion_path, viable, reason, flags); 2242 } 2243 2244 /* Create an overload candidate for the conversion function FN which will 2245 be invoked for expression OBJ, producing a pointer-to-function which 2246 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2247 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2248 passed on to implicit_conversion. 2249 2250 Actually, we don't really care about FN; we care about the type it 2251 converts to. There may be multiple conversion functions that will 2252 convert to that type, and we rely on build_user_type_conversion_1 to 2253 choose the best one; so when we create our candidate, we record the type 2254 instead of the function. */ 2255 2256 static struct z_candidate * 2257 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2258 const vec<tree, va_gc> *arglist, 2259 tree access_path, tree conversion_path, 2260 tsubst_flags_t complain) 2261 { 2262 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2263 int i, len, viable, flags; 2264 tree parmlist, parmnode; 2265 conversion **convs; 2266 struct rejection_reason *reason; 2267 2268 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2269 parmlist = TREE_TYPE (parmlist); 2270 parmlist = TYPE_ARG_TYPES (parmlist); 2271 2272 len = vec_safe_length (arglist) + 1; 2273 convs = alloc_conversions (len); 2274 parmnode = parmlist; 2275 viable = 1; 2276 flags = LOOKUP_IMPLICIT; 2277 reason = NULL; 2278 2279 /* Don't bother looking up the same type twice. */ 2280 if (*candidates && (*candidates)->fn == totype) 2281 return NULL; 2282 2283 for (i = 0; i < len; ++i) 2284 { 2285 tree arg, argtype, convert_type = NULL_TREE; 2286 conversion *t; 2287 2288 if (i == 0) 2289 arg = obj; 2290 else 2291 arg = (*arglist)[i - 1]; 2292 argtype = lvalue_type (arg); 2293 2294 if (i == 0) 2295 { 2296 t = build_identity_conv (argtype, NULL_TREE); 2297 t = build_conv (ck_user, totype, t); 2298 /* Leave the 'cand' field null; we'll figure out the conversion in 2299 convert_like_real if this candidate is chosen. */ 2300 convert_type = totype; 2301 } 2302 else if (parmnode == void_list_node) 2303 break; 2304 else if (parmnode) 2305 { 2306 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2307 /*c_cast_p=*/false, flags, complain); 2308 convert_type = TREE_VALUE (parmnode); 2309 } 2310 else 2311 { 2312 t = build_identity_conv (argtype, arg); 2313 t->ellipsis_p = true; 2314 convert_type = argtype; 2315 } 2316 2317 convs[i] = t; 2318 if (! t) 2319 break; 2320 2321 if (t->bad_p) 2322 { 2323 viable = -1; 2324 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type); 2325 } 2326 2327 if (i == 0) 2328 continue; 2329 2330 if (parmnode) 2331 parmnode = TREE_CHAIN (parmnode); 2332 } 2333 2334 if (i < len 2335 || ! sufficient_parms_p (parmnode)) 2336 { 2337 int remaining = remaining_arguments (parmnode); 2338 viable = 0; 2339 reason = arity_rejection (NULL_TREE, i + remaining, len); 2340 } 2341 2342 return add_candidate (candidates, totype, obj, arglist, len, convs, 2343 access_path, conversion_path, viable, reason, flags); 2344 } 2345 2346 static void 2347 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2348 tree type1, tree type2, tree *args, tree *argtypes, 2349 int flags, tsubst_flags_t complain) 2350 { 2351 conversion *t; 2352 conversion **convs; 2353 size_t num_convs; 2354 int viable = 1, i; 2355 tree types[2]; 2356 struct rejection_reason *reason = NULL; 2357 2358 types[0] = type1; 2359 types[1] = type2; 2360 2361 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2362 convs = alloc_conversions (num_convs); 2363 2364 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2365 conversion ops are allowed. We handle that here by just checking for 2366 boolean_type_node because other operators don't ask for it. COND_EXPR 2367 also does contextual conversion to bool for the first operand, but we 2368 handle that in build_conditional_expr, and type1 here is operand 2. */ 2369 if (type1 != boolean_type_node) 2370 flags |= LOOKUP_ONLYCONVERTING; 2371 2372 for (i = 0; i < 2; ++i) 2373 { 2374 if (! args[i]) 2375 break; 2376 2377 t = implicit_conversion (types[i], argtypes[i], args[i], 2378 /*c_cast_p=*/false, flags, complain); 2379 if (! t) 2380 { 2381 viable = 0; 2382 /* We need something for printing the candidate. */ 2383 t = build_identity_conv (types[i], NULL_TREE); 2384 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], 2385 types[i]); 2386 } 2387 else if (t->bad_p) 2388 { 2389 viable = 0; 2390 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i], 2391 types[i]); 2392 } 2393 convs[i] = t; 2394 } 2395 2396 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2397 if (args[2]) 2398 { 2399 convs[2] = convs[1]; 2400 convs[1] = convs[0]; 2401 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2402 /*c_cast_p=*/false, flags, 2403 complain); 2404 if (t) 2405 convs[0] = t; 2406 else 2407 { 2408 viable = 0; 2409 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2410 boolean_type_node); 2411 } 2412 } 2413 2414 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2415 num_convs, convs, 2416 /*access_path=*/NULL_TREE, 2417 /*conversion_path=*/NULL_TREE, 2418 viable, reason, flags); 2419 } 2420 2421 static bool 2422 is_complete (tree t) 2423 { 2424 return COMPLETE_TYPE_P (complete_type (t)); 2425 } 2426 2427 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2428 2429 static bool 2430 promoted_arithmetic_type_p (tree type) 2431 { 2432 /* [over.built] 2433 2434 In this section, the term promoted integral type is used to refer 2435 to those integral types which are preserved by integral promotion 2436 (including e.g. int and long but excluding e.g. char). 2437 Similarly, the term promoted arithmetic type refers to promoted 2438 integral types plus floating types. */ 2439 return ((CP_INTEGRAL_TYPE_P (type) 2440 && same_type_p (type_promotes_to (type), type)) 2441 || TREE_CODE (type) == REAL_TYPE); 2442 } 2443 2444 /* Create any builtin operator overload candidates for the operator in 2445 question given the converted operand types TYPE1 and TYPE2. The other 2446 args are passed through from add_builtin_candidates to 2447 build_builtin_candidate. 2448 2449 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2450 If CODE is requires candidates operands of the same type of the kind 2451 of which TYPE1 and TYPE2 are, we add both candidates 2452 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2453 2454 static void 2455 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2456 enum tree_code code2, tree fnname, tree type1, 2457 tree type2, tree *args, tree *argtypes, int flags, 2458 tsubst_flags_t complain) 2459 { 2460 switch (code) 2461 { 2462 case POSTINCREMENT_EXPR: 2463 case POSTDECREMENT_EXPR: 2464 args[1] = integer_zero_node; 2465 type2 = integer_type_node; 2466 break; 2467 default: 2468 break; 2469 } 2470 2471 switch (code) 2472 { 2473 2474 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2475 and VQ is either volatile or empty, there exist candidate operator 2476 functions of the form 2477 VQ T& operator++(VQ T&); 2478 T operator++(VQ T&, int); 2479 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2480 type other than bool, and VQ is either volatile or empty, there exist 2481 candidate operator functions of the form 2482 VQ T& operator--(VQ T&); 2483 T operator--(VQ T&, int); 2484 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2485 complete object type, and VQ is either volatile or empty, there exist 2486 candidate operator functions of the form 2487 T*VQ& operator++(T*VQ&); 2488 T*VQ& operator--(T*VQ&); 2489 T* operator++(T*VQ&, int); 2490 T* operator--(T*VQ&, int); */ 2491 2492 case POSTDECREMENT_EXPR: 2493 case PREDECREMENT_EXPR: 2494 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2495 return; 2496 /* FALLTHRU */ 2497 case POSTINCREMENT_EXPR: 2498 case PREINCREMENT_EXPR: 2499 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2500 { 2501 type1 = build_reference_type (type1); 2502 break; 2503 } 2504 return; 2505 2506 /* 7 For every cv-qualified or cv-unqualified object type T, there 2507 exist candidate operator functions of the form 2508 2509 T& operator*(T*); 2510 2511 8 For every function type T, there exist candidate operator functions of 2512 the form 2513 T& operator*(T*); */ 2514 2515 case INDIRECT_REF: 2516 if (TYPE_PTR_P (type1) 2517 && (TYPE_PTROB_P (type1) 2518 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2519 break; 2520 return; 2521 2522 /* 9 For every type T, there exist candidate operator functions of the form 2523 T* operator+(T*); 2524 2525 10For every promoted arithmetic type T, there exist candidate operator 2526 functions of the form 2527 T operator+(T); 2528 T operator-(T); */ 2529 2530 case UNARY_PLUS_EXPR: /* unary + */ 2531 if (TYPE_PTR_P (type1)) 2532 break; 2533 /* FALLTHRU */ 2534 case NEGATE_EXPR: 2535 if (ARITHMETIC_TYPE_P (type1)) 2536 break; 2537 return; 2538 2539 /* 11For every promoted integral type T, there exist candidate operator 2540 functions of the form 2541 T operator~(T); */ 2542 2543 case BIT_NOT_EXPR: 2544 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2545 break; 2546 return; 2547 2548 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2549 is the same type as C2 or is a derived class of C2, T is a complete 2550 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2551 there exist candidate operator functions of the form 2552 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2553 where CV12 is the union of CV1 and CV2. */ 2554 2555 case MEMBER_REF: 2556 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2)) 2557 { 2558 tree c1 = TREE_TYPE (type1); 2559 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2560 2561 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2562 && (TYPE_PTRMEMFUNC_P (type2) 2563 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2564 break; 2565 } 2566 return; 2567 2568 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2569 didate operator functions of the form 2570 LR operator*(L, R); 2571 LR operator/(L, R); 2572 LR operator+(L, R); 2573 LR operator-(L, R); 2574 bool operator<(L, R); 2575 bool operator>(L, R); 2576 bool operator<=(L, R); 2577 bool operator>=(L, R); 2578 bool operator==(L, R); 2579 bool operator!=(L, R); 2580 where LR is the result of the usual arithmetic conversions between 2581 types L and R. 2582 2583 14For every pair of types T and I, where T is a cv-qualified or cv- 2584 unqualified complete object type and I is a promoted integral type, 2585 there exist candidate operator functions of the form 2586 T* operator+(T*, I); 2587 T& operator[](T*, I); 2588 T* operator-(T*, I); 2589 T* operator+(I, T*); 2590 T& operator[](I, T*); 2591 2592 15For every T, where T is a pointer to complete object type, there exist 2593 candidate operator functions of the form112) 2594 ptrdiff_t operator-(T, T); 2595 2596 16For every pointer or enumeration type T, there exist candidate operator 2597 functions of the form 2598 bool operator<(T, T); 2599 bool operator>(T, T); 2600 bool operator<=(T, T); 2601 bool operator>=(T, T); 2602 bool operator==(T, T); 2603 bool operator!=(T, T); 2604 2605 17For every pointer to member type T, there exist candidate operator 2606 functions of the form 2607 bool operator==(T, T); 2608 bool operator!=(T, T); */ 2609 2610 case MINUS_EXPR: 2611 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2612 break; 2613 if (TYPE_PTROB_P (type1) 2614 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2615 { 2616 type2 = ptrdiff_type_node; 2617 break; 2618 } 2619 /* FALLTHRU */ 2620 case MULT_EXPR: 2621 case TRUNC_DIV_EXPR: 2622 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2623 break; 2624 return; 2625 2626 case EQ_EXPR: 2627 case NE_EXPR: 2628 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2629 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))) 2630 break; 2631 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1])) 2632 { 2633 type2 = type1; 2634 break; 2635 } 2636 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0])) 2637 { 2638 type1 = type2; 2639 break; 2640 } 2641 /* Fall through. */ 2642 case LT_EXPR: 2643 case GT_EXPR: 2644 case LE_EXPR: 2645 case GE_EXPR: 2646 case MAX_EXPR: 2647 case MIN_EXPR: 2648 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2649 break; 2650 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2651 break; 2652 if (TREE_CODE (type1) == ENUMERAL_TYPE 2653 && TREE_CODE (type2) == ENUMERAL_TYPE) 2654 break; 2655 if (TYPE_PTR_P (type1) 2656 && null_ptr_cst_p (args[1])) 2657 { 2658 type2 = type1; 2659 break; 2660 } 2661 if (null_ptr_cst_p (args[0]) 2662 && TYPE_PTR_P (type2)) 2663 { 2664 type1 = type2; 2665 break; 2666 } 2667 return; 2668 2669 case PLUS_EXPR: 2670 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2671 break; 2672 /* FALLTHRU */ 2673 case ARRAY_REF: 2674 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2675 { 2676 type1 = ptrdiff_type_node; 2677 break; 2678 } 2679 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2680 { 2681 type2 = ptrdiff_type_node; 2682 break; 2683 } 2684 return; 2685 2686 /* 18For every pair of promoted integral types L and R, there exist candi- 2687 date operator functions of the form 2688 LR operator%(L, R); 2689 LR operator&(L, R); 2690 LR operator^(L, R); 2691 LR operator|(L, R); 2692 L operator<<(L, R); 2693 L operator>>(L, R); 2694 where LR is the result of the usual arithmetic conversions between 2695 types L and R. */ 2696 2697 case TRUNC_MOD_EXPR: 2698 case BIT_AND_EXPR: 2699 case BIT_IOR_EXPR: 2700 case BIT_XOR_EXPR: 2701 case LSHIFT_EXPR: 2702 case RSHIFT_EXPR: 2703 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2704 break; 2705 return; 2706 2707 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2708 type, VQ is either volatile or empty, and R is a promoted arithmetic 2709 type, there exist candidate operator functions of the form 2710 VQ L& operator=(VQ L&, R); 2711 VQ L& operator*=(VQ L&, R); 2712 VQ L& operator/=(VQ L&, R); 2713 VQ L& operator+=(VQ L&, R); 2714 VQ L& operator-=(VQ L&, R); 2715 2716 20For every pair T, VQ), where T is any type and VQ is either volatile 2717 or empty, there exist candidate operator functions of the form 2718 T*VQ& operator=(T*VQ&, T*); 2719 2720 21For every pair T, VQ), where T is a pointer to member type and VQ is 2721 either volatile or empty, there exist candidate operator functions of 2722 the form 2723 VQ T& operator=(VQ T&, T); 2724 2725 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2726 unqualified complete object type, VQ is either volatile or empty, and 2727 I is a promoted integral type, there exist candidate operator func- 2728 tions of the form 2729 T*VQ& operator+=(T*VQ&, I); 2730 T*VQ& operator-=(T*VQ&, I); 2731 2732 23For every triple L, VQ, R), where L is an integral or enumeration 2733 type, VQ is either volatile or empty, and R is a promoted integral 2734 type, there exist candidate operator functions of the form 2735 2736 VQ L& operator%=(VQ L&, R); 2737 VQ L& operator<<=(VQ L&, R); 2738 VQ L& operator>>=(VQ L&, R); 2739 VQ L& operator&=(VQ L&, R); 2740 VQ L& operator^=(VQ L&, R); 2741 VQ L& operator|=(VQ L&, R); */ 2742 2743 case MODIFY_EXPR: 2744 switch (code2) 2745 { 2746 case PLUS_EXPR: 2747 case MINUS_EXPR: 2748 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2749 { 2750 type2 = ptrdiff_type_node; 2751 break; 2752 } 2753 /* FALLTHRU */ 2754 case MULT_EXPR: 2755 case TRUNC_DIV_EXPR: 2756 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2757 break; 2758 return; 2759 2760 case TRUNC_MOD_EXPR: 2761 case BIT_AND_EXPR: 2762 case BIT_IOR_EXPR: 2763 case BIT_XOR_EXPR: 2764 case LSHIFT_EXPR: 2765 case RSHIFT_EXPR: 2766 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2767 break; 2768 return; 2769 2770 case NOP_EXPR: 2771 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2772 break; 2773 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2774 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2775 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2776 || ((TYPE_PTRMEMFUNC_P (type1) 2777 || TYPE_PTR_P (type1)) 2778 && null_ptr_cst_p (args[1]))) 2779 { 2780 type2 = type1; 2781 break; 2782 } 2783 return; 2784 2785 default: 2786 gcc_unreachable (); 2787 } 2788 type1 = build_reference_type (type1); 2789 break; 2790 2791 case COND_EXPR: 2792 /* [over.built] 2793 2794 For every pair of promoted arithmetic types L and R, there 2795 exist candidate operator functions of the form 2796 2797 LR operator?(bool, L, R); 2798 2799 where LR is the result of the usual arithmetic conversions 2800 between types L and R. 2801 2802 For every type T, where T is a pointer or pointer-to-member 2803 type, there exist candidate operator functions of the form T 2804 operator?(bool, T, T); */ 2805 2806 if (promoted_arithmetic_type_p (type1) 2807 && promoted_arithmetic_type_p (type2)) 2808 /* That's OK. */ 2809 break; 2810 2811 /* Otherwise, the types should be pointers. */ 2812 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2)) 2813 return; 2814 2815 /* We don't check that the two types are the same; the logic 2816 below will actually create two candidates; one in which both 2817 parameter types are TYPE1, and one in which both parameter 2818 types are TYPE2. */ 2819 break; 2820 2821 case REALPART_EXPR: 2822 case IMAGPART_EXPR: 2823 if (ARITHMETIC_TYPE_P (type1)) 2824 break; 2825 return; 2826 2827 default: 2828 gcc_unreachable (); 2829 } 2830 2831 /* Make sure we don't create builtin candidates with dependent types. */ 2832 bool u1 = uses_template_parms (type1); 2833 bool u2 = type2 ? uses_template_parms (type2) : false; 2834 if (u1 || u2) 2835 { 2836 /* Try to recover if one of the types is non-dependent. But if 2837 there's only one type, there's nothing we can do. */ 2838 if (!type2) 2839 return; 2840 /* And we lose if both are dependent. */ 2841 if (u1 && u2) 2842 return; 2843 /* Or if they have different forms. */ 2844 if (TREE_CODE (type1) != TREE_CODE (type2)) 2845 return; 2846 2847 if (u1 && !u2) 2848 type1 = type2; 2849 else if (u2 && !u1) 2850 type2 = type1; 2851 } 2852 2853 /* If we're dealing with two pointer types or two enumeral types, 2854 we need candidates for both of them. */ 2855 if (type2 && !same_type_p (type1, type2) 2856 && TREE_CODE (type1) == TREE_CODE (type2) 2857 && (TREE_CODE (type1) == REFERENCE_TYPE 2858 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2859 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2860 || TYPE_PTRMEMFUNC_P (type1) 2861 || MAYBE_CLASS_TYPE_P (type1) 2862 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2863 { 2864 if (TYPE_PTR_OR_PTRMEM_P (type1)) 2865 { 2866 tree cptype = composite_pointer_type (type1, type2, 2867 error_mark_node, 2868 error_mark_node, 2869 CPO_CONVERSION, 2870 tf_none); 2871 if (cptype != error_mark_node) 2872 { 2873 build_builtin_candidate 2874 (candidates, fnname, cptype, cptype, args, argtypes, 2875 flags, complain); 2876 return; 2877 } 2878 } 2879 2880 build_builtin_candidate 2881 (candidates, fnname, type1, type1, args, argtypes, flags, complain); 2882 build_builtin_candidate 2883 (candidates, fnname, type2, type2, args, argtypes, flags, complain); 2884 return; 2885 } 2886 2887 build_builtin_candidate 2888 (candidates, fnname, type1, type2, args, argtypes, flags, complain); 2889 } 2890 2891 tree 2892 type_decays_to (tree type) 2893 { 2894 if (TREE_CODE (type) == ARRAY_TYPE) 2895 return build_pointer_type (TREE_TYPE (type)); 2896 if (TREE_CODE (type) == FUNCTION_TYPE) 2897 return build_pointer_type (type); 2898 return type; 2899 } 2900 2901 /* There are three conditions of builtin candidates: 2902 2903 1) bool-taking candidates. These are the same regardless of the input. 2904 2) pointer-pair taking candidates. These are generated for each type 2905 one of the input types converts to. 2906 3) arithmetic candidates. According to the standard, we should generate 2907 all of these, but I'm trying not to... 2908 2909 Here we generate a superset of the possible candidates for this particular 2910 case. That is a subset of the full set the standard defines, plus some 2911 other cases which the standard disallows. add_builtin_candidate will 2912 filter out the invalid set. */ 2913 2914 static void 2915 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2916 enum tree_code code2, tree fnname, tree *args, 2917 int flags, tsubst_flags_t complain) 2918 { 2919 int ref1, i; 2920 int enum_p = 0; 2921 tree type, argtypes[3], t; 2922 /* TYPES[i] is the set of possible builtin-operator parameter types 2923 we will consider for the Ith argument. */ 2924 vec<tree, va_gc> *types[2]; 2925 unsigned ix; 2926 2927 for (i = 0; i < 3; ++i) 2928 { 2929 if (args[i]) 2930 argtypes[i] = unlowered_expr_type (args[i]); 2931 else 2932 argtypes[i] = NULL_TREE; 2933 } 2934 2935 switch (code) 2936 { 2937 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2938 and VQ is either volatile or empty, there exist candidate operator 2939 functions of the form 2940 VQ T& operator++(VQ T&); */ 2941 2942 case POSTINCREMENT_EXPR: 2943 case PREINCREMENT_EXPR: 2944 case POSTDECREMENT_EXPR: 2945 case PREDECREMENT_EXPR: 2946 case MODIFY_EXPR: 2947 ref1 = 1; 2948 break; 2949 2950 /* 24There also exist candidate operator functions of the form 2951 bool operator!(bool); 2952 bool operator&&(bool, bool); 2953 bool operator||(bool, bool); */ 2954 2955 case TRUTH_NOT_EXPR: 2956 build_builtin_candidate 2957 (candidates, fnname, boolean_type_node, 2958 NULL_TREE, args, argtypes, flags, complain); 2959 return; 2960 2961 case TRUTH_ORIF_EXPR: 2962 case TRUTH_ANDIF_EXPR: 2963 build_builtin_candidate 2964 (candidates, fnname, boolean_type_node, 2965 boolean_type_node, args, argtypes, flags, complain); 2966 return; 2967 2968 case ADDR_EXPR: 2969 case COMPOUND_EXPR: 2970 case COMPONENT_REF: 2971 return; 2972 2973 case COND_EXPR: 2974 case EQ_EXPR: 2975 case NE_EXPR: 2976 case LT_EXPR: 2977 case LE_EXPR: 2978 case GT_EXPR: 2979 case GE_EXPR: 2980 enum_p = 1; 2981 /* Fall through. */ 2982 2983 default: 2984 ref1 = 0; 2985 } 2986 2987 types[0] = make_tree_vector (); 2988 types[1] = make_tree_vector (); 2989 2990 for (i = 0; i < 2; ++i) 2991 { 2992 if (! args[i]) 2993 ; 2994 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2995 { 2996 tree convs; 2997 2998 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2999 return; 3000 3001 convs = lookup_conversions (argtypes[i]); 3002 3003 if (code == COND_EXPR) 3004 { 3005 if (lvalue_p (args[i])) 3006 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3007 3008 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i])); 3009 } 3010 3011 else if (! convs) 3012 return; 3013 3014 for (; convs; convs = TREE_CHAIN (convs)) 3015 { 3016 type = TREE_TYPE (convs); 3017 3018 if (i == 0 && ref1 3019 && (TREE_CODE (type) != REFERENCE_TYPE 3020 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 3021 continue; 3022 3023 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 3024 vec_safe_push (types[i], type); 3025 3026 type = non_reference (type); 3027 if (i != 0 || ! ref1) 3028 { 3029 type = cv_unqualified (type_decays_to (type)); 3030 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 3031 vec_safe_push (types[i], type); 3032 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3033 type = type_promotes_to (type); 3034 } 3035 3036 if (! vec_member (type, types[i])) 3037 vec_safe_push (types[i], type); 3038 } 3039 } 3040 else 3041 { 3042 if (code == COND_EXPR && lvalue_p (args[i])) 3043 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3044 type = non_reference (argtypes[i]); 3045 if (i != 0 || ! ref1) 3046 { 3047 type = cv_unqualified (type_decays_to (type)); 3048 if (enum_p && UNSCOPED_ENUM_P (type)) 3049 vec_safe_push (types[i], type); 3050 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3051 type = type_promotes_to (type); 3052 } 3053 vec_safe_push (types[i], type); 3054 } 3055 } 3056 3057 /* Run through the possible parameter types of both arguments, 3058 creating candidates with those parameter types. */ 3059 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t) 3060 { 3061 unsigned jx; 3062 tree u; 3063 3064 if (!types[1]->is_empty ()) 3065 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u) 3066 add_builtin_candidate 3067 (candidates, code, code2, fnname, t, 3068 u, args, argtypes, flags, complain); 3069 else 3070 add_builtin_candidate 3071 (candidates, code, code2, fnname, t, 3072 NULL_TREE, args, argtypes, flags, complain); 3073 } 3074 3075 release_tree_vector (types[0]); 3076 release_tree_vector (types[1]); 3077 } 3078 3079 3080 /* If TMPL can be successfully instantiated as indicated by 3081 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 3082 3083 TMPL is the template. EXPLICIT_TARGS are any explicit template 3084 arguments. ARGLIST is the arguments provided at the call-site. 3085 This does not change ARGLIST. The RETURN_TYPE is the desired type 3086 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 3087 as for add_function_candidate. If an OBJ is supplied, FLAGS and 3088 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 3089 3090 static struct z_candidate* 3091 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 3092 tree ctype, tree explicit_targs, tree first_arg, 3093 const vec<tree, va_gc> *arglist, tree return_type, 3094 tree access_path, tree conversion_path, 3095 int flags, tree obj, unification_kind_t strict, 3096 tsubst_flags_t complain) 3097 { 3098 int ntparms = DECL_NTPARMS (tmpl); 3099 tree targs = make_tree_vec (ntparms); 3100 unsigned int len = vec_safe_length (arglist); 3101 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 3102 unsigned int skip_without_in_chrg = 0; 3103 tree first_arg_without_in_chrg = first_arg; 3104 tree *args_without_in_chrg; 3105 unsigned int nargs_without_in_chrg; 3106 unsigned int ia, ix; 3107 tree arg; 3108 struct z_candidate *cand; 3109 tree fn; 3110 struct rejection_reason *reason = NULL; 3111 int errs; 3112 3113 /* We don't do deduction on the in-charge parameter, the VTT 3114 parameter or 'this'. */ 3115 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 3116 { 3117 if (first_arg_without_in_chrg != NULL_TREE) 3118 first_arg_without_in_chrg = NULL_TREE; 3119 else if (return_type && strict == DEDUCE_CALL) 3120 /* We're deducing for a call to the result of a template conversion 3121 function, so the args don't contain 'this'; leave them alone. */; 3122 else 3123 ++skip_without_in_chrg; 3124 } 3125 3126 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 3127 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 3128 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 3129 { 3130 if (first_arg_without_in_chrg != NULL_TREE) 3131 first_arg_without_in_chrg = NULL_TREE; 3132 else 3133 ++skip_without_in_chrg; 3134 } 3135 3136 if (len < skip_without_in_chrg) 3137 return NULL; 3138 3139 if (DECL_CONSTRUCTOR_P (tmpl) && nargs == 2 3140 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (first_arg), 3141 TREE_TYPE ((*arglist)[0]))) 3142 { 3143 /* 12.8/6 says, "A declaration of a constructor for a class X is 3144 ill-formed if its first parameter is of type (optionally cv-qualified) 3145 X and either there are no other parameters or else all other 3146 parameters have default arguments. A member function template is never 3147 instantiated to produce such a constructor signature." 3148 3149 So if we're trying to copy an object of the containing class, don't 3150 consider a template constructor that has a first parameter type that 3151 is just a template parameter, as we would deduce a signature that we 3152 would then reject in the code below. */ 3153 if (tree firstparm = FUNCTION_FIRST_USER_PARMTYPE (tmpl)) 3154 { 3155 firstparm = TREE_VALUE (firstparm); 3156 if (PACK_EXPANSION_P (firstparm)) 3157 firstparm = PACK_EXPANSION_PATTERN (firstparm); 3158 if (TREE_CODE (firstparm) == TEMPLATE_TYPE_PARM) 3159 { 3160 gcc_assert (!explicit_targs); 3161 reason = invalid_copy_with_fn_template_rejection (); 3162 goto fail; 3163 } 3164 } 3165 } 3166 3167 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 3168 + (len - skip_without_in_chrg)); 3169 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 3170 ia = 0; 3171 if (first_arg_without_in_chrg != NULL_TREE) 3172 { 3173 args_without_in_chrg[ia] = first_arg_without_in_chrg; 3174 ++ia; 3175 } 3176 for (ix = skip_without_in_chrg; 3177 vec_safe_iterate (arglist, ix, &arg); 3178 ++ix) 3179 { 3180 args_without_in_chrg[ia] = arg; 3181 ++ia; 3182 } 3183 gcc_assert (ia == nargs_without_in_chrg); 3184 3185 errs = errorcount+sorrycount; 3186 fn = fn_type_unification (tmpl, explicit_targs, targs, 3187 args_without_in_chrg, 3188 nargs_without_in_chrg, 3189 return_type, strict, flags, false, 3190 complain & tf_decltype); 3191 3192 if (fn == error_mark_node) 3193 { 3194 /* Don't repeat unification later if it already resulted in errors. */ 3195 if (errorcount+sorrycount == errs) 3196 reason = template_unification_rejection (tmpl, explicit_targs, 3197 targs, args_without_in_chrg, 3198 nargs_without_in_chrg, 3199 return_type, strict, flags); 3200 else 3201 reason = template_unification_error_rejection (); 3202 goto fail; 3203 } 3204 3205 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 3206 { 3207 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 3208 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 3209 ctype)) 3210 { 3211 /* We're trying to produce a constructor with a prohibited signature, 3212 as discussed above; handle here any cases we didn't catch then, 3213 such as X(X<T>). */ 3214 reason = invalid_copy_with_fn_template_rejection (); 3215 goto fail; 3216 } 3217 } 3218 3219 if (obj != NULL_TREE) 3220 /* Aha, this is a conversion function. */ 3221 cand = add_conv_candidate (candidates, fn, obj, arglist, 3222 access_path, conversion_path, complain); 3223 else 3224 cand = add_function_candidate (candidates, fn, ctype, 3225 first_arg, arglist, access_path, 3226 conversion_path, flags, complain); 3227 if (DECL_TI_TEMPLATE (fn) != tmpl) 3228 /* This situation can occur if a member template of a template 3229 class is specialized. Then, instantiate_template might return 3230 an instantiation of the specialization, in which case the 3231 DECL_TI_TEMPLATE field will point at the original 3232 specialization. For example: 3233 3234 template <class T> struct S { template <class U> void f(U); 3235 template <> void f(int) {}; }; 3236 S<double> sd; 3237 sd.f(3); 3238 3239 Here, TMPL will be template <class U> S<double>::f(U). 3240 And, instantiate template will give us the specialization 3241 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 3242 for this will point at template <class T> template <> S<T>::f(int), 3243 so that we can find the definition. For the purposes of 3244 overload resolution, however, we want the original TMPL. */ 3245 cand->template_decl = build_template_info (tmpl, targs); 3246 else 3247 cand->template_decl = DECL_TEMPLATE_INFO (fn); 3248 cand->explicit_targs = explicit_targs; 3249 3250 return cand; 3251 fail: 3252 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 3253 access_path, conversion_path, 0, reason, flags); 3254 } 3255 3256 3257 static struct z_candidate * 3258 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 3259 tree explicit_targs, tree first_arg, 3260 const vec<tree, va_gc> *arglist, tree return_type, 3261 tree access_path, tree conversion_path, int flags, 3262 unification_kind_t strict, tsubst_flags_t complain) 3263 { 3264 return 3265 add_template_candidate_real (candidates, tmpl, ctype, 3266 explicit_targs, first_arg, arglist, 3267 return_type, access_path, conversion_path, 3268 flags, NULL_TREE, strict, complain); 3269 } 3270 3271 /* Create an overload candidate for the conversion function template TMPL, 3272 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a 3273 pointer-to-function which will in turn be called with the argument list 3274 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 3275 passed on to implicit_conversion. */ 3276 3277 static struct z_candidate * 3278 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3279 tree obj, 3280 const vec<tree, va_gc> *arglist, 3281 tree return_type, tree access_path, 3282 tree conversion_path, tsubst_flags_t complain) 3283 { 3284 /* Making this work broke PR 71117 and 85118, so until the committee resolves 3285 core issue 2189, let's disable this candidate if there are any call 3286 operators. */ 3287 if (*candidates) 3288 return NULL; 3289 3290 return 3291 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3292 NULL_TREE, arglist, return_type, access_path, 3293 conversion_path, 0, obj, DEDUCE_CALL, 3294 complain); 3295 } 3296 3297 /* The CANDS are the set of candidates that were considered for 3298 overload resolution. Return the set of viable candidates, or CANDS 3299 if none are viable. If any of the candidates were viable, set 3300 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3301 considered viable only if it is strictly viable. */ 3302 3303 static struct z_candidate* 3304 splice_viable (struct z_candidate *cands, 3305 bool strict_p, 3306 bool *any_viable_p) 3307 { 3308 struct z_candidate *viable; 3309 struct z_candidate **last_viable; 3310 struct z_candidate **cand; 3311 bool found_strictly_viable = false; 3312 3313 /* Be strict inside templates, since build_over_call won't actually 3314 do the conversions to get pedwarns. */ 3315 if (processing_template_decl) 3316 strict_p = true; 3317 3318 viable = NULL; 3319 last_viable = &viable; 3320 *any_viable_p = false; 3321 3322 cand = &cands; 3323 while (*cand) 3324 { 3325 struct z_candidate *c = *cand; 3326 if (!strict_p 3327 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL)) 3328 { 3329 /* Be strict in the presence of a viable candidate. Also if 3330 there are template candidates, so that we get deduction errors 3331 for them instead of silently preferring a bad conversion. */ 3332 strict_p = true; 3333 if (viable && !found_strictly_viable) 3334 { 3335 /* Put any spliced near matches back onto the main list so 3336 that we see them if there is no strict match. */ 3337 *any_viable_p = false; 3338 *last_viable = cands; 3339 cands = viable; 3340 viable = NULL; 3341 last_viable = &viable; 3342 } 3343 } 3344 3345 if (strict_p ? c->viable == 1 : c->viable) 3346 { 3347 *last_viable = c; 3348 *cand = c->next; 3349 c->next = NULL; 3350 last_viable = &c->next; 3351 *any_viable_p = true; 3352 if (c->viable == 1) 3353 found_strictly_viable = true; 3354 } 3355 else 3356 cand = &c->next; 3357 } 3358 3359 return viable ? viable : cands; 3360 } 3361 3362 static bool 3363 any_strictly_viable (struct z_candidate *cands) 3364 { 3365 for (; cands; cands = cands->next) 3366 if (cands->viable == 1) 3367 return true; 3368 return false; 3369 } 3370 3371 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3372 words, it is about to become the "this" pointer for a member 3373 function call. Take the address of the object. */ 3374 3375 static tree 3376 build_this (tree obj) 3377 { 3378 /* In a template, we are only concerned about the type of the 3379 expression, so we can take a shortcut. */ 3380 if (processing_template_decl) 3381 return build_address (obj); 3382 3383 return cp_build_addr_expr (obj, tf_warning_or_error); 3384 } 3385 3386 /* Returns true iff functions are equivalent. Equivalent functions are 3387 not '==' only if one is a function-local extern function or if 3388 both are extern "C". */ 3389 3390 static inline int 3391 equal_functions (tree fn1, tree fn2) 3392 { 3393 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3394 return 0; 3395 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3396 return fn1 == fn2; 3397 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3398 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3399 return decls_match (fn1, fn2); 3400 return fn1 == fn2; 3401 } 3402 3403 /* Print information about a candidate being rejected due to INFO. */ 3404 3405 static void 3406 print_conversion_rejection (location_t loc, struct conversion_info *info) 3407 { 3408 tree from = info->from; 3409 if (!TYPE_P (from)) 3410 from = lvalue_type (from); 3411 if (info->n_arg == -1) 3412 { 3413 /* Conversion of implicit `this' argument failed. */ 3414 if (!TYPE_P (info->from)) 3415 /* A bad conversion for 'this' must be discarding cv-quals. */ 3416 inform (loc, " passing %qT as %<this%> " 3417 "argument discards qualifiers", 3418 from); 3419 else 3420 inform (loc, " no known conversion for implicit " 3421 "%<this%> parameter from %qH to %qI", 3422 from, info->to_type); 3423 } 3424 else if (!TYPE_P (info->from)) 3425 { 3426 if (info->n_arg >= 0) 3427 inform (loc, " conversion of argument %d would be ill-formed:", 3428 info->n_arg + 1); 3429 perform_implicit_conversion (info->to_type, info->from, 3430 tf_warning_or_error); 3431 } 3432 else if (info->n_arg == -2) 3433 /* Conversion of conversion function return value failed. */ 3434 inform (loc, " no known conversion from %qH to %qI", 3435 from, info->to_type); 3436 else 3437 inform (loc, " no known conversion for argument %d from %qH to %qI", 3438 info->n_arg + 1, from, info->to_type); 3439 } 3440 3441 /* Print information about a candidate with WANT parameters and we found 3442 HAVE. */ 3443 3444 static void 3445 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3446 { 3447 inform_n (loc, want, 3448 " candidate expects %d argument, %d provided", 3449 " candidate expects %d arguments, %d provided", 3450 want, have); 3451 } 3452 3453 /* Print information about one overload candidate CANDIDATE. MSGSTR 3454 is the text to print before the candidate itself. 3455 3456 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3457 to have been run through gettext by the caller. This wart makes 3458 life simpler in print_z_candidates and for the translators. */ 3459 3460 static void 3461 print_z_candidate (location_t loc, const char *msgstr, 3462 struct z_candidate *candidate) 3463 { 3464 const char *msg = (msgstr == NULL 3465 ? "" 3466 : ACONCAT ((msgstr, " ", NULL))); 3467 tree fn = candidate->fn; 3468 if (flag_new_inheriting_ctors) 3469 fn = strip_inheriting_ctors (fn); 3470 location_t cloc = location_of (fn); 3471 3472 if (identifier_p (fn)) 3473 { 3474 cloc = loc; 3475 if (candidate->num_convs == 3) 3476 inform (cloc, "%s%<%D(%T, %T, %T)%> <built-in>", msg, fn, 3477 candidate->convs[0]->type, 3478 candidate->convs[1]->type, 3479 candidate->convs[2]->type); 3480 else if (candidate->num_convs == 2) 3481 inform (cloc, "%s%<%D(%T, %T)%> <built-in>", msg, fn, 3482 candidate->convs[0]->type, 3483 candidate->convs[1]->type); 3484 else 3485 inform (cloc, "%s%<%D(%T)%> <built-in>", msg, fn, 3486 candidate->convs[0]->type); 3487 } 3488 else if (TYPE_P (fn)) 3489 inform (cloc, "%s%qT <conversion>", msg, fn); 3490 else if (candidate->viable == -1) 3491 inform (cloc, "%s%#qD <near match>", msg, fn); 3492 else if (DECL_DELETED_FN (fn)) 3493 inform (cloc, "%s%#qD <deleted>", msg, fn); 3494 else 3495 inform (cloc, "%s%#qD", msg, fn); 3496 if (fn != candidate->fn) 3497 { 3498 cloc = location_of (candidate->fn); 3499 inform (cloc, " inherited here"); 3500 } 3501 /* Give the user some information about why this candidate failed. */ 3502 if (candidate->reason != NULL) 3503 { 3504 struct rejection_reason *r = candidate->reason; 3505 3506 switch (r->code) 3507 { 3508 case rr_arity: 3509 print_arity_information (cloc, r->u.arity.actual, 3510 r->u.arity.expected); 3511 break; 3512 case rr_arg_conversion: 3513 print_conversion_rejection (cloc, &r->u.conversion); 3514 break; 3515 case rr_bad_arg_conversion: 3516 print_conversion_rejection (cloc, &r->u.bad_conversion); 3517 break; 3518 case rr_explicit_conversion: 3519 inform (cloc, " return type %qT of explicit conversion function " 3520 "cannot be converted to %qT with a qualification " 3521 "conversion", r->u.conversion.from, 3522 r->u.conversion.to_type); 3523 break; 3524 case rr_template_conversion: 3525 inform (cloc, " conversion from return type %qT of template " 3526 "conversion function specialization to %qT is not an " 3527 "exact match", r->u.conversion.from, 3528 r->u.conversion.to_type); 3529 break; 3530 case rr_template_unification: 3531 /* We use template_unification_error_rejection if unification caused 3532 actual non-SFINAE errors, in which case we don't need to repeat 3533 them here. */ 3534 if (r->u.template_unification.tmpl == NULL_TREE) 3535 { 3536 inform (cloc, " substitution of deduced template arguments " 3537 "resulted in errors seen above"); 3538 break; 3539 } 3540 /* Re-run template unification with diagnostics. */ 3541 inform (cloc, " template argument deduction/substitution failed:"); 3542 fn_type_unification (r->u.template_unification.tmpl, 3543 r->u.template_unification.explicit_targs, 3544 (make_tree_vec 3545 (r->u.template_unification.num_targs)), 3546 r->u.template_unification.args, 3547 r->u.template_unification.nargs, 3548 r->u.template_unification.return_type, 3549 r->u.template_unification.strict, 3550 r->u.template_unification.flags, 3551 true, false); 3552 break; 3553 case rr_invalid_copy: 3554 inform (cloc, 3555 " a constructor taking a single argument of its own " 3556 "class type is invalid"); 3557 break; 3558 case rr_constraint_failure: 3559 { 3560 tree tmpl = r->u.template_instantiation.tmpl; 3561 tree args = r->u.template_instantiation.targs; 3562 diagnose_constraints (cloc, tmpl, args); 3563 } 3564 break; 3565 case rr_inherited_ctor: 3566 inform (cloc, " an inherited constructor is not a candidate for " 3567 "initialization from an expression of the same or derived " 3568 "type"); 3569 break; 3570 case rr_none: 3571 default: 3572 /* This candidate didn't have any issues or we failed to 3573 handle a particular code. Either way... */ 3574 gcc_unreachable (); 3575 } 3576 } 3577 } 3578 3579 static void 3580 print_z_candidates (location_t loc, struct z_candidate *candidates) 3581 { 3582 struct z_candidate *cand1; 3583 struct z_candidate **cand2; 3584 3585 if (!candidates) 3586 return; 3587 3588 /* Remove non-viable deleted candidates. */ 3589 cand1 = candidates; 3590 for (cand2 = &cand1; *cand2; ) 3591 { 3592 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3593 && !(*cand2)->viable 3594 && DECL_DELETED_FN ((*cand2)->fn)) 3595 *cand2 = (*cand2)->next; 3596 else 3597 cand2 = &(*cand2)->next; 3598 } 3599 /* ...if there are any non-deleted ones. */ 3600 if (cand1) 3601 candidates = cand1; 3602 3603 /* There may be duplicates in the set of candidates. We put off 3604 checking this condition as long as possible, since we have no way 3605 to eliminate duplicates from a set of functions in less than n^2 3606 time. Now we are about to emit an error message, so it is more 3607 permissible to go slowly. */ 3608 for (cand1 = candidates; cand1; cand1 = cand1->next) 3609 { 3610 tree fn = cand1->fn; 3611 /* Skip builtin candidates and conversion functions. */ 3612 if (!DECL_P (fn)) 3613 continue; 3614 cand2 = &cand1->next; 3615 while (*cand2) 3616 { 3617 if (DECL_P ((*cand2)->fn) 3618 && equal_functions (fn, (*cand2)->fn)) 3619 *cand2 = (*cand2)->next; 3620 else 3621 cand2 = &(*cand2)->next; 3622 } 3623 } 3624 3625 for (; candidates; candidates = candidates->next) 3626 print_z_candidate (loc, "candidate:", candidates); 3627 } 3628 3629 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3630 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3631 the result of the conversion function to convert it to the final 3632 desired type. Merge the two sequences into a single sequence, 3633 and return the merged sequence. */ 3634 3635 static conversion * 3636 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3637 { 3638 conversion **t; 3639 bool bad = user_seq->bad_p; 3640 3641 gcc_assert (user_seq->kind == ck_user); 3642 3643 /* Find the end of the second conversion sequence. */ 3644 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3645 { 3646 /* The entire sequence is a user-conversion sequence. */ 3647 (*t)->user_conv_p = true; 3648 if (bad) 3649 (*t)->bad_p = true; 3650 } 3651 3652 if ((*t)->rvaluedness_matches_p) 3653 /* We're binding a reference directly to the result of the conversion. 3654 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return 3655 type, but we want it back. */ 3656 user_seq->type = TREE_TYPE (TREE_TYPE (user_seq->cand->fn)); 3657 3658 /* Replace the identity conversion with the user conversion 3659 sequence. */ 3660 *t = user_seq; 3661 3662 return std_seq; 3663 } 3664 3665 /* Handle overload resolution for initializing an object of class type from 3666 an initializer list. First we look for a suitable constructor that 3667 takes a std::initializer_list; if we don't find one, we then look for a 3668 non-list constructor. 3669 3670 Parameters are as for add_candidates, except that the arguments are in 3671 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and 3672 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3673 3674 static void 3675 add_list_candidates (tree fns, tree first_arg, 3676 const vec<tree, va_gc> *args, tree totype, 3677 tree explicit_targs, bool template_only, 3678 tree conversion_path, tree access_path, 3679 int flags, 3680 struct z_candidate **candidates, 3681 tsubst_flags_t complain) 3682 { 3683 gcc_assert (*candidates == NULL); 3684 3685 /* We're looking for a ctor for list-initialization. */ 3686 flags |= LOOKUP_LIST_INIT_CTOR; 3687 /* And we don't allow narrowing conversions. We also use this flag to 3688 avoid the copy constructor call for copy-list-initialization. */ 3689 flags |= LOOKUP_NO_NARROWING; 3690 3691 unsigned nart = num_artificial_parms_for (OVL_FIRST (fns)) - 1; 3692 tree init_list = (*args)[nart]; 3693 3694 /* Always use the default constructor if the list is empty (DR 990). */ 3695 if (CONSTRUCTOR_NELTS (init_list) == 0 3696 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3697 ; 3698 /* If the class has a list ctor, try passing the list as a single 3699 argument first, but only consider list ctors. */ 3700 else if (TYPE_HAS_LIST_CTOR (totype)) 3701 { 3702 flags |= LOOKUP_LIST_ONLY; 3703 add_candidates (fns, first_arg, args, NULL_TREE, 3704 explicit_targs, template_only, conversion_path, 3705 access_path, flags, candidates, complain); 3706 if (any_strictly_viable (*candidates)) 3707 return; 3708 } 3709 3710 /* Expand the CONSTRUCTOR into a new argument vec. */ 3711 vec<tree, va_gc> *new_args; 3712 vec_alloc (new_args, nart + CONSTRUCTOR_NELTS (init_list)); 3713 for (unsigned i = 0; i < nart; ++i) 3714 new_args->quick_push ((*args)[i]); 3715 for (unsigned i = 0; i < CONSTRUCTOR_NELTS (init_list); ++i) 3716 new_args->quick_push (CONSTRUCTOR_ELT (init_list, i)->value); 3717 3718 /* We aren't looking for list-ctors anymore. */ 3719 flags &= ~LOOKUP_LIST_ONLY; 3720 /* We allow more user-defined conversions within an init-list. */ 3721 flags &= ~LOOKUP_NO_CONVERSION; 3722 3723 add_candidates (fns, first_arg, new_args, NULL_TREE, 3724 explicit_targs, template_only, conversion_path, 3725 access_path, flags, candidates, complain); 3726 } 3727 3728 /* Returns the best overload candidate to perform the requested 3729 conversion. This function is used for three the overloading situations 3730 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3731 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3732 per [dcl.init.ref], so we ignore temporary bindings. */ 3733 3734 static struct z_candidate * 3735 build_user_type_conversion_1 (tree totype, tree expr, int flags, 3736 tsubst_flags_t complain) 3737 { 3738 struct z_candidate *candidates, *cand; 3739 tree fromtype; 3740 tree ctors = NULL_TREE; 3741 tree conv_fns = NULL_TREE; 3742 conversion *conv = NULL; 3743 tree first_arg = NULL_TREE; 3744 vec<tree, va_gc> *args = NULL; 3745 bool any_viable_p; 3746 int convflags; 3747 3748 if (!expr) 3749 return NULL; 3750 3751 fromtype = TREE_TYPE (expr); 3752 3753 /* We represent conversion within a hierarchy using RVALUE_CONV and 3754 BASE_CONV, as specified by [over.best.ics]; these become plain 3755 constructor calls, as specified in [dcl.init]. */ 3756 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3757 || !DERIVED_FROM_P (totype, fromtype)); 3758 3759 if (CLASS_TYPE_P (totype)) 3760 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3761 creating a garbage BASELINK; constructors can't be inherited. */ 3762 ctors = get_class_binding (totype, complete_ctor_identifier); 3763 3764 if (MAYBE_CLASS_TYPE_P (fromtype)) 3765 { 3766 tree to_nonref = non_reference (totype); 3767 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3768 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3769 && DERIVED_FROM_P (to_nonref, fromtype))) 3770 { 3771 /* [class.conv.fct] A conversion function is never used to 3772 convert a (possibly cv-qualified) object to the (possibly 3773 cv-qualified) same object type (or a reference to it), to a 3774 (possibly cv-qualified) base class of that type (or a 3775 reference to it)... */ 3776 } 3777 else 3778 conv_fns = lookup_conversions (fromtype); 3779 } 3780 3781 candidates = 0; 3782 flags |= LOOKUP_NO_CONVERSION; 3783 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3784 flags |= LOOKUP_NO_NARROWING; 3785 3786 /* It's OK to bind a temporary for converting constructor arguments, but 3787 not in converting the return value of a conversion operator. */ 3788 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION 3789 | (flags & LOOKUP_NO_NARROWING)); 3790 flags &= ~LOOKUP_NO_TEMP_BIND; 3791 3792 if (ctors) 3793 { 3794 int ctorflags = flags; 3795 3796 first_arg = build_dummy_object (totype); 3797 3798 /* We should never try to call the abstract or base constructor 3799 from here. */ 3800 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_FIRST (ctors)) 3801 && !DECL_HAS_VTT_PARM_P (OVL_FIRST (ctors))); 3802 3803 args = make_tree_vector_single (expr); 3804 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3805 { 3806 /* List-initialization. */ 3807 add_list_candidates (ctors, first_arg, args, totype, NULL_TREE, 3808 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3809 ctorflags, &candidates, complain); 3810 } 3811 else 3812 { 3813 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3814 TYPE_BINFO (totype), TYPE_BINFO (totype), 3815 ctorflags, &candidates, complain); 3816 } 3817 3818 for (cand = candidates; cand; cand = cand->next) 3819 { 3820 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3821 3822 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3823 set, then this is copy-initialization. In that case, "The 3824 result of the call is then used to direct-initialize the 3825 object that is the destination of the copy-initialization." 3826 [dcl.init] 3827 3828 We represent this in the conversion sequence with an 3829 rvalue conversion, which means a constructor call. */ 3830 if (TREE_CODE (totype) != REFERENCE_TYPE 3831 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3832 cand->second_conv 3833 = build_conv (ck_rvalue, totype, cand->second_conv); 3834 } 3835 } 3836 3837 if (conv_fns) 3838 { 3839 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3840 first_arg = CONSTRUCTOR_ELT (expr, 0)->value; 3841 else 3842 first_arg = expr; 3843 } 3844 3845 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3846 { 3847 tree conversion_path = TREE_PURPOSE (conv_fns); 3848 struct z_candidate *old_candidates; 3849 3850 /* If we are called to convert to a reference type, we are trying to 3851 find a direct binding, so don't even consider temporaries. If 3852 we don't find a direct binding, the caller will try again to 3853 look for a temporary binding. */ 3854 if (TREE_CODE (totype) == REFERENCE_TYPE) 3855 convflags |= LOOKUP_NO_TEMP_BIND; 3856 3857 old_candidates = candidates; 3858 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3859 NULL_TREE, false, 3860 conversion_path, TYPE_BINFO (fromtype), 3861 flags, &candidates, complain); 3862 3863 for (cand = candidates; cand != old_candidates; cand = cand->next) 3864 { 3865 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 3866 conversion *ics 3867 = implicit_conversion (totype, 3868 rettype, 3869 0, 3870 /*c_cast_p=*/false, convflags, 3871 complain); 3872 3873 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 3874 copy-initialization. In that case, "The result of the 3875 call is then used to direct-initialize the object that is 3876 the destination of the copy-initialization." [dcl.init] 3877 3878 We represent this in the conversion sequence with an 3879 rvalue conversion, which means a constructor call. But 3880 don't add a second rvalue conversion if there's already 3881 one there. Which there really shouldn't be, but it's 3882 harmless since we'd add it here anyway. */ 3883 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3884 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3885 ics = build_conv (ck_rvalue, totype, ics); 3886 3887 cand->second_conv = ics; 3888 3889 if (!ics) 3890 { 3891 cand->viable = 0; 3892 cand->reason = arg_conversion_rejection (NULL_TREE, -2, 3893 rettype, totype); 3894 } 3895 else if (DECL_NONCONVERTING_P (cand->fn) 3896 && ics->rank > cr_exact) 3897 { 3898 /* 13.3.1.5: For direct-initialization, those explicit 3899 conversion functions that are not hidden within S and 3900 yield type T or a type that can be converted to type T 3901 with a qualification conversion (4.4) are also candidate 3902 functions. */ 3903 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 3904 I've raised this issue with the committee. --jason 9/2011 */ 3905 cand->viable = -1; 3906 cand->reason = explicit_conversion_rejection (rettype, totype); 3907 } 3908 else if (cand->viable == 1 && ics->bad_p) 3909 { 3910 cand->viable = -1; 3911 cand->reason 3912 = bad_arg_conversion_rejection (NULL_TREE, -2, 3913 rettype, totype); 3914 } 3915 else if (primary_template_specialization_p (cand->fn) 3916 && ics->rank > cr_exact) 3917 { 3918 /* 13.3.3.1.2: If the user-defined conversion is specified by 3919 a specialization of a conversion function template, the 3920 second standard conversion sequence shall have exact match 3921 rank. */ 3922 cand->viable = -1; 3923 cand->reason = template_conversion_rejection (rettype, totype); 3924 } 3925 } 3926 } 3927 3928 candidates = splice_viable (candidates, false, &any_viable_p); 3929 if (!any_viable_p) 3930 { 3931 if (args) 3932 release_tree_vector (args); 3933 return NULL; 3934 } 3935 3936 cand = tourney (candidates, complain); 3937 if (cand == 0) 3938 { 3939 if (complain & tf_error) 3940 { 3941 error ("conversion from %qH to %qI is ambiguous", 3942 fromtype, totype); 3943 print_z_candidates (location_of (expr), candidates); 3944 } 3945 3946 cand = candidates; /* any one will do */ 3947 cand->second_conv = build_ambiguous_conv (totype, expr); 3948 cand->second_conv->user_conv_p = true; 3949 if (!any_strictly_viable (candidates)) 3950 cand->second_conv->bad_p = true; 3951 if (flags & LOOKUP_ONLYCONVERTING) 3952 cand->second_conv->need_temporary_p = true; 3953 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3954 ambiguous conversion is no worse than another user-defined 3955 conversion. */ 3956 3957 return cand; 3958 } 3959 3960 tree convtype; 3961 if (!DECL_CONSTRUCTOR_P (cand->fn)) 3962 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn))); 3963 else if (cand->second_conv->kind == ck_rvalue) 3964 /* DR 5: [in the first step of copy-initialization]...if the function 3965 is a constructor, the call initializes a temporary of the 3966 cv-unqualified version of the destination type. */ 3967 convtype = cv_unqualified (totype); 3968 else 3969 convtype = totype; 3970 /* Build the user conversion sequence. */ 3971 conv = build_conv 3972 (ck_user, 3973 convtype, 3974 build_identity_conv (TREE_TYPE (expr), expr)); 3975 conv->cand = cand; 3976 if (cand->viable == -1) 3977 conv->bad_p = true; 3978 3979 /* Remember that this was a list-initialization. */ 3980 if (flags & LOOKUP_NO_NARROWING) 3981 conv->check_narrowing = true; 3982 3983 /* Combine it with the second conversion sequence. */ 3984 cand->second_conv = merge_conversion_sequences (conv, 3985 cand->second_conv); 3986 3987 return cand; 3988 } 3989 3990 /* Wrapper for above. */ 3991 3992 tree 3993 build_user_type_conversion (tree totype, tree expr, int flags, 3994 tsubst_flags_t complain) 3995 { 3996 struct z_candidate *cand; 3997 tree ret; 3998 3999 bool subtime = timevar_cond_start (TV_OVERLOAD); 4000 cand = build_user_type_conversion_1 (totype, expr, flags, complain); 4001 4002 if (cand) 4003 { 4004 if (cand->second_conv->kind == ck_ambig) 4005 ret = error_mark_node; 4006 else 4007 { 4008 expr = convert_like (cand->second_conv, expr, complain); 4009 ret = convert_from_reference (expr); 4010 } 4011 } 4012 else 4013 ret = NULL_TREE; 4014 4015 timevar_cond_stop (TV_OVERLOAD, subtime); 4016 return ret; 4017 } 4018 4019 /* Subroutine of convert_nontype_argument. 4020 4021 EXPR is an expression used in a context that requires a converted 4022 constant-expression, such as a template non-type parameter. Do any 4023 necessary conversions (that are permitted for converted 4024 constant-expressions) to convert it to the desired type. 4025 4026 If conversion is successful, returns the converted expression; 4027 otherwise, returns error_mark_node. */ 4028 4029 tree 4030 build_converted_constant_expr (tree type, tree expr, tsubst_flags_t complain) 4031 { 4032 conversion *conv; 4033 void *p; 4034 tree t; 4035 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 4036 4037 if (error_operand_p (expr)) 4038 return error_mark_node; 4039 4040 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4041 p = conversion_obstack_alloc (0); 4042 4043 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 4044 /*c_cast_p=*/false, 4045 LOOKUP_IMPLICIT, complain); 4046 4047 /* A converted constant expression of type T is an expression, implicitly 4048 converted to type T, where the converted expression is a constant 4049 expression and the implicit conversion sequence contains only 4050 4051 * user-defined conversions, 4052 * lvalue-to-rvalue conversions (7.1), 4053 * array-to-pointer conversions (7.2), 4054 * function-to-pointer conversions (7.3), 4055 * qualification conversions (7.5), 4056 * integral promotions (7.6), 4057 * integral conversions (7.8) other than narrowing conversions (11.6.4), 4058 * null pointer conversions (7.11) from std::nullptr_t, 4059 * null member pointer conversions (7.12) from std::nullptr_t, and 4060 * function pointer conversions (7.13), 4061 4062 and where the reference binding (if any) binds directly. */ 4063 4064 for (conversion *c = conv; 4065 conv && c->kind != ck_identity; 4066 c = next_conversion (c)) 4067 { 4068 switch (c->kind) 4069 { 4070 /* A conversion function is OK. If it isn't constexpr, we'll 4071 complain later that the argument isn't constant. */ 4072 case ck_user: 4073 /* The lvalue-to-rvalue conversion is OK. */ 4074 case ck_rvalue: 4075 /* Array-to-pointer and function-to-pointer. */ 4076 case ck_lvalue: 4077 /* Function pointer conversions. */ 4078 case ck_fnptr: 4079 /* Qualification conversions. */ 4080 case ck_qual: 4081 break; 4082 4083 case ck_ref_bind: 4084 if (c->need_temporary_p) 4085 { 4086 if (complain & tf_error) 4087 error_at (loc, "initializing %qH with %qI in converted " 4088 "constant expression does not bind directly", 4089 type, next_conversion (c)->type); 4090 conv = NULL; 4091 } 4092 break; 4093 4094 case ck_base: 4095 case ck_pmem: 4096 case ck_ptr: 4097 case ck_std: 4098 t = next_conversion (c)->type; 4099 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t) 4100 && INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 4101 /* Integral promotion or conversion. */ 4102 break; 4103 if (NULLPTR_TYPE_P (t)) 4104 /* Conversion from nullptr to pointer or pointer-to-member. */ 4105 break; 4106 4107 if (complain & tf_error) 4108 error_at (loc, "conversion from %qH to %qI in a " 4109 "converted constant expression", t, type); 4110 /* fall through. */ 4111 4112 default: 4113 conv = NULL; 4114 break; 4115 } 4116 } 4117 4118 /* Avoid confusing convert_nontype_argument by introducing 4119 a redundant conversion to the same reference type. */ 4120 if (conv && conv->kind == ck_ref_bind 4121 && REFERENCE_REF_P (expr)) 4122 { 4123 tree ref = TREE_OPERAND (expr, 0); 4124 if (same_type_p (type, TREE_TYPE (ref))) 4125 return ref; 4126 } 4127 4128 if (conv) 4129 expr = convert_like (conv, expr, complain); 4130 else 4131 expr = error_mark_node; 4132 4133 /* Free all the conversions we allocated. */ 4134 obstack_free (&conversion_obstack, p); 4135 4136 return expr; 4137 } 4138 4139 /* Do any initial processing on the arguments to a function call. */ 4140 4141 static vec<tree, va_gc> * 4142 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain) 4143 { 4144 unsigned int ix; 4145 tree arg; 4146 4147 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 4148 { 4149 if (error_operand_p (arg)) 4150 return NULL; 4151 else if (VOID_TYPE_P (TREE_TYPE (arg))) 4152 { 4153 if (complain & tf_error) 4154 error ("invalid use of void expression"); 4155 return NULL; 4156 } 4157 else if (invalid_nonstatic_memfn_p (input_location, arg, complain)) 4158 return NULL; 4159 } 4160 return args; 4161 } 4162 4163 /* Perform overload resolution on FN, which is called with the ARGS. 4164 4165 Return the candidate function selected by overload resolution, or 4166 NULL if the event that overload resolution failed. In the case 4167 that overload resolution fails, *CANDIDATES will be the set of 4168 candidates considered, and ANY_VIABLE_P will be set to true or 4169 false to indicate whether or not any of the candidates were 4170 viable. 4171 4172 The ARGS should already have gone through RESOLVE_ARGS before this 4173 function is called. */ 4174 4175 static struct z_candidate * 4176 perform_overload_resolution (tree fn, 4177 const vec<tree, va_gc> *args, 4178 struct z_candidate **candidates, 4179 bool *any_viable_p, tsubst_flags_t complain) 4180 { 4181 struct z_candidate *cand; 4182 tree explicit_targs; 4183 int template_only; 4184 4185 bool subtime = timevar_cond_start (TV_OVERLOAD); 4186 4187 explicit_targs = NULL_TREE; 4188 template_only = 0; 4189 4190 *candidates = NULL; 4191 *any_viable_p = true; 4192 4193 /* Check FN. */ 4194 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 4195 || TREE_CODE (fn) == TEMPLATE_DECL 4196 || TREE_CODE (fn) == OVERLOAD 4197 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 4198 4199 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4200 { 4201 explicit_targs = TREE_OPERAND (fn, 1); 4202 fn = TREE_OPERAND (fn, 0); 4203 template_only = 1; 4204 } 4205 4206 /* Add the various candidate functions. */ 4207 add_candidates (fn, NULL_TREE, args, NULL_TREE, 4208 explicit_targs, template_only, 4209 /*conversion_path=*/NULL_TREE, 4210 /*access_path=*/NULL_TREE, 4211 LOOKUP_NORMAL, 4212 candidates, complain); 4213 4214 *candidates = splice_viable (*candidates, false, any_viable_p); 4215 if (*any_viable_p) 4216 cand = tourney (*candidates, complain); 4217 else 4218 cand = NULL; 4219 4220 timevar_cond_stop (TV_OVERLOAD, subtime); 4221 return cand; 4222 } 4223 4224 /* Print an error message about being unable to build a call to FN with 4225 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 4226 be located; CANDIDATES is a possibly empty list of such 4227 functions. */ 4228 4229 static void 4230 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args, 4231 struct z_candidate *candidates) 4232 { 4233 tree targs = NULL_TREE; 4234 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4235 { 4236 targs = TREE_OPERAND (fn, 1); 4237 fn = TREE_OPERAND (fn, 0); 4238 } 4239 tree name = OVL_NAME (fn); 4240 location_t loc = location_of (name); 4241 if (targs) 4242 name = lookup_template_function (name, targs); 4243 4244 if (!any_strictly_viable (candidates)) 4245 error_at (loc, "no matching function for call to %<%D(%A)%>", 4246 name, build_tree_list_vec (args)); 4247 else 4248 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 4249 name, build_tree_list_vec (args)); 4250 if (candidates) 4251 print_z_candidates (loc, candidates); 4252 } 4253 4254 /* Return an expression for a call to FN (a namespace-scope function, 4255 or a static member function) with the ARGS. This may change 4256 ARGS. */ 4257 4258 tree 4259 build_new_function_call (tree fn, vec<tree, va_gc> **args, 4260 tsubst_flags_t complain) 4261 { 4262 struct z_candidate *candidates, *cand; 4263 bool any_viable_p; 4264 void *p; 4265 tree result; 4266 4267 if (args != NULL && *args != NULL) 4268 { 4269 *args = resolve_args (*args, complain); 4270 if (*args == NULL) 4271 return error_mark_node; 4272 } 4273 4274 if (flag_tm) 4275 tm_malloc_replacement (fn); 4276 4277 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4278 p = conversion_obstack_alloc (0); 4279 4280 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p, 4281 complain); 4282 4283 if (!cand) 4284 { 4285 if (complain & tf_error) 4286 { 4287 // If there is a single (non-viable) function candidate, 4288 // let the error be diagnosed by cp_build_function_call_vec. 4289 if (!any_viable_p && candidates && ! candidates->next 4290 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 4291 return cp_build_function_call_vec (candidates->fn, args, complain); 4292 4293 // Otherwise, emit notes for non-viable candidates. 4294 print_error_for_call_failure (fn, *args, candidates); 4295 } 4296 result = error_mark_node; 4297 } 4298 else 4299 { 4300 int flags = LOOKUP_NORMAL; 4301 /* If fn is template_id_expr, the call has explicit template arguments 4302 (e.g. func<int>(5)), communicate this info to build_over_call 4303 through flags so that later we can use it to decide whether to warn 4304 about peculiar null pointer conversion. */ 4305 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4306 { 4307 /* If overload resolution selects a specialization of a 4308 function concept for non-dependent template arguments, 4309 the expression is true if the constraints are satisfied 4310 and false otherwise. 4311 4312 NOTE: This is an extension of Concepts Lite TS that 4313 allows constraints to be used in expressions. */ 4314 if (flag_concepts && !processing_template_decl) 4315 { 4316 tree tmpl = DECL_TI_TEMPLATE (cand->fn); 4317 tree targs = DECL_TI_ARGS (cand->fn); 4318 tree decl = DECL_TEMPLATE_RESULT (tmpl); 4319 if (DECL_DECLARED_CONCEPT_P (decl)) 4320 return evaluate_function_concept (decl, targs); 4321 } 4322 4323 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 4324 } 4325 4326 result = build_over_call (cand, flags, complain); 4327 } 4328 4329 /* Free all the conversions we allocated. */ 4330 obstack_free (&conversion_obstack, p); 4331 4332 return result; 4333 } 4334 4335 /* Build a call to a global operator new. FNNAME is the name of the 4336 operator (either "operator new" or "operator new[]") and ARGS are 4337 the arguments provided. This may change ARGS. *SIZE points to the 4338 total number of bytes required by the allocation, and is updated if 4339 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 4340 be used. If this function determines that no cookie should be 4341 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK 4342 is not NULL_TREE, it is evaluated before calculating the final 4343 array size, and if it fails, the array size is replaced with 4344 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN 4345 is non-NULL, it will be set, upon return, to the allocation 4346 function called. */ 4347 4348 tree 4349 build_operator_new_call (tree fnname, vec<tree, va_gc> **args, 4350 tree *size, tree *cookie_size, 4351 tree align_arg, tree size_check, 4352 tree *fn, tsubst_flags_t complain) 4353 { 4354 tree original_size = *size; 4355 tree fns; 4356 struct z_candidate *candidates; 4357 struct z_candidate *cand = NULL; 4358 bool any_viable_p; 4359 4360 if (fn) 4361 *fn = NULL_TREE; 4362 /* Set to (size_t)-1 if the size check fails. */ 4363 if (size_check != NULL_TREE) 4364 { 4365 tree errval = TYPE_MAX_VALUE (sizetype); 4366 if (cxx_dialect >= cxx11 && flag_exceptions) 4367 errval = throw_bad_array_new_length (); 4368 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4369 original_size, errval); 4370 } 4371 vec_safe_insert (*args, 0, *size); 4372 *args = resolve_args (*args, complain); 4373 if (*args == NULL) 4374 return error_mark_node; 4375 4376 /* Based on: 4377 4378 [expr.new] 4379 4380 If this lookup fails to find the name, or if the allocated type 4381 is not a class type, the allocation function's name is looked 4382 up in the global scope. 4383 4384 we disregard block-scope declarations of "operator new". */ 4385 fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0); 4386 fns = lookup_arg_dependent (fnname, fns, *args); 4387 4388 if (align_arg) 4389 { 4390 vec<tree, va_gc>* align_args 4391 = vec_copy_and_insert (*args, align_arg, 1); 4392 cand = perform_overload_resolution (fns, align_args, &candidates, 4393 &any_viable_p, tf_none); 4394 if (cand) 4395 *args = align_args; 4396 /* If no aligned allocation function matches, try again without the 4397 alignment. */ 4398 } 4399 4400 /* Figure out what function is being called. */ 4401 if (!cand) 4402 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p, 4403 complain); 4404 4405 /* If no suitable function could be found, issue an error message 4406 and give up. */ 4407 if (!cand) 4408 { 4409 if (complain & tf_error) 4410 print_error_for_call_failure (fns, *args, candidates); 4411 return error_mark_node; 4412 } 4413 4414 /* If a cookie is required, add some extra space. Whether 4415 or not a cookie is required cannot be determined until 4416 after we know which function was called. */ 4417 if (*cookie_size) 4418 { 4419 bool use_cookie = true; 4420 tree arg_types; 4421 4422 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 4423 /* Skip the size_t parameter. */ 4424 arg_types = TREE_CHAIN (arg_types); 4425 /* Check the remaining parameters (if any). */ 4426 if (arg_types 4427 && TREE_CHAIN (arg_types) == void_list_node 4428 && same_type_p (TREE_VALUE (arg_types), 4429 ptr_type_node)) 4430 use_cookie = false; 4431 /* If we need a cookie, adjust the number of bytes allocated. */ 4432 if (use_cookie) 4433 { 4434 /* Update the total size. */ 4435 *size = size_binop (PLUS_EXPR, original_size, *cookie_size); 4436 if (size_check) 4437 { 4438 /* Set to (size_t)-1 if the size check fails. */ 4439 gcc_assert (size_check != NULL_TREE); 4440 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4441 *size, TYPE_MAX_VALUE (sizetype)); 4442 } 4443 /* Update the argument list to reflect the adjusted size. */ 4444 (**args)[0] = *size; 4445 } 4446 else 4447 *cookie_size = NULL_TREE; 4448 } 4449 4450 /* Tell our caller which function we decided to call. */ 4451 if (fn) 4452 *fn = cand->fn; 4453 4454 /* Build the CALL_EXPR. */ 4455 return build_over_call (cand, LOOKUP_NORMAL, complain); 4456 } 4457 4458 /* Build a new call to operator(). This may change ARGS. */ 4459 4460 static tree 4461 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4462 { 4463 struct z_candidate *candidates = 0, *cand; 4464 tree fns, convs, first_mem_arg = NULL_TREE; 4465 bool any_viable_p; 4466 tree result = NULL_TREE; 4467 void *p; 4468 4469 obj = mark_lvalue_use (obj); 4470 4471 if (error_operand_p (obj)) 4472 return error_mark_node; 4473 4474 tree type = TREE_TYPE (obj); 4475 4476 obj = prep_operand (obj); 4477 4478 if (TYPE_PTRMEMFUNC_P (type)) 4479 { 4480 if (complain & tf_error) 4481 /* It's no good looking for an overloaded operator() on a 4482 pointer-to-member-function. */ 4483 error ("pointer-to-member function %qE cannot be called without " 4484 "an object; consider using %<.*%> or %<->*%>", obj); 4485 return error_mark_node; 4486 } 4487 4488 if (TYPE_BINFO (type)) 4489 { 4490 fns = lookup_fnfields (TYPE_BINFO (type), call_op_identifier, 1); 4491 if (fns == error_mark_node) 4492 return error_mark_node; 4493 } 4494 else 4495 fns = NULL_TREE; 4496 4497 if (args != NULL && *args != NULL) 4498 { 4499 *args = resolve_args (*args, complain); 4500 if (*args == NULL) 4501 return error_mark_node; 4502 } 4503 4504 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4505 p = conversion_obstack_alloc (0); 4506 4507 if (fns) 4508 { 4509 first_mem_arg = obj; 4510 4511 add_candidates (BASELINK_FUNCTIONS (fns), 4512 first_mem_arg, *args, NULL_TREE, 4513 NULL_TREE, false, 4514 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4515 LOOKUP_NORMAL, &candidates, complain); 4516 } 4517 4518 convs = lookup_conversions (type); 4519 4520 for (; convs; convs = TREE_CHAIN (convs)) 4521 { 4522 tree totype = TREE_TYPE (convs); 4523 4524 if (TYPE_PTRFN_P (totype) 4525 || TYPE_REFFN_P (totype) 4526 || (TREE_CODE (totype) == REFERENCE_TYPE 4527 && TYPE_PTRFN_P (TREE_TYPE (totype)))) 4528 for (ovl_iterator iter (TREE_VALUE (convs)); iter; ++iter) 4529 { 4530 tree fn = *iter; 4531 4532 if (DECL_NONCONVERTING_P (fn)) 4533 continue; 4534 4535 if (TREE_CODE (fn) == TEMPLATE_DECL) 4536 add_template_conv_candidate 4537 (&candidates, fn, obj, *args, totype, 4538 /*access_path=*/NULL_TREE, 4539 /*conversion_path=*/NULL_TREE, complain); 4540 else 4541 add_conv_candidate (&candidates, fn, obj, 4542 *args, /*conversion_path=*/NULL_TREE, 4543 /*access_path=*/NULL_TREE, complain); 4544 } 4545 } 4546 4547 /* Be strict here because if we choose a bad conversion candidate, the 4548 errors we get won't mention the call context. */ 4549 candidates = splice_viable (candidates, true, &any_viable_p); 4550 if (!any_viable_p) 4551 { 4552 if (complain & tf_error) 4553 { 4554 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4555 build_tree_list_vec (*args)); 4556 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4557 } 4558 result = error_mark_node; 4559 } 4560 else 4561 { 4562 cand = tourney (candidates, complain); 4563 if (cand == 0) 4564 { 4565 if (complain & tf_error) 4566 { 4567 error ("call of %<(%T) (%A)%> is ambiguous", 4568 TREE_TYPE (obj), build_tree_list_vec (*args)); 4569 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4570 } 4571 result = error_mark_node; 4572 } 4573 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4574 && DECL_OVERLOADED_OPERATOR_P (cand->fn) 4575 && DECL_OVERLOADED_OPERATOR_IS (cand->fn, CALL_EXPR)) 4576 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4577 else 4578 { 4579 if (TREE_CODE (cand->fn) == FUNCTION_DECL) 4580 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, 4581 -1, complain); 4582 else 4583 { 4584 gcc_checking_assert (TYPE_P (cand->fn)); 4585 obj = convert_like (cand->convs[0], obj, complain); 4586 } 4587 obj = convert_from_reference (obj); 4588 result = cp_build_function_call_vec (obj, args, complain); 4589 } 4590 } 4591 4592 /* Free all the conversions we allocated. */ 4593 obstack_free (&conversion_obstack, p); 4594 4595 return result; 4596 } 4597 4598 /* Wrapper for above. */ 4599 4600 tree 4601 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4602 { 4603 tree ret; 4604 bool subtime = timevar_cond_start (TV_OVERLOAD); 4605 ret = build_op_call_1 (obj, args, complain); 4606 timevar_cond_stop (TV_OVERLOAD, subtime); 4607 return ret; 4608 } 4609 4610 /* Called by op_error to prepare format strings suitable for the error 4611 function. It concatenates a prefix (controlled by MATCH), ERRMSG, 4612 and a suffix (controlled by NTYPES). */ 4613 4614 static const char * 4615 op_error_string (const char *errmsg, int ntypes, bool match) 4616 { 4617 const char *msg; 4618 4619 const char *msgp = concat (match ? G_("ambiguous overload for ") 4620 : G_("no match for "), errmsg, NULL); 4621 4622 if (ntypes == 3) 4623 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL); 4624 else if (ntypes == 2) 4625 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL); 4626 else 4627 msg = concat (msgp, G_(" (operand type is %qT)"), NULL); 4628 4629 return msg; 4630 } 4631 4632 static void 4633 op_error (location_t loc, enum tree_code code, enum tree_code code2, 4634 tree arg1, tree arg2, tree arg3, bool match) 4635 { 4636 bool assop = code == MODIFY_EXPR; 4637 const char *opname = OVL_OP_INFO (assop, assop ? code2 : code)->name; 4638 4639 switch (code) 4640 { 4641 case COND_EXPR: 4642 if (flag_diagnostics_show_caret) 4643 error_at (loc, op_error_string (G_("ternary %<operator?:%>"), 4644 3, match), 4645 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4646 else 4647 error_at (loc, op_error_string (G_("ternary %<operator?:%> " 4648 "in %<%E ? %E : %E%>"), 3, match), 4649 arg1, arg2, arg3, 4650 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4651 break; 4652 4653 case POSTINCREMENT_EXPR: 4654 case POSTDECREMENT_EXPR: 4655 if (flag_diagnostics_show_caret) 4656 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4657 opname, TREE_TYPE (arg1)); 4658 else 4659 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"), 4660 1, match), 4661 opname, arg1, opname, TREE_TYPE (arg1)); 4662 break; 4663 4664 case ARRAY_REF: 4665 if (flag_diagnostics_show_caret) 4666 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match), 4667 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4668 else 4669 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"), 4670 2, match), 4671 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4672 break; 4673 4674 case REALPART_EXPR: 4675 case IMAGPART_EXPR: 4676 if (flag_diagnostics_show_caret) 4677 error_at (loc, op_error_string (G_("%qs"), 1, match), 4678 opname, TREE_TYPE (arg1)); 4679 else 4680 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match), 4681 opname, opname, arg1, TREE_TYPE (arg1)); 4682 break; 4683 4684 default: 4685 if (arg2) 4686 if (flag_diagnostics_show_caret) 4687 error_at (loc, op_error_string (G_("%<operator%s%>"), 2, match), 4688 opname, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4689 else 4690 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"), 4691 2, match), 4692 opname, arg1, opname, arg2, 4693 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4694 else 4695 if (flag_diagnostics_show_caret) 4696 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4697 opname, TREE_TYPE (arg1)); 4698 else 4699 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"), 4700 1, match), 4701 opname, opname, arg1, TREE_TYPE (arg1)); 4702 break; 4703 } 4704 } 4705 4706 /* Return the implicit conversion sequence that could be used to 4707 convert E1 to E2 in [expr.cond]. */ 4708 4709 static conversion * 4710 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain) 4711 { 4712 tree t1 = non_reference (TREE_TYPE (e1)); 4713 tree t2 = non_reference (TREE_TYPE (e2)); 4714 conversion *conv; 4715 bool good_base; 4716 4717 /* [expr.cond] 4718 4719 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4720 implicitly converted (clause _conv_) to the type "lvalue reference to 4721 T2", subject to the constraint that in the conversion the 4722 reference must bind directly (_dcl.init.ref_) to an lvalue. 4723 4724 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be 4725 implicitly converted to the type "rvalue reference to T2", subject to 4726 the constraint that the reference must bind directly. */ 4727 if (glvalue_p (e2)) 4728 { 4729 tree rtype = cp_build_reference_type (t2, !lvalue_p (e2)); 4730 conv = implicit_conversion (rtype, 4731 t1, 4732 e1, 4733 /*c_cast_p=*/false, 4734 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4735 |LOOKUP_ONLYCONVERTING, 4736 complain); 4737 if (conv && !conv->bad_p) 4738 return conv; 4739 } 4740 4741 /* If E2 is a prvalue or if neither of the conversions above can be done 4742 and at least one of the operands has (possibly cv-qualified) class 4743 type: */ 4744 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2)) 4745 return NULL; 4746 4747 /* [expr.cond] 4748 4749 If E1 and E2 have class type, and the underlying class types are 4750 the same or one is a base class of the other: E1 can be converted 4751 to match E2 if the class of T2 is the same type as, or a base 4752 class of, the class of T1, and the cv-qualification of T2 is the 4753 same cv-qualification as, or a greater cv-qualification than, the 4754 cv-qualification of T1. If the conversion is applied, E1 is 4755 changed to an rvalue of type T2 that still refers to the original 4756 source class object (or the appropriate subobject thereof). */ 4757 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4758 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4759 { 4760 if (good_base && at_least_as_qualified_p (t2, t1)) 4761 { 4762 conv = build_identity_conv (t1, e1); 4763 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4764 TYPE_MAIN_VARIANT (t2))) 4765 conv = build_conv (ck_base, t2, conv); 4766 else 4767 conv = build_conv (ck_rvalue, t2, conv); 4768 return conv; 4769 } 4770 else 4771 return NULL; 4772 } 4773 else 4774 /* [expr.cond] 4775 4776 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4777 converted to the type that expression E2 would have if E2 were 4778 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4779 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4780 LOOKUP_IMPLICIT, complain); 4781 } 4782 4783 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4784 arguments to the conditional expression. */ 4785 4786 static tree 4787 build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3, 4788 tsubst_flags_t complain) 4789 { 4790 tree arg2_type; 4791 tree arg3_type; 4792 tree result = NULL_TREE; 4793 tree result_type = NULL_TREE; 4794 bool is_glvalue = true; 4795 struct z_candidate *candidates = 0; 4796 struct z_candidate *cand; 4797 void *p; 4798 tree orig_arg2, orig_arg3; 4799 4800 /* As a G++ extension, the second argument to the conditional can be 4801 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 4802 c'.) If the second operand is omitted, make sure it is 4803 calculated only once. */ 4804 if (!arg2) 4805 { 4806 if (complain & tf_error) 4807 pedwarn (loc, OPT_Wpedantic, 4808 "ISO C++ forbids omitting the middle term of a ?: expression"); 4809 4810 if ((complain & tf_warning) && !truth_value_p (TREE_CODE (arg1))) 4811 warn_for_omitted_condop (loc, arg1); 4812 4813 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 4814 if (lvalue_p (arg1)) 4815 arg2 = arg1 = cp_stabilize_reference (arg1); 4816 else 4817 arg2 = arg1 = cp_save_expr (arg1); 4818 } 4819 4820 /* If something has already gone wrong, just pass that fact up the 4821 tree. */ 4822 if (error_operand_p (arg1) 4823 || error_operand_p (arg2) 4824 || error_operand_p (arg3)) 4825 return error_mark_node; 4826 4827 orig_arg2 = arg2; 4828 orig_arg3 = arg3; 4829 4830 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1))) 4831 { 4832 tree arg1_type = TREE_TYPE (arg1); 4833 4834 /* If arg1 is another cond_expr choosing between -1 and 0, 4835 then we can use its comparison. It may help to avoid 4836 additional comparison, produce more accurate diagnostics 4837 and enables folding. */ 4838 if (TREE_CODE (arg1) == VEC_COND_EXPR 4839 && integer_minus_onep (TREE_OPERAND (arg1, 1)) 4840 && integer_zerop (TREE_OPERAND (arg1, 2))) 4841 arg1 = TREE_OPERAND (arg1, 0); 4842 4843 arg1 = force_rvalue (arg1, complain); 4844 arg2 = force_rvalue (arg2, complain); 4845 arg3 = force_rvalue (arg3, complain); 4846 4847 /* force_rvalue can return error_mark on valid arguments. */ 4848 if (error_operand_p (arg1) 4849 || error_operand_p (arg2) 4850 || error_operand_p (arg3)) 4851 return error_mark_node; 4852 4853 arg2_type = TREE_TYPE (arg2); 4854 arg3_type = TREE_TYPE (arg3); 4855 4856 if (!VECTOR_TYPE_P (arg2_type) 4857 && !VECTOR_TYPE_P (arg3_type)) 4858 { 4859 /* Rely on the error messages of the scalar version. */ 4860 tree scal = build_conditional_expr_1 (loc, integer_one_node, 4861 orig_arg2, orig_arg3, complain); 4862 if (scal == error_mark_node) 4863 return error_mark_node; 4864 tree stype = TREE_TYPE (scal); 4865 tree ctype = TREE_TYPE (arg1_type); 4866 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype) 4867 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype))) 4868 { 4869 if (complain & tf_error) 4870 error_at (loc, "inferred scalar type %qT is not an integer or " 4871 "floating point type of the same size as %qT", stype, 4872 COMPARISON_CLASS_P (arg1) 4873 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0))) 4874 : ctype); 4875 return error_mark_node; 4876 } 4877 4878 tree vtype = build_opaque_vector_type (stype, 4879 TYPE_VECTOR_SUBPARTS (arg1_type)); 4880 /* We could pass complain & tf_warning to unsafe_conversion_p, 4881 but the warnings (like Wsign-conversion) have already been 4882 given by the scalar build_conditional_expr_1. We still check 4883 unsafe_conversion_p to forbid truncating long long -> float. */ 4884 if (unsafe_conversion_p (loc, stype, arg2, NULL_TREE, false)) 4885 { 4886 if (complain & tf_error) 4887 error_at (loc, "conversion of scalar %qH to vector %qI " 4888 "involves truncation", arg2_type, vtype); 4889 return error_mark_node; 4890 } 4891 if (unsafe_conversion_p (loc, stype, arg3, NULL_TREE, false)) 4892 { 4893 if (complain & tf_error) 4894 error_at (loc, "conversion of scalar %qH to vector %qI " 4895 "involves truncation", arg3_type, vtype); 4896 return error_mark_node; 4897 } 4898 4899 arg2 = cp_convert (stype, arg2, complain); 4900 arg2 = save_expr (arg2); 4901 arg2 = build_vector_from_val (vtype, arg2); 4902 arg2_type = vtype; 4903 arg3 = cp_convert (stype, arg3, complain); 4904 arg3 = save_expr (arg3); 4905 arg3 = build_vector_from_val (vtype, arg3); 4906 arg3_type = vtype; 4907 } 4908 4909 if (VECTOR_TYPE_P (arg2_type) != VECTOR_TYPE_P (arg3_type)) 4910 { 4911 enum stv_conv convert_flag = 4912 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3, 4913 complain & tf_error); 4914 4915 switch (convert_flag) 4916 { 4917 case stv_error: 4918 return error_mark_node; 4919 case stv_firstarg: 4920 { 4921 arg2 = save_expr (arg2); 4922 arg2 = convert (TREE_TYPE (arg3_type), arg2); 4923 arg2 = build_vector_from_val (arg3_type, arg2); 4924 arg2_type = TREE_TYPE (arg2); 4925 break; 4926 } 4927 case stv_secondarg: 4928 { 4929 arg3 = save_expr (arg3); 4930 arg3 = convert (TREE_TYPE (arg2_type), arg3); 4931 arg3 = build_vector_from_val (arg2_type, arg3); 4932 arg3_type = TREE_TYPE (arg3); 4933 break; 4934 } 4935 default: 4936 break; 4937 } 4938 } 4939 4940 if (!same_type_p (arg2_type, arg3_type) 4941 || maybe_ne (TYPE_VECTOR_SUBPARTS (arg1_type), 4942 TYPE_VECTOR_SUBPARTS (arg2_type)) 4943 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type)) 4944 { 4945 if (complain & tf_error) 4946 error_at (loc, 4947 "incompatible vector types in conditional expression: " 4948 "%qT, %qT and %qT", TREE_TYPE (arg1), 4949 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3)); 4950 return error_mark_node; 4951 } 4952 4953 if (!COMPARISON_CLASS_P (arg1)) 4954 { 4955 tree cmp_type = build_same_sized_truth_vector_type (arg1_type); 4956 arg1 = build2 (NE_EXPR, cmp_type, arg1, build_zero_cst (arg1_type)); 4957 } 4958 return build3_loc (loc, VEC_COND_EXPR, arg2_type, arg1, arg2, arg3); 4959 } 4960 4961 /* [expr.cond] 4962 4963 The first expression is implicitly converted to bool (clause 4964 _conv_). */ 4965 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 4966 LOOKUP_NORMAL); 4967 if (error_operand_p (arg1)) 4968 return error_mark_node; 4969 4970 /* [expr.cond] 4971 4972 If either the second or the third operand has type (possibly 4973 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 4974 array-to-pointer (_conv.array_), and function-to-pointer 4975 (_conv.func_) standard conversions are performed on the second 4976 and third operands. */ 4977 arg2_type = unlowered_expr_type (arg2); 4978 arg3_type = unlowered_expr_type (arg3); 4979 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 4980 { 4981 /* Do the conversions. We don't these for `void' type arguments 4982 since it can't have any effect and since decay_conversion 4983 does not handle that case gracefully. */ 4984 if (!VOID_TYPE_P (arg2_type)) 4985 arg2 = decay_conversion (arg2, complain); 4986 if (!VOID_TYPE_P (arg3_type)) 4987 arg3 = decay_conversion (arg3, complain); 4988 arg2_type = TREE_TYPE (arg2); 4989 arg3_type = TREE_TYPE (arg3); 4990 4991 /* [expr.cond] 4992 4993 One of the following shall hold: 4994 4995 --The second or the third operand (but not both) is a 4996 throw-expression (_except.throw_); the result is of the 4997 type of the other and is an rvalue. 4998 4999 --Both the second and the third operands have type void; the 5000 result is of type void and is an rvalue. 5001 5002 We must avoid calling force_rvalue for expressions of type 5003 "void" because it will complain that their value is being 5004 used. */ 5005 if (TREE_CODE (arg2) == THROW_EXPR 5006 && TREE_CODE (arg3) != THROW_EXPR) 5007 { 5008 if (!VOID_TYPE_P (arg3_type)) 5009 { 5010 arg3 = force_rvalue (arg3, complain); 5011 if (arg3 == error_mark_node) 5012 return error_mark_node; 5013 } 5014 arg3_type = TREE_TYPE (arg3); 5015 result_type = arg3_type; 5016 } 5017 else if (TREE_CODE (arg2) != THROW_EXPR 5018 && TREE_CODE (arg3) == THROW_EXPR) 5019 { 5020 if (!VOID_TYPE_P (arg2_type)) 5021 { 5022 arg2 = force_rvalue (arg2, complain); 5023 if (arg2 == error_mark_node) 5024 return error_mark_node; 5025 } 5026 arg2_type = TREE_TYPE (arg2); 5027 result_type = arg2_type; 5028 } 5029 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 5030 result_type = void_type_node; 5031 else 5032 { 5033 if (complain & tf_error) 5034 { 5035 if (VOID_TYPE_P (arg2_type)) 5036 error_at (EXPR_LOC_OR_LOC (arg3, loc), 5037 "second operand to the conditional operator " 5038 "is of type %<void%>, but the third operand is " 5039 "neither a throw-expression nor of type %<void%>"); 5040 else 5041 error_at (EXPR_LOC_OR_LOC (arg2, loc), 5042 "third operand to the conditional operator " 5043 "is of type %<void%>, but the second operand is " 5044 "neither a throw-expression nor of type %<void%>"); 5045 } 5046 return error_mark_node; 5047 } 5048 5049 is_glvalue = false; 5050 goto valid_operands; 5051 } 5052 /* [expr.cond] 5053 5054 Otherwise, if the second and third operand have different types, 5055 and either has (possibly cv-qualified) class type, or if both are 5056 glvalues of the same value category and the same type except for 5057 cv-qualification, an attempt is made to convert each of those operands 5058 to the type of the other. */ 5059 else if (!same_type_p (arg2_type, arg3_type) 5060 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type) 5061 || (same_type_ignoring_top_level_qualifiers_p (arg2_type, 5062 arg3_type) 5063 && glvalue_p (arg2) && glvalue_p (arg3) 5064 && lvalue_p (arg2) == lvalue_p (arg3)))) 5065 { 5066 conversion *conv2; 5067 conversion *conv3; 5068 bool converted = false; 5069 5070 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5071 p = conversion_obstack_alloc (0); 5072 5073 conv2 = conditional_conversion (arg2, arg3, complain); 5074 conv3 = conditional_conversion (arg3, arg2, complain); 5075 5076 /* [expr.cond] 5077 5078 If both can be converted, or one can be converted but the 5079 conversion is ambiguous, the program is ill-formed. If 5080 neither can be converted, the operands are left unchanged and 5081 further checking is performed as described below. If exactly 5082 one conversion is possible, that conversion is applied to the 5083 chosen operand and the converted operand is used in place of 5084 the original operand for the remainder of this section. */ 5085 if ((conv2 && !conv2->bad_p 5086 && conv3 && !conv3->bad_p) 5087 || (conv2 && conv2->kind == ck_ambig) 5088 || (conv3 && conv3->kind == ck_ambig)) 5089 { 5090 if (complain & tf_error) 5091 { 5092 error_at (loc, "operands to ?: have different types %qT and %qT", 5093 arg2_type, arg3_type); 5094 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p) 5095 inform (loc, " and each type can be converted to the other"); 5096 else if (conv2 && conv2->kind == ck_ambig) 5097 convert_like (conv2, arg2, complain); 5098 else 5099 convert_like (conv3, arg3, complain); 5100 } 5101 result = error_mark_node; 5102 } 5103 else if (conv2 && !conv2->bad_p) 5104 { 5105 arg2 = convert_like (conv2, arg2, complain); 5106 arg2 = convert_from_reference (arg2); 5107 arg2_type = TREE_TYPE (arg2); 5108 /* Even if CONV2 is a valid conversion, the result of the 5109 conversion may be invalid. For example, if ARG3 has type 5110 "volatile X", and X does not have a copy constructor 5111 accepting a "volatile X&", then even if ARG2 can be 5112 converted to X, the conversion will fail. */ 5113 if (error_operand_p (arg2)) 5114 result = error_mark_node; 5115 converted = true; 5116 } 5117 else if (conv3 && !conv3->bad_p) 5118 { 5119 arg3 = convert_like (conv3, arg3, complain); 5120 arg3 = convert_from_reference (arg3); 5121 arg3_type = TREE_TYPE (arg3); 5122 if (error_operand_p (arg3)) 5123 result = error_mark_node; 5124 converted = true; 5125 } 5126 5127 /* Free all the conversions we allocated. */ 5128 obstack_free (&conversion_obstack, p); 5129 5130 if (result) 5131 return result; 5132 5133 /* If, after the conversion, both operands have class type, 5134 treat the cv-qualification of both operands as if it were the 5135 union of the cv-qualification of the operands. 5136 5137 The standard is not clear about what to do in this 5138 circumstance. For example, if the first operand has type 5139 "const X" and the second operand has a user-defined 5140 conversion to "volatile X", what is the type of the second 5141 operand after this step? Making it be "const X" (matching 5142 the first operand) seems wrong, as that discards the 5143 qualification without actually performing a copy. Leaving it 5144 as "volatile X" seems wrong as that will result in the 5145 conditional expression failing altogether, even though, 5146 according to this step, the one operand could be converted to 5147 the type of the other. */ 5148 if (converted 5149 && CLASS_TYPE_P (arg2_type) 5150 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 5151 arg2_type = arg3_type = 5152 cp_build_qualified_type (arg2_type, 5153 cp_type_quals (arg2_type) 5154 | cp_type_quals (arg3_type)); 5155 } 5156 5157 /* [expr.cond] 5158 5159 If the second and third operands are glvalues of the same value 5160 category and have the same type, the result is of that type and 5161 value category. */ 5162 if (((lvalue_p (arg2) && lvalue_p (arg3)) 5163 || (xvalue_p (arg2) && xvalue_p (arg3))) 5164 && same_type_p (arg2_type, arg3_type)) 5165 { 5166 result_type = arg2_type; 5167 if (processing_template_decl) 5168 /* Let lvalue_kind know this was a glvalue. */ 5169 result_type = cp_build_reference_type (result_type, xvalue_p (arg2)); 5170 5171 arg2 = mark_lvalue_use (arg2); 5172 arg3 = mark_lvalue_use (arg3); 5173 goto valid_operands; 5174 } 5175 5176 /* [expr.cond] 5177 5178 Otherwise, the result is an rvalue. If the second and third 5179 operand do not have the same type, and either has (possibly 5180 cv-qualified) class type, overload resolution is used to 5181 determine the conversions (if any) to be applied to the operands 5182 (_over.match.oper_, _over.built_). */ 5183 is_glvalue = false; 5184 if (!same_type_p (arg2_type, arg3_type) 5185 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 5186 { 5187 tree args[3]; 5188 conversion *conv; 5189 bool any_viable_p; 5190 5191 /* Rearrange the arguments so that add_builtin_candidate only has 5192 to know about two args. In build_builtin_candidate, the 5193 arguments are unscrambled. */ 5194 args[0] = arg2; 5195 args[1] = arg3; 5196 args[2] = arg1; 5197 add_builtin_candidates (&candidates, 5198 COND_EXPR, 5199 NOP_EXPR, 5200 ovl_op_identifier (false, COND_EXPR), 5201 args, 5202 LOOKUP_NORMAL, complain); 5203 5204 /* [expr.cond] 5205 5206 If the overload resolution fails, the program is 5207 ill-formed. */ 5208 candidates = splice_viable (candidates, false, &any_viable_p); 5209 if (!any_viable_p) 5210 { 5211 if (complain & tf_error) 5212 error_at (loc, "operands to ?: have different types %qT and %qT", 5213 arg2_type, arg3_type); 5214 return error_mark_node; 5215 } 5216 cand = tourney (candidates, complain); 5217 if (!cand) 5218 { 5219 if (complain & tf_error) 5220 { 5221 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 5222 print_z_candidates (loc, candidates); 5223 } 5224 return error_mark_node; 5225 } 5226 5227 /* [expr.cond] 5228 5229 Otherwise, the conversions thus determined are applied, and 5230 the converted operands are used in place of the original 5231 operands for the remainder of this section. */ 5232 conv = cand->convs[0]; 5233 arg1 = convert_like (conv, arg1, complain); 5234 conv = cand->convs[1]; 5235 arg2 = convert_like (conv, arg2, complain); 5236 arg2_type = TREE_TYPE (arg2); 5237 conv = cand->convs[2]; 5238 arg3 = convert_like (conv, arg3, complain); 5239 arg3_type = TREE_TYPE (arg3); 5240 } 5241 5242 /* [expr.cond] 5243 5244 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 5245 and function-to-pointer (_conv.func_) standard conversions are 5246 performed on the second and third operands. 5247 5248 We need to force the lvalue-to-rvalue conversion here for class types, 5249 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 5250 that isn't wrapped with a TARGET_EXPR plays havoc with exception 5251 regions. */ 5252 5253 arg2 = force_rvalue (arg2, complain); 5254 if (!CLASS_TYPE_P (arg2_type)) 5255 arg2_type = TREE_TYPE (arg2); 5256 5257 arg3 = force_rvalue (arg3, complain); 5258 if (!CLASS_TYPE_P (arg3_type)) 5259 arg3_type = TREE_TYPE (arg3); 5260 5261 if (arg2 == error_mark_node || arg3 == error_mark_node) 5262 return error_mark_node; 5263 5264 /* [expr.cond] 5265 5266 After those conversions, one of the following shall hold: 5267 5268 --The second and third operands have the same type; the result is of 5269 that type. */ 5270 if (same_type_p (arg2_type, arg3_type)) 5271 result_type = arg2_type; 5272 /* [expr.cond] 5273 5274 --The second and third operands have arithmetic or enumeration 5275 type; the usual arithmetic conversions are performed to bring 5276 them to a common type, and the result is of that type. */ 5277 else if ((ARITHMETIC_TYPE_P (arg2_type) 5278 || UNSCOPED_ENUM_P (arg2_type)) 5279 && (ARITHMETIC_TYPE_P (arg3_type) 5280 || UNSCOPED_ENUM_P (arg3_type))) 5281 { 5282 /* In this case, there is always a common type. */ 5283 result_type = type_after_usual_arithmetic_conversions (arg2_type, 5284 arg3_type); 5285 if (complain & tf_warning) 5286 do_warn_double_promotion (result_type, arg2_type, arg3_type, 5287 "implicit conversion from %qH to %qI to " 5288 "match other result of conditional", 5289 loc); 5290 5291 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 5292 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 5293 { 5294 if (TREE_CODE (orig_arg2) == CONST_DECL 5295 && TREE_CODE (orig_arg3) == CONST_DECL 5296 && DECL_CONTEXT (orig_arg2) == DECL_CONTEXT (orig_arg3)) 5297 /* Two enumerators from the same enumeration can have different 5298 types when the enumeration is still being defined. */; 5299 else if (complain & tf_warning) 5300 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in " 5301 "conditional expression: %qT vs %qT", 5302 arg2_type, arg3_type); 5303 } 5304 else if (extra_warnings 5305 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 5306 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 5307 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 5308 && !same_type_p (arg2_type, 5309 type_promotes_to (arg3_type))))) 5310 { 5311 if (complain & tf_warning) 5312 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in " 5313 "conditional expression"); 5314 } 5315 5316 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5317 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5318 } 5319 /* [expr.cond] 5320 5321 --The second and third operands have pointer type, or one has 5322 pointer type and the other is a null pointer constant; pointer 5323 conversions (_conv.ptr_) and qualification conversions 5324 (_conv.qual_) are performed to bring them to their composite 5325 pointer type (_expr.rel_). The result is of the composite 5326 pointer type. 5327 5328 --The second and third operands have pointer to member type, or 5329 one has pointer to member type and the other is a null pointer 5330 constant; pointer to member conversions (_conv.mem_) and 5331 qualification conversions (_conv.qual_) are performed to bring 5332 them to a common type, whose cv-qualification shall match the 5333 cv-qualification of either the second or the third operand. 5334 The result is of the common type. */ 5335 else if ((null_ptr_cst_p (arg2) 5336 && TYPE_PTR_OR_PTRMEM_P (arg3_type)) 5337 || (null_ptr_cst_p (arg3) 5338 && TYPE_PTR_OR_PTRMEM_P (arg2_type)) 5339 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 5340 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type)) 5341 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 5342 { 5343 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 5344 arg3, CPO_CONDITIONAL_EXPR, 5345 complain); 5346 if (result_type == error_mark_node) 5347 return error_mark_node; 5348 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5349 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5350 } 5351 5352 if (!result_type) 5353 { 5354 if (complain & tf_error) 5355 error_at (loc, "operands to ?: have different types %qT and %qT", 5356 arg2_type, arg3_type); 5357 return error_mark_node; 5358 } 5359 5360 if (arg2 == error_mark_node || arg3 == error_mark_node) 5361 return error_mark_node; 5362 5363 valid_operands: 5364 result = build3_loc (loc, COND_EXPR, result_type, arg1, arg2, arg3); 5365 5366 /* If the ARG2 and ARG3 are the same and don't have side-effects, 5367 warn here, because the COND_EXPR will be turned into ARG2. */ 5368 if (warn_duplicated_branches 5369 && (complain & tf_warning) 5370 && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0))) 5371 warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches, 5372 "this condition has identical branches"); 5373 5374 /* We can't use result_type below, as fold might have returned a 5375 throw_expr. */ 5376 5377 if (!is_glvalue) 5378 { 5379 /* Expand both sides into the same slot, hopefully the target of 5380 the ?: expression. We used to check for TARGET_EXPRs here, 5381 but now we sometimes wrap them in NOP_EXPRs so the test would 5382 fail. */ 5383 if (CLASS_TYPE_P (TREE_TYPE (result))) 5384 result = get_target_expr_sfinae (result, complain); 5385 /* If this expression is an rvalue, but might be mistaken for an 5386 lvalue, we must add a NON_LVALUE_EXPR. */ 5387 result = rvalue (result); 5388 } 5389 else 5390 result = force_paren_expr (result); 5391 5392 return result; 5393 } 5394 5395 /* Wrapper for above. */ 5396 5397 tree 5398 build_conditional_expr (location_t loc, tree arg1, tree arg2, tree arg3, 5399 tsubst_flags_t complain) 5400 { 5401 tree ret; 5402 bool subtime = timevar_cond_start (TV_OVERLOAD); 5403 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain); 5404 timevar_cond_stop (TV_OVERLOAD, subtime); 5405 return ret; 5406 } 5407 5408 /* OPERAND is an operand to an expression. Perform necessary steps 5409 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 5410 returned. */ 5411 5412 static tree 5413 prep_operand (tree operand) 5414 { 5415 if (operand) 5416 { 5417 if (CLASS_TYPE_P (TREE_TYPE (operand)) 5418 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 5419 /* Make sure the template type is instantiated now. */ 5420 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 5421 } 5422 5423 return operand; 5424 } 5425 5426 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 5427 OVERLOAD) to the CANDIDATES, returning an updated list of 5428 CANDIDATES. The ARGS are the arguments provided to the call; 5429 if FIRST_ARG is non-null it is the implicit object argument, 5430 otherwise the first element of ARGS is used if needed. The 5431 EXPLICIT_TARGS are explicit template arguments provided. 5432 TEMPLATE_ONLY is true if only template functions should be 5433 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 5434 add_function_candidate. */ 5435 5436 static void 5437 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args, 5438 tree return_type, 5439 tree explicit_targs, bool template_only, 5440 tree conversion_path, tree access_path, 5441 int flags, 5442 struct z_candidate **candidates, 5443 tsubst_flags_t complain) 5444 { 5445 tree ctype; 5446 const vec<tree, va_gc> *non_static_args; 5447 bool check_list_ctor = false; 5448 bool check_converting = false; 5449 unification_kind_t strict; 5450 5451 if (!fns) 5452 return; 5453 5454 /* Precalculate special handling of constructors and conversion ops. */ 5455 tree fn = OVL_FIRST (fns); 5456 if (DECL_CONV_FN_P (fn)) 5457 { 5458 check_list_ctor = false; 5459 check_converting = (flags & LOOKUP_ONLYCONVERTING) != 0; 5460 if (flags & LOOKUP_NO_CONVERSION) 5461 /* We're doing return_type(x). */ 5462 strict = DEDUCE_CONV; 5463 else 5464 /* We're doing x.operator return_type(). */ 5465 strict = DEDUCE_EXACT; 5466 /* [over.match.funcs] For conversion functions, the function 5467 is considered to be a member of the class of the implicit 5468 object argument for the purpose of defining the type of 5469 the implicit object parameter. */ 5470 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg)); 5471 } 5472 else 5473 { 5474 if (DECL_CONSTRUCTOR_P (fn)) 5475 { 5476 check_list_ctor = (flags & LOOKUP_LIST_ONLY) != 0; 5477 /* For list-initialization we consider explicit constructors 5478 and complain if one is chosen. */ 5479 check_converting 5480 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 5481 == LOOKUP_ONLYCONVERTING); 5482 } 5483 strict = DEDUCE_CALL; 5484 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 5485 } 5486 5487 if (first_arg) 5488 non_static_args = args; 5489 else 5490 /* Delay creating the implicit this parameter until it is needed. */ 5491 non_static_args = NULL; 5492 5493 for (lkp_iterator iter (fns); iter; ++iter) 5494 { 5495 fn = *iter; 5496 5497 if (check_converting && DECL_NONCONVERTING_P (fn)) 5498 continue; 5499 if (check_list_ctor && !is_list_ctor (fn)) 5500 continue; 5501 5502 tree fn_first_arg = NULL_TREE; 5503 const vec<tree, va_gc> *fn_args = args; 5504 5505 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 5506 { 5507 /* Figure out where the object arg comes from. If this 5508 function is a non-static member and we didn't get an 5509 implicit object argument, move it out of args. */ 5510 if (first_arg == NULL_TREE) 5511 { 5512 unsigned int ix; 5513 tree arg; 5514 vec<tree, va_gc> *tempvec; 5515 vec_alloc (tempvec, args->length () - 1); 5516 for (ix = 1; args->iterate (ix, &arg); ++ix) 5517 tempvec->quick_push (arg); 5518 non_static_args = tempvec; 5519 first_arg = (*args)[0]; 5520 } 5521 5522 fn_first_arg = first_arg; 5523 fn_args = non_static_args; 5524 } 5525 5526 if (TREE_CODE (fn) == TEMPLATE_DECL) 5527 add_template_candidate (candidates, 5528 fn, 5529 ctype, 5530 explicit_targs, 5531 fn_first_arg, 5532 fn_args, 5533 return_type, 5534 access_path, 5535 conversion_path, 5536 flags, 5537 strict, 5538 complain); 5539 else if (!template_only) 5540 add_function_candidate (candidates, 5541 fn, 5542 ctype, 5543 fn_first_arg, 5544 fn_args, 5545 access_path, 5546 conversion_path, 5547 flags, 5548 complain); 5549 } 5550 } 5551 5552 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first, 5553 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */ 5554 5555 static int 5556 op_is_ordered (tree_code code) 5557 { 5558 switch (code) 5559 { 5560 // 5. b @= a 5561 case MODIFY_EXPR: 5562 return (flag_strong_eval_order > 1 ? -1 : 0); 5563 5564 // 6. a[b] 5565 case ARRAY_REF: 5566 return (flag_strong_eval_order > 1 ? 1 : 0); 5567 5568 // 1. a.b 5569 // Not overloadable (yet). 5570 // 2. a->b 5571 // Only one argument. 5572 // 3. a->*b 5573 case MEMBER_REF: 5574 // 7. a << b 5575 case LSHIFT_EXPR: 5576 // 8. a >> b 5577 case RSHIFT_EXPR: 5578 return (flag_strong_eval_order ? 1 : 0); 5579 5580 default: 5581 return 0; 5582 } 5583 } 5584 5585 static tree 5586 build_new_op_1 (location_t loc, enum tree_code code, int flags, tree arg1, 5587 tree arg2, tree arg3, tree *overload, tsubst_flags_t complain) 5588 { 5589 struct z_candidate *candidates = 0, *cand; 5590 vec<tree, va_gc> *arglist; 5591 tree args[3]; 5592 tree result = NULL_TREE; 5593 bool result_valid_p = false; 5594 enum tree_code code2 = NOP_EXPR; 5595 enum tree_code code_orig_arg1 = ERROR_MARK; 5596 enum tree_code code_orig_arg2 = ERROR_MARK; 5597 conversion *conv; 5598 void *p; 5599 bool strict_p; 5600 bool any_viable_p; 5601 5602 if (error_operand_p (arg1) 5603 || error_operand_p (arg2) 5604 || error_operand_p (arg3)) 5605 return error_mark_node; 5606 5607 bool ismodop = code == MODIFY_EXPR; 5608 if (ismodop) 5609 { 5610 code2 = TREE_CODE (arg3); 5611 arg3 = NULL_TREE; 5612 } 5613 tree fnname = ovl_op_identifier (ismodop, ismodop ? code2 : code); 5614 5615 arg1 = prep_operand (arg1); 5616 5617 bool memonly = false; 5618 switch (code) 5619 { 5620 case NEW_EXPR: 5621 case VEC_NEW_EXPR: 5622 case VEC_DELETE_EXPR: 5623 case DELETE_EXPR: 5624 /* Use build_op_new_call and build_op_delete_call instead. */ 5625 gcc_unreachable (); 5626 5627 case CALL_EXPR: 5628 /* Use build_op_call instead. */ 5629 gcc_unreachable (); 5630 5631 case TRUTH_ORIF_EXPR: 5632 case TRUTH_ANDIF_EXPR: 5633 case TRUTH_AND_EXPR: 5634 case TRUTH_OR_EXPR: 5635 /* These are saved for the sake of warn_logical_operator. */ 5636 code_orig_arg1 = TREE_CODE (arg1); 5637 code_orig_arg2 = TREE_CODE (arg2); 5638 break; 5639 case GT_EXPR: 5640 case LT_EXPR: 5641 case GE_EXPR: 5642 case LE_EXPR: 5643 case EQ_EXPR: 5644 case NE_EXPR: 5645 /* These are saved for the sake of maybe_warn_bool_compare. */ 5646 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1)); 5647 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2)); 5648 break; 5649 5650 /* =, ->, [], () must be non-static member functions. */ 5651 case MODIFY_EXPR: 5652 if (code2 != NOP_EXPR) 5653 break; 5654 /* FALLTHRU */ 5655 case COMPONENT_REF: 5656 case ARRAY_REF: 5657 memonly = true; 5658 break; 5659 5660 default: 5661 break; 5662 } 5663 5664 arg2 = prep_operand (arg2); 5665 arg3 = prep_operand (arg3); 5666 5667 if (code == COND_EXPR) 5668 /* Use build_conditional_expr instead. */ 5669 gcc_unreachable (); 5670 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1)) 5671 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2)))) 5672 goto builtin; 5673 5674 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 5675 arg2 = integer_zero_node; 5676 5677 vec_alloc (arglist, 3); 5678 arglist->quick_push (arg1); 5679 if (arg2 != NULL_TREE) 5680 arglist->quick_push (arg2); 5681 if (arg3 != NULL_TREE) 5682 arglist->quick_push (arg3); 5683 5684 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5685 p = conversion_obstack_alloc (0); 5686 5687 /* Add namespace-scope operators to the list of functions to 5688 consider. */ 5689 if (!memonly) 5690 { 5691 tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0); 5692 fns = lookup_arg_dependent (fnname, fns, arglist); 5693 add_candidates (fns, NULL_TREE, arglist, NULL_TREE, 5694 NULL_TREE, false, NULL_TREE, NULL_TREE, 5695 flags, &candidates, complain); 5696 } 5697 5698 args[0] = arg1; 5699 args[1] = arg2; 5700 args[2] = NULL_TREE; 5701 5702 /* Add class-member operators to the candidate set. */ 5703 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 5704 { 5705 tree fns; 5706 5707 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 5708 if (fns == error_mark_node) 5709 { 5710 result = error_mark_node; 5711 goto user_defined_result_ready; 5712 } 5713 if (fns) 5714 add_candidates (BASELINK_FUNCTIONS (fns), 5715 NULL_TREE, arglist, NULL_TREE, 5716 NULL_TREE, false, 5717 BASELINK_BINFO (fns), 5718 BASELINK_ACCESS_BINFO (fns), 5719 flags, &candidates, complain); 5720 } 5721 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then 5722 only non-member functions that have type T1 or reference to 5723 cv-qualified-opt T1 for the first argument, if the first argument 5724 has an enumeration type, or T2 or reference to cv-qualified-opt 5725 T2 for the second argument, if the second argument has an 5726 enumeration type. Filter out those that don't match. */ 5727 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2))) 5728 { 5729 struct z_candidate **candp, **next; 5730 5731 for (candp = &candidates; *candp; candp = next) 5732 { 5733 tree parmlist, parmtype; 5734 int i, nargs = (arg2 ? 2 : 1); 5735 5736 cand = *candp; 5737 next = &cand->next; 5738 5739 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 5740 5741 for (i = 0; i < nargs; ++i) 5742 { 5743 parmtype = TREE_VALUE (parmlist); 5744 5745 if (TREE_CODE (parmtype) == REFERENCE_TYPE) 5746 parmtype = TREE_TYPE (parmtype); 5747 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE 5748 && (same_type_ignoring_top_level_qualifiers_p 5749 (TREE_TYPE (args[i]), parmtype))) 5750 break; 5751 5752 parmlist = TREE_CHAIN (parmlist); 5753 } 5754 5755 /* No argument has an appropriate type, so remove this 5756 candidate function from the list. */ 5757 if (i == nargs) 5758 { 5759 *candp = cand->next; 5760 next = candp; 5761 } 5762 } 5763 } 5764 5765 add_builtin_candidates (&candidates, code, code2, fnname, args, 5766 flags, complain); 5767 5768 switch (code) 5769 { 5770 case COMPOUND_EXPR: 5771 case ADDR_EXPR: 5772 /* For these, the built-in candidates set is empty 5773 [over.match.oper]/3. We don't want non-strict matches 5774 because exact matches are always possible with built-in 5775 operators. The built-in candidate set for COMPONENT_REF 5776 would be empty too, but since there are no such built-in 5777 operators, we accept non-strict matches for them. */ 5778 strict_p = true; 5779 break; 5780 5781 default: 5782 strict_p = false; 5783 break; 5784 } 5785 5786 candidates = splice_viable (candidates, strict_p, &any_viable_p); 5787 if (!any_viable_p) 5788 { 5789 switch (code) 5790 { 5791 case POSTINCREMENT_EXPR: 5792 case POSTDECREMENT_EXPR: 5793 /* Don't try anything fancy if we're not allowed to produce 5794 errors. */ 5795 if (!(complain & tf_error)) 5796 return error_mark_node; 5797 5798 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 5799 distinguish between prefix and postfix ++ and 5800 operator++() was used for both, so we allow this with 5801 -fpermissive. */ 5802 else 5803 { 5804 const char *msg = (flag_permissive) 5805 ? G_("no %<%D(int)%> declared for postfix %qs," 5806 " trying prefix operator instead") 5807 : G_("no %<%D(int)%> declared for postfix %qs"); 5808 permerror (loc, msg, fnname, OVL_OP_INFO (false, code)->name); 5809 } 5810 5811 if (!flag_permissive) 5812 return error_mark_node; 5813 5814 if (code == POSTINCREMENT_EXPR) 5815 code = PREINCREMENT_EXPR; 5816 else 5817 code = PREDECREMENT_EXPR; 5818 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE, 5819 NULL_TREE, overload, complain); 5820 break; 5821 5822 /* The caller will deal with these. */ 5823 case ADDR_EXPR: 5824 case COMPOUND_EXPR: 5825 case COMPONENT_REF: 5826 result = NULL_TREE; 5827 result_valid_p = true; 5828 break; 5829 5830 default: 5831 if (complain & tf_error) 5832 { 5833 /* If one of the arguments of the operator represents 5834 an invalid use of member function pointer, try to report 5835 a meaningful error ... */ 5836 if (invalid_nonstatic_memfn_p (loc, arg1, tf_error) 5837 || invalid_nonstatic_memfn_p (loc, arg2, tf_error) 5838 || invalid_nonstatic_memfn_p (loc, arg3, tf_error)) 5839 /* We displayed the error message. */; 5840 else 5841 { 5842 /* ... Otherwise, report the more generic 5843 "no matching operator found" error */ 5844 op_error (loc, code, code2, arg1, arg2, arg3, FALSE); 5845 print_z_candidates (loc, candidates); 5846 } 5847 } 5848 result = error_mark_node; 5849 break; 5850 } 5851 } 5852 else 5853 { 5854 cand = tourney (candidates, complain); 5855 if (cand == 0) 5856 { 5857 if (complain & tf_error) 5858 { 5859 op_error (loc, code, code2, arg1, arg2, arg3, TRUE); 5860 print_z_candidates (loc, candidates); 5861 } 5862 result = error_mark_node; 5863 } 5864 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 5865 { 5866 if (overload) 5867 *overload = cand->fn; 5868 5869 if (resolve_args (arglist, complain) == NULL) 5870 result = error_mark_node; 5871 else 5872 result = build_over_call (cand, LOOKUP_NORMAL, complain); 5873 5874 if (trivial_fn_p (cand->fn)) 5875 /* There won't be a CALL_EXPR. */; 5876 else if (result && result != error_mark_node) 5877 { 5878 tree call = extract_call_expr (result); 5879 CALL_EXPR_OPERATOR_SYNTAX (call) = true; 5880 5881 if (processing_template_decl && DECL_HIDDEN_FRIEND_P (cand->fn)) 5882 /* This prevents build_new_function_call from discarding this 5883 function during instantiation of the enclosing template. */ 5884 KOENIG_LOOKUP_P (call) = 1; 5885 5886 /* Specify evaluation order as per P0145R2. */ 5887 CALL_EXPR_ORDERED_ARGS (call) = false; 5888 switch (op_is_ordered (code)) 5889 { 5890 case -1: 5891 CALL_EXPR_REVERSE_ARGS (call) = true; 5892 break; 5893 5894 case 1: 5895 CALL_EXPR_ORDERED_ARGS (call) = true; 5896 break; 5897 5898 default: 5899 break; 5900 } 5901 } 5902 } 5903 else 5904 { 5905 /* Give any warnings we noticed during overload resolution. */ 5906 if (cand->warnings && (complain & tf_warning)) 5907 { 5908 struct candidate_warning *w; 5909 for (w = cand->warnings; w; w = w->next) 5910 joust (cand, w->loser, 1, complain); 5911 } 5912 5913 /* Check for comparison of different enum types. */ 5914 switch (code) 5915 { 5916 case GT_EXPR: 5917 case LT_EXPR: 5918 case GE_EXPR: 5919 case LE_EXPR: 5920 case EQ_EXPR: 5921 case NE_EXPR: 5922 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 5923 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 5924 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 5925 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 5926 && (complain & tf_warning)) 5927 { 5928 warning (OPT_Wenum_compare, 5929 "comparison between %q#T and %q#T", 5930 TREE_TYPE (arg1), TREE_TYPE (arg2)); 5931 } 5932 break; 5933 default: 5934 break; 5935 } 5936 5937 /* We need to strip any leading REF_BIND so that bitfields 5938 don't cause errors. This should not remove any important 5939 conversions, because builtins don't apply to class 5940 objects directly. */ 5941 conv = cand->convs[0]; 5942 if (conv->kind == ck_ref_bind) 5943 conv = next_conversion (conv); 5944 arg1 = convert_like (conv, arg1, complain); 5945 5946 if (arg2) 5947 { 5948 conv = cand->convs[1]; 5949 if (conv->kind == ck_ref_bind) 5950 conv = next_conversion (conv); 5951 else 5952 arg2 = decay_conversion (arg2, complain); 5953 5954 /* We need to call warn_logical_operator before 5955 converting arg2 to a boolean_type, but after 5956 decaying an enumerator to its value. */ 5957 if (complain & tf_warning) 5958 warn_logical_operator (loc, code, boolean_type_node, 5959 code_orig_arg1, arg1, 5960 code_orig_arg2, arg2); 5961 5962 arg2 = convert_like (conv, arg2, complain); 5963 } 5964 if (arg3) 5965 { 5966 conv = cand->convs[2]; 5967 if (conv->kind == ck_ref_bind) 5968 conv = next_conversion (conv); 5969 arg3 = convert_like (conv, arg3, complain); 5970 } 5971 5972 } 5973 } 5974 5975 user_defined_result_ready: 5976 5977 /* Free all the conversions we allocated. */ 5978 obstack_free (&conversion_obstack, p); 5979 5980 if (result || result_valid_p) 5981 return result; 5982 5983 builtin: 5984 switch (code) 5985 { 5986 case MODIFY_EXPR: 5987 return cp_build_modify_expr (loc, arg1, code2, arg2, complain); 5988 5989 case INDIRECT_REF: 5990 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 5991 5992 case TRUTH_ANDIF_EXPR: 5993 case TRUTH_ORIF_EXPR: 5994 case TRUTH_AND_EXPR: 5995 case TRUTH_OR_EXPR: 5996 if (complain & tf_warning) 5997 warn_logical_operator (loc, code, boolean_type_node, 5998 code_orig_arg1, arg1, 5999 code_orig_arg2, arg2); 6000 /* Fall through. */ 6001 case GT_EXPR: 6002 case LT_EXPR: 6003 case GE_EXPR: 6004 case LE_EXPR: 6005 case EQ_EXPR: 6006 case NE_EXPR: 6007 if ((complain & tf_warning) 6008 && ((code_orig_arg1 == BOOLEAN_TYPE) 6009 ^ (code_orig_arg2 == BOOLEAN_TYPE))) 6010 maybe_warn_bool_compare (loc, code, arg1, arg2); 6011 if (complain & tf_warning && warn_tautological_compare) 6012 warn_tautological_cmp (loc, code, arg1, arg2); 6013 /* Fall through. */ 6014 case PLUS_EXPR: 6015 case MINUS_EXPR: 6016 case MULT_EXPR: 6017 case TRUNC_DIV_EXPR: 6018 case MAX_EXPR: 6019 case MIN_EXPR: 6020 case LSHIFT_EXPR: 6021 case RSHIFT_EXPR: 6022 case TRUNC_MOD_EXPR: 6023 case BIT_AND_EXPR: 6024 case BIT_IOR_EXPR: 6025 case BIT_XOR_EXPR: 6026 return cp_build_binary_op (loc, code, arg1, arg2, complain); 6027 6028 case UNARY_PLUS_EXPR: 6029 case NEGATE_EXPR: 6030 case BIT_NOT_EXPR: 6031 case TRUTH_NOT_EXPR: 6032 case PREINCREMENT_EXPR: 6033 case POSTINCREMENT_EXPR: 6034 case PREDECREMENT_EXPR: 6035 case POSTDECREMENT_EXPR: 6036 case REALPART_EXPR: 6037 case IMAGPART_EXPR: 6038 case ABS_EXPR: 6039 return cp_build_unary_op (code, arg1, candidates != 0, complain); 6040 6041 case ARRAY_REF: 6042 return cp_build_array_ref (input_location, arg1, arg2, complain); 6043 6044 case MEMBER_REF: 6045 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR, 6046 complain), 6047 arg2, complain); 6048 6049 /* The caller will deal with these. */ 6050 case ADDR_EXPR: 6051 case COMPONENT_REF: 6052 case COMPOUND_EXPR: 6053 return NULL_TREE; 6054 6055 default: 6056 gcc_unreachable (); 6057 } 6058 return NULL_TREE; 6059 } 6060 6061 /* Wrapper for above. */ 6062 6063 tree 6064 build_new_op (location_t loc, enum tree_code code, int flags, 6065 tree arg1, tree arg2, tree arg3, 6066 tree *overload, tsubst_flags_t complain) 6067 { 6068 tree ret; 6069 bool subtime = timevar_cond_start (TV_OVERLOAD); 6070 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3, 6071 overload, complain); 6072 timevar_cond_stop (TV_OVERLOAD, subtime); 6073 return ret; 6074 } 6075 6076 /* CALL was returned by some call-building function; extract the actual 6077 CALL_EXPR from any bits that have been tacked on, e.g. by 6078 convert_from_reference. */ 6079 6080 tree 6081 extract_call_expr (tree call) 6082 { 6083 while (TREE_CODE (call) == COMPOUND_EXPR) 6084 call = TREE_OPERAND (call, 1); 6085 if (REFERENCE_REF_P (call)) 6086 call = TREE_OPERAND (call, 0); 6087 if (TREE_CODE (call) == TARGET_EXPR) 6088 call = TARGET_EXPR_INITIAL (call); 6089 gcc_assert (TREE_CODE (call) == CALL_EXPR 6090 || TREE_CODE (call) == AGGR_INIT_EXPR 6091 || call == error_mark_node); 6092 return call; 6093 } 6094 6095 /* Returns true if FN has two parameters, of which the second has type 6096 size_t. */ 6097 6098 static bool 6099 second_parm_is_size_t (tree fn) 6100 { 6101 tree t = FUNCTION_ARG_CHAIN (fn); 6102 if (!t || !same_type_p (TREE_VALUE (t), size_type_node)) 6103 return false; 6104 t = TREE_CHAIN (t); 6105 if (t == void_list_node) 6106 return true; 6107 if (aligned_new_threshold && t 6108 && same_type_p (TREE_VALUE (t), align_type_node) 6109 && TREE_CHAIN (t) == void_list_node) 6110 return true; 6111 return false; 6112 } 6113 6114 /* True if T, an allocation function, has std::align_val_t as its second 6115 argument. */ 6116 6117 bool 6118 aligned_allocation_fn_p (tree t) 6119 { 6120 if (!aligned_new_threshold) 6121 return false; 6122 6123 tree a = FUNCTION_ARG_CHAIN (t); 6124 return (a && same_type_p (TREE_VALUE (a), align_type_node)); 6125 } 6126 6127 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation 6128 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of 6129 std::align_val_t. */ 6130 6131 static bool 6132 aligned_deallocation_fn_p (tree t) 6133 { 6134 if (!aligned_new_threshold) 6135 return false; 6136 6137 /* A template instance is never a usual deallocation function, 6138 regardless of its signature. */ 6139 if (TREE_CODE (t) == TEMPLATE_DECL 6140 || primary_template_specialization_p (t)) 6141 return false; 6142 6143 tree a = FUNCTION_ARG_CHAIN (t); 6144 if (same_type_p (TREE_VALUE (a), align_type_node) 6145 && TREE_CHAIN (a) == void_list_node) 6146 return true; 6147 if (!same_type_p (TREE_VALUE (a), size_type_node)) 6148 return false; 6149 a = TREE_CHAIN (a); 6150 if (a && same_type_p (TREE_VALUE (a), align_type_node) 6151 && TREE_CHAIN (a) == void_list_node) 6152 return true; 6153 return false; 6154 } 6155 6156 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 6157 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 6158 6159 bool 6160 usual_deallocation_fn_p (tree t) 6161 { 6162 /* A template instance is never a usual deallocation function, 6163 regardless of its signature. */ 6164 if (TREE_CODE (t) == TEMPLATE_DECL 6165 || primary_template_specialization_p (t)) 6166 return false; 6167 6168 /* If a class T has a member deallocation function named operator delete 6169 with exactly one parameter, then that function is a usual 6170 (non-placement) deallocation function. If class T does not declare 6171 such an operator delete but does declare a member deallocation 6172 function named operator delete with exactly two parameters, the second 6173 of which has type std::size_t (18.2), then this function is a usual 6174 deallocation function. */ 6175 bool global = DECL_NAMESPACE_SCOPE_P (t); 6176 tree chain = FUNCTION_ARG_CHAIN (t); 6177 if (!chain) 6178 return false; 6179 if (chain == void_list_node 6180 || ((!global || flag_sized_deallocation) 6181 && second_parm_is_size_t (t))) 6182 return true; 6183 if (aligned_deallocation_fn_p (t)) 6184 return true; 6185 return false; 6186 } 6187 6188 /* Build a call to operator delete. This has to be handled very specially, 6189 because the restrictions on what signatures match are different from all 6190 other call instances. For a normal delete, only a delete taking (void *) 6191 or (void *, size_t) is accepted. For a placement delete, only an exact 6192 match with the placement new is accepted. 6193 6194 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 6195 ADDR is the pointer to be deleted. 6196 SIZE is the size of the memory block to be deleted. 6197 GLOBAL_P is true if the delete-expression should not consider 6198 class-specific delete operators. 6199 PLACEMENT is the corresponding placement new call, or NULL_TREE. 6200 6201 If this call to "operator delete" is being generated as part to 6202 deallocate memory allocated via a new-expression (as per [expr.new] 6203 which requires that if the initialization throws an exception then 6204 we call a deallocation function), then ALLOC_FN is the allocation 6205 function. */ 6206 6207 tree 6208 build_op_delete_call (enum tree_code code, tree addr, tree size, 6209 bool global_p, tree placement, 6210 tree alloc_fn, tsubst_flags_t complain) 6211 { 6212 tree fn = NULL_TREE; 6213 tree fns, fnname, type, t; 6214 6215 if (addr == error_mark_node) 6216 return error_mark_node; 6217 6218 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 6219 6220 fnname = ovl_op_identifier (false, code); 6221 6222 if (CLASS_TYPE_P (type) 6223 && COMPLETE_TYPE_P (complete_type (type)) 6224 && !global_p) 6225 /* In [class.free] 6226 6227 If the result of the lookup is ambiguous or inaccessible, or if 6228 the lookup selects a placement deallocation function, the 6229 program is ill-formed. 6230 6231 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 6232 { 6233 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 6234 if (fns == error_mark_node) 6235 return error_mark_node; 6236 } 6237 else 6238 fns = NULL_TREE; 6239 6240 if (fns == NULL_TREE) 6241 fns = lookup_name_nonclass (fnname); 6242 6243 /* Strip const and volatile from addr. */ 6244 addr = cp_convert (ptr_type_node, addr, complain); 6245 6246 if (placement) 6247 { 6248 /* "A declaration of a placement deallocation function matches the 6249 declaration of a placement allocation function if it has the same 6250 number of parameters and, after parameter transformations (8.3.5), 6251 all parameter types except the first are identical." 6252 6253 So we build up the function type we want and ask instantiate_type 6254 to get it for us. */ 6255 t = FUNCTION_ARG_CHAIN (alloc_fn); 6256 t = tree_cons (NULL_TREE, ptr_type_node, t); 6257 t = build_function_type (void_type_node, t); 6258 6259 fn = instantiate_type (t, fns, tf_none); 6260 if (fn == error_mark_node) 6261 return NULL_TREE; 6262 6263 fn = MAYBE_BASELINK_FUNCTIONS (fn); 6264 6265 /* "If the lookup finds the two-parameter form of a usual deallocation 6266 function (3.7.4.2) and that function, considered as a placement 6267 deallocation function, would have been selected as a match for the 6268 allocation function, the program is ill-formed." */ 6269 if (second_parm_is_size_t (fn)) 6270 { 6271 const char *const msg1 6272 = G_("exception cleanup for this placement new selects " 6273 "non-placement operator delete"); 6274 const char *const msg2 6275 = G_("%qD is a usual (non-placement) deallocation " 6276 "function in C++14 (or with -fsized-deallocation)"); 6277 6278 /* But if the class has an operator delete (void *), then that is 6279 the usual deallocation function, so we shouldn't complain 6280 about using the operator delete (void *, size_t). */ 6281 if (DECL_CLASS_SCOPE_P (fn)) 6282 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); 6283 iter; ++iter) 6284 { 6285 tree elt = *iter; 6286 if (usual_deallocation_fn_p (elt) 6287 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 6288 goto ok; 6289 } 6290 /* Before C++14 a two-parameter global deallocation function is 6291 always a placement deallocation function, but warn if 6292 -Wc++14-compat. */ 6293 else if (!flag_sized_deallocation) 6294 { 6295 if ((complain & tf_warning) 6296 && warning (OPT_Wc__14_compat, msg1)) 6297 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6298 goto ok; 6299 } 6300 6301 if (complain & tf_warning_or_error) 6302 { 6303 if (permerror (input_location, msg1)) 6304 { 6305 /* Only mention C++14 for namespace-scope delete. */ 6306 if (DECL_NAMESPACE_SCOPE_P (fn)) 6307 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6308 else 6309 inform (DECL_SOURCE_LOCATION (fn), 6310 "%qD is a usual (non-placement) deallocation " 6311 "function", fn); 6312 } 6313 } 6314 else 6315 return error_mark_node; 6316 ok:; 6317 } 6318 } 6319 else 6320 /* "Any non-placement deallocation function matches a non-placement 6321 allocation function. If the lookup finds a single matching 6322 deallocation function, that function will be called; otherwise, no 6323 deallocation function will be called." */ 6324 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter) 6325 { 6326 tree elt = *iter; 6327 if (usual_deallocation_fn_p (elt)) 6328 { 6329 if (!fn) 6330 { 6331 fn = elt; 6332 continue; 6333 } 6334 6335 /* -- If the type has new-extended alignment, a function with a 6336 parameter of type std::align_val_t is preferred; otherwise a 6337 function without such a parameter is preferred. If exactly one 6338 preferred function is found, that function is selected and the 6339 selection process terminates. If more than one preferred 6340 function is found, all non-preferred functions are eliminated 6341 from further consideration. */ 6342 if (aligned_new_threshold) 6343 { 6344 bool want_align = type_has_new_extended_alignment (type); 6345 bool fn_align = aligned_deallocation_fn_p (fn); 6346 bool elt_align = aligned_deallocation_fn_p (elt); 6347 6348 if (elt_align != fn_align) 6349 { 6350 if (want_align == elt_align) 6351 fn = elt; 6352 continue; 6353 } 6354 } 6355 6356 /* -- If the deallocation functions have class scope, the one 6357 without a parameter of type std::size_t is selected. */ 6358 bool want_size; 6359 if (DECL_CLASS_SCOPE_P (fn)) 6360 want_size = false; 6361 6362 /* -- If the type is complete and if, for the second alternative 6363 (delete array) only, the operand is a pointer to a class type 6364 with a non-trivial destructor or a (possibly multi-dimensional) 6365 array thereof, the function with a parameter of type std::size_t 6366 is selected. 6367 6368 -- Otherwise, it is unspecified whether a deallocation function 6369 with a parameter of type std::size_t is selected. */ 6370 else 6371 { 6372 want_size = COMPLETE_TYPE_P (type); 6373 if (code == VEC_DELETE_EXPR 6374 && !TYPE_VEC_NEW_USES_COOKIE (type)) 6375 /* We need a cookie to determine the array size. */ 6376 want_size = false; 6377 } 6378 bool fn_size = second_parm_is_size_t (fn); 6379 bool elt_size = second_parm_is_size_t (elt); 6380 gcc_assert (fn_size != elt_size); 6381 if (want_size == elt_size) 6382 fn = elt; 6383 } 6384 } 6385 6386 /* If we have a matching function, call it. */ 6387 if (fn) 6388 { 6389 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 6390 6391 /* If the FN is a member function, make sure that it is 6392 accessible. */ 6393 if (BASELINK_P (fns)) 6394 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn, 6395 complain); 6396 6397 /* Core issue 901: It's ok to new a type with deleted delete. */ 6398 if (DECL_DELETED_FN (fn) && alloc_fn) 6399 return NULL_TREE; 6400 6401 if (placement) 6402 { 6403 /* The placement args might not be suitable for overload 6404 resolution at this point, so build the call directly. */ 6405 int nargs = call_expr_nargs (placement); 6406 tree *argarray = XALLOCAVEC (tree, nargs); 6407 int i; 6408 argarray[0] = addr; 6409 for (i = 1; i < nargs; i++) 6410 argarray[i] = CALL_EXPR_ARG (placement, i); 6411 if (!mark_used (fn, complain) && !(complain & tf_error)) 6412 return error_mark_node; 6413 return build_cxx_call (fn, nargs, argarray, complain); 6414 } 6415 else 6416 { 6417 tree ret; 6418 vec<tree, va_gc> *args = make_tree_vector (); 6419 args->quick_push (addr); 6420 if (second_parm_is_size_t (fn)) 6421 args->quick_push (size); 6422 if (aligned_deallocation_fn_p (fn)) 6423 { 6424 tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type)); 6425 args->quick_push (al); 6426 } 6427 ret = cp_build_function_call_vec (fn, &args, complain); 6428 release_tree_vector (args); 6429 return ret; 6430 } 6431 } 6432 6433 /* [expr.new] 6434 6435 If no unambiguous matching deallocation function can be found, 6436 propagating the exception does not cause the object's memory to 6437 be freed. */ 6438 if (alloc_fn) 6439 { 6440 if ((complain & tf_warning) 6441 && !placement) 6442 warning (0, "no corresponding deallocation function for %qD", 6443 alloc_fn); 6444 return NULL_TREE; 6445 } 6446 6447 if (complain & tf_error) 6448 error ("no suitable %<operator %s%> for %qT", 6449 OVL_OP_INFO (false, code)->name, type); 6450 return error_mark_node; 6451 } 6452 6453 /* If the current scope isn't allowed to access DECL along 6454 BASETYPE_PATH, give an error. The most derived class in 6455 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 6456 the declaration to use in the error diagnostic. */ 6457 6458 bool 6459 enforce_access (tree basetype_path, tree decl, tree diag_decl, 6460 tsubst_flags_t complain, access_failure_info *afi) 6461 { 6462 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 6463 6464 if (flag_new_inheriting_ctors 6465 && DECL_INHERITED_CTOR (decl)) 6466 { 6467 /* 7.3.3/18: The additional constructors are accessible if they would be 6468 accessible when used to construct an object of the corresponding base 6469 class. */ 6470 decl = strip_inheriting_ctors (decl); 6471 basetype_path = lookup_base (basetype_path, DECL_CONTEXT (decl), 6472 ba_any, NULL, complain); 6473 } 6474 6475 if (!accessible_p (basetype_path, decl, true)) 6476 { 6477 if (complain & tf_error) 6478 { 6479 if (flag_new_inheriting_ctors) 6480 diag_decl = strip_inheriting_ctors (diag_decl); 6481 if (TREE_PRIVATE (decl)) 6482 { 6483 error ("%q#D is private within this context", diag_decl); 6484 inform (DECL_SOURCE_LOCATION (diag_decl), 6485 "declared private here"); 6486 if (afi) 6487 afi->record_access_failure (basetype_path, diag_decl); 6488 } 6489 else if (TREE_PROTECTED (decl)) 6490 { 6491 error ("%q#D is protected within this context", diag_decl); 6492 inform (DECL_SOURCE_LOCATION (diag_decl), 6493 "declared protected here"); 6494 if (afi) 6495 afi->record_access_failure (basetype_path, diag_decl); 6496 } 6497 else 6498 { 6499 error ("%q#D is inaccessible within this context", diag_decl); 6500 inform (DECL_SOURCE_LOCATION (diag_decl), "declared here"); 6501 if (afi) 6502 afi->record_access_failure (basetype_path, diag_decl); 6503 } 6504 } 6505 return false; 6506 } 6507 6508 return true; 6509 } 6510 6511 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 6512 bitwise or of LOOKUP_* values. If any errors are warnings are 6513 generated, set *DIAGNOSTIC_FN to "error" or "warning", 6514 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 6515 to NULL. */ 6516 6517 static tree 6518 build_temp (tree expr, tree type, int flags, 6519 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 6520 { 6521 int savew, savee; 6522 vec<tree, va_gc> *args; 6523 6524 *diagnostic_kind = DK_UNSPECIFIED; 6525 6526 /* If the source is a packed field, calling the copy constructor will require 6527 binding the field to the reference parameter to the copy constructor, and 6528 we'll end up with an infinite loop. If we can use a bitwise copy, then 6529 do that now. */ 6530 if ((lvalue_kind (expr) & clk_packed) 6531 && CLASS_TYPE_P (TREE_TYPE (expr)) 6532 && !type_has_nontrivial_copy_init (TREE_TYPE (expr))) 6533 return get_target_expr_sfinae (expr, complain); 6534 6535 savew = warningcount + werrorcount, savee = errorcount; 6536 args = make_tree_vector_single (expr); 6537 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 6538 &args, type, flags, complain); 6539 release_tree_vector (args); 6540 if (warningcount + werrorcount > savew) 6541 *diagnostic_kind = DK_WARNING; 6542 else if (errorcount > savee) 6543 *diagnostic_kind = DK_ERROR; 6544 return expr; 6545 } 6546 6547 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 6548 EXPR is implicitly converted to type TOTYPE. 6549 FN and ARGNUM are used for diagnostics. */ 6550 6551 static void 6552 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 6553 { 6554 /* Issue warnings about peculiar, but valid, uses of NULL. */ 6555 if (null_node_p (expr) && TREE_CODE (totype) != BOOLEAN_TYPE 6556 && ARITHMETIC_TYPE_P (totype)) 6557 { 6558 source_location loc = 6559 expansion_point_location_if_in_system_header (input_location); 6560 6561 if (fn) 6562 warning_at (loc, OPT_Wconversion_null, 6563 "passing NULL to non-pointer argument %P of %qD", 6564 argnum, fn); 6565 else 6566 warning_at (loc, OPT_Wconversion_null, 6567 "converting to non-pointer type %qT from NULL", totype); 6568 } 6569 6570 /* Issue warnings if "false" is converted to a NULL pointer */ 6571 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 6572 && TYPE_PTR_P (totype)) 6573 { 6574 if (fn) 6575 warning_at (input_location, OPT_Wconversion_null, 6576 "converting %<false%> to pointer type for argument %P " 6577 "of %qD", argnum, fn); 6578 else 6579 warning_at (input_location, OPT_Wconversion_null, 6580 "converting %<false%> to pointer type %qT", totype); 6581 } 6582 } 6583 6584 /* We gave a diagnostic during a conversion. If this was in the second 6585 standard conversion sequence of a user-defined conversion sequence, say 6586 which user-defined conversion. */ 6587 6588 static void 6589 maybe_print_user_conv_context (conversion *convs) 6590 { 6591 if (convs->user_conv_p) 6592 for (conversion *t = convs; t; t = next_conversion (t)) 6593 if (t->kind == ck_user) 6594 { 6595 print_z_candidate (0, " after user-defined conversion:", 6596 t->cand); 6597 break; 6598 } 6599 } 6600 6601 /* Locate the parameter with the given index within FNDECL. 6602 ARGNUM is zero based, -1 indicates the `this' argument of a method. 6603 Return the location of the FNDECL itself if there are problems. */ 6604 6605 location_t 6606 get_fndecl_argument_location (tree fndecl, int argnum) 6607 { 6608 int i; 6609 tree param; 6610 6611 /* Locate param by index within DECL_ARGUMENTS (fndecl). */ 6612 for (i = 0, param = FUNCTION_FIRST_USER_PARM (fndecl); 6613 i < argnum && param; 6614 i++, param = TREE_CHAIN (param)) 6615 ; 6616 6617 /* If something went wrong (e.g. if we have a builtin and thus no arguments), 6618 return the location of FNDECL. */ 6619 if (param == NULL) 6620 return DECL_SOURCE_LOCATION (fndecl); 6621 6622 return DECL_SOURCE_LOCATION (param); 6623 } 6624 6625 /* Perform the conversions in CONVS on the expression EXPR. FN and 6626 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 6627 indicates the `this' argument of a method. INNER is nonzero when 6628 being called to continue a conversion chain. It is negative when a 6629 reference binding will be applied, positive otherwise. If 6630 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 6631 conversions will be emitted if appropriate. If C_CAST_P is true, 6632 this conversion is coming from a C-style cast; in that case, 6633 conversions to inaccessible bases are permitted. */ 6634 6635 static tree 6636 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 6637 bool issue_conversion_warnings, 6638 bool c_cast_p, tsubst_flags_t complain) 6639 { 6640 tree totype = convs->type; 6641 diagnostic_t diag_kind; 6642 int flags; 6643 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 6644 6645 if (convs->bad_p && !(complain & tf_error)) 6646 return error_mark_node; 6647 6648 if (convs->bad_p 6649 && convs->kind != ck_user 6650 && convs->kind != ck_list 6651 && convs->kind != ck_ambig 6652 && (convs->kind != ck_ref_bind 6653 || (convs->user_conv_p && next_conversion (convs)->bad_p)) 6654 && (convs->kind != ck_rvalue 6655 || SCALAR_TYPE_P (totype)) 6656 && convs->kind != ck_base) 6657 { 6658 bool complained = false; 6659 conversion *t = convs; 6660 6661 /* Give a helpful error if this is bad because of excess braces. */ 6662 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6663 && SCALAR_TYPE_P (totype) 6664 && CONSTRUCTOR_NELTS (expr) > 0 6665 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 6666 { 6667 complained = permerror (loc, "too many braces around initializer " 6668 "for %qT", totype); 6669 while (BRACE_ENCLOSED_INITIALIZER_P (expr) 6670 && CONSTRUCTOR_NELTS (expr) == 1) 6671 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6672 } 6673 6674 /* Give a helpful error if this is bad because a conversion to bool 6675 from std::nullptr_t requires direct-initialization. */ 6676 if (NULLPTR_TYPE_P (TREE_TYPE (expr)) 6677 && TREE_CODE (totype) == BOOLEAN_TYPE) 6678 complained = permerror (loc, "converting to %qH from %qI requires " 6679 "direct-initialization", 6680 totype, TREE_TYPE (expr)); 6681 6682 for (; t ; t = next_conversion (t)) 6683 { 6684 if (t->kind == ck_user && t->cand->reason) 6685 { 6686 complained = permerror (loc, "invalid user-defined conversion " 6687 "from %qH to %qI", TREE_TYPE (expr), 6688 totype); 6689 if (complained) 6690 print_z_candidate (loc, "candidate is:", t->cand); 6691 expr = convert_like_real (t, expr, fn, argnum, 6692 /*issue_conversion_warnings=*/false, 6693 /*c_cast_p=*/false, 6694 complain); 6695 if (convs->kind == ck_ref_bind) 6696 expr = convert_to_reference (totype, expr, CONV_IMPLICIT, 6697 LOOKUP_NORMAL, NULL_TREE, 6698 complain); 6699 else 6700 expr = cp_convert (totype, expr, complain); 6701 if (complained && fn) 6702 inform (DECL_SOURCE_LOCATION (fn), 6703 " initializing argument %P of %qD", argnum, fn); 6704 return expr; 6705 } 6706 else if (t->kind == ck_user || !t->bad_p) 6707 { 6708 expr = convert_like_real (t, expr, fn, argnum, 6709 /*issue_conversion_warnings=*/false, 6710 /*c_cast_p=*/false, 6711 complain); 6712 break; 6713 } 6714 else if (t->kind == ck_ambig) 6715 return convert_like_real (t, expr, fn, argnum, 6716 /*issue_conversion_warnings=*/false, 6717 /*c_cast_p=*/false, 6718 complain); 6719 else if (t->kind == ck_identity) 6720 break; 6721 } 6722 if (!complained) 6723 complained = permerror (loc, "invalid conversion from %qH to %qI", 6724 TREE_TYPE (expr), totype); 6725 if (complained && fn) 6726 inform (get_fndecl_argument_location (fn, argnum), 6727 " initializing argument %P of %qD", argnum, fn); 6728 6729 return cp_convert (totype, expr, complain); 6730 } 6731 6732 if (issue_conversion_warnings && (complain & tf_warning)) 6733 conversion_null_warnings (totype, expr, fn, argnum); 6734 6735 switch (convs->kind) 6736 { 6737 case ck_user: 6738 { 6739 struct z_candidate *cand = convs->cand; 6740 6741 if (cand == NULL) 6742 /* We chose the surrogate function from add_conv_candidate, now we 6743 actually need to build the conversion. */ 6744 cand = build_user_type_conversion_1 (totype, expr, 6745 LOOKUP_NO_CONVERSION, complain); 6746 6747 tree convfn = cand->fn; 6748 6749 /* When converting from an init list we consider explicit 6750 constructors, but actually trying to call one is an error. */ 6751 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 6752 && BRACE_ENCLOSED_INITIALIZER_P (expr) 6753 /* Unless this is for direct-list-initialization. */ 6754 && !CONSTRUCTOR_IS_DIRECT_INIT (expr) 6755 /* And in C++98 a default constructor can't be explicit. */ 6756 && cxx_dialect >= cxx11) 6757 { 6758 if (!(complain & tf_error)) 6759 return error_mark_node; 6760 location_t loc = location_of (expr); 6761 if (CONSTRUCTOR_NELTS (expr) == 0 6762 && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node) 6763 { 6764 if (pedwarn (loc, 0, "converting to %qT from initializer list " 6765 "would use explicit constructor %qD", 6766 totype, convfn)) 6767 inform (loc, "in C++11 and above a default constructor " 6768 "can be explicit"); 6769 } 6770 else 6771 error ("converting to %qT from initializer list would use " 6772 "explicit constructor %qD", totype, convfn); 6773 } 6774 6775 /* If we're initializing from {}, it's value-initialization. */ 6776 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6777 && CONSTRUCTOR_NELTS (expr) == 0 6778 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 6779 { 6780 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 6781 if (abstract_virtuals_error_sfinae (NULL_TREE, totype, complain)) 6782 return error_mark_node; 6783 expr = build_value_init (totype, complain); 6784 expr = get_target_expr_sfinae (expr, complain); 6785 if (expr != error_mark_node) 6786 { 6787 TARGET_EXPR_LIST_INIT_P (expr) = true; 6788 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 6789 } 6790 return expr; 6791 } 6792 6793 /* We don't know here whether EXPR is being used as an lvalue or 6794 rvalue, but we know it's read. */ 6795 mark_exp_read (expr); 6796 6797 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow 6798 any more UDCs. */ 6799 expr = build_over_call (cand, LOOKUP_NORMAL|LOOKUP_NO_CONVERSION, 6800 complain); 6801 6802 /* If this is a constructor or a function returning an aggr type, 6803 we need to build up a TARGET_EXPR. */ 6804 if (DECL_CONSTRUCTOR_P (convfn)) 6805 { 6806 expr = build_cplus_new (totype, expr, complain); 6807 6808 /* Remember that this was list-initialization. */ 6809 if (convs->check_narrowing && expr != error_mark_node) 6810 TARGET_EXPR_LIST_INIT_P (expr) = true; 6811 } 6812 6813 return expr; 6814 } 6815 case ck_identity: 6816 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 6817 { 6818 int nelts = CONSTRUCTOR_NELTS (expr); 6819 if (nelts == 0) 6820 expr = build_value_init (totype, complain); 6821 else if (nelts == 1) 6822 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6823 else 6824 gcc_unreachable (); 6825 } 6826 expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p, 6827 /*read_p=*/true, UNKNOWN_LOCATION, 6828 /*reject_builtin=*/true); 6829 6830 if (type_unknown_p (expr)) 6831 expr = instantiate_type (totype, expr, complain); 6832 if (expr == null_node 6833 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 6834 /* If __null has been converted to an integer type, we do not want to 6835 continue to warn about uses of EXPR as an integer, rather than as a 6836 pointer. */ 6837 expr = build_int_cst (totype, 0); 6838 return expr; 6839 case ck_ambig: 6840 /* We leave bad_p off ck_ambig because overload resolution considers 6841 it valid, it just fails when we try to perform it. So we need to 6842 check complain here, too. */ 6843 if (complain & tf_error) 6844 { 6845 /* Call build_user_type_conversion again for the error. */ 6846 int flags = (convs->need_temporary_p 6847 ? LOOKUP_IMPLICIT : LOOKUP_NORMAL); 6848 build_user_type_conversion (totype, convs->u.expr, flags, complain); 6849 gcc_assert (seen_error ()); 6850 if (fn) 6851 inform (DECL_SOURCE_LOCATION (fn), 6852 " initializing argument %P of %qD", argnum, fn); 6853 } 6854 return error_mark_node; 6855 6856 case ck_list: 6857 { 6858 /* Conversion to std::initializer_list<T>. */ 6859 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 6860 tree new_ctor = build_constructor (init_list_type_node, NULL); 6861 unsigned len = CONSTRUCTOR_NELTS (expr); 6862 tree array, val, field; 6863 vec<constructor_elt, va_gc> *vec = NULL; 6864 unsigned ix; 6865 6866 /* Convert all the elements. */ 6867 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 6868 { 6869 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 6870 false, false, complain); 6871 if (sub == error_mark_node) 6872 return sub; 6873 if (!BRACE_ENCLOSED_INITIALIZER_P (val) 6874 && !check_narrowing (TREE_TYPE (sub), val, complain)) 6875 return error_mark_node; 6876 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 6877 if (!TREE_CONSTANT (sub)) 6878 TREE_CONSTANT (new_ctor) = false; 6879 } 6880 /* Build up the array. */ 6881 elttype = cp_build_qualified_type 6882 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 6883 array = build_array_of_n_type (elttype, len); 6884 array = finish_compound_literal (array, new_ctor, complain, fcl_c99); 6885 /* Take the address explicitly rather than via decay_conversion 6886 to avoid the error about taking the address of a temporary. */ 6887 array = cp_build_addr_expr (array, complain); 6888 array = cp_convert (build_pointer_type (elttype), array, complain); 6889 if (array == error_mark_node) 6890 return error_mark_node; 6891 6892 /* Build up the initializer_list object. Note: fail gracefully 6893 if the object cannot be completed because, for example, no 6894 definition is provided (c++/80956). */ 6895 totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain); 6896 if (!totype) 6897 return error_mark_node; 6898 field = next_initializable_field (TYPE_FIELDS (totype)); 6899 CONSTRUCTOR_APPEND_ELT (vec, field, array); 6900 field = next_initializable_field (DECL_CHAIN (field)); 6901 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 6902 new_ctor = build_constructor (totype, vec); 6903 return get_target_expr_sfinae (new_ctor, complain); 6904 } 6905 6906 case ck_aggr: 6907 if (TREE_CODE (totype) == COMPLEX_TYPE) 6908 { 6909 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 6910 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 6911 real = perform_implicit_conversion (TREE_TYPE (totype), 6912 real, complain); 6913 imag = perform_implicit_conversion (TREE_TYPE (totype), 6914 imag, complain); 6915 expr = build2 (COMPLEX_EXPR, totype, real, imag); 6916 return expr; 6917 } 6918 expr = reshape_init (totype, expr, complain); 6919 expr = get_target_expr_sfinae (digest_init (totype, expr, complain), 6920 complain); 6921 if (expr != error_mark_node) 6922 TARGET_EXPR_LIST_INIT_P (expr) = true; 6923 return expr; 6924 6925 default: 6926 break; 6927 }; 6928 6929 expr = convert_like_real (next_conversion (convs), expr, fn, argnum, 6930 convs->kind == ck_ref_bind 6931 ? issue_conversion_warnings : false, 6932 c_cast_p, complain); 6933 if (expr == error_mark_node) 6934 return error_mark_node; 6935 6936 switch (convs->kind) 6937 { 6938 case ck_rvalue: 6939 expr = decay_conversion (expr, complain); 6940 if (expr == error_mark_node) 6941 { 6942 if (complain & tf_error) 6943 { 6944 maybe_print_user_conv_context (convs); 6945 if (fn) 6946 inform (DECL_SOURCE_LOCATION (fn), 6947 " initializing argument %P of %qD", argnum, fn); 6948 } 6949 return error_mark_node; 6950 } 6951 6952 if (! MAYBE_CLASS_TYPE_P (totype)) 6953 return expr; 6954 6955 /* Don't introduce copies when passing arguments along to the inherited 6956 constructor. */ 6957 if (current_function_decl 6958 && flag_new_inheriting_ctors 6959 && DECL_INHERITED_CTOR (current_function_decl)) 6960 return expr; 6961 6962 if (TREE_CODE (expr) == TARGET_EXPR 6963 && TARGET_EXPR_LIST_INIT_P (expr)) 6964 /* Copy-list-initialization doesn't actually involve a copy. */ 6965 return expr; 6966 6967 /* Fall through. */ 6968 case ck_base: 6969 if (convs->kind == ck_base && !convs->need_temporary_p) 6970 { 6971 /* We are going to bind a reference directly to a base-class 6972 subobject of EXPR. */ 6973 /* Build an expression for `*((base*) &expr)'. */ 6974 expr = convert_to_base (expr, totype, 6975 !c_cast_p, /*nonnull=*/true, complain); 6976 return expr; 6977 } 6978 6979 /* Copy-initialization where the cv-unqualified version of the source 6980 type is the same class as, or a derived class of, the class of the 6981 destination [is treated as direct-initialization]. [dcl.init] */ 6982 flags = LOOKUP_NORMAL; 6983 if (convs->user_conv_p) 6984 /* This conversion is being done in the context of a user-defined 6985 conversion (i.e. the second step of copy-initialization), so 6986 don't allow any more. */ 6987 flags |= LOOKUP_NO_CONVERSION; 6988 else 6989 flags |= LOOKUP_ONLYCONVERTING; 6990 if (convs->rvaluedness_matches_p) 6991 /* standard_conversion got LOOKUP_PREFER_RVALUE. */ 6992 flags |= LOOKUP_PREFER_RVALUE; 6993 expr = build_temp (expr, totype, flags, &diag_kind, complain); 6994 if (diag_kind && complain) 6995 { 6996 maybe_print_user_conv_context (convs); 6997 if (fn) 6998 inform (DECL_SOURCE_LOCATION (fn), 6999 " initializing argument %P of %qD", argnum, fn); 7000 } 7001 7002 return build_cplus_new (totype, expr, complain); 7003 7004 case ck_ref_bind: 7005 { 7006 tree ref_type = totype; 7007 7008 if (convs->bad_p && !next_conversion (convs)->bad_p) 7009 { 7010 tree extype = TREE_TYPE (expr); 7011 if (TYPE_REF_IS_RVALUE (ref_type) 7012 && lvalue_p (expr)) 7013 error_at (loc, "cannot bind rvalue reference of type %qH to " 7014 "lvalue of type %qI", totype, extype); 7015 else if (!TYPE_REF_IS_RVALUE (ref_type) && !lvalue_p (expr) 7016 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))) 7017 error_at (loc, "cannot bind non-const lvalue reference of " 7018 "type %qH to an rvalue of type %qI", totype, extype); 7019 else if (!reference_compatible_p (TREE_TYPE (totype), extype)) 7020 error_at (loc, "binding reference of type %qH to %qI " 7021 "discards qualifiers", totype, extype); 7022 else 7023 gcc_unreachable (); 7024 maybe_print_user_conv_context (convs); 7025 if (fn) 7026 inform (DECL_SOURCE_LOCATION (fn), 7027 " initializing argument %P of %qD", argnum, fn); 7028 return error_mark_node; 7029 } 7030 7031 /* If necessary, create a temporary. 7032 7033 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 7034 that need temporaries, even when their types are reference 7035 compatible with the type of reference being bound, so the 7036 upcoming call to cp_build_addr_expr doesn't fail. */ 7037 if (convs->need_temporary_p 7038 || TREE_CODE (expr) == CONSTRUCTOR 7039 || TREE_CODE (expr) == VA_ARG_EXPR) 7040 { 7041 /* Otherwise, a temporary of type "cv1 T1" is created and 7042 initialized from the initializer expression using the rules 7043 for a non-reference copy-initialization (8.5). */ 7044 7045 tree type = TREE_TYPE (ref_type); 7046 cp_lvalue_kind lvalue = lvalue_kind (expr); 7047 7048 gcc_assert (same_type_ignoring_top_level_qualifiers_p 7049 (type, next_conversion (convs)->type)); 7050 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 7051 && !TYPE_REF_IS_RVALUE (ref_type)) 7052 { 7053 /* If the reference is volatile or non-const, we 7054 cannot create a temporary. */ 7055 if (lvalue & clk_bitfield) 7056 error_at (loc, "cannot bind bitfield %qE to %qT", 7057 expr, ref_type); 7058 else if (lvalue & clk_packed) 7059 error_at (loc, "cannot bind packed field %qE to %qT", 7060 expr, ref_type); 7061 else 7062 error_at (loc, "cannot bind rvalue %qE to %qT", 7063 expr, ref_type); 7064 return error_mark_node; 7065 } 7066 /* If the source is a packed field, and we must use a copy 7067 constructor, then building the target expr will require 7068 binding the field to the reference parameter to the 7069 copy constructor, and we'll end up with an infinite 7070 loop. If we can use a bitwise copy, then we'll be 7071 OK. */ 7072 if ((lvalue & clk_packed) 7073 && CLASS_TYPE_P (type) 7074 && type_has_nontrivial_copy_init (type)) 7075 { 7076 error_at (loc, "cannot bind packed field %qE to %qT", 7077 expr, ref_type); 7078 return error_mark_node; 7079 } 7080 if (lvalue & clk_bitfield) 7081 { 7082 expr = convert_bitfield_to_declared_type (expr); 7083 expr = fold_convert (type, expr); 7084 } 7085 expr = build_target_expr_with_type (expr, type, complain); 7086 } 7087 7088 /* Take the address of the thing to which we will bind the 7089 reference. */ 7090 expr = cp_build_addr_expr (expr, complain); 7091 if (expr == error_mark_node) 7092 return error_mark_node; 7093 7094 /* Convert it to a pointer to the type referred to by the 7095 reference. This will adjust the pointer if a derived to 7096 base conversion is being performed. */ 7097 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 7098 expr, complain); 7099 /* Convert the pointer to the desired reference type. */ 7100 return build_nop (ref_type, expr); 7101 } 7102 7103 case ck_lvalue: 7104 return decay_conversion (expr, complain); 7105 7106 case ck_fnptr: 7107 /* ??? Should the address of a transaction-safe pointer point to the TM 7108 clone, and this conversion look up the primary function? */ 7109 return build_nop (totype, expr); 7110 7111 case ck_qual: 7112 /* Warn about deprecated conversion if appropriate. */ 7113 string_conv_p (totype, expr, 1); 7114 break; 7115 7116 case ck_ptr: 7117 if (convs->base_p) 7118 expr = convert_to_base (expr, totype, !c_cast_p, 7119 /*nonnull=*/false, complain); 7120 return build_nop (totype, expr); 7121 7122 case ck_pmem: 7123 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 7124 c_cast_p, complain); 7125 7126 default: 7127 break; 7128 } 7129 7130 if (convs->check_narrowing 7131 && !check_narrowing (totype, expr, complain)) 7132 return error_mark_node; 7133 7134 if (issue_conversion_warnings) 7135 expr = cp_convert_and_check (totype, expr, complain); 7136 else 7137 expr = cp_convert (totype, expr, complain); 7138 7139 return expr; 7140 } 7141 7142 /* ARG is being passed to a varargs function. Perform any conversions 7143 required. Return the converted value. */ 7144 7145 tree 7146 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain) 7147 { 7148 tree arg_type; 7149 location_t loc = EXPR_LOC_OR_LOC (arg, input_location); 7150 7151 /* [expr.call] 7152 7153 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 7154 standard conversions are performed. */ 7155 arg = decay_conversion (arg, complain); 7156 arg_type = TREE_TYPE (arg); 7157 /* [expr.call] 7158 7159 If the argument has integral or enumeration type that is subject 7160 to the integral promotions (_conv.prom_), or a floating point 7161 type that is subject to the floating point promotion 7162 (_conv.fpprom_), the value of the argument is converted to the 7163 promoted type before the call. */ 7164 if (TREE_CODE (arg_type) == REAL_TYPE 7165 && (TYPE_PRECISION (arg_type) 7166 < TYPE_PRECISION (double_type_node)) 7167 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 7168 { 7169 if ((complain & tf_warning) 7170 && warn_double_promotion && !c_inhibit_evaluation_warnings) 7171 warning_at (loc, OPT_Wdouble_promotion, 7172 "implicit conversion from %qH to %qI when passing " 7173 "argument to function", 7174 arg_type, double_type_node); 7175 arg = convert_to_real_nofold (double_type_node, arg); 7176 } 7177 else if (NULLPTR_TYPE_P (arg_type)) 7178 arg = null_pointer_node; 7179 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 7180 { 7181 if (SCOPED_ENUM_P (arg_type)) 7182 { 7183 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg, 7184 complain); 7185 prom = cp_perform_integral_promotions (prom, complain); 7186 if (abi_version_crosses (6) 7187 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type) 7188 && (complain & tf_warning)) 7189 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as " 7190 "%qT before -fabi-version=6, %qT after", arg_type, 7191 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type)); 7192 if (!abi_version_at_least (6)) 7193 arg = prom; 7194 } 7195 else 7196 arg = cp_perform_integral_promotions (arg, complain); 7197 } 7198 7199 arg = require_complete_type_sfinae (arg, complain); 7200 arg_type = TREE_TYPE (arg); 7201 7202 if (arg != error_mark_node 7203 /* In a template (or ill-formed code), we can have an incomplete type 7204 even after require_complete_type_sfinae, in which case we don't know 7205 whether it has trivial copy or not. */ 7206 && COMPLETE_TYPE_P (arg_type) 7207 && !cp_unevaluated_operand) 7208 { 7209 /* [expr.call] 5.2.2/7: 7210 Passing a potentially-evaluated argument of class type (Clause 9) 7211 with a non-trivial copy constructor or a non-trivial destructor 7212 with no corresponding parameter is conditionally-supported, with 7213 implementation-defined semantics. 7214 7215 We support it as pass-by-invisible-reference, just like a normal 7216 value parameter. 7217 7218 If the call appears in the context of a sizeof expression, 7219 it is not potentially-evaluated. */ 7220 if (type_has_nontrivial_copy_init (arg_type) 7221 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)) 7222 { 7223 arg = force_rvalue (arg, complain); 7224 if (complain & tf_warning) 7225 warning (OPT_Wconditionally_supported, 7226 "passing objects of non-trivially-copyable " 7227 "type %q#T through %<...%> is conditionally supported", 7228 arg_type); 7229 return build1 (ADDR_EXPR, build_reference_type (arg_type), arg); 7230 } 7231 /* Build up a real lvalue-to-rvalue conversion in case the 7232 copy constructor is trivial but not callable. */ 7233 else if (CLASS_TYPE_P (arg_type)) 7234 force_rvalue (arg, complain); 7235 7236 } 7237 7238 return arg; 7239 } 7240 7241 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 7242 7243 tree 7244 build_x_va_arg (source_location loc, tree expr, tree type) 7245 { 7246 if (processing_template_decl) 7247 { 7248 tree r = build_min (VA_ARG_EXPR, type, expr); 7249 SET_EXPR_LOCATION (r, loc); 7250 return r; 7251 } 7252 7253 type = complete_type_or_else (type, NULL_TREE); 7254 7255 if (expr == error_mark_node || !type) 7256 return error_mark_node; 7257 7258 expr = mark_lvalue_use (expr); 7259 7260 if (TREE_CODE (type) == REFERENCE_TYPE) 7261 { 7262 error ("cannot receive reference type %qT through %<...%>", type); 7263 return error_mark_node; 7264 } 7265 7266 if (type_has_nontrivial_copy_init (type) 7267 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 7268 { 7269 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat 7270 it as pass by invisible reference. */ 7271 warning_at (loc, OPT_Wconditionally_supported, 7272 "receiving objects of non-trivially-copyable type %q#T " 7273 "through %<...%> is conditionally-supported", type); 7274 7275 tree ref = cp_build_reference_type (type, false); 7276 expr = build_va_arg (loc, expr, ref); 7277 return convert_from_reference (expr); 7278 } 7279 7280 tree ret = build_va_arg (loc, expr, type); 7281 if (CLASS_TYPE_P (type)) 7282 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to 7283 know how to handle it. */ 7284 ret = get_target_expr (ret); 7285 return ret; 7286 } 7287 7288 /* TYPE has been given to va_arg. Apply the default conversions which 7289 would have happened when passed via ellipsis. Return the promoted 7290 type, or the passed type if there is no change. */ 7291 7292 tree 7293 cxx_type_promotes_to (tree type) 7294 { 7295 tree promote; 7296 7297 /* Perform the array-to-pointer and function-to-pointer 7298 conversions. */ 7299 type = type_decays_to (type); 7300 7301 promote = type_promotes_to (type); 7302 if (same_type_p (type, promote)) 7303 promote = type; 7304 7305 return promote; 7306 } 7307 7308 /* ARG is a default argument expression being passed to a parameter of 7309 the indicated TYPE, which is a parameter to FN. PARMNUM is the 7310 zero-based argument number. Do any required conversions. Return 7311 the converted value. */ 7312 7313 static GTY(()) vec<tree, va_gc> *default_arg_context; 7314 void 7315 push_defarg_context (tree fn) 7316 { vec_safe_push (default_arg_context, fn); } 7317 7318 void 7319 pop_defarg_context (void) 7320 { default_arg_context->pop (); } 7321 7322 tree 7323 convert_default_arg (tree type, tree arg, tree fn, int parmnum, 7324 tsubst_flags_t complain) 7325 { 7326 int i; 7327 tree t; 7328 7329 /* See through clones. */ 7330 fn = DECL_ORIGIN (fn); 7331 /* And inheriting ctors. */ 7332 if (flag_new_inheriting_ctors) 7333 fn = strip_inheriting_ctors (fn); 7334 7335 /* Detect recursion. */ 7336 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t) 7337 if (t == fn) 7338 { 7339 if (complain & tf_error) 7340 error ("recursive evaluation of default argument for %q#D", fn); 7341 return error_mark_node; 7342 } 7343 7344 /* If the ARG is an unparsed default argument expression, the 7345 conversion cannot be performed. */ 7346 if (TREE_CODE (arg) == DEFAULT_ARG) 7347 { 7348 if (complain & tf_error) 7349 error ("call to %qD uses the default argument for parameter %P, which " 7350 "is not yet defined", fn, parmnum); 7351 return error_mark_node; 7352 } 7353 7354 push_defarg_context (fn); 7355 7356 if (fn && DECL_TEMPLATE_INFO (fn)) 7357 arg = tsubst_default_argument (fn, parmnum, type, arg, complain); 7358 7359 /* Due to: 7360 7361 [dcl.fct.default] 7362 7363 The names in the expression are bound, and the semantic 7364 constraints are checked, at the point where the default 7365 expressions appears. 7366 7367 we must not perform access checks here. */ 7368 push_deferring_access_checks (dk_no_check); 7369 /* We must make a copy of ARG, in case subsequent processing 7370 alters any part of it. */ 7371 arg = break_out_target_exprs (arg, /*clear location*/true); 7372 7373 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 7374 ICR_DEFAULT_ARGUMENT, fn, parmnum, 7375 complain); 7376 arg = convert_for_arg_passing (type, arg, complain); 7377 pop_deferring_access_checks(); 7378 7379 pop_defarg_context (); 7380 7381 return arg; 7382 } 7383 7384 /* Returns the type which will really be used for passing an argument of 7385 type TYPE. */ 7386 7387 tree 7388 type_passed_as (tree type) 7389 { 7390 /* Pass classes with copy ctors by invisible reference. */ 7391 if (TREE_ADDRESSABLE (type)) 7392 { 7393 type = build_reference_type (type); 7394 /* There are no other pointers to this temporary. */ 7395 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 7396 } 7397 else if (targetm.calls.promote_prototypes (NULL_TREE) 7398 && INTEGRAL_TYPE_P (type) 7399 && COMPLETE_TYPE_P (type) 7400 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7401 type = integer_type_node; 7402 7403 return type; 7404 } 7405 7406 /* Actually perform the appropriate conversion. */ 7407 7408 tree 7409 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain) 7410 { 7411 tree bitfield_type; 7412 7413 /* If VAL is a bitfield, then -- since it has already been converted 7414 to TYPE -- it cannot have a precision greater than TYPE. 7415 7416 If it has a smaller precision, we must widen it here. For 7417 example, passing "int f:3;" to a function expecting an "int" will 7418 not result in any conversion before this point. 7419 7420 If the precision is the same we must not risk widening. For 7421 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 7422 often have type "int", even though the C++ type for the field is 7423 "long long". If the value is being passed to a function 7424 expecting an "int", then no conversions will be required. But, 7425 if we call convert_bitfield_to_declared_type, the bitfield will 7426 be converted to "long long". */ 7427 bitfield_type = is_bitfield_expr_with_lowered_type (val); 7428 if (bitfield_type 7429 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 7430 val = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type), val); 7431 7432 if (val == error_mark_node) 7433 ; 7434 /* Pass classes with copy ctors by invisible reference. */ 7435 else if (TREE_ADDRESSABLE (type)) 7436 val = build1 (ADDR_EXPR, build_reference_type (type), val); 7437 else if (targetm.calls.promote_prototypes (NULL_TREE) 7438 && INTEGRAL_TYPE_P (type) 7439 && COMPLETE_TYPE_P (type) 7440 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7441 val = cp_perform_integral_promotions (val, complain); 7442 if (complain & tf_warning) 7443 { 7444 if (warn_suggest_attribute_format) 7445 { 7446 tree rhstype = TREE_TYPE (val); 7447 const enum tree_code coder = TREE_CODE (rhstype); 7448 const enum tree_code codel = TREE_CODE (type); 7449 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 7450 && coder == codel 7451 && check_missing_format_attribute (type, rhstype)) 7452 warning (OPT_Wsuggest_attribute_format, 7453 "argument of function call might be a candidate " 7454 "for a format attribute"); 7455 } 7456 maybe_warn_parm_abi (type, EXPR_LOC_OR_LOC (val, input_location)); 7457 } 7458 return val; 7459 } 7460 7461 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for 7462 which just decay_conversion or no conversions at all should be done. 7463 This is true for some builtins which don't act like normal functions. 7464 Return 2 if no conversions at all should be done, 1 if just 7465 decay_conversion. Return 3 for special treatment of the 3rd argument 7466 for __builtin_*_overflow_p. */ 7467 7468 int 7469 magic_varargs_p (tree fn) 7470 { 7471 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 7472 switch (DECL_FUNCTION_CODE (fn)) 7473 { 7474 case BUILT_IN_CLASSIFY_TYPE: 7475 case BUILT_IN_CONSTANT_P: 7476 case BUILT_IN_NEXT_ARG: 7477 case BUILT_IN_VA_START: 7478 return 1; 7479 7480 case BUILT_IN_ADD_OVERFLOW_P: 7481 case BUILT_IN_SUB_OVERFLOW_P: 7482 case BUILT_IN_MUL_OVERFLOW_P: 7483 return 3; 7484 7485 default:; 7486 return lookup_attribute ("type generic", 7487 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 7488 } 7489 7490 return 0; 7491 } 7492 7493 /* Returns the decl of the dispatcher function if FN is a function version. */ 7494 7495 tree 7496 get_function_version_dispatcher (tree fn) 7497 { 7498 tree dispatcher_decl = NULL; 7499 7500 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 7501 && DECL_FUNCTION_VERSIONED (fn)); 7502 7503 gcc_assert (targetm.get_function_versions_dispatcher); 7504 dispatcher_decl = targetm.get_function_versions_dispatcher (fn); 7505 7506 if (dispatcher_decl == NULL) 7507 { 7508 error_at (input_location, "use of multiversioned function " 7509 "without a default"); 7510 return NULL; 7511 } 7512 7513 retrofit_lang_decl (dispatcher_decl); 7514 gcc_assert (dispatcher_decl != NULL); 7515 return dispatcher_decl; 7516 } 7517 7518 /* fn is a function version dispatcher that is marked used. Mark all the 7519 semantically identical function versions it will dispatch as used. */ 7520 7521 void 7522 mark_versions_used (tree fn) 7523 { 7524 struct cgraph_node *node; 7525 struct cgraph_function_version_info *node_v; 7526 struct cgraph_function_version_info *it_v; 7527 7528 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7529 7530 node = cgraph_node::get (fn); 7531 if (node == NULL) 7532 return; 7533 7534 gcc_assert (node->dispatcher_function); 7535 7536 node_v = node->function_version (); 7537 if (node_v == NULL) 7538 return; 7539 7540 /* All semantically identical versions are chained. Traverse and mark each 7541 one of them as used. */ 7542 it_v = node_v->next; 7543 while (it_v != NULL) 7544 { 7545 mark_used (it_v->this_node->decl); 7546 it_v = it_v->next; 7547 } 7548 } 7549 7550 /* Build a call to "the copy constructor" for the type of A, even if it 7551 wouldn't be selected by normal overload resolution. Used for 7552 diagnostics. */ 7553 7554 static tree 7555 call_copy_ctor (tree a, tsubst_flags_t complain) 7556 { 7557 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a)); 7558 tree binfo = TYPE_BINFO (ctype); 7559 tree copy = get_copy_ctor (ctype, complain); 7560 copy = build_baselink (binfo, binfo, copy, NULL_TREE); 7561 tree ob = build_dummy_object (ctype); 7562 vec<tree, va_gc>* args = make_tree_vector_single (a); 7563 tree r = build_new_method_call (ob, copy, &args, NULL_TREE, 7564 LOOKUP_NORMAL, NULL, complain); 7565 release_tree_vector (args); 7566 return r; 7567 } 7568 7569 /* Return true iff T refers to a base field. */ 7570 7571 static bool 7572 is_base_field_ref (tree t) 7573 { 7574 STRIP_NOPS (t); 7575 if (TREE_CODE (t) == ADDR_EXPR) 7576 t = TREE_OPERAND (t, 0); 7577 if (TREE_CODE (t) == COMPONENT_REF) 7578 t = TREE_OPERAND (t, 1); 7579 if (TREE_CODE (t) == FIELD_DECL) 7580 return DECL_FIELD_IS_BASE (t); 7581 return false; 7582 } 7583 7584 /* We can't elide a copy from a function returning by value to a base 7585 subobject, as the callee might clobber tail padding. Return true iff this 7586 could be that case. */ 7587 7588 static bool 7589 unsafe_copy_elision_p (tree target, tree exp) 7590 { 7591 /* Copy elision only happens with a TARGET_EXPR. */ 7592 if (TREE_CODE (exp) != TARGET_EXPR) 7593 return false; 7594 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 7595 /* It's safe to elide the copy for a class with no tail padding. */ 7596 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type))) 7597 return false; 7598 /* It's safe to elide the copy if we aren't initializing a base object. */ 7599 if (!is_base_field_ref (target)) 7600 return false; 7601 tree init = TARGET_EXPR_INITIAL (exp); 7602 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */ 7603 while (TREE_CODE (init) == COMPOUND_EXPR) 7604 init = TREE_OPERAND (init, 1); 7605 if (TREE_CODE (init) == COND_EXPR) 7606 { 7607 /* We'll end up copying from each of the arms of the COND_EXPR directly 7608 into the target, so look at them. */ 7609 if (tree op = TREE_OPERAND (init, 1)) 7610 if (unsafe_copy_elision_p (target, op)) 7611 return true; 7612 return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2)); 7613 } 7614 return (TREE_CODE (init) == AGGR_INIT_EXPR 7615 && !AGGR_INIT_VIA_CTOR_P (init)); 7616 } 7617 7618 /* True iff C is a conversion that binds a reference to a prvalue. */ 7619 7620 static bool 7621 conv_binds_ref_to_prvalue (conversion *c) 7622 { 7623 if (c->kind != ck_ref_bind) 7624 return false; 7625 if (c->need_temporary_p) 7626 return true; 7627 7628 c = next_conversion (c); 7629 7630 if (c->kind == ck_rvalue) 7631 return true; 7632 if (c->kind == ck_user && TREE_CODE (c->type) != REFERENCE_TYPE) 7633 return true; 7634 if (c->kind == ck_identity && c->u.expr 7635 && TREE_CODE (c->u.expr) == TARGET_EXPR) 7636 return true; 7637 7638 return false; 7639 } 7640 7641 /* Subroutine of the various build_*_call functions. Overload resolution 7642 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 7643 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 7644 bitmask of various LOOKUP_* flags which apply to the call itself. */ 7645 7646 static tree 7647 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 7648 { 7649 tree fn = cand->fn; 7650 const vec<tree, va_gc> *args = cand->args; 7651 tree first_arg = cand->first_arg; 7652 conversion **convs = cand->convs; 7653 conversion *conv; 7654 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 7655 int parmlen; 7656 tree val; 7657 int i = 0; 7658 int j = 0; 7659 unsigned int arg_index = 0; 7660 int is_method = 0; 7661 int nargs; 7662 tree *argarray; 7663 bool already_used = false; 7664 7665 /* In a template, there is no need to perform all of the work that 7666 is normally done. We are only interested in the type of the call 7667 expression, i.e., the return type of the function. Any semantic 7668 errors will be deferred until the template is instantiated. */ 7669 if (processing_template_decl) 7670 { 7671 tree expr, addr; 7672 tree return_type; 7673 const tree *argarray; 7674 unsigned int nargs; 7675 7676 if (undeduced_auto_decl (fn)) 7677 mark_used (fn, complain); 7678 else 7679 /* Otherwise set TREE_USED for the benefit of -Wunused-function. 7680 See PR80598. */ 7681 TREE_USED (fn) = 1; 7682 7683 return_type = TREE_TYPE (TREE_TYPE (fn)); 7684 nargs = vec_safe_length (args); 7685 if (first_arg == NULL_TREE) 7686 argarray = args->address (); 7687 else 7688 { 7689 tree *alcarray; 7690 unsigned int ix; 7691 tree arg; 7692 7693 ++nargs; 7694 alcarray = XALLOCAVEC (tree, nargs); 7695 alcarray[0] = build_this (first_arg); 7696 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 7697 alcarray[ix + 1] = arg; 7698 argarray = alcarray; 7699 } 7700 7701 addr = build_addr_func (fn, complain); 7702 if (addr == error_mark_node) 7703 return error_mark_node; 7704 expr = build_call_array_loc (input_location, return_type, 7705 addr, nargs, argarray); 7706 if (TREE_THIS_VOLATILE (fn) && cfun) 7707 current_function_returns_abnormally = 1; 7708 return convert_from_reference (expr); 7709 } 7710 7711 /* Give any warnings we noticed during overload resolution. */ 7712 if (cand->warnings && (complain & tf_warning)) 7713 { 7714 struct candidate_warning *w; 7715 for (w = cand->warnings; w; w = w->next) 7716 joust (cand, w->loser, 1, complain); 7717 } 7718 7719 /* Core issue 2327: P0135 doesn't say how to handle the case where the 7720 argument to the copy constructor ends up being a prvalue after 7721 conversion. Let's do the normal processing, but pretend we aren't 7722 actually using the copy constructor. */ 7723 bool force_elide = false; 7724 if (cxx_dialect >= cxx17 7725 && cand->num_convs == 1 7726 && DECL_COMPLETE_CONSTRUCTOR_P (fn) 7727 && (DECL_COPY_CONSTRUCTOR_P (fn) 7728 || DECL_MOVE_CONSTRUCTOR_P (fn)) 7729 && conv_binds_ref_to_prvalue (convs[0])) 7730 { 7731 force_elide = true; 7732 goto not_really_used; 7733 } 7734 7735 /* OK, we're actually calling this inherited constructor; set its deletedness 7736 appropriately. We can get away with doing this here because calling is 7737 the only way to refer to a constructor. */ 7738 if (DECL_INHERITED_CTOR (fn)) 7739 deduce_inheriting_ctor (fn); 7740 7741 /* Make =delete work with SFINAE. */ 7742 if (DECL_DELETED_FN (fn)) 7743 { 7744 if (complain & tf_error) 7745 mark_used (fn); 7746 return error_mark_node; 7747 } 7748 7749 if (DECL_FUNCTION_MEMBER_P (fn)) 7750 { 7751 tree access_fn; 7752 /* If FN is a template function, two cases must be considered. 7753 For example: 7754 7755 struct A { 7756 protected: 7757 template <class T> void f(); 7758 }; 7759 template <class T> struct B { 7760 protected: 7761 void g(); 7762 }; 7763 struct C : A, B<int> { 7764 using A::f; // #1 7765 using B<int>::g; // #2 7766 }; 7767 7768 In case #1 where `A::f' is a member template, DECL_ACCESS is 7769 recorded in the primary template but not in its specialization. 7770 We check access of FN using its primary template. 7771 7772 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 7773 because it is a member of class template B, DECL_ACCESS is 7774 recorded in the specialization `B<int>::g'. We cannot use its 7775 primary template because `B<T>::g' and `B<int>::g' may have 7776 different access. */ 7777 if (DECL_TEMPLATE_INFO (fn) 7778 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 7779 access_fn = DECL_TI_TEMPLATE (fn); 7780 else 7781 access_fn = fn; 7782 if (!perform_or_defer_access_check (cand->access_path, access_fn, 7783 fn, complain)) 7784 return error_mark_node; 7785 } 7786 7787 /* If we're checking for implicit delete, don't bother with argument 7788 conversions. */ 7789 if (flags & LOOKUP_SPECULATIVE) 7790 { 7791 if (cand->viable == 1) 7792 return fn; 7793 else if (!(complain & tf_error)) 7794 /* Reject bad conversions now. */ 7795 return error_mark_node; 7796 /* else continue to get conversion error. */ 7797 } 7798 7799 not_really_used: 7800 7801 /* N3276 magic doesn't apply to nested calls. */ 7802 tsubst_flags_t decltype_flag = (complain & tf_decltype); 7803 complain &= ~tf_decltype; 7804 /* No-Cleanup doesn't apply to nested calls either. */ 7805 tsubst_flags_t no_cleanup_complain = complain; 7806 complain &= ~tf_no_cleanup; 7807 7808 /* Find maximum size of vector to hold converted arguments. */ 7809 parmlen = list_length (parm); 7810 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0); 7811 if (parmlen > nargs) 7812 nargs = parmlen; 7813 argarray = XALLOCAVEC (tree, nargs); 7814 7815 /* The implicit parameters to a constructor are not considered by overload 7816 resolution, and must be of the proper type. */ 7817 if (DECL_CONSTRUCTOR_P (fn)) 7818 { 7819 tree object_arg; 7820 if (first_arg != NULL_TREE) 7821 { 7822 object_arg = first_arg; 7823 first_arg = NULL_TREE; 7824 } 7825 else 7826 { 7827 object_arg = (*args)[arg_index]; 7828 ++arg_index; 7829 } 7830 argarray[j++] = build_this (object_arg); 7831 parm = TREE_CHAIN (parm); 7832 /* We should never try to call the abstract constructor. */ 7833 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 7834 7835 if (DECL_HAS_VTT_PARM_P (fn)) 7836 { 7837 argarray[j++] = (*args)[arg_index]; 7838 ++arg_index; 7839 parm = TREE_CHAIN (parm); 7840 } 7841 7842 if (flags & LOOKUP_PREFER_RVALUE) 7843 { 7844 /* The implicit move specified in 15.8.3/3 fails "...if the type of 7845 the first parameter of the selected constructor is not an rvalue 7846 reference to the object’s type (possibly cv-qualified)...." */ 7847 gcc_assert (!(complain & tf_error)); 7848 tree ptype = convs[0]->type; 7849 if (TREE_CODE (ptype) != REFERENCE_TYPE 7850 || !TYPE_REF_IS_RVALUE (ptype) 7851 || CONVERSION_RANK (convs[0]) > cr_exact) 7852 return error_mark_node; 7853 } 7854 } 7855 /* Bypass access control for 'this' parameter. */ 7856 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 7857 { 7858 tree parmtype = TREE_VALUE (parm); 7859 tree arg = build_this (first_arg != NULL_TREE 7860 ? first_arg 7861 : (*args)[arg_index]); 7862 tree argtype = TREE_TYPE (arg); 7863 tree converted_arg; 7864 tree base_binfo; 7865 7866 if (arg == error_mark_node) 7867 return error_mark_node; 7868 7869 if (convs[i]->bad_p) 7870 { 7871 if (complain & tf_error) 7872 { 7873 if (permerror (input_location, "passing %qT as %<this%> " 7874 "argument discards qualifiers", 7875 TREE_TYPE (argtype))) 7876 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn); 7877 } 7878 else 7879 return error_mark_node; 7880 } 7881 7882 /* See if the function member or the whole class type is declared 7883 final and the call can be devirtualized. */ 7884 if (DECL_FINAL_P (fn) 7885 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 7886 flags |= LOOKUP_NONVIRTUAL; 7887 7888 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 7889 X is called for an object that is not of type X, or of a type 7890 derived from X, the behavior is undefined. 7891 7892 So we can assume that anything passed as 'this' is non-null, and 7893 optimize accordingly. */ 7894 gcc_assert (TYPE_PTR_P (parmtype)); 7895 /* Convert to the base in which the function was declared. */ 7896 gcc_assert (cand->conversion_path != NULL_TREE); 7897 converted_arg = build_base_path (PLUS_EXPR, 7898 arg, 7899 cand->conversion_path, 7900 1, complain); 7901 /* Check that the base class is accessible. */ 7902 if (!accessible_base_p (TREE_TYPE (argtype), 7903 BINFO_TYPE (cand->conversion_path), true)) 7904 { 7905 if (complain & tf_error) 7906 error ("%qT is not an accessible base of %qT", 7907 BINFO_TYPE (cand->conversion_path), 7908 TREE_TYPE (argtype)); 7909 else 7910 return error_mark_node; 7911 } 7912 /* If fn was found by a using declaration, the conversion path 7913 will be to the derived class, not the base declaring fn. We 7914 must convert from derived to base. */ 7915 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 7916 TREE_TYPE (parmtype), ba_unique, 7917 NULL, complain); 7918 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 7919 base_binfo, 1, complain); 7920 7921 argarray[j++] = converted_arg; 7922 parm = TREE_CHAIN (parm); 7923 if (first_arg != NULL_TREE) 7924 first_arg = NULL_TREE; 7925 else 7926 ++arg_index; 7927 ++i; 7928 is_method = 1; 7929 } 7930 7931 gcc_assert (first_arg == NULL_TREE); 7932 for (; arg_index < vec_safe_length (args) && parm; 7933 parm = TREE_CHAIN (parm), ++arg_index, ++i) 7934 { 7935 tree type = TREE_VALUE (parm); 7936 tree arg = (*args)[arg_index]; 7937 bool conversion_warning = true; 7938 7939 conv = convs[i]; 7940 7941 /* If the argument is NULL and used to (implicitly) instantiate a 7942 template function (and bind one of the template arguments to 7943 the type of 'long int'), we don't want to warn about passing NULL 7944 to non-pointer argument. 7945 For example, if we have this template function: 7946 7947 template<typename T> void func(T x) {} 7948 7949 we want to warn (when -Wconversion is enabled) in this case: 7950 7951 void foo() { 7952 func<int>(NULL); 7953 } 7954 7955 but not in this case: 7956 7957 void foo() { 7958 func(NULL); 7959 } 7960 */ 7961 if (null_node_p (arg) 7962 && DECL_TEMPLATE_INFO (fn) 7963 && cand->template_decl 7964 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 7965 conversion_warning = false; 7966 7967 /* Warn about initializer_list deduction that isn't currently in the 7968 working draft. */ 7969 if (cxx_dialect > cxx98 7970 && flag_deduce_init_list 7971 && cand->template_decl 7972 && is_std_init_list (non_reference (type)) 7973 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 7974 { 7975 tree tmpl = TI_TEMPLATE (cand->template_decl); 7976 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 7977 tree patparm = get_pattern_parm (realparm, tmpl); 7978 tree pattype = TREE_TYPE (patparm); 7979 if (PACK_EXPANSION_P (pattype)) 7980 pattype = PACK_EXPANSION_PATTERN (pattype); 7981 pattype = non_reference (pattype); 7982 7983 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 7984 && (cand->explicit_targs == NULL_TREE 7985 || (TREE_VEC_LENGTH (cand->explicit_targs) 7986 <= TEMPLATE_TYPE_IDX (pattype)))) 7987 { 7988 pedwarn (input_location, 0, "deducing %qT as %qT", 7989 non_reference (TREE_TYPE (patparm)), 7990 non_reference (type)); 7991 pedwarn (DECL_SOURCE_LOCATION (cand->fn), 0, 7992 " in call to %qD", cand->fn); 7993 pedwarn (input_location, 0, 7994 " (you can disable this with -fno-deduce-init-list)"); 7995 } 7996 } 7997 7998 /* Set user_conv_p on the argument conversions, so rvalue/base handling 7999 knows not to allow any more UDCs. This needs to happen after we 8000 process cand->warnings. */ 8001 if (flags & LOOKUP_NO_CONVERSION) 8002 conv->user_conv_p = true; 8003 8004 tsubst_flags_t arg_complain = complain; 8005 if (!conversion_warning) 8006 arg_complain &= ~tf_warning; 8007 8008 val = convert_like_with_context (conv, arg, fn, i - is_method, 8009 arg_complain); 8010 val = convert_for_arg_passing (type, val, arg_complain); 8011 8012 if (val == error_mark_node) 8013 return error_mark_node; 8014 else 8015 argarray[j++] = val; 8016 } 8017 8018 /* Default arguments */ 8019 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 8020 { 8021 if (TREE_VALUE (parm) == error_mark_node) 8022 return error_mark_node; 8023 val = convert_default_arg (TREE_VALUE (parm), 8024 TREE_PURPOSE (parm), 8025 fn, i - is_method, 8026 complain); 8027 if (val == error_mark_node) 8028 return error_mark_node; 8029 argarray[j++] = val; 8030 } 8031 8032 /* Ellipsis */ 8033 int magic = magic_varargs_p (fn); 8034 for (; arg_index < vec_safe_length (args); ++arg_index) 8035 { 8036 tree a = (*args)[arg_index]; 8037 if ((magic == 3 && arg_index == 2) || magic == 2) 8038 { 8039 /* Do no conversions for certain magic varargs. */ 8040 a = mark_type_use (a); 8041 if (TREE_CODE (a) == FUNCTION_DECL && reject_gcc_builtin (a)) 8042 return error_mark_node; 8043 } 8044 else if (magic != 0) 8045 /* For other magic varargs only do decay_conversion. */ 8046 a = decay_conversion (a, complain); 8047 else if (DECL_CONSTRUCTOR_P (fn) 8048 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn), 8049 TREE_TYPE (a))) 8050 { 8051 /* Avoid infinite recursion trying to call A(...). */ 8052 if (complain & tf_error) 8053 /* Try to call the actual copy constructor for a good error. */ 8054 call_copy_ctor (a, complain); 8055 return error_mark_node; 8056 } 8057 else 8058 a = convert_arg_to_ellipsis (a, complain); 8059 if (a == error_mark_node) 8060 return error_mark_node; 8061 argarray[j++] = a; 8062 } 8063 8064 gcc_assert (j <= nargs); 8065 nargs = j; 8066 8067 /* Avoid to do argument-transformation, if warnings for format, and for 8068 nonnull are disabled. Just in case that at least one of them is active 8069 the check_function_arguments function might warn about something. */ 8070 8071 bool warned_p = false; 8072 if (warn_nonnull 8073 || warn_format 8074 || warn_suggest_attribute_format 8075 || warn_restrict) 8076 { 8077 tree *fargs = (!nargs ? argarray 8078 : (tree *) alloca (nargs * sizeof (tree))); 8079 for (j = 0; j < nargs; j++) 8080 { 8081 /* For -Wformat undo the implicit passing by hidden reference 8082 done by convert_arg_to_ellipsis. */ 8083 if (TREE_CODE (argarray[j]) == ADDR_EXPR 8084 && TREE_CODE (TREE_TYPE (argarray[j])) == REFERENCE_TYPE) 8085 fargs[j] = TREE_OPERAND (argarray[j], 0); 8086 else 8087 fargs[j] = maybe_constant_value (argarray[j]); 8088 } 8089 8090 warned_p = check_function_arguments (input_location, fn, TREE_TYPE (fn), 8091 nargs, fargs, NULL); 8092 } 8093 8094 if (DECL_INHERITED_CTOR (fn)) 8095 { 8096 /* Check for passing ellipsis arguments to an inherited constructor. We 8097 could handle this by open-coding the inherited constructor rather than 8098 defining it, but let's not bother now. */ 8099 if (!cp_unevaluated_operand 8100 && cand->num_convs 8101 && cand->convs[cand->num_convs-1]->ellipsis_p) 8102 { 8103 if (complain & tf_error) 8104 { 8105 sorry ("passing arguments to ellipsis of inherited constructor " 8106 "%qD", cand->fn); 8107 inform (DECL_SOURCE_LOCATION (cand->fn), "declared here"); 8108 } 8109 return error_mark_node; 8110 } 8111 8112 /* A base constructor inheriting from a virtual base doesn't get the 8113 inherited arguments, just this and __vtt. */ 8114 if (ctor_omit_inherited_parms (fn)) 8115 nargs = 2; 8116 } 8117 8118 /* Avoid actually calling copy constructors and copy assignment operators, 8119 if possible. */ 8120 8121 if (! flag_elide_constructors && !force_elide) 8122 /* Do things the hard way. */; 8123 else if (cand->num_convs == 1 8124 && (DECL_COPY_CONSTRUCTOR_P (fn) 8125 || DECL_MOVE_CONSTRUCTOR_P (fn)) 8126 /* It's unsafe to elide the constructor when handling 8127 a noexcept-expression, it may evaluate to the wrong 8128 value (c++/53025). */ 8129 && (force_elide || cp_noexcept_operand == 0)) 8130 { 8131 tree targ; 8132 tree arg = argarray[num_artificial_parms_for (fn)]; 8133 tree fa; 8134 bool trivial = trivial_fn_p (fn); 8135 8136 /* Pull out the real argument, disregarding const-correctness. */ 8137 targ = arg; 8138 /* Strip the reference binding for the constructor parameter. */ 8139 if (CONVERT_EXPR_P (targ) 8140 && TREE_CODE (TREE_TYPE (targ)) == REFERENCE_TYPE) 8141 targ = TREE_OPERAND (targ, 0); 8142 /* But don't strip any other reference bindings; binding a temporary to a 8143 reference prevents copy elision. */ 8144 while ((CONVERT_EXPR_P (targ) 8145 && TREE_CODE (TREE_TYPE (targ)) != REFERENCE_TYPE) 8146 || TREE_CODE (targ) == NON_LVALUE_EXPR) 8147 targ = TREE_OPERAND (targ, 0); 8148 if (TREE_CODE (targ) == ADDR_EXPR) 8149 { 8150 targ = TREE_OPERAND (targ, 0); 8151 if (!same_type_ignoring_top_level_qualifiers_p 8152 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 8153 targ = NULL_TREE; 8154 } 8155 else 8156 targ = NULL_TREE; 8157 8158 if (targ) 8159 arg = targ; 8160 else 8161 arg = cp_build_fold_indirect_ref (arg); 8162 8163 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base 8164 subobject. */ 8165 if (CHECKING_P && cxx_dialect >= cxx17) 8166 gcc_assert (TREE_CODE (arg) != TARGET_EXPR 8167 || force_elide 8168 /* It's from binding the ref parm to a packed field. */ 8169 || convs[0]->need_temporary_p 8170 || seen_error () 8171 /* See unsafe_copy_elision_p. */ 8172 || DECL_BASE_CONSTRUCTOR_P (fn)); 8173 8174 /* [class.copy]: the copy constructor is implicitly defined even if 8175 the implementation elided its use. */ 8176 if (!trivial && !force_elide) 8177 { 8178 if (!mark_used (fn, complain) && !(complain & tf_error)) 8179 return error_mark_node; 8180 already_used = true; 8181 } 8182 8183 /* If we're creating a temp and we already have one, don't create a 8184 new one. If we're not creating a temp but we get one, use 8185 INIT_EXPR to collapse the temp into our target. Otherwise, if the 8186 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 8187 temp or an INIT_EXPR otherwise. */ 8188 fa = argarray[0]; 8189 if (is_dummy_object (fa)) 8190 { 8191 if (TREE_CODE (arg) == TARGET_EXPR) 8192 return arg; 8193 else if (trivial) 8194 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 8195 } 8196 else if ((trivial || TREE_CODE (arg) == TARGET_EXPR) 8197 && !unsafe_copy_elision_p (fa, arg)) 8198 { 8199 tree to = cp_stabilize_reference (cp_build_fold_indirect_ref (fa)); 8200 8201 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 8202 return val; 8203 } 8204 } 8205 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 8206 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR) 8207 && trivial_fn_p (fn)) 8208 { 8209 tree to = cp_stabilize_reference 8210 (cp_build_fold_indirect_ref (argarray[0])); 8211 tree type = TREE_TYPE (to); 8212 tree as_base = CLASSTYPE_AS_BASE (type); 8213 tree arg = argarray[1]; 8214 8215 if (is_really_empty_class (type)) 8216 { 8217 /* Avoid copying empty classes. */ 8218 val = build2 (COMPOUND_EXPR, type, arg, to); 8219 TREE_NO_WARNING (val) = 1; 8220 } 8221 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 8222 { 8223 arg = cp_build_fold_indirect_ref (arg); 8224 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 8225 } 8226 else 8227 { 8228 /* We must only copy the non-tail padding parts. */ 8229 tree arg0, arg2, t; 8230 tree array_type, alias_set; 8231 8232 arg2 = TYPE_SIZE_UNIT (as_base); 8233 arg0 = cp_build_addr_expr (to, complain); 8234 8235 array_type = build_array_type (unsigned_char_type_node, 8236 build_index_type 8237 (size_binop (MINUS_EXPR, 8238 arg2, size_int (1)))); 8239 alias_set = build_int_cst (build_pointer_type (type), 0); 8240 t = build2 (MODIFY_EXPR, void_type_node, 8241 build2 (MEM_REF, array_type, arg0, alias_set), 8242 build2 (MEM_REF, array_type, arg, alias_set)); 8243 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 8244 TREE_NO_WARNING (val) = 1; 8245 } 8246 8247 return val; 8248 } 8249 else if (trivial_fn_p (fn)) 8250 { 8251 if (DECL_DESTRUCTOR_P (fn)) 8252 return fold_convert (void_type_node, argarray[0]); 8253 else if (default_ctor_p (fn)) 8254 { 8255 if (is_dummy_object (argarray[0])) 8256 return force_target_expr (DECL_CONTEXT (fn), void_node, 8257 no_cleanup_complain); 8258 else 8259 return cp_build_fold_indirect_ref (argarray[0]); 8260 } 8261 } 8262 8263 gcc_assert (!force_elide); 8264 8265 if (!already_used 8266 && !mark_used (fn, complain)) 8267 return error_mark_node; 8268 8269 /* Warn if the built-in writes to an object of a non-trivial type. */ 8270 if (warn_class_memaccess 8271 && vec_safe_length (args) >= 2 8272 && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 8273 maybe_warn_class_memaccess (input_location, fn, args); 8274 8275 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0 8276 /* Don't mess with virtual lookup in instantiate_non_dependent_expr; 8277 virtual functions can't be constexpr. */ 8278 && !in_template_function ()) 8279 { 8280 tree t; 8281 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 8282 DECL_CONTEXT (fn), 8283 ba_any, NULL, complain); 8284 gcc_assert (binfo && binfo != error_mark_node); 8285 8286 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 8287 complain); 8288 if (TREE_SIDE_EFFECTS (argarray[0])) 8289 argarray[0] = save_expr (argarray[0]); 8290 t = build_pointer_type (TREE_TYPE (fn)); 8291 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 8292 TREE_TYPE (fn) = t; 8293 } 8294 else 8295 { 8296 fn = build_addr_func (fn, complain); 8297 if (fn == error_mark_node) 8298 return error_mark_node; 8299 } 8300 8301 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag); 8302 if (call == error_mark_node) 8303 return call; 8304 if (cand->flags & LOOKUP_LIST_INIT_CTOR) 8305 { 8306 tree c = extract_call_expr (call); 8307 /* build_new_op_1 will clear this when appropriate. */ 8308 CALL_EXPR_ORDERED_ARGS (c) = true; 8309 } 8310 if (warned_p) 8311 { 8312 tree c = extract_call_expr (call); 8313 if (TREE_CODE (c) == CALL_EXPR) 8314 TREE_NO_WARNING (c) = 1; 8315 } 8316 return call; 8317 } 8318 8319 namespace 8320 { 8321 8322 /* Return the DECL of the first non-static subobject of class TYPE 8323 that satisfies the predicate PRED or null if none can be found. */ 8324 8325 template <class Predicate> 8326 tree 8327 first_non_static_field (tree type, Predicate pred) 8328 { 8329 if (!type || !CLASS_TYPE_P (type)) 8330 return NULL_TREE; 8331 8332 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8333 { 8334 if (TREE_CODE (field) != FIELD_DECL) 8335 continue; 8336 if (TREE_STATIC (field)) 8337 continue; 8338 if (pred (field)) 8339 return field; 8340 } 8341 8342 int i = 0; 8343 8344 for (tree base_binfo, binfo = TYPE_BINFO (type); 8345 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8346 { 8347 tree base = TREE_TYPE (base_binfo); 8348 if (pred (base)) 8349 return base; 8350 if (tree field = first_non_static_field (base, pred)) 8351 return field; 8352 } 8353 8354 return NULL_TREE; 8355 } 8356 8357 struct NonPublicField 8358 { 8359 bool operator() (const_tree t) 8360 { 8361 return DECL_P (t) && (TREE_PRIVATE (t) || TREE_PROTECTED (t)); 8362 } 8363 }; 8364 8365 /* Return the DECL of the first non-public subobject of class TYPE 8366 or null if none can be found. */ 8367 8368 static inline tree 8369 first_non_public_field (tree type) 8370 { 8371 return first_non_static_field (type, NonPublicField ()); 8372 } 8373 8374 struct NonTrivialField 8375 { 8376 bool operator() (const_tree t) 8377 { 8378 return !trivial_type_p (DECL_P (t) ? TREE_TYPE (t) : t); 8379 } 8380 }; 8381 8382 /* Return the DECL of the first non-trivial subobject of class TYPE 8383 or null if none can be found. */ 8384 8385 static inline tree 8386 first_non_trivial_field (tree type) 8387 { 8388 return first_non_static_field (type, NonTrivialField ()); 8389 } 8390 8391 } /* unnamed namespace */ 8392 8393 /* Return true if all copy and move assignment operator overloads for 8394 class TYPE are trivial and at least one of them is not deleted and, 8395 when ACCESS is set, accessible. Return false otherwise. Set 8396 HASASSIGN to true when the TYPE has a (not necessarily trivial) 8397 copy or move assignment. */ 8398 8399 static bool 8400 has_trivial_copy_assign_p (tree type, bool access, bool *hasassign) 8401 { 8402 tree fns = get_class_binding (type, assign_op_identifier); 8403 bool all_trivial = true; 8404 8405 /* Iterate over overloads of the assignment operator, checking 8406 accessible copy assignments for triviality. */ 8407 8408 for (ovl_iterator oi (fns); oi; ++oi) 8409 { 8410 tree f = *oi; 8411 8412 /* Skip operators that aren't copy assignments. */ 8413 if (!copy_fn_p (f)) 8414 continue; 8415 8416 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8417 || accessible_p (TYPE_BINFO (type), f, true)); 8418 8419 /* Skip template assignment operators and deleted functions. */ 8420 if (TREE_CODE (f) != FUNCTION_DECL || DECL_DELETED_FN (f)) 8421 continue; 8422 8423 if (accessible) 8424 *hasassign = true; 8425 8426 if (!accessible || !trivial_fn_p (f)) 8427 all_trivial = false; 8428 8429 /* Break early when both properties have been determined. */ 8430 if (*hasassign && !all_trivial) 8431 break; 8432 } 8433 8434 /* Return true if they're all trivial and one of the expressions 8435 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */ 8436 tree ref = cp_build_reference_type (type, false); 8437 return (all_trivial 8438 && (is_trivially_xible (MODIFY_EXPR, type, type) 8439 || is_trivially_xible (MODIFY_EXPR, type, ref))); 8440 } 8441 8442 /* Return true if all copy and move ctor overloads for class TYPE are 8443 trivial and at least one of them is not deleted and, when ACCESS is 8444 set, accessible. Return false otherwise. Set each element of HASCTOR[] 8445 to true when the TYPE has a (not necessarily trivial) default and copy 8446 (or move) ctor, respectively. */ 8447 8448 static bool 8449 has_trivial_copy_p (tree type, bool access, bool hasctor[2]) 8450 { 8451 tree fns = get_class_binding (type, complete_ctor_identifier); 8452 bool all_trivial = true; 8453 8454 for (ovl_iterator oi (fns); oi; ++oi) 8455 { 8456 tree f = *oi; 8457 8458 /* Skip template constructors. */ 8459 if (TREE_CODE (f) != FUNCTION_DECL) 8460 continue; 8461 8462 bool cpy_or_move_ctor_p = copy_fn_p (f); 8463 8464 /* Skip ctors other than default, copy, and move. */ 8465 if (!cpy_or_move_ctor_p && !default_ctor_p (f)) 8466 continue; 8467 8468 if (DECL_DELETED_FN (f)) 8469 continue; 8470 8471 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8472 || accessible_p (TYPE_BINFO (type), f, true)); 8473 8474 if (accessible) 8475 hasctor[cpy_or_move_ctor_p] = true; 8476 8477 if (cpy_or_move_ctor_p && (!accessible || !trivial_fn_p (f))) 8478 all_trivial = false; 8479 8480 /* Break early when both properties have been determined. */ 8481 if (hasctor[0] && hasctor[1] && !all_trivial) 8482 break; 8483 } 8484 8485 return all_trivial; 8486 } 8487 8488 /* Issue a warning on a call to the built-in function FNDECL if it is 8489 a raw memory write whose destination is not an object of (something 8490 like) trivial or standard layout type with a non-deleted assignment 8491 and copy ctor. Detects const correctness violations, corrupting 8492 references, virtual table pointers, and bypassing non-trivial 8493 assignments. */ 8494 8495 static void 8496 maybe_warn_class_memaccess (location_t loc, tree fndecl, 8497 const vec<tree, va_gc> *args) 8498 { 8499 /* Except for bcopy where it's second, the destination pointer is 8500 the first argument for all functions handled here. Compute 8501 the index of the destination and source arguments. */ 8502 unsigned dstidx = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_BCOPY; 8503 unsigned srcidx = !dstidx; 8504 8505 tree dest = (*args)[dstidx]; 8506 if (!TREE_TYPE (dest) || !POINTER_TYPE_P (TREE_TYPE (dest))) 8507 return; 8508 8509 tree srctype = NULL_TREE; 8510 8511 /* Determine the type of the pointed-to object and whether it's 8512 a complete class type. */ 8513 tree desttype = TREE_TYPE (TREE_TYPE (dest)); 8514 8515 if (!desttype || !COMPLETE_TYPE_P (desttype) || !CLASS_TYPE_P (desttype)) 8516 return; 8517 8518 /* Check to see if the raw memory call is made by a non-static member 8519 function with THIS as the destination argument for the destination 8520 type. If so, and if the class has no non-trivial bases or members, 8521 be more permissive. */ 8522 if (current_function_decl 8523 && DECL_NONSTATIC_MEMBER_FUNCTION_P (current_function_decl) 8524 && is_this_parameter (tree_strip_nop_conversions (dest))) 8525 { 8526 tree ctx = DECL_CONTEXT (current_function_decl); 8527 bool special = same_type_ignoring_top_level_qualifiers_p (ctx, desttype); 8528 tree binfo = TYPE_BINFO (ctx); 8529 8530 /* FIXME: The following if statement is overly permissive (see 8531 bug 84851). Remove it in GCC 9. */ 8532 if (special 8533 && !BINFO_VTABLE (binfo) 8534 && !BINFO_N_BASE_BINFOS (binfo) 8535 && (DECL_CONSTRUCTOR_P (current_function_decl) 8536 || DECL_DESTRUCTOR_P (current_function_decl))) 8537 return; 8538 8539 if (special 8540 && !BINFO_VTABLE (binfo) 8541 && !first_non_trivial_field (desttype)) 8542 return; 8543 } 8544 8545 /* True if the class is trivial. */ 8546 bool trivial = trivial_type_p (desttype); 8547 8548 /* Set to true if DESTYPE has an accessible copy assignment. */ 8549 bool hasassign = false; 8550 /* True if all of the class' overloaded copy assignment operators 8551 are all trivial (and not deleted) and at least one of them is 8552 accessible. */ 8553 bool trivassign = has_trivial_copy_assign_p (desttype, true, &hasassign); 8554 8555 /* Set to true if DESTTYPE has an accessible default and copy ctor, 8556 respectively. */ 8557 bool hasctors[2] = { false, false }; 8558 8559 /* True if all of the class' overloaded copy constructors are all 8560 trivial (and not deleted) and at least one of them is accessible. */ 8561 bool trivcopy = has_trivial_copy_p (desttype, true, hasctors); 8562 8563 /* Set FLD to the first private/protected member of the class. */ 8564 tree fld = trivial ? first_non_public_field (desttype) : NULL_TREE; 8565 8566 /* The warning format string. */ 8567 const char *warnfmt = NULL; 8568 /* A suggested alternative to offer instead of the raw memory call. 8569 Empty string when none can be come up with. */ 8570 const char *suggest = ""; 8571 bool warned = false; 8572 8573 switch (DECL_FUNCTION_CODE (fndecl)) 8574 { 8575 case BUILT_IN_MEMSET: 8576 if (!integer_zerop (maybe_constant_value ((*args)[1]))) 8577 { 8578 /* Diagnose setting non-copy-assignable or non-trivial types, 8579 or types with a private member, to (potentially) non-zero 8580 bytes. Since the value of the bytes being written is unknown, 8581 suggest using assignment instead (if one exists). Also warn 8582 for writes into objects for which zero-initialization doesn't 8583 mean all bits clear (pointer-to-member data, where null is all 8584 bits set). Since the value being written is (most likely) 8585 non-zero, simply suggest assignment (but not copy assignment). */ 8586 suggest = "; use assignment instead"; 8587 if (!trivassign) 8588 warnfmt = G_("%qD writing to an object of type %#qT with " 8589 "no trivial copy-assignment"); 8590 else if (!trivial) 8591 warnfmt = G_("%qD writing to an object of non-trivial type %#qT%s"); 8592 else if (fld) 8593 { 8594 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 8595 warned = warning_at (loc, OPT_Wclass_memaccess, 8596 "%qD writing to an object of type %#qT with " 8597 "%qs member %qD", 8598 fndecl, desttype, access, fld); 8599 } 8600 else if (!zero_init_p (desttype)) 8601 warnfmt = G_("%qD writing to an object of type %#qT containing " 8602 "a pointer to data member%s"); 8603 8604 break; 8605 } 8606 /* Fall through. */ 8607 8608 case BUILT_IN_BZERO: 8609 /* Similarly to the above, diagnose clearing non-trivial or non- 8610 standard layout objects, or objects of types with no assignmenmt. 8611 Since the value being written is known to be zero, suggest either 8612 copy assignment, copy ctor, or default ctor as an alternative, 8613 depending on what's available. */ 8614 8615 if (hasassign && hasctors[0]) 8616 suggest = G_("; use assignment or value-initialization instead"); 8617 else if (hasassign) 8618 suggest = G_("; use assignment instead"); 8619 else if (hasctors[0]) 8620 suggest = G_("; use value-initialization instead"); 8621 8622 if (!trivassign) 8623 warnfmt = G_("%qD clearing an object of type %#qT with " 8624 "no trivial copy-assignment%s"); 8625 else if (!trivial) 8626 warnfmt = G_("%qD clearing an object of non-trivial type %#qT%s"); 8627 else if (!zero_init_p (desttype)) 8628 warnfmt = G_("%qD clearing an object of type %#qT containing " 8629 "a pointer-to-member%s"); 8630 break; 8631 8632 case BUILT_IN_BCOPY: 8633 case BUILT_IN_MEMCPY: 8634 case BUILT_IN_MEMMOVE: 8635 case BUILT_IN_MEMPCPY: 8636 /* Determine the type of the source object. */ 8637 srctype = TREE_TYPE ((*args)[srcidx]); 8638 if (!srctype || !POINTER_TYPE_P (srctype)) 8639 srctype = void_type_node; 8640 else 8641 srctype = TREE_TYPE (srctype); 8642 8643 /* Since it's impossible to determine wheter the byte copy is 8644 being used in place of assignment to an existing object or 8645 as a substitute for initialization, assume it's the former. 8646 Determine the best alternative to use instead depending on 8647 what's not deleted. */ 8648 if (hasassign && hasctors[1]) 8649 suggest = G_("; use copy-assignment or copy-initialization instead"); 8650 else if (hasassign) 8651 suggest = G_("; use copy-assignment instead"); 8652 else if (hasctors[1]) 8653 suggest = G_("; use copy-initialization instead"); 8654 8655 if (!trivassign) 8656 warnfmt = G_("%qD writing to an object of type %#qT with no trivial " 8657 "copy-assignment%s"); 8658 else if (!trivially_copyable_p (desttype)) 8659 warnfmt = G_("%qD writing to an object of non-trivially copyable " 8660 "type %#qT%s"); 8661 else if (!trivcopy) 8662 warnfmt = G_("%qD writing to an object with a deleted copy constructor"); 8663 8664 else if (!trivial 8665 && !VOID_TYPE_P (srctype) 8666 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 8667 && !same_type_ignoring_top_level_qualifiers_p (desttype, 8668 srctype)) 8669 { 8670 /* Warn when copying into a non-trivial object from an object 8671 of a different type other than void or char. */ 8672 warned = warning_at (loc, OPT_Wclass_memaccess, 8673 "%qD copying an object of non-trivial type " 8674 "%#qT from an array of %#qT", 8675 fndecl, desttype, srctype); 8676 } 8677 else if (fld 8678 && !VOID_TYPE_P (srctype) 8679 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 8680 && !same_type_ignoring_top_level_qualifiers_p (desttype, 8681 srctype)) 8682 { 8683 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 8684 warned = warning_at (loc, OPT_Wclass_memaccess, 8685 "%qD copying an object of type %#qT with " 8686 "%qs member %qD from an array of %#qT; use " 8687 "assignment or copy-initialization instead", 8688 fndecl, desttype, access, fld, srctype); 8689 } 8690 else if (!trivial && vec_safe_length (args) > 2) 8691 { 8692 tree sz = maybe_constant_value ((*args)[2]); 8693 if (!tree_fits_uhwi_p (sz)) 8694 break; 8695 8696 /* Finally, warn on partial copies. */ 8697 unsigned HOST_WIDE_INT typesize 8698 = tree_to_uhwi (TYPE_SIZE_UNIT (desttype)); 8699 if (unsigned HOST_WIDE_INT partial = tree_to_uhwi (sz) % typesize) 8700 warned = warning_at (loc, OPT_Wclass_memaccess, 8701 (typesize - partial > 1 8702 ? G_("%qD writing to an object of " 8703 "a non-trivial type %#qT leaves %wu " 8704 "bytes unchanged") 8705 : G_("%qD writing to an object of " 8706 "a non-trivial type %#qT leaves %wu " 8707 "byte unchanged")), 8708 fndecl, desttype, typesize - partial); 8709 } 8710 break; 8711 8712 case BUILT_IN_REALLOC: 8713 8714 if (!trivially_copyable_p (desttype)) 8715 warnfmt = G_("%qD moving an object of non-trivially copyable type " 8716 "%#qT; use %<new%> and %<delete%> instead"); 8717 else if (!trivcopy) 8718 warnfmt = G_("%qD moving an object of type %#qT with deleted copy " 8719 "constructor; use %<new%> and %<delete%> instead"); 8720 else if (!get_dtor (desttype, tf_none)) 8721 warnfmt = G_("%qD moving an object of type %#qT with deleted " 8722 "destructor"); 8723 else if (!trivial) 8724 { 8725 tree sz = maybe_constant_value ((*args)[1]); 8726 if (TREE_CODE (sz) == INTEGER_CST 8727 && tree_int_cst_lt (sz, TYPE_SIZE_UNIT (desttype))) 8728 /* Finally, warn on reallocation into insufficient space. */ 8729 warned = warning_at (loc, OPT_Wclass_memaccess, 8730 "%qD moving an object of non-trivial type " 8731 "%#qT and size %E into a region of size %E", 8732 fndecl, desttype, TYPE_SIZE_UNIT (desttype), 8733 sz); 8734 } 8735 break; 8736 8737 default: 8738 return; 8739 } 8740 8741 if (warnfmt) 8742 { 8743 if (suggest) 8744 warned = warning_at (loc, OPT_Wclass_memaccess, 8745 warnfmt, fndecl, desttype, suggest); 8746 else 8747 warned = warning_at (loc, OPT_Wclass_memaccess, 8748 warnfmt, fndecl, desttype); 8749 } 8750 8751 if (warned) 8752 inform (location_of (desttype), "%#qT declared here", desttype); 8753 } 8754 8755 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 8756 This function performs no overload resolution, conversion, or other 8757 high-level operations. */ 8758 8759 tree 8760 build_cxx_call (tree fn, int nargs, tree *argarray, 8761 tsubst_flags_t complain) 8762 { 8763 tree fndecl; 8764 8765 /* Remember roughly where this call is. */ 8766 location_t loc = EXPR_LOC_OR_LOC (fn, input_location); 8767 fn = build_call_a (fn, nargs, argarray); 8768 SET_EXPR_LOCATION (fn, loc); 8769 8770 fndecl = get_callee_fndecl (fn); 8771 8772 /* Check that arguments to builtin functions match the expectations. */ 8773 if (fndecl 8774 && DECL_BUILT_IN (fndecl) 8775 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) 8776 { 8777 int i; 8778 8779 /* We need to take care that values to BUILT_IN_NORMAL 8780 are reduced. */ 8781 for (i = 0; i < nargs; i++) 8782 argarray[i] = fold_non_dependent_expr (argarray[i]); 8783 8784 if (!check_builtin_function_arguments (EXPR_LOCATION (fn), vNULL, fndecl, 8785 nargs, argarray)) 8786 return error_mark_node; 8787 } 8788 8789 if (VOID_TYPE_P (TREE_TYPE (fn))) 8790 return fn; 8791 8792 /* 5.2.2/11: If a function call is a prvalue of object type: if the 8793 function call is either the operand of a decltype-specifier or the 8794 right operand of a comma operator that is the operand of a 8795 decltype-specifier, a temporary object is not introduced for the 8796 prvalue. The type of the prvalue may be incomplete. */ 8797 if (!(complain & tf_decltype)) 8798 { 8799 fn = require_complete_type_sfinae (fn, complain); 8800 if (fn == error_mark_node) 8801 return error_mark_node; 8802 8803 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 8804 { 8805 fn = build_cplus_new (TREE_TYPE (fn), fn, complain); 8806 maybe_warn_parm_abi (TREE_TYPE (fn), loc); 8807 } 8808 } 8809 return convert_from_reference (fn); 8810 } 8811 8812 /* Returns the value to use for the in-charge parameter when making a 8813 call to a function with the indicated NAME. 8814 8815 FIXME:Can't we find a neater way to do this mapping? */ 8816 8817 tree 8818 in_charge_arg_for_name (tree name) 8819 { 8820 if (IDENTIFIER_CTOR_P (name)) 8821 { 8822 if (name == complete_ctor_identifier) 8823 return integer_one_node; 8824 gcc_checking_assert (name == base_ctor_identifier); 8825 } 8826 else 8827 { 8828 if (name == complete_dtor_identifier) 8829 return integer_two_node; 8830 else if (name == deleting_dtor_identifier) 8831 return integer_three_node; 8832 gcc_checking_assert (name == base_dtor_identifier); 8833 } 8834 8835 return integer_zero_node; 8836 } 8837 8838 /* We've built up a constructor call RET. Complain if it delegates to the 8839 constructor we're currently compiling. */ 8840 8841 static void 8842 check_self_delegation (tree ret) 8843 { 8844 if (TREE_CODE (ret) == TARGET_EXPR) 8845 ret = TARGET_EXPR_INITIAL (ret); 8846 tree fn = cp_get_callee_fndecl_nofold (ret); 8847 if (fn && DECL_ABSTRACT_ORIGIN (fn) == current_function_decl) 8848 error ("constructor delegates to itself"); 8849 } 8850 8851 /* Build a call to a constructor, destructor, or an assignment 8852 operator for INSTANCE, an expression with class type. NAME 8853 indicates the special member function to call; *ARGS are the 8854 arguments. ARGS may be NULL. This may change ARGS. BINFO 8855 indicates the base of INSTANCE that is to be passed as the `this' 8856 parameter to the member function called. 8857 8858 FLAGS are the LOOKUP_* flags to use when processing the call. 8859 8860 If NAME indicates a complete object constructor, INSTANCE may be 8861 NULL_TREE. In this case, the caller will call build_cplus_new to 8862 store the newly constructed object into a VAR_DECL. */ 8863 8864 tree 8865 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args, 8866 tree binfo, int flags, tsubst_flags_t complain) 8867 { 8868 tree fns; 8869 /* The type of the subobject to be constructed or destroyed. */ 8870 tree class_type; 8871 vec<tree, va_gc> *allocated = NULL; 8872 tree ret; 8873 8874 gcc_assert (IDENTIFIER_CDTOR_P (name) || name == assign_op_identifier); 8875 if (TYPE_P (binfo)) 8876 { 8877 /* Resolve the name. */ 8878 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 8879 return error_mark_node; 8880 8881 binfo = TYPE_BINFO (binfo); 8882 } 8883 8884 gcc_assert (binfo != NULL_TREE); 8885 8886 class_type = BINFO_TYPE (binfo); 8887 8888 /* Handle the special case where INSTANCE is NULL_TREE. */ 8889 if (name == complete_ctor_identifier && !instance) 8890 instance = build_dummy_object (class_type); 8891 else 8892 { 8893 if (IDENTIFIER_DTOR_P (name)) 8894 gcc_assert (args == NULL || vec_safe_is_empty (*args)); 8895 8896 /* Convert to the base class, if necessary. */ 8897 if (!same_type_ignoring_top_level_qualifiers_p 8898 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 8899 { 8900 if (IDENTIFIER_CDTOR_P (name)) 8901 /* For constructors and destructors, either the base is 8902 non-virtual, or it is virtual but we are doing the 8903 conversion from a constructor or destructor for the 8904 complete object. In either case, we can convert 8905 statically. */ 8906 instance = convert_to_base_statically (instance, binfo); 8907 else 8908 { 8909 /* However, for assignment operators, we must convert 8910 dynamically if the base is virtual. */ 8911 gcc_checking_assert (name == assign_op_identifier); 8912 instance = build_base_path (PLUS_EXPR, instance, 8913 binfo, /*nonnull=*/1, complain); 8914 } 8915 } 8916 } 8917 8918 gcc_assert (instance != NULL_TREE); 8919 8920 /* In C++17, "If the initializer expression is a prvalue and the 8921 cv-unqualified version of the source type is the same class as the class 8922 of the destination, the initializer expression is used to initialize the 8923 destination object." Handle that here to avoid doing overload 8924 resolution. */ 8925 if (cxx_dialect >= cxx17 8926 && args && vec_safe_length (*args) == 1 8927 && name == complete_ctor_identifier) 8928 { 8929 tree arg = (**args)[0]; 8930 8931 if (BRACE_ENCLOSED_INITIALIZER_P (arg) 8932 && !TYPE_HAS_LIST_CTOR (class_type) 8933 && CONSTRUCTOR_NELTS (arg) == 1) 8934 arg = CONSTRUCTOR_ELT (arg, 0)->value; 8935 8936 if ((TREE_CODE (arg) == TARGET_EXPR 8937 || TREE_CODE (arg) == CONSTRUCTOR) 8938 && (same_type_ignoring_top_level_qualifiers_p 8939 (class_type, TREE_TYPE (arg)))) 8940 { 8941 if (is_dummy_object (instance)) 8942 return arg; 8943 else if (TREE_CODE (arg) == TARGET_EXPR) 8944 TARGET_EXPR_DIRECT_INIT_P (arg) = true; 8945 8946 if ((complain & tf_error) 8947 && (flags & LOOKUP_DELEGATING_CONS)) 8948 check_self_delegation (arg); 8949 /* Avoid change of behavior on Wunused-var-2.C. */ 8950 instance = mark_lvalue_use (instance); 8951 return build2 (INIT_EXPR, class_type, instance, arg); 8952 } 8953 } 8954 8955 fns = lookup_fnfields (binfo, name, 1); 8956 8957 /* When making a call to a constructor or destructor for a subobject 8958 that uses virtual base classes, pass down a pointer to a VTT for 8959 the subobject. */ 8960 if ((name == base_ctor_identifier 8961 || name == base_dtor_identifier) 8962 && CLASSTYPE_VBASECLASSES (class_type)) 8963 { 8964 tree vtt; 8965 tree sub_vtt; 8966 8967 /* If the current function is a complete object constructor 8968 or destructor, then we fetch the VTT directly. 8969 Otherwise, we look it up using the VTT we were given. */ 8970 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 8971 vtt = decay_conversion (vtt, complain); 8972 if (vtt == error_mark_node) 8973 return error_mark_node; 8974 vtt = build_if_in_charge (vtt, current_vtt_parm); 8975 if (BINFO_SUBVTT_INDEX (binfo)) 8976 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 8977 else 8978 sub_vtt = vtt; 8979 8980 if (args == NULL) 8981 { 8982 allocated = make_tree_vector (); 8983 args = &allocated; 8984 } 8985 8986 vec_safe_insert (*args, 0, sub_vtt); 8987 } 8988 8989 ret = build_new_method_call (instance, fns, args, 8990 TYPE_BINFO (BINFO_TYPE (binfo)), 8991 flags, /*fn=*/NULL, 8992 complain); 8993 8994 if (allocated != NULL) 8995 release_tree_vector (allocated); 8996 8997 if ((complain & tf_error) 8998 && (flags & LOOKUP_DELEGATING_CONS) 8999 && name == complete_ctor_identifier) 9000 check_self_delegation (ret); 9001 9002 return ret; 9003 } 9004 9005 /* Return the NAME, as a C string. The NAME indicates a function that 9006 is a member of TYPE. *FREE_P is set to true if the caller must 9007 free the memory returned. 9008 9009 Rather than go through all of this, we should simply set the names 9010 of constructors and destructors appropriately, and dispense with 9011 ctor_identifier, dtor_identifier, etc. */ 9012 9013 static char * 9014 name_as_c_string (tree name, tree type, bool *free_p) 9015 { 9016 const char *pretty_name; 9017 9018 /* Assume that we will not allocate memory. */ 9019 *free_p = false; 9020 /* Constructors and destructors are special. */ 9021 if (IDENTIFIER_CDTOR_P (name)) 9022 { 9023 pretty_name 9024 = identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))); 9025 /* For a destructor, add the '~'. */ 9026 if (IDENTIFIER_DTOR_P (name)) 9027 { 9028 pretty_name = concat ("~", pretty_name, NULL); 9029 /* Remember that we need to free the memory allocated. */ 9030 *free_p = true; 9031 } 9032 } 9033 else if (IDENTIFIER_CONV_OP_P (name)) 9034 { 9035 pretty_name = concat ("operator ", 9036 type_as_string_translate (TREE_TYPE (name), 9037 TFF_PLAIN_IDENTIFIER), 9038 NULL); 9039 /* Remember that we need to free the memory allocated. */ 9040 *free_p = true; 9041 } 9042 else 9043 pretty_name = identifier_to_locale (IDENTIFIER_POINTER (name)); 9044 9045 return CONST_CAST (char *, pretty_name); 9046 } 9047 9048 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 9049 be set, upon return, to the function called. ARGS may be NULL. 9050 This may change ARGS. */ 9051 9052 static tree 9053 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args, 9054 tree conversion_path, int flags, 9055 tree *fn_p, tsubst_flags_t complain) 9056 { 9057 struct z_candidate *candidates = 0, *cand; 9058 tree explicit_targs = NULL_TREE; 9059 tree basetype = NULL_TREE; 9060 tree access_binfo, binfo; 9061 tree optype; 9062 tree first_mem_arg = NULL_TREE; 9063 tree name; 9064 bool skip_first_for_error; 9065 vec<tree, va_gc> *user_args; 9066 tree call; 9067 tree fn; 9068 int template_only = 0; 9069 bool any_viable_p; 9070 tree orig_instance; 9071 tree orig_fns; 9072 vec<tree, va_gc> *orig_args = NULL; 9073 void *p; 9074 9075 gcc_assert (instance != NULL_TREE); 9076 9077 /* We don't know what function we're going to call, yet. */ 9078 if (fn_p) 9079 *fn_p = NULL_TREE; 9080 9081 if (error_operand_p (instance) 9082 || !fns || error_operand_p (fns)) 9083 return error_mark_node; 9084 9085 if (!BASELINK_P (fns)) 9086 { 9087 if (complain & tf_error) 9088 error ("call to non-function %qD", fns); 9089 return error_mark_node; 9090 } 9091 9092 orig_instance = instance; 9093 orig_fns = fns; 9094 9095 /* Dismantle the baselink to collect all the information we need. */ 9096 if (!conversion_path) 9097 conversion_path = BASELINK_BINFO (fns); 9098 access_binfo = BASELINK_ACCESS_BINFO (fns); 9099 binfo = BASELINK_BINFO (fns); 9100 optype = BASELINK_OPTYPE (fns); 9101 fns = BASELINK_FUNCTIONS (fns); 9102 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 9103 { 9104 explicit_targs = TREE_OPERAND (fns, 1); 9105 fns = TREE_OPERAND (fns, 0); 9106 template_only = 1; 9107 } 9108 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 9109 || TREE_CODE (fns) == TEMPLATE_DECL 9110 || TREE_CODE (fns) == OVERLOAD); 9111 fn = OVL_FIRST (fns); 9112 name = DECL_NAME (fn); 9113 9114 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 9115 gcc_assert (CLASS_TYPE_P (basetype)); 9116 9117 user_args = args == NULL ? NULL : *args; 9118 /* Under DR 147 A::A() is an invalid constructor call, 9119 not a functional cast. */ 9120 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 9121 { 9122 if (! (complain & tf_error)) 9123 return error_mark_node; 9124 9125 basetype = DECL_CONTEXT (fn); 9126 name = constructor_name (basetype); 9127 if (permerror (input_location, 9128 "cannot call constructor %<%T::%D%> directly", 9129 basetype, name)) 9130 inform (input_location, "for a function-style cast, remove the " 9131 "redundant %<::%D%>", name); 9132 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 9133 complain); 9134 return call; 9135 } 9136 9137 if (processing_template_decl) 9138 { 9139 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 9140 instance = build_non_dependent_expr (instance); 9141 if (args != NULL) 9142 make_args_non_dependent (*args); 9143 } 9144 9145 /* Process the argument list. */ 9146 if (args != NULL && *args != NULL) 9147 { 9148 *args = resolve_args (*args, complain); 9149 if (*args == NULL) 9150 return error_mark_node; 9151 user_args = *args; 9152 } 9153 9154 /* Consider the object argument to be used even if we end up selecting a 9155 static member function. */ 9156 instance = mark_type_use (instance); 9157 9158 /* Figure out whether to skip the first argument for the error 9159 message we will display to users if an error occurs. We don't 9160 want to display any compiler-generated arguments. The "this" 9161 pointer hasn't been added yet. However, we must remove the VTT 9162 pointer if this is a call to a base-class constructor or 9163 destructor. */ 9164 skip_first_for_error = false; 9165 if (IDENTIFIER_CDTOR_P (name)) 9166 { 9167 /* Callers should explicitly indicate whether they want to ctor 9168 the complete object or just the part without virtual bases. */ 9169 gcc_assert (name != ctor_identifier); 9170 9171 /* Remove the VTT pointer, if present. */ 9172 if ((name == base_ctor_identifier || name == base_dtor_identifier) 9173 && CLASSTYPE_VBASECLASSES (basetype)) 9174 skip_first_for_error = true; 9175 9176 /* It's OK to call destructors and constructors on cv-qualified 9177 objects. Therefore, convert the INSTANCE to the unqualified 9178 type, if necessary. */ 9179 if (!same_type_p (basetype, TREE_TYPE (instance))) 9180 { 9181 instance = build_this (instance); 9182 instance = build_nop (build_pointer_type (basetype), instance); 9183 instance = build_fold_indirect_ref (instance); 9184 } 9185 } 9186 else 9187 gcc_assert (!DECL_DESTRUCTOR_P (fn) && !DECL_CONSTRUCTOR_P (fn)); 9188 9189 /* For the overload resolution we need to find the actual `this` 9190 that would be captured if the call turns out to be to a 9191 non-static member function. Do not actually capture it at this 9192 point. */ 9193 if (DECL_CONSTRUCTOR_P (fn)) 9194 /* Constructors don't use the enclosing 'this'. */ 9195 first_mem_arg = instance; 9196 else 9197 first_mem_arg = maybe_resolve_dummy (instance, false); 9198 9199 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9200 p = conversion_obstack_alloc (0); 9201 9202 /* The number of arguments artificial parms in ARGS; we subtract one because 9203 there's no 'this' in ARGS. */ 9204 unsigned skip = num_artificial_parms_for (fn) - 1; 9205 9206 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 9207 initializer, not T({ }). */ 9208 if (DECL_CONSTRUCTOR_P (fn) 9209 && vec_safe_length (user_args) > skip 9210 && DIRECT_LIST_INIT_P ((*user_args)[skip])) 9211 { 9212 tree init_list = (*user_args)[skip]; 9213 tree init = NULL_TREE; 9214 9215 gcc_assert (user_args->length () == skip + 1 9216 && !(flags & LOOKUP_ONLYCONVERTING)); 9217 9218 /* If the initializer list has no elements and T is a class type with 9219 a default constructor, the object is value-initialized. Handle 9220 this here so we don't need to handle it wherever we use 9221 build_special_member_call. */ 9222 if (CONSTRUCTOR_NELTS (init_list) == 0 9223 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 9224 /* For a user-provided default constructor, use the normal 9225 mechanisms so that protected access works. */ 9226 && type_has_non_user_provided_default_constructor (basetype) 9227 && !processing_template_decl) 9228 init = build_value_init (basetype, complain); 9229 9230 /* If BASETYPE is an aggregate, we need to do aggregate 9231 initialization. */ 9232 else if (CP_AGGREGATE_TYPE_P (basetype)) 9233 { 9234 init = reshape_init (basetype, init_list, complain); 9235 init = digest_init (basetype, init, complain); 9236 } 9237 9238 if (init) 9239 { 9240 if (is_dummy_object (instance)) 9241 return get_target_expr_sfinae (init, complain); 9242 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init); 9243 TREE_SIDE_EFFECTS (init) = true; 9244 return init; 9245 } 9246 9247 /* Otherwise go ahead with overload resolution. */ 9248 add_list_candidates (fns, first_mem_arg, user_args, 9249 basetype, explicit_targs, template_only, 9250 conversion_path, access_binfo, flags, 9251 &candidates, complain); 9252 } 9253 else 9254 add_candidates (fns, first_mem_arg, user_args, optype, 9255 explicit_targs, template_only, conversion_path, 9256 access_binfo, flags, &candidates, complain); 9257 9258 any_viable_p = false; 9259 candidates = splice_viable (candidates, false, &any_viable_p); 9260 9261 if (!any_viable_p) 9262 { 9263 if (complain & tf_error) 9264 { 9265 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 9266 cxx_incomplete_type_error (instance, basetype); 9267 else if (optype) 9268 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 9269 basetype, optype, build_tree_list_vec (user_args), 9270 TREE_TYPE (instance)); 9271 else 9272 { 9273 tree arglist = build_tree_list_vec (user_args); 9274 tree errname = name; 9275 bool twiddle = false; 9276 if (IDENTIFIER_CDTOR_P (errname)) 9277 { 9278 twiddle = IDENTIFIER_DTOR_P (errname); 9279 errname = constructor_name (basetype); 9280 } 9281 if (explicit_targs) 9282 errname = lookup_template_function (errname, explicit_targs); 9283 if (skip_first_for_error) 9284 arglist = TREE_CHAIN (arglist); 9285 error ("no matching function for call to %<%T::%s%E(%A)%#V%>", 9286 basetype, &"~"[!twiddle], errname, arglist, 9287 TREE_TYPE (instance)); 9288 } 9289 print_z_candidates (location_of (name), candidates); 9290 } 9291 call = error_mark_node; 9292 } 9293 else 9294 { 9295 cand = tourney (candidates, complain); 9296 if (cand == 0) 9297 { 9298 char *pretty_name; 9299 bool free_p; 9300 tree arglist; 9301 9302 if (complain & tf_error) 9303 { 9304 pretty_name = name_as_c_string (name, basetype, &free_p); 9305 arglist = build_tree_list_vec (user_args); 9306 if (skip_first_for_error) 9307 arglist = TREE_CHAIN (arglist); 9308 if (!any_strictly_viable (candidates)) 9309 error ("no matching function for call to %<%s(%A)%>", 9310 pretty_name, arglist); 9311 else 9312 error ("call of overloaded %<%s(%A)%> is ambiguous", 9313 pretty_name, arglist); 9314 print_z_candidates (location_of (name), candidates); 9315 if (free_p) 9316 free (pretty_name); 9317 } 9318 call = error_mark_node; 9319 } 9320 else 9321 { 9322 fn = cand->fn; 9323 call = NULL_TREE; 9324 9325 if (!(flags & LOOKUP_NONVIRTUAL) 9326 && DECL_PURE_VIRTUAL_P (fn) 9327 && instance == current_class_ref 9328 && (complain & tf_warning)) 9329 { 9330 /* This is not an error, it is runtime undefined 9331 behavior. */ 9332 if (!current_function_decl) 9333 warning (0, "pure virtual %q#D called from " 9334 "non-static data member initializer", fn); 9335 else if (DECL_CONSTRUCTOR_P (current_function_decl) 9336 || DECL_DESTRUCTOR_P (current_function_decl)) 9337 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) 9338 ? G_("pure virtual %q#D called from constructor") 9339 : G_("pure virtual %q#D called from destructor")), 9340 fn); 9341 } 9342 9343 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 9344 && !DECL_CONSTRUCTOR_P (fn) 9345 && is_dummy_object (instance)) 9346 { 9347 instance = maybe_resolve_dummy (instance, true); 9348 if (instance == error_mark_node) 9349 call = error_mark_node; 9350 else if (!is_dummy_object (instance)) 9351 { 9352 /* We captured 'this' in the current lambda now that 9353 we know we really need it. */ 9354 cand->first_arg = instance; 9355 } 9356 else if (any_dependent_bases_p ()) 9357 /* We can't tell until instantiation time whether we can use 9358 *this as the implicit object argument. */; 9359 else 9360 { 9361 if (complain & tf_error) 9362 error ("cannot call member function %qD without object", 9363 fn); 9364 call = error_mark_node; 9365 } 9366 } 9367 9368 if (call != error_mark_node) 9369 { 9370 /* Optimize away vtable lookup if we know that this 9371 function can't be overridden. We need to check if 9372 the context and the type where we found fn are the same, 9373 actually FN might be defined in a different class 9374 type because of a using-declaration. In this case, we 9375 do not want to perform a non-virtual call. */ 9376 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 9377 && same_type_ignoring_top_level_qualifiers_p 9378 (DECL_CONTEXT (fn), BINFO_TYPE (binfo)) 9379 && resolves_to_fixed_type_p (instance, 0)) 9380 flags |= LOOKUP_NONVIRTUAL; 9381 if (explicit_targs) 9382 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 9383 /* Now we know what function is being called. */ 9384 if (fn_p) 9385 *fn_p = fn; 9386 /* Build the actual CALL_EXPR. */ 9387 call = build_over_call (cand, flags, complain); 9388 /* In an expression of the form `a->f()' where `f' turns 9389 out to be a static member function, `a' is 9390 none-the-less evaluated. */ 9391 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 9392 && !is_dummy_object (instance) 9393 && TREE_SIDE_EFFECTS (instance)) 9394 { 9395 /* But avoid the implicit lvalue-rvalue conversion when 'a' 9396 is volatile. */ 9397 tree a = instance; 9398 if (TREE_THIS_VOLATILE (a)) 9399 a = build_this (a); 9400 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), a, call); 9401 } 9402 else if (call != error_mark_node 9403 && DECL_DESTRUCTOR_P (cand->fn) 9404 && !VOID_TYPE_P (TREE_TYPE (call))) 9405 /* An explicit call of the form "x->~X()" has type 9406 "void". However, on platforms where destructors 9407 return "this" (i.e., those where 9408 targetm.cxx.cdtor_returns_this is true), such calls 9409 will appear to have a return value of pointer type 9410 to the low-level call machinery. We do not want to 9411 change the low-level machinery, since we want to be 9412 able to optimize "delete f()" on such platforms as 9413 "operator delete(~X(f()))" (rather than generating 9414 "t = f(), ~X(t), operator delete (t)"). */ 9415 call = build_nop (void_type_node, call); 9416 } 9417 } 9418 } 9419 9420 if (processing_template_decl && call != error_mark_node) 9421 { 9422 bool cast_to_void = false; 9423 9424 if (TREE_CODE (call) == COMPOUND_EXPR) 9425 call = TREE_OPERAND (call, 1); 9426 else if (TREE_CODE (call) == NOP_EXPR) 9427 { 9428 cast_to_void = true; 9429 call = TREE_OPERAND (call, 0); 9430 } 9431 if (INDIRECT_REF_P (call)) 9432 call = TREE_OPERAND (call, 0); 9433 call = (build_min_non_dep_call_vec 9434 (call, 9435 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 9436 orig_instance, orig_fns, NULL_TREE), 9437 orig_args)); 9438 SET_EXPR_LOCATION (call, input_location); 9439 call = convert_from_reference (call); 9440 if (cast_to_void) 9441 call = build_nop (void_type_node, call); 9442 } 9443 9444 /* Free all the conversions we allocated. */ 9445 obstack_free (&conversion_obstack, p); 9446 9447 if (orig_args != NULL) 9448 release_tree_vector (orig_args); 9449 9450 return call; 9451 } 9452 9453 /* Wrapper for above. */ 9454 9455 tree 9456 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args, 9457 tree conversion_path, int flags, 9458 tree *fn_p, tsubst_flags_t complain) 9459 { 9460 tree ret; 9461 bool subtime = timevar_cond_start (TV_OVERLOAD); 9462 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 9463 fn_p, complain); 9464 timevar_cond_stop (TV_OVERLOAD, subtime); 9465 return ret; 9466 } 9467 9468 /* Returns true iff standard conversion sequence ICS1 is a proper 9469 subsequence of ICS2. */ 9470 9471 static bool 9472 is_subseq (conversion *ics1, conversion *ics2) 9473 { 9474 /* We can assume that a conversion of the same code 9475 between the same types indicates a subsequence since we only get 9476 here if the types we are converting from are the same. */ 9477 9478 while (ics1->kind == ck_rvalue 9479 || ics1->kind == ck_lvalue) 9480 ics1 = next_conversion (ics1); 9481 9482 while (1) 9483 { 9484 while (ics2->kind == ck_rvalue 9485 || ics2->kind == ck_lvalue) 9486 ics2 = next_conversion (ics2); 9487 9488 if (ics2->kind == ck_user 9489 || ics2->kind == ck_ambig 9490 || ics2->kind == ck_aggr 9491 || ics2->kind == ck_list 9492 || ics2->kind == ck_identity) 9493 /* At this point, ICS1 cannot be a proper subsequence of 9494 ICS2. We can get a USER_CONV when we are comparing the 9495 second standard conversion sequence of two user conversion 9496 sequences. */ 9497 return false; 9498 9499 ics2 = next_conversion (ics2); 9500 9501 while (ics2->kind == ck_rvalue 9502 || ics2->kind == ck_lvalue) 9503 ics2 = next_conversion (ics2); 9504 9505 if (ics2->kind == ics1->kind 9506 && same_type_p (ics2->type, ics1->type) 9507 && (ics1->kind == ck_identity 9508 || same_type_p (next_conversion (ics2)->type, 9509 next_conversion (ics1)->type))) 9510 return true; 9511 } 9512 } 9513 9514 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 9515 be any _TYPE nodes. */ 9516 9517 bool 9518 is_properly_derived_from (tree derived, tree base) 9519 { 9520 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 9521 return false; 9522 9523 /* We only allow proper derivation here. The DERIVED_FROM_P macro 9524 considers every class derived from itself. */ 9525 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 9526 && DERIVED_FROM_P (base, derived)); 9527 } 9528 9529 /* We build the ICS for an implicit object parameter as a pointer 9530 conversion sequence. However, such a sequence should be compared 9531 as if it were a reference conversion sequence. If ICS is the 9532 implicit conversion sequence for an implicit object parameter, 9533 modify it accordingly. */ 9534 9535 static void 9536 maybe_handle_implicit_object (conversion **ics) 9537 { 9538 if ((*ics)->this_p) 9539 { 9540 /* [over.match.funcs] 9541 9542 For non-static member functions, the type of the 9543 implicit object parameter is "reference to cv X" 9544 where X is the class of which the function is a 9545 member and cv is the cv-qualification on the member 9546 function declaration. */ 9547 conversion *t = *ics; 9548 tree reference_type; 9549 9550 /* The `this' parameter is a pointer to a class type. Make the 9551 implicit conversion talk about a reference to that same class 9552 type. */ 9553 reference_type = TREE_TYPE (t->type); 9554 reference_type = build_reference_type (reference_type); 9555 9556 if (t->kind == ck_qual) 9557 t = next_conversion (t); 9558 if (t->kind == ck_ptr) 9559 t = next_conversion (t); 9560 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 9561 t = direct_reference_binding (reference_type, t); 9562 t->this_p = 1; 9563 t->rvaluedness_matches_p = 0; 9564 *ics = t; 9565 } 9566 } 9567 9568 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 9569 and return the initial reference binding conversion. Otherwise, 9570 leave *ICS unchanged and return NULL. */ 9571 9572 static conversion * 9573 maybe_handle_ref_bind (conversion **ics) 9574 { 9575 if ((*ics)->kind == ck_ref_bind) 9576 { 9577 conversion *old_ics = *ics; 9578 *ics = next_conversion (old_ics); 9579 (*ics)->user_conv_p = old_ics->user_conv_p; 9580 return old_ics; 9581 } 9582 9583 return NULL; 9584 } 9585 9586 /* Compare two implicit conversion sequences according to the rules set out in 9587 [over.ics.rank]. Return values: 9588 9589 1: ics1 is better than ics2 9590 -1: ics2 is better than ics1 9591 0: ics1 and ics2 are indistinguishable */ 9592 9593 static int 9594 compare_ics (conversion *ics1, conversion *ics2) 9595 { 9596 tree from_type1; 9597 tree from_type2; 9598 tree to_type1; 9599 tree to_type2; 9600 tree deref_from_type1 = NULL_TREE; 9601 tree deref_from_type2 = NULL_TREE; 9602 tree deref_to_type1 = NULL_TREE; 9603 tree deref_to_type2 = NULL_TREE; 9604 conversion_rank rank1, rank2; 9605 9606 /* REF_BINDING is nonzero if the result of the conversion sequence 9607 is a reference type. In that case REF_CONV is the reference 9608 binding conversion. */ 9609 conversion *ref_conv1; 9610 conversion *ref_conv2; 9611 9612 /* Compare badness before stripping the reference conversion. */ 9613 if (ics1->bad_p > ics2->bad_p) 9614 return -1; 9615 else if (ics1->bad_p < ics2->bad_p) 9616 return 1; 9617 9618 /* Handle implicit object parameters. */ 9619 maybe_handle_implicit_object (&ics1); 9620 maybe_handle_implicit_object (&ics2); 9621 9622 /* Handle reference parameters. */ 9623 ref_conv1 = maybe_handle_ref_bind (&ics1); 9624 ref_conv2 = maybe_handle_ref_bind (&ics2); 9625 9626 /* List-initialization sequence L1 is a better conversion sequence than 9627 list-initialization sequence L2 if L1 converts to 9628 std::initializer_list<X> for some X and L2 does not. */ 9629 if (ics1->kind == ck_list && ics2->kind != ck_list) 9630 return 1; 9631 if (ics2->kind == ck_list && ics1->kind != ck_list) 9632 return -1; 9633 9634 /* [over.ics.rank] 9635 9636 When comparing the basic forms of implicit conversion sequences (as 9637 defined in _over.best.ics_) 9638 9639 --a standard conversion sequence (_over.ics.scs_) is a better 9640 conversion sequence than a user-defined conversion sequence 9641 or an ellipsis conversion sequence, and 9642 9643 --a user-defined conversion sequence (_over.ics.user_) is a 9644 better conversion sequence than an ellipsis conversion sequence 9645 (_over.ics.ellipsis_). */ 9646 /* Use BAD_CONVERSION_RANK because we already checked for a badness 9647 mismatch. If both ICS are bad, we try to make a decision based on 9648 what would have happened if they'd been good. This is not an 9649 extension, we'll still give an error when we build up the call; this 9650 just helps us give a more helpful error message. */ 9651 rank1 = BAD_CONVERSION_RANK (ics1); 9652 rank2 = BAD_CONVERSION_RANK (ics2); 9653 9654 if (rank1 > rank2) 9655 return -1; 9656 else if (rank1 < rank2) 9657 return 1; 9658 9659 if (ics1->ellipsis_p) 9660 /* Both conversions are ellipsis conversions. */ 9661 return 0; 9662 9663 /* User-defined conversion sequence U1 is a better conversion sequence 9664 than another user-defined conversion sequence U2 if they contain the 9665 same user-defined conversion operator or constructor and if the sec- 9666 ond standard conversion sequence of U1 is better than the second 9667 standard conversion sequence of U2. */ 9668 9669 /* Handle list-conversion with the same code even though it isn't always 9670 ranked as a user-defined conversion and it doesn't have a second 9671 standard conversion sequence; it will still have the desired effect. 9672 Specifically, we need to do the reference binding comparison at the 9673 end of this function. */ 9674 9675 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr) 9676 { 9677 conversion *t1; 9678 conversion *t2; 9679 9680 for (t1 = ics1; t1->kind != ck_user; t1 = next_conversion (t1)) 9681 if (t1->kind == ck_ambig || t1->kind == ck_aggr 9682 || t1->kind == ck_list) 9683 break; 9684 for (t2 = ics2; t2->kind != ck_user; t2 = next_conversion (t2)) 9685 if (t2->kind == ck_ambig || t2->kind == ck_aggr 9686 || t2->kind == ck_list) 9687 break; 9688 9689 if (t1->kind != t2->kind) 9690 return 0; 9691 else if (t1->kind == ck_user) 9692 { 9693 tree f1 = t1->cand ? t1->cand->fn : t1->type; 9694 tree f2 = t2->cand ? t2->cand->fn : t2->type; 9695 if (f1 != f2) 9696 return 0; 9697 } 9698 else 9699 { 9700 /* For ambiguous or aggregate conversions, use the target type as 9701 a proxy for the conversion function. */ 9702 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 9703 return 0; 9704 } 9705 9706 /* We can just fall through here, after setting up 9707 FROM_TYPE1 and FROM_TYPE2. */ 9708 from_type1 = t1->type; 9709 from_type2 = t2->type; 9710 } 9711 else 9712 { 9713 conversion *t1; 9714 conversion *t2; 9715 9716 /* We're dealing with two standard conversion sequences. 9717 9718 [over.ics.rank] 9719 9720 Standard conversion sequence S1 is a better conversion 9721 sequence than standard conversion sequence S2 if 9722 9723 --S1 is a proper subsequence of S2 (comparing the conversion 9724 sequences in the canonical form defined by _over.ics.scs_, 9725 excluding any Lvalue Transformation; the identity 9726 conversion sequence is considered to be a subsequence of 9727 any non-identity conversion sequence */ 9728 9729 t1 = ics1; 9730 while (t1->kind != ck_identity) 9731 t1 = next_conversion (t1); 9732 from_type1 = t1->type; 9733 9734 t2 = ics2; 9735 while (t2->kind != ck_identity) 9736 t2 = next_conversion (t2); 9737 from_type2 = t2->type; 9738 } 9739 9740 /* One sequence can only be a subsequence of the other if they start with 9741 the same type. They can start with different types when comparing the 9742 second standard conversion sequence in two user-defined conversion 9743 sequences. */ 9744 if (same_type_p (from_type1, from_type2)) 9745 { 9746 if (is_subseq (ics1, ics2)) 9747 return 1; 9748 if (is_subseq (ics2, ics1)) 9749 return -1; 9750 } 9751 9752 /* [over.ics.rank] 9753 9754 Or, if not that, 9755 9756 --the rank of S1 is better than the rank of S2 (by the rules 9757 defined below): 9758 9759 Standard conversion sequences are ordered by their ranks: an Exact 9760 Match is a better conversion than a Promotion, which is a better 9761 conversion than a Conversion. 9762 9763 Two conversion sequences with the same rank are indistinguishable 9764 unless one of the following rules applies: 9765 9766 --A conversion that does not a convert a pointer, pointer to member, 9767 or std::nullptr_t to bool is better than one that does. 9768 9769 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 9770 so that we do not have to check it explicitly. */ 9771 if (ics1->rank < ics2->rank) 9772 return 1; 9773 else if (ics2->rank < ics1->rank) 9774 return -1; 9775 9776 to_type1 = ics1->type; 9777 to_type2 = ics2->type; 9778 9779 /* A conversion from scalar arithmetic type to complex is worse than a 9780 conversion between scalar arithmetic types. */ 9781 if (same_type_p (from_type1, from_type2) 9782 && ARITHMETIC_TYPE_P (from_type1) 9783 && ARITHMETIC_TYPE_P (to_type1) 9784 && ARITHMETIC_TYPE_P (to_type2) 9785 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 9786 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 9787 { 9788 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 9789 return -1; 9790 else 9791 return 1; 9792 } 9793 9794 if (TYPE_PTR_P (from_type1) 9795 && TYPE_PTR_P (from_type2) 9796 && TYPE_PTR_P (to_type1) 9797 && TYPE_PTR_P (to_type2)) 9798 { 9799 deref_from_type1 = TREE_TYPE (from_type1); 9800 deref_from_type2 = TREE_TYPE (from_type2); 9801 deref_to_type1 = TREE_TYPE (to_type1); 9802 deref_to_type2 = TREE_TYPE (to_type2); 9803 } 9804 /* The rules for pointers to members A::* are just like the rules 9805 for pointers A*, except opposite: if B is derived from A then 9806 A::* converts to B::*, not vice versa. For that reason, we 9807 switch the from_ and to_ variables here. */ 9808 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2) 9809 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2)) 9810 || (TYPE_PTRMEMFUNC_P (from_type1) 9811 && TYPE_PTRMEMFUNC_P (from_type2) 9812 && TYPE_PTRMEMFUNC_P (to_type1) 9813 && TYPE_PTRMEMFUNC_P (to_type2))) 9814 { 9815 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 9816 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 9817 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 9818 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 9819 } 9820 9821 if (deref_from_type1 != NULL_TREE 9822 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 9823 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 9824 { 9825 /* This was one of the pointer or pointer-like conversions. 9826 9827 [over.ics.rank] 9828 9829 --If class B is derived directly or indirectly from class A, 9830 conversion of B* to A* is better than conversion of B* to 9831 void*, and conversion of A* to void* is better than 9832 conversion of B* to void*. */ 9833 if (VOID_TYPE_P (deref_to_type1) 9834 && VOID_TYPE_P (deref_to_type2)) 9835 { 9836 if (is_properly_derived_from (deref_from_type1, 9837 deref_from_type2)) 9838 return -1; 9839 else if (is_properly_derived_from (deref_from_type2, 9840 deref_from_type1)) 9841 return 1; 9842 } 9843 else if (VOID_TYPE_P (deref_to_type1) 9844 || VOID_TYPE_P (deref_to_type2)) 9845 { 9846 if (same_type_p (deref_from_type1, deref_from_type2)) 9847 { 9848 if (VOID_TYPE_P (deref_to_type2)) 9849 { 9850 if (is_properly_derived_from (deref_from_type1, 9851 deref_to_type1)) 9852 return 1; 9853 } 9854 /* We know that DEREF_TO_TYPE1 is `void' here. */ 9855 else if (is_properly_derived_from (deref_from_type1, 9856 deref_to_type2)) 9857 return -1; 9858 } 9859 } 9860 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 9861 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 9862 { 9863 /* [over.ics.rank] 9864 9865 --If class B is derived directly or indirectly from class A 9866 and class C is derived directly or indirectly from B, 9867 9868 --conversion of C* to B* is better than conversion of C* to 9869 A*, 9870 9871 --conversion of B* to A* is better than conversion of C* to 9872 A* */ 9873 if (same_type_p (deref_from_type1, deref_from_type2)) 9874 { 9875 if (is_properly_derived_from (deref_to_type1, 9876 deref_to_type2)) 9877 return 1; 9878 else if (is_properly_derived_from (deref_to_type2, 9879 deref_to_type1)) 9880 return -1; 9881 } 9882 else if (same_type_p (deref_to_type1, deref_to_type2)) 9883 { 9884 if (is_properly_derived_from (deref_from_type2, 9885 deref_from_type1)) 9886 return 1; 9887 else if (is_properly_derived_from (deref_from_type1, 9888 deref_from_type2)) 9889 return -1; 9890 } 9891 } 9892 } 9893 else if (CLASS_TYPE_P (non_reference (from_type1)) 9894 && same_type_p (from_type1, from_type2)) 9895 { 9896 tree from = non_reference (from_type1); 9897 9898 /* [over.ics.rank] 9899 9900 --binding of an expression of type C to a reference of type 9901 B& is better than binding an expression of type C to a 9902 reference of type A& 9903 9904 --conversion of C to B is better than conversion of C to A, */ 9905 if (is_properly_derived_from (from, to_type1) 9906 && is_properly_derived_from (from, to_type2)) 9907 { 9908 if (is_properly_derived_from (to_type1, to_type2)) 9909 return 1; 9910 else if (is_properly_derived_from (to_type2, to_type1)) 9911 return -1; 9912 } 9913 } 9914 else if (CLASS_TYPE_P (non_reference (to_type1)) 9915 && same_type_p (to_type1, to_type2)) 9916 { 9917 tree to = non_reference (to_type1); 9918 9919 /* [over.ics.rank] 9920 9921 --binding of an expression of type B to a reference of type 9922 A& is better than binding an expression of type C to a 9923 reference of type A&, 9924 9925 --conversion of B to A is better than conversion of C to A */ 9926 if (is_properly_derived_from (from_type1, to) 9927 && is_properly_derived_from (from_type2, to)) 9928 { 9929 if (is_properly_derived_from (from_type2, from_type1)) 9930 return 1; 9931 else if (is_properly_derived_from (from_type1, from_type2)) 9932 return -1; 9933 } 9934 } 9935 9936 /* [over.ics.rank] 9937 9938 --S1 and S2 differ only in their qualification conversion and yield 9939 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 9940 qualification signature of type T1 is a proper subset of the cv- 9941 qualification signature of type T2 */ 9942 if (ics1->kind == ck_qual 9943 && ics2->kind == ck_qual 9944 && same_type_p (from_type1, from_type2)) 9945 { 9946 int result = comp_cv_qual_signature (to_type1, to_type2); 9947 if (result != 0) 9948 return result; 9949 } 9950 9951 /* [over.ics.rank] 9952 9953 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 9954 to an implicit object parameter of a non-static member function 9955 declared without a ref-qualifier, and either S1 binds an lvalue 9956 reference to an lvalue and S2 binds an rvalue reference or S1 binds an 9957 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x 9958 draft standard, 13.3.3.2) 9959 9960 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 9961 types to which the references refer are the same type except for 9962 top-level cv-qualifiers, and the type to which the reference 9963 initialized by S2 refers is more cv-qualified than the type to 9964 which the reference initialized by S1 refers. 9965 9966 DR 1328 [over.match.best]: the context is an initialization by 9967 conversion function for direct reference binding (13.3.1.6) of a 9968 reference to function type, the return type of F1 is the same kind of 9969 reference (i.e. lvalue or rvalue) as the reference being initialized, 9970 and the return type of F2 is not. */ 9971 9972 if (ref_conv1 && ref_conv2) 9973 { 9974 if (!ref_conv1->this_p && !ref_conv2->this_p 9975 && (ref_conv1->rvaluedness_matches_p 9976 != ref_conv2->rvaluedness_matches_p) 9977 && (same_type_p (ref_conv1->type, ref_conv2->type) 9978 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 9979 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 9980 { 9981 if (ref_conv1->bad_p 9982 && !same_type_p (TREE_TYPE (ref_conv1->type), 9983 TREE_TYPE (ref_conv2->type))) 9984 /* Don't prefer a bad conversion that drops cv-quals to a bad 9985 conversion with the wrong rvalueness. */ 9986 return 0; 9987 return (ref_conv1->rvaluedness_matches_p 9988 - ref_conv2->rvaluedness_matches_p); 9989 } 9990 9991 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 9992 { 9993 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type)); 9994 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type)); 9995 if (ref_conv1->bad_p) 9996 { 9997 /* Prefer the one that drops fewer cv-quals. */ 9998 tree ftype = next_conversion (ref_conv1)->type; 9999 int fquals = cp_type_quals (ftype); 10000 q1 ^= fquals; 10001 q2 ^= fquals; 10002 } 10003 return comp_cv_qualification (q2, q1); 10004 } 10005 } 10006 10007 /* Neither conversion sequence is better than the other. */ 10008 return 0; 10009 } 10010 10011 /* The source type for this standard conversion sequence. */ 10012 10013 static tree 10014 source_type (conversion *t) 10015 { 10016 for (;; t = next_conversion (t)) 10017 { 10018 if (t->kind == ck_user 10019 || t->kind == ck_ambig 10020 || t->kind == ck_identity) 10021 return t->type; 10022 } 10023 gcc_unreachable (); 10024 } 10025 10026 /* Note a warning about preferring WINNER to LOSER. We do this by storing 10027 a pointer to LOSER and re-running joust to produce the warning if WINNER 10028 is actually used. */ 10029 10030 static void 10031 add_warning (struct z_candidate *winner, struct z_candidate *loser) 10032 { 10033 candidate_warning *cw = (candidate_warning *) 10034 conversion_obstack_alloc (sizeof (candidate_warning)); 10035 cw->loser = loser; 10036 cw->next = winner->warnings; 10037 winner->warnings = cw; 10038 } 10039 10040 /* Compare two candidates for overloading as described in 10041 [over.match.best]. Return values: 10042 10043 1: cand1 is better than cand2 10044 -1: cand2 is better than cand1 10045 0: cand1 and cand2 are indistinguishable */ 10046 10047 static int 10048 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn, 10049 tsubst_flags_t complain) 10050 { 10051 int winner = 0; 10052 int off1 = 0, off2 = 0; 10053 size_t i; 10054 size_t len; 10055 10056 /* Candidates that involve bad conversions are always worse than those 10057 that don't. */ 10058 if (cand1->viable > cand2->viable) 10059 return 1; 10060 if (cand1->viable < cand2->viable) 10061 return -1; 10062 10063 /* If we have two pseudo-candidates for conversions to the same type, 10064 or two candidates for the same function, arbitrarily pick one. */ 10065 if (cand1->fn == cand2->fn 10066 && (IS_TYPE_OR_DECL_P (cand1->fn))) 10067 return 1; 10068 10069 /* Prefer a non-deleted function over an implicitly deleted move 10070 constructor or assignment operator. This differs slightly from the 10071 wording for issue 1402 (which says the move op is ignored by overload 10072 resolution), but this way produces better error messages. */ 10073 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10074 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10075 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn)) 10076 { 10077 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn) 10078 && move_fn_p (cand1->fn)) 10079 return -1; 10080 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn) 10081 && move_fn_p (cand2->fn)) 10082 return 1; 10083 } 10084 10085 /* a viable function F1 10086 is defined to be a better function than another viable function F2 if 10087 for all arguments i, ICSi(F1) is not a worse conversion sequence than 10088 ICSi(F2), and then */ 10089 10090 /* for some argument j, ICSj(F1) is a better conversion sequence than 10091 ICSj(F2) */ 10092 10093 /* For comparing static and non-static member functions, we ignore 10094 the implicit object parameter of the non-static function. The 10095 standard says to pretend that the static function has an object 10096 parm, but that won't work with operator overloading. */ 10097 len = cand1->num_convs; 10098 if (len != cand2->num_convs) 10099 { 10100 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 10101 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 10102 10103 if (DECL_CONSTRUCTOR_P (cand1->fn) 10104 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 10105 /* We're comparing a near-match list constructor and a near-match 10106 non-list constructor. Just treat them as unordered. */ 10107 return 0; 10108 10109 gcc_assert (static_1 != static_2); 10110 10111 if (static_1) 10112 off2 = 1; 10113 else 10114 { 10115 off1 = 1; 10116 --len; 10117 } 10118 } 10119 10120 for (i = 0; i < len; ++i) 10121 { 10122 conversion *t1 = cand1->convs[i + off1]; 10123 conversion *t2 = cand2->convs[i + off2]; 10124 int comp = compare_ics (t1, t2); 10125 10126 if (comp != 0) 10127 { 10128 if ((complain & tf_warning) 10129 && warn_sign_promo 10130 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 10131 == cr_std + cr_promotion) 10132 && t1->kind == ck_std 10133 && t2->kind == ck_std 10134 && TREE_CODE (t1->type) == INTEGER_TYPE 10135 && TREE_CODE (t2->type) == INTEGER_TYPE 10136 && (TYPE_PRECISION (t1->type) 10137 == TYPE_PRECISION (t2->type)) 10138 && (TYPE_UNSIGNED (next_conversion (t1)->type) 10139 || (TREE_CODE (next_conversion (t1)->type) 10140 == ENUMERAL_TYPE))) 10141 { 10142 tree type = next_conversion (t1)->type; 10143 tree type1, type2; 10144 struct z_candidate *w, *l; 10145 if (comp > 0) 10146 type1 = t1->type, type2 = t2->type, 10147 w = cand1, l = cand2; 10148 else 10149 type1 = t2->type, type2 = t1->type, 10150 w = cand2, l = cand1; 10151 10152 if (warn) 10153 { 10154 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 10155 type, type1, type2); 10156 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 10157 } 10158 else 10159 add_warning (w, l); 10160 } 10161 10162 if (winner && comp != winner) 10163 { 10164 winner = 0; 10165 goto tweak; 10166 } 10167 winner = comp; 10168 } 10169 } 10170 10171 /* warn about confusing overload resolution for user-defined conversions, 10172 either between a constructor and a conversion op, or between two 10173 conversion ops. */ 10174 if ((complain & tf_warning) 10175 && winner && warn_conversion && cand1->second_conv 10176 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 10177 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 10178 { 10179 struct z_candidate *w, *l; 10180 bool give_warning = false; 10181 10182 if (winner == 1) 10183 w = cand1, l = cand2; 10184 else 10185 w = cand2, l = cand1; 10186 10187 /* We don't want to complain about `X::operator T1 ()' 10188 beating `X::operator T2 () const', when T2 is a no less 10189 cv-qualified version of T1. */ 10190 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 10191 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 10192 { 10193 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 10194 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 10195 10196 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 10197 { 10198 t = TREE_TYPE (t); 10199 f = TREE_TYPE (f); 10200 } 10201 if (!comp_ptr_ttypes (t, f)) 10202 give_warning = true; 10203 } 10204 else 10205 give_warning = true; 10206 10207 if (!give_warning) 10208 /*NOP*/; 10209 else if (warn) 10210 { 10211 tree source = source_type (w->convs[0]); 10212 if (POINTER_TYPE_P (source)) 10213 source = TREE_TYPE (source); 10214 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 10215 && warning (OPT_Wconversion, " for conversion from %qH to %qI", 10216 source, w->second_conv->type)) 10217 { 10218 inform (input_location, " because conversion sequence for the argument is better"); 10219 } 10220 } 10221 else 10222 add_warning (w, l); 10223 } 10224 10225 if (winner) 10226 return winner; 10227 10228 /* DR 495 moved this tiebreaker above the template ones. */ 10229 /* or, if not that, 10230 the context is an initialization by user-defined conversion (see 10231 _dcl.init_ and _over.match.user_) and the standard conversion 10232 sequence from the return type of F1 to the destination type (i.e., 10233 the type of the entity being initialized) is a better conversion 10234 sequence than the standard conversion sequence from the return type 10235 of F2 to the destination type. */ 10236 10237 if (cand1->second_conv) 10238 { 10239 winner = compare_ics (cand1->second_conv, cand2->second_conv); 10240 if (winner) 10241 return winner; 10242 } 10243 10244 /* or, if not that, 10245 F1 is a non-template function and F2 is a template function 10246 specialization. */ 10247 10248 if (!cand1->template_decl && cand2->template_decl) 10249 return 1; 10250 else if (cand1->template_decl && !cand2->template_decl) 10251 return -1; 10252 10253 /* or, if not that, 10254 F1 and F2 are template functions and the function template for F1 is 10255 more specialized than the template for F2 according to the partial 10256 ordering rules. */ 10257 10258 if (cand1->template_decl && cand2->template_decl) 10259 { 10260 winner = more_specialized_fn 10261 (TI_TEMPLATE (cand1->template_decl), 10262 TI_TEMPLATE (cand2->template_decl), 10263 /* [temp.func.order]: The presence of unused ellipsis and default 10264 arguments has no effect on the partial ordering of function 10265 templates. add_function_candidate() will not have 10266 counted the "this" argument for constructors. */ 10267 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 10268 if (winner) 10269 return winner; 10270 } 10271 10272 // C++ Concepts 10273 // or, if not that, F1 is more constrained than F2. 10274 if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn)) 10275 { 10276 winner = more_constrained (cand1->fn, cand2->fn); 10277 if (winner) 10278 return winner; 10279 } 10280 10281 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */ 10282 if (deduction_guide_p (cand1->fn)) 10283 { 10284 gcc_assert (deduction_guide_p (cand2->fn)); 10285 /* We distinguish between candidates from an explicit deduction guide and 10286 candidates built from a constructor based on DECL_ARTIFICIAL. */ 10287 int art1 = DECL_ARTIFICIAL (cand1->fn); 10288 int art2 = DECL_ARTIFICIAL (cand2->fn); 10289 if (art1 != art2) 10290 return art2 - art1; 10291 10292 if (art1) 10293 { 10294 /* Prefer the special copy guide over a declared copy/move 10295 constructor. */ 10296 if (copy_guide_p (cand1->fn)) 10297 return 1; 10298 if (copy_guide_p (cand2->fn)) 10299 return -1; 10300 10301 /* Prefer a candidate generated from a non-template constructor. */ 10302 int tg1 = template_guide_p (cand1->fn); 10303 int tg2 = template_guide_p (cand2->fn); 10304 if (tg1 != tg2) 10305 return tg2 - tg1; 10306 } 10307 } 10308 10309 /* F1 is a member of a class D, F2 is a member of a base class B of D, and 10310 for all arguments the corresponding parameters of F1 and F2 have the same 10311 type (CWG 2273/2277). */ 10312 if (DECL_P (cand1->fn) && DECL_CLASS_SCOPE_P (cand1->fn) 10313 && !DECL_CONV_FN_P (cand1->fn) 10314 && DECL_P (cand2->fn) && DECL_CLASS_SCOPE_P (cand2->fn) 10315 && !DECL_CONV_FN_P (cand2->fn)) 10316 { 10317 tree base1 = DECL_CONTEXT (strip_inheriting_ctors (cand1->fn)); 10318 tree base2 = DECL_CONTEXT (strip_inheriting_ctors (cand2->fn)); 10319 10320 bool used1 = false; 10321 bool used2 = false; 10322 if (base1 == base2) 10323 /* No difference. */; 10324 else if (DERIVED_FROM_P (base1, base2)) 10325 used1 = true; 10326 else if (DERIVED_FROM_P (base2, base1)) 10327 used2 = true; 10328 10329 if (int diff = used2 - used1) 10330 { 10331 for (i = 0; i < len; ++i) 10332 { 10333 conversion *t1 = cand1->convs[i + off1]; 10334 conversion *t2 = cand2->convs[i + off2]; 10335 if (!same_type_p (t1->type, t2->type)) 10336 break; 10337 } 10338 if (i == len) 10339 return diff; 10340 } 10341 } 10342 10343 /* Check whether we can discard a builtin candidate, either because we 10344 have two identical ones or matching builtin and non-builtin candidates. 10345 10346 (Pedantically in the latter case the builtin which matched the user 10347 function should not be added to the overload set, but we spot it here. 10348 10349 [over.match.oper] 10350 ... the builtin candidates include ... 10351 - do not have the same parameter type list as any non-template 10352 non-member candidate. */ 10353 10354 if (identifier_p (cand1->fn) || identifier_p (cand2->fn)) 10355 { 10356 for (i = 0; i < len; ++i) 10357 if (!same_type_p (cand1->convs[i]->type, 10358 cand2->convs[i]->type)) 10359 break; 10360 if (i == cand1->num_convs) 10361 { 10362 if (cand1->fn == cand2->fn) 10363 /* Two built-in candidates; arbitrarily pick one. */ 10364 return 1; 10365 else if (identifier_p (cand1->fn)) 10366 /* cand1 is built-in; prefer cand2. */ 10367 return -1; 10368 else 10369 /* cand2 is built-in; prefer cand1. */ 10370 return 1; 10371 } 10372 } 10373 10374 /* For candidates of a multi-versioned function, make the version with 10375 the highest priority win. This version will be checked for dispatching 10376 first. If this version can be inlined into the caller, the front-end 10377 will simply make a direct call to this function. */ 10378 10379 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10380 && DECL_FUNCTION_VERSIONED (cand1->fn) 10381 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10382 && DECL_FUNCTION_VERSIONED (cand2->fn)) 10383 { 10384 tree f1 = TREE_TYPE (cand1->fn); 10385 tree f2 = TREE_TYPE (cand2->fn); 10386 tree p1 = TYPE_ARG_TYPES (f1); 10387 tree p2 = TYPE_ARG_TYPES (f2); 10388 10389 /* Check if cand1->fn and cand2->fn are versions of the same function. It 10390 is possible that cand1->fn and cand2->fn are function versions but of 10391 different functions. Check types to see if they are versions of the same 10392 function. */ 10393 if (compparms (p1, p2) 10394 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2))) 10395 { 10396 /* Always make the version with the higher priority, more 10397 specialized, win. */ 10398 gcc_assert (targetm.compare_version_priority); 10399 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0) 10400 return 1; 10401 else 10402 return -1; 10403 } 10404 } 10405 10406 /* If the two function declarations represent the same function (this can 10407 happen with declarations in multiple scopes and arg-dependent lookup), 10408 arbitrarily choose one. But first make sure the default args we're 10409 using match. */ 10410 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 10411 && equal_functions (cand1->fn, cand2->fn)) 10412 { 10413 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 10414 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 10415 10416 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 10417 10418 for (i = 0; i < len; ++i) 10419 { 10420 /* Don't crash if the fn is variadic. */ 10421 if (!parms1) 10422 break; 10423 parms1 = TREE_CHAIN (parms1); 10424 parms2 = TREE_CHAIN (parms2); 10425 } 10426 10427 if (off1) 10428 parms1 = TREE_CHAIN (parms1); 10429 else if (off2) 10430 parms2 = TREE_CHAIN (parms2); 10431 10432 for (; parms1; ++i) 10433 { 10434 if (!cp_tree_equal (TREE_PURPOSE (parms1), 10435 TREE_PURPOSE (parms2))) 10436 { 10437 if (warn) 10438 { 10439 if (complain & tf_error) 10440 { 10441 if (permerror (input_location, 10442 "default argument mismatch in " 10443 "overload resolution")) 10444 { 10445 inform (DECL_SOURCE_LOCATION (cand1->fn), 10446 " candidate 1: %q#F", cand1->fn); 10447 inform (DECL_SOURCE_LOCATION (cand2->fn), 10448 " candidate 2: %q#F", cand2->fn); 10449 } 10450 } 10451 else 10452 return 0; 10453 } 10454 else 10455 add_warning (cand1, cand2); 10456 break; 10457 } 10458 parms1 = TREE_CHAIN (parms1); 10459 parms2 = TREE_CHAIN (parms2); 10460 } 10461 10462 return 1; 10463 } 10464 10465 tweak: 10466 10467 /* Extension: If the worst conversion for one candidate is worse than the 10468 worst conversion for the other, take the first. */ 10469 if (!pedantic && (complain & tf_warning_or_error)) 10470 { 10471 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 10472 struct z_candidate *w = 0, *l = 0; 10473 10474 for (i = 0; i < len; ++i) 10475 { 10476 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 10477 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 10478 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 10479 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 10480 } 10481 if (rank1 < rank2) 10482 winner = 1, w = cand1, l = cand2; 10483 if (rank1 > rank2) 10484 winner = -1, w = cand2, l = cand1; 10485 if (winner) 10486 { 10487 /* Don't choose a deleted function over ambiguity. */ 10488 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 10489 return 0; 10490 if (warn) 10491 { 10492 pedwarn (input_location, 0, 10493 "ISO C++ says that these are ambiguous, even " 10494 "though the worst conversion for the first is better than " 10495 "the worst conversion for the second:"); 10496 print_z_candidate (input_location, _("candidate 1:"), w); 10497 print_z_candidate (input_location, _("candidate 2:"), l); 10498 } 10499 else 10500 add_warning (w, l); 10501 return winner; 10502 } 10503 } 10504 10505 gcc_assert (!winner); 10506 return 0; 10507 } 10508 10509 /* Given a list of candidates for overloading, find the best one, if any. 10510 This algorithm has a worst case of O(2n) (winner is last), and a best 10511 case of O(n/2) (totally ambiguous); much better than a sorting 10512 algorithm. */ 10513 10514 static struct z_candidate * 10515 tourney (struct z_candidate *candidates, tsubst_flags_t complain) 10516 { 10517 struct z_candidate *champ = candidates, *challenger; 10518 int fate; 10519 int champ_compared_to_predecessor = 0; 10520 10521 /* Walk through the list once, comparing each current champ to the next 10522 candidate, knocking out a candidate or two with each comparison. */ 10523 10524 for (challenger = champ->next; challenger; ) 10525 { 10526 fate = joust (champ, challenger, 0, complain); 10527 if (fate == 1) 10528 challenger = challenger->next; 10529 else 10530 { 10531 if (fate == 0) 10532 { 10533 champ = challenger->next; 10534 if (champ == 0) 10535 return NULL; 10536 champ_compared_to_predecessor = 0; 10537 } 10538 else 10539 { 10540 champ = challenger; 10541 champ_compared_to_predecessor = 1; 10542 } 10543 10544 challenger = champ->next; 10545 } 10546 } 10547 10548 /* Make sure the champ is better than all the candidates it hasn't yet 10549 been compared to. */ 10550 10551 for (challenger = candidates; 10552 challenger != champ 10553 && !(champ_compared_to_predecessor && challenger->next == champ); 10554 challenger = challenger->next) 10555 { 10556 fate = joust (champ, challenger, 0, complain); 10557 if (fate != 1) 10558 return NULL; 10559 } 10560 10561 return champ; 10562 } 10563 10564 /* Returns nonzero if things of type FROM can be converted to TO. */ 10565 10566 bool 10567 can_convert (tree to, tree from, tsubst_flags_t complain) 10568 { 10569 tree arg = NULL_TREE; 10570 /* implicit_conversion only considers user-defined conversions 10571 if it has an expression for the call argument list. */ 10572 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to)) 10573 arg = build1 (CAST_EXPR, from, NULL_TREE); 10574 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain); 10575 } 10576 10577 /* Returns nonzero if things of type FROM can be converted to TO with a 10578 standard conversion. */ 10579 10580 bool 10581 can_convert_standard (tree to, tree from, tsubst_flags_t complain) 10582 { 10583 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain); 10584 } 10585 10586 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 10587 10588 bool 10589 can_convert_arg (tree to, tree from, tree arg, int flags, 10590 tsubst_flags_t complain) 10591 { 10592 conversion *t; 10593 void *p; 10594 bool ok_p; 10595 10596 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10597 p = conversion_obstack_alloc (0); 10598 /* We want to discard any access checks done for this test, 10599 as we might not be in the appropriate access context and 10600 we'll do the check again when we actually perform the 10601 conversion. */ 10602 push_deferring_access_checks (dk_deferred); 10603 10604 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 10605 flags, complain); 10606 ok_p = (t && !t->bad_p); 10607 10608 /* Discard the access checks now. */ 10609 pop_deferring_access_checks (); 10610 /* Free all the conversions we allocated. */ 10611 obstack_free (&conversion_obstack, p); 10612 10613 return ok_p; 10614 } 10615 10616 /* Like can_convert_arg, but allows dubious conversions as well. */ 10617 10618 bool 10619 can_convert_arg_bad (tree to, tree from, tree arg, int flags, 10620 tsubst_flags_t complain) 10621 { 10622 conversion *t; 10623 void *p; 10624 10625 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10626 p = conversion_obstack_alloc (0); 10627 /* Try to perform the conversion. */ 10628 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 10629 flags, complain); 10630 /* Free all the conversions we allocated. */ 10631 obstack_free (&conversion_obstack, p); 10632 10633 return t != NULL; 10634 } 10635 10636 /* Convert EXPR to TYPE. Return the converted expression. 10637 10638 Note that we allow bad conversions here because by the time we get to 10639 this point we are committed to doing the conversion. If we end up 10640 doing a bad conversion, convert_like will complain. */ 10641 10642 tree 10643 perform_implicit_conversion_flags (tree type, tree expr, 10644 tsubst_flags_t complain, int flags) 10645 { 10646 conversion *conv; 10647 void *p; 10648 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 10649 10650 if (TREE_CODE (type) == REFERENCE_TYPE) 10651 expr = mark_lvalue_use (expr); 10652 else 10653 expr = mark_rvalue_use (expr); 10654 10655 if (error_operand_p (expr)) 10656 return error_mark_node; 10657 10658 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10659 p = conversion_obstack_alloc (0); 10660 10661 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 10662 /*c_cast_p=*/false, 10663 flags, complain); 10664 10665 if (!conv) 10666 { 10667 if (complain & tf_error) 10668 { 10669 /* If expr has unknown type, then it is an overloaded function. 10670 Call instantiate_type to get good error messages. */ 10671 if (TREE_TYPE (expr) == unknown_type_node) 10672 instantiate_type (type, expr, complain); 10673 else if (invalid_nonstatic_memfn_p (loc, expr, complain)) 10674 /* We gave an error. */; 10675 else 10676 error_at (loc, "could not convert %qE from %qH to %qI", expr, 10677 TREE_TYPE (expr), type); 10678 } 10679 expr = error_mark_node; 10680 } 10681 else if (processing_template_decl && conv->kind != ck_identity) 10682 { 10683 /* In a template, we are only concerned about determining the 10684 type of non-dependent expressions, so we do not have to 10685 perform the actual conversion. But for initializers, we 10686 need to be able to perform it at instantiation 10687 (or instantiate_non_dependent_expr) time. */ 10688 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 10689 if (!(flags & LOOKUP_ONLYCONVERTING)) 10690 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 10691 } 10692 else 10693 expr = convert_like (conv, expr, complain); 10694 10695 /* Free all the conversions we allocated. */ 10696 obstack_free (&conversion_obstack, p); 10697 10698 return expr; 10699 } 10700 10701 tree 10702 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 10703 { 10704 return perform_implicit_conversion_flags (type, expr, complain, 10705 LOOKUP_IMPLICIT); 10706 } 10707 10708 /* Convert EXPR to TYPE (as a direct-initialization) if that is 10709 permitted. If the conversion is valid, the converted expression is 10710 returned. Otherwise, NULL_TREE is returned, except in the case 10711 that TYPE is a class type; in that case, an error is issued. If 10712 C_CAST_P is true, then this direct-initialization is taking 10713 place as part of a static_cast being attempted as part of a C-style 10714 cast. */ 10715 10716 tree 10717 perform_direct_initialization_if_possible (tree type, 10718 tree expr, 10719 bool c_cast_p, 10720 tsubst_flags_t complain) 10721 { 10722 conversion *conv; 10723 void *p; 10724 10725 if (type == error_mark_node || error_operand_p (expr)) 10726 return error_mark_node; 10727 /* [dcl.init] 10728 10729 If the destination type is a (possibly cv-qualified) class type: 10730 10731 -- If the initialization is direct-initialization ..., 10732 constructors are considered. ... If no constructor applies, or 10733 the overload resolution is ambiguous, the initialization is 10734 ill-formed. */ 10735 if (CLASS_TYPE_P (type)) 10736 { 10737 vec<tree, va_gc> *args = make_tree_vector_single (expr); 10738 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 10739 &args, type, LOOKUP_NORMAL, complain); 10740 release_tree_vector (args); 10741 return build_cplus_new (type, expr, complain); 10742 } 10743 10744 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10745 p = conversion_obstack_alloc (0); 10746 10747 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 10748 c_cast_p, 10749 LOOKUP_NORMAL, complain); 10750 if (!conv || conv->bad_p) 10751 expr = NULL_TREE; 10752 else if (processing_template_decl && conv->kind != ck_identity) 10753 { 10754 /* In a template, we are only concerned about determining the 10755 type of non-dependent expressions, so we do not have to 10756 perform the actual conversion. But for initializers, we 10757 need to be able to perform it at instantiation 10758 (or instantiate_non_dependent_expr) time. */ 10759 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 10760 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 10761 } 10762 else 10763 expr = convert_like_real (conv, expr, NULL_TREE, 0, 10764 /*issue_conversion_warnings=*/false, 10765 c_cast_p, 10766 complain); 10767 10768 /* Free all the conversions we allocated. */ 10769 obstack_free (&conversion_obstack, p); 10770 10771 return expr; 10772 } 10773 10774 /* When initializing a reference that lasts longer than a full-expression, 10775 this special rule applies: 10776 10777 [class.temporary] 10778 10779 The temporary to which the reference is bound or the temporary 10780 that is the complete object to which the reference is bound 10781 persists for the lifetime of the reference. 10782 10783 The temporaries created during the evaluation of the expression 10784 initializing the reference, except the temporary to which the 10785 reference is bound, are destroyed at the end of the 10786 full-expression in which they are created. 10787 10788 In that case, we store the converted expression into a new 10789 VAR_DECL in a new scope. 10790 10791 However, we want to be careful not to create temporaries when 10792 they are not required. For example, given: 10793 10794 struct B {}; 10795 struct D : public B {}; 10796 D f(); 10797 const B& b = f(); 10798 10799 there is no need to copy the return value from "f"; we can just 10800 extend its lifetime. Similarly, given: 10801 10802 struct S {}; 10803 struct T { operator S(); }; 10804 T t; 10805 const S& s = t; 10806 10807 we can extend the lifetime of the return value of the conversion 10808 operator. 10809 10810 The next several functions are involved in this lifetime extension. */ 10811 10812 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The 10813 reference is being bound to a temporary. Create and return a new 10814 VAR_DECL with the indicated TYPE; this variable will store the value to 10815 which the reference is bound. */ 10816 10817 tree 10818 make_temporary_var_for_ref_to_temp (tree decl, tree type) 10819 { 10820 tree var = create_temporary_var (type); 10821 10822 /* Register the variable. */ 10823 if (VAR_P (decl) 10824 && (TREE_STATIC (decl) || CP_DECL_THREAD_LOCAL_P (decl))) 10825 { 10826 /* Namespace-scope or local static; give it a mangled name. */ 10827 /* FIXME share comdat with decl? */ 10828 10829 TREE_STATIC (var) = TREE_STATIC (decl); 10830 CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl); 10831 set_decl_tls_model (var, DECL_TLS_MODEL (decl)); 10832 10833 tree name = mangle_ref_init_variable (decl); 10834 DECL_NAME (var) = name; 10835 SET_DECL_ASSEMBLER_NAME (var, name); 10836 } 10837 else 10838 /* Create a new cleanup level if necessary. */ 10839 maybe_push_cleanup_level (type); 10840 10841 return pushdecl (var); 10842 } 10843 10844 /* EXPR is the initializer for a variable DECL of reference or 10845 std::initializer_list type. Create, push and return a new VAR_DECL 10846 for the initializer so that it will live as long as DECL. Any 10847 cleanup for the new variable is returned through CLEANUP, and the 10848 code to initialize the new variable is returned through INITP. */ 10849 10850 static tree 10851 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups, 10852 tree *initp) 10853 { 10854 tree init; 10855 tree type; 10856 tree var; 10857 10858 /* Create the temporary variable. */ 10859 type = TREE_TYPE (expr); 10860 var = make_temporary_var_for_ref_to_temp (decl, type); 10861 layout_decl (var, 0); 10862 /* If the rvalue is the result of a function call it will be 10863 a TARGET_EXPR. If it is some other construct (such as a 10864 member access expression where the underlying object is 10865 itself the result of a function call), turn it into a 10866 TARGET_EXPR here. It is important that EXPR be a 10867 TARGET_EXPR below since otherwise the INIT_EXPR will 10868 attempt to make a bitwise copy of EXPR to initialize 10869 VAR. */ 10870 if (TREE_CODE (expr) != TARGET_EXPR) 10871 expr = get_target_expr (expr); 10872 10873 if (TREE_CODE (decl) == FIELD_DECL 10874 && extra_warnings && !TREE_NO_WARNING (decl)) 10875 { 10876 warning (OPT_Wextra, "a temporary bound to %qD only persists " 10877 "until the constructor exits", decl); 10878 TREE_NO_WARNING (decl) = true; 10879 } 10880 10881 /* Recursively extend temps in this initializer. */ 10882 TARGET_EXPR_INITIAL (expr) 10883 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups); 10884 10885 /* Any reference temp has a non-trivial initializer. */ 10886 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true; 10887 10888 /* If the initializer is constant, put it in DECL_INITIAL so we get 10889 static initialization and use in constant expressions. */ 10890 init = maybe_constant_init (expr); 10891 /* As in store_init_value. */ 10892 init = cp_fully_fold (init); 10893 if (TREE_CONSTANT (init)) 10894 { 10895 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 10896 { 10897 /* 5.19 says that a constant expression can include an 10898 lvalue-rvalue conversion applied to "a glvalue of literal type 10899 that refers to a non-volatile temporary object initialized 10900 with a constant expression". Rather than try to communicate 10901 that this VAR_DECL is a temporary, just mark it constexpr. 10902 10903 Currently this is only useful for initializer_list temporaries, 10904 since reference vars can't appear in constant expressions. */ 10905 DECL_DECLARED_CONSTEXPR_P (var) = true; 10906 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 10907 TREE_CONSTANT (var) = true; 10908 } 10909 DECL_INITIAL (var) = init; 10910 init = NULL_TREE; 10911 } 10912 else 10913 /* Create the INIT_EXPR that will initialize the temporary 10914 variable. */ 10915 init = split_nonconstant_init (var, expr); 10916 if (at_function_scope_p ()) 10917 { 10918 add_decl_expr (var); 10919 10920 if (TREE_STATIC (var)) 10921 init = add_stmt_to_compound (init, register_dtor_fn (var)); 10922 else 10923 { 10924 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 10925 if (cleanup) 10926 vec_safe_push (*cleanups, cleanup); 10927 } 10928 10929 /* We must be careful to destroy the temporary only 10930 after its initialization has taken place. If the 10931 initialization throws an exception, then the 10932 destructor should not be run. We cannot simply 10933 transform INIT into something like: 10934 10935 (INIT, ({ CLEANUP_STMT; })) 10936 10937 because emit_local_var always treats the 10938 initializer as a full-expression. Thus, the 10939 destructor would run too early; it would run at the 10940 end of initializing the reference variable, rather 10941 than at the end of the block enclosing the 10942 reference variable. 10943 10944 The solution is to pass back a cleanup expression 10945 which the caller is responsible for attaching to 10946 the statement tree. */ 10947 } 10948 else 10949 { 10950 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 10951 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 10952 { 10953 if (CP_DECL_THREAD_LOCAL_P (var)) 10954 tls_aggregates = tree_cons (NULL_TREE, var, 10955 tls_aggregates); 10956 else 10957 static_aggregates = tree_cons (NULL_TREE, var, 10958 static_aggregates); 10959 } 10960 else 10961 /* Check whether the dtor is callable. */ 10962 cxx_maybe_build_cleanup (var, tf_warning_or_error); 10963 } 10964 /* Avoid -Wunused-variable warning (c++/38958). */ 10965 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 10966 && VAR_P (decl)) 10967 TREE_USED (decl) = DECL_READ_P (decl) = true; 10968 10969 *initp = init; 10970 return var; 10971 } 10972 10973 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 10974 initializing a variable of that TYPE. */ 10975 10976 tree 10977 initialize_reference (tree type, tree expr, 10978 int flags, tsubst_flags_t complain) 10979 { 10980 conversion *conv; 10981 void *p; 10982 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 10983 10984 if (type == error_mark_node || error_operand_p (expr)) 10985 return error_mark_node; 10986 10987 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10988 p = conversion_obstack_alloc (0); 10989 10990 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 10991 flags, complain); 10992 if (!conv || conv->bad_p) 10993 { 10994 if (complain & tf_error) 10995 { 10996 if (conv) 10997 convert_like (conv, expr, complain); 10998 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 10999 && !TYPE_REF_IS_RVALUE (type) 11000 && !lvalue_p (expr)) 11001 error_at (loc, "invalid initialization of non-const reference of " 11002 "type %qH from an rvalue of type %qI", 11003 type, TREE_TYPE (expr)); 11004 else 11005 error_at (loc, "invalid initialization of reference of type " 11006 "%qH from expression of type %qI", type, 11007 TREE_TYPE (expr)); 11008 } 11009 return error_mark_node; 11010 } 11011 11012 if (conv->kind == ck_ref_bind) 11013 /* Perform the conversion. */ 11014 expr = convert_like (conv, expr, complain); 11015 else if (conv->kind == ck_ambig) 11016 /* We gave an error in build_user_type_conversion_1. */ 11017 expr = error_mark_node; 11018 else 11019 gcc_unreachable (); 11020 11021 /* Free all the conversions we allocated. */ 11022 obstack_free (&conversion_obstack, p); 11023 11024 return expr; 11025 } 11026 11027 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 11028 which is bound either to a reference or a std::initializer_list. */ 11029 11030 static tree 11031 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups) 11032 { 11033 tree sub = init; 11034 tree *p; 11035 STRIP_NOPS (sub); 11036 if (TREE_CODE (sub) == COMPOUND_EXPR) 11037 { 11038 TREE_OPERAND (sub, 1) 11039 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups); 11040 return init; 11041 } 11042 if (TREE_CODE (sub) != ADDR_EXPR) 11043 return init; 11044 /* Deal with binding to a subobject. */ 11045 for (p = &TREE_OPERAND (sub, 0); 11046 (TREE_CODE (*p) == COMPONENT_REF 11047 || TREE_CODE (*p) == ARRAY_REF); ) 11048 p = &TREE_OPERAND (*p, 0); 11049 if (TREE_CODE (*p) == TARGET_EXPR) 11050 { 11051 tree subinit = NULL_TREE; 11052 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit); 11053 recompute_tree_invariant_for_addr_expr (sub); 11054 if (init != sub) 11055 init = fold_convert (TREE_TYPE (init), sub); 11056 if (subinit) 11057 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 11058 } 11059 return init; 11060 } 11061 11062 /* INIT is part of the initializer for DECL. If there are any 11063 reference or initializer lists being initialized, extend their 11064 lifetime to match that of DECL. */ 11065 11066 tree 11067 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups) 11068 { 11069 tree type = TREE_TYPE (init); 11070 if (processing_template_decl) 11071 return init; 11072 if (TREE_CODE (type) == REFERENCE_TYPE) 11073 init = extend_ref_init_temps_1 (decl, init, cleanups); 11074 else 11075 { 11076 tree ctor = init; 11077 if (TREE_CODE (ctor) == TARGET_EXPR) 11078 ctor = TARGET_EXPR_INITIAL (ctor); 11079 if (TREE_CODE (ctor) == CONSTRUCTOR) 11080 { 11081 if (is_std_init_list (type)) 11082 { 11083 /* The temporary array underlying a std::initializer_list 11084 is handled like a reference temporary. */ 11085 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 11086 array = extend_ref_init_temps_1 (decl, array, cleanups); 11087 CONSTRUCTOR_ELT (ctor, 0)->value = array; 11088 } 11089 else 11090 { 11091 unsigned i; 11092 constructor_elt *p; 11093 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor); 11094 FOR_EACH_VEC_SAFE_ELT (elts, i, p) 11095 p->value = extend_ref_init_temps (decl, p->value, cleanups); 11096 } 11097 recompute_constructor_flags (ctor); 11098 if (decl_maybe_constant_var_p (decl) && TREE_CONSTANT (ctor)) 11099 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true; 11100 } 11101 } 11102 11103 return init; 11104 } 11105 11106 /* Returns true iff an initializer for TYPE could contain temporaries that 11107 need to be extended because they are bound to references or 11108 std::initializer_list. */ 11109 11110 bool 11111 type_has_extended_temps (tree type) 11112 { 11113 type = strip_array_types (type); 11114 if (TREE_CODE (type) == REFERENCE_TYPE) 11115 return true; 11116 if (CLASS_TYPE_P (type)) 11117 { 11118 if (is_std_init_list (type)) 11119 return true; 11120 for (tree f = next_initializable_field (TYPE_FIELDS (type)); 11121 f; f = next_initializable_field (DECL_CHAIN (f))) 11122 if (type_has_extended_temps (TREE_TYPE (f))) 11123 return true; 11124 } 11125 return false; 11126 } 11127 11128 /* Returns true iff TYPE is some variant of std::initializer_list. */ 11129 11130 bool 11131 is_std_init_list (tree type) 11132 { 11133 if (!TYPE_P (type)) 11134 return false; 11135 if (cxx_dialect == cxx98) 11136 return false; 11137 /* Look through typedefs. */ 11138 type = TYPE_MAIN_VARIANT (type); 11139 return (CLASS_TYPE_P (type) 11140 && CP_TYPE_CONTEXT (type) == std_node 11141 && init_list_identifier == DECL_NAME (TYPE_NAME (type))); 11142 } 11143 11144 /* Returns true iff DECL is a list constructor: i.e. a constructor which 11145 will accept an argument list of a single std::initializer_list<T>. */ 11146 11147 bool 11148 is_list_ctor (tree decl) 11149 { 11150 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 11151 tree arg; 11152 11153 if (!args || args == void_list_node) 11154 return false; 11155 11156 arg = non_reference (TREE_VALUE (args)); 11157 if (!is_std_init_list (arg)) 11158 return false; 11159 11160 args = TREE_CHAIN (args); 11161 11162 if (args && args != void_list_node && !TREE_PURPOSE (args)) 11163 /* There are more non-defaulted parms. */ 11164 return false; 11165 11166 return true; 11167 } 11168 11169 #include "gt-cp-call.h" 11170